• Geomechanics and Engineering
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• v.16 no.2
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• pp.113-124
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• 2018

Under repeated loading, the residual stresses within the subgrade and subsoil can accelerate the deformation of the road structures. In this paper, a series of laboratory cyclic loading model tests and small-scale model tests were conducted to investigate the dynamic stress response within soils under different loading conditions. The experimental results showed that a dynamic stress accumulation effect occurred if the soil showed cumulative deformation: (1) the residual stress increased and accumulated with an increasing number of loading cycles, and (2) the residual stress was superimposed on the stress response of the subsequent loading cycles, inducing a greater peak stress response. There are two conditions that must be met for the dynamic stress accumulation effect to occur. A threshold state exists only if the external load exceeds the cyclic threshold stress. Then, the stress accumulation effect occurs. A higher loading frequency results in a higher rate of increase for the residual stress. In addition to the superposition of the increasing residual stress, soil densification might contribute to the increasing peak stress during cyclic loading. An increase in soil stiffness and a decrease in dissipative energy induce a greater stress transmission within the material.

• Molecules and Cells
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• v.39 no.3
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• pp.250-257
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• 2016

Abiotic stresses such as drought and low temperature critically restrict plant growth, reproduction, and productivity. Higher plants have developed various defense strategies against these unfavorable conditions. CaPUB1 (Capsicum annuum Putative U-box protein 1) is a hot pepper U-box E3 Ub ligase. Transgenic Arabidopsis plants that constitutively expressed CaPUB1 exhibited drought-sensitive phenotypes, suggesting that it functions as a negative regulator of the drought stress response. In this study, CaPUB1 was over-expressed in rice (Oryza sativa L.), and the phenotypic properties of transgenic rice plants were examined in terms of their drought and cold stress tolerance. Ubi:CaPUB1 T3 transgenic rice plants displayed phenotypes hypersensitive to dehydration, suggesting that its role in the negative regulation of drought stress response is conserved in dicot Arabidopsis and monocot rice plants. In contrast, Ubi:CaPUB1 progeny exhibited phenotypes markedly tolerant to prolonged low temperature ($4^{\circ}C$) treatment, compared to those of wild-type plants, as determined by survival rates, electrolyte leakage, and total chlorophyll content. Cold stress-induced marker genes, including DREB1A, DREB1B, DREB1C, and Cytochrome P450, were more up-regulated by cold treatment in Ubi:CaPUB1 plants than in wild-type plants. These results suggest that CaPUB1 serves as both a negative regulator of the drought stress response and a positive regulator of the cold stress response in transgenic rice plants. This raises the possibility that CaPUB1 participates in the cross-talk between drought and low-temperature signaling pathways.

• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.736-741
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• 2012

In this study, we analyzed the oxidative stress response of wblA ($\underline{w}$hi$\underline{B}$-$\underline{l}$ike gene $\underline{A}$, SCO3579), which was previously shown to be a global antibiotic down-regulator in Streptomyces coelicolor. Ever since a WblA ortholog named WhcA in Corynebacterium glutamicum was found to play a negative role in the oxidative stress response, S. coelicolor wblA has been proposed to have a similar effect. A wblA-deletion mutant exhibited a less sensitive response to oxidative stress induced by diamide present in solid plate culture. Using real-time RT-PCR analysis, we also compared the transcription levels of oxidative stress-related genes, including sodF, sodF2, sodN, trxB, and trxB2, between S. coelicolor wild type and a wblA-deletion mutant in the presence or absence of oxidative stress. Target genes were expressed higher in the wblA-deletion mutant compared with wild type, both in the absence and presence of oxidative stress. Moreover, expression of these target genes in S. coelicolor wild type was stimulated only in the presence of oxidative stress, suggesting that WblA plays a negative role in the oxidative stress response of S. coelicolor, similar to that of C. glutamicum WhcA, through the transcriptional regulation of oxidative stress-related genes.

• Journal of Microbiology and Biotechnology
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• v.25 no.1
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• pp.50-56
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• 2015

During pretreatment of lignocellulosic biomass, a variety of fermentation inhibitors, including acetic acid and vanillin, are released. Using DNA microarray analysis, this study explored genes of the budding yeast Saccharomyces cerevisiae that respond to vanillin-induced stress. The expression of 273 genes was upregulated and that of 205 genes was downregulated under vanillin stress. Significantly induced genes included MCH2, SNG1, GPH1, and TMA10, whereas NOP2, UTP18, FUR1, and SPR1 were down regulated. Sequence analysis of the 5'-flanking region of upregulated genes suggested that vanillin might regulate gene expression in a stress response element (STRE)-dependent manner, in addition to a pathway that involved the transcription factor Yap1p. Retardation in the cell growth of mutant strains indicated that MCH2, SNG1, and GPH1 are intimately involved in vanillin stress response. Deletion of the genes whose expression levels were decreased under vanillin stress did not result in a notable change in S. cerevisiae growth under vanillin stress. This study will provide the basis for a better understanding of the stress response of the yeast S. cerevisiae to fermentation inhibitors.

