• Journal of Animal Science and Technology
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• v.46 no.5
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• pp.879-886
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• 2004

Effects of culture mediwn supplements and osmotic stress treatment on embryogenic callus induction and somatic embryogenesis were investigated in order to optimize tissue culture conditions of alfalfa(Medicago sativa L.). SH mediwn containing 5mgIL 2,4-D and 0.2mgIL kinetin was optimal for embryogenic callus induction from cotyledon tissue of alfalfa. Somatic embryos were formed when the embryogenic callus was cultured on SH mediwn supplemented with ImgIL 2,4-D and 2mgIL BA. Supplementation of 5mM L-proline and IgIL casein hydrolysate into the regeneration mediwn further increased plant regeneration frequency. Osmotic stress treatment of callus appeared to improve the frequency of somatic embryo formation, but the frequency of somatic embryo formation differed by the osmotic stress treatment using different osmotic stressors. The highest plant regeneration frequency of 30.7% was observed when embryogenic callus was treated with 0.7M sucrose for 18h. Efficient regeneration system established in this study will be useful for molecular breeding of alfalfa through genetic transformation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.4036-4044
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• 2012

This study is aimed to investigate the association between web-based visual stress and MBTI personality types. The stressor deriving visual stress is built by 14 vowels out of Korean alphabet as a content and parallel striples as a background on the screen, which is given to each subject during 5min. The dependent variable indicating how much human takes visual stress is the reduction rate of flicker fusion frequency, which is evaluated with visual flicker fusion frequency tester. The independent variables are gender and 8 MBTI personality types(E-I, S-N, T-F, and J-P), and hypotheses are based on human information processing model and previous studies. The results address that the reduction rate is not significantly affected by gender, S-N, and J-P, but E-I and T-F have significant influences on it. The reduction rate in I-type is almost 2 times as much as that in E-type and T-type has the rate 2.2 times more than F-type. This study can be applicable to determine the adequate personnel for jobs requiring less sensibility to visual stressors in areas that human error may lead to critical damages to an overall system.

• Korean Journal of Biological Psychiatry
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• v.2 no.1
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• pp.115-122
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• 1995

This study was performed to know the relationship between neurologic soft signs (NSS) and clinical variables such as psychopathology. history of illness, and premorbid social adjustment in patients with schizophrenia. The authors evaluated NSS in 31 patients with schizophrenia using the structured tool for measuring neurologic abnormalities, Neurological Evaluation Scale- Korean Version(NES-K). Relationships between NSS and clinical variables such as duration of illness, intensity of precipitating stressors, duration of outpatient treatment, schooling, peer relationship, total duration of unemployment, total days of psychiatric admission, age, total days of being medicated, age at the first psychiatric admission, frequency of admissions, content of treatment, social adjustment, and severity of symptoms were analyzed. Differences between paranoid and non-paranoid schizophrenics were examined. In addition, Differences between patients with schizophrenia who have predominant positive symptoms and who have predominant negative symptoms were examined too. Total scores of NES-K were correlated with lower schooling (${\gamma}$=0.44, p<0.01). Scores of motor coordination subcategory were correlated with poor peer relationship(${\gamma}$=0.67, p<0.001). Other clinical variables were not correlated with any scores of NES-K. Paranoid and non-paranoid schizophrenics were not different in scores of NES-K. Also positive and negative schizophrenics were not different in scores of NES-K. Most clinical variables except schooling and peer relationship were not related with NSS. This results indicated that the meaning of these signs was not fully be understood. Introduction of the new classification concepts such as deficit or non-deficit syndrome will be helpful to elucidate the meaning of NSS in patients with schizophrenia.

