• Horticultural Science & Technology
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• v.32 no.5
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• pp.590-599
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• 2014

This study was conducted to compare the cold tolerance of seven ground cover species, Orostachys japonica, Sedum oryzifolium, S. kamtschaticum 'SG1', S. reflexum, S. rupestre 'Blue Spruce', S. spurium 'Green Mental', and S. takesimense, which have been used for green roof and wall systems in Korea. Plants were grown in 10-cm pots and 1 g of tissues at stem-end and crown of each species were kept under either light or dark condition, respectively. For cold tolerance tests, plants were initially left at $4^{\circ}C$ and linearly cooled to 0, -4, -8, -12, -16, and $-20^{\circ}C$ at $-2^{\circ}C{\cdot}h^{-1}$ rate. Low temperature injury and regrowth rates were visually evaluated and assessed by image analysis, respectively. The lethal temperature ($LT_{50}$) of plant species was determined using electrolyte leakage measurements. S. reflexum was the most cold tolerant, showing the most survival at $-16^{\circ}C$, whereas S. oryzifolium and S. takesimense showed low temperature injury at $-8^{\circ}C$. Similar results were found with electrolyte leakage measurements at the stem end. For each species, the crown (Mean $LT_{50}:\;-12.15^{\circ}C$) was more cold tolerant than the stem end (Mean $LT_{50}:\;-10.47^{\circ}C$). In conclusion, S. reflexum and S. rupestre 'Blue Spruce' are recommended for planting in the central region of Korea during late fall and early winter, as they were more cold tolerant and showed more vigorous regrowth than the other tested plant species.

• Childhood Kidney Diseases
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• v.2 no.2
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• pp.152-160
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• 1998

Purpose : Vesicoureteral reflux (VUR), which can result in renal failure in children, is expected to resolve spontaneously in mild cases, but severe cases require surgical correction, posing dilemma in deciding the right measures in some cases. Therefore, to delineate the factors affecting spontaneous resolution of VUR and to apply them in assessing the prognosis, we reviewed the patients with VUR who had been treated medically. Patients and Methods : 32 children (49 renal units) with reflux who had been admitted during the 5-year period from Jan '92 to Dec '96 were classified into 4 groups (Resolved, Improved, Unchanged, and Worsened) and analyzed. Results : 1) 25 were boys and 7 girls. The age at diagnosis ranged from 13 days to 9 years (mean $24.6{\pm}11.4$ mo) 2) Among 49 refluxing ureters, 4 were below 1 me of age,21 between 1 me to 1 yr, 16 between 1 yr to 6 yr, 8 beyond 6 yr. Two belonged to Grade I, 16 to Crade II, 17 to Grade III, 12 to Grade IV, and 2 to Grade V. 3) Spontaneous resolution rates of reflux were 100, 81, 47, 8, 0$\%$ for each Grade, respectively. Resolution plus improvement rates in Grade III and IV were 71 and $50\%$, each. 4) Resolution rates in relation to the age at diagnosis were $100\%$ for below 1 mo, $48\%$ between 1 mo to 1 yr, $56\%$ between 1 to 6 yr, and $13\%$ beyond 6 yr. 5) Of 15 unilateral refluxing ureters, 14 ($93\%$) resulted in resolution. Of 34 bilateral refluxing ureters, 11 ($32\%$) resolved spontaneously 6) Resolution occurred within 1 year in 20 units of 24 renal units in regular follow-up. Conclusion: The lower the initial grade and the younger the patient, the sooner the reflux resolved. Resolution was better when VUR was unilateral than bilateral. Long-term regular follow-up is essential because even the cases falling in Grades III and IV have high rates of spontaneous resolution and improvement with medical treatment.

• Korean Journal of Ecology and Environment
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• v.39 no.2 s.116
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• pp.271-283
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• 2006

