• The Plant Pathology Journal
• /
• v.33 no.5
• /
• pp.522-527
• /
• 2017

We determined the effects of atmospheric temperature ($10-30{\pm}2^{\circ}C$ in $5^{\circ}C$ increments) and carbon dioxide ($CO_2$) levels ($400{\pm}50ppm$, $540{\pm}50ppm$, and $940{\pm}50ppm$) on the infection of Solanum tuberosum cv. Chubaek by Potato leafroll virus (PLRV). Below $CO_2$ levels of $400{\pm}50ppm$, the PLRV infection rate and RNA content in plant tissues increased as the temperature increased to $20{\pm}2^{\circ}C$, but declined at higher temperatures. At high $CO_2$ levels ($940{\pm}50ppm$), more plants were infected by PLRV at $30{\pm}2^{\circ}C$ than at 20 or $25{\pm}2^{\circ}C$, whereas PLRV RNA content was unchanged in the $20-30{\pm}2^{\circ}C$ temperature range. The effects of atmospheric $CO_2$ concentration on the acquisition of PLRV by Myzus persicae and accumulation of PLRV RNA in plant tissues were investigated using a growth chamber at $20{\pm}2^{\circ}C$. The M. persicae PLRV RNA content slightly increased at elevated $CO_2$ levels ($940{\pm}50ppm$), but this increase was not statistically significant. Transmission rates of PLRV by Physalis floridana increased as $CO_2$ concentration increased. More PLRV RNA accumulated in potato plants maintained at 540 or $940{\pm}50ppm$ $CO_2$, than in plants maintained at $400{\pm}50ppm$. This is the first evidence of greater PLRV RNA accumulation and larger numbers of S. tuberosum plants infected by PLRV under conditions of combined high $CO_2$ levels ($940{\pm}50ppm$) and high temperature ($30{\pm}2^{\circ}C$).

• Korean Journal of Poultry Science
• /
• v.41 no.1
• /
• pp.39-44
• /
• 2014

The goal of this study was to evaluate the growth performance of crossbred strains using Korean native chicken (KNC). The data were collected from 2012 through 2013 at Poultry Science Division, National Institute of Animal Science, Korea. The number of chicks analyzed in this study was 375. Crossbred were (A) $R{\times}S$, (B) $D{\times}H$, (C) $D{\times}S$, (D) $C{\times}Y$ and (E) $Y{\times}H$. The fertility rates of strains were 94.9% in crossbred A, 91.9% in crossbred B, 91.8% in crossbred C, 89.7% in crossbred D and 93.8% in crossbred E, respectively. The fertility was highest in crossbred A, but crossbred C showed the lowest (p<0.05) based on the hatchability. The crossbreds B and C exhibited a superior performance on body weight gains during growing stages but crossbred D showed the lowest (p<0.05). The feed intake was to the pattern of body weight. The feed intake of crossbred D was significantly lower than other crossbreds. Also, feed conversion ratio of crossbred D showed the lowest (p<0.05). Egg production ratio of crossbred D was significantly higher compared to the other crossbreds. These results suggest that the development of new crossbreds of commercial Korean Native Chickens should be required for better performance.

• Journal of Preventive Medicine and Public Health
• /
• v.32 no.4
• /
• pp.526-537
• /
• 1999

