• Title/Summary/Keyword: Environmental Disturbance

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Effect of Subchronic 3-Monochloro-1,2-propanediol Exposure on the Expression of Inducible Nitric Oxide Synthase in Rat Brain

  • Nam, Jung-Min;Eum, Si-Yoon;Lee, Eun-Ah;Kim, Ki-Sok
    • 한국환경보건학회:학술대회논문집
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    • 한국환경보건학회 2005년도 국제학술대회
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    • pp.303-305
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    • 2005
  • 3-Monochloro-1,2-propanediol (3-MCPD) is a contaminant of acid-hydrolyzed vegetable protein. Several reports have suggested that chronic exposure to 3-MCPD could produce neurotoxicity in vitro or neurobehavioral effects inaspects of experimental animals. Disturbance of the nitric oxide signaling pathway by chronic exposure to 3-MCPD may be a causal factor of neurological disorders in rats. In order to investigate the relationship between 3-MCPD administration and expression of inducibal nitric oxide synthase (iNOS), the numbers and distribution patterns of iNOS-immunoreactive neurons were examined. At the all three bregma level examined, the optical density of iNOS-postive neurons was significantly increased following exposure to 3-MCPD. The change was more severe in the upper layer than in deep layer of the cortex. These data suggest that 3-MCPD toxicity may be mediated through disturbances to the nitric oxide signaling pathway.

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Non-linear Responses of Hordeum vulgare Germs to Low Doses of Ionizing Radiation

  • Kim, Jin-Kyu;Alla A. Oudalova;Vladimir G. Dikarev
    • 환경생물
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    • 제21권4호
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    • pp.384-391
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    • 2003
  • The induction of chromosome aberrations in Hordeum vulgare germs after irradiation is studied for the dose range of 10 to 1,000 mGy. The relationship between the frequency of aberrant cells and the absorbed dose is shown to be non -linear and has a dose-independent plateau within the range of 56-467 mGy where the level of cytogenetic damage is statistically significantly distinguished from the spontaneous level. The comparison of the goodness of the experimental data fitting with mathematical models of different complexities, using the most common quantitative criteria, demonstrates the benefit of the piecewise linear model over the linear and polynomial ones in approximating the cytogenetical disturbance frequency. The results of our study support the conclusion about indirect mechanism of chromosome aberrations induced by low doses or dose rates mutagenesis.

생태학의 새로운 분야로서 경관생태학의 발전과 역할 (Development and Roles of Landscape Ecology as An Emerging Opportunity for Ecology)

  • 홍선기;이창석
    • The Korean Journal of Ecology
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    • 제20권3호
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    • pp.217-227
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    • 1997
  • Landscape ecology is an emerging interdisciplinary ecology field to understand the holistic human and natural systems on the basis of concept and database obtained from pure ecology. Landscape ecology is an integrated ecology widely available for environmental science such as nature conservation and sustainable land-use planning. It is also a practical study as an applied ecology to restore and to manage local environment. Landscape ecological study is realized by embodiment of human disturbance system which is rigorously extending on natural system. Considering Korean status without landscape ecological studies, we briefly reviewed establishing process, study goal and methodology of landscape ecology as well as the related several concepts through current landscape ecological studies in the world. We hope that this paper will be helpful to ecologists having interest in landscape ecology.

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Tributyltin induce apoptosis by disturbance of $\textrm{Ca}^{+}$ and mitochondrial activity, causing oxidative stress and activation of caspases in R2C

  • Lee, Kyung-Jin;Shin, Dong-Weon;Kim, Ji-Young;Oh, Duk-Hee;Cho, Young-Rhan;Park, Chul-Yung;Jeong, Hye-Gwang
    • 한국독성학회:학술대회논문집
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    • 한국독성학회 2003년도 춘계학술대회 논문집
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    • pp.68-69
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    • 2003
  • Tributyltin (TBT) used world-wide in antifouling paints for ships is a widespread environmental pollutant and cause reproductive organs atrophy in rodents. At low doses, antiproliferative modes of action have been shown to be involved, whereas at higher doses apoptosis seems to be the mechanism of toxicity in reproductive organs by TBT. (omitted)

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Minamata Disease and the Mercury Pollution of the Globe

  • Harada Masazumi
    • 한국환경보건학회지
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    • 제31권6호
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    • pp.451-456
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    • 2005
  • Minamata disease made its first appearance in the world at Minamata City, Kumamoto Prefecture, in May 1956. In 1962 methyl mercury poisoning through the placenta was found for the first time in the world. This was called congenital Minamata disease. In all cases the clinical symptoms were consistent with those of cerebral palsy. The time and place of outbreak were the same as those for Minamata disease. Their mothers had eaten fish and shellfish during pregnancy. The principal symptoms of congenital Minamata disease are mentalretardation ($100\%$); primitive reflexes ($100\%$); disturbance of coordination ($100\%$); dysarthria ($100\%$); limb deformation (100%); growth disorders ($100\%$); nutritional disorders ($100\%$); chorea-athetose ($95\%$); and hypersalivation ($95\%$). However, today, when the world is polluted by mercury in various places and at various levels, the data we need is not represented by those severe cases, but rather by the chronic milder type. Even in Minamata, the issue of Minamata disease has not been resolved. And likewise, on a global scale the problem of Minamata disease is not yet over.

