• 한국산업보건학회지
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• 제25권4호
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• pp.573-583
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• 2015

Objectives: This study was carried out to evaluate the effect of noise exposure and aging on changes in hearing threshold level and the relationship between age and noise. Materials: The author selected 274 male shipyard and assembly line workers as the noise exposed group and 582 males not exposed to noise as the general population group. Data were collected from five years of consecutive annual audiometric tests performed from 2008 to 2012. Results: In the general population and noise exposed groups, there was a reverse phenomenon that hearing threshold level for 2009 was lower than that of 2008, which seemed to be due to the learning effect, but from 2010 hearing threshold level increased. In the noise exposed group, the mean hearing threshold level in the left ear was significantly higher than that for right ear. In the general population group, the older was the age, the higher was the hearing threshold level, especially at 4000 Hz. In the general population and noise exposed groups, frequency, age group and noise exposure independently affected hearing threshold level, and there was no relationship between age and noise exposure. Over all frequencies, the change of hearing threshold level was larger in the noise exposed group than in the general population group. In the noise exposed group below thirty years old, the change at 4000 Hz was remarkable. Conclusions: Age and noise exposure seem to affect hearing threshold level independently and contribute to an additive effect on hearing threshold level.

• 한국산학기술학회논문지
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• 제12권6호
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• pp.2528-2534
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• 2011

본 연구는 106개 국가 간 통계자료를 사용해 인구구조의 변화와 교육투자의 효율성 간의 관계를 검토했다. 선행연구에 기초해 전체인구 대비 청소년층 인구비율과 교육투자의 효율성과 간에는 음(-)의 관계가 존재하는 반면, 노인층 인구비율과 교육투자의 효율성 간에는 양(+)의 관계가 존재한다는 가설을 설정했다. 실증분석 결과 이상의 가설은 표본이나 모형의 선택에 상관없이 성립하는 것으로 추정됐다. 따라서 본 연구의 결과는 고령화와 저출산으로 인해 생산가능인구 감소가 심각한 사회문제로 인식되고 있는 우리나라와 같은 국가의 경우 보다 교육비지출이 효율적으로 이뤄져야 하며, 교육성과를 극대화하기 위한 제도적 장치를 마련해야 한다는 시사점을 제공한다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권7호
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• pp.3105-3112
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• 2014

Purpose: To examine breast cancer (BC) incidence trends in relation to mammographic screening and risk factor prevalence in South Australia (SA). Materials and Methods: Trends in annual BC incidence rates were calculated using direct standardisation and compared with projected incidence derived from Poisson regression analysis of pre-screening rates. Annual percentage change and change time points were estimated using Joinpoint software. Biennial mammography screening participation rates were calculated using data from BreastScreen SA. Trends in overweight/obesity, alcohol use and hormone replacement therapy (HRT) use were examined using 1991-2009 Health Omnibus Survey data. Trends in total fertility were examined using data from the Australian Bureau of Statistics. Results: BC incidence increased around the time BreastScreen commenced and then stabilised in the mid-1990s. However rates have remained higher than projected, even though the proportion and age distribution of first time screening attendees stabilised around 1998. A decrease in BC incidence was observed among women aged 50-59yrs from the late-1990's but not among older women. Obesity and alcohol use have increased steadily in all age groups, while HRT use declined sharply from the late-1990s. Conclusions: BC incidence has remained higher than projected since mammography screening began. The sustained elevation is likely to be due to lead time effects, though over-diagnosis cannot be excluded. Declining HRT use has also impacted incidence trends. Implications: Studies using individual level data, which can account for changes in risk factor prevalence and lead time effects, are required to evaluate 'over-diagnosis' due to screening.

