A physical/psychological and biological stress combine to enhance endoplasmic reticulum stress

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Mondal, Tapan Kumar; Emeny, Rebecca T.; Gao, Donghong; Ault, Jeffrey G.; Kasten-Jolly, Jane; Lawrence, David A., E-mail: david.lawrence@health.ny.gov

2015-12-01

The generation of an immune response against infectious and other foreign agents is substantially modified by allostatic load, which is increased with chemical, physical and/or psychological stressors. The physical/psychological stress from cold-restraint (CR) inhibits host defense against Listeria monocytogenes (LM), due to early effects of the catecholamine norepinephrine (NE) from sympathetic nerves on β1-adrenoceptors (β1AR) of immune cells. Although CR activates innate immunity within 2 h, host defenses against bacterial growth are suppressed 2–3 days after infection (Cao and Lawrence 2002). CR enhances inducible nitric oxide synthase (iNOS) expression and NO production. The early innate activation leads to cellular reduction-oxidation (redox) changes of immune cells. Lymphocytes from CR-treated mice express fewer surface thiols. Splenic and hepatic immune cells also have fewer proteins with free thiols after CR and/or LM, and macrophages have less glutathione after the in vivo CR exposure or exposure to NE in vitro. The early induction of CR-induced oxidative stress elevates endoplasmic reticulum (ER) stress, which could interfere with keeping phagocytized LM within the phagosome or re-encapsuling LM by autophagy once they escape from the phagosome. ER stress-related proteins, such as glucose-regulated protein 78 (GRP78), have elevated expression with CR and LM. The results indicate that CR enhances the unfolded protein response (UPR), which interferes with host defenses against LM. Thus, it is postulated that increased stress, as exists with living conditions at low socioeconomic conditions, can lower host defenses against pathogens because of oxidative and ER stress processes. - Highlights: • Cold-restraint (physical/psychological stress) induces early oxidative stress. • The oxidative stress relates to catecholamine signaling beta-adrenoceptors. • Physical/psychological stress combines infection enhancing inflammation. • Endoplasmic reticulum

Chronic mild stress influences nerve growth factor through a matrix metalloproteinase-dependent mechanism.

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Kucharczyk, Mateusz; Kurek, Anna; Detka, Jan; Slusarczyk, Joanna; Papp, Mariusz; Tota, Katarzyna; Basta-Kaim, Agnieszka; Kubera, Marta; Lason, Wladyslaw; Budziszewska, Bogusława

2016-04-01

Stress is generally a beneficial experience that motivates an organism to action to overcome the stressful challenge. In particular situations, when stress becomes chronic might be harmful and devastating. The hypothalamus is a critical coordinator of stress and the metabolic response; therefore, disruptions in this structure may be a significant cause of the hormonal and metabolic disturbances observed in depression. Chronic stress induces adverse changes in the morphology of neural cells that are often associated with a deficiency of neurotrophic factors (NTFs); additionally, many studies indicate that insufficient NTF synthesis may participate in the pathogenesis of depression. The aim of the present study was to determine the expression of the nerve growth factor (NGF) in the hypothalamus of male rats subjected to chronic mild stress (CMS) or to prenatal stress (PS) and to PS in combination with an acute stress event (AS). It has been found that chronic mild stress, but not prenatal stress, acute stress or a combination of PS with AS, decreased the concentration of the mature form of NGF (m-NGF) in the rat hypothalamus. A discrepancy between an increase in the Ngf mRNA and a decrease in the m-NGF levels suggested that chronic mild stress inhibited NGF maturation or enhanced the degradation of this factor. We have shown that NGF degradation in the hypothalamus of rats subjected to chronic mild stress is matrix metalloproteinase-dependent and related to an increase in the active forms of some metalloproteinases (MMP), including MMP2, MMP3, MMP9 and MMP13, while the NGF maturation process does not seem to be changed. We suggested that activated MMP2 and MMP9 potently cleave the mature but not the pro- form of NGF into biologically inactive products, which is the reason for m-NGF decomposition. In turn, the enhanced expression of Ngf in the hypothalamus of these rats is an attempt to overcome the reduced levels of m-NGF. Additionally, the decreased level of m

Stress as a common risk factor for obesity and addiction.

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Sinha, Rajita; Jastreboff, Ania M

2013-05-01

Stress is associated with obesity, and the neurobiology of stress overlaps significantly with that of appetite and energy regulation. This review will discuss stress, allostasis, the neurobiology of stress and its overlap with neural regulation of appetite, and energy homeostasis. Stress is a key risk factor in the development of addiction and in addiction relapse. High levels of stress changes eating patterns and augments consumption of highly palatable (HP) foods, which in turn increases incentive salience of HP foods and allostatic load. The neurobiological mechanisms by which stress affects reward pathways to potentiate motivation and consumption of HP foods as well as addictive drugs is discussed. With enhanced incentive salience of HP foods and overconsumption of these foods, there are adaptations in stress and reward circuits that promote stress-related and HP food-related motivation as well as concomitant metabolic adaptations, including alterations in glucose metabolism, insulin sensitivity, and other hormones related to energy homeostasis. These metabolic changes in turn might also affect dopaminergic activity to influence food motivation and intake of HP foods. An integrative heuristic model is proposed, wherein repeated high levels of stress alter the biology of stress and appetite/energy regulation, with both components directly affecting neural mechanisms contributing to stress-induced and food cue-induced HP food motivation and engagement in overeating of such foods to enhance risk of weight gain and obesity. Future directions in research are identified to increase understanding of the mechanisms by which stress might increase risk of weight gain and obesity. Copyright © 2013 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

Shear Stress Enhances Chemokine Secretion from Chlamydia pneumoniae-infected Monocytes.

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Evani, Shankar J; Dallo, Shatha F; Murthy, Ashlesh K; Ramasubramanian, Anand K

2013-09-01

Chlamydia pneumoniae is a common respiratory pathogen that is considered a highly likely risk factor for atherosclerosis. C. pneumoniae is disseminated from the lung into systemic circulation via infected monocytes and lodges at the atherosclerotic sites. During transit, C. pneumoniae -infected monocytes in circulation are subjected to shear stress due to blood flow. The effect of mechanical stimuli on infected monocytes is largely understudied in the context of C. pneumoniae infection and inflammation. We hypothesized that fluid shear stress alters the inflammatory response of C. pneumoniae -infected monocytes and contributes to immune cell recruitment to the site of tissue damage. Using an in vitro model of blood flow, we determined that a physiological shear stress of 7.5 dyn/cm 2 for 1 h on C. pneumoniae -infected monocytes enhances the production of several chemokines, which in turn is correlated with the recruitment of significantly large number of monocytes. Taken together, these results suggest synergistic interaction between mechanical and chemical factors in C. pneumoniae infection and associated inflammation.

A seed preferential heat shock transcription factor from wheat provides abiotic stress tolerance and yield enhancement in transgenic Arabidopsis under heat stress environment.

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Harsh Chauhan

Full Text Available Reduction in crop yield and quality due to various abiotic stresses is a worldwide phenomenon. In the present investigation, a heat shock factor (HSF gene expressing preferentially in developing seed tissues of wheat grown under high temperatures was cloned. This newly identified heat shock factor possesses the characteristic domains of class A type plant HSFs and shows high similarity to rice OsHsfA2d, hence named as TaHsfA2d. The transcription factor activity of TaHsfA2d was confirmed through transactivation assay in yeast. Transgenic Arabidopsis plants overexpressing TaHsfA2d not only possess higher tolerance towards high temperature but also showed considerable tolerance to salinity and drought stresses, they also showed higher yield and biomass accumulation under constant heat stress conditions. Analysis of putative target genes of AtHSFA2 through quantitative RT-PCR showed higher and constitutive expression of several abiotic stress responsive genes in transgenic Arabidopsis plants over-expressing TaHsfA2d. Under stress conditions, TaHsfA2d can also functionally complement the T-DNA insertion mutants of AtHsfA2, although partially. These observations suggest that TaHsfA2d may be useful in molecular breeding of crop plants, especially wheat, to improve yield under abiotic stress conditions.

Genetically engineered Rice with transcription factor DREB genes for abiotic stress tolerance(abstract)

International Nuclear Information System (INIS)

Datta, S.K.; Datta, K.

2005-01-01

Water stress (drought and Salinity) is the most severe limitation to rice productivity. Several breeding approaches (MAS, QTL) applied to suitable genotypes are in place at IRRI and elsewhere. Phenotyping of water stress tolerance is in progress with potential predictability. Dr. Shinozaki's group has cloned a number of transcription factor genes, which have been shown to work in Arabidopsis to achieve drought, cold, and salinity tolerant plants. None of these genes have as yet displayed their potential functioning in rice. Genetic engineering aims at cross talk between different stress signaling pathways leading to stress tolerance. Osmotic Adjustment (OA) is an effective component of abiotic stress (drought and salinity) tolerance in many plants including rice. When plant experiences water stress, OA contributes to turgor maintenance of both shoots and roots. Conventional breeding could not achieve the OA in rice excepting a few rice cultivars, which are partially adapted to water-stress conditions. Several stress-related genes have now been cloned and transferred in to enhance the osmolytes and some transgenic lines showed increased tolerance to osmotic stress. A few strategies could be effectively deployed for a better understanding of water-stress tolerance in rice and to develop transgenic rice, which can survive for a critical period of water-stress conditions: 1) Switching on of transcription factor regulating the expression of several genes related to abiotic stress, 2) Use of a suitable stress inducible promoter driving the target gene for an efficient and directed expression in plants, 3) Understanding of phenotyping and GxE in a given environment, 4) Selection of a few adaptive rice cultivars suitable in drought/salinity prone areas, 5) Microarray, proteomics, QTL and MAS may expedite the cloning and characterizing the stress induced genes, and 6) Finally, the efficient transformation system for generating a large number of transgenic rice of different

Stress concentration factor and stress intensity factor on hard metals in connection with the wear characteristics

International Nuclear Information System (INIS)

Dawihl, W.; Altmeyer, G.

1977-01-01

Description of a method to determine stress intensity factors on hard metals by lapping in notches of different diameter. Dependence of the values of the stress intensity factors on the size of the notch base diameter. For tungsten carbide hard metals with 6% Co, determination of a final value of 250 Nmm -3 / 2 . Characterisation of the stress intensity factor governed by the surface roughness which is decisive for the assessment of the wear-resistant behaviour. (orig.) [de

Transcriptional profiling of Medicago truncatula under salt stress identified a novel CBF transcription factor MtCBF4 that plays an important role in abiotic stress responses

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Su Zhen

2011-07-01

Full Text Available Abstract Background Salt stress hinders the growth of plants and reduces crop production worldwide. However, different plant species might possess different adaptive mechanisms to mitigate salt stress. We conducted a detailed pathway analysis of transcriptional dynamics in the roots of Medicago truncatula seedlings under salt stress and selected a transcription factor gene, MtCBF4, for experimental validation. Results A microarray experiment was conducted using root samples collected 6, 24, and 48 h after application of 180 mM NaCl. Analysis of 11 statistically significant expression profiles revealed different behaviors between primary and secondary metabolism pathways in response to external stress. Secondary metabolism that helps to maintain osmotic balance was induced. One of the highly induced transcription factor genes was successfully cloned, and was named MtCBF4. Phylogenetic analysis revealed that MtCBF4, which belongs to the AP2-EREBP transcription factor family, is a novel member of the CBF transcription factor in M. truncatula. MtCBF4 is shown to be a nuclear-localized protein. Expression of MtCBF4 in M. truncatula was induced by most of the abiotic stresses, including salt, drought, cold, and abscisic acid, suggesting crosstalk between these abiotic stresses. Transgenic Arabidopsis over-expressing MtCBF4 enhanced tolerance to drought and salt stress, and activated expression of downstream genes that contain DRE elements. Over-expression of MtCBF4 in M. truncatula also enhanced salt tolerance and induced expression level of corresponding downstream genes. Conclusion Comprehensive transcriptomic analysis revealed complex mechanisms exist in plants in response to salt stress. The novel transcription factor gene MtCBF4 identified here played an important role in response to abiotic stresses, indicating that it might be a good candidate gene for genetic improvement to produce stress-tolerant plants.

Transcriptional profiling of Medicago truncatula under salt stress identified a novel CBF transcription factor MtCBF4 that plays an important role in abiotic stress responses

Science.gov (United States)

2011-01-01

Background Salt stress hinders the growth of plants and reduces crop production worldwide. However, different plant species might possess different adaptive mechanisms to mitigate salt stress. We conducted a detailed pathway analysis of transcriptional dynamics in the roots of Medicago truncatula seedlings under salt stress and selected a transcription factor gene, MtCBF4, for experimental validation. Results A microarray experiment was conducted using root samples collected 6, 24, and 48 h after application of 180 mM NaCl. Analysis of 11 statistically significant expression profiles revealed different behaviors between primary and secondary metabolism pathways in response to external stress. Secondary metabolism that helps to maintain osmotic balance was induced. One of the highly induced transcription factor genes was successfully cloned, and was named MtCBF4. Phylogenetic analysis revealed that MtCBF4, which belongs to the AP2-EREBP transcription factor family, is a novel member of the CBF transcription factor in M. truncatula. MtCBF4 is shown to be a nuclear-localized protein. Expression of MtCBF4 in M. truncatula was induced by most of the abiotic stresses, including salt, drought, cold, and abscisic acid, suggesting crosstalk between these abiotic stresses. Transgenic Arabidopsis over-expressing MtCBF4 enhanced tolerance to drought and salt stress, and activated expression of downstream genes that contain DRE elements. Over-expression of MtCBF4 in M. truncatula also enhanced salt tolerance and induced expression level of corresponding downstream genes. Conclusion Comprehensive transcriptomic analysis revealed complex mechanisms exist in plants in response to salt stress. The novel transcription factor gene MtCBF4 identified here played an important role in response to abiotic stresses, indicating that it might be a good candidate gene for genetic improvement to produce stress-tolerant plants. PMID:21718548

Increased amygdala reactivity following early life stress: a potential resilience enhancer role.

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Yamamoto, Tetsuya; Toki, Shigeru; Siegle, Greg J; Takamura, Masahiro; Takaishi, Yoshiyuki; Yoshimura, Shinpei; Okada, Go; Matsumoto, Tomoya; Nakao, Takashi; Muranaka, Hiroyuki; Kaseda, Yumiko; Murakami, Tsuneji; Okamoto, Yasumasa; Yamawaki, Shigeto

2017-01-18

Amygdala hyper-reactivity is sometimes assumed to be a vulnerability factor that predates depression; however, in healthy people, who experience early life stress but do not become depressed, it may represent a resilience mechanism. We aimed to test these hypothesis examining whether increased amygdala activity in association with a history of early life stress (ELS) was negatively or positively associated with depressive symptoms and impact of negative life event stress in never-depressed adults. Twenty-four healthy participants completed an individually tailored negative mood induction task during functional magnetic resonance imaging (fMRI) assessment along with evaluation of ELS. Mood change and amygdala reactivity were increased in never-depressed participants who reported ELS compared to participants who reported no ELS. Yet, increased amygdala reactivity lowered effects of ELS on depressive symptoms and negative life events stress. Amygdala reactivity also had positive functional connectivity with the bilateral DLPFC, motor cortex and striatum in people with ELS during sad memory recall. Increased amygdala activity in those with ELS was associated with decreased symptoms and increased neural features, consistent with emotion regulation, suggesting that preservation of robust amygdala reactions may reflect a stress buffering or resilience enhancing factor against depression and negative stressful events.

Nod factor supply under water stress conditions modulates cytokinin biosynthesis and enhances nodule formation and N nutrition in soybean.

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Prudent, Marion; Salon, Christophe; Smith, Donald L; Emery, R J Neil

2016-09-01

Nod factors (NF) are molecules produced by rhizobia which are involved in the N 2 -fixing symbiosis with legume plants, enabling the formation of specific organs called nodules. Under drought conditions, nitrogen acquisition by N 2 -fixation is depressed, resulting in low legume productivity. In this study, we evaluated the effects of NF supply on nitrogen acquisition and on cytokinin biosynthesis of soybean plants grown under drought. NF supply to water stressed soybeans increased the CK content of all organs. The profile of CK metabolites also shifted from t-Z to cis-Z and an accumulation of nucleotide and glucoside conjugates. The changes in CK coincided with enhanced nodule formation with sustained nodule specific activity, which ultimately increased the total nitrogen fixed by the plant.

Context-dependent enhancement of declarative memory performance following acute psychosocial stress.

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Smeets, T; Giesbrecht, T; Jelicic, M; Merckelbach, H

2007-09-01

Studies on how acute stress affects learning and memory have yielded inconsistent findings, with some studies reporting enhancing effects while others report impairing effects. Recently, Joëls et al. [Joëls, M., Pu, Z., Wiegert, O., Oitzl, M.S., Krugers, H.J., 2006. Learning under stress: how does it work? Trends in Cognitive Sciences, 10, 152-158] argued that stress will enhance memory only when the memory acquisition phase and stressor share the same spatiotemporal context (i.e., context-congruency). The current study tested this hypothesis by looking at whether context-congruent stress enhances declarative memory performance. Undergraduates were assigned to a personality stress group (n=16), a memory stress group (n=18), or a no-stress control group (n=18). While being exposed to the acute stressor or a control task, participants encoded personality- and memory-related words and were tested for free recall 24h later. Relative to controls, stress significantly enhanced recall of context-congruent words, but only for personality words. This suggests that acute stress may strengthen the consolidation of memory material when the stressor matches the to-be-remembered information in place and time.

Dominant Repression by Arabidopsis Transcription Factor MYB44 Causes Oxidative Damage and Hypersensitivity to Abiotic Stress

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Helene Persak

2014-02-01

Full Text Available In any living species, stress adaptation is closely linked with major changes of the gene expression profile. As a substrate protein of the rapidly stress-induced mitogen-activated protein kinase MPK3, Arabidopsis transcription factor MYB44 likely acts at the front line of stress-induced re-programming. We recently characterized MYB44 as phosphorylation-dependent positive regulator of salt stress signaling. Molecular events downstream of MYB44 are largely unknown. Although MYB44 binds to the MBSII element in vitro, it has no discernible effect on MBSII-driven reporter gene expression in plant co-transfection assays. This may suggest limited abundance of a synergistic co-regulator. MYB44 carries a putative transcriptional repression (Ethylene responsive element binding factor-associated Amphiphilic Repression, EAR motif. We employed a dominant repressor strategy to gain insights into MYB44-conferred stress resistance. Overexpression of a MYB44-REP fusion markedly compromised salt and drought stress tolerance—the opposite was seen in MYB44 overexpression lines. MYB44-mediated resistance likely results from induction of tolerance-enhancing, rather than from repression of tolerance-diminishing factors. Salt stress-induced accumulation of destructive reactive oxygen species is efficiently prevented in transgenic MYB44, but accelerated in MYB44-REP lines. Furthermore, heterologous overexpression of MYB44-REP caused tissue collapse in Nicotiana. A mechanistic model of MAPK-MYB-mediated enhancement in the antioxidative capacity and stress tolerance is proposed. Genetic engineering of MYB44 variants with higher trans-activating capacity may be a means to further raise stress resistance in crops.

Irradiation behavior of bonded structures: impact of stress-enhanced swelling on irradiation creep and elastic properties

International Nuclear Information System (INIS)

Hassan, M.H.; Blanchard, J.P.; Kulcinski, G.L.

1992-01-01

The objective of this work is to understand the factors that govern the adhesion of coatings on fusion reactor first walls which are subjected to neutron irradiation. Radiation damage will be a major key point in the design of the many duplex components in fusion reactors. There is a substantial amount of available data showing that stress plays a major role in the onset, and possibly the rate, of void growth in austenitic stainless steels. There is also strong support models which predict a coupling of swelling and creep through the stress environment. A parametric study for evidence to stress-enhanced swelling and its connection to creep is conducted for a typical fusion power demonstration reactor. Since microstructural changes are known to affect elastic moduli, the impact of stress enhanced swelling on these moduli are also evaluated

Estimation of stress intensity factors for circumferential cracked pipes under welding residual stress filed

International Nuclear Information System (INIS)

Oh, Chang Young; Kim, Yun Jae; Oh, Young Jin; Song, Tae Kwang; Kim, Yong Beum; Oh, Young Jin; Song, Tae Kwang; Kim, Yong Beum

2012-01-01

Recently, stress corrosion cracking(SCC) have been found in dissimilar metal welds of nozzles in some pressurized water reactors and on low carbon stainless steel piping systems of boiling water reactors. The important factor of SCC is the residual stress field caused by weld. For the evaluation of crack growth analysis due to SCC, stress intensity factor under a residual stress field should be estimated. Several solutions for stress intensity factor under residual stress field were recommended in flaw assessment codes such as the American Society of Mechanical Engineers (ASME) Section XI, R6, American Petroleum Institute (API579). Some relevant works have been studied. Dong et al. evaluated stress intensity factors in welded structures. Miyazaki et al. estimated stress intensity factors of surface crack in simple stress fields. This paper presents a simple method to estimate stress intensity factors in welding residual stress field. For general application, results of structure integrity assessment codes KI solutions were compared Finite element analyses of welding simulation and cracked pipes are described. Comparison results of KI solutions and proposed simplified solution are presented in the works

Role stress in nurses: review of related factors and strategies for moving forward.

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Chang, Esther M; Hancock, Karen M; Johnson, Amanda; Daly, John; Jackson, Debra

2005-03-01

The aim of this paper was to review the literature on factors related to role stress in nurses, and present strategies for addressing this issue based on the findings of this review while considering potential areas for development and research. Computerized databases were searched as well as hand searching of articles in order to conduct this review. This review identified multiple factors related to the experience of role stress in nurses. Role stress, in particular, work overload, has been reported as one of the main reasons for nurses leaving the workforce. This paper concludes that it is a priority to find new and innovative ways of supporting nurses in their experience of role stress. Some examples discussed in this article include use of stress education and management strategies; team-building strategies; balancing priorities; enhancing social and peer support; flexibility in work hours; protocols to deal with violence; and retention and attraction of nursing staff strategies. These strategies need to be empirically evaluated for their efficacy in reducing role stress.

Stress-inducible expression of AtDREB1A transcription factor greatly improves drought stress tolerance in transgenic indica rice.

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Ravikumar, G; Manimaran, P; Voleti, S R; Subrahmanyam, D; Sundaram, R M; Bansal, K C; Viraktamath, B C; Balachandran, S M

2014-06-01

The cultivation of rice (Oryza sativa L.), a major food crop, requires ample water (30 % of the fresh water available worldwide), and its productivity is greatly affected by drought, the most significant environmental factor. Much research has focussed on identifying quantitative trait loci, stress-regulated genes and transcription factors that will contribute towards the development of climate-resilient/tolerant crop plants in general and rice in particular. The transcription factor DREB1A, identified from the model plant Arabidopsis thaliana, has been reported to enhance stress tolerance against drought stress. We developed transgenic rice plants with AtDREB1A in the background of indica rice cultivar Samba Mahsuri through Agrobacterium-mediated transformation. The AtDREB1A gene was stably inherited and expressed in T1 and T2 plants and in subsequent generations, as indicated by the results of PCR, Southern blot and RT-PCR analyses. Expression of AtDREB1A was induced by drought stress in transgenic rice lines, which were highly tolerant to severe water deficit stress in both the vegetative and reproductive stages without affecting their morphological or agronomic traits. The physiological studies revealed that the expression of AtDREB1A was associated with an increased accumulation of the osmotic substance proline, maintenance of chlorophyll, increased relative water content and decreased ion leakage under drought stress. Most of the homozygous lines were highly tolerant to drought stress and showed significantly a higher grain yield and spikelet fertility relative to the nontransgenic control plants under both stressed and unstressed conditions. The improvement in drought stress tolerance in combination with agronomic traits is very essential in high premium indica rice cultivars, such as Samba Mahsuri, so that farmers can benefit in times of seasonal droughts and water scarcity.

Enhanced transfection by antioxidative polymeric gene carrier that reduces polyplex-mediated cellular oxidative stress.

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Lee, Min Sang; Kim, Nak Won; Lee, Kyuri; Kim, Hongtae; Jeong, Ji Hoon

2013-06-01

To test the hypothesis in which polyplex-induced oxidative stress may affect overall transfection efficiency, an antioxidative transfection system minimizing cellular oxidative stress was designed for enhanced transfection. An amphiphilic copolymer (PEI-PLGA) was synthesized and used as a micelle-type gene carrier containing hydrophobic antioxidant, α-tocopherol. Cellular oxidative stress and the change of mitochondrial membrane potential after transfection was measured by using a fluorescent probe (H₂DCFDA) and lipophilic cationic probe (JC-1), respectively. Transfection efficiency was determined by measuring a reporter gene (luciferase) expression level. The initial transfection study with conventional PEI/plasmid DNA polyplex showed significant generation of reactive oxygen species (ROS). The PEI-PLGA copolymer successfully carried out the simultaneous delivery of α-tocopherol and plasmid DNA (PEI-PLGA/Toco/pDNA polyplex) into cells, resulting in a significant reduction in cellular ROS generation after transfection and helped to maintain the mitochondrial membrane potential (ΔΨ). In addition, the transfection efficiency was dramatically increased using the antioxidative transfection system. This work showed that oxidative stress would be one of the important factors that should be considered in designing non-viral gene carriers and suggested a possible way to reduce the carrier-mediated oxidative stress, which consequently leads to enhanced transfection.

NUR TRANSCRIPTION FACTORS IN STRESS AND ADDICTION

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Danae eCampos-Melo

2013-12-01

Full Text Available The Nur transcription factors Nur77 (NGFI-B, NR4A1, Nurr1 (NR4A2 and Nor-1 (NR4A3 are a sub-family of orphan members of the nuclear receptor superfamily. These transcription factors are products of immediate early genes, whose expression is rapidly and transiently induced in the central nervous system by several types of stimuli. Nur factors are present throughout the hypothalamus-pituitary-adrenal axis where are prominently induced in response to stress. Drugs of abuse and stress also induce the expression of Nur factors in nuclei of the motivation/reward circuit of the brain, indicating their participation in the process of drug addiction and in non-hypothalamic responses to stress. Repeated use of addictive drugs and chronic stress induce long-lasting dysregulation of the brain motivation/reward circuit, due to reprogramming of gene expression and enduring alterations in neuronal function. Here, we review the data supporting that Nur transcription factors are key players in the molecular basis of the dysregulation of neuronal circuits involved in chronic stress and addiction.

Stress factors for the deformation systems of zirconium under multiaxial stress

International Nuclear Information System (INIS)

Hobson, D.O.

1976-01-01

Calculation of the resolved shear stresses (rss) that act on various deformation systems in metals and, in particular, the determination of those systems subjected to the highest rss by a given set of multiaxial stresses is of importance in the study of texture development, yielding and plastic flow. This study examines the geometrical influences of any stress state on the deformation modes of zirconium. One slip mode and three twinning modes, comprising twenty-one deformation systems, are considered. Stress factors computed for these systems are shown on a coordinate system that allows specimen orientation, most highly stressed deformation system, and stress factor to be shown without ambiguity. The information in this report allows the determination of the rss that results from any multiaxial stress state; this information also allows the prediction of the deformation modes that might operate for any specimen orientation in that strss state

Work-related stress and cognitive enhancement among university teachers.

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Wiegel, Constantin; Sattler, Sebastian; Göritz, Anja S; Diewald, Martin

2016-01-01

Working conditions of academic staff have become increasingly complex and occupational exposure has risen. This study investigates whether work-related stress is associated with the use of prescription drugs for cognitive enhancement (CE). The study was designed around three web-based surveys (n1 = 1131; n2 = 936; n3 = 906) to which university teachers at four German universities were asked to respond. It assessed past CE-drug use and the willingness to use CE-drugs as factors influencing future use. Overlap among participants across the surveys allowed for analyses of stability of the results across time. Our study suggests a currently very low prevalence of CE-drug use as well as a low willingness to use such drugs. The results showed a strong association between perceptions of work-related stress and all measures of CE-drug use (when controlling for potential confounding factors). They also showed that past use of CE-drugs increased participants' willingness to use them again in the future, as did lower levels of social support. Two different measures showed that participants' moral qualms against the use of CE-drugs decreased their probability of using them. The results increase our knowledge about the prevalence of CE-drug use and our understanding of what motivates and inhibits the use of CE-drug.

Evaluation of stress intensity factors due to welding residual stresses for circumferential cracked pipes

International Nuclear Information System (INIS)

Oh, Chang-Young; Kim, Yun-Jae; Oh, Young-Jin; Kim, Jong-Sung; Song, Tae-Kwang; Kim, Yong-Beum

2013-01-01

To investigate the applicability of existing methods to estimate stress intensity factors due to welding residual stresses, comparisons with finite element (FE) solutions are made for two types of generic welding residual stress profiles, generated by simulating repair welds. It is found that fitting residual stresses over the crack depth using third-order polynomials gives good estimates of stress intensity factors but fitting over the entire thickness can result in inaccurate estimates even with fourth-order polynomials. Noting that welding residual stresses are often determined from FE analyses, linearization of residual stresses to estimate stress intensity factors is proposed. Comparison with FE solutions shows good agreements. -- Highlights: ► Applicability of K estimation methods is investigated for welding residual stresses. ► Two types of generic residual stress profiles with repair welds are considered. ► Fitting residual stresses over the crack depth gives good estimates of K. ► A method to estimate K by linearising residual stress profiles is proposed

Stress intensity factors and constant stress terms for interface cracks

International Nuclear Information System (INIS)

Fett, T.; Rizzi, G.

2004-01-01

In bi-material joints cracks can propagate along the interface or kink into one of the two materials. Whereas the energy release rate can be applied for interface cracks in the same way as usual for homogeneous materials, the computation of stresses in the vicinity of the crack tip is significantly more complicated. In order to assess crack kinking, it is necessary to know the mixed-mode stress intensity factor contributions K I and K II as well as the constant stress terms in the two materials. Whereas the stress intensity factors are available for a large number of infinite and semi-infinite bodies, there is experimental interest in practically used test specimens. This especially holds for the constant x-stress terms. Finite element computations are performed for the special case of a disappearing second Dundurs parameter, i.e. β=0. The fracture mechanics parameters K I , K II , σ 0 for the interface crack are reported in the form of diagrams and approximate relations. (orig.)

Stress concentration factors for pressurized elliptic crossbores in blocks

International Nuclear Information System (INIS)

Badr, Elie A.

2006-01-01

Intersecting bore geometries are used in a number of industrial applications including heavy-walled pressure vessels containing oil holes for lubrication, ports for valves and fluid ends of reciprocating pumps. The bore intersection location is a stress concentration point where the maximum hoop stress can be many times the fluid pressure in the bores. Intersecting circular holes in heavy-walled cylinders and rectangular blocks have been extensively investigated. Specifically, stress/pressure concentration curves for intersecting circular bores in rectangular blocks were presented by Sorem et al. [Sorem JR, Shadley JR, Tipton SM. Design curves for maximum stresses in blocks containing pressurized bore intersections. ASME J Mech Des 1990; 113: 427-31.]. However, stress/pressure concentrations due to intersecting elliptic bores have not been broadly investigated. With the availability of computer numerical control (CNC) machinery, bores with elliptic crosssection can be produced with relative ease. In this paper, hoop stress concentration ratios are developed for elliptic crossbores in rectangular blocks. Results indicate that introducing elliptic crossbores, rather than circular ones, significantly reduces the hoop stress concentration factor at the crossbore intersection. Also, the presence of intersecting crossbores has a major effect on the fatigue life of pressure vessels [Badr EA, Sorem JR, Jr Tipton SM. Evaluation of the autofrettage effect on fatigue lives of steel blocks with crossbores using a statistical and a strain-based method. ASTM J Test Eval 2000; 28: 181-8.] and the reduction of hoop stress concentration is expected to enhance the fatigue life of pressure vessels containing crossbores

Lack of A-factor production induces the expression of nutrient scavenging and stress-related proteins in Streptomyces griseus.

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Birkó, Zsuzsanna; Swiatek, Magdalena; Szájli, Emília; Medzihradszky, Katalin F; Vijgenboom, Erik; Penyige, András; Keseru, Judit; van Wezel, Gilles P; Biró, Sándor

2009-10-01

The small gamma-butyrolactone A-factor is an important autoregulatory signaling molecule for the soil-inhabiting streptomycetes. Starvation is a major trigger for development, and nutrients are provided by degradation of the vegetative mycelium via a process of programmed cell death, reusing proteins, nucleic acids, and cell wall material. The A-factor regulon includes many extracellular hydrolases. Here we show via proteomics analysis that many nutrient-scavenging and stress-related proteins were overexpressed in an A-factor non-producing mutant of Streptomyces griseus B-2682. Transcript analysis showed that this is primarily due to differential transcription of the target genes during early development. The targets include proteins relating to nutrient stress and environmental stress and an orthologue of the Bacillus sporulation control protein Spo0M. The enhanced expression of these proteins underlines the stress that is generated by the absence of A-factor. Wild-type developmental gene expression was restored to the A-factor non-producing mutant by the signaling protein Factor C in line with our earlier observation that Factor C triggers A-factor production.

Enhancing effects of acute psychosocial stress on priming of non-declarative memory in healthy young adults.

Science.gov (United States)

Hidalgo, Vanesa; Villada, Carolina; Almela, Mercedes; Espín, Laura; Gómez-Amor, Jesús; Salvador, Alicia

2012-05-01

Social stress affects cognitive processes in general, and memory performance in particular. However, the direction of these effects has not been clearly established, as it depends on several factors. Our aim was to determine the impact of the hypothalamus-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS) reactivity to psychosocial stress on short-term non-declarative memory and declarative memory performance. Fifty-two young participants (18 men, 34 women) were subjected to the Trier Social Stress Task (TSST) and a control condition in a crossover design. Implicit memory was assessed by a priming test, and explicit memory was assessed by the Rey Auditory Verbal Learning Test (RAVLT). The TSST provoked greater salivary cortisol and salivary alpha-amylase (sAA) responses than the control task. Men had a higher cortisol response to stress than women, but no sex differences were found for sAA release. Stress was associated with an enhancement of priming but did not affect declarative memory. Additionally, the enhancement on the priming test was higher in those whose sAA levels increased more in response to stress (r(48) = 0.339, p = 0.018). Our results confirm an effect of acute stress on priming, and that this effect is related to SNS activity. In addition, they suggest a different relationship between stress biomarkers and the different memory systems.

Molecular Stress-inducing Compounds Increase Osteoclast Formation in a Heat Shock Factor 1 Protein-dependent Manner*

Science.gov (United States)

Chai, Ryan C.; Kouspou, Michelle M.; Lang, Benjamin J.; Nguyen, Chau H.; van der Kraan, A. Gabrielle J.; Vieusseux, Jessica L.; Lim, Reece C.; Gillespie, Matthew T.; Benjamin, Ivor J.; Quinn, Julian M. W.; Price, John T.

2014-01-01

Many anticancer therapeutic agents cause bone loss, which increases the risk of fractures that severely reduce quality of life. Thus, in drug development, it is critical to identify and understand such effects. Anticancer therapeutic and HSP90 inhibitor 17-(allylamino)-17-demethoxygeldanamycin (17-AAG) causes bone loss by increasing osteoclast formation, but the mechanism underlying this is not understood. 17-AAG activates heat shock factor 1 (Hsf1), the master transcriptional regulator of heat shock/cell stress responses, which may be involved in this negative action of 17-AAG upon bone. Using mouse bone marrow and RAW264.7 osteoclast differentiation models we found that HSP90 inhibitors that induced a heat shock response also enhanced osteoclast formation, whereas HSP90 inhibitors that did not (including coumermycin A1 and novobiocin) did not affect osteoclast formation. Pharmacological inhibition or shRNAmir knockdown of Hsf1 in RAW264.7 cells as well as the use of Hsf1 null mouse bone marrow cells demonstrated that 17-AAG-enhanced osteoclast formation was Hsf1-dependent. Moreover, ectopic overexpression of Hsf1 enhanced 17-AAG effects upon osteoclast formation. Consistent with these findings, protein levels of the essential osteoclast transcription factor microphthalmia-associated transcription factor were increased by 17-AAG in an Hsf1-dependent manner. In addition to HSP90 inhibitors, we also identified that other agents that induced cellular stress, such as ethanol, doxorubicin, and methotrexate, also directly increased osteoclast formation, potentially in an Hsf1-dependent manner. These results, therefore, indicate that cellular stress can enhance osteoclast differentiation via Hsf1-dependent mechanisms and may significantly contribute to pathological and therapeutic related bone loss. PMID:24692538

Molecular stress-inducing compounds increase osteoclast formation in a heat shock factor 1 protein-dependent manner.

Science.gov (United States)

Chai, Ryan C; Kouspou, Michelle M; Lang, Benjamin J; Nguyen, Chau H; van der Kraan, A Gabrielle J; Vieusseux, Jessica L; Lim, Reece C; Gillespie, Matthew T; Benjamin, Ivor J; Quinn, Julian M W; Price, John T

2014-05-09

Many anticancer therapeutic agents cause bone loss, which increases the risk of fractures that severely reduce quality of life. Thus, in drug development, it is critical to identify and understand such effects. Anticancer therapeutic and HSP90 inhibitor 17-(allylamino)-17-demethoxygeldanamycin (17-AAG) causes bone loss by increasing osteoclast formation, but the mechanism underlying this is not understood. 17-AAG activates heat shock factor 1 (Hsf1), the master transcriptional regulator of heat shock/cell stress responses, which may be involved in this negative action of 17-AAG upon bone. Using mouse bone marrow and RAW264.7 osteoclast differentiation models we found that HSP90 inhibitors that induced a heat shock response also enhanced osteoclast formation, whereas HSP90 inhibitors that did not (including coumermycin A1 and novobiocin) did not affect osteoclast formation. Pharmacological inhibition or shRNAmir knockdown of Hsf1 in RAW264.7 cells as well as the use of Hsf1 null mouse bone marrow cells demonstrated that 17-AAG-enhanced osteoclast formation was Hsf1-dependent. Moreover, ectopic overexpression of Hsf1 enhanced 17-AAG effects upon osteoclast formation. Consistent with these findings, protein levels of the essential osteoclast transcription factor microphthalmia-associated transcription factor were increased by 17-AAG in an Hsf1-dependent manner. In addition to HSP90 inhibitors, we also identified that other agents that induced cellular stress, such as ethanol, doxorubicin, and methotrexate, also directly increased osteoclast formation, potentially in an Hsf1-dependent manner. These results, therefore, indicate that cellular stress can enhance osteoclast differentiation via Hsf1-dependent mechanisms and may significantly contribute to pathological and therapeutic related bone loss.

Factors Associated with Urinary Stress Incontinence in Primiparas

OpenAIRE

Pei-Ling Chou; Fang-Ping Chen; Li-Fen Teng

2005-01-01

Objective: To evaluate obstetric and maternal risk factors for stress urinary incontinence in primiparas. Materials and Methods: From January 2001 to August 2002, 378 primiparas were interviewed about stress urinary incontinence 1 year after delivery. The association between symptoms of urinary stress incontinence and obstetric factors was assessed. Results: Twenty-four (6%) primiparas had urinary stress incontinence after delivery. Maternal age was positively associated with urinary st...

Human Factors Effecting Forensic Decision Making: Workplace Stress and Well-being.

Science.gov (United States)

Jeanguenat, Amy M; Dror, Itiel E

2018-01-01

Over the past decade, there has been a growing openness about the importance of human factors in forensic work. However, most of it focused on cognitive bias, and neglected issues of workplace wellness and stress. Forensic scientists work in a dynamic environment that includes common workplace pressures such as workload volume, tight deadlines, lack of advancement, number of working hours, low salary, technology distractions, and fluctuating priorities. However, in addition, forensic scientists also encounter a number of industry-specific pressures, such as technique criticism, repeated exposure to crime scenes or horrific case details, access to funding, working in an adversarial legal system, and zero tolerance for "errors". Thus, stress is an important human factor to mitigate for overall error management, productivity and decision quality (not to mention the well-being of the examiners themselves). Techniques such as mindfulness can become powerful tools to enhance work and decision quality. © 2017 American Academy of Forensic Sciences.

Vagal modulation of resting heart rate in rats: the role of stress, psychosocial factors and physical exercise

Directory of Open Access Journals (Sweden)

Luca eCarnevali

2014-03-01

Full Text Available In humans, there are large individual differences in the levels of vagal modulation of resting heart rate. High levels are a recognized index of cardiac health, whereas low levels are considered an important risk factor for cardiovascular morbidity and mortality. Several factors are thought to contribute significantly to this inter-individual variability. While regular physical exercise seems to induce an increase in resting vagal tone, chronic life stress and psychosocial factors such as negative moods and personality traits appear associated with vagal withdrawal. Preclinical research has been attempting to clarify such relationships and to provide insights into the neurobiological mechanisms underlying vagal tone impairment/enhancement. This paper focuses on rat studies that have explored the effects of stress, psychosocial factors and physical exercise on vagal modulation of resting heart rate. Results are discussed with regard to: (i individual differences in resting vagal tone, cardiac stress reactivity and arrhythmia vulnerability; (ii elucidation of the neurobiological determinants of resting vagal tone.

The maximum possible stress intensity factor for a crack in an unknown residual stress field

International Nuclear Information System (INIS)

Coules, H.E.; Smith, D.J.

2015-01-01

Residual and thermal stress fields in engineering components can act on cracks and structural flaws, promoting or inhibiting fracture. However, these stresses are limited in magnitude by the ability of materials to sustain them elastically. As a consequence, the stress intensity factor which can be applied to a given defect by a self-equilibrating stress field is also limited. We propose a simple weight function method for determining the maximum stress intensity factor which can occur for a given crack or defect in a one-dimensional self-equilibrating stress field, i.e. an upper bound for the residual stress contribution to K I . This can be used for analysing structures containing defects and subject to residual stress without any information about the actual stress field which exists in the structure being analysed. A number of examples are given, including long radial cracks and fully-circumferential cracks in thick-walled hollow cylinders containing self-equilibrating stresses. - Highlights: • An upper limit to the contribution of residual stress to stress intensity factor. • The maximum K I for self-equilibrating stresses in several geometries is calculated. • A weight function method can determine this maximum for 1-dimensional stress fields. • Simple MATLAB scripts for calculating maximum K I provided as supplementary material.

Chronic stress as a factor in aircraft mishaps

Science.gov (United States)

Alkov, Robert A.

1988-01-01

Naval aviation is an unusually stressful career because of the inherent demands of the work. Stress is recognized as a cause of mishaps which involve pilot error. A questionnaire was adapted from Rahe and Homes' list of stressful life events in order to determine the relationship between pilot behavioral, personality, and life change factors on the one hand and responsibility for accidents on the other. A number of factors regarding interpersonal relationships, changes in personal behavior, personality factors, and life changes were found to discriminate between pilots who were and were not at fault in accidents.

HSP72 protects cells from ER stress-induced apoptosis via enhancement of IRE1alpha-XBP1 signaling through a physical interaction.

LENUS (Irish Health Repository)

Gupta, Sanjeev

2010-01-01

Endoplasmic reticulum (ER) stress is a feature of secretory cells and of many diseases including cancer, neurodegeneration, and diabetes. Adaptation to ER stress depends on the activation of a signal transduction pathway known as the unfolded protein response (UPR). Enhanced expression of Hsp72 has been shown to reduce tissue injury in response to stress stimuli and improve cell survival in experimental models of stroke, sepsis, renal failure, and myocardial ischemia. Hsp72 inhibits several features of the intrinsic apoptotic pathway. However, the molecular mechanisms by which Hsp72 expression inhibits ER stress-induced apoptosis are not clearly understood. Here we show that Hsp72 enhances cell survival under ER stress conditions. The UPR signals through the sensor IRE1alpha, which controls the splicing of the mRNA encoding the transcription factor XBP1. We show that Hsp72 enhances XBP1 mRNA splicing and expression of its target genes, associated with attenuated apoptosis under ER stress conditions. Inhibition of XBP1 mRNA splicing either by dominant negative IRE1alpha or by knocking down XBP1 specifically abrogated the inhibition of ER stress-induced apoptosis by Hsp72. Regulation of the UPR was associated with the formation of a stable protein complex between Hsp72 and the cytosolic domain of IRE1alpha. Finally, Hsp72 enhanced the RNase activity of recombinant IRE1alpha in vitro, suggesting a direct regulation. Our data show that binding of Hsp72 to IRE1alpha enhances IRE1alpha\\/XBP1 signaling at the ER and inhibits ER stress-induced apoptosis. These results provide a physical connection between cytosolic chaperones and the ER stress response.

High salt intake enhances swim stress-induced PVN vasopressin cell activation and active stress coping.

Science.gov (United States)

Mitchell, N C; Gilman, T L; Daws, L C; Toney, G M

2018-07-01

antagonist dGly[Phaa1,d-tyr(et), Lys, Arg]-VP bilaterally into the amygdala prior to the SS. SL increased serum osmolality (P < 0.01), which positively correlated with time spent mobile during, and time spent grooming after a SS (P < 0.01, P < 0.01), and SL increased serum corticosterone levels (P < 0.01). SL alone increased c-Fos immunoreactivity among PVN neurons (P = .02), including VP positive neurons (P < 0.01). SL increased SS-induced c-Fos activation of PVN neurons as well (P < 0.01). In addition, SL and SS each increased the total number of PVN neurons that were immunoreactive for VP (P < 0.01). An enhancing effect of SL and SS was observed on c-Fos positive cell counts in the central (P = .02) and basolateral (P < 0.01) nuclei of the amygdala and bilateral nano-injections of V1R antagonist into the amygdala reduced time spent mobile both in salt loaded and control mice during SS (P < 0.05, P < 0.05). Taken together, these data indicate that neuronal and behavioral responsivity to an acute psychogenic stressor is potentiated by prior exposure to high salt intake. This synergistic effect was associated with activation of PVN VP neurons and depended, in part, on activity of V1 receptors in the amygdala. Findings provide novel insight into neural mechanisms whereby prior exposure to a homeostatic stressor such as osmotic dehydration by excessive salt intake increases responsivity to a perceived stress. These experiments show that high dietary salt can influence stress responsivity and raise the possibility that excessive salt intake could be a contributing factor in the development of stress-related psychiatric disorders. Published by Elsevier Ltd.

A study of job stress and burnout and related factors in the hospital personnel of Iran

Science.gov (United States)

Abarghouei, Mohammad Reza; Sorbi, Mohammad Hossein; Abarghouei, Mehdi; Bidaki, Reza; Yazdanpoor, Shirin

2016-01-01

Introduction Job stress has become one of the main factors in reducing efficiency and the loss of human resources that may cause physical and psychological adverse effects in employees. Hospital personnel are facing different stressful events, such as birth, pain and death, in a single day. Hence, identifying the job stress rates and related factors may be effective in offering proper strategies. Therefore, the present research was done to study the rate of job stress and burnout in hospital personnel and compare some of the related factors in hospitals personnel of Yazd, Iran. Methods This cross-sectional study was conducted on 306 hospital personnel (Male: 114, Female: 192) in Yazd in 2015–16. The data were collected using a demographic questionnaire, Maslach Burnout Inventory (MBI), and Hospital Stress (HSS-35). SPSS-16 software and Pearson-product moment correlation and independent-samples t-test were used for data analysis. Results The mean job stress score was above average. The mean burnout dimensions that were above average included emotional exhaustion (21.7 ± 7.27), depersonalization (9.61 ± 3.74) and personal accomplishment (26.80 ± 6.17). While Pearson correlation revealed a significant positive relationship between job stress, emotional exhaustion, and depersonalization, there was a negative relationship between job stress and personal accomplishment (p hospital personnel is worrying and it has adverse effects on personnel health, effective strategies on physical and mental health, such as employment support and stress management training, seem crucial to enhance physical and psychological health of hospital personnel. PMID:27648189

Microorganisms having enhanced tolerance to inhibitors and stress

Energy Technology Data Exchange (ETDEWEB)

Brown, Steven D.; Yang, Shihui

2014-07-29

The present invention provides genetically modified strains of microorganisms that display enhanced tolerance to stress and/or inhibitors such as sodium acetate and vanillin. The enhanced tolerance can be achieved by increasing the expression of a protein of the Sm-like superfamily such as a bacterial Hfq protein and a fungal Sm or Lsm protein. Further, the present invention provides methods of producing alcohol from biomass materials by using the genetically modified microorganisms of the present invention.

Overexpression of Late Embryogenesis Abundant 14 enhances Arabidopsis salt stress tolerance

International Nuclear Information System (INIS)

Jia, Fengjuan; Qi, Shengdong; Li, Hui; Liu, Pu; Li, Pengcheng; Wu, Changai; Zheng, Chengchao; Huang, Jinguang

2014-01-01

Highlights: • It is the first time to investigate the biological function of AtLEA14 in salt stress response. • AtLEA14 enhances the salt stress tolerance both in Arabidopsis and yeast. • AtLEA14 responses to salt stress by stabilizing AtPP2-B11, an E3 ligase, under normal or salt stress conditions. - Abstract: Late embryogenesis abundant (LEA) proteins are implicated in various abiotic stresses in higher plants. In this study, we identified a LEA protein from Arabidopsis thaliana, AtLEA14, which was ubiquitously expressed in different tissues and remarkably induced with increased duration of salt treatment. Subcellular distribution analysis demonstrated that AtLEA14 was mainly localized in the cytoplasm. Transgenic Arabidopsis and yeast overexpressing AtLEA14 all exhibited enhanced tolerance to high salinity. The transcripts of salt stress-responsive marker genes (COR15a, KIN1, RD29B and ERD10) were overactivated in AtLEA14 overexpressing lines compared with those in wild type plants under normal or salt stress conditions. In vivo and in vitro analysis showed that AtLEA14 could effectively stabilize AtPP2-B11, an important E3 ligase. These results suggested that AtLEA14 had important protective functions under salt stress conditions in Arabidopsis

Overexpression of Late Embryogenesis Abundant 14 enhances Arabidopsis salt stress tolerance

Energy Technology Data Exchange (ETDEWEB)

Jia, Fengjuan, E-mail: jfj.5566@163.com; Qi, Shengdong, E-mail: zisexanwu@163.com; Li, Hui, E-mail: 332453593@qq.com; Liu, Pu, E-mail: banbaokezhan@163.com; Li, Pengcheng, E-mail: lpcsdau@163.com; Wu, Changai, E-mail: cawu@sdau.edu.cn; Zheng, Chengchao, E-mail: cczheng@sdau.edu.cn; Huang, Jinguang, E-mail: jghuang@sdau.edu.cn

2014-11-28

Highlights: • It is the first time to investigate the biological function of AtLEA14 in salt stress response. • AtLEA14 enhances the salt stress tolerance both in Arabidopsis and yeast. • AtLEA14 responses to salt stress by stabilizing AtPP2-B11, an E3 ligase, under normal or salt stress conditions. - Abstract: Late embryogenesis abundant (LEA) proteins are implicated in various abiotic stresses in higher plants. In this study, we identified a LEA protein from Arabidopsis thaliana, AtLEA14, which was ubiquitously expressed in different tissues and remarkably induced with increased duration of salt treatment. Subcellular distribution analysis demonstrated that AtLEA14 was mainly localized in the cytoplasm. Transgenic Arabidopsis and yeast overexpressing AtLEA14 all exhibited enhanced tolerance to high salinity. The transcripts of salt stress-responsive marker genes (COR15a, KIN1, RD29B and ERD10) were overactivated in AtLEA14 overexpressing lines compared with those in wild type plants under normal or salt stress conditions. In vivo and in vitro analysis showed that AtLEA14 could effectively stabilize AtPP2-B11, an important E3 ligase. These results suggested that AtLEA14 had important protective functions under salt stress conditions in Arabidopsis.

Transgenic Alfalfa Plants Expressing the Sweetpotato Orange Gene Exhibit Enhanced Abiotic Stress Tolerance

Science.gov (United States)

Wang, Zhi; Ke, Qingbo; Kim, Myoung Duck; Kim, Sun Ha; Ji, Chang Yoon; Jeong, Jae Cheol; Lee, Haeng-Soon; Park, Woo Sung; Ahn, Mi-Jeong; Li, Hongbing; Xu, Bingcheng; Deng, Xiping; Lee, Sang-Hoon; Lim, Yong Pyo; Kwak, Sang-Soo

2015-01-01

Alfalfa (Medicago sativa L.), a perennial forage crop with high nutritional content, is widely distributed in various environments worldwide. We recently demonstrated that the sweetpotato Orange gene (IbOr) is involved in increasing carotenoid accumulation and enhancing resistance to multiple abiotic stresses. In this study, in an effort to improve the nutritional quality and environmental stress tolerance of alfalfa, we transferred the IbOr gene into alfalfa (cv. Xinjiang Daye) under the control of an oxidative stress-inducible peroxidase (SWPA2) promoter through Agrobacterium tumefaciens-mediated transformation. Among the 11 transgenic alfalfa lines (referred to as SOR plants), three lines (SOR2, SOR3, and SOR8) selected based on their IbOr transcript levels were examined for their tolerance to methyl viologen (MV)-induced oxidative stress in a leaf disc assay. The SOR plants exhibited less damage in response to MV-mediated oxidative stress and salt stress than non-transgenic plants. The SOR plants also exhibited enhanced tolerance to drought stress, along with higher total carotenoid levels. The results suggest that SOR alfalfa plants would be useful as forage crops with improved nutritional value and increased tolerance to multiple abiotic stresses, which would enhance the development of sustainable agriculture on marginal lands. PMID:25946429

Oxidative stress impairs the heat stress response and delays unfolded protein recovery.

Directory of Open Access Journals (Sweden)

Masaaki Adachi

2009-11-01

Full Text Available Environmental changes, air pollution and ozone depletion are increasing oxidative stress, and global warming threatens health by heat stress. We now face a high risk of simultaneous exposure to heat and oxidative stress. However, there have been few studies investigating their combined adverse effects on cell viability.Pretreatment of hydrogen peroxide (H(2O(2 specifically and highly sensitized cells to heat stress, and enhanced loss of mitochondrial membrane potential. H(2O(2 exposure impaired the HSP40/HSP70 induction as heat shock response (HSR and the unfolded protein recovery, and enhanced eIF2alpha phosphorylation and/or XBP1 splicing, land marks of ER stress. These H(2O(2-mediated effects mimicked enhanced heat sensitivity in HSF1 knockdown or knockout cells. Importantly, thermal preconditioning blocked H(2O(2-mediated inhibitory effects on refolding activity and rescued HSF1 +/+ MEFs, but neither blocked the effects nor rescued HSF1 -/- MEFs. These data strongly suggest that inhibition of HSR and refolding activity is crucial for H(2O(2-mediated enhanced heat sensitivity.H(2O(2 blocks HSR and refolding activity under heat stress, thereby leading to insufficient quality control and enhancing ER stress. These uncontrolled stress responses may enhance cell death. Our data thus highlight oxidative stress as a crucial factor affecting heat tolerance.

