• Korean Journal of Plant Resources
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• v.27 no.4
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• pp.380-391
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• 2014

Plants as well as crops are damaged by a combination of the hot and dry winds that has been a major factor in the reduction of crop production. A means to protect them from damaging conditions is to consider a coating material. In this study, we established laboratory screening methods to find a coating material to protect a crop from rapid transpiration caused by various factors. In a test measuring the weight loss of kidney bean seedlings for 6 days, Avion treatments decreased its weight loss (P=0.05). Owing to long-time spend in completing this assay, we performed a more simple method using a cobalt chloride paper strip, which changes from blue to red colors under water condition. Beewax, guagum, paraffin liquid, soybean oil, and PE-635 gave a waterproofing effect above 37 and 43% at 0.5 and 1 h after treatment, respectively. However, these tested materials did not show significant waterproofing results at 2 h. Although the methods produced reasonable results, a screening method to obtain more objective data is needed. An alternative is to use an instrument that can detect the transpiration of crop leaves. In a preliminary test using barley leaves, a portable photosynthesis system showed transpiration inhibition of 2% soybean oil and 10 times-diluted Avion under field conditions. In another test using the leaves of maize seedlings and apricot tree, 2% liquid paraffin and plant oils such as apricot oil, linseed oil, olive oil, and soybean oil showed significant transpiration inhibition (P=0.05). Especially, paraffin liquid and soybean oil selected from above tests gave good transpiration inhibitory effects against rice at 2%. In addition, the mixture of 2% soybean oil and a spreader showed more elevated inhibition results comparing with soybean oil or the spreader alone indicating that the spreader may be attributed to more uniform diffusion of the hydrophobic material onto the leaf surface of maize seedlings. The hydrophobic material coated physically the stomata and cuticle layers on leaf surfaces of rice. These hydrophobic materials screened in this study are expected to be used as plant coating materials.

• Korean Journal of Environment and Ecology
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• v.29 no.3
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• pp.333-343
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• 2015

This research aims at identifying the goshawk's possible and replaceable breeding ground by using the MaxEnt prediction model which has so far been insufficiently used in Korea, and providing evidence to expand possible protection areas for the goshawk's breeding for the future. The field research identified 10 goshawk's nests, and 23 appearance points confirmed during the 3rd round of environmental research were used for analysis. 4 geomorphic, 3 environmental, 7 distance, and 9 weather factors were used as model variables. The final environmental variables were selected through non-parametric verification between appearance and non-appearance coordinates identified by random sampling. The final predictive model (MaxEnt) was structured using 10 factors related to breeding ground and 7 factors related to appearance area selected by statistics verification. According to the results of the study, the factor that affected breeding point structure model the most was temperature seasonality, followed by distance from mixforest, density-class on the forest map and relief energy. The factor that affected appearance point structure model the most was temperature seasonality, followed by distance from rivers and ponds, distance from agricultural land and gradient. The nature of the goshawk's breeding environment and habit to breed inside forests were reflected in this modeling that targets breeding points. The northern central area which is about $189.5 km^2$(2.55 %) is expected to be suitable breeding ground. Large cities such as Cheongju and Chungju are located in the southern part of Chungcheongbuk-do whereas the northern part of Chungcheongbuk-do has evenly distributed forests and farmlands, which helps goshawks have a scope of influence and food source to breed. Appearance point modeling predicted an area of $3,071 km^2$(41.38 %) showing a wider ranging habitat than that of the breeding point modeling due to some limitations such as limited moving observation and non-consideration of seasonal changes. When targeting the breeding points, a specific predictive area can be deduced but it is difficult to check the points of nests and it is impossible to reflect the goshawk's behavioral area. On the other hand, when targeting appearance points, a wider ranging area can be covered but it is less accurate compared to predictive breeding point since simple movements and constant use status are not reflected. However, with these results, the goshawk's habitat can be predicted with reasonable accuracy. In particular, it is necessary to apply precise predictive breeding area data based on habitat modeling results when enforcing an environmental evaluation or establishing a development plan.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.207-216
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• 2013

