Attentional Bias towards Positive Emotion Predicts Stress Resilience.

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Thoern, Hanna A; Grueschow, Marcus; Ehlert, Ulrike; Ruff, Christian C; Kleim, Birgit

2016-01-01

There is extensive evidence for an association between an attentional bias towards emotionally negative stimuli and vulnerability to stress-related psychopathology. Less is known about whether selective attention towards emotionally positive stimuli relates to mental health and stress resilience. The current study used a modified Dot Probe task to investigate if individual differences in attentional biases towards either happy or angry emotional stimuli, or an interaction between these biases, are related to self-reported trait stress resilience. In a nonclinical sample (N = 43), we indexed attentional biases as individual differences in reaction time for stimuli preceded by either happy or angry (compared to neutral) face stimuli. Participants with greater attentional bias towards happy faces (but not angry faces) reported higher trait resilience. However, an attentional bias towards angry stimuli moderated this effect: The attentional bias towards happy faces was only predictive for resilience in those individuals who also endorsed an attentional bias towards angry stimuli. An attentional bias towards positive emotional stimuli may thus be a protective factor contributing to stress resilience, specifically in those individuals who also endorse an attentional bias towards negative emotional stimuli. Our findings therefore suggest a novel target for prevention and treatment interventions addressing stress-related psychopathology.

Different finite element techniques to predict welding residual stresses in aluminum alloy plates

International Nuclear Information System (INIS)

Moein, Hadi; Sattari-Far, Iradj

2014-01-01

This study is a 3D thermomechanical finite element (FE) analysis of a single-pass and butt-welded work-hardened aluminum (Al) 5456 plates. It aims to validate the use of FE welding simulations to predict residual stress states in assessing the integrity of welded components. The predicted final residual stresses in the plate from the FE simulations are verified through comparison with experimental measurements. Three techniques are used to simulate the welding process. In the first two approaches, welding deposition is applied by using element birth and interaction techniques. In the third approach, the entire weld zone is simultaneously deposited. Results show a value at approximately the yield strength for longitudinal residual stresses of the welded center of the butt-welded Al alloy plates with a thickness of 2 mm. Considering the application of a comprehensive heat source, along with heat loss modeling and the temperature dependent properties of the material, the approach without deposition predicts a reasonable distribution of residual stresses. However, the element birth and interaction techniques, compared with the no-deposit technique, provide more accurate results in calculating residual stresses. Furthermore, the element interaction technique, compared with the element birth technique, exhibits higher efficiency and flexibility in modeling the deposition of welded metals as well as less modeling cost.

Predicting Heat Stress to Inform Reef Management: NOAA Coral Reef Watch's 4-Month Coral Bleaching Outlook

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Gang Liu

2018-03-01

Full Text Available The U.S. National Oceanic and Atmospheric Administration's (NOAA Coral Reef Watch (CRW operates a global 4-Month Coral Bleaching Outlook system for shallow-water coral reefs in collaboration with NOAA's National Centers for Environmental Prediction (NCEP. The Outlooks are generated by applying the algorithm used in CRW's operational satellite coral bleaching heat stress monitoring, with slight modifications, to the sea surface temperature (SST predictions from NCEP's operational Climate Forecast System Version 2 (CFSv2. Once a week, the probability of heat stress capable of causing mass coral bleaching is predicted for 4-months in advance. Each day, CFSv2 generates an ensemble of 16 forecasts, with nine runs out to 45-days, three runs out to 3-months, and four runs out to 9-months. This results in 28–112 ensemble members produced each week. A composite for each predicted week is derived from daily predictions within each ensemble member. The probability of each of four heat stress ranges (Watch and higher, Warning and higher, Alert Level 1 and higher, and Alert Level 2 is determined from all the available ensemble members for the week to form the weekly probabilistic Outlook. The probabilistic 4-Month Outlook is the highest weekly probability predicted among all the weekly Outlooks during a 4-month period for each of the stress ranges. An initial qualitative skill analysis of the Outlooks for 2011–2015, compared with CRW's satellite-based coral bleaching heat stress products, indicated the Outlook has performed well with high hit rates and low miss rates for most coral reef areas. Regions identified with high false alarm rates will guide future improvements. This Outlook system, as the first and only freely available global coral bleaching prediction system, has been providing critical early warning to marine resource managers, scientists, and decision makers around the world to guide management, protection, and monitoring of coral reefs

Maternal Weight Predicts Children's Psychosocial Development via Parenting Stress and Emotional Availability

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Bergmann, Sarah; Schlesier-Michel, Andrea; Wendt, Verena; Grube, Matthias; Keitel-Korndörfer, Anja; Gausche, Ruth; von Klitzing, Kai; Klein, Annette M.

2016-01-01

Introduction: Maternal obesity has been shown to be a risk factor for obesity in children and may also affect children's psychosocial outcomes. It is not yet clear whether there are also psycho-emotional mechanisms explaining the effects of maternal weight on young children's weight and psychosocial development. We aimed to evaluate whether maternal body mass index (BMI), mother–child emotional availability (EA), and maternal parenting stress are associated with children's weight and psychosocial development (i.e., internalizing/externalizing symptoms and social competence) and whether these predictors interact with each other. Methods: This longitudinal study included three assessment points (~11 months apart). The baseline sample consisted of N = 194 mothers and their children aged 5–47 months (M = 28.18, SD = 8.44, 99 girls). At t1, we measured maternal weight and height to calculate maternal BMI. We videotaped mother–child interactions, coding them with the EA Scales (fourth edition). We assessed maternal parenting stress with the Parenting Stress Index (PSI) short form. At t1 to t3, we measured height and weight of children and calculated BMI–SDS scores. Children's externalizing and internalizing problems (t1–t3) and social competence (t3, N = 118) were assessed using questionnaires: Child Behavior Checklist (CBCL 1.5–5), Strengths and Difficulties Questionnaire (SDQ: prosocial behavior), and a checklist for behavioral problems at preschool age (VBV 3–6: social-emotional competence). Results: By applying structural equation modeling (SEM) and a latent regression analysis, we found maternal BMI to predict higher BMI–SDS and a poorer psychosocial development (higher externalizing symptoms, lower social competence) in children. Higher parenting stress predicted higher levels of externalizing and internalizing symptoms and lower social competence. Better maternal EA was associated with higher social competence. We found parenting stress to serve as

Occupational role stress is associated with higher cortisol reactivity to acute stress.

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Wirtz, Petra H; Ehlert, Ulrike; Kottwitz, Maria U; La Marca, Roberto; Semmer, Norbert K

2013-04-01

We investigated whether occupational role stress is associated with differential levels of the stress hormone cortisol in response to acute psychosocial stress. Forty-three medication-free nonsmoking men aged between 22 and 65 years (mean ± SEM: 44.5 ± 2) underwent an acute standardized psychosocial stress task combining public speaking and mental arithmetic in front of an audience. We assessed occupational role stress in terms of role conflict and role ambiguity (combined into a measure of role uncertainty) as well as further work characteristics and psychological control variables including time pressure, overcommitment, perfectionism, and stress appraisal. Moreover, we repeatedly measured salivary cortisol and blood pressure levels before and after stress exposure, and several times up to 60 min thereafter. Higher role uncertainty was associated with a more pronounced cortisol stress reactivity (p = .016), even when controlling for the full set of potential confounders (p stress reactivity was not associated with role uncertainty. Our findings suggest that occupational role stress in terms of role uncertainty acts as a background stressor that is associated with increased HPA-axis reactivity to acute stress. This finding may represent a potential mechanism regarding how occupational role stress may precipitate adverse health outcomes.

Predicting stress from the ability to eavesdrop on feelings: Emotional intelligence and testosterone jointly predict cortisol reactivity.

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Bechtoldt, Myriam N; Schneider, Vanessa K

2016-09-01

While emotional intelligence (EI) is recognized as a resource in social interactions, we hypothesized a positive association with stress in socially evaluative contexts. In particular, we expected emotion recognition, the core component of EI, to inflict stress on individuals in negatively valenced interactions. We expected this association to be stronger for status-driven individuals, that is, for individuals scoring high on basal testosterone. In a laboratory experiment, N = 166 male participants underwent the Trier Social Stress Test (Kirschbaum, Pirke, & Hellhammer, 1993). As expected, EI measured by the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT V2.0; Mayer et al., 2003) predicted higher cortisol reactivity, including slower recovery from stress. The effect was moderated by basal testosterone, such that the association was positive when basal testosterone was high but not when it was low. On the component level of EI, the interaction was replicated for negative emotion recognition. These findings lend support to the hypothesis that EI is associated with higher activity of the hypothalamic-pituitary-adrenal axis in contexts where social status is at stake, particularly for those individuals who are more status-driven. Thus, the effects of EI are not unequivocally positive: While EI may positively affect the course of social interactions, it also inflicts stress on the emotionally intelligent individuals themselves. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

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.

Predicting sleep quality from stress and prior sleep--a study of day-to-day covariation across six weeks.

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Åkerstedt, Torbjörn; Orsini, Nicola; Petersen, Helena; Axelsson, John; Lekander, Mats; Kecklund, Göran

2012-06-01

The connection between stress and sleep is well established in cross-sectional questionnaire studies and in a few prospective studies. Here, the intention was to study the link between stress and sleep on a day-to-day basis across 42 days. Fifty participants kept a sleep/wake diary across 42 days and responded to daily questions on sleep and stress. The results were analyzed with a mixed model approach using stress during the prior day to predict morning ratings of sleep quality. The results showed that bedtime stress and worries were the main predictors of sleep quality, but that, also, late awakening, short prior sleep, high quality of prior sleep, and good health the prior day predicted higher sleep quality. Stress during the day predicts subsequent sleep quality on a day-to-day basis across 42 days. The observed range of variation in stress/worries was modest, which is why it is suggested that the present data underestimates the impact of stress on subsequent sleep quality. Copyright © 2012 Elsevier B.V. All rights reserved.

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

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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…

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 is associated with exercise differently among individuals with higher and lower eating disorder symptoms: An ecological momentary assessment study.

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Sala, Margarita; Brosof, Leigh C; Rosenfield, David; Fernandez, Katya C; Levinson, Cheri A

2017-12-01

Stress is associated with the maintenance of eating disorders and exercise behaviors. However, it is unclear how stress is associated with exercise and vice-versa among individuals with higher levels of eating disorder symptoms in daily life. The current study tested the moderating effect of eating disorder symptoms on the relationships between (1) daily stress and later exercise behavior and (2) daily exercise behavior and later stress. Female college students [N = 129, mean age = 19.19 (SD = 1.40)] completed the Eating Disorder Inventory-2. Participants then completed measures of stress and exercise four times daily across seven days using an automated telephone ecological momentary assessment system. Data were analyzed using multilevel models. Drive for thinness, bulimic symptoms, and body dissatisfaction significantly moderated the relationship between daily stress and later exercise (ps = .01-.05), such that higher daily stress predicted higher later exercise only in individuals who were low (but not average or high) in drive for thinness, bulimic symptoms, and body dissatisfaction symptoms. Stress is associated with exercise differentially depending on individuals' eating disorder symptoms. Our findings suggest that only individuals with lower levels of eating disorder symptoms exercise when stressed. © 2017 Wiley Periodicals, Inc.

Overgeneral autobiographical memory predicts higher prospective levels of depressive symptoms and intrusions in borderline patients.

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Van den Broeck, Kris; Pieters, Guido; Claes, Laurence; Berens, Ann; Raes, Filip

2016-11-01

Overgeneral memory (OGM), the tendency to retrieve categories of events from autobiographical memory instead of single events, is found to be a reliable predictor for future mood disturbances and post-traumatic symptom severity. Patients with borderline personality disorder (BPD) often report co-morbid episodes of major depressive disorder (MDD) and post-traumatic stress disorder (PTSD). Therefore, we investigated whether OGM would predict depression severity and (post-traumatic) stress symptoms in BPD patients. At admission (N = 54) and at six-month follow-up (N ≥ 31), BPD patients completed the Structured Clinical Interview for DSM-IV Disorders, the Assessment of DSM-IV Personality Disorders, the Autobiographical Memory Test, the Beck Depression Inventory-2nd edition (BDI-II), and the Impact of Event Scale. OGM at baseline predicted (a) higher levels of depressive symptoms at follow-up and (b) more intrusions related to a stressful event over and above baseline levels of borderline symptoms, depressive symptoms, and intrusions, respectively. No association was found between memory specificity and event-related avoidance at follow-up. Despite previous findings suggesting that OGM in BPD is less robust than in MDD and PTSD, our results suggest that memory specificity in BPD patients may have some relevance for the course of depressive and stress symptomatology in BPD.

Fiscal Stress: Worldwide Trends in Higher Education Finance

NARCIS (Netherlands)

Vossensteyn, Johan J.

2004-01-01

While higher education is regarded of high priority in boosting economic development, public budgets to sustain expansion of higher education systems remain limited around the globe. In practice, this situation of fiscal stress creates an impetus for governments to develop various strategies to meet

Maternal weight predicts children’s psychosocial development via parenting stress and emotional availability

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Sarah Bergmann

2016-08-01

Full Text Available Introduction: Maternal obesity has been shown to be a risk factor for obesity in children and may also affect children’s psychosocial outcomes. It is not yet clear whether there are also psycho-emotional mechanisms explaining the effects of maternal weight on young children’s weight and psychosocial development. We aimed to evaluate whether maternal body mass index (BMI, mother-child emotional availability (EA and maternal parenting stress are associated with children’s weight and psychosocial development (i.e. internalizing/externalizing symptoms and social competence and whether these predictors interact with each other. Methods: This longitudinal study included 3 assessment points (approx. 11 months apart. The baseline sample consisted of N=194 mothers and their children aged 5 to 47 months (M=28.18, SD=8.44, 99 girls. At t1, we measured maternal weight and height to calculate maternal BMI. We videotaped mother-child interactions, coding them with the Emotional Availability Scales (4th edition. We assessed maternal parenting stress with the Parenting Stress Index (PSI short form. At t1 to t3, we measured height and weight of children and calculated BMI-SDS scores. Children’s externalizing and internalizing problems (t1-t3 and social competence (t3, N=118 were assessed using questionnaires: Child Behavior Checklist (CBCL1, 5-5, Strength and Difficulties Questionnaire (SDQ: prosocial behavior and a checklist for behavioral problems at preschool age (VBV 3-6: social-emotional competence. Results: By applying structural equation modeling (SEM and a latent regression analysis, we found maternal BMI to predict higher BMI-SDS and a poorer psychosocial development (higher externalizing symptoms, lower social competence in children. Higher parenting stress predicted higher levels of externalizing and internalizing symptoms and lower social competence. Better maternal EA was associated with higher social competence. We found parenting stress to

Blunted hypothalamo-pituitary adrenal axis response to predator odor predicts high stress reactivity.

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Whitaker, Annie M; Gilpin, Nicholas W

2015-08-01

Individuals with trauma- and stress-related disorders exhibit increases in avoidance of trauma-related stimuli, heightened anxiety and altered neuroendocrine stress responses. Our laboratory uses a rodent model of stress that mimics the avoidance symptom cluster associated with stress-related disorders. Animals are classified as 'Avoiders' or 'Non-Avoiders' post-stress based on avoidance of predator-odor paired context. Utilizing this model, we are able to examine subpopulation differences in stress reactivity. Here, we used this predator odor model of stress to examine differences in anxiety-like behavior and hypothalamo-pituitary adrenal (HPA) axis function in animals that avoid a predator-paired context relative to those that do not. Rats were exposed to predator odor stress paired with a context and tested for avoidance (24h and 11days), anxiety-like behavior (48h and 5days) and HPA activation following stress. Control animals were exposed to room air. Predator odor stress produced avoidance in approximately 65% of the animals at 24h that persisted 11days post-stress. Both Avoiders and Non-Avoiders exhibited a heightened anxiety-like behavior at 48h and 5days post-stress when compared to unstressed Controls. Non-Avoiders exhibited significant increases in circulating adrenocorticotropin hormone (ACTH) and corticosterone (CORT) concentrations immediately following predator odor stress compared to Controls and this response was significantly attenuated in Avoiders. There was an inverse correlation between circulating ACTH/CORT concentrations and avoidance, indicating that lower levels of ACTH/CORT predicted higher levels of avoidance. These results suggest that stress effects on HPA stress axis activation predict long-term avoidance of stress-paired stimuli, and build on previous data showing the utility of this model for exploring the neurobiological mechanisms of trauma- and stress-related disorders. Copyright © 2015. Published by Elsevier Inc.

Perceived injustice predicts stress and pain in adults with sickle cell disease.

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Ezenwa, Miriam O; Molokie, Robert E; Wilkie, Diana J; Suarez, Marie L; Yao, Yingwei

2015-06-01

Research evidence shows that perceived injustice is a context-based unfair treatment that has negative influence on health outcomes. We examined the contribution of patients' perceived injustice regarding interactions with health care providers to stress and pain in adults with sickle cell disease (SCD). This study was a cross-sectional correlational pilot study. Included in the study were adults with SCD who received their care from a university-affiliated comprehensive sickle cell clinic. Participants were 52 adults whose mean age was 34 ± 11 years (minimum [min] 20 years, maximum [max] 70 years). Most of the patients were African American (n = 48, 92%) and female (n = 41, 79%). Forty-eight patients (92%) reported having a high school diploma or higher. Participants completed the perceived injustice questionnaire, perceived stress questionnaire, and the PAINReportIt, which includes questions to measure pain and demographics. We analyzed the data using the linear regression analyses. Perceived injustice from doctors was a significant predictor of perceived stress (p pain (p = .002). Perceived injustice from nurses also was a significant predictor of perceived stress (p pain (p = .02). The procedural, distributive, and informational domains of perceived injustice attributed to both doctors and nurses consistently predicted patients' perceived stress, but only the procedural and distributive domains of perceived injustice consistently predicted patients' pain. Findings suggest that perceived injustice was negatively associated with stress and pain in adults with SCD and warrant further investigation in a larger sample. Published by Elsevier Inc.

