• Asian Pacific Journal of Cancer Prevention
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• v.17 no.6
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• pp.2979-2982
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• 2016

Background: High dose ionizing radiation can induce ovarian cancer, but the effect of low dose radiation on the development of ovarian cancer has not been extensively studied. We evaluated the effect of low dose radiation and total background radiation, and the radiation delivered to the ovaries during the treatment of rectosigmoid cancer and breast cancer on ovarian cancer incidence. Materials and Methods: Background radiation measurements are from Assessment of Variations in Radiation Exposure in the United States, 2011. Ovarian cancer incidence data are from the Centers for Disease Control and Prevention. Standardized incidence ratios (SIR) of ovarian cancer following breast cancer and rectosigmoid cancer are from Surveillance, Epidemiology, and End Results (SEER) data. Obesity data by US state are from the Centers for Disease Control and Prevention. Mean ages of US state populations are from the United States Census Bureau. Results: We calculated standardized incidence ratios (SIR) from Surveillance, Epidemiology, and End Results (SEER) data, which reveal that in 194,042 cases of breast cancer treated with beam radiation, there were 796 cases of ovarian cancer by 120+ months of treatment (0.41%); in 283, 875 cases of breast cancer not treated with radiation, there were 1,531 cases of ovarian cancer by 120+ months (0.54%). The difference in ovarian cancer incidence in the two groups was significant (p < 0.001, two tailed Fisher exact test). The small dose of scattered ovarian radiation (about 3.09 cGy) from beam radiation to the breast appears to have reduced the risk of ovarian cancer by 24%. In 13,099 cases of rectal or rectosigmoid junction cancer treated with beam radiation in the SEER data, there were 20 cases of ovarian cancer by 120+ months of treatment (0.15%). In 33,305 cases of rectal or rectosigmoid junction cancer not treated with radiation, there were 91 cases of ovarian cancer by 120+ months (0.27%). The difference in ovarian cancer incidence in the two groups was significant (p = 0.017, two tailed Fisher exact test). In other words, the beam radiation to rectum and rectosigmoid that also reached the ovaries reduced the risk of ovarian cancer by 44%. In addition, there was a significant inverse relationship between ovarian cancer in white women and radon background radiation (r = - 0.465. p = 0.002) and total background radiation (r = -0.456, p = 0.002). Because increasing age and obesity are risk factors for ovarian cancer, multivariate linear regression was performed. The inverse relationship between ovarian cancer incidence and radon background was significant (${\beta}=-0.463$, p = 0.002) but unrelated to age (${\beta}=-0.080$, p = 0.570) or obesity (${\beta}=-0.180$, p = 0.208). Conclusions: The reduction of ovarian cancer risk following low dose radiation may be the result of radiation hormesis. Hormesis is a favorable biological response to low toxin exposure. A pollutant or toxin demonstrating hormesis has the opposite effect in small doses as in large doses. In the case of radiation, large doses are carcinogenic. However, lower overall cancer rates are found in U.S. states with high impact radiation. Moreover, there is reduced lung cancer incidence in high radiation background US states where nuclear weapons testing was done. Women at increased risk of ovarian cancer have two choices. They may be closely followed (surveillance) or undergo immediate prophylactic bilateral salpingo-oophorectomy. However, the efficacy of surveillance is questionable. Bilateral salpingo-oophorectomy is considered preferable, although it carries the risk of surgical complications. The data analysis above suggests that low-dose pelvic irradiation might be a good third choice to reduce ovarian cancer risk. Further studies would be worthwhile to establish the lowest optimum radiation dose.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.43-54
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• 2001