• Journal of Families and Better Life
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• v.20 no.6
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• pp.49-60
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• 2002

This study focused on family stresses and coping strategies among commuting couples. The participants of this study consisted of a national samples of 134 couples(268 individuals), who had been commuting for at least six months. The major findings obtained from the study are summarized in the following: First, the degree of family stresses among commuting couples was 2.98, when the maximal stress value was set to 5.0. No difference in the level of stress was detected from the roles of the wife and those of the husband. The most stressful aspect for the commuting couples came from the role of parents who care for their children. The second stressful aspect was their responsibility for their own parents, and finally the stress from the housework and maintenance of their marital lives followed next. There was no difference between the wives and husbands on the stressors. Secondly, the level of the coping strategies developed by the commuting couples themselves against their stresses was 3.37, when the maximal stress coping value was set to 5.0. Again, there was no difference in this level between wives and husbands. Among the strategies, they used ‘cognitive restructuring’the most frequently; sharing their responsibilities with other members in family life came next; and developing their own techniques to manage their stresses followed. Thirdly, the ages of the couple, the age of the first child, type of jobs, duration of the marriage and commute, and frequency of meeting affected the level of family stress among commuting couples. Finally, commuting couples developed quite different strategies to cope with their family stresses, and religion and family type affected significantly the type of coping strategies.

• Sleep Medicine and Psychophysiology
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• v.2 no.1
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• pp.23-30
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• 1995

Bedwetting is the most common urologic complaint among children. Wetting frequency decreases from birth to adolescence. Etiology is multifactorial : genetic, neuromuscular or urologic maturation, psychosocial stressors, toilet training, or biologic aspects. Treatment has been also multimodal : drugs to depress bladder activity, increase urethral resistance, or modulate sleep. and recently urine reduction modulation. All of these approaches reflect a lack of sufficient knowledge of the underlying pathophysiology of nocturnal enuresis. Recent researches have focused on sleep disturbances, bladder reservoir function, urine output, and a combination of the three. Sleep studies indicate that enuretic patients are normal sleepers, and enuresis can take place during any stage of sleep, but generally occurs when the bladder is filled to the equivalent of maximal daytime functional capacity. Bladder reservior capacity appears to be normal, and bladder instability is somewhat related with the pathology of nocturnal enuresis. However, enuretic patients have shown the lack of normal nocturnal increase in antidiuretic hormone levels, and nocturnal urine production increases up to 2-4 times volume of functional bladder capacity, which explains the need for bladder emptying. But behavioral approaches, especially Bell-alarm method, remain important in the treatment of primary enuresis.

• Science of Emotion and Sensibility
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• v.22 no.1
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• pp.55-64
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• 2019

Stress is accompanied by changes in the responses of the autonomic nervous system, and the heart rate variability (HRV) index is a quantitative marker that reflects autonomic responses induced by stressors. In this study, we observed changes in the autonomic responses induced by combinations of 30% oxygen administration and color light for stress relaxation. In all, 42 participants produced stress symptoms over the preceding two weeks, as rated on the stress response scale. After stress assessment, they were exposed to three therapeutic conditions, and electrocardiogram (ECG) signals were recorded before, during, and after therapy. The three therapy conditions consisted of only 30% oxygen administration with white light, a combination of 30% oxygen and orange light, and a combination of 30% oxygen and blue light. The HRV indices extracted from ECG signals were heart rate (HR), the standard deviation of the RR interval (SDNN), the mean square root of consecutive RR interval difference values (RMSSD), the low frequency component of HRV (LF), the high frequency component (HF), and the LF/HF ratio. These indicators were used to compare mean values before and after therapy. The results showed that HR and the LF/HF ratio were significantly lower after therapy than before it. In particular, the condition with 30% oxygen and blue light yielded significantly greater RMSSD and HF increases, as well as decreases in LF/HF ratio than in other two conditions. Our results suggest that therapy with 30% oxygen and blue light is the most effective for the relaxation of stress, which implies autonomic balance by parasympathetic activation.