Depression, anxiety and stress among higher secondary school students of Imphal, Manipur

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K Sathish Kumar

2017-01-01

Full Text Available Introduction: Adolescence is a stressful period due to physical, psychological, sexual changes, and the presence of psychiatric disorders such as depression, anxiety, and stress at this stage of life is a matter of concern. Objectives: The objectives of the study were to determine the prevalences of depression, anxiety, and stress among higher secondary school students of Imphal and to determine the association between depression, anxiety, and stress and selected variables such as gender, standard, and religion. Materials and methods: From September 2014 to October 2014, a cross-sectional study was conducted among higher secondary school students of Imphal. The sample size was calculated to be 750. Seven schools were randomly selected, and all the students in that school were enrolled in the study. The study tool used was a questionnaire containing DASS (Depression Anxiety Stress Scale and sociodemographic characteristics. Results: The prevalences of depression, anxiety, and stress among 830 valid respondents were 19.5%, 24.4%, and 21.1%, respectively. In total, 81.6% of the respondents had at least one of the studied disorders and 34.7% of the respondents had all the three negative states. The prevalences of depression, anxiety, and stress were high among females and were significant for anxiety (P = 0.00 and stress (P = 0.04. The prevalences of depression and stress were significantly higher among 12th standard students with P-values of 0.00 and 0.02. Conclusion: The prevalences of depression, anxiety, and stress were high with anxiety and stress significantly higher among females, whereas prevalences of depression and stress were significantly higher among 12th standard students. More studies are recommended to determine the factors leading to these mental disorders.

Parent and family stress factors predict health-related quality in pediatric patients with new-onset epilepsy.

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Wu, Yelena P; Follansbee-Junger, Katherine; Rausch, Joseph; Modi, Avani

2014-06-01

To examine the influence of parent and family general and epilepsy-related stress on longitudinal generic and epilepsy-specific health-related quality of life (HRQOL) for children with new-onset epilepsy, while controlling for demographic characteristics, disease factors, and antiepileptic drug (AED) adherence. This prospective, longitudinal study included 124 children with new-onset epilepsy (mean age 7.2 years, standard deviation [SD] 2.9 years). Parents completed questionnaires on parenting stress, perceived stigma, fears and concerns, and HRQOL at 1, 13, and 25 months after diagnosis. Adherence to AEDs was assessed using electronic monitors. A medical chart review was conducted at each visit to obtain seizure and side effect data. Higher levels of general and epilepsy-specific parent and family stress, fears and concerns, and perceived stigma negatively affected child generic and epilepsy-specific HRQOL, above and beyond disease and demographic factors. General parenting and family stress affected child generic and epilepsy-specific HRQOL more in the first year of disease management than at 2 years after diagnosis. Higher fears and concerns predicted higher epilepsy-specific HRQOL at 13 months postdiagnosis, whereas 2 years postdiagnosis, higher fears and concerns predicted lower epilepsy-specific HRQOL. Several demographic (i.e., age) and disease-related variables (i.e., side effects and AED adherence) influenced child generic and epilepsy-specific HRQOL. Although some findings were consistent across generic and epilepsy-specific HRQOL measures, others were unique. Modifiable parent factors (i.e., general and disease-specific parent and family stress, perceived stigma) impact HRQOL for children with new-onset epilepsy differently over the first 2 years postdiagnosis. Psychosocial interventions to improve HRQOL within the first year postdiagnosis should address parenting and family stress, overall coping, and anticipatory guidance on managing epilepsy

Occupational stress and organisational commitment of employees at higher educational institution

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Simbarashe Zhuwao

2015-12-01

Full Text Available The objective of this study was to determine the relationship between occupational stress and organisational commitment of employees at a higher education institution. A random sample (N=30 was chosen from academic staff within the university. The study used a quantitative design. The Organisational Stress Screening Tool (ASSET and Allen and Meyer’s Organisational Commitment Tool (OCT were administered. The study revealed that a statistical significant relationship exists between occupational stress and organizational commitment of employees. The study also showed that academic staff overall experienced average levels of occupational stress and organisational commitment. Job characteristics and work relationship were found to be the major sources of occupation stress. It is recommended that higher education institutions should improve employee participation in decision making to reduce employees’ stress as a result of unmanageable workloads and overload.

Residual stress analysis on materials with steep stress gradient by using X-ray incidence at higher angles

International Nuclear Information System (INIS)

Ohya, Shin-ichi; Yoshioka, Yasuo; Maeno, Shigeki

1996-01-01

X-ray stress measurements for isotropic polycrystalline are materials are usually carried out by the sin 2 ψ method under the assumption of no stress gradient in X-ray penetration depth. When a steep stress gradient exists in the vicinity of surface layer, however, non-linear sin 2 ψ relation is observed and the sin 2 ψ method cannot be applied on such cases. Although several X-ray stress analyzers have been developed for materials with steep stress gradient in the surface layer, it is desirable to use diffraction data at higher incident angles of ψ 0 as possible as close on 90 degrees in order to determine the both values of surface stress and stress gradient with high accuracy. In the present study, an X-ray stress analyzer based on Ω geometry was fabricated to enable X-ray incidence at higher angle of ψ 0 . The X-ray detector was positioned on -η side against X-ray incident beam. Both of the residual surface stress and stress gradient were determined by use of the COSψ method on shot-peened steel and silicon nitride specimens. This prototype stress analyzer was found effective to perform a biaxial or triaxial stress analysis. (author)

Testing the Predictive Power of Coulomb Stress on Aftershock Sequences

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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.

Computational modeling for prediction of the shear stress of three-dimensional isotropic and aligned fiber networks.

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Park, Seungman

2017-09-01

Interstitial flow (IF) is a creeping flow through the interstitial space of the extracellular matrix (ECM). IF plays a key role in diverse biological functions, such as tissue homeostasis, cell function and behavior. Currently, most studies that have characterized IF have focused on the permeability of ECM or shear stress distribution on the cells, but less is known about the prediction of shear stress on the individual fibers or fiber networks despite its significance in the alignment of matrix fibers and cells observed in fibrotic or wound tissues. In this study, I developed a computational model to predict shear stress for different structured fibrous networks. To generate isotropic models, a random growth algorithm and a second-order orientation tensor were employed. Then, a three-dimensional (3D) solid model was created using computer-aided design (CAD) software for the aligned models (i.e., parallel, perpendicular and cubic models). Subsequently, a tetrahedral unstructured mesh was generated and flow solutions were calculated by solving equations for mass and momentum conservation for all models. Through the flow solutions, I estimated permeability using Darcy's law. Average shear stress (ASS) on the fibers was calculated by averaging the wall shear stress of the fibers. By using nonlinear surface fitting of permeability, viscosity, velocity, porosity and ASS, I devised new computational models. Overall, the developed models showed that higher porosity induced higher permeability, as previous empirical and theoretical models have shown. For comparison of the permeability, the present computational models were matched well with previous models, which justify our computational approach. ASS tended to increase linearly with respect to inlet velocity and dynamic viscosity, whereas permeability was almost the same. Finally, the developed model nicely predicted the ASS values that had been directly estimated from computational fluid dynamics (CFD). The present

Prediction of microstructure, residual stress, and deformation in laser powder bed fusion process

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Yang, Y. P.; Jamshidinia, M.; Boulware, P.; Kelly, S. M.

2017-12-01

Laser powder bed fusion (L-PBF) process has been investigated significantly to build production parts with a complex shape. Modeling tools, which can be used in a part level, are essential to allow engineers to fine tune the shape design and process parameters for additive manufacturing. This study focuses on developing modeling methods to predict microstructure, hardness, residual stress, and deformation in large L-PBF built parts. A transient sequentially coupled thermal and metallurgical analysis method was developed to predict microstructure and hardness on L-PBF built high-strength, low-alloy steel parts. A moving heat-source model was used in this analysis to accurately predict the temperature history. A kinetics based model which was developed to predict microstructure in the heat-affected zone of a welded joint was extended to predict the microstructure and hardness in an L-PBF build by inputting the predicted temperature history. The tempering effect resulting from the following built layers on the current-layer microstructural phases were modeled, which is the key to predict the final hardness correctly. It was also found that the top layers of a build part have higher hardness because of the lack of the tempering effect. A sequentially coupled thermal and mechanical analysis method was developed to predict residual stress and deformation for an L-PBF build part. It was found that a line-heating model is not suitable for analyzing a large L-PBF built part. The layer heating method is a potential method for analyzing a large L-PBF built part. The experiment was conducted to validate the model predictions.

Prediction of microstructure, residual stress, and deformation in laser powder bed fusion process

Science.gov (United States)

Yang, Y. P.; Jamshidinia, M.; Boulware, P.; Kelly, S. M.

2018-05-01

Laser powder bed fusion (L-PBF) process has been investigated significantly to build production parts with a complex shape. Modeling tools, which can be used in a part level, are essential to allow engineers to fine tune the shape design and process parameters for additive manufacturing. This study focuses on developing modeling methods to predict microstructure, hardness, residual stress, and deformation in large L-PBF built parts. A transient sequentially coupled thermal and metallurgical analysis method was developed to predict microstructure and hardness on L-PBF built high-strength, low-alloy steel parts. A moving heat-source model was used in this analysis to accurately predict the temperature history. A kinetics based model which was developed to predict microstructure in the heat-affected zone of a welded joint was extended to predict the microstructure and hardness in an L-PBF build by inputting the predicted temperature history. The tempering effect resulting from the following built layers on the current-layer microstructural phases were modeled, which is the key to predict the final hardness correctly. It was also found that the top layers of a build part have higher hardness because of the lack of the tempering effect. A sequentially coupled thermal and mechanical analysis method was developed to predict residual stress and deformation for an L-PBF build part. It was found that a line-heating model is not suitable for analyzing a large L-PBF built part. The layer heating method is a potential method for analyzing a large L-PBF built part. The experiment was conducted to validate the model predictions.

Perceived Stress Predicts Lower Physical Activity in African-American Boys, but not Girls.

Science.gov (United States)

McGlumphy, Kellye C; Shaver, Erika R; Ajibewa, Tiwaloluwa A; Hasson, Rebecca E

2018-03-01

The purpose of this study was to examine cross-sectional relationships of psychological stress, stress coping, and minutes of moderate-to-vigorous physical activity (MVPA) in Amer- ican-American (AA) boys and girls. A community-based sample of 139 AA adolescents (mean age 14.7 years; SD = 1.8 years; 64.7% girls; 30% obese) from Washtenaw County, Michigan was included in this analysis. Psychological stress was assessed using the Daily Stress Inventory and the Perceived Stress Scale. Coping strategies were evaluated using the Schoolager's Coping Strategies questionnaire. Physical activity was measured objectively via accelerometry. Compared to boys, girls participated in approximately 13 fewer minutes of MVPA (p girls reported using a greater number of coping strategies (p = .01) at a greater frequency (p = .04) compared to boys. However, perceived stress significantly predicted lower levels of MVPA (p = .03) in boys only. There are important gender differences in how AA girls perceive, experience, and cope with stress compared to AA boys. Although AA girls reported higher levels of stress and employed more coping strategies, perceived stress was associated with physical inactivity in AA boys, but not girls. Additional research is warranted to better understand the influence of stress on the choice to be physically active in AA youth.

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

Science.gov (United States)

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.

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.

Emotional Memory Formation Under Lower Versus Higher Stress Conditions

OpenAIRE

Kogan, Inna; Richter-Levin, Gal

2010-01-01

An exposure to stress can enhance memory for emotionally arousing experiences. The phenomenon is suggested to be amygdala-dependent and in accordance with that view the amygdala was found to modulate mnemonic processes in other brain regions. Previously, we illustrated increased amygdala activation and reduced activation of CA1 following spatial learning under higher versus lower stress conditions. When spatial learning was followed by reversal training interference, impaired retention was de...

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.

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.

Understanding Stress among Retirees of Higher Educational Institutions in Nigeria

Directory of Open Access Journals (Sweden)

N.S. Oguzor

2011-12-01

Full Text Available This study examines the effect of stress on retirees. The study also identifies the cause of stress and strategies for reducing stress on retirees. The population of the study comprised 4000 male and female retirees of a Nigerian institution of higher learning. The sample of the study was 400 selected from the institution using simple random sampling technique. A questionnaire was used for data collection. Data collected were analyzed applying frequency counts and mean statistic. Findings revealed that standing for a long time can cause stress for retirees. The finding of the study also revealed that non-payment of gratuity and pension can cause stress for retirees. The findings of the study further showed eight strategies for reducing stress. Based on the findings recommendations were made.

Stress, cortisol, and other appetite-related hormones: Prospective prediction of 6-month changes in food cravings and weight.

Science.gov (United States)

Chao, Ariana M; Jastreboff, Ania M; White, Marney A; Grilo, Carlos M; Sinha, Rajita

2017-04-01

To examine whether baseline chronic stress, morning cortisol, and other appetite-related hormones (leptin, ghrelin, and insulin) predict future weight gain and food cravings in a naturalistic, longitudinal, 6-month follow-up study. A prospective community cohort of 339 adults (age 29.1 ± 9.0 years; BMI = 26.7 ± 5.4 kg/m 2 ; 56.9% female; 70.2% white) completed assessments at baseline and 6-month follow-up. Fasting blood draws were used to assess cortisol and other appetite-related hormone levels at baseline. At baseline and follow-up, body weight was measured, and the Cumulative Adversity Interview and Food Craving Inventory were administered. Data were analyzed using linear mixed models adjusting for demographic and clinical covariates. Over the 6-month period, 49.9% of the sample gained weight. Food cravings and chronic stress decreased over 6 months (Ps < 0.05). However, after adjusting for covariates, individuals with higher baseline total ghrelin had significantly higher food cravings at 6 months (P = 0.04). Furthermore, higher cortisol, insulin, and chronic stress were each predictive of greater future weight gain (Ps < 0.05). These results suggest that ghrelin plays a role in increased food cravings and reward-driven eating behaviors. Studies are needed that examine the utility of stress reduction methods for normalizing disrupted cortisol responses and preventing future weight gain. © 2017 The Obesity Society.

Stress in parents of children born very preterm is predicted by child externalising behaviour and parent coping at age 7 years.

Science.gov (United States)

Linden, Mark A; Cepeda, Ivan L; Synnes, Anne; Grunau, Ruth E

2015-06-01

To examine factors which predict parenting stress in a longitudinal cohort of children born very preterm, and seen at age 7 years. We recruited 100 very preterm (≤32 weeks gestational age) child-parent dyads and a control group of 50 term-born dyads born between 2001 and 2004 with follow-up at 7 years. Parents completed the Parenting Stress Index, Ways of Coping Questionnaire, Child Behavior Check List, Beck Depression Inventory and the State Trait Anxiety Inventory questionnaires. Child IQ was assessed using the Wechsler Intelligence Scale-IV. After controlling for maternal education, parents of preterm children (95% CI 111.1 to 121.4) scored higher (p=0.027) on the Parenting Stress Index than term-born controls (95% CI 97.8 to 113.2). Regression analyses showed that child externalising behaviour, sex and parent escape/avoidance coping style, predicted higher parenting stress in the preterm group. Parents of preterm girls expressed higher levels of stress than those of boys. Maladaptive coping strategies contribute to greater stress in parents of very preterm children. Our findings suggest that these parents need support for many years after birth of a very preterm infant. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

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

Animal-Assisted Stress Reduction Programs in Higher Education

Science.gov (United States)

Haggerty, Julie M.; Mueller, Megan Kiely

2017-01-01

This study investigated the prevalence of increasingly popular animal-assisted stress relief programs at higher education institutions across the United States. Although research on animal-assisted programs is increasing, there is still a lack of information documenting implementation of these programs. Therefore, the purpose of this study was to…

Interrelationships between trait anxiety, situational stress and mental effort predict phonological processing efficiency, but not effectiveness.

Science.gov (United States)

Edwards, Elizabeth J; Edwards, Mark S; Lyvers, Michael

2016-08-01

Attentional control theory (ACT) describes the mechanisms associated with the relationship between anxiety and cognitive performance. We investigated the relationship between cognitive trait anxiety, situational stress and mental effort on phonological performance using a simple (forward-) and complex (backward-) word span task. Ninety undergraduate students participated in the study. Predictor variables were cognitive trait anxiety, indexed using questionnaire scores; situational stress, manipulated using ego threat instructions; and perceived level of mental effort, measured using a visual analogue scale. Criterion variables (a) performance effectiveness (accuracy) and (b) processing efficiency (accuracy divided by response time) were analyzed in separate multiple moderated-regression analyses. The results revealed (a) no relationship between the predictors and performance effectiveness, and (b) a significant 3-way interaction on processing efficiency for both the simple and complex tasks, such that at higher effort, trait anxiety and situational stress did not predict processing efficiency, whereas at lower effort, higher trait anxiety was associated with lower efficiency at high situational stress, but not at low situational stress. Our results were in full support of the assumptions of ACT and implications for future research are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

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)

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.

A prospective cohort study of deficient maternal nurturing attitudes predicting adulthood work stress independent of adulthood hostility and depressive symptoms.

Science.gov (United States)

Hintsanen, M; Kivimäki, M; Hintsa, T; Theorell, T; Elovainio, M; Raitakari, O T; Viikari, J S A; Keltikangas-Järvinen, L

2010-09-01

Stressful childhood environments arising from deficient nurturing attitudes are hypothesized to contribute to later stress vulnerability. We examined whether deficient nurturing attitudes predict adulthood work stress. Participants were 443 women and 380 men from the prospective Cardiovascular Risk in Young Finns Study. Work stress was assessed as job strain and effort-reward imbalance in 2001 when the participants were from 24 to 39 years old. Deficient maternal nurturance (intolerance and low emotional warmth) was assessed based on mothers' reports when the participants were at the age of 3-18 years and again at the age of 6-21 years. Linear regressions showed that deficient emotional warmth in childhood predicted lower adulthood job control and higher job strain. These associations were not explained by age, gender, socioeconomic circumstances, maternal mental problems or participant hostility, and depressive symptoms. Deficient nurturing attitudes in childhood might affect sensitivity to work stress and selection into stressful work conditions in adulthood. More attention should be paid to pre-employment factors in work stress research.

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

Personality traits and types predict medical school stress: a six-year longitudinal and nationwide study.