• Safety and Health at Work
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• 제9권2호
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• pp.172-179
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• 2018

Background: Insufficient training in infection control and occupational health among healthcare workers (HCWs) in countries with high human immunodeficiency virus (HIV) and tuberculosis (TB) burdens requires attention. We examined the effectiveness of a 1-year Certificate Program in Occupational Health and Infection Control conducted in Free State Province, South Africa in an international partnership to empower HCWs to become change agents to promote workplace-based HIV and TB prevention. Methods: Questionnaires assessing reactions to the program and Knowledge, Attitudes, Skills, and Practices were collected pre-, mid-, and postprogram. Individual interviews, group project evaluations, and participant observation were also conducted. Quantitative data were analyzed using Wilcoxon signed-rank test. Qualitative data were thematically coded and analyzed using the Kirkpatrick framework. Results: Participants recruited (n = 32) were mostly female (81%) and nurses (56%). Pre-to-post-program mean scores improved in knowledge (+12%, p = 0.002) and skills/practices (+14%, p = 0.002). Preprogram attitude scores were high but did not change. Participants felt empowered and demonstrated attitudinal improvements regarding HIV, TB, infection control, and occupational health. Successful projects were indeed implemented. However, participants encountered considerable difficulties in trying to sustain improvement, due largely to lack of pre-existing knowledge and experience, combined with inadequate staffing and insufficient management support. Conclusion: Training is essential to strengthen HCWs' occupational health and infection control knowledge, attitudes, skills, and practices, and workplace-based training programs such as this can yield impressive results. However, the considerable mentorship resources required for such programs and the substantial infrastructural supports needed for implementation and sustainability of improvements in settings without pre-existing experience in such endeavors should not be underestimated.

• Applied Biological Chemistry
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• 제49권3호
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• pp.175-179
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• 2006

동일비료를 장기연용한 토양에서 벼를 단작으로 재배하여 비료의 시용에 따른 벼 품종간 근권 세균 및 방선균의 밀도와 우점균을 조사하였다. 비료는 3요소(NPK)를 기본으로 하여 무질소(PK), 무인산(NK) 무칼리(NP) 및 NPK+퇴비를 처리하였다. 벼의 근권 미생물 밀도는 품종에 따라서는 큰 차이를 보이지 않았고 시용비료에 의해 약간의 차이를 보였는데 세균은 감소하고 방선균은 증가하는 경향을 나타내었다. 근권 미생물의 분포상에는 유기물의 영향이 뚜렷하여 방선균의 경우 NPK+퇴비구 처리구에서 가장 높은 균 밀도를 나타냈다. 배양가능한 호기성 세균에서는 Bacillus속의 B. megaterium, B. mycoides, B. licheniformis, B. subtilis 등이, 방선균에서는 Streptomyces속의 S. spororaveus, S. canus, S. tauricus, S. galbus 등과 Micromonospora속이 우점하여 분포하였다.

• 생태와환경
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• 제46권3호
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• pp.319-331
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• 2013

Recent climate change, which is mostly ascribed to anthropogenic activities, is believed to be a major factor leading to biodiversity decreases and ecosystem service deteriorations. I have reviewed recent studies on climate change effects for many ecological processes involved with plants, in order to improve our understanding of the nature of ecological complexity. Plants in general have better growth and productivity under high levels of $CO_2$, although the long term effects of such $CO_2$ fertilizers are still controversial. Over the last 30 years, the Earth has been greening, particularly at higher latitudes of the Northern Hemisphere, perhaps due to a relaxation of climatic constraints. Human appropriation of net primary productivity (NPP), which corresponds up to 1/3 of global NPP, is ultimately responsible for climate change and biodiversity decreases. Climate change causes phenological variations in plants, especially in regards to spring flowering and fall leaf coloring. Many plants migrate polewards and towards higher altitudes to seek more appropriate climates. On the other hand, tree mortality and population declines have recently been reported in many continents. Landscape disturbance not only hinders the plant migration, but also makes it difficult to predict the plants' potential habitats. Plant and animal population declines, as well as local extinctions, are largely due to the disruption of species interactions through temporal mismatching. Temperature and $CO_2$ increase rates in Korea are higher than global means. The degree of landscape disturbances is also relatively high. Furthermore, long-term data on individual species responses and species interactions are lacking or quite limited in Korea. This review emphasizes the complex nature of species responses to climate change at both global and local scales. In order to keep pace with the direction and speed of climate change, it is urgently necessary to observe and analyze the patterns of phenology, migration, and trophic interactions of plants and animals in Korea's landscape.