• Science of Emotion and Sensibility
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• v.21 no.1
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• pp.71-82
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• 2018

Stress involves changes in behavior, autonomic function and the secretion of hormones. Autonomic nervous system (ANS) contributes to physiological adaptive process in short durations. In particular, heart rate variability (HRV) analysis is commonly used as a quantitative marker depicting the ANS activity related to mental stress. The aim of this study is to investigate correlations between psychological responses to stress and HRV indices induced by the cognitive stressor. Thirty-three participants rated their mental and physical symptoms occurred during the past two weeks on Stress Response Inventory (SRI), which is composed of seven stress factors that may influence the status of mental stress levels. Then, they underwent the psychophysiological procedures, which are collected electrocardiogram (ECG) signals during a cognitive stress task. HRV indices, the standard deviation of R-R interval (SDNN), root mean square of successive R-R interval difference (RMSSD) and low frequency (LF)/high frequency (HF) ratio were extracted from ECG signals. Physiological responses were calculated stress responses by subtracting mean of the baseline from the mean of recovery. Stress factors such as tension, aggression, depression, fatigue, and frustration were positively correlated to HRV indices. In particular, aggression had significant positive correlations to SDNN, RMSSD and LF/HF ratio. Increased aggressive responses to stress correlated with the increases of all HRV indices. This means the increased autonomic coactivation. Additionally, tension, depression, fatigue, and frustration were positively associated with RMSSD reflecting increases in parasympathetic activation. The autonomic coactivation may represent an integrated response to specific cognitive reactions such as the orienting response.

• Science of Emotion and Sensibility
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• v.10 no.3
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• pp.411-418
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• 2007

Exposure to low frequency noise(LFN) can lead to vibroacoustic diseases(VADs), which include a systemic disease with lesions in a broad spectrum of organs and a psychiatric condition. It is known that VAD is an established risk factor for the development of many psychological conditions in humans and rodents, including major depression and anxiety disorder. The present study investigated the effects of LFN on neuronal stress responses in the rat brain. The neuronal expression of the proto-oncogene c-fos in the paraventricular nucleus(PVN) of the hypothalamus and tyrosine hydroxylase(TH) in the LC was observed. The immunocytochemical detection of the Fos protein and TH has been used as a marker of neuronal activation in response to stress. In addition, corticosterone concentration was evaluated by using an enzyme-linked immunosorbent assay(ELISA). The LFN groups were exposed to 32.5Hz and 125Hz of noise(4hr/day for 2days). The numbers of c-fos and TH-immunoreactive cells in the PVN and LC were significantly increased in the LFN groups(32.5Hz and 125Hz) compared to the normal group. Corticosterone concentration in plasma was also increased in LFN groups. The present results demonstrated that exposure with LFN produced a pronounced increase in expression of c-Fos and TH in stress-relevant brain areas. These results suggest that the neural characteristics involved in LFN are similar to those activated by typical processive stressors. These results also suggest that the central and peripheral activations by LFN may be related to LFN-related negative behavioral dysfunctions such as VADs.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.446-454
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• 2023

The impact of climate change on agriculture is substantial, especially as global warming is projected to lead to varying temperature and humidity patterns in the future. These changes pose a higher risk for both crops and livestock, exposing them to environmental stressors under altered climatic conditions. Specifically, as temperatures are expected to rise, the risk of heat stress is assessable through the Temperature-Humidity Index (THI), derived from temperature and relative humidity data. This study involved the comparison of THI collected from 10 Korea Meteorological Administration ASOS stations spanning a 60-year period from 1961 to 2020. Moreover, high-resolution temperature and humidity distribution data from 1981 to 2020 were employed to generate high-resolution TH I distributions, analyzing temporal changes. Additionally, the number of days characterized by heat stress, derived from TH I, was compared over different time periods. Generally, TH I showed an upward trend over the past, albeit with varying rates across different locations. As TH I increased, the frequency of heat stress days also rose, indicating potential future cost increases in the livestock industry due to heat-related challenges. The findings emphasize the feasibility of evaluating heat stress risk in livestock using THI and underscore the need for research analyzing THI under future climate change scenarios.