Science.gov (United States)

Tyssen, Reidar; Dolatowski, Filip C; Røvik, Jan Ole; Thorkildsen, Ruth F; Ekeberg, Oivind; Hem, Erlend; Gude, Tore; Grønvold, Nina T; Vaglum, Per

2007-08-01

Personality types (combinations of traits) that take into account the interplay between traits give a more detailed picture of an individual's character than do single traits. This study examines whether both personality types and traits predict stress during medical school training. We surveyed Norwegian medical students (n = 421) 1 month after they began medical school (T1), at the mid-point of undergraduate Year 3 (T2), and at the end of undergraduate Year 6 (T3). A total of 236 medical students (56%) responded at all time-points. They were categorised according to Torgersen's personality typology by their combination of high and low scores on the 'Big Three' personality traits of extroversion, neuroticism and conscientiousness. We studied the effects of both personality types (spectator, insecure, sceptic, brooder, hedonist, impulsive, entrepreneur and complicated) and traits on stress during medical school. There was a higher level of stress among female students. The traits of neuroticism (P = 0.002) and conscientiousness (P = 0.03) were independent predictors of stress, whereas female gender was absorbed by neuroticism in the multivariate model. When controlled for age and gender, 'brooders' (low extroversion, high neuroticism, high conscientiousness) were at risk of experiencing more stress (P = 0.02), whereas 'hedonists' (high extroversion, low neuroticism, low conscientiousness) were more protected against stress (P = 0.001). This is the first study to show that a specific combination of personality traits can predict medical school stress. The combination of high neuroticism and high conscientiousness is considered to be particularly high risk.

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

Modelling Occupational Stress and Employee Health and Wellbeing in a Chinese Higher Education Institution

Science.gov (United States)

Sang, Xiaoli; Teo, Stephen T. T.; Cooper, Cary L.; Bohle, Philip

2013-01-01

Extensive change is evident in higher education in the People's Republic of China but there have been few studies of the effect of work stress on wellbeing in the higher education sector. The main aim of this study is to test and refine the ASSET ("An Organizational Stress Screening Tool") model of occupational stress in a sample of 150…

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.

Transgenic tobacco plants having a higher level of methionine are more sensitive to oxidative stress.

Science.gov (United States)

Hacham, Yael; Matityahu, Ifat; Amir, Rachel

2017-07-01

Methionine is an essential amino acid the low level of which limits the nutritional quality of plants. We formerly produced transgenic tobacco (Nicotiana tabacum) plants overexpressing CYSTATHIONE γ-SYNTHASE (CGS) (FA plants), methionine's main regulatory enzyme. These plants accumulate significantly higher levels of methionine compared with wild-type (WT) plants. The aim of this study was to gain more knowledge about the effect of higher methionine content on the metabolic profile of vegetative tissue and on the morphological and physiological phenotypes. FA plants exhibit slightly reduced growth, and metabolic profiling analysis shows that they have higher contents of stress-related metabolites. Despite this, FA plants were more sensitive to short- and long-term oxidative stresses. In addition, compared with WT plants and transgenic plants expressing an empty vector, the primary metabolic profile of FA was altered less during oxidative stress. Based on morphological and metabolic phenotypes, we strongly proposed that FA plants having higher levels of methionine suffer from stress under non-stress conditions. This might be one of the reasons for their lesser ability to cope with oxidative stress when it appeared. The observation that their metabolic profiling is much less responsive to stress compared with control plants indicates that the delta changes in metabolite contents between non-stress and stress conditions is important for enabling the plants to cope with stress conditions. © 2017 Scandinavian Plant Physiology Society.

Does the arrival index predict physiological stress reactivity in children.

Science.gov (United States)

de Veld, Danielle M J; Riksen-Walraven, J Marianne; de Weerth, Carolina

2014-09-01

Knowledge about children's stress reactivity and its correlates is mostly based on one stress task, making it hard to assess the generalizability of the results. The development of an additional stress paradigm for children, that also limits stress exposure and test time, could greatly advance this field of research. Research in adults may provide a starting point for the development of such an additional stress paradigm, as changes in salivary cortisol and alpha-amylase (sAA) over a 1-h pre-stress period in the laboratory correlated strongly with subsequent reactivity to stress task (Balodis et al., 2010, Psychoneuroendocrinology 35:1363-73). The present study examined whether such strong correlations could be replicated in 9- to 11-year-old children. Cortisol and sAA samples were collected from 158 children (83 girls) during a 2.5-h visit to the laboratory. This visit included a 1-h pre-stress period in which children performed some non-stressful tasks and relaxed before taking part in a psychosocial stress task (TSST-C). A higher cortisol arrival index was significantly and weakly correlated with a higher AUCg but unrelated to cortisol reactivity to the stressor. A higher sAA arrival index was significantly and moderately related to lower stress reactivity and to a lower AUCi. Children's personality and emotion regulation variables were unrelated to the cortisol and sAA arrival indices. The results of this study do not provide a basis for the development of an additional stress paradigm for children. Further replications in children and adults are needed to clarify the potential meaning of an arrival index.

Influence of subject choice, work overload and work stress on expatriate higher education teachers.

OpenAIRE

Naithani, Pranav

2013-01-01

Subject choice, work overload and work stress influence personal and professional lives of higher education teachers. Though the majority of higher education teachers in the Gulf Cooperation Council (GCC) countries are expatriates, yet research on expatriate higher education teachers working in the GCC countries is limited. This paper presents one part of the work life balance survey and focuses on the influence of subject choice, work overload and work stress on higher education teachers in ...

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.

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

When bad stress goes good: increased threat reactivity predicts improved category learning performance.

Science.gov (United States)

Ell, Shawn W; Cosley, Brandon; McCoy, Shannon K

2011-02-01

The way in which we respond to everyday stressors can have a profound impact on cognitive functioning. Maladaptive stress responses in particular are generally associated with impaired cognitive performance. We argue, however, that the cognitive system mediating task performance is also a critical determinant of the stress-cognition relationship. Consistent with this prediction, we observed that stress reactivity consistent with a maladaptive, threat response differentially predicted performance on two categorization tasks. Increased threat reactivity predicted enhanced performance on an information-integration task (i.e., learning is thought to depend upon a procedural-based memory system), and a (nonsignificant) trend for impaired performance on a rule-based task (i.e., learning is thought to depend upon a hypothesis-testing system). These data suggest that it is critical to consider both variability in the stress response and variability in the cognitive system mediating task performance in order to fully understand the stress-cognition relationship.

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

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

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.

Neighborhood disadvantage and adolescent stress reactivity

Directory of Open Access Journals (Sweden)

Daniel A. Hackman

2012-10-01

Full Text Available Lower socioeconomic status (SES is associated with higher levels of life stress, which in turn affect stress physiology. SES is related to basal cortisol and diurnal change, but it is not clear if SES is associated with cortisol reactivity to stress. To address this question, we examined the relationship between two indices of SES, parental education and concentrated neighborhood disadvantage, and the cortisol reactivity of African-American adolescents to a modified version of the Trier Social Stress Test. We found that concentrated disadvantage was associated with cortisol reactivity and this relationship was moderated by gender, such that higher concentrated disadvantage predicted higher cortisol reactivity and steeper recovery in boys but not in girls. Parental education, alone or as moderated by gender, did not predict reactivity or recovery, while neither education nor concentrated disadvantage predicted estimates of baseline cortisol. This finding is consistent with animal literature showing differential vulnerability, by gender, to the effects of adverse early experience on stress regulation and the differential effects of neighborhood disadvantage in adolescent males and females. This suggests that the mechanisms underlying SES differences in brain development and particularly reactivity to environmental stressors may vary across genders.

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

Stress responsiveness predicts individual variation in mate selectivity.

Science.gov (United States)

Vitousek, Maren N; Romero, L Michael

2013-06-15

Steroid hormones, including glucocorticoids, mediate a variety of behavioral and physiological processes. Circulating hormone concentrations vary substantially within populations, and although hormone titers predict reproductive success in several species, little is known about how individual variation in circulating hormone concentrations is linked with most reproductive behaviors in free-living organisms. Mate choice is an important and often costly component of reproduction that also varies substantially within populations. We examined whether energetically costly mate selection behavior in female Galápagos marine iguanas (Amblyrhynchus cristatus) was associated with individual variation in the concentrations of hormones previously shown to differ between reproductive and non-reproductive females during the breeding season (corticosterone and testosterone). Stress-induced corticosterone levels - which are suppressed in female marine iguanas during reproduction - were individually repeatable throughout the seven-week breeding period. Mate selectivity was strongly predicted by individual variation in stress-induced corticosterone: reproductive females that secreted less corticosterone in response to a standardized stressor assessed more displaying males. Neither baseline corticosterone nor testosterone predicted variation in mate selectivity. Scaled body mass was not significantly associated with mate selectivity, but females that began the breeding period in lower body condition showed a trend towards being less selective about potential mates. These results provide the first evidence that individual variation in the corticosterone stress response is associated with how selective females are in their choice of a mate, an important contributor to fitness in many species. Future research is needed to determine the functional basis of this association, and whether transient acute increases in circulating corticosterone directly mediate mate choice behaviors

Job Pressure and SES-contingent Buffering: Resource Reinforcement, Substitution, or the Stress of Higher Status?

Science.gov (United States)

Koltai, Jonathan; Schieman, Scott

2015-06-01

Analyses of the 2008 National Study of the Changing Workforce demonstrate that job pressure is associated with greater anxiety and job dissatisfaction. In this paper we ask, What conditions protect workers? The conventional buffering hypothesis in the Job-Demands Resource (JD-R) model predicts that job resources should attenuate the relationship. We test whether the conventional buffering hypothesis depends on socioeconomic status (SES). Support for conventional buffering is evident only for job dissatisfaction--and that generalizes across SES. When anxiety is assessed, however, we observe an SES contingency: Job resources attenuate the positive association between job pressure and anxiety among workers with lower SES, but exacerbate it among those with higher SES. We discuss the implications of this SES-contingent pattern for theoretical scenarios about "resource reinforcement," "resource substitution," and the "stress of higher status." Future research should consider SES indicators as potential contingencies in the relationship between job conditions and mental health. © American Sociological Association 2015.

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.

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.

Physical Stress Echocardiography: Prediction of Mortality and Cardiac Events in Patients with Exercise Test showing Ischemia

Directory of Open Access Journals (Sweden)

Ana Carla Pereira de Araujo

2014-11-01

Full Text Available Background: Studies have demonstrated the diagnostic accuracy and prognostic value of physical stress echocardiography in coronary artery disease. However, the prediction of mortality and major cardiac events in patients with exercise test positive for myocardial ischemia is limited. Objective: To evaluate the effectiveness of physical stress echocardiography in the prediction of mortality and major cardiac events in patients with exercise test positive for myocardial ischemia. Methods: This is a retrospective cohort in which 866 consecutive patients with exercise test positive for myocardial ischemia, and who underwent physical stress echocardiography were studied. Patients were divided into two groups: with physical stress echocardiography negative (G1 or positive (G2 for myocardial ischemia. The endpoints analyzed were all-cause mortality and major cardiac events, defined as cardiac death and non-fatal acute myocardial infarction. Results: G2 comprised 205 patients (23.7%. During the mean 85.6 ± 15.0-month follow-up, there were 26 deaths, of which six were cardiac deaths, and 25 non-fatal myocardial infarction cases. The independent predictors of mortality were: age, diabetes mellitus, and positive physical stress echocardiography (hazard ratio: 2.69; 95% confidence interval: 1.20 - 6.01; p = 0.016. The independent predictors of major cardiac events were: age, previous coronary artery disease, positive physical stress echocardiography (hazard ratio: 2.75; 95% confidence interval: 1.15 - 6.53; p = 0.022 and absence of a 10% increase in ejection fraction. All-cause mortality and the incidence of major cardiac events were significantly higher in G2 (p < 0. 001 and p = 0.001, respectively. Conclusion: Physical stress echocardiography provides additional prognostic information in patients with exercise test positive for myocardial ischemia.

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.

A prospective examination of depression, anxiety and stress throughout pregnancy.

Science.gov (United States)

Rallis, Sofia; Skouteris, Helen; McCabe, Marita; Milgrom, Jeannette

2014-12-01

Perinatal distress has largely been conceptualised as the experience of depression and/or anxiety. Recent research has shown that the affective state of stress is also present during the perinatal period and thus may add to a broader understanding of perinatal distress. The aims of the present study were to investigate the changes in depression, anxiety and stress symptoms across pregnancy, and to explore the prospective relationships between these symptoms. Two-hundred and fourteen pregnant women were recruited when they were less than 16 weeks gestation. Women completed depression, anxiety and stress measures on a monthly basis, from 16 weeks gestation through to 36 weeks gestation. The covariate measures of sleep quality and social support were assessed bi-monthly at 16, 24 and 32 weeks gestation. Levels of depression, anxiety and stress symptoms were all shown to change over time, with women experiencing fewer symptoms during the middle of their pregnancy. Higher symptoms early in pregnancy predicted higher symptom levels throughout the rest of pregnancy. Higher depression scores early in pregnancy were also shown to predict higher anxiety and higher stress scores in late pregnancy. Increased stress scores during mid pregnancy also predicted higher anxiety scores in late pregnancy. Current findings indicate that symptom levels of depression, anxiety and stress vary over the course of pregnancy. Increased depression in early pregnancy seemed to be particularly pertinent as it not only predicted later depression symptoms, but also increased anxiety and stress in late pregnancy. Collectively, these results further highlight the importance of emotional health screening early in pregnancy. Copyright © 2014 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

Despite higher glucocorticoid levels and stress responses in female rats, both sexes exhibit similar stress-induced changes in hippocampal neurogenesis.

Science.gov (United States)

Hulshof, Henriëtte J; Novati, Arianna; Luiten, Paul G M; den Boer, Johan A; Meerlo, Peter

2012-10-01

Sex differences in stress reactivity may be one of the factors underlying the increased sensitivity for the development of psychopathologies in women. Particularly, an increased hypothalamic-pituitary-adrenal (HPA) axis reactivity in females may exacerbate stress-induced changes in neuronal plasticity and neurogenesis, which in turn may contribute to an increased sensitivity to psychopathology. The main aim of the present study was to examine male-female differences in stress-induced changes in different aspects of hippocampal neurogenesis, i.e. cell proliferation, differentiation and survival. Both sexes were exposed to a wide variety of stressors, where after differences in HPA-axis reactivity and neurogenesis were assessed. To study the role of oestradiol in potential sex differences, ovariectomized females received low or high physiological oestradiol level replacement pellets. The results show that females in general have a higher basal and stress-induced HPA-axis activity than males, with minimal differences between the two female groups. Cell proliferation in the dorsal hippocampus was significantly higher in high oestradiol females compared to low oestradiol females and males, while doublecortin (DCX) expression as a marker of cell differentiation was significantly higher in males compared to females, independent of oestradiol level. Stress exposure did not significantly influence cell proliferation or survival of new cells, but did reduce DCX expression. In conclusion, despite the male-female differences in HPA-axis activity, the effect of repeated stress exposure on hippocampal cell differentiation was not significantly different between sexes. Copyright © 2012 Elsevier B.V. All rights reserved.

Predicting who will undergo surgery after physiotherapy for female stress urinary incontinence

NARCIS (Netherlands)

Labrie, J.; Lagro-Janssen, A.; Fischer, K.; Berghmans, L.C.; Vaart, C.H. van der

2015-01-01

INTRODUCTION AND HYPOTHESIS: To predict who will undergo midurethral sling surgery (surgery) after initial pelvic floor muscle training (physiotherapy) for stress urinary incontinence in women. METHODS: This was a cohort study including women with moderate to severe stress incontinence who were

Stress, cortisol, and other appetite-related hormones: Prospective prediction of 6-month changes in food cravings and weight

Science.gov (United States)

Chao, Ariana M.; Jastreboff, Ania M.; White, Marney A.; Grilo, Carlos M.; Sinha, Rajita

2017-01-01

Objective To examine whether baseline chronic stress, morning cortisol, and other appetite-related hormones (leptin, ghrelin, and insulin) predict future weight gain and food cravings in a naturalistic longitudinal 6-month follow-up study. Methods A prospective community cohort of three hundred and thirty-nine adults (age=29.1± 9.0 years; BMI=26.7±5.4 kg/m2; 56.9% female; 70.2% White) completed assessments at baseline and 6-month follow-up. Fasting blood draws were used to assess cortisol and other appetite-related hormones levels at baseline. At baseline and follow-up, body weight was measured and the Cumulative Adversity Interview and Food Craving Inventory were administered. Data were analyzed using linear mixed models adjusting for demographic and clinical covariates. Results Over the 6-month period, 49.9% of the sample gained weight. Food cravings and chronic stress decreased over 6 months (psfood cravings at 6 months (p=0.04). Furthermore, higher cortisol, insulin, and chronic stress were each predictive of greater future weight gain (psfood cravings and reward-driven eating behaviors. Studies are needed that examine the utility of stress reduction methods for normalizing disrupted cortisol responses and preventing future weight gain. PMID:28349668

A Study of Occupational Stress and Organizational Climate of Higher Secondary Teachers

Science.gov (United States)

Benedicta, A. Sneha

2014-01-01

This study mainly aims to describe the occupational stress and organizational climate of higher secondary teachers with regard to gender, locality, family type, experience and type of management. Simple random sampling technique was adopted for the selection of sample. The data is collected from 200 higher secondary teachers from government and…

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)

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

Science.gov (United States)

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.

Examining the specific dimensions of distress tolerance that prospectively predict perceived stress.

Science.gov (United States)

Bardeen, Joseph R; Fergus, Thomas A; Orcutt, Holly K

2017-04-01

We examined five dimensions of distress tolerance (i.e. uncertainty, ambiguity, frustration, negative emotion, physical discomfort) as prospective predictors of perceived stress. Undergraduate students (N = 135) completed self-report questionnaires over the course of two assessment sessions (T1 and T2). Results of a linear regression in which the five dimensions of distress tolerance and covariates (i.e. T1 perceived stress, duration between T1 and T2) served as predictor variables and T2 perceived stress served as the outcome variable showed that intolerance of uncertainty was the only dimension of distress tolerance to predict T2 perceived stress. To better understand this prospective association, we conducted a post hoc analysis simultaneously regressing two subdimensions of intolerance of uncertainty on T2 perceived stress. The subdimension representing beliefs that "uncertainty has negative behavioral and self-referent implications" significantly predicted T2 perceived stress, while the subdimension indicating that "uncertainty is unfair and spoils everything" did not. Results support a growing body of research suggesting intolerance of uncertainty as a risk factor for a wide variety of maladaptive psychological outcomes. Clinical implications will be discussed.

