Experimental studies on possible regulatory role of nitric oxide on the differential effects of chronic predictable and unpredictable stress on adaptive immune responses.

Science.gov (United States)

Thakur, Tarun; Gulati, Kavita; Rai, Nishant; Ray, Arunabha

2017-09-01

The present study was designed to investigate the effects of chronic predictable stress (CPS) and chronic unpredictable stress (CUS) on immunological responses in KLH-sensitized rats and involvement of NOergic signaling pathways mediating such responses. Male Wistar rats (200-250g) were exposed to either CPS or CUS for 14days and IgG antibody levels and delayed type hypersensitivity (DTH) response was determined to assess changes in adaptive immunity. To evaluate the role of nitric oxide during such immunomodulation, biochemical estimation of stable metabolite of nitric oxide (NOx) and 3-nitrotyrosine (3-NT, a marker of peroxynitrite formation) were done in both blood and brain. Chronic stress exposure resulted in suppression of IgG and DTH response and elevated NOx and 3-NT levels, with a difference in magnitude of response in CPS vs CUS. Pretreatment with aminoguanidine (iNOS inhibitor) caused further reduction of adaptive immune responses and attenuated the increased NOx and 3-NT levels in CPS or CUS exposed rats. On the other hand 7-NI (nNOS inhibitor) did not significantly affect these estimated parameters. The results suggest involvement of iNOS and lesser/no role of nNOS during modulation of adaptive immunity to stress. Thus, the result showed that predictability of stressors results in differential degree of modulation of immune responses and complex NO-mediated signaling mechanisms may be involved during responses. Copyright © 2017. Published by Elsevier B.V.

Prediction of permeability changes in an excavation response zone

International Nuclear Information System (INIS)

Kinoshita, Naoto; Ishii, Takashi; Kuroda, Hidetaka; Tada, Hiroyuki

1992-01-01

In geologic disposal of radioactive wastes, stress changes due to cavern excavation may expand the existing fractures and create possible bypasses for groundwater. This paper proposes a simple method for predicting permeability changes in the excavation response zones. Numerical analyses using this method predict that the response zones created by cavern excavation would differ greatly in thickness and permeability depending on the depth of the cavern site and the initial in-situ stress, that when the cavern site is deeper, response zones would expand more and permeability would increases more, and that if the ratio of horizontal to vertical in-situ stress is small, extensive permeable zones at the crown and the bottom would occur, whereas if the ratio is large, extensive permeable zones would occur in the side walls. (orig.)

The relationship between personality and the response to acute psychological stress.

Science.gov (United States)

Xin, Yuanyuan; Wu, Jianhui; Yao, Zhuxi; Guan, Qing; Aleman, André; Luo, Yuejia

2017-12-04

The present study examined the relationship between personality traits and the response to acute psychological stress induced by a standardized laboratory stress induction procedure (the Trier Social Stress Test, TSST). The stress response was measured with a combination of cardiovascular reactivity, hypothalamic-pituitary-adrenal axis reactivity, and subjective affect (including positive affect, negative affect and subjective controllability) in healthy individuals. The Generalized Estimating Equations (GEE) approach was applied to account for the relationship between personality traits and stress responses. Results suggested that higher neuroticism predicted lower heart rate stress reactivity, lower cortisol stress response, more decline of positive affect and lower subjective controllability. Individuals higher in extraversion showed smaller cortisol activation to stress and less increase of negative affect. In addition, higher openness score was associated with lower cortisol stress response. These findings elucidate that neuroticism, extraversion and openness are important variables associated with the stress response and different dimensions of personality trait are associated with different aspects of the stress response.

Differential Response of Coral Assemblages to Thermal Stress Underscores the Complexity in Predicting Bleaching Susceptibility.

Science.gov (United States)

Chou, Loke Ming; Toh, Tai Chong; Toh, Kok Ben; Ng, Chin Soon Lionel; Cabaitan, Patrick; Tun, Karenne; Goh, Eugene; Afiq-Rosli, Lutfi; Taira, Daisuke; Du, Rosa Celia Poquita; Loke, Hai Xin; Khalis, Aizat; Li, Jinghan; Song, Tiancheng

2016-01-01

Coral bleaching events have been predicted to occur more frequently in the coming decades with global warming. The susceptibility of corals to bleaching during thermal stress episodes is dependent on many factors and an understanding of these underlying drivers is crucial for conservation management. In 2013, a mild bleaching episode ensued in response to elevated sea temperature on the sediment-burdened reefs in Singapore. Surveys of seven sites highlighted variable bleaching susceptibility among coral genera-Pachyseris and Podabacia were the most impacted (31% of colonies of both genera bleached). The most susceptible genera such as Acropora and Pocillopora, which were expected to bleach, did not. Susceptibility varied between less than 6% and more than 11% of the corals bleached, at four and three sites respectively. Analysis of four of the most bleached genera revealed that a statistical model that included a combination of the factors (genus, colony size and site) provided a better explanation of the observed bleaching patterns than any single factor alone. This underscored the complexity in predicting the coral susceptibility to future thermal stress events and the importance of monitoring coral bleaching episodes to facilitate more effective management of coral reefs under climate change.

Differential Response of Coral Assemblages to Thermal Stress Underscores the Complexity in Predicting Bleaching Susceptibility

Science.gov (United States)

Toh, Kok Ben; Ng, Chin Soon Lionel; Cabaitan, Patrick; Tun, Karenne; Goh, Eugene; Afiq-Rosli, Lutfi; Taira, Daisuke; Du, Rosa Celia Poquita; Loke, Hai Xin; Khalis, Aizat; Li, Jinghan; Song, Tiancheng

2016-01-01

Coral bleaching events have been predicted to occur more frequently in the coming decades with global warming. The susceptibility of corals to bleaching during thermal stress episodes is dependent on many factors and an understanding of these underlying drivers is crucial for conservation management. In 2013, a mild bleaching episode ensued in response to elevated sea temperature on the sediment-burdened reefs in Singapore. Surveys of seven sites highlighted variable bleaching susceptibility among coral genera–Pachyseris and Podabacia were the most impacted (31% of colonies of both genera bleached). The most susceptible genera such as Acropora and Pocillopora, which were expected to bleach, did not. Susceptibility varied between less than 6% and more than 11% of the corals bleached, at four and three sites respectively. Analysis of four of the most bleached genera revealed that a statistical model that included a combination of the factors (genus, colony size and site) provided a better explanation of the observed bleaching patterns than any single factor alone. This underscored the complexity in predicting the coral susceptibility to future thermal stress events and the importance of monitoring coral bleaching episodes to facilitate more effective management of coral reefs under climate change. PMID:27438593

Executive functioning performance predicts subjective and physiological acute stress reactivity: preliminary results.

Science.gov (United States)

Hendrawan, Donny; Yamakawa, Kaori; Kimura, Motohiro; Murakami, Hiroki; Ohira, Hideki

2012-06-01

Individual differences in baseline executive functioning (EF) capacities have been shown to predict state anxiety during acute stressor exposure. However, no previous studies have clearly demonstrated the relationship between EF and physiological measures of stress. The present study investigated the efficacy of several well-known EF tests (letter fluency, Stroop test, and Wisconsin Card Sorting Test) in predicting both subjective and physiological stress reactivity during acute psychosocial stress exposure. Our results show that letter fluency served as the best predictor for both types of reactivity. Specifically, the higher the letter fluency score, the lower the acute stress reactivity after controlling for the baseline stress response, as indicated by lower levels of state anxiety, negative mood, salivary cortisol, and skin conductance. Moreover, the predictive power of the letter fluency test remained significant for state anxiety and cortisol indices even after further adjustments for covariates by adding the body mass index (BMI) as a covariate. Thus, good EF performance, as reflected by high letter fluency scores, may dampen acute stress responses, which suggests that EF processes are directly associated with aspects of stress regulation. Copyright © 2012 Elsevier B.V. All rights reserved.

Physiological stress responses predict sexual functioning and satisfaction differently in women who have and have not been sexually abused in childhood.

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Meston, Cindy M; Lorenz, Tierney A

2013-07-01

Physiological responses to sexual stimuli may contribute to the increased rate of sexual problems seen in women with childhood sexual abuse (CSA) histories. We compared two physiological stress responses as predictors of sexual function and satisfaction, sympathetic nervous system (SNS) activation and cortisol in women with (CSA, N = 136) and without CSA histories (NSA, N = 102). In CSA survivors, cortisol response to sexual stimuli did not significantly predict sexual functioning; however, in NSA women, cortisol increases were associated with poorer sexual functioning, and decreases with higher functioning. For women with CSA histories, lower SNS activity was associated with poorer sexual functioning. For CSA survivors with low lifetime trauma, lower SNS activity was associated with higher sexual satisfaction; for women with high lifetime trauma, the reverse was true. Decreased SNS activity during sexual stimuli predicted higher sexual functioning in NSA women with low lifetime exposure to traumatic events, but lower sexual functioning in those with high exposure. Differences between women with and without CSA histories in the association between cortisol and SNS response and sexual functioning and satisfaction suggests that CSA causes disruptions in both short and long-term stress responses to sexual stimuli that perpetuate into adulthood.

Differentiating anticipatory from reactive cortisol responses to psychosocial stress

NARCIS (Netherlands)

Engert, V.; Efanov, S.I.; Duchesne, A.; Vogel, S.; Corbo, V.; Pruessner, J.C.

2013-01-01

Most psychosocial stress studies assess the overall cortisol response without further identifying the temporal dynamics within hormone levels. It has been shown, however, that the amplitude of anticipatory cortisol stress levels has a unique predictive value for psychological health. So far, no

Physiological stress responses predict sexual functioning and satisfaction differently in women who have and have not been sexually abused in childhood

OpenAIRE

Meston, Cindy M.; Lorenz, Tierney A.

2012-01-01

Physiological responses to sexual stimuli may contribute to the increased rate of sexual problems seen in women with childhood sexual abuse (CSA) histories. We compared two physiological stress responses as predictors of sexual function and satisfaction, sympathetic nervous system (SNS) activation and cortisol in women with (CSA, N = 136) and without CSA histories (NSA, N = 102). In CSA survivors, cortisol response to sexual stimuli did not significantly predict sexual functioning; however, i...

Predicting Job Stress Based on Elements of Coping Styles in Nurses

Directory of Open Access Journals (Sweden)

Mansoureh Nezari Sedeh

2016-07-01

Full Text Available Using coping methods can help to dominate on physical, mental, and social relationships, individual contradiction problems, and can be considered as one of effective factors in general and mental health of nurses. The objective of the present research is predicting job stress based on elements of coping styles in nurses. By correlative methodology for this research, 120 female20-45 years old nurses in Tehran city were selected by simple random sampling method based on Cochran formula. The research instrument includes job stress questionnaire and coping style questionnaire of Lazzarus & Folkman; the Pearson correlation coefficient test, and linear regression were used to test hypotheses and generalize the obtained information from tests. Findings showed that participants’ scores were near normal range and Cronbach’s alpha coefficient was 0.58 which indicated scores internal consistency. The obtained results showed that coping elements in 0.05 significant level with f-value of 12.403 significantly predicted job stress. In addition, regression coefficient among support, responsibility, and managerial solution elements was negative and positive with two other relationships including job stress and escape-avoidance. Therefore, it can be concluded that elements of support, responsibility, escape-avoidance, and managerial solution significantly predict nurses’ job stress among coping elements.

Differential Response of Coral Assemblages to Thermal Stress Underscores the Complexity in Predicting Bleaching Susceptibility.

Directory of Open Access Journals (Sweden)

Loke Ming Chou

Full Text Available Coral bleaching events have been predicted to occur more frequently in the coming decades with global warming. The susceptibility of corals to bleaching during thermal stress episodes is dependent on many factors and an understanding of these underlying drivers is crucial for conservation management. In 2013, a mild bleaching episode ensued in response to elevated sea temperature on the sediment-burdened reefs in Singapore. Surveys of seven sites highlighted variable bleaching susceptibility among coral genera-Pachyseris and Podabacia were the most impacted (31% of colonies of both genera bleached. The most susceptible genera such as Acropora and Pocillopora, which were expected to bleach, did not. Susceptibility varied between less than 6% and more than 11% of the corals bleached, at four and three sites respectively. Analysis of four of the most bleached genera revealed that a statistical model that included a combination of the factors (genus, colony size and site provided a better explanation of the observed bleaching patterns than any single factor alone. This underscored the complexity in predicting the coral susceptibility to future thermal stress events and the importance of monitoring coral bleaching episodes to facilitate more effective management of coral reefs under climate change.

Predicting behavior during interracial interactions: a stress and coping approach.

Science.gov (United States)

Trawalter, Sophie; Richeson, Jennifer A; Shelton, J Nicole

2009-11-01

The social psychological literature maintains unequivocally that interracial contact is stressful. Yet research and theory have rarely considered how stress may shape behavior during interracial interactions. To address this empirical and theoretical gap, the authors propose a framework for understanding and predicting behavior during interracial interactions rooted in the stress and coping literature. Specifically, they propose that individuals often appraise interracial interactions as a threat, experience stress, and therefore cope-they antagonize, avoid, freeze, or engage. In other words, the behavioral dynamics of interracial interactions can be understood as initial stress reactions and subsequent coping responses. After articulating the framework and its predictions for behavior during interracial interactions, the authors examine its ability to organize the extant literature on behavioral dynamics during interracial compared with same-race contact. They conclude with a discussion of the implications of the stress and coping framework for improving research and fostering more positive interracial contact.

Refining the multisystem view of the stress response: Coordination among cortisol, alpha-amylase, and subjective stress in response to relationship conflict

Science.gov (United States)

Powers, Sally I.; Granger, Douglas A.

2013-01-01

This study investigated associations among young adults' hypothalamic-pituitary-adrenal axis activity, autonomic nervous system activity, and subjective stress in response to interpersonal conflict to better characterize coordination across stress systems. Seven saliva samples were collected from 199 young adult opposite-sex couples before, during, and after they discussed an unresolved relationship conflict. Samples were later assayed for cortisol and alpha-amylase (sAA). Couples rated anticipatory stress prior to the conflict and perceived stress immediately following the task. Growth curve modeling was used to examine two possible levels of within-person coordination across physiological systems: alignment between cortisol and sAA responses throughout the sampling period (“matched phase coordination”), and association between overall levels of cortisol and sAA in response to conflict (“average level coordination”). Whereas both partners showed the former type of coordination, only women showed the latter type. Positive anticipation of the stressor predicted stronger cortisol-sAA matched phase coordination for women. Pre-task ratings related to women's sAA, and post-task ratings related to both partners' cortisol responses. Implications for a multisystem interpretation of normal and pathological responses to daily stress are discussed. PMID:23684904

Refining the multisystem view of the stress response: coordination among cortisol, alpha-amylase, and subjective stress in response to relationship conflict.

Science.gov (United States)

Laurent, Heidemarie K; Powers, Sally I; Granger, Douglas A

2013-07-02

This study investigated associations among young adults' hypothalamic-pituitary-adrenal axis activity, autonomic nervous system activity, and subjective stress in response to interpersonal conflict to better characterize coordination across stress systems. Seven saliva samples were collected from 199 young adult opposite-sex couples before, during, and after they discussed an unresolved relationship conflict. Samples were later assayed for cortisol and alpha-amylase (sAA). Couples rated anticipatory stress prior to the conflict and perceived stress immediately following the task. Growth curve modeling was used to examine two possible levels of within-person coordination across physiological systems: alignment between cortisol and sAA responses throughout the sampling period ("matched phase coordination"), and association between overall levels of cortisol and sAA in response to conflict ("average level coordination"). Whereas both partners showed the former type of coordination, only women showed the latter type. Positive anticipation of the stressor predicted stronger cortisol-sAA matched phase coordination for women. Pre-task ratings related to women's sAA, and post-task ratings related to both partners' cortisol responses. Implications for a multisystem interpretation of normal and pathological responses to daily stress are discussed. Copyright © 2013 Elsevier Inc. All rights reserved.

Individual reactions to stress predict performance during a critical aviation incident.

Science.gov (United States)

Vine, Samuel J; Uiga, Liis; Lavric, Aureliu; Moore, Lee J; Tsaneva-Atanasova, Krasimira; Wilson, Mark R

2015-01-01

Understanding the influence of stress on human performance is of theoretical and practical importance. An individual's reaction to stress predicts their subsequent performance; with a "challenge" response to stress leading to better performance than a "threat" response. However, this contention has not been tested in truly stressful environments with highly skilled individuals. Furthermore, the effect of challenge and threat responses on attentional control during visuomotor tasks is poorly understood. Thus, this study aimed to examine individual reactions to stress and their influence on attentional control, among a cohort of commercial pilots performing a stressful flight assessment. Sixteen pilots performed an "engine failure on take-off" scenario, in a high-fidelity flight simulator. Reactions to stress were indexed via self-report; performance was assessed subjectively (flight instructor assessment) and objectively (simulator metrics); gaze behavior data were captured using a mobile eye tracker, and measures of attentional control were subsequently calculated (search rate, stimulus driven attention, and entropy). Hierarchical regression analyses revealed that a threat response was associated with poorer performance and disrupted attentional control. The findings add to previous research showing that individual reactions to stress influence performance and shed light on the processes through which stress influences performance.

Tonic immobility differentiates stress responses in PTSD.

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Fragkaki, Iro; Stins, John; Roelofs, Karin; Jongedijk, Ruud A; Hagenaars, Muriel A

2016-11-01

Tonic immobility (TI) is a state of physical immobility associated with extreme stress and the development of posttraumatic stress disorder (PTSD). However, it is unknown whether TI is associated with a distinct actual stress response, i.e., objective immobility measured by a stabilometric platform. This study made a first step in exploring this as well as differences in body sway responses between PTSD patients and healthy controls. We hypothesized that PTSD would be related to increased body sway under stress, whereas TI would be related to decreased body sway under stress. Eye closure was selected as a PTSD-relevant stress induction procedure. Body sway and heart rate (HR) were measured in 12 PTSD patients and 12 healthy controls in four conditions: (1) maintaining a stable stance with eyes open, (2) with eyes closed, (3) during a mental arithmetic task with eyes open, and (4) with eyes closed. As predicted, PTSD patients showed increased body sway from eyes open to eyes closed compared to controls and this effect was eliminated by executing the arithmetic task. Most importantly, retrospective self-reported TI was associated with lower body sway increases in PTSD and higher body sway decreases in controls from eyes-open to eyes-closed conditions. These preliminary findings suggest that eye closure has a different effect on PTSD patients than controls and that high self-reported TI might indicate a distinct stress response pattern, i.e., a proneness for immobility. It may be relevant to take such individual differences in stress-response into account in PTSD treatment.

Behavioural stress responses predict environmental perception in European sea bass (Dicentrarchus labrax).

Science.gov (United States)

Millot, Sandie; Cerqueira, Marco; Castanheira, Maria-Filipa; Overli, Oyvind; Oliveira, Rui F; Martins, Catarina I M

2014-01-01

Individual variation in the response to environmental challenges depends partly on innate reaction norms, partly on experience-based cognitive/emotional evaluations that individuals make of the situation. The goal of this study was to investigate whether pre-existing differences in behaviour predict the outcome of such assessment of environmental cues, using a conditioned place preference/avoidance (CPP/CPA) paradigm. A comparative vertebrate model (European sea bass, Dicentrarchus labrax) was used, and ninety juvenile individuals were initially screened for behavioural reactivity using a net restraining test. Thereafter each individual was tested in a choice tank using net chasing as aversive stimulus or exposure to familiar conspecifics as appetitive stimulus in the preferred or non preferred side respectively (called hereafter stimulation side). Locomotor behaviour (i.e. time spent, distance travelled and swimming speed in each tank side) of each individual was recorded and analysed with video software. The results showed that fish which were previously exposed to appetitive stimulus increased significantly the time spent on the stimulation side, while aversive stimulus led to a strong decrease in time spent on the stimulation side. Moreover, this study showed clearly that proactive fish were characterised by a stronger preference for the social stimulus and when placed in a putative aversive environment showed a lower physiological stress responses than reactive fish. In conclusion, this study showed for the first time in sea bass, that the CPP/CPA paradigm can be used to assess the valence (positive vs. negative) that fish attribute to different stimuli and that individual behavioural traits is predictive of how stimuli are perceived and thus of the magnitude of preference or avoidance behaviour.

Predictive Accuracy of Exercise Stress Testing the Healthy Adult.

Science.gov (United States)

Lamont, Linda S.

1981-01-01

Exercise stress testing provides information on the aerobic capacity, heart rate, and blood pressure responses to graded exercises of a healthy adult. The reliability of exercise tests as a diagnostic procedure is discussed in relation to sensitivity and specificity and predictive accuracy. (JN)

Context and strain-dependent behavioral response to stress

Directory of Open Access Journals (Sweden)

Baum Amber E

2008-06-01

Full Text Available Abstract Background This study posed the question whether strain differences in stress-reactivity lead to differential behavioral responses in two different tests of anxiety. Strain differences in anxiety-measures are known, but strain differences in the behavioral responses to acute prior stress are not well characterized. Methods We studied male Fisher 344 (F344 and Wistar Kyoto (WKY rats basally and immediately after one hour restraint stress. To distinguish between the effects of novelty and prior stress, we also investigated behavior after repeated exposure to the test chamber. Two behavioral tests were explored; the elevated plus maze (EPM and the open field (OFT, both of which are thought to measure activity, exploration and anxiety-like behaviors. Additionally, rearing, a voluntary behavior, and grooming, a relatively automatic, stress-responsive stereotyped behavior were measured in both tests. Results Prior exposure to the test environment increased anxiety-related measures regardless of prior stress, reflecting context-dependent learning process in both tests and strains. Activity decreased in response to repeated testing in both tests and both strains, but prior stress decreased activity only in the OFT which was reversed by repeated testing. Prior stress decreased anxiety-related measures in the EPM, only in F344s, while in the OFT, stress led to increased freezing mainly in WKYs. Conclusion Data suggest that differences in stressfulness of these tests predict the behavior of the two strains of animals according to their stress-reactivity and coping style, but that repeated testing can overcome some of these differences.

Predictors and moderators of biopsychological social stress responses following brief self-compassion meditation training.

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Arch, Joanna J; Landy, Lauren N; Brown, Kirk Warren

2016-07-01

Arch et al. (2014) demonstrated that brief self-compassion meditation training (SCT) dampened sympathetic (salivary alpha-amylase) and subjective anxiety responses to the Trier Social Stress Test (TSST), relative to attention and no-instruction control conditions. The present study examined baseline predictors and moderators of these SCT intervention effects. Baseline characteristics included two stress vulnerability traits (social anxiety and rumination) and two potential resiliency traits (non-attachment and self-compassion). We investigated how these traits moderated the effects of SCT on response to the TSST, relative to the control conditions. We also tested how these individual differences predicted TSST responses across conditions in order to uncover characteristics that confer increased vulnerability and resiliency to social stressors. Trait non-attachment, rumination (for sympathetic TSST response only), and social anxiety (for subjective TSST response only) interacted with training condition to moderate TSST responses such that following SCT, lower attachment and lower social anxiety predicted lower TSST stress responses, relative to those scoring higher on these traits. In contrast, trait self-compassion neither moderated nor predicted responses to the TSST. Thus, although SCT had robust effects on buffering stress across individuals with varying levels of trait self-compassion, other psychological traits enhanced or dampened the effect of SCT on TSST responses. These findings support the importance of examining the role of relevant baseline psychological traits to predict sympathetic and subjective responses to social evaluative threat, particularly in the context of resiliency training. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Role of Trauma-Specific Irrational Beliefs and Sociodemographic Risk Factors in Posttraumatic Stress Responses

OpenAIRE

Hyland, Philip; Shevlin, Mark; Adamson, Gary; Boduszek, Daniel

2013-01-01

Posttraumatic stress responses have been linked to a range of social-cognitive and sociodemographic factors. Rational Emotive Behaviour Therapy suggests that responding to a traumatic life event with a set of irrational beliefs should play a crucial role in predicting the development of posttraumatic stress disorder (PTSD: Ellis, 2001). The current study assessed the role of trauma-specific irrational beliefs in the prediction of clinically relevant posttraumatic stress responses, while contr...

Leptin concentrations in response to acute stress predict subsequent intake of comfort foods

Science.gov (United States)

Tomiyama, A. Janet; Schamarek, Imke; Lustig, Robert H.; Kirschbaum, Clemens; Puterman, Eli; Havel, Peter J.; Epel, Elissa S.

2012-01-01

Both animals and humans show a tendency toward eating more “comfort food” (high fat, sweet food) after acute stress. Such stress eating may be contributing to the obesity epidemic, and it is important to understand the underlying psychobiological mechanisms. Prior investigations have studied what makes individuals eat more after stress; this study investigates what might make individuals eat less. Leptin has been shown to increase following a laboratory stressor, and is known to affect eating behavior. This study examined whether leptin reactivity accounts for individual differences in stress eating. To test this, we exposed forty women to standardized acute psychological laboratory stress (Trier Social Stress Test) while blood was sampled repeatedly for measurements of plasma leptin. We then measured food intake after the stressor in 29 of these women. Increasing leptin during the stressor predicted lower intake of comfort food. These initial findings suggest that acute changes in leptin may be one of the factors modulating down the consumption of comfort food following stress. PMID:22579988

Acute stress responses: A review and synthesis of ASD, ASR, and CSR.

Science.gov (United States)

Isserlin, Leanna; Zerach, Gadi; Solomon, Zahava

2008-10-01

Toward the development of a unifying diagnosis for acute stress responses this article attempts to find a place for combat stress reaction (CSR) within the spectrum of other defined acute stress responses. This article critically compares the diagnostic criteria of acute stress disorder (ASD), acute stress reaction (ASR), and CSR. Prospective studies concerning the predictive value of ASD, ASR, and CSR are reviewed. Questions, recommendations, and implications for clinical practice are raised concerning the completeness of the current acute stress response diagnoses, the heterogeneity of different stressors, the scope of expected outcomes, and the importance of decline in function as an indicator of future psychological, psychiatric, and somatic distress. PsycINFO Database Record 2009 APA.

When does stress help or harm? The effects of stress controllability and subjective stress response on stroop performance.

Science.gov (United States)

Henderson, Roselinde K; Snyder, Hannah R; Gupta, Tina; Banich, Marie T

2012-01-01

The ability to engage in goal-directed behavior despite exposure to stress is critical to resilience. Questions of how stress can impair or improve behavioral functioning are important in diverse settings, from athletic competitions to academic testing. Previous research suggests that controllability is a key factor in the impact of stress on behavior: learning how to control stressors buffers people from the negative effects of stress on subsequent cognitively demanding tasks. In addition, research suggests that the impact of stress on cognitive functioning depends on an individual's response to stressors: moderate responses to stress can lead to improved performance while extreme (high or low) responses can lead to impaired performance. The present studies tested the hypothesis that (1) learning to behaviorally control stressors leads to improved performance on a test of general executive functioning, the color-word Stroop, and that (2) this improvement emerges specifically for people who report moderate (subjective) responses to stress. Experiment 1: Stroop performance, measured before and after a stress manipulation, was compared across groups of undergraduate participants (n = 109). People who learned to control a noise stressor and received accurate performance feedback demonstrated reduced Stroop interference compared with people exposed to uncontrollable noise stress and feedback indicating an exaggerated rate of failure. In the group who learned behavioral control, those who reported moderate levels of stress showed the greatest reduction in Stroop interference. In contrast, in the group exposed to uncontrollable events, self-reported stress failed to predict performance. Experiment 2: In a second sample (n = 90), we specifically investigated the role of controllability by keeping the rate of failure feedback constant across groups. In the group who learned behavioral control, those who reported moderate levels of stress showed the greatest Stroop

Does the stress response predict the ability of wild birds to adjust to short-term captivity? A study of the rock pigeon (Columbia livia).

Science.gov (United States)

Angelier, Frédéric; Parenteau, Charline; Trouvé, Colette; Angelier, Nicole

2016-12-01

Although the transfer of wild animals to captivity is crucial for conservation purposes, this process is often challenging because some species or individuals do not adjust well to captive conditions. Chronic stress has been identified as a major concern for animals held on long-term captivity. Surprisingly, the first hours or days of captivity have been relatively overlooked. However, they are certainly very stressful, because individuals are being transferred to a totally novel and confined environment. To ensure the success of conservation programmes, it appears crucial to better understand the proximate causes of interspecific and interindividual variability in the sensitivity to these first hours of captivity. In that respect, the study of stress hormones is relevant, because the hormonal stress response may help to assess whether specific individuals or species adjust, or not, to such captive conditions ('the stress response-adjustment to captivity hypothesis'). We tested this hypothesis in rock pigeons by measuring their corticosterone stress response and their ability to adjust to short-term captivity (body mass loss and circulating corticosterone levels after a day of captivity). We showed that an increased corticosterone stress response is associated with a lower ability to adjust to short-term captivity (i.e. higher body mass loss and circulating corticosterone levels). Our study suggests, therefore, that a low physiological sensitivity to stress may be beneficial for adjusting to captivity. Future studies should now explore whether the stress response can be useful to predict the ability of individuals from different populations or species to not only adjust to short-term but also long-term captivity.

Infants, Mothers, and Dyadic Contributions to Stability and Prediction of Social Stress Response at 6 Months

Science.gov (United States)

Provenzi, Livio; Olson, Karen L.; Montirosso, Rosario; Tronick, Ed

2016-01-01

The study of infants' interactive style and social stress response to repeated stress exposures is of great interest for developmental and clinical psychologists. Stable maternal and dyadic behavior is critical to sustain infants' development of an adaptive social stress response, but the association between infants' interactive style and social…

Early life adversity influences stress response association with smoking relapse.

Science.gov (United States)

al'Absi, Mustafa; Lemieux, Andrine; Westra, Ruth; Allen, Sharon

2017-11-01

We examined the hypothesis that stress-related blunting of cortisol in smokers is particularly pronounced in those with a history of severe life adversity. The two aims of this study were first to examine hormonal, craving, and withdrawal symptoms during ad libitum smoking and after the first 24 h of abstinence in smokers who experienced high or low levels of adversity. Second, we sought to examine the relationship between adversity and hypothalamic-pituitary-adrenal (HPA) hormones to predict relapse during the first month of a smoking cessation attempt. Hormonal and self-report measures were collected from 103 smokers (49 women) during ad libitum smoking and after the first 24 h of abstinence. HPA hormones were measured during baseline rest and in response to acute stress in both conditions. All smokers were interested in smoking cessation, and we prospectively used stress response measures to predict relapse during the first 4 weeks of the smoking cessation attempt. The results showed that high adversity was associated with higher distress and smoking withdrawal symptoms. High level of early life adversity was associated with elevated HPA activity, which was found in both salivary and plasma cortisol. Enhanced adrenocorticotropic hormone (ACTH) stress response was evident in high-adversity but not in low-adversity relapsers. This study demonstrated that early life adversity is associated with stress-related HPA responses. The study also demonstrated that, among smokers who experienced a high level of life adversity, heightened ACTH and cortisol responses were linked with increased risk for smoking relapse.

Response to stress in Drosophila is mediated by gender, age and stress paradigm.

Science.gov (United States)

Neckameyer, Wendi S; Nieto-Romero, Andres R

2015-01-01

All living organisms must maintain equilibrium in response to internal and external challenges within their environment. Changes in neural plasticity (alterations in neuronal populations, dendritic remodeling, and synaptic turnover) are critical components of the homeostatic response to stress, which has been strongly implicated in the onset of affective disorders. However, stress is differentially perceived depending on the type of stress and its context, as well as genetic background, age and sex; therefore, an individual's maintenance of neuronal homeostasis must differ depending upon these variables. We established Drosophila as a model to analyze homeostatic responses to stress. Sexually immature and mature females and males from an isogenic wild-type strain raised under controlled environmental conditions were exposed to four reproducible and high-throughput translatable stressors to facilitate the analysis of a large number of animals for direct comparisons. These animals were assessed in an open-field arena, in a light-dark box, and in a forced swim test, as well as for sensitivity to the sedative effects of ethanol. These studies establish that immature and mature females and males represent behaviorally distinct populations under control conditions as well as after exposure to different stressors. Therefore, the neural substrates mediating the stress response must be differentially expressed depending upon the hormonal status of the brain. In addition, an adaptive response to a given stressor in one paradigm was not predictive for outcomes in other paradigms.

Callous-unemotional traits and early life stress predict treatment effects on stress and sex hormone functioning in incarcerated male adolescents.

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Johnson, Megan; Vitacco, Michael J; Shirtcliff, Elizabeth A

2018-03-01

The stress response system is highly plastic, and hormone rhythms may "adaptively calibrate" in response to treatment. This investigation assessed whether stress and sex hormone diurnal rhythms changed over the course of behavioral treatment, and whether callous-unemotional (CU) traits and history of early adversity affected treatment results on diurnal hormone functioning in a sample of 28 incarcerated adolescent males. It was hypothesized that the treatment would have beneficial effects, such that healthier diurnal rhythms would emerge post-treatment. Diurnal cortisol, testosterone, and dehydroepiandrosterone (DHEA) were sampled two weeks after admission to the correctional/treatment facility, and again approximately four months later. Positive treatment effects were detected for the whole sample, such that testosterone dampened across treatment. CU traits predicted a non-optimal hormone response to treatment, potentially indicating biological preparedness to respond to acts of social dominance and aggression. The interaction between CU traits and adversity predicted a promising and sensitized response to treatment including increased cortisol and a steeper testosterone drop across treatment. Results suggest that stress and sex hormones are highly receptive to treatment during this window of development.

When does stress help or harm? The effects of stress controllability and subjective stress response on Stroop performance.

Directory of Open Access Journals (Sweden)

Roselinde Kaiser Henderson

2012-06-01

Full Text Available The ability to engage in goal-directed behavior despite exposure to stress is critical to resilience. Questions of how stress can impair or improve behavioral functioning are important in diverse settings, from athletic competitions to academic testing to clinical therapy. Previous research suggests that controllability is a key factor in the impact of stress on behavior: learning how to control stressors buffers people from the negative effects of stress on subsequent cognitively demanding tasks. In addition, research suggests that the impact of stress on cognitive functioning depends on an individual’s response to stressors: moderate responses to stress can lead to improved performance while extreme (high or low responses can lead to impaired performance. The present studies tested the hypothesis that 1 learning to behaviorally control stressors leads to improved performance on a test of general executive functioning, the color-word Stroop, and that 2 this improvement emerges specifically for people who report moderate (subjective responses to stress. Experiment 1: Stroop performance, measured before and after a stress manipulation, was compared across groups of undergraduate participants (n=109. People who learned to control a noise stressor and received accurate performance feedback demonstrated reduced Stroop interference compared with people exposed to uncontrollable noise stress and feedback indicating an exaggerated rate of failure. In the group who learned behavioral control, those who reported moderate levels of stress showed the greatest reduction in Stroop interference. In contrast, in the group exposed to uncontrollable events, self-reported stress failed to predict performance. Experiment 2: In a second sample (n=90, we specifically investigated the role of controllability by keeping the rate of failure feedback constant across groups. In the group who learned behavioral control, those who reported moderate levels of stress

Predicting post-traumatic stress disorder treatment response in refugees : Multilevel analysis

NARCIS (Netherlands)

Haagen, Joris F G; Ter Heide, F Jackie June; Mooren, Trudy M; Knipscheer, Jeroen W; Kleber, Rolf J

2017-01-01

OBJECTIVES: Given the recent peak in refugee numbers and refugees' high odds of developing post-traumatic stress disorder (PTSD), finding ways to alleviate PTSD in refugees is of vital importance. However, there are major differences in PTSD treatment response between refugees, the determinants of

Blood pressure reactivity to psychological stress predicts hypertension in the CARDIA study.

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Matthews, Karen A; Katholi, Charles R; McCreath, Heather; Whooley, Mary A; Williams, David R; Zhu, Sha; Markovitz, Jerry H

2004-07-06

A longstanding but controversial hypothesis is that individuals who exhibit frequent, large increases in blood pressure (BP) during psychological stress are at risk for developing essential hypertension. We tested whether BP changes during psychological stress predict incident hypertension in young adults. We used survival analysis to predict hypertensive status during 13 years of follow-up in a sample of >4100 normotensive black and white men and women (age at entry, 18 to 30 years) enrolled in the CARDIA study. BP responses to 3 psychological challenges--cold pressor, star tracing, and video game tasks--were measured. Hypertensive status was defined as use of antihypertensive medication or measured BP > or =140/90 mm Hg. After adjustment for race, gender, covariates (education, body mass index, age, and resting pressure), and their significant interactions, the larger the BP responses were to each of the 3 tasks, the earlier hypertension occurred (Pvideo game was apparent for men. Young adults who show a large BP response to psychological stress may be at risk for hypertension as they approach midlife.

Stress Responses in Staphylococcus aureus

DEFF Research Database (Denmark)

Frees, Dorte; Ingmer, Hanne

2016-01-01

stress responses allowing it to sense and adapt to its very different niches. The stress responses often involve dramatic cellular reprogramming, and the technological advances provided by the access to whole genome sequences have let to an unprecedented insight into the global reorganization of gene...... and protein expression following stress-exposure. Characterization of global gene responses has been very helpful both in identifying regulators sensing specific environmental stress signals and overlaps between different stress responses. In this chapter we review the recent progress in our understanding...... of the specific and general S. aureusstress responses, with a special emphasis on how stress responses contribute to virulence and antibiotic resistance in this important human pathogen....

Differential reproductive responses to stress reveal the role of life-history strategies within a species.

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Schultner, J; Kitaysky, A S; Gabrielsen, G W; Hatch, S A; Bech, C

2013-11-22

Life-history strategies describe that 'slow'- in contrast to 'fast'-living species allocate resources cautiously towards reproduction to enhance survival. Recent evidence suggests that variation in strategies exists not only among species but also among populations of the same species. Here, we examined the effect of experimentally induced stress on resource allocation of breeding seabirds in two populations with contrasting life-history strategies: slow-living Pacific and fast-living Atlantic black-legged kittiwakes. We tested the hypothesis that reproductive responses in kittiwakes under stress reflect their life-history strategies. We predicted that in response to stress, Pacific kittiwakes reduce investment in reproduction compared with Atlantic kittiwakes. We exposed chick-rearing kittiwakes to a short-term (3-day) period of increased exogenous corticosterone (CORT), a hormone that is released during food shortages. We examined changes in baseline CORT levels, parental care and effects on offspring. We found that kittiwakes from the two populations invested differently in offspring when facing stress. In response to elevated CORT, Pacific kittiwakes reduced nest attendance and deserted offspring more readily than Atlantic kittiwakes. We observed lower chick growth, a higher stress response in offspring and lower reproductive success in response to CORT implantation in Pacific kittiwakes, whereas the opposite occurred in the Atlantic. Our findings support the hypothesis that life-history strategies predict short-term responses of individuals to stress within a species. We conclude that behaviour and physiology under stress are consistent with trade-off priorities as predicted by life-history theory. We encourage future studies to consider the pivotal role of life-history strategies when interpreting inter-population differences of animal responses to stressful environmental events.

Social stress response in adolescents with bipolar disorder.

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Casement, Melynda D; Goldstein, Tina R; Gratzmiller, Sarah M; Franzen, Peter L

2018-05-01

Theoretical models posit that stressors contribute to the onset and maintenance of bipolar disorder in adolescence through disruptions in stress physiology, but physiological response to stressors has not been evaluated in adolescents with bipolar illness. The present study tests the hypothesis that adolescents with bipolar disorder will have greater reactivity to a laboratory social stress task than healthy adolescents. Adolescents with bipolar illness (n = 27) and healthy adolescents (n = 28) completed a modified version of the Trier Social Stress Task. Stress response was assessed using high frequency heart rate variability (HF-HRV), heart rate (HR), mean arterial blood pressure (MAP), salivary cortisol, and subjective stress. Multilevel models were used to test for group differences in resting-state physiology, and stress reactivity and recovery. Adolescents with bipolar disorder had greater reactivity in HF-HRV (z = 3.32), but blunted reactivity in MAP (z = -3.08) and cortisol (z = -2.60), during the stressor compared to healthy adolescents. They also had lower resting HF-HRV (z = -3.49) and cortisol (z = -2.86), and higher resting HR (z = 3.56), than healthy adolescents. These results indicate that bipolar disorder is associated with disruptions in autonomic and endocrine response to stress during adolescence, including greater HF-HRV reactivity. Further research should evaluate whether these individual differences in stress physiology precede and predict the onset of mood episodes. Copyright © 2018 Elsevier Ltd. All rights reserved.

Virtual Institute of Microbial Stress and Survival: Deduction of Stress Response Pathways in Metal and Radionuclide Reducing Microorganisms

Energy Technology Data Exchange (ETDEWEB)

None

2004-04-17

The projects application goals are to: (1) To understand bacterial stress-response to the unique stressors in metal/radionuclide contamination sites; (2) To turn this understanding into a quantitative, data-driven model for exploring policies for natural and biostimulatory bioremediation; (3) To implement proposed policies in the field and compare results to model predictions; and (4) Close the experimental/computation cycle by using discrepancies between models and predictions to drive new measurements and construction of new models. The projects science goals are to: (1) Compare physiological and molecular response of three target microorganisms to environmental perturbation; (2) Deduce the underlying regulatory pathways that control these responses through analysis of phenotype, functional genomic, and molecular interaction data; (3) Use differences in the cellular responses among the target organisms to understand niche specific adaptations of the stress and metal reduction pathways; (4) From this analysis derive an understanding of the mechanisms of pathway evolution in the environment; and (5) Ultimately, derive dynamical models for the control of these pathways to predict how natural stimulation can optimize growth and metal reduction efficiency at field sites.

Thermal Stress Limit Rafting Migration of Seahorses: Prediction Based on Physiological and Behavioral Responses to Thermal Stress

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Qin, G.; Li, C.; Lin, Q.

2017-12-01

Marine fish species escape from harmful environment by migration. Seahorses, with upright posture and low mobility, could migrate from unfavorable environment by rafting with their prehensile tail. The present study was designed to examine the tolerance of lined seahorse Hippocampus erectus to thermal stress and evaluate the effects of temperature on seahorse migration. The results figured that seahorses' tolerance to thermal stress was time dependent. Acute thermal stress (30°C) increased breathing rate and HSP genes expression significantly, but didn't affect seahorse feeding behavior. Chronic thermal treatment lead to persistent high expression of HSP genes, higher breathing rate, and decreasing feeding, and final higher mortality, suggesting that seahorse cannot adapt to thermal stress by acclimation. No significant negative effects were found in seahorse reproduction in response to chronic thermal stress. Given that seahorses make much slower migration by rafting on sea surface compared to other fishes, we suggest that thermal stress might limit seahorse migration range. and the influence might be magnified by global warming in future.

Occupational imbalance and the role of perceived stress in predicting stress-related disorders.

Science.gov (United States)

Håkansson, Carita; Ahlborg, Gunnar

2017-03-02

Stress-related disorders are the main reason for sick leave in many European countries. The aim of the present study was to explore whether perceived occupational imbalance predicts stress-related disorders, potential gender differences, and to explore the mediating role of perceived stress. Longitudinal data on 2223 employees in a public organization in Sweden were collected by surveys, and analyzed by logistic regression. Occupational imbalance predicted stress-related disorders among both women and men. However, what aspects of occupational imbalance which predicted stress-related disorders differ by gender. Perceived stress was not a mediator in these associations. How women and men perceived their occupational balance affected the risk of stress-related disorders. The results may be used to develop effective strategies to decrease stress-related disorders.

Prediction of heat-illness symptoms with the prediction of human vascular response in hot environment under resting condition.

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Aggarwal, Yogender; Karan, Bhuwan Mohan; Das, Barsa Nand; Sinha, Rakesh Kumar

2008-04-01

The thermoregulatory control of human skin blood flow is vital to maintain the body heat storage during challenges of thermal homeostasis under heat stress. Whenever thermal homeostasis disturbed, the heat load exceeds heat dissipation capacity, which alters the cutaneous vascular responses along with other body physiological variables. Whole body skin blood flow has been calculated from the forearm blood flow. Present model has been designed using electronics circuit simulator (Multisim 8.0, National Instruments, USA), is to execute a series of predictive equations for early prediction of physiological parameters of young nude subjects during resting condition at various level of dry heat stress under almost still air to avoid causalities associated with hot environmental. The users can execute the model by changing the environmental temperature in degrees C and exposure time in minutes. The model would be able to predict and detect the changes in human vascular responses along with other physiological parameters and from this predicted values heat related-illness symptoms can be inferred.

Plant Nucleolar Stress Response, a New Face in the NAC-Dependent Cellular Stress Responses

Directory of Open Access Journals (Sweden)

Iwai Ohbayashi

2018-01-01

Full Text Available The nucleolus is the most prominent nuclear domain, where the core processes of ribosome biogenesis occur vigorously. All these processes are finely orchestrated by many nucleolar factors to build precisely ribosome particles. In animal cells, perturbations of ribosome biogenesis, mostly accompanied by structural disorders of the nucleolus, cause a kind of cellular stress to induce cell cycle arrest, senescence, or apoptosis, which is called nucleolar stress response. The best-characterized pathway of this stress response involves p53 and MDM2 as key players. p53 is a crucial transcription factor that functions in response to not only nucleolar stress but also other cellular stresses such as DNA damage stress. These cellular stresses release p53 from the inhibition by MDM2, an E3 ubiquitin ligase targeting p53, in various ways, which leads to p53-dependent activation of a set of genes. In plants, genetic impairments of ribosome biogenesis factors or ribosome components have been shown to cause characteristic phenotypes, including a narrow and pointed leaf shape, implying a common signaling pathway connecting ribosomal perturbations and certain aspects of growth and development. Unlike animals, however, plants have neither p53 nor MDM2 family proteins. Then the question arises whether plant cells have a nucleolar stress response pathway. In recent years, it has been reported that several members of the plant-specific transcription factor family NAC play critical roles in the pathways responsive to various cellular stresses. In this mini review, we outline the plant cellular stress response pathways involving NAC transcription factors with reference to the p53-MDM2-dependent pathways of animal cells, and discuss the possible involvement of a plant-unique, NAC-mediated pathway in the nucleolar stress response in plants.

Plant Nucleolar Stress Response, a New Face in the NAC-Dependent Cellular Stress Responses.

Science.gov (United States)

Ohbayashi, Iwai; Sugiyama, Munetaka

2017-01-01

The nucleolus is the most prominent nuclear domain, where the core processes of ribosome biogenesis occur vigorously. All these processes are finely orchestrated by many nucleolar factors to build precisely ribosome particles. In animal cells, perturbations of ribosome biogenesis, mostly accompanied by structural disorders of the nucleolus, cause a kind of cellular stress to induce cell cycle arrest, senescence, or apoptosis, which is called nucleolar stress response. The best-characterized pathway of this stress response involves p53 and MDM2 as key players. p53 is a crucial transcription factor that functions in response to not only nucleolar stress but also other cellular stresses such as DNA damage stress. These cellular stresses release p53 from the inhibition by MDM2, an E3 ubiquitin ligase targeting p53, in various ways, which leads to p53-dependent activation of a set of genes. In plants, genetic impairments of ribosome biogenesis factors or ribosome components have been shown to cause characteristic phenotypes, including a narrow and pointed leaf shape, implying a common signaling pathway connecting ribosomal perturbations and certain aspects of growth and development. Unlike animals, however, plants have neither p53 nor MDM2 family proteins. Then the question arises whether plant cells have a nucleolar stress response pathway. In recent years, it has been reported that several members of the plant-specific transcription factor family NAC play critical roles in the pathways responsive to various cellular stresses. In this mini review, we outline the plant cellular stress response pathways involving NAC transcription factors with reference to the p53-MDM2-dependent pathways of animal cells, and discuss the possible involvement of a plant-unique, NAC-mediated pathway in the nucleolar stress response in plants.

The role of dehydroepiandrosterone on functional innate immune responses to acute stress.

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Prall, Sean P; Larson, Emilee E; Muehlenbein, Michael P

2017-12-01

The androgen dehydroepiandrosterone (DHEA) responds to stress activation, exhibits anti-glucocorticoid properties, and modulates immunity in diverse ways, yet little is known of its role in acute stress responses. In this study, the effects of DHEA and its sulfate ester DHEA-S on human male immune function during exposure to an acute stressor is explored. Variation in DHEA, DHEA-S, testosterone, and cortisol, along with bacterial killing assays, was measured in response to a modified Trier Social Stress test in 27 young adult males. Cortisol was positively related to salivary innate immunity but only for participants who also exhibited high DHEA responses. Additionally, DHEA positively and DHEA-S negatively predicted salivary immunity, but the opposite was observed for serum-based innate immunity. The DHEA response to acute stress appears to be an important factor in stress-mediated immunological responses, with differential effects on immunity dependent upon the presence of other hormones, primarily cortisol and DHEA-S. These results suggest that DHEA plays an important role, alongside other hormones, in modulating immunological shifts during acute stress. Copyright © 2017 John Wiley & Sons, Ltd.