• BMB Reports
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• v.50 no.11
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• pp.539-545
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• 2017

The Integrated Stress Response (ISR) refers to a signaling pathway initiated by stress-activated $eIF2{\alpha}$ kinases. Once activated, the pathway causes attenuation of global mRNA translation while also paradoxically inducing stress response gene expression. A detailed analysis of this pathway has helped us better understand how stressed cells coordinate gene expression at translational and transcriptional levels. The translational attenuation associated with this pathway has been largely attributed to the phosphorylation of the translational initiation factor $eIF2{\alpha}$. However, independent studies are now pointing to a second translational regulation step involving a downstream ISR target, 4E-BP, in the inhibition of eIF4E and specifically cap-dependent translation. The activation of 4E-BP is consistent with previous reports implicating the roles of 4E-BP resistant, Internal Ribosome Entry Site (IRES) dependent translation in ISR active cells. In this review, we provide an overview of the translation inhibition mechanisms engaged by the ISR and how they impact the translation of stress response genes.

• Journal of Digital Convergence
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• v.14 no.3
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• pp.391-399
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• 2016

This study aimed to investigate the effect of verbal abuse experience, coping style and resilience on emotional response and practical stress. 261 nursing students participated in this study. The Data were collected using self-report questionnaires from Dec. 1 to Dec. 20, 2014. We found a positive correlation among verbal abuse experience, emotional coping style and stress during clinical practicum; a positive correlation among problem coping style, emotional coping style and resilience; a positive correlation among emotional coping style, emotional response and stress; a negative correlation among resilience and emotional response; a positive correlation among emotional response and stress during clinical practicum. The highest impact factors affecting the emotional response was emotional coping style(${\beta}=.422$). The highest impact factors affecting stress during clinical practicum was verbal abuse experience(${\beta}=.283$). Future efforts should be focused to provide interpersonal relation training and communication skills training for a safe environment of nursing students.

• The Journal of the Convergence on Culture Technology
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• v.5 no.2
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• pp.83-91
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• 2019

The purpose of this study was to investigate the relationship among the variables and the influence of premenstrual syndrome and stress response on the learning flow of nursing students. Method : The participants were 162 nursing students in K city, who were surveyed between June 1 and June 10, 2018, using self-report questionnaire. Result: There were positive correlation between premenstrual syndrome of participants and stress response(r=.389, p<.001). There were negative correlation between premenstrual syndrome and learning flow(r=-1.93, p<.014), between stress response and learning flow(r=-.216 p<.001). The variables for learning flow where stress response(${\beta}=-.314$, p<.001) and Psychological change of menstruation(${\beta}=-.358$, p<.001), with a coefficient of determination($R^2$) of 30.3%. The result of this study will be useful in preparing basic date for improvement of the learning flow of the nursing students and it will be necessary to develop educational programs and strategies related with the premenstrual syndrome and stress response disposition.

• Journal of Korean Academy of Nursing
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• v.33 no.3
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• pp.433-439
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• 2003

Purpose: The purpose of this study was to examine the relationship among subjective symptoms, depression, and stress coping behavior of university students. Method: The survey was carried out on a convenience sample of 298 university students. The questionnaire consisted of each scale for symptoms, depression, and stress coping behaviors. Data analysis procedure included the factor analysis for stress coping behaviors, and the correlation analysis describing a relationship among symptoms, depression, and stress coping behaviors. Result: There were significant correlations between depression and the three types of symptoms: general, psychological, and somatic symptom. Subjects using the negative-emotional-response coping and the self-control coping showed a more severe depression, and those using the problem-solvingㆍreappraisal coping and the positive-emotional-response coping showed a milder depression. Subjects using the negative-emotional-response coping complained of all 3 types of symptoms severely, and those using the positive-emotional-response coping complained of general symptoms mildly. Of five stress coping methods, the negative-emotional-response and the positive-emotional-response coping methods were related to both symptoms and depression significantly. Conclusion: This study suggests that the emotional-oriented coping method has more important role for university student’s depression and their subjective symptoms than the problem-oriented coping or social supports seeking coping. Further study needs to be conducted to help students effective coping mechanism for good mental health. Also it is necessary for university students to recognize that their symptoms are associated with depression.

• Journal of the Korea Safety Management & Science
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• v.10 no.2
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• pp.25-31
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• 2008

The purpose of this paper is to review the relationship between job characteristics and job stress responses(physiological response, psychological response, behavioral response), and the moderating effect of social support. Based on the responses from 187 employees in small & medium manufacturing industry, hierarchical regressional analysis showed that job characteristics factors have partly negative relationships with job stress response. However, job variety has positive relationship. Social support has partly moderating effect on the relationship between job characteristics and job stress.

• Biomedical Science Letters
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• v.13 no.2
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• pp.157-160
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• 2007

Endoplasmic reticulum (ER) plays formation of disulfide bonds and proper folding of secretory proteins. Cellular responses to ER stress enhances the stress-activated kinase pathway and the induces a lot of immediate-early genes. Among of them, the early growth response-1 (Egr-1), a transcription factor, which plays an important role in cell growth, development, differentiation, apoptosis and various types of injury. For that reason, we have tested the expression of Egr-1 against ER stress inducible drugs (tunicamycin, DTT, A23187 and BFA) to understand what kind of aspect occurred by ER stresses.