• Title/Summary/Keyword: Environmental Stimulus

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Mechanisms of 5-azacytidine-induced damage and repair process in the fetal brain

  • Ueno, Masaki
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2006.11a
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    • pp.55-64
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    • 2006
  • The fetal central nervous system (CNS) is sensitive to diverse environmental factors, such as alcohol, heavy metals, irradiation, mycotoxins, neurotransmitters, and DNA damage, because a large number of processes occur during an extended period of development. Fetal neural damage is an important issue affecting the completion of normal CNS development. As many concepts about the brain development have been recently revealed, it is necessary to compare the mechanism of developmental abnormalities induced by extrinsic factors with the normal brain development. To clarify the mechanism of fetal CNS damage, we used one experimental model in which 5-azacytidine (5AZC), a DNA damaging and demethylating agent, was injected to the dams of rodents to damage the fetal brain. 5AzC induced cell death (apoptosis)and cell cycle arrest in the fetal brain, and it lead to microencephaly in the neonatal brain. We investigated the mechanism of apoptosis and cell cycle arrest in the neural progenitor cells in detail, and demonstrated that various cell cycle regulators were changed in response to DNA damage. p53, the guardian of genome, played a main role in these processes. Further, using DNA microarray analysis, tile signal cascades of cell cycle regulation were clearly shown. Our results indicate that neural progenitor cells have the potential to repair the DNA damages via cell cyclearrest and to exclude highly affected cells through the apoptotic process. If the stimulus and subsequent DNA damage are high, brain development proceeds abnormally and results in malformation in the neonatal brain. Although the mechanisms of fetal brain injury and features of brain malformation afterbirth have been well studied, the process between those stages is largely unknown. We hypothesized that the fetal CNS has the ability to repair itself post-injuring, and investigated the repair process after 5AZC-induced damage. Wefound that the damages were repaired by 60 h after the treatment and developmental processes continued. During the repair process, amoeboid microglial cells infiltrated in the brain tissue, some of which ingested apoptotic cells. The expressions of genes categorized to glial cells, inflammation, extracellular matrix, glycolysis, and neurogenesis were upregulated in the DNA microarray analysis. We show here that the developing brain has a capacity to repair the damage induced by the extrinsic stresses, including changing the expression of numerous genes and the induction of microglia to aid the repair process.

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The Relationship between Use of Sunblocks and Dry Eye (자외선 차단제 사용과 건성안의 연관성)

  • Yoo, Hyun;Lee, Eun-Hee
    • Journal of Digital Convergence
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    • v.14 no.6
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    • pp.347-353
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    • 2016
  • Dry eye symptoms can occur by various environmental exposure. This study aimed to investigate the relationship between eye symptom especially dry eye and sunblocks. Study subjects were total 30 (28 male, 2 female) and NIBUT, McMonnies dry eye questionnaire, subjective questionnaire were performed. NIBUT after rubbing sunblocks was decreased compared to that of not-rubbing. Sunblocks C showed the largest difference of NIBUT value and was chosen most uncomfortable sunblocks in subjective questionnaire. Half of the subjects (15) felt eyes discomfort after rubbing sunblocks and showed larger McMonnies dry eye questionnaire score than other subjects. The same result was founded about dry eye suspect criterion. Both showed borderline significant relation(p=0.049, p=0.051). This study suggested that sunblock could cause damage to the eyes and related to dry eye when rubbing sunblock around eyes. Because digital environmental factors could affect stimulus and modify the eyes, a convergence study will be required for additional research.

Neural Activation in the Somatosensory Cortex by Electrotactile Stimulation of the Fingers: A Human fMRI Study