Genetic modulation of plasma NPY stress response is suppressed in substance abuse: association with clinical outcomes.

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Xu, Ke; Hong, Kwangik Adam; Zhou, Zhifeng; Hauger, Richard L; Goldman, David; Sinha, Rajita

2012-04-01

Neuropeptide Y (NPY) is involved in stress regulation. Genetic variations predict plasma NPY and neural correlates of emotion and stress. We examined whether the functional NPY haplotype modulates stress-induced NPY and anxiety responses, and if plasma NPY stress responses are associated with substance dependence outcomes. Thirty-seven treatment-engaged, abstinent substance dependent (SD) patients and 28 healthy controls (HCs) characterized on NPY diplotypes (HH: high expression; HLLL: intermediate/low expression) were exposed to stress, alcohol/drug cues and neutral relaxing cues, using individualized guided imagery, in a 3-session laboratory experiment. Plasma NPY, heart rate and anxiety were assessed. Patients were prospectively followed for 90-days post-treatment to assess relapse outcomes. HH individuals showed significantly lower stress-induced NPY with greater heart rate and anxiety ratings, while the HLLL group showed the reverse pattern of NPY, anxiety and heart rate responses. This differential genetic modulation of NPY stress response was suppressed in the SD group, who showed no stress-related increases in NPY and higher heart rate and greater anxiety, regardless of diplotype. Lower NPY predicted subsequent higher number of days and greater amounts of post-treatment drug use. These preliminary findings are the first to document chronic drug abuse influences on NPY diplotype expression where NPY diplotype modulation of stress-related plasma NPY, heart rate and anxiety responses was absent in the substance abuse sample. The finding that lower stress-related NPY is predictive of greater relapse severity provides support for therapeutic development of neuropeptide Y targets in the treatment of substance use disorders. Copyright © 2011 Elsevier Ltd. All rights reserved.

Age differences in emotional responses to daily stress: the role of timing, severity, and global perceived stress.

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Scott, Stacey B; Sliwinski, Martin J; Blanchard-Fields, Fredda

2013-12-01

Research on age differences in emotional responses to daily stress has produced inconsistent findings. Guided by recent theoretical advances in aging theory (S. T. Charles, 2010, Strength and vulnerability integration: A model of emotional well-being across adulthood, Psychological Bulletin, Vol. 136, pp. 1068-1091) that emphasize the importance of context for predicting when and how age is related to affective well-being, the current study examined age differences in emotional responses to everyday stressors. The present study examined how three contextual features (e.g., timing of exposure, stressor severity, global perceived stress [GPS]) moderate age differences in emotional experience in an ecological momentary assessment study of adults (N = 190) aged 18-81 years. Results indicated that older adults' negative affect (NA) was less affected by exposure to recent stressors than younger adults, but that there were no age differences in the effects of stressor exposure 3-6 hr afterward. Higher levels of GPS predicted amplified NA responses to daily stress, and controlling for GPS eliminated age differences in NA responses to stressors. No age differences in NA responses as a function of stressor severity were observed. In contrast, older age was associated with less of a decrease in PA when exposed to recent stressors or with more severe recent stressors. There were no age differences in the effect of previous stressor exposure or severity on PA, or any interactions between momentary or previous stress and GPS on PA. Together, these results support the notion that chronic stress plays a central role in emotional experience in daily life. We discuss the implications of these results for emotion theories of aging. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Bruxism affects stress responses in stressed rats.

Science.gov (United States)

Sato, Chikatoshi; Sato, Sadao; Takashina, Hirofumi; Ishii, Hidenori; Onozuka, Minoru; Sasaguri, Kenichi

2010-04-01

It has been proposed that suppression of stress-related emotional responses leads to the simultaneous activation of both sympathetic and parasympathetic divisions of the autonomic nervous system (ANS) and that the expression of these emotional states has a protective effect against ulcerogenesis. In the present study, we investigated whether stress-induced bruxism activity (SBA) has a physiological effect of on the stress-induced changes of the stomach, thymus, and spleen as well as blood leukocytes, cortisol, and adrenaline. This study demonstrated that SBA attenuated the stress-induced ulcer genesis as well as degenerative changes of thymus and spleen. SBA also attenuated increases of adrenaline, cortisol, and neutrophils in the blood. In conclusion, expression of aggression through SBA during stress exposure attenuates both stress-induced ANS response, including gastric ulcer formation.

A marker of biological age explains individual variation in the strength of the adult stress response.

Science.gov (United States)

Andrews, Clare; Nettle, Daniel; Larriva, Maria; Gillespie, Robert; Reichert, Sophie; Brilot, Ben O; Bedford, Thomas; Monaghan, Pat; Spencer, Karen A; Bateson, Melissa

2017-09-01

The acute stress response functions to prioritize behavioural and physiological processes that maximize survival in the face of immediate threat. There is variation between individuals in the strength of the adult stress response that is of interest in both evolutionary biology and medicine. Age is an established source of this variation-stress responsiveness diminishes with increasing age in a range of species-but unexplained variation remains. Since individuals of the same chronological age may differ markedly in their pace of biological ageing, we asked whether biological age-measured here via erythrocyte telomere length-predicts variation in stress responsiveness in adult animals of the same chronological age. We studied two cohorts of European starlings in which we had previously manipulated the rate of biological ageing by experimentally altering the competition experienced by chicks in the fortnight following hatching. We predicted that individuals with greater developmental telomere attrition, and hence greater biological age, would show an attenuated corticosterone (CORT) response to an acute stressor when tested as adults. In both cohorts, we found that birds with greater developmental telomere attrition had lower peak CORT levels and a more negative change in CORT levels between 15 and 30 min following stress exposure. Our results, therefore, provide strong evidence that a measure of biological age explains individual variation in stress responsiveness: birds that were biologically older were less stress responsive. Our results provide a novel explanation for the phenomenon of developmental programming of the stress response: observed changes in stress physiology as a result of exposure to early-life adversity may reflect changes in ageing.

Predicting stress in pre-registration nursing students.

Science.gov (United States)

Pryjmachuk, Steven; Richards, David A

2007-02-01

To determine which variables from a pool of potential predictors predict General Health Questionnaire 'caseness' in pre-registration nursing students. Cross-sectional survey, utilizing self-report measures of sources of stress, stress (psychological distress) and coping, together with pertinent demographic measures such as sex, ethnicity, educational programme and nursing specialty being pursued, and age, social class and highest qualifications on entry to the programme. Questionnaire packs were distributed to all pre-registration nursing students (N=1,362) in a large English university. Completed packs were coded, entered into statistical software and subjected to a series of logistic regression analyses. Of the questionnaire packs 1,005 (74%) were returned, of which up to 973 were available for the regression analyses undertaken. Four logistic regression models were considered and, on the principle of parsimony, a single model was chosen for discussion. This model suggested that the key predictors of caseness in the population studied were self-report of pressure, whether or not respondents had children (specifically, whether these children were pre-school or school-age), scores on a 'personal problems' scale and the type of coping employed. The overall caseness rate among the population was around one-third. Since self-report and personal, rather than academic, concerns predict stress, personal teachers need to play a key role in supporting students through 'active listening', especially when students self-report high levels of stress and where personal/social problems are evident. The work-life balance of students, especially those with child-care responsibilities, should be a central tenet in curriculum design in nurse education (and, indeed, the education of other professional and occupational groups). There may be some benefit in offering stress management (coping skills) training to nursing students and, indeed, students of other disciplines.

Ground Motion Prediction Equations Empowered by Stress Drop Measurement

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Miyake, H.; Oth, A.

2015-12-01

Significant variation of stress drop is a crucial issue for ground motion prediction equations and probabilistic seismic hazard assessment, since only a few ground motion prediction equations take into account stress drop. In addition to average and sigma studies of stress drop and ground motion prediction equations (e.g., Cotton et al., 2013; Baltay and Hanks, 2014), we explore 1-to-1 relationship for each earthquake between stress drop and between-event residual of a ground motion prediction equation. We used the stress drop dataset of Oth (2013) for Japanese crustal earthquakes ranging 0.1 to 100 MPa and K-NET/KiK-net ground motion dataset against for several ground motion prediction equations with volcanic front treatment. Between-event residuals for ground accelerations and velocities are generally coincident with stress drop, as investigated by seismic intensity measures of Oth et al. (2015). Moreover, we found faster attenuation of ground acceleration and velocities for large stress drop events for the similar fault distance range and focal depth. It may suggest an alternative parameterization of stress drop to control attenuation distance rate for ground motion prediction equations. We also investigate 1-to-1 relationship and sigma for regional/national-scale stress drop variation and current national-scale ground motion equations.

Behavioral phenotype relates to physiological differences in immunological and stress responsiveness in reactive and proactive birds.

Science.gov (United States)

Pusch, Elizabeth A; Navara, Kristen J

2018-05-15

It has now been demonstrated in many species that individuals display substantial variation in coping styles, generally separating into two major behavioral phenotypes that appear to be linked to the degree of physiological stress responsiveness. Laying hens are perfect examples of these dichotomous phenotypes; white laying hens are reactive, flighty, and exhibit large hormonal and behavioral responses to both acute and chronic stress, while brown laying hens are proactive, exploratory, and exhibit low hormonal and behavioral responses to stress. Given the linkages between stress physiology and many other body systems, we hypothesized that behavioral phenotype would correspond to additional physiological responses beyond the stress response, in this case, immunological responses. Because corticosterone is widely known to be immunosuppressive, we predicted that the reactive white hens would show more dampened immune responses than the proactive brown hens due to their exposure to higher levels of corticosterone throughout life. To assess immune function in white and brown hens, we compared febrile responses, corticosterone elevations, feed consumption, and egg production that occurred in response an injection of lipopolysaccharide (LPS) or saline, inflammatory responses to phytohemagglutinin (PHA) injection in the toe web, innate phagocytic activity in whole blood, and antibody responses to an injection of Sheep Red Blood Cells (SRBCs). Contrary to our predictions, white hens had significantly greater swelling of the toe web in response to PHA and showed a greater inhibition of feeding and reproductive output in response to LPS. These results indicated that reactive individuals are more reactive in both stress and immunological responsiveness. Copyright © 2018 Elsevier Inc. All rights reserved.

Compound risk: History of traumatic stress predicts posttraumatic stress disorder symptoms and severity in sudden cardiac arrest survivors.

Science.gov (United States)

Rosman, Lindsey; Ford, Jessica; Whited, Amanda; Cahill, John; Lampert, Rachel; Mosesso, Vincent N; Lawless, Christine; Sears, Samuel F

2016-08-01

Sudden cardiac arrest (SCA) survivors can develop posttraumatic stress disorder (PTSD) which is associated with worse clinical outcomes. The purpose of this study was to evaluate the prevalence and predictors of PTSD in a large sample of SCA survivors. Prior history of psychological trauma and the effects of repeated trauma exposure on subsequent PTSD and symptom severity after SCA were also explored. A retrospective, cross-sectional study of 188 SCA survivors from the Sudden Cardiac Arrest Association patient registry completed an online questionnaire that included measures of PTSD, trauma history, sociodemographics, general health, and cardiac history. Sixty-three (36.2%) SCA survivors in this sample scored above the clinical cutoff for PTSD. Female gender, worse general health, and younger age predicted PTSD symptoms after SCA. Additionally, 50.2% of SCA survivors (n = 95) reported a history of trauma exposure and 25.4% (n = 48) of the total sample endorsed a traumatic stress response to a historic trauma. Results indicated that a traumatic stress response to a historic trauma was a stronger predictor of PTSD after SCA (odds ratio = 4.77) than all other variables in the model. PTSD symptoms are present in over one-third of SCA survivors. While demographic or health history variables predicted PTSD after SCA, a history of traumatic stress response to a previous trauma emerged as the strongest predictor of these symptoms. Routine assessment and interdisciplinary management are discussed as potential ways to expedite survivors' recovery and return to daily living. © The European Society of Cardiology 2015.

Neural responses to threat and reward interact to predict stress-related problem drinking: A novel protective role of the amygdala

Science.gov (United States)

2012-01-01

Background Research into neural mechanisms of drug abuse risk has focused on the role of dysfunction in neural circuits for reward. In contrast, few studies have examined the role of dysfunction in neural circuits of threat in mediating drug abuse risk. Although typically regarded as a risk factor for mood and anxiety disorders, threat-related amygdala reactivity may serve as a protective factor against substance use disorders, particularly in individuals with exaggerated responsiveness to reward. Findings We used well-established neuroimaging paradigms to probe threat-related amygdala and reward-related ventral striatum reactivity in a sample of 200 young adult students from the ongoing Duke Neurogenetics Study. Recent life stress and problem drinking were assessed using self-report. We found a significant three-way interaction between threat-related amygdala reactivity, reward-related ventral striatum reactivity, and recent stress, wherein individuals with higher reward-related ventral striatum reactivity exhibit higher levels of problem drinking in the context of stress, but only if they also have lower threat-related amygdala reactivity. This three-way interaction predicted both contemporaneous problem drinking and problem drinking reported three-months later in a subset of participants. Conclusions These findings suggest complex interactions between stress and neural responsiveness to both threat and reward mediate problem drinking. Furthermore, they highlight a novel protective role for threat-related amygdala reactivity against drug use in individuals with high neural reactivity to reward. PMID:23151390

Cortisol Stress Response Variability in Early Adolescence Attachment, Affect and Sex

Science.gov (United States)

Cameron, Catherine Ann; McKay, Stacey; Susman, Elizabeth J.; Wynne-Edwards, Katherine; Wright, Joan M.; Weinberg, Joanne

2017-01-01

Attachment, affect, and sex shape responsivity to psychosocial stress. Concurrent social contexts influence cortisol secretion, a stress hormone and biological marker of hypothalamic–pituitary–adrenal axis activity. Patterns of attachment, emotion status, and sex were hypothesized to relate to bifurcated, that is, accentuated and attenuated, cortisol reactivity. The theoretical framework for this study posits that multiple individual differences mediate a cortisol stress response. The effects of two psychosocial stress interventions, a modified Trier Social Stress Test for Teens and the Frustration Social Stressor for Adolescents were developed and investigated with early adolescents. Both of these protocols induced a significant stress reaction and evoked predicted bifurcation in cortisol responses; an increase or decrease from baseline to reactivity. In Study I, 120 predominantly middle-class, Euro-Canadian early adolescents with a mean age of 13.43 years were studied. The girls' attenuated cortisol reactivity to the public performance stressor related significantly to their self-reported lower maternal-attachment and higher trait-anger. In Study II, a community sample of 146 predominantly Euro-Canadian middle-class youth, with an average age of 14.5 years participated. Their self-reports of higher trait-anger and trait-anxiety, and lower parental attachment by both sexes related differentially to accentuated and attenuated cortisol reactivity to the frustration stressor. Thus, attachment, affect, sex, and the stressor contextual factors were associated with the adrenal-cortical responses of these adolescents through complex interactions. Further studies of individual differences in physiological responses to stress are called for in order to clarify the identities of concurrent protective and risk factors in the psychosocial stress and physiological stress responses of early adolescents. PMID:27468997

Cortisol Stress Response Variability in Early Adolescence: Attachment, Affect and Sex.

Science.gov (United States)

Cameron, Catherine Ann; McKay, Stacey; Susman, Elizabeth J; Wynne-Edwards, Katherine; Wright, Joan M; Weinberg, Joanne

2017-01-01

Attachment, affect, and sex shape responsivity to psychosocial stress. Concurrent social contexts influence cortisol secretion, a stress hormone and biological marker of hypothalamic-pituitary-adrenal axis activity. Patterns of attachment, emotion status, and sex were hypothesized to relate to bifurcated, that is, accentuated and attenuated, cortisol reactivity. The theoretical framework for this study posits that multiple individual differences mediate a cortisol stress response. The effects of two psychosocial stress interventions, a modified Trier Social Stress Test for Teens and the Frustration Social Stressor for Adolescents were developed and investigated with early adolescents. Both of these protocols induced a significant stress reaction and evoked predicted bifurcation in cortisol responses; an increase or decrease from baseline to reactivity. In Study I, 120 predominantly middle-class, Euro-Canadian early adolescents with a mean age of 13.43 years were studied. The girls' attenuated cortisol reactivity to the public performance stressor related significantly to their self-reported lower maternal-attachment and higher trait-anger. In Study II, a community sample of 146 predominantly Euro-Canadian middle-class youth, with an average age of 14.5 years participated. Their self-reports of higher trait-anger and trait-anxiety, and lower parental attachment by both sexes related differentially to accentuated and attenuated cortisol reactivity to the frustration stressor. Thus, attachment, affect, sex, and the stressor contextual factors were associated with the adrenal-cortical responses of these adolescents through complex interactions. Further studies of individual differences in physiological responses to stress are called for in order to clarify the identities of concurrent protective and risk factors in the psychosocial stress and physiological stress responses of early adolescents.

ZmbZIP60 mRNA is spliced in maize in response to ER stress

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Li Yanjie

2012-03-01

Full Text Available Abstract Background Adverse environmental conditions produce ER stress and elicit the unfolded protein response (UPR in plants. Plants are reported to have two "arms" of the ER stress signaling pathway-one arm involving membrane-bound transcription factors and the other involving a membrane-associated RNA splicing factor, IRE1. IRE1 in yeast to mammals recognizes a conserved twin loop structure in the target RNA. Results A segment of the mRNA encoding ZmbZIP60 in maize can be folded into a twin loop structure, and in response to ER stress this mRNA is spliced, excising a 20b intron. Splicing converts the predicted protein from a membrane-associated transcription factor to one that is targeted to the nucleus. Splicing of ZmbZIP60 can be elicited in maize seedlings by ER stress agents such as dithiothreitol (DTT or tunicamycin (TM or by heat treatment. Younger, rather than older seedlings display a more robust splicing response as do younger parts of leaf, along a developmental gradient in a leaf. The molecular signature of an ER stress response in plants includes the upregulation of Binding Protein (BIP genes. Maize has numerous BIP-like genes, and ER stress was found to upregulate one of these, ZmBIPb. Conclusions The splicing of ZmbZIP60 mRNA is an indicator of ER stress in maize seedlings resulting from adverse environmental conditions such as heat stress. ZmbZIP60 mRNA splicing in maize leads predictively to the formation of active bZIP transcription factor targeted to the nucleus to upregulate stress response genes. Among the genes upregulated by ER stress in maize is one of 22 BIP-like genes, ZmBIPb.

Stress-specific response of the p53-Mdm2 feedback loop

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Jensen Mogens H

2010-07-01

Full Text Available Abstract Background The p53 signalling pathway has hundreds of inputs and outputs. It can trigger cellular senescence, cell-cycle arrest and apoptosis in response to diverse stress conditions, including DNA damage, hypoxia and nutrient deprivation. Signals from all these inputs are channeled through a single node, the transcription factor p53. Yet, the pathway is flexible enough to produce different downstream gene expression patterns in response to different stresses. Results We construct a mathematical model of the negative feedback loop involving p53 and its inhibitor, Mdm2, at the core of this pathway, and use it to examine the effect of different stresses that trigger p53. In response to DNA damage, hypoxia, etc., the model exhibits a wide variety of specific output behaviour - steady states with low or high levels of p53 and Mdm2, as well as spiky oscillations with low or high average p53 levels. Conclusions We show that even a simple negative feedback loop is capable of exhibiting the kind of flexible stress-specific response observed in the p53 system. Further, our model provides a framework for predicting the differences in p53 response to different stresses and single nucleotide polymorphisms.

Contingent self-worth moderates the relationship between school stressors and psychological stress responses.

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Ishizu, Kenichiro

2017-04-01

This study examined the moderating role of contingent self-worth on the relationships between school stressors and psychological stress responses among Japanese adolescents. A total of 371 Japanese junior high school students (184 boys and 187 girls, M age  = 12.79 years, SD = 0.71) completed the Japanese version of the Self-Worth Contingency Questionnaire and a mental health checklist at two points separated by a two-month interval. Hierarchical multiple regression analyses were then used to determine whether contingent self-worth moderated the relationship between school stressors and psychological stress responses. The results indicated that, when psychological stress responses were controlled for at Time 1, contingent self-worth did not predict the psychological stress responses at Time 2. However, a two-way interaction between contingent self-worth and stressors was found to significantly influence psychological stress responses, thus indicating that stressors had a stronger impact on psychological stress responses among those with high contingent self-worth compared to those with low contingent self-worth. Copyright © 2017 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Stress corrosion cracking lifetime prediction of spring screw

International Nuclear Information System (INIS)

Koh, S. K.; Ryu, C. H.

2004-01-01

A lifetime prediction of holddown spring screw in nuclear fuel assembly was performed using fracture mechanics approach. The spring screw was designed such that it was capable of sustaining the loads imposed by the initial tensile preload and operational loads. In order to investigate the cause of failure and to predict the stress corrosion cracking life of the screw, a stress analysis of the top nozzle spring assembly was done using finite element analysis. The elastic-plastic finite element analysis showed that the local stresses at the critical regions of head-shank fillet and thread root significantly exceeded than the yield strength of the screw material, resulting in local plastic deformation. Normalized stress intensity factors for PWSCC life prediction was proposed. Primary water stress corrosion cracking life of the Inconel 600 screw was predicted by using integration of the Scott model and resulted in 1.78 years, which was fairly close to the actual service life of the holddown spring screw

Sleep spindles predict stress-related increases in sleep disturbances

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Thien Thanh eDang-Vu

2015-02-01

Full Text Available Background and Aim: Predisposing factors place certain individuals at higher risk for insomnia, especially in the presence of precipitating conditions such as stressful life events. Sleep spindles have been shown to play an important role in the preservation of sleep continuity. Lower spindle density might thus constitute an objective predisposing factor for sleep reactivity to stress. The aim of this study was therefore to evaluate the relationship between baseline sleep spindle density and the prospective change in insomnia symptoms in response to a standardized academic stressor. Methods: 12 healthy students had a polysomnography (PSG recording during a period of lower stress at the beginning of the academic semester, along with an assessment of insomnia complaints using the Insomnia Severity Index (ISI. They completed a second ISI assessment at the end of the semester, a period coinciding with the week prior to final examinations and thus higher stress. Spindle density, amplitude, duration and frequency, as well as sigma power were computed from C4-O2 electroencephalography (EEG derivation during stages N2-N3 of non-rapid-eye-movement (NREM sleep, across the whole night and for each NREM sleep period. To test for the relationship between spindle density and changes in insomnia symptoms in response to academic stress, spindle measurements at baseline were correlated with changes in ISI across the academic semester.Results: Spindle density (as well as spindle amplitude and sigma power, particularly during the first NREM sleep period, negatively correlated with changes in ISI (p < 0.05. Conclusion: Lower spindle activity, especially at the beginning of the night, prospectively predicted larger increases in insomnia symptoms in response to stress. This result indicates that individual differences in sleep spindle activity contribute to the differential vulnerability to sleep disturbances in the face of precipitating factors.

Gene Expression Dynamics Accompanying the Sponge Thermal Stress Response.

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Guzman, Christine; Conaco, Cecilia

2016-01-01

Marine sponges are important members of coral reef ecosystems. Thus, their responses to changes in ocean chemistry and environmental conditions, particularly to higher seawater temperatures, will have potential impacts on the future of these reefs. To better understand the sponge thermal stress response, we investigated gene expression dynamics in the shallow water sponge, Haliclona tubifera (order Haplosclerida, class Demospongiae), subjected to elevated temperature. Using high-throughput transcriptome sequencing, we show that these conditions result in the activation of various processes that interact to maintain cellular homeostasis. Short-term thermal stress resulted in the induction of heat shock proteins, antioxidants, and genes involved in signal transduction and innate immunity pathways. Prolonged exposure to thermal stress affected the expression of genes involved in cellular damage repair, apoptosis, signaling and transcription. Interestingly, exposure to sublethal temperatures may improve the ability of the sponge to mitigate cellular damage under more extreme stress conditions. These insights into the potential mechanisms of adaptation and resilience of sponges contribute to a better understanding of sponge conservation status and the prediction of ecosystem trajectories under future climate conditions.

Linking physiological and cellular responses to thermal stress: β-adrenergic blockade reduces the heat shock response in fish.

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Templeman, Nicole M; LeBlanc, Sacha; Perry, Steve F; Currie, Suzanne

2014-08-01

When faced with stress, animals use physiological and cellular strategies to preserve homeostasis. We were interested in how these high-level stress responses are integrated at the level of the whole animal. Here, we investigated the capacity of the physiological stress response, and specifically the β-adrenergic response, to affect the induction of the cellular heat shock proteins, HSPs, following a thermal stress in vivo. We predicted that blocking β-adrenergic stimulation during an acute heat stress in the whole animal would result in reduced levels of HSPs in red blood cells (RBCs) of rainbow trout compared to animals where adrenergic signaling remained intact. We first determined that a 1 h heat shock at 25 °C in trout acclimated to 13 °C resulted in RBC adrenergic stimulation as determined by a significant increase in cell swelling, a hallmark of the β-adrenergic response. A whole animal injection with the β2-adrenergic antagonist, ICI-118,551, successfully reduced this heat-induced RBC swelling. The acute heat shock caused a significant induction of HSP70 in RBCs of 13 °C-acclimated trout as well as a significant increase in plasma catecholamines. When heat-shocked fish were treated with ICI-118,551, we observed a significant attenuation of the HSP70 response. We conclude that circulating catecholamines influence the cellular heat shock response in rainbow trout RBCs, demonstrating physiological/hormonal control of the cellular stress response.

Does acute stress disorder predict posttraumatic stress disorder following bank robbery?

DEFF Research Database (Denmark)

Hansen, M.; Elklit, A.

2013-01-01

Unfortunately, the number of bank robberies is increasing and little is known about the subsequent risk of posttraumatic stress disorder (PTSD). Several studies have investigated the prediction of PTSD through the presence of acute stress disorder (ASD). However, there have only been a few studies...... following nonsexual assault. The present study investigated the predictive power of different aspects of the ASD diagnosis and symptom severity on PTSD prevalence and symptom severity in 132 bank employees. The PTSD diagnosis, based on the three core symptom clusters, was best identified using cutoff scores...... on the Acute Stress Disorder scale. ASD severity accounted for 40% and the inclusion of other risk factors accounted for 50% of the PTSD severity variance. In conclusion, results indicated that ASD appears to predict PTSD differently following nonsexual assault than other trauma types. ASD severity...

The predictive value of early maladaptive schemas in paranoid responses to social stress.

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Sundag, Johanna; Ascone, Leonie; Lincoln, Tania M

2018-01-01

Social stress and negatively valenced cognitive representations of the self (self-schemas) play an important role in the formation of delusions. However, it has not been investigated whether and which self-schemas explain paranoid responses to social stress. Building on the framework of schema theory, the aim of this study was thus to investigate whether more pronounced early maladaptive schemas (EMSs) were associated with increased paranoid ideation after a social stress induction in patients with persecutory delusions (PD). Patients with PD (n = 20) and healthy controls (n = 40) were assessed for EMSs with the Young Schema Questionnaire. They were then exposed to a social stress situation in which they were socially excluded in a Cyberball paradigm. Prior to and after the social stress induction, paranoid symptoms were assessed. Patients with PD responded with a stronger increase in paranoia and revealed a significantly higher EMS total score compared to the healthy controls. As expected, higher increases in paranoia following the social stress were accounted for by higher EMS total scores. Exploratory analyses showed that particularly the specific EMSs Defectiveness/Shame and Enmeshment/Undeveloped Self were associated with the increase in paranoia. EMSs are associated with stress-related symptom increases in patients with PD. It thus seems worthwhile to further investigate the relevance of specific schemas for paranoia. The findings also suggest that addressing EMSs in psychological treatment of patients with PD holds potential. Copyright © 2017 John Wiley & Sons, Ltd.

Genetic Differences in the Immediate Transcriptome Response to Stress Predict Risk-Related Brain Function and Psychiatric Disorders

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Arloth, Janine; Bogdan, Ryan; Weber, Peter; Frishman, Goar; Menke, Andreas; Wagner, Klaus V.; Balsevich, Georgia; Schmidt, Mathias V.; Karbalai, Nazanin; Czamara, Darina; Altmann, Andre; Trümbach, Dietrich; Wurst, Wolfgang; Mehta, Divya; Uhr, Manfred; Klengel, Torsten; Erhardt, Angelika; Carey, Caitlin E.; Conley, Emily Drabant; Ripke, Stephan; Wray, Naomi R.; Lewis, Cathryn M.; Hamilton, Steven P.; Weissman, Myrna M.; Breen, Gerome; Byrne, Enda M.; Blackwood, Douglas H.R.; Boomsma, Dorret I.; Cichon, Sven; Heath, Andrew C.; Holsboer, Florian; Lucae, Susanne; Madden, Pamela A.F.; Martin, Nicholas G.; McGuffin, Peter; Muglia, Pierandrea; Noethen, Markus M.; Penninx, Brenda P.; Pergadia, Michele L.; Potash, James B.; Rietschel, Marcella; Lin, Danyu; Müller-Myhsok, Bertram; Shi, Jianxin; Steinberg, Stacy; Grabe, Hans J.; Lichtenstein, Paul; Magnusson, Patrik; Perlis, Roy H.; Preisig, Martin; Smoller, Jordan W.; Stefansson, Kari; Uher, Rudolf; Kutalik, Zoltan; Tansey, Katherine E.; Teumer, Alexander; Viktorin, Alexander; Barnes, Michael R.; Bettecken, Thomas; Binder, Elisabeth B.; Breuer, René; Castro, Victor M.; Churchill, Susanne E.; Coryell, William H.; Craddock, Nick; Craig, Ian W.; Czamara, Darina; De Geus, Eco J.; Degenhardt, Franziska; Farmer, Anne E.; Fava, Maurizio; Frank, Josef; Gainer, Vivian S.; Gallagher, Patience J.; Gordon, Scott D.; Goryachev, Sergey; Gross, Magdalena; Guipponi, Michel; Henders, Anjali K.; Herms, Stefan; Hickie, Ian B.; Hoefels, Susanne; Hoogendijk, Witte; Hottenga, Jouke Jan; Iosifescu, Dan V.; Ising, Marcus; Jones, Ian; Jones, Lisa; Jung-Ying, Tzeng; Knowles, James A.; Kohane, Isaac S.; Kohli, Martin A.; Korszun, Ania; Landen, Mikael; Lawson, William B.; Lewis, Glyn; MacIntyre, Donald; Maier, Wolfgang; Mattheisen, Manuel; McGrath, Patrick J.; McIntosh, Andrew; McLean, Alan; Middeldorp, Christel M.; Middleton, Lefkos; Montgomery, Grant M.; Murphy, Shawn N.; Nauck, Matthias; Nolen, Willem A.; Nyholt, Dale R.; O’Donovan, Michael; Oskarsson, Högni; Pedersen, Nancy; Scheftner, William A.; Schulz, Andrea; Schulze, Thomas G.; Shyn, Stanley I.; Sigurdsson, Engilbert; Slager, Susan L.; Smit, Johannes H.; Stefansson, Hreinn; Steffens, Michael; Thorgeirsson, Thorgeir; Tozzi, Federica; Treutlein, Jens; Uhr, Manfred; van den Oord, Edwin J.C.G.; Van Grootheest, Gerard; Völzke, Henry; Weilburg, Jeffrey B.; Willemsen, Gonneke; Zitman, Frans G.; Neale, Benjamin; Daly, Mark; Levinson, Douglas F.; Sullivan, Patrick F.; Ruepp, Andreas; Müller-Myhsok, Bertram; Hariri, Ahmad R.; Binder, Elisabeth B.

2015-01-01

Summary Depression risk is exacerbated by genetic factors and stress exposure; however, the biological mechanisms through which these factors interact to confer depression risk are poorly understood. One putative biological mechanism implicates variability in the ability of cortisol, released in response to stress, to trigger a cascade of adaptive genomic and non-genomic processes through glucocorticoid receptor (GR) activation. Here, we demonstrate that common genetic variants in long-range enhancer elements modulate the immediate transcriptional response to GR activation in human blood cells. These functional genetic variants increase risk for depression and co-heritable psychiatric disorders. Moreover, these risk variants are associated with inappropriate amygdala reactivity, a transdiagnostic psychiatric endophenotype and an important stress hormone response trigger. Network modeling and animal experiments suggest that these genetic differences in GR-induced transcriptional activation may mediate the risk for depression and other psychiatric disorders by altering a network of functionally related stress-sensitive genes in blood and brain. Video Abstract PMID:26050039

Genome-wide targeted prediction of ABA responsive genes in rice based on over-represented cis-motif in co-expressed genes.

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Lenka, Sangram K; Lohia, Bikash; Kumar, Abhay; Chinnusamy, Viswanathan; Bansal, Kailash C

2009-02-01

Abscisic acid (ABA), the popular plant stress hormone, plays a key role in regulation of sub-set of stress responsive genes. These genes respond to ABA through specific transcription factors which bind to cis-regulatory elements present in their promoters. We discovered the ABA Responsive Element (ABRE) core (ACGT) containing CGMCACGTGB motif as over-represented motif among the promoters of ABA responsive co-expressed genes in rice. Targeted gene prediction strategy using this motif led to the identification of 402 protein coding genes potentially regulated by ABA-dependent molecular genetic network. RT-PCR analysis of arbitrarily chosen 45 genes from the predicted 402 genes confirmed 80% accuracy of our prediction. Plant Gene Ontology (GO) analysis of ABA responsive genes showed enrichment of signal transduction and stress related genes among diverse functional categories.

Predicting developmental changes in internalizing symptoms: examining the interplay between parenting and neuroendocrine stress reactivity.

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Kuhlman, Kate R; Olson, Sheryl L; Lopez-Duran, Nestor L

2014-07-01

In this study, we examined whether parenting and HPA-axis reactivity during middle childhood predicted increases in internalizing symptoms during the transition to adolescence, and whether HPA-axis reactivity mediated the impact of parenting on internalizing symptoms. The study included 65 children (35 boys) who were assessed at age 5, 7, and 11. Parenting behaviors were assessed via parent report at age 5 and 11. The child's HPA-axis reactivity was measured at age 7 via a stress task. Internalizing symptoms were measured via teacher reports at age 5 and 11. High maternal warmth at age 5 predicted lower internalizing symptoms at age 11. Also, high reported maternal warmth and induction predicted lower HPA-axis reactivity. Additionally, greater HPA-axis reactivity at age 7 was associated with greater increases in internalizing symptoms from age 5 to 11. Finally, the association between age 5 maternal warmth and age 11 internalizing symptoms was partially mediated by lower cortisol in response to the stress task. Thus, parenting behaviors in early development may influence the physiological stress response system and therefore buffer the development of internalizing symptoms during preadolescence when risk for disorder onset is high. © 2013 Wiley Periodicals, Inc.

Plasma omega 3 polyunsaturated fatty acid status and monounsaturated fatty acids are altered by chronic social stress and predict endocrine responses to acute stress in titi monkeys

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Disturbances in fatty acid (FA) metabolism may link chronic psychological stress, endocrine responsiveness, and psychopathology. Therefore, lipid metabolome-wide responses and their relationships with endocrine (cortisol; insulin; adiponectin) responsiveness to acute stress (AS) were assessed in a ...

Does short-term fasting lead to stressed-out parents? A study of incubation commitment and the hormonal stress responses and recoveries in snow petrels.

Science.gov (United States)

Angelier, Frédéric; Wingfield, John C; Parenteau, Charline; Pellé, Marie; Chastel, Olivier

2015-01-01

The hormonal stress response is flexible and can be modulated by individuals according to its costs and benefits. Therefore, it is predicted that parents in poor body condition should modify their hormonal stress response, and thus, redirect energy allocation processes from parental care to self-maintenance when stressors occur. To test this prediction, most studies on free-living vertebrates have only focused on the stress response while the stress recovery - how quickly hormonal levels return to baseline values - has been neglected. Moreover, most studies have only focused on corticosterone - the primary mediator of allostasis - without paying attention to prolactin despite its major role in mediating parental behaviors. Here, we examined the effect of a short-term fasting event on the corticosterone and prolactin stress responses and recoveries, and we subsequently explored their relationships with parental decision in the snow petrel (Pagodroma nivea). By comparing the hormonal profiles of fasting and non-fasting snow petrels, we showed that parents modulate their corticosterone (but not prolactin) stress response according to their energetic status. We also described for the first time the hormonal stress recoveries in wild birds and found that they did not differ between fasting and non-fasting birds. Importantly, egg neglect was negatively correlated with circulating prolactin but not corticosterone levels in this species, demonstrating therefore a complex link between body condition, parental behavior and circulating corticosterone and prolactin levels. We suggest that both corticosterone and prolactin play a major role in the way parents adjust to stressors. This multiple signaling may allow parents to fine-tune their response to stressors, and especially, to activate specific allostasis-related mechanisms in a timely manner. Copyright © 2014 Elsevier Inc. All rights reserved.

Using the reactive scope model to understand why stress physiology predicts survival during starvation in Galápagos marine iguanas.

Science.gov (United States)

Romero, L Michael

2012-05-01

Even though the term "stress" is widely used, a precise definition is notoriously difficult. Notwithstanding this difficulty, stress continues to be an important concept in biology because it attempts to describe how animals cope with environmental change under emergency conditions. Without a precise definition, however, it becomes nearly impossible to make testable a priori predictions about how physiological and hormonal systems will respond to emergency conditions and what the ultimate impact on the animal will be. The reactive scope model is a recent attempt to formulate testable predictions. This model provides a physiological basis to explain why corticosterone negative feedback, but not baseline corticosterone concentrations, corticosterone responses to acute stress, or the interrenal capacity to secrete corticosterone, is correlated with survival during famine conditions in Galápagos marine iguanas. Reactive scope thus provides a foundation for interpreting and predicting physiological stress responses. Copyright © 2011 Elsevier Inc. All rights reserved.

Early Childhood Stress and Child Age Predict Longitudinal Increases in Obesogenic Eating Among Low-Income Children.

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Miller, Alison L; Gearhardt, Ashley N; Retzloff, Lauren; Sturza, Julie; Kaciroti, Niko; Lumeng, Julie C

2018-01-31

To identify whether psychosocial stress exposure during early childhood predicts subsequent increased eating in the absence of hunger (EAH), emotional overeating, food responsiveness, and enjoyment of food. This was an observational longitudinal study. Among 207 low-income children (54.6% non-Hispanic white, 46.9% girls), early childhood stress exposure was measured by parent report and a stress exposure index calculated, with higher scores indicating more stress exposure. Eating behaviors were measured in early (mean, 4.3; standard deviation, 0.5 years) and middle (mean, 7.9; standard deviation, 0.7 years) childhood. Observed EAH was assessed by measuring kilocalories of palatable food the child consumed after a meal. Parents reported on child eating behaviors on the Child Eating Behavior Questionnaire. Child weight and height were measured and body mass index z score (BMIz) calculated. Multivariable linear regression, adjusting for child sex, race/ethnicity, and BMIz, was used to examine the association of stress exposure with rate of change per year in each child eating behavior. Early childhood stress exposure predicted yearly increases in EAH (β = 0.14; 95% confidence interval, 0.002, 0.27) and Emotional Overeating (β = 0.14; 95% confidence interval, 0.008, 0.27). Stress exposure was not associated with Food Responsiveness (trend for decreased Enjoyment of Food; β = -0.13; 95% confidence interval, 0.002, -0.26). All child obesogenic eating behaviors increased with age (P Early stress exposure predicted increases in child eating behaviors known to associate with overweight/obesity. Psychosocial stress may confer overweight/obesity risk through eating behavior pathways. Targeting eating behaviors may be an important prevention strategy for children exposed to stress. Copyright © 2018 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

Plant Core Environmental Stress Response Genes Are Systemically Coordinated during Abiotic Stresses

Directory of Open Access Journals (Sweden)

Kenneth W. Berendzen

2013-04-01

Full Text Available Studying plant stress responses is an important issue in a world threatened by global warming. Unfortunately, comparative analyses are hampered by varying experimental setups. In contrast, the AtGenExpress abiotic stress experiment displays intercomparability. Importantly, six of the nine stresses (wounding, genotoxic, oxidative, UV-B light, osmotic and salt can be examined for their capacity to generate systemic signals between the shoot and root, which might be essential to regain homeostasis in Arabidopsis thaliana. We classified the systemic responses into two groups: genes that are regulated in the non-treated tissue only are defined as type I responsive and, accordingly, genes that react in both tissues are termed type II responsive. Analysis of type I and II systemic responses suggest distinct functionalities, but also significant overlap between different stresses. Comparison with salicylic acid (SA and methyl-jasmonate (MeJA responsive genes implies that MeJA is involved in the systemic stress response. Certain genes are predominantly responding in only one of the categories, e.g., WRKY genes respond mainly non-systemically. Instead, genes of the plant core environmental stress response (PCESR, e.g., ZAT10, ZAT12, ERD9 or MES9, are part of different response types. Moreover, several PCESR genes switch between the categories in a stress-specific manner.

The role of anxiety in cortisol stress response and cortisol recovery in boys with oppositional defiant disorder/conduct disorder.

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Schoorl, Jantiene; Rijn, Sophie van; Wied, Minet de; van Goozen, Stephanie; Swaab, Hanna

2016-11-01

Children with antisocial and aggressive behaviors have been found to show abnormal neurobiological responses to stress, specifically impaired cortisol stress reactivity. The role of individual characteristics, such as comorbid anxiety, in the stress response is far less studied. Furthermore, this study extended previous studies in that not only baseline and reactivity to a psychosocial stressor were examined, but also recovery from a stressor. These three phases of cortisol could be impacted differentially in boys with oppositional defiant disorder/conduct disorder (ODD/CD) with (+ANX) and without anxiety (-ANX). The results revealed that cortisol patterns in response to psychosocial stress were different for boys with ODD/CD+ANX (n=32), ODD/CD-ANX (n=22) and non-clinical controls (NC) (n=34), with age range of 7.8-12.9 years. The ODD/CD-ANX group showed lower overall cortisol levels than the NC group. When considering the three phases of cortisol separately, the ODD/CD-ANX group had lower baseline cortisol levels relative to the other groups, whereas the ODD/CD+ANX showed an impaired cortisol recovery response. Within those with ODD/CD, callous-unemotional traits were predictive of high baseline cortisol levels. Also, anxiety predicted high baseline and recovery cortisol levels, whereas a high number of CD symptoms predicted reduced cortisol stress reactivity. These results clearly indicate that comorbid anxiety is an important factor in explaining differences in stress response profiles in boys with ODD/CD; although boys with CD/ODD are generally characterized by an impaired cortisol stress response, we found that those with comorbid anxiety showed impaired cortisol recovery, whereas those without anxiety showed reduced baseline cortisol levels. Copyright © 2016 Elsevier Ltd. All rights reserved.

Caregiver Responsiveness to the Family Bereavement Program: What predicts responsiveness? What does responsiveness predict?

OpenAIRE

Schoenfelder, Erin N.; Sandler, Irwin N.; Millsap, Roger E.; Wolchik, Sharlene A.; Berkel, Cady; Ayers, Timothy S.

2013-01-01

The study developed a multi-dimensional measure to assess participant responsiveness to a preventive intervention, and applied this measure to study how participant baseline characteristics predict responsiveness and how responsiveness predicts program outcomes. The study was conducted with caregivers who participated in the parenting-focused component of the Family Bereavement Program (FBP), a prevention program for families that have experienced parental death. The sample consisted of 89 ca...

Familial Risk for Insomnia Is Associated With Abnormal Cortisol Response to Stress.

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Drake, Christopher L; Cheng, Philip; Almeida, David M; Roth, Thomas

2017-10-01

Abnormalities in the stress system have been implicated in insomnia. However, studies examining physiological stress regulation in insomnia have not consistently detected differences in the hypothalamic-pituitary-adrenal (HPA)-axis response to stress. One explanation may be that deficits in the stress system are associated specifically with a biological vulnerability to insomnia rather than the phenotypic expression of insomnia. To examine stress response as a function of vulnerability to insomnia, this study tested response to the Trier Social Stress Test in a sample of healthy sleepers with varying familial risks for insomnia. Thirty-five healthy individuals with and without familial risk for insomnia were recruited to complete a laboratory stressor. Participants with one or both biological parents with insomnia were categorized as positive for familial risk, whereas those without biological parents with insomnia were categorized as negative for familial risk. Participants completed the Trier Social Stress Test in the laboratory, and psychological and physiological (autonomic and HPA-axis) responses were compared. Despite self-reported increases in anxiety, those positive for familial risk exhibited a blunted cortisol response relative to those without familial risk for insomnia. Individuals with blunted cortisol also reported heightened reactivity to personal life stressors, including increased sleep disturbances, elevated cognitive intrusions, and more behavioral avoidance. Findings from this study provide initial evidence that abnormal stress regulation may be a biological predisposing factor conferred via familial risk for insomnia. This deficit may also predict negative consequences over time, including insomnia and the associated psychiatric comorbidities. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

STRESS RESPONSE STUDIES USING ANIMAL MODELS

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This presentation will provide the evidence that ozone exposure in animal models induce neuroendocrine stress response and this stress response modulates lung injury and inflammation through adrenergic and glucocorticoid receptors.

Pre-treatment cortisol awakening response predicts symptom reduction in posttraumatic stress disorder after treatment

NARCIS (Netherlands)

Rapcencu, A.E.; Gorter, R.; Kennis, Mitzy; van Rooij, S.J.H.; Geuze, E.

2017-01-01

Dysfunction of the HPA-axis has frequently been found in the aftermath of trauma exposure with or without PTSD. Decreasing HPA-axis reactivity to different stress cues has been reported during PTSD treatment. The cortisol awakening response (CARi) is a well-validated, standardized measure of

Pre-treatment cortisol awakening response predicts symptom reduction in posttraumatic stress disorder after treatment

NARCIS (Netherlands)

Rapcencu, A E; Gorter, R; Kennis, M; van Rooij, S J H; Geuze, E

Dysfunction of the HPA-axis has frequently been found in the aftermath of trauma exposure with or without PTSD. Decreasing HPA-axis reactivity to different stress cues has been reported during PTSD treatment. The cortisol awakening response (CARi) is a well-validated, standardized measure of

Does Acute Stress Disorder Predict Posttraumatic Stress Disorder Following Bank Robbery?

Science.gov (United States)

Hansen, Maj; Elklit, Ask

2013-01-01

Unfortunately, the number of bank robberies is increasing and little is known about the subsequent risk of posttraumatic stress disorder (PTSD). Several studies have investigated the prediction of PTSD through the presence of acute stress disorder (ASD). However, there have only been a few studies following nonsexual assault. The present study…

Longevity and the stress response in Drosophila

DEFF Research Database (Denmark)

Vermeulen, Corneel J.; Loeschcke, Volker

2007-01-01

briefly review the state of the art of research on ageing and longevity in the model organism Drosophila, with focus on the role of the general stress response. We will conclude by contemplating some of the implications of the findings in this research and will suggest several directions for future...... research. Keywords: Ageing; Stress response; Hsp; Drosophila; Stress......The concept that lifespan is a function of the capacity to withstand extrinsic stress is very old. In concordance with this, long-lived individuals often have increased resistance against a variety of stresses throughout life. Genes underlying the stress response may therefore have the ability...

Predicting adolescent posttraumatic stress in the aftermath of war: differential effects of coping strategies across trauma reminder, loss reminder, and family conflict domains.

Science.gov (United States)

Howell, Kathryn H; Kaplow, Julie B; Layne, Christopher M; Benson, Molly A; Compas, Bruce E; Katalinski, Ranka; Pasalic, Hafiza; Bosankic, Nina; Pynoos, Robert

2015-01-01

The vast majority of youth who lived through the Bosnian war were exposed to multiple traumatic events, including interpersonal violence, community destruction, and the loss of a loved one. This study examined factors that predict post-war psychological adjustment, specifically posttraumatic stress, in Bosnian adolescents. Regression analyses evaluated theorized differential relations between three types of post-war stressors - exposure to trauma reminders, loss reminders, and intrafamilial conflict - specific coping strategies, and posttraumatic stress symptom dimensions. We examined 555 Bosnian adolescents, aged 15-19 years, to predict their long-term posttraumatic stress reactions in the aftermath of war. Findings indicated that post-war exposure to trauma reminders, loss reminders, and family conflict, as well as engagement and disengagement coping strategies, predicted posttraumatic stress symptoms. Secondary control engagement coping responses to all three types of post-war stressors were inversely associated with posttraumatic stress symptoms, whereas primary control engagement coping responses to family conflict were inversely associated with hyperarousal symptoms. Disengagement responses to trauma reminders and family conflict were positively associated with re-experiencing symptoms. These findings shed light on ways in which trauma reminders, loss reminders, and family conflict may intersect with coping responses to influence adolescent postwar adjustment.