Stress intensity factors of corner cracks in two nozzle-cylinder intersections

International Nuclear Information System (INIS)

Kobayashi, A.S.; Polvanich, N.; Emery, A.F.; Love, W.J.

1977-01-01

In a recent paper, the authors presented the stress-intensity-magnification factors of a quarter-elliptical surface crack in a quarter-infinite solid and a circular crack approaching a reentry corner in a three-quarter infinite solid. These stress-intensity-magnification factors were used together with a curvature-correction factor to estimate the stress-intensity factor of a corner crack at a nozzle-cylinder intersection. Through appropriate superposition of the above stress-intensity-magnification factors, stress-intensity factors for hypothetical corner cracks at a nozzle-cylinder intersection subjected to internal pressure and transient thermal-stress loadings can be obtained. A description of a computer code based on this procedure as well as its applications in analyzing two corner-crack problems at a nozzle-cylinder intersection are discussed in this paper

Stress intensity factors of corner cracks in two nozzle-cylinder interactions

International Nuclear Information System (INIS)

Kobayashi, A.S.; Polvanich, N.; Emery, A.F.; Love, W.J.

1977-01-01

In a recent paper, the authors presented the stress-intensity-magnification factors of a quarter-elliptical surface crack in a quarter-infinite solid and a circular crack approaching a reentry corner in a three-quarter infinite solid. These stress-intensity-magnification factors were used together with a curvature-correction factor to estimate the stress-intensity factor of a corner crack at a nozzle-cylinder interaction. Through appropriate superposition of the above stress-intensity-magnification factors, stress-intensity factors for hypothetical corner cracks at a nozzle-cylinder intersection subjected to internal pressure and transient thermal-stress loadings can be obtained. A description of a computer code based on this procedure as well as its applications in analyzing two corner-crack probems at a nozzle-cylinder intersection are discussed in this paper. (Auth.)

Acute stress blocks the caffeine-induced enhancement of contextual memory retrieval in mice.

Science.gov (United States)

Pierard, Chistophe; Krazem, Ali; Henkous, Nadia; Decorte, Laurence; Béracochéa, Daniel

2015-08-15

This study investigated in mice the dose-effect of caffeine on memory retrieval in non-stress and stress conditions. C57 Bl/6 Jico mice learned two consecutive discriminations (D1 and D2) in a four-hole board which involved either distinct contextual (CSD) or similar contextual (SSD) cues. All mice received an i.p. injection of vehicle or caffeine (8, 16 or 32mg/kg) 30min before the test session. Results showed that in non-stress conditions, the 16mg/kg caffeine dose induced a significant enhancement of D1 performance in CSD but not in SSD. Hence, we studied the effect of an acute stress (electric footshocks) administered 15min before the test session on D1 performance in caffeine-treated mice. Results showed that stress significantly decreased D1 performance in vehicle-treated controls and the memory-enhancing effect induced by the 16mg/kg caffeine dose in non-stress condition is no longer observed. Interestingly, whereas caffeine-treated mice exhibited weaker concentrations of plasma corticosterone as compared to vehicles in non-stress condition, stress significantly increased plasma corticosterone concentrations in caffeine-treated mice which reached similar level to that of controls. Overall, the acute stress blocked both the endocrinological and memory retrieval enhancing effects of caffeine. Copyright © 2015 Elsevier B.V. All rights reserved.

HSP72 protects cells from ER stress-induced apoptosis via enhancement of IRE1alpha-XBP1 signaling through a physical interaction.

Directory of Open Access Journals (Sweden)

Sanjeev Gupta

2010-07-01

Full Text Available Endoplasmic reticulum (ER stress is a feature of secretory cells and of many diseases including cancer, neurodegeneration, and diabetes. Adaptation to ER stress depends on the activation of a signal transduction pathway known as the unfolded protein response (UPR. Enhanced expression of Hsp72 has been shown to reduce tissue injury in response to stress stimuli and improve cell survival in experimental models of stroke, sepsis, renal failure, and myocardial ischemia. Hsp72 inhibits several features of the intrinsic apoptotic pathway. However, the molecular mechanisms by which Hsp72 expression inhibits ER stress-induced apoptosis are not clearly understood. Here we show that Hsp72 enhances cell survival under ER stress conditions. The UPR signals through the sensor IRE1alpha, which controls the splicing of the mRNA encoding the transcription factor XBP1. We show that Hsp72 enhances XBP1 mRNA splicing and expression of its target genes, associated with attenuated apoptosis under ER stress conditions. Inhibition of XBP1 mRNA splicing either by dominant negative IRE1alpha or by knocking down XBP1 specifically abrogated the inhibition of ER stress-induced apoptosis by Hsp72. Regulation of the UPR was associated with the formation of a stable protein complex between Hsp72 and the cytosolic domain of IRE1alpha. Finally, Hsp72 enhanced the RNase activity of recombinant IRE1alpha in vitro, suggesting a direct regulation. Our data show that binding of Hsp72 to IRE1alpha enhances IRE1alpha/XBP1 signaling at the ER and inhibits ER stress-induced apoptosis. These results provide a physical connection between cytosolic chaperones and the ER stress response.

L-histidine enhances learning in stressed zebrafish

Directory of Open Access Journals (Sweden)

L.P.V. Cofiel

2009-01-01

Full Text Available The aim of the present study was to determine the effect of the histaminergic precursor L-histidine and the H3 receptor antagonist thioperamide on the learning process of zebrafish submitted or not to confinement stress. On each of the 5 consecutive days of experiment (D1, D2, D3, D4, D5, animals had to associate an interruption of the aquarium air supply with food offering. Non-stressed zebrafish received an intraperitoneal injection of 100 mg/kg L-histidine, 10 mg/kg thioperamide or saline after training. Stressed animals received drug treatment and then were submitted to confinement stress for 1 h before the learning procedure. Time to approach the feeder was measured (in seconds and was considered to be indicative of learning. A decrease in time to approach the feeder was observed in the saline-treated group (D1 = 141.92 ± 13.57; D3 = 55 ± 13.54, indicating learning. A delay in learning of stressed animals treated with saline was observed (D1 = 217.5 ± 25.66. L-histidine facilitated learning in stressed (D1 = 118.68 ± 13.9; D2 = 45.88 ± 8.2 and non-stressed (D1 = 151.11 ± 19.20; D5 = 62 ± 14.68 animals. Thioperamide inhibited learning in non-stressed (D1 = 110.38 ± 9.49; D4 = 58.79 ± 16.83 and stressed animals (D1 = 167.3 ± 26.39; D5 = 172.15 ± 27.35. L-histidine prevented the increase in blood glucose after one session of confinement (L-histidine = 65.88 ± 4.50; control = 53 ± 3.50 mg/dL. These results suggest that the histaminergic system enhances learning and modulates stress responses in zebrafish.

A stressful microenvironment: opposing effects of the endoplasmic reticulum stress response in the suppression and enhancement of adaptive tumor immunity.

Science.gov (United States)

Rausch, Matthew P; Sertil, Aparna Ranganathan

2015-03-01

The recent clinical success of immunotherapy in the treatment of certain types of cancer has demonstrated the powerful ability of the immune system to control tumor growth, leading to significantly improved patient survival. However, despite these promising results current immunotherapeutic strategies are still limited and have not yet achieved broad acceptance outside the context of metastatic melanoma. The limitations of current immunotherapeutic approaches can be attributed in part to suppressive mechanisms present in the tumor microenvironment that hamper the generation of robust antitumor immune responses thus allowing tumor cells to escape immune-mediated destruction. The endoplasmic reticulum (ER) stress response has recently emerged as a potent regulator of tumor immunity. The ER stress response is an adaptive mechanism that allows tumor cells to survive in the harsh growth conditions inherent to the tumor milieu such as low oxygen (hypoxia), low pH and low levels of glucose. Activation of ER stress can also alter the cancer cell response to therapies. In addition, the ER stress response promotes tumor immune evasion by inducing the production of protumorigenic inflammatory cytokines and impairing tumor antigen presentation. However, the ER stress response can boost antitumor immunity in some situations by enhancing the processing and presentation of tumor antigens and by inducing the release of immunogenic factors from stressed tumor cells. Here, we discuss the dualistic role of the ER stress response in the modulation of tumor immunity and highlight how strategies to either induce or block ER stress can be employed to improve the clinical efficacy of tumor immunotherapy.

Performance enhancement in uniaxially tensile stressed GeSn n-channel fin tunneling field-effect transistor: Impact of stress direction

Science.gov (United States)

Wang, Hongjuan; Han, Genquan; Jiang, Xiangwei; Liu, Yan; Zhang, Chunfu; Zhang, Jincheng; Hao, Yue

2017-04-01

In this work, the boosting effect on the performance of GeSn n-channel fin tunneling FET (nFinTFET) enabled by uniaxial tensile stress is investigated theoretically. As the fin rotates within the (001) plane, the uniaxial tensile stress is always along its direction. The electrical characteristics of tensile-stressed GeSn nFinTFETs with point and line tunneling modes are computed utilizing the technology computer aided design (TCAD) simulator in which the dynamic nonlocal band-to-band tunneling (BTBT) algorithm is employed. In comparison with the relaxed devices, tensile-stressed GeSn nFinTFETs achieve a substantial enhancement in band-to-band tunneling generation rate (G BTBT) and on-state current I ON owing to the reduced bandgap E G induced by the tensile stress. Performance improvement of GeSn nFinTFETs induced by tensile stress demonstrates a strong dependence on channel direction and tunneling modes. Under the same magnitude of stress, line-nFinTFETs obtain a more pronounced I ON enhancement over the transistors with point tunneling mode.

A wheat WRKY transcription factor TaWRKY10 confers tolerance to multiple abiotic stresses in transgenic tobacco.

Directory of Open Access Journals (Sweden)

Chen Wang

Full Text Available WRKY transcription factors are reported to be involved in defense regulation, stress response and plant growth and development. However, the precise role of WRKY transcription factors in abiotic stress tolerance is not completely understood, especially in crops. In this study, we identified and cloned 10 WRKY genes from genome of wheat (Triticum aestivum L.. TaWRKY10, a gene induced by multiple stresses, was selected for further investigation. TaWRKY10 was upregulated by treatment with polyethylene glycol, NaCl, cold and H2O2. Result of Southern blot indicates that the wheat genome contains three copies of TaWRKY10. The TaWRKY10 protein is localized in the nucleus and functions as a transcriptional activator. Overexpression of TaWRKY10 in tobacco (Nicotiana tabacum L. resulted in enhanced drought and salt stress tolerance, mainly demonstrated by the transgenic plants exhibiting of increased germination rate, root length, survival rate, and relative water content under these stress conditions. Further investigation showed that transgenic plants also retained higher proline and soluble sugar contents, and lower reactive oxygen species and malonaldehyde contents. Moreover, overexpression of the TaWRKY10 regulated the expression of a series of stress related genes. Taken together, our results indicate that TaWRKY10 functions as a positive factor under drought and salt stresses by regulating the osmotic balance, ROS scavenging and transcription of stress related genes.

Stress enhances the consolidation of extinction memory in a predictive learning task

Directory of Open Access Journals (Sweden)

Tanja eHamacher-Dang

2013-08-01

Full Text Available Extinction is not always permanent, as indicated by several types of recovery effects, such as the renewal effect, which may occur after a context change and points towards the importance of contextual cues. Strengthening the retrieval of extinction memory is a crucial aim of extinction-based psychotherapeutic treatments of anxiety disorders to prevent relapse. Stress is known to modulate learning and memory, with mostly enhancing effects on memory consolidation. However, whether such a consolidation-enhancing effect of acute stress can also be found for extinction memory has not yet been examined in humans. In this study, we investigated the effect of stress after extinction learning on the retrieval of extinction memory in a predictive learning renewal paradigm. Participants took the part of being the doctor of a fictitious patient and learned to predict whether certain food stimuli were associated with ‘stomach trouble’ in two different restaurants (contexts. On the first day, critical stimuli were associated with stomach trouble in context A (acquisition phase. On the second day, these associations were extinguished in context B. Directly after extinction, participants were either exposed to a stressor (socially evaluated cold pressor test; n = 22 or a control condition (n = 24. On the third day, we tested retrieval of critical associations in contexts A and B. Participants exposed to stress after extinction exhibited a reduced recovery of responding at test in context B, suggesting that stress may context-dependently enhance the consolidation of extinction memory. Furthermore, the increase in cortisol in response to the stressor was negatively correlated with the recovery of responding in context A. Our findings suggest that in parallel to the known effects of stress on the consolidation of episodic memory, stress also enhances the consolidation of extinction memory, which might be relevant for potential applications in extinction

Exploring the Factors Contributing to Stress and Coping Strategies ...

African Journals Online (AJOL)

Exploring the Factors Contributing to Stress and Coping Strategies of Nurses at ... explore the factors contributing to nurses' stress and related coping strategies used ... of staff and materials, facing death and dying, dissatisfaction with the work ...

Imaging shear stress distribution and evaluating the stress concentration factor of the human eye

Science.gov (United States)

Joseph Antony, S.

2015-03-01

Healthy eyes are vital for a better quality of human life. Historically, for man-made materials, scientists and engineers use stress concentration factors to characterise the effects of structural non-homogeneities on their mechanical strength. However, such information is scarce for the human eye. Here we present the shear stress distribution profiles of a healthy human cornea surface in vivo using photo-stress analysis tomography, which is a non-intrusive and non-X-ray based method. The corneal birefringent retardation measured here is comparable to that of previous studies. Using this, we derive eye stress concentration factors and the directional alignment of major principal stress on the surface of the cornea. Similar to thermometers being used for monitoring the general health in humans, this report provides a foundation to characterise the shear stress carrying capacity of the cornea, and a potential bench mark for validating theoretical modelling of stresses in the human eye in future.

Repeated homotypic stress elevates 2-arachidonoylglycerol levels and enhances short-term endocannabinoid signaling at inhibitory synapses in basolateral amygdala.

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Patel, Sachin; Kingsley, Philip J; Mackie, Ken; Marnett, Lawrence J; Winder, Danny G

2009-12-01

Psychosocial stress is a risk factor for development and exacerbation of neuropsychiatric illness. Repeated stress causes biochemical adaptations in endocannabinoid (eCB) signaling that contribute to stress-response habituation, however, the synaptic correlates of these adaptations have not been examined. Here, we show that the synthetic enzyme for the eCB 2-arachidonoylglycerol (2-AG), diacylglycerol (DAG) lipase alpha, is heterogeneously expressed in the amygdala, and that levels of 2-AG and precursor DAGs are increased in the basolateral amygdala (BLA) after 10 days, but not 1 day, of restraint stress. In contrast, arachidonic acid was decreased after both 1 and 10 days of restraint stress. To examine the synaptic correlates of these alterations in 2-AG metabolism, we used whole-cell electrophysiology to determine the effects of restraint stress on depolarization-induced suppression of inhibition (DSI) in the BLA. A single restraint stress exposure did not alter DSI compared with control mice. However, after 10 days of restraint stress, DSI duration, but not magnitude, was significantly prolonged. Inhibition of 2-AG degradation with MAFP also prolonged DSI duration; the effects of repeated restraint stress and MAFP were mutually occlusive. These data indicate that exposure to repeated, but not acute, stress produces neuroadaptations that confer BLA neurons with an enhanced capacity to elevate 2-AG content and engage in 2-AG-mediated short-term retrograde synaptic signaling. We suggest stress-induced enhancement of eCB-mediated suppression of inhibitory transmission in the BLA could contribute to affective dysregulation associated with chronic stress.

Short-term stress enhances cellular immunity and increases early resistance to squamous cell carcinoma.

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Dhabhar, Firdaus S; Saul, Alison N; Daugherty, Christine; Holmes, Tyson H; Bouley, Donna M; Oberyszyn, Tatiana M

2010-01-01

In contrast to chronic/long-term stress that suppresses/dysregulates immune function, an acute/short-term fight-or-flight stress response experienced during immune activation can enhance innate and adaptive immunity. Moderate ultraviolet-B (UV) exposure provides a non-invasive system for studying the naturalistic emergence, progression and regression of squamous cell carcinoma (SCC). Because SCC is an immunoresponsive cancer, we hypothesized that short-term stress experienced before UV exposure would enhance protective immunity and increase resistance to SCC. Control and short-term stress groups were treated identically except that the short-term stress group was restrained (2.5h) before each of nine UV-exposure sessions (minimum erythemal dose, 3-times/week) during weeks 4-6 of the 10-week UV exposure protocol. Tumors were measured weekly, and tissue collected at weeks 7, 20, and 32. Chemokine and cytokine gene expression was quantified by real-time PCR, and CD4+ and CD8+ T cells by flow cytometry and immunohistochemistry. Compared to controls, the short-term stress group showed greater cutaneous T-cell attracting chemokine (CTACK)/CCL27, RANTES, IL-12, and IFN-gamma gene expression at weeks 7, 20, and 32, higher skin infiltrating T cell numbers (weeks 7 and 20), lower tumor incidence (weeks 11-20) and fewer tumors (weeks 11-26). These results suggest that activation of short-term stress physiology increased chemokine expression and T cell trafficking and/or function during/following UV exposure, and enhanced Type 1 cytokine-driven cell-mediated immunity that is crucial for resistance to SCC. Therefore, the physiological fight-or-flight stress response and its adjuvant-like immuno-enhancing effects, may provide a novel and important mechanism for enhancing immune system mediated tumor-detection/elimination that merits further investigation.

Chronic environmental stress enhances tolerance to seasonal gradual warming in marine mussels.

Directory of Open Access Journals (Sweden)

Ionan Marigómez

Full Text Available In global climate change scenarios, seawater warming acts in concert with multiple stress sources, which may enhance the susceptibility of marine biota to thermal stress. Here, the responsiveness to seasonal gradual warming was investigated in temperate mussels from a chronically stressed population in comparison with a healthy one. Stressed and healthy mussels were subjected to gradual temperature elevation for 8 days (1°C per day; fall: 16-24°C, winter: 12-20°C, summer: 20-28°C and kept at elevated temperature for 3 weeks. Healthy mussels experienced thermal stress and entered the time-limited survival period in the fall, became acclimated in winter and exhibited sublethal damage in summer. In stressed mussels, thermal stress and subsequent health deterioration were elicited in the fall but no transition into the critical period of time-limited survival was observed. Stressed mussels did not become acclimated to 20°C in winter, when they experienced low-to-moderate thermal stress, and did not experience sublethal damage at 28°C in summer, showing instead signs of metabolic rate depression. Overall, although the thermal threshold was lowered in chronically stressed mussels, they exhibited enhanced tolerance to seasonal gradual warming, especially in summer. These results challenge current assumptions on the susceptibility of marine biota to the interactive effects of seawater warming and pollution.

Enhanced emotional empathy after psychosocial stress in young healthy men.

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Wolf, Oliver T; Schulte, Judith M; Drimalla, Hanna; Hamacher-Dang, Tanja C; Knoch, Daria; Dziobek, Isabel

2015-01-01

Empathy is a core prerequisite for human social behavior. Relatively, little is known about how empathy is influenced by social stress and its associated neuroendocrine alterations. The current study was designed to test the impact of acute stress on emotional and cognitive empathy. Healthy male participants were exposed to a psychosocial laboratory stressor (trier social stress test, (TSST)) or a well-matched control condition (Placebo-TSST). Afterwards they participated in an empathy test measuring emotional and cognitive empathy (multifaceted empathy test, (MET)). Stress exposure caused an increase in negative affect, a rise in salivary alpha amylase and a rise in cortisol. Participants exposed to stress reported more emotional empathy in response to pictures displaying both positive and negative emotional social scenes. Cognitive empathy (emotion recognition) in contrast did not differ between the stress and the control group. The current findings provide initial evidence for enhanced emotional empathy after acute psychosocial stress.

NAC transcription factor JUNGBRUNNEN1 enhances drought tolerance in tomato

KAUST Repository

Thirumalaikumar, Venkatesh P.

2017-06-22

Water deficit (drought stress) massively restricts plant growth and the yield of crops; reducing the deleterious effects of drought is therefore of high agricultural relevance. Drought triggers diverse cellular processes including the inhibition of photosynthesis, the accumulation of cell-damaging reactive oxygen species, and gene expression reprogramming, besides others. Transcription factors (TF) are central regulators of transcriptional reprogramming and expression of many TF genes is affected by drought, including members of the NAC family. Here, we identify the NAC factor JUNGBRUNNEN1 (JUB1) as a regulator of drought tolerance in tomato (Solanum lycopersicum). Expression of tomato JUB1 (SlJUB1) is enhanced by various abiotic stresses, including drought. Inhibiting SlJUB1 by virus-induced gene silencing drastically lowers drought tolerance concomitant with an increase in ion leakage, an elevation of hydrogen peroxide (H2 O2 ) levels, and a decrease of the expression of various drought-responsive genes. In contrast, overexpression of AtJUB1 from Arabidopsis thaliana increases drought tolerance in tomato, alongside with a higher relative leaf water content during drought and reduced H2 O2 levels. AtJUB1 was previously shown to stimulate expression of DREB2A, a TF involved in drought responses, and of the DELLA genes GAI and RGL1. We show here that SlJUB1 similarly controls the expression of the tomato orthologs SlDREB1, SlDREB2, and SlDELLA. Furthermore, AtJUB1 directly binds to the promoters of SlDREB1, SlDREB2 and SlDELLA in tomato. Our study highlights JUB1 as a transcriptional regulator of drought tolerance and suggests considerable conservation of the abiotic stress-related gene regulatory networks controlled by this NAC factor between Arabidopsis and tomato. This article is protected by copyright. All rights reserved.

The contribution of stress, cultural factors, and sexual identity on the substance abuse, violence, HIV, and depression syndemic among Hispanic men.

Science.gov (United States)

González-Guarda, Rosa Maria; McCabe, Brian E; Leblanc, Natalie; De Santis, Joseph P; Provencio-Vasquez, Elias

2016-10-01

The purpose of this study was to confirm the substance abuse, violence, HIV, and depression syndemic among Hispanic men, and to test whether stress and sociocultural factors, including acculturation, family support, and sexual orientation, predict this syndemic. A cross-sectional survey was administered to 164 Hispanic men using standardized measures for Hispanic Stress (Cervantes, Padilla, & Salgado de Snyder, 1991), substance abuse (Kelly et al., 1994), violence (Peragallo et al., 2005), risk for HIV (González-Guarda, Peragallo, Urrutia, Vasquez, & Mitrani, 2008), and depression (Center for Epidemiologic Studies Scale, CES-D; Radloff, 1977). Results from Structural Equation Modeling (SEM) supported the syndemic factor among Hispanic men. While family/cultural stress and homosexual identity were risk factors for the syndemic factor, family support was protective. More longitudinal research is needed to identify influences on the syndemic factor among diverse Hispanic communities. Interventions that address stress and enhance family supports may show promise in addressing and preventing syndemics among Hispanic men. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Subjective stress factors in centrifuge training for military aircrews.

Science.gov (United States)

Lin, Pei-Chun; Wang, Jenhung; Li, Shih-Chin

2012-07-01

This study investigates stress-influence factors perceived by military aircrews undergoing centrifuge training, which lowers the incidence of G-induced loss of consciousness (G-LOC) for the crews of high-performance combat aircrafts. We used questionnaires to assess the subjective stress-influence factors of crews undergoing centrifuge training. Professionals in aviation physiology identified attributes measuring the perceived stress induced by centrifuge training, which were segmented into three constructs by factor analysis, theory lecture, centrifuge equipment, and physical fitness. Considerable interpenetration was discernible between these factors and military rank, age, length of service, flight hours accrued, and type of aircraft piloted. Identifying and quantifying the perceived stressors experienced in human-use centrifuge training enables aviators, astronauts, and air forces of the world to determine which constructs perceptibly increase or alleviate the perceived stress undergone by trainees when partaking in centrifuge training. Copyright © 2011 Elsevier Ltd and The Ergonomics Society. All rights reserved.

A modified model of pharmacists' job stress: the role of organizational, extra-role, and individual factors on work-related outcomes.

Science.gov (United States)

Gaither, Caroline A; Kahaleh, Abir A; Doucette, William R; Mott, David A; Pederson, Craig A; Schommer, Jon C

2008-09-01

outcomes. Increased focus on enhancing interpersonal interactions, developing commitment to the profession, and greater consideration of nonwork factors could help pharmacists better manage their work environments. Future research should continue to refine these models to further enhance our understanding of the effects of job stress in the health professional workplace.

Study on applicability of stress intensity factor solutions for flaw evaluation

International Nuclear Information System (INIS)

Miura, Naoki; Nagai, Masaki; Takahashi, Yukio

2014-01-01

Stress intensity factor is the quantity which characterizes the singularity of the stress field near a crack tip in the scheme of the linear elastic fracture mechanics, and is used for fatigue and/or SCC crack propagation evaluation. Stress intensity factor depends on the shape and the size of cracked structures, and is frequently prepared as the tabulated correction factors which are the functions of crack depth ratio, aspect ratio, etc. Some stress intensity factor solutions have been included in the JSME rules on fitness-for-service for nuclear power plants. Many of them have been significantly revised on the latest (2012) version of the rules, however, the validation of the revised solutions was not adequate so far. In this study, the implication of the revision was investigated together with its technical basis. A comprehensive comparison was made between available solutions including the 2008 and 2012 version of the rules. It was ascertained that the solutions in the 2012 version provided stress intensity factors consistent with the previous version and the referential stress intensity factors. (author)

Weight functions for the determination of stress intensity factor and T-stress for edge-cracked plates with built-in ends

International Nuclear Information System (INIS)

Li, J.; Wang, X.; Tan, C.L.

2004-01-01

This paper presents the weight functions for the determination of the stress intensity factor and T-stress solutions for edge-cracked plates with built-in ends under complex stress distributions. First, a compliance analysis approach is used to calculate stress intensity factor and T-stress for edge cracks in finite width plates with built-in ends with uniform or linear stress distributions acting on the crack face. The results serve as the reference solutions for the next step in which the approaches of deriving weight functions from reference stress intensity factor and T-stress solutions developed for stress boundary conditions are extended to obtain the corresponding weight functions for edge-cracked plates with built-in ends. Finite element analysis is conducted to validate the derived solutions. The weight functions derived are suitable for obtaining stress intensity factors and T-stress solutions under any complex stress field

Endoplasmic reticulum stress-responsive transcription factor ATF6α directs recruitment of the Mediator of RNA polymerase II transcription and multiple histone acetyltransferase complexes.

Science.gov (United States)

Sela, Dotan; Chen, Lu; Martin-Brown, Skylar; Washburn, Michael P; Florens, Laurence; Conaway, Joan Weliky; Conaway, Ronald C

2012-06-29

The basic leucine zipper transcription factor ATF6α functions as a master regulator of endoplasmic reticulum (ER) stress response genes. Previous studies have established that, in response to ER stress, ATF6α translocates to the nucleus and activates transcription of ER stress response genes upon binding sequence specifically to ER stress response enhancer elements in their promoters. In this study, we investigate the biochemical mechanism by which ATF6α activates transcription. By exploiting a combination of biochemical and multidimensional protein identification technology-based mass spectrometry approaches, we have obtained evidence that ATF6α functions at least in part by recruiting to the ER stress response enhancer elements of ER stress response genes a collection of RNA polymerase II coregulatory complexes, including the Mediator and multiple histone acetyltransferase complexes, among which are the Spt-Ada-Gcn5 acetyltransferase (SAGA) and Ada-Two-A-containing (ATAC) complexes. Our findings shed new light on the mechanism of action of ATF6α, and they outline a straightforward strategy for applying multidimensional protein identification technology mass spectrometry to determine which RNA polymerase II transcription factors and coregulators are recruited to promoters and other regulatory elements to control transcription.

Determinants of job stress in chemical process industry: A factor analysis approach.

Science.gov (United States)

Menon, Balagopal G; Praveensal, C J; Madhu, G

2015-01-01

Job stress is one of the active research domains in industrial safety research. The job stress can result in accidents and health related issues in workers in chemical process industries. Hence it is important to measure the level of job stress in workers so as to mitigate the same to avoid the worker's safety related problems in the industries. The objective of this study is to determine the job stress factors in the chemical process industry in Kerala state, India. This study also aims to propose a comprehensive model and an instrument framework for measuring job stress levels in the chemical process industries in Kerala, India. The data is collected through a questionnaire survey conducted in chemical process industries in Kerala. The collected data out of 1197 surveys is subjected to principal component and confirmatory factor analysis to develop the job stress factor structure. The factor analysis revealed 8 factors that influence the job stress in process industries. It is also found that the job stress in employees is most influenced by role ambiguity and the least by work environment. The study has developed an instrument framework towards measuring job stress utilizing exploratory factor analysis and structural equation modeling.

ABI-like transcription factor gene TaABL1 from wheat improves multiple abiotic stress tolerances in transgenic plants.

Science.gov (United States)

Xu, Dong-Bei; Gao, Shi-Qing; Ma, You-Zhi; Xu, Zhao-Shi; Zhao, Chang-Ping; Tang, Yi-Miao; Li, Xue-Yin; Li, Lian-Cheng; Chen, Yao-Feng; Chen, Ming

2014-12-01

The phytohormone abscisic acid (ABA) plays crucial roles in adaptive responses of plants to abiotic stresses. ABA-responsive element binding proteins (AREBs) are basic leucine zipper transcription factors that regulate the expression of downstream genes containing ABA-responsive elements (ABREs) in promoter regions. A novel ABI-like (ABA-insensitive) transcription factor gene, named TaABL1, containing a conserved basic leucine zipper (bZIP) domain was cloned from wheat. Southern blotting showed that three copies were present in the wheat genome. Phylogenetic analyses indicated that TaABL1 belonged to the AREB subfamily of the bZIP transcription factor family and was most closely related to ZmABI5 in maize and OsAREB2 in rice. Expression of TaABL1 was highly induced in wheat roots, stems, and leaves by ABA, drought, high salt, and low temperature stresses. TaABL1 was localized inside the nuclei of transformed wheat mesophyll protoplast. Overexpression of TaABL1 enhanced responses of transgenic plants to ABA and hastened stomatal closure under stress, thereby improving tolerance to multiple abiotic stresses. Furthermore, overexpression of TaABL1 upregulated or downregulated the expression of some stress-related genes controlling stomatal closure in transgenic plants under ABA and drought stress conditions, suggesting that TaABL1 might be a valuable genetic resource for transgenic molecular breeding.

Daidzein enhances immune function in late lactation cows under heat stress.

Science.gov (United States)

Liu, De-Yi; He, Shao-Jun; Liu, Shi-Qing; Tang, Yi-Guo; Jin, Er-Hui; Chen, Hui-Liang; Li, Sheng-He; Zhong, Liang-Ting

2014-01-01

Heat stress decreases natural immunity making cows more vulnerable to diseases. A previous study reported that daidzein can enhance animal resistance to heat stress and regulate animal immunocompetence. However, it is unclear whether daidzein regulates the immune performance of late lactation cows under heat stress. In this study, late lactation cows in four groups were raised in hot weather and fed with basic diet, basic diet plus 200, 300, 400 mg/day daidzein, respectively, and the experimental period was 60 days. Blood was collected to examine the changes of serum total protein (TP), albumin (ALB), immunoglobulin G (IgG), interferon alpha (IFN-α), and interleukin-2 (IL-2). We found the levels of serum IgG and INF-α were significantly higher in late lactation cows after 300 and 400 mg/day daidzein treatment compared to those in the control group and 200 mg/day daidzein treatment (P 0.05). Daidzein can enhance the immunocompetence of late lactation cows and strengthen cow resistance to heat stress. © 2013 Japanese Society of Animal Science.

Double overexpression of DREB and PIF transcription factors improves drought stress tolerance and cell elongation in transgenic plants.

Science.gov (United States)

Kudo, Madoka; Kidokoro, Satoshi; Yoshida, Takuya; Mizoi, Junya; Todaka, Daisuke; Fernie, Alisdair R; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko

2017-04-01

Although a variety of transgenic plants that are tolerant to drought stress have been generated, many of these plants show growth retardation. To improve drought tolerance and plant growth, we applied a gene-stacking approach using two transcription factor genes: DEHYDRATION-RESPONSIVE ELEMENT-BINDING 1A (DREB1A) and rice PHYTOCHROME-INTERACTING FACTOR-LIKE 1 (OsPIL1). The overexpression of DREB1A has been reported to improve drought stress tolerance in various crops, although it also causes a severe dwarf phenotype. OsPIL1 is a rice homologue of Arabidopsis PHYTOCHROME-INTERACTING FACTOR 4 (PIF4), and it enhances cell elongation by activating cell wall-related gene expression. We found that the OsPIL1 protein was more stable than PIF4 under light conditions in Arabidopsis protoplasts. Transactivation analyses revealed that DREB1A and OsPIL1 did not negatively affect each other's transcriptional activities. The transgenic plants overexpressing both OsPIL1 and DREB1A showed the improved drought stress tolerance similar to that of DREB1A overexpressors. Furthermore, double overexpressors showed the enhanced hypocotyl elongation and floral induction compared with the DREB1A overexpressors. Metabolome analyses indicated that compatible solutes, such as sugars and amino acids, accumulated in the double overexpressors, which was similar to the observations of the DREB1A overexpressors. Transcriptome analyses showed an increased expression of abiotic stress-inducible DREB1A downstream genes and cell elongation-related OsPIL1 downstream genes in the double overexpressors, which suggests that these two transcription factors function independently in the transgenic plants despite the trade-offs required to balance plant growth and stress tolerance. Our study provides a basis for plant genetic engineering designed to overcome growth retardation in drought-tolerant transgenic plants. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology

Factors related to teamwork performance and stress of operating room nurses.

Science.gov (United States)

Sonoda, Yukio; Onozuka, Daisuke; Hagihara, Akihito

2018-01-01

To evaluate operating room nurses' perception of teamwork performance and their level of mental stress and to identify related factors. Little is known about the factors affecting teamwork and the mental stress of surgical nurses, although the performance of the surgical team is essential for patient safety. The questionnaire survey for operation room nurses consisted of simple questions about teamwork performance and mental stress. Multivariate analyses were used to identify factors causing a sense of teamwork performance or mental stress. A large number of surgical nurses had a sense of teamwork performance, but 30-40% of operation room nurses were mentally stressed during surgery. Neither the patient nor the operation factors were related to the sense of teamwork performance in both types of nurses. Among scrub nurses, endoscopic and abdominal surgery, body mass index, blood loss and the American Society of Anesthesiologists physical status class were related to their mental stress. Conversely, circulating nurses were stressed about teamwork performance. The factors related to teamwork performance and mental stress during surgery differed between scrub and circulating nurses. Increased support for operation room nurses is necessary. The increased support leads to safer surgical procedures and better patient outcomes. © 2017 John Wiley & Sons Ltd.

Confirmatory factor analysis of posttraumatic stress symptoms in sexually harassed women.

Science.gov (United States)

Palmieri, Patrick A; Fitzgerald, Louise F

2005-12-01

Posttraumatic stress disorder (PTSD) factor analytic research to date has not provided a clear consensus on the structure of posttraumatic stress symptoms. Seven hypothesized factor structures were evaluated using confirmatory factor analysis of the Posttraumatic Stress Disorder Checklist, a paper-and-pencil measure of posttraumatic stress symptom severity, in a sample of 1,218 women who experienced a broad range of workplace sexual harassment. The model specifying correlated re-experiencing, effortful avoidance, emotional numbing, and hyperarousal factors provided the best fit to the data. Virtually no support was obtained for the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV; American Psychiatric Association, 1994) three-factor model of re-experiencing, avoidance, and hyperarousal factors. Different patterns of correlations with external variables were found for the avoidance and emotional numbing factors, providing further validation of the supported model.

The membrane tethered transcription factor EcbZIP17 from finger millet promotes plant growth and enhances tolerance to abiotic stresses.

Science.gov (United States)

Ramakrishna, Chopperla; Singh, Sonam; Raghavendrarao, Sangala; Padaria, Jasdeep C; Mohanty, Sasmita; Sharma, Tilak Raj; Solanke, Amolkumar U

2018-02-01

The occurrence of various stresses, as the outcome of global climate change, results in the yield losses of crop plants. Prospecting of genes in stress tolerant plant species may help to protect and improve their agronomic performance. Finger millet (Eleusine coracana L.) is a valuable source of superior genes and alleles for stress tolerance. In this study, we isolated a novel endoplasmic reticulum (ER) membrane tethered bZIP transcription factor from finger millet, EcbZIP17. Transgenic tobacco plants overexpressing this gene showed better vegetative growth and seed yield compared with wild type (WT) plants under optimal growth conditions and confirmed upregulation of brassinosteroid signalling genes. Under various abiotic stresses, such as 250 mM NaCl, 10% PEG6000, 400 mM mannitol, water withdrawal, and heat stress, the transgenic plants showed higher germination rate, biomass, primary and secondary root formation, and recovery rate, compared with WT plants. The transgenic plants exposed to an ER stress inducer resulted in greater leaf diameter and plant height as well as higher expression of the ER stress-responsive genes BiP, PDIL, and CRT1. Overall, our results indicated that EcbZIP17 improves plant growth at optimal conditions through brassinosteroid signalling and provide tolerance to various environmental stresses via ER signalling pathways.

CRFR1 in the ventromedial caudate putamen modulates acute stress-enhanced expression of cocaine locomotor sensitization.

Science.gov (United States)

Liu, Shuli; Wang, Zhiyan; Li, Yijing; Sun, Xiaowei; Ge, Feifei; Yang, Mingda; Wang, Xinjuan; Wang, Na; Wang, Junkai; Cui, Cailian

2017-07-15

Repeated exposure to psychostimulants induces a long-lasting enhancement of locomotor activity called behavioral sensitization, which is often reinforced by stress after drug withdrawal. The mechanisms underlying these phenomena remain elusive. Here we explored the effects of acute stress 3 or 14 days after the cessation of chronic cocaine treatment on the expression of locomotor sensitization induced by a cocaine challenge in rats and the key brain region and molecular mechanism underlying the phenomenon. A single session of forced swimming, as an acute stress (administered 2 days after the cessation of cocaine), significantly enhanced the expression of cocaine locomotor sensitization 14 days after the final cocaine injection (challenge at 12 days after acute stress) but not 3 days after the cessation of cocaine (challenge at 1 day after acute stress). The result indicated that acute stress enhanced the expression of cocaine locomotor sensitization after incubation for 12 days rather than 1 day after the last cocaine injection. Moreover, the enhancement in locomotor sensitization was paralleled by a selective increase in the number of the c-Fos + cells, the level of CRFR1 mRNA in the ventromedial caudate putamen (vmCPu). Furthermore, the enhancement was significantly attenuated by CRFR1 antagonist NBI-27914 into the vmCPu, implying that the up-regulation of CRFR1 in the vmCPu seems to be critical in the acute stress-enhanced expression of cocaine locomotor sensitization. The findings demonstrate that the long-term effect of acute stress on the expression of cocaine locomotor sensitization is partially mediated by CRFR1 in the vmCPu. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Stress intensity factors and weight functions for cracks in front of notches

International Nuclear Information System (INIS)

Fett, T.

1993-12-01

The knowledge of stress intensity factors for cracks at notch roots is important for the fracture mechanical treatment of real components. Stress intensity factor solutions are available only for special notches and externally applied loads. For the treatment of more complex loadings as thermal stresses near the notch root the weight function is needed in addition. In the first part of this report weight functions for cracks in front of internal notches are derived from stress intensity factor solutions under external loading available in the literature. The second part deals with cracks in front of edge notches. Limit cases of stress intensity factors are derived which allow to estimate stress intensity factors for cracks in front of internal elliptical notches with arbitrary aspect ratio of the ellipse and for external notches. (orig.) [de

Stress indices and flexibility factors in thin elbows

International Nuclear Information System (INIS)

Berton, M.N.; Carbonnier, J.L.

1983-01-01

Usually piping calculations are done with a beam model. Ovalisation in elbows is taken into account by the means of flexibility factors and stress indices. This paper compares results from a beam model calculation with results from a 3 D shell model calculation. (codes TEDEL and TRICO from the CEA-SEMT System). The aim of this comparison is to study the validity of the stress indices and flexibility factors used in the beam model for several kinds of loading

Modified stress intensity factor as a crack growth parameter applicable under large scale yielding conditions

International Nuclear Information System (INIS)

Yasuoka, Tetsuo; Mizutani, Yoshihiro; Todoroki, Akira

2014-01-01

High-temperature water stress corrosion cracking has high tensile stress sensitivity, and its growth rate has been evaluated using the stress intensity factor, which is a linear fracture mechanics parameter. Stress corrosion cracking mainly occurs and propagates around welded metals or heat-affected zones. These regions have complex residual stress distributions and yield strength distributions because of input heat effects. The authors previously reported that the stress intensity factor becomes inapplicable when steep residual stress distributions or yield strength distributions occur along the crack propagation path, because small-scale yielding conditions deviate around those distributions. Here, when the stress intensity factor is modified by considering these distributions, the modified stress intensity factor may be used for crack growth evaluation for large-scale yielding. The authors previously proposed a modified stress intensity factor incorporating the stress distribution or yield strength distribution in front of the crack using the rate of change of stress intensity factor and yield strength. However, the applicable range of modified stress intensity factor for large-scale yielding was not clarified. In this study, the range was analytically investigated by comparison with the J-integral solution. A three-point bending specimen with parallel surface crack was adopted as the analytical model and the stress intensity factor, modified stress intensity factor and equivalent stress intensity factor derived from the J-integral were calculated and compared under large-scale yielding conditions. The modified stress intensity was closer to the equivalent stress intensity factor when compared with the stress intensity factor. If deviation from the J-integral solution is acceptable up to 2%, the modified stress intensity factor is applicable up to 30% of the J-integral limit, while the stress intensity factor is applicable up to 10%. These results showed that

FACTORS CAUSING OCCUPATIONAL STRESS AMONG SENIOR SECONDARY SCHOOL TEACHERS OF AMRITSAR DISTRICT

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Mandeep Singh

2009-12-01

Full Text Available The study attempts to investigate the various factors causing occupational stress experienced by senior secondary school teachers. A sample of 100 teachers (50 science teachers and 50 physical education teachers was randomly selected. They were administered a comprehensive questionnaire which measures various factors of stress. Factor analyses were used to identify underlying factors causing stress. The analysis showed that non cooperation from the colleagues, hastiness to finish the work, unable to perform duty smoothly, unclear instructions and insufficient facilities, unclear expectations of higher authority and having more work load in less time were the significant factors causing occupational stress among the teachers. The monotonous nature of work, ignorance of higher authority and violation of administrative processes and policies were factors also contributing towards occupational stress among teachers

ORGANIZATIONAL AND PERSONALITY FACTORS OF STRESS IN ACCOUNTING AND CONSEQUENCES OF STRESS ON HEALTH

OpenAIRE

Vesna Stager

2017-01-01

Stress in accounting is popular in the area of research for many researchers in the fields of Psychology, Organizational Behavior, Health and Medicine. A significant part of empirical research has been focused on the analysis of the relationships between different individual and organizational stress factors on the job, including the effects of stress on the job. In the paper, we are showing an overview of the key concepts in the field of stress in accounting, covering organizational and pers...

Occupational stress and related factors among surgical residents in Korea.

Science.gov (United States)

Kang, Sanghee; Jo, Hye Sung; Boo, Yoon Jung; Lee, Ji Sung; Kim, Chong Suk

2015-11-01

The application rate for surgical residents in Korea has continuously decreased over the past few years. The demanding workload and the occupational stress of surgical training are likely causes of this problem. The aim of this study was to investigate occupational stress and its related factors in Korean surgical residents. With the support of the Korean Surgical Society, we conducted an electronic survey of Korean surgical residents related to occupational stress. We used the Korean Occupational Stress Scale (KOSS) to measure occupational stress. We analyzed the data focused on the stress level and the factors associated with occupational stress. The mean KOSS score of the surgical residents was 55.39, which was significantly higher than that of practicing surgeons (48.16, P occupation rate and exercise were all significantly associated with KOSS score. Surgical residents have high occupational stress compared to practicing surgeons and other professionals. Their mean number of assigned patients, resident recruitment rate and exercise were all significantly associated with occupational stress for surgical residents.

Stress fracture risk factors in female football players and their clinical implications.

Science.gov (United States)

Warden, Stuart J; Creaby, Mark W; Bryant, Adam L; Crossley, Kay M

2007-08-01

A stress fracture represents the inability of the skeleton to withstand repetitive bouts of mechanical loading, which results in structural fatigue, and resultant signs and symptoms of localised pain and tenderness. Reports of stress fractures in female football players are not prevalent; however, they are probably under-reported and their importance lies in the morbidity that they cause in terms of time lost from participation. By considering risk factors for stress fractures in female football players it may be possible to reduce the impact of these troublesome injuries. Risk factors for stress fractures in female football players include intrinsic risk factors such as gender, endocrine, nutritional, physical fitness and neuromusculoskeletal factors, as well as extrinsic risk factors such as training programme, equipment and environmental factors. This paper discusses these risk factors and their implications in terms of developing prevention and management strategies for stress fractures in female football players.

Work stress and metabolic and hemostatic risk factors

NARCIS (Netherlands)

Vrijkotte, T. G.; van Doornen, L. J.; de Geus, E. J.

1999-01-01

A high level of work stress has been associated with cardiovascular disease. However, the pathophysiological mechanisms underlying this association remain unclear. This study examined the effect of work stress on a cluster of metabolic and hemostatic risk factors. Blood was collected three times, on

Acute stress enhances learning and memory by activating acid-sensing ion channels in rats.

Science.gov (United States)

Ye, Shunjie; Yang, Rong; Xiong, Qiuju; Yang, Youhua; Zhou, Lianying; Gong, Yeli; Li, Changlei; Ding, Zhenhan; Ye, Guohai; Xiong, Zhe

2018-04-15

Acute stress has been shown to enhance learning and memory ability, predominantly through the action of corticosteroid stress hormones. However, the valuable targets for promoting learning and memory induced by acute stress and the underlying molecular mechanisms remain unclear. Acid-sensing ion channels (ASICs) play an important role in central neuronal systems and involves in depression, synaptic plasticity and learning and memory. In the current study, we used a combination of electrophysiological and behavioral approaches in an effort to explore the effects of acute stress on ASICs. We found that corticosterone (CORT) induced by acute stress caused a potentiation of ASICs current via glucocorticoid receptors (GRs) not mineralocorticoid receptors (MRs). Meanwhile, CORT did not produce an increase of ASICs current by pretreated with GF109203X, an antagonist of protein kinase C (PKC), whereas CORT did result in a markedly enhancement of ASICs current by bryostatin 1, an agonist of PKC, suggesting that potentiation of ASICs function may be depended on PKC activating. More importantly, an antagonist of ASICs, amiloride (10 μM) reduced the performance of learning and memory induced by acute stress, which is further suggesting that ASICs as the key components involves in cognitive processes induced by acute stress. These results indicate that acute stress causes the enhancement of ASICs function by activating PKC signaling pathway, which leads to potentiated learning and memory. Copyright © 2018 Elsevier Inc. All rights reserved.

Selected Abiotic and Biotic Environmental Stress Factors Affecting Two Economically Important Sugarcane Stalk Boring Pests in the United States

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Allan T. Showler

2016-02-01

Full Text Available Sugarcane, Saccharum spp., in the United States is attacked by a number of different arthropod pests. The most serious among those pests are two stalk boring moths in the Family Crambidae: the sugarcane borer, Diatraea saccharalis (F., and the Mexican rice borer, Eoreuma loftini (Dyar. The two species are affected by abiotic and biotic environmental stress factors. Water deficit and excessive soil nitrogen alter physical and physiochemical aspects of the sugarcane plant that make the crop increasingly vulnerable to E. loftini. Weed growth can be competitive with sugarcane but it also supports enhanced abundances and diversity of natural enemies that can suppress infestations of D. saccharalis. In an instance where the stalk borer is considered a stress factor, proximity of vulnerable crops to sugarcane can influence levels of E. loftini infestation of sugarcane. The adverse effects of each stress factor, in terms of stalk borer attack, can be reduced by adopting appropriate cultural practices, such as adequate irrigation, judicious use of nitrogen fertilizer, using noncompetitive weed growth, and not planting vulnerable crops near sugarcane fields. Understanding the relationships between stress factors and crop pests can provide valuable insights for plant breeders and tools for incorporation into integrated pest management strategies.

Postnatal Treadmill Exercise Alleviates Prenatal Stress-Induced Anxiety in Offspring Rats by Enhancing Cell Proliferation Through 5-Hydroxytryptamine 1A Receptor Activation

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Sam Jun Lee

2016-05-01

Full Text Available Purpose: Stress during pregnancy is a risk factor for the development of anxiety-related disorders in offspring later in life. The effects of treadmill exercise on anxiety-like behaviors and hippocampal cell proliferation were investigated using rats exposed to prenatal stress. Methods: Exposure of pregnant rats to a hunting dog in an enclosed room was used to induce stress. Anxiety-like behaviors of offspring were evaluated using the elevated plus maze test. Immunohistochemistry for the detection of 5-bromo-2ʹ- deoxyuridine and doublecortin (DCX in the hippocampal dentate gyrus and 5-hydroxytryptamine 1A receptors (5-HT1A in the dorsal raphe was conducted. Brain-derived neurotrophic factor (BDNF and tyrosine kinase B (TrkB levels in the hippocampus were evaluated by western blot analysis. Results: Offspring of maternal rats exposed to stress during pregnancy showed anxiety-like behaviors. Offspring also showed reduced expression of BDNF, TrkB, and DCX in the dentate gyrus, decreased cell proliferation in the hippocampus, and reduced 5-HT1A expression in the dorsal raphe. Postnatal treadmill exercise by offspring, but not maternal exercise during pregnancy, enhanced cell proliferation and expression of these proteins. Conclusions: Postnatal treadmill exercise ameliorated anxiety-like behaviors in offspring of stressed pregnant rats, and the alleviating effect of exercise on these behaviors is hypothesized to result from enhancement of cell proliferation through 5-HT1A activation in offspring rats.

Evaluation of factors important to enhance productivity

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Sanjay Kumar

2016-12-01

Full Text Available Productivity as a measure for output is important to industry and academia. In this research, factors to enhance productivity have been identified from the literature by reviewing various international and national sources to explore this evergreen field of research that is “productivity,” which has always been an increasingly interesting area of research for researchers over decades or perhaps over centuries. In total, 15 number of factors have been identified to enhance productivity. Analytic hierarchy process approach has been appropriately chosen to rank these factors because of its simplicity and effectiveness. The tool has been used by taking perception of experts from the Indian manufacturing industry. Positive attitude and involvement of management, proactive employees, and good working conditions have been ranked as top three factors as per the experts’ opinion. The ranking of factors to enhance productivity, categorization of the factors into four perspectives, and hierarchy of perspective and action plan as a final outcome of the paper may help academia and operations managers toward effective management of “operations and production activities of firms/supply chains.”

Transgenerational Social Stress, Immune Factors, Hormones, and Social Behavior

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Christopher Anthony Murgatroyd

2016-01-01

Full Text Available A social signal transduction theory of depression has been proposed that states that exposure to social adversity alters the immune response and these changes mediate symptoms of depression such as anhedonia and impairments in social behavior. The exposure of maternal rats to the chronic social stress (CSS of a male intruder depresses maternal care and impairs social behavior in the F1 and F2 offspring of these dams. The objective of the present study was to characterize basal peripheral levels of several immune factors and related hormone levels in the adult F2 offspring of CSS exposed dams and assess whether changes in these factors are associated with previously reported deficits in allogrooming behavior. CSS decreased acid glycoprotein (α1AGP and intercellular adhesion molecule-1 (ICAM-1 in F2 females, and increased granulocyte macrophage-colony stimulating factor (GM-CSF in F2 males. There were also sex dependent changes in IL-18, tissue inhibitors of metalloproteinases 1 (TIMP-1, and vascular endothelial growth factor (VEGF. Progesterone was decreased and alpha melanocyte stimulating hormone (α-MSH was increased in F2 males, and brain-derived neurotrophic factor (BDNF was decreased in F2 females. Changes in α1AGP, GM-CSF, progesterone and α-MSH were correlated with decreased allogrooming in the F2 offspring of stressed dams. These results support the hypothesis that transgenerational social stress affects both the immune system and social behavior, and also support previous studies on the adverse effects of early life stress on immune functioning and stress associated immunological disorders, including the increasing prevalence of asthma. The immune system may represent an important transgenerational etiological factor in disorders which involve social and/or early life stress associated changes in social behavior, such as depression, anxiety, and autism, as well as comorbid immune disorders. Future studies involving immune and

Stress and addiction: contribution of the corticotropin releasing factor (CRF system in neuroplasticity

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Carolina L Haass-Koffler

2012-09-01

Full Text Available Corticotropin releasing factor (CRF has been shown to induce various behavioral changes related to adaptation to stress. Dysregulation of the CRF system at any point can lead to a variety of psychiatric disorders, including substance use disorders (SUDs. CRF has been associated with stress-induced drug reinforcement. Extensive literature has identified CRF to play an important role in the molecular mechanisms that lead to an increase in susceptibility that precipitates relapse to SUDs. The CRF system has a heterogeneous role in SUDs. It enhances the acute effects of drugs of abuse and is also responsible for the potentiation of drug-induced neuroplasticity evoked during the withdrawal period. We present in this review the brain regions and circuitries where CRF is expressed and may participate in stress-induced drug abuse. Finally, we attempt to evaluate the role of modulating the CRF system as a possible therapeutic strategy for treating the dysregulation of emotional behaviors that result from the acute positive reinforcement of substances of abuse as well as the negative reinforcement produced by withdrawal.

Risk factors for antenatal depression, postnatal depression and parenting stress

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Milgrom Jeannette

2008-04-01

Full Text Available Abstract Background Given that the prevalence of antenatal and postnatal depression is high, with estimates around 13%, and the consequences serious, efforts have been made to identify risk factors to assist in prevention, identification and treatment. Most risk factors associated with postnatal depression have been well researched, whereas predictors of antenatal depression have been less researched. Risk factors associated with early parenting stress have not been widely researched, despite the strong link with depression. The aim of this study was to further elucidate which of some previously identified risk factors are most predictive of three outcome measures: antenatal depression, postnatal depression and parenting stress and to examine the relationship between them. Methods Primipara and multiparae women were recruited antenatally from two major hoitals as part of the beyondblue National Postnatal Depression Program 1. In this subsidiary study, 367 women completed an additional large battery of validated questionnaires to identify risk factors in the antenatal period at 26–32 weeks gestation. A subsample of these women (N = 161 also completed questionnaires at 10–12 weeks postnatally. Depression level was measured by the Beck Depression Inventory (BDI. Results Regression analyses identified significant risk factors for the three outcome measures. (1. Significant predictors for antenatal depression: low self-esteem, antenatal anxiety, low social support, negative cognitive style, major life events, low income and history of abuse. (2. Significant predictors for postnatal depression: antenatal depression and a history of depression while also controlling for concurrent parenting stress, which was a significant variable. Antenatal depression was identified as a mediator between seven of the risk factors and postnatal depression. (3. Postnatal depression was the only significant predictor for parenting stress and also acted as a mediator

Risk factors for antenatal depression, postnatal depression and parenting stress.