  • Seok, Ji-Woo;Jang, Un-Jung;Sohn, Jin-Hun
    • Journal of the Ergonomics Society of Korea
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    • v.33 no.5
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    • pp.395-405
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    • 2014
  • Objective: The aim of this study is to investigate 1) somatotopic arrangement of the second and third fingers in SI area 2) difference of neural activation in the SI area produced by stimulation with different frequencies 3) correlation between the intensity of tactile perception by different stimulus intensity and the level of brain activation measurable by means of fMRI. Background: Somatosensory cortex can obtain the information of environmental stimuli about "where" (e.g., on the left palm), "what" (e.g., a book or a dog), and "how" (e.g., scrub gently or scrub roughly) to organism. However, compared to visual sense, the neural mechanism underlying the processing of specific electrotactile stimulus is still unknown. Method: 10 right-handed subjects participated in this study. Non-painful electrotactile stimuli were delivered to two different finger tips of right hand. Functional brain images were collected from 3.0T MRI using the single-shot EPI method. The scanning parameters were as follows: TR and TE were 3000, 35ms, respectively, flip angle 60, FOV $24{\times}24cm$, matrix size $64{\times}64$, slice thickness 4mm (no gap). SPM5 was used to analyze the fMRI data. Results: Significant activations produced by the stimulation were found in the SI, SII, the subcentral gyrus, the precentral gyrus, and the insula. In all participants, statistically significant activation was observed in the contralateral SI area and the bilateral SII areas by the stimulation on the fingers but ipsilaterally dominant. The SI area representing the second finger generally located in the more lateral and inferior side than that of the third finger across all the subjects. But no difference in brain area was found for the stimulation of the fingers by different frequencies. And two typical patterns were observed on the relationship between the perceived psychological intensity and the amount of voxels in the primary sensory cortex during the stimulation. Conclusion: It was possible to discriminate the representation sites in the SI by electrotactile stimulation of digit2 and digit3. But we could not find the differences of the brain areas according to different stimulation frequencies from 3 to 300Hz. Application: The results of the study can provide a deeper understanding of somatosensory cortex and offer the information for tactile display for blinds.

Adaptive Expertise in Pilot Situation Awareness: Comparison of Expert and Novice Instrument Flight Performance (조종사 상황인식의 적응적 전문성: 전문가와 초보자의 계기비행 수행 비교)

  • Sohn, Young-Woo;Lee, Kyung-Soo
    • Science of Emotion and Sensibility
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    • v.12 no.1
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    • pp.55-64
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    • 2009
  • Previous research has mainly investigated the characteristics of expertise by using typical and routine tasks. This research to overcome these limitations included non-routine task situations and observed expert and novice pilots' situation awareness (SA) performance in routine and non-routine situations. Additionally, whether the ability to aware or perceive the environmental information in limited time varies with the level of expertise was tested. To this end, $2^*2^*2$ mixed factorial design was employed, including expertise (novice/expert) as a between-subjects variable and normality of fight situation (routine/non-routine) and stimulus display time (long/short) as within-subjects variables. As results, there was no performance difference in routine situations between experts and novices, while experts significantly outperformed novices in non-routine situations. When the display time became shorter, overall SA accuracy was decreased for both experts and novices, whereas experts' performance remained significantly higher than novices in short and long conditions. When we examined the interaction between the normality of fight situation and stimulus display time, there was no difference between experts and novices in routine situations for both short and long conditions. In non-routine situations, however, experts' SA accuracy was significantly higher than novices both in short and long conditions. Overall, non-routineness of flight situation does not have any impact on SA performance of experts, while it has a critical impact on SA performance of novices.

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Development of a Smoking and Drinking Prevention Program for Adolescents using Intervention Mapping (Intervention Mapping 설계를 통한 중학생 대상 흡연음주예방 교육프로그램 개발)

  • Kye, Su-Yeon;Choi, Seul-Ki;Park, Kee-Ho
    • The Journal of Korean Society for School & Community Health Education
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    • v.12 no.3
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    • pp.1-15
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    • 2011
  • Objectives: We describe the development of a smoking and drinking prevention program for adolescents, using intervention mapping. Methods: The study sample consisted of 1,000 high school second-grade students from 6 high schools in Seoul. The PRECEDE model was applied for the needs assessment. We carried out a social diagnosis by assessing the factors such as the quality of life, happiness level, and satisfaction with school life; an epidemiological diagnosis on the perceived health status, stress levels, and priority of health issues; a behavioral diagnosis on the smoking and drinking rate and the intention to smoke and drink; and an educational diagnosis on knowledge, beliefs, attitudes, self-efficacy, outcome expectations, social norms and life skills. Results: The development process included a needs assessment, identifying factors that influence smoking and drinking among adolescents. Intention, knowledge, perceived norms, perceived benefit, perceived cost, perceived susceptibility, self-efficacy, and life skills were identified as determinants. Three performance objectives were formulated to describe what an individual needs to do in order to avoid smoking and drinking. Subsequently, we constructed an intervention matrix by crossing the performance objectives with the selected determinants. Each cell describes the learning objectives of the smoking and drinking prevention program. The program used methods from the transtheoretical model, such as consciousness raising, outcome expectations, self-reevaluation, self-liberation, counterconditioning, environmental reevaluation, and stimulus control. The program deals with the effects of smoking and drinking, self-improvement, decision making, understanding advertisements, communication skills, social relationships, and assertiveness. Conclusions: By using the process of intervention mapping, the program developer was able to ensure a systematical incorporation of empirical and new data and theories to guide the intervention design. Programs targeting other health-related behavior and other methods or strategies can also be developed using this intervention mapping process.