Generalized Unsafety Theory of Stress: Unsafe Environments and Conditions, and the Default Stress Response.

Science.gov (United States)

Brosschot, Jos F; Verkuil, Bart; Thayer, Julian F

2018-03-07

Prolonged physiological stress responses form an important risk factor for disease. According to neurobiological and evolution-theoretical insights the stress response is a default response that is always "on" but inhibited by the prefrontal cortex when safety is perceived. Based on these insights the Generalized Unsafety Theory of Stress (GUTS) states that prolonged stress responses are due to generalized and largely unconsciously perceived unsafety rather than stressors. This novel perspective necessitates a reconstruction of current stress theory, which we address in this paper. We discuss a variety of very common situations without stressors but with prolonged stress responses, that are not, or not likely to be caused by stressors, including loneliness, low social status, adult life after prenatal or early life adversity, lack of a natural environment, and less fit bodily states such as obesity or fatigue. We argue that in these situations the default stress response may be chronically disinhibited due to unconsciously perceived generalized unsafety. Also, in chronic stress situations such as work stress, the prolonged stress response may be mainly caused by perceived unsafety in stressor-free contexts. Thus, GUTS identifies and explains far more stress-related physiological activity that is responsible for disease and mortality than current stress theories.

Generalized Unsafety Theory of Stress: Unsafe Environments and Conditions, and the Default Stress Response

Directory of Open Access Journals (Sweden)

Jos F. Brosschot

2018-03-01

Full Text Available Prolonged physiological stress responses form an important risk factor for disease. According to neurobiological and evolution-theoretical insights the stress response is a default response that is always “on” but inhibited by the prefrontal cortex when safety is perceived. Based on these insights the Generalized Unsafety Theory of Stress (GUTS states that prolonged stress responses are due to generalized and largely unconsciously perceived unsafety rather than stressors. This novel perspective necessitates a reconstruction of current stress theory, which we address in this paper. We discuss a variety of very common situations without stressors but with prolonged stress responses, that are not, or not likely to be caused by stressors, including loneliness, low social status, adult life after prenatal or early life adversity, lack of a natural environment, and less fit bodily states such as obesity or fatigue. We argue that in these situations the default stress response may be chronically disinhibited due to unconsciously perceived generalized unsafety. Also, in chronic stress situations such as work stress, the prolonged stress response may be mainly caused by perceived unsafety in stressor-free contexts. Thus, GUTS identifies and explains far more stress-related physiological activity that is responsible for disease and mortality than current stress theories.

Hierarchical Status Predicts Behavioral Vulnerability and Nucleus Accumbens Metabolic Profile Following Chronic Social Defeat Stress.

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Larrieu, Thomas; Cherix, Antoine; Duque, Aranzazu; Rodrigues, João; Lei, Hongxia; Gruetter, Rolf; Sandi, Carmen

2017-07-24

Extensive data highlight the existence of major differences in individuals' susceptibility to stress [1-4]. While genetic factors [5, 6] and exposure to early life stress [7, 8] are key components for such neurobehavioral diversity, intriguing observations revealed individual differences in response to stress in inbred mice [9-12]. This raised the possibility that other factors might be critical in stress vulnerability. A key challenge in the field is to identify non-invasively risk factors for vulnerability to stress. Here, we investigated whether behavioral factors, emerging from preexisting dominance hierarchies, could predict vulnerability to chronic stress [9, 13-16]. We applied a chronic social defeat stress (CSDS) model of depression in C57BL/6J mice to investigate the predictive power of hierarchical status to pinpoint which individuals will exhibit susceptibility to CSDS. Given that the high social status of dominant mice would be the one particularly challenged by CSDS, we predicted and found that dominant individuals were the ones showing a strong susceptibility profile as indicated by strong social avoidance following CSDS, while subordinate mice were not affected. Data from 1 H-NMR spectroscopy revealed that the metabolic profile in the nucleus accumbens (NAc) relates to social status and vulnerability to stress. Under basal conditions, subordinates show lower levels of energy-related metabolites compared to dominants. In subordinates, but not dominants, levels of these metabolites were increased after exposure to CSDS. To the best of our knowledge, this is the first study that identifies non-invasively the origin of behavioral risk factors predictive of stress-induced depression-like behaviors associated with metabolic changes. Copyright © 2017 Elsevier Ltd. All rights reserved.

General Stress Responses in the Honey Bee

Directory of Open Access Journals (Sweden)

Naïla Even

2012-12-01

Full Text Available The biological concept of stress originated in mammals, where a “General Adaptation Syndrome” describes a set of common integrated physiological responses to diverse noxious agents. Physiological mechanisms of stress in mammals have been extensively investigated through diverse behavioral and physiological studies. One of the main elements of the stress response pathway is the endocrine hypothalamo-pituitary-adrenal (HPA axis, which underlies the “fight-or-flight” response via a hormonal cascade of catecholamines and corticoid hormones. Physiological responses to stress have been studied more recently in insects: they involve biogenic amines (octopamine, dopamine, neuropeptides (allatostatin, corazonin and metabolic hormones (adipokinetic hormone, diuretic hormone. Here, we review elements of the physiological stress response that are or may be specific to honey bees, given the economical and ecological impact of this species. This review proposes a hypothetical integrated honey bee stress pathway somewhat analogous to the mammalian HPA, involving the brain and, particularly, the neurohemal organ corpora cardiaca and peripheral targets, including energy storage organs (fat body and crop. We discuss how this system can organize rapid coordinated changes in metabolic activity and arousal, in response to adverse environmental stimuli. We highlight physiological elements of the general stress responses that are specific to honey bees, and the areas in which we lack information to stimulate more research into how this fascinating and vital insect responds to stress.

Psychophysiological responses to stress after stress management training in patients with rheumatoid arthritis.

Directory of Open Access Journals (Sweden)

Sabine J M de Brouwer

Full Text Available BACKGROUND: Stress management interventions may prove useful in preventing the detrimental effects of stress on health. This study assessed the effects of a stress management intervention on the psychophysiological response to stress in patients with rheumatoid arthritis (RA. METHODS: Seventy-four patients with RA, who were randomly assigned to either a control group or a group that received short-term stress management training, performed a standardized psychosocial stress task (Trier Social Stress Test; TSST 1 week after the stress management training and at a 9-week follow-up. Psychological and physical functioning, and the acute psychophysiological response to the stress test were assessed. RESULTS: Patients in the intervention group showed significantly lower psychological distress levels of anxiety after the training than did the controls. While there were no between-group differences in stress-induced tension levels, and autonomic (α-amylase or endocrine (cortisol responses to the stress test 1 week after the intervention, levels of stress-induced tension and cortisol were significantly lower in the intervention group at the 9-week follow-up. Overall, the response to the intervention was particularly evident in a subgroup of patients with a psychological risk profile. CONCLUSION: A relatively short stress management intervention can improve psychological functioning and influences the psychophysiological response to stress in patients with RA, particularly those psychologically at risk. These findings might help understand how stress can affect health and the role of individual differences in stress responsiveness. TRIAL REGISTRATION: TrialRegister.nl NTR1193.

Predicting parenting stress in caregivers of children with brain tumours.

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Bennett, Emily; English, Martin William; Rennoldson, Michael; Starza-Smith, Arleta

2013-03-01

The purpose of the study was to identify factors that contribute to parenting stress in caregivers of children diagnosed with brain tumours. The study was cross-sectional and recruited 37 participants from a clinical database at a specialist children's hospital. Parents were sent questionnaires, which were used to measure factors related to stress in caregivers of children diagnosed with a brain tumour. Stress levels were measured using the Parenting Stress Index-Short Form (PSI/SF). Correlation analysis and multiple linear regression were used to examine the associations between parenting stress and coping styles, locus of control, parent-perceived child disability and time since diagnosis. Results revealed that 51% of parents were experiencing clinically significant levels of stress. The mean stress level of parents in the study was significantly higher than the PSI/SF norms (t = 4.7, p parenting stress. Other styles of coping, child behaviour problems and the amount of time since diagnosis were not found to be predictive of levels of parenting stress. There was a high prevalence of parenting stress in caregivers of children with a brain tumour. An external locus of control and coping by accepting responsibility increased the likelihood of elevated levels of stress. Results emphasised the importance of ongoing support for parents of children with brain tumours. Intervention might helpfully be centred on strategies to increase parents' internal locus of control. Copyright © 2012 John Wiley & Sons, Ltd.

Methods for predicting isochronous stress-strain curves

International Nuclear Information System (INIS)

Kiyoshige, Masanori; Shimizu, Shigeki; Satoh, Keisuke.

1976-01-01

Isochronous stress-strain curves show the relation between stress and total strain at a certain temperature with time as a parameter, and they are drawn up from the creep test results at various stress levels at a definite temperature. The concept regarding the isochronous stress-strain curves was proposed by McVetty in 1930s, and has been used for the design of aero-engines. Recently the high temperature characteristics of materials are shown as the isochronous stress-strain curves in the design guide for the nuclear energy equipments and structures used in high temperature creep region. It is prescribed that these curves are used as the criteria for determining design stress intensity or the data for analyzing the superposed effects of creep and fatigue. In case of the isochronous stress-strain curves used for the design of nuclear energy equipments with very long service life, it is impractical to determine the curves directly from the results of long time creep test, accordingly the method of predicting long time stress-strain curves from short time creep test results must be established. The method proposed by the authors, for which the creep constitution equations taking the first and second creep stages into account are used, and the method using Larson-Miller parameter were studied, and it was found that both methods were reliable for the prediction. (Kako, I.)

Stress corrosion cracking of zircaloy. The use of laboratory data to predict in-reactor behaviour

International Nuclear Information System (INIS)

Miller, A.K.; Ocken, H.

1981-01-01

Pellet-cladding interaction (PCI) can lead to failure of the Zircaloy tubing used as cladding in water-cooled reactors. Many investigations have shown that the mechanism directly responsible for such fuel rod failures is stress corrosion cracking (SCC) of Zircaloy tubing. Laboratory studies have yielded extensive data on the time-to-failure (tsub(f)) behaviour of Zircaloy tubing specimens as a function of such important variables as the applied hoop stress (σ sub(h)), the iodine concentration (I 2 ), the temperature (T) and the fluence (F). These data have been used to predict the response of Zircaloy tubing exposed in-reactor. A typical approach is to fit laboratory data to obtain an empirical equation for tsub(f) in terms of the variables identified above. The question can then be posed as to whether it is appropriate to use such an empirical expression for predicting in-reactor behaviour. This paper describes the approach which has been taken in modelling the SCC process. It first reviews the experimental observations upon which the model is based. A summary of the key features of the model is then presented. The model's capabilities, emphasizing those predictions that are independent of data used to evaluate empirical constants, are briefly discussed. Finally, it is shown how the model can be used to predict important differences between the response of tubing specimens exposed in the laboratory and the response of large quantities of tubing exposed in-reactor

Plant responses to water stress

Science.gov (United States)

Kar, Rup Kumar

2011-01-01

Terrestrial plants most often encounter drought stress because of erratic rainfall which has become compounded due to present climatic changes.Responses of plants to water stress may be assigned as either injurious change or tolerance index. One of the primary and cardinal changes in response to drought stress is the generation of reactive oxygen species (ROS), which is being considered as the cause of cellular damage. However, recently a signaling role of such ROS in triggering the ROS scavenging system that may confer protection or tolerance against stress is emerging. Such scavenging system consists of antioxidant enzymes like SOD, catalase and peroxidases, and antioxidant compounds like ascorbate, reduced glutathione; a balance between ROS generation and scavenging ultimately determines the oxidative load. As revealed in case of defence against pathogen, signaling via ROS is initiated by NADPH oxidase-catalyzed superoxide generation in the apoplastic space (cell wall) followed by conversion to hydrogen peroxide by the activity of cell wall-localized SOD. Wall peroxidase may also play role in ROS generation for signaling. Hydrogen peroxide may use Ca2+ and MAPK pathway as downstream signaling cascade. Plant hormones associated with stress responses like ABA and ethylene play their role possibly via a cross talk with ROS towards stress tolerance, thus projecting a dual role of ROS under drought stress. PMID:22057331

Response of rocks to large stresses

International Nuclear Information System (INIS)

Schock, R.N.

1976-01-01

To predict the dimensions and characteristics of impact- and explosion-induced craters, one must know the equation of state of the rocks in which the crater is formed. Recent experimental data shed light upon inelastic processes that influence the stress/strain behavior of rocks. We examine these data with a view to developing models that could be used in predicting cratering phenomena. New data is presented on the volume behavior of two dissimilar rocks subjected to tensile stresses

The stress response and exploratory behaviour in Yucatan minipigs (Sus scrofa): Relations to sex and social rank.

Science.gov (United States)

Adcock, Sarah J J; Martin, Gerard M; Walsh, Carolyn J

2015-12-01

According to the coping styles hypothesis, an individual demonstrates an integrated behavioural and physiological response to environmental challenge that is consistent over time and across situations. Individual consistency in behavioural responses to challenge has been documented across the animal kingdom. Comparatively few studies, however, have examined inter-individual variation in the physiological response, namely glucocorticoid and catecholamine levels, the stress hormones secreted by the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system, respectively. Variation in coping styles between individuals may be explained in part by differences in social rank and sex. Using 20 Yucatan minipigs (Sus scrofa) we: (1) investigated the existence of consistent inter-individual variation in exploratory behaviour and the hormonal stress response, and tested for correlations as predicted by the coping styles hypothesis; and (2) evaluated whether inter-individual behavioural and hormonal variation is related to social rank and sex. Salivary stress biomarkers (cortisol, alpha-amylase, chromogranin A) were assessed in the presence and absence of a stressor consisting of social isolation in a crate for 10 min. Principal components analysis on a set of behavioural variables revealed two traits, which we labelled exploratory tendency and neophobia. Neither exploratory tendency nor neophobia predicted the physiological stress response. Subordinate pigs exhibited higher catecholamine levels compared to dominant conspecifics. We observed sex differences in the repeatability of salivary stress markers and reactivity of the stress systems. The results do not provide support for the existence of behavioural-physiological coping styles in pigs. Sex is an important determinant of the physiological stress response and warrants consideration in research addressing behavioural and hormonal variation. Copyright © 2015 Elsevier Inc. All rights reserved.

Abiotic stressors and stress responses

DEFF Research Database (Denmark)

Sulmon, Cecile; Van Baaren, Joan; Cabello-Hurtado, Francisco

2015-01-01

Abstract Organisms are regularly subjected to abiotic stressors related to increasing anthropogenic activities, including chemicals and climatic changes that induce major stresses. Based on various key taxa involved in ecosystem functioning (photosynthetic microorganisms, plants, invertebrates), we...... review how organisms respond and adapt to chemical- and temperature-induced stresses from molecular to population level. Using field-realistic studies, our integrative analysis aims to compare i) how molecular and physiological mechanisms related to protection, repair and energy allocation can impact...... life history traits of stressed organisms, and ii) to what extent trait responses influence individual and population responses. Common response mechanisms are evident at molecular and cellular scales but become rather difficult to define at higher levels due to evolutionary distance and environmental...

Dominance relationships in Syrian hamsters modulate neuroendocrine and behavioral responses to social stress.

Science.gov (United States)

Dulka, Brooke N; Koul-Tiwari, Richa; Grizzell, J Alex; Harvey, Marquinta L; Datta, Subimal; Cooper, Matthew A

2018-06-22

Stress is a well-known risk factor for psychopathology and rodent models of social defeat have strong face, etiological, construct and predictive validity for these conditions. Syrian hamsters are highly aggressive and territorial, but after an acute social defeat experience they become submissive and no longer defend their home territory, even from a smaller, non-aggressive intruder. This defeat-induced change in social behavior is called conditioned defeat (CD). We have shown that dominant hamsters show increased neural activity in the ventromedial prefrontal cortex (vmPFC) following social defeat stress and exhibit a reduced CD response at social interaction testing compared to subordinates. Although the vmPFC can inhibit the neuroendocrine stress response, it is unknown whether dominants and subordinates differ in stress-induced activity of the extended hypothalamic-pituitary-adrenal (HPA) axis. Here, we show that, following acute social defeat, dominants exhibit decreased submissive and defensive behavior compared to subordinates but do not differ from subordinates or social status controls (SSCs) in defeat-induced cortisol concentrations. Furthermore, both dominants and SSCs show greater corticotropin-releasing hormone (CRH) mRNA expression in the basolateral/central amygdala compared to subordinates, while there was no effect of social status on CRH mRNA expression in the paraventricular nucleus of the hypothalamus or bed nucleus of the stria terminalis. Overall, status-dependent differences in the CD response do not appear linked to changes in stress-induced cortisol concentrations or CRH gene expression, which is consistent with the view that stress resilience is not a lack of a physiological stress response but the addition of stress coping mechanisms. Lay summary Dominant hamsters show resistance to the behavioral effects of acute social defeat compared to subordinates, but it is unclear whether social status modulates the neuroendocrine stress response

The Yeast Environmental Stress Response Regulates Mutagenesis Induced by Proteotoxic Stress

Science.gov (United States)

Shor, Erika; Fox, Catherine A.; Broach, James R.

2013-01-01

Conditions of chronic stress are associated with genetic instability in many organisms, but the roles of stress responses in mutagenesis have so far been elucidated only in bacteria. Here, we present data demonstrating that the environmental stress response (ESR) in yeast functions in mutagenesis induced by proteotoxic stress. We show that the drug canavanine causes proteotoxic stress, activates the ESR, and induces mutagenesis at several loci in an ESR-dependent manner. Canavanine-induced mutagenesis also involves translesion DNA polymerases Rev1 and Polζ and non-homologous end joining factor Ku. Furthermore, under conditions of chronic sub-lethal canavanine stress, deletions of Rev1, Polζ, and Ku-encoding genes exhibit genetic interactions with ESR mutants indicative of ESR regulating these mutagenic DNA repair processes. Analyses of mutagenesis induced by several different stresses showed that the ESR specifically modulates mutagenesis induced by proteotoxic stress. Together, these results document the first known example of an involvement of a eukaryotic stress response pathway in mutagenesis and have important implications for mechanisms of evolution, carcinogenesis, and emergence of drug-resistant pathogens and chemotherapy-resistant tumors. PMID:23935537

Stress-Induced Impairment of a Working Memory Task: Role of Spiking Rate and Spiking History Predicted Discharge

Science.gov (United States)

Devilbiss, David M.; Jenison, Rick L.; Berridge, Craig W.

2012-01-01

Stress, pervasive in society, contributes to over half of all work place accidents a year and over time can contribute to a variety of psychiatric disorders including depression, schizophrenia, and post-traumatic stress disorder. Stress impairs higher cognitive processes, dependent on the prefrontal cortex (PFC) and that involve maintenance and integration of information over extended periods, including working memory and attention. Substantial evidence has demonstrated a relationship between patterns of PFC neuron spiking activity (action-potential discharge) and components of delayed-response tasks used to probe PFC-dependent cognitive function in rats and monkeys. During delay periods of these tasks, persistent spiking activity is posited to be essential for the maintenance of information for working memory and attention. However, the degree to which stress-induced impairment in PFC-dependent cognition involves changes in task-related spiking rates or the ability for PFC neurons to retain information over time remains unknown. In the current study, spiking activity was recorded from the medial PFC of rats performing a delayed-response task of working memory during acute noise stress (93 db). Spike history-predicted discharge (SHPD) for PFC neurons was quantified as a measure of the degree to which ongoing neuronal discharge can be predicted by past spiking activity and reflects the degree to which past information is retained by these neurons over time. We found that PFC neuron discharge is predicted by their past spiking patterns for nearly one second. Acute stress impaired SHPD, selectively during delay intervals of the task, and simultaneously impaired task performance. Despite the reduction in delay-related SHPD, stress increased delay-related spiking rates. These findings suggest that neural codes utilizing SHPD within PFC networks likely reflects an additional important neurophysiological mechanism for maintenance of past information over time. Stress

The influence of social support and perceived stress on response time inconsistency.

Science.gov (United States)

Phibbs, Sandi; Stawski, Robert S; MacDonald, Stuart W S; Munoz, Elizabeth; Smyth, Joshua M; Sliwinski, Martin J

2017-11-24

Lack of social support and high levels of stress represent potentially modifiable risk factors for cognitive aging. In this study we examined the relationships between these two risk factors and response time inconsistency (RTI), or trial-to-trial variability in choice response time tasks. RTI is an early indicator of declining cognitive health, and examining the influence of modifiable psychosocial risk factors on RTI is important for understanding and promoting cognitive health during adulthood and old age. Using data from a community sample study (n = 317; M age = 49, range = 19-83), we examined the effects of social support, including size of network and satisfaction with support, global perceived stress, and their interactions on RTI. Neither size of network nor satisfaction with support was associated with RTI independent of perceived stress. Stress was positively associated with increased RTI on all tasks, independent of social support. Perceived stress did not interact with either dimension of social support to predict RTI, and perceived stress effects were invariant across age and sex. Perceived stress, but not social support, may be a unique and modifiable risk factor for normal and pathological cognitive aging. Discussion focuses on the importance of perceived stress and its impact on RTI in supporting cognitive health in adulthood and old age.

Aging causes decreased resistance to multiple stresses and a failure to activate specific stress response pathways

Science.gov (United States)

Bergsma, Alexis L.; Senchuk, Megan M.; Van Raamsdonk, Jeremy M.

2016-01-01

In this work, we examine the relationship between stress resistance and aging. We find that resistance to multiple types of stress peaks during early adulthood and then declines with age. To dissect the underlying mechanisms, we use C. elegans transcriptional reporter strains that measure the activation of different stress responses including: the heat shock response, mitochondrial unfolded protein response, endoplasmic reticulum unfolded protein response, hypoxia response, SKN-1-mediated oxidative stress response, and the DAF-16-mediated stress response. We find that the decline in stress resistance with age is at least partially due to a decreased ability to activate protective mechanisms in response to stress. In contrast, we find that any baseline increase in stress caused by the advancing age is too mild to detectably upregulate any of the stress response pathways. Further exploration of how worms respond to stress with increasing age revealed that the ability to mount a hormetic response to heat stress is also lost with increasing age. Overall, this work demonstrates that resistance to all types of stress declines with age. Based on our data, we speculate that the decrease in stress resistance with advancing age results from a genetically-programmed inactivation of stress response pathways, not accumulation of damage. PMID:27053445

Aging causes decreased resistance to multiple stresses and a failure to activate specific stress response pathways.

Science.gov (United States)

Dues, Dylan J; Andrews, Emily K; Schaar, Claire E; Bergsma, Alexis L; Senchuk, Megan M; Van Raamsdonk, Jeremy M

2016-04-01

In this work, we examine the relationship between stress resistance and aging. We find that resistance to multiple types of stress peaks during early adulthood and then declines with age. To dissect the underlying mechanisms, we use C. elegans transcriptional reporter strains that measure the activation of different stress responses including: the heat shock response, mitochondrial unfolded protein response, endoplasmic reticulum unfolded protein response, hypoxia response, SKN-1-mediated oxidative stress response, and the DAF-16-mediated stress response. We find that the decline in stress resistance with age is at least partially due to a decreased ability to activate protective mechanisms in response to stress. In contrast, we find that any baseline increase in stress caused by the advancing age is too mild to detectably upregulate any of the stress response pathways. Further exploration of how worms respond to stress with increasing age revealed that the ability to mount a hormetic response to heat stress is also lost with increasing age. Overall, this work demonstrates that resistance to all types of stress declines with age. Based on our data, we speculate that the decrease in stress resistance with advancing age results from a genetically-programmed inactivation of stress response pathways, not accumulation of damage.

Event terms in the response spectra prediction equation and their deviation due to stress drop variations

Science.gov (United States)

Kawase, H.; Nakano, K.

2015-12-01

We investigated the characteristics of strong ground motions separated from acceleration Fourier spectra and acceleration response spectra of 5% damping calculated from weak and moderate ground motions observed by K-NET, KiK-net, and the JMA Shindokei Network in Japan using the generalized spectral inversion method. The separation method used the outcrop motions at YMGH01 as reference where we extracted site responses due to shallow weathered layers. We include events with JMA magnitude equal to or larger than 4.5 observed from 1996 to 2011. We find that our frequency-dependent Q values are comparable to those of previous studies. From the corner frequencies of Fourier source spectra, we calculate Brune's stress parameters and found a clear magnitude dependence, in which smaller events tend to spread over a wider range while maintaining the same maximum value. We confirm that this is exactly the case for several mainshock-aftershock sequences. The average stress parameters for crustal earthquakes are much smaller than those of subduction zone, which can be explained by their depth dependence. We then compared the strong motion characteristics based on the acceleration response spectra and found that the separated characteristics of strong ground motions are different, especially in the lower frequency range less than 1Hz. These differences comes from the difference between Fourier spectra and response spectra found in the observed data; that is, predominant components in high frequency range of Fourier spectra contribute to increase the response in lower frequency range with small Fourier amplitude because strong high frequency component acts as an impulse to a Single-Degree-of-Freedom system. After the separation of the source terms for 5% damping response spectra we can obtain regression coefficients with respect to the magnitude, which lead to a new GMPE as shown in Fig.1 on the left. Although stress drops for inland earthquakes are 1/7 of the subduction

Alternative Splicing Control of Abiotic Stress Responses.

Science.gov (United States)

Laloum, Tom; Martín, Guiomar; Duque, Paula

2018-02-01

Alternative splicing, which generates multiple transcripts from the same gene, is an important modulator of gene expression that can increase proteome diversity and regulate mRNA levels. In plants, this post-transcriptional mechanism is markedly induced in response to environmental stress, and recent studies have identified alternative splicing events that allow rapid adjustment of the abundance and function of key stress-response components. In agreement, plant mutants defective in splicing factors are severely impaired in their response to abiotic stress. Notably, mounting evidence indicates that alternative splicing regulates stress responses largely by targeting the abscisic acid (ABA) pathway. We review here current understanding of post-transcriptional control of plant stress tolerance via alternative splicing and discuss research challenges for the near future. Copyright © 2017 Elsevier Ltd. All rights reserved.

Peritraumatic startle response predicts the vulnerability to develop PTSD-like behaviors in rats: a model for peritraumatic dissociation

Directory of Open Access Journals (Sweden)

Xinwen eDong

2014-01-01

Full Text Available Peritraumatic dissociation, a state characterized by alteration in perception and reduced awareness of surroundings, is considered to be a risk factor for the development of post-traumatic stress disorder (PTSD. However, the predictive ability of peritraumatic dissociation is questioned for the inconsistent results in different time points of assessment. The startle reflex is an objective behavioral measurement of defensive response to abrupt and intense sensory stimulus of surroundings, with potential to be used as an assessment on the dissociative status in both humans and rodents. The present study examined the predictive effect of acoustic startle response (ASR in different time points around the traumatic event in an animal model of PTSD. The PTSD-like symptoms, including hyperarousal, avoidance, and contextual fear, were assessed 2-3 weeks post-trauma. The results showed that 1 the startle amplitude attenuated immediate after intense footshock in almost half of the stress animals, 2 the attenuated startle responses at 1 hour but not 24 hours after stress predicted the development of severe PTSD-like symptoms. These data indicate that the startle alteration at the immediate period after trauma, including 1 hour, is more important in PTSD prediction than 24 hours after trauma. Our study also suggests that the startle attenuation immediate after intense stress may serve as an objective measurement of peritraumatic dissociation in rats.

Mitochondria, Energetics, Epigenetics, and Cellular Responses to Stress

Science.gov (United States)

McAllister, Kimberly; Worth, Leroy; Haugen, Astrid C.; Meyer, Joel N.; Domann, Frederick E.; Van Houten, Bennett; Mostoslavsky, Raul; Bultman, Scott J.; Baccarelli, Andrea A.; Begley, Thomas J.; Sobol, Robert W.; Hirschey, Matthew D.; Ideker, Trey; Santos, Janine H.; Copeland, William C.; Tice, Raymond R.; Balshaw, David M.; Tyson, Frederick L.

2014-01-01

Background: Cells respond to environmental stressors through several key pathways, including response to reactive oxygen species (ROS), nutrient and ATP sensing, DNA damage response (DDR), and epigenetic alterations. Mitochondria play a central role in these pathways not only through energetics and ATP production but also through metabolites generated in the tricarboxylic acid cycle, as well as mitochondria–nuclear signaling related to mitochondria morphology, biogenesis, fission/fusion, mitophagy, apoptosis, and epigenetic regulation. Objectives: We investigated the concept of bidirectional interactions between mitochondria and cellular pathways in response to environmental stress with a focus on epigenetic regulation, and we examined DNA repair and DDR pathways as examples of biological processes that respond to exogenous insults through changes in homeostasis and altered mitochondrial function. Methods: The National Institute of Environmental Health Sciences sponsored the Workshop on Mitochondria, Energetics, Epigenetics, Environment, and DNA Damage Response on 25–26 March 2013. Here, we summarize key points and ideas emerging from this meeting. Discussion: A more comprehensive understanding of signaling mechanisms (cross-talk) between the mitochondria and nucleus is central to elucidating the integration of mitochondrial functions with other cellular response pathways in modulating the effects of environmental agents. Recent studies have highlighted the importance of mitochondrial functions in epigenetic regulation and DDR with environmental stress. Development and application of novel technologies, enhanced experimental models, and a systems-type research approach will help to discern how environmentally induced mitochondrial dysfunction affects key mechanistic pathways. Conclusions: Understanding mitochondria–cell signaling will provide insight into individual responses to environmental hazards, improving prediction of hazard and susceptibility to

Stress proteins and the immune response.

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Moseley, P

2000-07-25

The heat shock or stress response is one of the most highly conserved adaptive responses in nature. In single cell organisms, the stress response confers tolerance to a variety of stresses including hyperthermia, hyperoxia, hypoxia, and other perturbations, which alter protein synthesis. This tolerance phenomenon is also extremely important in the multicellular organism, resulting in not only thermal tolerance, but also resistance to stresses of the whole organism such as ischemia-reperfusion injury. Moreover, recent data indicates that these stress proteins have the ability to modulate the cellular immune response. Although the terms heat shock proteins (HSPs) and stress proteins are often used interchangeably, the term stress proteins includes the HSPs, the glucose-regulated proteins (GRPs) and ubiquitin. The stress proteins may be grouped by molecular weight ranging from the large 110 kDa HSP110 to ubiquitin at 8 kDa. These proteins serve as cellular chaperones, participating in protein synthesis and transport through the various cellular compartments. Because these proteins have unique cellular localizations, the chaperone function of the stress proteins often involves a transfer of peptides between stress proteins as the peptide is moved between cellular compartments. For example, HSP70 is a cytosolic and nuclear chaperone, which is critical for the transfer of cellular peptides in the mitochondrion through a hand-off that involves mitochondrial HSP60 at the inner mitochondrial membrane. Similarly, cytosolic proteins are transferred from HSP70 to gp96 as they move into the endoplasmic reticulum. The central role of the stress proteins in the transfer of peptides through the cell may be responsible for the recently recognized importance of the stress proteins in the modulation of the immune system [Feder, M.E., Hofmann, G.E., 1999. Heat-shock proteins, molecular chaperones, and the stress response: evolutionary and ecological physiology. Annu. Rev. Physiol. 61

Social group dynamics predict stress variability among children in a New Zealand classroom.

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Spray, Julie; Floyd, Bruce; Littleton, Judith; Trnka, Susanna; Mattison, Siobhan

2018-03-27

Previous research proposes stress as a mechanism for linking social environments and biological bodies. In particular, non-human primate studies investigate relationships between cortisol as a measure of stress response and social hierarchies. Because human social structures often include hierarchies of dominance and social status, humans may exhibit similar patterns. Studies of non-human primates, however, have not reached consistent conclusions with respect to relationships between social position and levels of cortisol. While human studies report associations between cortisol and various aspects of social environments, studies that consider social status as a predictor of stress response also report mixed results. Others have argued that perceptions of social status may have different implications for stress response depending upon social context. We propose here that characteristics of children's social networks may be a better predictor of central tendencies and variability of stress response than their perceptions of social status. This is evaluated among 24 children from 9.4 to 11.3 years of age in one upper middle-class New Zealand primary school classroom, assessed through observation within the classroom, self-reports during semi-structured interviews and 221 serial saliva samples provided daily over 10 consecutive school days. A synthetic assessment of the children's networks and peer-relationships was developed prior to saliva-cortisol analysis. We found that greater stability of peer-relationships within groups significantly predicts lower within-group variation in mid-morning cortisol over the two-week period, but not overall within-group differences in mean cortisol. Copyright © 2018 Elsevier GmbH. All rights reserved.

Transcriptional 'memory' of a stress: transient chromatin and memory (epigenetic) marks at stress-response genes.

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Avramova, Zoya

2015-07-01

Drought, salinity, extreme temperature variations, pathogen and herbivory attacks are recurring environmental stresses experienced by plants throughout their life. To survive repeated stresses, plants provide responses that may be different from their response during the first encounter with the stress. A different response to a similar stress represents the concept of 'stress memory'. A coordinated reaction at the organismal, cellular and gene/genome levels is thought to increase survival chances by improving the plant's tolerance/avoidance abilities. Ultimately, stress memory may provide a mechanism for acclimation and adaptation. At the molecular level, the concept of stress memory indicates that the mechanisms responsible for memory-type transcription during repeated stresses are not based on repetitive activation of the same response pathways activated by the first stress. Some recent advances in the search for transcription 'memory factors' are discussed with an emphasis on super-induced dehydration stress memory response genes in Arabidopsis. © 2015 The Author The Plant Journal © 2015 John Wiley & Sons Ltd.

Opposite Effects of Stress on Pain Modulation Depend on the Magnitude of Individual Stress Response.

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Geva, Nirit; Defrin, Ruth

2018-04-01

The effect of acute stress on pain threshold and intolerance threshold are reported as producing either hypoalgesia or hyperalgesia. Yet, the contribution of individual stress reactivity in this respect has not been established. The aim was to test 2 pain modulation paradigms under acute stress manipulation, to our knowledge, for the first time, to study whether stress differentially affects pain modulation, and whether the effect is related to individual stress response. Participants were 31 healthy subjects. Conditioned pain modulation (CPM) and pain adaptation were measured before and after inducing an acute stress response using the Montreal Imaging Stress Task. Subjects' stress response was evaluated according to salivary cortisol, autonomic function, and perceived stress and anxiety. The Montreal Imaging Stress Task induced a validated stress response. On a group level, stress induced reduction in CPM magnitude and increase in pain adaptation compared with baseline. These responses correlated with stress reactivity. When the group was subdivided according to stress reactivity, only high stress responders exhibited reduced CPM whereas only low stress responders exhibited increased pain adaptation. The results suggest that acute stress may induce opposite effects on pain modulation, depending on individual stress reactivity magnitude, with an advantage to low stress responders. This study evaluated the effect of acute stress on pain modulation. Pain modulation under stress is affected by individual stress responsiveness; decreased CPM occurs in high stress responders whereas increased pain adaptation occurs in low stress responders. Identification of high stress responders may promote better pain management. Copyright © 2017 The American Pain Society. Published by Elsevier Inc. All rights reserved.

Plant responses to simultaneous stress of waterlogging and shade: amplified or hierarchical effects?

NARCIS (Netherlands)

Lenssen, J.P.M.; Menting, F.B.J.; Putten, van der W.H.

2003-01-01

Community ecologists often assume a hierarchy of environmental sieves to predict the impact of multiple stresses on species distribution. We tested whether this assumption corresponds to physiological responses using impact of water level and shade in wetland vegetation as a model. Seedlings of four

Extraversion and cardiovascular responses to recurrent social stress: Effect of stress intensity.

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Lü, Wei; Xing, Wanying; Hughes, Brian M; Wang, Zhenhong

2017-10-28

The present study sought to establish whether the effects of extraversion on cardiovascular responses to recurrent social stress are contingent on stress intensity. A 2×5×1 mixed-factorial experiment was conducted, with social stress intensity as a between-subject variable, study phase as a within-subject variable, extraversion as a continuous independent variable, and cardiovascular parameter (HR, SBP, DBP, or RSA) as a dependent variable. Extraversion (NEO-FFI), subjective stress, and physiological stress were measured in 166 undergraduate students randomly assigned to undergo moderate (n=82) or high-intensity (n=84) social stress (a public speaking task with different levels of social evaluation). All participants underwent continuous physiological monitoring while facing two consecutive stress exposures distributed across five laboratory phases: baseline, stress exposure 1, post-stress 1, stress exposure 2, post-stress 2. Results indicated that under moderate-intensity social stress, participants higher on extraversion exhibited lesser HR reactivity to stress than participants lower on extraversion, while under high-intensity social stress, they exhibited greater HR, SBP, DBP and RSA reactivity. Under both moderate- and high-intensity social stress, participants higher on extraversion exhibited pronounced SBP and DBP response adaptation to repeated stress, and showed either better degree of HR recovery or greater amount of SBP and DBP recovery after stress. These findings suggest that individuals higher on extraversion exhibit physiological flexibility to cope with social challenges and benefit from adaptive cardiovascular responses. Copyright © 2017 Elsevier B.V. All rights reserved.

Emotional Stress and Cardiovascular Complications in Animal Models: A Review of the Influence of Stress Type.

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Crestani, Carlos C

2016-01-01

Emotional stress has been recognized as a modifiable risk factor for cardiovascular diseases. The impact of stress on physiological and psychological processes is determined by characteristics of the stress stimulus. For example, distinct responses are induced by acute vs. chronic aversive stimuli. Additionally, the magnitude of stress responses has been reported to be inversely related to the degree of predictability of the aversive stimulus. Therefore, the purpose of the present review was to discuss experimental research in animal models describing the influence of stressor stimulus characteristics, such as chronicity and predictability, in cardiovascular dysfunctions induced by emotional stress. Regarding chronicity, the importance of cardiovascular and autonomic adjustments during acute stress sessions and cardiovascular consequences of frequent stress response activation during repeated exposure to aversive threats (i.e., chronic stress) is discussed. Evidence of the cardiovascular and autonomic changes induced by chronic stressors involving daily exposure to the same stressor (predictable) vs. different stressors (unpredictable) is reviewed and discussed in terms of the impact of predictability in cardiovascular dysfunctions induced by stress.

Ecological and soil hydraulic implications of microbial responses to stress - A modeling analysis

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Brangarí, Albert C.; Fernàndez-Garcia, Daniel; Sanchez-Vila, Xavier; Manzoni, Stefano

2018-06-01

A better understanding of microbial dynamics in porous media may lead to improvements in the design and management of a number of technological applications, ranging from the degradation of contaminants to the optimization of agricultural systems. To this aim, there is a recognized need for predicting the proliferation of soil microbial biomass (often organized in biofilms) under different environments and stresses. We present a general multi-compartment model to account for physiological responses that have been extensively reported in the literature. The model is used as an explorative tool to elucidate the ecological and soil hydraulic consequences of microbial responses, including the production of extracellular polymeric substances (EPS), the induction of cells into dormancy, and the allocation and reuse of resources between biofilm compartments. The mechanistic model is equipped with indicators allowing the microorganisms to monitor environmental and biological factors and react according to the current stress pressures. The feedbacks of biofilm accumulation on the soil water retention are also described. Model runs simulating different degrees of substrate and water shortage show that adaptive responses to the intensity and type of stress provide a clear benefit to microbial colonies. Results also demonstrate that the model may effectively predict qualitative patterns in microbial dynamics supported by empirical evidence, thereby improving our understanding of the effects of pore-scale physiological mechanisms on the soil macroscale phenomena.

Basal blood DHEA-S/cortisol levels predicts EMDR treatment response in adolescents with PTSD.

Science.gov (United States)

Usta, Mirac Baris; Gumus, Yusuf Yasin; Say, Gokce Nur; Bozkurt, Abdullah; Şahin, Berkan; Karabekiroğlu, Koray

2018-04-01

In literature, recent evidence has shown that the hypothalamic-pituitary-adrenal (HPA) axis can be dysregulated in patients with post-traumatic stress disorder (PTSD) and HPA axis hormones may predict the psychotherapy treatment response in patients with PTSD. In this study, it was aimed to investigate changing cortisol and DHEA-S levels post-eye movement desensitization and reprocessing (EMDR) therapy and the relationship between treatment response and basal cortisol, and DHEA-S levels before treatment. The study group comprised 40 adolescents (age, 12-18 years) with PTSD. The PTSD symptoms were assessed using the Child Depression Inventory (CDI) and Child Post-traumatic Stress Reaction Index (CPSRI) and the blood cortisol and DHEA-S were measured with the chemiluminescence method before and after treatment. A maximum of six sessions of EMDR therapy were conducted by an EMDR level-1 trained child psychiatry resident. Treatment response was measured by the pre- to post-treatment decrease in self-reported and clinical PTSD severity. Pre- and post-treatment DHEA-S and cortisol levels did not show any statistically significant difference. Pre-treatment CDI scores were negatively correlated with pre-treatment DHEA-S levels (r: -0.39). ROC analysis demonstrated that the DHEA-S/cortisol ratio predicts treatment response at a medium level (AUC: 0.703, p: .030, sensitivity: 0.65, specificity: 0.86). The results of this study suggested that the DHEA-S/cortisol ratio may predict treatment response in adolescents with PTSD receiving EMDR therapy. The biochemical parameter of HPA-axis activity appears to be an important predictor of positive clinical response in adolescent PTSD patients, and could be used in clinical practice to predict PTSD treatment in the future.

Oxidative potential of particulate matter 2.5 as predictive indicator of cellular stress

International Nuclear Information System (INIS)

Crobeddu, Bélinda; Aragao-Santiago, Leticia; Bui, Linh-Chi; Boland, Sonja; Baeza Squiban, Armelle

2017-01-01

Particulate air pollution being recognized to be responsible for short and long term health effects, regulations for particulate matter with an aerodynamic diameter less than 2.5 (PM 2.5 ) are more and more restrictive. PM 2.5 regulation is based on mass without taking into account PM 2.5 composition that drives toxicity. Measurement of the oxidative potential (OP) of PM could be an additional PM indicator that would encompass the PM components involved in oxidative stress, the main mechanism of PM toxicity. We compared different methods to evaluate the intrinsic oxidative potential of PM 2.5 sampled in Paris and their ability to reflect the oxidative and inflammatory response in bronchial epithelial cells used as relevant target organ cells. The dithiothreitol depletion assay, the antioxidant (ascorbic acid and glutathione) depletion assay (OP AO ), the plasmid scission assay and the dichlorofluorescein (DCFH) oxidation assay used to characterize the OP of PM 2.5 (10–100 μg/mL) provided positive results of different magnitude with all the PM 2.5 samples used with significant correlation with different metals such as Cu and Zn as well as total polyaromatic hydrocarbons and the soluble organic fraction. The OP AO assay showed the best correlation with the production of intracellular reactive oxygen species by NCI-H292 cell line assessed by DCFH oxidation and with the expression of anti-oxidant genes (superoxide dismutase 2, heme-oxygenase-1) as well as the proinflammatory response (Interleukin 6) when exposed from 1 to 10 μg/cm 2 . The OP AO assay appears as the most prone to predict the biological effect driven by PM 2.5 and related to oxidative stress. - Highlights: • 5 Acellular assays were used to compare the intrinsic oxidative potential (OP) of PM. • The amount of ROS generation in bronchial cells is particle dependent. • Particles induce the expression of anti-oxidant and proinflammatory genes. • Biological effects correlates with OP assay

Dose response relationship in anti-stress gene regulatory networks.

Science.gov (United States)

Zhang, Qiang; Andersen, Melvin E

2007-03-02

the level of local gains, presence of gain-changing events, and degree of feedforward gene activation, this region can appear as superlinear, sublinear, or even J-shaped. The general dose response transition proposed here was further examined in a complex anti-electrophilic stress pathway, which involves multiple genes, enzymes, and metabolic reactions. This work would help biologists and especially toxicologists to better assess and predict the cellular impact brought about by biological stressors.

Dose response relationship in anti-stress gene regulatory networks.

Directory of Open Access Journals (Sweden)

Qiang Zhang

2007-03-01

, and depending on the level of local gains, presence of gain-changing events, and degree of feedforward gene activation, this region can appear as superlinear, sublinear, or even J-shaped. The general dose response transition proposed here was further examined in a complex anti-electrophilic stress pathway, which involves multiple genes, enzymes, and metabolic reactions. This work would help biologists and especially toxicologists to better assess and predict the cellular impact brought about by biological stressors.

Everyday stress response targets in the science of behavior change.

Science.gov (United States)

Smyth, Joshua M; Sliwinski, Martin J; Zawadzki, Matthew J; Scott, Stacey B; Conroy, David E; Lanza, Stephanie T; Marcusson-Clavertz, David; Kim, Jinhyuk; Stawski, Robert S; Stoney, Catherine M; Buxton, Orfeu M; Sciamanna, Christopher N; Green, Paige M; Almeida, David M

2018-02-01

Stress is an established risk factor for negative health outcomes, and responses to everyday stress can interfere with health behaviors such as exercise and sleep. In accordance with the Science of Behavior Change (SOBC) program, we apply an experimental medicine approach to identifying stress response targets, developing stress response assays, intervening upon these targets, and testing intervention effectiveness. We evaluate an ecologically valid, within-person approach to measuring the deleterious effects of everyday stress on physical activity and sleep patterns, examining multiple stress response components (i.e., stress reactivity, stress recovery, and stress pile-up) as indexed by two key response indicators (negative affect and perseverative cognition). Our everyday stress response assay thus measures multiple malleable stress response targets that putatively shape daily health behaviors (physical activity and sleep). We hypothesize that larger reactivity, incomplete recovery, and more frequent stress responses (pile-up) will negatively impact health behavior enactment in daily life. We will identify stress-related reactivity, recovery, and response in the indicators using coordinated analyses across multiple naturalistic studies. These results are the basis for developing a new stress assay and replicating the initial findings in a new sample. This approach will advance our understanding of how specific aspects of everyday stress responses influence health behaviors, and can be used to develop and test an innovative ambulatory intervention for stress reduction in daily life to enhance health behaviors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dehydration Stress Contributes to the Enhancement of Plant Defense Response and Mite Performance on Barley

Directory of Open Access Journals (Sweden)

M. E. Santamaria

2018-04-01

Full Text Available Under natural conditions, plants suffer different stresses simultaneously or in a sequential way. At present, the combined effect of biotic and abiotic stressors is one of the most important threats to crop production. Understanding how plants deal with the panoply of potential stresses affecting them is crucial to develop biotechnological tools to protect plants. As well as for drought stress, the economic importance of the spider mite on agriculture is expected to increase due to climate change. Barley is a host of the polyphagous spider mite Tetranychus urticae and drought produces important yield losses. To obtain insights on the combined effect of drought and mite stresses on the defensive response of this cereal, we have analyzed the transcriptomic responses of barley plants subjected to dehydration (water-deficit treatment, spider mite attack, or to the combined dehydration-spider mite stress. The expression patterns of mite-induced responsive genes included many jasmonic acid responsive genes and were quickly induced. In contrast, genes related to dehydration tolerance were later up-regulated. Besides, a higher up-regulation of mite-induced defenses was showed by the combined dehydration and mite treatment than by the individual mite stress. On the other hand, the performance of the mite in dehydration stressed and well-watered plants was tested. Despite the stronger defensive response in plants that suffer dehydration and mite stresses, the spider mite demonstrates a better performance under dehydration condition than in well-watered plants. These results highlight the complexity of the regulatory events leading to the response to a combination of stresses and emphasize the difficulties to predict their consequences on crop production.

Dehydration Stress Contributes to the Enhancement of Plant Defense Response and Mite Performance on Barley

Science.gov (United States)

Santamaria, M. E.; Diaz, Isabel; Martinez, Manuel

2018-01-01

Under natural conditions, plants suffer different stresses simultaneously or in a sequential way. At present, the combined effect of biotic and abiotic stressors is one of the most important threats to crop production. Understanding how plants deal with the panoply of potential stresses affecting them is crucial to develop biotechnological tools to protect plants. As well as for drought stress, the economic importance of the spider mite on agriculture is expected to increase due to climate change. Barley is a host of the polyphagous spider mite Tetranychus urticae and drought produces important yield losses. To obtain insights on the combined effect of drought and mite stresses on the defensive response of this cereal, we have analyzed the transcriptomic responses of barley plants subjected to dehydration (water-deficit) treatment, spider mite attack, or to the combined dehydration-spider mite stress. The expression patterns of mite-induced responsive genes included many jasmonic acid responsive genes and were quickly induced. In contrast, genes related to dehydration tolerance were later up-regulated. Besides, a higher up-regulation of mite-induced defenses was showed by the combined dehydration and mite treatment than by the individual mite stress. On the other hand, the performance of the mite in dehydration stressed and well-watered plants was tested. Despite the stronger defensive response in plants that suffer dehydration and mite stresses, the spider mite demonstrates a better performance under dehydration condition than in well-watered plants. These results highlight the complexity of the regulatory events leading to the response to a combination of stresses and emphasize the difficulties to predict their consequences on crop production. PMID:29681917

Hypothesis: NDL proteins function in stress responses by regulating microtubule organization.