Genetic differentiation of populations is resulted from the environmental and the genetic effects, and the interactions between them. Whereas, the major factors influencing to the genetic differentiation within populations are the gene flow induced by seed or pollen dispersial, the microsite heterogeneity, and the density-dependent distribution of individuals. For the purpose of studying spatial genetic structure and the distribution pattern of Korean pines(Pinus koraiensis), we set up one $100{\times}100m$ plot at a Korean pine stand in Quercus mongolica community on Mt. Jumbong in Korea. To estimate the coefficient of spatial autocorrelation as Moran's index and an analogue, simple block distance, isozyme markers were analyzed in 325 Korean pines. For 11 polymorphic loci observed in 9 enzyme systems, the average percentage of polymorphic loci, the observed and expected heterozygocity were 72.2% 0.200, and 0.251, respectively. It was revealed the excess of homozygotes was observed in the plot, which suggests that here may be more number of consanguineous trees than expected. On the basis of isozyme genotypes observed in this study, 325 trees were classified into 147 groups in which the maximum number of trees for one group was 34. From the distance class of 24-32m, the genetic heterogeneity began to increase. The variation of simple block distance against the growth performance by tree height and diameter also showed the same trend at 24~32m class. According to high fixation index(F=0.204), the spatial genetic structure within a stand, the analysis of the growth performance, and the distribution patterns of identical genotypes, we inferred that the genetic structure of a Korean pine stand in Mt. Jumbong has been maintained rather density-dependent mechanism than the gene flow, such as the pollen dispersial or the heavy input of seeds following the forest gaps. The genetic patchy size was determined between 24~32m, which suggests that the selection of individuals for the ex situ conservation of Korean pine in Mt. Jumbong may be desirable to be made with the spatial distance over 37 meters between trees.

• Journal of dental hygiene science
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• v.12 no.6
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• pp.682-688
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• 2012

This study investigates the stressors of dental hygienists and student hygienists during the bedside training by the medical center type. The survey is based on some dental hygienists who are working for dental college hospitals, general hospitals, dental hospitals and dental clinics in Seoul and Gyeonggi area which the Clinical Practice of dental hygienics students is under way in. Included are the students who are studying dental hygienics at Kyungbok University and have taken the bedside training in dental college hospitals, general hospitals, dental hospitals and dental clinics. A statistical analysis shows the following results using SPSS program. By medical center type, dental hygienists described the clinical practice of students as relatively satisfying. It also found that there is a positive correlation between stress zones, and they feel most stressed in the "Role and Activity" zone. Student hygienists felt relatively satisfied with the bedside training, and there is a positive correlation between stress zones except "Practice". It found students, who have taken the bedside training in all types of medical centers except dental clinics, felt most stressed in "Environment". It also found that students who have taken the bedside training in dental clinics felt most stressed in "Role and Activity". In conclusion, most of the dental hygienists are satisfied with students' clinical practice by pattern of hospital. Positive correlation was shown between stress factors. Behavior and attitude and ideal and value are high in stress in college dental hospitals, role and activity and treatment fields are high in stress in dental hospital, and interpersonal relationships are high in stress in dental clinics.

• Journal of agriculture & life science
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• v.45 no.6
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• pp.163-173
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• 2011

The objective of this study was to determine microbiological risk factors in hot pepper farms for the application of good agricultural practices (GAP). Samples were collected from cultivation environments and utensils, plants, workers, and air at 3 hot pepper farms located in Cheongsong, Korea and were tested to detect sanitary indications [aerobic plate bacteria (APC), coliform, and Escherichia coli], foodborne pathogens, and fungi. APC, coliform, and fungi were detected at the levels of 0.7~6.2, 0.2~4.7, and 0.4~4.3 log CFU, respectively, in the three farms. Four (4.4%; l leaf, l irrigation water, and 2 soil) of 90 samples collected were revealed to be E. coli positives. For foodborne pathogens, Staphylococcus aureus was only detected at $1.0log\;CFU/100cm^2$ in the worker's cloth of B farm, and Bacillus cereus was detected at the levels 1.0~2.5 log CFU in the cultivation environments and utensils and worker of B and C farms. However, other pathogens were not detected. The results demonstrated potential microbiological risks for hot pepper cultivated in the farms. Therefore, a management system to minimize the microbial risk such as GAP is required to ensure the safety of hot pepper.

• Korean Journal of Social Welfare Studies
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• v.44 no.3
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• pp.177-206
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• 2013