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.

Cardiovascular risk and stress in employees of a higher education institution

Directory of Open Access Journals (Sweden)

Eugênio Barbosa de Melo Júnior

2016-01-01

Full Text Available Objective: to analyze the association between high levels of stress and the frequency of cardiovascular risk factors in employees of a higher education institution. Methods: this is a cross-sectional study with 201 employees of a university. A form containing socioeconomic data, the International Physical Activity Questionnaire (short version, the Alcohol Use Disorders Identification Test and the Work Stress Scale were used for data collection. Data analysis was performed using the probability ratio and One-way analysis of variance tests. Results: worrisome frequencies of cardiovascular risk factors were identified, in which sedentary lifestyle, excess weight, and increased abdominal circumference presented the most expressive indexes. Regarding the stressors evaluated, some of the employees had increased stress indexes, distributed between the medium and high levels. Conclusion: sedentary lifestyle, excess weight, and increased abdominal circumference presented expressive high indexes, without statistically significant associations with the level of stress.

Predicting heat stress index in Sasso hens using automatic linear modeling and artificial neural network

Science.gov (United States)

Yakubu, A.; Oluremi, O. I. A.; Ekpo, E. I.

2018-03-01

There is an increasing use of robust analytical algorithms in the prediction of heat stress. The present investigation therefore, was carried out to forecast heat stress index (HSI) in Sasso laying hens. One hundred and sixty seven records on the thermo-physiological parameters of the birds were utilized. They were reared on deep litter and battery cage systems. Data were collected when the birds were 42- and 52-week of age. The independent variables fitted were housing system, age of birds, rectal temperature (RT), pulse rate (PR), and respiratory rate (RR). The response variable was HSI. Data were analyzed using automatic linear modeling (ALM) and artificial neural network (ANN) procedures. The ALM model building method involved Forward Stepwise using the F Statistic criterion. As regards ANN, multilayer perceptron (MLP) with back-propagation network was used. The ANN network was trained with 90% of the data set while 10% were dedicated to testing for model validation. RR and PR were the two parameters of utmost importance in the prediction of HSI. However, the fractional importance of RR was higher than that of PR in both ALM (0.947 versus 0.053) and ANN (0.677 versus 0.274) models. The two models also predicted HSI effectively with high degree of accuracy [r = 0.980, R 2 = 0.961, adjusted R 2 = 0.961, and RMSE = 0.05168 (ALM); r = 0.983, R 2 = 0.966; adjusted R 2 = 0.966, and RMSE = 0.04806 (ANN)]. The present information may be exploited in the development of a heat stress chart based largely on RR. This may aid detection of thermal discomfort in a poultry house under tropical and subtropical conditions.

Predicting who will undergo surgery after physiotherapy for female stress urinary incontinence

NARCIS (Netherlands)

Labrie, J.; Lagro-Janssen, A. L. M.; Fischer, K.; Berghmans, L. C. M.; van der Vaart, C. H.

To predict who will undergo midurethral sling surgery (surgery) after initial pelvic floor muscle training (physiotherapy) for stress urinary incontinence in women. This was a cohort study including women with moderate to severe stress incontinence who were allocated to the physiotherapy arm from a

Positive childhood experiences predict less psychopathology and stress in pregnant women with childhood adversity: A pilot study of the benevolent childhood experiences (BCEs) scale.

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Narayan, Angela J; Rivera, Luisa M; Bernstein, Rosemary E; Harris, William W; Lieberman, Alicia F

2018-04-01

This pilot study examined the psychometric properties of the Benevolent Childhood Experiences (BCEs) scale, a new instrument designed to assess positive early life experiences in adults with histories of childhood maltreatment and other adversities. A counterpart to the Adverse Childhood Experiences (ACEs) questionnaire, the BCEs was developed to be multiculturally-sensitive and applicable regardless of socioeconomic position, urban-rural background, or immigration status. Higher levels of BCEs were hypothesized to predict lower levels of psychopathology and stress beyond the effects of ACES in a sample of ethnically diverse, low-income pregnant women. BCEs were also expected to show adequate internal validity across racial/ethnic groups and test-retest stability from the prenatal to the postnatal period. Participants were 101 pregnant women (M=29.10years, SD=6.56, range=18-44; 37% Latina, 22% African-American, 20% White, 21% biracial/multiracial/other; 37% foreign-born, 26% Spanish-speaking) who completed the BCEs and ACEs scales; assessments of prenatal depression and post-traumatic stress disorder (PTSD) symptoms, perceived stress, and exposure to stressful life events (SLEs) during pregnancy; and demographic information. Higher levels of BCEs predicted less PTSD symptoms and SLEs, above and beyond ACEs. The BCEs showed excellent test-retest reliability, and mean levels were comparable across racial/ethnic and Spanish-English groups of women. Person-oriented analyses also showed that higher levels of BCEs offset the effects of ACEs on prenatal stress and psychopathology. The BCEs scale indexes promising promotive factors associated with lower trauma-related symptomatology and stress exposure during pregnancy and illuminates how favorable childhood experiences may counteract long-term effects of childhood adversity. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Academic stress, desertion, and retention strategies for students in higher education].

Science.gov (United States)

Suárez-Montes, Nancy; Díaz-Subieta, Luz B

2015-04-01

A systematic review was performed to specify the characteristics of academic stress that affect the mental health of the university population. To do this, recent publications regarding academic stress, student desertion, and retention strategies were examined. Throughout this text, we present the results of the review in terms of the definitions of academic stress, student desertion, and retention strategies. In the same way, we examine the interpretative models with regard to student desertion and approach retention strategies in higher education. We also review retention experiences of several other countries. In terms of Colombia, we present aspects related to student desertion and retention programs from the point of view of the National Ministry of Education and from the experience of some universities with consolidated programs.

Do positive or negative stressful events predict the development of new brain lesions in people with Multiple Sclerosis?

Science.gov (United States)

Burns, Michelle Nicole; Nawacki, Ewa; Kwasny, Mary J.; Pelletier, Daniel; Mohr, David C.

2014-01-01

Background Stressful life events have long been suspected to contribute to multiple sclerosis (MS) disease activity. The few studies examining the relationship between stressful events and neuroimaging markers have been small and inconsistent. This study examined whether different types of stressful events and perceived stress could predict development of brain lesions. Methods This was a secondary analysis of 121 patients with MS followed for 48 weeks during a randomized controlled trial comparing Stress Management Therapy for MS to a waitlist control. Patients underwent MRI’s every 8 weeks. Monthly, patients completed an interview measure assessing stressful life events, and self-report measures of perceived stress, anxiety, and depressive symptoms, which were used to predict the presence of gadolinium enhancing (Gd+) and T2 lesions on MRI’s 29–62 days later. Participants classified stressful events as positive or negative. Negative events were considered “major” if they involved physical threat or threat to the patient’s family structure, and “moderate” otherwise. Results Positive stressful events predicted decreased risk for subsequent Gd+ lesions in the control group (OR=.53 for each additional positive stressful event, 95% CI=.30–.91) and less risk for new or enlarging T2 lesions regardless of group assignment (OR=.74, 95% CI=.55–.99). Across groups, major negative stressful events predicted Gd+ lesions (OR=1.77, 95% CI=1.18–2.64) and new or enlarging T2 lesions (OR=1.57, 95% CI=1.11–2.23), while moderate negative stressful events, perceived stress, anxiety, and depressive symptoms did not. Conclusions Major negative stressful events predict increased risk for Gd+ and T2 lesions, while positive stressful events predict decreased risk. PMID:23680407

Socioeconomic Status, Subjective Social Status, and Perceived Stress: Associations with Stress Physiology and Executive Functioning.

Science.gov (United States)

Ursache, Alexandra; Noble, Kimberly G; Blair, Clancy

2015-01-01

Several studies have investigated associations between socioeconomic status (SES) and indicators of children's physiological and cognitive self-regulation. Although objective measures of family SES may be good proxies for families' experiences of disadvantage, less is known about subjective aspects of families' experiences. We hypothesize that subjective social status (SSS) and perceived stress may be important independent predictors of children's stress physiology and executive functioning (EF). Eighty-two children from diverse SES backgrounds were administered EF measures and provided saliva samples for cortisol assay. Caregivers reported on objective SES, SSS, and perceived stress. Results suggest that SES and SSS are both independently and positively related to EF. In models predicting stress physiology, higher perceived stress was associated with lower baseline cortisol. Moreover, SES and age interacted to predict cortisol levels such that among younger children, lower SES was associated with higher cortisol, whereas among older children, lower SES was associated with lower cortisol. Results highlight the importance of considering both objective and subjective indicators of families' SES and stressful experiences in relation to multiple aspects of children's self-regulation.

Job stress models for predicting burnout syndrome: a review.

Science.gov (United States)

Chirico, Francesco

2016-01-01

In Europe, the Council Directive 89/391 for improvement of workers' safety and health has emphasized the importance of addressing all occupational risk factors, and hence also psychosocial and organizational risk factors. Nevertheless, the construct of "work-related stress" elaborated from EU-OSHA is not totally corresponding with the "psychosocial" risk, that is a broader category of risk, comprising various and different psychosocial risk factors. The term "burnout", without any binding definition, tries to integrate symptoms as well as cause of the burnout process. In Europe, the most important methods developed for the work related stress risk assessment are based on the Cox's transactional model of job stress. Nevertheless, there are more specific models for predicting burnout syndrome. This literature review provides an overview of job burnout, highlighting the most important models of job burnout, such as the Job Strain, the Effort/Reward Imbalance and the Job Demands-Resources models. The difference between these models and the Cox's model of job stress is explored.

Predicted thermal and stress environments in the vicinity of repository openings

International Nuclear Information System (INIS)

Bauer, S.J.; Hardy, M.P.; Lin, M.

1991-01-01

An understanding of the thermal and stress environment in the vicinity of repository openings is important for preclosure performance considerations and worker health and safety considerations for the proposed high-level radioactive waste repository at Yucca Mountain. This paper presents the results of two and three dimensional numerical analyses which have determined the thermal and stress environments for typical repository openings. In general, it is predicted that openings close to heat sources attain high temperatures and experience a significant stress increase. Openings away from heat sources experience more uniform temperature changes and experience a stress change which results in part from a far-field thermal loading

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

Science.gov (United States)

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.

Demographic differences, occupational stress and organisational commitment among employees in higher education institution

Directory of Open Access Journals (Sweden)

Simbarashe Zhuwao

2015-11-01

Full Text Available The objectives of this study was to determine the levels of occupational stress and organizational commitment of employees and to determine the differences of occupational stress and organisational commitment based on demographic information in a higher education institution. The sample consisted of 141 academic staff. The Organisational Stress Screening Tool (ASSET, and Allen and Meyer’s Organisational Commitment Tool (OCT were used. The results showed that different occupational stressors contributed significantly to low organisational commitment. Occupational stress levels about job characteristics, work relationships, job overload and job control contributed to low levels of organisational commitment. The results also showed that there is a significant difference in occupational stress and organisational commitment levels based on the demographic differences of employees

Predicting guar seed splitting by compression between two plates using Hertz theory of contact stresses.

Science.gov (United States)

Vishwakarma, R K; Shivhare, U S; Nanda, S K

2012-09-01

Hertz's theory of contact stresses was applied to predict the splitting of guar seeds during uni-axial compressive loading between 2 rigid parallel plates. The apparent modulus of elasticity of guar seeds varied between 296.18 and 116.19 MPa when force was applied normal to hilum joint (horizontal position), whereas it varied between 171.86 and 54.18 MPa when force was applied in the direction of hilum joint (vertical position) with in moisture content range of 5.16% to 15.28% (d.b.). At higher moisture contents, the seeds yielded after considerable deformation, thus showing ductile nature. Distribution of stresses below the point of contact were plotted to predict the location of critical point, which was found at 0.44 to 0.64 mm and 0.37 to 0.53 mm below the contact point in vertical and horizontal loading, respectively, depending upon moisture content. The separation of cotyledons from each other initiated before yielding of cotyledons and thus splitting of seed took place. The relationships between apparent modulus of elasticity, principal stresses with moisture content were described using second-order polynomial equations and validated experimentally. Manufacture of guar gum powder requires dehulling and splitting of guar seeds. This article describes splitting behavior of guar seeds under compressive loading. Results of this study may be used for design of dehulling and splitting systems of guar seeds. © 2012 Institute of Food Technologists®

Maternal stress predicted by characteristics of children with autism spectrum disorder and intellectual disability

NARCIS (Netherlands)

Peters-Scheffer, N.C.; Didden, H.C.M.; Korzilius, H.P.L.M.

2012-01-01

To determine maternal stress and child variables predicting maternal stress, 104 mothers of children with autism spectrum disorder (ASD) and intellectual disability (ID) completed the Dutch version of the Parental Stress Index (PSI; De Brock, Vermulst, Gerris, & Abidin, 1992) every six months over a

Through-Thickness Residual Stress Profiles in Austenitic Stainless Steel Welds: A Combined Experimental and Prediction Study

Science.gov (United States)

Mathew, J.; Moat, R. J.; Paddea, S.; Francis, J. A.; Fitzpatrick, M. E.; Bouchard, P. J.

2017-12-01

Economic and safe management of nuclear plant components relies on accurate prediction of welding-induced residual stresses. In this study, the distribution of residual stress through the thickness of austenitic stainless steel welds has been measured using neutron diffraction and the contour method. The measured data are used to validate residual stress profiles predicted by an artificial neural network approach (ANN) as a function of welding heat input and geometry. Maximum tensile stresses with magnitude close to the yield strength of the material were observed near the weld cap in both axial and hoop direction of the welds. Significant scatter of more than 200 MPa was found within the residual stress measurements at the weld center line and are associated with the geometry and welding conditions of individual weld passes. The ANN prediction is developed in an attempt to effectively quantify this phenomenon of `innate scatter' and to learn the non-linear patterns in the weld residual stress profiles. Furthermore, the efficacy of the ANN method for defining through-thickness residual stress profiles in welds for application in structural integrity assessments is evaluated.

The Role of Resilience, Delayed Gratification and Stress in Predicting Academic Performance

Science.gov (United States)

Cheng, Vivienne; Catling, Jonathan

2015-01-01

Transition to university is an important and potentially stressful life event for students. Previous studies have shown that resilience, delay of gratification and stress can affect the academic performance of students. However, none have shown the effect of these factors in predicting academic performance, hence the current study aimed to look at…

Women in Higher Education: Exploring Stressful Workplace Factors and Coping Strategies

Science.gov (United States)

Kersh, Renique

2018-01-01

For women administrators in higher education, workplace factors like managing multiple roles; work bleeding into personal life; issues with leadership; discrimination and marginalization; and role insufficiency (i.e., ambiguity in work roles and reduced sense of control) contribute to increased workplace stress. Individual coping responses are…

Probability of failure prediction for step-stress fatigue under sine or random stress

Science.gov (United States)

Lambert, R. G.

1979-01-01

A previously proposed cumulative fatigue damage law is extended to predict the probability of failure or fatigue life for structural materials with S-N fatigue curves represented as a scatterband of failure points. The proposed law applies to structures subjected to sinusoidal or random stresses and includes the effect of initial crack (i.e., flaw) sizes. The corrected cycle ratio damage function is shown to have physical significance.

The Promise and Peril of Predictive Analytics in Higher Education: A Landscape Analysis

Science.gov (United States)

Ekowo, Manuela; Palmer, Iris

2016-01-01

Predictive analytics in higher education is a hot-button topic among educators and administrators as institutions strive to better serve students by becoming more data-informed. In this paper, the authors describe how predictive analytics are used in higher education to identify students who need extra support, steer students in courses they will…

Chronic and Acute Stress, Gender, and Serotonin Transporter Gene-Environment Interactions Predicting Depression Symptoms in Youth

Science.gov (United States)

Hammen, Constance; Brennan, Patricia A.; Keenan-Miller, Danielle; Hazel, Nicholas A.; Najman, Jake M.

2010-01-01

Background: Many recent studies of serotonin transporter gene by environment effects predicting depression have used stress assessments with undefined or poor psychometric methods, possibly contributing to wide variation in findings. The present study attempted to distinguish between effects of acute and chronic stress to predict depressive…

Design prediction for long term stress rupture service of composite pressure vessels

Science.gov (United States)

Robinson, Ernest Y.

1992-01-01

Extensive stress rupture studies on glass composites and Kevlar composites were conducted by the Lawrence Radiation Laboratory beginning in the late 1960's and extending to about 8 years in some cases. Some of the data from these studies published over the years were incomplete or were tainted by spurious failures, such as grip slippage. Updated data sets were defined for both fiberglass and Kevlar composite stand test specimens. These updated data are analyzed in this report by a convenient form of the bivariate Weibull distribution, to establish a consistent set of design prediction charts that may be used as a conservative basis for predicting the stress rupture life of composite pressure vessels. The updated glass composite data exhibit an invariant Weibull modulus with lifetime. The data are analyzed in terms of homologous service load (referenced to the observed median strength). The equations relating life, homologous load, and probability are given, and corresponding design prediction charts are presented. A similar approach is taken for Kevlar composites, where the updated stand data do show a turndown tendency at long life accompanied by a corresponding change (increase) of the Weibull modulus. The turndown characteristic is not present in stress rupture test data of Kevlar pressure vessels. A modification of the stress rupture equations is presented to incorporate a latent, but limited, strength drop, and design prediction charts are presented that incorporate such behavior. The methods presented utilize Cartesian plots of the probability distributions (which are a more natural display for the design engineer), based on median normalized data that are independent of statistical parameters and are readily defined for any set of test data.

