• BMB Reports
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• 제48권4호
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• pp.209-216
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• 2015

Stress is now recognized as a universal premorbid factor associated with many risk factors of various chronic diseases. Acute stress may induce an individual's adaptive response to environmental demands. However, chronic, excessive stress causes cumulative negative impacts on health outcomes through "allostatic load". Thus, monitoring the quantified levels of long-term stress mediators would provide a timely opportunity for prevention or earlier intervention of stressrelated chronic illnesses. Although either acute or chronic stress could be quantified through measurement of changes in physiological parameters such as heart rate, blood pressure, and levels of various metabolic hormones, it is still elusive to interpret whether the changes in circulating levels of stress mediators such as cortisol can reflect the acute, chronic, or diurnal variations. Both serum and salivary cortisol levels reveal acute changes at a single point in time, but the overall long-term systemic cortisol exposure is difficult to evaluate due to circadian variations and its protein-binding capacity. Scalp hair has a fairy predictable growth rate of approximately 1 cm/month, and the most 1 cm segment approximates the last month's cortisol production as the mean value. The analysis of cortisol in hair is a highly promising technique for the retrospective assessment of chronic stress. [BMB Reports 2015; 48(4): 209-216]

• Journal of Ecology and Environment
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• 제31권3호
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• pp.167-176
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• 2008

Atmospheric N deposition has far-reaching impacts on forest ecosystems, including on-site impacts such as soil acidification, fertilization, and nutrient imbalances, and off-site environmental impacts such as nitrate leaching and nitrous oxide emission. Although chronic N deposition has been believed to lead to forest N saturation, recent evidence suggests that N retention capacity, particularly in the forest floor, can be surprisingly high even under high N deposition. This review aims to provide an overview of N retention processes in the forest floor and the implications of changing C-N interactions for C sequestration. The fate of available N in forest soils has been explained by the competitive balance between tree roots, soil heterotrophs, and nitrifiers. However, high rates of N retention have been observed in numerous N addition experiments without noticeable increases in tree growth and soil respiration. Alternative hypotheses have been proposed to explain the gap between the input and loss of N in N-enriched, C-limited systems, including abiotic immobilization and mycorrhizal assimilation, both of which do not require additional C sources to incorporate N in soil N pools. Different fates of N in the forest floor have different implications for C sequestration. N-induced tree growth can enhance C accumulation in tree biomass as observed across temperate regions. C loss from forests can amount to or outweigh C gain in N-saturated, declining forests, while another type of 'C-N decoupling' can have positive or neutral effects on soil C sequestration through hampered organic matter decomposition or abiotic N immobilization, respectively.

• Journal of Preventive Medicine and Public Health
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• 제25권4호
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• pp.429-447
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• 1992

The effects and roles of social support and stressors (stressful life events and chronic strains) on psychosocial distress were examined in a model with data from a sample of the white-collar workers (N=416) in Korea. The findings of this study present that mean levels of psychosocial distress were higher in the female, youth, unmarried and divorced, and low economic status (monthly income). The analysis also shows that, as expected, stressful life and chronic strains as stressors are positively related to occurrence of psychosocial distress, and social support is negatively related to psychosocial distress. Further, the contribution of social support to predicting psychosocial distress is greater in magnitude than that of stressful events, chronic strains, and seciodemographic variables. There is no evidence that social support buffers the impacts of stressors on psychosocial distress, rather social support takes a role of mai or direct effects on psychosocial distress. Therefore, the strength of the social support is an important and meaningful strategy to prevent from stress and mental, physical illness.

• 한국물환경학회지
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• 제23권1호
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• pp.144-154
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• 2007

The acute and chronic toxicity of ambient and effluent water discharged to Lake Shihwa were investigated by using Vibrio fischeri, Daphnia magna and Oryzias latipes. Physicochemical characteristics including biochemical oxygen demand (BOD) and nine heavy metals in a total of 15 water samples were evaluated and were satisfied with relevant Korean Water Quality Standards (KWQS) except for Hg in one sample. Acute toxicity was observed in five samples collected from three sampling locations. When impacts on reproduction and growth after chronic exposure were evaluated with D. magna, all the samples showed significant chronic effects. Reproduction appeared relatively more sensitive endpoint. In 21 days chronic tests on O. latipes, survival, mean egg number per female per day, hatching success rate and time to hatch were affected by increasing sample concentration. The organ-level changes such as gonadosomatic index (GSI), and hepatosomatic index (HSI), and molecular biomarker of vitellogenin (Vtg) induction that evaluated with O. latipes increased as exposure concentrations increased. It is noteworthy that the samples that did not exceed the KWQS resulted in acute and chronic toxicities. The results suggested that numeric criteria based on physicochemical parameters may not be protective of aquatic ecosystem. Acute and chronic toxicity tests with organisms representing different trophic groups should be supplemented in order to provide adequate level of environmental protection.

