• Journal of the Korean Society of Tobacco Science
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• v.16 no.1
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• pp.43-52
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• 1994

To investigate the factors of the improvement of cultivation methods according to the plant type, three Burley tobacco cultivars were done. Experiments on the variability of plant type and factors representing the productivity and quality of the cultivar were subsequently carried out in relation to different fertilizer levels. Results are summarized as below. Use of more fertilizer resulted in higher plant height and longer leaf length but smaller mean leaf inclination(MLI). The horizontal leaf area distribution became greater in parts distal to the stem and the vertical leaf area distribution became greater in lower half than in upper half as the amount of fertilizer applied was increased. Br. 49 was the largest but Br. 21 and NTN 77 were similar with respect to both CGR and NAR. The yield was greater in larger MLI cultivars. These three characteristics became greater when the tobacco were heavier in the cultivars of larger MLI and increased with higher amount of fertilizer. Harvest index became greater as the amount of fertilizer decreased but not significantly differ among the cultivars. Total nitrogen content and nitrate - form nitrogen content were greater, more amount of fertilizer, and larger MLI cultivar plots. Total nitrogen content was higher in upper leaves. The filling power of tobacco leaves decreased but combustibility of leaves showed not significant trend as fertilizer application level increased.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.3
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• pp.161-167
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• 1998

Root and shoot development of two rice (Oryza sativa L.) cultivars with different genetic backgrounds was studied with reference to their relative growth. Tongil type (indica-japonica hybrid) cultivar 'Kuemkangbyeo' and japonica cultivar 'Koshihikari' were grown in $5000^{-1}$ a Wagnar pots under flooded condition. Three plants with roots of both cultivars were taken in every phyllochron through the heading stage to record morphological characteristics of shoot and root system. Compared to Koshihikari, Kuemkangbyeo produced more tillers and had greater shoot weight and leaf area per hill. Length and weight of the root system in both cultivars increased exponentially with time. At the same time, root system development was significantly faster in Kuemkangbyeo than in Koshihikari after the panicle initiation stage. As a result, Kuemkangbyeo has a vigorous root system which consists of larger number of nodal roots compared to Koshihikari. Also, the root length and weight per unit leaf area of Kuemkangbyeo were larger than those of Koshihikari in the later half of growing period, which suggests possible higher physiological activity of the root system of Kuemkangbyeo which is known as a high-yielding cultivar. The relationship between root traits (crown root number, total root length, and root dry weight) and shoot traits (leaf area and leaf+culm dry weight) in both cultivars closely showed allometry until the flag leaf stage.

• Progress in Medical Physics
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• v.15 no.1
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• pp.17-22
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• 2004

Multileaf collimator (MLC) is now rapidly replacing the lead ahoy block to shape the radiation treatment field. In addition to its defect of rectangular field shaping and increased penumbra width, it has another possible problem, and that is of radiation transmission between leaves, which needs to be maintained at as low a level as is permissible. The authors measured and analyzed the inter-leaf and cross-leaf transmissions of MLC by Varian Associates Inc, before its clinical application. The inter-leaf and cross-leaf transmissions were calculated by comparing the measured point doses in the polystyrene phantom in the open field and in a total closure of MLC. The beam profile of the inter-leaf and cross-leaf transmissions were depicted by using a water phantom. A photon beam of 6 MV was used in the measurement. The inter-leaf transmission was 1.63∼1.67%, indicating that the shielding effect of MLC is excellent. However, the cross-leaf transmission in the central area was 18.4∼18.7% and this is well over the clinically acceptable limitation of 5%. The beam profile of cross-leaf transmission displayed 80∼90% transmission near the field edge, so that the cross-leaf transmission was 14∼17% in this area. The multileaf collimator has an excellent shi디ding effect and the inter-leaf transmission is negligible so that it can be used in clinic as a good replacement of the conventional lead alloy block. However, care must be taken to avoid the cross-leaf transmission in the radiation field.

• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.143-152
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• 2008