This study was conducted to establish the method for preserving PGCs that enables long-term storage in liquid nitrogen for developmental engineering or preservation of species. The purpose of this study is to clarify the effects of freeze-thaw treatment on viability of PGCs in chickens. PGCs were collected separately from a germinal gonad of an early embryo of 5.5~6 day (stage 28) of Isa brown, Korean Oge (KO), White Leghorn and Commercial breeds. PGCs separated from a germinal gonad of an early embryo of 5.5~6 day (stage 28) are suspended in a freezing medium containing a freezing and protecting agents (e.g. dimethyl sulfoxide (DMSO), ethylene glycol (EG) and glycerol). The PGCs were then purified using magnetic activated cell sorting (MACS) method. The viability of PGCs after thawing was $87.4{\pm}0.4%$ and $89.4{\pm}0.2%$ with the 10% EG treatments with no significant difference between the Isa brown and Commercial breeds. The viability of PGCs after freeze- thawing was significantly higher for Isa brown ($87.4{\pm}0.4%$) and Commercial breeds ($89.4{\pm}0.2%$) than Korean Oge (KO) ($77.6{\pm}1.1%$) and White Leghorn ($76.2{\pm}0.9%$)(p<0.05) using 10% EG cryoprotectant. This study established a method for pre- serving chicken PGCs that enables systematic storage and labeling of cryopreserved PGCs in liquid ($LN_2$) at agermplasm repository and ease of entry into a data base. In the future, the importance for this new technology is that poultry lines can be conserved while work is being conducted on improving the production of germline chimeras.

• Korean Journal of Plant Resources
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• v.22 no.5
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• pp.403-411
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• 2009

This study was conducted to gather the basic data on the increase of utilization for the Japanese staunton vine (Stauntonia hexaphylla), native plants which were grown in the southern districts in Korea. We have also determined their partial physical and chemical compositions and their physiological activities. Vitamin C contents in fruit skin was 85.23 mg/100 g, and that in flesh was 61.67 mg/100 g. Total amino acids contents in fruit skin increased much more by 762.72 mg/100 g DW compared to that in flesh by 434.05 mg/100 g DW. Inorganic matter contents were more increased in the fruit skin (108.48 mg/$\ell$) and its main components were K (76.53 mg/$\ell$), Ca (20.20 mg/$\ell$) and Mg (6.22 mg/$\ell$). Total phenol compound and flavonoid contents in 1,000 mg/$\ell$ methanol extracts were 7.3-9.6 mg/$\ell$ and 5.1-6.7 mg/$\ell$. Nitrite radical scavenging activity in 4,000 mg/$\ell$ methanol extracts of fruit skin and flesh for Stauntonia hexaphylla were 79.5% and 77.8%, however, that in seeds was 17.1%. Overall mushroom tyrosinase inhibition activity (% of control) was less than 10.8%. Anti-microbial activities of methanol extracts from the fruit skin against the gram negative and positive microbial strains were not significant in the lower concentration of extracting solution, however, that from flesh and seeds in terms of the inhibition diameter were $8.91{\sim}12.25\;mm$.

• Journal of Korean Society of Forest Science
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• v.36 no.1
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• pp.38-46
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• 1977

The purpose of this study are to analyze economic and psychological factors associated with the forest protection of the mountain people, and to explain the forms of the forest management by ownership classes, especially with forest in the production structure of the mountain villages, particulary from Aprial 1st to 20th in 1975. And the basis of the data for this study is to have been obtained by the sample of 462 households, in Jeonbuk province, which were selected by the method of Yandom sampling. In order to determine what relations there are between the forest ownership classes are independent and each of the selected economic and psychological factors, the chi-squre test was used. The findings may be summarized as follows; 1. The area per household forest land of the mountain villages farm families with forest was 1.4ha and are middle classes with the cultivated area, and manage their forest in favor of the forest fuel and the byproducts, which we call "Earn Ownership Management Form". As it is acomplished by the agricultural surplus labor, we can't expect the positive forest investments. 2. The expectation of the proceeds of forest investments seems to be high but 30% of them doubtful. And the mountain villages farm families with above 3ha forest area expect their forest investments to be positive and in future they have hope in the economic management from. 3. The mountainous mountain fram families reply to a small sums of capital and the control of after the fact on account of the negative factors of forest investment. But rural mountain villages farm famillies assist on spending too much money for the control and nexious insects damage. 4. The reason about illegal cut away was mainly their fuels problem and then most of moumtain farm villages was used to forest fuel in their fuel. But 57% of mountainous mountain villages farm families not having forest area, and 66% of them get their fual on the self-supply, and 66.9% of them get from public and nationat forest and other's forest. That is one of the big problems of the forest protection. 5. Above 66% of mountain people think that forest law is severe and 50% of mountainous mountain villages farm families think if usual. Especially ones not having forest area but taking advantage of forest among them think so. 6. Rural mountain villages farm families have comparatively positive attitude for protecting forest, but mountainous mountain villages farm families negative. Classes with above 3ha forest area have more outlook of forest protection. And the more such classes are, the better they can protect forest. 7. There are problem about operation and education of the forest law on the mountainous mountain villages farm families.

