• Journal of Environmental Health Sciences
• /
• v.28 no.3
• /
• pp.72-76
• /
• 2002

This study aims to explore the importance of job stress for hospital employees and psychosocial risk factors of their job stress. 1,890 survey questionnaires collected from 14 hospitals are used for the analysis. The study results shows that stress is the most important risk factor perceived by hospital workers. Also stress-related symptoms and diseases are perceived to occur most frequently among hospital employees. The multiple logistic regression analysis shows age, working hours, shiftwork, job demand, decision-latitude and social support from supervisor and colleagues affect stress level of hospital employees.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.21 no.3
• /
• pp.146-155
• /
• 2011

Objectives: This study was conducted to investigate the association between job stress and mental health among male and female workers in a large electric manufacture company. Methods: A cross-sectional study was carried out on 3,228 employees who participated in annual medical check-up working in a large electric manufacture company in Gyeonggi Province. Medical check-up and self-administrated questionnaire were performed at the same time. Korean Occupational Stress Scale Short Form (KOSS-SF) and Psychosocial Wellbeing Index Short Form (PWI-SF) were applied to assess occupational stress and mental health. Hierarchical multiple linear regression and multiple logistic regression were performed to estimate the association between job stress and mental health. Results: The proportion of high risk of mental health was 17.1% in male, and 46.9% in women. Job stress had a greater effect on mental health than other general and work characteristics. All subscales of job stress were revealed to affect mental health. Bad occupational climate and lack of reward are the strongest risk factors in mental health of male and female respectively. Conclusions: Our results suggest that job stress could affect mental health among large electronic manufacture workers.

• Journal of Preventive Medicine and Public Health
• /
• v.45 no.6
• /
• pp.374-380
• /
• 2012

Objectives: Stress is considered a causal factor in many diseases, allergic disease being one of them. The prevalence of allergic disease is increasing in Korea, but the relationship between allergic symptoms and stress is not empirically well known. We aimed to evaluate the relationship between allergy-related symptoms and stress in children and adolescents. Methods: We investigated 698 children and adolescents living in Gwangyang Bay, Korea, using a multi-stage cluster sampling method. Using the International Study of Asthma and Allergies in Childhood and the Psychosocial Well-being Index, these subjects were surveyed on allergy-related symptoms and psychosocial stressors in their lives, respectively. We used a multivariate logistic analysis for odds ratios for the complaint rate of allergic symptoms, after adjusting for age, gender, household income, body mass index, and residence. Results: After adjustments, lifetime rhinitis (odds ratio [OR], 1.024), rhinoconjunctivitis (OR, 1.090), diagnosis of itchy eczema (OR, 1.040), treatment of itchy eczema (OR, 1.049), 12-month allergic conjunctivitis (OR, 1.026), diagnosis of allergic conjunctivitis (OR, 1.031), and treatment of allergic conjunctivitis (OR, 1.034) were found to be significantly associated with stress. Conclusions: Our results support the notion that there is a relationship between stress and allergic symptoms in children and adolescents. Further research into any causal relationship between stress and allergies, as well as preventative public health plans for decreasing stress in children and adolescents are needed.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2010.10a
• /
• pp.17-17
• /
• 2010

Rhizobacteria are a diverse group of free-living soil bacteria that live in plant rhizosphere and colonized the root system. Plant growth-promoting rhizobacteria (PGPR) possessing ACC deaminase (ACCD) can reduce ACC and ethylene in plant tissue and mediated the growth of plants under various stresses including salt stress. ACCD decrease ethylene levels in plant tissue that produce high levels of ethylene in tissue via elevated levels of ACC under salt stress. We selected strains of Pseudomonas sp. possessing ACCD activity for their ability to promote plant growth under salt stress from soil sample collected at Byeonsan, Jeonbuk, South Korea. The Pseudomonas strains possessing ACCD increased the rate of the seedling and growth of chinese cabbage seeds under salt stress. We cloned ACCD gene from P.fluorescens and expressed recombinant protein in Escherichia coli. The active form of recombinant ACCD converted ACC to a-ketobutyrate. The in vivo treatment of recombinant ACCD itself increase the rate of the seedling and growth of Chinese cabbage seeds under salt stress. The polyclonal P.fluorescens anti-ACCD antibody specifically reacted with ACCD originated from Pseudomonas. This indicates that the antibody might act as an important indicator for ACCD driven from Pseudomonas exhibiting plant growth-promoting activity. This study will be useful for identification of newly isolated PGPR containing ACCD and exploioting the ACCD activity from PGPR against various biotic and abiotic stresses.