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Process of Change, Decisional Balance and Self-Efficacy Corresponding to the Stage of Exercise Behavior in Patients with Type 2 Diabetes Mellitus (제 2형 당뇨 환자의 운동행위 변화단계에 따른 변화과정, 의사결정균형 및 자기 효능감에 관한 연구)

  • Kim, Chun-Ja
    • Korean Journal of Adult Nursing
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    • v.14 no.1
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    • pp.83-92
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    • 2002
  • Purpose: This study was performed to identify the process of change, decisional balance and self-efficacy corresponding to the stage of exercise behavior using Transtheoretical Model in patients with type 2 diabetes mellitus. Method: The study method was a survey in 100 type 2 DM patients at out-patients clinic of Y medical center from March 19, 2000 to October 30, 2000. Result: The results were as follows: The subjects were divided into five stages of exercise behavior ; 15.0% in pre-contemplation stage, 33.0% in contemplation stage, 17.0% in preparation stage, 16.0% in action stage and 19.0% in maintenance stage. The subjects in pre-contemplation stage used all processes of change in the least. "Dramatic relief(DR)", "Environmental reevaluation(ER)" and "Self reevaluation(SR)" were identified as main processes of change in contemplation stage. "Consciousness raising(CR)", "DR" were used higher than average in preparation stage. Helping relationships(HR)", "CR", "ER", "SR", "Social liberation(SL)", "Counter conditioning (CC)", "Reinforcement management(RM)", "Self iberation(SEL)" and "Stimulus control(SC)" were used higher than average in action stage. The subjects in maintenance stage used all process of change the highest except "DR"and "HR". "Cons" score of decisional balance was the highest in pre-contemplation stage, "Pros" score was the highest in action stage and "Self-efficacy" score was the highest in maintenance stage. Conclusion: This study can provide the basis of staged matching exercise program using TTM for more effective and useful intervention.

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Study of the Thermal Properties of Warm Needle and the Development of Warm Needle Apparatus (온침의 열특성과 온침기기 개발에 관한 연구)

  • Kim, Jung-Wo;Lee, Hye-Jung;Ahn, Chang-Beohm;Yi, Seung-Ho
    • Journal of Acupuncture Research
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    • v.28 no.1
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    • pp.15-28
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    • 2011
  • Objectives : To understand the strength and weakness of traditional warm needle acupuncture based on existing research outcomes in Korea mostly and to suggest how to build the desirable warm needle acupuncture apparatus by overcoming demerits of traditional and currently existing ones. Methods : We searched warm needle relating papers in Korean with the key words of '온침, 화침, 열자극' by using DBpia, Journal of Korean Oriental Medical Society, Journal of Korean Acupuncture & Moxibustion Society and Journal of Society for Meridian and Acupoint. Degree dissertations in Korean were also searched with the same words through the search engine of Library of Kyung Hee University. We also searched with words of 'warm, thermal, heat, needle, acupuncture, temperature' via Pubmed and found a small number of English written papers and large number of Chinese written ones. To find english translated version of those papers, we googled with the same words with no success. Results : About 20 papers on warm needle acupuncture written in Korean were found and analyzed with respect to experimental factors that affected the thermal properties or the amount of heat stimulus of the acupuncture. More rigorous descriptions seemed to be required on the insertion depth, duration and manipulation of warm needle treatment. A basic heat transfer model was presented for the clarification of heat loss through the needle of warm needle acupuncture. Environmental factors such as air flow on the properties seems to be considered for the warm needle acupuncture. Conclusions : Papers on warm needle acupuncture were reviewed and analyzed based on their thermal properties and tools such as needles and moxa cones. Several suggestions were made on the descriptions relating the properties. Necessary specifications were introduced to aim modernized warm needle systems.