This study was conducted to obtain basic information on mainstem, branch and leaf characteristics related to canopy for development of high yielding cultivar using 70 Korean soybean cultivars developed from 1913 to 2000. Variations of canopy width, branch length, and canopy width/length ratio were higher compared to other characteristics among 12 mainstem and branch characters. Variations of petiole angle, leaflet width/length ratio and compound leaf dry weight were higher than other characteristics among eight leaf characters related to plant canopy. Three classifications of soybean cultivars were used based on usage: I)soy sauce and tofu, II)bean sprout, and III)cooking with rice. Canopy width/length ratio was higher in group III, cooking with rice than group I, soy sauce and tofu, and group II, bean sprout, and there was no difference between the two, group I and group II. The total branch length/main stem height ratio was higher in group II, bean sprout and group III, cooking with rice than group I, soy sauce and tofu. Mainstem and branch characteristics related to plant canopy were classified into four groups by ratio of canopy width/length and total branch length/main stem length, respectively. Soybean cultivars with narrow canopy and high dependence of mainstem were Danweonkong, Keumkangkong, Shelby, and Shinpaldalkong. Soybean cultivars with broad canopy and high dependence of mainstem were Kanglim, Keumkangdaelip, and Jinyulkong, and a cultivar with broad canopy and high dependence of branch were Geomjeongkong 2. Leaflet length/width ratio was lowest in cooking with rice and there was no difference between soy sauce and tofu and bean sprout. Compound leaf area was largest in cooking with rice and smallest in bean sprout. Leaf petiole length was short in bean sprout and there was no difference between soy sauce and tofu and bean sprout. Leaf petiole angle was highest in cooking with rice and lowest in bean sprout. Leaf type was classified into four groups based on leaflet width/length ratio and compound leaf area, respectivly. Buseok and Taekwangkong had an oval leaflet and largest area of compound leaf. Eunhakong and Sohokong had extreme narrow leaflet and smallest area of compound leaf. Leaf petiole type was classified into three and four groups based on leaf petiole length and angle, respectively. A soybean cultivar with the shortest petiole length and smallest petiole angle was Eunhakong and cultivars with short petiole length and large petiole angle were Alchankong, Muhankong, and Pureunkong. A soybean cultivar with long petiole length and small petiole angle was Sinpaldalkong 2. Among a total of 70 Korean soybean cultivars, Eunhakong had an extreme narrow type in leaf, smallest compound leaf area, shortest petiole length, and smallest petiole angle of compound leaf.

• Journal of Plant Biology
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• v.14 no.3
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• pp.21-28
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• 1971

Dry matter production, leaf area growth and total nitrogen changes were studied in Glycine max. soybean communities, which were grown in sandy loam soils controlled to provide various moisture levels, i.e., 5-7%(level 1), 8-10%(level 2), 11-13%(level 3), 14-15%(lev디 4), 17-20%(level 5) and 22-24%(level 6). A summary of the results is shown. The maximum dry matter production of leaves, stems and nodules and the maximum leaf area per unit area were at level 5, but the maximum of root dry matter production was at level 4. Total nitrogen content of the soybean plant decreased with growth, but each level of soil moisture content also showed a little difference. Water content of the plant decreased with plant age and soil water deficiency, especially in roots and nodules. Nodule formation increased in proportion to soil moisture content. total nitrogen content of the soil on which the soybeans grew, increased from 0.23% before sowing to 0.30% at 100 days after sowing. It seems that soil water content acts as a linear factor in the elongation or dry weight increase of shoots and roots until increasing to level 5. Considering the pattern of plant growth through analysis of the shoot and root dry weight ratio, or the photosynthetic organ and non-photosynthetic organ dry weight ratio, the asymptote of plant growth at a high soil water content exceeded that at a low soil water content.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.4
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• pp.364-369
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• 1989

Leaf characteristics of main stem and tiller of IK type maize (IK/ /IRI/B68) were compared with those of Jinjoo Ok hybrid which are not usually tillered. A total of nine leaves from flag leaf to the third or the fourth leaf below ear-bearing node were sampled from each stem or tiller. There was no significant difference in mean leaf length between IK/ /IRI/B68 and Jinjoo Ok. But the mean leaf width of IK/ /IRI/ B68 was about 2 cm narrower than that of Jinjoo Ok. The mean leaf area of the IK/ /IRI/B68 was also smaller than that of Jinjoo Ok due to the narrower leaf width. There were not significant differences in mean leaf characteristics between main stem and tillers of IK/IRI/B68. The longest leaf was the leaf below the ear-bearing node and the widest leaf was the leaf just above the ear-bearing node. Mean length. width and area of leaf on main stem and tillers were similar. Coefficients of variation calculated for individual leaf indicated that the leaves near the ear-bearing node were more uniform than others. The leaf area measured was significantly greater than that estimated by formular, length x width x 0.75. New constant to estimate leaf area of tillering maize was derived as 0.8.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.6
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• pp.460-464
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• 2007

This study was carried out to elucidate the proper split application method of nitrogen fertilizer for early dry seeding culture of rice in Honam plain area from 1997 to 1998 in Korea. Dongjinbyeo was selected as rice variety for this experiment. The rate of $160kg\;ha^{-1}$ of nitrogen was split as 40-30-30% of total nitrogen at three different application time combination ; T1) basal-5th leaf-panicle formation(PF) stage, T2) 3rd leaf-5th leaf-PF, and T3) 3rd leaf-7th leaf-PF. The content of $NH_4-N$ in soil at 5th leaf stage was higher in top dressing plots(T2, T3) compared with basal application(T1), at 7th leaf stage it was most in top dressed at 3rd leaf and 5th leaf stage, but there was no difference at heading stage. Amount of nitrogen uptake and nitrogen use efficiency was higher in the order of T3, T2 and T1(basal application). Spikelet number per unit area was more in the order of T3, T2 and T1, but rate of ripened grain and 1,000 grain weight were not significantly different among three nitrogen split application methods. Milled rice yields were higher in top dressed plots compared with basal nitrogen application plots. From the results of this experiment, reasonable nitrogen split application method for early dry seeding culture of rice could be 40-30-30% of total nitrogen at 3rd leaf, 7th leaf and panicle formation stage.