Science.gov (United States)

Leigh, Bronwyn; Milgrom, Jeannette

2008-04-16

Given that the prevalence of antenatal and postnatal depression is high, with estimates around 13%, and the consequences serious, efforts have been made to identify risk factors to assist in prevention, identification and treatment. Most risk factors associated with postnatal depression have been well researched, whereas predictors of antenatal depression have been less researched. Risk factors associated with early parenting stress have not been widely researched, despite the strong link with depression. The aim of this study was to further elucidate which of some previously identified risk factors are most predictive of three outcome measures: antenatal depression, postnatal depression and parenting stress and to examine the relationship between them. Primipara and multiparae women were recruited antenatally from two major hoitals as part of the beyondblue National Postnatal Depression Program 1. In this subsidiary study, 367 women completed an additional large battery of validated questionnaires to identify risk factors in the antenatal period at 26-32 weeks gestation. A subsample of these women (N = 161) also completed questionnaires at 10-12 weeks postnatally. Depression level was measured by the Beck Depression Inventory (BDI). Regression analyses identified significant risk factors for the three outcome measures. (1). Significant predictors for antenatal depression: low self-esteem, antenatal anxiety, low social support, negative cognitive style, major life events, low income and history of abuse. (2). Significant predictors for postnatal depression: antenatal depression and a history of depression while also controlling for concurrent parenting stress, which was a significant variable. Antenatal depression was identified as a mediator between seven of the risk factors and postnatal depression. (3). Postnatal depression was the only significant predictor for parenting stress and also acted as a mediator for other risk factors. Risk factor profiles for

Mechanical stress activates Smad pathway through PKCδ to enhance interleukin-11 gene transcription in osteoblasts.

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Shinsuke Kido

Full Text Available BACKGROUND: Mechanical stress rapidly induces ΔFosB expression in osteoblasts, which binds to interleukin (IL-11 gene promoter to enhance IL-11 expression, and IL-11 enhances osteoblast differentiation. Because bone morphogenetic proteins (BMPs also stimulate IL-11 expression in osteoblasts, there is a possibility that BMP-Smad signaling is involved in the enhancement of osteoblast differentiation by mechanical stress. The present study was undertaken to clarify whether mechanical stress affects BMP-Smad signaling, and if so, to elucidate the role of Smad signaling in mechanical stress-induced enhancement of IL-11 gene transcription. METHODOLOGY/PRINCIPAL FINDINGS: Mechanical loading by fluid shear stress (FSS induced phosphorylation of BMP-specific receptor-regulated Smads (BR-Smads, Smad1/5, in murine primary osteoblasts (mPOBs. FSS rapidly phosphorylated Y311 of protein kinase C (PKCδ, and phosphorylated PKCδ interacted with BR-Smads to phosphorylate BR-Smads. Transfection of PKCδ siRNA or Y311F mutant PKCδ abrogated BR-Smads phosphorylation and suppressed IL-11 gene transcription enhanced by FSS. Activated BR-Smads bound to the Smad-binding element (SBE of IL-11 gene promoter and formed complex with ΔFosB/JunD heterodimer via binding to the C-terminal region of JunD. Site-directed mutagenesis in the SBE and the AP-1 site revealed that both SBE and AP-1 sites were required for full activation of IL-11 gene promoter by FSS. CONCLUSIONS/SIGNIFICANCE: These results demonstrate that PKCδ-BR-Smads pathway plays an important role in the intracellular signaling in response to mechanical stress, and that a cross-talk between PKCδ-BR-Smads and ΔFosB/JunD pathways synergistically stimulates IL-11 gene transcription in response to mechanical stress.

Risk factors in pregnancy for post-traumatic stress and depression after childbirth.

Science.gov (United States)

Söderquist, J; Wijma, B; Thorbert, G; Wijma, K

2009-04-01

The objective of this study was to find risk factors in pregnancy for post-traumatic stress and depression 1 month after childbirth. Furthermore, the relation between post-traumatic stress and depression was explored. A prospective longitudinal study. Pregnant women in Linköping and Kalmar, Sweden. A total of 1224 women were assessed in pregnancy, week 12-20 and 32, as well as 1 month postpartum. Post-traumatic stress and depression after delivery were assessed 1 month postpartum. Potential risk factors were assessed in early and late pregnancy. Variables measured during pregnancy were trait anxiety, depression, fear of childbirth, childbirth-related traumatic stress, stress coping capacity, social support, parity, educational level, age, gestation week, parity, educational level, civil status, previous psychological/psychiatric counselling, and previous experience of any traumatic events. Delivery mode was assessed from the medical records. Prevalence of post-traumatic stress (criteria A, B, C, D, E, and F according to DSM-IV) and depression (Beck's depression inventory). One month postpartum, 12 (1.3%) women had post-traumatic stress (met symptom criteria B, C, and D for post-traumatic stress disorder according to Diagnostic and statistical manual of mental disorders, 4th edition [DSM-IV]). The most important risk factors in pregnancy were depression in early pregnancy (OR=16.3), severe fear of childbirth (OR=6.2), and 'pre'-traumatic stress (in view of the forthcoming delivery) in late pregnancy (OR=12.5). The prevalence of depression was 5.6%. Post-traumatic stress and depression were positively related 1 month postpartum and were predicted by mainly the same factors. Risk factors for post-traumatic stress and depression after childbirth can be assessed in early pregnancy. Post-traumatic stress and depression also seem to share the same underlying vulnerability factors.

Diagnosis of abiotic and biotic stress factors using the visible symptoms in foliage

International Nuclear Information System (INIS)

Vollenweider, P.; Guenthardt-Goerg, Madeleine S.

2005-01-01

Visible symptoms in the foliage of trees are recorded to monitor the effects of abiotic and biotic stress. Difficulties are reported in diagnosing the origin of stress. The present paper discusses several diagnostic criteria which are usable in different species for a better determination of the stress factor type. A new diagnosis scheme to differentiate between classes of abiotic and biotic stress factors is supplied. Abiotic stress generates gradients of symptoms. The symptom specificity is determined by the degree of interaction between the stress factor and plant defense system. Symptoms caused by abiotic stress and natural autumnal senescence can be morphologically different or undistinguishable according to the stress and plant species. With biotic stress, the class of parasitic is generally recognizable on the basis of the visible symptoms. Structurally and physiologically based explanations of the symptom morphology are still missing for many stress factors. - The morphology and distribution of visible stress symptoms in tree foliage provides diagnostic tools to identify plant defense responses and differentiate stress from natural senescence symptoms

Effects of overload on the threshold stress intensity factor for SCC

International Nuclear Information System (INIS)

Takahashi, Koji; Ando, Kotoji; Miyazaki, Yuji; Hashikura, Yasuaki

2009-01-01

The effects of overload on the threshold stress intensity factor for stress corrosion crack (K ISCC ) of stainless steel were studied. Tensile overload was applied to a wedge opening loaded (WOL) specimen of SUS316. Then, SCC tests were carried out to determine the resultant K ISCC . As a result, the apparent value of K ISCC increases as increasing a stress intensity factor by tensile overload (K OV ). The effects of tensile overload on K ISCC and the threshold stress intensity factor range for fatigue (ΔK th ) were compared. It was found that the effects of tensile overload on K ISCC were larger than that on ΔK th . (author)

Role of the mRNA export factor Sus1 in oxidative stress tolerance in Candida albicans.

Science.gov (United States)

Xiao, Chenpeng; Yu, Qilin; Zhang, Bing; Li, Jianrong; Zhang, Dan; Li, Mingchun

2018-02-05

In eukaryotes, the nuclear export of mRNAs is essential for gene expression. However, little is known about the role of mRNA nuclear export in the important fungal pathogen, Candida albicans. In this study, we identified C. albicans Sus1, a nucleus-localized protein that is required for mRNA export. Interestingly, the sus1Δ/Δ displayed hyper-sensitivity to extracellular oxidative stress, enhanced ROS accumulation and severe oxidative stress-related cell death. More strikingly, although the mutant exhibited normal activation of the expression of oxidative stress response (OSR) genes, it had attenuated activity of ROS scavenging system, which may be attributed to the defect in OSR mRNA export in this mutant. In addition, the virulence of the sus1Δ/Δ was seriously attenuated. Taken together, our findings provide evidence that the mRNA export factor Sus1 plays an important role in oxidative stress tolerance and pathogenesis. Copyright © 2018 Elsevier Inc. All rights reserved.

Ectopic Expression of Pumpkin NAC Transcription Factor CmNAC1 Improves Multiple Abiotic Stress Tolerance in Arabidopsis

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Haishun Cao

2017-11-01

Full Text Available Drought, cold and salinity are the major environmental stresses that limit agricultural productivity. NAC transcription factors regulate the stress response in plants. Pumpkin (Cucurbita moschata is an important cucurbit vegetable crop and it has strong resistance to abiotic stress; however, the biological functions of stress-related NAC genes in this crop are largely unknown. This study reports the function of CmNAC1, a stress-responsive pumpkin NAC domain protein. The CmNAC1-GFP fusion protein was transiently expressed in tobacco leaves for subcellular localization analysis, and we found that CmNAC1 is localized in the nucleus. Transactivation assay in yeast cells revealed that CmNAC1 functions as a transcription activator, and its transactivation domain is located in the C-terminus. CmNAC1 was ubiquitously expressed in different organs, and its transcript was induced by salinity, cold, dehydration, H2O2, and abscisic acid (ABA treatment. Furthermore, the ectopic expression (EE of CmNAC1 in Arabidopsis led to ABA hypersensitivity and enhanced tolerance to salinity, drought and cold stress. In addition, five ABA-responsive elements were enriched in CmNAC1 promoter. The CmNAC1-EE plants exhibited different root architecture, leaf morphology, and significantly high concentration of ABA compared with WT Arabidopsis under normal conditions. Our results indicated that CmNAC1 is a critical factor in ABA signaling pathways and it can be utilized in transgenic breeding to improve the abiotic stress tolerance of crops.

Glycinebetaine synthesizing transgenic potato plants exhibit enhanced tolerance to salt and cold stresses

International Nuclear Information System (INIS)

Ahmad, R.; Hussain, J.

2014-01-01

Abiotic stresses are the most important contributors towards low productivity of major food crops. Various attempts have been made to enhance abiotic stress tolerance of crop plants by classical breeding and genetic transformation. Genetic transformation with glycinebetaine (GB) synthesizing enzymes' gene(s) in naturally non accumulating plants has resulted in enhanced tolerance against variety of abiotic stresses. Present study was aimed to evaluate the performance of GB synthesizing transgenic potato plants against salt and cold stresses. Transgenic potato plants were challenged against salt and cold stresses at whole plant level. Transgenic lines were characterized to determine the transgene copy number. Different parameters like integrity, chlorophyll contents, tuber yield and vegetative biomass were studied to monitor the stress tolerance of transgenic potato plants. The results were compared with Non-transgenic (NT) plants and statistically analyzed to evaluate significant differences. Multi-copy insertion of expression cassette was found in both transgenic lines. Upon salt stress, transgenic plants maintained better growth as compared to NT plants. The tuber yield of transgenic plants was significantly greater than NT plants in salt stress. Transgenic plants showed improved membrane integrity against cold stress by depicting appreciably reduced ion leakage as compared to NT plants. Moreover, transgenic plants showed significantly less chlorophyll bleaching than NT plants upon cold stress. In addition, NT plants accumulated significantly less biomass, and yielded fewer tubers as compared to transgenic plants after cold stress treatment. The study will be a committed step for field evaluation of transgenic plants with the aim of commercialization. (author)

Expression of a finger millet transcription factor, EcNAC1, in tobacco confers abiotic stress-tolerance.

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Venkategowda Ramegowda

Full Text Available NAC (NAM, ATAF1-2, and CUC2 proteins constitute one of the largest families of plant-specific transcription factors and have been shown to be involved in diverse plant processes including plant growth, development, and stress-tolerance. In this study, a stress-responsive NAC gene, EcNAC1, was isolated from the subtracted stress cDNA library generated from a drought adapted crop, finger millet, and characterized for its role in stress-tolerance. The expression analysis showed that EcNAC1 was highly induced during water-deficit and salt stress. EcNAC1 shares high amino acid similarity with rice genes that have been phylogenetically classified into stress-related NAC genes. Our results demonstrated that tobacco transgenic plants expressing EcNAC1 exhibit tolerance to various abiotic stresses like simulated osmotic stress, by polyethylene glycol (PEG and mannitol, and salinity stress. The transgenic plants also showed enhanced tolerance to methyl-viologen (MV induced oxidative stress. Reduced levels of reactive oxygen species (ROS and ROS-induced damage were noticed in pot grown transgenic lines under water-deficit and natural high light conditions. Root growth under stress and recovery growth after stress alleviation was more in transgenic plants. Many stress-responsive genes were found to be up-regulated in transgenic lines expressing EcNAC1. Our results suggest that EcNAC1 overexpression confers tolerance against abiotic stress in susceptible species, tobacco.

Early Stress History Alters Serum Insulin-Like Growth Factor-1 and Impairs Muscle Mitochondrial Function in Adult Male Rats.

Science.gov (United States)

Ghosh, S; Banerjee, K K; Vaidya, V A; Kolthur-Seetharam, U

2016-09-01

Early-life adversity is associated with an enhanced risk for adult psychopathology. Psychiatric disorders such as depression exhibit comorbidity for metabolic dysfunction, including obesity and diabetes. However, it is poorly understood whether, besides altering anxiety and depression-like behaviour, early stress also evokes dysregulation of metabolic pathways and enhances vulnerability for metabolic disorders. We used the rodent model of the early stress of maternal separation (ES) to examine the effects of early stress on serum metabolites, insulin-like growth factor (IGF)-1 signalling, and muscle mitochondrial content. Adult ES animals exhibited dyslipidaemia, decreased serum IGF1 levels, increased expression of liver IGF binding proteins, and a decline in the expression of specific metabolic genes in the liver and muscle, including Pck1, Lpl, Pdk4 and Hmox1. These changes occurred in the absence of alterations in body weight, food intake, glucose tolerance, insulin tolerance or insulin levels. ES animals also exhibited a decline in markers of muscle mitochondrial content, such as mitochondrial DNA levels and expression of TFAM (transcription factor A, mitochondrial). Furthermore, the expression of several genes involved in mitochondrial function, such as Ppargc1a, Nrf1, Tfam, Cat, Sesn3 and Ucp3, was reduced in skeletal muscle. Adult-onset chronic unpredictable stress resulted in overlapping and distinct consequences from ES, including increased circulating triglyceride levels, and a decline in the expression of specific metabolic genes in the liver and muscle, with no change in the expression of genes involved in muscle mitochondrial function. Taken together, our results indicate that a history of early adversity can evoke persistent changes in circulating IGF-1 and muscle mitochondrial function and content, which could serve to enhance predisposition for metabolic dysfunction in adulthood. © 2016 British Society for Neuroendocrinology.

Heterologous expression of a plastid EF-Tu reduces protein thermal aggregation and enhances CO2 fixation in wheat (Triticum aestivum) following heat stress.

Science.gov (United States)

Fu, Jianming; Momcilović, Ivana; Clemente, Thomas E; Nersesian, Natalya; Trick, Harold N; Ristic, Zoran

2008-10-01

Heat stress is a major constraint to wheat production and negatively impacts grain quality, causing tremendous economic losses, and may become a more troublesome factor due to global warming. At the cellular level, heat stress causes denaturation and aggregation of proteins and injury to membranes leading to alterations in metabolic fluxes. Protein aggregation is irreversible, and protection of proteins from thermal aggregation is a strategy a cell uses to tolerate heat stress. Here we report on the development of transgenic wheat (Triticum aestivum) events, expressing a maize gene coding for plastidal protein synthesis elongation factor (EF-Tu), which, compared to non-transgenic plants, display reduced thermal aggregation of leaf proteins, reduced heat injury to photosynthetic membranes (thylakoids), and enhanced rate of CO(2) fixation after exposure to heat stress. The results support the concept that EF-Tu ameliorates negative effects of heat stress by acting as a molecular chaperone. This is the first demonstration of the introduction of a plastidal EF-Tu in plants that leads to protection against heat injury and enhanced photosynthesis after heat stress. This is also the first demonstration that a gene other than HSP gene can be used for improvement of heat tolerance and that the improvement is possible in a species that has a complex genome, hexaploid wheat. The results strongly suggest that heat tolerance of wheat, and possibly other crop plants, can be improved by modulating expression of plastidal EF-Tu and/or by selection of genotypes with increased endogenous levels of this protein.

Stress-intensity factor equations for cracks in three-dimensional finite bodies

Science.gov (United States)

Newman, J. C., Jr.; Raju, I. S.

1981-01-01

Empirical stress intensity factor equations are presented for embedded elliptical cracks, semi-elliptical surface cracks, quarter-elliptical corner cracks, semi-elliptical surface cracks at a hole, and quarter-elliptical corner cracks at a hole in finite plates. The plates were subjected to remote tensile loading. Equations give stress intensity factors as a function of parametric angle, crack depth, crack length, plate thickness, and where applicable, hole radius. The stress intensity factors used to develop the equations were obtained from three dimensional finite element analyses of these crack configurations.

Calculation of mixed mode stress intensity factors using an alternating method

International Nuclear Information System (INIS)

Sakai, Takayuki

1999-01-01

In this study, mixed mode stress intensity factors (K I and K II ) of a square plate with a notch were calculated using a finite element alternating method. The obtained results were compared with the ones by a finite element method, and it was shown that the finite element alternating method can accurately estimate mixed mode stress intensity factors. Then, using this finite element alternating method, mixed mode stress intensity factors were calculated as changing the size and position of the notch, and its simplified equations were proposed. (author)

Intrinsic factors associated with medial tibial stress syndrome in ...

African Journals Online (AJOL)

Intrinsic factors associated with medial tibial stress syndrome in athletes: A large case-control study. ... Medial tibial stress syndrome (MTSS) is the most common lower-leg injury in athletes, and is thought to be caused by ... from 32 Countries:.

Enhancing resilience of farmer seed system to climate-induced stresses

NARCIS (Netherlands)

Kansiime, Monica K.; Mastenbroek, Astrid

2016-01-01

Given the challenges facing African agriculture resulting from climate-induced stresses, building resilience is a priority. Seed systems are important for enhancing such resilience as seed security has direct links to food security, and resilient livelihoods in general. Using data from a case

Performance Enhancement with Low Stress and Anxiety Modulated by Cognitive Flexibility

Science.gov (United States)

Park, Hyung Woo; Kee, Baik Seok; Na, Churl; Na, Do-Hyun E.; Zaichkowsky, Leonard

2011-01-01

Objective The purpose of this study was to compare cognitive flexibility abilities, stress, and anxiety between starters and non-starter athletes. Methods A total of 30 male professional-soccer and 40 professional-baseball athletes were recruited. Wisconsin Card Sorting Test (WCST) and Trail Making Test A & B (TMT A & B) were administered to assess cognitive flexibility during competition. The Korean version of the STAI form Y (STAI-KY) and Visual analogue scale for anxiety and stress were used to assess the anxiety and stress. Results The starter group had better cognitive function (fewer perseverative errors and rapid TMTB times) (Z=3.32, panxiety (F=4.34, p=0.01; F=6.61, pcognitive performances were negatively correlated with stress and anxiety. Current results suggested that cognitive flexibility would enhance human performance by modulation of the anxiety and stress during competition. PMID:21994509

Psychological stress-relieving effects of chewing - Relationship between masticatory function-related factors and stress-relieving effects.

Science.gov (United States)

Tasaka, Akinori; Kikuchi, Manaki; Nakanishi, Kousuke; Ueda, Takayuki; Yamashita, Shuichiro; Sakurai, Kaoru

2018-01-01

The objective of the present study was to investigate the relationship between masticatory function-related factors (masticatory performance, occlusal contact area, maximum bite force, number of chewing strokes, and muscle activity) and the stress-relieving effects of chewing. A total of 28 healthy male subjects were instructed to rest or chew for 10min after 30min of stress loading with arithmetic calculations. Their stress state was assessed by measuring salivary cortisol levels. Saliva was collected at three time points: before stress loading, immediately after stress loading, and 10min after stress loading. Compared to resting, chewing produced a significantly greater reduction in the rate of change in salivary cortisol levels 10min after stress loading. A negative correlation was observed between the rate of decrease in salivary cortisol levels and the number of chewing strokes. No significant correlation was observed between the rate of decrease in salivary cortisol levels and other measurement items. In healthy dentulous people, the number of chewing strokes has been shown to be a masticatory function-related factor that affects stress relief from chewing, suggesting the possibility that more appropriate chewing would produce a greater effect psychological stress relief. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Hypoxic stress up-regulates the expression of Toll-like receptor 4 in macrophages via hypoxia-inducible factor.

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Kim, So Young; Choi, Yong Jun; Joung, Sun Myung; Lee, Byung Ho; Jung, Yi-Sook; Lee, Joo Young

2010-04-01

Toll-like receptors (TLRs) are germline-encoded innate immune receptors that recognize invading micro-organisms and induce immune and inflammatory responses. Deregulation of TLRs is known to be closely linked to various immune disorders and inflammatory diseases. Cells at sites of inflammation are exposed to hypoxic stress, which further aggravates inflammatory processes. We have examined if hypoxic stress modulates the TLR activity of macrophages. Hypoxia and CoCl(2) (a hypoxia mimetic) enhanced the expression of TLR4 messenger RNA and protein in macrophages (RAW264.7 cells), whereas the messenger RNA of other TLRs was not increased. To determine the underlying mechanism, we investigated the role of hypoxia-inducible factor 1 (HIF-1) in the regulation of TLR4 expression. Knockdown of HIF-1alpha expression by small interfering RNA inhibited hypoxia-induced and CoCl(2)-induced TLR4 expression in macrophages, while over-expression of HIF-1alpha potentiated TLR4 expression. Chromatin immunoprecipitation assays revealed that HIF-1alpha binds to the TLR4 promoter region under hypoxic conditions. In addition, deletion or mutation of a putative HIF-1-binding motif in the TLR4 promoter greatly attenuated HIF-1alpha-induced TLR4 promoter reporter expression. Up-regulation of TLR4 expression by hypoxic stress enhanced the response of macrophages to lipopolysaccharide, resulting in increased expression of cyclooxygenase-2, interleukin-6, regulated on activation normal T cell expressed and secreted, and interferon-inducible protein-10. These results demonstrate that TLR4 expression in macrophages is up-regulated via HIF-1 in response to hypoxic stress, suggesting that hypoxic stress at sites of inflammation enhances susceptibility to subsequent infection and inflammatory signals by up-regulating TLR4.

gender and school types as factors responsible for job stress

African Journals Online (AJOL)

Emeka Egbochuku

public Universities should be looked into so that all factors responsible for stress might be .... universities in Malaysia, university academic staffs faced more problems .... adjustment with different coping styles. .... in college students: The role of rumination and stress. ... International Journal of Stress Management, 8, 285–29.

The Wheat NAC Transcription Factor TaNAC2L Is Regulated at the Transcriptional and Post-Translational Levels and Promotes Heat Stress Tolerance in Transgenic Arabidopsis.

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Guo, Weiwei; Zhang, Jinxia; Zhang, Ning; Xin, Mingming; Peng, Huiru; Hu, Zhaorong; Ni, Zhongfu; Du, Jinkun

2015-01-01

Heat stress poses a serious threat to global crop production. In efforts that aim to mitigate the adverse effects of heat stress on crops, a variety of genetic tools are being used to develop plants with improved thermotolerance. The characterization of important regulators of heat stress tolerance provides essential information for this aim. In this study, we examine the wheat (Triticum aestivum) NAC transcription factor gene TaNAC2L. High temperature induced TaNAC2L expression in wheat and overexpression of TaNAC2L in Arabidopsis thaliana enhanced acquired heat tolerance without causing obvious alterations in phenotype compared with wild type under normal conditions. TaNAC2L overexpression also activated the expression of heat-related genes in the transgenic Arabidopsis plants, suggesting that TaNAC2L may improve heat tolerance by regulating the expression of stress-responsive genes. Notably, TaNAC2L is also regulated at the post-translational level and might be degraded via a proteasome-mediated pathway. Thus, this wheat transcription factor may have potential uses in enhancing thermotolerance in crops.

The Wheat NAC Transcription Factor TaNAC2L Is Regulated at the Transcriptional and Post-Translational Levels and Promotes Heat Stress Tolerance in Transgenic Arabidopsis.

Directory of Open Access Journals (Sweden)

Weiwei Guo

Full Text Available Heat stress poses a serious threat to global crop production. In efforts that aim to mitigate the adverse effects of heat stress on crops, a variety of genetic tools are being used to develop plants with improved thermotolerance. The characterization of important regulators of heat stress tolerance provides essential information for this aim. In this study, we examine the wheat (Triticum aestivum NAC transcription factor gene TaNAC2L. High temperature induced TaNAC2L expression in wheat and overexpression of TaNAC2L in Arabidopsis thaliana enhanced acquired heat tolerance without causing obvious alterations in phenotype compared with wild type under normal conditions. TaNAC2L overexpression also activated the expression of heat-related genes in the transgenic Arabidopsis plants, suggesting that TaNAC2L may improve heat tolerance by regulating the expression of stress-responsive genes. Notably, TaNAC2L is also regulated at the post-translational level and might be degraded via a proteasome-mediated pathway. Thus, this wheat transcription factor may have potential uses in enhancing thermotolerance in crops.

A bHLH gene from Tamarix hispida improves abiotic stress tolerance by enhancing osmotic potential and decreasing reactive oxygen species accumulation.

Science.gov (United States)

Ji, Xiaoyu; Nie, Xianguang; Liu, Yujia; Zheng, Lei; Zhao, Huimin; Zhang, Bing; Huo, Lin; Wang, Yucheng

2016-02-01

Basic helix-loop-helix (bHLH) leucine-zipper transcription factors play important roles in abiotic stress responses. However, their specific roles in abiotic stress tolerance are not fully known. Here, we functionally characterized a bHLH gene, ThbHLH1, from Tamarix hispida in abiotic stress tolerance. ThbHLH1 specifically binds to G-box motif with the sequence of 'CACGTG'. Transiently transfected T. hispida plantlets with transiently overexpressed ThbHLH1 and RNAi-silenced ThbHLH1 were generated for gain- and loss-of-function analysis. Transgenic Arabidopsis thaliana lines overexpressing ThbHLH1 were generated to confirm the gain- and loss-of-function analysis. Overexpression of ThbHLH1 significantly elevates glycine betaine and proline levels, increases Ca(2+) concentration and enhances peroxidase (POD) and superoxide dismutase (SOD) activities to decrease reactive oxygen species (ROS) accumulation. Additionally, ThbHLH1 regulates the expression of the genes including P5CS, BADH, CaM, POD and SOD, to activate the above physiological changes, and also induces the expression of stress tolerance-related genes LEAs and HSPs. These data suggest that ThbHLH1 induces the expression of stress tolerance-related genes to improve abiotic stress tolerance by increasing osmotic potential, improving ROS scavenging capability and enhancing second messenger in stress signaling cascades. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Stress, coping and burnout among Intensive Care Unit nursing staff: associated factors.

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Andolhe, Rafaela; Barbosa, Ricardo Luis; Oliveira, Elaine Machado de; Costa, Ana Lúcia Siqueira; Padilha, Katia Grillo

2015-02-01

Objective To investigate emotional stress, coping and burnout among nursing staff and their association with biosocial factors and characteristics of work in Intensive Care Units (ICU). Method This was a cross-sectional study, conducted in eight ICUs at a teaching hospital in the city of São Paulo, Brazil, in October 2012. Biosocial data and information about the professionals' work was gathered, and they were given the Scale of Occupational Stress, Scale of Occupational Coping, List of Signs and Symptoms of Stress and the Maslach Burnout Inventory. Results The study sample consisted of 287 subjects, predominately women, with partners and children. Most professionals presented moderate stress levels and control as a coping strategy (74.47% and 79.93%, respectively), and burnout was present among 12.54%. Factors associated with stress were related to working conditions. The most prevalent protective factors were having a partner, working in the clinical ICU and liking work, while adequate amount of sleep was a protective factor for burnout. Conclusion Control of the working environment and adequate sleep are decisive and protective factors in dealing with situations of occupational stress.

Overexpression of AtEDT1/HDG11 in Chinese Kale (Brassica oleracea var. alboglabra) Enhances Drought and Osmotic Stress Tolerance.

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Zhu, Zhangsheng; Sun, Binmei; Xu, Xiaoxia; Chen, Hao; Zou, Lifang; Chen, Guoju; Cao, Bihao; Chen, Changming; Lei, Jianjun

2016-01-01

Plants are constantly challenged by environmental stresses, including drought and high salinity. Improvement of drought and osmotic stress tolerance without yield decrease has been a great challenge in crop improvement. The Arabidopsis ENHANCED DROUGHT TOLERANCE1/HOMEODOMAIN GLABROUS11 (AtEDT1/HDG11), a protein of the class IV HD-Zip family, has been demonstrated to significantly improve drought tolerance in Arabidopsis, rice, and pepper. Here, we report that AtEDT1/HDG11 confers drought and osmotic stress tolerance in the Chinese kale. AtEDT1/HDG11-overexpression lines exhibit auxin-overproduction phenotypes, such as long hypocotyls, tall stems, more root hairs, and a larger root system architecture. Compared with the untransformed control, transgenic lines have significantly reduced stomatal density. In the leaves of transgenic Chinese kale plants, proline (Pro) content and reactive oxygen species-scavenging enzyme activity was significantly increased after drought and osmotic stress, particularly compared to wild kale. More importantly, AtEDT1/HDG11-overexpression leads to abscisic acid (ABA) hypersensitivity, resulting in ABA inhibitor germination and induced stomatal closure. Consistent with observed phenotypes, the expression levels of auxin, ABA, and stress-related genes were also altered under both normal and/or stress conditions. Further analysis showed that AtEDT1/HDG11, as a transcription factor, can target the auxin biosynthesis gene YUCC6 and ABA response genes ABI3 and ABI5. Collectively, our results provide a new insight into the role of AtEDT1/HDG11 in enhancing abiotic stress resistance through auxin- and ABA-mediated signaling response in Chinese kale.

Workplace Stress, Organizational Factors and EAP Utilization.

Science.gov (United States)

Azzone, Vanessa; McCann, Bernard; Merrick, Elizabeth Levy; Hiatt, Deirdre; Hodgkin, Dominic; Horgan, Constance

2009-01-01

This study examined relationships between workplace stress, organizational factors and use of EAP counseling services delivered by network providers in a large, privately-insured population. Claims data were linked to measures of workplace stress, focus on wellness/prevention, EAP promotion, and EAP activities for health care plan enrollees from 26 employers. The association of external environment and work organization variables with use of EAP counseling services was examined. Higher levels of EAP promotion and worksite activities were associated with greater likelihood of service use. Greater focus on wellness/prevention and unusual and significant stress were associated with lower likelihood of service use. Results provide stakeholders with insights on approaches to increasing utilization of EAP services.

NAC Transcription Factors in Stress Responses and Senescence

DEFF Research Database (Denmark)

O'Shea, Charlotte

Plant-specific NAM/ATAF/CUC (NAC) transcription factors have recently received considerable attention due to their significant roles in plant development and stress signalling. This interest has resulted in a number of physiological, genetic and cell biological studies of their functions. Some...... of these studies have also revealed emerging gene regulatory networks and protein-protein interaction networks. However, structural studies relating structure to function are lagging behind. Structure-function analysis of the NAC transcription factors has therefore been the main focus of this PhD thesis...... not involve significant folding-upon-binding but fuzziness or an extended ANAC046 region. The ANAC046 regulatory domain functions as an entropic chain with a bait for interactions with for example RCD1. RCD1 interacts with transcription factors from several different families, and the large stress...

Influences of Pinpoint Plantar Long-Wavelength Infrared Light Irradiation (Stress-Free Therapy on Chorioretinal Hemodynamics, Atherosclerosis Factors, and Vascular Endothelial Growth Factor

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Keisou Ishimaru

2018-03-01

Full Text Available Background: We previously reported that pinpoint plantar long-wavelength infrared light irradiation (stress-free therapy; SFT is useful for alleviating insulin resistance and improving intracranial blood flow in patients with type 2 diabetes mellitus. This study was undertaken to evaluate the influences of SFT on chorioretinal hemodynamics (retinal artery and vein blood flows as well as atherosclerosis-related factors (TG, LDL-C and VEGF in patients with dyslipidemia. Methods: Four patients with dyslipidemia received 15-minute irradiation with a stress-free apparatus (far-infrared wavelength, 30 mW. Using laser speckle flowgraphy, associations of chorioretinal blood flow with peripheral atherosclerosis-inducing factors/VEGF levels before and after irradiation were analyzed. Results: Chorioretinal blood flow increased, while TG/LDL-C levels decreased, after irradiation. VEGF tended to rise in cases with pre-irradiation baseline levels at the lower limit but tended to decrease in cases in which baseline levels had exceeded the normal range. Conclusion: SFT was suggested to enhance chorioretinal circulation and to normalize VEGF, thereby possibly contributing to amelioration of atherosclerosis-inducing factors. Abnormalities in chorioretinal hemodynamics are known to be highly involved in the pathophysiology of diabetic retinopathy and age-related macular degeneration, and anti-VEGF antibody has been used for treating these conditions. The necessity of risk management, involving chorioretinal blood flow, has been pointed out when dealing with central retinal vein occlusion, diabetes mellitus, ischemic cerebral/cardiac disease, dementia and so on. SFT is therefore a potential complementary medical strategy which can be expected to contribute to normalization of chorioretinal blood flow and atherosclerosis-inducing factors/VEGF levels, and thereby to the prevention of lifestyle-related chronic diseases. Keywords: Pinpoint plantar long

The short-term stress response - Mother nature's mechanism for enhancing protection and performance under conditions of threat, challenge, and opportunity.

Science.gov (United States)

Dhabhar, Firdaus S

2018-03-26

Our group has proposed that in contrast to chronic stress that can have harmful effects, the short-term (fight-or-flight) stress response (lasting for minutes to hours) is nature's fundamental survival mechanism that enhances protection and performance under conditions involving threat/challenge/opportunity. Short-term stress enhances innate/primary, adaptive/secondary, vaccine-induced, and anti-tumor immune responses, and post-surgical recovery. Mechanisms and mediators include stress hormones, dendritic cell, neutrophil, macrophage, and lymphocyte trafficking/function and local/systemic chemokine and cytokine production. Short-term stress may also enhance mental/cognitive and physical performance through effects on brain, musculo-skeletal, and cardiovascular function, reappraisal of threat/anxiety, and training-induced stress-optimization. Therefore, short-term stress psychology/physiology could be harnessed to enhance immuno-protection, as well as mental and physical performance. This review aims to provide a conceptual framework and targets for further investigation of mechanisms and conditions under which the protective/adaptive aspects of short-term stress/exercise can be optimized/harnessed, and for developing pharmacological/biobehavioral interventions to enhance health/healing, and mental/cognitive/physical performance. Copyright © 2018 Elsevier Inc. All rights reserved.

Overexpression of EcbHLH57 Transcription Factor from Eleusine coracana L. in Tobacco Confers Tolerance to Salt, Oxidative and Drought Stress.

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K C Babitha

Full Text Available Basic helix-loop-helix (bHLH transcription factors constitute one of the largest families in plants and are known to be involved in various developmental processes and stress tolerance. We report the characterization of a stress responsive bHLH transcription factor from stress adapted species finger millet which is homologous to OsbHLH57 and designated as EcbHLH57. The full length sequence of EcbHLH57 consisted of 256 amino acids with a conserved bHLH domain followed by leucine repeats. In finger millet, EcbHLH57 transcripts were induced by ABA, NaCl, PEG, methyl viologen (MV treatments and drought stress. Overexpression of EcbHLH57 in tobacco significantly increased the tolerance to salinity and drought stress with improved root growth. Transgenic plants showed higher photosynthetic rate and stomatal conductance under drought stress that resulted in higher biomass. Under long-term salinity stress, the transgenic plants accumulated higher seed weight/pod and pod number. The transgenic plants were also tolerant to oxidative stress and showed less accumulation of H202 and MDA levels. The overexpression of EcbHLH57 enhanced the expression of stress responsive genes such as LEA14, rd29A, rd29B, SOD, APX, ADH1, HSP70 and also PP2C and hence improved tolerance to diverse stresses.

An epidemiologic study of occupational stress factors in Mumbai police personnel.

Science.gov (United States)

Almale, Balaji D; Vankudre, Ashok J; Bansode-Gokhe, Seema S; Pawar, Vrushali K

2014-01-01

Occupational stress is common to each and every organization at various levels of hierarchy. The police organization is no exception to this. Rather policing is widely recognized as more stressful than any other occupation, nature of work, irregular duty hours, and many more factors, which can trigger stress. The present study was done to highlight some of these stressful factors in Mumbai police. Simple as well as systematic random sampling technique was adopted to get equal representation from each zone as well as region from Mumbai police. Occupational stress index (OSI) questionnaire was prepared, pilot tested, and validated for screening stress. We screened 276 policemen for occupational stress. Seventy-three percent of them were in the 30-50 years age group, and most of them (49%) studied up to H.S.C. Ninety-one percent were married and 56% had reported duty hours 12-16 h/day. Seventy-one percent were addicted to any of the substance. After screening we found 73% moderately stressed, whereas 18% highly stressed policemen. Sociodemographic factors which were age group (50-58 years), duration of service in years (>25 years), duration of duty hours (>16 h/day), addiction habits, and number of monthly holidays (no holiday). We found role ambiguity, under participation, role overload, strenuous working condition, and unprofitability as predominant scales in OSI. So prevention as well as management of stress in policemen is the necessity of the current situation. This stress can be managed at organizational level by adopting right techniques, whereas at individual level by habituating right behavior and attitude.

Stress-enhanced fear learning in rats is resistant to the effects of immediate massed extinction

Science.gov (United States)

Long, Virginia A.; Fanselow, Michael S.

2014-01-01

Enhanced fear learning occurs subsequent to traumatic or stressful events and is a persistent challenge to the treatment of post-traumatic stress disorder (PTSD). Facilitation of learning produced by prior stress can elicit an exaggerated fear response to a minimally aversive event or stimulus. Stress-enhanced fear learning (SEFL) is a rat model of PTSD; rats previously exposed to the SEFL 15 electrical shocks procedure exhibit several behavioral responses similar to those seen in patients with PTSD. However, past reports found that SEFL is not mitigated by extinction (a model of exposure therapy) when the spaced extinction began 24 h after stress. Recent studies found that extinction from 10 min to 1 h subsequent to fear conditioning “erased” learning, whereas later extinction, occurring from 24 to 72 h after conditioning did not. Other studies indicate that massed extinction is more effective than spaced procedures. Therefore, we examined the time-dependent nature of extinction on the stress-induced enhancement of fear learning using a massed trial’s procedure. Experimental rats received 15 foot shocks and were given either no extinction or massed extinction 10 min or 72 h later. Our present data indicate that SEFL, following traumatic stress, is resistant to immediate massed extinction. Experimental rats showed exaggerated new fear learning regardless of when extinction training occurred. Thus, post-traumatic reactivity such as SEFL does not seem responsive to extinction treatments. PMID:22176467

PREDICTION OF STRESS CONCENTRATION FACTORS IN

African Journals Online (AJOL)

ES OBE

consider the effect of brace spacing on strengths of tubular K joints without consideration of same effect on square section K Joints. This lack of studies design strengths of gapped square section K joints makes availability of information on stress concentration factors in same joints scarce. However, information on 'Hot Spot' ...

Factor associated with stress among parents of children with autism

International Nuclear Information System (INIS)

Shahida, S.; Khurshid, S.

2015-01-01

To determine the factors associated with stress among parents of children with autism. Study Design: A cross-sectional field survey study. Place and Duration of Study: Department of Psychology, GC University, Lahore, from September 2012 to November 2013. Methodology: The sample consisted of 100 parents (50 mothers and 50 fathers) of children with autism. Measures of childhood autism rating, sense of coherence, parenting self-efficacy, parenting stress, and demographic data sheet were completed by the parents in outdoor units of children hospital, institutes, and at their homes. Results: Significant correlations were found between severity of impairment and parenting stress (r = .53, p < .01), between parenting self-efficacy and parenting stress (r = -.35, p < .01, and between sense of coherence and parenting stress (r = -.26, p < .05). No significant gender difference emerged in terms of parenting self-efficacy, sense of coherence, and parenting stress. Results of stepwise regression partially supported our hypothesized model, as severity of child impairment, and parenting self-efficacy appeared as significant predictors of parenting stress (R2 = .35). However, there was no evidence of role of demographic variables in the parenting stress. Conclusion: The severity of child's impairment emerged as the most salient risk factor for parenting stress; however, it was concluded that parents ability and confidence in their competence of parenting a child in challenging situations may reduce their stress. (author)

Transient Stress Intensity Factors of Functionally Graded Hollow Cylinders with Internal Circumferential Cracks

Directory of Open Access Journals (Sweden)

Iman Eshraghi

Full Text Available Abstract In this paper, transient thermomechanical stress intensity factors for functionally graded cylinders with complete internal circumferential cracks are obtained using the weight function method. The finite difference method is used to calculate the time dependent temperature distribution and thermal stresses along the cylinder thickness. Furthermore, finite element analysis is performed to determine the weight function coefficients and to investigate the accuracy of the predicted stress intensity factors from the weight functions. Variation of the stress intensity factors with time and effects of the material gradation on the results are investigated, as well. It is shown that the proposed technique can be used to accurately predict transient thermomechanical stress intensity factors for functionally graded cylinders with arbitrary material gradation.

Use of frozen stress in extracting stress intensity factor distributions in three dimensional cracked body problems

Science.gov (United States)

Smith, C. W.

1992-01-01

The adaptation of the frozen stress photoelastic method to the determination of the distribution of stress intensity factors in three dimensional problems is briefly reviewed. The method is then applied to several engineering problems of practical significance.

Stress and asthma

Directory of Open Access Journals (Sweden)

Shoji Nagata

1999-01-01

Full Text Available Three factors in recent medical research and treatment (advances in the field of psychoneuroimmunology, epidemiological evidence regarding important interaction between psychosocial factors and development of disease, and the recognition of the importance of patient education for self-management of asthma have led clinicians and researchers to reconsider the role of psychosocial stress in asthma. There are many reports suggesting that stressful life events, family problems and a behavior pattern that increases psychological conflict may influence the development or relapse of asthma and influence its clinical course. Depression is known as one of the risk factors of fatal asthmatic attack. In laboratory studies, about 20% of asthmatics were considered reactors who showed an airway change after exposure to emotional stress. Studies regarding the pathway of stress effect on allergy and asthma are reviewed and discussed from the standpoint of psychoneuroimmunology; for example, the enhancement of IgE production and increased susceptibility to respiratory infection by stress, conditioned anaphylaxis and nerve/mast cell interaction, the effect of stress on various bronchial responses and the inhibition of the immediate and late asthmatic response by anterior hypothalamic lesioning.

Stress intensity factors for complete internal and external cracks in spherical shells

International Nuclear Information System (INIS)

Chao, Y.J.; Chen, H.

1989-01-01

Cracks or flows found in the nuclear structure must be fully evaluated to assure the safety of the plant. The weight function method has been widely used in the determination of stress intensity factors for cracks under stress gradient e.g. for thermal shock loading. The unique features of the weight function method is that once the weight function for a particular cracked geometry is determined the stress intensity factors at the crack tip for any loading applied to the flawed structure can be calculated by a simple integration. In this paper the stress intensity factors of the complete, part-through internal and external cracks in a spherical shell are determined. The finite element method was used to develop the weight functions for the flawed geometry. The approximate crack surface profile was used to derive the weight functions. The stress intensity factors associated with the cracks in spherical shells under internal pressure are determined by both the weight functions and the direct finite element method

Overexpression of wheat ferritin gene TaFER-5B enhances tolerance to heat stress and other abiotic stresses associated with the ROS scavenging.

Science.gov (United States)

Zang, Xinshan; Geng, Xiaoli; Wang, Fei; Liu, Zhenshan; Zhang, Liyuan; Zhao, Yue; Tian, Xuejun; Ni, Zhongfu; Yao, Yingyin; Xin, Mingming; Hu, Zhaorong; Sun, Qixin; Peng, Huiru

2017-01-14

The yield of wheat (Triticum aestivum L.), an important crop, is adversely affected by heat stress in many regions of the world. However, the molecular mechanisms underlying thermotolerance are largely unknown. A novel ferritin gene, TaFER, was identified from our previous heat stress-responsive transcriptome analysis of a heat-tolerant wheat cultivar (TAM107). TaFER was mapped to chromosome 5B and named TaFER-5B. Expression pattern analysis revealed that TaFER-5B was induced by heat, polyethylene glycol (PEG), H 2 O 2 and Fe-ethylenediaminedi(o-hydroxyphenylacetic) acid (Fe-EDDHA). To confirm the function of TaFER-5B in wheat, TaFER-5B was transformed into the wheat cultivar Jimai5265 (JM5265), and the transgenic plants exhibited enhanced thermotolerance. To examine whether the function of ferritin from mono- and dico-species is conserved, TaFER-5B was transformed into Arabidopsis, and overexpression of TaFER-5B functionally complemented the heat stress-sensitive phenotype of a ferritin-lacking mutant of Arabidopsis. Moreover, TaFER-5B is essential for protecting cells against heat stress associated with protecting cells against ROS. In addition, TaFER-5B overexpression also enhanced drought, oxidative and excess iron stress tolerance associated with the ROS scavenging. Finally, TaFER-5B transgenic Arabidopsis and wheat plants exhibited improved leaf iron content. Our results suggest that TaFER-5B plays an important role in enhancing tolerance to heat stress and other abiotic stresses associated with the ROS scavenging.

The Influence of Cardiac Risk Factor Burden on Cardiac Stress Test Outcomes.

Science.gov (United States)

Schrock, Jon W; Li, Morgan; Orazulike, Chidubem; Emerman, Charles L

2011-06-01

Chest pain is the most common admission diagnosis for observation unit patients. These patients often undergo cardiac stress testing to further risk stratify for coronary artery disease (CAD). The decision of whom to stress is currently based on clinical judgment. We sought to determine the influence of cardiac risk factor burden on cardiac stress test outcome for patients tested from an observation unit, inpatient or outpatient setting. We performed a retrospective observational cohort study for all patients undergoing stress testing in our institution from June 2006 through July 2007. Cardiac risk factors were collected at the time of stress testing. Risk factors were evaluated in a summative fashion using multivariate regression adjusting for age and known coronary artery disease. The model was tested for goodness of fit and collinearity and the c statistic was calculated using the receiver operating curve. A total of 4026 subjects were included for analysis of which 22% had known CAD. The rates of positive outcome were 89 (12.0%), 95 (12.6%), and 343 (16.9%) for the OU, outpatients, and hospitalized patients respectively. While the odds of a positive test outcome increased for additional cardiac risk factors, ROC curve analysis indicates that simply adding the number of risk factors does not add significant diagnostic value. Hospitalized patients were more likely to have a positive stress test, OR 1.41 (1.10 - 1.81). Our study does not support basing the decision to perform a stress test on the number of cardiac risk factors.

Stress intensity factor analyses of surface cracks in three-dimensional structures

International Nuclear Information System (INIS)

Miyazaki, Noriyuki; Shibata, Katsuyuki; Watanabe, Takayuki; Tagata, Kazunori.

1983-11-01

The stress intensity factor analyses of surface cracks in various three-dimensional structures were performed using the finite element computer program EPAS-J1. The results obtained by EPAS-J1 were compared with other finite element solutions or results obtained by the simplified estimation methods. Among the simplified estimation methods, the equations proposed by Newman and Raju give the distributions of the stress intensity factor along a crack front, which were compared with the result obtained by EPAS-J1. It was confirmed by comparing the results that EPAS-J1 gives reasonable stress intensity factors of surface cracks in three-dimensional structures. (author)

Stressful situations and factors in students of nursing in clinical practice

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Eliana Ofélia Llapa Rodrigues

Full Text Available Objective.To assess the risk factors for stress in undergraduate students of nursing in clinical practice in a public university in the Northeast region of Brazil. Methods. Cross-sectional descriptive study with 116 students from the fifth to the ninth period. The bilingual KEZKAK questionnaire, validated for Portuguese, was used. Stress was considered to be present when the score was equal or superior to 2. Results. The students with stress in clinical practice were 18 to 22 years old (2.82 ± 0.98, women (2.81 ± 0.96, married (2.80 ± 0.97, and who were permanent contracted employees (2.74 ± 0.94. The factors which were most associated with stress were: Lack of competence (2.99 ± 0.88; Impotence and uncertainty (2.98 ± 0.85; and Patients seeking a closer relationship (2.93 ± 1.01. The students of the sixth period were the most vulnerable to stress (2.85±0.96. Conclusion. The studies showed the main risk factors for stress among students of nursing in their clinical practice. These results could be used in the development of strategies seeking to reduce stress in this context as well as to contribute to promoting mental health.

Characterization of a eukaryotic translation initiation factor 5A homolog from Tamarix androssowii involved in plant abiotic stress tolerance

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Wang Liuqiang

2012-07-01

Full Text Available Abstract Background The eukaryotic translation initiation factor 5A (eIF5A promotes formation of the first peptide bond at the onset of protein synthesis. However, the function of eIF5A in plants is not well understood. Results In this study, we characterized the function of eIF5A (TaeIF5A1 from Tamarix androssowii. The promoter of TaeIF5A1 with 1,486 bp in length was isolated, and the cis-elements in the promoter were identified. A WRKY (TaWRKY and RAV (TaRAV protein can specifically bind to a W-box motif in the promoter of TaeIF5A1 and activate the expression of TaeIF5A1. Furthermore, TaeIF5A1, TaWRKY and TaRAV share very similar expression pattern and are all stress-responsive gene that functions in the abscisic acid (ABA signaling pathway, indicating that they are components of a single regulatory pathway. Transgenic yeast and poplar expressing TaeIF5A1 showed elevated protein levels combined with improved abiotic stresses tolerance. Furthermore, TaeIF5A1-transformed plants exhibited enhanced superoxide dismutase (SOD and peroxidase (POD activities, lower electrolyte leakage and higher chlorophyll content under salt stress. Conclusions These results suggested that TaeIF5A1 is involved in abiotic stress tolerance, and is likely regulated by transcription factors TaWRKY and TaRAV both of which can bind to the W-box motif. In addition, TaeIF5A1 may mediate stress tolerance by increasing protein synthesis, enhancing ROS scavenging by improving SOD and POD activities, and preventing chlorophyll loss and membrane damage. Therefore, eIF5A may play an important role in plant adaptation to changing environmental conditions.

Characterization of a eukaryotic translation initiation factor 5A homolog from Tamarix androssowii involved in plant abiotic stress tolerance.

Science.gov (United States)

Wang, Liuqiang; Xu, Chenxi; Wang, Chao; Wang, Yucheng

2012-07-26

The eukaryotic translation initiation factor 5A (eIF5A) promotes formation of the first peptide bond at the onset of protein synthesis. However, the function of eIF5A in plants is not well understood. In this study, we characterized the function of eIF5A (TaeIF5A1) from Tamarix androssowii. The promoter of TaeIF5A1 with 1,486 bp in length was isolated, and the cis-elements in the promoter were identified. A WRKY (TaWRKY) and RAV (TaRAV) protein can specifically bind to a W-box motif in the promoter of TaeIF5A1 and activate the expression of TaeIF5A1. Furthermore, TaeIF5A1, TaWRKY and TaRAV share very similar expression pattern and are all stress-responsive gene that functions in the abscisic acid (ABA) signaling pathway, indicating that they are components of a single regulatory pathway. Transgenic yeast and poplar expressing TaeIF5A1 showed elevated protein levels combined with improved abiotic stresses tolerance. Furthermore, TaeIF5A1-transformed plants exhibited enhanced superoxide dismutase (SOD) and peroxidase (POD) activities, lower electrolyte leakage and higher chlorophyll content under salt stress. These results suggested that TaeIF5A1 is involved in abiotic stress tolerance, and is likely regulated by transcription factors TaWRKY and TaRAV both of which can bind to the W-box motif. In addition, TaeIF5A1 may mediate stress tolerance by increasing protein synthesis, enhancing ROS scavenging by improving SOD and POD activities, and preventing chlorophyll loss and membrane damage. Therefore, eIF5A may play an important role in plant adaptation to changing environmental conditions.

Intrinsic functional connectivity between amygdala and hippocampus during rest predicts enhanced memory under stress.

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de Voogd, Lycia D; Klumpers, Floris; Fernández, Guillén; Hermans, Erno J

2017-01-01

Declarative memories of stressful events are less prone to forgetting than mundane events. Animal research has demonstrated that such stress effects on consolidation of hippocampal-dependent memories require the amygdala. In humans, it has been shown that during learning, increased amygdala-hippocampal interactions are related to more efficient memory encoding. Animal models predict that following learning, amygdala-hippocampal interactions are instrumental to strengthening the consolidation of such declarative memories. Whether this is the case in humans is unknown and remains to be empirically verified. To test this, we analyzed data from a sample of 120 healthy male participants who performed an incidental encoding task and subsequently underwent resting-state functional MRI in a stressful and a neutral context. Stress was assessed by measures of salivary cortisol, blood pressure, heart rate, and subjective ratings. Memory was tested afterwards outside of the scanner. Our data show that memory was stronger in the stress context compared to the neutral context and that stress-induced cortisol responses were associated with this memory enhancement. Interestingly, amygdala-hippocampal connectivity during post-encoding awake rest regardless of context (stress or neutral) was associated with the enhanced memory performance under stress. Thus, our findings are in line with a role for intrinsic functional connectivity during rest between the amygdala and the hippocampus in the state effects of stress on strengthening memory. Copyright © 2016 Elsevier Ltd. All rights reserved.

Stress Factors Associated With Burnout Among Attending Physicians: A Cross-Sectional Study.