The Korean government has implemented the senior employment policy as a direct job creation policy since 2004. A realistic discussion of policy alternatives and orientation for this has been given little attention even though senior employment policy has been carried out for the last 10 years and it will be expanded next year. This study tries to examine active labor market policy especially focusing on direct job creation programs and policies for the disadvantaged low-income elderly in OECD countries, and then it suggests some developmental alternatives for senior employment policy based on the study's results. The main results from this analysis are summarized in two points. Firstly, except pension policies, employment policy for older workers in the OECD countries is highly proportional to the tackling of objective factors reducing the demand for older workers (wage subsidies, reduced social security contribution rate etc). And the strategies of improving employability have not been relatively important and direct job creation policy has been marginal. Secondly, employment support policies for the low-income elderly can be divided into three types: support for the low-income elderly, alleviating early retirement and support for full employment according to the criteria which are determined by policy objectives and the social economic index. Korea's employment support policies belong to the type of direct job creation among them. This seems to be due to the fact that the rate of elderly poverty is extremely high and an income security system has not been developed in Korea. However, the policy objective is still uncertain. Therefore, this policy needs to set up clear objectives and establish a proper system for the achievement of its goals. If we focus on the strength of its employment characteristics, we need to modify the policy's plan in the perspective of labor market policy. But if we intend to keep both of the current objectives, it is better for this policy to be divided into two parts: social participation and income supplements. Or it also may be a solution to transform the system into an employment service, a training system which supports participants to move into unsubsidized jobs such as SCSEP in the U. S.

• Journal of Environmental Impact Assessment
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• v.28 no.5
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• pp.440-456
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• 2019

The controversy of the risk perception related to particulate matters becomes significant. Therefore, in order to understand the nature of the particulate matters, we gathered articles and comments in on-line community related to bicycling which is affected by exposure of the particulate matters. As a result, firstly, the government - led particulate matter policy was strengthened and segmented every period, butthe risk perception related to particulate matters in the bicycle community has become active and serious. Second, as a result of analyzing the perception change of outdoor activities related to particulate matters, bicycle users in community showed a tendency of outdoor activity depending on the degree of particulate matters ratherthan the weather. In addition, the level of the risk perception related to particulate matters has been moved from fears of serious threat in daily life and health, combined with the disregard of domestic particulate matter levels or mask performance. Ultimately, these risk perception related to particulate matters have led some of the bicycling that were mainly enjoyed outdoors to the indoor space. However, in comparison with outdoor bicycling enjoyed by various factors such as scenery, people, and weather, the monotonous indoor bicycling was converted into another type of indoor exercise such as fitness and yoga. In summary, it was derived from mistrust of excessive information or policy provided by the government or local governments. It is considered that environmental policy should be implemented after discussion of risk communication that can reduce the gap between public anxiety and concern so as to cope with the risk perception related to particulate matters. Therefore,this study should be provided as an academic basis for the effective communication direction when decision makers establish the policy related to particulate matters.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.4
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• pp.325-335
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• 1985

Biogas production from agricultural wastes were summarized as follows: 1. Biogas Generation Characteristics of Various Manures and Residues a. Gas yield from crop residues like rice straw, rice hull, corn stalk and coconut husk can be improved by addition of animal manures. b. Gas yield from coconut husk can be improved through aerobic fermentation for at least one week before loading in the digester. c. Gas yield from fresh rice straw is better than from pre-fermented one, whether alone or in combination with animal manures. d. Initial study has shown that fresh azolla can be substituted for animal manures in manurerice straw combinations and gas yield derived based on unit volatile solids loaded is actually better than for manure-residue combinations. e. Gas production is highly sensitive to substrate pH and becomes almost nil at a pH of below 6. 2. Effect of ambient conditions and other factors on biogas production in a house hold-size digester. a. Results showed that compaction of rice straw in straw-manure combination can reduce gas yield compared with loosely mixed straw. b. The effective gas production period extended to 70 days using freshly threshed rice straw and fresh cattle manure as feed material. c. Underground and above ground digesters with shade have relatively more stable substrate temperature than aboveground exposed digesters. This relative temperature instability may likely be the reason for lower gas yield for the exposed aboveground digester loaded with loose straw-cattle manure substrate, compared with the underground digester with the same substrate. 3. Economic Analysis a. Based on prevailing costs of fuel, materials, and labor in the Philippines, biogas produced from the household size system is cheaper than either LPG or kerosene. b. If other benefits like organic fertilizer, pollution control and convenience are considered, biogas will surely be the best alternative fuel source.