Maternal Stress Predicted by Characteristics of Children with Autism Spectrum Disorder and Intellectual Disability

Science.gov (United States)

Peters-Scheffer, Nienke; Didden, Robert; Korzilius, Hubert

2012-01-01

To determine maternal stress and child variables predicting maternal stress, 104 mothers of children with autism spectrum disorder (ASD) and intellectual disability (ID) completed the Dutch version of the Parental Stress Index (PSI; De Brock, Vermulst, Gerris, & Abidin, 1992) every six months over a period of two years. The level of maternal…

Prediction of macroscopic and local stress-strain behaviors of perforated plates under primary and secondary creep conditions

International Nuclear Information System (INIS)

Igari, Toshihide; Tokiyoshi, Takumi; Mizokami, Yorikata

2000-01-01

Prediction methods of macroscopic and local creep behaviors of perforated plates are examined in order to apply these methods to the structural design of perforated structures such as heat exchangers used in elevated temperatures. Both primary and secondary creeps are considered for predicting macroscopic and local creep behaviors of perorated plates which are made of actual structural materials. Both uniaxial and multiaxial loading of perforated plates are taken into consideration. The concept of effective stress is applied to the prediction of macroscopic creep behaviors of perforated plates, and the predicted results are compared with the numerical results by FEM for the unit section of perorated plated under creep, in order to confirm the propriety of the proposed method. Based on the idea that stress exponents in creep equations govern the stress distribution of perforated plates, a modified Neuber's rule is used for predicting local stress and strain concentrations. The propriety of this prediction method is shown through a comparison of the prediction with the numerical results by FEM for the unit section of perforated plates under creep, and experimental results by the Moire method. (author)

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.

Cumulative trauma and partner conflict predict post-traumatic stress disorder in postpartum African-American women.

Science.gov (United States)

Hauff, Nancy J; Fry-McComish, Judith; Chiodo, Lisa M

2017-08-01

To describe relationships between cumulative trauma, partner conflict and post-traumatic stress in African-American postpartum women. Cumulative trauma exposure estimates for women in the USA range from 51-69%. During pregnancy, most trauma research has focused on physical injury to the mother. Post-traumatic stress disorder (PTSD) is associated with trauma and more prevalent in African-American women than women of other groups. Knowledge about both the rate and impact of cumulative trauma on pregnancy may contribute to our understanding of women seeking prenatal care, and disparities in infant morbidity and mortality. This retrospective, correlational, cross-sectional study took place on postpartum units of two Detroit hospitals. Participants were 150 African-American women aged between 18-45 who had given birth. Mothers completed the Cumulative Trauma Scale, Conflict Tactics Scale, Clinician Administered Post-traumatic Stress Scale, Edinburgh Postnatal Depression Scale and a Demographic Data form. Descriptive statistics, correlations and multiple regressions were used for data analysis. All participants reported at least one traumatic event in their lifetime. Cumulative trauma and partner conflict predicted PTSD, with the trauma of a life-threatening event for a loved one reported by 60% of the sample. Nearly, one-fourth of the women screened were at risk for PTSD. Increased cumulative trauma, increased partner conflict and lower level of education were related to higher rates of PTSD symptoms. Both cumulative trauma and partner conflict in the past year predict PTSD. Reasoning was used most often for partner conflict resolution. The results of this study offer additional knowledge regarding relationships between cumulative trauma, partner conflict and PTSD in African-American women. Healthcare providers need to be sensitive to patient life-threatening events, personal failures, abuse and other types of trauma. Current evidence supports the need to assess for

Perceived Medical School stress of undergraduate medical students predicts academic performance: an observational study.

Science.gov (United States)

Kötter, Thomas; Wagner, Josefin; Brüheim, Linda; Voltmer, Edgar

2017-12-16

Medical students are exposed to high amounts of stress. Stress and poor academic performance can become part of a vicious circle. In order to counteract this circularity, it seems important to better understand the relationship between stress and performance during medical education. The most widespread stress questionnaire designed for use in Medical School is the "Perceived Medical School Stress Instrument" (PMSS). It addresses a wide range of stressors, including workload, competition, social isolation and financial worries. Our aim was to examine the relation between the perceived Medical School stress of undergraduate medical students and academic performance. We measured Medical School stress using the PMSS at two different time points (at the end of freshman year and at the end of sophomore year) and matched stress scores together with age and gender to the first medical examination (M1) grade of the students (n = 456). PMSS scores from 2 and 14 months before M1 proved to be significant predictors for medical students' M1 grade. Age and gender also predict academic performance, making older female students with high stress scores a potential risk group for entering the vicious circle of stress and poor academic performance. PMSS sum scores 2 and 14 months before the M1 exam seem to have an independent predictive validity for medical students' M1 grade. More research is needed to identify potential confounders.

Prediction of residual stress distribution in multi-stacked thin film by curvature measurement and iterative FEA

International Nuclear Information System (INIS)

Choi, Hyeon Chang; Park, Jun Hyub

2005-01-01

In this study, residual stress distribution in multi-stacked film by MEMS (Micro-Electro Mechanical System) process is predicted using Finite Element Method (FEM). We develop a finite element program for REsidual Stress Analysis (RESA) in multi-stacked film. The RESA predicts the distribution of residual stress field in multi-stacked film. Curvatures of multi-stacked film and single layers which consist of the multi-stacked film are used as the input to the RESA. To measure those curvatures is easier than to measure a distribution of residual stress. To verify the RESA, mean stresses and stress gradients of single and multilayers are measured. The mean stresses are calculated from curvatures of deposited wafer by using Stoney's equation. The stress gradients are calculated from the vertical deflection at the end of cantilever beam. To measure the mean stress of each layer in multi-stacked film, we measure the curvature of wafer with the film after etching layer by layer in multi-stacked film

Differential Exposure and Reactivity to Interpersonal Stress Predict Sex Differences in Adolescent Depression

Science.gov (United States)

Shih, Josephine H.; Eberhart, Nicole K.; Hammen, Constance L.; Brennan, Patricia A.

2006-01-01

This study tested the hypothesis that higher rates of depression in adolescent girls are explained by their greater exposure and reactivity to stress in the interpersonal domain in a large sample of 15-year-olds. Findings indicate that adolescent girls experienced higher levels of total and interpersonal episodic stress, whereas boys experienced…

Numerical predictions and measurements of Reynolds normal stresses in turbulent pipe flow of polymers

Energy Technology Data Exchange (ETDEWEB)

Resende, P.R. [Centro de Estudos de Fenomenos de Transporte, DEMEGI, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, 4200-465 Porto (Portugal)]. E-mail: resende@fe.up.pt; Escudier, M.P. [Department of Engineering, University of Liverpool, Brownlow Street, Liverpool L69 3GH (United Kingdom)]. E-mail: escudier@liv.ac.uk; Presti, F [Department of Engineering, University of Liverpool, Brownlow Street, Liverpool L69 3GH (United Kingdom); Pinho, F.T. [Centro de Estudos de Fenomenos de Transporte, DEM, Universidade do Minho Campus de Azurem, 4800-058 Guimaraes (Portugal)]. E-mail: fpinho@dem.uminho.pt; Cruz, D.O.A. [Departamento de Engenharia Mecanica, Universidade Federal do Para-UFPa Campus Universitario do Guama, 66075-900 Belem, Para (Brazil)]. E-mail: doac@ufpa.br

2006-04-15

An anisotropic low Reynolds number k-{epsilon} turbulence model has been developed and its performance compared with experimental data for fully-developed turbulent pipe flow of four different polymer solutions. Although the predictions of friction factor, mean velocity and turbulent kinetic energy show only slight improvements over those of a previous isotropic model [Cruz, D.O.A., Pinho, F.T., Resende, P.R., 2004. Modeling the new stress for improved drag reduction predictions of viscoelastic pipe flow. J. Non-Newt. Fluid Mech. 121, 127-141], the new turbulence model is capable of predicting the enhanced anisotropy of the Reynolds normal stresses that accompanies polymer drag reduction in turbulent flow.

Numerical predictions and measurements of Reynolds normal stresses in turbulent pipe flow of polymers

International Nuclear Information System (INIS)

Resende, P.R.; Escudier, M.P.; Presti, F; Pinho, F.T.; Cruz, D.O.A.

2006-01-01

An anisotropic low Reynolds number k-ε turbulence model has been developed and its performance compared with experimental data for fully-developed turbulent pipe flow of four different polymer solutions. Although the predictions of friction factor, mean velocity and turbulent kinetic energy show only slight improvements over those of a previous isotropic model [Cruz, D.O.A., Pinho, F.T., Resende, P.R., 2004. Modeling the new stress for improved drag reduction predictions of viscoelastic pipe flow. J. Non-Newt. Fluid Mech. 121, 127-141], the new turbulence model is capable of predicting the enhanced anisotropy of the Reynolds normal stresses that accompanies polymer drag reduction in turbulent flow

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...

Higher oxidative stress in skeletal muscle of McArdle disease patients

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Jan J. Kaczor

2017-09-01

Full Text Available McArdle disease (MCD is an autosomal recessive condition resulting from skeletal muscle glycogen phosphorylase deficiency. The resultant block in glycogenolysis leads to an increased flux through the xanthine oxidase pathway (myogenic hyperuricemia and could lead to an increase in oxidative stress. We examined markers of oxidative stress (8-isoprostane and protein carbonyls, NAD(PH-oxidase, xanthine oxidase and antioxidant enzyme (superoxide dismutase, catalase and glutathione peroxidase activity in skeletal muscle of MCD patients (N = 12 and controls (N = 12. Eight-isoprostanes and protein carbonyls were higher in MCD patients as compared to controls (p < 0.05. There was a compensatory up-regulation of catalase protein content and activity (p < 0.05, mitochondrial superoxide dismutase (MnSOD protein content (p < 0.01 and activity (p < 0.05 in MCD patients, yet this increase was not sufficient to protect the muscle against elevated oxidative damage. These results suggest that oxidative stress in McArdle patients occurs and future studies should evaluate a potential role for oxidative stress contributing to acute pathology (rhabdomyolysis and possibly later onset fixed myopathy.

Different Methods of Predicting Permeability in Shale

DEFF Research Database (Denmark)

Mbia, Ernest Ncha; Fabricius, Ida Lykke; Krogsbøll, Anette

by two to five orders of magnitudes at lower vertical effective stress below 40 MPa as the content of clay minerals increases causing heterogeneity in shale material. Indirect permeability from consolidation can give maximum and minimum values of shale permeability needed in simulating fluid flow......Permeability is often very difficult to measure or predict in shale lithology. In this work we are determining shale permeability from consolidation tests data using Wissa et al., (1971) approach and comparing the results with predicted permeability from Kozeny’s model. Core and cuttings materials...... effective stress to 9 μD at high vertical effective stress of 100 MPa. The indirect permeability calculated from consolidation tests falls in the same magnitude at higher vertical effective stress, above 40 MPa, as that of the Kozeny model for shale samples with high non-clay content ≥ 70% but are higher...

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

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Mozhgan Saeidi

2018-01-01

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

The scaling of stress distribution under small scale yielding by T-scaling method and application to prediction of the temperature dependence on fracture toughness

International Nuclear Information System (INIS)

Ishihara, Kenichi; Hamada, Takeshi; Meshii, Toshiyuki

2017-01-01

In this paper, a new method for scaling the crack tip stress distribution under small scale yielding condition was proposed and named as T-scaling method. This method enables to identify the different stress distributions for materials with different tensile properties but identical load in terms of K or J. Then by assuming that the temperature dependence of a material is represented as the stress-strain relationship temperature dependence, a method to predict the fracture load at an arbitrary temperature from the already known fracture load at a reference temperature was proposed. This method combined the T-scaling method and the knowledge “fracture stress for slip induced cleavage fracture is temperature independent.” Once the fracture load is predicted, fracture toughness J c at the temperature under consideration can be evaluated by running elastic-plastic finite element analysis. Finally, the above-mentioned framework to predict the J c temperature dependency of a material in the ductile-to-brittle temperature distribution was validated for 0.55% carbon steel JIS S55C. The proposed framework seems to have a possibility to solve the problem the master curve is facing in the relatively higher temperature region, by requiring only tensile tests. (author)

Faculty Stress at Higher Education: A Study on the Business Schools of Pakistan

OpenAIRE

Aqsa Akbar; Waheed Akhter

2011-01-01

Job stress is one of the most important concepts for the today-s corporate as well as institutional world. The current study is conducted to identify the causes of faculty stress at Higher Education in Pakistan. For the purpose, Public & Private Business Schools of Punjab is selected as representative of Pakistan. A sample of 300 faculty members (214 males, 86 females) responded to the survey. Regression analysis shows that the Workload, Student Related issues and Role Co...

Predicting deformation and stress as a function of additive manufacturing process parameters for Europa drill

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National Aeronautics and Space Administration — We will combine part-level FEM model of residual stresses with phase-field transformation model to predict deformation and cracking due to thermal stresses from the...

Early Risk and Resiliency Factors Predict Chronic Posttraumatic Stress Disorder in Caregivers of Patients Admitted to a Neuroscience ICU.

Science.gov (United States)

Choi, Karmel W; Shaffer, Kelly M; Zale, Emily L; Funes, Christopher J; Koenen, Karestan C; Tehan, Tara; Rosand, Jonathan; Vranceanu, Ana-Maria

2018-05-01

Informal caregivers-that is, close family and friends providing unpaid emotional or instrumental care-of patients admitted to ICUs are at risk for posttraumatic stress disorder. As a first step toward developing interventions to prevent posttraumatic stress disorder in ICU caregivers, we examined the predictive validity of psychosocial risk screening during admission for caregiver posttraumatic stress disorder at 3 and 6 months post hospitalization. An observational, prospective study. Ninety-nine caregivers were recruited as part of a longitudinal research program of patient-caregiver dyads in a neuroscience ICU. None. Caregiver posttraumatic stress disorder symptoms were assessed during admission (baseline), 3 months, and 6 months post hospitalization. We 1) characterized prevalence of clinically significant symptoms at each time point 2); calculated sensitivity and specificity of baseline posttraumatic stress disorder screening in predicting posttraumatic stress disorder at 3 and 6 months; and 3) used recursive partitioning to select potential baseline factors and examine the extent to which they helped predict clinically significant posttraumatic stress disorder symptoms at each time point. Rates of caregiver posttraumatic stress disorder remained relatively stable over time (16-22%). Screening for posttraumatic stress disorder at baseline predicted posttraumatic stress disorder at 3 and 6 months with moderate sensitivity (75-80%) and high specificity (92-95%). Screening for posttraumatic stress disorder at baseline was associated with caregiver anxiety, mindfulness (i.e., ability to be aware of one's thoughts and feelings in the moment), and bond with patient. Furthermore, baseline posttraumatic stress disorder screening was the single most relevant predictor of posttraumatic stress disorder at 3 and 6 months, such that other baseline factors did not significantly improve predictive ability. Screening neuroscience ICU caregivers for clinically significant

Prediction of three-dimensional residual stresses at localised indentations in pipes

International Nuclear Information System (INIS)

Hyde, T.H.; Luo, R.; Becker, A.A.

2012-01-01

Residual stresses are investigated using Finite Element (FE) analyses at localised indentations in pipes with and without internal pressures due to reverse plasticity caused by springback of the surrounding material after removal of the indenter. The indentation loading is applied via rigid 3D short indenters. The effects of the residual indentation depth, internal pressure, indenter size and different material properties on the residual stresses for different pipes have been investigated by carrying out parametric sensitivity studies. In order to predict the residual stresses, empirical formulations have been developed, which show a good correlation with the FE for residual stresses for pipes with diameter to thickness ratios of 35–72. - Highlights: ► A comprehensive elastic–plastic FE analysis of residual stresses caused by localised pipe indentations is presented. ► The effects of residual indentation depth, internal pressure, indenter size and material properties have been studied. ► Empirical formulations have been developed, which show a good correlation with the FE for residual stresses for pipes with diameter to thickness ratios of 35–72.

Evaluating penalized logistic regression models to predict Heat-Related Electric grid stress days

Energy Technology Data Exchange (ETDEWEB)

Bramer, L. M.; Rounds, J.; Burleyson, C. D.; Fortin, D.; Hathaway, J.; Rice, J.; Kraucunas, I.

2017-11-01

Understanding the conditions associated with stress on the electricity grid is important in the development of contingency plans for maintaining reliability during periods when the grid is stressed. In this paper, heat-related grid stress and the relationship with weather conditions is examined using data from the eastern United States. Penalized logistic regression models were developed and applied to predict stress on the electric grid using weather data. The inclusion of other weather variables, such as precipitation, in addition to temperature improved model performance. Several candidate models and datasets were examined. A penalized logistic regression model fit at the operation-zone level was found to provide predictive value and interpretability. Additionally, the importance of different weather variables observed at different time scales were examined. Maximum temperature and precipitation were identified as important across all zones while the importance of other weather variables was zone specific. The methods presented in this work are extensible to other regions and can be used to aid in planning and development of the electrical grid.

Higher-status occupations and breast cancer: a life-course stress approach.

Science.gov (United States)

Pudrovska, Tetyana; Carr, Deborah; McFarland, Michael; Collins, Caitlyn

2013-07-01

Using the 1957-2011 data from 3682 White non-Hispanic women (297 incident breast cancer cases) in the Wisconsin Longitudinal Study, United States, we explore the effect of occupation in 1975 (at age 36) on breast cancer incidence up to age 72. Our study is motivated by the paradoxical association between higher-status occupations and elevated breast cancer risk, which presents a challenge to the consistent health advantage of higher social class. We found that women in professional occupations had 72122% and women in managerial occupations had 57-89% higher risk of a breast cancer diagnosis than housewives and women in lower-status occupations. We explored an estrogen-related pathway (reproductive history, health behaviors, and life-course estrogen cycle) as well as a social stress pathway (occupational experiences) as potential explanations for the effect of higher-status occupations. The elevated risk of breast cancer among professional women was partly explained by estrogen-related variables but remained large and statistically significant. The association between managerial occupations and breast cancer incidence was fully explained by job authority defined as control over others' work. Exercising job authority was related to higher breast cancer risk (HR = 1.57, 95% CI: 1.12, 2.18), especially with longer duration of holding the professional/managerial job. We suggest that the assertion of job authority by women in the 1970s involved stressful interpersonal experiences that may have promoted breast cancer development via prolonged dysregulation of the glucocorticoid system and exposure of the breast tissue to adverse effects of chronically elevated cortisol. Our study emphasizes complex biosocial pathways through which women's gendered occupational experiences become embodied and drive forward physiological repercussions. Copyright © 2013 Elsevier Ltd. All rights reserved.