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Kawamura, Yurika; Takayashiki, Ayumi; Ito, Makoto; Maeno, Takami; Seo, Emiko; Maeno, Tetsuhiro

2018-03-01

Burnout in attending physicians is a crucial issue that may negatively impact patient outcomes, as well as affect the quality of training provided to residents. To investigate the association between burnout and stress-coping ability, we conducted a cross-sectional study of attending physicians. From April 2013 to March 2014, we distributed an anonymous, self-administered questionnaire to 1,897 attending physicians who attended teaching-related training sessions and workshops. The questionnaire included the Maslach Burnout Inventory General Survey (MBI-GS, Japanese version) to evaluate burnout; the sense of coherence scale (SOC, Japanese version) to measure stress-coping ability, with higher scores indicating higher stress-coping ability; the Brief Scales for Job Stress (BSJS) to assess stress and buffering factors; demographic factors; mean weekly working hours; and factors related to instructing residents. The MBI-GS was used to determine the presence of physician burnout. Subjects were divided into tertiles based on SOC scores. We conducted logistic regression analysis of burnout using the following independent variables: physician experience, sex, mean weekly working hours, SOC group, mental workload, and reward from work. Of the 1,543 (81.3%) attending physicians who responded, 376 did not meet the inclusion criteria and 106 had missing data, thus 1,061 (55.9%) were analyzed. The prevalence of burnout was 17.2%. Physicians with burnout had significantly fewer years of experience as a doctor (P burnout. On the BSJS, the mean score of all stress factors was higher and that of buffering factors was lower in physicians with burnout (P burnout were 35.7%, 12.8%, and 3.2% in the low, middle, and high SOC groups, respectively (P burnout in the low SOC group was 4.7 (95% confidence interval: 2.31 - 9.63) (P burnout among attending physicians was significantly associated with SOC scores after adjustment for stress factors and buffering factors.

Posttraumatic stress disorder in bosnian war veterans: Analysis of stress events and risk factors

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Kuljić Blagoje

2004-01-01

Full Text Available The aim of this study was to determine the incidence of Post-Traumatic Stress Disorder (PTSD, the characteristics of stress-related events, and the risk factors for the development of PTSD. The total patient sample consisted of 100 Bosnian war veterans. Watson’s PTSD module was used in establishing PTSD diagnosis. Patients fulfilled the following questionnaires: personal data form, Posttraumatic Symptom Scale PTSS-10 (Holen, Impact of Event Scale (Horowitz, Life Event Scale, and Eysenck Personality Inventory. PTSD was diagnosed in 30% of the examined patients. Larger number of stress-related events, particularly of those regarded as life-threatening, wounding/death of a close person, and material losses were more frequent in persons with PTSD. The risk factors for the development of PTSD in this study were: age (30-40, marital status (married, lower level of education, the front-line combat exposure, neurotic manifestations, family problems in childhood, and neuroticism.

SHORT-TERM STRESS ENHANCES CELLULAR IMMUNITY AND INCREASES EARLY RESISTANCE TO SQUAMOUS CELL CARCINOMA

OpenAIRE

Dhabhar, Firdaus S.; Saul, Alison N.; Daugherty, Christine; Holmes, Tyson H.; Bouley, Donna M.; Oberyszyn, Tatiana M.

2009-01-01

In contrast to chronic/long-term stress that suppresses/dysregulates immune function, an acute/short-term fight-or-flight stress response experienced during immune activation can enhance innate and adaptive immunity. Moderate ultraviolet-B (UV) exposure provides a non-invasive system for studying the naturalistic emergence, progression and regression of squamous cell carcinoma (SCC). Because SCC is an immunoresponsive cancer, we hypothesized that short-term stress experienced before UV exposu...

Multivariable analysis of clinical influence factors on liver enhancement of Gd-EOB-DTPA-enhanced 3T MRI

International Nuclear Information System (INIS)

Verloh, N.; Haimerl, M.; Stroszczynski, C.; Fellner, C.; Wiggermann, P.; Zeman, F.; Teufel, A.; Lang, S.

2015-01-01

The purpose of this study was to identify clinical factors influencing Gd-EOB-DTPA liver uptake in patients with healthy liver parenchyma. A total of 124 patients underwent contrast-enhanced MRI with a hepatocyte-specific contrast agent at 3T. T1-weighted volume interpolated breath-hold examination (VIBE) sequences with fat suppression were acquired before and 20 minutes after contrast injection. The relative enhancement (RE) between plain and contrast-enhanced signal intensity was calculated. Simple and multiple linear regression analyses were performed to evaluate clinical factors influencing the relative enhancement. Patients were subdivided into three groups according to their relative liver enhancement (HRE, RE ≥ 100 %; MRE, 100 % > RE > 50 %; NRE, RE ≤ 50 %) and were analyzed according to the relevant risk factors. Simple regression analyses revealed patient age, transaminases (AST, ALT, GGT), liver, spleen and delta-liver volume (the difference between the volumetrically measured liver volume and the estimated liver volume based on body weight) as significant factors influencing relative enhancement. In the multiple analysis the transaminase AST, spleen and delta liver volume remained significant factors influencing relative enhancement. Delta liver volume showed a significant difference between all analyzed groups. Liver enhancement in the hepatobiliary phase depends on a variety of factors. Body weight-adapted administration of Gd-EOB-DTPA may lead to inadequate liver enhancement after 20 minutes especially when the actual liver volume differs from the expected volume.

The Arabidopsis thaliana RNA editing factor SLO2, which affects the mitochondrial electron transport chain, participates in multiple stress and hormone responses.

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Zhu, Qiang; Dugardeyn, Jasper; Zhang, Chunyi; Mühlenbock, Per; Eastmond, Peter J; Valcke, Roland; De Coninck, Barbara; Oden, Sevgi; Karampelias, Michael; Cammue, Bruno P A; Prinsen, Els; Van Der Straeten, Dominique

2014-02-01

Recently, we reported that the novel mitochondrial RNA editing factor SLO2 is essential for mitochondrial electron transport, and vital for plant growth through regulation of carbon and energy metabolism. Here, we show that mutation in SLO2 causes hypersensitivity to ABA and insensitivity to ethylene, suggesting a link with stress responses. Indeed, slo2 mutants are hypersensitive to salt and osmotic stress during the germination stage, while adult plants show increased drought and salt tolerance. Moreover, slo2 mutants are more susceptible to Botrytis cinerea infection. An increased expression of nuclear-encoded stress-responsive genes, as well as mitochondrial-encoded NAD genes of complex I and genes of the alternative respiratory pathway, was observed in slo2 mutants, further enhanced by ABA treatment. In addition, H2O2 accumulation and altered amino acid levels were recorded in slo2 mutants. We conclude that SLO2 is required for plant sensitivity to ABA, ethylene, biotic, and abiotic stress. Although two stress-related RNA editing factors were reported very recently, this study demonstrates a unique role of SLO2, and further supports a link between mitochondrial RNA editing events and stress response.

Osmotic stress confers enhanced cell integrity to hydrostatic pressure but impairs growth in Alcanivorax borkumensis SK2

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Alberto eScoma

2016-05-01

Full Text Available Alcanivorax is a hydrocarbonoclastic genus dominating oil spills worldwide. While its presence has been detected in oil-polluted seawaters, marine sediment and salt marshes under ambient pressure, its presence in deep-sea contaminated environments is negligible. Recent laboratory evidences highlighted the piezosensitive nature of some Alcanivorax species, whose growth yields are highly impacted by mild hydrostatic pressures (HPs. In the present study, osmotic stress was used as a tool to increase HP resistance in the type strain A. borkumensis SK2. Control cultures grown under standard conditions of salinity and osmotic pressure with respect to seawater (35.6 ppt or 1136 mOsm kg-1, respectively were compared with cultures subjected to hypo- and hyperosmosis (330 and 1720 mOsm kg-1, or 18 and 62 ppt in salinity, equivalent to brackish and brine waters, respectively, under atmospheric or increased HP (0.1 and 10MPa. Osmotic stress had a remarkably positive impact on cell metabolic activity in terms of CO2 production (thus, oil bioremediation and O2 respiration under hyperosmosis, as acclimation to high salinity enhanced cell activity under 10MPa by a factor of 10. Both osmotic shocks significantly enhanced cell protection by reducing membrane damage under HP, with cell integrities close to 100% under hyposmosis. The latter was likely due to intracellular water-reclamation as no trace of the piezolyte ectoine was found, contrary to hyperosmosis. Notably, ectoine production was equivalent at 0.1MPa in hyperosmosis-acclimated cells and at 10MPa under isosmotic conditions, supporting the hypothesis that ectoine synthesis may be primarily triggered by HP rather than osmotic stress. While stimulating cell metabolism and enhancing cell integrity, osmotic stress had always a negative impact on culture growth and performance. No net growth was observed during 4-day incubation tests, and CO2:O2 ratios and pH values indicated that culture performance in

The role of eye fixation in memory enhancement under stress - An eye tracking study.

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Herten, Nadja; Otto, Tobias; Wolf, Oliver T

2017-04-01

In a stressful situation, attention is shifted to potentially relevant stimuli. Recent studies from our laboratory revealed that participants stressed perform superior in a recognition task involving objects of the stressful episode. In order to characterize the role of a stress induced alteration in visual exploration, the present study investigated whether participants experiencing a laboratory social stress situation differ in their fixation from participants of a control group. Further, we aimed at shedding light on the relation of fixation behaviour with obtained memory measures. We randomly assigned 32 male and 31 female participants to a control or a stress condition consisting of the Trier Social Stress Test (TSST), a public speaking paradigm causing social evaluative threat. In an established 'friendly' control condition (f-TSST) participants talk to a friendly committee. During both conditions, the committee members used ten office items (central objects) while another ten objects were present without being used (peripheral objects). Participants wore eye tracking glasses recording their fixations. On the next day, participants performed free recall and recognition tasks involving the objects present the day before. Stressed participants showed enhanced memory for central objects, accompanied by longer fixation times and larger fixation amounts on these objects. Contrasting this, fixation towards the committee faces showed the reversed pattern; here, control participants exhibited longer fixations. Fixation indices and memory measures were, however, not correlated with each other. Psychosocial stress is associated with altered fixation behaviour. Longer fixation on objects related to the stressful situation may reflect enhanced encoding, whereas diminished face fixation suggests gaze avoidance of aversive, socially threatening stimuli. Modified visual exploration should be considered in future stress research, in particular when focussing on memory for a

[Stress and attitudes toward negative emotions in adolescence].

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Ozawa, Eiji

2010-12-01

This study investigated the relationship between stress and attitudes toward negative emotions in adolescents. Adolescent students (N=1500) completed a questionnaire that measured attitudes toward negative emotions, emotional-stress reactions, and stress coping. Analysis of date yielded, two factors of the attitudes toward negative emotions: "Negative feelings about negative emotions" and "Capabilities of switching of negative emotions". In order to examine the theoretical relationships among attitudes toward negative emotions, emotional-stress reactions, and stress coping, a hypothetical model was tested by covariance structure analysis. This model predicted that students who have a high level of attitudes toward negative emotions would report enhanced problem solving which promoted stress coping. The results indicated that "Negative feelings about negative emotions" enhanced avoidable coping, and avoidable coping enhanced stress reactions. "Capabilities of switching of negative emotions" was related to a decrease of avoidable coping. Based on the results from covariance structure analysis and a multiple population analysis, the clinical significance and developmental characteristics were discussed.

Personal Risk and Resilience Factors in the Context of Daily Stress

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Diehl, Manfred; Hay, Elizabeth L.; Chui, Helena

2012-01-01

This chapter focuses on the role that personal risk and resilience factors play as adults of all ages cope with the stressors encountered in everyday life. Theorists have suggested that researchers should focus on the effects of daily stress and coping rather than focusing exclusively on major life events and chronic stress and have proposed that understanding how adults cope with daily stress is a key aspect of understanding long-term well-being and adaptation in adulthood. After presenting a conceptual model outlining the major components of the daily stress process, the chapter reviews the existing empirical literature on personal risk and resilience factors in the context of daily stress. This research clearly suggests that there is no universal generalization that can be made regarding whether chronological age, in and of itself, confers greater vulnerability or resilience onto adults. Instead, we argue that researchers should ask when and under what conditions is age associated with greater vulnerability to daily stress and when and under what conditions is age associated with greater resilience to daily stress. Age differences in reactivity to daily stress are clearly embedded within a complex system of factors—structural, individual, and situational—that influence stress reactivity and stress recovery in several ways. This complexity should not be taken to mean that stress reactivity and recovery cannot be charted or understood. Researchers, however, will need to approach this complexity with a great deal of theoretical, methodological, and statistical rigor to move our understanding of the importance of age in shaping risk and resilience to daily stress forward. The final section of the chapter outlines several directions for future research in the area of aging and resilience. In particular, we argue that a focus on personal risk and resilience factors in the context of daily stress, in combination with the application of sophisticated statistical

Supplementation with vitamin A enhances oxidative stress in the lungs of rats submitted to aerobic exercise.

Science.gov (United States)

Gasparotto, Juciano; Petiz, Lyvia Lintzmaier; Girardi, Carolina Saibro; Bortolin, Rafael Calixto; de Vargas, Amanda Rodrigues; Henkin, Bernardo Saldanha; Chaves, Paloma Rodrigues; Roncato, Sabrina; Matté, Cristiane; Zanotto-Filho, Alfeu; Moreira, José Cláudio Fonseca; Gelain, Daniel Pens

2015-12-01

Exercise training induces reactive oxygen species production and low levels of oxidative damage, which are required for induction of antioxidant defenses and tissue adaptation. This process is physiological and essential to improve physical conditioning and performance. During exercise, endogenous antioxidants are recruited to prevent excessive oxidative stress, demanding appropriate intake of antioxidants from diet or supplements; in this context, the search for vitamin supplements that enhance the antioxidant defenses and improve exercise performance has been continuously increasing. On the other hand, excess of antioxidants may hinder the pro-oxidant signals necessary for this process of adaptation. The aim of this study was to investigate the effects of vitamin A supplementation (2000 IU/kg, oral) upon oxidative stress and parameters of pro-inflammatory signaling in lungs of rats submitted to aerobic exercise (swimming protocol). When combined with exercise, vitamin A inhibited biochemical parameters of adaptation/conditioning by attenuating exercise-induced antioxidant enzymes (superoxide dismutase and glutathione peroxidase) and decreasing the content of the receptor for advanced glycation end-products. Increased oxidative damage to proteins (carbonylation) and lipids (lipoperoxidation) was also observed in these animals. In sedentary animals, vitamin A decreased superoxide dismutase and increased lipoperoxidation. Vitamin A also enhanced the levels of tumor necrosis factor alpha and decreased interleukin-10, effects partially reversed by aerobic training. Taken together, the results presented herein point to negative effects associated with vitamin A supplementation at the specific dose here used upon oxidative stress and pro-inflammatory cytokines in lung tissues of rats submitted to aerobic exercise.

Relationship between occupational stress and cardiovascular diseases risk factors in drivers.

Science.gov (United States)

Biglari, Hamed; Ebrahimi, Mohammad Hossein; Salehi, Maryam; Poursadeghiyan, Mohsen; Ahmadnezhad, Iman; Abbasi, Milad

2016-11-18

Of all work stressors, occupational stress is the leading cause of many disorders among workers. Drivers are classified as a high risk group for work related stress. This study set out to determine the relationship between risk factors of cardiovascular diseases and occupational stress among drivers. Two hundred and twenty two Ilam's intercity drivers were selected for the study. For measuring work stress, the Osipow work stress questionnaire was used. After a 10-h fasting period, systolic and diastolic blood pressure was recorded. Intravenous blood samples were taken to determine cholesterol, triglyceride and blood glucose levels. The independent samples t-test and Pearson's correlation test were used to assess the relationship between variables and occupational stress. Seventy-one percent of the intercity drivers suffered from average to acute stress, and 3.1% of them suffered from acute stress. There was no significant relationship between occupational stress and diastolic blood pressure (p = 0.254) among the drivers. Nevertheless, the Pearson's correlation test demonstrated a strong relationship between work stress and blood glucose (p stress were observed in the Ilam's intercity drivers. Occupational stress may have effect on blood glucose levels but the results did not suggest a considerable relationship between risk factors of cardiovascular diseases and occupational stress among intercity drivers. Int J Occup Med Environ Health 2016;29(6):895-901. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Acute Social Stress Engages Synergistic Activity of Stress Mediators in the VTA to Promote Pavlovian Reward Learning

OpenAIRE

Kan, Russell; Pomrenze, Matthew; Tovar-Diaz, Jorge; Morikawa, Hitoshi; Drew, Michael; Pahlavan, Bahram

2017-01-01

Stressful events rapidly trigger activity-dependent synaptic plasticity in certain brain areas, driving the formation of aversive memories. However, it remains unclear how stressful experience affects plasticity mechanisms to regulate learning of appetitive events, such as intake of addictive drugs or palatable foods. Using rats, we show that two acute stress mediators, corticotropin-releasing factor (CRF) and norepinephrine (NE), enhance plasticity of NMDA receptor-mediated glutamatergic tra...

An empirical investigation on factors influencing on work stress: Evidence from banking industry

Directory of Open Access Journals (Sweden)

Alireza Davoudzadeh Moghaddam

2015-08-01

Full Text Available An individual with a career faced with various career challenges may experience work-related stress. Work related stress is a factor that threatens employees’ health. The most common negative consequences of stress are particularly the deterioration of performance and efficiency, decrease in productivity and quality of customer’s services, which results in health problems. Work-related stress is a global issue, and banks are no exception. This paper presents a survey to investigate the influencing factors on work stress in banking industry. The study designs a questionnaire and distributes it among 200 randomly selected bank department managers in city of Tehran, Iran. Using principle component analysis, the study has detected five factors including organizational characteristics, external environment, work content, personal characteristics and top management.

Obesity-induced endoplasmic reticulum stress suppresses nuclear factor-Y expression.

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Liu, Yulan; Zhang, Yuwei; Zhang, Yanjie; Zhang, Jinlong; Liu, Yin; Feng, Peiqun; Su, Zhiguang

2017-02-01

Nuclear transcription factor Y (NF-Y) is an evolutionarily conserved transcription factor composed of three subunits, NF-YA, NF-YB, and NF-YC. NF-Y plays crucial roles in pre-adipocyte maintenance and/or commitment to adipogenesis. NF-YA dysfunction in adipocyte resulted in an age-dependent progressive loss of adipose tissue associated with metabolic complications. Endoplasmic reticulum (ER) stress has emerged as an important mediator in the pathogenesis of obesity. However, it is not known if NF-YA is involved in the ER stress-mediated pathogenesis of obesity. We first examined the effects of ER stress on the NF-YA expression in cultured 3T3-L1 adipocytes; then in ob/ob genetic obesity mice, we tested the effect of chemical chaperones alleviating ER stress on the expression levels of NF-YA. Subsequently, we inhibited the new mRNA synthesis using actinomycin D in 3T3-L1 cells to explore the mechanism modulating NF-YA expression. Finally, we evaluated the involvement of PPARg in the regulation of NF-YA expression by ER stress. We demonstrated that both obesity- and chemical chaperone -induced ER stress suppressed NF-YA expression and alleviation of ER stress by chemical chaperone could recover NF-YA expression in ob/ob mice. Moreover, we showed that ER stress suppressed NF-YA mRNA transcription through the involvement of peroxisome proliferator-activated receptor gamma (PPARg). Activation of PPARg ameliorates the ER stress-induced NF-YA suppression. Our findings may point to a possible role of NF-YA in stress conditions that occur in chronic obesity, ER stress might be involved in the pathogenesis of obesity through NF-YA depletion.

Class I and II Small Heat Shock Proteins Together with HSP101 Protect Protein Translation Factors during Heat Stress.

Science.gov (United States)

McLoughlin, Fionn; Basha, Eman; Fowler, Mary E; Kim, Minsoo; Bordowitz, Juliana; Katiyar-Agarwal, Surekha; Vierling, Elizabeth

2016-10-01

The ubiquitous small heat shock proteins (sHSPs) are well documented to act in vitro as molecular chaperones to prevent the irreversible aggregation of heat-sensitive proteins. However, the in vivo activities of sHSPs remain unclear. To investigate the two most abundant classes of plant cytosolic sHSPs (class I [CI] and class II [CII]), RNA interference (RNAi) and overexpression lines were created in Arabidopsis (Arabidopsis thaliana) and shown to have reduced and enhanced tolerance, respectively, to extreme heat stress. Affinity purification of CI and CII sHSPs from heat-stressed seedlings recovered eukaryotic translation elongation factor (eEF) 1B (α-, β-, and γ-subunits) and eukaryotic translation initiation factor 4A (three isoforms), although the association with CI sHSPs was stronger and additional proteins involved in translation were recovered with CI sHSPs. eEF1B subunits became partially insoluble during heat stress and, in the CI and CII RNAi lines, showed reduced recovery to the soluble cell fraction after heat stress, which was also dependent on HSP101. Furthermore, after heat stress, CI sHSPs showed increased retention in the insoluble fraction in the CII RNAi line and vice versa. Immunolocalization revealed that both CI and CII sHSPs were present in cytosolic foci, some of which colocalized with HSP101 and with eEF1Bγ and eEF1Bβ. Thus, CI and CII sHSPs have both unique and overlapping functions and act either directly or indirectly to protect specific translation factors in cytosolic stress granules. © 2016 American Society of Plant Biologists. All Rights Reserved.

Inhibition of nuclear factor-kappaB or Bax prevents endoplasmic reticulum stress- but not nitric oxide-mediated apoptosis in INS-1E cells

DEFF Research Database (Denmark)

Tonnesen, Morten F; Grunnet, Lars G; Friberg, Josefine

2009-01-01

. Exposure of INS-1E cells to TG or SNAP caused caspase-3 cleavage and apoptosis. Both TG and SNAP induced activation of the proapoptotic transcription factor CCAAT/enhancer-binding protein homologous protein (CHOP). However, other classical ER stress-induced markers such as up-regulation of ER chaperone Bip...

Manipulating environmental stresses and stress tolerance of microalgae for enhanced production of lipids and value-added products-A review.

Science.gov (United States)

Chen, Bailing; Wan, Chun; Mehmood, Muhammad Aamer; Chang, Jo-Shu; Bai, Fengwu; Zhao, Xinqing

2017-11-01

Microalgae have promising potential to produce lipids and a variety of high-value chemicals. Suitable stress conditions such as nitrogen starvation and high salinity could stimulate synthesis and accumulation of lipids and high-value products by microalgae, therefore, various stress-modification strategies were developed to manipulate and optimize cultivation processes to enhance bioproduction efficiency. On the other hand, advancements in omics-based technologies have boosted the research to globally understand microalgal gene regulation under stress conditions, which enable further improvement of production efficiency via genetic engineering. Moreover, integration of multi-omics data, synthetic biology design, and genetic engineering manipulations exhibits a tremendous potential in the betterment of microalgal biorefinery. This review discusses the process manipulation strategies and omics studies on understanding the regulation of metabolite biosynthesis under various stressful conditions, and proposes genetic engineering of microalgae to improve bioproduction via manipulating stress tolerance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Job stress and its related factors in Tehran firefighters in year 2000

Directory of Open Access Journals (Sweden)

Yazdi SM

2001-11-01

Full Text Available Job stress results from a mismatch between job requirements and capabilities, resources, or needs of the worker. Physiological, psychological and behavioral outcomes caused by job stress not only hurt the person but also impose expensive costs on organizations. Firefighting is a job that exposes workers to job stress. The purpose of this study is to determine the level of job stress and some related factors in firefighters of Tehran safety services and firefighters organization. This cross sectional study includes 155 male firefighters whom had selected randomly. In this research we used Leiden University Questionnaire. Also Karasek Questionnaire is used for classification of workers according to karasek’s model. Collected data were analyzed by spss9 software. The final grade of firefighter’s job stress shows a significant positive relationship with second job and a significant negative relationship with age. The level of job satisfaction have a significant negative relationship with job insecurity and lack of meaningfulness, and a significant positive relationship with skill discretion, social support supervisor and social support co-workers. According to karasek classification this job is grouped in active not in high strain grup. The highest level of job stress was seen in physical exertion and hazardous exposure factors. Also in work and time pressure factor, job stress level is high. But job stress is in a moderate or low level in other factors. The level of job stress in younger firefighters and in individuals with a second job indicate a significant increase. However, in western country’s studies, this job is classified as high-strain but in this research it is classified as active group.

Role of epidermal growth factor receptor and endoplasmic reticulum stress in vascular remodeling induced by angiotensin II.

Science.gov (United States)

Takayanagi, Takehiko; Kawai, Tatsuo; Forrester, Steven J; Obama, Takashi; Tsuji, Toshiyuki; Fukuda, Yamato; Elliott, Katherine J; Tilley, Douglas G; Davisson, Robin L; Park, Joon-Young; Eguchi, Satoru

2015-06-01

The mechanisms by which angiotensin II (AngII) elevates blood pressure and enhances end-organ damage seem to be distinct. However, the signal transduction cascade by which AngII specifically mediates vascular remodeling such as medial hypertrophy and perivascular fibrosis remains incomplete. We have previously shown that AngII-induced epidermal growth factor receptor (EGFR) transactivation is mediated by disintegrin and metalloproteinase domain 17 (ADAM17), and that this signaling is required for vascular smooth muscle cell hypertrophy but not for contractile signaling in response to AngII. Recent studies have implicated endoplasmic reticulum (ER) stress in hypertension. Interestingly, EGFR is capable of inducing ER stress. The aim of this study was to test the hypothesis that activation of EGFR and ER stress are critical components required for vascular remodeling but not hypertension induced by AngII. Mice were infused with AngII for 2 weeks with or without treatment of EGFR inhibitor, erlotinib, or ER chaperone, 4-phenylbutyrate. AngII infusion induced vascular medial hypertrophy in the heart, kidney and aorta, and perivascular fibrosis in heart and kidney, cardiac hypertrophy, and hypertension. Treatment with erlotinib as well as 4-phenylbutyrate attenuated vascular remodeling and cardiac hypertrophy but not hypertension. In addition, AngII infusion enhanced ADAM17 expression, EGFR activation, and ER/oxidative stress in the vasculature, which were diminished in both erlotinib-treated and 4-phenylbutyrate-treated mice. ADAM17 induction and EGFR activation by AngII in vascular cells were also prevented by inhibition of EGFR or ER stress. In conclusion, AngII induces vascular remodeling by EGFR activation and ER stress via a signaling mechanism involving ADAM17 induction independent of hypertension. © 2015 American Heart Association, Inc.

Brief, pre-learning stress reduces false memory production and enhances true memory selectively in females.

Science.gov (United States)

Zoladz, Phillip R; Peters, David M; Kalchik, Andrea E; Hoffman, Mackenzie M; Aufdenkampe, Rachael L; Woelke, Sarah A; Wolters, Nicholas E; Talbot, Jeffery N

2014-04-10

Some of the previous research on stress-memory interactions has suggested that stress increases the production of false memories. However, as accumulating work has shown that the effects of stress on learning and memory depend critically on the timing of the stressor, we hypothesized that brief stress administered immediately before learning would reduce, rather than increase, false memory production. In the present study, participants submerged their dominant hand in a bath of ice cold water (stress) or sat quietly (no stress) for 3 min. Then, participants completed a short-term memory task, the Deese-Roediger-McDermott paradigm, in which they were presented with 10 different lists of semantically related words (e.g., candy, sour, sugar) and, after each list, were tested for their memory of presented words (e.g., candy), non-presented unrelated "distractor" words (e.g., hat), and non-presented semantically related "critical lure" words (e.g., sweet). Stress, overall, significantly reduced the number of critical lures recalled (i.e., false memory) by participants. In addition, stress enhanced memory for the presented words (i.e., true memory) in female, but not male, participants. These findings reveal that stress does not unequivocally enhance false memory production and that the timing of the stressor is an important variable that could mediate such effects. Such results could have important implications for understanding the dependability of eyewitness accounts of events that are observed following stress. Copyright © 2014 Elsevier Inc. All rights reserved.

Gold nanodisc arrays as near infrared metal-enhanced fluorescence platforms with tuneable enhancement factors

KAUST Repository

Pang, J.; Theodorou, I. G.; Centeno, A.; Petrov, P. K.; Alford, N. M.; Ryan, M. P.; Xie, F.

2016-01-01

Metal enhanced fluorescence (MEF) is a physical effect through which the near-field interaction of fluorophores with metallic nanoparticles can lead to large fluorescence enhancement. MEF can be exploited in many fluorescence-based biomedical applications, with potentially significant improvement in detection sensitivity and contrast enhancement. Offering lower autofluorescence and minimal photoinduced damage, the development of effective and multifunctional MEF platforms in the near-infrared (NIR) region, is particularly desirable. In this work, the enhancement of NIR fluorescence caused by interaction with regular arrays of cylindrical gold (Au) nanoparticles (nanodiscs), fabricated through nanosphere lithography, is reported. Significant MEF of up to 235 times is obtained, with tuneable enhancement factors. The effect of array structure on fluorescence enhancement is investigated by semi-quantitatively de-convoluting excitation enhancement from emission enhancement, and modelling the local electric field enhancement. By considering arrays of Au nanodiscs with the same extinction maximum, it is shown that the excitation enhancement, due to increased electric field, is not significantly different for the particle sizes and separation distances considered. Rather, it is seen that the emission from the fluorophore is strongly enhanced, and is dependent on the topography, in particular particle size. The results show that the structural characteristics of Au nanodisc arrays can be manipulated to tune their enhancement factor, and hence their sensitivity.

Gold nanodisc arrays as near infrared metal-enhanced fluorescence platforms with tuneable enhancement factors

KAUST Repository

Pang, J.

2016-12-28

Metal enhanced fluorescence (MEF) is a physical effect through which the near-field interaction of fluorophores with metallic nanoparticles can lead to large fluorescence enhancement. MEF can be exploited in many fluorescence-based biomedical applications, with potentially significant improvement in detection sensitivity and contrast enhancement. Offering lower autofluorescence and minimal photoinduced damage, the development of effective and multifunctional MEF platforms in the near-infrared (NIR) region, is particularly desirable. In this work, the enhancement of NIR fluorescence caused by interaction with regular arrays of cylindrical gold (Au) nanoparticles (nanodiscs), fabricated through nanosphere lithography, is reported. Significant MEF of up to 235 times is obtained, with tuneable enhancement factors. The effect of array structure on fluorescence enhancement is investigated by semi-quantitatively de-convoluting excitation enhancement from emission enhancement, and modelling the local electric field enhancement. By considering arrays of Au nanodiscs with the same extinction maximum, it is shown that the excitation enhancement, due to increased electric field, is not significantly different for the particle sizes and separation distances considered. Rather, it is seen that the emission from the fluorophore is strongly enhanced, and is dependent on the topography, in particular particle size. The results show that the structural characteristics of Au nanodisc arrays can be manipulated to tune their enhancement factor, and hence their sensitivity.

Transient thermal stresses and stress intensity factors induced by thermal stratification in feedwater lines

International Nuclear Information System (INIS)

Sanchez Sarmiento, G.; Pardo, E.

1985-01-01

General analytical solutions for the thermal stresses and circumferential crack propagation in piping branches of nuclear power plants, that connect two circuits of the same fluid at different temperatures, are presented in this paper. Under certain conditions, two regions of the fluid possessing both temperatures with a separating layer of small thickness are formed ('flow stratification'). Dimensionless analytical expressions for the steady state temperature distribution in the pipe wall and the corresponding thermal stress are here derived, in terms of the basic geometrical and physical parameters. The position and thickness of the separating layer are considered as data of the model. Stress intensity ranges at any point of the tube wall are then determined. Finally, thermally induced stress intensity factors are calculated for hipothetically inside surface cracks. (orig.)

Prenatal Stress as a Risk-and an Opportunity-Factor.

Science.gov (United States)

Hartman, Sarah; Freeman, Sara M; Bales, Karen L; Belsky, Jay

2018-04-01

Two separate lines of research indicate (a) that prenatal stress is associated with heightened behavioral and physiological reactivity and (b) that these postnatal phenotypes are associated with increased susceptibility to both positive and negative developmental experiences. Therefore, prenatal stress may increase sensitivity to the rearing environment. We tested this hypothesis by manipulating prenatal stress and rearing-environment quality, using a cross-fostering paradigm, in prairie voles. Results showed that prenatally stressed voles, as adults, displayed the highest behavioral and physiological reactivity when cross-fostered to low-contact (i.e., low-quality) rearing but the lowest behavioral and physiological reactivity when cross-fostered to high-contact (i.e., high-quality) rearing; non-prenatally stressed voles showed no effect of rearing condition. Additionally, while neither prenatal stress nor rearing condition affected oxytocin receptor binding, prenatally stressed voles cross-fostered to high-contact rearing showed the highest vasopressin-1a receptor binding in the amygdala. Results indicate that prenatal stress induces greater environmental sensitivity, making it both a risk and an opportunity factor.

Transgenerational inheritance of modified DNA methylation patterns and enhanced tolerance induced by heavy metal stress in rice (Oryza sativa L.).

Science.gov (United States)

Ou, Xiufang; Zhang, Yunhong; Xu, Chunming; Lin, Xiuyun; Zang, Qi; Zhuang, Tingting; Jiang, Lili; von Wettstein, Diter; Liu, Bao

2012-01-01

DNA methylation is sensitive and responsive to stressful environmental conditions. Nonetheless, the extent to which condition-induced somatic methylation modifications can impose transgenerational effects remains to be fully understood. Even less is known about the biological relevance of the induced epigenetic changes for potentially altered well-being of the organismal progenies regarding adaptation to the specific condition their progenitors experienced. We analyzed DNA methylation pattern by gel-blotting at genomic loci representing transposable elements and protein-coding genes in leaf-tissue of heavy metal-treated rice (Oryza sativa) plants (S0), and its three successive organismal generations. We assessed expression of putative genes involved in establishing and/or maintaining DNA methylation patterns by reverse transcription (RT)-PCR. We measured growth of the stressed plants and their unstressed progenies vs. the control plants. We found (1) relative to control, DNA methylation patterns were modified in leaf-tissue of the immediately treated plants, and the modifications were exclusively confined to CHG hypomethylation; (2) the CHG-demethylated states were heritable via both maternal and paternal germline, albeit often accompanying further hypomethylation; (3) altered expression of genes encoding for DNA methyltransferases, DNA glycosylase and SWI/SNF chromatin remodeling factor (DDM1) were induced by the stress; (4) progenies of the stressed plants exhibited enhanced tolerance to the same stress their progenitor experienced, and this transgenerational inheritance of the effect of condition accompanying heritability of modified methylation patterns. Our findings suggest that stressful environmental condition can produce transgenerational epigenetic modifications. Progenies of stressed plants may develop enhanced adaptability to the condition, and this acquired trait is inheritable and accord with transmission of the epigenetic modifications. We suggest

Ribosomal elongation factor 4 promotes cell death associated with lethal stress.

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Li, Liping; Hong, Yuzhi; Luan, Gan; Mosel, Michael; Malik, Muhammad; Drlica, Karl; Zhao, Xilin

2014-12-09

Ribosomal elongation factor 4 (EF4) is highly conserved among bacteria, mitochondria, and chloroplasts. However, the EF4-encoding gene, lepA, is nonessential and its deficiency shows no growth or fitness defect. In purified systems, EF4 back-translocates stalled, posttranslational ribosomes for efficient protein synthesis; consequently, EF4 has a protective role during moderate stress. We were surprised to find that EF4 also has a detrimental role during severe stress: deletion of lepA increased Escherichia coli survival following treatment with several antimicrobials. EF4 contributed to stress-mediated lethality through reactive oxygen species (ROS) because (i) the protective effect of a ΔlepA mutation against lethal antimicrobials was eliminated by anaerobic growth or by agents that block hydroxyl radical accumulation and (ii) the ΔlepA mutation decreased ROS levels stimulated by antimicrobial stress. Epistasis experiments showed that EF4 functions in the same genetic pathway as the MazF toxin, a stress response factor implicated in ROS-mediated cell death. The detrimental action of EF4 required transfer-messenger RNA (tmRNA, which tags truncated proteins for degradation and is known to be inhibited by EF4) and the ClpP protease. Inhibition of a protective, tmRNA/ClpP-mediated degradative activity would allow truncated proteins to indirectly perturb the respiratory chain and thereby provide a potential link between EF4 and ROS. The connection among EF4, MazF, tmRNA, and ROS expands a pathway leading from harsh stress to bacterial self-destruction. The destructive aspect of EF4 plus the protective properties described previously make EF4 a bifunctional factor in a stress response that promotes survival or death, depending on the severity of stress. Translation elongation factor 4 (EF4) is one of the most conserved proteins in nature, but it is dispensable. Lack of strong phenotypes for its genetic knockout has made EF4 an enigma. Recent biochemical work has

Brain-derived neurotropic factor polymorphisms, traumatic stress, mild traumatic brain injury, and combat exposure contribute to postdeployment traumatic stress.

Science.gov (United States)

Dretsch, Michael N; Williams, Kathy; Emmerich, Tanja; Crynen, Gogce; Ait-Ghezala, Ghania; Chaytow, Helena; Mathura, Venkat; Crawford, Fiona C; Iverson, Grant L

2016-01-01

In addition to experiencing traumatic events while deployed in a combat environment, there are other factors that contribute to the development of posttraumatic stress disorder (PTSD) in military service members. This study explored the contribution of genetics, childhood environment, prior trauma, psychological, cognitive, and deployment factors to the development of traumatic stress following deployment. Both pre- and postdeployment data on 231 of 458 soldiers were analyzed. Postdeployment assessments occurred within 30 days from returning stateside and included a battery of psychological health, medical history, and demographic questionnaires; neurocognitive tests; and blood serum for the D2 dopamine receptor (DRD2), apolipoprotein E (APOE), and brain-derived neurotropic factor (BDNF) genes. Soldiers who screened positive for traumatic stress at postdeployment had significantly higher scores in depression (d = 1.91), anxiety (d = 1.61), poor sleep quality (d = 0.92), postconcussion symptoms (d = 2.21), alcohol use (d = 0.63), traumatic life events (d = 0.42), and combat exposure (d = 0.91). BDNF Val66 Met genotype was significantly associated with risk for sustaining a mild traumatic brain injury (mTBI) and screening positive for traumatic stress. Predeployment traumatic stress, greater combat exposure and sustaining an mTBI while deployed, and the BDNF Met/Met genotype accounted for 22% of the variance of postdeployment PTSD scores (R (2)  = 0.22, P PTSD scores. These findings suggest predeployment traumatic stress, genetic, and environmental factors have unique contributions to the development of combat-related traumatic stress in military service members.

Expression of Endoplasmic Reticulum Stress-Related Factors in the Retinas of Diabetic Rats

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Shu Yan

2012-01-01

Full Text Available Recent reports show that ER stress plays an important role in diabetic retinopathy (DR, but ER stress is a complicated process involving a network of signaling pathways and hundreds of factors, What factors involved in DR are not yet understood. We selected 89 ER stress factors from more than 200, A rat diabetes model was established by intraperitoneal injection of streptozotocin (STZ. The expression of 89 ER stress-related factors was found in the retinas of diabetic rats, at both 1- and 3-months after development of diabetes, by quantitative real-time polymerase chain reaction arrays. There were significant changes in expression levels of 13 and 12 ER stress-related factors in the diabetic rat retinas in the first and third month after the development of diabetes, Based on the array results, homocysteine- inducible, endoplasmic reticulum stress-inducible, ubiquitin-like domain member 1(HERP, and synoviolin(HRD1 were studied further by immunofluorescence and Western blot. Immunofluorescence and Western blot analyses showed that the expression of HERP was reduced in the retinas of diabetic rats in first and third month. The expression of Hrd1 did not change significantly in the retinas of diabetic rats in the first month but was reduced in the third month.

Functional role of CCCTC binding factor (CTCF) in stress-induced apoptosis

International Nuclear Information System (INIS)

Li Tie; Lu Luo

2007-01-01

CTCF, a nuclear transcriptional factor, is a multifunctional protein and involves regulation of growth factor- and cytokine-induced cell proliferation/differentiation. In the present study, we investigated the role of CTCF in protecting stress-induced apoptosis in various human cell types. We found that UV irradiation and hyper-osmotic stress induced human corneal epithelial (HCE) and hematopoietic myeloid cell apoptosis detected by significantly increased caspase 3 activity and decreased cell viability. The stress-induced apoptotic response in these cells requires down-regulation of CTCF at both mRNA and protein levels, suggesting that CTCF may play an important role in downstream events of stress-induced signaling pathways. Inhibition of NFκB activity prevented stress-induced down-regulation of CTCF and increased cell viability against stress-induced apoptosis. The anti-apoptotic effect of CTCF was further studied by manipulating CTCF activities in HCE and hematopoietic cells. Transient transfection of cDNAs encoding full-length human CTCF markedly suppressed stress-induced apoptosis in these cells. In contrast, knocking down of CTCF mRNA using siRNA specific to CTCF significantly promoted stress-induced apoptosis. Thus, our results reveal that CTCF is a down stream target of stress-induced signaling cascades and it plays a significant anti-apoptotic role in regulation of stress-induced cellular responses in HCE and hematopoietic myeloid cells

Enhancement to Non-Contacting Stress Measurement of Blade Vibration Frequency

Science.gov (United States)

Platt, Michael; Jagodnik, John

2011-01-01

A system for turbo machinery blade vibration has been developed that combines time-of-arrival sensors for blade vibration amplitude measurement and radar sensors for vibration frequency and mode identification. The enabling technology for this continuous blade monitoring system is the radar sensor, which provides a continuous time series of blade displacement over a portion of a revolution. This allows the data reduction algorithms to directly calculate the blade vibration frequency and to correctly identify the active modes of vibration. The work in this project represents a significant enhancement in the mode identification and stress calculation accuracy in non-contacting stress measurement system (NSMS) technology when compared to time-of-arrival measurements alone.

PWSCC Growth Assessment Model Considering Stress Triaxiality Factor for Primary Alloy 600 Components

Directory of Open Access Journals (Sweden)

Jong-Sung Kim

2016-08-01

Full Text Available We propose a primary water stress corrosion cracking (PWSCC initiation model of Alloy 600 that considers the stress triaxiality factor to apply to finite element analysis. We investigated the correlation between stress triaxiality effects and PWSCC growth behavior in cold-worked Alloy 600 stream generator tubes, and identified an additional stress triaxiality factor that can be added to Garud's PWSCC initiation model. By applying the proposed PWSCC initiation model considering the stress triaxiality factor, PWSCC growth simulations based on the macroscopic phenomenological damage mechanics approach were carried out on the PWSCC growth tests of various cold-worked Alloy 600 steam generator tubes and compact tension specimens. As a result, PWSCC growth behavior results from the finite element prediction are in good agreement with the experimental results.

Model calculation of the scanned field enhancement factor of CNTs

International Nuclear Information System (INIS)

Ahmad, Amir; Tripathi, V K

2006-01-01

The field enhancement factor of a carbon nanotube (CNT) placed in a cluster of CNTs is smaller than an isolated CNT because the electric field on one tube is screened by neighbouring tubes. This screening depends on the length of the CNTs and the spacing between them. We have derived an expression to compute the field enhancement factor of CNTs under any positional distribution of CNTs using a model of a floating sphere between parallel anode and cathode plates. Using this expression we can compute the field enhancement factor of a CNT in a cluster (non-uniformly distributed CNTs). This expression is used to compute the field enhancement factor of a CNT in an array (uniformly distributed CNTs). Comparison has been shown with experimental results and existing models

Numerical Determination of Crack Opening and Closure Stress Intensity Factors

DEFF Research Database (Denmark)

Ricardo, Luiz Carlos Hernandes

2009-01-01

The present work shows the numerical determination of fatigue crack opening and closure stress intensity factors of a C(T) specimen under variable amplitude loading using a finite element method. A half compact tension C(T) specimen, assuming plane stress constraint was used by finite element...

Post-learning stress enhances long-term memory and differentially influences memory in females depending on menstrual stage.

Science.gov (United States)

Zoladz, Phillip R; Peters, David M; Cadle, Chelsea E; Kalchik, Andrea E; Aufdenkampe, Rachael L; Dailey, Alison M; Brown, Callie M; Scharf, Amanda R; Earley, McKenna B; Knippen, Courtney L; Rorabaugh, Boyd R

2015-09-01

Most work has shown that post-learning stress enhances long-term memory; however, there have been recent inconsistencies in this literature. The purpose of the present study was to examine further the effects of post-learning stress on long-term memory and to explore any sex differences that may exist. Male and female participants learned a list of 42 words that varied in emotional valence and arousal level. Following encoding, participants completed a free recall assessment and then submerged their hand into a bath of ice cold (stress) or lukewarm (no stress) water for 3 min. The next day, participants were given free recall and recognition tests. Stressed participants recalled more words than non-stressed participants 24h after learning. Stress also enhanced female participants' recall of arousing words when they were in the follicular, but not luteal, phase. These findings replicate previous work examining post-learning stress effects on memory and implicate the involvement of sex-related hormones in such effects. Copyright © 2015 Elsevier B.V. All rights reserved.

Unravelling chemical priming machinery in plants: the role of reactive oxygen-nitrogen-sulfur species in abiotic stress tolerance enhancement.

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Antoniou, Chrystalla; Savvides, Andreas; Christou, Anastasis; Fotopoulos, Vasileios

2016-10-01

Abiotic stresses severely limit crop yield and their detrimental effects are aggravated by climate change. Chemical priming is an emerging field in crop stress management. The exogenous application of specific chemical agents before stress events results in tolerance enhancement and reduction of stress impacts on plant physiology and growth. However, the molecular mechanisms underlying the remarkable effects of chemical priming on plant physiology remain to be elucidated. Reactive oxygen, nitrogen and sulfur species (RONSS) are molecules playing a vital role in the stress acclimation of plants. When applied as priming agents, RONSS improve stress tolerance. This review summarizes the recent knowledge on the role of RONSS in cell signalling and gene regulation contributing to abiotic stress tolerance enhancement. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cannabinoid receptors activation and glucocorticoid receptors deactivation in the amygdala prevent the stress-induced enhancement of a negative learning experience.

Science.gov (United States)

Ramot, Assaf; Akirav, Irit

2012-05-01

The enhancement of emotional memory is clearly important as emotional stimuli are generally more significant than neutral stimuli for surviving and reproduction purposes. Yet, the enhancement of a negative emotional memory following exposure to stress may result in dysfunctional or intrusive memory that underlies several psychiatric disorders. Here we examined the effects of stress exposure on a negative emotional learning experience as measured by a decrease in the magnitude of the expected quantity of reinforcements in an alley maze. In contrast to other fear-related negative experiences, reward reduction is more associated with frustration and is assessed by measuring the latency to run the length of the alley to consume the reduced quantity of reward. We also examined whether the cannabinoid receptors agonist WIN55,212-2 (5 μg/side) and the glucocorticoid receptors (GRs) antagonist RU-486 (10 ng/side) administered into the rat basolateral amygdala (BLA) could prevent the stress-induced enhancement. We found that intra-BLA RU-486 or WIN55,212 before stress exposure prevented the stress-induced enhancement of memory consolidation for reduction in reward magnitude. These findings suggest that cannabinoid receptors and GRs in the BLA are important modulators of stress-induced enhancement of emotional memory. Copyright © 2012 Elsevier Inc. All rights reserved.

Fibroblast growth factor 21 participates in adaptation to endoplasmic reticulum stress and attenuates obesity-induced hepatic metabolic stress.

Science.gov (United States)

Kim, Seong Hun; Kim, Kook Hwan; Kim, Hyoung-Kyu; Kim, Mi-Jeong; Back, Sung Hoon; Konishi, Morichika; Itoh, Nobuyuki; Lee, Myung-Shik

2015-04-01

Fibroblast growth factor 21 (FGF21) is an endocrine hormone that exhibits anti-diabetic and anti-obesity activity. FGF21 expression is increased in patients with and mouse models of obesity or nonalcoholic fatty liver disease (NAFLD). However, the functional role and molecular mechanism of FGF21 induction in obesity or NAFLD are not clear. As endoplasmic reticulum (ER) stress is triggered in obesity and NAFLD, we investigated whether ER stress affects FGF21 expression or whether FGF21 induction acts as a mechanism of the unfolded protein response (UPR) adaptation to ER stress induced by chemical stressors or obesity. Hepatocytes or mouse embryonic fibroblasts deficient in UPR signalling pathways and liver-specific eIF2α mutant mice were employed to investigate the in vitro and in vivo effects of ER stress on FGF21 expression, respectively. The in vivo importance of FGF21 induction by ER stress and obesity was determined using inducible Fgf21-transgenic mice and Fgf21-null mice with or without leptin deficiency. We found that ER stressors induced FGF21 expression, which was dependent on a PKR-like ER kinase-eukaryotic translation factor 2α-activating transcription factor 4 pathway both in vitro and in vivo. Fgf21-null mice exhibited increased expression of ER stress marker genes and augmented hepatic lipid accumulation after tunicamycin treatment. However, these changes were attenuated in inducible Fgf21-transgenic mice. We also observed that Fgf21-null mice with leptin deficiency displayed increased hepatic ER stress response and liver injury, accompanied by deteriorated metabolic variables. Our results suggest that FGF21 plays an important role in the adaptive response to ER stress- or obesity-induced hepatic metabolic stress.

Mother's postnatal stress: an investigation of links to various factors during pregnancy and post-partum.

Science.gov (United States)

Andersson, Ewa; Hildingsson, Ingegerd

2016-12-01

Higher levels of parental stress have long-term effects on children's health and could lead to dysfunction in the parent-child interaction. Different background factors can be predictors of high parental stress. The aim of this study was to examine parental stress among Swedish women and identify different factors linked to women's parental stress. About 702 women were recruited to a clinical study and followed up six months after birth. Data were collected by two questionnaires, and 279 women completed the Swedish Parental Stress Questionnaire (SPSQ). Less than very good mental health and depressive symptoms after birth were strongly associated with parental stress, and the strongest association was found between post-partum depressive symptoms and high levels of stress in the subscale Incompetence. Multiparity was associated with high stress in two subscales, and lower level of education was a protective factor for stress in nearly all subscales. Depressive symptoms and perceived poor mental health post-partum are the most important factors related to high parental stress. The results point to the importance of identifying and supporting mothers with depressive symptoms, since these women have both mental illness and increased stress. © 2015 Nordic College of Caring Science.

Effect of abiotic and biotic stress factors analysis using machine learning methods in zebrafish.

Science.gov (United States)

Gutha, Rajasekar; Yarrappagaari, Suresh; Thopireddy, Lavanya; Reddy, Kesireddy Sathyavelu; Saddala, Rajeswara Reddy

2018-03-01

In order to understand the mechanisms underlying stress responses, meta-analysis of transcriptome is made to identify differentially expressed genes (DEGs) and their biological, molecular and cellular mechanisms in response to stressors. The present study is aimed at identifying the effect of abiotic and biotic stress factors, and it is found that several stress responsive genes are common for both abiotic and biotic stress factors in zebrafish. The meta-analysis of micro-array studies revealed that almost 4.7% i.e., 108 common DEGs are differentially regulated between abiotic and biotic stresses. This shows that there is a global coordination and fine-tuning of gene regulation in response to these two types of challenges. We also performed dimension reduction methods, principal component analysis, and partial least squares discriminant analysis which are able to segregate abiotic and biotic stresses into separate entities. The supervised machine learning model, recursive-support vector machine, could classify abiotic and biotic stresses with 100% accuracy using a subset of DEGs. Beside these methods, the random forests decision tree model classified five out of 8 stress conditions with high accuracy. Finally, Functional enrichment analysis revealed the different gene ontology terms, transcription factors and miRNAs factors in the regulation of stress responses. Copyright © 2017 Elsevier Inc. All rights reserved.

Occupational stress and cardiovascular risk factors in high-ranking government officials and office workers.

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Mirmohammadi, Seyyed Jalil; Taheri, Mahmoud; Mehrparvar, Amir Houshang; Heydari, Mohammad; Saadati Kanafi, Ali; Mostaghaci, Mehrdad

2014-08-01

Cardiovascular diseases are among the most important sources of mortality and morbidity, and have a high disease burden. There are some major well-known risk factors, which contribute to the development of these diseases. Occupational stress is caused due to imbalance between job demands and individual's ability, and it has been implicated as an etiology for cardiovascular diseases. This study was conducted to evaluate the cardiovascular risk factors and different dimensions of occupational stress in high-ranking government officials, comparing an age and sex-matched group of office workers with them. We invited 90 high-ranking officials who managed the main governmental offices in a city, and 90 age and sex-matched office workers. The subjects were required to fill the occupational role questionnaire (Osipow) which evaluated their personal and medical history as well as occupational stress. Then, we performed physical examination and laboratory tests to check for cardiovascular risk factors. Finally, the frequency of cardiovascular risk factors and occupational stress of two groups were compared. High-ranking officials in our study had less work experience in their current jobs and smoked fewer pack-years of cigarette, but they had higher waist and hip circumference, higher triglyceride level, more stress from role overload and responsibility, and higher total stress score. Our group of office workers had more occupational stress because of role ambiguity and insufficiency, but their overall job stress was less than officials. The officials have higher scores in some dimensions of occupational stress and higher overall stress score. Some cardiovascular risk factors were also more frequent in managers.

Stress hysteresis during thermal cycling of plasma-enhanced chemical vapor deposited silicon oxide films

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Thurn, Jeremy; Cook, Robert F.

2002-02-01

The mechanical response of plasma-enhanced chemical vapor deposited SiO2 to thermal cycling is examined by substrate curvature measurement and depth-sensing indentation. Film properties of deposition stress and stress hysteresis that accompanied thermal cycling are elucidated, as well as modulus, hardness, and coefficient of thermal expansion. Thermal cycling is shown to result in major plastic deformation of the film and a switch from a compressive to a tensile state of stress; both athermal and thermal components of the net stress alter in different ways during cycling. A mechanism of hydrogen incorporation and release from as-deposited silanol groups is proposed that accounts for the change in film properties and state of stress.

Factors Contributing to Perceived Stress among Doctor of Pharmacy (PharmD) Students

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Ford, Kentya C.; Olotu, Busuyi S.; Thach, Andrew V.; Roberts, Rochelle; Davis, Patrick

2014-01-01

Objective: The purpose of this study was to report on perceived stress levels, identify its contributing factors, and evaluate the association between perceived stress and usage of university resources to cope with stress among a cross-section of Doctor of Pharmacy (PharmD) students. Methods: Perceived stress was measured via a web-based survey of…

[The role of environmental factors in managing labour stress].

Science.gov (United States)

Rados, Melinda; Mészáros, Judit

2017-07-01

Emotional, cognitive and behavioural aspects of birth and labour stress are strongly associated with the underlying physiological processes. To study the factors of physical security and social support, the administration of synthetic oxytocin, and how they relate to perceived stress during childbirth. Women's experienced physical security, social support and oxytocin administration was measured with targeted questions, and their perceived stress with the short and modified version of the Perceived Stress Scale. A strong negative association was found between perceived stress and physical and social security. The group of women experiencing low physical and social security perceived significantly higher stress, while those given synthetic oxytocin perceived higher stress, and lower physical and social security. Since physiological, psychological processes and behaviours are strongly intertwined, the support of natural physiological birth without interventions is recommended, which considers not only short-term but long-term health consequences for mother and child. The contribution of calming physical surroundings, minimal interventions and empowering support of caregivers to safe and satisfying birth is demonstrated in a model. Orv Hetil. 2017; 158(29): 1149-1156.