• Journal of Preventive Medicine and Public Health
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• 제50권4호
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• pp.251-261
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• 2017

Objectives: This study aimed to predict the 10-year impacts of the introduction of pictorial warning labels (PWLs) on cigarette packaging in 2016 in Korea for adults using DYNAMO-HIA. Methods: In total, four scenarios were constructed to better understand the potential health impacts of PWLs: two for PWLs and the other two for a hypothetical cigarette tax increase. In both policies, an optimistic and a conservative scenario were constructed. The reference scenario assumed the 2015 smoking rate would remain the same. Demographic data and epidemiological data were obtained from various sources. Differences in the predicted smoking prevalence and prevalence, incidence, and mortality from diseases were compared between the reference scenario and the four policy scenarios. Results: It was predicted that the optimistic PWLs scenario (PWO) would lower the smoking rate by 4.79% in males and 0.66% in females compared to the reference scenario in 2017. However, the impact on the reduction of the smoking rate was expected to diminish over time. PWO will prevent 85 238 cases of diabetes, 67 948 of chronic obstructive pulmonary disease, 31 526 of ischemic heart disease, 21 036 of lung cancer, and 3972 prevalent cases of oral cancer in total over the 10-year span due to the reductions in smoking prevalence. The impacts of PWO are expected to be between the impact of the optimistic and the conservative cigarette tax increase scenarios. The results were sensitive to the transition probability of smoking status. Conclusions: The introduction of PWLs in 2016 in Korea is expected reduce smoking prevalence and disease cases for the next 10 years, but regular replacements of PWLs are needed for persistent impacts.

• Fisheries and Aquatic Sciences
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• 제6권4호
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• pp.225-227
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• 2003

Acetylcholinesterase (AChE) activity is a potential biomarker for phenanthrene exposure in aquatic organisms. Olive flounder (Paralichthys olivaceus) were exposed to three different concentrations (0.5, 1.0 and 2.0, uM) of phenanthrene for four weeks. AChE activities in the brain, heart and eyes were documented. Inhibition of AChE activity was found significant in flounder treated with a concentration greater than $1.0 {\mu}M$ of phenanthrene. This indicates that a chronic exposure to phenanthrene induces damage in various organs (brain, heart and eyes) and changes of AChE activities might be a useful biomarker to assess the impacts induced by polycyclic aromatic hydrocarbon (PAH). Evidence from this study confirms that the measurement of AChE in the brain and eyes of flounder is a valuable tool that along with other biomarkers can maximize an ecotoxicologists' confidence in assessing the impacts of oil and PAH pollution in the aquatic environment.

• Annals of Occupational and Environmental Medicine
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• 제35권
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• pp.20.1-20.7
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• 2023

The policy proposal by the current Korean government that proposes flexible overtime rules is causing social controversy. This study has explored the 612 experts' opinions on the occupational safety and health impacts of the policy using an online self-report survey. They expected short-term overwork (87.25%), overwork inequality (86.44%), irregular working hours (84.31%), chronic overwork (84.15%), long working hours (83.66%), and unpredictability of working hours (81.86%) as a result of the policy change. They also responded that the policy change would increase industrial accident deaths (87.25%), mental illnesses (87.09%), deaths due to overwork or cardiovascular diseases (83.84%), and accidents (83.33%). They disagreed that the government's flexibilization policy, while agreeing that the necessity of policies on regulating night work (94.77%), guaranteeing wages to eliminate overtime (90.36%), establishing working time regulations for the bogus self-employed (82.84%), and applying the 52-hour workweek system to all workplaces (76.47%). These expert opinions are consistent with previous research on the health effects of working hours.

• 수면정신생리
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• 제10권2호
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• pp.77-83
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• 2003

Industrialization has brought great changes in human life. Human sleep patterns have also been much influenced by industrialization and the invention of electricity and the light bulb. Insufficient sleep is a common problem with considerable health, social, and economical impacts on modern society. In this review, we will outline the present state of insufficient sleep in our society, especially catastrophic accidents related with chronic sleep insufficiency. We will discuss the effect of sleep deprivation on human performance by reviewing the literature. We will also emphasize the role of sleep specialists in this issue and highlight the areas in which the principles of sleep medicine can constructively improve public policy and public health.

• 산업경영시스템학회지
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• 제19권40호
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• pp.311-319
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• 1996

Cumulative trauma disorders (CTD) refer to a category of physical signs and symptoms due to chronic musculoskeletal injuries where the antecedents appear to be related to some aspect of repetitive work which can be found commonly in modern industries. This paper describes impacts of CTD on modern industry and summarizes recent resent research efforts and suggests an ergonomic program to prevent incident of CTD in hand-intensive industry.

• 대한산업공학회지
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• 제11권2호
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• pp.165-172
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• 1985

Since energy consumption of developing countries is expected to grow rapidly over the coming decades, the oil-importing developing countries are likely to encounter chronic balance-of-payments difficulties. To analyze the quantitative impacts of this problem, we develop a computable model of international trade. This paper presents four alternative cases - varying the assumptions with respect to energy supplies. This shows that relatively small difference in supplies can lead to 100% differences in the energy prices projected for 1990.