The predictive role of health-promoting behaviours and perceived stress in aneurysmal rupture.

Science.gov (United States)

Lee, Mi-Sun; Park, Chang G; Hughes, Tonda L; Jun, Sang-Eun; Whang, Kum; Kim, Nahyun

2018-03-01

To examine the roles of two modifiable factors-health-promoting behaviours and perceived stress-in predicting aneurysmal rupture. Unruptured intracranial aneurysm detection produces significant stress and anxiety in patients because of the risk of rupture. Compared to nonmodifiable risk factors for rupture such as age, gender and aneurysm size/location, less attention has been given to modifiable risk factors. Two modifiable factors, health-promoting behaviours and perceived stress, have hardly been examined as potential predictors of rupture. This study used a cross-sectional design. We assessed 155 patients with intracranial aneurysms-that is, subarachnoid haemorrhage (n = 77) or unruptured intracranial aneurysm (n = 78)-to examine (i) baseline characteristics (patient and aneurysmal factors), (ii) health-related factors (lifestyle habits and health-promoting behaviour) and (iii) perceived stress levels (psychological stress and physical stress). Patient records provided medical histories and aneurysmal factors; other data were collected using a structured questionnaire addressing lifestyle habits, the Health-Promoting Lifestyle Profile-II to measure health-promoting behaviour and the Perceived Stress Questionnaire to measure perceived-psychological stress and perceived-physical stress levels. Bivariate analysis indicated that aneurysm rupture risk was associated with female gender, aneurysm size/location, defecation frequency, hyperlipidaemia, sedentary time, low Health-Promoting Lifestyle Profile-II mean scores and high perceived-psychological stress scores. After adjusting for known risk factors, the mean Health-Promoting Lifestyle Profile-II and perceived-psychological stress scores remained robust predictors of rupture. Furthermore, known risk factors combined with these scores had greater predictive power than known risk factors alone. Health-promoting behaviour and psychological stress are promising modifiable factors for reducing risk of aneurysmal

Prediction of the remaining lifetime of stainless steels under conditions of stress corrosion cracking

International Nuclear Information System (INIS)

Tandler, M.; Vehovar, L.; Dolecek, V.; Rotnik, U.

2003-01-01

The prediction of the lifetime of metal structures and equipment under conditions of stress corrosion is very complicated because of the complexity of this process of degradation. Recently a new method, based on the so-called corrosion elongation curves, has been found, which can be used to predict the time to failure under these conditions. By upgrading of these curves (and thus obtaining Upgraded Corrosion Elongation Curves - UCEC's) it has been possible to obtain a precise definition of the time needed for the initiation of the corrosion crack, and for its stable growth. It is upon this basis that diagrams for the prediction of remaining lifetime (DPRL's) have been developed. DPRL's can also be used to predict the values of various critical parameters which have to be achieved if a stress corrosion crack is to occur. (Abstract Copyright [2003], Wiley Periodicals, Inc.) [de

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

Science.gov (United States)

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.

Physical condition and stress levels during early development reflect feeding rates and predict pre- and post-fledging survival in a nearshore seabird.

Science.gov (United States)

Lamb, Juliet S; O'Reilly, Kathleen M; Jodice, Patrick G R

2016-01-01

The effects of acute environmental stressors on reproduction in wildlife are often difficult to measure because of the labour and disturbance involved in collecting accurate reproductive data. Stress hormones represent a promising option for assessing the effects of environmental perturbations on altricial young; however, it is necessary first to establish how stress levels are affected by environmental conditions during development and whether elevated stress results in reduced survival and recruitment rates. In birds, the stress hormone corticosterone is deposited in feathers during the entire period of feather growth, making it an integrated measure of background stress levels during development. We tested the utility of feather corticosterone levels in 3- to 4-week-old nestling brown pelicans ( Pelecanus occidentalis ) for predicting survival rates at both the individual and colony levels. We also assessed the relationship of feather corticosterone to nestling body condition and rates of energy delivery to nestlings. Chicks with higher body condition and lower corticosterone levels were more likely to fledge and to be resighted after fledging, whereas those with lower body condition and higher corticosterone levels were less likely to fledge or be resighted after fledging. Feather corticosterone was also associated with intracolony differences in survival between ground and elevated nest sites. Colony-wide, mean feather corticosterone predicted nest productivity, chick survival and post-fledging dispersal more effectively than did body condition, although these relationships were strongest before fledglings dispersed away from the colony. Both reproductive success and nestling corticosterone were strongly related to nutritional conditions, particularly meal delivery rates. We conclude that feather corticosterone is a powerful predictor of reproductive success and could provide a useful metric for rapidly assessing the effects of changes in environmental

Occupational Stress in UK Higher Education Institutions: A Comparative Study of All Staff Categories

Science.gov (United States)

Tytherleigh, M. Y.; Webb, C.; Cooper, C. L.; Ricketts, C.

2005-01-01

The higher education sector in the UK continues to experience significant change. This includes restructuring, use of short-term contracts, external scrutiny and accountability, and major reductions in funding. In line with this, reports of stress at work in higher education institutions have also increased. The study reported here was carried out…

Boosting recovery rather than buffering reactivity: Higher stress-induced oxytocin secretion is associated with increased cortisol reactivity and faster vagal recovery after acute psychosocial stress.

Science.gov (United States)

Engert, Veronika; Koester, Anna M; Riepenhausen, Antje; Singer, Tania

2016-12-01

Animal models and human studies using paradigms designed to stimulate endogenous oxytocin release suggest a stress-buffering role of oxytocin. We here examined the involvement of stress-induced peripheral oxytocin secretion in reactivity and recovery phases of the human psychosocial stress response. Healthy male and female participants (N=114) were subjected to a standardized laboratory stressor, the Trier Social Stress Test. In addition to plasma oxytocin, cortisol was assessed as a marker of hypothalamic-pituitary-adrenal (HPA-) axis activity, alpha-amylase and heart rate as markers of sympathetic activity, high frequency heart rate variability as a marker of vagal tone and self-rated anxiety as an indicator of subjective stress experience. On average, oxytocin levels increased by 51% following psychosocial stress. The stress-induced oxytocin secretion, however, did not reduce stress reactivity. To the contrary, higher oxytocin secretion was associated with greater cortisol reactivity and peak cortisol levels in both sexes. In the second phase of the stress response the opposite pattern was observed, with higher oxytocin secretion associated with faster vagal recovery. We suggest that after an early stage of oxytocin and HPA-axis co-activation, the stress-reducing action of oxytocin unfolds. Due to the time lag it manifests as a recovery-boosting rather than a reactivity-buffering effect. By reinforcing parasympathetic autonomic activity, specifically during stress recovery, oxytocin may provide an important protective function against the health-compromising effects of sustained stress. Copyright © 2016 Elsevier Ltd. All rights reserved.

Stress Management Coping Strategies of Academic Leaders in an Institution of Higher Learning in Malaysia

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Gurnam Kaur Sidhu

2015-12-01

Full Text Available In today’s demanding academic environment, academic leaders need to be well equipped with stress management coping strategies as they often find themselves in challenging situations and responsibilities. Therefore, the main aim of this paper is to investigate the stress management coping strategies used by academic leaders in an institution of higher learning located in Selangor, Malaysia. A mixed-methods research design was employed and the sample population involved 46 academic leaders from a public university. Data were collected using a questionnaire and semistructured interviews. The quantitative data were statistically analyzed using SPSS while the qualitative data were analyzed thematically. The findings showed that a majority of the academic leaders opted towards positive problem-focused engagement strategies such as cognitive restructuring and problem solving strategies followed by emotion-focused engagement which included expressing emotion and social support strategies. Besides that, academic leaders did confess that they sometimes do use disengagement strategies such as wishful thinking, problem avoidance and self-criticism coping strategies but they stressed that they faced problems and stress in a positive and constructive manner. The findings of this study imply that academic leaders in this study are engaged and well informed of stress coping strategies. However, it is recommended that top management in institutions of higher learning take the initiatives in providing necessary support to academic leaders by educating them on stress management coping strategies.

Constitutive analysis to predict the hot deformation behavior of 34CrMo4 steel with an optimum solution method for stress multiplier

International Nuclear Information System (INIS)

Xu, Wujiao; Zou, Mingping; Zhang, Lei

2014-01-01

The hot deformation behaviors of steel 34CrMo4 is investigated by hot compression test with the temperature range of 1073–1373 K and the strain rate range of 0.01–10 s −1 . The flow behaviors of 34CrMo4 steel were characterized based on the true stress–true strain curves. The hyperbolic sine law in Arrhenius type is adopted in the constitutive modeling for 34CrMo4. Solving algorithm of the stress multiplier α in hyperbolic sine law is a key factor to guarantee the constitutive model accuracy. How to solve the stress multiplier α is investigated and an optimum solution method for α is proposed. Meanwhile, the influence of strain is incorporated in constitutive analysis by considering the effect of strain on material constants α, n, Q and A. With the optimum solution method for stress multiplier α proposed, the stress prediction is satisfactory with the higher correlation coefficient, R = 0.988 and the lower average absolute relative error, AARE = 3.44% for the entire strain rate-temperature domain. The optimum solution method for stress multiplier α can also be applied for other materials to predict the flow behavior more accurately. - Highlights: • Isothermal compression tests were conducted to study the flow behavior of 34CrMo4. • The influence of strain is incorporated in constitutive model. • An optimum solution method for stress multiplier α is proposed

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

Science.gov (United States)

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 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

Measurement and prediction of residual stress in a bead-on-plate weld benchmark specimen

International Nuclear Information System (INIS)

Ficquet, X.; Smith, D.J.; Truman, C.E.; Kingston, E.J.; Dennis, R.J.

2009-01-01

This paper presents measurements and predictions of the residual stresses generated by laying a single weld bead on a flat, austenitic stainless steel plate. The residual stress field that is created is strongly three-dimensional and is considered representative of that found in a repair weld. Through-thickness measurements are made using the deep hole drilling technique, and near-surface measurements are made using incremental centre hole drilling. Measurements are compared to predictions at the same locations made using finite element analysis incorporating an advanced, non-linear kinematic hardening model. The work was conducted as part of an European round robin exercise, coordinated as part of the NeT network. Overall, there was broad agreement between measurements and predictions, but there were notable differences

Higher stress scores for female medical students measured by the Kessler Psychological Distress Scale (K10 in Pakistan

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Khadija Qamar

2014-10-01

Full Text Available The aim of this study was to determine the stress level of medical students and the relationship between stress and academic year. A cross-sectional, descriptive study was conducted at an undergraduate medical school with a five-year curriculum, in Pakistan, from January 2014 to April 2014. Medical students in the first four years were included in the study. The Kessler Psychological Distress Scale (K10, a self-administered questionnaire, was distributed to the students. A total of 445 medical students completed the questionnaire. The average stress score was 19.61 (SD = 6.76 with a range from 10 to 43. Stress was experienced by 169 students (41.7%. The scores of female students were higher than scores of males, indicating a higher stress level (P = 0.011. The relationship between stress and academic year was insignificant (P = 0.392.

Modelling of loading, stress relaxation and stress recovery in a shape memory polymer.

Science.gov (United States)

Sweeney, J; Bonner, M; Ward, I M

2014-09-01

A multi-element constitutive model for a lactide-based shape memory polymer has been developed that represents loading to large tensile deformations, stress relaxation and stress recovery at 60, 65 and 70°C. The model consists of parallel Maxwell arms each comprising neo-Hookean and Eyring elements. Guiu-Pratt analysis of the stress relaxation curves yields Eyring parameters. When these parameters are used to define the Eyring process in a single Maxwell arm, the resulting model yields at too low a stress, but gives good predictions for longer times. Stress dip tests show a very stiff response on unloading by a small strain decrement. This would create an unrealistically high stress on loading to large strain if it were modelled by an elastic element. Instead it is modelled by an Eyring process operating via a flow rule that introduces strain hardening after yield. When this process is incorporated into a second parallel Maxwell arm, there results a model that fully represents both stress relaxation and stress dip tests at 60°C. At higher temperatures a third arm is required for valid predictions. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Predicting early academic achievement: The role of higher-versus lower-order personality traits

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Zupančič Maja

2011-01-01

Full Text Available The study explored the role of children’s (N = 193 individual differences and parental characteristics at the beginning of the first year of schooling in predicting students’ attainment of academic standards at the end of the year. Special attention was paid to children’s personality as perceived by the teachers’ assistants. Along with parents’ education, parenting practices and first-graders’ cognitive ability, the incremental predictive power of children’s higher-order (robust personality traits was compared to the contribution of lower-order (specific traits in explaining academic achievement. The specific traits provided a somewhat more accurate prediction than the robust traits. Unique contributions of maternal authoritative parenting, children’s cognitive ability, and personality to academic achievement were established. The ratings of first-graders’ conscientiousness (a higher-order trait improved the prediction of academic achievement based on parenting and cognitive ability by 12%, whereas assistant teacher’s perceived children’s intelligence and low antagonism (lower-order traits improved the prediction by 17%.

Prediction of Weld Residual Stress of Narrow Gap Welds

International Nuclear Information System (INIS)

Yang, Jun Seog; Huh, Nam Su

2010-01-01

The conventional welding technique such as shield metal arc welding has been mostly applied to the piping system of the nuclear power plants. It is well known that this welding technique causes the overheating and welding defects due to the large groove angle of weld. On the other hand, the narrow gap welding(NGW) technique has many merits, for instance, the reduction of welding time, the shrinkage of weld and the small deformation of the weld due to the small groove angle and welding bead width comparing with the conventional welds. These characteristics of NGW affect the deformation behavior and the distribution of welding residual stress of NGW, thus it is believed that the residual stress results obtained from conventional welding procedure may not be applied to structural integrity evaluation of NGW. In this paper, the welding residual stress of NGW was predicted using the nonlinear finite element analysis to simulate the thermal and mechanical effects of the NGW. The present results can be used as the important information to perform the flaw evaluation and to improve the weld procedure of NGW

Interaction of CD38 Variant and Chronic Interpersonal Stress Prospectively Predicts Social Anxiety and Depression Symptoms Over Six Years

Science.gov (United States)

Tabak, Benjamin A.; Vrshek-Schallhorn, Suzanne; Zinbarg, Richard E.; Prenoveau, Jason M.; Mineka, Susan; Redei, Eva E.; Adam, Emma K.; Craske, Michelle G.

2015-01-01

Variation in the CD38 gene, which regulates secretion of the neuropeptide oxytocin, has been associated with several social phenotypes. Specifically, rs3796863 A allele carriers have demonstrated increased social sensitivity. In 400 older adolescents, we used trait-state-occasion modeling to investigate how rs3796863 genotype, baseline ratings of chronic interpersonal stress, and their gene-environment (GxE) interaction predicted trait social anxiety and depression symptoms over six years. We found significant GxE effects for CD38 A-carrier genotypes and chronic interpersonal stress at baseline predicting greater social anxiety and depression symptoms. A significant GxE effect of smaller magnitude was also found for C/C genotype and chronic interpersonal stress predicting greater depression; however, this effect was small compared to the main effect of chronic interpersonal stress. Thus, in the context of chronic interpersonal stress, heightened social sensitivity associated with the rs3796863 A allele may prospectively predict risk for social anxiety and (to a lesser extent) depression. PMID:26958455

A prediction method of temperature distribution and thermal stress for the throttle turbine rotor and its application

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Yang Yu

2017-01-01

Full Text Available In this paper, a prediction method of the temperature distribution for the thermal stress for the throttle-regulated steam turbine rotor is proposed. The rotor thermal stress curve can be calculated according to the preset power requirement, the operation mode and the predicted critical parameters. The results of the 660 MW throttle turbine rotor show that the operators are able to predict the operation results and to adjust the operation parameters in advance with the help of the inertial element method. Meanwhile, it can also raise the operation level, thus providing the technical guarantee for the thermal stress optimization control and the safety of the steam turbine rotor under the variable load operation.

Potential for Drug Abuse: the Predictive Role of Parenting Styles, Stress and Type D Personality

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mahin soheili

2015-06-01

Full Text Available Objective: This study was an attempt to predict potential for drug abuse on the basis of three predictors of parenting style, stress and type D personality. Method: In this descriptive-correlational study, 200 students (100 males and 100 females of Islamic Azad University of Karaj were selected by convenience sampling. For data collection, perceived parenting styles questionnaire, perceived stress scale, type D personality scale, and addiction potential scale were used. Results: The results showed that rejecting/neglecting parenting style and emotional warmth were positively and negatively correlated with addiction potential, respectively. Conclusion: The child-parent relationship and also the relationship between stress and type D personality can be considered as predictive factors in addiction potential.

Predicting changes in posttraumatic growth and subjective well-being among breast cancer survivors: the role of social support and stress.

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McDonough, Meghan H; Sabiston, Catherine M; Wrosch, Carsten

2014-01-01

Social support is theoretically expected to be positively associated with posttraumatic growth (PTG) and subjective well-being, and stress is expected to be positively associated with PTG and negatively associated with subjective well-being among breast cancer (BC) survivors. However, empirical evidence is mixed, predominantly cross-sectional, and few studies have examined the unique effects of these predictors on positive changes in psychological experiences post cancer diagnosis and systemic treatment. This study examined both general and BC-specific social support and stress as predictors of change in PTG and subjective well-being among BC survivors. Women (N = 173, Mage  = 55.40, SD = 10.99) who had recently finished treatment completed demographic and treatment measures at baseline (T1); general and cancer-specific social support and stress, PTG and subjective well-being at 3 months (T2); and PTG and subjective well-being again at 6 months (T3). Longitudinal predictors of change in PTG and subjective well-being were examined using hierarchical multiple regression. The BC-specific social support (β = .12) and stress (cancer worry; β = .10) predicted increasing levels of PTG. Improvements in subjective well-being were predicted by higher levels of general social support (β = .21) and lower levels of general stress (β = -.59). There are distinct predictors of change in PTG and subjective well-being among BC survivors, supporting the distinction between the trauma-specific process of PTG and well-being. Copyright © 2013 John Wiley & Sons, Ltd.

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

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Hotchkiss, Jason T; Lesher, Ruth

2018-06-01

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

Task-related increases in fatigue predict recovery time after academic stress.