Science.gov (United States)

Khatri, Nisha; Mudgil, Yashwanti

2015-01-01

N-MYC DOWNREGULATED-LIKE proteins (NDL), members of the alpha/beta hydrolase superfamily were recently rediscovered as interactors of G-protein signaling in Arabidopsis thaliana. Although the precise molecular function of NDL proteins is still elusive, in animals these proteins play protective role in hypoxia and expression is induced by hypoxia and nickel, indicating role in stress. Homology of NDL1 with animal counterpart N-MYC DOWNREGULATED GENE (NDRG) suggests similar functions in animals and plants. It is well established that stress responses leads to the microtubule depolymerization and reorganization which is crucial for stress tolerance. NDRG is a microtubule-associated protein which mediates the microtubule organization in animals by causing acetylation and increases the stability of α-tubulin. As NDL1 is highly homologous to NDRG, involvement of NDL1 in the microtubule organization during plant stress can also be expected. Discovery of interaction of NDL with protein kinesin light chain- related 1, enodomembrane family protein 70, syntaxin-23, tubulin alpha-2 chain, as a part of G protein interactome initiative encourages us to postulate microtubule stabilizing functions for NDL family in plants. Our search for NDL interactors in G protein interactome also predicts the role of NDL proteins in abiotic stress tolerance management. Based on published report in animals and predicted interacting partners for NDL in G protein interactome lead us to hypothesize involvement of NDL in the microtubule organization during abiotic stress management in plants.

Child anxiety symptoms related to longitudinal cortisol trajectories and acute stress responses: evidence of developmental stress sensitization.

Science.gov (United States)

Laurent, Heidemarie K; Gilliam, Kathryn S; Wright, Dorianne B; Fisher, Philip A

2015-02-01

Cross-sectional research suggests that individuals at risk for internalizing disorders show differential activation levels and/or dynamics of stress-sensitive physiological systems, possibly reflecting a process of stress sensitization. However, there is little longitudinal research to clarify how the development of these systems over time relates to activation during acute stress, and how aspects of such activation map onto internalizing symptoms. We investigated children's (n = 107) diurnal hypothalamic-pituitary-adrenal activity via salivary cortisol (morning and evening levels) across 29 assessments spanning 6+ years, and related longitudinal patterns to acute stress responses at the end of this period (age 9-10). Associations with child psychiatric symptoms at age 10 were also examined to determine internalizing risk profiles. Increasing morning cortisol levels across assessments predicted less of a cortisol decline following interpersonal stress at age 9, and higher cortisol levels during performance stress at age 10. These same profiles of high and/or sustained cortisol elevation during psychosocial stress were associated with child anxiety symptoms. Results suggest developmental sensitization to stress-reflected in rising morning cortisol and eventual hyperactivation during acute stress exposure-may distinguish children at risk for internalizing disorders. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

Periodic and chaotic psychological stress variations as predicted by a social support buffered response model

Science.gov (United States)

Field, Richard J.; Gallas, Jason A. C.; Schuldberg, David

2017-08-01

Recent work has introduced social dynamic models of people's stress-related processes, some including amelioration of stress symptoms by support from others. The effects of support may be ;direct;, depending only on the level of support, or ;buffering;, depending on the product of the level of support and level of stress. We focus here on the nonlinear buffering term and use a model involving three variables (and 12 control parameters), including stress as perceived by the individual, physical and psychological symptoms, and currently active social support. This model is quantified by a set of three nonlinear differential equations governing its stationary-state stability, temporal evolution (sometimes oscillatory), and how each variable affects the others. Chaos may appear with periodic forcing of an environmental stress parameter. Here we explore this model carefully as the strength and amplitude of this forcing, and an important psychological parameter relating to self-kindling in the stress response, are varied. Three significant observations are made: 1. There exist many complex but orderly regions of periodicity and chaos, 2. there are nested regions of increasing number of peaks per cycle that may cascade to chaos, and 3. there are areas where more than one state, e.g., a period-2 oscillation and chaos, coexist for the same parameters; which one is reached depends on initial conditions.

Energetic stress: The reciprocal relationship between energy availability and the stress response.

Science.gov (United States)

Harrell, C S; Gillespie, C F; Neigh, G N

2016-11-01

The worldwide epidemic of metabolic syndromes and the recognized burden of mental health disorders have driven increased research into the relationship between the two. A maladaptive stress response is implicated in both mental health disorders and metabolic disorders, implicating the hypothalamic-pituitary-adrenal (HPA) axis as a key mediator of this relationship. This review explores how an altered energetic state, such as hyper- or hypoglycemia, as may be manifested in obesity or diabetes, affects the stress response and the HPA axis in particular. We propose that changes in energetic state or energetic demands can result in "energetic stress" that can, if prolonged, lead to a dysfunctional stress response. In this review, we summarize the role of the hypothalamus in modulating energy homeostasis and then briefly discuss the relationship between metabolism and stress-induced activation of the HPA axis. Next, we examine seven mechanisms whereby energetic stress interacts with neuroendocrine stress response systems, including by glucocorticoid signaling both within and beyond the HPA axis; by nutrient-induced changes in glucocorticoid signaling; by impacting the sympathetic nervous system; through changes in other neuroendocrine factors; by inducing inflammatory changes; and by altering the gut-brain axis. Recognizing these effects of energetic stress can drive novel therapies and prevention strategies for mental health disorders, including dietary intervention, probiotics, and even fecal transplant. Copyright © 2015 Elsevier Inc. All rights reserved.

Approaches to modeling the development of physiological stress responsivity.

Science.gov (United States)

Hinnant, J Benjamin; Philbrook, Lauren E; Erath, Stephen A; El-Sheikh, Mona

2018-05-01

Influential biopsychosocial theories have proposed that some developmental periods in the lifespan are potential pivot points or opportunities for recalibration of stress response systems. To date, however, there have been few longitudinal studies of physiological stress responsivity and no studies comparing change in physiological stress responsivity across developmental periods. Our goals were to (a) address conceptual and methodological issues in studying the development of physiological stress responsivity within and between individuals, and (b) provide an exemplar for evaluating development of responsivity to stress in the parasympathetic nervous system, comparing respiratory sinus arrhythmia (RSA) responsivity from middle to late childhood with middle to late adolescence. We propose the use of latent growth modeling of stress responsivity that includes time-varying covariates to account for conceptual and methodological issues in the measurement of physiological stress responsivity. Such models allow researchers to address key aspects of developmental sensitivity including within-individual variability, mean level change over time, and between-individual variability over time. In an empirical example, we found significant between-individual variability over time in RSA responsivity to stress during middle to late childhood but not during middle to late adolescence, suggesting that childhood may be a period of greater developmental sensitivity at the between-individual level. © 2017 Society for Psychophysiological Research.

Proteomic studies of drought stress response in Fabaceae

Directory of Open Access Journals (Sweden)

Tanja ZADRAŽNIK

2015-11-01

Full Text Available Drought stress is a serious threat to crop production that influences plant growth and development and subsequently causes reduced quantity and quality of the yield. Plant stress induces changes in cell metabolism, which includes differential expression of proteins. Proteomics offer a powerful approach to analyse proteins involved in drought stress response of plants. Analyses of changes in protein abundance of legumes under drought stress are very important, as legumes play an important role in human and animal diet and are often exposed to drought. The presented results of proteomic studies of selected legumes enable better understanding of molecular mechanisms of drought stress response. The study of drought stress response of plants with proteomic approach may contribute to the development of potential drought-response markers and to the development of drought-tolerant cultivars of different legume crop species.

Biological stress response terminology: Integrating the concepts of adaptive response and preconditioning stress within a hormetic dose-response framework

International Nuclear Information System (INIS)

Calabrese, Edward J.; Bachmann, Kenneth A.; Bailer, A. John; Bolger, P. Michael; Borak, Jonathan; Cai, Lu; Cedergreen, Nina; Cherian, M. George; Chiueh, Chuang C.; Clarkson, Thomas W.; Cook, Ralph R.; Diamond, David M.; Doolittle, David J.; Dorato, Michael A.; Duke, Stephen O.; Feinendegen, Ludwig; Gardner, Donald E.; Hart, Ronald W.; Hastings, Kenneth L.; Hayes, A. Wallace; Hoffmann, George R.; Ives, John A.; Jaworowski, Zbigniew; Johnson, Thomas E.; Jonas, Wayne B.; Kaminski, Norbert E.; Keller, John G.; Klaunig, James E.; Knudsen, Thomas B.; Kozumbo, Walter J.; Lettieri, Teresa; Liu, Shu-Zheng; Maisseu, Andre; Maynard, Kenneth I.; Masoro, Edward J.; McClellan, Roger O.; Mehendale, Harihara M.; Mothersill, Carmel; Newlin, David B.; Nigg, Herbert N.; Oehme, Frederick W.; Phalen, Robert F.; Philbert, Martin A.; Rattan, Suresh I.S.; Riviere, Jim E.; Rodricks, Joseph; Sapolsky, Robert M.; Scott, Bobby R.; Seymour, Colin; Sinclair, David A.; Smith-Sonneborn, Joan; Snow, Elizabeth T.; Spear, Linda; Stevenson, Donald E.; Thomas, Yolene; Tubiana, Maurice; Williams, Gary M.; Mattson, Mark P.

2007-01-01

Many biological subdisciplines that regularly assess dose-response relationships have identified an evolutionarily conserved process in which a low dose of a stressful stimulus activates an adaptive response that increases the resistance of the cell or organism to a moderate to severe level of stress. Due to a lack of frequent interaction among scientists in these many areas, there has emerged a broad range of terms that describe such dose-response relationships. This situation has become problematic because the different terms describe a family of similar biological responses (e.g., adaptive response, preconditioning, hormesis), adversely affecting interdisciplinary communication, and possibly even obscuring generalizable features and central biological concepts. With support from scientists in a broad range of disciplines, this article offers a set of recommendations we believe can achieve greater conceptual harmony in dose-response terminology, as well as better understanding and communication across the broad spectrum of biological disciplines

Response of Desulfovibrio vulgaris to Alkaline Stress

Energy Technology Data Exchange (ETDEWEB)

Stolyar, S.; He, Q.; He, Z.; Yang, Z.; Borglin, S.E.; Joyner, D.; Huang, K.; Alm, E.; Hazen, T.C.; Zhou, J.; Wall, J.D.; Arkin, A.P.; Stahl, D.A.

2007-11-30

The response of exponentially growing Desulfovibrio vulgarisHildenborough to pH 10 stress was studied using oligonucleotidemicroarrays and a study set of mutants with genes suggested by microarraydata to be involved in the alkaline stress response deleted. The datashowed that the response of D. vulgaris to increased pH is generallysimilar to that of Escherichia coli but is apparently controlled byunique regulatory circuits since the alternative sigma factors (sigma Sand sigma E) contributing to this stress response in E. coli appear to beabsent in D. vulgaris. Genes previously reported to be up-regulated in E.coli were up-regulated in D. vulgaris; these genes included three ATPasegenes and a tryptophan synthase gene. Transcription of chaperone andprotease genes (encoding ATP-dependent Clp and La proteases and DnaK) wasalso elevated in D. vulgaris. As in E. coli, genes involved in flagellumsynthesis were down-regulated. The transcriptional data also identifiedregulators, distinct from sigma S and sigma E, that are likely part of aD. vulgaris Hildenborough-specific stress response system.Characterization of a study set of mutants with genes implicated inalkaline stress response deleted confirmed that there was protectiveinvolvement of the sodium/proton antiporter NhaC-2, tryptophanase A, andtwo putative regulators/histidine kinases (DVU0331 andDVU2580).

Testing the Predictive Power of Coulomb Stress on Aftershock Sequences

Science.gov (United States)

Woessner, J.; Lombardi, A.; Werner, M. J.; Marzocchi, W.

2009-12-01

Empirical and statistical models of clustered seismicity are usually strongly stochastic and perceived to be uninformative in their forecasts, since only marginal distributions are used, such as the Omori-Utsu and Gutenberg-Richter laws. In contrast, so-called physics-based aftershock models, based on seismic rate changes calculated from Coulomb stress changes and rate-and-state friction, make more specific predictions: anisotropic stress shadows and multiplicative rate changes. We test the predictive power of models based on Coulomb stress changes against statistical models, including the popular Short Term Earthquake Probabilities and Epidemic-Type Aftershock Sequences models: We score and compare retrospective forecasts on the aftershock sequences of the 1992 Landers, USA, the 1997 Colfiorito, Italy, and the 2008 Selfoss, Iceland, earthquakes. To quantify predictability, we use likelihood-based metrics that test the consistency of the forecasts with the data, including modified and existing tests used in prospective forecast experiments within the Collaboratory for the Study of Earthquake Predictability (CSEP). Our results indicate that a statistical model performs best. Moreover, two Coulomb model classes seem unable to compete: Models based on deterministic Coulomb stress changes calculated from a given fault-slip model, and those based on fixed receiver faults. One model of Coulomb stress changes does perform well and sometimes outperforms the statistical models, but its predictive information is diluted, because of uncertainties included in the fault-slip model. Our results suggest that models based on Coulomb stress changes need to incorporate stochastic features that represent model and data uncertainty.

Cortisol responses to psychosocial stress predict depression trajectories: social-evaluative threat and prior depressive episodes as moderators.

Science.gov (United States)

Morris, Matthew C; Rao, Uma; Garber, Judy

2012-12-20

Alterations of hypothalamic-pituitary-adrenal (HPA) function are well-established in adults with current depression. HPA alterations may persist into remission and confer increased risk for recurrence. A modified version of the Trier Social Stress Test (TSST) was administered at baseline to 32 young adults with remitted major depressive disorder and 36 never-depressed controls. Participants were randomly assigned to either a 'high-stress' condition involving social evaluation or a 'low-stress' control condition. Cortisol concentrations were measured in saliva samples throughout the TSST. Participants were assessed again after 6 months for the occurrence of stressful life events and depressive symptoms/disorders during the follow-up period. Participants who exhibited enhanced cortisol reactivity in the low-stress condition showed increases in depressive symptoms over follow-up, after controlling for stressful life events during the follow-up period. Anticipatory stress cortisol and cortisol reactivity each interacted with history of depressive episodes to predict depression trajectories. The single TSST administration limits conclusions about whether alterations of cortisol reactivity represent trait-like vulnerability factors or consequences ("scars') of past depression. These results extend previous findings on stress sensitivity in depression and suggest that altered HPA function during remission could reflect an endophenotype for vulnerability to depression recurrence. Findings support interactive models of risk for depression recurrence implicating HPA function, depression history, and sensitivity to minor stressors. Results may have implications for interventions that match treatment approaches to profiles of HPA function. Copyright © 2012 Elsevier B.V. All rights reserved.

Staphylococcal response to oxidative stress

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Rosmarie eGaupp

2012-03-01

Full Text Available Staphylococci are a versatile genus of bacteria that are capable of causing acute and chronic infections in diverse host species. The success of staphylococci as pathogens is due in part to their ability to mitigate endogenous and exogenous oxidative and nitrosative stress. Endogenous oxidative stress is a consequence of life in an aerobic environment; whereas, exogenous oxidative and nitrosative stress are often due to the bacteria’s interaction with host immune systems. To overcome the deleterious effects of oxidative and nitrosative stress, staphylococci have evolved protection, detoxification, and repair mechanisms that are controlled by a network of regulators. In this review, we summarize the cellular targets of oxidative stress, the mechanisms by which staphylococci sense oxidative stress and damage, oxidative stress protection and repair mechanisms, and regulation of the oxidative stress response. When possible, special attention is given to how the oxidative stress defense mechanisms help staphylococci control oxidative stress in the host.

Plant Responses to Nanoparticle Stress

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Zahed Hossain

2015-11-01

Full Text Available With the rapid advancement in nanotechnology, release of nanoscale materials into the environment is inevitable. Such contamination may negatively influence the functioning of the ecosystems. Many manufactured nanoparticles (NPs contain heavy metals, which can cause soil and water contamination. Proteomic techniques have contributed substantially in understanding the molecular mechanisms of plant responses against various stresses by providing a link between gene expression and cell metabolism. As the coding regions of genome are responsible for plant adaptation to adverse conditions, protein signatures provide insights into the phytotoxicity of NPs at proteome level. This review summarizes the recent contributions of plant proteomic research to elaborate the complex molecular pathways of plant response to NPs stress.

Quantitative Proteomics for the Comprehensive Analysis of Stress Responses of Lactobacillus paracasei subsp. paracasei F19.

Science.gov (United States)

Schott, Ann-Sophie; Behr, Jürgen; Geißler, Andreas J; Kuster, Bernhard; Hahne, Hannes; Vogel, Rudi F

2017-10-06

Lactic acid bacteria are broadly employed as starter cultures in the manufacture of foods. Upon technological preparation, they are confronted with drying stress that amalgamates numerous stress conditions resulting in losses of fitness and survival. To better understand and differentiate physiological stress responses, discover general and specific markers for the investigated stress conditions, and predict optimal preconditioning for starter cultures, we performed a comprehensive genomic and quantitative proteomic analysis of a commonly used model system, Lactobacillus paracasei subsp. paracasei TMW 1.1434 (isogenic with F19) under 11 typical stress conditions, including among others oxidative, osmotic, pH, and pressure stress. We identified and quantified >1900 proteins in triplicate analyses, representing 65% of all genes encoded in the genome. The identified genes were thoroughly annotated in terms of subcellular localization prediction and biological functions, suggesting unbiased and comprehensive proteome coverage. In total, 427 proteins were significantly differentially expressed in at least one condition. Most notably, our analysis suggests that optimal preconditioning toward drying was predicted to be alkaline and high-pressure stress preconditioning. Taken together, we believe the presented strategy may serve as a prototypic example for the analysis and utility of employing quantitative-mass-spectrometry-based proteomics to study bacterial physiology.

Response inhibition and cognitive appraisal in clients with acute stress disorder and posttraumatic stress disorder.

Science.gov (United States)

Abolghasemi, Abass; Bakhshian, Fereshteh; Narimani, Mohammad

2013-08-01

The purpose of the present study was to compare response inhibition and cognitive appraisal in clients with acute stress disorder, clients with posttraumatic stress disorder, and normal individuals. This was a comparative study. The sample consisted of 40 clients with acute stress disorder, 40 patients with posttraumatic stress disorder, and 40 normal individuals from Mazandaran province selected through convenience sampling method. Data were collected using Composite International Diagnostic Interview, Stroop Color-Word Test, Posttraumatic Cognitions Inventory, and the Impact of Event Scale. Results showed that individuals with acute stress disorder are less able to inhibit inappropriate responses and have more impaired cognitive appraisals compared to those with posttraumatic stress disorder. Moreover, results showed that response inhibition and cognitive appraisal explain 75% of the variance in posttraumatic stress disorder symptoms and 38% of the variance in posttraumatic stress disorder symptoms. The findings suggest that response inhibition and cognitive appraisal are two variables that influence the severity of posttraumatic stress disorder and acute stress disorder symptoms. Also, these results have important implications for pathology, prevention, and treatment of posttraumatic stress disorder and acute stress disorder.

SKA2 Methylation is Involved in Cortisol Stress Reactivity and Predicts the Development of Post-Traumatic Stress Disorder (PTSD) After Military Deployment.

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Boks, Marco P; Rutten, Bart P F; Geuze, Elbert; Houtepen, Lotte C; Vermetten, Eric; Kaminsky, Zachary; Vinkers, Christiaan H

2016-04-01

Genomic variation in the SKA2 gene has recently been identified as a promising suicide biomarker. In light of its role in glucocorticoid receptor transactivation, we investigated whether SKA2 DNA methylation influences cortisol stress reactivity and is involved in the development of post-traumatic stress disorder (PTSD). Increased SKA2 methylation was significantly associated with lower cortisol stress reactivity in 85 healthy individuals exposed to the Trier Social Stress Test (B=-173.40, t=-2.324, p-value=0.023). Next, we observed that longitudinal decreases in SKA2 methylation after deployment were associated with the emergence of post-deployment PTSD symptoms in a Dutch military cohort (N=93; B=-0.054, t=-3.706, p-value=3.66 × 10(-4)). In contrast, exposure to traumatic stress during deployment by itself resulted in longitudinal increases in SKA2 methylation (B=0.037, t=4.173, p-value=6.98 × 10(-5)). Using pre-deployment SKA2 methylation levels and childhood trauma exposure, we found that the previously published suicide prediction rule significantly predicted post-deployment PTSD symptoms (AUC=0.66, 95% CI: 0.53-0.79) with an optimal sensitivity of 0.81 and specificity of 0.91. Permutation analysis using random methylation loci supported these findings. Together, these data establish the importance of SKA2 for cortisol stress responsivity and the development of PTSD and provide further evidence that SKA2 is a promising biomarker for stress-related disorders including PTSD.

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

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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

Interaction between serotonin transporter gene variants and life events predicts response to antidepressants in the GENDEP project

DEFF Research Database (Denmark)

Keers, R.; Uher, R.; Huezo-Diaz, P.

2011-01-01

, and several polymorphisms in the serotonin transporter gene (SLC6A4) have been genotyped including the serotonin transporter-linked polymorphic region (5-HTTLPR). Stressful life events were shown to predict a significantly better response to escitalopram but had no effect on response to nortriptyline...

Dysfunctional stress responses in chronic pain.

Science.gov (United States)

Woda, Alain; Picard, Pascale; Dutheil, Frédéric

2016-09-01

Many dysfunctional and chronic pain conditions overlap. This review describes the different modes of chronic deregulation of the adaptive response to stress which may be a common factor for these conditions. Several types of dysfunction can be identified within the hypothalamo-pituitary-adrenal axis: basal hypercortisolism, hyper-reactivity, basal hypocortisolism and hypo-reactivity. Neuroactive steroid synthesis is another component of the adaptive response to stress. Dehydroepiandrosterone (DHEA) and its sulfated form DHEA-S, and progesterone and its derivatives are synthetized in cutaneous, nervous, and adipose cells. They are neuroactive factors that act locally. They may have a role in the localization of the symptoms and their levels can vary both in the central nervous system and in the periphery. Persistent changes in neuroactive steroid levels or precursors can induce localized neurodegeneration. The autonomic nervous system is another component of the stress response. Its dysfunction in chronic stress responses can be expressed by decreased basal parasympathethic activity, increased basal sympathetic activity or sympathetic hyporeactivity to a stressful stimulus. The immune and genetic systems also participate. The helper-T cells Th1 secrete pro-inflammatory cytokines such as IL-1-β, IL-2, IL-6, IL-8, IL-12, IFN-γ, and TNF-α, whereas Th2 secrete anti-inflammatory cytokines: IL-4, IL-10, IGF-10, IL-13. Chronic deregulation of the Th1/Th2 balance can occur in favor of anti- or pro-inflammatory direction, locally or systemically. Individual vulnerability to stress can be due to environmental factors but can also be genetically influenced. Genetic polymorphisms and epigenetics are the main keys to understanding the influence of genetics on the response of individuals to constraints. Copyright © 2016 Elsevier Ltd. All rights reserved.

Glucocorticoid exposure in preterm babies predicts saliva cortisol response to immunization at 4 months.

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Glover, Vivette; Miles, Rachel; Matta, Simon; Modi, Neena; Stevenson, James

2005-12-01

Preterm babies are exposed to multiple stressors and this may have long-term effects. In particular, high levels of endogenous cortisol might have a programming effect on the hypothalamic-pituitary-adrenal axis as may administered glucocorticoids. In this study, we aimed to test the hypothesis that the level of endogenous and exogenous glucocorticoid exposure during the neonatal period predicts the saliva cortisol response to immunization at 4 mo of age. We followed 45 babies born below 32 wk gestation. We showed that their concentration of plasma cortisol during the first 4 wk was 358, 314, 231, and 195 nmol/L cortisol, respectively (geometric mean). This is four to seven times higher than fetal levels at the same gestational age range. We used routine immunization at 4 mo and 12 mo as a stressor and measured the change in saliva cortisol as the stress response. Mean circulating cortisol in the first 4 wk predicted the cortisol response at 4 but not at 12 mo. Path analysis showed that birthweight for gestational age, therapeutic antenatal steroids, and therapeutic postnatal steroids also contributed to the magnitude of the saliva cortisol response at 4 mo. This provides evidence that the magnitude of glucocorticoid exposure, both endogenous and exogenous, may have an effect on later stress responses.

The human coronary vasodilatory response to acute mental stress is mediated by neuronal nitric oxide synthase.

Science.gov (United States)

Khan, Sitara G; Melikian, Narbeh; Shabeeh, Husain; Cabaco, Ana R; Martin, Katherine; Khan, Faisal; O'Gallagher, Kevin; Chowienczyk, Philip J; Shah, Ajay M

2017-09-01

Mental stress-induced ischemia approximately doubles the risk of cardiac events in patients with coronary artery disease, yet the mechanisms underlying changes in coronary blood flow in response to mental stress are poorly characterized. Neuronal nitric oxide synthase (nNOS) regulates basal coronary blood flow in healthy humans and mediates mental stress-induced vasodilation in the forearm. However, its possible role in mental stress-induced increases in coronary blood flow is unknown. We studied 11 patients (6 men and 5 women, mean age: 58 ± 14 yr) undergoing elective diagnostic cardiac catheterization and assessed the vasodilator response to mental stress elicited by the Stroop color-word test. Intracoronary substance P (20 pmol/min) and isosorbide dinitrate (1 mg) were used to assess endothelium-dependent and -independent vasodilation, respectively. Coronary blood flow was estimated using intracoronary Doppler recordings and quantitative coronary angiography to measure coronary artery diameter. Mental stress increased coronary flow by 34 ± 7.0% over the preceding baseline during saline infusion ( P stress increased coronary artery diameter by 6.9 ± 3.7% ( P = 0.02) and 0.5 ± 2.8% ( P = 0.51) in the presence of S -methyl-l-thiocitrulline. The response to substance P did not predict the response to mental stress ( r 2 = -0.22, P = 0.83). nNOS mediates the human coronary vasodilator response to mental stress, predominantly through actions at the level of coronary resistance vessels. NEW & NOTEWORTHY Acute mental stress induces vasodilation of the coronary microvasculature. Here, we show that this response involves neuronal nitric oxide synthase in the human coronary circulation.Listen to this article's corresponding podcast at http://ajpheart.podbean.com/e/nnos-and-coronary-flow-during-mental-stress/. Copyright © 2017 the American Physiological Society.

Comfort food is comforting to those most stressed: evidence of the chronic stress response network in high stress women.

Science.gov (United States)

Tomiyama, A Janet; Dallman, Mary F; Epel, Elissa S

2011-11-01

Chronically stressed rodents who are allowed to eat calorie-dense "comfort" food develop greater mesenteric fat, which in turn dampens hypothalamic-pituitary-adrenocortical (HPA) axis activity. We tested whether similar relations exist in humans, at least cross-sectionally. Fifty-nine healthy premenopausal women were exposed to a standard laboratory stressor to examine HPA response to acute stress and underwent diurnal saliva sampling for basal cortisol and response to dexamethasone administration. Based on perceived stress scores, women were divided into extreme quartiles of low versus high stress categories. We found as hypothesized that the high stress group had significantly greater BMI and sagittal diameter, and reported greater emotional eating. In response to acute lab stressor, the high stress group showed a blunted cortisol response, lower diurnal cortisol levels, and greater suppression in response to dexamethasone. These cross-sectional findings support the animal model, which suggests that long-term adaptation to chronic stress in the face of dense calories result in greater visceral fat accumulation (via ingestion of calorie-dense food), which in turn modulates HPA axis response, resulting in lower cortisol levels. Copyright © 2011 Elsevier Ltd. All rights reserved.

Associations between circadian and stress response cortisol in children.

Science.gov (United States)

Simons, Sterre S H; Cillessen, Antonius H N; de Weerth, Carolina

2017-01-01

Hypothalamic-pituitary-adrenal (HPA) axis functioning is characterized by the baseline production of cortisol following a circadian rhythm, as well as by the superimposed production of cortisol in response to a stressor. However, it is relatively unknown whether the basal cortisol circadian rhythm is associated with the cortisol stress response in children. Since alterations in cortisol stress responses have been associated with mental and physical health, this study investigated whether the cortisol circadian rhythm is associated with cortisol stress responses in 6-year-old children. To this end, 149 normally developing children (M age  = 6.09 years; 70 girls) participated in an innovative social evaluative stress test that effectively provoked increases in cortisol. To determine the cortisol stress response, six cortisol saliva samples were collected and two cortisol stress response indices were calculated: total stress cortisol and cortisol stress reactivity. To determine children's cortisol circadian rhythm eight cortisol circadian samples were collected during two days. Total diurnal cortisol and diurnal cortisol decline scores were calculated as indices of the cortisol circadian rhythm. Hierarchical regression analyses indicated that higher total diurnal cortisol as well as a smaller diurnal cortisol decline, were both uniquely associated with higher total stress cortisol. No associations were found between the cortisol circadian rhythm indices and cortisol stress reactivity. Possible explanations for the patterns found are links with children's self-regulatory capacities and parenting quality.

Stress-related cortisol responsivity modulates prospective memory.

Science.gov (United States)

Glienke, K; Piefke, M

2017-12-01

It is known that there is inter-individual variation in behavioural and physiological stress reactions to the same stressor. The present study aimed to examine the impact of cortisol responsivity on performance in a complex real life-like prospective memory (PM) paradigm by a re-analysis of data published previously, with a focus on the taxonomy of cognitive dimensions of PM. Twenty-one male subjects were stressed with the Socially Evaluated Cold Pressor Test (SECPT) before the planning of intentions. Another group of 20 males underwent a control procedure. Salivary cortisol was measured to assess the intensity of the biological stress response. Additionally, participants rated the subjective experience of stress on a 5-point rating scale. Stressed participants were post-hoc differentiated in high (n = 11) and low cortisol responders (n = 10). Cortisol niveau differed significantly between the two groups, whereas subjective stress ratings did not. PM performance of low cortisol responders was stable across time and the PM performance of controls declined. High cortisol responders showed a nominally weaker PM retrieval across the early trails and significantly improved only on the last trial. The data demonstrate for the first time that participants with a low cortisol responsivity may benefit from stress exposure before the planning phase of PM. PM performance of high cortisol responders shows a more inconsistent pattern, which may be interpreted in the sense of a recency effect in PM retrieval. Alternatively, high cortisol responses may have a deteriorating effect on PM retrieval, which disappeared on the last trials of the task as a result of the decrease of cortisol levels across time. Importantly, the data also demonstrate that the intensity of cortisol responses does not necessarily correspond to the intensity of the mental experience of stress. © 2017 British Society for Neuroendocrinology.

Response Inhibition and Cognitive Appraisal in Clients with Acute Stress Disorder and Posttraumatic Stress Disorder

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Abass Abolghasemi

2013-09-01

Full Text Available Objective: The purpose of the present study was to compare response inhibition and cognitive appraisal in clients with acute stress disorder, clients with posttraumatic stress disorder, and normal individuals .Method:This was a comparative study. The sample consisted of 40 clients with acute stress disorder, 40 patients with posttraumatic stress disorder, and 40 normal individuals from Mazandaran province selected through convenience sampling method. Data were collected using Composite International Diagnostic Interview, Stroop Color-Word Test, Posttraumatic Cognitions Inventory, and the Impact of Event Scale. Results:Results showed that individuals with acute stress disorder are less able to inhibit inappropriate responses and have more impaired cognitive appraisals compared to those with posttraumatic stress disorder. Moreover, results showed that response inhibition and cognitive appraisal explain 75% of the variance in posttraumatic stress disorder symptoms and 38% of the variance in posttraumatic stress disorder symptoms .Conclusion:The findings suggest that response inhibition and cognitive appraisal are two variables that influence the severity of posttraumatic stress disorder and acute stress disorder symptoms. Also, these results have important implications for pathology, prevention, and treatment of posttraumatic stress disorder and acute stress disorder

Shy and bold great tits (Parus major): body temperature and breath rate in response to handling stress

NARCIS (Netherlands)

Carere, C.; Van Oers, K.

2004-01-01

A standard handling protocol was used to test the hypothesis that boldness predicts stress responsiveness in body temperature and breath rate. Great tit (Parus major) nestlings were taken from the field, hand reared until independence, and their response to a novel object was assessed. At the age of

Shy and bold great tits (Parus major) : body temperature and breath rate in response to handling stress

NARCIS (Netherlands)

Carere, C; van Oers, K

2004-01-01

A standard handling protocol was used to test the hypothesis that boldness predicts stress responsiveness in body temperature and breath rate. Great tit (Parus major) nestlings were taken from the field, hand reared until independence, and their response to a novel object was assessed. At the age of

The glucocorticoid stress response is attenuated but unrelated to reproductive investment during parental care in a teleost fish.

Science.gov (United States)

O'Connor, Constance M; Yick, Claire Y; Gilmour, Kathleen M; Van Der Kraak, Glen; Cooke, Steven J

2011-01-15

We investigated whether circulating glucocorticoids and androgens are correlated with reproductive investment in smallmouth bass (Micropterus dolomieu), a teleost fish with sole paternal care. Circulating cortisol and androgens prior to and 25 min following a standardized 3 min emersion stressor were quantified for non-reproductive and parental fish across the parental care period. To experimentally investigate the influence of reproductive investment on endocrine parameters, we manipulated brood size (reduced, enlarged, sham-treated, or unmanipulated) 24h prior to sampling parental fish. We predicted that fish guarding offspring would exhibit increased androgens and baseline cortisol levels, and an attenuated cortisol response to the stressor when compared with non-reproductive individuals. We further predicted that these effects would scale with reproductive investment. As predicted, parental care-providing fish exhibited lower post-stress plasma cortisol concentrations than non-reproductive fish. This difference was strongest early during parental care. However, no differences in baseline or post-stress cortisol concentrations were detected among parents guarding offspring with varying brood sizes. There was, however, a trend for parental fish to exhibit an increased cortisol response following brood manipulation, regardless of the direction of change in brood size, a response that likely reflected disturbance. No differences were found in baseline cortisol concentrations. Circulating androgens were found to be highest during early parental care, and no differences were found among parents guarding manipulated broods. Collectively, these findings demonstrate that the endocrine stress response is affected by reproductive status, but the response in this model species does not appear to be scaled according to reproductive investment as predicted by life-history theory. Copyright © 2010 Elsevier Inc. All rights reserved.

A Prospective Examination of Emotional Clarity, Stress Responses, and Depressive Symptoms during Early Adolescence

Science.gov (United States)

Flynn, Megan; Rudolph, Karen D.

2014-01-01

This study examined the proposal that difficulty understanding one's emotional experiences (i.e., deficits in emotional clarity) would interfere with the formulation of adaptive responses to interpersonal stress, which would then predict depressive symptoms. This process was examined across 3 years (fourth to sixth grade) during early…

Plasticity of the MAPK signaling network in response to mechanical stress.

Directory of Open Access Journals (Sweden)

Andrea M Pereira

Full Text Available Cells display versatile responses to mechanical inputs and recent studies have identified the mitogen-activated protein kinase (MAPK cascades mediating the biological effects observed upon mechanical stimulation. Although, MAPK pathways can act insulated from each other, several mechanisms facilitate the crosstalk between the components of these cascades. Yet, the combinatorial complexity of potential molecular interactions between these elements have prevented the understanding of their concerted functions. To analyze the plasticity of the MAPK signaling network in response to mechanical stress we performed a non-saturating epistatic screen in resting and stretched conditions employing as readout a JNK responsive dJun-FRET biosensor. By knocking down MAPKs, and JNK pathway regulators, singly or in pairs in Drosophila S2R+ cells, we have uncovered unexpected regulatory links between JNK cascade kinases, Rho GTPases, MAPKs and the JNK phosphatase Puc. These relationships have been integrated in a system network model at equilibrium accounting for all experimentally validated interactions. This model allows predicting the global reaction of the network to its modulation in response to mechanical stress. It also highlights its context-dependent sensitivity.

Neuronal responses to physiological stress

DEFF Research Database (Denmark)

Kagias, Konstantinos; Nehammer, Camilla; Pocock, Roger David John

2012-01-01

damage during aging that results in decline and eventual death. Studies have shown that the nervous system plays a pivotal role in responding to stress. Neurons not only receive and process information from the environment but also actively respond to various stresses to promote survival. These responses......Physiological stress can be defined as any external or internal condition that challenges the homeostasis of a cell or an organism. It can be divided into three different aspects: environmental stress, intrinsic developmental stress, and aging. Throughout life all living organisms are challenged...... by changes in the environment. Fluctuations in oxygen levels, temperature, and redox state for example, trigger molecular events that enable an organism to adapt, survive, and reproduce. In addition to external stressors, organisms experience stress associated with morphogenesis and changes in inner...

HPA axis response to psychological stress and treatment retention in residential substance abuse treatment: a prospective study.

Science.gov (United States)

Daughters, Stacey B; Richards, Jessica M; Gorka, Stephanie M; Sinha, Rajita

2009-12-01

Substance abuse treatment programs are often characterized by high rates of premature treatment dropout, which increases the likelihood of relapse to drug use. Negative reinforcement models of addiction emphasize an individual's inability to tolerate stress as a key factor for understanding poor substance use treatment outcomes, and evidence indicates that dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis contributes to an individual's inability to respond adaptively to stress. The aim of the current study was to examine whether HPA axis response to stress is predictive of treatment retention among a sample of drug users in residential substance abuse treatment. Prospective study assessing treatment retention among 102 individuals enrolled in residential substance abuse treatment. Participants completed two computerized stress tasks, and HPA axis response to stress was measured via salivary cortisol at five time points from baseline (pre-stress) to 30 min post-stress exposure. The main outcome measures were treatment dropout (categorical) and total number of days in treatment (continuous). A significantly higher salivary cortisol response to stress was observed in treatment dropouts compared to treatment completers. Further, Cox proportional hazards survival analyses indicated that a higher peak cortisol response to stress was associated with a shorter number of days to treatment dropout. Results indicate that a higher salivary cortisol level in response to stress is associated with an inability to remain in substance abuse treatment. These findings are the first to document a biological marker of stress as a predictor of substance abuse treatment dropout, and support the development and implementation of treatments targeting this vulnerability.

Prediction of elastic-plastic response of structural elements subjected to cyclic loading

International Nuclear Information System (INIS)

El Haddad, M.H.; Samaan, S.

1985-01-01

A simplified elastic-plastic analysis is developed to predict stress strain and force deformation response of structural metallic elements subjected to irregular cyclic loadings. In this analysis a simple elastic-plastic method for predicting the skeleton force deformation curve is developed. In this method, elastic and fully plastic solutions are first obtained for unknown quantities, such as deflection or local strains. Elastic and fully plastic contributions are then combined to obtain an elastic-plastic solution. The skeleton curve is doubled to establish the shape of the hysteresis loop. The complete force deformation response can therefore be simulated through reversal by reversal in accordance with hysteresis looping and material memory. Several examples of structural elements with various cross sections made from various materials and subjected to irregular cyclic loadings, are analysed. A close agreement is obtained between experimental results found in the literature and present predictions. (orig.)

Coping as a mediator of the relationship between stress mindset and psychological stress response: a pilot study.

Science.gov (United States)

Horiuchi, Satoshi; Tsuda, Akira; Aoki, Shuntaro; Yoneda, Kenichiro; Sawaguchi, Yusuke

2018-01-01

Coping, the cognitive and behavioral effort required to manage the effects of stressors, is important in determining psychological stress responses (ie, the emotional, behavioral, and cognitive responses to stressors). Coping was classified into categories of emotional expression (eg, negative feelings and thoughts), emotional support seeking (eg, approaching loved ones to request encouragement), cognitive reinterpretation (eg, reframing a problem positively), and problem solving (eg, working to solve the problem). Stress mindset refers to the belief that stress has enhancing (stress-is-enhancing mindset) or debilitating consequences (stress-is-debilitating mindset). This study examined whether coping mediated the relationship between stress mindset and psychological stress responses. Psychological stress responses were conceptualized as depression-anxiety, irritability-anger, and helplessness. The following two hypotheses were tested: 1) a stronger stress-is-enhancing mindset is associated with less frequent use of emotional expression, emotional support seeking, and problem solving, which in turn is associated with lower levels of depression-anxiety, irritability-anger, and helplessness; 2) a stronger stress-is-debilitating mindset is associated with more frequent use of these coping strategies, which in turn is associated with higher levels of these psychological stress responses. The participants were 30 male and 94 female undergraduate and graduate students (mean age =20.4 years). Stress mindset, coping, and psychological stress responses were measured using self-report questionnaires. Six mediation analyses were performed with stress-is-enhancing mindset or stress-is-debilitating mindset as the independent variable, one of the psychological stress responses as the dependent variable, and the four coping strategies as mediators. Emotional expression partially mediated the relationship between a strong stress-is-debilitating mindset and higher irritability

The human coronary vasodilatory response to acute mental stress is mediated by neuronal nitric oxide synthase

Science.gov (United States)

Khan, Sitara G.; Melikian, Narbeh; Shabeeh, Husain; Cabaco, Ana R.; Martin, Katherine; Khan, Faisal; O’Gallagher, Kevin; Chowienczyk, Philip J.

2017-01-01

Mental stress-induced ischemia approximately doubles the risk of cardiac events in patients with coronary artery disease, yet the mechanisms underlying changes in coronary blood flow in response to mental stress are poorly characterized. Neuronal nitric oxide synthase (nNOS) regulates basal coronary blood flow in healthy humans and mediates mental stress-induced vasodilation in the forearm. However, its possible role in mental stress-induced increases in coronary blood flow is unknown. We studied 11 patients (6 men and 5 women, mean age: 58 ± 14 yr) undergoing elective diagnostic cardiac catheterization and assessed the vasodilator response to mental stress elicited by the Stroop color-word test. Intracoronary substance P (20 pmol/min) and isosorbide dinitrate (1 mg) were used to assess endothelium-dependent and -independent vasodilation, respectively. Coronary blood flow was estimated using intracoronary Doppler recordings and quantitative coronary angiography to measure coronary artery diameter. Mental stress increased coronary flow by 34 ± 7.0% over the preceding baseline during saline infusion (P coronary artery diameter by 6.9 ± 3.7% (P = 0.02) and 0.5 ± 2.8% (P = 0.51) in the presence of S-methyl-l-thiocitrulline. The response to substance P did not predict the response to mental stress (r2 = −0.22, P = 0.83). nNOS mediates the human coronary vasodilator response to mental stress, predominantly through actions at the level of coronary resistance vessels. NEW & NOTEWORTHY Acute mental stress induces vasodilation of the coronary microvasculature. Here, we show that this response involves neuronal nitric oxide synthase in the human coronary circulation. Listen to this article’s corresponding podcast at http://ajpheart.podbean.com/e/nnos-and-coronary-flow-during-mental-stress/. PMID:28646032

Antagonistic pleiotropy and mutation accumulation contribute to age-related decline in stress response.

Science.gov (United States)

Everman, Elizabeth R; Morgan, Theodore J

2018-02-01

As organisms age, the effectiveness of natural selection weakens, leading to age-related decline in fitness-related traits. The evolution of age-related changes associated with senescence is likely influenced by mutation accumulation (MA) and antagonistic pleiotropy (AP). MA predicts that age-related decline in fitness components is driven by age-specific sets of alleles, nonnegative genetic correlations within trait across age, and an increase in the coefficient of genetic variance. AP predicts that age-related decline in a trait is driven by alleles with positive effects on fitness in young individuals and negative effects in old individuals, and is expected to lead to negative genetic correlations within traits across age. We build on these predictions using an association mapping approach to investigate the change in additive effects of SNPs across age and among traits for multiple stress-response fitness-related traits, including cold stress with and without acclimation and starvation resistance. We found support for both MA and AP theories of aging in the age-related decline in stress tolerance. Our study demonstrates that the evolution of age-related decline in stress tolerance is driven by a combination of alleles that have age-specific additive effects, consistent with MA, as well as nonindependent and antagonistic genetic architectures characteristic of AP. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Prediction of life stress on athletes' burnout: the dual role of perceived stress.

Science.gov (United States)

Chyi, Theresa; Lu, Frank Jing-Horng; Wang, Erica T W; Hsu, Ya-Wen; Chang, Ko-Hsin

2018-01-01

Although many studies adopted Smith's (1986) cognitive-affective model of athletic burnout in examining stress-burnout relationship, very few studies examined the mediating/moderating role of perceived stress on the stress-burnout relationship. We sampled 195 college student-athletes and assessed their life stress, perceived stress, and burnout. Correlation analyses found all study variables correlated. Two separate hierarchical regression analyses found that the "distress" component of perceived stress mediated athletes' two types of life stress-burnout relationship but "counter-stress" component of perceived stress-moderated athletes' general-life stress-burnout relationship. We concluded that interweaving relationships among athletes' life stress, perceived stress, and burnout are not straightforward. Future research should consider the nature of athletes life stress, and dual role of perceived stress in examining its' association with related psychological responses in athletic settings.

Fundamental approaches to predicting stress corrosion: 'Quantitative micro-nano' (QMN) approach to predicting stress corrosion cracking in water cooled nuclear plants

International Nuclear Information System (INIS)

Staehle, R.W.

2010-01-01

This paper describes the modeling and experimental studies of stress corrosion cracking with full disciplinary set at the atomic level. Its objective is to develop an intellectual structure for quantitative prediction of stress corrosion cracking in water cooled reactors.

Consequences of ecological, evolutionary and biogeochemical uncertainty for coral reef responses to climatic stress.

Science.gov (United States)

Mumby, Peter J; van Woesik, Robert

2014-05-19

Coral reefs are highly sensitive to the stress associated with greenhouse gas emissions, in particular ocean warming and acidification. While experiments show negative responses of most reef organisms to ocean warming, some autotrophs benefit from ocean acidification. Yet, we are uncertain of the response of coral reefs as systems. We begin by reviewing sources of uncertainty and complexity including the translation of physiological effects into demographic processes, indirect ecological interactions among species, the ability of coral reefs to modify their own chemistry, adaptation and trans-generational plasticity. We then incorporate these uncertainties into two simple qualitative models of a coral reef system under climate change. Some sources of uncertainty are far more problematic than others. Climate change is predicted to have an unambiguous negative effect on corals that is robust to several sources of uncertainty but sensitive to the degree of biogeochemical coupling between benthos and seawater. Macroalgal, zoanthid, and herbivorous fish populations are generally predicted to increase, but the ambiguity (confidence) of such predictions are sensitive to the source of uncertainty. For example, reversing the effect of climate-related stress on macroalgae from being positive to negative had no influence on system behaviour. By contrast, the system was highly sensitive to a change in the stress upon herbivorous fishes. Minor changes in competitive interactions had profound impacts on system behaviour, implying that the outcomes of mesocosm studies could be highly sensitive to the choice of taxa. We use our analysis to identify new hypotheses and suggest that the effects of climatic stress on coral reefs provide an exceptional opportunity to test emerging theories of ecological inheritance. Copyright © 2014 Elsevier Ltd. All rights reserved.

WRKY transcription factors in plant responses to stresses.

Science.gov (United States)

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 Role of the Transcriptional Response to DNA Replication Stress.

Science.gov (United States)

Herlihy, Anna E; de Bruin, Robertus A M

2017-03-02

During DNA replication many factors can result in DNA replication stress. The DNA replication stress checkpoint prevents the accumulation of replication stress-induced DNA damage and the potential ensuing genome instability. A critical role for post-translational modifications, such as phosphorylation, in the replication stress checkpoint response has been well established. However, recent work has revealed an important role for transcription in the cellular response to DNA replication stress. In this review, we will provide an overview of current knowledge of the cellular response to DNA replication stress with a specific focus on the DNA replication stress checkpoint transcriptional response and its role in the prevention of replication stress-induced DNA damage.

The Role of the Transcriptional Response to DNA Replication Stress

Science.gov (United States)

Herlihy, Anna E.; de Bruin, Robertus A.M.

2017-01-01

During DNA replication many factors can result in DNA replication stress. The DNA replication stress checkpoint prevents the accumulation of replication stress-induced DNA damage and the potential ensuing genome instability. A critical role for post-translational modifications, such as phosphorylation, in the replication stress checkpoint response has been well established. However, recent work has revealed an important role for transcription in the cellular response to DNA replication stress. In this review, we will provide an overview of current knowledge of the cellular response to DNA replication stress with a specific focus on the DNA replication stress checkpoint transcriptional response and its role in the prevention of replication stress-induced DNA damage. PMID:28257104

Can the responses of photosynthesis and stomatal conductance to water and nitrogen stress combinations be modeled using a single set of parameters?