• Korean Journal of Psychosomatic Medicine
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• v.24 no.2
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• pp.227-235
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• 2016

Objectives : The aims of this study were to know the frequency of cognitive dysfunction among patients with autoimmune thyroid disorders, and to reveal influencing factors on it, especially to clarify association with autoimmune thyroid antibodies. Methods : From sixty-five female patients with autoimmune thyroid disorders, demographic data were obtained by structured interview. Their cognitive funtions were measured using the MMSE-K and the MoCA-K tests. Depression was evaluated by the K-HDRS. Results : 1) Among patients with autoimmune thyroid disorders, 7.69% of them were below 24 on the MMSE-K, while 10.77% were below 22 on the MoCA-K. The frequency of cognitive deficit was not significantly different according to having positivity to antimicrosomal antibodies or not. 2) The antimicrosomal antibody-positive patients had significantly higher antithyroglobulin antibody titers, antimicrosomal antibody titers, and TSH concentration, while had significantly lower free T4 levels(p<0.05, respectively). 3) The total scores of the MMSE-K and the MoCA-K had significant correlation with age, marital status, antithyroglobulin antibody titers and K-HDRS(p<0.05, respectively). 4) The regression analysis revealed that variables such as age, education, autoimmune thyroid antibodies, thyroid function and depression did not influence on cognitive function of patients with autoimmune thyroid disorders. Conclusions : Our results could not support that cognitive function of patients with autoimmune thyroid disorders had correlation with autoimmune thyroid antibodies.

• Journal of Environmental Impact Assessment
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• v.30 no.6
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• pp.339-354
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• 2021

The purpose of this study is to provide valuable information and data by analyzing the environmental status and potential forrenewable energy projects (or plans) based on environmental assessment (EA) data, so that more objective and scientific environmental assessments can be conducted. The study also suggests regional directions that could satisfy the goals of nature conservation and renewable energy. Based on the analysis of EA data that was conducted up until June 2019, the study analyzed the size, location and characteristics of both onshore wind power and onshore photovoltaic. The environmentally available potential by region was also derived by considering the main constraints and requirements related to the potential siting ofrenewable energy projects at the EA. Based on EA data, 63 out of 80 (79%) onshore wind power projects are shown to be located in mountainous areas. For onshore photovoltaic projects, a total of 7,363 projects were subjected to environmental assessment over the country. The environmentally potential area for onshore wind power, considering all the environmental regulatory factors, is 2,440 km². For onshore photovoltaic, the environmentally available area estimated as idle farmland is 2,877 km². The distribution and characteristics of the environmentally available potential of the region may be the most important factor that local governments should bear in mind in terms of promoting renewable energy development projects in the region. Based on the results of this study, even if we consider the national energy plan including the expected future increase, as well as environmental goals and socio-economic acceptance through an environmental assessment, the available resources forrenewable energy projects are not insufficient. It is possible to examine the adequacy of the target distribution rate of renewable energy sources by region taking into consideration the quantitative and scientific results such as the environmentally available potential data derived from this study.

• Journal of Korea Water Resources Association
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• v.54 no.10
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• pp.835-848
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• 2021

In Jeju Island which has peculiarity for its geological features and hydrology system, hydrological factor analysis for the effective water management is necessary. Because in-situ hydro-meteorological data is affected by surrounding environment, the in-situ dataset could not be the spatially representative for the study area. For this reason, remote sensing data may be used to overcome the limit of the in-situ data. In this study, applicability assessment of MOD16 evapotranspiration data, Globas Land Data Assimilation System (GLDAS) based evapotranspiration/soil moisture data, and Advanced SCATterometer (ASCAT) soil moisture product which were evaluated their applicability on other study areas was conducted. In the case of evapotranspiration, comparison with total precipitation and flux-tower based evapotranspiration were conducted. And for soil moisture, 6 in-situ data and ASCAT soil moisture product were compared on each site. As a result, 57% of annual precipitation was calculated as evapotranspiration, and the correlation coefficient between MOD16 evapotranspiration and GLDAS evapotranspiration was 0.759, which was a robust value. The correlation coefficient was 0.434, indicating a relatively low fit. In the case of soil moisture, in the case of the GLDAS data, the RMSE value was less than 0.05 at all sites compared to the in-situ data, and a statistically significant result was obtained as a result of the significance test of the correlation coefficient. However, for satellite data, RMSE over than 0.05 were found at Wolgak and there was no correlation at Sehwa and Handong points. It is judged that the above results are due to insufficient quality control and spatial representation of the evapotranspiration and soil moisture sensors installed in Jeju Island. It is estimated as the error that appears when adjacent to the coast. Through this study, the necessity of improving the existing ground observation data of hydrometeorological factors is emphasized.