• Structural Engineering and Mechanics
• /
• v.75 no.6
• /
• pp.723-736
• /
• 2020

In this paper, acoustic emission (AE) and pattern recognition are utilized to identify the AE signal signatures caused by propagation of stress corrosion cracking (SCC) in a 304 stainless steel plate. The surface of the plate is under almost uniform tensile stress at a notch. A corrosive environment is provided by exposing the notch to a solution of 1% Potassium Tetrathionate by weight. The Global b-value indicated an occurrence of the first visible crack and damage stages during the SCC. Furthermore, a method based on linear regression has been developed for damage identification using AE data.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2010.03a
• /
• pp.730-739
• /
• 2010

Stress history increases in penetration resistance due to the increase in residual horizontal stress of granular soil. This study analyzes the effect of stress history on the results of CPT and DMT from calibration chamber specimen in OC as well as NC state. Test results show that the normalized cone resistance by mean effective stress correlates well with the relative density and the state parameter, whereas the normalized cone resistance with regard to vertical effective stress is a little affected by stress history. The horizontal stress index($K_D$) in DMT more reflects the influence of stress history on granular soil than the dilatometer modulus($E_D$) and cone resistance($q_c$). The $K_D/K_0$, in which the effect of stress history on $K_D$ is compensated by the at-rest coefficient of earth pressure, $K_0$, is related to relative density, state parameter and the normalized cone resistance by mean effective stress. It is also observed that the normalized dilatometer modulus by mean effective stress($E_D/{\sigma_m}'$) is unique correlated with the state parameter, regardless of stress history.

• Journal of Plant Biotechnology
• /
• v.32 no.3
• /
• pp.151-159
• /
• 2005

Injury caused by reactive oxygen species (ROS), known as oxidative stress, is one of the major damaging factors in plants exposed to environmental stress. Chloroplasts are specially sensitive to damage by ROS because electrons that escape from the photosynthetic electron transfer system are able to react with relatively high concentration of $O_2$ in chloroplasts. To cope with oxidative stress, plants have evolved an efficient ROS-scavenging enzymes such as superoxide dismutase (SOD) and ascorbate peroxidase (APX), and low molecular weight antioxidants including ascorbate, glutathione and phenolic compounds. To maintain the productivity of plants under the stress condition, it is possible to fortify the antioxidative mechanisms in the chloroplasts by manipulating the antioxidation genes. A powerful gene expression system with an appropriate promoter is key requisite for excellent stress-tolerant plants. We developed a strong oxidative stress-inducible peroxidase (SWPA2) promoter from cultured cells of sweetpotato (Ipomoea batatas) as an industrial platform technology to develop transgenic plants with enhanced tolerance to environmental stress. Recently, in order to develop transgenic sweetpotato (tv. Yulmi) and potato (Solanum tuberosum L. cv. Atlantic and Superior) plants with enhanced tolerance to multiple stress, the genes of both CuZnSOD and APX were expressed in chloroplasts under the control of an SWPA2 promoter (referred to SSA plants). As expected, SSA sweetpotato and potato plants showed enhanced tolerance to methyl viologen-mediated oxidative stress. In addition, SSA plants showed enhanced tolerance to multiple stresses such as temperature stress, drought and sulphur dioxide. Our results strongly suggested that the rational manipulation of antioxidative mechanism in chloroplasts will be applicable to the development of all plant species with enhanced tolerance to multiple environmental stresses to contribute in solving the global food and environmental problems in the 21st century.

• Journal of environmental and Sanitary engineering
• /
• v.5 no.2
• /
• pp.37-43
• /
• 1990

The term of stress was used by many scientists, but there were several difinitions about stress, and this term are using in societies frequently. Generally stress is defined as equilibrium, harmony, and adaptation to external stimulations, in 1930 s Hans Selye was the first scientist who used the term of stress and he pointed out the stress mean the function of force in body. When we get stress the stimulation go to the sympathetic-adrenomedulla system and epinephrine and norepinnephrine are secreted from adrenal medulla. Author tried to investigate the change of catecholamine secretion from rat urine which were exposed to 80 dB noise environment. The control rat urine released 0.03 $\pm$ 0.01 ng/ml of epinephrine and 0.18 $\pm$ 0.04 ng/ml, but in noise exposed group the epinephrine was 0.42 $\pm$ 0.07 ng/ml and norepinephrine was 2.16 $\pm$ 0.48 ng/ml.

• International journal of steel structures
• /
• v.18 no.4
• /
• pp.1242-1251
• /
• 2018

Not all loads contribute to fatigue crack propagation in the welded detail of steel bridges when they are subjected to variable amplitude loading. For fatigue assessment, therefore, non-contributing stress cycles should be truncated. However, stress range truncation is not considered during typical fatigue reliability assessment. When applying the first order reliability method, stress range truncation occurs mismatch between the expected number of cycles to failure and the number of cycles obtained at the time of evaluation, because the expected number of cycles only counts the stress cycles that contribute to fatigue crack growth. Herein, we introduce a calibration factor to coordinate the expected number of cycles to failure to the equivalent value which includes both contributing and non-contributing stress cycles. The effectiveness of stress range truncation and the proposed calibration factor was validated via case studies.

• Journal of the Korean housing association
• /
• v.7 no.2
• /
• pp.9-17
• /
• 1996

The Purpose of this study is to understand the relationship between residential environment and healthy behavior by examining the effect of environmental stress on psychology and physiology. With anxiety, the acute environmental stressor activates sympathy nerve system and the chonic environmental stressor activates the intenal secretion system because this stress induces depression. Thus, we could find that the continuity of these kinds of stresses brings the chronic disease.