NARCIS (Netherlands)

Zhang, Ningyi; Li, Gang; Yu, Shanxiang; An, Dongsheng; Sun, Qian; Luo, Weihong; Yin, Xinyou

2017-01-01

Accurately predicting photosynthesis in response to water and nitrogen stress is the first step toward predicting crop growth, yield and many quality traits under fluctuating environmental conditions. While mechanistic models are capable of predicting photosynthesis under fluctuating environmental

Acute stress response and recovery after whiplash injuries. A one-year prospective study.

Science.gov (United States)

Kongsted, Alice; Bendix, Tom; Qerama, Erisela; Kasch, Helge; Bach, Flemming W; Korsholm, Lars; Jensen, Troels S

2008-05-01

Chronic whiplash-associated disorder (WAD) represents a major medical and psycho-social problem. The typical symptomatology presented in WAD is to some extent similar to symptoms of post traumatic stress disorder. In this study we examined if the acute stress reaction following a whiplash injury predicted long-term sequelae. Participants with acute whiplash-associated symptoms after a motor vehicle accident were recruited from emergency units and general practitioners. The predictor variable was the sum score of the impact of event scale (IES) completed within 10 days after the accident. The main outcome-measures were neck pain and headache, neck disability, general health, and working ability one year after the accident. A total of 737 participants were included and completed the IES, and 668 (91%) participated in the 1-year follow-up. A baseline IES-score denoting a moderate to severe stress response was obtained by 13% of the participants. This was associated with increased risk of considerable persistent pain (OR=3.3; 1.8-5.9), neck disability (OR=3.2; 1.7-6.0), reduced working ability (OR=2.8; 1.6-4.9), and lowered self-reported general health one year after the accident. These associations were modified by baseline neck pain intensity. It was not possible to distinguish between participants who recovered and those who did not by means of the IES (AUC=0.6). In conclusion, the association between the acute stress reaction and persistent WAD suggests that post traumatic stress reaction may be important to consider in the early management of whiplash injury. However, the emotional response did not predict chronicity in individuals.

Uncertainty Quantification and Comparison of Weld Residual Stress Measurements and Predictions.

Energy Technology Data Exchange (ETDEWEB)

Lewis, John R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brooks, Dusty Marie [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2016-10-01

In pressurized water reactors, the prevention, detection, and repair of cracks within dissimilar metal welds is essential to ensure proper plant functionality and safety. Weld residual stresses, which are difficult to model and cannot be directly measured, contribute to the formation and growth of cracks due to primary water stress corrosion cracking. Additionally, the uncertainty in weld residual stress measurements and modeling predictions is not well understood, further complicating the prediction of crack evolution. The purpose of this document is to develop methodology to quantify the uncertainty associated with weld residual stress that can be applied to modeling predictions and experimental measurements. Ultimately, the results can be used to assess the current state of uncertainty and to build confidence in both modeling and experimental procedures. The methodology consists of statistically modeling the variation in the weld residual stress profiles using functional data analysis techniques. Uncertainty is quantified using statistical bounds (e.g. confidence and tolerance bounds) constructed with a semi-parametric bootstrap procedure. Such bounds describe the range in which quantities of interest, such as means, are expected to lie as evidenced by the data. The methodology is extended to provide direct comparisons between experimental measurements and modeling predictions by constructing statistical confidence bounds for the average difference between the two quantities. The statistical bounds on the average difference can be used to assess the level of agreement between measurements and predictions. The methodology is applied to experimental measurements of residual stress obtained using two strain relief measurement methods and predictions from seven finite element models developed by different organizations during a round robin study.

ABA signaling in stress-response and seed development.

Science.gov (United States)

Nakashima, Kazuo; Yamaguchi-Shinozaki, Kazuko

2013-07-01

KEY MESSAGE : We review the recent progress on ABA signaling, especially ABA signaling for ABA-dependent gene expression, including the AREB/ABF regulon, SnRK2 protein kinase, 2C-type protein phosphatases and ABA receptors. Drought negatively impacts plant growth and the productivity of crops. Drought causes osmotic stress to organisms, and the osmotic stress causes dehydration in plant cells. Abscisic acid (ABA) is produced under osmotic stress conditions, and it plays an important role in the stress response and tolerance of plants. ABA regulates many genes under osmotic stress conditions. It also regulates gene expression during seed development and germination. The ABA-responsive element (ABRE) is the major cis-element for ABA-responsive gene expression. ABRE-binding protein (AREB)/ABRE-binding factor (ABF) transcription factors (TFs) regulate ABRE-dependent gene expression. Other TFs are also involved in ABA-responsive gene expression. SNF1-related protein kinases 2 are the key regulators of ABA signaling including the AREB/ABF regulon. Recently, ABA receptors and group A 2C-type protein phosphatases were shown to govern the ABA signaling pathway. Moreover, recent studies have suggested that there are interactions between the major ABA signaling pathway and other signaling factors in stress-response and seed development. The control of the expression of ABA signaling factors may improve tolerance to environmental stresses.

Mini-review: Biofilm responses to oxidative stress.

Science.gov (United States)

Gambino, Michela; Cappitelli, Francesca

2016-01-01

Biofilms constitute the predominant microbial style of life in natural and engineered ecosystems. Facing harsh environmental conditions, microorganisms accumulate reactive oxygen species (ROS), potentially encountering a dangerous condition called oxidative stress. While high levels of oxidative stress are toxic, low levels act as a cue, triggering bacteria to activate effective scavenging mechanisms or to shift metabolic pathways. Although a complex and fragmentary picture results from current knowledge of the pathways activated in response to oxidative stress, three main responses are shown to be central: the existence of common regulators, the production of extracellular polymeric substances, and biofilm heterogeneity. An investigation into the mechanisms activated by biofilms in response to different oxidative stress levels could have important consequences from ecological and economic points of view, and could be exploited to propose alternative strategies to control microbial virulence and deterioration.

Stress induction in the bacteria Shewanella oneidensis and Deinococcus radiodurans in response to below-background ionizing radiation.

Science.gov (United States)

Castillo, Hugo; Schoderbek, Donald; Dulal, Santosh; Escobar, Gabriela; Wood, Jeffrey; Nelson, Roger; Smith, Geoffrey

2015-01-01

The 'Linear no-threshold' (LNT) model predicts that any amount of radiation increases the risk of organisms to accumulate negative effects. Several studies at below background radiation levels (4.5-11.4 nGy h(-1)) show decreased growth rates and an increased susceptibility to oxidative stress. The purpose of our study is to obtain molecular evidence of a stress response in Shewanella oneidensis and Deinococcus radiodurans grown at a gamma dose rate of 0.16 nGy h(-1), about 400 times less than normal background radiation. Bacteria cultures were grown at a dose rate of 0.16 or 71.3 nGy h(-1) gamma irradiation. Total RNA was extracted from samples at early-exponential and stationary phases for the rt-PCR relative quantification (radiation-deprived treatment/background radiation control) of the stress-related genes katB (catalase), recA (recombinase), oxyR (oxidative stress transcriptional regulator), lexA (SOS regulon transcriptional repressor), dnaK (heat shock protein 70) and SOA0154 (putative heavy metal efflux pump). Deprivation of normal levels of radiation caused a reduction in growth of both bacterial species, accompanied by the upregulation of katB, recA, SOA0154 genes in S. oneidensis and the upregulation of dnaK in D. radiodurans. When cells were returned to background radiation levels, growth rates recovered and the stress response dissipated. Our results indicate that below-background levels of radiation inhibited growth and elicited a stress response in two species of bacteria, contrary to the LNT model prediction.

Frictional response of simulated faults to normal stresses perturbations probed with ultrasonic waves

Science.gov (United States)

Shreedharan, S.; Riviere, J.; Marone, C.

2017-12-01

We report on a suite of laboratory friction experiments conducted on saw-cut Westerly Granite surfaces to probe frictional response to step changes in normal stress and loading rate. The experiments are conducted to illuminate the fundamental processes that yield friction rate and state dependence. We quantify the microphysical frictional response of the simulated fault surfaces to normal stress steps, in the range of 1% - 600% step increases and decreases from a nominal baseline normal stress. We measure directly the fault slip rate and account for changes in slip rate with changes in normal stress and complement mechanical data acquisition by continuously probing the faults with ultrasonic pulses. We conduct the experiments at room temperature and humidity conditions in a servo controlled biaxial testing apparatus in the double direct shear configuration. The samples are sheared over a range of velocities, from 0.02 - 100 μm/s. We report observations of a transient shear stress and friction evolution with step increases and decreases in normal stress. Specifically, we show that, at low shear velocities and small increases in normal stress ( 5% increases), the shear stress evolves immediately with normal stress. We show that the excursions in slip rate resulting from the changes in normal stress must be accounted for in order to predict fault strength evolution. Ultrasonic wave amplitudes which first increase immediately in response to normal stress steps, then decrease approximately linearly to a new steady state value, in part due to changes in fault slip rate. Previous descriptions of frictional state evolution during normal stress perturbations have not adequately accounted for the effect of large slip velocity excursions. Here, we attempt to do so by using the measured ultrasonic amplitudes as a proxy for frictional state during transient shear stress evolution. Our work aims to improve understanding of induced and triggered seismicity with focus on

Identifying salt stress-responsive transcripts from Roselle ( Hibiscus ...

African Journals Online (AJOL)

Hibiscus sabdariffa L.). Identifying the potentially novel transcripts responsible for salt stress tolerance in roselle will increase knowledge of the molecular mechanism underlying salt stress responses. In this study, differential display reverse ...

Identification and Target Prediction of MicroRNAs in Ulmus pumila L. Seedling Roots under Salt Stress by High-Throughput Sequencing

Directory of Open Access Journals (Sweden)

Jianfeng Zhu

2016-12-01

Full Text Available MicroRNAs (miRNAs are a class of endogenous small RNAs with important roles in plant growth, development, and environmental stress responses. Ulmus pumila L., a deciduous broadleaved tree species of northern temperate regions, is widely distributed in central and northern Asia and has important economic and ecological value. With the spread and aggravation of soil salinization, salt stress has become a major abiotic stress affecting the normal growth and development of U. pumila. However, the influence of salt stress on U. pumila miRNA expression has not been investigated. To identify miRNAs and predict their target mRNA genes under salt stress, three small RNA libraries were generated and sequenced from roots of U. pumila seedlings treated with various concentrations of NaCl corresponding to no salt stress, light short-term salt stress, and medium-heavy long-term salt stress. Integrative analysis identified 254 conserved miRNAs representing 29 families and 49 novel miRNAs; 232 potential targets of the miRNAs were also predicted. Expression profiling of miRNAs between libraries was performed, and the expression of six miRNAs was validated by quantitative reverse transcription polymerase chain reaction (qRT-PCR. Our findings provide an overview of potential miRNAs and corresponding targets involved in regulating U. pumila salt defense responses. These results lay the foundation for further research into molecular mechanisms involved in salt stress resistance in U. pumila and other Ulmaceae species.

Stress before extinction learning enhances and generalizes extinction memory in a predictive learning task.

Science.gov (United States)

Meir Drexler, Shira; Hamacher-Dang, Tanja C; Wolf, Oliver T

2017-05-01

In extinction learning, the individual learns that a previously acquired association (e.g. between a threat and its predictor) is no longer valid. This learning is the principle underlying many cognitive-behavioral psychotherapeutic treatments, e.g. 'exposure therapy'. However, extinction is often highly-context dependent, leading to renewal (relapse of extinguished conditioned response following context change). We have previously shown that post-extinction stress leads to a more context-dependent extinction memory in a predictive learning task. Yet as stress prior to learning can impair the integration of contextual cues, here we aim to create a more generalized extinction memory by inducing stress prior to extinction. Forty-nine men and women learned the associations between stimuli and outcomes in a predictive learning task (day 1), extinguished them shortly after an exposure to a stress/control condition (day 2), and were tested for renewal (day 3). No group differences were seen in acquisition and extinction learning, and a renewal effect was present in both groups. However, the groups differed in the strength and context-dependency of the extinction memory. Compared to the control group, the stress group showed an overall reduced recovery of responding to the extinguished stimuli, in particular in the acquisition context. These results, together with our previous findings, demonstrate that the effects of stress exposure on extinction memory depend on its timing. While post-extinction stress makes the memory more context-bound, pre-extinction stress strengthens its consolidation for the acquisition context as well, making it potentially more resistant to relapse. These results have implications for the use of glucocorticoids as extinction-enhancers in exposure therapy. Copyright © 2017 Elsevier Inc. All rights reserved.

Plant Nucleolar Stress Response, a New Face in the NAC-Dependent Cellular Stress Responses

OpenAIRE

Iwai Ohbayashi; Munetaka Sugiyama

2018-01-01

The nucleolus is the most prominent nuclear domain, where the core processes of ribosome biogenesis occur vigorously. All these processes are finely orchestrated by many nucleolar factors to build precisely ribosome particles. In animal cells, perturbations of ribosome biogenesis, mostly accompanied by structural disorders of the nucleolus, cause a kind of cellular stress to induce cell cycle arrest, senescence, or apoptosis, which is called nucleolar stress response. The best-characterized p...

Thyroid Allostasis–Adaptive Responses of Thyrotropic Feedback Control to Conditions of Strain, Stress, and Developmental Programming

OpenAIRE

Apostolos Chatzitomaris; Rudolf Hoermann; John E. Midgley; Steffen Hering; Aline Urban; Barbara Dietrich; Assjana Abood; Harald H. Klein; Harald H. Klein; Johannes W. Dietrich; Johannes W. Dietrich

2017-01-01

The hypothalamus–pituitary–thyroid feedback control is a dynamic, adaptive system. In situations of illness and deprivation of energy representing type 1 allostasis, the stress response operates to alter both its set point and peripheral transfer parameters. In contrast, type 2 allostatic load, typically effective in psychosocial stress, pregnancy, metabolic syndrome, and adaptation to cold, produces a nearly opposite phenotype of predictive plasticity. The non-thyroidal illness syndrome (NTI...

In response to community violence: coping strategies and involuntary stress responses among Latino adolescents.

Science.gov (United States)

Epstein-Ngo, Quyen; Maurizi, Laura K; Bregman, Allyson; Ceballo, Rosario

2013-01-01

Among poor, urban adolescents, high rates of community violence are a pressing public health concern. This study relies on a contextual framework of stress and coping to investigate how coping strategies and involuntary stress responses may both mediate and moderate the relation between exposure to community violence and psychological well-being. Our sample consists of 223 ninth grade Latino adolescents from poor, urban families. In response to community violence, these adolescents reported using an array of coping strategies as well as experiencing a number of involuntary stress responses; the most frequent coping responses were turning to religion and seeking social support. Hierarchical regression analyses demonstrated that involuntary stress responses mediated the relations between both witnessing or being victimized by violence and poorer psychological functioning, while coping strategies moderated these relations. These findings suggest that the negative psychological effects of exposure to community violence may, in part, be explained by involuntary stress responses, while religious-based coping may serve as a protective factor.

Psychophysiological responses to stress after stress management training in patients with rheumatoid arthritis.

NARCIS (Netherlands)

Brouwer, S.J.M. de; Kraaimaat, F.W.; Sweep, F.C.; Donders, A.R.T.; Eijsbouts, A.; Koulil, S. van; Riel, P.L.C.M. van; Evers, A.W.M.

2011-01-01

BACKGROUND: Stress management interventions may prove useful in preventing the detrimental effects of stress on health. This study assessed the effects of a stress management intervention on the psychophysiological response to stress in patients with rheumatoid arthritis (RA). METHODS: Seventy-four

Behavioural and Hormonal Stress Responses to Social Separation in Ravens, Corvus corax.

Science.gov (United States)

Munteanu, Alexandru M; Stocker, Martina; Stöwe, Mareike; Massen, Jorg J M; Bugnyar, Thomas

2017-02-01

Social life is profitable, but it facilitates conflicts over resources and creates interdependence between individuals. Separating highly social animals triggers intense reactions aimed at re-establishing lost connections. Less is known, however, about behavioural and physiological responses to separation in socially facultative species, where individuals temporarily form groups and may subsequently leave them. Non-breeding common ravens ( Corvus corax ) gather in large numbers at feeding and roosting sites, but otherwise spend time seemingly solitary or in small subgroups. We here studied how ravens cope with being socially isolated, and investigated the life characteristics that might explain potential individual differences. For this, we individually separated captive subadult ravens (n = 25) and housed them in physical and visual isolation from their group members across 4 d. During the separation period, we collected behavioural data and measured the amount of immunoreactive corticosterone metabolites from bird droppings to assess the ravens' physiological stress response. We found behavioural indicators of stress at the start of the separation, when ravens showed higher levels of tension than of comfort - a pattern that reversed at the end of the separation. Furthermore, we found that the upbringing of ravens affected their behaviour during separation. Hand-raised birds produced more vocalisations in the beginning of the separation, and were less active at the end, while the reverse pattern occurred with parent-raised ravens. Contrary to our predictions, we did not find differences in hormonal responses between the beginning and end of the separation period or any link between hormonal responses and behaviours. Ravens' behavioural responses to social separation stress seem to be dependent on their arousal states, although possible links with hormonal reactions remain unclear. Our results show that behavioural reactions are not always linked with hormonal

Heart rate during conflicts predicts post-conflict stress-related behavior in greylag geese.

Directory of Open Access Journals (Sweden)

Claudia A F Wascher

Full Text Available BACKGROUND: Social stressors are known to be among the most potent stressors in group-living animals. This is not only manifested in individual physiology (heart rate, glucocorticoids, but also in how individuals behave directly after a conflict. Certain 'stress-related behaviors' such as autopreening, body shaking, scratching and vigilance have been suggested to indicate an individual's emotional state. Such behaviors may also alleviate stress, but the behavioral context and physiological basis of those behaviors is still poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: We recorded beat-to-beat heart rates (HR of 22 greylag geese in response to agonistic encounters using fully implanted sensor-transmitter packages. Additionally, for 143 major events we analyzed the behavior shown by our focal animals in the first two minutes after an interaction. Our results show that the HR during encounters and characteristics of the interaction predicted the frequency and duration of behaviors shown after a conflict. CONCLUSIONS/SIGNIFICANCE: To our knowledge this is the first study to quantify the physiological and behavioral responses to single agonistic encounters and to link this to post conflict behavior. Our results demonstrate that 'stress-related behaviors' are flexibly modulated by the characteristics of the preceding aggressive interaction and reflect the individual's emotional strain, which is linked to autonomic arousal. We found no support for the stress-alleviating hypothesis, but we propose that stress-related behaviors may play a role in communication with other group members, particularly with pair-partners.

Coping as a mediator of the relationship between stress mindset and psychological stress response: a pilot study

Directory of Open Access Journals (Sweden)

Horiuchi S

2018-03-01

Full Text Available Satoshi Horiuchi,1 Akira Tsuda,2 Shuntaro Aoki,3,4 Kenichiro Yoneda,5 Yusuke Sawaguchi6 1Faculty of Social Welfare, Iwate Prefectural University, Iwate, 2Department of Psychology, Kurume University, Fukuoka, 3Research Fellow of Japan Society for the Promotion of Science, Tokyo, 4Graduate School of Psychological Science, Health Sciences University of Hokkaido, Hokkaido, 5Graduate School of Psychology, Kurume University, Fukuoka, 6Graduate School of Social Welfare, Iwate Prefectural University, Iwate, Japan Background: Coping, the cognitive and behavioral effort required to manage the effects of stressors, is important in determining psychological stress responses (ie, the emotional, behavioral, and cognitive responses to stressors. Coping was classified into categories of emotional expression (eg, negative feelings and thoughts, emotional support seeking (eg, approaching loved ones to request encouragement, cognitive reinterpretation (eg, reframing a problem positively, and problem solving (eg, working to solve the problem. Stress mindset refers to the belief that stress has enhancing (stress-is-enhancing mindset or debilitating consequences (stress-is-debilitating mindset. This study examined whether coping mediated the relationship between stress mindset and psychological stress responses. Psychological stress responses were conceptualized as depression-anxiety, irritability-anger, and helplessness. The following two hypotheses were tested: 1 a stronger stress-is-enhancing mindset is associated with less frequent use of emotional expression, emotional support seeking, and problem solving, which in turn is associated with lower levels of depression-anxiety, irritability-anger, and helplessness; 2 a stronger stress-is-debilitating mindset is associated with more frequent use of these coping strategies, which in turn is associated with higher levels of these psychological stress responses. Materials and methods: The participants were 30 male and

Tonic immobility differentiates stress responses in PTSD

NARCIS (Netherlands)

Fragkaki, I; Stins, J.F.; Roelofs, K.; Jongedijk, R.A.; Hagenaars, M.A.

2016-01-01

Background: Tonic immobility (TI) is a state of physical immobility associated with extreme stress and the development of posttraumatic stress disorder (PTSD). However, it is unknown whether TI is associated with a distinct actual stress response, i.e., objective immobility measured by a

ADRA2B deletion variant selectively predicts stress-induced enhancement of long-term memory in females.

Science.gov (United States)

Zoladz, Phillip R; Kalchik, Andrea E; Hoffman, Mackenzie M; Aufdenkampe, Rachael L; Lyle, Sarah M; Peters, David M; Brown, Callie M; Cadle, Chelsea E; Scharf, Amanda R; Dailey, Alison M; Wolters, Nicholas E; Talbot, Jeffery N; Rorabaugh, Boyd R

2014-10-01

Clarifying the mechanisms that underlie stress-induced alterations of learning and memory may lend important insight into susceptibility factors governing the development of stress-related psychological disorders, such as post-traumatic stress disorder (PTSD). Previous work has shown that carriers of the ADRA2B Glu(301)-Glu(303) deletion variant exhibit enhanced emotional memory, greater amygdala responses to emotional stimuli and greater intrusiveness of traumatic memories. We speculated that carriers of this deletion variant might also be more vulnerable to stress-induced enhancements of long-term memory, which would implicate the variant as a possible susceptibility factor for traumatic memory formation. One hundred and twenty participants (72 males, 48 females) submerged their hand in ice cold (stress) or warm (no stress) water for 3min. Immediately afterwards, they studied a list of 42 words varying in emotional valence and arousal and then completed an immediate free recall test. Twenty-four hours later, participants' memory for the word list was examined via free recall and recognition assessments. Stressed participants exhibiting greater heart rate responses to the stressor had enhanced recall on the 24-h assessment. Importantly, this enhancement was independent of the emotional nature of the learned information. In contrast to previous work, we did not observe a general enhancement of memory for emotional information in ADRA2B deletion carriers. However, stressed female ADRA2B deletion carriers, particularly those exhibiting greater heart rate responses to the stressor, did demonstrate greater recognition memory than all other groups. Collectively, these findings implicate autonomic mechanisms in the pre-learning stress-induced enhancement of long-term memory and suggest that the ADRA2B deletion variant may selectively predict stress effects on memory in females. Such findings lend important insight into the physiological mechanisms underlying stress

finite element model for predicting residual stresses in shielded

African Journals Online (AJOL)

eobe

This paper investigates the prediction of residual stresses developed ... steel plates through Finite Element Model simulation and experiments. ... The experimental values as measured by the X-Ray diffractometer were of ... Based on this, it can be concluded that Finite Element .... Comparison of Residual Stresses from X.

Prepartum autobiographical memory specificity predicts post-traumatic stress symptoms following complicated pregnancy

NARCIS (Netherlands)

Hauer, Beatrijs J. A.; Wessel, Ineke; Engelhard, Iris M.; Peeters, Louis L.; Dalgleish, Tim

2009-01-01

Prior research has shown that reduced autobiographical memory specificity predicts an increase in post-traumatic stress severity in traumatised individuals. Studies have also demonstrated that reduced memory specificity predicts later symptoms of depression after pregnancy-related life stress. So

Phosphate-dependent root system architecture responses to salt stress

KAUST Repository

Kawa, Dorota; Julkowska, Magdalena; Montero Sommerfeld, Hector; Horst, Anneliek ter; Haring, Michel A; Testerink, Christa

2016-01-01

Nutrient availability and salinity of the soil affect growth and development of plant roots. Here, we describe how phosphate availability affects root system architecture (RSA) of Arabidopsis and how phosphate levels modulate responses of the root to salt stress. Phosphate (Pi) starvation reduced main root length and increased the number of lateral roots of Arabidopsis Col-0 seedlings. In combination with salt, low Pi dampened the inhibiting effect of mild salt stress (75mM) on all measured RSA components. At higher NaCl concentrations, the Pi deprivation response prevailed over the salt stress only for lateral root elongation. The Pi deprivation response of lateral roots appeared to be oppositely affected by abscisic acid (ABA) signaling compared to the salt stress response. Natural variation in the response to the combination treatment of salt and Pi starvation within 330 Arabidopsis accessions could be grouped into four response patterns. When exposed to double stress, in general lateral roots prioritized responses to salt, while the effect on main root traits was additive. Interestingly, these patterns were not identical for all accessions studied and multiple strategies to integrate the signals from Pi deprivation and salinity were identified. By Genome Wide Association Mapping (GWAS) 13 genomic loci were identified as putative factors integrating responses to salt stress and Pi starvation. From our experiments, we conclude that Pi starvation interferes with salt responses mainly at the level of lateral roots and that large natural variation exists in the available genetic repertoire of accessions to handle the combination of stresses.

Phosphate-dependent root system architecture responses to salt stress

KAUST Repository

Kawa, Dorota

2016-05-20

Nutrient availability and salinity of the soil affect growth and development of plant roots. Here, we describe how phosphate availability affects root system architecture (RSA) of Arabidopsis and how phosphate levels modulate responses of the root to salt stress. Phosphate (Pi) starvation reduced main root length and increased the number of lateral roots of Arabidopsis Col-0 seedlings. In combination with salt, low Pi dampened the inhibiting effect of mild salt stress (75mM) on all measured RSA components. At higher NaCl concentrations, the Pi deprivation response prevailed over the salt stress only for lateral root elongation. The Pi deprivation response of lateral roots appeared to be oppositely affected by abscisic acid (ABA) signaling compared to the salt stress response. Natural variation in the response to the combination treatment of salt and Pi starvation within 330 Arabidopsis accessions could be grouped into four response patterns. When exposed to double stress, in general lateral roots prioritized responses to salt, while the effect on main root traits was additive. Interestingly, these patterns were not identical for all accessions studied and multiple strategies to integrate the signals from Pi deprivation and salinity were identified. By Genome Wide Association Mapping (GWAS) 13 genomic loci were identified as putative factors integrating responses to salt stress and Pi starvation. From our experiments, we conclude that Pi starvation interferes with salt responses mainly at the level of lateral roots and that large natural variation exists in the available genetic repertoire of accessions to handle the combination of stresses.

Aging causes decreased resistance to multiple stresses and a failure to activate specific stress response pathways

OpenAIRE

Dues, Dylan J.; Andrews, Emily K.; Schaar, Claire E.; Bergsma, Alexis L.; Senchuk, Megan M.; Van Raamsdonk, Jeremy M.

2016-01-01

In this work, we examine the relationship between stress resistance and aging. We find that resistance to multiple types of stress peaks during early adulthood and then declines with age. To dissect the underlying mechanisms, we use C. elegans transcriptional reporter strains that measure the activation of different stress responses including: the heat shock response, mitochondrial unfolded protein response, endoplasmic reticulum unfolded protein response, hypoxia response, SKN-1-mediated oxi...

Work stress and innate immune response.

Science.gov (United States)

Boscolo, P; Di Gioacchino, M; Reale, M; Muraro, R; Di Giampaolo, L

2011-01-01

Several reports highlight the relationship between blood NK cytotoxic activity and life style. Easy life style, including physical activity, healthy dietary habits as well as good mental health are characterized by an efficient immune response. Life style is related to the type of occupational activity since work has a central part in life either as source of income or contributing to represent the social identity. Not only occupational stress, but also job loss or insecurity are thus considered serious stressful situations, inducing emotional disorders which may affect both neuroendocrine and immune systems; reduced reactivity to mitogens and/or decreased blood NK cytotoxic activity was reported in unemployed workers or in those with a high perception of job insecurity and/or job stress. Although genetic factors have a key role in the pathogenesis of autoimmune disorders, occupational stress (as in night shifts) was reported associated to an increased incidence of autoimmune disorders. Monitoring blood NK response may thus be included in the health programs as an indirect index of stressful job and/or poor lifestyle.

Cortisol responses to naturalistic and laboratory stress in student teachers: comparison with a non-stress control day.

Science.gov (United States)

Wolfram, Maren; Bellingrath, Silja; Feuerhahn, Nicolas; Kudielka, Brigitte M

2013-04-01

Ambulatory assessments of hypothalamus-pituitary-adrenal axis responses to acute natural stressors yield evidence on stress regulation with high ecological validity. Sampling of salivary cortisol is a standard technique in this field. In 21 healthy student teachers, we assessed cortisol responses to a demonstration lesson. On a control day, sampling was repeated at analogous times. Additionally, the cortisol awakening response (CAR) was assessed on both days. Participants were also exposed to a laboratory stressor, the Trier Social Stress Test, and rated their individual levels of chronic work stress. In pre-to-post-stress assessment, cortisol levels declined after the lesson. However, post-stress cortisol levels were significantly higher compared with those on the control day. Also, the Trier Social Stress Test yielded higher cortisol responses when using the control day as reference baseline. Associations between the CAR and chronic stress measures were observed solely on the control day. There were no significant associations between cortisol responses to the natural and laboratory stressors. Our results indicate that a control day might be an important complement in laboratory but especially in ambulatory stress research. Furthermore, associations between chronic stress measures and the CAR might be obscured by acute stress exposure. Finally, responses to the laboratory stressor do not seem to mirror natural stress responses. Copyright © 2012 John Wiley & Sons, Ltd.

Puff and bite: the relationship between the glucocorticoid stress response and anti-predator performance in checkered puffer (Sphoeroides testudineus).

Science.gov (United States)

Cull, Felicia; O'Connor, Constance M; Suski, Cory D; Shultz, Aaron D; Danylchuk, Andy J; Cooke, Steven J

2015-04-01

Individual variation in the endocrine stress response has been linked to survival and performance in a variety of species. Here, we evaluate the relationship between the endocrine stress response and anti-predator behaviors in wild checkered puffers (Sphoeroides testudineus) captured at Eleuthera Island, Bahamas. The checkered puffer has a unique and easily measurable predator avoidance strategy, which is to inflate or 'puff' to deter potential predators. In this study, we measured baseline and stress-induced circulating glucocorticoid levels, as well as bite force, a performance measure that is relevant to both feeding and predator defence, and 'puff' performance. We found that puff performance and bite force were consistent within individuals, but generally decreased following a standardized stressor. Larger puffers were able to generate a higher bite force, and larger puffers were able to maintain a more robust puff performance following a standardized stressor relative to smaller puffers. In terms of the relationship between the glucocorticoid stress response and performance metrics, we found no relationship between post-stress glucocorticoid levels and either puff performance or bite force. However, we did find that baseline glucocorticoid levels predicted the ability of a puffer to maintain a robust puff response following a repeated stressor, and this relationship was more pronounced in larger individuals. Our work provides a novel example of how baseline glucocorticoids can predict a fitness-related anti-predator behavior. Copyright © 2015 Elsevier Inc. All rights reserved.

Hair cortisol concentrations and cortisol stress reactivity predict PTSD symptom increase after trauma exposure during military deployment.

Science.gov (United States)

Steudte-Schmiedgen, Susann; Stalder, Tobias; Schönfeld, Sabine; Wittchen, Hans-Ulrich; Trautmann, Sebastian; Alexander, Nina; Miller, Robert; Kirschbaum, Clemens

2015-09-01

Previous evidence on endocrine risk markers for posttraumatic stress disorder (PTSD) has been inconclusive. Here, we report results of the first prospective study to investigate whether long-term hair cortisol levels and experimentally-induced cortisol stress reactivity are predictive of the development of PTSD symptomatology in response to trauma during military deployment. Male soldiers were examined before deployment to Afghanistan and at a 12-month post-deployment follow-up using dimensional measures for psychopathological symptoms. The predictive value of baseline (i) hair cortisol concentrations (HCC, N=90) and (ii) salivary cortisol stress reactivity (measured by the Trier Social Stress Test, N=80) for the development of PTSD symptomatology after being exposed to new-onset traumatic events was analyzed. Baseline cortisol activity significantly predicted PTSD symptom change from baseline to follow-up upon trauma exposure. Specifically, our results consistently revealed that lower HCC and lower cortisol stress reactivity were predictive of a greater increase in PTSD symptomatology in soldiers who had experienced new-onset traumatic events (explaining 5% and 10.3% of variance, respectively). Longitudinal analyses revealed an increase in HCC from baseline to follow-up and a trend for a negative relationship between HCC changes and the number of new-onset traumatic events. Additional pre-deployment analyses revealed that trauma history was reflected in lower HCC (at trend level) and that HCC were negatively related to stressful load. Our data indicate that attenuated cortisol secretion is a risk marker for subsequent development of PTSD symptomatology upon trauma exposure. Future studies are needed to confirm our findings in other samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

Modulation of immune responses in stress by Yoga

Directory of Open Access Journals (Sweden)

Arora Sarika

2008-01-01

Full Text Available Stress is a constant factor in today′s fastpaced life that can jeopardize our health if left unchecked. It is only in the last half century that the role of stress in every ailment from the common cold to AIDS has been emphasized, and the mechanisms involved in this process have been studied. Stress influences the immune response presumably through the activation of the hypothalamic-pituitary adrenal axis, hypothalamic pituitary-gonadal axis, and the sympathetic-adrenal-medullary system. Various neurotransmitters, neuropeptides, hormones, and cytokines mediate these complex bidirectional interactions between the central nervous system (CNS and the immune system. The effects of stress on the immune responses result in alterations in the number of immune cells and cytokine dysregulation. Various stress management strategies such as meditation, yoga, hypnosis, and muscle relaxation have been shown to reduce the psychological and physiological effects of stress in cancers and HIV infection. This review aims to discuss the effect of stress on the immune system and examine how relaxation techniques such as Yoga and meditation could regulate the cytokine levels and hence, the immune responses during stress.

Sex differences, hormones, and fMRI stress response circuitry deficits in psychoses.

Science.gov (United States)

Goldstein, Jill M; Lancaster, Katie; Longenecker, Julia M; Abbs, Brandon; Holsen, Laura M; Cherkerzian, Sara; Whitfield-Gabrieli, Susan; Makris, Nicolas; Tsuang, Ming T; Buka, Stephen L; Seidman, Larry J; Klibanski, Anne

2015-06-30

Response to stress is dysregulated in psychosis (PSY). fMRI studies showed hyperactivity in hypothalamus (HYPO), hippocampus (HIPP), amygdala (AMYG), anterior cingulate (ACC), orbital and medial prefrontal (OFC; mPFC) cortices, with some studies reporting sex differences. We predicted abnormal steroid hormone levels in PSY would be associated with sex differences in hyperactivity in HYPO, AMYG, and HIPP, and hypoactivity in PFC and ACC, with more severe deficits in men. We studied 32 PSY cases (50.0% women) and 39 controls (43.6% women) using a novel visual stress challenge while collecting blood. PSY males showed BOLD hyperactivity across all hypothesized regions, including HYPO and ACC by FWE-correction. Females showed hyperactivity in HIPP and AMYG and hypoactivity in OFC and mPFC, the latter FWE-corrected. Interaction of group by sex was significant in mPFC (F = 7.00, p = 0.01), with PSY females exhibiting the lowest activity. Male hyperactivity in HYPO and ACC was significantly associated with hypercortisolemia post-stress challenge, and mPFC with low androgens. Steroid hormones and neural activity were dissociated in PSY women. Findings suggest disruptions in neural circuitry-hormone associations in response to stress are sex-dependent in psychosis, particularly in prefrontal cortex. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Persistent high job demands and reactivity to mental stress predict future ambulatory blood pressure.

Science.gov (United States)

Steptoe, A; Cropley, M

2000-05-01

To test the hypothesis that work stress (persistent high job demands over 1 year) in combination with high reactivity to mental stress predict ambulatory blood pressure. Assessment of cardiovascular responses to standardized behavioural tasks, job demands, and ambulatory blood pressure over a working day and evening after 12 months. We studied 81 school teachers (26 men, 55 women), 36 of whom experienced persistent high job demands over 1 year, while 45 reported lower job demands. Participants were divided on the basis of high and low job demands, and high and low systolic pressure reactions to an uncontrollable stress task. Blood pressure and concurrent physical activity were monitored using ambulatory apparatus from 0900 to 2230 h on a working day. Cardiovascular stress reactivity was associated with waist/hip ratio. Systolic and diastolic pressure during the working day were greater in high job demand participants who were stress reactive than in other groups, after adjustment for age, baseline blood pressure, body mass index and negative affectivity. The difference was not accounted for by variations in physical activity. Cardiovascular stress reactivity and sustained psychosocial stress may act in concert to increase cardiovascular risk in susceptible individuals.

Results of fatigue tests and prediction of fatigue life under superposed stress wave and combined superposed stress wave

International Nuclear Information System (INIS)

Takasugi, Shunji; Horikawa, Takeshi; Tsunenari, Toshiyasu; Nakamura, Hiroshi

1983-01-01

In order to examine fatigue life prediction methods at high temperatures where creep damage need not be taken into account, fatigue tests were carried out on plane bending specimens of alloy steels (SCM 435, 2 1/4Cr-1Mo) under superposed and combined superposed stress waves at room temperature and 500 0 C. The experimental data were compared with the fatigue lives predicted by using the cycle counting methods (range pair, range pair mean and zero-cross range pair mean methods), the modified Goodman's equation and the modified Miner's rule. The main results were as follows. (1) The fatigue life prediction method which is being used for the data at room temperature is also applicable to predict the life at high temperatures. The range pair mean method is especially better than other cycle counting methods. The zero-cross range pair mean method gives the estimated lives on the safe side of the experimental lives. (2) The scatter bands of N-bar/N-barsub(es) (experimental life/estimated life) becomes narrower when the following equation is used instead of the modified Goodman's equation for predicting the effect of mean stress on fatigue life. σ sub(t) = σ sub(a) / (1 - Sigma-s sub(m) / kσ sub(B)) σ sub(t); stress amplitude at zero mean stress (kg/mm 2 ) σ sub(B); tensile strength (kg/mm 2 ) σ sub(m); mean stress (kg/mm 2 ) σ sub(a); stress amplitude (kg/mm 2 ) k; modified coefficient of σ sub(B) (author)

Prediction of residual stress using explicit finite element method

Directory of Open Access Journals (Sweden)

W.A. Siswanto

2015-12-01

Full Text Available This paper presents the residual stress behaviour under various values of friction coefficients and scratching displacement amplitudes. The investigation is based on numerical solution using explicit finite element method in quasi-static condition. Two different aeroengine materials, i.e. Super CMV (Cr-Mo-V and Titanium alloys (Ti-6Al-4V, are examined. The usage of FEM analysis in plate under normal contact is validated with Hertzian theoretical solution in terms of contact pressure distributions. The residual stress distributions along with normal and shear stresses on elastic and plastic regimes of the materials are studied for a simple cylinder-on-flat contact configuration model subjected to normal loading, scratching and followed by unloading. The investigated friction coefficients are 0.3, 0.6 and 0.9, while scratching displacement amplitudes are 0.05 mm, 0.10 mm and 0.20 mm respectively. It is found that friction coefficient of 0.6 results in higher residual stress for both materials. Meanwhile, the predicted residual stress is proportional to the scratching displacement amplitude, higher displacement amplitude, resulting in higher residual stress. It is found that less residual stress is predicted on Super CMV material compared to Ti-6Al-4V material because of its high yield stress and ultimate strength. Super CMV material with friction coefficient of 0.3 and scratching displacement amplitude of 0.10 mm is recommended to be used in contact engineering applications due to its minimum possibility of fatigue.

Individual stress vulnerability is predicted by short-term memory and AMPA receptor subunit ratio in the hippocampus.

Science.gov (United States)

Schmidt, Mathias V; Trümbach, Dietrich; Weber, Peter; Wagner, Klaus; Scharf, Sebastian H; Liebl, Claudia; Datson, Nicole; Namendorf, Christian; Gerlach, Tamara; Kühne, Claudia; Uhr, Manfred; Deussing, Jan M; Wurst, Wolfgang; Binder, Elisabeth B; Holsboer, Florian; Müller, Marianne B

2010-12-15

Increased vulnerability to aversive experiences is one of the main risk factors for stress-related psychiatric disorders as major depression. However, the molecular bases of vulnerability, on the one hand, and stress resilience, on the other hand, are still not understood. Increasing clinical and preclinical evidence suggests a central involvement of the glutamatergic system in the pathogenesis of major depression. Using a mouse paradigm, modeling increased stress vulnerability and depression-like symptoms in a genetically diverse outbred strain, and we tested the hypothesis that differences in AMPA receptor function may be linked to individual variations in stress vulnerability. Vulnerable and resilient animals differed significantly in their dorsal hippocampal AMPA receptor expression and AMPA receptor binding. Treatment with an AMPA receptor potentiator during the stress exposure prevented the lasting effects of chronic social stress exposure on physiological, neuroendocrine, and behavioral parameters. In addition, spatial short-term memory, an AMPA receptor-dependent behavior, was found to be predictive of individual stress vulnerability and response to AMPA potentiator treatment. Finally, we provide evidence that genetic variations in the AMPA receptor subunit GluR1 are linked to the vulnerable phenotype. Therefore, we propose genetic variations in the AMPA receptor system to shape individual stress vulnerability. Those individual differences can be predicted by the assessment of short-term memory, thereby opening up the possibility for a specific treatment by enhancing AMPA receptor function.

Thermotolerance and responses to short duration heat stress in tropical and temperate species

Science.gov (United States)

Marias, D.; Meinzer, F. C.; Still, C. J.

2017-12-01

Temperature and heat waves are predicted to increase throughout the 21st century in both tropical and temperate regions. Tropical species are vulnerable to heat stress because of the higher radiation load and the narrower distribution of temperatures typically experienced compared to extratropical species. Germinant seedlings are also vulnerable to heat stress because they inhabit the boundary layer close to the soil surface where intense heating occurs. We quantified the effect of leaf age and heat stress duration (45 min, 90 min) on leaf thermotolerance and whole plant physiological responses to heat stress in Coffea arabica (COAR) saplings. We also evaluated leaf thermotolerance and whole plant responses to heat stress of seedlings in two populations each of Pinus ponderosa (PIPO) and Pseudotsuga menziesii (PSME) from contrasting climates. Thermotolerance of detached leaves/needles was evaluated using chlorophyll fluorescence (FV/FM, FO) and electrolyte leakage. After exposure of whole plants to a simulated heat wave in a growth chamber, we monitored FV/FM, photosynthesis (A), stomatal conductance (gs), non-structural carbohydrates (NSCs), and carbon isotope ratios (δ13C). In COAR, thermotolerance and rate of recovery increased with leaf age. Following heat treatment, reductions in A and gs led to reduced intrinsic water use efficiency (iWUE) and increased leaf temperatures. NSC results suggested that starch was converted to sugars for recovery from heat stress and phloem transport was inhibited. Plants failed to flower in both heat stress duration treatments. In PIPO and PSME, heat treatment induced significant reductions in FV/FM and A. NSC results suggested that starch was converted to glucose + fructose to aid recovery from heat-induced damage. Populations from drier sites had greater δ13C values than those from wetter sites, consistent with higher iWUE of populations from drier climates. Thermotolerance and heat stress responses appeared to be

The surgical stress response: should it be prevented?

DEFF Research Database (Denmark)

Kehlet, H

1991-01-01

clinical trials have demonstrated a reduction in various aspects of postoperative morbidity by such a nociceptive blockade. Although a causal relationship has still to be demonstrated, these findings strongly argue the concept of "stress-free anesthesia and surgery" as an important instrument in improving......Postoperative complications such as myocardial infarction, pulmonary infection, thromboembolism and fatigue are probably related to increased demands, hypermetabolism, catabolism and other physiologic changes included in the global "surgical stress response." Strategies have been developed...... to suppress the detrimental components of the stress response so as to improve postoperative outcome. Of the various techniques to reduce the surgical stress response, afferent neural blockade with regional anesthesia to relieve pain is the most effective, although not optimal. Data from numerous controlled...

Stress hormones predict hyperbolic time-discount rates six months later in adults.

Science.gov (United States)

Takahashi, Taiki; Shinada, Mizuho; Inukai, Keigo; Tanida, Shigehito; Takahashi, Chisato; Mifune, Nobuhiro; Takagishi, Haruto; Horita, Yutaka; Hashimoto, Hirofumi; Yokota, Kunihiro; Kameda, Tatsuya; Yamagishi, Toshio

2010-01-01

Stress hormones have been associated with temporal discounting. Although time-discount rate is shown to be stable over a long term, no study to date examines whether individual differences in stress hormones could predict individuals' time-discount rates in the relatively distant future (e.g., six month later), which is of interest in neuroeconomics of stress-addiction association. We assessed 87 participants' salivary stress hormone (cortisol, cortisone, and alpha-amylase) levels and hyperbolic discounting of delayed rewards consisting of three magnitudes, at the time-interval of six months. For salivary steroid assays, we employed a liquid chromatography/ mass spectroscopy (LC/MS) method. The correlations between the stress hormone levels and time-discount rates were examined. We observed that salivary alpha-amylase (sAA) levels were negatively associated with time-discount rates in never-smokers. Notably, salivary levels of stress steroids (i.e., cortisol and cortisone) negatively and positively related to time-discount rates in men and women, respectively, in never-smokers. Ever-smokers' discount rates were not predicted from these stress hormone levels. Individual differences in stress hormone levels predict impulsivity in temporal discounting in the future. There are sex differences in the effect of stress steroids on temporal discounting; while there was no sex defference in the relationship between sAA and temporal discounting.

Are narcissists hardy or vulnerable? The role of narcissism in the production of stress-related biomarkers in response to emotional distress.

Science.gov (United States)

Cheng, Joey T; Tracy, Jessica L; Miller, Gregory E

2013-12-01

Does narcissism provide a source of hardiness or vulnerability in the face of adversity? The present research addressed this question by testing whether narcissism is associated with increased physiological reactivity to emotional distress, among women. Drawing on the "fragile-ego" account, we predicted that narcissists would show a heightened physiological stress profile in response to everyday frustrations. Results supported this prediction; across a 3-day period, highly narcissistic individuals showed elevated output of 2 biomarkers of stress--cortisol and alpha--amylase-to the extent that they experienced negative emotions. In contrast, among those low in narcissism there was no association between these biomarkers and emotions. These findings suggest that narcissists' stress-response systems are particularly sensitive to everyday negative emotions, consistent with the notion that narcissism comes with physiological costs.

Stability and change: Stress responses and the shaping of behavioral phenotypes over the life span.

Science.gov (United States)

Hennessy, Michael B; Kaiser, Sylvia; Tiedtke, Tobias; Sachser, Norbert

2015-01-01

In mammals, maternal signals conveyed via influences on hypothalamic-pituitary-adrenal (HPA) activity may shape behavior of the young to be better adapted for prevailing environmental conditions. However, the mother's influence extends beyond classic stress response systems. In guinea pigs, several hours (h) of separation from the mother activates not only the HPA axis, but also the innate immune system, which effects immediate behavioral change, as well as modifies behavioral responsiveness in the future. Moreover, the presence of the mother potently suppresses the behavioral consequences of this innate immune activation. These findings raise the possibility that long-term adaptive behavioral change can be mediated by the mother's influence on immune-related activity of her pups. Furthermore, the impact of social partners on physiological stress responses and their behavioral outcomes are not limited to the infantile period. A particularly crucial period for social development in male guinea pigs is that surrounding the attainment of sexual maturation. At this time, social interactions with adults can dramatically affect circulating cortisol concentrations and social behavior in ways that appear to prepare the male to best cope in its likely future social environment. Despite such multiple social influences on the behavior of guinea pigs at different ages, inter-individual differences in the magnitude of the cortisol response remain surprisingly stable over most of the life span. Together, it appears that throughout the life span, physiological stress responses may be regulated by social stimuli. These influences are hypothesized to adjust behavior for predicted environmental conditions. In addition, stable individual differences might provide a means of facilitating adaptation to less predictable conditions.

Species as Stressors: Heterospecific Interactions and the Cellular Stress Response under Global Change.