Objectives : It is known that the prevalence of diabetes mellitus(DM) appears to be rapidly increasing in recent times in Korea, presumably due to a westernized diet and change of life style followed by rapid economic growth. Based on the Seoul male cohort which was constructed in 1993, this study was conducted to estimate the annual incidence rates of DM through 4 years' follow up and to determine which factors are associated with DM risk in Korean middle-aged men. Methods : Among 14,533 men recruited at baseline, 559 were excluded because they reported a history of diabetes or were found to be diabetes at 1992 routine health examination. During 4 years' follow-up, 237 incident DM cases were ascertained through chart reviews and telephone contacts for those who have ever visited hospitals or clinics under suspicion of DM during 1993-1996 and the biennial routine health examinations in 1994 and 1996. Results : In this study the annual incidence of DM among the study population was estimated to be 0.5 per 100. This study showed that fasting glucose level at initial baseline examination was a powerful predictor of risk for diabetes several years later(fasting blood glucose of $\geq$ 110 mg/dl compared with $\leq$ 80 mg/dl, Hazard Ratio[HR]:15.6, 95% Confidence interval[CI]=9.1-26.6) after considering potential covariates such as age, family history, smoking and alcohol history, body mass index, physical activity, total energy intake, and total fiber intake. Adjusted hazard ratios of family history of diabetes was 1.95(95% CI=1.38-2.75); of obesity as measured by BMI(BMI $\geq$ 25.3 compared with $\leq$ 21.3) was 7.19(95% CI=3,75-13.8); of weight change during middle life(>10kg compared with $\leq$ 5) was 1.77(95% CI=1.16-2.69); of smoking(current vs none) was 1.93(95% CI=1.06-3.51); and fat intake(upper fertile compared with lower fertile) was 1.88(95% CI=1.01-3.49), while fiber intake was associated with the reduced risk(HR=0.36, 95% CI=0.19-0.67). Conclusion : The factors identified in this study indicate that the greatest reduction in risk of diabetes might be achieved through population-based efforts that promote fiber intake and reduce obesity, smoking, and fat intake.

• Journal of environmental and Sanitary engineering
• /
• v.5 no.2
• /
• pp.117-122
• /
• 1990

The Jido Pond system was investigated from April, 1979 through March, 1980, in respect of seasonal changes in physico-chemical factors: i.e., temperature, pH, DO, BOD, COD, $Cl^-, \; Mg^{++}$, alkalinity, detergent, $SiO_2, PO_4\;^{3-}, NH_4\;^+, NO_2\;^-, NO_3\;^-$, total N, OM and OC; phytoplankton community growth; and the ecosystem metabolism. The phytoplankton community was represented by 23 species belonging to Chlorophyta, Bacillariophyta and Cyanophyta; each sharing 11, 9 3 respectively. The Chlorophyceans dominated the phytoplankton community contributing 75% of the total ？미 counts. The ranges of biotic diversity indices were, d, 0.85~2.80; H, 1.10~2.40; c, 0.13~0/40; and 3, 0.56~0.90. The chlorophyll standing crop varied in between 0.043 and 0.385g/$\textrm{cm}^2$ surface area. The ranges of photosynthetic and respiratory rates were 0.36~4.50; and 0.10~1.40 $O_2$ mg/1/hr, respectively. The monthly areal net primary production varied from 23.9 to 305.1C g/$\textrm{m}^2$/month. The Eu of the net production seasonally varied in between 0.31 and 7.80%, and the annual mean was 2.44%. The annual turnover times of phosphorus and nitrogen were 20 and 3 days, respectively.

• Korean Journal of Soil Science and Fertilizer
• /
• v.16 no.2
• /
• pp.92-97
• /
• 1983

This experiment was designed to establish the soil physical improvement practice to increase the rice yields at fine textured fluvio-marine paddy field. After chiseling and trenching the paddy soil, the rice growth and soil physical properties were investigated for 4 years. The results are summarize as follows; 1. The soil physical properties, such as bulk density, hardness, porosity and permeability were prominently improved by trenching and chiseling. 2. There were significant relationships among the soil physical properties, root developments and rice yields. 3. The increasing rates of rice yields by soil physical improvement were about 10%, which is better than 5% of drainage effects. 4. The effects of trenching and chiseling on rice yields were continued to fourth year. Even if trenching effects was better than chiseling the chiseling was considered as a useful treatment for its simple working practice by using a heavy machine. 5. In case of trenching, straw application were increased the rice yields.