In vitro Biological Control Against Trichoderma harzianum Using Antifungal Bacteria

  • Lee, Ho-Yong;Hyun, Soung-Hee
    • 환경생물
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    • 제18권4호
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    • pp.441-446
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    • 2000
  • Trichoderma harzianum is an aggressive causal agent of green mold disease on mushroom cultivation. Some bacterial strains isolated, from oyster mushroom compost in Wonju, were found to have in vitro antifungal activity against Trichoderma harzianum ATCC 6385, 6504, and our isolates Trichoderma spp. Y and G. Further in vitro antifungal studies on several strains of phytopathogenic fungi showed that all of 12 phytopathogenic fungal strains were significantly inhibited by the isolated antifungal bacteria in Petri dishes. Of these, KATB 99121 showed the broadest inhibiting effect and displayed as negative coagulase, negative sulfide production and rod shape. KATB 99121 was resistant to ampicillin, chlorampenicol, and kanamycin. Identification of isolates was determined by Biolog GN system, and KATB 99121 was identified as Photobacterium logei because of 96 probability, 0.65 similarity, and 4.97 disturbance. With electron microscopy, thin section of KATB 99121 strain revealed typical rod-like shaped cell (0.6-0.8${\mu}{\textrm}{m}$$\times$1.5-2.0${\mu}{\textrm}{m}$) with prokaryotic structure and organization.

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Experimental investigation of an active mass damper system with time delay control algorithm

  • Jang, Dong-Doo;Park, Jeongsu;Jung, Hyung-Jo
    • Smart Structures and Systems
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    • 제15권3호
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    • pp.863-879
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    • 2015
  • This paper experimentally investigates the effectiveness and applicability of the time delay control (TDC) algorithm, which is simple and robust to unknown system dynamics and disturbance, for an active mass damper (AMD) system to mitigate the excessive vibration of a building structure. To this end, the theoretical background including the mathematical formulation of the control system is first described; and then, a thorough experimental study using a shaking table system with a small-scale three-story building structural model is conducted. In the experimental tests, the performance of the proposed control system is examined by comparing its structural responses with those of the uncontrolled system in the free vibration and forced vibration cases. It is clearly verified from the test results that the TDC algorithm embedded AMD system can effectively reduce the structural response of the building structure.

The Health Effect of Hand Arm Transmitted Vibration

  • Koo, Jung-Wan
    • 대한인간공학회지
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    • 제32권4호
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    • pp.303-308
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    • 2013
  • Objective: The aim of this study is to understand health effect of hand-arm transmitted vibration. Background: Electronic vibration tools have been used in many industries. These tools evoke hand-arm transmitted vibration that cause hand-arm vibration syndrome. Method: Various papers on the hand-arm transmitted vibration and its health effects have been reviewed to know what health effect caused. Results: Hand-arm transmitted vibration causes circulatory, neural, musculoskeletal and other disturbance. Conclusion: The previous studies focused on the epidemiology and physiology for hand-arm transmitted vibration. So, now we should focus on a prevention and guideline of hand-arm transmitted vibration. Application: These results can be used to know health effect of hand-arm transmitted vibration.

중학교 환경교육 학습방안에 관한 사례 비교 연구 (A Comparative Case Study on the Environment Lesson in a Middle School)

  • 김미정;조영민
    • 한국환경교육학회:학술대회논문집
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    • 한국환경교육학회 2005년도 후반기 학술대회 발표논문집
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    • pp.138-147
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    • 2005
  • In the present study, the middle school students' perception on the environment course was surveyed before and after three different lessons. It was found that most students were taking environment related issues mainly from mass media including internet and broadcasting. The young students were satisfied at practical experiments, but at the same time a few old fashioned experimental programs would not be preferred. Utilization of multimedia such as audio-visual tools was one of the effective tools for the environment class, because it could help to understand even the profound principles of the chemical and physical processes. However, some students did not concentrate on the display, causing frequent disturbance of the class. Since the school for this investigation did not choose the environment as a selective course, practical tools and materials for the experiment should not be sufficient, and thereby a further detailed work must be followed with the students who are taking environment lessons.

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