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Blasche, Gerhard; Zilic, Jelena; Frischenschlager, Oskar

2016-01-01

The aim of this study was to investigate the time course of recovery after an academic exam as a model of high workload and its association with stress-related fatigue. Thirty-six medical students (17 females, 19 males) filled out diaries during an exam phase, starting 2 days prior to the exam, and a control phase 4 weeks after the exam for 14 days, respectively. Fatigue, distress, quality of sleep, and health complaints were assessed. Recovery time was determined for each individual and variable by comparing the 3-day average with the confidence interval of the control phase. Recovery time was predicted by Cox regression analyses. Recovery times of all variables except health complaints were predicted by stress-related fatigue. Half of the individuals had recovered after 6 days, and 80% of the individuals had recovered after 8 days. The time necessary for recovery from work demands is determined by fatigue as a measure of resource depletion.

Fatigue life prediction method for contact wire using maximum local stress

Energy Technology Data Exchange (ETDEWEB)

Kim, Yong Seok; Haochuang, Li; Seok, Chang Sung; Koo, Jae Mean [Sungkyunkwan University, Suwon (Korea, Republic of); Lee, Ki Won; Kwon, Sam Young; Cho, Yong Hyeon [Korea Railroad Research Institute, Uiwang (Korea, Republic of)

2015-01-15

Railway contact wires supplying electricity to trains are exposed to repeated mechanical strain and stress caused by their own weight and discontinuous contact with a pantograph during train operation. Since the speed of railway transportation has increased continuously, railway industries have recently reported a number of contact wire failures caused by mechanical fatigue fractures instead of normal wear, which has been a more common failure mechanism. To secure the safety and durability of contact wires in environments with increased train speeds, a bending fatigue test on contact wire has been performed. The test equipment is too complicated to evaluate the fatigue characteristics of contact wire. Thus, the axial tension fatigue test was performed for a standard specimen, and the bending fatigue life for the contact wire structure was then predicted using the maximum local stress occurring at the top of the contact wire. Lastly, the tested bending fatigue life of the structure was compared with the fatigue life predicted by the axial tension fatigue test for verification.

Fatigue life prediction method for contact wire using maximum local stress

International Nuclear Information System (INIS)

Kim, Yong Seok; Haochuang, Li; Seok, Chang Sung; Koo, Jae Mean; Lee, Ki Won; Kwon, Sam Young; Cho, Yong Hyeon

2015-01-01

Railway contact wires supplying electricity to trains are exposed to repeated mechanical strain and stress caused by their own weight and discontinuous contact with a pantograph during train operation. Since the speed of railway transportation has increased continuously, railway industries have recently reported a number of contact wire failures caused by mechanical fatigue fractures instead of normal wear, which has been a more common failure mechanism. To secure the safety and durability of contact wires in environments with increased train speeds, a bending fatigue test on contact wire has been performed. The test equipment is too complicated to evaluate the fatigue characteristics of contact wire. Thus, the axial tension fatigue test was performed for a standard specimen, and the bending fatigue life for the contact wire structure was then predicted using the maximum local stress occurring at the top of the contact wire. Lastly, the tested bending fatigue life of the structure was compared with the fatigue life predicted by the axial tension fatigue test for verification.

Thermal stress effects in intermetallic matrix composites

Science.gov (United States)

Wright, P. K.; Sensmeier, M. D.; Kupperman, D. S.; Wadley, H. N. G.

1993-01-01

Intermetallic matrix composites develop residual stresses from the large thermal expansion mismatch (delta-alpha) between the fibers and matrix. This work was undertaken to: establish improved techniques to measure these thermal stresses in IMC's; determine residual stresses in a variety of IMC systems by experiments and modeling; and, determine the effect of residual stresses on selected mechanical properties of an IMC. X ray diffraction (XRD), neutron diffraction (ND), synchrotron XRD (SXRD), and ultrasonics (US) techniques for measuring thermal stresses in IMC were examined and ND was selected as the most promising technique. ND was demonstrated on a variety of IMC systems encompassing Ti- and Ni-base matrices, SiC, W, and Al2O3 fibers, and different fiber fractions (Vf). Experimental results on these systems agreed with predictions of a concentric cylinder model. In SiC/Ti-base systems, little yielding was found and stresses were controlled primarily by delta-alpha and Vf. In Ni-base matrix systems, yield strength of the matrix and Vf controlled stress levels. The longitudinal residual stresses in SCS-6/Ti-24Al-llNb composite were modified by thermomechanical processing. Increasing residual stress decreased ultimate tensile strength in agreement with model predictions. Fiber pushout strength showed an unexpected inverse correlation with residual stress. In-plane shear yield strength showed no dependence on residual stress. Higher levels of residual tension led to higher fatigue crack growth rates, as suggested by matrix mean stress effects.

Classroom Organization and Teacher Stress Predict Learning Motivation in Kindergarten Children

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Pakarinen, Eija; Kiuru, Noona; Lerkkanen, Marja-Kristiina; Poikkeus, Anna-Maija; Siekkinen, Martti; Nurmi, Jari-Erik

2010-01-01

This study examined the extent to which observed teaching practices and self-reported teacher stress predict children's learning motivation and phonological awareness in kindergarten. The pre-reading skills of 1,268 children were measured at the beginning of their kindergarten year. Their learning motivation and phonological awareness were…

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

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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

The interactive role of eating regulation and stress in the prediction of weight-related outcomes among college students.

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Arsiwalla, Dilbur D; Arnold, Amanda W; Teel, Karla P; Ulrich, Pamela V; Gropper, Sareen S

2018-02-01

The interactive role of eating regulation and perceived stress on weight-related outcomes was examined among 319 sophomore year college students (110 males and 209 females). Moderated regressions were used to examine interactions between stress and eating regulation on study outcomes including body mass index (BMI) and body fat. Eating regulation moderated associations between stress and BMI and body fat outcomes. Students reporting high perceived stress, high autonomous eating regulation, low controlled regulation, and low amotivation exhibited higher outcomes (BMI and body fat) than those with similar eating regulation but lower perceived stress. Students with lower autonomous eating regulation and higher controlled regulation had no differences in study outcomes across levels of stress. College students who regulate their eating behaviours for health reasons (specifically showing autonomous regulation) exhibit higher BMI and body fat when they report higher levels of perceived stress. Health promotion programs for college students need to target education efforts towards stress reduction and healthy eating behaviours. Copyright © 2017 John Wiley & Sons, Ltd.

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.

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.

Predicting Posttraumatic Stress Symptom Prevalence and Local Distribution after an Earthquake with Scarce Data.

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Dussaillant, Francisca; Apablaza, Mauricio

2017-08-01

After a major earthquake, the assignment of scarce mental health emergency personnel to different geographic areas is crucial to the effective management of the crisis. The scarce information that is available in the aftermath of a disaster may be valuable in helping predict where are the populations that are in most need. The objectives of this study were to derive algorithms to predict posttraumatic stress (PTS) symptom prevalence and local distribution after an earthquake and to test whether there are algorithms that require few input data and are still reasonably predictive. A rich database of PTS symptoms, informed after Chile's 2010 earthquake and tsunami, was used. Several model specifications for the mean and centiles of the distribution of PTS symptoms, together with posttraumatic stress disorder (PTSD) prevalence, were estimated via linear and quantile regressions. The models varied in the set of covariates included. Adjusted R2 for the most liberal specifications (in terms of numbers of covariates included) ranged from 0.62 to 0.74, depending on the outcome. When only including peak ground acceleration (PGA), poverty rate, and household damage in linear and quadratic form, predictive capacity was still good (adjusted R2 from 0.59 to 0.67 were obtained). Information about local poverty, household damage, and PGA can be used as an aid to predict PTS symptom prevalence and local distribution after an earthquake. This can be of help to improve the assignment of mental health personnel to the affected localities. Dussaillant F , Apablaza M . Predicting posttraumatic stress symptom prevalence and local distribution after an earthquake with scarce data. Prehosp Disaster Med. 2017;32(4):357-367.

Total Quality Management in Higher Education: Applying Deming's Fourteen Points.

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Masters, Robert J.; Leiker, Linda

1992-01-01

This article presents guidelines to aid administrators of institutions of higher education in applying the 14 principles of Total Quality Management. The principles stress understanding process improvements, handling variation, fostering prediction, and using psychology to capitalize on human resources. (DB)

Evolutionary history and stress regulation of the lectin superfamily in higher plants

Directory of Open Access Journals (Sweden)

Ramachandran Srinivasan

2010-03-01

Full Text Available Abstract Background Lectins are a class of carbohydrate-binding proteins. They play roles in various biological processes. However, little is known about their evolutionary history and their functions in plant stress regulation. The availability of full genome sequences from various plant species makes it possible to perform a whole-genome exploration for further understanding their biological functions. Results Higher plant genomes encode large numbers of lectin proteins. Based on their domain structures and phylogenetic analyses, a new classification system has been proposed. In this system, 12 different families have been classified and four of them consist of recently identified plant lectin members. Further analyses show that some of lectin families exhibit species-specific expansion and rapid birth-and-death evolution. Tandem and segmental duplications have been regarded as the major mechanisms to drive lectin expansion although retrogenes also significantly contributed to the birth of new lectin genes in soybean and rice. Evidence shows that lectin genes have been involved in biotic/abiotic stress regulations and tandem/segmental duplications may be regarded as drivers for plants to adapt various environmental stresses through duplication followed by expression divergence. Each member of this gene superfamily may play specialized roles in a specific stress condition and function as a regulator of various environmental factors such as cold, drought and high salinity as well as biotic stresses. Conclusions Our studies provide a new outline of the plant lectin gene superfamily and advance the understanding of plant lectin genes in lineage-specific expansion and their functions in biotic/abiotic stress-related developmental processes.

Predicting thermally stressful events in rivers with a strategy to evaluate management alternatives

Science.gov (United States)

Maloney, K.O.; Cole, J.C.; Schmid, M.

2016-01-01

Water temperature is an important factor in river ecology. Numerous models have been developed to predict river temperature. However, many were not designed to predict thermally stressful periods. Because such events are rare, traditionally applied analyses are inappropriate. Here, we developed two logistic regression models to predict thermally stressful events in the Delaware River at the US Geological Survey gage near Lordville, New York. One model predicted the probability of an event >20.0 °C, and a second predicted an event >22.2 °C. Both models were strong (independent test data sensitivity 0.94 and 1.00, specificity 0.96 and 0.96) predicting 63 of 67 events in the >20.0 °C model and all 15 events in the >22.2 °C model. Both showed negative relationships with released volume from the upstream Cannonsville Reservoir and positive relationships with difference between air temperature and previous day's water temperature at Lordville. We further predicted how increasing release volumes from Cannonsville Reservoir affected the probabilities of correctly predicted events. For the >20.0 °C model, an increase of 0.5 to a proportionally adjusted release (that accounts for other sources) resulted in 35.9% of events in the training data falling below cutoffs; increasing this adjustment by 1.0 resulted in 81.7% falling below cutoffs. For the >22.2 °C these adjustments resulted in 71.1% and 100.0% of events falling below cutoffs. Results from these analyses can help managers make informed decisions on alternative release scenarios.

Daily stress interacts with trait dissociation to predict sleep-related experiences in young adults.

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Soffer-Dudek, Nirit; Shahar, Golan

2011-08-01

Building on the previously documented effects of stress and dissociation on sleep and dreaming, we examined their interactive role in general sleep-related experiences (GSEs; e.g., nightmares, falling dreams, hypnagogic hallucinations; see Watson, 2001). Stress, sleep quality, and GSEs were assessed daily for 14 days among young adults. Baseline assessment included life stress, sleep quality, psychopathology, dissociation, and related dimensions. Multilevel analyses indicated that daily stress brings about GSEs among highly dissociative young adults. Additionally, baseline trait dissociation predicted within-subject elevation in GSEs when daily stress was high. Flawed sleep-wake transitions, previously linked to dissociation and sleep-related experiences, might account for this effect. © 2011 American Psychological Association

Dexamethasone-suppressed cortisol awakening response predicts treatment outcome in posttraumatic stress disorder

NARCIS (Netherlands)

Nijdam, M. J.; van Amsterdam, J. G. C.; Gersons, B. P. R.; Olff, M.

2015-01-01

Posttraumatic stress disorder (PTSD) has been associated with several alterations in the neuroendocrine system, including enhanced cortisol suppression in response to the dexamethasone suppression test. The aim of this study was to examine whether specific biomarkers of PTSD predict treatment

Machine learning methods to predict child posttraumatic stress: a proof of concept study.

Science.gov (United States)

Saxe, Glenn N; Ma, Sisi; Ren, Jiwen; Aliferis, Constantin

2017-07-10

The care of traumatized children would benefit significantly from accurate predictive models for Posttraumatic Stress Disorder (PTSD), using information available around the time of trauma. Machine Learning (ML) computational methods have yielded strong results in recent applications across many diseases and data types, yet they have not been previously applied to childhood PTSD. Since these methods have not been applied to this complex and debilitating disorder, there is a great deal that remains to be learned about their application. The first step is to prove the concept: Can ML methods - as applied in other fields - produce predictive classification models for childhood PTSD? Additionally, we seek to determine if specific variables can be identified - from the aforementioned predictive classification models - with putative causal relations to PTSD. ML predictive classification methods - with causal discovery feature selection - were applied to a data set of 163 children hospitalized with an injury and PTSD was determined three months after hospital discharge. At the time of hospitalization, 105 risk factor variables were collected spanning a range of biopsychosocial domains. Seven percent of subjects had a high level of PTSD symptoms. A predictive classification model was discovered with significant predictive accuracy. A predictive model constructed based on subsets of potentially causally relevant features achieves similar predictivity compared to the best predictive model constructed with all variables. Causal Discovery feature selection methods identified 58 variables of which 10 were identified as most stable. In this first proof-of-concept application of ML methods to predict childhood Posttraumatic Stress we were able to determine both predictive classification models for childhood PTSD and identify several causal variables. This set of techniques has great potential for enhancing the methodological toolkit in the field and future studies should seek to

Cement stress predictions after anatomic total shoulder arthroplasty are correlated with preoperative glenoid bone quality.

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Terrier, Alexandre; Obrist, Raphaël; Becce, Fabio; Farron, Alain

2017-09-01

We hypothesized that biomechanical parameters typically associated with glenoid implant failure after anatomic total shoulder arthroplasty (aTSA) would be correlated with preoperative glenoid bone quality. We developed an objective automated method to quantify preoperative glenoid bone quality in different volumes of interest (VOIs): cortical bone, subchondral cortical plate, subchondral bone after reaming, subchondral trabecular bone, and successive layers of trabecular bone. Average computed tomography (CT) numbers (in Hounsfield units [HU]) were measured in each VOI from preoperative CT scans. In parallel, we built patient-specific finite element models of simulated aTSAs to predict cement stress, bone-cement interfacial stress, and bone strain around the glenoid implant. CT measurements and finite element predictions were obtained for 20 patients undergoing aTSA for primary glenohumeral osteoarthritis. We tested all linear correlations between preoperative patient characteristics (age, sex, height, weight, glenoid bone quality) and biomechanical predictions (cement stress, bone-cement interfacial stress, bone strain). Average CT numbers gradually decreased from cortical (717 HU) to subchondral and trabecular (362 HU) bone. Peak cement stress (4-10 MPa) was located within the keel hole, above the keel, or behind the glenoid implant backside. Cement stress, bone-cement interfacial stress, and bone strain were strongly negatively correlated with preoperative glenoid bone quality, particularly in VOIs behind the implant backside (subchondral trabecular bone) but also in deeper trabecular VOIs. Our numerical study suggests that preoperative glenoid bone quality is an important parameter to consider in aTSA, which may be associated with aseptic loosening of the glenoid implant. These initial results should now be confronted with clinical and radiologic outcomes. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc

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.

Longitudinal Associations Among Pain, Posttraumatic Stress Disorder Symptoms, and Stress Appraisals.

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Vaughan, Christine A; Miles, Jeremy N V; Eisenman, David P; Meredith, Lisa S

2016-04-01

Comorbidity of posttraumatic stress disorder (PTSD) and pain is well documented, but the mechanisms underlying their comorbidity are not well understood. Cross-lagged regression models were estimated with 3 waves of longitudinal data to examine the reciprocal associations between PTSD symptom severity, as measured by the Clinician-Administered PTSD Scale (CAPS), and pain, as measured by a brief self-report measure of pain called the PEG (pain intensity [P], interference with enjoyment of life [E], and interference with general activity [G]). We evaluated stress appraisals as a mediator of these associations in a sample of low-income, underserved patients with PTSD (N = 355) at federally qualified health centers in a northeastern metropolitan area. Increases in PTSD symptom severity between baseline and 6-month and 6- and 12-month assessments were independently predicted by higher levels of pain (β = .14 for both lags) and appraisals of life stress as uncontrollable (β = .15 for both lags). Stress appraisals, however, did not mediate these associations, and PTSD symptom severity did not predict change in pain. Thus, the results did not support the role of stress appraisals as a mechanism underlying the associations between pain and PTSD. Copyright © 2016 International Society for Traumatic Stress Studies.

A Study of Structural Stress Technique for Fracture Prediction of an Auto-Mobile Clutch Snap-Ring

International Nuclear Information System (INIS)

Kim, Ju Hee; Myeong, Man Sik; Oh, Chang Sik; Kim, Yun Jae

2016-01-01

The endurance reliability assessment of a highly complex mechanism is generally predicted by the fatigue life based on simple stress analysis. This study discusses various fatigue life assessment techniques for an automobile clutch snap ring. Finite element analyses were conducted to determine the structural stress on the snap ring. Structural stress that is insensitive in regards to the mesh size and type definition is presented in this study. The structural stress definition is consistent with elementary structural mechanics theory and provides an effective measure of a stress state that pertains to fatigue behavior of welded joints in the form of both membrane and bending components. Numerical procedures for both solid models and shell or plate element models are presented to demonstrate the mesh-size insensitivity when extracting the structural stress parameters. Conventional finite element models can be used with the structural stress calculations as a post-processing procedure. The two major implications from this research were: (a) structural stresses pertaining to fatigue behavior can be consistently calculated in a mesh-insensitive manner regardless of the types of finite element models; and (b) by comparing with the clutch snap-ring fatigue test data, we should predict the fatigue fractures of an automobile clutch snap ring using this method

Investigation of an alternative generic model for predicting pharmacokinetic changes during physiological stress.