• Journal of Environmental Science International
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• v.12 no.8
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• pp.853-860
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• 2003

Plants sequester atmospheric CO$_2$, a major agent of climate change, during the growing periods and mitigate its rising accumulation in the atmosphere. Pinus densiflora and Quercus mongolica are the native tree species dominant in the temperate forests of Korea. This study quantified the annual CO$_2$ uptake by the two species at forest sites in Chuncheon in the middle of the country. The quantification was based on seasonal measurements of CO$_2$ exchange rates under natural conditions by an infrared gas analyzer over the growing season (1999). The monthly CO$_2$ uptake per unit leaf area ranged from 1.6-6.7 mg/d㎡/h for P. densiflora and from 3.7-8.9 mg/d㎡/h for Q. mongolica, with a maximum in mid-summer. An equation for each species was generated to estimate easily the annual CO$_2$ uptake by total leaf area per tree, which subtracted the CO$_2$ release (i.e. respiration) by leaves and woody organs from the gross CO$_2$ uptake (diurnal uptake and release by leaves). Annual CO$_2$ release by leaves and woody organs accounted for 58-73％ of the gross CO$_2$ uptake across tree specimens. Annual CO$_2$ uptake per tree increased with increasing dbh (stem diameter at breast height) for the study diameter range, and was greater for Q. mongolica than for P. densiflora in the same dbh sizes. This was mainly associated with a greater total leaf area in the former. For example, the annual CO$_2$ uptake by one tree with dbh of 25 cm was 35.6 kg/yr for P. densiflora and 47.9 kg/yr for Q. mongolica. The results from this study can be applied to evaluate an atmospheric CO$_2$ reduction of woody plants by forest type and age class.

• The Korean Journal of Ecology
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• v.26 no.4
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• pp.173-180
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• 2003

To clarify whether the closely related species living in the same area is a population or populations ecologically, leaf morphology, specific leaf area, and fruit and seed production were studied in the natural group of sect. Pes-gallinaceua of Corydalis of Namhansansung area from 1999 to 2000. There were 352 plants in one square meter and total eight species or varieties were identified. Of the 352 plants, the number of C. turtschaninovii was the most with 103(29.3%), and that of C. ambigua was the next with 78(22.2%), and that of C. turtschaninovii var. fumariaefolia was the smallest with 9(2.6%). In the 28 plants having spotted leaves, central leaflet did not parted or again parted. The extent of partition with the plant was various from non-parted type to perfectly two-parted type (three leaflet). Between two extreme types, there were diverse types so that this character formed a gradient. The rate of length/breadth was in the range of 0.79~2.17. This character was related to the extent of leaflet partition but did not well expressed the distinguishing trait along a species. The number and the type of serration were diverse and there was no sharp borderline among the species or varieties. Ecological properties, specific leaf area, the number of fruit per plant, and the number of seed per fruit, varied with a wide range in a species or variety but differences between species or variety were not significant. Therefore, the Corydalis group studied was regarded as a population on the three criteria: (1) possibility of interbreeding, (2) continuity of leaf morphology, (3) irrelevance between character and species, (4) similarity of several ecological properties.

• Nutrition Research and Practice
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• v.7 no.3
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• pp.166-171
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• 2013

The purpose of this study was to investigate the effects of lotus leaf on hyperglycemia and dyslipidemia in animal model of diabetes. Inhibitory activity of ethanol extract of lotus leaf against yeast ${\alpha}$-glucosidase was measured in vitro. The effect of lotus leaf on the postprandial increase in blood glucose levels was assessed in streptozotocin-induced diabetic rats. A starch solution (1 g/kg) with and without lotus leaf extract (500 mg/kg) was administered to the rats after an overnight fast, and postprandial plasma glucose levels were monitored. Four-week-old db/db mice were fed a basal diet or a diet containing 1% lotus leaf extract for 7 weeks after 1 week of acclimation to study the chronic effect of lotus leaf. After sacrifice, plasma glucose, insulin, triglycerides (TG), total cholesterol (CHOL), high-density lipoprotein (HDL)-CHOL, and blood glycated hemoglobin levels were measured. Lotus leaf extract inhibited ${\alpha}$-glucosidase activity by 37.9%, which was 1.3 times stronger than inhibition by acarbose at a concentration of 0.5 mg/mL in vitro. Oral administration of lotus leaf extract significantly decreased the area under the glucose response curve by 35.1% compared with that in the control group (P < 0.01). Chronic feeding of lotus leaf extract significantly lowered plasma glucose and blood glycated hemoglobin compared with those in the control group. Lotus leaf extract significantly reduced plasma TG and total CHOL and elevated HDL-CHOL levels compared with those in the control group. Therefore, we conclude that lotus leaf is effective for controlling hyperglycemia and dyslipidemia in an animal model of diabetes mellitus.