Risk factors for stress fracture among young female cross-country runners.

Science.gov (United States)

Kelsey, Jennifer L; Bachrach, Laura K; Procter-Gray, Elizabeth; Nieves, Jeri; Greendale, Gail A; Sowers, Maryfran; Brown, Byron W; Matheson, Kim A; Crawford, Sybil L; Cobb, Kristin L

2007-09-01

To identify risk factors for stress fracture among young female distance runners. Participants were 127 competitive female distance runners, aged 18-26, who provided at least some follow-up data in a randomized trial among 150 runners of the effects of oral contraceptives on bone health. After completing a baseline questionnaire and undergoing bone densitometry, they were followed an average of 1.85 yr. Eighteen participants had at least one stress fracture during follow-up. Baseline characteristics associated (Pstress fracture occurrence were one or more previous stress fractures (rate ratio [RR] [95% confidence interval]=6.42 (1.80-22.87), lower whole-body bone mineral content (RR=2.70 [1.26-5.88] per 1-SD [293.2 g] decrease), younger chronologic age (RR=1.42 [1.05-1.92] per 1-yr decrease), lower dietary calcium intake (RR=1.11 [0.98-1.25] per 100-mg decrease), and younger age at menarche (RR=1.92 [1.15-3.23] per 1-yr decrease). Although not statistically significant, a history of irregular menstrual periods was also associated with increased risk (RR=3.41 [0.69-16.91]). Training-related factors did not affect risk. The results of this and other studies indicate that risk factors for stress fracture among young female runners include previous stress fractures, lower bone mass, and, although not statistically significant in this study, menstrual irregularity. More study is needed of the associations between stress fracture and age, calcium intake, and age at menarche. Given the importance of stress fractures to runners, identifying preventive measures is of high priority.

Determinants of Perceived Stress in Individuals with Obesity: Exploring the Relationship of Potentially Obesity-Related Factors and Perceived Stress.

Science.gov (United States)

Junne, Florian; Ziser, Katrin; Giel, Katrin Elisabeth; Schag, Kathrin; Skoda, Eva; Mack, Isabelle; Niess, Andreas; Zipfel, Stephan; Teufel, Martin

2017-01-01

Associations of specific types of stress with increased food intake and subsequent weight gain have been demonstrated in animal models as well as in experimental and epidemiological studies on humans. This study explores the research question of to what extent potentially obesity-related factors determine perceived stress in individuals with obesity. N = 547 individuals with obesity participated in a cross-sectional study assessing perceived stress as the outcome variable and potential determinants of stress related to obesity. Based on the available evidence, a five factorial model of 'obesity-related obesogenic stressors' was hypothesized, including the dimensions, 'drive for thinness', 'impulse regulation', 'ineffectiveness', 'social insecurity', and 'body dissatisfaction'. The model was tested using multiple linear regression analyses. The five factorial model of 'potentially obesity-related stressors' resulted in a total variance explanation of adjusted R² = 0.616 for males and adjusted R² = 0.595 for females for perceived stress. The relative variance contribution of the five included factors differed substantially for the two sexes. The findings of this cross-sectional study support the hypothesized, potentially obesity-related factors: 'drive for thinness', 'impulse regulation', 'ineffectiveness', 'social insecurity', and 'body dissatisfaction' as relevant determinants of perceived stress in individuals with obesity. © 2017 The Author(s) Published by S. Karger GmbH, Freiburg.

Enhanced oxidative stress in the jasmonic acid-deficient tomato mutant def-1 exposed to NaCl stress.

Science.gov (United States)

Abouelsaad, Ibrahim; Renault, Sylvie

2018-04-21

Jasmonic acid (JA) has been mostly studied in responses to biotic stresses, such as herbivore attack and pathogenic infection. More recently, the involvement of JA in abiotic stresses including salinity was highlighted; yet, its role in salt stress remained unclear. In the current study, we compared the physiological and biochemical responses of wild-type (WT) tomato (Solanum lycopersicum) cv Castlemart and its JA-deficient mutant defenseless-1 (def-1) under salt stress to investigate the role of JA. Plant growth, photosynthetic pigment content, ion accumulation, oxidative stress-related parameters, proline accumulation and total phenolic compounds, in addition to both enzymatic and non-enzymatic antioxidant activities, were measured in both genotypes after 14 days of 100 mM NaCl treatment. Although we observed in both genotypes similar growth pattern and sodium, calcium and potassium levels in leaves under salt stress, def-1 plants exhibited a more pronounced decrease of nitrogen content in both leaves and roots and a slightly higher level of sodium in roots compared to WT plants. In addition, def-1 plants exposed to salt stress showed reactive oxygen species (ROS)-associated injury phenotypes. These oxidative stress symptoms in def-1 were associated with lower activity of both enzymatic antioxidants and non-enzymatic antioxidants. Furthermore, the levels of the non-enzymatic ROS scavengers proline and total phenolic compounds increased in both genotypes exposed to salt stress, with a higher amount of proline in the WT plants. Overall the results of this study suggest that endogenous JA mainly enhanced tomato salt tolerance by maintaining ROS homeostasis. Copyright © 2018 Elsevier GmbH. All rights reserved.

Analysis of stress intensity factors for a new mechanical corrosion specimen

International Nuclear Information System (INIS)

Rassineux, B.; Crouzet, D.; Le Hong, S.

1996-03-01

Electricite de France is conducting a research program to determine corrosion cracking rates in the steam generators Alloy 600 tubes of the primary system. The objective is to correlate the cracking rates with the specimen stress intensity factor K I . One of the samples selected for the purpose of this study is the longitudinal notched specimen TEL (TEL: ''Tubulaire a Entailles Longitudinales''). This paper presents the analysis of the stress intensity factor and its experimental validation. The stress intensity factor has been evaluated for different loads using 3D finite element calculations with the Hellen-Parks and G(θ) methods. Both crack initiation and propagation are considered. As an assessment of the method, the numerical simulations are in good agreement with the fatigue crack growth rates measured experimentally for TEL and compact tension (CT) specimens. (authors). 8 refs., 6 figs., 2 tabs

Calculation of stress intensity factors for circumferential semi-elliptical cracks with high aspect ratio in pipes

International Nuclear Information System (INIS)

Zareei, A.; Nabavi, S.M.

2016-01-01

In this paper, stress intensity factors are calculated at the deepest point of an internal circumferential semi-elliptical crack in a pipe subjected to any arbitrary load. Based on the three dimensional finite element analysis, a weight function is proposed for high aspect ratio semi-elliptical cracks in pipes. An effective expression is developed analytically to evaluate the stress intensity factor using the weight function method. For several crack face stress fields and welding residual stress distributions, the weight function is validated against finite element data and those in the literature. Based on the comparison results, it can be concluded that the solution proposed in this paper is effective in engineering applications. - Highlights: • Analysis of internal circumferential semi-elliptical cracks with high aspect ratio in pipes. • A weight function is proposed for the calculation of the stress intensity factors for the deepest point of the crack. • An effective closed form expression is proposed to evaluate the stress intensity factors. • Prediction of stress intensity factors for any applied stress gradients through the wall thickness without any limitations. • A three-dimensional finite element modeling employs to calculate the stress intensity factors for different geometries.

Personality factors and posttraumatic stress: associations in civilians one year after air attacks.

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Lecic-Tosevski, Dusica; Gavrilovic, Jelena; Knezevic, Goran; Priebe, Stefan

2003-12-01

There is an ongoing debate on which risk factors for developing posttraumatic stress symptoms are more important--personality traits reflecting vulnerability, previous stressful experiences or characteristics of the traumatic event. In this study, posttraumatic stress symptoms and their relationship with personality traits, previous stressful experiences and exposure to stressful events during air attacks in Yugoslavia were investigated. The Millon Clinical Multiaxial Inventory (MCMI; Millon, 1983), Impact of Events Scale (IES; Horowitz, Wilner, & Alvarez, 1979), Life Stressor Checklist Revised (LSCL-R; Wolfe & Kimerling, 1997), and List of Stressors were administered to a homogeneous group of medical students 1 year after the attacks. In multiple regression analyses, compulsive and passive-aggressive personality traits and a higher level of exposure to stressors during air attacks independently predicted the degree of intrusion symptoms. Avoidance symptoms were predicted by avoidant personality traits and a higher exposure to stressors both previously in life and during the attacks. In the next step, we tested in analyses of variance whether personality traits, previous stressful experiences, and stressful events during attacks as independent variables interact in predicting intrusion and avoidance symptoms. For this, students were clustered into three groups depending on their predominant personality traits. In addition to direct predictive effects, there were significant interaction effects in predicting both intrusion and avoidance. The findings suggest that each of the tested factors, i.e., personality traits, previous stressful experiences, and exposure to traumatic events may have an independent and direct influence on developing posttraumatic stress. However, the effect of these factors cannot just be added up. Rather, the factors interact in their impact on posttraumatic stress symptoms. Bigger samples and longitudinal designs will be required to

A social work study using factor analysis on detecting important factors creating stress: A case study of hydro-power employees

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Batoul Aminjafari

2012-08-01

Full Text Available The study performs an empirical study based on the implementation of factor analysis to detect different factors influencing people to have more stress in a hydropower unit located in city of Esfahan, Iran. The study performed the survey among all 81 people who were working for customer service section of this company and consisted of two parts, in the first part; we gather all private information such as age, gender, education, job experience, etc. through seven important questions. In the second part of the survey, there were 66 questions, which included all the relevant factors impacting employees' stress. Cronbach alpha was calculated as 0.946, which is well above the minimum acceptable level. The implementation of factor analysis has detected 16 important groups of factors and each factor is determined by an appropriate name. The results of our factor analysis show that among different factors, difficulty of working condition as well as work pressure are two most important factors increasing stress among employees.

Stress enhances fear by forming new synapses with greater capacity for long-term potentiation in the amygdala.

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Suvrathan, Aparna; Bennur, Sharath; Ghosh, Supriya; Tomar, Anupratap; Anilkumar, Shobha; Chattarji, Sumantra

2014-01-05

Prolonged and severe stress leads to cognitive deficits, but facilitates emotional behaviour. Little is known about the synaptic basis for this contrast. Here, we report that in rats subjected to chronic immobilization stress, long-term potentiation (LTP) and NMDA receptor (NMDAR)-mediated synaptic responses are enhanced in principal neurons of the lateral amygdala, a brain area involved in fear memory formation. This is accompanied by electrophysiological and morphological changes consistent with the formation of 'silent synapses', containing only NMDARs. In parallel, chronic stress also reduces synaptic inhibition. Together, these synaptic changes would enable amygdalar neurons to undergo further experience-dependent modifications, leading to stronger fear memories. Consistent with this prediction, stressed animals exhibit enhanced conditioned fear. Hence, stress may leave its mark in the amygdala by generating new synapses with greater capacity for plasticity, thereby creating an ideal neuronal substrate for affective disorders. These findings also highlight the unique features of stress-induced plasticity in the amygdala that are strikingly different from the stress-induced impairment of structure and function in the hippocampus.

Malaysian adolescent students' needs for enhancing thinking skills, counteracting risk factors and demonstrating academic resilience

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Kuldas, Seffetullah; Hashim, Shahabuddin; Ismail, Hairul Nizam

2015-01-01

The adolescence period of life comes along with changes and challenges in terms of physical and cognitive development. In this hectic period, many adolescents may suffer more from various risk factors such as low socioeconomic status, substance abuse, sexual abuse and teenage pregnancy. Findings indicate that such disadvantaged backgrounds of Malaysian adolescent students lead to failure or underachievement in their academic performance. This narrative review scrutinises how some of these students are able to demonstrate academic resilience, which is satisfactory performance in cognitive or academic tasks in spite of their disadvantaged backgrounds. The review stresses the need for developing a caregiving relationship model for at-risk adolescent students in Malaysia. Such a model would allow educators to meet the students' needs for enhancing thinking skills, counteracting risk factors and demonstrating academic resilience. PMID:25663734

Factors causing stress among Pakistani working women

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Ahmed Arif

2017-09-01

Full Text Available Women are traditionally considered to be confined within the four walls of their houses in the developing countries. They are still unable to play an active role in the development of society. They are striving to make their identity as an integral part of the society. Being a member of conservative developing society, women are still facing many hindrances, causing stressful situation for them, which prohibits them to participate actively in the economic development. This paper attempts to explore the critical factors creating stress among Pakistani working women. Based on literature review, the key stressors were identified to be as work life balance, gender discrimination, peers behaviour, lack of promotional opportunities and sexual harassment. These factors were found to be creating physiological, behavioural and psychological problems. The target of this study was the women working in secretarial and administrative positions in Pakistani organisations. Regression analysis was conducted to find out the impact of these stressors on working women. The results revealed that sexual harassment, peers behaviour and lack of promotional opportunities were the most dominant stressors.

Stress-induced enhancement of mouse amygdalar synaptic plasticity depends on glucocorticoid and ß-adrenergic activity.

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Ratna Angela Sarabdjitsingh

Full Text Available BACKGROUND: Glucocorticoid hormones, in interaction with noradrenaline, enable the consolidation of emotionally arousing and stressful experiences in rodents and humans. Such interaction is thought to occur at least partly in the basolateral nucleus of the amygdala (BLA which is crucially involved in emotional memory formation. Extensive evidence points to long-term synaptic potentiation (LTP as a mechanism contributing to memory formation. Here we determined in adolescent C57/Bl6 mice the effects of stress on LTP in the LA-BLA pathway and the specific roles of corticosteroid and β-adrenergic receptor activation in this process. PRINCIPAL FINDINGS: Exposure to 20 min of restraint stress (compared to control treatment prior to slice preparation enhanced subsequent LTP induction in vitro, without affecting baseline fEPSP responses. The role of glucocorticoid receptors, mineralocorticoid receptors and β2-adrenoceptors in the effects of stress was studied by treating mice with the antagonists mifepristone, spironolactone or propranolol respectively (or the corresponding vehicles prior to stress or control treatment. In undisturbed controls, mifepristone and propranolol administration in vivo did not influence LTP induced in vitro. By contrast, spironolactone caused a gradually attenuating form of LTP, both in unstressed and stressed mice. Mifepristone treatment prior to stress strongly reduced the ability to induce LTP in vitro. Propranolol normalized the stress-induced enhancement of LTP to control levels during the first 10 min after high frequency stimulation, after which synaptic responses further declined. CONCLUSIONS: Acute stress changes BLA electrical properties such that subsequent LTP induction is facilitated. Both β-adrenergic and glucocorticoid receptors are involved in the development of these changes. Mineralocorticoid receptors are important for the maintenance of LTP in the BLA, irrespective of stress-induced changes in the

RSK2-induced stress tolerance enhances cell survival signals mediated by inhibition of GSK3β activity

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Lee, Cheol-Jung; Lee, Mee-Hyun; Lee, Ji-Young; Song, Ji Hong; Lee, Hye Suk; Cho, Yong-Yeon

2013-01-01

Highlights: •We demonstrated a novel function of RSK2 in stress tolerance. •RSK2 deficiency enhanced apoptosis by calcium stress. •RSK2-mediated GSK3β phosphorylation at serine 9 increased calcium-induced stress tolerance. •Calcium stress-induced apoptosis inhibited by adding back of RSK2 into RSK2 −/− MEFs. -- Abstract: Our previous studies demonstrated that RSK2 plays a key role in cell proliferation and transformation induced by tumor promoters such as epidermal growth factor (EGF) in mouse and human skin cells. However, no direct evidence has been found regarding the relationship of RSK2 and cell survival. In this study, we found that RSK2 interacted and phosphorylated GSK3β at Ser9. Notably, GSK3β phosphorylation at Ser9 was suppressed in RSK2 −/− MEFs compared with RSK2 +/+ MEFs by stimulation of EGF and calcium ionophore A23187, a cellular calcium stressor. In proliferation, we found that RSK2 deficiency suppressed cell proliferation compared with RSK2 +/+ MEFs. In contrast, GSK3β −/− MEFs induced the cell proliferation compared with GSK3β +/+ MEFs. Importantly, RSK2 −/− MEFs were induced severe cellular morphology change by A23187 and enhanced G1/G0 and sub-G1 accumulation of the cell cycle phase compared with RSK2 +/+ MEFs. The sub-G1 induction in RSK2 −/− MEFs by A23187 was correlated with increase of cytochrome c release, caspase-3 cleavage and apoptotic DNA fragmentation compared with RSK2 +/+ MEFs. Notably, return back of RSK2 into RSK2 −/− MEFs restored A23187-induced morphological change, and decreased apoptosis, apoptotic DNA fragmentation and caspase-3 induction compared with RSK2 −/− /mock MEFs. Taken together, our results demonstrated that RSK2 plays an important role in stress-tolerance and cell survival, resulting in cell proliferation and cancer development

Research Progress on Measurement Methods and Influence Factors of Thin-film Stress

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MA Yibo

2018-02-01

Full Text Available With the size of thin-film electronic devices decreasing, the film stress became an important reason for the failure of thin film devices. Film stress not only affected the membrane structure, but also associated with film optics, electricity, mechanics and other properties, therefore film stress turned into one hot spot in the research field of thin-film materials. This paper reviewed the latest research progress of film stress, substrate curvature method, X-ray diffraction technique and Raman spectroscopy, several frequently used stress measuring techniques were compared and analyzed, and composition ratios of thin film, substrate types, magnetron sputtering process parameters (sputtering power, work pressure, substrate temperature and annealing etc. factors influencing thin film stress were summarized. It was found that substrate curvature method was suitable for measuring almost all kinds of thin film materials. X-ray diffraction and Raman spectroscopy were just fit for measuring materials with characteristic peaks. Nanoindentation method required extra stress-free samples as comparison experiments. During film fabrication and annealing process, film stress usually transited from compressive to tensile status, and several factors combined together could affect stress, so film stress could be reached the minimum value or even stress-free status through setting appropriate parameters. Finally, combined with film stress research status, accurate stress measurement methods for different materials as a thin-film stress research direction were introduced, and challenges in thin film detection range were pointed out.

Salinity induced oxidative stress enhanced biofuel production potential of microalgae Scenedesmus sp. CCNM 1077.

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Pancha, Imran; Chokshi, Kaumeel; Maurya, Rahulkumar; Trivedi, Khanjan; Patidar, Shailesh Kumar; Ghosh, Arup; Mishra, Sandhya

2015-01-01

Microalgal biomass is considered as potential feedstock for biofuel production. Enhancement of biomass, lipid and carbohydrate contents in microalgae is important for the commercialization of microalgal biofuels. In the present study, salinity stress induced physiological and biochemical changes in microalgae Scenedesmus sp. CCNM 1077 were studied. During single stage cultivation, 33.13% lipid and 35.91% carbohydrate content was found in 400 mM NaCl grown culture. During two stage cultivation, salinity stress of 400 mM for 3 days resulted in 24.77% lipid (containing 74.87% neutral lipid) along with higher biomass compared to single stage, making it an efficient strategy to enhance biofuel production potential of Scenedesmus sp. CCNM 1077. Apart from biochemical content, stress biomarkers like hydrogen peroxide, lipid peroxidation, ascorbate peroxidase, proline and mineral contents were also studied to understand the role of reactive oxygen species (ROS) mediated lipid accumulation in microalgae Scenedesmus sp. CCNM 1077. Copyright © 2015 Elsevier Ltd. All rights reserved.

Regulation of Pancreatic β Cell Mass by Cross-Interaction between CCAAT Enhancer Binding Protein β Induced by Endoplasmic Reticulum Stress and AMP-Activated Protein Kinase Activity.

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Tomokazu Matsuda

Full Text Available During the development of type 2 diabetes, endoplasmic reticulum (ER stress leads to not only insulin resistance but also to pancreatic beta cell failure. Conversely, cell function under various stressed conditions can be restored by reducing ER stress by activating AMP-activated protein kinase (AMPK. However, the details of this mechanism are still obscure. Therefore, the current study aims to elucidate the role of AMPK activity during ER stress-associated pancreatic beta cell failure. MIN6 cells were loaded with 5-amino-1-β-D-ribofuranosyl-imidazole-4-carboxamide (AICAR and metformin to assess the relationship between AMPK activity and CCAAT enhancer binding protein β (C/EBPβ expression levels. The effect of C/EBPβ phosphorylation on expression levels was also investigated. Vildagliptin and metformin were administered to pancreatic beta cell-specific C/EBPβ transgenic mice to investigate the relationship between C/EBPβ expression levels and AMPK activity in the pancreatic islets. When pancreatic beta cells are exposed to ER stress, the accumulation of the transcription factor C/EBPβ lowers the AMP/ATP ratio, thereby decreasing AMPK activity. In an opposite manner, incubation of MIN6 cells with AICAR or metformin activated AMPK, which suppressed C/EBPβ expression. In addition, administration of the dipeptidyl peptidase-4 inhibitor vildagliptin and metformin to pancreatic beta cell-specific C/EBPβ transgenic mice decreased C/EBPβ expression levels and enhanced pancreatic beta cell mass in proportion to the recovery of AMPK activity. Enhanced C/EBPβ expression and decreased AMPK activity act synergistically to induce ER stress-associated pancreatic beta cell failure.

Genome wide analysis of stress responsive WRKY transcription factors in Arabidopsis thaliana

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Shaiq Sultan

2016-04-01

Full Text Available WRKY transcription factors are a class of DNA-binding proteins that bind with a specific sequence C/TTGACT/C known as W-Box found in promoters of genes which are regulated by these WRKYs. From previous studies, 43 different stress responsive WRKY transcription factors in Arabidopsis thaliana, identified and then categorized in three groups viz., abiotic, biotic and both of these stresses. A comprehensive genome wide analysis including chromosomal localization, gene structure analysis, multiple sequence alignment, phylogenetic analysis and promoter analysis of these WRKY genes was carried out in this study to determine the functional homology in Arabidopsis. This analysis led to the classification of these WRKY family members into 3 major groups and subgroups and showed evolutionary relationship among these groups on the base of their functional WRKY domain, chromosomal localization and intron/exon structure. The proposed groups of these stress responsive WRKY genes and annotation based on their position on chromosomes can also be explored to determine their functional homology in other plant species in relation to different stresses. The result of the present study provides indispensable genomic information for the stress responsive WRKY transcription factors in Arabidopsis and will pave the way to explain the precise role of various AtWRKYs in plant growth and development under stressed conditions.

Occupational stress and its related factors among university teachers in China.

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Sun, Wei; Wu, Hui; Wang, Lie

2011-01-01

University teachers in China are expected to suffer serious occupational stress due to the expanding enrollment in universities without a proportional increase in teacher resources and the fact that all promotions for university teachers are determined based on not only teaching but also the outcome of scientific research. This study was designed to assess the occupational stress among university teachers in China and clarify its risk factors. A cross-sectional study was performed in Liaoning Province, the centralized area of higher education in Northeast China. Eight universities (2 multidiscipline and 6 specialized) and 10% of academic staff each were randomly sampled. Questionnaires pertaining to occupational stress indicated by the Chinese Version Personal Strain Questionnaire (PSQ) and demographic characteristics, health status, work situations, and personal and social resources were distributed in October 2008. A total of 827 effective respondents (response rate 76.4%) became our participants. The average raw score of PSQ was 91.0 among the university teachers. General linear model analysis showed that the factors significantly associated with the PSQ score were, in standardized estimate (β) sequence, mental health, role overload, role insufficiency, social support, monthly income, role limitations due to physical problems, research finance and self-rated disease with adjustment for age and sex. We concluded that, in comparison to work-related factors and social support, mental health is a prominent risk factor for occupational stress in university teachers in China. Improvement of mental health and organizational climate should be considered to lessen the occupational stress of university teachers.

The Reaumuria trigyna transcription factor RtWRKY1 confers tolerance to salt stress in transgenic Arabidopsis.

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Du, Chao; Zhao, Pingping; Zhang, Huirong; Li, Ningning; Zheng, Linlin; Wang, Yingchun

2017-08-01

Reaumuria trigyna (R. trigyna) is an endangered small shrub endemic to the Eastern Alxa-Western Ordos area in Inner Mongolia, China. Based on R. trigyna transcriptome data, the Group I WRKY transcription factor gene RtWRKY1 was cloned from R. trigyna. The full-length RtWRKY1 gene was 2100bp, including a 1261-bp open reading frame (ORF) encoding 573 amino acids. RtWRKY1 was mainly expressed in the stem and was induced by salt, cold stress, and ABA treatment. Overexpression of RtWRKY1 in Arabidopsis significantly enhanced the chlorophyll content, root length, and fresh weight of the transgenic lines under salt stress. RtWRKY1 transgenic Arabidopsis exhibited higher proline content, GSH-PX, POD, SOD, and CAT activities, and lower MDA content, Na + content, and Na + /K + ratio than wild-type Arabidopsis under salt stress conditions. Salt stress affected the expression of ion transport, proline biosynthesis, and antioxidant related genes, including AtAPX1, AtCAT1, AtSOD1, AtP5CS1, AtP5CS2, AtPRODH1, AtPRODH2, and AtSOS1 in transgenic lines. RtWRKY1 confers tolerance to salt stress in transgenic Arabidopsis by regulating plant growth, osmotic balance, Na + /K + homeostasis, and the antioxidant system. Copyright © 2017 Elsevier GmbH. All rights reserved.

Stress and multiple sclerosis: A systematic review considering potential moderating and mediating factors and methods of assessing stress

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Laia Briones-Buixassa

2015-11-01

Full Text Available Research about the effects of stress on multiple sclerosis has yielded contradictory results. This study aims to systematically review the evidence focusing on two possible causes: the role of stress assessment and potential moderating and mediating factors. The Web of Knowledge (MEDLINE and Web of Science, Scopus, and PsycINFO databases were searched for relevant articles published from 1900 through December 2014 using the terms “stress*” AND “multiple sclerosis.” Twenty-three articles were included. Studies focused on the effect of stress on multiple sclerosis onset ( n  = 9 were mostly retrospective, and semi-structured interviews and scales yielded the most consistent associations. Studies focused on multiple sclerosis progression ( n  = 14 were mostly prospective, and self-reported diaries yielded the most consistent results. The most important modifying factors were stressor duration, severity, and frequency; cardiovascular reactivity and heart rate; and social support and escitalopram intake. Future studies should consider the use of prospective design with self-reported evaluations and the study of moderators and mediators related to amount of stress and autonomic nervous system reactivity to determine the effects of stress on multiple sclerosis.

Stress and multiple sclerosis: A systematic review considering potential moderating and mediating factors and methods of assessing stress.

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Briones-Buixassa, Laia; Milà, Raimon; Mª Aragonès, Josep; Bufill, Enric; Olaya, Beatriz; Arrufat, Francesc Xavier

2015-07-01

Research about the effects of stress on multiple sclerosis has yielded contradictory results. This study aims to systematically review the evidence focusing on two possible causes: the role of stress assessment and potential moderating and mediating factors. The Web of Knowledge (MEDLINE and Web of Science), Scopus, and PsycINFO databases were searched for relevant articles published from 1900 through December 2014 using the terms "stress*" AND "multiple sclerosis." Twenty-three articles were included. Studies focused on the effect of stress on multiple sclerosis onset ( n  = 9) were mostly retrospective, and semi-structured interviews and scales yielded the most consistent associations. Studies focused on multiple sclerosis progression ( n  = 14) were mostly prospective, and self-reported diaries yielded the most consistent results. The most important modifying factors were stressor duration, severity, and frequency; cardiovascular reactivity and heart rate; and social support and escitalopram intake. Future studies should consider the use of prospective design with self-reported evaluations and the study of moderators and mediators related to amount of stress and autonomic nervous system reactivity to determine the effects of stress on multiple sclerosis.

Urban social stress – Risk factor for mental disorders. The case of schizophrenia

International Nuclear Information System (INIS)

Lederbogen, Florian; Haddad, Leila; Meyer-Lindenberg, Andreas

2013-01-01

Living in an urban environment is associated with an increased prevalence of specific mental health disorders, particularly schizophrenia. While many factors have been discussed as possible mediators of this association, most researchers favour the hypothesis that urban living stands as a proxy for an increased exposure to social stress. This factor has been recognized as one of the most powerful causes for the development of mental disorders, and appears to correlate with the markedly increased incidence of schizophrenia in urban minority groups. However, the hypothesis that the general urban population is exposed to increased levels of social stress has to be validated. Pursuing the goal of understanding how social stress acts as a risk factor for mental disorder in urban populations must include factors like social conditions, environmental pollutants, infrastructure and economic issues. -- Highlights: • City living is associated with an increased prevalence of mental health disorders, particularly schizophrenia. • Possible mediators of this association include exposure to social stress. • This mechanism seems plausible in urban minority groups. • However, it is unclear whether social stress exposure is increased in the general urban population. -- New data support the hypothesis that increased exposure to social stressors is a key factor mediating the increased prevalence of specific mental disorders in urban populations

Nucleus accumbens corticotropin-releasing factor increases cue-triggered motivation for sucrose reward: paradoxical positive incentive effects in stress?

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Peciña, Susana; Schulkin, Jay; Berridge, Kent C

2006-04-13

Corticotropin-releasing factor (CRF) is typically considered to mediate aversive aspects of stress, fear and anxiety. However, CRF release in the brain is also elicited by natural rewards and incentive cues, raising the possibility that some CRF systems in the brain mediate an independent function of positive incentive motivation, such as amplifying incentive salience. Here we asked whether activation of a limbic CRF subsystem magnifies the increase in positive motivation for reward elicited by incentive cues previously associated with that reward, in a way that might exacerbate cue-triggered binge pursuit of food or other incentives? We assessed the impact of CRF microinjections into the medial shell of nucleus accumbens using a pure incentive version of Pavlovian-Instrumental transfer, a measure specifically sensitive to the incentive salience of reward cues (which it separates from influences of aversive stress, stress reduction, frustration and other traditional explanations for stress-increased behavior). Rats were first trained to press one of two levers to obtain sucrose pellets, and then separately conditioned to associate a Pavlovian cue with free sucrose pellets. On test days, rats received microinjections of vehicle, CRF (250 or 500 ng/0.2 microl) or amphetamine (20 microg/0.2 microl). Lever pressing was assessed in the presence or absence of the Pavlovian cues during a half-hour test. Microinjections of the highest dose of CRF (500 ng) or amphetamine (20 microg) selectively enhanced the ability of Pavlovian reward cues to trigger phasic peaks of increased instrumental performance for a sucrose reward, each peak lasting a minute or so before decaying after the cue. Lever pressing was not enhanced by CRF microinjections in the baseline absence of the Pavlovian cue or during the presentation without a cue, showing that the CRF enhancement could not be explained as a result of generalized motor arousal, frustration or stress, or by persistent attempts to

Exposing women to workplace stress factors as a risk factor for developing arterial hypertension.

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Bojar, Iwona; Humeniuk, Ewa; Owoc, Alfred; Wierzba, Waldemar; Wojtyła, Andrzej

2011-01-01

The purpose of this study is the evaluation of women's exposure to stress-inducing factors at work, definition of a scale of the problem, as well as assessment of the impact of professional work on the value of arterial pressure. The research was conducted on four professional groups of women: working in agriculture, working as clerks, seamstresses, as well as those working as medical representative in the period from August- September 2008 in the Lublin region. A total number of 416 women was examined, ages ranging from 30-40, who had not been previously treated due to arterial hypertension. The women under examination had their arterial blood pressure measured twice on a working day at 08:00 and at 14:00. The values of measurements were averaged. The research tool was also the standardised Questionnaire for Subjective Work Evaluation. The raw result was obtained on the basis of summing up all the points, which were afterwards transformed into 10 standard values. The general result was given in 10 standard values, whereas the results of stress factors were quoted as mean results of raw values and were referred to results defined as high for a given factor. The results obtained were statistically analysed on the basis of t-Student test. The significance level adopted was pplace of residence, on the intensification of stress related to a particular factor of work evaluation, was also analysed. Stress experienced by women at a workplace affects not ony their professional life, but also family life and social intercourses. In the women's opinion, an unpleasant workplace is such a workplace where the feeling of mental workload is connected with the lack of rewards (motivation), uncertainty resulting from organisation of daily chores and lack of support from others. The high general level of stress was noted among the group of women working in agriculture, in pharmaceutical companies, as well as among those who perform physical work (seamstresses). The intensification

WRKY transcription factors in plant responses to stresses.

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Jiang, Jingjing; Ma, Shenghui; Ye, Nenghui; Jiang, Ming; Cao, Jiashu; Zhang, Jianhua

2017-02-01

The WRKY gene family is among the largest families of transcription factors (TFs) in higher plants. By regulating the plant hormone signal transduction pathway, these TFs play critical roles in some plant processes in response to biotic and abiotic stress. Various bodies of research have demonstrated the important biological functions of WRKY TFs in plant response to different kinds of biotic and abiotic stresses and working mechanisms. However, very little summarization has been done to review their research progress. Not just important TFs function in plant response to biotic and abiotic stresses, WRKY also participates in carbohydrate synthesis, senescence, development, and secondary metabolites synthesis. WRKY proteins can bind to W-box (TGACC (A/T)) in the promoter of its target genes and activate or repress the expression of downstream genes to regulate their stress response. Moreover, WRKY proteins can interact with other TFs to regulate plant defensive responses. In the present review, we focus on the structural characteristics of WRKY TFs and the research progress on their functions in plant responses to a variety of stresses. © 2016 Institute of Botany, Chinese Academy of Sciences.

The potential of epigenetics in stress-enhanced fear learning models of PTSD.

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Blouin, Ashley M; Sillivan, Stephanie E; Joseph, Nadine F; Miller, Courtney A

2016-10-01

Prolonged distress and dysregulated memory processes are the core features of post-traumatic stress disorder (PTSD) and represent the debilitating, persistent nature of the illness. However, the neurobiological mechanisms underlying the expression of these symptoms are challenging to study in human patients. Stress-enhanced fear learning (SEFL) paradigms, which encompass both stress and memory components in rodents, are emerging as valuable preclinical models of PTSD. Rodent models designed to study the long-term mechanisms of either stress or fear memory alone have identified a critical role for numerous epigenetic modifications to DNA and histone proteins. However, the epigenetic modifications underlying SEFL remain largely unknown. This review will provide a brief overview of the epigenetic modifications implicated in stress and fear memory independently, followed by a description of existing SEFL models and the few epigenetic mechanisms found to date to underlie SEFL. The results of the animal studies discussed here highlight neuroepigenetics as an essential area for future research in the context of PTSD through SEFL studies, because of its potential to identify novel candidates for neurotherapeutics targeting stress-induced pathogenic memories. © 2016 Blouin et al.; Published by Cold Spring Harbor Laboratory Press.

A Factor Analytic Study of the Teaching Events Stress Inventory.

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Alexander, Livingston; And Others

The purpose of this study was to determine if definitive factors emerge from the responses of teachers to the Teaching Events Stress Inventory (TESI). In a series of three studies during the years 1980 to 1982, data were collected to assess the levels and sources of stress experienced by 660 teachers in central and western Kentucky. The subjects…

Enhancement of BDNF Concentration and Restoration of the Hypothalamic-Pituitary-Adrenal Axis Accompany Reduced Depressive-Like Behaviour in Stressed Ovariectomised Rats Treated with Either Tualang Honey or Estrogen

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Badriya Al-Rahbi

2014-01-01

Full Text Available A possible interaction between glucocorticoids and estrogen-induced increases in brain-derived-neurotrophic factor (BDNF expression in enhancing depressive-like behaviour has been documented. Here we evaluated the effects of Tualang honey, a phytoestrogen, and 17β-estradiol (E2 on the depressive-like behaviour, stress hormones, and BDNF concentration in stressed ovariectomised (OVX rats. The animals were divided into six groups: (i nonstressed sham-operated control, (ii stressed sham-operated control, (iii nonstressed OVX, (iv stressed OVX, (v stressed OVX treated with E2 (20 μg daily, sc, and (vi stressed OVX treated with Tualang honey (0.2 g/kg body weight daily, orally. Two months after surgery, the animals were subjected to social instability stress procedure followed by forced swimming test. Struggling time, immobility time, and swimming time were scored. Serum adrenocorticotropic hormone (ACTH and corticosterone levels, and the BDNF concentration were determined using commercially available ELISA kits. Stressed OVX rats displayed increased depressive-like behaviour with significantly increased serum ACTH and corticosterone levels, while the BDNF concentration was significantly decreased compared to other experimental groups. These changes were notably reversed by both E2 and Tualang honey. In conclusion, both Tualang honey and E2 mediate antidepressive-like effects in stressed OVX rats, possibly acting via restoration of hypothalamic-pituitary-adrenal axis and enhancement of the BDNF concentration.

Stress Causing Factors Among Teachers in Elementary Schools and Their Relationship with Demographic and Job Characteristics.

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Agai-Demjaha, Teuta; Minov, Jordan; Stoleski, Sasho; Zafirova, Beti

2015-09-15

Once high levels of work-related stress among teachers were confirmed many studies concentrated on identifying and investigating key stress factors among school teachers. Unfortunately there are very few researches made on stress causing factors among teachers in Republic of Macedonia. To determine the most frequent stress causing factors among teachers in elementary schools and to investigate their relationship with demographic and job characteristics. We performed a descriptive-analytical model of a cross-sectional study which involved 300 teachers employed in nine elementary schools. Evaluation of examined subjects included completion of a specially designed questionnaire. Among six categories of factors that generate work related stress (job demands, control, relationships, role, changes and support) control and support had the highest mean scores. Within the control category the highest levels of perceived teacher's work-related stress were caused by the following factors - changes in terms and conditions without consultation and given responsibility without the authority to take decisions. 141 out of the interviewed teachers (47%) have mentioned changes in terms and conditions without consultation as very stressful, while another 50 (16.67%) have reported it as stressful. 123 out of interviewed teachers (41%) have stated given responsibility without the authority to take decisions as very stressful, with another 105 (35%) have reported it as stressful. In the category support the highest levels of perceived teacher's work-related stress were caused by stress factors - lack of funds/resources to do the job and limited or no access to training. Out of 300 interviewed teachers, 179 (59.67%) have reported lack of funds/resources to do the job as very stressful, while another 50 (16.67%) as stressful. There is no significant relationship between the stress factor limited or no access to training and demographic and job characteristics. Our findings confirm that

Assessment of environmental stresses for enhanced microalgal biofuel production-an overview

Directory of Open Access Journals (Sweden)

Dan eCheng

2014-07-01

Full Text Available Microalgal biofuels are currently considered to be the most promising alternative to future renewable energy source. Microalgae have great potential to produce various biofuels, including biodiesel, bioethanol, biomethane, and biohydrogen. Cultivation of biofuel-producing microalgae demands favorable environmental conditions, such as suitable light, temperature, nutrients, salinity, and pH. However, these conditions are not always compatible with the conditions beneficial to biofuel production, because biofuel-related compounds (such as lipids and carbohydrates tend to accumulate under environmental-stress conditions of light, temperature, nutrient, and salt. This paper presents a brief overview of the effects of environmental conditions on production of microalgal biomass and biofuel, with specific emphasis on how to utilize environmental stresses to improve biofuel productivity. The potential avenues of reaping the benefits of enhanced biofuel production by environmental stresses while maintaining high yields of biomass production have been discussed.

Probiotics enhance pancreatic glutathione biosynthesis and reduce oxidative stress in experimental acute pancreatitis

NARCIS (Netherlands)

Lutgendorff, Femke; Trulsson, Lena M.; van Minnen, L. Paul; Rijkers, Ger T.; Timmerman, Harro M.; Franzen, Lennart E.; Gooszen, Hein G.; Akkermans, Louis M. A.; Soderholm, Johan D.; Sandstrom, Per A.

2008-01-01

Factors determining severity of acute pancreatitis (AP) are poorly understood. Oxidative stress causes acinar cell injury and contributes to the severity, whereas prophylactic probiotics ameliorate experimental pancreatitis. Our objective was to study how probiotics affect oxidative stress,

Empirical research on the influencing factors of the occupational stress for construction workers

Science.gov (United States)

LV, Xing; WU, Xiang; CI, Huipeng; LIU, Qing; YAO, Yongzheng

2017-04-01

Employee’s occupational stress and safety performance are highly related, which has been generally recognized by the researchers. We did this research to understand the status of the stress for construction workers, and explore the influence factors of pressure source with characteristics of construction industry. Based on the results of previous studies, we designed questionnaire to collect the influence factors on occupational stressors. The study selected workers from certain construction units at the grass-roots level as sample source. According to the results of the questionnaire, we redesigned the interview outline, and did the semi-structured interviews on workers randomly selected. Finally, we developed a scale which combined the characteristics of construction projects in China. Using SPSS software for factor analysis, reliability analysis, and descriptive statistical analysis, the results show that there are six factors affecting the workers’ occupational stress, including The Work Itself, Family-Work, Career Development, Organization Style, Interpersonal Relationship and Role Management Style. The work itself is the main sources of occupational stress. The results can be used by the construction company to provide guidance for workers to control and manage occupational stress.

Long-term programing of psychopathology-like behaviors in male rats by peripubertal stress depends on individual's glucocorticoid responsiveness to stress.

Science.gov (United States)

Walker, Sophie E; Sandi, Carmen

2018-02-07

Experience of adversity early in life and dysregulation of hypothalamus-pituitary-adrenocortical (HPA) axis activity are risk factors often independently associated with the development of psychopathological disorders, including depression, PTSD and pathological aggression. Additional evidence suggests that in combination these factors may interact to shape the development and expression of psychopathology differentially, though little is known about underlying mechanisms. Here, we studied the long-term consequences of early life stress exposure on individuals with differential constitutive glucocorticoid responsiveness to repeated stressor exposure, assessing both socio-affective behaviors and brain activity in regions sensitive to pathological alterations following stress. Two rat lines, genetically selected for either low or high glucocorticoid responsiveness to repeated stress were exposed to a series of unpredictable, fear-inducing stressors on intermittent days during the peripuberty period. Results obtained at adulthood indicated that having high glucocorticoid responses to repeated stress and having experience of peripuberty stress independently enhanced levels of psychopathology-like behaviors, as well as increasing basal activity in several prefrontal and limbic brain regions in a manner associated with enhanced behavioral inhibition. Interestingly, peripuberty stress had a differential impact on aggression in the two rat lines, enhancing aggression in the low-responsive line but not in the already high-aggressive, high-responsive rats. Taken together, these findings indicate that aberrant HPA axis activity around puberty, a key period in the development of social repertoire in both rats and humans, may alter behavior such that it becomes anti-social in nature.

Baicalin Ameliorates Experimental Liver Cholestasis in Mice by Modulation of Oxidative Stress, Inflammation, and NRF2 Transcription Factor

Directory of Open Access Journals (Sweden)

Kezhen Shen

2017-01-01

Full Text Available Experimental cholestatic liver fibrosis was performed by bile duct ligation (BDL in mice, and significant liver injury was observed in 15 days. Administration of baicalin in mice significantly ameliorates liver fibrosis. Experimental cholestatic liver fibrosis was associated with induced gene expression of fibrotic markers such as collagen I, fibronectin, alpha smooth muscle actin (SMA, and connective tissue growth factor (CTGF; increased inflammatory cytokines (TNFα, MIP1α, IL1β, and MIP2; increased oxidative stress and reactive oxygen species- (ROS- inducing enzymes (NOX2 and iNOS; dysfunctional mitochondrial electron chain complexes; and apoptotic/necrotic cell death markers (DNA fragmentation, caspase 3 activity, and PARP activity. Baicalin administration on alternate day reduced fibrosis along with profibrotic gene expression, proinflammatory cytokines, oxidative stress, and cell death whereas improving the function of mitochondrial electron transport chain. We observed baicalin enhanced NRF2 activation by nuclear translocation and induced its target genes HO-1 and GCLM, thus enhancing antioxidant defense. Interplay of oxidative stress/inflammation and NRF2 were key players for baicalin-mediated protection. Stellate cell activation is crucial for initiation of fibrosis. Baicalin alleviated stellate cell activation and modulated TIMP1, SMA, collagen 1, and fibronectin in vitro. This study indicates that baicalin might be beneficial for reducing inflammation and fibrosis in liver injury models.

Enhanced Densification of White Cast Iron Powders by Cyclic Phase Transformations under Stress.

Science.gov (United States)

1981-08-01

Little or no significant enhancement in densification was reported in these cases where no applied stresses were used. Kohara [9) extended this work...enhancement of densification observed by Kohara , although limited, was attributed to the occurrence of transformation superplasticity. As will be shown... Kohara : Metall. Trans., 1976, vol. 7, p. 1239. 10. Y. Oshida, J. Jpn. Soc, Powder and Powder Metall., 1975, vol. 22, p. 147. 11. M. de Jong and G. W

The impact of environmental factors on nursing stress, job satisfaction, and turnover intention.

Science.gov (United States)

Applebaum, Diane; Fowler, Susan; Fiedler, Nancy; Osinubi, Omowunmi; Robson, Mark

2010-01-01

The purpose of this study was to investigate relationships between environmental factors of odor, noise, light, and color and perceived stress, job satisfaction, and turnover intention. The physical work environment may positively or negatively influence nurses' stress, and stress may negatively impact their job satisfaction and intention to change jobs. The research questions were answered using a descriptive, correlational design. The sample (n = 116) consisted of medical-surgical nurses working in acute-care settings. A 36-item questionnaire addressed odor, noise, light, color, perceived stress, job satisfaction, and turnover intention. Significant relationships were found between noise and perceived stress, perceived stress and job satisfaction, job satisfaction and turnover intention, and perceived stress and turnover intention. Nurses tend to overlook their physical environment and "do their job." Common environmental stressors in the work environment can be stressful to staff and influence job satisfaction and, ultimately, intention to change jobs. Mitigating or eliminating these environmental factors has the potential to improve staff satisfaction and retention. Stress influences nursing job satisfaction and, ultimately, intention to change jobs.

Experimental Study of Laser - enhanced 5A03 Aluminum Alloy and Its Stress Corrosion Resistance

Science.gov (United States)

Wang, Guicheng; Chen, Jing; Pang, Tao

2018-02-01

Based on the study of improving the stress corrosion resistance of 5A03 aluminum alloy for ship, this paper mainly studied the tensile test, surface morphology and residual stress under laser shock, high temperature and stress corrosion. It is found that the residual compressive stress and the grain refinement on the surface of the material during the heat strengthening process increase the breaking strength of the sample in the stress corrosion environment. Appropriate high temperature maintenance helps to enhance the effect of deformation strengthening. In the 300°C environment insulation, due to recrystallization of the material, the performance decreased significantly. This study provides an experimental basis for effectively improving the stress corrosion resistance of 5A03 aluminum alloy.

Stress Causing Factors Among Teachers in Elementary Schools and Their Relationship with Demographic and Job Characteristics

OpenAIRE

Agai–Demjaha, Teuta; Minov, Jordan; Stoleski, Sasho; Zafirova, Beti

2015-01-01

BACKGROUND: Once high levels of work-related stress among teachers were confirmed many studies concentrated on identifying and investigating key stress factors among school teachers. Unfortunately there are very few researches made on stress causing factors among teachers in Republic of Macedonia. AIM: To determine the most frequent stress causing factors among teachers in elementary schools and to investigate their relationship with demographic and job characteristics. METHODOLOGY: W...

A Novel WRKY Transcription Factor, MuWRKY3 (Macrotyloma uniflorum Lam. Verdc. Enhances Drought Stress Tolerance in Transgenic Groundnut (Arachis hypogaea L. Plants

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Kurnool Kiranmai

2018-03-01

Full Text Available Drought stress has adverse effects on growth, water relations, photosynthesis and yield of groundnut. WRKY transcription factors (TFs are the plant-specific TFs which regulate several down-stream stress-responsive genes and play an essential role in plant biotic and abiotic stress responses. We found that WRKY3 gene is highly up-regulated under drought stress conditions and therefore isolated a new WRKY3TF gene from a drought-adapted horsegram (Macrotyloma uniflorum Lam. Verdc.. Conserved domain studies revealed that protein encoded by this gene contains highly conserved regions of two WRKY domains and two C2H2 zinc-finger motifs. The fusion protein localization studies of transient MuWRKY3-YFP revealed its nuclear localization. Overexpression of MuWRKY3 TF gene in groundnut (Arachis hypogaea L. showed increased tolerance to drought stress compared to wild-type (WT plants. MuWRKY3 groundnut transgenics displayed lesser and delayed wilting symptoms than WT plants after 10-days of drought stress imposition. The transgenic groundnut plants expressing MuWRKY3 showed less accumulation of malondialdehyde, hydrogen peroxide (H2O2, and superoxide anion (O2∙-, accompanied by more free proline, total soluble sugar content, and activities of antioxidant enzymes than WT plants under drought stress. Moreover, a series of stress-related LEA, HSP, MIPS, APX, SOD, and CAT genes found up-regulated in the transgenic groundnut plants. The study demonstrates that nuclear-localized MuWRKY3 TF regulates the expression of stress-responsive genes and the activity of ROS scavenging enzymes which results in improved drought tolerance in groundnut. We conclude that MuWRKY3 may serve as a new putative candidate gene for the improvement of stress resistance in plants.

A Novel WRKY Transcription Factor, MuWRKY3 (Macrotyloma uniflorum Lam. Verdc.) Enhances Drought Stress Tolerance in Transgenic Groundnut (Arachis hypogaea L.) Plants.

Science.gov (United States)

Kiranmai, Kurnool; Lokanadha Rao, Gunupuru; Pandurangaiah, Merum; Nareshkumar, Ambekar; Amaranatha Reddy, Vennapusa; Lokesh, Uppala; Venkatesh, Boya; Anthony Johnson, A M; Sudhakar, Chinta

2018-01-01

Drought stress has adverse effects on growth, water relations, photosynthesis and yield of groundnut. WRKY transcription factors (TFs) are the plant-specific TFs which regulate several down-stream stress-responsive genes and play an essential role in plant biotic and abiotic stress responses. We found that WRKY3 gene is highly up-regulated under drought stress conditions and therefore isolated a new WRKY3TF gene from a drought-adapted horsegram ( Macrotyloma uniflorum Lam. Verdc.). Conserved domain studies revealed that protein encoded by this gene contains highly conserved regions of two WRKY domains and two C2H2 zinc-finger motifs. The fusion protein localization studies of transient MuWRKY 3-YFP revealed its nuclear localization. Overexpression of MuWRKY3 TF gene in groundnut ( Arachis hypogaea L.) showed increased tolerance to drought stress compared to wild-type (WT) plants. MuWRKY3 groundnut transgenics displayed lesser and delayed wilting symptoms than WT plants after 10-days of drought stress imposition. The transgenic groundnut plants expressing MuWRKY3 showed less accumulation of malondialdehyde, hydrogen peroxide (H 2 O 2 ), and superoxide anion (O 2 ∙- ), accompanied by more free proline, total soluble sugar content, and activities of antioxidant enzymes than WT plants under drought stress. Moreover, a series of stress-related LEA, HSP, MIPS, APX, SOD , and CAT genes found up-regulated in the transgenic groundnut plants. The study demonstrates that nuclear-localized MuWRKY3 TF regulates the expression of stress-responsive genes and the activity of ROS scavenging enzymes which results in improved drought tolerance in groundnut. We conclude that MuWRKY3 may serve as a new putative candidate gene for the improvement of stress resistance in plants.

Effect of Couple Stresses on the Stress Intensity Factors for Two Parallel Cracks in an Infinite Elastic Medium under Tension

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Shouetsu Itou

2012-01-01

Full Text Available Stresses around two parallel cracks of equal length in an infinite elastic medium are evaluated based on the linearized couple-stress theory under uniform tension normal to the cracks. Fourier transformations are used to reduce the boundary conditions with respect to the upper crack to dual integral equations. In order to solve these equations, the differences in the displacements and in the rotation at the upper crack are expanded through a series of functions that are zero valued outside the crack. The unknown coefficients in each series are solved in order to satisfy the boundary conditions inside the crack using the Schmidt method. The stresses are expressed in terms of infinite integrals, and the stress intensity factors can be determined using the characteristics of the integrands for an infinite value of the variable of integration. Numerical calculations are carried out for selected crack configurations, and the effect of the couple stresses on the stress intensity factors is revealed.

Virtual nature environment with nature sound exposure induce stress recovery by enhanced parasympathetic activity

DEFF Research Database (Denmark)

Annerstedt, Matilda; Jönsson, Peter; Wallergård, Mattias

2013-01-01

. The group that recovered in virtual nature without sound and the control group displayed no particular autonomic activation or deactivation. The results demonstrate a potential mechanistic link between nature, the sounds of nature, and stress recovery, and suggest the potential importance of virtual reality......Experimental research on stress recovery in natural environments is limited, as is study of the effect of sounds of nature. After inducing stress by means of a virtual stress test, we explored physiological recovery in two different virtual natural environments (with and without exposure to sounds...... of nature) and in one control condition. Cardiovascular data and saliva cortisol were collected. Repeated ANOVA measurements indicated parasympathetic activation in the group subjected to sounds of nature in a virtual natural environment, suggesting enhanced stress recovery may occur in such surroundings...

Experimental and numerical determination of critical stress intensity factor of aluminum curved thin sheets under tensile stress

Energy Technology Data Exchange (ETDEWEB)

Heidarvand, Majid; Soltani, Naser; Hajializadeh, Farshid [University of Tehran, Tehran (Iran, Islamic Republic of)

2017-05-15

We determined the fracture toughness of aluminum curved thin sheets using tensile stress tests and finite element method. We applied Linear elastic fracture mechanics (LEFM) and Feddersen procedure to evaluate stress intensity factor of the samples with central wire-cut cracks and fatigue cracks with different lengths to investigate the notch radius effect. Special fixture design was utilized to establish uniform stress distribution at the crack zone. Less than 9 % difference was found between the wire-cut and the fatigue cracked samples. Since generating central fatigue crack with different lengths required so much effort, wire-cut cracked samples were used to determine critical stress intensity factor. Finite element analysis was also performed on one-quarter of the specimen using both the singular Borsum elements and the regular isoparametric elements to further investigate fracture toughness of the samples. It was observed that the singular elements presented better results than the isoparametric ones. A slight difference was also found between the results obtained from finite element method using singular elements and the experimental results.

Structure of the nucleotide exchange factor eIF2B reveals mechanism of memory-enhancing molecule.