• The Korean Journal of Mycology
• /
• v.32 no.2
• /
• pp.105-111
• /
• 2004

The changes of microflora and chemical characteristics during fermentation process of cotton waste for oyster mushroom cultivation were investigated with 5 l bench-scale reactors placed in an incubator at different temperatures ($40,\;50\;and\;60^{\circ}C$). Cotton waste was wetted to 70% moisture, and air flow rates to the substrate were 50, 100 and 300 cc/min. In processing of composting, the mesophilic bacterial population decreased sharply but thermophilic bacterial population increased. In case of fungi, both mesophilic and thermophilic population decreased. The daily $CO_2$ evolution showed little difference in all treatments, while $NH_3$ dropped sharply after 3 days. The desirable composting temperature and air flow based on the mycelial growth of oyster mushroom were $50^{\circ}C$ and 100 cc/min, respectively.

• The Korean Journal of Mycology
• /
• v.30 no.2
• /
• pp.173-175
• /
• 2002

Sooty leaf blight was found on Dendrobium sp. in several farmers' fields located in Namji-eup, Changnyeong-gun, Gyeongnam province, Korea in 2001. Symptoms of the disease appeared on leaves. Sooty leaf spots were started with amphigenous, subeircular to irregular spots, with light grayish brown to black color with definite margin lines on the upper surface of leaves. Infected leaves became defoliated and whole plants eventually were died. The infection rates of the disease in the surveyed area reached up to 64.8%, in the early September. Conidiophores of the causal fungus were dark grayish brown in color, densely fasciculate, straight, curved to sinuous, branched, $5{\sim}10$ septate and $63{\sim}164{\times}3.2{\sim}4.9{\mu}m$ in size. Conidia were pale to olivaceous in color, obclavatecylindric, straight to slightly curved in shape, $1{\sim}5$ septate and $46{\sim}98{\times}3.2{\sim}3.9{\mu}m$ in size. The optimum temperature for mycelial growth of the fungus was $25^{\circ}C$. The fungus was identified as Pseudocercospora dendrobii on the basis of its mycological characteristics. This is the first report on sooty leaf light of Dendrobium sp. caused by Pseudocercospora dendrobii in Korea.

• Journal of Environmental Science International
• /
• v.20 no.10
• /
• pp.1319-1328
• /
• 2011

Rhododendron brachycarpum is a evergreen broad-leaved shrub and belongs to the Ericaceae family and the Rhododendron genus. It is well known for its beautiful leaves and flowers. There are 11 species of the Rhododendron genus in Korea. It includes 3 species - Rhododendron brachycarpum, Rhododendron aureum Georgi and Rhododendron brachycarpum var. roseum Koidz. They grow naturally over 1,000 meters above sea level of the Baekdu Mountain Range in Korea. These habitats, according to investigations of 9 Rhododendron brachycarpum natural habitats, are mostly located on the slope of mountains facing north at an altitude of 1,200 m to 1,526 m above sea level with angle of inclination from 30 degrees to 45 degrees. Based on the result of vegetation analysis of dominance species in the quadrates, there are Quercus aliena, Quercus mongolica Fisch. ex Ledeb, Abies holophylla in species of upper trees, and so on. Dominant species of woody plants in tree layer are Quercus aliena, Quercus mongolica Fisch. ex Ledeb, Abies holophylla, Betula platyphylla and Veeatrum patulum Loes. fil, Erythronium japonicum, Dryopteris crassirhizoma, Paeonia japonica var. glabra Makino are founded in herbaceous plants. And we can see another result of the investigation that the flowering rates of the plants with the buds are highly ranked mountains such as Mt. Hambaek 68%, Mt. Gyebang 40%, Mt. Yagksu 9%, Mt. Gaein 7% and Mt. Seolag 0%. The results show that there are 24 over 15-year-old Rhododendron brachycarpums in Mt. Odae and are 56 under 15-year-old trees in Mt. Hambaek and are no trees in Mt. Gyebang and are 9 over 30-year-dead trees only in Mt. Taebaeg. Out of found trees, the highest tree is 7 m in height and 0.6 m in diameter. Also this result shows what are the vulnerability factors of the natural habitats. They are as follows: indiscriminate trails in mountains, damages by mountain climbers, uncareful plant collecting, the fierce competitions with other plants such as Acer pseudosieboldianum var. ishidoyanum Uyeki, Quercus aliena, Celastrus orbiculatus and damages by disease and insect, unusual temperature in natural habitats, etc. Rhododendron brachycarpums have high ornamental value and excellent pharmaceutical effect. But the areas of its habitats decrease dramatically. So we need measures to protect and their natural habitats. It is necessary that we conductfurther investigations to designate conservation area for Rhododendron brachycarpums.