Science.gov (United States)

Gunderson, Alex R; King, Emily E; Boyer, Kirsten; Tsukimura, Brian; Stillman, Jonathon H

2017-07-01

Anthropogenic global change is predicted to increase the physiological stress of organisms through changes in abiotic conditions such as temperature, pH, and pollution. However, organisms can also experience physiological stress through interactions with other species, especially parasites, predators, and competitors. The stress of species interactions could be an important driver of species' responses to global change as the composition of biological communities change through factors such as distributional and phenological shifts. Interactions between biotic and abiotic stressors could also induce non-linear physiological stress responses under global change. One of the primary means by which organisms deal with physiological stress is through the cellular stress response (CSR), which is broadly the upregulation of a conserved set of genes that facilitate the removal and repair of damaged macromolecules. Here, we present data on behavioral interactions and CSR gene expression for two competing species of intertidal zone porcelain crab (Petrolisthes cinctipes and Petrolisthes manimaculis). We found that P. cinctipes and P. manimaculis engage in more agonistic behaviors when interacting with heterospecifics than conspecifics; however, we found no evidence that heterospecific interactions induced a CSR in these species. In addition to our new data, we review the literature with respect to CSR induction via species interactions, focusing on predator-prey systems and heterospecific competition. We find extensive evidence for predators to induce cellular stress and aspects of the CSR in prey, even in the absence of direct physical contact between species. Effects of heterospecific competition on the CSR have been studied far less, but we do find evidence that agonistic interactions with heterospecifics can induce components of the CSR. Across all published studies, there is clear evidence that species interactions can lead to cellular stress and induction of the CSR

Stretching the stress boundary: Linking air pollution health effects to a neurohormonal stress response.

Science.gov (United States)

Kodavanti, Urmila P

2016-12-01

Inhaled pollutants produce effects in virtually all organ systems in our body and have been linked to chronic diseases including hypertension, atherosclerosis, Alzheimer's and diabetes. A neurohormonal stress response (referred to here as a systemic response produced by activation of the sympathetic nervous system and hypothalamus-pituitary-adrenal (HPA)-axis) has been implicated in a variety of psychological and physical stresses, which involves immune and metabolic homeostatic mechanisms affecting all organs in the body. In this review, we provide new evidence for the involvement of this well-characterized neurohormonal stress response in mediating systemic and pulmonary effects of a prototypic air pollutant - ozone. A plethora of systemic metabolic and immune effects are induced in animals exposed to inhaled pollutants, which could result from increased circulating stress hormones. The release of adrenal-derived stress hormones in response to ozone exposure not only mediates systemic immune and metabolic responses, but by doing so, also modulates pulmonary injury and inflammation. With recurring pollutant exposures, these effects can contribute to multi-organ chronic conditions associated with air pollution. This review will cover, 1) the potential mechanisms by which air pollutants can initiate the relay of signals from respiratory tract to brain through trigeminal and vagus nerves, and activate stress responsive regions including hypothalamus; and 2) the contribution of sympathetic and HPA-axis activation in mediating systemic homeostatic metabolic and immune effects of ozone in various organs. The potential contribution of chronic environmental stress in cardiovascular, neurological, reproductive and metabolic diseases, and the knowledge gaps are also discussed. This article is part of a Special Issue entitled Air Pollution, edited by Wenjun Ding, Andrew J. Ghio and Weidong Wu. Published by Elsevier B.V.

Predicted strains in austenitic stainless steels at stresses above yield

International Nuclear Information System (INIS)

Hammond, J.P.; Sikka, V.K.

1977-01-01

Tensile results on austenitic stainless steels were analyzed to develop means for predicting strains at stresses above yield for reactor regulatory applications. Eight heats each of types 316 and 304 were tested at 24, 93, 204, and 316 0 C as mill-annealed and at 24 0 C after reannealing. The effects of heat-to-heat variations on total strain (to 5%) at discrete stress levels were portrayed by a rational polynomial incorporating three constants that relate to the basic features of the true-stress-true-strain diagram. Because these constants usually are interrelated, a single parameter, yield strength (YS), proved adequate to predict results. For predictions analytical expressions of yield strength, an average value (YSa), and a lower bound value [YSa - 1.65SEE (standard error of estimate)] were used. Using the rational polynomial with these parameters we determined (1) limits of total maximum strain and (2) ratios of strain of material of lower bound YS to that of average YS. These are recorded at regular increments of stress [34 MPa (5 ksi)] and at ASME Code-related stresses (S/sub y), S/sub m/, 1.2S/sub m/ and 1.5S/sub m/). At intermediate stresses, strain penalties for using material of lower bound strength were large, generally larger for type 316 than type 304. For mill-annealed type 316 at 24, 93, 204, and 316 0 C, the maximum ratios of strain were 8.8, 13.0, 14.1, and 14.9, respectively, whereas for type 304 they were 3.5, 3.4, 5.6, and 4.6. At 1.5S/sub m/ and 316 0 C, a maximum strain of 2.08% was predicted for type 316 and 1.66% for type 304, as contrasted to values of 0.14 and 0.39% for average strain

Prediction of life stress on athletes’ burnout: the dual role of perceived stress

Science.gov (United States)

Wang, Erica T.W.; Hsu, Ya-Wen; Chang, Ko-Hsin

2018-01-01

Although many studies adopted Smith’s (1986) cognitive–affective model of athletic burnout in examining stress–burnout relationship, very few studies examined the mediating/moderating role of perceived stress on the stress–burnout relationship. We sampled 195 college student-athletes and assessed their life stress, perceived stress, and burnout. Correlation analyses found all study variables correlated. Two separate hierarchical regression analyses found that the “distress” component of perceived stress mediated athletes’ two types of life stress–burnout relationship but “counter-stress” component of perceived stress-moderated athletes’ general-life stress–burnout relationship. We concluded that interweaving relationships among athletes’ life stress, perceived stress, and burnout are not straightforward. Future research should consider the nature of athletes life stress, and dual role of perceived stress in examining its’ association with related psychological responses in athletic settings. PMID:29362691

Prediction of life stress on athletes’ burnout: the dual role of perceived stress

Directory of Open Access Journals (Sweden)

Theresa Chyi

2018-01-01

Full Text Available Although many studies adopted Smith’s (1986 cognitive–affective model of athletic burnout in examining stress–burnout relationship, very few studies examined the mediating/moderating role of perceived stress on the stress–burnout relationship. We sampled 195 college student-athletes and assessed their life stress, perceived stress, and burnout. Correlation analyses found all study variables correlated. Two separate hierarchical regression analyses found that the “distress” component of perceived stress mediated athletes’ two types of life stress–burnout relationship but “counter-stress” component of perceived stress-moderated athletes’ general-life stress–burnout relationship. We concluded that interweaving relationships among athletes’ life stress, perceived stress, and burnout are not straightforward. Future research should consider the nature of athletes life stress, and dual role of perceived stress in examining its’ association with related psychological responses in athletic settings.

Cortisol Response to Stress in Adults with Attention Deficit Hyperactivity Disorder.

Science.gov (United States)

Corominas-Roso, Margarida; Palomar, Gloria; Ferrer, Roser; Real, Alberto; Nogueira, Mariana; Corrales, Montserrat; Casas, Miguel; Ramos-Quiroga, Josep Antoni

2015-03-17

Differences in the cortisol response have been reported between children exhibiting the inattentive and hyperactive/impulsive subtypes of attention deficit hyperactivity disorder. However, there is no such information about adults. The aim of the present study was to determine the possible differences between the combined and inattentive subtypes in the cortisol response to stress. Ninety-six adults with attention deficit hyperactivity disorder, 38 inattentive and 58 combined, without any medical or psychiatric comorbidities and 25 healthy controls were included. The Trier Social Stress Test was used to assess physiological stress responses. Clinical data and subjective stress levels, including the Perceived Stress Scale, were also recorded. No significant differences in the cortisol response to the Trier Social Stress Test were found between patients and controls. However, albeit there were no basal differences, lower cortisol levels at 15 (P=.015), 30 (P=.015), and 45 minutes (P=.045) were observed in the combined compared with the inattentive subtype after the stress induction; these differences disappeared 60 minutes after the stress. In contrast, the subjective stress responses showed significant differences between attention deficit hyperactivity disorder patients and controls (Pattention deficit hyperactivity disorder subtypes. In turn, subjective stress measures, such as the Perceived Stress Scale, positively correlated with the whole cortisol stress response (Pattention deficit hyperactivity disorder adults exhibited a normal cortisol response to stress when challenged. Nevertheless, the inattentive patients displayed a higher level of cortisol after stress compared with the combined patients. Despite the differences in the cortisol response, adults with attention deficit hyperactivity disorder reported high levels of subjective stress in their every-day life. © The Author 2015. Published by Oxford University Press on behalf of CINP.

Cell Wall Metabolism in Response to Abiotic Stress

Science.gov (United States)

Gall, Hyacinthe Le; Philippe, Florian; Domon, Jean-Marc; Gillet, Françoise; Pelloux, Jérôme; Rayon, Catherine

2015-01-01

This review focuses on the responses of the plant cell wall to several abiotic stresses including drought, flooding, heat, cold, salt, heavy metals, light, and air pollutants. The effects of stress on cell wall metabolism are discussed at the physiological (morphogenic), transcriptomic, proteomic and biochemical levels. The analysis of a large set of data shows that the plant response is highly complex. The overall effects of most abiotic stress are often dependent on the plant species, the genotype, the age of the plant, the timing of the stress application, and the intensity of this stress. This shows the difficulty of identifying a common pattern of stress response in cell wall architecture that could enable adaptation and/or resistance to abiotic stress. However, in most cases, two main mechanisms can be highlighted: (i) an increased level in xyloglucan endotransglucosylase/hydrolase (XTH) and expansin proteins, associated with an increase in the degree of rhamnogalacturonan I branching that maintains cell wall plasticity and (ii) an increased cell wall thickening by reinforcement of the secondary wall with hemicellulose and lignin deposition. Taken together, these results show the need to undertake large-scale analyses, using multidisciplinary approaches, to unravel the consequences of stress on the cell wall. This will help identify the key components that could be targeted to improve biomass production under stress conditions. PMID:27135320

Heart rate variability response to mental arithmetic stress in patients with schizophrenia Autonomic response to stress in schizophrenia

NARCIS (Netherlands)

Castro, Mariana N.; Vigo, Daniel E.; Weidema, Hylke; Fahrer, Rodolfo D.; Chu, Elvina M.; De Achaval, Delfina; Nogues, Martin; Leiguarda, Ramon C.; Cardinali, Daniel P.; Guinjoan, Salvador N.

Background: The vulnerability-stress hypothesis is an established model of schizophrenia symptom formation. We sought to characterise the pattern of the cardiac autonomic response to mental arithmetic stress in patients with stable schizophrenia. Methods: We performed heart rate variability (HRV)

Moving through the Stressed Genome: Emerging Regulatory Roles for Transposons in Plant Stress Response.

Science.gov (United States)

Negi, Pooja; Rai, Archana N; Suprasanna, Penna

2016-01-01

The recognition of a positive correlation between organism genome size with its transposable element (TE) content, represents a key discovery of the field of genome biology. Considerable evidence accumulated since then suggests the involvement of TEs in genome structure, evolution and function. The global genome reorganization brought about by transposon activity might play an adaptive/regulatory role in the host response to environmental challenges, reminiscent of McClintock's original 'Controlling Element' hypothesis. This regulatory aspect of TEs is also garnering support in light of the recent evidences, which project TEs as "distributed genomic control modules." According to this view, TEs are capable of actively reprogramming host genes circuits and ultimately fine-tuning the host response to specific environmental stimuli. Moreover, the stress-induced changes in epigenetic status of TE activity may allow TEs to propagate their stress responsive elements to host genes; the resulting genome fluidity can permit phenotypic plasticity and adaptation to stress. Given their predominating presence in the plant genomes, nested organization in the genic regions and potential regulatory role in stress response, TEs hold unexplored potential for crop improvement programs. This review intends to present the current information about the roles played by TEs in plant genome organization, evolution, and function and highlight the regulatory mechanisms in plant stress responses. We will also briefly discuss the connection between TE activity, host epigenetic response and phenotypic plasticity as a critical link for traversing the translational bridge from a purely basic study of TEs, to the applied field of stress adaptation and crop improvement.

Moving through the Stressed Genome: Emerging Regulatory Roles for Transposons in Plant Stress Response

Science.gov (United States)

Negi, Pooja; Rai, Archana N.; Suprasanna, Penna

2016-01-01

The recognition of a positive correlation between organism genome size with its transposable element (TE) content, represents a key discovery of the field of genome biology. Considerable evidence accumulated since then suggests the involvement of TEs in genome structure, evolution and function. The global genome reorganization brought about by transposon activity might play an adaptive/regulatory role in the host response to environmental challenges, reminiscent of McClintock's original ‘Controlling Element’ hypothesis. This regulatory aspect of TEs is also garnering support in light of the recent evidences, which project TEs as “distributed genomic control modules.” According to this view, TEs are capable of actively reprogramming host genes circuits and ultimately fine-tuning the host response to specific environmental stimuli. Moreover, the stress-induced changes in epigenetic status of TE activity may allow TEs to propagate their stress responsive elements to host genes; the resulting genome fluidity can permit phenotypic plasticity and adaptation to stress. Given their predominating presence in the plant genomes, nested organization in the genic regions and potential regulatory role in stress response, TEs hold unexplored potential for crop improvement programs. This review intends to present the current information about the roles played by TEs in plant genome organization, evolution, and function and highlight the regulatory mechanisms in plant stress responses. We will also briefly discuss the connection between TE activity, host epigenetic response and phenotypic plasticity as a critical link for traversing the translational bridge from a purely basic study of TEs, to the applied field of stress adaptation and crop improvement. PMID:27777577

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.

Comparison of Damage Models for Predicting the Non-Linear Response of Laminates Under Matrix Dominated Loading Conditions

Science.gov (United States)

Schuecker, Clara; Davila, Carlos G.; Rose, Cheryl A.

2010-01-01

Five models for matrix damage in fiber reinforced laminates are evaluated for matrix-dominated loading conditions under plane stress and are compared both qualitatively and quantitatively. The emphasis of this study is on a comparison of the response of embedded plies subjected to a homogeneous stress state. Three of the models are specifically designed for modeling the non-linear response due to distributed matrix cracking under homogeneous loading, and also account for non-linear (shear) behavior prior to the onset of cracking. The remaining two models are localized damage models intended for predicting local failure at stress concentrations. The modeling approaches of distributed vs. localized cracking as well as the different formulations of damage initiation and damage progression are compared and discussed.

Tomato NAC transcription factor SlSRN1 positively regulates defense response against biotic stress but negatively regulates abiotic stress response.

Directory of Open Access Journals (Sweden)

Bo Liu

Full Text Available Biotic and abiotic stresses are major unfavorable factors that affect crop productivity worldwide. NAC proteins comprise a large family of transcription factors that play important roles in plant growth and development as well as in responses to biotic and abiotic stresses. In a virus-induced gene silencing-based screening to identify genes that are involved in defense response against Botrytis cinerea, we identified a tomato NAC gene SlSRN1 (Solanum lycopersicum Stress-related NAC1. SlSRN1 is a plasma membrane-localized protein with transactivation activity in yeast. Expression of SlSRN1 was significantly induced by infection with B. cinerea or Pseudomonas syringae pv. tomato (Pst DC3000, leading to 6-8 folds higher than that in the mock-inoculated plants. Expression of SlSRN1 was also induced by salicylic acid, jasmonic acid and 1-amino cyclopropane-1-carboxylic acid and by drought stress. Silencing of SlSRN1 resulted in increased severity of diseases caused by B. cinerea and Pst DC3000. However, silencing of SlSRN1 resulted in increased tolerance against oxidative and drought stresses. Furthermore, silencing of SlSRN1 accelerated accumulation of reactive oxygen species but attenuated expression of defense genes after infection by B. cinerea. Our results demonstrate that SlSRN1 is a positive regulator of defense response against B. cinerea and Pst DC3000 but is a negative regulator for oxidative and drought stress response in tomato.

Stress response in medically important Mucorales.

Science.gov (United States)

Singh, Pankaj; Paul, Saikat; Shivaprakash, M Rudramurthy; Chakrabarti, Arunaloke; Ghosh, Anup K

2016-10-01

Mucorales are saprobes, ubiquitously distributed and able to infect a heterogeneous population of human hosts. The fungi require robust stress responses to survive in human host. We tested the growth of Mucorales in the presence of different abiotic stress. Eight pathogenic species of Mucorales, including Rhizopus arrhizus, Rhizopus microsporus, Rhizomucor pusillus, Apophysomyces elegans, Licthemia corymbifera, Cunninghamella bertholletiae, Syncephalastrum racemosum and Mucor racemosus, were exposed to different stress inducers: osmotic (sodium chloride and d-sorbitol), oxidative (hydrogen peroxide and menadione), pH, cell wall and metal ions (Cu, Zn, Fe and Mg). Wide variation in stress responses was noted: R. arrhizus showed maximum resistance to both osmotic and oxidative stresses, whereas R. pusillus and M. indicus were relatively sensitive. Rhizopus arrhizus and R. microsporus showed maximum resistance to alkaline pH, whereas C. bertholletiae, L. corymbifera, M. racemosus and A. elegans were resistant to acidic pH. Maximum tolerance was noted in R. microsporus to Cu, R. microsporus and R. arrhizus to Fe and C. bertholletiae to Zn. In contrast, L. corymbifera, A. elegans and M. indicus were sensitive to Cu, Zn and Fe respectively. In conclusion, R. arrhizus showed high stress tolerance in comparison to other species of Mucorales, and this could be the possible reason for high pathogenic potential of this fungi. © 2016 Blackwell Verlag GmbH.

2010 MICROBIAL STRESS RESPONSE GORDON RESEARCH CONFERENCE, JULY 18-23, 2010

Energy Technology Data Exchange (ETDEWEB)

Sarah Ades

2011-07-23

The 2010 Gordon Research Conference on Microbial Stress Responses provides an open and exciting forum for the exchange of scientific discoveries on the remarkable mechanisms used by microbes to survive in nearly every niche on the planet. Understanding these stress responses is critical for our ability to control microbial survival, whether in the context of biotechnology, ecology, or pathogenesis. From its inception in 1994, this conference has traditionally employed a very broad definition of stress in microbial systems. Sessions will cover the major steps of stress responses from signal sensing to transcriptional regulation to the effectors that mediate responses. A wide range of stresses will be represented. Some examples include (but are not limited to) oxidative stress, protein quality control, antibiotic-induced stress and survival, envelope stress, DNA damage, and nutritional stress. The 2010 meeting will also focus on the role of stress responses in microbial communities, applied and environmental microbiology, and microbial development. This conference brings together researchers from both the biological and physical sciences investigating stress responses in medically- and environmentally relevant microbes, as well as model organisms, using cutting-edge techniques. Computational, systems-level, and biophysical approaches to exploring stress responsive circuits will be integrated throughout the sessions alongside the more traditional molecular, physiological, and genetic approaches. The broad range of excellent speakers and topics, together with the intimate and pleasant setting at Mount Holyoke College, provide a fertile ground for the exchange of new ideas and approaches.

The War Fighter's Stress Response: Telemetric and Noninvasive Assessment

National Research Council Canada - National Science Library

O'Donnell, Amanda

2003-01-01

... and biological responses to stress. Specifically, stress-hardy individuals retain mental focus and clarity of memory under stress, commit fewer errors during stress, experience less burnout, demonstrate better navigational skills...

Adaptive Responses to Thermal Stress in Mammals

Directory of Open Access Journals (Sweden)

Yasser Lenis Sanin

2015-12-01

Full Text Available The environment animals have to cope with is a combination of natural factors such as temperature. Extreme changes in these factors can alter homeostasis, which can lead to thermal stress. This stress can be due to either high temperatures or low temperatures. Energy transference for thermoregulation in homoeothermic animals occurs through several mechanisms: conduction, convection, radiation and evaporation. When animals are subjected to thermal stress, physiological mechanisms are activated which may include endocrine, neuroendocrine and behavioral responses. Activation of the neuroendocrine system affects the secretion of hormones and neurotransmitters which act collectively as response mechanisms that allow them to adapt to stress. Mechanisms which have developed through evolution to allow animals to adapt to high environmental temperatures and to achieve thermo tolerance include physiological and physical changes in order to reduce food intake and metabolic heat production, to increase surface area of skin to dissipate heat, to increase blood flow to take heat from the body core to the skin and extremities to dissipate the heat, to increase numbers and activity of sweat glands, panting, water intake and color adaptation of integument system to reflect heat. Chronic exposure to thermal stress can cause disease, reduce growth, decrease productive and reproductive performance and, in extreme cases, lead to death. This paper aims to briefly explain the physical and physiological responses of mammals to thermal stress, like a tool for biological environment adaptation, emphasizing knowledge gaps and offering some recommendations to stress control for the animal production system.

HPA AXIS RESPONSE TO STRESS PREDICTS SHORT-TERM SNACK INTAKE IN OBESE WOMEN

OpenAIRE

Appelhans, Bradley M.; Pagoto, Sherry L.; Peters, Erica N.; Spring, Bonnie J.

2009-01-01

Prior research has linked heightened cortisol reactivity to stress with increased food consumption. This pilot study tested corollaries of the hypothesis that cortisol stress reactivity promotes obesity. Thirty-four lean and obese women completed an acute stress task and a non-stressful control task in counterbalanced order. Contrary to expectations, higher post-stress cortisol was associated with decreased post-stress snack intake in obese women but was unrelated to snack intake in lean wome...

Intracellular proteins produced by mammalian cells in response to environmental stress

Science.gov (United States)

Goochee, Charles F.; Passini, Cheryl A.

1988-01-01

The nature of the response of mammalian cells to environmental stress is examined by reviewing results of studies where cultured mouse L cells and baby hamster kidney cells were exposed to heat shock and the synthesis of heat-shock proteins and stress-response proteins (including HSP70, HSC70, HSP90, ubiquitin, and GRP70) in stressed and unstressed cells was evaluated using 2D-PAGE. The intracellular roles of the individual stress response proteins are discussed together with the regulation of the stress response system.

Stress, cortisol, and obesity: a role for cortisol responsiveness in identifying individuals prone to obesity.

Science.gov (United States)

Hewagalamulage, S D; Lee, T K; Clarke, I J; Henry, B A

2016-07-01

There is a strong inter-relationship between activation of the hypothalamo-pituitary-adrenal axis and energy homeostasis. Patients with abdominal obesity have elevated cortisol levels. Furthermore, stress and glucocorticoids act to control both food intake and energy expenditure. In particular, glucocorticoids are known to increase the consumption of foods enriched in fat and sugar. It is well-known that, in all species, the cortisol response to stress or adrenocorticotropin is highly variable. It has now emerged that cortisol responsiveness is an important determinant in the metabolic sequelae to stress. Sheep that are characterized as high-cortisol responders (HRs) have greater propensity to weight gain and obesity than low-cortisol responders (LRs). This difference in susceptibility to become obese is associated with a distinct metabolic, neuroendocrine, and behavioral phenotype. In women and ewes, HR individuals eat more in response to stress than LR. Furthermore, HR sheep have impaired melanocortin signaling and reduced skeletal muscle thermogenesis. High-cortisol responder sheep exhibit reactive coping strategies, whereas LRs exhibit proactive coping strategies. This complex set of traits leads to increased food intake and reduced energy expenditure in HR and thus, predisposition to obesity. We predict that cortisol responsiveness may be used as a marker to identify individuals who are at risk of weight gain and subsequent obesity. Copyright © 2016 Elsevier Inc. All rights reserved.

Hypothalamic oxytocin mediates social buffering of the stress response.

Science.gov (United States)

Smith, Adam S; Wang, Zuoxin

2014-08-15

While stressful life events can enhance the risk of mental disorders, positive social interactions can propagate good mental health and normal behavioral routines. Still, the neural systems that promote these benefits are undetermined. Oxytocin is a hormone involved in social behavior and stress; thus, we focus on the impact that social buffering has on the stress response and the governing effects of oxytocin. Female prairie voles (Microtus ochrogaster) were exposed to 1 hour immobilization stress and then recovered alone or with their male partner to characterize the effect of social contact on the behavioral, physiological, and neuroendocrine stress response. In addition, we treated immobilized female voles recovering alone with oxytocin or vehicle and female voles recovering with their male partner with a selective oxytocin receptor antagonist or vehicle. Group sizes varied from 6 to 8 voles (N = 98 total). We found that 1 hour immobilization increased anxiety-like behaviors and circulating levels of corticosterone, a stress hormone, in female prairie voles recovering alone but not the female prairie voles recovering with their male partner. This social buffering by the male partner on biobehavioral responses to stress was accompanied by increased oxytocin release in the paraventricular nucleus of the hypothalamus. Intra-paraventricular nucleus oxytocin injections reduced behavioral and corticosterone responses to immobilization, whereas injections of an oxytocin receptor antagonist blocked the effects of the social buffering. Together, our data demonstrate that paraventricular nucleus oxytocin mediates the social buffering effects on the stress response and thus may be a target for treatment of stress-related disorders. Published by Society of Biological Psychiatry on behalf of Society of Biological Psychiatry.

Identification and expression analysis of cold and freezing stress responsive genes of Brassica oleracea.

Science.gov (United States)

Ahmed, Nasar Uddin; Jung, Hee-Jeong; Park, Jong-In; Cho, Yong-Gu; Hur, Yoonkang; Nou, Ill-Sup

2015-01-10

Cold and freezing stress is a major environmental constraint to the production of Brassica crops. Enhancement of tolerance by exploiting cold and freezing tolerance related genes offers the most efficient approach to address this problem. Cold-induced transcriptional profiling is a promising approach to the identification of potential genes related to cold and freezing stress tolerance. In this study, 99 highly expressed genes were identified from a whole genome microarray dataset of Brassica rapa. Blast search analysis of the Brassica oleracea database revealed the corresponding homologous genes. To validate their expression, pre-selected cold tolerant and susceptible cabbage lines were analyzed. Out of 99 BoCRGs, 43 were differentially expressed in response to varying degrees of cold and freezing stress in the contrasting cabbage lines. Among the differentially expressed genes, 18 were highly up-regulated in the tolerant lines, which is consistent with their microarray expression. Additionally, 12 BoCRGs were expressed differentially after cold stress treatment in two contrasting cabbage lines, and BoCRG54, 56, 59, 62, 70, 72 and 99 were predicted to be involved in cold regulatory pathways. Taken together, the cold-responsive genes identified in this study provide additional direction for elucidating the regulatory network of low temperature stress tolerance and developing cold and freezing stress resistant Brassica crops. Copyright © 2014 Elsevier B.V. All rights reserved.

Molecular Analysis of Rice CIPKs Involved in Both Biotic and Abiotic Stress Responses

Institute of Scientific and Technical Information of China (English)

CHEN Xi-feng; Gu Zhi-min; LIU Feng; MA Bo-jun; ZHANG Hong-sheng

2011-01-01

Plant calcineurin B-like (CBL) proteins have been proposed as important Ca2+ sensors and specifically interact with CBL-interacting protein kinases (CIPKs) in plant-specific calcium signaling.Here,we identified and isolated 15 CIPK genes in a japonica rice variety Nipponbare based on the predicted sequences of rice CIPK gene family.Gene structure analysis showed that these 15 genes were divided into intron-less and intron-rich groups,and OsCIPK3 and OsCIPK24 exhibited alternative splicing in their mature process.The phylogenetic analyses indicated that rice CIPKs shared an ancestor with Arabidopsis and poplar CIPKs.Analyses of gene expression showed that these OsCIPK genes were differentially induced by biotic stresses such as bacterial blight and abiotic stresses (heavy metal such as Hg2+,high salinity,cold and ABA).Interestingly,five OsCIPK genes,OsCIPK1,2,10,11 and 12,were transcriptionally up-regulated after bacterial blight infection whereas four OsCIPK genes,OsCIPK2,10,11 and 14,were induced by all treatments,indicating that some of OsCIPK genes are involved in multiple stress response pathways in plants.Our finding suggests that CIPKs play a key role in both biotic and abiotic stress responses.

Perceived stress at work is associated with attenuated DHEA-S response during acute psychosocial stress.

Science.gov (United States)

Lennartsson, Anna-Karin; Theorell, Töres; Kushnir, Mark M; Bergquist, Jonas; Jonsdottir, Ingibjörg H

2013-09-01

Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEA-S) have been suggested to play a protective role during acute psychosocial stress, because they act as antagonists to the effects of the stress hormone cortisol. This study aims to investigate whether prolonged psychosocial stress, measured as perceived stress at work during the past week, is related to the capacity to produce DHEA and DHEA-S during acute psychosocial stress. It also aims to investigate whether prolonged perceived stress affects the balance between production of cortisol and DHEA-S during acute psychosocial stress. Thirty-six healthy subjects (19 men and 17 women, mean age 37 years, SD 5 years), were included. Perceived stress at work during the past week was measured by using the Stress-Energy (SE) Questionnaire. The participants were divided into three groups based on their mean scores; Low stress, Medium stress and High stress. The participants underwent the Trier Social Stress Test (TSST) and blood samples were collected before, directly after the stress test, and after 30 min of recovery. General Linear Models were used to investigate if the Medium stress group and the High stress group differ regarding stress response compared to the Low stress group. Higher perceived stress at work was associated with attenuated DHEA-S response during acute psychosocial stress. Furthermore, the ratio between the cortisol production and the DHEA-S production during the acute stress test were higher in individuals reporting higher perceived stress at work compared to individuals reporting low perceived stress at work. There was no statistical difference in DHEA response between the groups. This study shows that prolonged stress, measured as perceived stress at work during the past week, seems to negatively affect the capacity to produce DHEA-S during acute stress. Given the protective functions of DHEA-S, attenuated DHEA-S production during acute stress may lead to higher risk for adverse

Lipolysis Response to Endoplasmic Reticulum Stress in Adipose Cells*

Science.gov (United States)

Deng, Jingna; Liu, Shangxin; Zou, Liangqiang; Xu, Chong; Geng, Bin; Xu, Guoheng

2012-01-01

In obesity and diabetes, adipocytes show significant endoplasmic reticulum (ER) stress, which triggers a series of responses. This study aimed to investigate the lipolysis response to ER stress in rat adipocytes. Thapsigargin, tunicamycin, and brefeldin A, which induce ER stress through different pathways, efficiently activated a time-dependent lipolytic reaction. The lipolytic effect of ER stress occurred with elevated cAMP production and protein kinase A (PKA) activity. Inhibition of PKA reduced PKA phosphosubstrates and attenuated the lipolysis. Although both ERK1/2 and JNK are activated during ER stress, lipolysis is partially suppressed by inhibiting ERK1/2 but not JNK and p38 MAPK and PKC. Thus, ER stress induces lipolysis by activating cAMP/PKA and ERK1/2. In the downstream lipolytic cascade, phosphorylation of lipid droplet-associated protein perilipin was significantly promoted during ER stress but attenuated on PKA inhibition. Furthermore, ER stress stimuli did not alter the levels of hormone-sensitive lipase and adipose triglyceride lipase but caused Ser-563 and Ser-660 phosphorylation of hormone-sensitive lipase and moderately elevated its translocation from the cytosol to lipid droplets. Accompanying these changes, total activity of cellular lipases was promoted to confer the lipolysis. These findings suggest a novel pathway of the lipolysis response to ER stress in adipocytes. This lipolytic activation may be an adaptive response that regulates energy homeostasis but with sustained ER stress challenge could contribute to lipotoxicity, dyslipidemia, and insulin resistance because of persistently accelerated free fatty acid efflux from adipocytes to the bloodstream and other tissues. PMID:22223650

Exercise-Induced Oxidative Stress Responses in the Pediatric Population

Directory of Open Access Journals (Sweden)

Alexandra Avloniti

2017-01-01

Full Text Available Adults demonstrate an upregulation of their pro- and anti-oxidant mechanisms in response to acute exercise while systematic exercise training enhances their antioxidant capacity, thereby leading to a reduced generation of free radicals both at rest and in response to exercise stress. However, less information exists regarding oxidative stress responses and the underlying mechanisms in the pediatric population. Evidence suggests that exercise-induced redox perturbations may be valuable in order to monitor exercise-induced inflammatory responses and as such training overload in children and adolescents as well as monitor optimal growth and development. The purpose of this review was to provide an update on oxidative stress responses to acute and chronic exercise in youth. It has been documented that acute exercise induces age-specific transient alterations in both oxidant and antioxidant markers in children and adolescents. However, these responses seem to be affected by factors such as training phase, training load, fitness level, mode of exercise etc. In relation to chronic adaptation, the role of training on oxidative stress adaptation has not been adequately investigated. The two studies performed so far indicate that children and adolescents exhibit positive adaptations of their antioxidant system, as adults do. More studies are needed in order to shed light on oxidative stress and antioxidant responses, following acute exercise and training adaptations in youth. Available evidence suggests that small amounts of oxidative stress may be necessary for growth whereas the transition to adolescence from childhood may promote maturation of pro- and anti-oxidant mechanisms. Available evidence also suggests that obesity may negatively affect basal and exercise-related antioxidant responses in the peripubertal period during pre- and early-puberty.

Genome-wide identification of conserved microRNA and their response to drought stress in Dongxiang wild rice (Oryza rufipogon Griff.).

Science.gov (United States)

Zhang, Fantao; Luo, Xiangdong; Zhou, Yi; Xie, Jiankun

2016-04-01

To identify drought stress-responsive conserved microRNA (miRNA) from Dongxiang wild rice (Oryza rufipogon Griff., DXWR) on a genome-wide scale, high-throughput sequencing technology was used to sequence libraries of DXWR samples, treated with and without drought stress. 505 conserved miRNAs corresponding to 215 families were identified. 17 were significantly down-regulated and 16 were up-regulated under drought stress. Stem-loop qRT-PCR revealed the same expression patterns as high-throughput sequencing, suggesting the accuracy of the sequencing result was high. Potential target genes of the drought-responsive miRNA were predicted to be involved in diverse biological processes. Furthermore, 16 miRNA families were first identified to be involved in drought stress response from plants. These results present a comprehensive view of the conserved miRNA and their expression patterns under drought stress for DXWR, which will provide valuable information and sequence resources for future basis studies.

Observed Parent-Child Relationship Quality Predicts Antibody Response to Vaccination in Children

Science.gov (United States)

O'Connor, Thomas G; Wang, Hongyue; Moynihan, Jan A; Wyman, Peter A.; Carnahan, Jennifer; Lofthus, Gerry; Quataert, Sally A.; Bowman, Melissa; Burke, Anne S.; Caserta, Mary T

2015-01-01

Background Quality of the parent-child relationship is a robust predictor of behavioral and emotional health for children and adolescents; the application to physical health is less clear. Methods We investigated the links between observed parent-child relationship quality in an interaction task and antibody response to meningococcal conjugate vaccine in a longitudinal study of 164 ambulatory 10-11 year-old children; additional analyses examine associations with cortisol reactivity, BMI, and somatic illness. Results Observed negative/conflict behavior in the interaction task predicted a less robust antibody response to meningococcal serotype C vaccine in the child over a 6 month-period, after controlling for socio-economic and other covariates. Observer rated interaction conflict also predicted increased cortisol reactivity following the interaction task and higher BMI, but these factors did not account for the link between relationship quality and antibody response. Conclusions The results begin to document the degree to which a major source of child stress exposure, parent-child relationship conflict, is associated with altered immune system development in children, and may constitute an important public health consideration. PMID:25862953

Modeling Stress Strain Relationships and Predicting Failure Probabilities For Graphite Core Components

Energy Technology Data Exchange (ETDEWEB)

Duffy, Stephen [Cleveland State Univ., Cleveland, OH (United States)

2013-09-09

This project will implement inelastic constitutive models that will yield the requisite stress-strain information necessary for graphite component design. Accurate knowledge of stress states (both elastic and inelastic) is required to assess how close a nuclear core component is to failure. Strain states are needed to assess deformations in order to ascertain serviceability issues relating to failure, e.g., whether too much shrinkage has taken place for the core to function properly. Failure probabilities, as opposed to safety factors, are required in order to capture the bariability in failure strength in tensile regimes. The current stress state is used to predict the probability of failure. Stochastic failure models will be developed that can accommodate possible material anisotropy. This work will also model material damage (i.e., degradation of mechanical properties) due to radiation exposure. The team will design tools for components fabricated from nuclear graphite. These tools must readily interact with finite element software--in particular, COMSOL, the software algorithm currently being utilized by the Idaho National Laboratory. For the eleastic response of graphite, the team will adopt anisotropic stress-strain relationships available in COMSO. Data from the literature will be utilized to characterize the appropriate elastic material constants.

Modeling Stress Strain Relationships and Predicting Failure Probabilities For Graphite Core Components

International Nuclear Information System (INIS)

Duffy, Stephen

2013-01-01

This project will implement inelastic constitutive models that will yield the requisite stress-strain information necessary for graphite component design. Accurate knowledge of stress states (both elastic and inelastic) is required to assess how close a nuclear core component is to failure. Strain states are needed to assess deformations in order to ascertain serviceability issues relating to failure, e.g., whether too much shrinkage has taken place for the core to function properly. Failure probabilities, as opposed to safety factors, are required in order to capture the bariability in failure strength in tensile regimes. The current stress state is used to predict the probability of failure. Stochastic failure models will be developed that can accommodate possible material anisotropy. This work will also model material damage (i.e., degradation of mechanical properties) due to radiation exposure. The team will design tools for components fabricated from nuclear graphite. These tools must readily interact with finite element software--in particular, COMSOL, the software algorithm currently being utilized by the Idaho National Laboratory. For the eleastic response of graphite, the team will adopt anisotropic stress-strain relationships available in COMSO. Data from the literature will be utilized to characterize the appropriate elastic material constants.

Oxidative stress response after laparoscopic versus conventional sigmoid resection

DEFF Research Database (Denmark)

Madsen, Michael Tvilling; Kücükakin, Bülent; Lykkesfeldt, Jens

2012-01-01

Surgery is accompanied by a surgical stress response, which results in increased morbidity and mortality. Oxidative stress is a part of the surgical stress response. Minimally invasive laparoscopic surgery may result in reduced oxidative stress compared with open surgery. Nineteen patients...... scheduled for sigmoid resection were randomly allocated to open or laparoscopic sigmoid resection in a double-blind, prospective clinical trial. Three biochemical markers of oxidative stress (malondialdehyde, ascorbic acid, and dehydroascorbic acid) were measured at 6 different time points (preoperatively......, 1 h, 6 h, 24 h, 48 h, and 72 h postoperatively). There were no statistical significant differences between laparoscopic and open surgery for any of the 3 oxidative stress parameters. Malondialdehyde was reduced 1 hour postoperatively (P...

Most oxidative stress response in water samples comes from unknown chemicals: the need for effect-based water quality trigger values.

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Escher, Beate I; van Daele, Charlotte; Dutt, Mriga; Tang, Janet Y M; Altenburger, Rolf

2013-07-02

The induction of adaptive stress response pathways is an early and sensitive indicator of the presence of chemical and non-chemical stressors in cells. An important stress response is the Nrf-2 mediated oxidative stress response pathway where electrophilic chemicals or chemicals that cause the formation of reactive oxygen species initiate the production of antioxidants and metabolic detoxification enzymes. The AREc32 cell line is sensitive to chemicals inducing oxidative stress and has been previously applied for water quality monitoring of organic micropollutants and disinfection byproducts. Here we propose an algorithm for the derivation of effect-based water quality trigger values for this end point that is based on the combined effects of mixtures of regulated chemicals. Mixture experiments agreed with predictions by the mixture toxicity concept of concentration addition. The responses in the AREc32 and the concentrations of 269 individual chemicals were quantified in nine environmental samples, ranging from treated effluent, recycled water, stormwater to drinking water. The effects of the detected chemicals could explain less than 0.1% of the observed induction of the oxidative stress response in the sample, affirming the need to use effect-based trigger values that account for all chemicals present.

The relationship between personality and the response to acute psychological stress

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Xin, Yuanyuan; Wu, Jianhui; Yao, Zhuxi; Guan, Qing; Aleman, Andre; Luo, Yuejia

2017-01-01

The present study examined the relationship between personality traits and the response to acute psychological stress induced by a standardized laboratory stress induction procedure (the Trier Social Stress Test, TSST). The stress response was measured with a combination of cardiovascular

Heart rate and autonomic response to stress after experimental induction of worry versus relaxation in healthy, high-worry, and generalized anxiety disorder individuals.

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Fisher, Aaron J; Newman, Michelle G

2013-04-01

Generalized anxiety disorder (GAD) is the most commonly occurring anxiety disorder and has been related to cardiovascular morbidity such as cardiac ischemia, sudden cardiac death, and myocardial infarction. Both GAD and its cardinal symptom - worry - have been shown to promote muted physiological reactivity in response to laboratory and ecological stressors. Importantly, no study to date has examined the concurrent and relative contributions of trait and state worry within healthy controls, (non-clinical) high trait-worry controls, and GAD participants. The present study examined heart rate (HR), respiratory sinus arrhythmia (RSA), and salivary alpha-amylase (sAA) responses to laboratory stress during and following the experimental induction of worry versus relaxation in healthy controls (n=42), high trait worriers (n=33) and participants with GAD (n=76). All groups exhibited increased HR and decreased RSA in response to the stressor, with no differences by condition. Baseline sAA significantly moderated HR and RSA reactivity, such that higher sAA predicted greater increases in HR and decreases in RSA. There was a significant group by baseline sAA interaction such that in GAD, higher baseline sAA predicted decreased change in sAA during stress, whereas higher baseline sAA predicted greater sAA change in healthy controls. High-worry controls fell non-significantly between these groups. The present study provides additional evidence for the effect of worry on diminished HR stress response and points to possible suppression of adrenergic sympathetic stress responses in GAD. Copyright © 2013 Elsevier B.V. All rights reserved.

Individual variation in baseline and stress-induced corticosterone and prolactin levels predicts parental effort by nesting mourning doves

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Miller, David A.; Vleck, Carol M.; Otis, David L.

2009-01-01

Endocrine systems have an important mechanistic role in structuring life-history trade-offs. During breeding, individual variation in prolactin (PRL) and corticosterone (CORT) levels affects behavioral and physiological processes that drive trade-offs between reproduction and self-maintenance. We examined patterns in baseline (BL) and stress induced (SI; level following a standard capture-restraint protocol) levels of PRL and CORT for breeding mourning doves (Zenaida macroura). We determined whether the relationship of adult condition and parental effort to hormone levels in wild birds was consistent with life-history predictions. Both BL PRL and BL CORT level in adults were positively related to nestling weight at early nestling ages, consistent with the prediction of a positive relationship of hormone levels to current parental effort of adults and associated increased energy demand. Results are consistent with the two hormones acting together at baseline levels to limit negative effects of CORT on reproduction while maintaining beneficial effects such as increased foraging for nestling feeding. Our data did not support predictions that SI responses would vary in response to nestling or adult condition. The magnitude of CORT response in the parents to our capture-restraint protocol was negatively correlated with subsequent parental effort. Average nestling weights for adults with the highest SI CORT response were on average 10–15% lighter than expected for their age in follow-up visits after the stress event. Our results demonstrated a relationship between individual hormone levels and within population variation in parental effort and suggested that hormonal control plays an important role in structuring reproductive decisions for mourning doves.

Analysis of Stress-Responsive Gene Expression in Cultivated and Weedy Rice Differing in Cold Stress Tolerance.

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Caroline Borges Bevilacqua

Full Text Available Rice (Oryza sativa L. cultivars show impairment of growth in response to environmental stresses such as cold at the early seedling stage. Locally adapted weedy rice is able to survive under adverse environmental conditions, and can emerge in fields from greater soil depth. Cold-tolerant weedy rice can be a good genetic source for developing cold-tolerant, weed-competitive rice cultivars. An in-depth analysis is presented here of diverse indica and japonica rice genotypes, mostly weedy rice, for cold stress response to provide an understanding of different stress adaptive mechanisms towards improvement of the rice crop performance in the field. We have tested a collection of weedy rice genotypes to: 1 classify the subspecies (ssp. grouping (japonica or indica of 21 accessions; 2 evaluate their sensitivity to cold stress; and 3 analyze the expression of stress-responsive genes under cold stress and a combination of cold and depth stress. Seeds were germinated at 25°C at 1.5- and 10-cm sowing depth for 10d. Seedlings were then exposed to cold stress at 10°C for 6, 24 and 96h, and the expression of cold-, anoxia-, and submergence-inducible genes was analyzed. Control plants were seeded at 1.5cm depth and kept at 25°C. The analysis revealed that cold stress signaling in indica genotypes is more complex than that of japonica as it operates via both the CBF-dependent and CBF-independent pathways, implicated through induction of transcription factors including OsNAC2, OsMYB46 and OsF-BOX28. When plants were exposed to cold + sowing depth stress, a complex signaling network was induced that involved cross talk between stresses mediated by CBF-dependent and CBF-independent pathways to circumvent the detrimental effects of stresses. The experiments revealed the importance of the CBF regulon for tolerance to both stresses in japonica and indica ssp. The mechanisms for cold tolerance differed among weedy indica genotypes and also between weedy indica and

Cortisol stress response in post-traumatic stress disorder, panic disorder, and major depressive disorder patients.

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Wichmann, Susann; Kirschbaum, Clemens; Böhme, Carsten; Petrowski, Katja

2017-09-01

Previous research has focussed extensively on the distinction of HPA-axis functioning between patient groups and healthy volunteers, with relatively little emphasis on a direct comparison of patient groups. The current study's aim was to analyse differences in the cortisol stress response as a function of primary diagnosis of panic disorder (PD), post-traumatic stress disorder (PTSD), and major depressive disorder (MDD). A total of n=30 PD (mean age±SD: 36.07±12.56), n=23 PTSD (41.22±10.17), n=18 MDD patients (39.00±14.93) and n=47 healthy control (HC) individuals (35.51±13.15) participated in this study. All the study participants were female. The Trier Social Stress Test (TSST) was used for reliable laboratory stress induction. Blood sampling accompanied the TSST for cortisol and ACTH assessment. Panic-related, PTSD-specific questionnaires and the Beck Depression Inventory II were handed out for the characterisation of the study groups. Repeated measure ANCOVAs were conducted to test for main effects of time or group and for interaction effects. Regression analyses were conducted to take comorbid depression into account. 26.7% of the PD patients, 43.5% of the PTSD patients, 72.2% of the MDD patients and 80.6% of the HC participants showed a cortisol stress response upon the TSST. ANCOVA revealed a cortisol hypo-responsiveness both in PD and PTSD patients, while no significant group differences were seen in the ACTH concentrations. Additional analyses showed no impact of comorbid depressiveness on the cortisol stress response. MDD patients did not differ in the hormonal stress response neither compared to the HC participants nor to the PD and PTSD patients. Our main findings provide evidence of a dissociation between the cortisol and ACTH concentrations in response to the TSST in PTSD and in PD patients, independent of comorbid depression. Our results further support overall research findings of a cortisol hypo-responsiveness in PD patients. A hypo-response

Psychological stress during exercise: cardiorespiratory and hormonal responses.

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Webb, Heather E; Weldy, Michael L; Fabianke-Kadue, Emily C; Orndorff, G R; Kamimori, Gary H; Acevedo, Edmund O

2008-12-01

The purpose of this study was to examine the cardiorespiratory (CR) and stress hormone responses to a combined physical and mental stress. Eight participants (VO2(max) = 41.24 +/- 6.20 ml kg(-1) min(-1)) completed two experimental conditions, a treatment condition including a 37 min ride at 60% of VO2(max) with participants responding to a computerized mental challenge dual stress condition (DSC) and a control condition of the same duration and intensity without the mental challenge exercise alone condition (EAC). Significant interactions across time were found for CR responses, with heart rate, ventilation, and respiration rate demonstrating higher increases in the DSC. Additionally, norepinephrine was significantly greater in the DSC at the end of the combined challenge. Furthermore, cortisol area-under-the-curve (AUC) was also significantly elevated during the DSC. These results demonstrate that a mental challenge during exercise can exacerbate the stress response, including the release of hormones that have been linked to negative health consequences (cardiovascular, metabolic, autoimmune illnesses).

Psychological and hormonal stress response patterns during a blood donation.

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Hoogerwerf, M D; Veldhuizen, I J T; Merz, E-M; de Kort, W L A M; Frings-Dresen, M H W; Sluiter, J K

2017-11-01

Donating blood has been associated with increased stress responses, with scarce evidence indicating that levels of psychological and hormonal stress are higher pre-donation than post-donation. We investigated whether a blood donation induces psychological and/or hormonal stress during the course of a blood donation, and whether responses differed between men and women, first-time and experienced donors and donors with high or low non-acute stress. In 363 donors, psychological (donation-stress and arousal) and hormonal (cortisol) stress were measured by questionnaire and salivary sample at seven key moments during a routine donation. Non-acute stress was assessed by a questionnaire. Repeated measurement analyses were performed, using the last measurement (leaving the donation center) as reference value. Levels of donation-stress, arousal and cortisol were significantly higher during donation than when leaving the donation center. When compared with men, women reported higher levels of donation-stress and cortisol in the first part of the visit. When compared with first-time donors, experienced donors reported lower levels of donation-stress during the first part of the visit, and higher levels of arousal but less reactivity throughout the visit. When compared to donors high on non-acute stress, donors low on non-acute stress reported lower levels of donation-stress during the first part of the visit, and showed less cortisol reactivity throughout the visit. Donating blood influences psychological and hormonal stress response patterns. The response patterns differ between women and men, first-time and experienced donors and between donors high and low on non-acute stress. © 2017 International Society of Blood Transfusion.