Science.gov (United States)

Tsai, Jordan C; Miller-Vedam, Lakshmi E; Anand, Aditya A; Jaishankar, Priyadarshini; Nguyen, Henry C; Renslo, Adam R; Frost, Adam; Walter, Peter

2018-03-30

Regulation by the integrated stress response (ISR) converges on the phosphorylation of translation initiation factor eIF2 in response to a variety of stresses. Phosphorylation converts eIF2 from a substrate to a competitive inhibitor of its dedicated guanine nucleotide exchange factor, eIF2B, thereby inhibiting translation. ISRIB, a drug-like eIF2B activator, reverses the effects of eIF2 phosphorylation, and in rodents it enhances cognition and corrects cognitive deficits after brain injury. To determine its mechanism of action, we solved an atomic-resolution structure of ISRIB bound in a deep cleft within decameric human eIF2B by cryo-electron microscopy. Formation of fully active, decameric eIF2B holoenzyme depended on the assembly of two identical tetrameric subcomplexes, and ISRIB promoted this step by cross-bridging a central symmetry interface. Thus, regulation of eIF2B assembly emerges as a rheostat for eIF2B activity that tunes translation during the ISR and that can be further modulated by ISRIB. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Numerical evaluation of stress intensity factor for vessel and pipe subjected to thermal shock

International Nuclear Information System (INIS)

Kim, Y.W.; Lee, H.Y.; Yoo, B.

1994-01-01

The thermal weight function method and the finite element method were employed in the numerical computation of the stress intensity factor for a cracked vessel and the cracked pipe subjected to thermal shock. A wall subjected to thermal shock was analyzed, and it has been shown that the effect of thermal shock on the stress intensity factor is dominant for the crack with small crack length to thickness ratio. Convection at the crack face had an influence on the stress intensity factor in the early stage of thermal shock. (Author)

Problem-solving skills and hardiness as protective factors against stress in Iranian nurses.

Science.gov (United States)

Abdollahi, Abbas; Talib, Mansor Abu; Yaacob, Siti Nor; Ismail, Zanariah

2014-02-01

Nursing is a stressful occupation, even when compared with other health professions; therefore, it is necessary to advance our knowledge about the protective factors that can help reduce stress among nurses. The present study sought to investigate the associations among problem-solving skills and hardiness with perceived stress in nurses. The participants, 252 nurses from six private hospitals in Tehran, completed the Personal Views Survey, the Perceived Stress Scale, and the Problem-Solving Inventory. Structural Equation Modeling (SEM) was used to analyse the data and answer the research hypotheses. As expected, greater hardiness was associated with low levels of perceived stress, and nurses low in perceived stress were more likely to be considered approachable, have a style that relied on their own sense of internal personal control, and demonstrate effective problem-solving confidence. These findings reinforce the importance of hardiness and problem-solving skills as protective factors against perceived stress among nurses, and could be important in training future nurses so that hardiness ability and problem-solving skills can be imparted, allowing nurses to have more ability to control their perceived stress.

Acculturative stress, work-related psychosocial factors and depression in Korean-Chinese migrant workers in Korea.

Science.gov (United States)

Lee, Hyeonkyeong; Ahn, Hyunmi; Miller, Arlene; Park, Chang Gi; Kim, Sun Jung

2012-01-01

The purposes of this study were to identify the relationships among acculturative stress, work-related psychosocial factors and depression in Korean-Chinese migrant workers living in Korea and to determine whether work-related psychosocial factors mediate the relationship between acculturative stress and depression. A descriptive correlational cross-sectional design was used. A convenience sample of 200 Korean-Chinese full-time migrant workers was recruited, and 170 completed questionnaires were included in the analysis. Acculturative stress was assessed by Sandh and Asrabadi's Acculturative Stress Scale. Work-related psychosocial factors were assessed by job demand, insufficient job control and interpersonal conflict measures from the Korean Occupational Stress Scale. Depression was assessed by the Center for Epidemiologic Studies Depression Scale. Self-administered or face-to-face surveys were conducted by trained data collectors. Multiple regression and path analysis were used. Roughly 30% of the sample met the criteria for depression. Female workers had significantly higher depression scores than male workers. Acculturative stress and work-related psychosocial factors significantly predicted 26.3% of the variance in depression. A path model revealed the mediating effect of job demand on the relationship between acculturative stress and depression. Our results indicate that work-related psychosocial factors are salient factors that lead to depression among Korean-Chinese migrant workers living in Korea. The results suggest that occupational health-care professionals should promote the prevention and management of depression in this population and highlight the importance of acculturation context in the development of interventions designed to reduce work-related stress.

Effects of distance from center of a weld to fixed end on residual stress and stress intensity factor of a piping weld. Evaluation of SCC growth under residual stress field. Report 1

International Nuclear Information System (INIS)

Miyazaki, Katsumasa; Numata, Masanori; Saito, Koichi; Mochizuki, Masahito

2006-01-01

The fixed conditions of butt welds between straight pipe and valve or pump in the actual piping system are different from those of straight pipes. However, the effect of fixed condition on the residual stress and the stress intensity factor for evaluation of structural integrity of cracked piping was not clear. In this study, the finite element analyses were conducted by considering the differences in the distance from the center of weld to the fixed end L to clarify the effect of fixed condition on the residual stress and the stress intensity factor. For the 600 A piping, the axial residual stress distribution was not affected by the distance L. Furthermore, the stress intensity factor of circumferential crack under the residual stress field with fixed condition could be estimated by using the existing simplified solution for piping. (author)

Stress from electricity and radiation

International Nuclear Information System (INIS)

Maes, W.

1992-01-01

The author, a journalist and a free expert in constructional biology, discusses the origins of electricity and radiation and their effects on human health. The emphasis is on the causes and measurement of stress-inducing or stress-enhancing factors. Preventive measures are pointed out. The book goes into detail about a.c. electric and magnetic fields, electromagnetic waves, d.c. electric and magnetic fields, natural radioactivity, terrestrial radiation, vibration, and airborne pollutants. (uhe) [de

Job Stress Risk Factors Among Power Generation and Machine Production Employees: A Case Study-2010

OpenAIRE

Z. Naghavi; M.R. Hajgholami; Y. Shokoohi; F. Zayeri

2013-01-01

Background and Objective: Job stress has been adverse effects on performance, quality of work, absents, unsafe behaviors and occupational accidents and also health problems. Risk factors of job stress can be different in various workplaces. Risk factors determination is the first step of job stress management. Identifying these risk factors among workers of Power production & Machine production industries was the aim of this study. Methods: First parts of Osipow questionnaire was used for ...

Overexpression of OLE1 enhances stress tolerance and constitutively activates the MAPK HOG pathway in Saccharomyces cerevisiae.

Science.gov (United States)

Nasution, Olviyani; Lee, Young Mi; Kim, Eunjung; Lee, Yeji; Kim, Wankee; Choi, Wonja

2017-03-01

OLE1 of Saccharomyces cerevisiae encodes the sole and essential Δ-9 desaturase catalyzing the conversion of saturated to unsaturated fatty acids. Upon ectopic overexpression of OLE1 in S. cerevisiae, significant increases in the membrane oleic acid content were observed. OLE1-overexpressing strains displayed enhanced tolerance to various stresses, better proton efflux, lower membrane permeability, and lessened internal hydrogen peroxide content. The OLE1-mediated enhanced stress tolerance was considerably diminished upon deletion of HOG1, which encodes the mitogen-activated protein kinase (MAPK) Hog1 of the high osmolarity glycerol (HOG) pathway. Furthermore, OLE1 overexpression constitutively activated Hog1, which remained in the cytoplasm. Hog1 activation was accomplished through the MAPK kinase kinase (MAPKKK) Ssk2, but not Ste11 and Ssk22, the other MAPKKKs of the HOG pathway. Despite its cytoplasmic location, activated Hog1 was able to activate the expression of its canonical targets, including CTT1, HSP12, and STL1, and further, the cAMP and stress response elements present in the promoter. OLE1 overexpression neither caused nor relieved endoplasmic reticulum stress. Individually or in combination, the physiological and molecular changes caused by OLE1 overexpression may contribute to enhanced tolerance to various types of stress. Biotechnol. Bioeng. 2017;114: 620-631. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Menopause as risk factor for oxidative stress.

Science.gov (United States)

Sánchez-Rodríguez, Martha A; Zacarías-Flores, Mariano; Arronte-Rosales, Alicia; Correa-Muñoz, Elsa; Mendoza-Núñez, Víctor Manuel

2012-03-01

The aim of this study was to determine the influence of menopause (hypoestrogenism) as a risk factor for oxidative stress. We carried out a cross-sectional study with 187 perimenopausal women from Mexico City, including 94 premenopausal (mean ± SD age, 44.9 ± 4.0 y; estrogen, 95.8 ± 65.7 pg/mL; follicle-stimulating hormone, 13.6 ± 16.9 mIU/mL) and 93 postmenopausal (mean ± SD age, 52.5 ± 3.3 y; estrogen, 12.8 ± 6.8 pg/mL; follicle-stimulating hormone, 51.4 ± 26.9 mIU/mL) women. We measured lipoperoxides using a thiobarbituric acid-reacting substance assay, erythrocyte superoxide dismutase and glutathione peroxidase activities, and the total antioxidant status with the Randox kit. An alternative cutoff value for lipoperoxide level of 0.320 μmol/L or higher was defined on the basis of the 90th percentile of young healthy participants. All women answered the Menopause Rating Scale, the Athens Insomnia Scale, and a structured questionnaire about pro-oxidant factors, that is, smoking, consumption of caffeinated and alcoholic beverages, and physical activity. Finally, we measured weight and height and calculated body mass index. The lipoperoxide levels were significantly higher in the postmenopausal group than in the premenopausal group (0.357 ± 0.05 vs 0.331 ± 0.05 μmol/L, P = 0.001). Using logistic regression to control pro-oxidant variables, we found that menopause was the main risk factor for oxidative stress (odds ratio, 2.62; 95% CI, 1.35-5.11; P menopause rating score, insomnia score, and lipoperoxides, and this relationship was most evident in the postmenopausal group (menopause scale, r = 0.327 [P = 0.001]; insomnia scale, r = 0.209 [P < 0.05]). Our findings suggest that the depletion of estrogen in postmenopause could cause oxidative stress in addition to the known symptoms.

Further studies on stress intensity factors of semi-elliptical cracks in pressurized cylinders

International Nuclear Information System (INIS)

Kobayashi, A.S.; Emery, A.F.; Love, W.J.; Jain, A.

1979-01-01

The authors have used, in the past, the three-dimensional stress intensity magnification factor, Msub(KS), for a semi-elliptical surface crack in a flat plate with a curvature correction factor, Msub(C), to estimate the stress intensity magnification factor, Msub(K) = Msub(C) x Msub(KS), for unpressurized and pressurized inner semi-elliptical cracks and unpressurized outer semi-elliptical cracks in pressurized and thermally shocked cylinders. Recent papers by Atluri/Kathiresan, Welliot/Labbens/Pellissier-Tanon and McGowan/Raymund, however, showed that while this plate analogy with curvature correction provided reasonable estimates of the stress intensity factors at the deepest crack penetration, it underestimated the stress intensity factors at the cylindrical surface. The source of this discrepancy was traced to the curvature correction factor Msub(C), which was re-evaluated for various crack configurations and cylindrical geometries studied. Using the updated Msub(C) together with the previously derived Msub(KS), stress intensity factor magnification factor, Msub(K), was rederived for: (1) Pressurized and unpressurized inner semi-elliptical cracks of two crack aspects ratios of b/a = 0.2 and 0.98 at crack depth of b/(Rsub(o)-Rsub(i)) = 0.4, 0.6, and 0.8 in pressurized cylinders with outside-to-inside radius ratios of Rsub(o)/Rsub(i) = 3/2, 5/4, 7/6, and 10/9. (2) Unpressurized outer semi-elliptical cracks of two crack aspect ratios of b/a = 0.2 and 0.98 at crack depths of b/(Rsub(o)-Rsub(i)) = 0.4, 0.6, and 0.8 in pressurized cylinders with outside-to-inside radius ratio of Rsub(o)/Rsub(i) = 3/2, 5/4, 7/6, and 10/9. (orig.)

The acute salivary ghrelin response to a psychosocial stress is enhanced in symptomatic patients with bulimia nervosa: a pilot study.

Science.gov (United States)

Monteleone, Palmiero; Tortorella, Alfonso; Scognamiglio, Pasquale; Serino, Ismene; Monteleone, Alessio Maria; Maj, Mario

2012-01-01

Stress is a precipitating factor for both binge eating and bulimia nervosa (BN); however, the biological mechanisms through which it may trigger binge eating are poorly understood. There is evidence that the adrenal hormone cortisol and the gastric peptide ghrelin might be involved in stress-induced food ingestion. We hypothesized that symptomatic patients with BN might disclose deranged responses of ghrelin and/or cortisol to stressors and that this could be related to their binge-eating behaviour. Here we investigated salivary cortisol and ghrelin responses to the Trier Social Stress Test (TSST) in 10 women with acute BN and 10 age-matched healthy females. Eating-related psychopathology and behaviours were assessed by self-report measures. No significant differences emerged between bulimic patients and healthy controls in the pre-stress salivary levels of both cortisol and ghrelin. The BN patients displayed normal cortisol but enhanced ghrelin responses to TSST. No significant correlations emerged between stress-induced salivary hormone changes and self-report measures of binge eating. To our knowledge, this is the first study showing deranged salivary ghrelin reactivity to a psychosocial stressor in symptomatic patients with BN. The extent to which this could contribute to the binge-eating behaviour of BN subjects awaits clarification. Copyright © 2012 S. Karger AG, Basel.

Numerical modeling of injection, stress and permeability enhancement during shear stimulation at the Desert Peak Enhanced Geothermal System

Science.gov (United States)

Dempsey, David; Kelkar, Sharad; Davatzes, Nick; Hickman, Stephen H.; Moos, Daniel

2015-01-01

Creation of an Enhanced Geothermal System relies on stimulation of fracture permeability through self-propping shear failure that creates a complex fracture network with high surface area for efficient heat transfer. In 2010, shear stimulation was carried out in well 27-15 at Desert Peak geothermal field, Nevada, by injecting cold water at pressure less than the minimum principal stress. An order-of-magnitude improvement in well injectivity was recorded. Here, we describe a numerical model that accounts for injection-induced stress changes and permeability enhancement during this stimulation. In a two-part study, we use the coupled thermo-hydrological-mechanical simulator FEHM to: (i) construct a wellbore model for non-steady bottom-hole temperature and pressure conditions during the injection, and (ii) apply these pressures and temperatures as a source term in a numerical model of the stimulation. In this model, a Mohr-Coulomb failure criterion and empirical fracture permeability is developed to describe permeability evolution of the fractured rock. The numerical model is calibrated using laboratory measurements of material properties on representative core samples and wellhead records of injection pressure and mass flow during the shear stimulation. The model captures both the absence of stimulation at low wellhead pressure (WHP ≤1.7 and ≤2.4 MPa) as well as the timing and magnitude of injectivity rise at medium WHP (3.1 MPa). Results indicate that thermoelastic effects near the wellbore and the associated non-local stresses further from the well combine to propagate a failure front away from the injection well. Elevated WHP promotes failure, increases the injection rate, and cools the wellbore; however, as the overpressure drops off with distance, thermal and non-local stresses play an ongoing role in promoting shear failure at increasing distance from the well.

Exposure to Acute Stress Enhances Decision-Making Competence: Evidence for the Role of DHEA

Science.gov (United States)

Shields, Grant S.; Lam, Jovian C. W.; Trainor, Brian C.; Yonelinas, Andrew P.

2016-01-01

Exposure to acute stress can impact performance on numerous cognitive abilities, but little is known about how acute stress affects real-world decision-making ability. In the present study, we induced acute stress with a standard laboratory task involving uncontrollable socio-evaluative stress and subsequently assessed decision-making ability using the Adult Decision Making Competence index. In addition, we took baseline and post-test saliva samples from participants to examine associations between decision-making competence and adrenal hormones. Participants in the stress induction group showed enhanced decision-making competence, relative to controls. Further, although both cortisol and dehydroepiandrosterone (DHEA) reactivity predicted decision-making competence when considered in isolation, DHEA was a significantly better predictor than cortisol when both hormones were considered simultaneously. Thus, our results show that exposure to acute stress can have beneficial effects on the cognitive ability underpinning real-world decision-making and that this effect relates to DHEA reactivity more than cortisol. PMID:26874561

Exposure to acute stress enhances decision-making competence: Evidence for the role of DHEA.

Science.gov (United States)

Shields, Grant S; Lam, Jovian C W; Trainor, Brian C; Yonelinas, Andrew P

2016-05-01

Exposure to acute stress can impact performance on numerous cognitive abilities, but little is known about how acute stress affects real-world decision-making ability. In the present study, we induced acute stress with a standard laboratory task involving uncontrollable socio-evaluative stress and subsequently assessed decision-making ability using the Adult Decision Making Competence index. In addition, we took baseline and post-test saliva samples from participants to examine associations between decision-making competence and adrenal hormones. Participants in the stress induction group showed enhanced decision-making competence, relative to controls. Further, although both cortisol and dehydroepiandrosterone (DHEA) reactivity predicted decision-making competence when considered in isolation, DHEA was a significantly better predictor than cortisol when both hormones were considered simultaneously. Thus, our results show that exposure to acute stress can have beneficial effects on the cognitive ability underpinning real-world decision-making and that this effect relates to DHEA reactivity more than cortisol. Copyright © 2016 Elsevier Ltd. All rights reserved.

Air pollution induces enhanced mitochondrial oxidative stress in cystic fibrosis airway epithelium.

Science.gov (United States)

Kamdar, O; Le, Wei; Zhang, J; Ghio, A J; Rosen, G D; Upadhyay, D

2008-10-29

We studied the effects of airborne particulate matters (PM) on cystic fibrosis (CF) epithelium. We noted that PM enhanced human CF bronchial epithelial apoptosis, activated caspase-9 and PARP-1; and reduced mitochondrial membrane potential. Mitochondrial inhibitors (4,4-diisothiocyanatostilbene-2,2'disulfonic acid, rotenone and thenoyltrifluoroacetone) blocked PM-induced generation of reactive oxygen species and apoptosis. PM upregulated pro-apoptotic Bad, Bax, p53 and p21; and enhanced mitochondrial localization of Bax. The anti-apoptotic Bcl-2, Bcl-xl, Mcl-1 and Xiap remained unchanged; however, overexpression of Bcl-xl blocked PM-induced apoptosis. Accordingly, we provide the evidence that PM enhances oxidative stress and mitochondrial signaling mediated apoptosis via the modulation of Bcl family proteins in CF.

Determination and applications of enhancement factors for positron and ortho-positronium annihilations

International Nuclear Information System (INIS)

Mitroy, J.

2005-01-01

Electron-positron annihilation rates calculated directly from the electron and positron densities are known to underestimate the true annihilation rate. A correction factor, known as the enhancement factor, allows for the local increase of the electron density around the positron caused by the attractive electron-positron interaction. Enhancement factors are given for positrons annihilating with the 1s electron in H, He + , He, Li 2+ , and Li + . The enhancement factor for a free positron annihilating with He + and He is found to be close to that of ortho-positronium (i.e., Ps in its triplet state) annihilating with these atoms. The enhancement factor for Ps-He scattering is used in conjunction with the known annihilation rate for pickoff annihilation to derive a scattering length of 1.47a 0 for Ps-He scattering. Further, enhancement factors for e + -Ne and e + -Ar annihilation are used in conjunction with the pickoff annihilation rate to estimate scattering lengths of 1.46a 0 for Ps-Ne scattering and 1.75a 0 for Ps-Ar scattering

Assessment of Environmental Stresses for Enhanced Microalgal Biofuel Production – An Overview

International Nuclear Information System (INIS)

Cheng, Dan; He, Qingfang

2014-01-01

Microalgal biofuels are currently considered to be the most promising alternative to future renewable energy source. Microalgae have great potential to produce various biofuels, including biodiesel, bioethanol, biomethane, and biohydrogen. Cultivation of biofuel-producing microalgae demands favorable environmental conditions, such as suitable light, temperature, nutrients, salinity, and pH. However, these conditions are not always compatible with the conditions beneficial to biofuel production, because biofuel-related compounds (such as lipids and carbohydrates) tend to accumulate under environmental-stress conditions of light, temperature, nutrient, and salt. This paper presents a brief overview of the effects of environmental conditions on production of microalgal biomass and biofuel, with specific emphasis on how to utilize environmental stresses to improve biofuel productivity. The potential avenues of reaping the benefits of enhanced biofuel production by environmental stresses while maintaining high yields of biomass production have been discussed.

Assessment of Environmental Stresses for Enhanced Microalgal Biofuel Production – An Overview

Energy Technology Data Exchange (ETDEWEB)

Cheng, Dan, E-mail: dxcheng@ualr.edu; He, Qingfang, E-mail: dxcheng@ualr.edu [Department of Applied Science, University of Arkansas at Little Rock, Little Rock, AR (United States)

2014-07-07

Microalgal biofuels are currently considered to be the most promising alternative to future renewable energy source. Microalgae have great potential to produce various biofuels, including biodiesel, bioethanol, biomethane, and biohydrogen. Cultivation of biofuel-producing microalgae demands favorable environmental conditions, such as suitable light, temperature, nutrients, salinity, and pH. However, these conditions are not always compatible with the conditions beneficial to biofuel production, because biofuel-related compounds (such as lipids and carbohydrates) tend to accumulate under environmental-stress conditions of light, temperature, nutrient, and salt. This paper presents a brief overview of the effects of environmental conditions on production of microalgal biomass and biofuel, with specific emphasis on how to utilize environmental stresses to improve biofuel productivity. The potential avenues of reaping the benefits of enhanced biofuel production by environmental stresses while maintaining high yields of biomass production have been discussed.

Evaluation of Stress-Inducing Factors of Educational Environment in Hamadan Dentistry School’s Students

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M. Dalband

2007-01-01

Full Text Available ntroduction & Objective: The aim of this study was to evaluate stressor factors of educational environment in Hamadan dental school’s students in year 2002.Materials & Methods: The study design was descriptive, cross-sectional and it was accomplished using a questionnaire which was taken from DES (dental environment stress questionnaire. According to restricted number of statistical population all members of population (154 students were evaluated as samples and this study was a survey one. Results: The results of this study indicated that most stressfull factors in dental students has been related to class work with mean score 3.18±0.83 and faculty-student relationship with mean score 3.05±0.83. Female students showed more total stress than male students (2.73 vs. 2.44. The fourth-year students had the most stress rate in all students of different years (3.05 and preclinical and clinical factors were the most stress-inducing factors of these students (3.63.Conclusion: It is concluded that the environment of Hamadan dental school and the process of education in the field of dentistry is potentially stressful. Also there is a reverse relationship between level of stress in students and their academic efficiencies.

Correlation of Stress Concentration Factors for T-Welded Connections – Finite Element Simulations and Fatigue Behavior

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Gerardo Terán Méndez

Full Text Available Abstract The stress concentration factors (SCFs in welded connections usually occur at zones with high stress levels. Stress concentrations reduce the fatigue behavior of welded connections in offshore structures and cracking can develop. By using the grinding technique, cracking can be eliminated. Stress concentration factors are defined as a ratio of maximum stress at the intersection to nominal stress on the brace. Defining the stress concentration factor is an important stage in the fatigue behavior of welded connections. Several approaches have evolved for designing structures with the classical S-N approach for estimating total life. This work correlates to the stress concentration factors of T-welded connections and the fatigue behavior. Stress concentration factors were computed with the finite element employing 3D T-welded connections with intact and grinding depth conditions. Then, T-welded connections were constructed with A36 plate steel and welded with E6013 electrodes to obtain the stress-life (S-N approach. The methodology from previous works was used to compute the SCF and fabricate the T-welded connections. The results indicated that the grinding process could restore the fatigue life of the T-welded connections for SCFs values in the range of 1.29. This value can be considered to be a low SCF value in T-welded connection. However, for higher SCF values, the fatigue life decreased, compromising and reducing the structural integrity of the T-welded connections.

Assessment of oxidative stress parameters of brain-derived neurotrophic factor heterozygous mice in acute stress model

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Gulay Hacioglu

2016-04-01

Full Text Available Objective(s: Exposing to stress may be associated with increased production of reactive oxygen species (ROS. Therefore, high level of oxidative stress may eventually give rise to accumulation of oxidative damage and development of numerous neurodegenerative diseases. It has been presented that brain-derived neurotrophic factor (BDNF supports neurons against various neurodegenerative conditions. Lately, there has been growing evidence that changes in the cerebral neurotrophic support and especially in the BDNF expression and its engagement with ROS might be important in various disorders and neurodegenerative diseases. Hence, we aimed to investigate protective effects of BDNF against stress-induced oxidative damage. Materials and Methods: Five- to six-month-old male wild-type and BDNF knock-down mice were used in this study. Activities of catalase (CAT and superoxide dismutase (SOD enzymes, and the amount of malondialdehyde (MDA were assessed in the cerebral homogenates of studied groups in response to acute restraint stress. Results: Exposing to acute physiological stress led to significant elevation in the markers of oxidative stress in the cerebral cortexes of experimental groups. Conclusion: As BDNF-deficient mice were observed to be more susceptible to stress-induced oxidative damage, it can be suggested that there is a direct interplay between oxidative stress indicators and BDNF levels in the brain.

Fibroblast growth factor 21 and its novel association with oxidative stress

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Miguel Ángel Gómez-Sámano

2017-04-01

Full Text Available Fibroblast growth factor 21 (FGF21 is an endocrine-member of the FGF family. It is synthesized mainly in the liver, but it is also expressed in adipose tissue, skeletal muscle, and many other organs. It has a key role in glucose and lipid metabolism, as well as in energy balance. FGF21 concentration in plasma is increased in patients with obesity, insulin resistance, and metabolic syndrome. Recent findings suggest that such increment protects tissue from an increased oxidative stress environment. Different types of physical stress, such as strenuous exercising, lactation, diabetic nephropathy, cardiovascular disease, and critical illnesses, also increase FGF21 circulating concentration. FGF21 is now considered a stress-responsive hormone in humans. The discovery of an essential response element in the FGF21 gene, for the activating transcription factor 4 (ATF4, involved in the regulation of oxidative stress, and its relation with genes such as NRF2, TBP-2, UCP3, SOD2, ERK, and p38, places FGF21 as a key regulator of the oxidative stress cell response. Its role in chronic diseases and its involvement in the treatment and follow-up of these diseases has been recently the target of new studies. The diminished oxidative stress through FGF21 pathways observed with anti-diabetic therapy is another clue of the new insights of this hormone.

Minimally invasive esthetic ridge preservation with growth-factor enhanced bone matrix.

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Nevins, Marc L; Said, Sherif

2017-12-28

Extraction socket preservation procedures are critical to successful esthetic implant therapy. Conventional surgical approaches are technique sensitive and often result in alteration of the soft tissue architecture, which then requires additional corrective surgical procedures. This case series report presents the ability of flapless surgical techniques combined with a growth factor-enhanced bone matrix to provide esthetic ridge preservation at the time of extraction for compromised sockets. When considering esthetic dental implant therapy, preservation, or further enhancement of the available tissue support at the time of tooth extraction may provide an improved esthetic outcome with reduced postoperative sequelae and decreased treatment duration. Advances in minimally invasive surgical techniques combined with recombinant growth factor technology offer an alternative for bone reconstruction while maintaining the gingival architecture for enhanced esthetic outcome. The combination of freeze-dried bone allograft (FDBA) and rhPDGF-BB (platelet-derived growth factor-BB) provides a growth-factor enhanced matrix to induce bone and soft tissue healing. The use of a growth-factor enhanced matrix is an option for minimally invasive ridge preservation procedures for sites with advanced bone loss. Further studies including randomized clinical trials are needed to better understand the extent and limits of these procedures. The use of minimally invasive techniques with growth factors for esthetic ridge preservation reduces patient morbidity associated with more invasive approaches and increases the predictability for enhanced patient outcomes. By reducing the need for autogenous bone grafts the use of this technology is favorable for patient acceptance and ease of treatment process for esthetic dental implant therapy. © 2017 Wiley Periodicals, Inc.

A Novel G-Protein-Coupled Receptors Gene from Upland Cotton Enhances Salt Stress Tolerance in Transgenic Arabidopsis.

Science.gov (United States)

Lu, Pu; Magwanga, Richard Odongo; Lu, Hejun; Kirungu, Joy Nyangasi; Wei, Yangyang; Dong, Qi; Wang, Xingxing; Cai, Xiaoyan; Zhou, Zhongli; Wang, Kunbo; Liu, Fang

2018-04-12

Plants have developed a number of survival strategies which are significant for enhancing their adaptation to various biotic and abiotic stress factors. At the transcriptome level, G-protein-coupled receptors (GPCRs) are of great significance, enabling the plants to detect a wide range of endogenous and exogenous signals which are employed by the plants in regulating various responses in development and adaptation. In this research work, we carried out genome-wide analysis of target of Myb1 ( TOM1 ), a member of the GPCR gene family. The functional role of TOM1 in salt stress tolerance was studied using a transgenic Arabidopsis plants over-expressing the gene. By the use of the functional domain PF06454, we obtained 16 TOM genes members in Gossypium hirsutum , 9 in Gossypium arboreum , and 11 in Gossypium raimondii . The genes had varying physiochemical properties, and it is significant to note that all the grand average of hydropathy (GRAVY) values were less than one, indicating that all are hydrophobic in nature. In all the genes analysed here, both the exonic and intronic regions were found. The expression level of Gh_A07G0747 (GhTOM) was significantly high in the transgenic lines as compared to the wild type; a similar trend in expression was observed in all the salt-related genes tested in this study. The study in epidermal cells confirmed the localization of the protein coded by the gene TOM1 in the plasma membrane. Analysis of anti-oxidant enzymes showed higher concentrations of antioxidants in transgenic lines and relatively lower levels of oxidant substances such as H₂O₂. The low malondialdehyde (MDA) level in transgenic lines indicated that the transgenic lines had relatively low level of oxidative damage compared to the wild types. The results obtained indicate that Gh_A07G0747 (GhTOM) can be a putative target gene for enhancing salt stress tolerance in plants and could be exploited in the future for the development of salt stress-tolerant cotton

A Novel G-Protein-Coupled Receptors Gene from Upland Cotton Enhances Salt Stress Tolerance in Transgenic Arabidopsis

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Pu Lu

2018-04-01

Full Text Available Plants have developed a number of survival strategies which are significant for enhancing their adaptation to various biotic and abiotic stress factors. At the transcriptome level, G-protein-coupled receptors (GPCRs are of great significance, enabling the plants to detect a wide range of endogenous and exogenous signals which are employed by the plants in regulating various responses in development and adaptation. In this research work, we carried out genome-wide analysis of target of Myb1 (TOM1, a member of the GPCR gene family. The functional role of TOM1 in salt stress tolerance was studied using a transgenic Arabidopsis plants over-expressing the gene. By the use of the functional domain PF06454, we obtained 16 TOM genes members in Gossypium hirsutum, 9 in Gossypium arboreum, and 11 in Gossypium raimondii. The genes had varying physiochemical properties, and it is significant to note that all the grand average of hydropathy (GRAVY values were less than one, indicating that all are hydrophobic in nature. In all the genes analysed here, both the exonic and intronic regions were found. The expression level of Gh_A07G0747 (GhTOM was significantly high in the transgenic lines as compared to the wild type; a similar trend in expression was observed in all the salt-related genes tested in this study. The study in epidermal cells confirmed the localization of the protein coded by the gene TOM1 in the plasma membrane. Analysis of anti-oxidant enzymes showed higher concentrations of antioxidants in transgenic lines and relatively lower levels of oxidant substances such as H2O2. The low malondialdehyde (MDA level in transgenic lines indicated that the transgenic lines had relatively low level of oxidative damage compared to the wild types. The results obtained indicate that Gh_A07G0747 (GhTOM can be a putative target gene for enhancing salt stress tolerance in plants and could be exploited in the future for the development of salt stress

Determinants of Perceived Stress in Individuals with Obesity: Exploring the Relationship of Potentially Obesity-Related Factors and Perceived Stress

OpenAIRE

Florian Junne; Katrin Ziser; Katrin Elisabeth Giel; Kathrin Schag; Eva Skoda; Isabelle Mack; Andreas Niess; Stephan Zipfel; Martin Teufel

2017-01-01

Objective: Associations of specific types of stress with increased food intake and subsequent weight gain have been demonstrated in animal models as well as in experimental and epidemiological studies on humans. This study explores the research question of to what extent potentially obesity-related factors determine perceived stress in individuals with obesity. Methods: N = 547 individuals with obesity participated in a cross-sectional study assessing perceived stress as the outcome variable ...

Stressful situations and factors in students of nursing in clinical practice

OpenAIRE

Llapa Rodrigues, Eliana Ofélia; Almeida Marques, Daniel; Lopes Neto, David; López Montesinos, María José; Amado de Oliveira, Adriana Sousa

2016-01-01

Objective.To assess the risk factors for stress in undergraduate students of nursing in clinical practice in a public university in the Northeast region of Brazil. Methods. Cross-sectional descriptive study with 116 students from the fifth to the ninth period. The bilingual KEZKAK questionnaire, validated for Portuguese, was used. Stress was considered to be present when the score was equal or superior to 2. Results. The students with stress in clinical practice were 18 to 22 years old (2.82 ...

Antioxidant N-acetyltransferase Mpr1/2 of industrial baker's yeast enhances fermentation ability after air-drying stress in bread dough.

Science.gov (United States)

Sasano, Yu; Takahashi, Shunsuke; Shima, Jun; Takagi, Hiroshi

2010-03-31

During bread-making processes, yeast cells are exposed to multiple stresses. Air-drying stress is one of the most harmful stresses by generation of reactive oxygen species (ROS). Previously, we discovered that the novel N-acetyltransferase Mpr1/2 confers oxidative stress tolerance by reducing intracellular ROS level in Saccharomyces cerevisiae Sigma1278b strain. In this study, we revealed that Japanese industrial baker's yeast possesses one MPR gene. The nucleotide sequence of the MPR gene in industrial baker's yeast was identical to the MPR2 gene in Sigma1278b strain. Gene disruption analysis showed that the MPR2 gene in industrial baker's yeast is involved in air-drying stress tolerance by reducing the intracellular oxidation levels. We also found that expression of the Lys63Arg and Phe65Leu variants with enhanced enzymatic activity and stability, respectively, increased the fermentation ability of bread dough after exposure to air-drying stress compared with the wild-type Mpr1. In addition, our recent study showed that industrial baker's yeast cells accumulating proline exhibited enhanced freeze tolerance in bread dough. Proline accumulation also enhanced the fermentation ability after air-drying stress treatment in industrial baker's yeast. Hence, the antioxidant enzyme Mpr1/2 could be promising for breeding novel yeast strains that are tolerant to air-drying stress. Copyright 2010 Elsevier B.V. All rights reserved.

Plant Growth-Promoting Rhizobacteria Enhance Salinity Stress Tolerance in Okra through ROS-Scavenging Enzymes

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Sheikh Hasna Habib

2016-01-01

Full Text Available Salinity is a major environmental stress that limits crop production worldwide. In this study, we characterized plant growth-promoting rhizobacteria (PGPR containing 1-aminocyclopropane-1-carboxylate (ACC deaminase and examined their effect on salinity stress tolerance in okra through the induction of ROS-scavenging enzyme activity. PGPR inoculated okra plants exhibited higher germination percentage, growth parameters, and chlorophyll content than control plants. Increased antioxidant enzyme activities (SOD, APX, and CAT and upregulation of ROS pathway genes (CAT, APX, GR, and DHAR were observed in PGPR inoculated okra plants under salinity stress. With some exceptions, inoculation with Enterobacter sp. UPMR18 had a significant influence on all tested parameters under salt stress, as compared to other treatments. Thus, the ACC deaminase-containing PGPR isolate Enterobacter sp. UPMR18 could be an effective bioresource for enhancing salt tolerance and growth of okra plants under salinity stress.

Nucleus accumbens corticotropin-releasing factor increases cue-triggered motivation for sucrose reward: paradoxical positive incentive effects in stress?

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Schulkin Jay

2006-04-01

Full Text Available Abstract Background Corticotropin-releasing factor (CRF is typically considered to mediate aversive aspects of stress, fear and anxiety. However, CRF release in the brain is also elicited by natural rewards and incentive cues, raising the possibility that some CRF systems in the brain mediate an independent function of positive incentive motivation, such as amplifying incentive salience. Here we asked whether activation of a limbic CRF subsystem magnifies the increase in positive motivation for reward elicited by incentive cues previously associated with that reward, in a way that might exacerbate cue-triggered binge pursuit of food or other incentives? We assessed the impact of CRF microinjections into the medial shell of nucleus accumbens using a pure incentive version of Pavlovian-Instrumental transfer, a measure specifically sensitive to the incentive salience of reward cues (which it separates from influences of aversive stress, stress reduction, frustration and other traditional explanations for stress-increased behavior. Rats were first trained to press one of two levers to obtain sucrose pellets, and then separately conditioned to associate a Pavlovian cue with free sucrose pellets. On test days, rats received microinjections of vehicle, CRF (250 or 500 ng/0.2 μl or amphetamine (20 μg/0.2 μl. Lever pressing was assessed in the presence or absence of the Pavlovian cues during a half-hour test. Results Microinjections of the highest dose of CRF (500 ng or amphetamine (20 μg selectively enhanced the ability of Pavlovian reward cues to trigger phasic peaks of increased instrumental performance for a sucrose reward, each peak lasting a minute or so before decaying after the cue. Lever pressing was not enhanced by CRF microinjections in the baseline absence of the Pavlovian cue or during the presentation without a cue, showing that the CRF enhancement could not be explained as a result of generalized motor arousal, frustration or stress

Moringa oleifera extract enhances sexual performance in stressed rats.

Science.gov (United States)

Prabsattroo, Thawatchai; Wattanathorn, Jintanaporn; Iamsaard, Sitthichai; Somsapt, Pichet; Sritragool, Opass; Thukhummee, Wipawee; Muchimapura, Supaporn

2015-03-01

Aphrodisiacs are required to improve male sexual function under stressful conditions. Due to the effects of oxidative stress and dopamine on male sexual function, we hypothesized that Moringa oleifera leaves might improve male sexual dysfunction induced by stress. Therefore, the effects on various factors playing important roles in male sexual behavior, such as antioxidant effects, the suppression of monoamine and phosphodiesterase type 5 (PDE-5) activities, serum testosterone and corticosterone levels, and histomorphological changes in the testes, of a hydroethanolic extract of M. oleifera leaves were investigated. Various doses of extract including 10, 50, and 250 mg/kg body weight (BW) were given orally to male Wistar rats before exposure to 12 h-immobilization stress for 7 d. The results demonstrated that the extract showed both antioxidant and monoamine oxidase type B (MAO-B) suppression activities. At 7 d of treatment, the low dose of extract improved sexual performance in stress-exposed rats by decreasing intromission latency and increasing intromission frequency. It also suppressed PDE-5 activity, decreased serum corticosterone level, but increased serum testosterone, numbers of interstitial cells of Leydig and spermatozoa. The increased numbers of interstitial cells of Leydig and spermatozoa might have been due to the antioxidant effect of the extract. The increased sexual performance during the intromission phase might have been due to the suppression of MAO-B and PDE-5 activities and increased testosterone. Therefore, M. oleifera is a potential aphrodisiac, but further research concerning the precise underlying mechanisms is still needed.

Chronic stress disrupts fear extinction and enhances amygdala and hippocampal Fos expression in an animal model of post-traumatic stress disorder.

Science.gov (United States)

Hoffman, Ann N; Lorson, Nickolaus G; Sanabria, Federico; Foster Olive, M; Conrad, Cheryl D

2014-07-01

Chronic stress may impose a vulnerability to develop maladaptive fear-related behaviors after a traumatic event. Whereas previous work found that chronic stress impairs the acquisition and recall of extinguished fear, it is unknown how chronic stress impacts nonassociative fear, such as in the absence of the conditioned stimulus (CS) or in a novel context. Male rats were subjected to chronic stress (STR; wire mesh restraint 6 h/d/21d) or undisturbed (CON), then tested on fear acquisition (3 tone-footshock pairings), and two extinction sessions (15 tones/session) within the same context. Then each group was tested (6 tones) in the same context (SAME) or a novel context (NOVEL), and brains were processed for functional activation using Fos immunohistochemistry. Compared to CON, STR showed facilitated fear acquisition, resistance to CS extinction on the first extinction day, and robust recovery of fear responses on the second extinction day. STR also showed robust freezing to the context alone during the first extinction day compared to CON. When tested in the same or a novel context, STR exhibited higher freezing to context than did CON, suggesting that STR-induced fear was independent of context. In support of this, STR showed increased Fos-like expression in the basolateral amygdala and CA1 region of the hippocampus in both the SAME and NOVEL contexts. Increased Fos-like expression was also observed in the central amygdala in STR-NOVEL vs. CON-NOVEL. These data demonstrate that chronic stress enhances fear learning and impairs extinction, and affects nonassociative processes as demonstrated by enhanced fear in a novel context. Copyright © 2014 Elsevier Inc. All rights reserved.

2-deoxy-D-glucose-induced metabolic stress enhances resistance to Listeria monocytogenes infection in mice

Science.gov (United States)

Miller, E. S.; Bates, R. A.; Koebel, D. A.; Fuchs, B. B.; Sonnenfeld, G.

1998-01-01

Exposure to different forms of psychological and physiological stress can elicit a host stress response, which alters normal parameters of neuroendocrine homeostasis. The present study evaluated the influence of the metabolic stressor 2-deoxy-D-glucose (2-DG; a glucose analog, which when administered to rodents, induces acute periods of metabolic stress) on the capacity of mice to resist infection with the facultative intracellular bacterial pathogen Listeria monocytogenes. Female BDF1 mice were injected with 2-DG (500 mg/kg b. wt.) once every 48 h prior to, concurrent with, or after the onset of a sublethal dose of virulent L. monocytogenes. Kinetics of bacterial growth in mice were not altered if 2-DG was applied concurrently or after the start of the infection. In contrast, mice exposed to 2-DG prior to infection demonstrated an enhanced resistance to the listeria challenge. The enhanced bacterial clearance in vivo could not be explained by 2-DG exerting a toxic effect on the listeria, based on the results of two experiments. First, 2-DG did not inhibit listeria replication in trypticase soy broth. Second, replication of L. monocytogenes was not inhibited in bone marrow-derived macrophage cultures exposed to 2-DG. Production of neopterin and lysozyme, indicators of macrophage activation, were enhanced following exposure to 2-DG, which correlated with the increased resistance to L. monocytogenes. These results support the contention that the host response to 2-DG-induced metabolic stress can influence the capacity of the immune system to resist infection by certain classes of microbial pathogens.

Factor analysis for exercise stress radionuclide ventriculography

International Nuclear Information System (INIS)

Hirota, Kazuyoshi; Yasuda, Mitsutaka; Oku, Hisao; Ikuno, Yoshiyasu; Takeuchi, Kazuhide; Takeda, Tadanao; Ochi, Hironobu

1987-01-01

Using factor analysis, a new image processing in exercise stress radionuclide ventriculography, changes in factors associated with exercise were evaluated in 14 patients with angina pectoris or old myocardial infarction. The patients were imaged in the left anterior oblique projection, and three factor images were presented on a color coded scale. Abnormal factors (AF) were observed in 6 patients before exercise, 13 during exercise, and 4 after exercise. In 7 patients, the occurrence of AF was associated with exercise. Five of them became free from AF after exercise. Three patients showing AF before exercise had aggravation of AF during exercise. Overall, the occurrence or aggravation of AF was associated with exercise in ten (71 %) of the patients. The other three patients, however, had disappearance of AF during exercise. In the last patient, none of the AF was observed throughout the study. In view of a high incidence of AF associated with exercise, the factor analysis may have the potential in evaluating cardiac reverse from the viewpoint of left ventricular wall motion abnormality. (Namekawa, K.)

Stress enhances reconsolidation of declarative memory.

Science.gov (United States)

Bos, Marieke G N; Schuijer, Jantien; Lodestijn, Fleur; Beckers, Tom; Kindt, Merel

2014-08-01

Retrieval of negative emotional memories is often accompanied by the experience of stress. Upon retrieval, a memory trace can temporarily return into a labile state, where it is vulnerable to change. An unresolved question is whether post-retrieval stress may affect the strength of declarative memory in humans by modulating the reconsolidation process. Here, we tested in two experiments whether post-reactivation stress may affect the strength of declarative memory in humans. In both experiments, participants were instructed to learn neutral, positive and negative words. Approximately 24h later, participants received a reminder of the word list followed by exposure to the social evaluative cold pressor task (reactivation/stress group, nexp1=20; nexp2=18) or control task (reactivation/no-stress group, nexp1=23; nexp2=18). An additional control group was solely exposed to the stress task, without memory reactivation (no-reactivation/stress group, nexp1=23; nexp2=21). The next day, memory performance was tested using a free recall and a recognition task. In the first experiment we showed that participants in the reactivation/stress group recalled more words than participants in the reactivation/no-stress and no-reactivation/stress group, irrespective of valence of the word stimuli. Furthermore, participants in the reactivation/stress group made more false recognition errors. In the second experiment we replicated our observations on the free recall task for a new set of word stimuli, but we did not find any differences in false recognition. The current findings indicate that post-reactivation stress can improve declarative memory performance by modulating the process of reconsolidation. This finding contributes to our understanding why some memories are more persistent than others. Copyright © 2014. Published by Elsevier Ltd.

Job stress and its related factors in accountant employees of Qazvin University of Medical Sciences

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S. Khoeniha

2011-07-01

Full Text Available Background and aims Job stress is defined as the harmful physical and emotional responses that occur when job requirements do not match the capabilities¸ resources ¸and needs. This factor can negatively influence worker’s mental and physical health and also decrease organizations productivity and success. Thus the aim of present study was to investigate the job stress and its related factors in accountant employees of Qazvin University of Medical Sciences in 1388.   Methods This study was a descriptive (cross-sectional research in which the sampling population included 80 accountant employees that were selected with census. The severity of job stress and its related factors were determined using a researcher-made questionnaire consisting of 36 items that validated by content validity. The reliability was also measured by test-retest (d=0/90 methods. Data was analyzed by descriptive analysis.     ResultsThe severity of job stress in most of accountant employees (%46/25 was in high level .There was a Significant relationship between severity of job stress and employees sex ¸ age and work record (p<0.001 . The higher job stress was experienced by women and employees with thelower age work record . Among different occupational stress variables, the most important factor that caused job stress was workload of the role (M=70/22. Conclusion With regard to the severity of job stress in accountant employees, it is necessary for organizational managers and policy makers to implement a protective strategy for prevention or alleviate longitudinal negative consequences of job stress in employees.

Knock-out of Arabidopsis AtNHX4 gene enhances tolerance to salt stress

International Nuclear Information System (INIS)

Li, Hong-Tao; Liu, Hua; Gao, Xiao-Shu; Zhang, Hongxia

2009-01-01

AtNHX4 belongs to the monovalent cation:proton antiporter-1 (CPA1) family in Arabidopsis. Several members of this family have been shown to be critical for plant responses to abiotic stress, but little is known on the biological functions of AtNHX4. Here, we provide the evidence that AtNHX4 plays important roles in Arabidopsis responses to salt stress. Expression of AtNHX4 was responsive to salt stress and abscisic acid. Experiments with CFP-AtNHX4 fusion protein indicated that AtNHX4 is vacuolar localized. The nhx4 mutant showed enhanced tolerance to salt stress, and lower Na + content under high NaCl stress compared with wild-type plants. Furthermore, heterologous expression of AtNHX4 in Escherichia coli BL21 rendered the transformants hypersensitive to NaCl. Deletion of the hydrophilic C-terminus of AtNHX4 dramatically increased the hypersensitivity of transformants, indicating that AtNHX4 may function in Na + homeostasis in plant cell, and its C-terminus plays a role in regulating the AtNHX4 activity.

Knock-out of Arabidopsis AtNHX4 gene enhances tolerance to salt stress

Energy Technology Data Exchange (ETDEWEB)

Li, Hong-Tao; Liu, Hua; Gao, Xiao-Shu [Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032 (China); Zhang, Hongxia, E-mail: hxzhang@sippe.ac.cn [Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032 (China)

2009-05-08

AtNHX4 belongs to the monovalent cation:proton antiporter-1 (CPA1) family in Arabidopsis. Several members of this family have been shown to be critical for plant responses to abiotic stress, but little is known on the biological functions of AtNHX4. Here, we provide the evidence that AtNHX4 plays important roles in Arabidopsis responses to salt stress. Expression of AtNHX4 was responsive to salt stress and abscisic acid. Experiments with CFP-AtNHX4 fusion protein indicated that AtNHX4 is vacuolar localized. The nhx4 mutant showed enhanced tolerance to salt stress, and lower Na{sup +} content under high NaCl stress compared with wild-type plants. Furthermore, heterologous expression of AtNHX4 in Escherichia coli BL21 rendered the transformants hypersensitive to NaCl. Deletion of the hydrophilic C-terminus of AtNHX4 dramatically increased the hypersensitivity of transformants, indicating that AtNHX4 may function in Na{sup +} homeostasis in plant cell, and its C-terminus plays a role in regulating the AtNHX4 activity.

Perceived heart risk factors can predict experienced psychological stress in outpatient cardiac rehabilitation

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Mozhgan Saeidi

2018-01-01

Full Text Available Background: The study was done to investigate the role of perceived heart risk factors (PHRFs in the prediction of psychological symptoms of cardiac rehabilitation (CR patients. Methods: In this cross-sectional study, 124 CR patients referred to Kermanshah Hospital of Imam Ali were assessed during April–July 2015. PHRFs scale and Depression, Anxiety, and Stress scale-21 used for data collection. The data were analyzed using linear multiple regression analysis. Results: The mean age of samples (69.4% male was 58.9 ± 9.7 years. The results of regression analysis evidenced that there is no significant relationship between any of the PHRFs with depression and anxiety (P > 0.05; however, biological (P = 0.018 and psychological (P = 0.019 risk factors significantly can predict stress. The model generally can explain 6.4% of the stress variance. Conclusion: PHRFs are included some significant predictors for experienced stress among the CR patients. Given that the biological and psychological risk factors are more effective in experienced stress by the patients, it is recommended that specialists pay more attention to the potential psychological outcomes of this group of patients.

Salicylic acid alleviates the adverse effects of salt stress in Torreya grandis cv. Merrillii seedlings by activating photosynthesis and enhancing antioxidant systems.

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Tingting Li

Full Text Available BACKGROUND: Salt stress is a major factor limiting plant growth and productivity. Salicylic acid (SA has been shown to ameliorate the adverse effects of environmental stress on plants. To investigate the protective role of SA in ameliorating salt stress on Torreya grandis (T. grandis trees, a pot experiment was conducted to analyze the biomass, relative water content (RWC, chlorophyll content, net photosynthesis (Pn, gas exchange parameters, relative leakage conductivity (REC, malondialdehyde (MDA content, and activities of superoxide dismutase (SOD and peroxidase (POD of T. grandis under 0.2% and 0.4% NaCl conditions with and without SA. METHODOLOGY/PRINCIPAL FINDINGS: The exposure of T. grandis seedlings to salt conditions resulted in reduced growth rates, which were associated with decreases in RWC and Pn and increases in REC and MDA content. The foliar application of SA effectively increased the chlorophyll (chl (a+b content, RWC, net CO2 assimilation rates (Pn, and proline content, enhanced the activities of SOD, CAT and POD, and minimized the increases in the REC and MDA content. These changes increased the capacity of T. grandis in acclimating to salt stress and thus increased the shoot and root dry matter. However, when the plants were under 0% and 0.2% NaCl stress, the dry mass of the shoots and roots did not differ significantly between SA-treated plants and control plants. CONCLUSIONS: SA induced the salt tolerance and increased the biomass of T. grandis cv. by enhancing the chlorophyll content and activity of antioxidative enzymes, activating the photosynthetic process, and alleviating membrane injury. A better understanding about the effect of salt stress in T. grandis is vital, in order gain knowledge over expanding the plantations to various regions and also for the recovery of T. grandis species in the future.

Water-avoidance stress enhances gastric contractions in freely moving conscious rats: role of peripheral CRF receptors.

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Nozu, Tsukasa; Kumei, Shima; Takakusaki, Kaoru; Okumura, Toshikatsu

2014-05-01

Stress alters gastrointestinal motility through central and peripheral corticotropin-releasing factor (CRF) pathways. Accumulating evidence has demonstrated that peripheral CRF is deeply involved in the regulation of gastric motility, and enhances gastric contractions through CRF receptor type 1 (CRF1) and delays gastric emptying (GE) through CRF receptor type 2 (CRF2). Since little is known whether water-avoidance stress (WAS) alters gastric motility, the present study tried to clarify this question and the involvement of peripheral CRF receptor subtypes in the mechanisms. We recorded intraluminal gastric pressure waves using a perfused manometric method. The rats were anesthetized and the manometric catheter was inserted into the stomach 4-6 days before the experiments. We assessed the area under the manometric trace as the motor index (MI), and compared this result with those obtained 1 h before and after initiation of WAS in nonfasted conscious rats. Solid GE for 1 h was also measured. WAS significantly increased gastric contractions. Intraperitoneal (ip) administration of astressin (100 μg/kg, 5 min prior to stress), a nonselective CRF antagonist, blocked the response to WAS. On the other hand, pretreatment (5 min prior to stress) with neither astressin2-B (200 μg/kg, ip), a selective CRF2 antagonist, nor urocortin 2 (30 μg/kg, ip), a selective CRF2 agonist, modified the response to WAS. These drugs did not alter the basal MI. WAS did not change GE. WAS may activate peripheral CRF1 but not CRF2 signaling and stimulates gastric contractions without altering GE.

Engineering tolerance to industrially relevant stress factors in yeast cell factories.

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Deparis, Quinten; Claes, Arne; Foulquié-Moreno, Maria R; Thevelein, Johan M

2017-06-01

The main focus in development of yeast cell factories has generally been on establishing optimal activity of heterologous pathways and further metabolic engineering of the host strain to maximize product yield and titer. Adequate stress tolerance of the host strain has turned out to be another major challenge for obtaining economically viable performance in industrial production. Although general robustness is a universal requirement for industrial microorganisms, production of novel compounds using artificial metabolic pathways presents additional challenges. Many of the bio-based compounds desirable for production by cell factories are highly toxic to the host cells in the titers required for economic viability. Artificial metabolic pathways also turn out to be much more sensitive to stress factors than endogenous pathways, likely because regulation of the latter has been optimized in evolution in myriads of environmental conditions. We discuss different environmental and metabolic stress factors with high relevance for industrial utilization of yeast cell factories and the experimental approaches used to engineer higher stress tolerance. Improving stress tolerance in a predictable manner in yeast cell factories should facilitate their widespread utilization in the bio-based economy and extend the range of products successfully produced in large scale in a sustainable and economically profitable way. © FEMS 2017.

Engineering tolerance to industrially relevant stress factors in yeast cell factories

Science.gov (United States)

Deparis, Quinten; Claes, Arne; Foulquié-Moreno, Maria R.