• Nutrition Research and Practice
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• 제15권sup1호
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• pp.53-69
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• 2021

BACKGROUND/OBJECTIVES: To determine the weight change trend among the adult Turkish population after 1 yr of the coronavirus disease 2019 (COVID-19) pandemic and factors associated with weight change. MATERIALS/METHODS: This cross-sectional study was conducted between 26 February and 6 March 2021 using an online questionnaire that included questions for sociodemographic variables, eating habits, stress level, and the Three-Factor Eating Questionnaire-R18. Those who weighed themselves 1-2 weeks before the pandemic was declared in Turkey and remembered their weight were invited to participate in the study. Trends in weight and body mass index (BMI) change were calculated. The variables associated with a 1% change in BMI were assessed using hierarchical regression analysis. RESULTS: The study was conducted with 1,630 adults (70.25% female) with a mean age of 32.09 (11.62) yrs. The trend of weight change was found to increase by an average of 1.15 ± 6.10 kg (female +0.72 ± 5.51, male +2.16 ± 7.22 kg) for the first year of the COVID-19 pandemic. The rate of participants with a normal BMI (18.50-24.99 kg/m²) decreased to 51.91% from 55.75%. Consuming an "Increased amount of food compared to before the pandemic" was found to be the independent variable that had the strongest association with a 1% increase in BMI (β = 0.23 P < 0.001). The average change in the BMI was higher in older individuals than in those who were younger. A high stress level was associated with a decrease in BMI (β = -0.04 P = 0.048). CONCLUSIONS: In this study, the factors associated with weight change after 1 yr of the pandemic in the Turkish population was reported for the first time. A high stress level and increased weight gain trend still occur in Turkey after 1 yr of the pandemic.

• 한국인구학
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• 제18권2호
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• pp.23-50
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• 1995

이 글은 한국의 인구변천이 환경변화에 어떻게 영향을 미치고 있는가를 규명하고 있다. 이 관계는 기본적으로 경로모형(path model)의 틀로서 설명되고 있다. 인구증가는 그 자체만으로도 직접적으로 환경을 오염시키는 원인이 되고 있다. 인구증가는 또한 각각 도시화 및 산업화를 유발시킴으로서 환경오염의 간접적인 원인이 되고 있다. 한편, 도시화와 산업화는 서로 상승작용을 통해서 환경오염에 영향을 미치고 있다. 이 글에서는 이와 같은 이론적 틀에 입각하여 한국의 인구성장, 도시화 및 공업화의 추세를 살펴보고 이들 요인들이 환경변화에 어떻게 영향을 미치고 있는가를 분석하고 있다. 또한 환경오염의 변화양태를 대기오염과 수질오염 그리고 폐기물의 변화추세로써 살펴보고 있다. 마지막으로 환경변화의 결과가 한국적인 상황에서 어떻게 나타나고 있는가가 논의되고 있다.

• Journal of Nutrition and Health
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• 제22권2호
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• pp.108-117
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• 1989

The purpose of this study was aimed to investigate the historical tends of population growth which has reflected direct effect of the ratio of food self sufficiency in Korea between the year of 1910 and 1980. Author divided the whole years between 1910 and 1980 into five different periods ; colonial period from 1910 to 1945, post colonial period from 1945 to 1950, Korean war period from 1950 to 1955, post Korean war period from 1955 to 1960, fast economic growing period 1960~1980. The ratio of national food self sufficiency has been profoundlly affected by dual factors ; rate of population group and increment of GNP which reflect the national economic development. Total food production never reached the level of population growth ratio in Korea. As a result food demand and supply has shown imbalaced condition which leads to import foods from outside contury to compensate food shortage. The increment of GNP sharply cut down the cereal consumption. The consumption of fish, milk, eggs and meat reflected to increase since 1970.

• Journal of Plant Biology
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• 제10권1_2호
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• pp.21-30
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• 1967

The aim of present study is to elucidate the relationship between decay rate of soil organic matter, and the change of soil microbial population under the oak and pine forest soils in Kwang-nung plantation stand. The results obtained are as follows: 1) The correlation coefficient between decay rate and the soil bacteria is 0.84 and fungi 0.93. 2) The distribution of soil microbial population is higher in both F horizon of the oak forest soil, and F and H horizon of the pine forest soil. However, the number of soil microorganisms decreases with the depth in each forest soil. 3) The population of soil microbes is related to moisture content, total nitrogen, available phosphorus, and exchangeable calcium, except organic carbon in fungi. 4) The soil organic matter has been mainly decomposed by fungi, and the size of its population are governed by the factors such as moisture content, organic carbon, total nitrogen, available phosphorus, and exchangeable calcium.