A systematic water quality survey was conducted in August, 2005 for a drinking water supply reservoir (the Jeolgol reseuoir located in an island), which is at an early stage of impoundment, to investigate the causes of water color deterioration of the reservoir and the clogging of filter beds of a water treatment plant. The reservoir shape was simple and its average depth was 5.5 m, increasing from upreservoir toward the downreservoir end near the dam. Dissolved oxygen (DO) and chloropllyll-a (chi-a) showed a large variation while water temperature had a smaller range. Transparency ranged from 0.6 to 0.9 m (average 0.7 m). The average value of turbidity was 9.3 NTU, ranging from 8.0 ${\sim}$ 12.1 NTU. The transparency and the turbidity appear to be affected by a combination of biological and non-biological factors. The poor transparency was explained by an increase of inorganic colloids and algal bloom in the reservoir. The blockage of the filter bed was attributed to the oversupply of phytoplanktons from the reservoir. The range and the average concentration of chi-a within the reservoir were 31.6 ${\sim}$ 258.9 ${\mu}g\;L^{-1}$, 123.6 ${\mu}g\;L^{-1}$ for the upper layer, and 17.0 ${\sim}$ 37.4 ${\mu}g\;L^{-1}$, 26.5 ${\mu}g\;L^{-1}$ for the bottom layer, respectively. A predominant species contributing the algal bloom was Dinophyceae, Peridinium bipes f. occultatum. The distribution of Peridinium spp. was correlated with chi-a concentrations. The standing crop of phytoplankton was highest in the upreservoir with $8.5\;{\times}\;103\;cells\;mL^{-1}$ and it decreased toward the downresevoir. Synedra of Bacillariophyceae and Microcystis aeruginosa of Cyanophyceae appeared to contribute to the algal bloom, although they are not dominated. It is mostly likely that sloped farmlands located in the watershed of the reservoir caused water quality problems because they may contain a significant amount of the nutrients originated from fertilizers. In addition, the aerators installed in the reservoir and a shortage of the inflowing water may be related to the poor water quality. A long-term monitoring and an integrated management plan for the water quality of the watersheds and the reservoir may be required to improve the water quality of the reservoir.

• Horticultural Science & Technology
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• v.34 no.4
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• pp.528-536
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• 2016

This study was conducted to examine the effect of 0.4% of $CaCl_2$, $2H_2O$, $1mg{\cdot}L^{-1}$ of Calmodulin (CaM)-SH, 250-folds of coating agent (WE-36), 1,000-folds of $GA_{4+7}+BA$ and 3 types of paper bagging treatments on russet incidence and fruit quality attributes of 'Gamhong' apple. The pattern of russet occurrence was slightly different for 4 years (from 2012 to 2015) in 'Gamhong' apple. The russet occurrence was lowest in $GA_{4+7}+BA$ treatment at 20 days after full bloom (DAFB), compared with other treatments. The $GA_{4+7}+BA$ treatment increased fruit weight at 20 DAFB, while the other fruit quality attributes were not influenced. The russet occurrence was lower not only in a single bag application than in untreated ones but also in yellow bagging and discolored bagging applications than in a white bagging application. The russet occurrence in a bagging application was lower at 20 DAFB than at 30 and 40 DAFB, while fruit quality attributes were not affected by bagging applications. The russet incidence was lower in $GA_{4+7}+BA$ twice treatments at 20 and 30 DAFB, and calcium coated bag at 30 DAFB after $GA_{4+7}+BA$ treatment at 20 DAFB than in untreated fruit. The rate of russet incidence was lowest at equator region in $GA_{4+7}+BA$ treatment, compared with the other fruit regions. Overall, the results suggest that one and/or two applications of $GA_{4+7}+BA$ (1,000-folds) treatment at 20 DAFB should reduce the risk of russet incidence in 'Gamhong' fruit.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.3
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• pp.206-213
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• 2004