2017-01-01

Abstract The main focus in development of yeast cell factories has generally been on establishing optimal activity of heterologous pathways and further metabolic engineering of the host strain to maximize product yield and titer. Adequate stress tolerance of the host strain has turned out to be another major challenge for obtaining economically viable performance in industrial production. Although general robustness is a universal requirement for industrial microorganisms, production of novel compounds using artificial metabolic pathways presents additional challenges. Many of the bio-based compounds desirable for production by cell factories are highly toxic to the host cells in the titers required for economic viability. Artificial metabolic pathways also turn out to be much more sensitive to stress factors than endogenous pathways, likely because regulation of the latter has been optimized in evolution in myriads of environmental conditions. We discuss different environmental and metabolic stress factors with high relevance for industrial utilization of yeast cell factories and the experimental approaches used to engineer higher stress tolerance. Improving stress tolerance in a predictable manner in yeast cell factories should facilitate their widespread utilization in the bio-based economy and extend the range of products successfully produced in large scale in a sustainable and economically profitable way. PMID:28586408

Endocrine disruptors found in food contaminants enhance allergic sensitization through an oxidative stress that promotes the development of allergic airway inflammation

International Nuclear Information System (INIS)

Kato, Takuma; Tada-Oikawa, Saeko; Wang, Linan; Murata, Mariko; Kuribayashi, Kagemasa

2013-01-01

In the past few decades, there has been a significant increase in incidence of allergic diseases. The hygiene hypothesis may provide some clues to explain this rising trend, but it may also be attributable to other environmental factors that exert a proallergic adjuvant effects. However, there is limited information on the risks of developing allergic asthma and related diseases through the ingestion of environmental chemicals found in food contaminants. In the present study, we have shown that oral administration of tributyltin, used as a model environmental chemical, induced oxidative-stress status in the bronchial lymph node, mesenteric lymph node and spleen, but not in the lung, where the initial step of allergic asthma pathogenesis takes place. Mice exposed to tributyltin exhibited heightened Th2 immunity to the allergen with more severe airway inflammation. Tributyltin also induced Treg cells apoptosis preferentially over non-Treg cells. All these effects of tributyltin exposure were canceled by the administration of glutathione monoethyl ester. Meanwhile, tributyltin did not affect airway inflammation of mice transferred with allergen-specific Th2 cells. Collectively, these results suggest that tributyltin exerts its pathological effect during the sensitization phase through oxidative stress that enhances the development of allergic diseases. The current study dissects the pathogenic role of oxidative stress induced by oral exposure to an environmental chemical during the sensitization phase of allergic airway inflammation and would be important for developing therapeutics for prevention of allergic diseases. - Highlights: • Oral exposure to TBT exacerbates airway inflammation. • TBT induces oxidative stress in secondary lymphoid organs, but not in the lung. • TBT preferentially induces regulatory T cell apoptosis over non-Treg cells. • TBT does not enhance pre-existing airway inflammation in sensitized mice. • Chemicals in food contaminants

Endocrine disruptors found in food contaminants enhance allergic sensitization through an oxidative stress that promotes the development of allergic airway inflammation

Energy Technology Data Exchange (ETDEWEB)

Kato, Takuma, E-mail: katotaku@doc.medic.mie-u.ac.jp [Department of Cellular and Molecular Immunology, Mie University Graduate School of Medicine (Japan); Tada-Oikawa, Saeko [Department of Environmental and Molecular Medicine, Mie University Graduate School of Medicine (Japan); Wang, Linan [Department of Cellular and Molecular Immunology, Mie University Graduate School of Medicine (Japan); Murata, Mariko [Department of Environmental and Molecular Medicine, Mie University Graduate School of Medicine (Japan); Kuribayashi, Kagemasa [Department of Cellular and Molecular Immunology, Mie University Graduate School of Medicine (Japan)

2013-11-15

In the past few decades, there has been a significant increase in incidence of allergic diseases. The hygiene hypothesis may provide some clues to explain this rising trend, but it may also be attributable to other environmental factors that exert a proallergic adjuvant effects. However, there is limited information on the risks of developing allergic asthma and related diseases through the ingestion of environmental chemicals found in food contaminants. In the present study, we have shown that oral administration of tributyltin, used as a model environmental chemical, induced oxidative-stress status in the bronchial lymph node, mesenteric lymph node and spleen, but not in the lung, where the initial step of allergic asthma pathogenesis takes place. Mice exposed to tributyltin exhibited heightened Th2 immunity to the allergen with more severe airway inflammation. Tributyltin also induced Treg cells apoptosis preferentially over non-Treg cells. All these effects of tributyltin exposure were canceled by the administration of glutathione monoethyl ester. Meanwhile, tributyltin did not affect airway inflammation of mice transferred with allergen-specific Th2 cells. Collectively, these results suggest that tributyltin exerts its pathological effect during the sensitization phase through oxidative stress that enhances the development of allergic diseases. The current study dissects the pathogenic role of oxidative stress induced by oral exposure to an environmental chemical during the sensitization phase of allergic airway inflammation and would be important for developing therapeutics for prevention of allergic diseases. - Highlights: • Oral exposure to TBT exacerbates airway inflammation. • TBT induces oxidative stress in secondary lymphoid organs, but not in the lung. • TBT preferentially induces regulatory T cell apoptosis over non-Treg cells. • TBT does not enhance pre-existing airway inflammation in sensitized mice. • Chemicals in food contaminants

Enhanced proline synthesis may determine resistance to salt stress in tomato cultivars

International Nuclear Information System (INIS)

Ali, S.; Khan, N.U.

2011-01-01

The physiological and biochemical responses of tomato cultivars were studied at Khyber Pakhtunkhwa Agricultural University, Peshawar, Pakistan during 2005-2006 for salt tolerance. Tomato cultivars were Roma Rio Super, Roma V.F., Chinese 87-5, Rio Grand and Super Blocky and subjected to salt stress (75 mM NaCl). Fresh weight, dry weight, and ions sodium and potassium accumulation, Na/sup +/K sup +/ ratio and proline content were determined after imposing the tomato cultivars to NaCl salt for 80 days. Salt stress significantly decreased the fresh and dry weight in Roma Rio Super, Roma V.F, Chinese 87-5 and Rio Grand, however, in Super Blocky the fresh and dry weight were enhanced under stress conditions. Salinity stress increased sodium uptake from 191.828 to 436.170 mu mg/sup -1/ D wt while potassium accumulation decreased from 1033.12 to 926.80 mu mg/sup -1/ D wt resulting in higher Na/sup +/ ratio in stressed (0.48 g) as compared to unstressed control (0.19). The mean proline contents also increased from 28.95 to 40.96 mu M Proline g/sup -1/ F. wt with the maximum increase (57.378%) in Super Blocky followed by Rio Grand (49.325%). (author)

Sulindac enhances the killing of cancer cells exposed to oxidative stress.

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Maria Marchetti

2009-06-01

Full Text Available Sulindac is an FDA-approved non-steroidal anti-inflammatory drug (NSAID that affects prostaglandin production by inhibiting cyclooxygenases (COX 1 and 2. Sulindac has also been of interest for more than decade as a chemopreventive for adenomatous colorectal polyps and colon cancer.Pretreatment of human colon and lung cancer cells with sulindac enhances killing by an oxidizing agent such as tert-butyl hydroperoxide (TBHP or hydrogen peroxide. This effect does not involve cyclooxygenase (COX inhibition. However, under the conditions used, there is a significant increase in reactive oxygen species (ROS within the cancer cells and a loss of mitochondrial membrane potential, suggesting that cell death is due to apoptosis, which was confirmed by Tunel assay. In contrast, this enhanced killing was not observed with normal lung or colon cells.These results indicate that normal and cancer cells handle oxidative stress in different ways and sulindac can enhance this difference. The combination of sulindac and an oxidizing agent could have therapeutic value.

Forkhead Box M1 Is Regulated by Heat Shock Factor 1 and Promotes Glioma Cells Survival under Heat Shock Stress*

Science.gov (United States)

Dai, Bingbing; Gong, Aihua; Jing, Zhitao; Aldape, Kenneth D.; Kang, Shin-Hyuk; Sawaya, Raymond; Huang, Suyun

2013-01-01

The forkhead box M1 (FoxM1) is a key transcription factor regulating multiple aspects of cell biology. Prior studies have shown that FoxM1 is overexpressed in a variety of human tumors, including brain tumor, and plays a critical role in cancer development and progression. In this study we found that FoxM1 was up-regulated by heat shock factor 1 (HSF1) under heat shock stress condition in multiple cell lines. Knockdown of HSF1 with HSF1 siRNA or inhibition of HSF1 with a HSF1 inhibitor abrogated heat shock-induced expression of FoxM1. Genetic deletion of HSF1 in mouse embryo fibroblast cells also abolished heat shock stress-induced FoxM1 expression. Moreover, we showed that HSF1 directly bound to FoxM1 promoter and increased FoxM1 promoter activity. Furthermore, we demonstrated that FoxM1 was required for the G2-M phase progression through regulating Cdc2, Cdc20, and Cdc25B under a mild heat shock stress but enhanced cell survival under lethal heat shock stress condition. Finally, in human glioblastoma specimens, FoxM1 overexpression correlated with elevated HSF1 expression. Our results indicate that FoxM1 is regulated by HSF1 and is critical for HSF1-mediated heat shock response. We demonstrated a novel mechanism of stress resistance controlled by HSF1 and a new HSF-FoxM1 connection that mediates cellular thermotolerance. PMID:23192351

Risk factors for stress in children after parental stroke

NARCIS (Netherlands)

Sieh, D.S.; Meijer, A.M.; Visser-Meily, J.M.

2010-01-01

Objectives: To assess risk factors for stress in children 3 years after parental stroke. Participants: Questionnaires were filled in by 44 children aged 7-18 years, parents who suffered a stroke and healthy spouses from 29 families recruited in 9 participating rehabilitation centers across the

Supramolecular Nanofibers Enhance Growth Factor Signaling by Increasing Lipid Raft Mobility

Energy Technology Data Exchange (ETDEWEB)

Newcomb, Christina J.; Sur, Shantanu; Lee, Sungsoo S.; Yu, Jeong Min; Zhou, Yan; Snead, Malcolm L.; Stupp, Samuel I. (NWU); (USC)

2016-04-12

The nanostructures of self-assembling biomaterials have been previously designed to tune the release of growth factors in order to optimize biological repair and regeneration. We report here on the discovery that weakly cohesive peptide nanostructures in terms of intermolecular hydrogen bonding, when combined with low concentrations of osteogenic growth factor, enhance both BMP-2 and Wnt mediated signaling in myoblasts and bone marrow stromal cells, respectively. Conversely, analogous nanostructures with enhanced levels of internal hydrogen bonding and cohesion lead to an overall reduction in BMP-2 signaling. We propose that the mechanism for enhanced growth factor signaling by the nanostructures is related to their ability to increase diffusion within membrane lipid rafts. The phenomenon reported here could lead to new nanomedicine strategies to mediate growth factor signaling for translational targets.

Over-expression of a NAC 67 transcription factor from finger millet (Eleusine coracana L.) confers tolerance against salinity and drought stress in rice.

Science.gov (United States)

Rahman, Hifzur; Ramanathan, Valarmathi; Nallathambi, Jagedeeshselvam; Duraialagaraja, Sudhakar; Muthurajan, Raveendran

2016-05-11

NAC proteins (NAM (No apical meristem), ATAF (Arabidopsis transcription activation factor) and CUC (cup-shaped cotyledon)) are plant-specific transcription factors reported to be involved in regulating growth, development and stress responses. Salinity responsive transcriptome profiling in a set of contrasting finger millet genotypes through RNA-sequencing resulted in the identification of a NAC homolog (EcNAC 67) exhibiting differential salinity responsive expression pattern. Full length cDNA of EcNAC67 was isolated, characterized and validated for its role in abiotic stress tolerance through agrobacterium mediated genetic transformation in a rice cultivar ASD16. Bioinformatics analysis of putative NAC transcription factor (TF) isolated from a salinity tolerant finger millet showed its genetic relatedness to NAC67 family TFs in related cereals. Putative transgenic lines of rice over-expressing EcNAC67 were generated through Agrobacterium mediated transformation and presence/integration of transgene was confirmed through PCR and southern hybridization analysis. Transgenic rice plants harboring EcNAC67 showed enhanced tolerance against drought and salinity under greenhouse conditions. Transgenic rice plants were found to possess higher root and shoot biomass during stress and showed better revival ability upon relief from salinity stress. Upon drought stress, transgenic lines were found to maintain higher relative water content and lesser reduction in grain yield when compared to non-transgenic ASD16 plants. Drought induced spikelet sterility was found to be much lower in the transgenic lines than the non-transgenic ASD16. Results revealed the significant role of EcNAC67 in modulating responses against dehydration stress in rice. No detectable abnormalities in the phenotypic traits were observed in the transgenic plants under normal growth conditions. Results indicate that EcNAC67 can be used as a novel source for engineering tolerance against drought and salinity

Chrysanthemum WRKY gene DgWRKY5 enhances tolerance to salt stress in transgenic chrysanthemum.

Science.gov (United States)

Liang, Qian-Yu; Wu, Yin-Huan; Wang, Ke; Bai, Zhen-Yu; Liu, Qing-Lin; Pan, Yuan-Zhi; Zhang, Lei; Jiang, Bei-Bei

2017-07-06

WRKY transcription factors play important roles in plant growth development, resistance and substance metabolism regulation. However, the exact function of the response to salt stress in plants with specific WRKY transcription factors remains unclear. In this research, we isolated a new WRKY transcription factor DgWRKY5 from chrysanthemum. DgWRKY5 contains two WRKY domains of WKKYGQK and two C 2 H 2 zinc fingers. The expression of DgWRKY5 in chrysanthemum was up-regulated under various treatments. Meanwhile, we observed higher expression levels in the leaves contrasted with other tissues. Under salt stress, the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) enzymes in transgenic chrysanthemum were significantly higher than those in WT, whereas the accumulation of H 2 O 2 , O 2 - and malondialdehyde (MDA) was reduced in transgenic chrysanthemum. Several parameters including root length, root length, fresh weight, chlorophyll content and leaf gas exchange parameters in transgenic chrysanthemum were much better compared with WT under salt stress. Moreover, the expression of stress-related genes DgAPX, DgCAT, DgNCED3A, DgNCED3B, DgCuZnSOD, DgP5CS, DgCSD1 and DgCSD2 was up-regulated in DgWRKY5 transgenic chrysanthemum compared with that in WT. These results suggested that DgWRKY5 could function as a positive regulator of salt stress in chrysanthemum.

Lycopene activates antioxidant enzymes and nuclear transcription factor systems in heat-stressed broilers.

Science.gov (United States)

Sahin, K; Orhan, C; Tuzcu, M; Sahin, N; Hayirli, A; Bilgili, S; Kucuk, O

2016-05-01

This study was conducted to evaluate the effects of dietary lycopene supplementation on growth performance, antioxidant status, and muscle nuclear transcription factor [Kelch like-ECH-associated protein 1 (Keap1) and (erythroid-derived 2)-like 2 (Nrf2)] expressions in broiler chickens exposed to heat stress (HS). A total of 180 one-day-old male broiler chicks (Ross 308) were assigned randomly to one of 2×3 factorially arranged treatments: two housing temperatures (22°C for 24 h/d; thermoneutral, TN or 34°C for 8 h/d HS) and three dietary lycopene levels (0, 200, or 400 mg/kg). Each treatment consisted of three replicates of 10 birds. Birds were reared to 42 d of age. Heat stress caused reductions in feed intake and weight gain by 12.2 and 20.7% and increased feed efficiency by 10.8% (Plycopene level improved performance in both environments. Birds reared under the HS environment had lower serum and muscle lycopene concentration (0.34 vs. 0.50 μg/mL and 2.80 vs. 2.13 μg/g), activities of superoxide dismutase (151 vs. 126 U/mL and 131 vs. 155 U/mg protein), glutathione peroxidase (184 vs. 154 U/mL and 1.39 vs. 1.74 U/mg protein), and higher malondialdehyde (MDA) concentration (0.53 vs. 0.83 μg/mL and 0.78 vs. 0.45 μg/ mg protein) than birds reared under the TN environment. Changes in levels of lycopene and MDA and activities of enzymes in serum and muscle varied by the environmental temperature as dietary lycopene level increased. Moreover, increasing dietary lycopene level suppressed muscle Keap1 expression and enhanced muscle Nrf2 expression, which had increased by 150% and decreased by 40%, respectively in response to HS. In conclusion, lycopene supplementation alleviates adverse effects of HS on performance through modulating expressions of stress-related nuclear transcription factors. © 2016 Poultry Science Association Inc.

Factors related to health-related quality of life among Chinese psychiatrists: occupational stress and psychological capital.

Science.gov (United States)

Liu, Chuan; Wang, Lie; Zhao, Qun

2015-01-22

Psychiatry has been considered as one of the most stressful medical specialities, and psychiatrists are likely to experience impaired health-related quality of life (HRQOL). However, few studies are available in regard to related factors of HRQOL among psychiatrists in China. This study aims to evaluate the condition of HRQOL of psychiatrists and explore its predictive factors, especially the effects of occupational stress and psychological capital. A cross-sectional, multicenter survey was conducted among psychiatrists from different regions of Liaoning province, China, during August 2013-April 2014. Self-administrated questionnaires including the 36-item Short-Form Health Survey (SF-36), the Chinese version Psychological Capital Questionnaire, effort-reward-imbalance (ERI) scale and participants' basic characteristics were distributed to 500 psychiatrists from 10 psychiatric hospitals of 8 major cities in Liaoning province. Overall, 373 psychiatrists became our final research objects. Hierarchical multiple regression analysis (HMR) was performed to explore the predictors of psychiatrists' HRQOL. The mean (SD) scores of PCS and MCS among psychiatrists were 79.78 (16.55) and 71.50 (19.24) respectively. The mean (SD) of ERR were 0.777 (0.493), and 89 (23.9%) had ERR scores above 1 (ERR > 1). Hierarchical multiple regression analysis showed that, psychiatrists' basic characteristics that significant correlated with PCS and MCS were educational level, turnover intention, and exercise; age, weekly working hours were associated with MCS; psychiatrists' experienced occupational stress (both ERR and overcommitment), and PsyCap were significant predictors for PCS and MCS. Chinese psychiatrists experienced relatively good physical QOL but impaired mental QOL, and they experienced high level of occupational stress. For the sake of psychiatrists' HRQOL, the reduction of occupational stress should be implemented. The enhancement of PsyCap could be a new intervention

Identification of activated enhancers and linked transcription factors in breast, prostate, and kidney tumors by tracing enhancer networks using epigenetic traits.

Science.gov (United States)

Rhie, Suhn Kyong; Guo, Yu; Tak, Yu Gyoung; Yao, Lijing; Shen, Hui; Coetzee, Gerhard A; Laird, Peter W; Farnham, Peggy J

2016-01-01

Although technological advances now allow increased tumor profiling, a detailed understanding of the mechanisms leading to the development of different cancers remains elusive. Our approach toward understanding the molecular events that lead to cancer is to characterize changes in transcriptional regulatory networks between normal and tumor tissue. Because enhancer activity is thought to be critical in regulating cell fate decisions, we have focused our studies on distal regulatory elements and transcription factors that bind to these elements. Using DNA methylation data, we identified more than 25,000 enhancers that are differentially activated in breast, prostate, and kidney tumor tissues, as compared to normal tissues. We then developed an analytical approach called Tracing Enhancer Networks using Epigenetic Traits that correlates DNA methylation levels at enhancers with gene expression to identify more than 800,000 genome-wide links from enhancers to genes and from genes to enhancers. We found more than 1200 transcription factors to be involved in these tumor-specific enhancer networks. We further characterized several transcription factors linked to a large number of enhancers in each tumor type, including GATA3 in non-basal breast tumors, HOXC6 and DLX1 in prostate tumors, and ZNF395 in kidney tumors. We showed that HOXC6 and DLX1 are associated with different clusters of prostate tumor-specific enhancers and confer distinct transcriptomic changes upon knockdown in C42B prostate cancer cells. We also discovered de novo motifs enriched in enhancers linked to ZNF395 in kidney tumors. Our studies characterized tumor-specific enhancers and revealed key transcription factors involved in enhancer networks for specific tumor types and subgroups. Our findings, which include a large set of identified enhancers and transcription factors linked to those enhancers in breast, prostate, and kidney cancers, will facilitate understanding of enhancer networks and mechanisms

An integrated enhancement and reconstruction strategy for the quantitative extraction of actin stress fibers from fluorescence micrographs.

Science.gov (United States)

Zhang, Zhen; Xia, Shumin; Kanchanawong, Pakorn

2017-05-22

The stress fibers are prominent organization of actin filaments that perform important functions in cellular processes such as migration, polarization, and traction force generation, and whose collective organization reflects the physiological and mechanical activities of the cells. Easily visualized by fluorescence microscopy, the stress fibers are widely used as qualitative descriptors of cell phenotypes. However, due to the complexity of the stress fibers and the presence of other actin-containing cellular features, images of stress fibers are relatively challenging to quantitatively analyze using previously developed approaches, requiring significant user intervention. This poses a challenge for the automation of their detection, segmentation, and quantitative analysis. Here we describe an open-source software package, SFEX (Stress Fiber Extractor), which is geared for efficient enhancement, segmentation, and analysis of actin stress fibers in adherent tissue culture cells. Our method made use of a carefully chosen image filtering technique to enhance filamentous structures, effectively facilitating the detection and segmentation of stress fibers by binary thresholding. We subdivided the skeletons of stress fiber traces into piecewise-linear fragments, and used a set of geometric criteria to reconstruct the stress fiber networks by pairing appropriate fiber fragments. Our strategy enables the trajectory of a majority of stress fibers within the cells to be comprehensively extracted. We also present a method for quantifying the dimensions of the stress fibers using an image gradient-based approach. We determine the optimal parameter space using sensitivity analysis, and demonstrate the utility of our approach by analyzing actin stress fibers in cells cultured on various micropattern substrates. We present an open-source graphically-interfaced computational tool for the extraction and quantification of stress fibers in adherent cells with minimal user input. This

Stress, anxiety, depression, and epilepsy: investigating the relationship between psychological factors and seizures.

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Thapar, Ajay; Kerr, Michael; Harold, Gordon

2009-01-01

The goal of the study described here was to examine the interrelationship between psychological factors (anxiety, stress, and depression) and seizures. In this longitudinal cohort study, data on anxiety, depression, perceived stress, and seizure recency (time since last seizure) and frequency were collected at two time points using standard validated questionnaire measures. Empirically based models with psychological factors explaining change in (1) seizure recency and (2) seizure frequency scores across time were specified. We then tested how these psychological factors acted together in predicting seizure recency and frequency. Our data were used to test whether these models were valid for the study population. Latent variable structural equation modeling was used for the analysis. Four hundred thirty-three of the 558 individuals who initially consented to participate provided two waves of data for this analysis. Stress (beta=0.25, Panxiety (beta=0.30, Pdepression (beta=0.30, Pdepression that mediated the relationship of both anxiety and stress with modeled change in seizure recency (beta=0.19, PDepression mediates the relationship between stress and anxiety and change in seizure recency and seizure frequency. These findings highlight the importance of depression management in addition to seizure management in the assessment and treatment of epilepsy in an adult population.

[Symptoms of Depression, Anxiety and Stress Among Dental Students: Prevalence and Related Factors].

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Arrieta Vergara, Katherine; Cárdenas, Shyrley Díaz; Martínez, Farith González

2013-06-01

To estimate the relationship between depressive symptoms, anxiety and stress and socio-demographic, academic and social factors among dental students. A cross-sectional study was carried out on dental students from a university in Cartagena, selected by simple random sampling. Students answered a self-report anonymous questionnaire of 20 questions that included demographic characteristics, depression, anxiety and stress symptoms (DASS scale 21), family function (APGAR family) and other factors associated with the academic, economic and social context. Data were analyzed computing odds ratios by binomial logistic regression. The prevalence of symptoms of anxiety, depression and stress were 37.4%, 56.6% and 45.4%, respectively. Factors associated with depressive symptoms were lack of support from friends (OR=6.2; 95%CI, 2.6-14.5), family dysfunction (OR=3.6; 95%CI, 1.9-6.6) and economic hardship (OR=2.2; 95%CI, 1.2-3.9). The anxiety symptoms were associated with family dysfunction (OR=3.1; 95%CI, 1.8-5.3) and lack of support from friends (OR=2.1; 95%CI, 1.1-5.8). Also for symptoms of stress factors family dysfunction (OR=2.3; 95%CI, 1.4-4.1), income (OR=2.4; 95%CI, 1.2-4.9) and time to rest (OR=2.3; 95%CI, 1.4-4.0). Dental students report a high prevalence of symptoms of anxiety, depression and stress. Associated factors are economic resources, family function, lack of time for rest, and social support. Copyright © 2013 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Stress-induced enhancement of leukocyte trafficking into sites of surgery or immune activation

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Viswanathan, Kavitha; Dhabhar, Firdaus S.

2005-04-01

Effective immunoprotection requires rapid recruitment of leukocytes into sites of surgery, wounding, infection, or vaccination. In contrast to immunosuppressive chronic stressors, short-term acute stressors have immunoenhancing effects. Here, we quantify leukocyte infiltration within a surgical sponge to elucidate the kinetics, magnitude, subpopulation, and chemoattractant specificity of an acute stress-induced increase in leukocyte trafficking to a site of immune activation. Mice acutely stressed before sponge implantation showed 200-300% higher neutrophil, macrophage, natural killer cell, and T cell infiltration than did nonstressed animals. We also quantified the effects of acute stress on lymphotactin- (LTN; a predominantly lymphocyte-specific chemokine), and TNF-- (a proinflammatory cytokine) stimulated leukocyte infiltration. An additional stress-induced increase in infiltration was observed for neutrophils, in response to TNF-, macrophages, in response to TNF- and LTN, and natural killer cells and T cells in response to LTN. These results show that acute stress initially increases trafficking of all major leukocyte subpopulations to a site of immune activation. Tissue damage-, antigen-, or pathogen-driven chemoattractants subsequently determine which subpopulations are recruited more vigorously. Such stress-induced increases in leukocyte trafficking may enhance immunoprotection during surgery, vaccination, or infection, but may also exacerbate immunopathology during inflammatory (cardiovascular disease or gingivitis) or autoimmune (psoriasis, arthritis, or multiple sclerosis) diseases. chemokine | psychophysiological stress | surgical sponge | wound healing | lymphotactin

Thermal stress intensity factor for an axial crack in a clad cylinder

International Nuclear Information System (INIS)

Kuo, An Yu; Deardorf, A.F.; Riccardella, P.C.

1993-01-01

Many clad pressure vessels have been found to have cracks running through the inside surface cladding and into the base material. Although Young's moduli and Poisson's ratios of the clad and base materials are about the same for most of the industrial applications, coefficients of thermal expansion of the two dissimilar materials, clad and base materials, are usually quite different. For example, low alloy ferritic steel is a common base material for reactor pressure vessels (RPV) and the vessels are usually clad with austenitic stainless steel. Young's moduli for the low alloy steel and stainless steel at 350 F are 29,000 ksi and 28,000 ksi, respectively, while their coefficients of thermal expansion are 7.47x10 -6 in/in and 9.50x10 -6 in/in-degree F, respectively. The mismatch in coefficients of thermal expansion will cause high residual thermal stress even when the entire vessel is at a uniform temperature. This residual stress is one of the primary reasons why so many cracks have been found in the cladded components. In performing reactor pressure vessel integrity evaluation, such as computing probability of brittle fracture of the RPV, it is necessary to calculate stress intensity factors for cracks, which initiate from the clad material and run into the base metal. This paper presents a convenient method of calculating stress intensity factor for an axial crack emanating from the inside surface of a cladded cylinder under thermal loading. A J-integral like line integral was derived and used to calculate the stress intensity factors from finite element stress solutions of the problem

Co-transforming bar and CsLEA enhanced tolerance to drought and salt stress in transgenic alfalfa (Medicago sativa L.).

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Zhang, Jiyu; Duan, Zhen; Zhang, Daiyu; Zhang, Jianquan; Di, Hongyan; Wu, Fan; Wang, Yanrong

2016-03-25

Drought and high salinity are two major abiotic factors that restrict alfalfa productivity. A dehydrin protein, CsLEA, from the desert grass Cleistogenes songorica was transformed into alfalfa (Medicago sativa L.) via Agrobacterium-mediated transformation using the bar gene as a selectable marker, and the drought and salt stress tolerances of the transgenic plants were assessed. Thirty-nine of 119 transformants were positive, as screened by Basta, and further molecularly authenticated using PCR and RT-PCR. Phenotype observations revealed that the transgenic plants grew better than the wild-type (WT) plants after 15d of drought stress and 10d of salt stress: the leaves of WT alfalfa turned yellow, whereas the transgenic alfalfa leaves only wilted; after rewatering, the transgenic plants returned to a normal state, though the WT plants could not be restored. Evaluation of physiologic and biochemical indices during drought and salt stresses showed a relatively lower Na(+) content in the leaves of the transgenic plants, which would reduce toxic ion effects. In addition, the transgenic plants were able to maintain a higher relative water content (RWC), higher shoot biomass, fewer photosystem changes, decreased membrane injury, and a lower level of osmotic stress injury. These results demonstrate that overexpression of the CsLEA gene can enhance the drought and salt tolerance of transgenic alfalfa; in addition, carrying the bar gene in the genome may increase herbicide resistance. Copyright © 2016 Elsevier Inc. All rights reserved.

Factors Influencing Stress, Burnout, and Retention of Secondary Teachers

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Fisher, Molly H.

2011-01-01

This study examines the stress, burnout, satisfaction, and preventive coping skills of nearly 400 secondary teachers to determine variables contributing to these major factors influencing teachers. Analysis of Variance (ANOVA) statistics were conducted that found the burnout levels between new and experienced teachers are significantly different,…

Utilizing Genetic Resources and Precision Agriculture to Enhance Resistance to Biotic and Abiotic Stress in Watermelon

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Mihail KANTOR

2018-03-01

Full Text Available Originally from Africa, watermelon is a staple crop in South Carolina and rich source of important phytochemicals that promote human health. As a result of many years of domestication and selection for desired fruit quality, modern watermelon cultivars are susceptible to biotic and abiotic stress. The present review discusses how genetic selection and breeding combined with geospatial technologies (precision agriculture may help enhance watermelon varieties for resistance to biotic and abiotic stress. Gene loci identified and selected in undomesticated watermelon accessions are responsible for resistance to diseases, pests and abiotic stress. Vegetable breeding programs use traditional breeding methodologies and genomic tools to introduce gene loci conferring biotic or abiotic resistance into the genome background of elite watermelon cultivars. This continuous approach of collecting, evaluating and identifying useful genetic material is valuable for enhancing genetic diversity and tolerance and combined with precision agriculture could increase food security in the Southeast.

[Labour factors associated with post-traumatic stress in uniformed workers in Medellín].

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González-Penagos, Catalina; Moreno-Bedoya, Juan P; Berbesi-Fernández, Dedsy Y; Segura-Cardona, Angela M

2013-01-01

Determining the labor factors associated with post-traumatic stress in uniformed workers in Medellin. A cross-sectional study was made of 124 uniformed workers aged 20 to 48 years-old. A survey was made using an adults' post-traumatic stress instrument which had been validated in Medellin. Statistical analysis was carried out. Post-traumatic stress disorder risk prevalence was 52.2 %. Multivariate analysis showed that the highest risk situations were those related to previous mental health diagnosis (PR=7.67), working schedule (4.24), violent episodes (PR=3.59) and community relationships (PR=2.73). A person's current labor situation seemed to be a risk factor for developing post-traumatic stress in the target population.

Enhancement of the proline and nitric oxide synthetic pathway improves fermentation ability under multiple baking-associated stress conditions in industrial baker's yeast.

Science.gov (United States)

Sasano, Yu; Haitani, Yutaka; Hashida, Keisuke; Ohtsu, Iwao; Shima, Jun; Takagi, Hiroshi

2012-04-01

During the bread-making process, industrial baker's yeast, mostly Saccharomyces cerevisiae, is exposed to baking-associated stresses, such as air-drying and freeze-thaw stress. These baking-associated stresses exert severe injury to yeast cells, mainly due to the generation of reactive oxygen species (ROS), leading to cell death and reduced fermentation ability. Thus, there is a great need for a baker's yeast strain with higher tolerance to baking-associated stresses. Recently, we revealed a novel antioxidative mechanism in a laboratory yeast strain that is involved in stress-induced nitric oxide (NO) synthesis from proline via proline oxidase Put1 and N-acetyltransferase Mpr1. We also found that expression of the proline-feedback inhibition-less sensitive mutant γ-glutamyl kinase (Pro1-I150T) and the thermostable mutant Mpr1-F65L resulted in an enhanced fermentation ability of baker's yeast in bread dough after freeze-thaw stress and air-drying stress, respectively. However, baker's yeast strains with high fermentation ability under multiple baking-associated stresses have not yet been developed. We constructed a self-cloned diploid baker's yeast strain with enhanced proline and NO synthesis by expressing Pro1-I150T and Mpr1-F65L in the presence of functional Put1. The engineered strain increased the intracellular NO level in response to air-drying stress, and the strain was tolerant not only to oxidative stress but also to both air-drying and freeze-thaw stresses probably due to the reduced intracellular ROS level. We also showed that the resultant strain retained higher leavening activity in bread dough after air-drying and freeze-thaw stress than that of the wild-type strain. On the other hand, enhanced stress tolerance and fermentation ability did not occur in the put1-deficient strain. This result suggests that NO is synthesized in baker's yeast from proline in response to oxidative stresses that induce ROS generation and that increased NO plays an important

Enhancement of the proline and nitric oxide synthetic pathway improves fermentation ability under multiple baking-associated stress conditions in industrial baker's yeast

Directory of Open Access Journals (Sweden)

Sasano Yu

2012-04-01

Full Text Available Abstract Background During the bread-making process, industrial baker's yeast, mostly Saccharomyces cerevisiae, is exposed to baking-associated stresses, such as air-drying and freeze-thaw stress. These baking-associated stresses exert severe injury to yeast cells, mainly due to the generation of reactive oxygen species (ROS, leading to cell death and reduced fermentation ability. Thus, there is a great need for a baker's yeast strain with higher tolerance to baking-associated stresses. Recently, we revealed a novel antioxidative mechanism in a laboratory yeast strain that is involved in stress-induced nitric oxide (NO synthesis from proline via proline oxidase Put1 and N-acetyltransferase Mpr1. We also found that expression of the proline-feedback inhibition-less sensitive mutant γ-glutamyl kinase (Pro1-I150T and the thermostable mutant Mpr1-F65L resulted in an enhanced fermentation ability of baker's yeast in bread dough after freeze-thaw stress and air-drying stress, respectively. However, baker's yeast strains with high fermentation ability under multiple baking-associated stresses have not yet been developed. Results We constructed a self-cloned diploid baker's yeast strain with enhanced proline and NO synthesis by expressing Pro1-I150T and Mpr1-F65L in the presence of functional Put1. The engineered strain increased the intracellular NO level in response to air-drying stress, and the strain was tolerant not only to oxidative stress but also to both air-drying and freeze-thaw stresses probably due to the reduced intracellular ROS level. We also showed that the resultant strain retained higher leavening activity in bread dough after air-drying and freeze-thaw stress than that of the wild-type strain. On the other hand, enhanced stress tolerance and fermentation ability did not occur in the put1-deficient strain. This result suggests that NO is synthesized in baker's yeast from proline in response to oxidative stresses that induce ROS

Enhancement of the proline and nitric oxide synthetic pathway improves fermentation ability under multiple baking-associated stress conditions in industrial baker's yeast

Science.gov (United States)

2012-01-01

Background During the bread-making process, industrial baker's yeast, mostly Saccharomyces cerevisiae, is exposed to baking-associated stresses, such as air-drying and freeze-thaw stress. These baking-associated stresses exert severe injury to yeast cells, mainly due to the generation of reactive oxygen species (ROS), leading to cell death and reduced fermentation ability. Thus, there is a great need for a baker's yeast strain with higher tolerance to baking-associated stresses. Recently, we revealed a novel antioxidative mechanism in a laboratory yeast strain that is involved in stress-induced nitric oxide (NO) synthesis from proline via proline oxidase Put1 and N-acetyltransferase Mpr1. We also found that expression of the proline-feedback inhibition-less sensitive mutant γ-glutamyl kinase (Pro1-I150T) and the thermostable mutant Mpr1-F65L resulted in an enhanced fermentation ability of baker's yeast in bread dough after freeze-thaw stress and air-drying stress, respectively. However, baker's yeast strains with high fermentation ability under multiple baking-associated stresses have not yet been developed. Results We constructed a self-cloned diploid baker's yeast strain with enhanced proline and NO synthesis by expressing Pro1-I150T and Mpr1-F65L in the presence of functional Put1. The engineered strain increased the intracellular NO level in response to air-drying stress, and the strain was tolerant not only to oxidative stress but also to both air-drying and freeze-thaw stresses probably due to the reduced intracellular ROS level. We also showed that the resultant strain retained higher leavening activity in bread dough after air-drying and freeze-thaw stress than that of the wild-type strain. On the other hand, enhanced stress tolerance and fermentation ability did not occur in the put1-deficient strain. This result suggests that NO is synthesized in baker's yeast from proline in response to oxidative stresses that induce ROS generation and that increased NO

Insulin Resistance in PCOS Patients Enhances Oxidative Stress and Leukocyte Adhesion: Role of Myeloperoxidase

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Victor, Victor M.; Rovira-Llopis, Susana; Bañuls, Celia; Diaz-Morales, Noelia; Martinez de Marañon, Arantxa; Rios-Navarro, Cesar; Alvarez, Angeles; Gomez, Marcelino; Rocha, Milagros; Hernández-Mijares, Antonio

2016-01-01

Cardiovascular diseases and oxidative stress are related to polycystic ovary syndrome (PCOS) and insulin resistance (IR). We have evaluated the relationship between myeloperoxidase (MPO) and leukocyte activation in PCOS patients according to homeostatic model assessment of IR (HOMA-IR), and have explored a possible correlation between these factors and endocrine and inflammatory parameters. This was a prospective controlled study conducted in an academic medical center. The study population consisted of 101 PCOS subjects and 105 control subjects. We divided PCOS subjects into PCOS non-IR (HOMA-IRPCOS IR (HOMA-IR>2.5). Metabolic and anthropometric parameters, total and mitochondrial reactive oxygen species (ROS) production, MPO levels, interactions between human umbilical vein endothelial cells and leukocytes, adhesion molecules (E-selectin, ICAM-1 and VCAM-1) and proinflammatory cytokines (IL-6 and TNF-α) were evaluated. Oxidative stress was observed in PCOS patients, in whom there was an increase in total and mitochondrial ROS production and MPO levels. Enhanced rolling flux and adhesion, and a decrease in polymorphonuclear cell rolling velocity were also detected in PCOS subjects. Increases in IL-6 and TNF-α and adhesion molecules (E-selectin, ICAM-1 and VCAM-1) were also observed, particularly in the PCOS IR group, providing evidence that inflammation and oxidative stress are related in PCOS patients. HOMA-IR was positively correlated with hsCRP (pPCOS patients in general, and particularly in those with IR. Inflammation in PCOS induces leukocyte-endothelium interactions and a simultaneous increase in IL-6, TNF-α, E-selectin, ICAM-1 and VCAM-1. These conditions are aggravated by the presence of IR. PMID:27007571

Stress and psychological factors before a migraine attack: A time-based analysis

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Makino Mariko

2008-09-01

Full Text Available Abstract Background The objective of this study is to examine the stress and mood changes of Japanese subjects over the 1–3 days before a migraine headache. Methods The study participants were 16 patients with migraines who consented to participate in this study. Each subject kept a headache diary four times a day for two weeks. They evaluated the number of stressful events, daily hassles, domestic and non-domestic stress, anxiety, depressive tendency and irritability by visual analog scales. The days were classified into migraine days, pre-migraine days, buffer days and control days based on the intensity of the headaches and accompanying symptoms, and a comparative study was conducted for each factor on the migraine days, pre-migraine days and control days. Results The stressful event value of pre-migraine days showed no significant difference compared to other days. The daily hassle value of pre-migraine days was the highest and was significantly higher than that of buffer days. In non-domestic stress, values on migraine days were significantly higher than on other days, and there was no significant difference between pre-migraine days and buffer days or between pre-migraine days and control days. There was no significant difference in the values of domestic stress between the categories. In non-domestic stress, values on migraine days were significantly higher than other days, and there was no significant difference between pre-migraine days and buffer days or between pre-migraine days and control days. There was little difference in sleep quality on migraine and pre-migraine days, but other psychological factors were higher on migraine days than on pre-migraine days. Conclusion Psychosocial stress preceding the onset of migraines by several days was suggested to play an important role in the occurrence of migraines. However, stress 2–3 days before a migraine attack was not so high as it has been reported to be in the United States and

Elevated plasma factor VIII enhances venous thrombus formation in rabbits: contribution of factor XI, von Willebrand factor and tissue factor.

Science.gov (United States)

Sugita, Chihiro; Yamashita, Atsushi; Matsuura, Yunosuke; Iwakiri, Takashi; Okuyama, Nozomi; Matsuda, Shuntaro; Matsumoto, Tomoko; Inoue, Osamu; Harada, Aya; Kitazawa, Takehisa; Hattori, Kunihiro; Shima, Midori; Asada, Yujiro

2013-07-01

Elevated plasma levels of factor VIII (FVIII) are associated with increased risk of deep venous thrombosis. The aim of this study is to elucidate how elevated FVIII levels affect venous thrombus formation and propagation in vivo. We examined rabbit plasma FVIII activity, plasma thrombin generation, whole blood coagulation, platelet aggregation and venous wall thrombogenicity before and one hour after an intravenous infusion of recombinant human FVIII (rFVIII). Venous thrombus induced by the endothelial denudation of rabbit jugular veins was histologically assessed. Thrombus propagation was evaluated as indocyanine green fluorescence intensity. Argatroban, a thrombin inhibitor, and neutralised antibodies for tissue factor (TF), factor XI (FXI), and von Willebrand factor (VWF) were infused before or after thrombus induction to investigate their effects on venous thrombus formation or propagation. Recombinant FVIII (100 IU/kg) increased rabbit plasma FVIII activity two-fold and significantly enhanced whole blood coagulation and total plasma thrombin generation, but did not affect initial thrombin generation time, platelet aggregation and venous wall thrombogenicity. The rFVIII infusion also increased the size of venous thrombus 1 hour after thrombus induction. Argatroban and the antibodies for TF, FXI or VWF inhibited such enhanced thrombus formation and all except TF suppressed thrombus propagation. In conclusion, elevated plasma FVIII levels enhance venous thrombus formation and propagation. Excess thrombin generation by FXI and VWF-mediated FVIII recruitment appear to contribute to the growth of FVIII-driven venous thrombus.

The GATA transcription factor egl-27 delays aging by promoting stress resistance in Caenorhabditis elegans.

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Xiao Xu

Full Text Available Stress is a fundamental aspect of aging, as accumulated damage from a lifetime of stress can limit lifespan and protective responses to stress can extend lifespan. In this study, we identify a conserved Caenorhabditis elegans GATA transcription factor, egl-27, that is involved in several stress responses and aging. We found that overexpression of egl-27 extends the lifespan of wild-type animals. Furthermore, egl-27 is required for the pro-longevity effects from impaired insulin/IGF-1 like signaling (IIS, as reduced egl-27 activity fully suppresses the longevity of worms that are mutant for the IIS receptor, daf-2. egl-27 expression is inhibited by daf-2 and activated by pro-longevity factors daf-16/FOXO and elt-3/GATA, suggesting that egl-27 acts at the intersection of IIS and GATA pathways to extend lifespan. Consistent with its role in IIS signaling, we found that egl-27 is involved in stress response pathways. egl-27 expression is induced in the presence of multiple stresses, its targets are significantly enriched for many types of stress genes, and altering levels of egl-27 itself affects survival to heat and oxidative stress. Finally, we found that egl-27 expression increases between young and old animals, suggesting that increased levels of egl-27 in aged animals may act to promote stress resistance. These results identify egl-27 as a novel factor that links stress and aging pathways.

Stress, sex, and addiction: potential roles of corticotropin-releasing factor, oxytocin, and arginine-vasopressin.

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Bisagno, Verónica; Cadet, Jean Lud

2014-09-01

Stress sensitivity and sex are predictive factors for the development of neuropsychiatric disorders. Life stresses are not only risk factors for the development of addiction but also are triggers for relapse to drug use. Therefore, it is imperative to elucidate the molecular mechanisms underlying the interactions between stress and drug abuse, as an understanding of this may help in the development of novel and more effective therapeutic approaches to block the clinical manifestations of drug addiction. The development and clinical course of addiction-related disorders do appear to involve neuroadaptations within neurocircuitries that modulate stress responses and are influenced by several neuropeptides. These include corticotropin-releasing factor, the prototypic member of this class, as well as oxytocin and arginine-vasopressin that play important roles in affiliative behaviors. Interestingly, these peptides function to balance emotional behavior, with sexual dimorphism in the oxytocin/arginine-vasopressin systems, a fact that might play an important role in the differential responses of women and men to stressful stimuli and the specific sex-based prevalence of certain addictive disorders. Thus, this review aims to summarize (i) the contribution of sex differences to the function of dopamine systems, and (ii) the behavioral, neurochemical, and anatomical changes in brain stress systems.

A Wheat R2R3-type MYB Transcription Factor TaODORANT1 Positively Regulates Drought and Salt Stress Responses in Transgenic Tobacco Plants

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Qiuhui Wei

2017-08-01

Full Text Available MYB transcription factors play important roles in plant responses to biotic and abiotic stress. In this study, TaODORANT1, a R2R3-MYB gene, was cloned from wheat (Triticum aestivum L.. TaODORANT1 was localized in the nucleus and functioned as a transcriptional activator. TaODORANT1 was up-regulated in wheat under PEG6000, NaCl, ABA, and H2O2 treatments. TaODORANT1-overexpressing transgenic tobacco plants exhibited higher relative water content and lower water loss rate under drought stress, as well as lower Na+ accumulation in leaves under salt stress. The transgenic plants showed higher CAT activity but lower ion leakage, H2O2 and malondialdehyde contents under drought and salt stresses. Besides, the transgenic plants also exhibited higher SOD activity under drought stress. Our results also revealed that TaODORANT1 overexpression up-regulated the expression of several ROS- and stress-related genes in response to both drought and salt stresses, thus enhancing transgenic tobacco plants tolerance. Our studies demonstrate that TaODORANT1 positively regulates plant tolerance to drought and salt stresses.

[The Effect of Social-Psychological Factors on the Development of Occupational Stress].

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Kalinina, S A; Yushkova, O I

2015-01-01

The article presents data on social-psychological factors which cause the occupational stress. The results showed that there is a link between the level of work motivation and the physiological cost of work. We observed a number of peculiarities of occupational stress development caused by psychoemotional tension depending on the class of intensity of intellectual labor; we also studied biological age of the subjects. The speed of ageing of the employees who work under conditions of emotional stress (direct or indirect responsibility for the safety of other people) was found to increase. The study suggested promising directions of occupational stress prevention.

Deciphering the role of the signal- and Sty1 kinase-dependent phosphorylation of the stress-responsive transcription factor Atf1 on gene activation.

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Salat-Canela, Clàudia; Paulo, Esther; Sánchez-Mir, Laura; Carmona, Mercè; Ayté, José; Oliva, Baldo; Hidalgo, Elena

2017-08-18

Adaptation to stress triggers the most dramatic shift in gene expression in fission yeast ( Schizosaccharomyces pombe ), and this response is driven by signaling via the MAPK Sty1. Upon activation, Sty1 accumulates in the nucleus and stimulates expression of hundreds of genes via the nuclear transcription factor Atf1, including expression of atf1 itself. However, the role of stress-induced, Sty1-mediated Atf1 phosphorylation in transcriptional activation is unclear. To this end, we expressed Atf1 phosphorylation mutants from a constitutive promoter to uncouple Atf1 activity from endogenous, stress-activated Atf1 expression. We found that cells expressing a nonphosphorylatable Atf1 variant are sensitive to oxidative stress because of impaired transcription of a subset of stress genes whose expression is also controlled by another transcription factor, Pap1. Furthermore, cells expressing a phospho-mimicking Atf1 mutant display enhanced stress resistance, and although expression of the Pap1-dependent genes still relied on stress induction, another subset of stress-responsive genes was constitutively expressed in these cells. We also observed that, in cells expressing the phospho-mimicking Atf1 mutant, the presence of Sty1 was completely dispensable, with all stress defects of Sty1-deficient cells being suppressed by expression of the Atf1 mutant. We further demonstrated that Sty1-mediated Atf1 phosphorylation does not stimulate binding of Atf1 to DNA but, rather, establishes a platform of interactions with the basal transcriptional machinery to facilitate transcription initiation. In summary, our results provide evidence that Atf1 phosphorylation by the MAPK Sty1 is required for oxidative stress responses in fission yeast cells by promoting transcription initiation. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Prevalence of and Factors Associated with Work Stress in Academia in Tanzania

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Mkumbo, Kitila

2014-01-01

Work stress has been identified as a common phenomenon in the teaching profession. However, little research has been done to examine the prevalence of and factors associated with work stress among employees in university context in Tanzania and sub-Saharan African countries in general. Using survey design within the quantitative approach, this…

Ampelopsin-induced reactive oxygen species enhance the apoptosis of colon cancer cells by activating endoplasmic reticulum stress-mediated AMPK/MAPK/XAF1 signaling

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Park, Ga Bin; Jeong, Jee-Yeong; Kim, Daejin

2017-01-01

Ampelopsin (Amp) is bioactive natural product and exerts anti-cancer effects against several cancer types. The present study investigated the anti-colon cancer activity of Amp and explored its mechanism of action. The treatment of colon cancer cells with Amp resulted in the dose- and time-dependent induction of apoptosis via the activation of endoplasmic reticulum (ER) stress, 5′ adenosine monophosphate-activated protein kinase (AMPK), and c-Jun N-terminal protein kinase (JNK)/p38 mitogen-activated protein kinases (MAPKs). Salubrinal, an ER stress inhibitor, prevented the upregulation of ER stress-associated proteins, including phosphorylated protein kinase RNA-like ER kinase, phosphorylated eukaryotic translation initiation factor 2α, glucose-regulated protein 78, and CCAAT/enhancer-binding protein homologous protein, as well as suppressing AMPK activation and the MAPK signaling pathway. Knockdown of AMPK by RNA interference failed to block ER stress. Additionally, SP600125 (a JNK inhibitor) and SB203580 (a p38-MAPK inhibitor) effectively inhibited apoptosis and attenuated the expression of X-linked IAP-associated factor 1 (XAF1) and apoptotic Bcl-2 family proteins (BCL2 antagonist/killer 1 and BCL2-associated X protein) in Amp-treated colon cancer cells. Furthermore, reactive oxygen species (ROS)-mediated ER stress/AMPK apoptotic signaling pathway in Amp-treated colon cancer cells were markedly inhibited by treatment with N-acetyl-L-cysteine, a ROS scavenger. These results demonstrate that treatment with Amp induces the apoptotic death of colon cancer cells through ER stress-initiated AMPK/MAPK/XAF1 signaling. These results also provide experimental information for developing Amp as therapeutic drug against colon cancer. PMID:29250183

The HaDREB2 transcription factor enhances basal thermotolerance and longevity of seeds through functional interaction with HaHSFA9

Directory of Open Access Journals (Sweden)

Carranco Raúl

2009-06-01

Full Text Available Abstract Background Transcription factor HaDREB2 was identified in sunflower (Helianthus annuus L. as a drought-responsive element-binding factor 2 (DREB2 with unique properties. HaDREB2 and the sunflower Heat Shock Factor A9 (HaHSFA9 co-activated the Hahsp17.6G1 promoter in sunflower embryos. Both factors could be involved in transcriptional co-activation of additional small heat stress protein (sHSP promoters, and thus contribute to the HaHSFA9-mediated enhancement of longevity and basal thermotolerance of seeds. Results We found that overexpression of HaDREB2 in seeds did not enhance longevity. This was deduced from assays of basal thermotolerance and controlled seed-deterioration, which were performed with transgenic tobacco. Furthermore, the constitutive overexpression of HaDREB2 did not increase thermotolerance in seedlings or result in the accumulation of HSPs at normal growth temperatures. In contrast, when HaDREB2 and HaHSFA9 were conjointly overexpressed in seeds, we observed positive effects on seed longevity, beyond those observed with overexpression of HaHSFA9 alone. Such additional effects are accompanied by a subtle enhancement of the accumulation of subsets of sHSPs belonging to the CI and CII cytosolic classes. Conclusion Our results reveal the functional interdependency of HaDREB2 and HaHSFA9 in seeds. HaDREB2 differs from other previously characterized DREB2 factors in plants in terms of its unique functional interaction with the seed-specific HaHSFA9 factor. No functional interaction between HaDREB2 and HaHSFA9 was observed when both factors were conjointly overexpressed in vegetative tissues. We therefore suggest that additional, seed-specific factors, or protein modifications, could be required for the functional interaction between HaDREB2 and HaHSFA9.

Direct and Indirect Effects of Five Factor Personality and Gender on Depressive Symptoms Mediated by Perceived Stress

Science.gov (United States)

Kim, Song E.; Cho, Juhee; Kwon, Min-Jung; Chang, Yoosoo; Ryu, Seungho; Shin, Hocheol

2016-01-01

This study was designed to investigate associations among five factor personality traits, perceived stress, and depressive symptoms and to examine the roles of personality and perceived stress in the relationship between gender and depressive symptoms. The participants (N = 3,950) were part of a cohort study for health screening and examination at the Kangbuk Samsung Hospital. Personality was measured with the Revised NEO Personality Inventory (NEO-PI-R). Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D). Perceived stress level was evaluated with a self-reported stress questionnaire developed for the Korea National Health and Nutrition Examination Survey. A higher degree of neuroticism and lower degrees of extraversion, agreeableness, and conscientiousness were significantly associated with greater perceived stress and depressive symptoms. Neuroticism and extraversion had significant direct and indirect effects (via stress as a mediator) on depressive symptoms in both genders. Agreeableness and conscientiousness had indirect effects on depression symptoms in both genders. Multiple mediation models were used to examine the mediational roles of each personality factor and perceived stress in the link between gender and depressive symptoms. Four of the personality factors (except openness) were significant mediators, along with stress, on the relationship between gender and depressive symptoms. Our findings suggest that the links between personality factors and depressive symptoms are mediated by perceived stress. As such, personality is an important factor to consider when examining the link between gender and depression. PMID:27120051

Direct and Indirect Effects of Five Factor Personality and Gender on Depressive Symptoms Mediated by Perceived Stress.