The role of stress mindset in shaping cognitive, emotional, and physiological responses to challenging and threatening stress.

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Crum, Alia J; Akinola, Modupe; Martin, Ashley; Fath, Sean

2017-07-01

Prior research suggests that altering situation-specific evaluations of stress as challenging versus threatening can improve responses to stress. The aim of the current study was to explore whether cognitive, physiological and affective stress responses can be altered independent of situation-specific evaluations by changing individuals' mindsets about the nature of stress in general. Using a 2 × 2 design, we experimentally manipulated stress mindset using multi-media film clips orienting participants (N = 113) to either the enhancing or debilitating nature of stress. We also manipulated challenge and threat evaluations by providing positive or negative feedback to participants during a social stress test. Results revealed that under both threat and challenge stress evaluations, a stress-is-enhancing mindset produced sharper increases in anabolic ("growth") hormones relative to a stress-is-debilitating mindset. Furthermore, when the stress was evaluated as a challenge, a stress-is-enhancing mindset produced sharper increases in positive affect, heightened attentional bias towards positive stimuli, and greater cognitive flexibility, whereas a stress-is-debilitating mindset produced worse cognitive and affective outcomes. These findings advance stress management theory and practice by demonstrating that a short manipulation designed to generate a stress-is-enhancing mindset can improve responses to both challenging and threatening stress.

Early Psychosocial Stress Predicts Extra-Pair Copulations

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Nicole Koehler

2007-01-01

Full Text Available Cheating on a mate, known as an extra-pair copulation (EPC, is considered unacceptable by most individuals. Nonetheless many individuals engage in such risky behaviors. Because individuals with high, as opposed to low, levels of early psychosocial stress are more risk prone and more likely to engage in opportunistic matings, we predicted that individuals reporting EPCs, one of many types of opportunistic mating (e.g., one-night stand, consecutive short-term relationships etc, have higher levels of early psychosocial stress than those who do not. Two types of EPCs were examined: EPC-self (EPC-S, having sex with someone other than one's mate, and EPC-other (EPC-O, having sex with someone else's mate. In a sample of 229 women and 161 men, significantly higher levels of early psychosocial stress were found amongst those reporting an EPC-S than those reporting none, irrespective of EPC-Os. Furthermore, the more EPC-Ss men, but not women, reported the higher their early psychosocial stress. Early psychosocial stress was not associated with EPC-Os irrespective of EPC-Ss. Participants were also classified into one of four groups (no EPCs, EPC-O only, EPC-S only, or EPC-S&O which significantly interacted with early psychosocial stress. Results are discussed from adaptationist and mechanist perspectives and why early psychosocial stress was higher in individuals reporting EPC-Ss irrespective of EPC-Os, but not EPC-Os irrespective of EPC-Ss, than those not reporting the EPC of interest.

Stress responses during ageing: molecular pathways regulating protein homeostasis.

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Kyriakakis, Emmanouil; Princz, Andrea; Tavernarakis, Nektarios

2015-01-01

The ageing process is characterized by deterioration of physiological function accompanied by frailty and ageing-associated diseases. The most broadly and well-studied pathways influencing ageing are the insulin/insulin-like growth factor 1 signaling pathway and the dietary restriction pathway. Recent studies in diverse organisms have also delineated emerging pathways, which collectively or independently contribute to ageing. Among them the proteostatic-stress-response networks, inextricably affect normal ageing by maintaining or restoring protein homeostasis to preserve proper cellular and organismal function. In this chapter, we survey the involvement of heat stress and endoplasmic reticulum stress responses in the regulation of longevity, placing emphasis on the cross talk between different response mechanisms and their systemic effects. We further discuss novel insights relevant to the molecular pathways mediating these stress responses that may facilitate the development of innovative interventions targeting age-related pathologies such as diabetes, cancer, cardiovascular and neurodegenerative diseases.

Timing matters: the interval between acute stressors within chronic mild stress modifies behavioral and physiologic stress responses in male rats.

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Cavigelli, Sonia A; Bao, Alexander D; Bourne, Rebecca A; Caruso, Michael J; Caulfield, Jasmine I; Chen, Mary; Smyth, Joshua M

2018-04-12

Chronic mild stress can lead to negative health outcomes. Frequency, duration, and intensity of acute stressors can affect health-related processes. We tested whether the temporal pattern of daily acute stressors (clustered or dispersed across the day) affects depression-related physiology. We used a rodent model to keep stressor frequency, duration, and intensity constant, and experimentally manipulated the temporal pattern of acute stressors delivered during the active phase of the day. Adult male Sprague-Dawley rats were exposed to one of three chronic mild stress groups: Clustered: stressors that occurred within 1 hour of each other (n = 21), Dispersed: stressors that were spread out across the active phase (n = 21), and Control: no stressors presented (n = 21). Acute mild stressors included noise, strobe lights, novel cage, cage tilt, wet bedding, and water immersion. Depression-related outcomes included: sucrose preference, body weight, circulating glucocorticoid (corticosterone) concentration after a novel acute stressor and during basal morning and evening times, and endotoxin-induced circulating interleukin-6 concentrations. Compared to control rats, those in the Clustered group gained less weight, consumed less sucrose, had a blunted acute corticosterone response, and an accentuated acute interleukin-6 response. Rats in the Dispersed group had an attenuated corticosterone decline during the active period and after an acute stressor compared to the Control group. During a chronic mild stress experience, the temporal distribution of daily acute stressors affected health-related physiologic processes. Regular exposure to daily stressors in rapid succession may predict more depression-related symptoms, whereas exposure to stressors dispersed throughout the day may predict diminished glucocorticoid negative feedback.

Effect of childhood physical abuse on cortisol stress response.

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Carpenter, Linda L; Shattuck, Thaddeus T; Tyrka, Audrey R; Geracioti, Thomas D; Price, Lawrence H

2011-03-01

Abuse and neglect are highly prevalent in children and have enduring neurobiological effects. Stressful early life environments perturb the hypothalamic-pituitary-adrenal (HPA) axis, which in turn may predispose to psychiatric disorders in adulthood. However, studies of childhood maltreatment and adult HPA function have not yet rigorously investigated the differential effects of maltreatment subtypes, including physical abuse. In this study, we sought to replicate our previous finding that childhood maltreatment was associated with attenuated cortisol responses to stress and determine whether the type of maltreatment was a determinant of the stress response. Salivary cortisol response to the Trier Social Stress Test (TSST) was examined in a non-clinical sample of women (n = 110). Subjects had no acute medical problems and were not seeking psychiatric treatment. Effects of five maltreatment types, as measured by the Childhood Trauma Questionnaire, on cortisol response to the TSST were investigated. To further examine the significant (p < 0.005) effect of one maltreatment type, women with childhood physical abuse (PA) (n = 20) were compared to those without past PA (n = 90). Women reporting childhood PA displayed a significantly blunted cortisol response to the TSST compared with subjects without PA, after controlling for estrogen use, age, other forms of maltreatment, and other potential confounds. There were no differences between PA and control groups with regard to physiological arousal during the stress challenge. In a non-clinical sample of women with minimal or no current psychopathology, physical abuse is associated with a blunted cortisol response to a psychosocial stress task.

Ebola Response: Modeling the Risk of Heat Stress from Personal Protective Clothing.

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Adam W Potter

Full Text Available A significant number of healthcare workers have responded to aid in the relief and containment of the 2013 Ebola virus disease (EVD outbreak in West Africa. Healthcare workers are required to wear personal protective clothing (PPC to impede the transmission of the virus; however, the impermeable design and the hot humid environment lead to risk of heat stress.Provide healthcare workers quantitative modeling and analysis to aid in the prevention of heat stress while wearing PPC in West Africa.A sweating thermal manikin was used to measure the thermal (Rct and evaporative resistance (Ret of the five currently used levels of PPC for healthcare workers in the West Africa EVD response. Mathematical methods of predicting the rise in core body temperature (Tc in response to clothing, activity, and environment was used to simulate different responses to PPC levels, individual body sizes, and two hot humid conditions: morning/evening (air temperature: 25°C, relative humidity: 40%, mean radiant temperature: 35°C, wind velocity: 1 m/s and mid-day (30°C, 60%, 70°C, 1 m/s.Nearly still air (0.4 m/s measures of Rct ranged from 0.18 to 0.26 m2 K/W and Ret ranged from 25.53 to 340.26 m2 Pa/W.Biophysical assessments and modeling in this study provide quantitative guidance for prevention of heat stress of healthcare workers wearing PPC responding to the EVD outbreak in West Africa.

Ebola Response: Modeling the Risk of Heat Stress from Personal Protective Clothing.

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Potter, Adam W; Gonzalez, Julio A; Xu, Xiaojiang

2015-01-01

A significant number of healthcare workers have responded to aid in the relief and containment of the 2013 Ebola virus disease (EVD) outbreak in West Africa. Healthcare workers are required to wear personal protective clothing (PPC) to impede the transmission of the virus; however, the impermeable design and the hot humid environment lead to risk of heat stress. Provide healthcare workers quantitative modeling and analysis to aid in the prevention of heat stress while wearing PPC in West Africa. A sweating thermal manikin was used to measure the thermal (Rct) and evaporative resistance (Ret) of the five currently used levels of PPC for healthcare workers in the West Africa EVD response. Mathematical methods of predicting the rise in core body temperature (Tc) in response to clothing, activity, and environment was used to simulate different responses to PPC levels, individual body sizes, and two hot humid conditions: morning/evening (air temperature: 25°C, relative humidity: 40%, mean radiant temperature: 35°C, wind velocity: 1 m/s) and mid-day (30°C, 60%, 70°C, 1 m/s). Nearly still air (0.4 m/s) measures of Rct ranged from 0.18 to 0.26 m2 K/W and Ret ranged from 25.53 to 340.26 m2 Pa/W. Biophysical assessments and modeling in this study provide quantitative guidance for prevention of heat stress of healthcare workers wearing PPC responding to the EVD outbreak in West Africa.

Critical-like features of stress response in frictional packings

International Nuclear Information System (INIS)

Cakir, Abdullah; Silbert, Leonardo E

2015-01-01

The mechanical response of static, unconfined, overcompressed face centred cubic, granular arrays is studied using large-scale, discrete element method simulations. Specifically, the stress response due to the application of a localised force perturbation—the Green function technique—is obtained in granular packings generated over several orders of magnitude in both the particle friction coefficient and the applied forcing. We observe crossover behaviour in the mechanical state of the system characterised by the changing nature of the resulting stress response. The transition between anisotropic and isotropic stress response exhibits critical-like features through the identification of a diverging length scale that distinguishes the spatial extent of anisotropic regions from those that display isotropic behaviour. A multidimensional phase diagram is constructed that parameterises the response of the system due to changing friction and force perturbations. (paper)

Soil microbial communities buffer physiological responses to drought stress in three hardwood species.

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Kannenberg, Steven A; Phillips, Richard P

2017-03-01

Trees possess myriad adaptations for coping with drought stress, but the extent to which their drought responses are influenced by interactions with soil microbes is poorly understood. To explore the role of microbes in mediating tree responses to drought stress, we exposed saplings of three species (Acer saccharum, Liriodendron tulipifera, and Quercus alba) to a four week experimental drought in mesocosms. Half of the pots were inoculated with a live soil slurry (i.e., a microbial inoculum derived from soils beneath the canopies of mature A. saccharum, L. tulipifera or Q. alba stands), while the other half of the pots received a sterile soil slurry. Soil microbes ameliorated drought stress in L. tulipifera by minimizing reductions in leaf water potential and by reducing photosynthetic declines. In A. saccharum, soil microbes reduced drought stress by lessening declines in leaf water potential, though these changes did not buffer the trees from declining photosynthetic rates. In Q. alba, soil microbes had no effects on leaf physiological parameters during drought stress. In all species, microbes had no significant effects on dynamic C allocation during drought stress, suggesting that microbial effects on plant physiology were unrelated to source-sink dynamics. Collectively, our results suggest that soil microbes have the potential to alter key parameters that are used to diagnose drought sensitivity (i.e., isohydry or anisohydry). To the extent that our results reflect dynamics occurring in forests, a revised perspective on plant hydraulic strategies that considers root-microbe interactions may lead to improved predictions of forest vulnerability to drought.

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.

Inclusion of biotic stress (consumer pressure) alters predictions from the stress gradient hypothesis

NARCIS (Netherlands)

Smit, Christian; Rietkerk, Max; Wassen, Martin J.

2009-01-01

The stress gradient hypothesis (SGH) predicts a shift from net negative interactions in benign environments towards net positive in harsh environments in ecological communities. While several studies found support for the SGH, others found evidence against it, leading to a debate on how nature and

Overexpression of a cytosolic abiotic stress responsive universal stress protein (SbUSP mitigates salt and osmotic stress in transgenic tobacco plants

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Pushpika eUdawat

2016-04-01

Full Text Available The Universal Stress Protein (USP is a ubiquitous protein and plays an indispensable role in plant abiotic stress tolerance. The genome of Salicornia brachiata contains two homologues of intron less SbUSP gene which encodes for salt and osmotic responsive universal stress protein. In vivo localization reveals that SbUSP is a membrane bound cytosolic protein. The role of the gene was functionally validated by developing transgenic tobacco and compared with control (wild type and vector control plants under different abiotic stress condition. Transgenic lines (T1 exhibited higher chlorophyll, relative water, proline, total sugar, reducing sugar, free amino acids, polyphenol contents, osmotic potential, membrane stability and lower electrolyte leakage and lipid peroxidation (malondialdehyde content under stress treatments than control (WT and VC plants. Lower accumulation of H2O2 and O2- radicals was also detected in transgenic lines compared to control plants under stress conditions. Present study confers that overexpression of the SbUSP gene enhances plant growth, alleviates ROS buildup, maintains ion homeostasis and improves the physiological status of the plant under salt and osmotic stresses. Principal component analysis (PCA exhibited a statistical distinction of plant response to salinity stress, and a significant response was observed for transgenic lines under stress, which provides stress endurance to the plant. A possible signaling role is proposed that some downstream genes may get activated by abiotic stress responsive cytosolic SbUSP, which leads to the protection of cell from oxidative damages. The study unveils that ectopic expression of the gene mitigates salt or osmotic stress by scavenging ROS and modulating the physiological process of the plant.

Growth and stress response mechanisms underlying post-feeding regenerative organ growth in the Burmese python.

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Andrew, Audra L; Perry, Blair W; Card, Daren C; Schield, Drew R; Ruggiero, Robert P; McGaugh, Suzanne E; Choudhary, Amit; Secor, Stephen M; Castoe, Todd A

2017-05-02

Previous studies examining post-feeding organ regeneration in the Burmese python (Python molurus bivittatus) have identified thousands of genes that are significantly differentially regulated during this process. However, substantial gaps remain in our understanding of coherent mechanisms and specific growth pathways that underlie these rapid and extensive shifts in organ form and function. Here we addressed these gaps by comparing gene expression in the Burmese python heart, liver, kidney, and small intestine across pre- and post-feeding time points (fasted, one day post-feeding, and four days post-feeding), and by conducting detailed analyses of molecular pathways and predictions of upstream regulatory molecules across these organ systems. Identified enriched canonical pathways and upstream regulators indicate that while downstream transcriptional responses are fairly tissue specific, a suite of core pathways and upstream regulator molecules are shared among responsive tissues. Pathways such as mTOR signaling, PPAR/LXR/RXR signaling, and NRF2-mediated oxidative stress response are significantly differentially regulated in multiple tissues, indicative of cell growth and proliferation along with coordinated cell-protective stress responses. Upstream regulatory molecule analyses identify multiple growth factors, kinase receptors, and transmembrane receptors, both within individual organs and across separate tissues. Downstream transcription factors MYC and SREBF are induced in all tissues. These results suggest that largely divergent patterns of post-feeding gene regulation across tissues are mediated by a core set of higher-level signaling molecules. Consistent enrichment of the NRF2-mediated oxidative stress response indicates this pathway may be particularly important in mediating cellular stress during such extreme regenerative growth.

Identification, Expression Analysis, and Target Prediction of Flax Genotroph MicroRNAs Under Normal and Nutrient Stress Conditions

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Melnikova, Nataliya V.; Dmitriev, Alexey A.; Belenikin, Maxim S.; Koroban, Nadezhda V.; Speranskaya, Anna S.; Krinitsina, Anastasia A.; Krasnov, George S.; Lakunina, Valentina A.; Snezhkina, Anastasiya V.; Sadritdinova, Asiya F.; Kishlyan, Natalya V.; Rozhmina, Tatiana A.; Klimina, Kseniya M.; Amosova, Alexandra V.; Zelenin, Alexander V.; Muravenko, Olga V.; Bolsheva, Nadezhda L.; Kudryavtseva, Anna V.

2016-01-01

Cultivated flax (Linum usitatissimum L.) is an important plant valuable for industry. Some flax lines can undergo heritable phenotypic and genotypic changes (LIS-1 insertion being the most common) in response to nutrient stress and are called plastic lines. Offspring of plastic lines, which stably inherit the changes, are called genotrophs. MicroRNAs (miRNAs) are involved in a crucial regulatory mechanism of gene expression. They have previously been assumed to take part in nutrient stress response and can, therefore, participate in genotroph formation. In the present study, we performed high-throughput sequencing of small RNAs (sRNAs) extracted from flax plants grown under normal, phosphate deficient and nutrient excess conditions to identify miRNAs and evaluate their expression. Our analysis revealed expression of 96 conserved miRNAs from 21 families in flax. Moreover, 475 novel potential miRNAs were identified for the first time, and their targets were predicted. However, none of the identified miRNAs were transcribed from LIS-1. Expression of seven miRNAs (miR168, miR169, miR395, miR398, miR399, miR408, and lus-miR-N1) with up- or down-regulation under nutrient stress (on the basis of high-throughput sequencing data) was evaluated on extended sampling using qPCR. Reference gene search identified ETIF3H and ETIF3E genes as most suitable for this purpose. Down-regulation of novel potential lus-miR-N1 and up-regulation of conserved miR399 were revealed under the phosphate deficient conditions. In addition, the negative correlation of expression of lus-miR-N1 and its predicted target, ubiquitin-activating enzyme E1 gene, as well as, miR399 and its predicted target, ubiquitin-conjugating enzyme E2 gene, was observed. Thus, in our study, miRNAs expressed in flax plastic lines and genotrophs were identified and their expression and expression of their targets was evaluated using high-throughput sequencing and qPCR for the first time. These data provide new insights

The Cortisol Awakening Response Mediates the Relationship Between Acculturative Stress and Self-Reported Health in Mexican Americans.

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Garcia, Antonio F; Wilborn, Kristin; Mangold, Deborah L

2017-12-01

The assessment of acculturative stress as synonymous with acculturation level overlooks the dynamic, interactive, and developmental nature of the acculturation process. An individual's unique perception and response to a range of stressors at each stage of the dynamic process of acculturation may be associated with stress-induced alterations in important biological response systems that mediate health outcomes. Evidence suggests the cortisol awakening response (CAR) is a promising pre-clinical biomarker of stress exposure that may link acculturative stress to self-reported health in Mexican Americans. The aim of the current study was to examine whether alterations in the CAR mediate the relationship between acculturative stress and self-reported health in Mexican Americans. Salivary cortisol samples were collected at awakening, 30, 45, and 60 min thereafter, on two consecutive weekdays from a sample of adult Mexican Americans. Acculturative stress and self-reported health were assessed. Data were aggregated and analyzed (n = 89) using a mixed effects regression model and path analysis. Poorer self-reported health was associated with attenuated CAR profiles (primarily due to a diminished post-awakening rise in cortisol) predicted by both moderate and high levels of exposure to acculturative stress. Stress-induced alterations in the CAR mediated the relationship between exposure to acculturative stressors and self-reported health. Findings demonstrate that different levels of acculturative stress are associated with distinct CAR profiles and suggest the CAR is one possible biological pathway through which exposure to culturally unique stressors may be linked to health disparities.

Emergence time and skin melanin spot patterns do not correlate with growth performance, social competitive ability or stress response in farmed rainbow trout

DEFF Research Database (Denmark)

Gesto, Manuel; Skov, Peter Vilhelm; Jokumsen, Alfred

2017-01-01

dissimilarities in the acute stress responses, emergence fraction displayed no correlation with growth rates, or the ability to compete for feed. Within the whole group of fish utilized in the experiments, no relationship between skinmelanin spot pattern and growth performance, stress response intensity......, or competitive ability was found. Altogether, the differences in physiological traits related to emergence time were not as strong as those found in earlier studies. It is hypothesized, that the origin and degree of domestication of the fish might be partly responsible for this. The predictive value of skin...... spots or emergence time to infer the fish stress coping style in farmed fish is also discussed...

Development of crankshaft dynamic stress prediction; Jitsudoji crankshaft oryoku yosoku shuho no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Takahashi, S; Iwamoto, A; Miyazawa, H; Sato, K; Ozaki, H [Honda R and D Co. Ltd., Tokyo (Japan)

1997-10-01

In this paper, the development of the simulation model which predicts the stress of the crankshaft under running condition precisely is described. This simulation model considers about the nonlinearity of the oil film stiffness in the main bearing, the dynamic characteristic of the crankshaft system including resonance and the cylinder block stiffness. By the development of this stress analysis simulation, the stress m each part of the crankshaft during durability testing could be precisely predicted. 1 ref., 10 figs.

Predictions and measurements of residual stress in repair welds in plates

Energy Technology Data Exchange (ETDEWEB)

Brown, T.B. [Mitsui Babcock Energy Limited, Technology and Engineering, Porterfield Road, Renfrew, PA4 8DJ, Scotland (United Kingdom)]. E-mail: bbrown@mitsuibabcock.com; Dauda, T.A. [Mitsui Babcock Energy Limited, Technology and Engineering, Porterfield Road, Renfrew, PA4 8DJ, Scotland (United Kingdom); Truman, C.E. [Department of Mechanical Engineering, University of Bristol, Bristol BS8 1TR, England (United Kingdom); Smith, D.J. [Department of Mechanical Engineering, University of Bristol, Bristol BS8 1TR (United Kingdom); Memhard, D. [Fraunhofer-Institut fuer Werkstoffmechanik, Freiburg (Germany); Pfeiffer, W. [Fraunhofer-Institut fuer Werkstoffmechanik, Freiburg (Germany)

2006-11-15

This paper presents the work, from the European Union FP-5 project ELIXIR, on a series of rectangular repair welds in P275 and S690 steels to validate the numerical modelling techniques used in the determination of the residual stresses generated during the repair process. The plates were 1,000 mm by 800 mm with thicknesses of 50 and 100 mm. The repair welds were 50%, 75% and 100% through the plate thickness. The repair welds were modelled using the finite element method to make predictions of the as-welded residual stress distributions. These predictions were compared with surface-strain measurements made on the parent plates during welding and found to be in good agreement. Through-thickness residual stress measurements were obtained from the test plates through, and local to, the weld repairs using the deep hole drilling technique. Comparisons between the measurements and the finite element predictions generally showed good agreement, thus providing confidence in the method.

Predictions and measurements of residual stress in repair welds in plates

International Nuclear Information System (INIS)

Brown, T.B.; Dauda, T.A.; Truman, C.E.; Smith, D.J.; Memhard, D.; Pfeiffer, W.

2006-01-01

This paper presents the work, from the European Union FP-5 project ELIXIR, on a series of rectangular repair welds in P275 and S690 steels to validate the numerical modelling techniques used in the determination of the residual stresses generated during the repair process. The plates were 1,000 mm by 800 mm with thicknesses of 50 and 100 mm. The repair welds were 50%, 75% and 100% through the plate thickness. The repair welds were modelled using the finite element method to make predictions of the as-welded residual stress distributions. These predictions were compared with surface-strain measurements made on the parent plates during welding and found to be in good agreement. Through-thickness residual stress measurements were obtained from the test plates through, and local to, the weld repairs using the deep hole drilling technique. Comparisons between the measurements and the finite element predictions generally showed good agreement, thus providing confidence in the method

The endoplasmic reticulum stress response in disease ...

African Journals Online (AJOL)

Rafael Vincent M. Manalo

2017-07-12

Jul 12, 2017 ... Review. The endoplasmic reticulum stress response in disease pathogenesis and pathophysiology .... This is an open access article under the CC BY-NC-ND license ... chain binding protein (BIP); however, ER stress permits the release, .... drugs designed to alleviate it often cause more harm long-term.

Overtime work and stress response in a group of Japanese workers.

Science.gov (United States)

Sato, Yuji; Miyake, Hitoshi; Thériault, Gilles

2009-01-01

Working long overtime hours is considered a cause of mental health problems among workers but such a relationship has yet to be empirically confirmed. To clarify the influence of overtime work on response to stress and to assess the role of other stress-related factors on this relationship. The study was conducted among 24 685 employees of a company in Japan. Stress response, job stressors and social supports were assessed by the Brief Job Stress Questionnaire. Participants were divided into five categories of overtime (0-19, 20-39, 40-59, >or=60 h of overtime per month and exempted employees). The nonadjusted odds ratios for stress response for 40-59 and >or=60 overtime hours per month in reference to 0-19 overtime hours were 1.11 [95% confidence interval (CI) 1.03-1.19] and 1.62 (95% CI 1.50-1.76), respectively. After adjustment for self-assessed amount of work, mental workload and sleeping time, the association between overtime work and stress response disappeared. This large cross-sectional study shows that overtime work appears to influence stress response indirectly through other stress factors such as self-assessed amount of work, mental workload and sleeping time.

A kinematic hardening constitutive model for the uniaxial cyclic stress-strain response of magnesium sheet alloys at room temperature

Science.gov (United States)

He, Zhitao; Chen, Wufan; Wang, Fenghua; Feng, Miaolin

2017-11-01

A kinematic hardening constitutive model is presented, in which a modified form of von Mises yield function is adopted, and the initial asymmetric tension and compression yield stresses of magnesium (Mg) alloys at room temperature (RT) are considered. The hardening behavior was classified into slip, twinning, and untwinning deformation modes, and these were described by two forms of back stress to capture the mechanical response of Mg sheet alloys under cyclic loading tests at RT. Experimental values were obtained for AZ31B-O and AZ31B sheet alloys under both tension-compression-tension (T-C-T) and compression-tension (C-T) loadings to calibrate the parameters of back stresses in the proposed model. The predicted parameters of back stresses in the twinning and untwinning modes were expressed as a cubic polynomial. The predicted curves based on these parameters showed good agreement with the tests.

Stress evaluation of baffle former bolt for IASCC failure prediction

International Nuclear Information System (INIS)

Matsubara, T.; Tsutsui, T.; Kamei, Y.; Kitsu, M.

2011-01-01

Baffle structure in PWRs Reactor is quite important assembly for the core safety, and Baffle Former Bolts (BFBs) are fastener members for maintaining Baffle structure. It has been reported worldwide that some of BFBs were cracked due to IASCC (Irradiation Assisted Stress Corrosion Cracking) because BFBs are located at core region under severe environments, high neutron flux, high temperature and high stress. According to the material studies of IASCC on austenitic stainless steel, a crack initiation of IASCC is strongly related with the stress and the neutron fluence. For this reason, it is very important for IASCC failure prediction to simulate the stress of BFBs. However, the stress of BFBs are considered to be influenced by several factors and to be changed complexly as operational time increases, by irradiation creep of Bolt itself, swelling of Baffle structure, and so on. Therefore, it is difficult to estimate the stress histories of BFBs (Bolt stress as a function of operational time) precisely. Then, the author has developed the calculation method of the stress histories of BFBs considering irradiation effects (swelling and irradiation creep). In this method, the stress histories of BFBs are calculated by combining two kinds of FE models, Global model (modeled whole Baffle structure which consists of Baffle plates, Former plates and Core Barrel) and Local model (modeled around BFB finely). The whole Baffle structure deformation changes as a function of heat, swelling and irradiated creep are calculated by Global model, and the stress histories of BFBs are calculated by Local model using the outputs (deformations on driving nodes) of Global model. In the FE analysis of Local model, the stress of BFBs are calculated considering irradiation effects and elastic-plastic characteristics depending on neutron fluence, so this method enables to calculate precisely the stress of extreme small area of BFBs surface. This paper shows the outline of the calculation method

Overexpression of a Cytosolic Abiotic Stress Responsive Universal Stress Protein (SbUSP) Mitigates Salt and Osmotic Stress in Transgenic Tobacco Plants

Science.gov (United States)

Udawat, Pushpika; Jha, Rajesh K.; Sinha, Dinkar; Mishra, Avinash; Jha, Bhavanath

2016-01-01

The universal stress protein (USP) is a ubiquitous protein and plays an indispensable role in plant abiotic stress tolerance. The genome of Salicornia brachiata contains two homologs of intron less SbUSP gene which encodes for salt and osmotic responsive USP. In vivo localization reveals that SbUSP is a membrane bound cytosolic protein. The role of the gene was functionally validated by developing transgenic tobacco and compared with control [wild-type (WT) and vector control (VC)] plants under different abiotic stress condition. Transgenic lines (T1) exhibited higher chlorophyll, relative water, proline, total sugar, reducing sugar, free amino acids, polyphenol contents, osmotic potential, membrane stability, and lower electrolyte leakage and lipid peroxidation (malondialdehyde content) under stress treatments than control (WT and VC) plants. Lower accumulation of H2O2 and O2− radicals was also detected in transgenic lines compared to control plants under stress conditions. Present study confers that overexpression of the SbUSP gene enhances plant growth, alleviates ROS buildup, maintains ion homeostasis and improves the physiological status of the plant under salt and osmotic stresses. Principal component analysis exhibited a statistical distinction of plant response to salinity stress, and a significant response was observed for transgenic lines under stress, which provides stress endurance to the plant. A possible signaling role is proposed that some downstream genes may get activated by abiotic stress responsive cytosolic SbUSP, which leads to the protection of cell from oxidative damages. The study unveils that ectopic expression of the gene mitigates salt or osmotic stress by scavenging ROS and modulating the physiological process of the plant. PMID:27148338

Demographic Responses to Oxidative Stress and Inflammation in the Wandering Albatross (Diomedea exulans.

Directory of Open Access Journals (Sweden)

David Costantini

Full Text Available One of the major challenges in ecological research is the elucidation of physiological mechanisms that underlie the demographic traits of wild animals. We have assessed whether a marker of plasma oxidative stress (TBARS and plasma haptoglobin (protein of the acute inflammatory phase response measured at time t predict five demographic parameters (survival rate, return rate to the breeding colony, breeding probability, hatching and fledging success in sexually mature wandering albatrosses over the next four years (Diomedea exulans using a five-year individual-based dataset. Non-breeder males, but not females, having higher TBARS at time t had reduced future breeding probabilities; haptoglobin was not related to breeding probability. Neither TBARS nor haptoglobin predicted future hatching or fledging success. Haptoglobin had a marginally positive effect on female survival rate, while TBARS had a marginally negative effect on return rate. Our findings do not support the role for oxidative stress as a constraint of future reproductive success in the albatross. However, our data point to a potential mechanism underlying some aspects of reproductive senescence and survival. Our results also highlight that the study of the consequences of oxidative stress should consider the life-cycle stage of an individual and its reproductive history.

Targeting the cell stress response of Plasmodium falciparum to overcome artemisinin resistance.

Directory of Open Access Journals (Sweden)

Con Dogovski

2015-04-01

Full Text Available Successful control of falciparum malaria depends greatly on treatment with artemisinin combination therapies. Thus, reports that resistance to artemisinins (ARTs has emerged, and that the prevalence of this resistance is increasing, are alarming. ART resistance has recently been linked to mutations in the K13 propeller protein. We undertook a detailed kinetic analysis of the drug responses of K13 wild-type and mutant isolates of Plasmodium falciparum sourced from a region in Cambodia (Pailin. We demonstrate that ART treatment induces growth retardation and an accumulation of ubiquitinated proteins, indicative of a cellular stress response that engages the ubiquitin/proteasome system. We show that resistant parasites exhibit lower levels of ubiquitinated proteins and delayed onset of cell death, indicating an enhanced cell stress response. We found that the stress response can be targeted by inhibiting the proteasome. Accordingly, clinically used proteasome inhibitors strongly synergize ART activity against both sensitive and resistant parasites, including isogenic lines expressing mutant or wild-type K13. Synergy is also observed against Plasmodium berghei in vivo. We developed a detailed model of parasite responses that enables us to infer, for the first time, in vivo parasite clearance profiles from in vitro assessments of ART sensitivity. We provide evidence that the clinical marker of resistance (delayed parasite clearance is an indirect measure of drug efficacy because of the persistence of unviable parasites with unchanged morphology in the circulation, and we suggest alternative approaches for the direct measurement of viability. Our model predicts that extending current three-day ART treatment courses to four days, or splitting the doses, will efficiently clear resistant parasite infections. This work provides a rationale for improving the detection of ART resistance in the field and for treatment strategies that can be employed in areas

Stress Response and Artemisinin Resistance in Malaria Parasite

Science.gov (United States)

2017-07-01

AWARD NUMBER: W81XWH-16-1-0241 TITLE: Stress Response and Artemisinin Resistance in Malaria Parasite PRINCIPAL INVESTIGATOR: Juan C. Pizarro...SUBTITLE Stress Response and Artemisinin Resistance in Malaria Parasite 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-16-1-0241 5c. PROGRAM ELEMENT...13. SUPPLEMENTARY NOTES 14. ABSTRACT In malaria , drug resistance is a major treat to disease control efforts. Unfortunately, there is a significant

The relationship between beginning teachers' stress causes, stress responses, teaching behaviour and attrition

NARCIS (Netherlands)

Harmsen, Ruth; Lorenz, Michelle; Maulana, Ridwan; van Veen, Klaas

2018-01-01

In this study, the relationships between beginning teachers’ perceived stress causes, stress responses, observed teaching behaviour and attrition is investigated employing structural equation modelling (SEM). A total of 143 BTs were surveyed using the Questionnaire on the Experience and Evaluation

Model and prediction of stress relaxation of polyurethane fiber

Science.gov (United States)

You, Gexin; Wang, Chunyan; Mei, Shuqin; Yang, Bo; Zhou, Xiuwen

2018-03-01

In this study, the effect of small strain (less than 10%) on hydrogen bond (H-bond) and crystallinity of dry-spun polyurethane fiber was investigated with fourier transform infrared spectroscopy and x-ray diffractometer, respectively. The results showed that the H-bond of hard segments hardly broke and its degree of crystallinity scarcely varied below strain of 10%. The fiber stress relaxation behavior at 25 °C under small strain was researched using dynamic mechanical analyzer. The stress relaxation modulus constitutive equation was obtained by transforming the non-linear relationship between stress and time into the linear relationship between stress and strain. The stress relaxation modulus master curve at 25 °C was established in terms of short-term stress relaxation tests at elevated temperatures (35 °C, 45 °C, 65 °C and 75 °C) according to time-temperature superposition principle (TTS) to predict long-term behavior within 353 year.

Associations between circadian and stress response cortisol in children

OpenAIRE

Simons, S.S.H.; Cillessen, A.H.N.; Weerth, C. de

2017-01-01

Hypothalamic-pituitary-adrenal (HPA) axis functioning is characterized by the baseline production of cortisol following a circadian rhythm, as well as by the superimposed production of cortisol in response to a stressor. However, it is relatively unknown whether the basal cortisol circadian rhythm is associated with the cortisol stress response in children. Since alterations in cortisol stress responses have been associated with mental and physical health, this study investigated whether the ...

Regulation of water, salinity, and cold stress responses by salicylic acid

Directory of Open Access Journals (Sweden)

Kenji eMiura

2014-01-01

Full Text Available Salicylic acid (SA is a naturally occurring phenolic compound. SA plays an important role in the regulation of plant growth, development, ripening, and defense responses. The role of SA in the plant-pathogen relationship has been extensively investigated. In addition to defense responses, SA plays an important role in the response to abiotic stresses, including drought, low temperature, and salinity stresses. It has been suggested that SA has great agronomic potential to improve the stress tolerance of agriculturally important crops. However, the utility of SA is dependent on the concentration of the applied SA, the mode of application, and the state of the plants (e.g., developmental stage and acclimation. Generally, low concentrations of applied SA alleviate the sensitivity to abiotic stresses, and high concentrations of applied induce high levels of oxidative stress, leading to a decreased tolerance to abiotic stresses. In this chapter, the effects of SA on the water stress responses and regulation of stomatal closure are reviewed.

Deep sequencing of Brachypodium small RNAs at the global genome level identifies microRNAs involved in cold stress response

Directory of Open Access Journals (Sweden)

Chong Kang

2009-09-01

Full Text Available Abstract Background MicroRNAs (miRNAs are endogenous small RNAs having large-scale regulatory effects on plant development and stress responses. Extensive studies of miRNAs have only been performed in a few model plants. Although miRNAs are proved to be involved in plant cold stress responses, little is known for winter-habit monocots. Brachypodium distachyon, with close evolutionary relationship to cool-season cereals, has recently emerged as a novel model plant. There are few reports of Brachypodium miRNAs. Results High-throughput sequencing and whole-genome-wide data mining led to the identification of 27 conserved miRNAs, as well as 129 predicted miRNAs in Brachypodium. For multiple-member conserved miRNA families, their sizes in Brachypodium were much smaller than those in rice and Populus. The genome organization of miR395 family in Brachypodium was quite different from that in rice. The expression of 3 conserved miRNAs and 25 predicted miRNAs showed significant changes in response to cold stress. Among these miRNAs, some were cold-induced and some were cold-suppressed, but all the conserved miRNAs were up-regulated under cold stress condition. Conclusion Our results suggest that Brachypodium miRNAs are composed of a set of conserved miRNAs and a large proportion of non-conserved miRNAs with low expression levels. Both kinds of miRNAs were involved in cold stress response, but all the conserved miRNAs were up-regulated, implying an important role for cold-induced miRNAs. The different size and genome organization of miRNA families in Brachypodium and rice suggest that the frequency of duplication events or the selection pressure on duplicated miRNAs are different between these two closely related plant species.

Stress Prediction for Distributed Structural Health Monitoring Using Existing Measurements and Pattern Recognition.

Science.gov (United States)

Lu, Wei; Teng, Jun; Zhou, Qiushi; Peng, Qiexin

2018-02-01

The stress in structural steel members is the most useful and directly measurable physical quantity to evaluate the structural safety in structural health monitoring, which is also an important index to evaluate the stress distribution and force condition of structures during structural construction and service phases. Thus, it is common to set stress as a measure in steel structural monitoring. Considering the economy and the importance of the structural members, there are only a limited number of sensors that can be placed, which means that it is impossible to obtain the stresses of all members directly using sensors. This study aims to develop a stress response prediction method for locations where there are insufficent sensors, using measurements from a limited number of sensors and pattern recognition. The detailed improved aspects are: (1) a distributed computing process is proposed, where the same pattern is recognized by several subsets of measurements; and (2) the pattern recognition using the subset of measurements is carried out by considering the optimal number of sensors and number of fusion patterns. The validity and feasibility of the proposed method are verified using two examples: the finite-element simulation of a single-layer shell-like steel structure, and the structural health monitoring of the space steel roof of Shenzhen Bay Stadium; for the latter, the anti-noise performance of this method is verified by the stress measurements from a real-world project.

The Effect of Music on the Human Stress Response

Science.gov (United States)

Thoma, Myriam V.; La Marca, Roberto; Brönnimann, Rebecca; Finkel, Linda; Ehlert, Ulrike; Nater, Urs M.

2013-01-01

Background Music listening has been suggested to beneficially impact health via stress-reducing effects. However, the existing literature presents itself with a limited number of investigations and with discrepancies in reported findings that may result from methodological shortcomings (e.g. small sample size, no valid stressor). It was the aim of the current study to address this gap in knowledge and overcome previous shortcomings by thoroughly examining music effects across endocrine, autonomic, cognitive, and emotional domains of the human stress response. Methods Sixty healthy female volunteers (mean age = 25 years) were exposed to a standardized psychosocial stress test after having been randomly assigned to one of three different conditions prior to the stress test: 1) relaxing music (‘Miserere’, Allegri) (RM), 2) sound of rippling water (SW), and 3) rest without acoustic stimulation (R). Salivary cortisol and salivary alpha-amylase (sAA), heart rate (HR), respiratory sinus arrhythmia (RSA), subjective stress perception and anxiety were repeatedly assessed in all subjects. We hypothesized that listening to RM prior to the stress test, compared to SW or R would result in a decreased stress response across all measured parameters. Results The three conditions significantly differed regarding cortisol response (p = 0.025) to the stressor, with highest concentrations in the RM and lowest in the SW condition. After the stressor, sAA (p=0.026) baseline values were reached considerably faster in the RM group than in the R group. HR and psychological measures did not significantly differ between groups. Conclusion Our findings indicate that music listening impacted the psychobiological stress system. Listening to music prior to a standardized stressor predominantly affected the autonomic nervous system (in terms of a faster recovery), and to a lesser degree the endocrine and psychological stress response. These findings may help better understanding the

Reconstructing a Network of Stress-Response Regulators via Dynamic System Modeling of Gene Regulation

Directory of Open Access Journals (Sweden)

Wei-Sheng Wu

2008-01-01

Full Text Available Unicellular organisms such as yeasts have evolved mechanisms to respond to environmental stresses by rapidly reorganizing the gene expression program. Although many stress-response genes in yeast have been discovered by DNA microarrays, the stress-response transcription factors (TFs that regulate these stress-response genes remain to be investigated. In this study, we use a dynamic system model of gene regulation to describe the mechanism of how TFs may control a gene’s expression. Then, based on the dynamic system model, we develop the Stress Regulator Identification Algorithm (SRIA to identify stress-response TFs for six kinds of stresses. We identified some general stress-response TFs that respond to various stresses and some specific stress-response TFs that respond to one specifi c stress. The biological significance of our findings is validated by the literature. We found that a small number of TFs is probably suffi cient to control a wide variety of expression patterns in yeast under different stresses. Two implications can be inferred from this observation. First, the response mechanisms to different stresses may have a bow-tie structure. Second, there may be regulatory cross-talks among different stress responses. In conclusion, this study proposes a network of stress-response regulators and the details of their actions.

The Predictive Role of Maternal Parenting and Stress on Pupils' Bullying involvement.

Science.gov (United States)

Alizadeh Maralani, Fatemeh; Mirnasab, Mirmahmoud; Hashemi, Touraj

2016-10-01

The link between inappropriate parenting style and both bullying and victimization is well documented. However, it is not clear as to which kind of parenting style is associated with victimization. Furthermore, no studies have yet been conducted regarding the role of parental stress in bullying and victimization. This study aimed to examine the role of parenting styles and maternal stress in pupils' bullying and victimization. A total of 300 primary school pupils, enrolled in fourth and fifth grades, participated in the study. Initially, 100 noninvolved pupils were randomly selected using a multistage cluster sampling method. Then using a screening method, 100 bully pupils and 100 victimized peers were selected. Olweus Bullying Scale and teacher nomination were administered for screening these pupils. Baumrind Parenting Style Questionnaire and revised version of Abidin Parental Stress Index (short form) were also applied to all pupils in the study. Data were analyzed using discriminant function analysis. The findings showed that (a) with regard to parenting styles, significant differences were found among groups. Authoritarian parenting style could significantly predict pupils' bullying behavior, whereas victimization was predictable in families with permissive parenting style. In addition, noninvolved pupils were predicted to have authoritative parenting style. (b) Considering maternal stress, significant differences were observed across groups. Parents of bullies and victims were predicted to have higher maternal stress than noninvolved pupils. The implications of the study in relation to the role of mothers in bullying and victimization are discussed.

Stress response and the adolescent transition: performance versus peer rejection stressors.

Science.gov (United States)

Stroud, Laura R; Foster, Elizabeth; Papandonatos, George D; Handwerger, Kathryn; Granger, Douglas A; Kivlighan, Katie T; Niaura, Raymond

2009-01-01

Little is known about normative variation in stress response over the adolescent transition. This study examined neuroendocrine and cardiovascular responses to performance and peer rejection stressors over the adolescent transition in a normative sample. Participants were 82 healthy children (ages 7-12 years, n = 39, 22 females) and adolescents (ages 13-17, n = 43, 20 females) recruited through community postings. Following a habituation session, participants completed a performance (public speaking, mental arithmetic, mirror tracing) or peer rejection (exclusion challenges) stress session. Salivary cortisol, salivary alpha amylase (sAA), systolic and diastolic blood pressure (SBP, DBP), and heart rate were measured throughout. Adolescents showed significantly greater cortisol, sAA, SBP, and DBP stress response relative to children. Developmental differences were most pronounced in the performance stress session for cortisol and DBP and in the peer rejection session for sAA and SBP. Heightened physiological stress responses in typical adolescents may facilitate adaptation to new challenges of adolescence and adulthood. In high-risk adolescents, this normative shift may tip the balance toward stress response dysregulation associated with depression and other psychopathology. Specificity of physiological response by stressor type highlights the importance of a multisystem approach to the psychobiology of stress and may also have implications for understanding trajectories to psychopathology.

Study on effect of mean stress on fatigue life prediction of thin film structure

Energy Technology Data Exchange (ETDEWEB)

Shin, Myung Soo [Ahtti Co., Seongnam (Korea, Republic of); Park, Jun Hyu [Tongmyong University, Busan (Korea, Republic of); Kim, Jung Yup [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

2016-04-15

This paper describes the effect of mean stress on fatigue life prediction of structure made with thin film. It is well known that the mean stress influences fatigue life prediction of mechanical structure. We investigated a reasonable method for considering mean stress when fatigue strength assessment of micro structure of thin film should be performed. Fatigue tests of smooth specimen of beryllium-copper (BeCu) thin film were performed in ambient air at R = 0.1 with 5 Hz. A micro probe was designed and made with BeCu thin film by the precision press process. Fatigue tests of micro structure were performed with 5 Hz frequency, in ambient air to verify the fatigue life predicted by computer simulation through FE analysis. The fatigue life predicted by the Sa -N curve modified by Goodman method with principal stress through FE analysis shows a more reasonable result than other methods.

Study on effect of mean stress on fatigue life prediction of thin film structure

International Nuclear Information System (INIS)

Shin, Myung Soo; Park, Jun Hyu; Kim, Jung Yup

2016-01-01

This paper describes the effect of mean stress on fatigue life prediction of structure made with thin film. It is well known that the mean stress influences fatigue life prediction of mechanical structure. We investigated a reasonable method for considering mean stress when fatigue strength assessment of micro structure of thin film should be performed. Fatigue tests of smooth specimen of beryllium-copper (BeCu) thin film were performed in ambient air at R = 0.1 with 5 Hz. A micro probe was designed and made with BeCu thin film by the precision press process. Fatigue tests of micro structure were performed with 5 Hz frequency, in ambient air to verify the fatigue life predicted by computer simulation through FE analysis. The fatigue life predicted by the Sa -N curve modified by Goodman method with principal stress through FE analysis shows a more reasonable result than other methods

Ghosts of thermal past: reef fish exposed to historic high temperatures have heightened stress response to further stressors

Science.gov (United States)

Mills, S. C.; Beldade, R.; Chabanet, P.; Bigot, L.; O'Donnell, J. L.; Bernardi, G.

2015-12-01

Individual exposure to stressors can induce changes in physiological stress responses through modulation of the hypothalamic-pituitary-interrenal (HPI) axis. Despite theoretical predictions, little is known about how individuals will respond to unpredictable short-lived stressors, such as thermal events. We examine the primary neuroendocrine response of coral reef fish populations from the Îles Eparses rarely exposed to anthropogenic stress, but that experienced different thermal histories. Skunk anemonefish, Amphiprion akallopisos, showed different cortisol responses to a generic stressor between islands, but not along a latitudinal gradient. Those populations previously exposed to higher maximum temperatures showed greater responses of their HPI axis. Archive data reveal thermal stressor events occur every 1.92-6 yr, suggesting that modifications to the HPI axis could be adaptive. Our results highlight the potential for adaptation of the HPI axis in coral reef fish in response to a climate-induced thermal stressor.

Eccentric-exercise induced inflammation attenuates the vascular responses to mental stress

NARCIS (Netherlands)

Paine, N.J.; Ring, C.; Aldred, S.; Bosch, J.A.; Wadley, A.J.; Veldhuijzen van Zanten, J.J.C.S.