As far as an opening device of fishing gears is concerned, applications of a kite are under development around the world. The typical examples are found in the opening device of the stow net on anchor and the buoyancy material of the trawl. While the stow net on anchor has proved its capability for the past 20 years, the trawl has not been wildly used since it has been first introduced for the commercial use only without sufficient studies and thus has revealed many drawbacks. Therefore, the fundamental hydrodynamics of the kite itself need to ne studied further. Models of plate and canvas kite were deployed in the circulating water tank for the mechanical test. For this situation lift and drag tests were performed considering a change in the shape of objects, which resulted in a different aspect ratio of rectangle and trapezoid. The results obtained from the above approaches are summarized as follows, where aspect ratio, attack angle, lift coefficient and maximum lift coefficient are denoted as A, B, $C_L$ and $C_{Lmax}$ respectively : 1. Given the triangular plate, $C_{Lmax}$ was produced as 1.26${\sim}$1.32 with A${\leq}$1 and 38$^{\circ}$B${\leq}$42$^{\circ}$. And when A${\geq}$1.5 and 20$^{\circ}$${\leq}$B${\leq}$50$^{\circ}$, $C_L$ was around 0.85. Given the inverted triangular plate, $C_{Lmax}$ was 1.46${\sim}$1.56 with A${\leq}$1 and 36$^{\circ}$B${\leq}$38$^{\circ}$. And When A${\geq}$1.5 and 22$^{\circ}$B${\leq}$26$^{\circ}$, $C_{Lmax}$ was 1.05${\sim}$1.21. Given the triangular kite, $C_{Lmax}$ was produced as 1.67${\sim}$1.77 with A${\leq}$1 and 46$^{\circ}$B${\leq}$48$^{\circ}$. And when A${\geq}$1.5 and 20$^{\circ}$B${\leq}$50$^{\circ}$, $C_L$ was around 1.10. Given the inverted triangular kite, $C_{Lmax}$ was 1.44${\sim}$1.68 with A${\leq}$1 and 28$^{\circ}$B${\leq}$32$^{\circ}$. And when A${\geq}$1.5 and 18$^{\circ}$B${\leq}$24$^{\circ}$, $C_{Lmax}$ was 1.03${\sim}$1.18. 2. For a model with A=1/2, an increase in B caused an increase in $C_L$ until $C_L$ has reached the maximum. Then there was a tendency of a very gradual decrease or no change in the value of $C_L$. For a model with A=2/3, the tendency of $C_L$ was similar to the case of a model with A=1/2. For a model with A=1, an increase in B caused an increase in $C_L$ until $C_L$ has reached the maximum. And the tendency of $C_L$ didn't change dramatically. For a model with A=1.5, the tendency of $C_L$ as a function of B was changed very small as 0.75${\sim}$1.22 with 20$^{\circ}$B${\leq}$50$^{\circ}$. For a model with A=2, the tendency of $C_L$ as a function of B was almost the same in the triangular model. There was no considerable change in the models with 20$^{\circ}$B${\leq}$50$^{\circ}$. 3. The inverted model's $C_L$ as a function of increase of B reached the maximum rapidly, then decreased gradually compared to the non-inverted models. Others were decreased dramatically. 4. The action point of dynamic pressure in accordance with the attack angle was close to the rear area of the model with small attack angle, and with large attack angle, the action point was close to the front part of the model. 5. There was camber vertex in the position in which the fluid pressure was generated, and the triangular canvas had large value of camber vertex when the aspect ratio was high, while the inverted triangular canvas was versa. 6. All canvas kite had larger camber ratio when the aspect ratio was high, and the triangular canvas had larger one when the attack angle was high, while the inverted triangluar canvas was versa.

• Childhood Kidney Diseases
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• v.4 no.1
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• pp.77-83
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• 2000

Purpose: Pregnancy in transplanted mother is considered as a high-risk pregnancy, and significant incidences of prematurity and low-birthweight(LBW) infants have been reported. The objective of this study is to examine the outcome of pregnancy in transplanted mothers and to evaluate the current growth status in their children. Patients and Methods: We retrospectively reviewed 54 pregnancies in 40 kidney recipients until June 1999. Outcomes of pregnancy were reviewed and assessment of the current growth status in children was performed. Results: 54 pregnancies in 40 recipients were identified; 22 ended in termination of pregnancy because of unwanted pregnancy or therapeutic purposes. And of the other 32, 29 livebirths resulted in 28 recipients. The mean age of conception was $30.3{\pm}3.8$ years, with a mean interval from transplantation to conception of $35.9{\pm}23.2$ months. All patients were maintained on immunosuppressive regimens. Incidence of drug-treated hypertension(HTN) prior to pregancy was $52\%$, HTN during pregnancy, $48\%$; preeclampsia, $41\%$; urinary tract infection, $48\%$; oligohydramnios $4\%$; and no rejection during pregnancy and up to 3month post delivery. Of the 29 liveborn infants, prematurity(<37wk) occurred in $52\%$, LBW(<2500g) in $62\%$, VLBW(<1500g) in $7\%$ and $48\%$ born intrauterine growth retardation(IUGR). Mean gestational age was $36.3{\pm}3.0\;wk$; a mean birthweight, $2.23{\pm}0.6\;kg$; a mean birth-height, $45.1{\pm}3.6cm$. Current mean height standard deviation score (height SDS) was $0.29{\pm}0.91$ and mean weight SDS was $0.62{\pm}1.34$. Only one child($4\%$) under 1 year of age was below 10 percentile in height. Most of children had no medical problems except for 4 children; cleft palate(1), tuberous sclerosis(1), essential hematuria(1), and one child expired due to sepsis. Conclusion: This study showed similar incidence of premaure birth($57\%$) and low birth weight infants($62\%$), but lower incidence of spontaneous abortion($5.6\%$) was observed and compared to other studies. Postnatal growth in majority of children($96\%$) achieved catch-up growth before 1 year. Present study supports a more optimistic view of pregnancy in renal transplant mother and normal growth in their children.