• Journal of Korean Society of Forest Science
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• v.76 no.1
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• pp.11-16
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• 1987

With the purpose of pursuing the increase and decrease of chlorophyll a and chlorophyll b caused by application of the simulated acid rain treatment on Pinus koraiensis seedlings and Ligustrum obtusifolium cuttings, the experimental design of randomized block arrangement with three replications was implemented in the experimental field of Yesan National Agricultural Junior College, during the growing season of 1985. Pinus koraiensis seeds stratified in cool and moist condition were sown on pots, and in case of Ligustrum obtusifolium, C1/1 cuttings were potted for experimental use in the early spring. The regime of artificial acid rain, based upon precipitation frequency and density, was simulated from the learning of climatological data averaged from 30 years records. The spray of acid water containing pH values of 4.0 and 2.0 was initiated from the 1st of May and ended on the 31st of August. As control, ground water was also treated at the same time. To analyse the chlorophyll content, those leaves looking representative and unaffected by other harmful agents were sampled on the 18th of September, and UV-visible spectrophotometer was used. With decrease in pH values of acid rain, the content of chlorophyll a and chlorophyll b decreased in both species. The decrease in chlorophyll a could be confirmed through statistical significance, but not in chlorophyll b. And when we discussed the chlorophyll decrease index which was explained in detail in the paper, an attention might be given to similarly decreasing values in both chlorophyll a and chlorophyll b, according as pH levels of acid rain decreased. The ratios of chlorophyll a to chlorophyll b in both species were not affected by different pH leaves of acid rain.

• Korean journal of applied entomology
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• v.50 no.3
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• pp.235-245
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• 2011

Temperature-related parameters of Panonychus citri (McGregor) (Acarina: Tetranychidae) development were estimated and a stage-structured matrix model was developed. The lower threshold temperatures were estimated as $8.4^{\circ}C$ for eggs, $9.9^{\circ}C$ for larvae, $9.2^{\circ}C$ for protonymphs, and $10.9^{\circ}C$ for deutonymphs. Thermal constants were 113.6, 29.1, 29.8, and 33.4 degree days for eggs, larvae, protonymphs, and deutonymphs, respectively. Non-linear development models were established for each stage of P. citri. In addition, temperature-dependent total fecundity, age-specific oviposition rate, and age-specific survival rate models were developed for the construction of an oviposition model. P. citri age was categorized into five stages to construct a matrix model: eggs, larvae, protonymphs, deutonymphs and adults. For the elements in the projection matrix, transition probabilities from an age class to the next age class or the probabilities of remaining in an age class were obtained from development rate function of each stage (age classes). Also, the fecundity coefficients of adult population were expressed as the products of adult longevity completion rate (1/longevity) by temperature-dependent total fecundity. To evaluate the predictability of the matrix model, model outputs were compared with actual field data in a cool early season and hot mid to late season in 2004. The model outputs closely matched the actual field patterns within 30 d after the model was run in both the early and mid to late seasons. Therefore, the developed matrix model can be used to estimate the population density of P. citri for a period of 30 d in citrus orchards.