• Journal of Nutrition and Health
• /
• v.53 no.2
• /
• pp.111-120
• /
• 2020

Purpose: Corosolic acid (CA), also known as 2α-hydroxyursolic acid, is present in numerous plants, and is reported to exhibit anti-cancer and anti-proliferative activities in various cancer cells such as osteosarcoma, hepatocellular carcinoma, lung adenocarcinoma, and colon cancer. However, the anti-cancer activity of CA on human breast cancer cells and the underlying mechanisms remain to be elucidated. The present study aimed to investigate the anticancer effects of CA in the human breast cancer cell line, MDA-MB-231. Methods: Cell viability, reactive oxygen species (ROS) production, apoptosis marker protein expression, migration, invasion rate, and vascular endothelial growth factor (VEGF) levels were assessed by treating MDA-MB-231 cells to increasing concentrations of CA. Results: The results showed that CA significantly inhibited the cell proliferation of MDA-MB-231 cells in a dose-dependent manner. To assess the effect of CA on apoptosis, nuclei of MDA-MB-231 cells were stained with DAPI solution. Chromatin condensation, which indicates apoptosis, was observed to increase dose-dependently. In addition, western-blot analysis revealed elevated levels of the apoptosis marker proteins (Bax and cleaved caspase 3) subsequent to MDA-MB-231 exposure to CA. ROS production was also increased in the CA-induced apoptosis in MDA-MB-231 treated cells. Interestingly, CA exposure resulted in significantly decreased migration and invasion rates in the MDA-MB-231 cells. Data further revealed that exposure to CA markedly decreased the VEGF concentration, thereby contributing to a reduction in angiogenesis. Conclusion: Our results determined that exposure to CA induces anti-proliferation, apoptosis, and ROS production, and suppresses cell migration and invasion rate in MDA-MB-231 cells. Taken together, these results indicate the potential of CA to be applied as an effective chemotherapeutic agent for treating breast cancer.

• Journal of Bio-Environment Control
• /
• v.20 no.1
• /
• pp.33-39
• /
• 2011

This experiment was carried out to understand the characteristics of inorganic ion uptake of strawberries to establish a labor saving, environmentally sound closed hydroponic system. Nitrate nitrogen is absorbed in the perlite and granule rockwood with the almost same rate and in the cocopeat with a little bit higher concentration. At the early growth stage, phosphate was absorbed in comparatively high rate, but it is gradually declining to $4me{\cdot}L^{-1}$ in the three treatments except for reused medium. Four treatments showed different absorption rates for potassium, respectively, however, it became $3{\sim}5me{\cdot}L^{-1}$ gradually. But there was few sign to absorb potassium in the reused medium. High concentration of calcium was absorbed in the cocopeat medium and the lowest absorption rate in the granule rockwool, and it turned out to be $2{\sim}3me{\cdot}L^{-1}$ absorption concentration rate in the perlite. All three treatments showed $1me{\cdot}L^{-1}$ at the average absorption concentration rate of magnesium. Iron showed high absorption rate but it showed steadily 1~2 ppm absorption rate. Results of this experiment will be utilized for developing the new substrates for strawberry closed hydroponic system.