Neurobehavioural Changes and Brain Oxidative Stress Induced by Acute Exposure to GSM900 Mobile Phone Radiations in Zebrafish (Danio rerio)

  • Nirwane, Abhijit;Sridhar, Vinay;Majumdar, Anuradha
    • Toxicological Research
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    • v.32 no.2
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    • pp.123-132
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    • 2016
  • The impact of mobile phone (MP) radiation on the brain is of specific interest to the scientific community and warrants investigations, as MP is held close to the head. Studies on humans and rodents revealed hazards MP radiation associated such as brain tumors, impairment in cognition, hearing etc. Melatonin (MT) is an important modulator of CNS functioning and is a neural antioxidant hormone. Zebrafish has emerged as a popular model organism for CNS studies. Herein, we evaluated the impact of GSM900MP (GSM900MP) radiation exposure daily for 1 hr for 14 days with the SAR of 1.34W/Kg on neurobehavioral and oxidative stress parameters in zebrafish. Our study revealed that, GSM900MP radiation exposure, significantly decreased time spent near social stimulus zone and increased total distance travelled, in social interaction test. In the novel tank dive test, the GSM900MP radiation exposure elicited anxiety as revealed by significantly increased time spent in bottom half; freezing bouts and duration and decreased distance travelled, average velocity, and number of entries to upper half of the tank. Exposed zebrafish spent less time in the novel arm of the Y-Maze, corroborating significant impairment in learning as compared to the control group. Exposure decreased superoxide dismutase (SOD), catalase (CAT) activities whereas, increased levels of reduced glutathione (GSH) and lipid peroxidation (LPO) was encountered showing compromised antioxidant defense. Treatment with MT significantly reversed the above neurobehavioral and oxidative derangements induced by GSM900MP radiation exposure. This study traced GSM900MP radiation exposure induced neurobehavioral aberrations and alterations in brain oxidative status. Furthermore, MT proved to be a promising therapeutic candidate in ameliorating such outcomes in zebrafish.

Innovation and Future Skills Needs-Green Car (기술혁신과 미래숙련수요 대응-그린카 발전을 중심으로)

  • Hwang, Gyu-Hee;Lee, Joong-Man
    • Journal of Korea Technology Innovation Society
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    • v.13 no.3
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    • pp.399-422
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    • 2010
  • Global expansion of regulation for carbon emission has brought new industrial regulations and trade barriers while the global economy is promoting economic stimulus through a variety of green investments such as renewable energy development, energy efficiency increase, and environmental improvement simultaneously. Korean government is trying to seek a new opportunity to grow through green investment in this change of business environment and businesses are facing the transition to low-carbon and eco-friendly structure for their survival. It is promoting not only industry structure changes and conversion but also demanding changes of workforce composition and requirement skills. In response to convergence of green economy, manpower development for future skills needs is provided the main impetus for response as well as promotion green growth. This study will analyze human resource development plan due to future skills needs emphasizing on automative industry. Also the study will be researched on the problems of present curriculum of undergraduate and look for improvements tasks. Upon the result, promotion plans for human resource development in other sectors of green car in response to future skills needs in green growth can be found.

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Rapid Effect of Low Temperature on the Freezing Resistance of Dehardening Trees (단기(短期) 저온처리(低溫處理)가 수목휴면지(樹木休眠枝) 내한성도(耐寒性度)에 미치는 효과(効果))

  • Hong, Sung Gak;Cho, Tae Hwan
    • Journal of Korean Society of Forest Science
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    • v.28 no.1
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    • pp.31-35
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    • 1975
  • The present study explored the rapid effect of low temperature on the freezing resistance of dehardening twigs of three apple cultivars and sweet cherry. The effect of low temperature was depending upon the thawing treatment following to the low temperature treatment. When the freezing temperature to $-9^{\circ}C$ for three hours followed by thawing treatment ($5^{\circ}C$) was given repeatedly twice, the low temperature increased apparently the cold hardiness of apple and cherry by 3 to $9^{\circ}C$. On the other hand, when the freezing temperature ($-9^{\circ}C$) for ten hours was pretreated without thawing, the low temperature appeared not affecting the cold resistance of the twigs. The role of freezing-thawing temperature cycle in nature was discussed as a signal of environmental stimulus to which dehardening plant may be responding to increase their cold hardiness so as to adapt against the damage of late frost in early spring.

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