• Journal of agricultural medicine and community health
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• v.23 no.1
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• pp.65-78
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• 1998

This study was conducted to find out the factors which have an effect on the rural aged's natural history by disability in Activities of Daily Living(ADL) and ADL decline with 475 old people which were chosen except the dead 90 and unconfirmable 56 old people by performing follow-up survey for 4 years since 1993 on the basis of presurveyed data about 621 home old people over 60 years residing in 13 villages at Kangdong-myon, Kyongju-city, Kyongsangbuk-do Province, Korea. Such activities of daily living as bathing, dressing, going to toilet, transfer, feeding and continence were examined. 1. In the follow-up survey for 4 years, the ADL distribution of the dead was remarkably lower than the subject group. 2. It was also shown in the 4-year follow-up survey that 82.1% of high ADL group maintained high ADL while 77.8% of low ADL group died within 4 years. 3. The occurrence percentage of disabilities of each group by ADL item for 4 years appeared high in such an order as bathing, continence, dressing, going to toilet, transfer and feeding. 6.7%(8.1% for female and 4.6% for male) of the old people who were the high ADL group at the time of the first survey had disabilities that occurred after 4 years. 4. In the change of ADL according to general characteristics used to analyse the factors which have an effect on ADL decline, there was a significant difference in age and job, that is, the jobless old people had the higher degree of ADL decline. In the change of ADL according to behavioral pattern, for the male old people there was a significant difference in support of living expenses and subjective health condition. In this case, the degree of ADL decline was higher if they depended on their sons & daughters or spouses and felt that they were not healthy.

• Journal of agricultural medicine and community health
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• v.23 no.2
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• pp.275-285
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• 1998

Antibody responses(IgG) to Paragonimus westermani. Clonorchis sinensis, Cysticercus cellulosae, Sparganum Anisakis simplex, Toxocara canis and Trichinella spiralis were studied. The ELISA technique was performed to determine the prevalence of above helminthic diseases. 975 cases obtained from Yanbian of China during October, 1995 to July, 1997 were examined with a positive antibody titer of 5.74% in clonorchiasis, 4.92% in paragonimiasis, 1.54% in cysticercosis. 8.51% in sparganosis, 1.85% in anisakiosis, 12.51% in toxocariasis, and 7.08% in trichinosis respectively. And 23.87% in showed positive antibody titer at least one of the seven helminths. The differences of the age and sex in the positive sera were analysed by the Chi-squared test and the level of significance accepted was p<0.05. The significant differences in positive antibody production were P.W.(p<0.01). C.S.(p<0.01), A.S.(p<0.05). T.C.(p<0.001), and T.S.(p<0.01) respectively in age groups. sparganosis(p<0.05) in sex groups. Other parasites showed that there were no significant differences among age groups and sex groups(males and females). Higher positive antibody rate of C.S. and P.W. occured in the 50-59 years old and those of T.C. and T.S. happened in the 20-29 years old. Patients of internal disease showed more positive antibody titer, that is to say, there was significant difference between positive rate of internal diseases and that of control (p<0.01. p<0.05) in 6 helminths except cysticercosis. The result showed that some cross reactions existed among nematodes, and the developed techniques(EITB) should be done for a correct diagnosis. Also the prevalence of some important helminths may be evaluated from the result and it would be a basic data for controlling parasitic diseases in Yanbian.

• Journal of agricultural medicine and community health
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• v.36 no.1
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• pp.36-46
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• 2011

Objectives: To investigate the experience and competence of physicians providing emergency medical services at public health sub-centers on remote Korean islands. Methods: This study enrolled 79 doctors who work at public health sub-centers on remote Korean islands. Data were collected in December 2009 via self-administered e-mail questionnaires. The response rate was 44.3%. Results: Emergent situations occurred at most (58.68%) of the public health sub-centers that were surveyed in December 2009. An average of 1.92 cases required treatment by public health physicians. Only 20.25% of the physicians were specialists in emergency medicine, while the remainder were general practitioners (GPs) without clinical experience as emergency doctors. We also found that the physicians we surveyed had insufficient knowledge of emergency medical care. At some health centers only one doctor was available, and there was no medical team in holiday, although most of the physicians indicated that the ideal number of doctors per center was two or three. In cases of emergency, patients were often sent to the mainland by ship without receiving first-aid treatment. The public health sub-centers lacked the necessary medical equipment to save lives in emergencies and lacked escort systems for emergency patients. Conclusions: The Korean government should address the importance of providing emergency care in remote areas. Health administrators should provide suitable manpower, medical equipment, guidelines for emergency medicine, and education for public health physicians on remote islands.