2013-01-01

Mental stress has been identified as a trigger of myocardial infarction (MI), with inflammation and vascular responses to mental stress independently implicated as contributing factors. This study examined whether inflammation moderates the vascular responses to mental stress. Eighteen healthy male

Growth and physiological responses to water and nutrient stress in ...

African Journals Online (AJOL)

Growth and physiological responses to water and nutrient stress in oil palm. ... changes in growth, physiology and nutrient concentration in response to two watering regimes (well-watered and water-stress conditions) and ... from 32 Countries:.

Physiological stress response patterns during a blood donation.

Science.gov (United States)

Hoogerwerf, M D; Veldhuizen, I J T; Tarvainen, M P; Merz, E-M; Huis In 't Veld, E M J; de Kort, W L A M; Sluiter, J K; Frings-Dresen, M H W

2018-03-24

Donating blood is associated with increased psychological stress. This study investigates whether a blood donation induces physiological stress and if response patterns differ by gender, donation experience and non-acute stress. In 372 donors, physiological stress [blood pressure, pulse rate, pulse rate variability (PRV)] was measured at seven moments during routine donation. PRV was assessed using time domain [root mean square of successive differences (RMSSD)] and frequency domain [high frequency (HF) and low frequency (LF) power] parameters. Non-acute stress was assessed by questionnaire. Shape and significance of time course patterns were assessed by fitting multilevel models for each stress measure and comparing men and women, first-time and experienced donors, and donors with high and low levels of non-acute stress. Significant response patterns were found for all stress measures, where levels of systolic blood pressure (F(1,1315) = 24·2, P blood pressure (F(1,1326) = 50·9, P blood pressure/pulse rate in women; higher pulse rate in first-time donors; higher RMSSD at arrival and from screening until leaving in first-time donors; and higher LF and HF in first-time donors. This study shows an increase in physiological stress related to needle insertion, followed by a decrease when leaving the donation centre. Some group effects were also found. © 2018 International Society of Blood Transfusion.

On the residual stress modeling of shot-peened AISI 4340 steel: finite element and response surface methods

Science.gov (United States)

Asgari, Ali; Dehestani, Pouya; Poruraminaie, Iman

2018-02-01

Shot peening is a well-known process in applying the residual stress on the surface of industrial parts. The induced residual stress improves fatigue life. In this study, the effects of shot peening parameters such as shot diameter, shot speed, friction coefficient, and the number of impacts on the applied residual stress will be evaluated. To assess these parameters effect, firstly the shot peening process has been simulated by finite element method. Then, effects of the process parameters on the residual stress have been evaluated by response surface method as a statistical approach. Finally, a strong model is presented to predict the maximum residual stress induced by shot peening process in AISI 4340 steel. Also, the optimum parameters for the maximum residual stress are achieved. The results indicate that effect of shot diameter on the induced residual stress is increased by increasing the shot speed. Also, enhancing the friction coefficient magnitude always cannot lead to increase in the residual stress.

The significance of translation regulation in the stress response

OpenAIRE

Picard, Flora; Loubière, Pascal; Girbal, Laurence; Bousquet, Muriel

2013-01-01

Background: The stress response in bacteria involves the multistage control of gene expression but is not entirely understood. To identify the translational response of bacteria in stress conditions and assess its contribution to the regulation of gene expression, the translational states of all mRNAs were compared under optimal growth condition and during nutrient (isoleucine) starvation. Results: A genome-scale study of the translational response to nutritional limitation was performed in t...

Identification and expression of the WRKY transcription factors of Carica papaya in response to abiotic and biotic stresses.

Science.gov (United States)

Pan, Lin-Jie; Jiang, Ling

2014-03-01

The WRKY transcription factor (TF) plays a very important role in the response of plants to various abiotic and biotic stresses. A local papaya database was built according to the GenBank expressed sequence tag database using the BioEdit software. Fifty-two coding sequences of Carica papaya WRKY TFs were predicted using the tBLASTn tool. The phylogenetic tree of the WRKY proteins was classified. The expression profiles of 13 selected C. papaya WRKY TF genes under stress induction were constructed by quantitative real-time polymerase chain reaction. The expression levels of these WRKY genes in response to 3 abiotic and 2 biotic stresses were evaluated. TF807.3 and TF72.14 are upregulated by low temperature; TF807.3, TF43.76, TF12.199 and TF12.62 are involved in the response to drought stress; TF9.35, TF18.51, TF72.14 and TF12.199 is involved in response to wound; TF12.199, TF807.3, TF21.156 and TF18.51 was induced by PRSV pathogen; TF72.14 and TF43.76 are upregulated by SA. The regulated expression levels of above eight genes normalized against housekeeping gene actin were significant at probability of 0.01 levels. These WRKY TFs could be related to corresponding stress resistance and selected as the candidate genes, especially, the two genes TF807.3 and TF12.199, which were regulated notably by four stresses respectively. This study may provide useful information and candidate genes for the development of transgenic stress tolerant papaya varieties.

Maternal buffering beyond glucocorticoids: impact of early life stress on corticolimbic circuits that control infant responses to novelty

Science.gov (United States)

Howell, Brittany R.; McMurray, Matthew S.; Guzman, Dora B.; Nair, Govind; Shi, Yundi; McCormack, Kai M.; Hu, Xiaoping; Styner, Martin A.; Sanchez, Mar M.

2017-01-01

Maternal presence has a potent buffering effect on infant fear and stress responses in primates. We previously reported that maternal presence is not effective in buffering the endocrine stress response in infant rhesus monkeys reared by maltreating mothers. We have also reported that maltreating mothers show low maternal responsiveness and permissiveness/secure-base behavior. Although still not understood, it is possible that this maternal buffering effect is mediated, at least partially, through deactivation of amygdala response circuits when mothers are present. Here we studied rhesus monkey infants that differed in the quality of early maternal care to investigate how this early experience modulated maternal buffering effects on behavioral responses to novelty during the weaning period. We also examined the relationship between these behavioral responses and structural connectivity in one of the underlying regulatory neural circuits: amygdala-prefrontal pathways. Our findings suggest that infant exploration in a novel situation is predicted by maternal responsiveness and structural integrity of amygdala-prefrontal white matter depending on maternal presence (positive relationships when mother is absent). These results provide evidence that maternal buffering of infant behavioral inhibition is dependent on the quality of maternal care and structural connectivity of neural pathways that are sensitive to early life stress. PMID:27295326

Stressor specificity of central neuroendocrine responses: implications for stress-related disorders.

Science.gov (United States)

Pacák, K; Palkovits, M

2001-08-01

Despite the fact that many research articles have been written about stress and stress-related diseases, no scientifically accepted definition of stress exists. Selye introduced and popularized stress as a medical and scientific idea. He did not deny the existence of stressor-specific response patterns; however, he emphasized that such responses did not constitute stress, only the shared nonspecific component. In this review we focus mainly on the similarities and differences between the neuroendocrine responses (especially the sympathoadrenal and the sympathoneuronal systems and the hypothalamo-pituitary-adrenocortical axis) among various stressors and a strategy for testing Selye's doctrine of nonspecificity. In our experiments, we used five different stressors: immobilization, hemorrhage, cold exposure, pain, or hypoglycemia. With the exception of immobilization stress, these stressors also differed in their intensities. Our results showed marked heterogeneity of neuroendocrine responses to various stressors and that each stressor has a neurochemical "signature." By examining changes of Fos immunoreactivity in various brain regions upon exposure to different stressors, we also attempted to map central stressor-specific neuroendocrine pathways. We believe the existence of stressor-specific pathways and circuits is a clear step forward in the study of the pathogenesis of stress-related disorders and their proper treatment. Finally, we define stress as a state of threatened homeostasis (physical or perceived treat to homeostasis). During stress, an adaptive compensatory specific response of the organism is activated to sustain homeostasis. The adaptive response reflects the activation of specific central circuits and is genetically and constitutionally programmed and constantly modulated by environmental factors.

Towards the prediction of pre-mining stresses in the European continent. [Estimates of vertical and probable maximum lateral stress in Europe

Energy Technology Data Exchange (ETDEWEB)

Blackwood, R. L.

1980-05-15

There are now available sufficient data from in-situ, pre-mining stress measurements to allow a first attempt at predicting the maximum stress magnitudes likely to occur in a given mining context. The sub-horizontal (lateral) stress generally dominates the stress field, becoming critical to stope stability in many cases. For cut-and-fill mining in particular, where developed fill pressures are influenced by lateral displacement of pillars or stope backs, extraction maximization planning by mathematical modelling techniques demands the best available estimate of pre-mining stresses. While field measurements are still essential for this purpose, in the present paper it is suggested that the worst stress case can be predicted for preliminary design or feasibility study purposes. In the Eurpoean continent the vertical component of pre-mining stress may be estimated by adding 2 MPa to the pressure due to overburden weight. The maximum lateral stress likely to be encountered is about 57 MPa at depths of some 800m to 1000m below the surface.

Development of residual stress prediction model in pipe weldment

Energy Technology Data Exchange (ETDEWEB)

Eom, Yun Yong; Lim, Se Young; Choi, Kang Hyeuk; Cho, Young Sam; Lim, Jae Hyuk [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

2002-03-15

When Leak Before Break(LBB) concepts is applied to high energy piping of nuclear power plants, residual weld stresses is a important variable. The main purpose of his research is to develop the numerical model which can predict residual weld stresses. Firstly, basic theories were described which need to numerical analysis of welding parts. Before the analysis of pipe, welding of a flat plate was analyzed and compared. Appling the data of used pipes, thermal/mechanical analysis were accomplished and computed temperature gradient and residual stress distribution. For thermal analysis, proper heat flux was regarded as the heat source and convection/radiation heat transfer were considered at surfaces. The residual stresses were counted from the computed temperature gradient and they were compared and verified with a result of another research.

Blunted cortisol response to acute pre-learning stress prevents misinformation effect in a forced confabulation paradigm.

Science.gov (United States)

Zoladz, Phillip R; Cadle, Chelsea E; Dailey, Alison M; Fiely, Miranda K; Peters, David M; Nagle, Hannah E; Mosley, Brianne E; Scharf, Amanda R; Brown, Callie M; Duffy, Tessa J; Earley, McKenna B; Rorabaugh, Boyd R; Payment, Kristie E

2017-07-01

Research examining the effects of stress on false memory formation has been equivocal, partly because of the complex nature of stress-memory interactions. A major factor influencing stress effects on learning is the timing of stress relative to encoding. Previous work has shown that brief stressors administered immediately before learning enhance long-term memory. Thus, we predicted that brief stress immediately before learning would decrease participants' susceptibility to subsequent misinformation and reduce false memory formation. Eighty-four male and female participants submerged their hand in ice cold (stress) or warm (no stress) water for 3min. Immediately afterwards, they viewed an 8-min excerpt from the Disney movie Looking for Miracles. The next day, participants were interviewed and asked several questions about the video, some of which forced them to confabulate responses. Three days and three weeks later, respectively, participants completed a recognition test in the lab and a free recall test via email. Our results revealed a robust misinformation effect, overall, as participants falsely recognized a significant amount of information that they had confabulated during the interview as having occurred in the original video. Stress, overall, did not significantly influence this misinformation effect. However, the misinformation effect was completely absent in stressed participants who exhibited a blunted cortisol response to the stress, for both recognition and recall tests. The complete absence of a misinformation effect in non-responders may lend insight into the interactive roles of autonomic arousal and corticosteroid levels in false memory development. Copyright © 2017 Elsevier Inc. All rights reserved.

Comprehensive phenotypic analysis of rice (Oryza sativa) response to salinity stress

KAUST Repository

Pires, Inê s S.; Negrã o, Só nia; Oliveira, M. Margarida; Purugganan, Michael D.

2015-01-01

affected by salt stress in rice, which puts in question the importance of K+/Na+ when analyzing rice salt stress response. Not only do our results contribute to improve our global understanding of salt stress response in an important crop, but we also use

Depersonalization experiences in undergraduates are related to heightened stress cortisol responses.

Science.gov (United States)

Giesbrecht, Timo; Smeets, Tom; Merckelbach, Harald; Jelicic, Marko

2007-04-01

The relationship between dissociative tendencies, as measured with the Dissociative Experiences Scale and its amnesia, absorption/imaginative involvement, and depersonalization/derealization subscales, and HPA axis functioning was studied in 2 samples of undergraduate students (N = 58 and 67). Acute stress was induced by means of the Trier Social Stress Test. Subjective and physiological stress (i.e., cortisol) responses were measured. Individuals high on the depersonalization/derealization subscale of the Dissociative Experiences Scale exhibited more pronounced cortisol responses, while individuals high on the absorption subscale showed attenuated responses. Interestingly, subjective stress experiences, as indicated by the Tension-Anxiety subscale of the Profile of Mood States, were positively related to trait dissociation. The present findings illustrate how various types of dissociation (i.e., depersonalization/derealization, absorption) are differentially related to cortisol stress responses.

A novel heat shock protein alpha 8 (Hspa8) molecular network mediating responses to stress- and ethanol-related behaviors.

Science.gov (United States)

Urquhart, Kyle R; Zhao, Yinghong; Baker, Jessica A; Lu, Ye; Yan, Lei; Cook, Melloni N; Jones, Byron C; Hamre, Kristin M; Lu, Lu

2016-04-01

Genetic differences mediate individual differences in susceptibility and responses to stress and ethanol, although, the specific molecular pathways that control these responses are not fully understood. Heat shock protein alpha 8 (Hspa8) is a molecular chaperone and member of the heat shock protein family that plays an integral role in the stress response and that has been implicated as an ethanol-responsive gene. Therefore, we assessed its role in mediating responses to stress and ethanol across varying genetic backgrounds. The hippocampus is an important mediator of these responses, and thus, was examined in the BXD family of mice in this study. We conducted bioinformatic analyses to dissect genetic factors modulating Hspa8 expression, identify downstream targets of Hspa8, and examined its role. Hspa8 is trans-regulated by a gene or genes on chromosome 14 and is part of a molecular network that regulates stress- and ethanol-related behaviors. To determine additional components of this network, we identified direct or indirect targets of Hspa8 and show that these genes, as predicted, participate in processes such as protein folding and organic substance metabolic processes. Two phenotypes that map to the Hspa8 locus are anxiety-related and numerous other anxiety- and/or ethanol-related behaviors significantly correlate with Hspa8 expression. To more directly assay this relationship, we examined differences in gene expression following exposure to stress or alcohol and showed treatment-related differential expression of Hspa8 and a subset of the members of its network. Our findings suggest that Hspa8 plays a vital role in genetic differences in responses to stress and ethanol and their interactions.

Low lifetime stress exposure is associated with reduced stimulus–response memory

Science.gov (United States)

Goldfarb, Elizabeth V.; Shields, Grant S.; Daw, Nathaniel D.; Slavich, George M.; Phelps, Elizabeth A.

2017-01-01

Exposure to stress throughout life can cumulatively influence later health, even among young adults. The negative effects of high cumulative stress exposure are well-known, and a shift from episodic to stimulus–response memory has been proposed to underlie forms of psychopathology that are related to high lifetime stress. At the other extreme, effects of very low stress exposure are mixed, with some studies reporting that low stress leads to better outcomes, while others demonstrate that low stress is associated with diminished resilience and negative outcomes. However, the influence of very low lifetime stress exposure on episodic and stimulus–response memory is unknown. Here we use a lifetime stress assessment system (STRAIN) to assess cumulative lifetime stress exposure and measure memory performance in young adults reporting very low and moderate levels of lifetime stress exposure. Relative to moderate levels of stress, very low levels of lifetime stress were associated with reduced use and retention (24 h later) of stimulus–response (SR) associations, and a higher likelihood of using context memory. Further, computational modeling revealed that participants with low levels of stress exhibited worse expression of memory for SR associations than those with moderate stress. These results demonstrate that very low levels of stress exposure can have negative effects on cognition. PMID:28298555

Glucocorticoids mediate stress-induced impairment of retrieval of stimulus-response memory.

Science.gov (United States)

Atsak, Piray; Guenzel, Friederike M; Kantar-Gok, Deniz; Zalachoras, Ioannis; Yargicoglu, Piraye; Meijer, Onno C; Quirarte, Gina L; Wolf, Oliver T; Schwabe, Lars; Roozendaal, Benno

2016-05-01

Acute stress and elevated glucocorticoid hormone levels are well known to impair the retrieval of hippocampus-dependent 'declarative' memory. Recent findings suggest that stress might also impair the retrieval of non-hippocampal memories. In particular, stress shortly before retention testing was shown to impair the retrieval of striatal stimulus-response associations in humans. However, the mechanism underlying this stress-induced retrieval impairment of non-hippocampal stimulus-response memory remains elusive. In the present study, we investigated whether an acute elevation in glucocorticoid levels mediates the impairing effects of stress on retrieval of stimulus-response memory. Male Sprague-Dawley rats were trained on a stimulus-response task in an eight-arm radial maze until they learned to associate a stimulus, i.e., cue, with a food reward in one of the arms. Twenty-four hours after successful acquisition, they received a systemic injection of vehicle, corticosterone (1mg/kg), the corticosterone-synthesis inhibitor metyrapone (35mg/kg) or were left untreated 1h before retention testing. We found that the corticosterone injection impaired the retrieval of stimulus-response memory. We further found that the systemic injection procedure per se was stressful as the vehicle administration also increased plasma corticosterone levels and impaired the retrieval of stimulus-response memory. However, memory retrieval was not impaired when rats were tested 2min after the systemic vehicle injection, before any stress-induced elevation in corticosterone levels had occurred. Moreover, metyrapone treatment blocked the effect of injection stress on both plasma corticosterone levels and memory retrieval impairment, indicating that the endogenous corticosterone response mediates the stress-induced memory retrieval impairment. None of the treatments affected rats' locomotor activity or motivation to search for the food reward within the maze. These findings show that stress

Renal sympathetic nerve, blood flow, and epithelial transport responses to thermal stress.

Science.gov (United States)

Wilson, Thad E

2017-05-01

Thermal stress is a profound sympathetic stress in humans; kidney responses involve altered renal sympathetic nerve activity (RSNA), renal blood flow, and renal epithelial transport. During mild cold stress, RSNA spectral power but not total activity is altered, renal blood flow is maintained or decreased, and epithelial transport is altered consistent with a sympathetic stress coupled with central volume loaded state. Hypothermia decreases RSNA, renal blood flow, and epithelial transport. During mild heat stress, RSNA is increased, renal blood flow is decreased, and epithelial transport is increased consistent with a sympathetic stress coupled with a central volume unloaded state. Hyperthermia extends these directional changes, until heat illness results. Because kidney responses are very difficult to study in humans in vivo, this review describes and qualitatively evaluates an in vivo human skin model of sympathetically regulated epithelial tissue compared to that of the nephron. This model utilizes skin responses to thermal stress, involving 1) increased skin sympathetic nerve activity (SSNA), decreased skin blood flow, and suppressed eccrine epithelial transport during cold stress; and 2) increased SSNA, skin blood flow, and eccrine epithelial transport during heat stress. This model appears to mimic aspects of the renal responses. Investigations of skin responses, which parallel certain renal responses, may aid understanding of epithelial-sympathetic nervous system interactions during cold and heat stress. Copyright © 2016 Elsevier B.V. All rights reserved.

Age-Related Decrease in Stress Responsiveness and Proactive Coping in Male Mice.

Science.gov (United States)

Oh, Hee-Jin; Song, Minah; Kim, Young Ki; Bae, Jae Ryong; Cha, Seung-Yun; Bae, Ji Young; Kim, Yeongmin; You, Minsu; Lee, Younpyo; Shim, Jieun; Maeng, Sungho

2018-01-01

Coping is a strategic approach to dealing with stressful situations. Those who use proactive coping strategies tend to accept changes and act before changes are expected. In contrast, those who use reactive coping are less flexible and more likely to act in response to changes. However, little research has assessed how coping style changes with age. This study investigated age-related changes in coping strategies and stress responsiveness and the influence of age on the processing of conditioned fear memory in 2-, 12- and 23-month-old male mice. Coping strategy was measured by comparing the escape latency in an active avoidance test and by comparing responses to a shock prod. The results showed that proactivity in coping response gradually decreased with age. Stress responsiveness, measured by stress-induced concentration of corticosterone, was also highest in 2-month-old mice and decreased with age. Consolidation of fear memory was highest in 12-month-old mice and was negatively correlated with the degree of stress responsiveness and proactivity in coping. Fear extinction did not differ among age groups and was not correlated with stress responsiveness or the proactivity of coping. However, the maintenance of extinct fear memory, which was best in 2-month-old mice and worst in 12-month-old mice, was negatively correlated with stress responsiveness but not with coping style. Age-dependent changes in the expression of glucocorticoid receptor (GR) and its regulatory co-chaperones, which are accepted mechanisms for stress hormone stimulation, were measured in the hippocampus. The expression of GR was increased at 12 months compared to other age groups. There were no differences in Hsp70 and BAG1 expression by age. These results can be summarized as follows: (1) stress responsiveness and proactivity in coping decreased with age class; (2) consolidation of fear memory was negatively correlated with both stress responsiveness and proactivity; however, maintenance of

Dispersal timing and drought history influence the response of bacterioplankton to drying-rewetting stress.

Science.gov (United States)

Székely, Anna J; Langenheder, Silke

2017-08-01

The extent and frequency of drought episodes is expected to increase in the following decades making it a crucial stress factor for smaller water bodies. However, very little is known about how bacterioplankton is affected by increased evaporation and how these communities reassemble after rewetting. Here, we present results from a microcosm experiment that assessed the effect of drying-rewetting stress on bacterioplankton in the light of the stress history and the rate and timing of dispersal after the rewetting. We found that the drying phase resulted mainly in a change of function, whereas the complete desiccation and rewetting processes strongly affected both composition and function, which were, however, influenced by the initial conditions and stress history of the communities. Effects of dispersal were generally stronger when it occurred at an early stage after the rewetting. At this stage, selective establishment of dispersed bacteria coupled with enhanced compositional and functional recovery was found, whereas effects of dispersal were neutral, that is, predictable by dispersal rates, at later stages. Our studies therefore show that both the stress history and the timing of dispersal are important factors that influence the response of bacterial communities to environmental change and stress events.

Chronic and episodic stress predict physical symptom bother following breast cancer diagnosis.

Science.gov (United States)

Harris, Lauren N; Bauer, Margaret R; Wiley, Joshua F; Hammen, Constance; Krull, Jennifer L; Crespi, Catherine M; Weihs, Karen L; Stanton, Annette L

2017-12-01

Breast cancer patients often experience adverse physical side effects of medical treatments. According to the biobehavioral model of cancer stress and disease, life stress during diagnosis and treatment may negatively influence the trajectory of women's physical health-related adjustment to breast cancer. This longitudinal study examined chronic and episodic stress as predictors of bothersome physical symptoms during the year after breast cancer diagnosis. Women diagnosed with breast cancer in the previous 4 months (N = 460) completed a life stress interview for contextual assessment of chronic and episodic stress severity at study entry and 9 months later. Physical symptom bother (e.g., pain, fatigue) was measured at study entry, every 6 weeks through 6 months, and at nine and 12 months. In multilevel structural equation modeling (MSEM) analyses, both chronic stress and episodic stress occurring shortly after diagnosis predicted greater physical symptom bother over the study period. Episodic stress reported to have occurred prior to diagnosis did not predict symptom bother in MSEM analyses, and the interaction between chronic and episodic stress on symptom bother was not significant. Results suggest that ongoing chronic stress and episodic stress occurring shortly after breast cancer diagnosis are important predictors of bothersome symptoms during and after cancer treatment. Screening for chronic stress and recent stressful life events in the months following diagnosis may help to identify breast cancer patients at risk for persistent and bothersome physical symptoms. Interventions to prevent or ameliorate treatment-related physical symptoms may confer added benefit by addressing ongoing non-cancer-related stress in women's lives.

Predicting the development of stress urinary incontinence 3 years after hysterectomy

NARCIS (Netherlands)

Lakeman, M.M.E.; van der Vaart, C.H.; van der Steeg, J.W.; Roovers, J.P.W.R.

2011-01-01

We aimed to develop a prediction rule to predict the individual risk to develop stress urinary incontinence (SUI) after hysterectomy. Prospective observational study with 3-year follow-up among women who underwent abdominal or vaginal hysterectomy for benign conditions, excluding vaginal prolapse,

Predicting the development of stress urinary incontinence 3 years after hysterectomy

NARCIS (Netherlands)

Lakeman, Marielle M. E.; Van Der Vaart, C. Huub; Van Der Steeg, Jan Willem; Roovers, Jan-Paul W. R.

Introduction and hypothesis We aimed to develop a prediction rule to predict the individual risk to develop stress urinary incontinence (SUI) after hysterectomy. Methods Prospective observational study with 3-year follow-up among women who underwent abdominal or vaginal hysterectomy for benign

Prediction of tectonic stresses and fracture networks with geomechanical reservoir models

International Nuclear Information System (INIS)

Henk, A.; Fischer, K.

2014-09-01

This project evaluates the potential of geomechanical Finite Element (FE) models for the prediction of in situ stresses and fracture networks in faulted reservoirs. Modeling focuses on spatial variations of the in situ stress distribution resulting from faults and contrasts in mechanical rock properties. In a first methodological part, a workflow is developed for building such geomechanical reservoir models and calibrating them to field data. In the second part, this workflow was applied successfully to an intensively faulted gas reservoir in the North German Basin. A truly field-scale geomechanical model covering more than 400km 2 was built and calibrated. It includes a mechanical stratigraphy as well as a network of 86 faults. The latter are implemented as distinct planes of weakness and allow the fault-specific evaluation of shear and normal stresses. A so-called static model describes the recent state of the reservoir and, thus, after calibration its results reveal the present-day in situ stress distribution. Further geodynamic modeling work considers the major stages in the tectonic history of the reservoir and provides insights in the paleo stress distribution. These results are compared to fracture data and hydraulic fault behavior observed today. The outcome of this project confirms the potential of geomechanical FE models for robust stress and fracture predictions. The workflow is generally applicable and can be used for modeling of any stress-sensitive reservoir.

Prediction of tectonic stresses and fracture networks with geomechanical reservoir models

Energy Technology Data Exchange (ETDEWEB)

Henk, A.; Fischer, K. [TU Darmstadt (Germany). Inst. fuer Angewandte Geowissenschaften

2014-09-15

This project evaluates the potential of geomechanical Finite Element (FE) models for the prediction of in situ stresses and fracture networks in faulted reservoirs. Modeling focuses on spatial variations of the in situ stress distribution resulting from faults and contrasts in mechanical rock properties. In a first methodological part, a workflow is developed for building such geomechanical reservoir models and calibrating them to field data. In the second part, this workflow was applied successfully to an intensively faulted gas reservoir in the North German Basin. A truly field-scale geomechanical model covering more than 400km{sup 2} was built and calibrated. It includes a mechanical stratigraphy as well as a network of 86 faults. The latter are implemented as distinct planes of weakness and allow the fault-specific evaluation of shear and normal stresses. A so-called static model describes the recent state of the reservoir and, thus, after calibration its results reveal the present-day in situ stress distribution. Further geodynamic modeling work considers the major stages in the tectonic history of the reservoir and provides insights in the paleo stress distribution. These results are compared to fracture data and hydraulic fault behavior observed today. The outcome of this project confirms the potential of geomechanical FE models for robust stress and fracture predictions. The workflow is generally applicable and can be used for modeling of any stress-sensitive reservoir.

Sex differences in the stress response in SD rats.

Science.gov (United States)

Lu, Jing; Wu, Xue-Yan; Zhu, Qiong-Bin; Li, Jia; Shi, Li-Gen; Wu, Juan-Li; Zhang, Qi-Jun; Huang, Man-Li; Bao, Ai-Min

2015-05-01

Sex differences play an important role in depression, the basis of which is an excessive stress response. We aimed at revealing the neurobiological sex differences in the same study in acute- and chronically-stressed rats. Female Sprague-Dawley (SD) rats were randomly divided into 6 groups: chronic unpredictable mild stress (CUMS), acute foot shock (FS) and controls, animals in all 3 groups were sacrificed in proestrus or diestrus. Male SD rats were randomly divided into 3 groups: CUMS, FS and controls. Comparisons were made of behavioral changes in CUMS and control rats, plasma levels of corticosterone (CORT), testosterone (T) and estradiol (E2), and of the hypothalamic mRNA-expression of stress-related molecules, i.e. estrogen receptor α and β, androgen receptor, aromatase, mineralocorticoid receptor, glucocorticoid receptor, corticotropin-releasing hormone, arginine vasopressin and oxytocin. CUMS resulted in disordered estrus cycles, more behavioral and hypothalamic stress-related molecules changes and a stronger CORT response in female rats compared with male rats. Female rats also showed decreased E2 and T levels after FS and CUMS, while male FS rats showed increased E2 and male CUMS rats showed decreased T levels. Stress affects the behavioral, endocrine and the molecular response of the stress systems in the hypothalamus of SD rats in a clear sexual dimorphic way, which has parallels in human data on stress and depression. Copyright © 2015 Elsevier B.V. All rights reserved.

Predicting effects of structural stress in a genome-reduced model bacterial metabolism

Science.gov (United States)

Güell, Oriol; Sagués, Francesc; Serrano, M. Ángeles

2012-08-01

Mycoplasma pneumoniae is a human pathogen recently proposed as a genome-reduced model for bacterial systems biology. Here, we study the response of its metabolic network to different forms of structural stress, including removal of individual and pairs of reactions and knockout of genes and clusters of co-expressed genes. Our results reveal a network architecture as robust as that of other model bacteria regarding multiple failures, although less robust against individual reaction inactivation. Interestingly, metabolite motifs associated to reactions can predict the propagation of inactivation cascades and damage amplification effects arising in double knockouts. We also detect a significant correlation between gene essentiality and damages produced by single gene knockouts, and find that genes controlling high-damage reactions tend to be expressed independently of each other, a functional switch mechanism that, simultaneously, acts as a genetic firewall to protect metabolism. Prediction of failure propagation is crucial for metabolic engineering or disease treatment.

Personality traits predict job stress, depression and anxiety among junior physicians.

Science.gov (United States)

Gramstad, Thomas Olsen; Gjestad, Rolf; Haver, Brit

2013-11-09

High levels of stress and deteriorating mental health among medical students are commonly reported. In Bergen, Norway, we explored the impact of personality traits measured early in their curriculum on stress reactions and levels of depression and anxiety symptoms as junior physicians following graduation. Medical students (n = 201) from two classes participated in a study on personality traits and mental health early in the curriculum. A questionnaire measuring personality traits (Basic Character Inventory (BCI)) was used during their third undergraduate year. BCI assesses four personality traits: neuroticism, extroversion, conscientiousness and reality weakness. Questionnaires measuring mental health (Hospital Anxiety and Depression Scale (HADS) and Symptom Checklist 25 (SCL-25)), and stress (Perceived Medical School Stress (PMSS)) were used during their third and sixth undergraduate year. During postgraduate internship, Cooper's Job Stress Questionnaire (CJSQ) was used to measure perceived job stress, while mental health and stress reactions were reassessed using HADS and SCL-25. Extroversion had the highest mean value (5.11) among the total group of participants, while reality weakness had the lowest (1.51). Neuroticism and reality weakness were related to high levels of perceived job stress (neuroticism r = .19, reality weakness r = .17) as well as higher levels of anxiety symptoms (neuroticism r = .23, reality weakness r = .33) and symptoms of depression (neuroticism r = .21, reality weakness r = .36) during internship. Neuroticism indirectly predicted stress reactions and levels of depression and anxiety symptoms. These relations were mediated by perceived job stress, while reality weakness predicted these mental health measures directly. Extroversion, on the other hand, protected against symptoms of depression (r = -.20). Furthermore, females reported higher levels of job stress than males (difference = 7.52). Certain personality traits measured early in

Spaceflight Modifies Escherichia coli Gene Expression in Response to Antibiotic Exposure and Reveals Role of Oxidative Stress Response

Directory of Open Access Journals (Sweden)

Thomas R. Aunins

2018-03-01

Full Text Available Bacteria grown in space experiments under microgravity conditions have been found to undergo unique physiological responses, ranging from modified cell morphology and growth dynamics to a putative increased tolerance to antibiotics. A common theory for this behavior is the loss of gravity-driven convection processes in the orbital environment, resulting in both reduction of extracellular nutrient availability and the accumulation of bacterial byproducts near the cell. To further characterize the responses, this study investigated the transcriptomic response of Escherichia coli to both microgravity and antibiotic concentration. E. coli was grown aboard International Space Station in the presence of increasing concentrations of the antibiotic gentamicin with identical ground controls conducted on Earth. Here we show that within 49 h of being cultured, E. coli adapted to grow at higher antibiotic concentrations in space compared to Earth, and demonstrated consistent changes in expression of 63 genes in response to an increase in drug concentration in both environments, including specific responses related to oxidative stress and starvation response. Additionally, we find 50 stress-response genes upregulated in response to the microgravity when compared directly to the equivalent concentration in the ground control. We conclude that the increased antibiotic tolerance in microgravity may be attributed not only to diminished transport processes, but also to a resultant antibiotic cross-resistance response conferred by an overlapping effect of stress response genes. Our data suggest that direct stresses of nutrient starvation and acid-shock conveyed by the microgravity environment can incidentally upregulate stress response pathways related to antibiotic stress and in doing so contribute to the increased antibiotic stress tolerance observed for bacteria in space experiments. These results provide insights into the ability of bacteria to adapt under

Spaceflight Modifies Escherichia coli Gene Expression in Response to Antibiotic Exposure and Reveals Role of Oxidative Stress Response.

Science.gov (United States)

Aunins, Thomas R; Erickson, Keesha E; Prasad, Nripesh; Levy, Shawn E; Jones, Angela; Shrestha, Shristi; Mastracchio, Rick; Stodieck, Louis; Klaus, David; Zea, Luis; Chatterjee, Anushree

2018-01-01

Bacteria grown in space experiments under microgravity conditions have been found to undergo unique physiological responses, ranging from modified cell morphology and growth dynamics to a putative increased tolerance to antibiotics. A common theory for this behavior is the loss of gravity-driven convection processes in the orbital environment, resulting in both reduction of extracellular nutrient availability and the accumulation of bacterial byproducts near the cell. To further characterize the responses, this study investigated the transcriptomic response of Escherichia coli to both microgravity and antibiotic concentration. E. coli was grown aboard International Space Station in the presence of increasing concentrations of the antibiotic gentamicin with identical ground controls conducted on Earth. Here we show that within 49 h of being cultured, E. coli adapted to grow at higher antibiotic concentrations in space compared to Earth, and demonstrated consistent changes in expression of 63 genes in response to an increase in drug concentration in both environments, including specific responses related to oxidative stress and starvation response. Additionally, we find 50 stress-response genes upregulated in response to the microgravity when compared directly to the equivalent concentration in the ground control. We conclude that the increased antibiotic tolerance in microgravity may be attributed not only to diminished transport processes, but also to a resultant antibiotic cross-resistance response conferred by an overlapping effect of stress response genes. Our data suggest that direct stresses of nutrient starvation and acid-shock conveyed by the microgravity environment can incidentally upregulate stress response pathways related to antibiotic stress and in doing so contribute to the increased antibiotic stress tolerance observed for bacteria in space experiments. These results provide insights into the ability of bacteria to adapt under extreme stress

Spaceflight Modifies Escherichia coli Gene Expression in Response to Antibiotic Exposure and Reveals Role of Oxidative Stress Response

Science.gov (United States)

Aunins, Thomas R.; Erickson, Keesha E.; Prasad, Nripesh; Levy, Shawn E.; Jones, Angela; Shrestha, Shristi; Mastracchio, Rick; Stodieck, Louis; Klaus, David; Zea, Luis; Chatterjee, Anushree

2018-01-01

Bacteria grown in space experiments under microgravity conditions have been found to undergo unique physiological responses, ranging from modified cell morphology and growth dynamics to a putative increased tolerance to antibiotics. A common theory for this behavior is the loss of gravity-driven convection processes in the orbital environment, resulting in both reduction of extracellular nutrient availability and the accumulation of bacterial byproducts near the cell. To further characterize the responses, this study investigated the transcriptomic response of Escherichia coli to both microgravity and antibiotic concentration. E. coli was grown aboard International Space Station in the presence of increasing concentrations of the antibiotic gentamicin with identical ground controls conducted on Earth. Here we show that within 49 h of being cultured, E. coli adapted to grow at higher antibiotic concentrations in space compared to Earth, and demonstrated consistent changes in expression of 63 genes in response to an increase in drug concentration in both environments, including specific responses related to oxidative stress and starvation response. Additionally, we find 50 stress-response genes upregulated in response to the microgravity when compared directly to the equivalent concentration in the ground control. We conclude that the increased antibiotic tolerance in microgravity may be attributed not only to diminished transport processes, but also to a resultant antibiotic cross-resistance response conferred by an overlapping effect of stress response genes. Our data suggest that direct stresses of nutrient starvation and acid-shock conveyed by the microgravity environment can incidentally upregulate stress response pathways related to antibiotic stress and in doing so contribute to the increased antibiotic stress tolerance observed for bacteria in space experiments. These results provide insights into the ability of bacteria to adapt under extreme stress

Prediction of treatment response to adalimumab

DEFF Research Database (Denmark)

Krintel, S B; Dehlendorff, C; Hetland, M L

2016-01-01

At least 30% of patients with rheumatoid arthritis (RA) do not respond to biologic agents, which emphasizes the need of predictive biomarkers. We aimed to identify microRNAs (miRNAs) predictive of response to adalimumab in 180 treatment-naïve RA patients enrolled in the OPtimized treatment algori...... of low expression of miR-22 and high expression of miR-886.3p was associated with EULAR good response. Future studies to assess the utility of these miRNAs as predictive biomarkers are needed.The Pharmacogenomics Journal advance online publication, 5 May 2015; doi:10.1038/tpj.2015.30....

Long-term changes in cognitive bias and coping response as a result of chronic unpredictable stress during adolescence

Directory of Open Access Journals (Sweden)

Lauren eChaby

2013-07-01

Full Text Available Animals that experience adverse events in early life often have life-long changes to their physiology and behavior. Long-term effects of stress during early life have been studied extensively, but less attention has been given to the consequences of negative experiences solely during the adolescent phase. Adolescence is a particularly sensitive period of life when regulation of the glucocorticoid stress hormone response matures and specific regions in the brain undergo considerable change. Aversive experiences during this time might, therefore, be expected to generate long-term consequences for the adult phenotype. Here we investigated the long-term effects of exposure to chronic unpredictable stress during adolescence on adult decision making, coping response, cognitive bias, and exploratory behavior in rats. Rats exposed to chronic unpredictable stress (e.g. isolation, crowding, cage tilt were compared to control animals that were maintained in standard, predictable conditions throughout development. Unpredictable stress during adolescence resulted in a suite of long-term behavioral and cognitive changes including a negative cognitive bias (F1,12 = 5.000, P < 0.05, altered coping response (T1,14 = 2.216, P = 0.04, and accelerated decision making (T1,14 = 3.245, P = 0.01. Exposure to chronic stress during adolescence also caused a short-term increase in boldness behaviors; in a novel object test 15 days after the last stressor, animals exposed to chronic unpredictable stress had decreased latencies to leave a familiar shelter and approach a novel object (T1,14 = 2.240, P = 0.04; T1,14 = 2.419, P = 0.03, respectively. The results showed that stress during adolescence has long-term impacts on behavior and cognition that affect the interpretation of ambiguous stimuli, behavioral response to adverse events, and how animals make decisions. Stress during adolescence also induced short-term changes in the way animals moved around a novel environment.

Abnormal stress responsivity in a rodent developmental disruption model of schizophrenia.

Science.gov (United States)

Zimmerman, Eric C; Bellaire, Mark; Ewing, Samuel G; Grace, Anthony A

2013-10-01

Although numerous studies have implicated stress in the pathophysiology of schizophrenia, less is known about how the effects of stress interact with genetic, developmental, and/or environmental determinants to promote disease progression. In particular, it has been proposed that in humans, stress exposure in adolescence could combine with a predisposition towards increased stress sensitivity, leading to prodromal symptoms and eventually psychosis. However, the neurobiological substrates for this interaction are not fully characterized. Previous work in our lab has demonstrated that rats born to dams administered with the DNA-methylating agent methylazoxymethanol acetate (MAM) at gestational day 17 exhibit as adults behavioral and anatomical abnormalities consistent with those observed in patients with schizophrenia. Here, we examined behavioral and neuroendocrine responses to stress in the MAM model of schizophrenia. MAM-treated male rats were exposed to acute and repeated footshock stress at prepubertal, peripubteral, and adult ages. Ultrasonic vocalizations (USVs), freezing, and corticosterone responses were quantified. We found that juvenile MAM-treated rats emitted significantly more calls, spent more time vocalizing, emitted calls at a higher rate, and showed more freezing in response to acute footshock stress when compared with their saline (SAL) treated counterparts, and that this difference is not present in older animals. In addition, adolescent MAM-treated animals displayed a blunted HPA axis corticosterone response to acute footshock that did not adapt after 10 days of stress exposure. These data demonstrate abnormal stress responsivity in the MAM model of schizophrenia and suggest that these animals are more sensitive to the effects of stress in youth.

Statistics of the Von Mises Stress Response For Structures Subjected To Random Excitations

Directory of Open Access Journals (Sweden)

Mu-Tsang Chen

1998-01-01

Full Text Available Finite element-based random vibration analysis is increasingly used in computer aided engineering software for computing statistics (e.g., root-mean-square value of structural responses such as displacements, stresses and strains. However, these statistics can often be computed only for Cartesian responses. For the design of metal structures, a failure criterion based on an equivalent stress response, commonly known as the von Mises stress, is more appropriate and often used. This paper presents an approach for computing the statistics of the von Mises stress response for structures subjected to random excitations. Random vibration analysis is first performed to compute covariance matrices of Cartesian stress responses. Monte Carlo simulation is then used to perform scatter and failure analyses using the von Mises stress response.

Stress and sleep duration predict headache severity in chronic headache sufferers.

Science.gov (United States)

Houle, Timothy T; Butschek, Ross A; Turner, Dana P; Smitherman, Todd A; Rains, Jeanetta C; Penzien, Donald B

2012-12-01

The objective of this study was to evaluate the time-series relationships between stress, sleep duration, and headache pain among patients with chronic headaches. Sleep and stress have long been recognized as potential triggers of episodic headache (headache days/month), though prospective evidence is inconsistent and absent in patients diagnosed with chronic headaches (≥15 days/month). We reanalyzed data from a 28-day observational study of chronic migraine (n=33) and chronic tension-type headache (n=22) sufferers. Patients completed the Daily Stress Inventory and recorded headache and sleep variables using a daily sleep/headache diary. Stress ratings, duration of previous nights' sleep, and headache severity were modeled using a series of linear mixed models with random effects to account for individual differences in observed associations. Models were displayed using contour plots. Two consecutive days of either high stress or low sleep were strongly predictive of headache, whereas 2 days of low stress or adequate sleep were protective. When patterns of stress or sleep were divergent across days, headache risk was increased only when the earlier day was characterized by high stress or poor sleep. As predicted, headache activity in the combined model was highest when high stress and low sleep occurred concurrently during the prior 2 days, denoting an additive effect. Future research is needed to expand on current findings among chronic headache patients and to develop individualized models that account for multiple simultaneous influences of headache trigger factors. Copyright © 2012 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Hydrogen-peroxide-induced oxidative stress responses in Desulfovibrio vulgaris Hildenborough

Energy Technology Data Exchange (ETDEWEB)

Zhou, A.; He, Z.; Redding-Johanson, A.M.; Mukhopadhyay, A.; Hemme, C.L.; Joachimiak, M.P.; Bender, K.S.; Keasling, J.D.; Stahl, D.A.; Fields, M.W.; Hazen, T.C.; Arkin, A.P.; Wall, J.D.; Zhou, J.; Luo, F.; Deng, Y.; He, Q.

2010-07-01

To understand how sulphate-reducing bacteria respond to oxidative stresses, the responses of Desulfovibrio vulgaris Hildenborough to H{sub 2}O{sub 2}-induced stresses were investigated with transcriptomic, proteomic and genetic approaches. H{sub 2}O{sub 2} and induced chemical species (e.g. polysulfide, ROS) and redox potential shift increased the expressions of the genes involved in detoxification, thioredoxin-dependent reduction system, protein and DNA repair, and decreased those involved in sulfate reduction, lactate oxidation and protein synthesis. A gene coexpression network analysis revealed complicated network interactions among differentially expressed genes, and suggested possible importance of several hypothetical genes in H{sub 2}O{sub 2} stress. Also, most of the genes in PerR and Fur regulons were highly induced, and the abundance of a Fur regulon protein increased. Mutant analysis suggested that PerR and Fur are functionally overlapped in response to stresses induced by H{sub 2}O{sub 2} and reaction products, and the upregulation of thioredoxin-dependent reduction genes was independent of PerR or Fur. It appears that induction of those stress response genes could contribute to the increased resistance of deletion mutants to H{sub 2}O{sub 2}-induced stresses. In addition, a conceptual cellular model of D. vulgaris responses to H{sub 2}O{sub 2} stress was constructed to illustrate that this bacterium may employ a complicated molecular mechanism to defend against the H{sub 2}O{sub 2}-induced stresses.

Sex and stress: Men and women show different cortisol responses to psychological stress induced by the Trier social stress test and the Iowa singing social stress test.

Science.gov (United States)

Reschke-Hernández, Alaine E; Okerstrom, Katrina L; Bowles Edwards, Angela; Tranel, Daniel

2017-01-02

Acute psychological stress affects each of us in our daily lives and is increasingly a topic of discussion for its role in mental illness, aging, cognition, and overall health. A better understanding of how such stress affects the body and mind could contribute to the development of more effective clinical interventions and prevention practices. Over the past 3 decades, the Trier Social Stress Test (TSST) has been widely used to induce acute stress in a laboratory setting based on the principles of social evaluative threat, namely, a judged speech-making task. A comparable alternative task may expand options for examining acute stress in a controlled laboratory setting. This study uses a within-subjects design to examine healthy adult participants' (n = 20 men, n = 20 women) subjective stress and salivary cortisol responses to the standard TSST (involving public speaking and math) and the newly created Iowa Singing Social Stress Test (I-SSST). The I-SSST is similar to the TSST but with a new twist: public singing. Results indicated that men and women reported similarly high levels of subjective stress in response to both tasks. However, men and women demonstrated different cortisol responses; men showed a robust response to both tasks, and women displayed a lesser response. These findings are in line with previous literature and further underscore the importance of examining possible sex differences throughout various phases of research, including design, analysis, and interpretation of results. Furthermore, this nascent examination of the I-SSST suggests a possible alternative for inducing stress in the laboratory. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Vaccine-induced inflammation attenuates the vascular responses to mental stress

NARCIS (Netherlands)

Paine, N.J.; Ring, C.; Bosch, J.A.; Drayson, M.T.; Aldred, S.; Veldhuijzen van Zanten, J.J.C.S.

2014-01-01

Inflammation is associated with poorer vascular function, with evidence to suggest that inflammation can also impair the vascular responses to mental stress. This study examined the effects of vaccine-induced inflammation on vascular responses to mental stress in healthy participants. Eighteen male

Influence of temperature on the corticosterone stress-response: an experiment in the Children's python (Antaresia childreni).

Science.gov (United States)

Dupoué, Andréaz; Brischoux, François; Lourdais, Olivier; Angelier, Frédéric

2013-11-01

To cope with environmental challenges, organisms have to adjust their behaviours and their physiology to the environmental conditions they face (i.e. allostasis). In vertebrates, such adjustments are often mediated through the secretion of glucocorticoids (GCs) that are well-known to activate and/or inhibit specific physiological and behavioural traits. In ectothermic species, most processes are temperature-dependent and according to previous studies, low external temperatures should be associated with low GC concentrations (both baseline and stress-induced concentrations). In this study, we experimentally tested this hypothesis by investigating the short term influence of temperature on the GC stress response in a squamate reptile, the Children's python (Antaresia childreni). Snakes were maintained in contrasting conditions (warm and cold groups), and their corticosterone (CORT) stress response was measured (baseline and stress-induced CORT concentrations), within 48h of treatment. Contrary to our prediction, baseline and stress-induced CORT concentrations were higher in the cold versus the warm treatment. In addition, we found a strong negative relationship between CORT concentrations (baseline and stress-induced) and temperature within the cold treatment. Although it remains unclear how cold temperatures can mechanistically result in increased CORT concentrations, we suggest that, at suboptimal temperature, high CORT concentrations may help the organism to maintain an alert state. Copyright © 2013 Elsevier Inc. All rights reserved.