Science.gov (United States)

Kim, Song E; Kim, Han-Na; Cho, Juhee; Kwon, Min-Jung; Chang, Yoosoo; Ryu, Seungho; Shin, Hocheol; Kim, Hyung-Lae

2016-01-01

This study was designed to investigate associations among five factor personality traits, perceived stress, and depressive symptoms and to examine the roles of personality and perceived stress in the relationship between gender and depressive symptoms. The participants (N = 3,950) were part of a cohort study for health screening and examination at the Kangbuk Samsung Hospital. Personality was measured with the Revised NEO Personality Inventory (NEO-PI-R). Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D). Perceived stress level was evaluated with a self-reported stress questionnaire developed for the Korea National Health and Nutrition Examination Survey. A higher degree of neuroticism and lower degrees of extraversion, agreeableness, and conscientiousness were significantly associated with greater perceived stress and depressive symptoms. Neuroticism and extraversion had significant direct and indirect effects (via stress as a mediator) on depressive symptoms in both genders. Agreeableness and conscientiousness had indirect effects on depression symptoms in both genders. Multiple mediation models were used to examine the mediational roles of each personality factor and perceived stress in the link between gender and depressive symptoms. Four of the personality factors (except openness) were significant mediators, along with stress, on the relationship between gender and depressive symptoms. Our findings suggest that the links between personality factors and depressive symptoms are mediated by perceived stress. As such, personality is an important factor to consider when examining the link between gender and depression.

The integrated endoplasmic reticulum stress response in Leishmania amazonensis macrophage infection: the role of X-box binding protein 1 transcription factor.

Science.gov (United States)

Dias-Teixeira, Karina Luiza; Calegari-Silva, Teresa Cristina; dos Santos, Guilherme R R M; Vitorino Dos Santos, José; Lima, Carolina; Medina, Jorge Mansur; Aktas, Bertal Huseyin; Lopes, Ulisses G

2016-04-01

Endoplasmic reticulum (ER) stress triggers the integrated ER-stress response (IERSR) that ensures cellular survival of ER stress and represents a primordial form of innate immunity. We investigated the role of IERSR duringLeishmania amazonensisinfection. Treatment of RAW 264.7 infected macrophages with the ER stress-inducing agent thapsigargin (TG; 1 μM) increasedL. amazonensisinfectivity in an IFN1-α receptor (IFNAR)-dependent manner. In Western blot assays, we showed thatL. amazonensisactivates the inositol-requiring enzyme (IRE1)/ X-box binding protein (XBP)-1-splicing arms of the IERSR in host cells. In chromatin immunoprecipitation (ChIP) assays, we showed an increased occupancy of enhancer and promoter sequences for theIfnbgene by XBP1 in infected RAW 264.7 cells. Knocking down XBP1 expression by transducing RAW 264.7 cells with the short hairpin XBP1 lentiviral vector significantly reduced the parasite proliferation associated with impaired translocation of phosphorylated IFN regulatory transcription factor (IRF)-3 to the nucleus and a decrease in IFN1-β expression. Knocking down XBP1 expression also increased NO concentration, as determined by Griess reaction and reduced the expression of antioxidant genes, such as heme oxygenase (HO)-1, that protect parasites from oxidative stress. We conclude thatL. amazonensisactivation of XBP1 plays a critical role in infection by protecting the parasites from oxidative stress and increasing IFN1-β expression.-Dias-Teixeira, K. L., Calegari-Silva, T. C., Dos Santos, G. R. R. M., Vitorino dos Santos, J., Lima, C., Medina, J. M., Aktas, B. H., Lopes, U. G. The integrated endoplasmic reticulum stress response inLeishmania amazonensismacrophage infection: the role of X-box binding protein 1 transcription factor. © FASEB.

Experimental evidence for stress enhanced swelling

International Nuclear Information System (INIS)

Bates, J.F.; Gilbert, E.R.

1976-01-01

Experimental evidence is presented which shows that the application of a biaxial stress during irradiation can increase the magnitude of irradiation-induced swelling observed in tubular specimens. It is shown that this increase in swelling is linear below the proportional elastic limit of the material and decreases above this value of stress. In the linear region a relationship is found between total swelling and stress free swelling. The phenomenon of reduced swelling is evaluated on the basis of increased cold work due to pre-irradiation straining. This analysis yields a relationship of dislocation density proportional to stress to the 3.82 power. Additional analyses using dislocation density proportional to sigma 2 (sigma = hoop stress) yield a similar but sharper decrease in swelling after the proportional elastic limit is reached. (Auth.)

Mechanisms Underlying the Delayed Activation of the Cap1 Transcription Factor in Candida albicans following Combinatorial Oxidative and Cationic Stress Important for Phagocytic Potency.

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Kos, Iaroslava; Patterson, Miranda J; Znaidi, Sadri; Kaloriti, Despoina; da Silva Dantas, Alessandra; Herrero-de-Dios, Carmen M; d'Enfert, Christophe; Brown, Alistair J P; Quinn, Janet

2016-03-29

Following phagocytosis, microbes are exposed to an array of antimicrobial weapons that include reactive oxygen species (ROS) and cationic fluxes. This is significant as combinations of oxidative and cationic stresses are much more potent than the corresponding single stresses, triggering the synergistic killing of the fungal pathogenCandida albicansby "stress pathway interference." Previously we demonstrated that combinatorial oxidative plus cationic stress triggers a dramatic increase in intracellular ROS levels compared to oxidative stress alone. Here we show that activation of Cap1, the major regulator of antioxidant gene expression inC. albicans, is significantly delayed in response to combinatorial stress treatments and to high levels of H2O2 Cap1 is normally oxidized in response to H2O2; this masks the nuclear export sequence, resulting in the rapid nuclear accumulation of Cap1 and the induction of Cap1-dependent genes. Here we demonstrate that following exposure of cells to combinatorial stress or to high levels of H2O2, Cap1 becomes trapped in a partially oxidized form, Cap1(OX-1) Notably, Cap1-dependent gene expression is not induced when Cap1 is in this partially oxidized form. However, while Cap1(OX-1)readily accumulates in the nucleus and binds to target genes following high-H2O2stress, the nuclear accumulation of Cap1(OX-1)following combinatorial H2O2and NaCl stress is delayed due to a cationic stress-enhanced interaction with the Crm1 nuclear export factor. These findings define novel mechanisms that delay activation of the Cap1 transcription factor, thus preventing the rapid activation of the stress responses vital for the survival ofC. albicanswithin the host. Combinatorial stress-mediated synergistic killing represents a new unchartered area in the field of stress signaling. This phenomenon contrasts starkly with "stress cross-protection," where exposure to one stress protects against subsequent exposure to a different stress. Previously we

Alteration of Transcripts of Stress-Protective Genes and Transcriptional Factors by γ-Aminobutyric Acid (GABA Associated with Improved Heat and Drought Tolerance in Creeping Bentgrass (Agrostis stolonifera

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Zhou Li

2018-05-01

Full Text Available Gamma-aminobutyric acid (GABA may play a positive role in regulating plant tolerance to drought or heat stress. The objectives of this study were to investigate the physiological effects of GABA on tolerance of creeping bentgrass (Agrostis stolonifera to heat and drought stress and to determine whether enhanced heat and drought tolerance due to GABA treatment was associated with the up-regulation of selected genes and transcriptional factors involved in stress protection. Creeping bentgrass (cultivar “Penncross” plants were treated with 0.5 mM GABA or water (untreated control as a foliar spray and were subsequently exposed to heat stress (35/30 °C, day/night, drought stress by withholding irrigation, or non-stress conditions in controlled-environment growth chambers. Exogenous application of GABA significantly improved plant tolerance to heat and drought stress, as reflected by increased leaf water content, cell membrane stability, and chlorophyll content. The analysis of gene transcript level revealed that exogenous GABA up-regulated the expression of ABF3, POD, APX, HSP90, DHN3, and MT1 during heat stress and the expression of CDPK26, MAPK1, ABF3, WRKY75, MYB13, HSP70, MT1, 14-3-3, and genes (SOD, CAT, POD, APX, MDHAR, DHAR, and GR encoding antioxidant enzymes during drought stress. The up-regulation of the aforementioned stress-protective genes and transcriptional factors could contribute to improved heat and drought tolerance in creeping bentgrass.

Alteration of Transcripts of Stress-Protective Genes and Transcriptional Factors by γ-Aminobutyric Acid (GABA) Associated with Improved Heat and Drought Tolerance in Creeping Bentgrass (Agrostis stolonifera).

Science.gov (United States)

Li, Zhou; Peng, Yan; Huang, Bingru

2018-05-31

Gamma-aminobutyric acid (GABA) may play a positive role in regulating plant tolerance to drought or heat stress. The objectives of this study were to investigate the physiological effects of GABA on tolerance of creeping bentgrass ( Agrostis stolonifera ) to heat and drought stress and to determine whether enhanced heat and drought tolerance due to GABA treatment was associated with the up-regulation of selected genes and transcriptional factors involved in stress protection. Creeping bentgrass (cultivar "Penncross") plants were treated with 0.5 mM GABA or water (untreated control) as a foliar spray and were subsequently exposed to heat stress (35/30 °C, day/night), drought stress by withholding irrigation, or non-stress conditions in controlled-environment growth chambers. Exogenous application of GABA significantly improved plant tolerance to heat and drought stress, as reflected by increased leaf water content, cell membrane stability, and chlorophyll content. The analysis of gene transcript level revealed that exogenous GABA up-regulated the expression of ABF3 , POD , APX , HSP90 , DHN3 , and MT1 during heat stress and the expression of CDPK26 , MAPK1 , ABF3 , WRKY75 , MYB13 , HSP70 , MT1 , 14-3-3 , and genes ( SOD , CAT , POD , APX , MDHAR , DHAR , and GR ) encoding antioxidant enzymes during drought stress. The up-regulation of the aforementioned stress-protective genes and transcriptional factors could contribute to improved heat and drought tolerance in creeping bentgrass.

An adverse early life environment can enhance stress resilience in adulthood.

Science.gov (United States)

Santarelli, Sara; Zimmermann, Christoph; Kalideris, Georgia; Lesuis, Sylvie L; Arloth, Janine; Uribe, Andrés; Dournes, Carine; Balsevich, Georgia; Hartmann, Jakob; Masana, Mercè; Binder, Elisabeth B; Spengler, Dietmar; Schmidt, Mathias V

2017-04-01

Chronic stress is a major risk factor for depression. Interestingly, not all individuals develop psychopathology after chronic stress exposure. In contrast to the prevailing view that stress effects are cumulative and increase stress vulnerability throughout life, the match/mismatch hypothesis of psychiatric disorders. The match/mismatch hypothesis proposes that individuals who experience moderate levels of early life psychosocial stress can acquire resilience to renewed stress exposure later in life. Here, we have tested this hypothesis by comparing the developmental effects of 2 opposite early life conditions, when followed by 2 opposite adult environments. Male Balb/c mice were exposed to either adverse early life conditions (limited nesting and bedding material) or a supportive rearing environment (early handling). At adulthood, the animals of each group were either housed with an ovariectomized female (supportive environment) or underwent chronic social defeat stress (socially adverse environment) for 3 weeks. At the end of the adult manipulations, all of the animals were returned to standard housing conditions. Then, we compared the neuroendocrine, behavioral and molecular effects of the interaction between early and adult environment. Our study shows that early life adversity does not necessarily result in increased vulnerability to stress. Specific endophenotypes, like hypothalamic-pituitary-adrenal axis activity, anxiety-related behavior and glucocorticoid receptor expression levels in the hippocampus were not significantly altered when adversity is experienced during early life and in adulthood, and are mainly affected by either early life or adult life adversity alone. Overall our data support the notion that being raised in a stressful environment prepares the offspring to better cope with a challenging adult environment and emphasize the role of early life experiences in shaping adult responsiveness to stress. Copyright © 2017 Elsevier Ltd. All rights

Factors Predicting Burnout Among Chaplains: Compassion Satisfaction, Organizational Factors, and the Mediators of Mindful Self-Care and Secondary Traumatic Stress.

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Hotchkiss, Jason T; Lesher, Ruth

2018-06-01

This study predicted Burnout from the self-care practices, compassion satisfaction, secondary traumatic stress, and organizational factors among chaplains who participated from all 50 states (N = 534). A hierarchical regression model indicated that the combined effect of compassion satisfaction, secondary traumatic stress, mindful self-care, demographic, and organizational factors explained 83.2% of the variance in Burnout. Chaplains serving in a hospital were slightly more at risk for Burnout than those in hospice or other settings. Organizational factors that most predicted Burnout were feeling bogged down by the "system" (25.7%) and an overwhelming caseload (19.9%). Each self-care category was a statistically significant protective factor against Burnout risk. The strongest protective factors against Burnout in order of strength were self-compassion and purpose, supportive structure, mindful self-awareness, mindful relaxation, supportive relationships, and physical care. For secondary traumatic stress, supportive structure, mindful self-awareness, and self-compassion and purpose were the strongest protective factors. Chaplains who engaged in multiple and frequent self-care strategies experienced higher professional quality of life and low Burnout risk. In the chaplain's journey toward wellness, a reflective practice of feeling good about doing good and mindful self-care are vital. The significance, implications, and limitations of the study were discussed.

Factors Affecting Role Stress and Burnout among School Counselors

Science.gov (United States)

Willingham, Wendy Elizabeth

2009-01-01

The purpose of this study is to determine factors affecting role stress and burnout among practicing school counselors as measured by the Maslach Burnout Inventory-Educators Survey (MBI-ES) and the Role Conflict and Ambiguity Scale. The MBI-ES utilizes three subscales to measure burnout: emotional exhaustion, depersonalization, and personal…

Reply to comment on 'Model calculation of the scanned field enhancement factor of CNTs'

International Nuclear Information System (INIS)

Ahmad, Amir; Tripathi, V K

2010-01-01

In the paper (Ahmad and Tripathi 2006 Nanotechnology 17 3798), we derived an expression to compute the field enhancement factor of CNTs under any positional distribution of CNTs by using the model of a floating sphere between parallel anode and cathode plates. Using this expression we can compute the field enhancement factor of a CNT in a cluster (non-uniformly distributed CNTs). This expression was used to compute the field enhancement factor of a CNT in an array (uniformly distributed CNTs). We used an approximation to calculate the field enhancement factor. Hence, our expressions are correct in that assumption only. Zhbanov et al (2010 Nanotechnology 21 358001) suggest a correction that can calculate the field enhancement factor without using the approximation. Hence, this correction can improve the applicability of this model. (reply)

Revisiting the Role of Plant Transcription Factors in the Battle against Abiotic Stress.

Science.gov (United States)

Khan, Sardar-Ali; Li, Meng-Zhan; Wang, Suo-Min; Yin, Hong-Ju

2018-05-31

Owing to diverse abiotic stresses and global climate deterioration, the agricultural production worldwide is suffering serious losses. Breeding stress-resilient crops with higher quality and yield against multiple environmental stresses via application of transgenic technologies is currently the most promising approach. Deciphering molecular principles and mining stress-associate genes that govern plant responses against abiotic stresses is one of the prerequisites to develop stress-resistant crop varieties. As molecular switches in controlling stress-responsive genes expression, transcription factors (TFs) play crucial roles in regulating various abiotic stress responses. Hence, functional analysis of TFs and their interaction partners during abiotic stresses is crucial to perceive their role in diverse signaling cascades that many researchers have continued to undertake. Here, we review current developments in understanding TFs, with particular emphasis on their functions in orchestrating plant abiotic stress responses. Further, we discuss novel molecular mechanisms of their action under abiotic stress conditions. This will provide valuable information for understanding regulatory mechanisms to engineer stress-tolerant crops.

Emotion regulation: Exploring the impact of stress and sex

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Valerie L. Kinner

2014-11-01

Full Text Available Emotion regulation is a major prerequisite for adaptive behavior. The capacity to regulate emotions is particularly important during and after the encounter of a stressor. However the impact of acute stress and its associated neuroendocrine alterations on emotion regulation have received little attention so far. This study aimed to explore how stress-induced cortisol increases affect three different emotion regulation strategies. 72 healthy men and women were either exposed to a stressor or a control condition. Subsequently participants viewed positive and negative images and were asked to up- or down-regulate their emotional responses or simultaneously required to solve an arithmetic task (distraction. The factors stress, sex and strategy were operationalized as between group factors (n = 6 per cell. Stress caused an increase in blood pressure and higher subjective stress ratings. An increase in cortisol was observed in male participants only. In contrast to controls, stressed participants were less effective in distracting themselves from the emotional pictures. The results further suggest that in women stress enhances the ability to decrease negative emotions. These findings characterize the impact of stress and sex on emotion regulation and provide initial evidence that these factors may interact.

A plastic stress intensity factor approach to turbine disk structural integrity assessment

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V. Shlyannikov

2016-07-01

Full Text Available This study based on a new fracture mechanics parameter is concerned with assessing the integrity of cracked steam turbine disk which operate under startup-shutdown cyclic loading conditions. Damage accumulation and growth in service have occurred on the inner surface of slot fillet of key. In order to determine elastic-plastic fracture mechanics parameters full-size stress-strain state analysis of turbine disk was performed for a quote-elliptical part-through cracks under considering loading conditions. As a result distributions of elastic and plastic stress intensity factors along crack front in slot fillet of key of turbine disk depending on surface crack form are defined. An engineering approach to the prediction of carrying capacity of cracked turbine disk which is sensitive to the loading history at maintenance is proposed. The predictions of the rate of crack growth and residual lifetime of steam turbine disk are compared for elastic and elastic-plastic solutions. It is shown that the previously proposed elastic crack growth models provide overestimate the lifetime with respect to the present one. An advantage to use the plastic stress intensity factor to characterize the fracture resistance as the self-dependent unified parameter for a variety of turbine disk configurations rather than the magnitude of the elastic stress intensity factors alone is discussed.

Use of cognitive enhancers among medical students in Lithuania

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Lengvenyte Aiste

2016-04-01

Full Text Available AIMS – The purpose of this study is to analyse the use of cognitive enhancers among medical students in Lithuania, determine the reasons for usage and evaluate the contributing factors such as socio-demographic characteristics, stress levels, sleep quality and knowing somebody who has used a neuro-enhancing drug.

β-Naphthoflavone enhances oxidative stress responses and the induction of preneoplastic lesions in a diethylnitrosamine-initiated hepatocarcinogenesis model in partially hepatectomized rats

International Nuclear Information System (INIS)

Dewa, Yasuaki; Nishimura, Jihei; Muguruma, Masako; Jin, Meilan; Saegusa, Yukie; Okamura, Toshiya; Tasaki, Masako; Umemura, Takashi; Mitsumori, Kunitoshi

2008-01-01

The tumour-promoting effects of β-naphthoflavone (BNF), a novel aryl hydrocarbon receptor (AhR) agonist, were investigated using a medium-term hepatocarcinogenesis model in rats. Six-week-old male F344 rats received an intraperitoneal injection of N-diethylnitrosamine (DEN) at a dose of 200 mg/kg body weight and were fed a diet containing 0% (basal diet), 0.5% or 1% BNF for 6 weeks from 2 weeks after DEN treatment. All animals were subjected to two-thirds partial hepatectomy 1 week after the BNF treatment. The number and area of glutathione S-transferase placental form (GST-P) positive foci significantly increased in the livers of rats treated with BNF with concomitantly increased cell proliferation compared to those in the livers of the DEN alone group. Global gene expression analysis and subsequent quantitative real-time reverse transcription-polymerase chain reaction revealed that BNF induced not only the 'AhR gene battery'Cyp1a1, Cyp1a2, Cyp1b1, Nqo1, Aldh3a1 and Ugt1a6 but also the transcription factor NF-E2-related factor 2 (Nrf2)-regulated genes such as Gstm1, Gpx2, Akr7a3 and Yc2 (and also Nqo1), presumably due to the adaptive response against BNF-triggered oxidative stress responses. Reactive oxygen species production increased in microsomes isolated from the livers of BNF-treated rats, and this enhancement was suppressed by the P450 inhibitor SKF-525A. Furthermore, BNF enhanced oxidative DNA damage and lipid peroxidation, estimated by the levels of 8-hydroxydeoxyguanosine (8-OHdG) and thiobarbituric acid-reactive substances. These results suggest that the administration of BNF at a high dose and over a long-term enhance oxidative stress responses which may contribute to its hepatocarcinogenic potential in rats

Improved Formula for the Stress Intensity Factor of Semi-Elliptical Surface Cracks in Welded Joints under Bending Stress

Science.gov (United States)

Peng, Yang; Wu, Chao; Zheng, Yifu; Dong, Jun

2017-01-01

Welded joints are prone to fatigue cracking with the existence of welding defects and bending stress. Fracture mechanics is a useful approach in which the fatigue life of the welded joint can be predicted. The key challenge of such predictions using fracture mechanics is how to accurately calculate the stress intensity factor (SIF). An empirical formula for calculating the SIF of welded joints under bending stress was developed by Baik, Yamada and Ishikawa based on the hybrid method. However, when calculating the SIF of a semi-elliptical crack, this study found that the accuracy of the Baik-Yamada formula was poor when comparing the benchmark results, experimental data and numerical results. The reasons for the reduced accuracy of the Baik-Yamada formula were identified and discussed in this paper. Furthermore, a new correction factor was developed and added to the Baik-Yamada formula by using theoretical analysis and numerical regression. Finally, the predictions using the modified Baik-Yamada formula were compared with the benchmark results, experimental data and numerical results. It was found that the accuracy of the modified Baik-Yamada formula was greatly improved. Therefore, it is proposed that this modified formula is used to conveniently and accurately calculate the SIF of semi-elliptical cracks in welded joints under bending stress. PMID:28772527

Exogenous Calcium Enhances the Photosystem II Photochemistry Response in Salt Stressed Tall Fescue.

Science.gov (United States)

Wang, Guangyang; Bi, Aoyue; Amombo, Erick; Li, Huiying; Zhang, Liang; Cheng, Cheng; Hu, Tao; Fu, Jinmin

2017-01-01

Calcium enhances turfgrass response to salt stress. However, little is known about PSII photochemical changes when exogenous calcium was applied in salinity-stressed turfgrass. Here, we probe into the rearrangements of PSII electron transport and endogenous ion accumulation in tall fescue ( Festuca arundinacea Schreber) treated with exogenous calcium under salt stress. Three-month-old seedlings of genotype "TF133" were subjected to the control (CK), salinity (S), salinity + calcium nitrate (SC), and salinity + ethylene glycol tetraacetic acid (SE). Calcium nitrate and ethylene glycol tetraacetic acid was used as exogenous calcium donor and calcium chelating agent respectively. At the end of a 5-day duration treatment, samples in SC regime had better photochemistry performance on several parameters than salinity only. Such as the Area (equal to the plastoquinone pool size), N (number of [Formula: see text] redox turnovers until F m is reached), ψE 0 , or δRo (Efficiencdy/probability with which a PSII trapped electron is transferred from Q A to Q B or PSI acceptors), ABS/RC (Absorbed photon flux per RC). All the above suggested that calcium enhanced the electron transfer of PSII (especially beyond [Formula: see text]) and prevented reaction centers from inactivation in salt-stressed tall fescue. Furthermore, both grass shoot and root tissues generally accumulated more C, N, Ca 2+ , and K + in the SC regime than S regime. Interrelated analysis indicated that ψE 0 , δRo, ABS/RC, C, and N content in shoots was highly correlated to each other and significantly positively related to Ca 2+ and K + content in roots. Besides, high salt increased ATP6E and CAMK2 transcription level in shoot at 1 and 5 day, respectively while exogenous calcium relieved it. In root, CAMK2 level was reduced by Salinity at 5 day and exogenous calcium recovered it. These observations involved in electron transport capacity and ion accumulation assist in understanding better the protective role

Exogenous Calcium Enhances the Photosystem II Photochemistry Response in Salt Stressed Tall Fescue

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Guangyang Wang

2017-11-01

Full Text Available Calcium enhances turfgrass response to salt stress. However, little is known about PSII photochemical changes when exogenous calcium was applied in salinity-stressed turfgrass. Here, we probe into the rearrangements of PSII electron transport and endogenous ion accumulation in tall fescue (Festuca arundinacea Schreber treated with exogenous calcium under salt stress. Three-month-old seedlings of genotype “TF133” were subjected to the control (CK, salinity (S, salinity + calcium nitrate (SC, and salinity + ethylene glycol tetraacetic acid (SE. Calcium nitrate and ethylene glycol tetraacetic acid was used as exogenous calcium donor and calcium chelating agent respectively. At the end of a 5-day duration treatment, samples in SC regime had better photochemistry performance on several parameters than salinity only. Such as the Area (equal to the plastoquinone pool size, N (number of QA- redox turnovers until Fm is reached, ψE0, or δRo (Efficiencdy/probability with which a PSII trapped electron is transferred from QA to QB or PSI acceptors, ABS/RC (Absorbed photon flux per RC. All the above suggested that calcium enhanced the electron transfer of PSII (especially beyond QA- and prevented reaction centers from inactivation in salt-stressed tall fescue. Furthermore, both grass shoot and root tissues generally accumulated more C, N, Ca2+, and K+ in the SC regime than S regime. Interrelated analysis indicated that ψE0, δRo, ABS/RC, C, and N content in shoots was highly correlated to each other and significantly positively related to Ca2+ and K+ content in roots. Besides, high salt increased ATP6E and CAMK2 transcription level in shoot at 1 and 5 day, respectively while exogenous calcium relieved it. In root, CAMK2 level was reduced by Salinity at 5 day and exogenous calcium recovered it. These observations involved in electron transport capacity and ion accumulation assist in understanding better the protective role of exogenous calcium in tall

[Effects of occupational stress on serum tumor necrosis factor-α and interleukins].

Science.gov (United States)

Zhou, Wen-Hui; Yu, Shan-Fa; Jiang, Kai-You

2010-12-01

To explore the effect of occupational stress on serum tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-2 and IL-4. A cross-sectional epidemiological study was conducted in 200 workers from the refrigerator assembly line in Henan province in China. Psychosocial work conditions were measured by using the job demand-control model, the effort-reward imbalance model questionnaires and occupational stress measurement scale. Serum TNF-α, IL-1β, IL-2, and IL-4 concentrations were measured by radioimmunoassay or immunoradiometric assay method respectively. Serum TNF-α concentration was statistically significantly different between workers with higher affective balance level and control groups [(1.947 ± 0.173) and (2.029 ± 0.240) fmol/ml] (P life stress level and control groups [(1.759 ± 0.361) and (1.606 ± 0.381) ng/ml] (P life stress and role ambiguity were the predictors of serum IL-2 (R(2) was 0.040, 0.078 and 0.104, respectively). Reward was the predictor of serum IL-4 (R(2) = 0.030). Unhealthy psychological stress factor might be induce a marked increase in the concentrations of serum TNF-α, IL-1β, IL-2, as well as IL-4.

DEPRESSION, ANXIETY, STRESS, AND THEIR ASSOCIATED FACTORS AMONG CORPS MEMBERS SERVING IN KEBBI STATE.

Science.gov (United States)

Balami, Ahmed D

2015-01-01

Depression, anxiety and stress, are not only health problems by themselves, but also associated with other negative health consequences. The national youth service is usually characterized by a number of new challenges and experiences which may require life style adjustments by the corps member. However, no previous study on psychological factors has been conducted among corps members. This study was conducted to determine the prevalence of depression, anxiety and, stress and their associated factors among corps members serving in Kebbi state. A cross-sectional study was conducted among 264 corps members from four local government areas of the state. Selection of the local government areas and the individual participants was by simple random sampling. Data was collected from May to June 2014 using a self-administered questionnaire. Data analysis used chi-square test to identify the relationship between categorical variables and multivariate logistic regression to identify the independent factors for depression, anxiety and stress each. The response rate was 97%. Most of the respondents were males (63.6%), single (85.5%), and above 20 years of age (71.6%). The overall prevalences of depression, anxiety and stress among the respondents were 36.4%, 54.5% and 18.2% respectively. The independent factors for depression were; being from the North central (OR = 5.99; 95% CI: 2.194-16.354) or South-south; and the perception of earning enough income (OR = 2.987; 95% CI: 1.062-8.400). For anxiety, male gender (OR = 0.411; 95% CI: 0.169-0.999); and being from the North central were significant risk factors (OR = 3.731; 95% CI: 1.450-9.599). Being above 26 years of age was an independent risk factor for stress (OR = 0.083; 95% CI: 0.018-0.381). Also, those who had ever schooled outside their towns of residence were less likely to be stressed compared to those who had never (OR = 0.30; 95% CI: 0.110-0.855). All other factors did not show any significant association with any of

Stress-related factors in the emergence of transient global amnesia with hippocampal lesion

Directory of Open Access Journals (Sweden)

Juliane eDöhring

2014-08-01

Full Text Available The transient global amnesia (TGA is a rare amnesic syndrome that is characterized by an acute onset episode of an anterograde and retrograde amnesia. Its origin is still debated, but there is evidence for psychological factors involved in TGA. In neuroimaging, selective lesions in the CA1 fields of the hippocampus can be detected, a region that is particularly involved in the processing of memory, stress and emotion. The aim of this study was to assess the role of psychological stress in TGA by studying the prevalence of stress related precipitating events and individual stress-related personality profiles as well as coping strategies in patients. The hypothesis of a functional differentiation of the hippocampus in mnemonic and stress-related compartments was also evaluated. From all 113 patients, 18 % (n= 24 patients experienced emotional and psychological stress episodes directly before the TGA. In a cohort of 21 acute patients, TGA patients tend to cope with stress less efficiently and less constructively than controls. Patients who experienced a stress related precipitant event exhibited a higher level of anxiety in comparison to non-stress patients and controls. However, there was no difference between the general experience of stress and the number of stress inducing life events. The majority of patients (73% did show typical MRI lesions in the CA1 region of the hippocampal cornu ammonis. There was no clear association between stressful events, distribution of hippocampal CA1 lesions and behavioral patterns during the TGA. Disadvantageous coping strategies and an elevated anxiety level may increase the susceptibility to psychological stress which may facilitate the pathophysiological cascade in TGA. The findings suggest a role of emotional stress factors in the manifestation of TGA in a subgroup of patients. Stress may be one trigger involved in the emergence of transient lesions in the hippocampal CA1 region, which are thought to be the

Effective Factors in Enhancing School Managers' Job Motivation

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S. Mahmoud Mirzamani

2011-10-01

Full Text Available "nObjective: This study examines the effective factors in enhancing school managers' job motivation from viewpoint of school mangers, teachers, education department managerial and staff experts in teaching, and also identifies and prioritizes each of these factors and indicators. "nMethod: For selecting a representative sample and increasing measurement precision, 587 people were selected using classified random sampling. The measurement tool was a 79-questionnaire made by the researcher. The questionnaire was collected using motivation theories and observing the findings of previous researches. Then, according to the three-stage Delphi technique, the questionnaire was sent to experts in education. The reliability of instruments was measured by calculating Cronbach's Alpha coefficient, and total reliability of the test was 0.99; the validity of the instrument was assessed by factor analysis (Construct Validity and its load factor was 0.4 which was high. "nResults: The results from factor analysis shows that the effective factors in enhancing managers' job motivation are as follows: self- actualization (51% including 28 indices; social factor (7/9% including 22 indices; self-esteem (3.2% including 17 indices; job desirable features (2.2% including 4 indices; physiologic (1.8% including 4 indices; and job richness (1.6% including 4 indices. "nConclusions: The results show that the six mentioned factors determine 68% of the total variance of managers' motivation.

Six habits to enhance MET performance under stress: A discussion paper reviewing team mechanisms for improved patient outcomes.

Science.gov (United States)

Fein, Erich C; Mackie, Benjamin; Chernyak-Hai, Lily; O'Quinn, C Richard V; Ahmed, Ezaz

2016-05-01

Effective team decision making has the potential to improve the quality of health care outcomes. Medical Emergency Teams (METs), a specific type of team led by either critical care nurses or physicians, must respond to and improve the outcomes of deteriorating patients. METs routinely make decisions under conditions of uncertainty and suboptimal care outcomes still occur. In response, the development and use of Shared Mental Models (SMMs), which have been shown to promote higher team performance under stress, may enhance patient outcomes. This discussion paper specifically focuses on the development and use of SMMs in the context of METs. Within this process, the psychological mechanisms promoting enhanced team performance are examined and the utility of this model is discussed through the narrative of six habits applied to MET interactions. A two stage, reciprocal model of both nonanalytic decision making within the acute care environment and analytic decision making during reflective action learning was developed. These habits are explored within the context of a MET, illustrating how applying SMMs and action learning processes may enhance team-based problem solving under stress. Based on this model, we make recommendations to enhance MET decision making under stress. It is suggested that the corresponding habits embedded within this model could be imparted to MET members and tested by health care researchers to assess the efficacy of this integrated decision making approach in respect to enhanced team performance and patient outcomes. Copyright © 2015. Published by Elsevier Ltd.

Factor structure and validity of the Depression, Anxiety and Stress Scale-21 in Swedish translation.

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Alfonsson, S; Wallin, E; Maathz, P

2017-03-01

WHAT IS KNOWN ON THE SUBJECT?: The Depression, Anxiety and Stress Scale-21 (DASS-21) is a widely used measurement for psychological symptoms and distress. Some previous studies have shown that the DASS-21 can accurately measure symptoms of anxiety, depression and stress, while other studies have indicated that the DASS-21 mainly measures overall distress. The factor structure of the DASS-21 is important and debated since if affects interpretations of findings. WHAT DOES THIS PAPER ADD TO EXISTING KNOWLEDGE?: In this study, the DASS-21 was translated into Swedish and evaluated in three diverse samples. The DASS-21 subscales of Depression and Anxiety correlated significantly with corresponding criteria instruments. The DASS-21 Stress subscale showed more diverse associations with psychological distress. The analyses supported a bifactor model of the DASS-21 with three specific factors of depression, anxiety and stress as well as a general distress factor. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: The results show that the DASS-21 may be used to measure unique symptoms of depression, anxiety and, with some caveat, stress as well as overall psychological distress. This study confirms that the DASS-21 is theoretically sound instrument that is feasible for both research and clinical practice. The DASS-21 can be an accessible tool for screening and evaluation in first-line mental health services. Introduction There is a constant need for theoretically sound and valid self-report instruments for measuring psychological distress. Previous studies have shown that the Depression, Anxiety and Stress Scale-21 (DASS-21) is theoretically sound, but there have been some inconsistent results regarding its factor structure. Aims The aim of the present study was to investigate and elucidate the factor structure and convergent validity of the DASS-21. Methods A total of 624 participants recruited from student, primary care and psychotherapy populations. The factor structure of the DASS

Factor XII (Hageman factor) is a missing link between stress and hypercoagulability and plays an important role in the pathophysiology of ischemic stroke.

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Eggers, Arnold E

2006-01-01

A new hypothesis is presented on the function of factor XII, which is postulated to be a "missing link" between acute stress and transient hypercoagulability. The implications of this idea are developed to show how chronic stress, which involves activation of hypertension and migraine as well as hypercoagulability, can cause of cerebrovascular disease. "Acute stress" is defined as "the normal short-term physiological response to the perception of major threats or demands". "Chronic stress" is "the abnormal ongoing physiological response to the continuing perception of unresolvable major threats or demands". The factor XII hypothesis is as follows: Acute stress includes release of epinephrine by the adrenal medulla. Epinephrine activates platelets by binding to alpha-2A adrenergic receptors. Activated platelets convert pre-bound factor XII to its active form, which then initiates the intrinsic coagulation cascade. This can be called the "activated platelet initiation pathway" for coagulation. Neither tissue factor nor pre-formed thrombin is required. Thrombosis proceeds to completion, but only a minute amount of thrombin is formed, and the process normally stops at this point. In people who lapse into a state of chronic stress, essential hypertension, which is also a manifestation of stress, synergizes with hypercoagulability: there is both a baseline rise in blood pressure and systemic platelet activation as well as superimposed labile rises of both. Upregulation of these two stress parameters is atherogenic: epinephrine-activated platelets stimulating thrombin formation interact with endothelial cells activated by angiotensin II to cause, first, smooth muscle cell proliferation, which is a histological hallmark of atherosclerosis, and, lastly, a symptomatic thrombotic occlusion-the stroke. The migraine symptoms which often accompany this process are a marker of chronic stress and ongoing pathophysiologic damage. Therapeutic predictions are made regarding novel

Enhancing China’s energy security: Determining influential factors and effective strategic measures

International Nuclear Information System (INIS)

Ren, Jingzheng; Sovacool, Benjamin K.

2014-01-01

Highlights: • The most influential factors affecting China’s energy security are identified. • Fuzzy AHP is used to quantify the importance of influential factors. • Strategic measures for enhancing China’s energy security are prioritized. • Fuzzy AHP is used to determine the priorities of the strategic measures. - Abstract: This study investigates the most influential factors affecting China’s energy security. It also identifies the most effective strategic measures for enhancing it. Fuzzy AHP has been used to determine weights for ranking the importance of Chinese energy security factors, and it has also been used to determine the priorities of the strategic measures with respect to enhancing those same factors. The study argues that a low proportion of renewable energy penetration is the most severe factor threatening China’s energy security, and that conducting research and development on energy technologies and improving energy efficiency is the most salient, positive, and necessary strategic measure

Arbuscular Mycorrhizal Fungi Enhance Basil Tolerance to Salt Stress through Improved Physiological and Nutritional Status

International Nuclear Information System (INIS)

Salwa, A.; Abeer, H.; Alqarawi, A. A.; Abdullah, E.F.; Egamberdieva, D.

2016-01-01

Pot experiments were conducted to evaluate the influence of salinity on some physio-biochemical traits in sweet basil (Ocimum basilicum L.) cultivars with contrasting salt stress tolerance and to determine the role of arbuscular mycorrhizal fungi (AMF) in ameliorating the salt stress in plant. Salt stress (250 mM NaCl) reduced the colonization potential of AMF and inhibited photosynthetic pigments, chlorophyll and carotenoids in plant tissue. AMF inoculated plants contained higher level of chlorophyll pigments. Salt stressed plants showed increased lipid peroxidation, antioxidant enzyme activities like superoxide dismutase (SOD), ascorbate peroxidase (APX) and peroxidase (POD). Plants inoculated with AMF showed lower lipid peroxidation and enhanced antioxidant enzyme activities. Moreover, the content of lipids, proline, and soluble sugars in basil plants was improved with AMF inoculation. AMF inoculation reduced accumulation of Na+ and improved nutrient acquisition. In conclusion, AMF were capable to reduce oxidative stress via supporting of the antioxidant system. Salt tolerant cultivar showed higher antioxidant enzyme activity and accumulation of osmolytes. (author)

Overexpression of a Pathogenesis-Related Protein 10 Enhances Biotic and Abiotic Stress Tolerance in Rice

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Jingni Wu

2016-12-01

Full Text Available Pathogenesis-related proteins play multiple roles in plant development and biotic and abiotic stress tolerance. Here, we characterize a rice defense related gene named “jasmonic acid inducible pathogenesis-related class 10” (JIOsPR10 to gain an insight into its functional properties. Semi-quantitative RT-PCR analysis showed up-regulation of JIOsPR10 under salt and drought stress conditions. Constitutive over-expression JIOsPR10 in rice promoted shoot and root development in transgenic plants, however, their productivity was unaltered. Further experiments exhibited that the transgenic plants showed reduced susceptibility to rice blast fungus, and enhanced salt and drought stress tolerance as compared to the wild type. A comparative proteomic profiling of wild type and transgenic plants showed that overexpression of JIOsPR10 led to the differential modulation of several proteins mainly related with oxidative stresses, carbohydrate metabolism, and plant defense. Taken together, our findings suggest that JIOsPR10 plays important roles in biotic and abiotic stresses tolerance probably by activation of stress related proteins.

Risk-factors for stress-related absence among health care employees: a bio-psychosocial perspective. Associations between self-rated health, working conditions and biological stress hormones

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Ann-Sophie Hansson

2006-12-01

Full Text Available

Background: Stress is a major cause of sickness absence and the health care sector appears to be especially at risk. This cross sectional study aimed to identify the risk factors for absence due to self-reported stress among health care employees. Methods: 225 health care employees were categorized into two groups based on presence or not of self-rated sickness absence for stress. Questionnaire data and stress sensitive hormones measurements were used.

Results: Employees with stress related sick leave experienced worse health, poorer work satisfaction as well as worse social and home situations than those employees without stress-related sick leave. No-significant differences were identified regarding stress-sensitive hormones. The risk for employees, not satisfied at work, of becoming absent due to stress was approximately three fold compared to those who reported being satisfied (OR 2.8, 95% confidence interval; (CI 1.3 - 5.9. For those not satisfied with their social situation, the risk for sickness absence appeared to be somewhat higher (OR 3.2; CI 1.2 - 8.6. Individual factors such as recovery potential and meaning of life as well as work related factors such as skill development and work tempo predicted employee’ s work satisfaction.

Conclusions: Based on cross sectional data, work-site and individual factors as well as social situations appear to increase the risk for absence due to stress among health care employees. Lower recovery potential, higher work tempo and poor leadership appeared to be related to the high degree of work related exhaustion experienced by employees.

Study on relationship of performance shaping factor in human error probability with prevalent stress of PUSPATI TRIGA reactor operators

Science.gov (United States)

Rahim, Ahmad Nabil Bin Ab; Mohamed, Faizal; Farid, Mohd Fairus Abdul; Fazli Zakaria, Mohd; Sangau Ligam, Alfred; Ramli, Nurhayati Binti

2018-01-01

Human factor can be affected by prevalence stress measured using Depression, Anxiety and Stress Scale (DASS). From the respondents feedback can be summarized that the main factor causes the highest prevalence stress is due to the working conditions that require operators to handle critical situation and make a prompt critical decisions. The relationship between the prevalence stress and performance shaping factors found that PSFFitness and PSFWork Process showed positive Pearson’s Correlation with the score of .763 and .826 while the level of significance, p = .028 and p = .012. These positive correlations with good significant values between prevalence stress and human performance shaping factor (PSF) related to fitness, work processes and procedures. The higher the stress level of the respondents, the higher the score of selected for the PSFs. This is due to the higher levels of stress lead to deteriorating physical health and cognitive also worsened. In addition, the lack of understanding in the work procedures can also be a factor that causes a growing stress. The higher these values will lead to the higher the probabilities of human error occur. Thus, monitoring the level of stress among operators RTP is important to ensure the safety of RTP.

Endoplasmic Reticulum Stress-Related Factors Protect against Diabetic Retinopathy

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Wei-Kun Hu

2012-01-01

Full Text Available The endoplasmic reticulum (ER is a principal mediator of signal transduction in the cell, and disruption of its normal function (a mechanism known as ER stress has been associated with the pathogenesis of several diseases. ER stress has been demonstrated to contribute to onset and progression of diabetic retinopathy (DR by induction of multiple inflammatory signaling pathways. Recent studies have begun to describe the gene expression profile of ER stress-related genes in DR; moreover, genes that play a protective role against DR have been identified. P58IPK was determined to be able to reduce retinal vascular leakage under high glucose conditions, thus protecting retinal cells. It has also been found by our lab that ER-associated protein degradation factors exhibit significantly different expression patterns in rat retinas under sustained high glucose conditions. Future research based upon these collective genomic findings will contribute to our overall understanding of DR pathogenesis as well as identify potential therapeutic targets.

Effect of Mild Water Stress and Enhanced Ultraviolet-B Irradiation on Leaf Growth of Rumex obtusifolius L. and Rumex patientia L. (Polygonaceae).

OpenAIRE

Holman, Steven R.

1981-01-01

Leaves of Rumex obtusifolius L. and R. patientia L.were exposed to combinations of mild water stress and enhanced ultraviolet-B irradiation during their ontogeny. Two UV-B treatments (enhanced UV-B and control) and three water stress treatments (-0.0 MPa, -0.2 MPa and -0.4 MPa rooting medium matric potentials) were employed. The impact of the stress interaction was assessed on the basis of changes in leaf area, average adaxial epidermal cell size, and total number of adaxial epidermal cells p...

Enhanced piezoelectricity in A B O3 ferroelectrics via intrinsic stress-driven flattening of the free-energy profile

Science.gov (United States)

Feng, Yu; Li, Wei-Li; Yu, Yang; Jia, He-Nan; Qiao, Yu-Long; Fei, Wei-Dong

2017-11-01

An approach to greatly enhance the piezoelectric properties (˜4 00 pC/N) of the tetragonal BaTi O3 polycrystal using a small number of A -site acceptor-donor substitutions [D. Xu et al., Acta Mater. 79, 84 (2014), 10.1016/j.actamat.2014.07.023] has been proposed. In this study, Pb (ZrTi ) O3 (PZT) based polycrystals with various crystal symmetries (tetragonal, rhombohedral, and so on) were chosen to investigate the piezoelectricity enhancement mechanism. X-ray diffraction results show that doping generates an intrinsic uniaxial compressive stress along the [001] pc direction in the A B O3 lattices. Piezoelectric maps in the parameter space of temperature and Ti concentration in the PZT and doped system show a more significant enhancement effect of L i+-A l3 + codoping in tetragonal PZT than in the rhombohedral phase. Phenomenological thermodynamic analysis indicates that the compressive stress results in more serious flattening of the free-energy profile in tetragonal PZT, compared with that in the rhombohedral phase. The chemical stress obtained by this acceptor-donor codoping can be utilized to optimize the piezoelectric performance on the tetragonal-phase site of the morphotropic phase boundary in the PZT system. The present study provides a promising route to the large piezoelectric effect induced by chemical-stress-driven flattening of the free-energy profile.

Measuring lifetime stress exposure and protective factors in life course research on racial inequality and birth outcomes.

Science.gov (United States)

Malat, Jennifer; Jacquez, Farrah; Slavich, George M

2017-07-01

There has been a long-standing interest in better understanding how social factors contribute to racial disparities in health, including birth outcomes. A recent emphasis in this context has been on identifying the effects of stress exposure and protective factors experienced over the entire lifetime. Yet despite repeated calls for a life course approach to research on this topic, very few studies have actually assessed how stressors and protective factors occurring over women's lives relate to birth outcomes. We discuss this issue here by describing how challenges in the measurement of lifetime stress exposure and protective factors have prevented researchers from developing an empirically-based life course perspective on health. First, we summarize prevailing views on racial inequality and birth outcomes; second, we discuss measurement challenges that exist in this context; and finally, we describe both new tools and needed tools for assessing lifetime stress exposure and suggest opportunities for integrating information on stress exposure and psychosocial protective factors. We conclude that more studies are needed that integrate information about lifetime stress exposures and the protective factors that promote resilience against such exposures to inform policy and practice recommendations to reduce racial disparities in birth outcomes.

Environmental heat stress enhances crystallization in urine

Science.gov (United States)

Setyawan, H.; Pratiwi, Q. C.; Sjarifah, I.; Atmojo, T. B.; Khotijah

2018-03-01

Over the past several decades, agriculture and plantations have been used as the main livelihood of most of the Karanganyar residents. However, these two sources of living are now replaced by industrial areas that employ thousands of people in that district. The development of this industry triggers multiple environmental impacts, including ecosystem and temperature changes. In consequence, there is an increase in air temperature that can cause a variety of diseases, especially in the workplace. According to the International Labour Organization (ILO) data in 2013, one worker dies every 15 second due to a work accident and 160 workers are suffering from the occupational disease. In Indonesia, the incidence of crystallization in urine is actually still unknown, but it is estimated that there are 170,000 cases annually. A high temperature or called heat stress is one among many factors causing this disease to appear. The workers in the textile industry, especially in the Finishing Department Kusumahadi Co. Ltd that exposed heat stress from the finishing machines and inadequate ventilation. This hot working climate causes the human body to adapt in the form of body cooling mechanism or called sweating This adaptation can cause an increase in sweat production and decrease the production of urine. If it is not followed by consuming the recommended amount of water intake, it can result in the precipitation of body salts that, in a long time, will cause crystallization in urine. The research used the analytic observational designs for a cross-sectional study. There were 34 samples collected from 57 finishing workers. The data were analyzed using Spearman correlation test. The results showed that heat stress (p=0,015) and water intake (p=0,034) has a significant correlation with crystallization in urine.

Role of Stress-Related Brain-Derived Neurotrophic Factor (BDNF) in the Rat Submandibular Gland

International Nuclear Information System (INIS)

Tsukinoki, Keiichi; Saruta, Juri

2012-01-01

The nerve growth factor (NGF) family comprises NGF, brain-derived neurotrophic factor (BDNF) and neurotrophins (NTs)-3, -4/5, -6 and -7, all of which are collectively referred to as neurotrophins. However, the expression of neurotrophins other than NGF in the salivary gland has not been described in detail. Through interaction with the TrkB receptor, BDNF plays an important role in long-term potentiation. We found that BDNF expression increased within submandibular gland tissue in response to stress, suggesting that the salivary glands are sensitive to stress. In addition, stress caused increases in plasma BDNF derived from the submandibular gland and in TrkB receptor mRNA in the adrenal medulla. Plasma BDNF might activate TrkB receptors in the adrenal medulla during acute stress. The salivary glands are likely to influence not only oral health, but also systemic organs. This review addressed the relationship between hormone-like effects and stress-related BDNF expression in the rat submandibular gland

A Dehydration-Induced Eukaryotic Translation Initiation Factor iso4G Identified in a Slow Wilting Soybean Cultivar Enhances Abiotic Stress Tolerance in Arabidopsis

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Juan P. Gallino

2018-03-01

Full Text Available Water is usually the main limiting factor for soybean productivity worldwide and yet advances in genetic improvement for drought resistance in this crop are still limited. In the present study, we investigated the physiological and molecular responses to drought in two soybean contrasting genotypes, a slow wilting N7001 and a drought sensitive TJS2049 cultivars. Measurements of stomatal conductance, carbon isotope ratios and accumulated dry matter showed that N7001 responds to drought by employing mechanisms resulting in a more efficient water use than TJS2049. To provide an insight into the molecular mechanisms that these cultivars employ to deal with water stress, their early and late transcriptional responses to drought were analyzed by suppression subtractive hybridization. A number of differentially regulated genes from N7001 were identified and their expression pattern was compared between in this genotype and TJS2049. Overall, the data set indicated that N7001 responds to drought earlier than TJ2049 by up-regulating a larger number of genes, most of them encoding proteins with regulatory and signaling functions. The data supports the idea that at least some of the phenotypic differences between slow wilting and drought sensitive plants may rely on the regulation of the level and timing of expression of specific genes. One of the genes that exhibited a marked N7001-specific drought induction profile encoded a eukaryotic translation initiation factor iso4G (GmeIFiso4G-1a. GmeIFiso4G-1a is one of four members of this protein family in soybean, all of them sharing high sequence identity with each other. In silico analysis of GmeIFiso4G-1 promoter sequences suggested a possible functional specialization between distinct family members, which can attain differences at the transcriptional level. Conditional overexpression of GmeIFiso4G-1a in Arabidopsis conferred the transgenic plants increased tolerance to osmotic, salt, drought and low

Factor Structure of the Acute Stress Disorder Scale in a Sample of Hurricane Katrina Evacuees

Science.gov (United States)

Edmondson, Donald; Mills, Mary Alice; Park, Crystal L.

2010-01-01

Acute stress disorder (ASD) is a poorly understood and controversial diagnosis (A. G. Harvey & R. A. Bryant, 2002). The present study used confirmatory factor analysis (CFA) to test the factor structure of the most widely used self-report measure of ASD, the Acute Stress Disorder Scale (R. A. Bryant, M. L. Moulds, & R. M. Guthrie, 2000),…

Structure, function and networks of transcription factors involved in abiotic stress responses

DEFF Research Database (Denmark)

Lindemose, Søren; O'Shea, Charlotte; Jensen, Michael Krogh

2013-01-01

Transcription factors (TFs) are master regulators of abiotic stress responses in plants. This review focuses on TFs from seven major TF families, known to play functional roles in response to abiotic stresses, including drought, high salinity, high osmolarity, temperature extremes...... and the phytohormone ABA. Although ectopic expression of several TFs has improved abiotic stress tolerance in plants, fine-tuning of TF expression and protein levels remains a challenge to avoid crop yield loss. To further our understanding of TFs in abiotic stress responses, emerging gene regulatory networks based...... on TFs and their direct targets genes are presented. These revealed components shared between ABA-dependent and independent signaling as well as abiotic and biotic stress signaling. Protein structure analysis suggested that TFs hubs of large interactomes have extended regions with protein intrinsic...

Regulation of hippocampal neurogenesis by systemic factors including stress, glucocorticoids, sleep, and inflammation

NARCIS (Netherlands)

Lucassen, P.J.; Oomen, C.; van Dam, A.-M.; Czéh, B.; Gage, F.H.; Kempermann, G.; Song, H.

2008-01-01

This review summarizes and discusses the regulation of adult neurogenesis and hippocampal cellular plasticity by systemic factors. We focus on the role of stress, glucocorticoids, and related factors such as sleep deprivation and inflammation.

Work stress and risk factors for health management trainees in canakkale, Turkey.

Science.gov (United States)

Tanışman, Beyhan; Cevizci, Sibel; Çelik, Merve; Sevim, Sezgin

2014-10-01

This study aims to investigate the general mental health situation, work-related stress and risk factors of health management trainees. This cross-sectional study was conducted on Health Management Musters students (N=96) in Canakkale Onsekiz Mart University Health Sciences Institute, May-June 2014. A total of 58 students who voluntarily participated in the study were reached (60.42%). Participants completed a 22-question sociodemographic survey form and a 12-item General Health Questionnaire in a face-to-face interview. Data were analyzed using the SPSS software version 20.0. The average age of participants was 36.4±6.2 (Min:24-Max:62) years. Thirty five of the participants were female (60.3%), 23 were male (39.7%). The number of people using cigarettes and alcohol were 23 (39.7%) and 9 (15.8%) respectively. In our study group according to GHQ scale 32 people (55.2%) were in the group at risk of depression. Eighty-six percent of participants reported experiencing work stress. The most frequently reported sources of stress were superiors (56.8%), work itself (41.3%), and work colleagues (25.8%). There was no significant difference between those at risk of depression and those not at risk in terms of gender, marital status, educational level, age, work-related factors (daily work, computer use, duration of sitting at desk), sleep duration, presence of chronic disease, substance use (cigarettes, alcohol), regular exercise, regular meals, fast-food consumption, sufficient family time and vacations (p>0.05). Our study results indicated that majority of participants reported experiencing work stress with more than half at high risk of developing depression. The most reported risk factors were superiors, the work itself and colleagues in the present study. Psychosocial risk factors at work environment should be investigated in terms of psychological, sociological and ergonomics in more detail to reduce the risk of health management trainees experiencing work stress and

Reassessing SERS enhancement factors: using thermodynamics to drive substrate design.