Science.gov (United States)

Peng, Henry T; Edginton, Andrea N; Cheung, Bob

2013-10-01

Physiologically based pharmacokinetic models were developed using MATLAB Simulink® and PK-Sim®. We compared the capability and usefulness of these two models by simulating pharmacokinetic changes of midazolam under exercise and heat stress to verify the usefulness of MATLAB Simulink® as a generic PBPK modeling software. Although both models show good agreement with experimental data obtained under resting condition, their predictions of pharmacokinetics changes are less accurate in the stressful conditions. However, MATLAB Simulink® may be more flexible to include physiologically based processes such as oral absorption and simulate various stress parameters such as stress intensity, duration and timing of drug administration to improve model performance. Further work will be conducted to modify algorithms in our generic model developed using MATLAB Simulink® and to investigate pharmacokinetics under other physiological stress such as trauma. © The Author(s) 2013.

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.

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

Models for prediction of soil precompression stress from readily available soil properties

DEFF Research Database (Denmark)

Schjønning, Per; Lamandé, Mathieu

2018-01-01

matric potentials. σpc was estimated from the original stress-strain curves by a novel, numerical method for estimating the stress at maximum curvature, assumingly partitioning the curve into elastic and plastic sections. Multiple regression was used to identify the drivers best describing the variation......Compaction of the subsoil is an almost irreversible damage to the soil resource. Modern machinery exerts high mechanical stresses to the subsoil, and a range of studies report significant effects on soil functions. There is an urgent need for quantitative knowledge of soil strength in order...... to evaluate sustainability of current field traffic. The aim of this study was to identify the most important drivers of soil precompression stress, σpc, and to develop pedotransfer functions for prediction of σpc. We revisited previously published data on σpc for a silty clay loam soil at a range of soil...

Prediction of vertical expansion pressure stresses in coke oven heating walls

Energy Technology Data Exchange (ETDEWEB)

Duerselen, H; Janicka, J

1987-08-01

The paper describes an accurate method developed by Krupp Koppers for calculating stresses in the central areas of coke oven heating walls. The results of this calculation model have provided the following conclusions for the design of coke ovens: 1) a rising pre-stressing of the heating walls caused by the weight of the top deck of the coke oven leads - compared with the stress limits of W. Ahlers - to lower permissible expansion pressures. 2) A given heating wall width has its corresponding maximum feasible oven height. Heating wall width and top deck weight are not interchangeable parameters. 3) The dependence of the permissible expansion pressure on the stretcher brick thickness should not be overlooked. Stretcher brick thicknesses of under 90 mm are not recomended for tall ovens and heavily swelling coal. 4) The capacity of mortar to absorb tensile stresses is ultimately an undesirable property, because the stresses at the points where the mortar is not holding are higher than in a straightforward stretch of brickwork.

Prediction of single versus multivessel disease following myocardial infarction using 201-thallium scintigraphy and electrocardiographic stress testing

International Nuclear Information System (INIS)

Weiss, R.J.; Morise, A.P.; Raabe, D.S. Jr.; Sbarbaro, J.A.

1983-01-01

Fifty patients were evaluated who suffered a single myocardial infarction with graded electrocardiographic stress testing, 201-thallium myocardial perfusion imaging and coronary angiography to assess the role of noninvasive indices as predictors of single versus multivessel coronary artery disease. Multivessel involvement was defined angiographically as the presence of two or more major coronary arteries with at least a 70% intraluminal diameter narrowing. Multivessel disease was defined scintigraphically as the presence of stress and/or redistribution perfusion defects in the distribution of more than one coronary artery. The results of stress electrocardiography were not useful in differentiating patients with single (9/16 positive) versus multivessel (22/34 positive) disease. The degree of exercise-induced ST-segment depression was also not helpful. Stress 201-thallium imaging did offer limited additional information with correct predictions of multivessel disease in 21 of 26 patients. Predictions of single-vessel disease were accurate in 11 of 24 patients. Eleven of these 13 incorrect predictions of single-vessel disease were due to the relative insensitivity of the thallium stress image to perceive defect in the anterior wall when the left anterior descending artery had significant obstruction at catheterization. Further refinements of stress perfusion imaging are needed before this method can be used to reliably separate patients with single and multivessel disease after myocardial infarction

Higher-order predictions for splitting functions and coefficient functions from physical evolution kernels

International Nuclear Information System (INIS)

Vogt, A; Soar, G.; Vermaseren, J.A.M.

2010-01-01

We have studied the physical evolution kernels for nine non-singlet observables in deep-inelastic scattering (DIS), semi-inclusive e + e - annihilation and the Drell-Yan (DY) process, and for the flavour-singlet case of the photon- and heavy-top Higgs-exchange structure functions (F 2 , F φ ) in DIS. All known contributions to these kernels show an only single-logarithmic large-x enhancement at all powers of (1-x). Conjecturing that this behaviour persists to (all) higher orders, we have predicted the highest three (DY: two) double logarithms of the higher-order non-singlet coefficient functions and of the four-loop singlet splitting functions. The coefficient-function predictions can be written as exponentiations of 1/N-suppressed contributions in Mellin-N space which, however, are less predictive than the well-known exponentiation of the ln k N terms. (orig.)

Prediction of strongly-heated gas flows in a vertical tube using explicit algebraic stress/heat-flux models

International Nuclear Information System (INIS)

Baek, Seong Gu; Park, Seung O.

2003-01-01

This paper provides the assessment of prediction performance of explicit algebraic stress and heat-flux models under conditions of mixed convective gas flows in a strongly-heated vertical tube. Two explicit algebraic stress models and four algebraic heat-flux models are selected for assessment. Eight combinations of explicit algebraic stress and heat-flux models are used in predicting the flows experimentally studied by Shehata and McEligot (IJHMT 41(1998) p.4333) in which property variation was significant. Among the various model combinations, the Wallin and Johansson (JFM 403(2000) p. 89) explicit algebraic stress model-Abe, Kondo, and Nagano (IJHFF 17(1996) p. 228) algebraic heat-flux model combination is found to perform best. We also found that the dimensionless wall distance y + should be calculated based on the local property rather than the property at the wall for property-variation flows. When the buoyancy or the property variation effects are so strong that the flow may relaminarize, the choice of the basic platform two-equation model is a most important factor in improving the predictions

Predicting Binge Drinking in College Students: Rational Beliefs, Stress, or Loneliness?

Science.gov (United States)

Chen, Yixin; Feeley, Thomas Hugh

2015-01-01

We proposed a conceptual model to predict binge-drinking behavior among college students, based on the theory of planned behavior and the stress-coping hypothesis. A two-wave online survey was conducted with predictors and drinking behavior measured separately over 2 weeks' time. In the Wave 1 survey, 279 students at a public university in the…

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

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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.

vmPFC activation during a stressor predicts positive emotions during stress recovery

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Yang, Xi; Garcia, Katelyn M; Jung, Youngkyoo; Whitlow, Christopher T; McRae, Kateri; Waugh, Christian E

2018-01-01

Abstract Despite accruing evidence showing that positive emotions facilitate stress recovery, the neural basis for this effect remains unclear. To identify the underlying mechanism, we compared stress recovery for people reflecting on a stressor while in a positive emotional context with that for people in a neutral context. While blood–oxygen-level dependent data were being collected, participants (N = 43) performed a stressful anagram task, which was followed by a recovery period during which they reflected on the stressor while watching a positive or neutral video. Participants also reported positive and negative emotions throughout the task as well as retrospective thoughts about the task. Although there was no effect of experimental context on emotional recovery, we found that ventromedial prefrontal cortex (vmPFC) activation during the stressor predicted more positive emotions during recovery, which in turn predicted less negative emotions during recovery. In addition, the relationship between vmPFC activation and positive emotions during recovery was mediated by decentering—the meta-cognitive detachment of oneself from one’s feelings. In sum, successful recovery from a stressor seems to be due to activation of positive emotion-related regions during the stressor itself as well as to their downstream effects on certain cognitive forms of emotion regulation. PMID:29462404

Fatigue Life Prediction of High Modulus Asphalt Concrete Based on the Local Stress-Strain Method

Directory of Open Access Journals (Sweden)

Mulian Zheng

2017-03-01

Full Text Available Previously published studies have proposed fatigue life prediction models for dense graded asphalt pavement based on flexural fatigue test. This study focused on the fatigue life prediction of High Modulus Asphalt Concrete (HMAC pavement using the local strain-stress method and direct tension fatigue test. First, the direct tension fatigue test at various strain levels was conducted on HMAC prism samples cut from plate specimens. Afterwards, their true stress-strain loop curves were obtained and modified to develop the strain-fatigue life equation. Then the nominal strain of HMAC course determined using finite element method was converted into local strain using the Neuber method. Finally, based on the established fatigue equation and converted local strain, a method to predict the pavement fatigue crack initiation life was proposed and the fatigue life of a typical HMAC overlay pavement which runs a risk of bottom-up cracking was predicted and validated. Results show that the proposed method was able to produce satisfactory crack initiation life.

Finite Element Simulation of Shot Peening: Prediction of Residual Stresses and Surface Roughness

Science.gov (United States)

Gariépy, Alexandre; Perron, Claude; Bocher, Philippe; Lévesque, Martin

Shot peening is a surface treatment that consists of bombarding a ductile surface with numerous small and hard particles. Each impact creates localized plastic strains that permanently stretch the surface. Since the underlying material constrains this stretching, compressive residual stresses are generated near the surface. This process is commonly used in the automotive and aerospace industries to improve fatigue life. Finite element analyses can be used to predict residual stress profiles and surface roughness created by shot peening. This study investigates further the parameters and capabilities of a random impact model by evaluating the representative volume element and the calculated stress distribution. Using an isotropic-kinematic hardening constitutive law to describe the behaviour of AA2024-T351 aluminium alloy, promising results were achieved in terms of residual stresses.

Consistency between analytical and finite element predictions for safety of cylindrical pressure vessels at higher temperatures

International Nuclear Information System (INIS)

Iancu, Otto Theodor

2014-01-01

The prediction of the plastic collapse load of cylindrical pressure vessels is very often made by using expensive Finite Element computations. The calculation of the collapse load requires an elastic-plastic material model and the consideration of non-linear geometry effects. The plastic collapse load causes overall structural instability and cannot be determined directly from a Finite Element analysis. In the present paper the plastic collapse load for a cylindrical pressure vessel is determined by an analytical method based on a linear elastic perfectly plastic material model. When plasticity occurs the material is considered to be incompressible and the tensor of plastic strains to be parallel to the stress deviator tensor. In this case the finite stress-strain relationships of Henkel can be used for calculating the pressure for which plastic flow occurs. The analytical results are completely confirmed by Finite Element predictions. (orig.)

Stressful Life Events Predict Eating Disorder Relapse Following Remission: Six-Year Prospective Outcomes

Science.gov (United States)

Grilo, Carlos M.; Pagano, Maria E.; Stout, Robert L.; Markowitz, John C.; Ansell, Emily B.; Pinto, Anthony; Zanarini, Mary C.; Yen, Shirley; Skodol, Andrew E.

2012-01-01

Objective To examine prospectively the natural course of bulimia nervosa (BN) and eating disorder not-otherwise-specified (EDNOS) and test for the effects of stressful life events (SLE) on relapse after remission from these eating disorders. Method 117 female patients with BN (N = 35) or EDNOS (N = 82) were prospectively followed for 72 months using structured interviews performed at baseline, 6- and 12-months, and then yearly thereafter. ED were assessed with the structured clinical interview for DSM-IV, and monitored over time with the longitudinal interval follow-up evaluation. Personality disorders were assessed with the diagnostic interview for DSM-IV-personality-disorders, and monitored over time with the follow-along-version. The occurrence and specific timing of SLE were assessed with the life events assessment interview. Cox proportional-hazard-regression-analyses tested associations between time-varying levels of SLE and ED relapse, controlling for comorbid psychiatric disorders, ED duration, and time-varying personality-disorder status. Results ED relapse probability was 43%; BN and EDNOS did not differ in time to relapse. Negative SLE significantly predicted ED relapse; elevated work and social stressors were significant predictors. Psychiatric comorbidity, ED duration, and time-varying personality-disorder status were not significant predictors. Discussion Higher work and social stress represent significant warning signs for triggering relapse for women with remitted BN and EDNOS. PMID:21448971

Disrupted rapid eye movement sleep predicts poor declarative memory performance in post-traumatic stress disorder.

Science.gov (United States)

Lipinska, Malgorzata; Timol, Ridwana; Kaminer, Debra; Thomas, Kevin G F

2014-06-01

Successful memory consolidation during sleep depends on healthy slow-wave and rapid eye movement sleep, and on successful transition across sleep stages. In post-traumatic stress disorder, sleep is disrupted and memory is impaired, but relations between these two variables in the psychiatric condition remain unexplored. We examined whether disrupted sleep, and consequent disrupted memory consolidation, is a mechanism underlying declarative memory deficits in post-traumatic stress disorder. We recruited three matched groups of participants: post-traumatic stress disorder (n = 16); trauma-exposed non-post-traumatic stress disorder (n = 15); and healthy control (n = 14). They completed memory tasks before and after 8 h of sleep. We measured sleep variables using sleep-adapted electroencephalography. Post-traumatic stress disorder-diagnosed participants experienced significantly less sleep efficiency and rapid eye movement sleep percentage, and experienced more awakenings and wake percentage in the second half of the night than did participants in the other two groups. After sleep, post-traumatic stress disorder-diagnosed participants retained significantly less information on a declarative memory task than controls. Rapid eye movement percentage, wake percentage and sleep efficiency correlated with retention of information over the night. Furthermore, lower rapid eye movement percentage predicted poorer retention in post-traumatic stress disorder-diagnosed individuals. Our results suggest that declarative memory consolidation is disrupted during sleep in post-traumatic stress disorder. These data are consistent with theories suggesting that sleep benefits memory consolidation via predictable neurobiological mechanisms, and that rapid eye movement disruption is more than a symptom of post-traumatic stress disorder. © 2014 European Sleep Research Society.

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.

Stress hormones at rest and following exercise testing predict coronary artery disease severity and outcome.

Science.gov (United States)

Popovic, Dejana; Damjanovic, Svetozar; Djordjevic, Tea; Martic, Dejana; Ignjatovic, Svetlana; Milinkovic, Neda; Banovic, Marko; Lasica, Ratko; Petrovic, Milan; Guazzi, Marco; Arena, Ross

2017-09-01

Despite considerable knowledge regarding the importance of stress in coronary artery disease (CAD) pathogenesis, its underestimation persists in routine clinical practice, in part attributable to lack of a standardized, objective assessment. The current study examined the ability of stress hormones to predict CAD severity and prognosis at basal conditions as well as during and following an exertional stimulus. Forty Caucasian subjects with significant coronary artery lesions (≥50%) were included. Within 2 months of coronary angiography, cardiopulmonary exercise testing (CPET) on a recumbent ergometer was performed in conjunction with stress echocardiography (SE). At rest, peak and after 3 min of recovery following CPET, plasma levels of cortisol, adrenocorticotropic hormone (ACTH) and NT-pro-brain natriuretic peptide (NT-pro-BNP) were measured by immunoassay sandwich technique, radioimmunoassay, and radioimmunometric technique, respectively. Subjects were subsequently followed a mean of 32 ± 10 months. Mean ejection fraction was 56.7 ± 9.6%. Subjects with 1-2 stenotic coronary arteries (SCA) demonstrated a significantly lower plasma cortisol levels during CPET compared to those with 3-SCA (p  .05). Among CPET, SE, and hormonal parameters, cortisol at rest and during CPET recovery demonstrated the best predictive value in distinguishing between 1-, 2-, and 3-SCA [area under ROC curve 0.75 and 0.77 (SE = 0.11, 0.10; p = .043, .04) for rest and recovery, respectively]. ΔCortisol peak/rest predicted cumulative cardiac events (area under ROC curve 0.75, SE = 0.10, p = .049). Cortisol at rest and following an exercise test holds predictive value for CAD severity and prognosis, further demonstrating a link between stress and unwanted cardiac events.

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

Science.gov (United States)

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.

Childhood maltreatment and combat posttraumatic stress differentially predict fear-related fronto-subcortical connectivity.

Science.gov (United States)

Birn, Rasmus M; Patriat, Rémi; Phillips, Mary L; Germain, Anne; Herringa, Ryan J

2014-10-01

Adult posttraumatic stress disorder (PTSD) has been characterized by altered fear-network connectivity. Childhood trauma is a major risk factor for adult PTSD, yet its contribution to fear-network connectivity in PTSD remains unexplored. We examined, within a single model, the contribution of childhood maltreatment, combat exposure, and combat-related posttraumatic stress symptoms (PTSS) to resting-state connectivity (rs-FC) of the amygdala and hippocampus in military veterans. Medication-free male veterans (n = 27, average 26.6 years) with a range of PTSS completed resting-state fMRI. Measures including the Clinician-Administered PTSD Scale (CAPS), Childhood Trauma Questionnaire (CTQ), and Combat Exposure Scale (CES) were used to predict rs-FC using multilinear regression. Fear-network seeds included the amygdala and hippocampus. Amygdala: CTQ predicted lower connectivity to ventromedial prefrontal cortex (vmPFC), but greater anticorrelation with dorsal/lateral PFC. CAPS positively predicted connectivity to insula, and loss of anticorrelation with dorsomedial/dorsolateral (dm/dl)PFC. Hippocampus: CTQ predicted lower connectivity to vmPFC, but greater anticorrelation with dm/dlPFC. CES predicted greater anticorrelation, whereas CAPS predicted less anticorrelation with dmPFC. Childhood trauma, combat exposure, and PTSS differentially predict fear-network rs-FC. Childhood maltreatment may weaken ventral prefrontal-subcortical circuitry important in automatic fear regulation, but, in a compensatory manner, may also strengthen dorsal prefrontal-subcortical pathways involved in more effortful emotion regulation. PTSD symptoms, in turn, appear to emerge with the loss of connectivity in the latter pathway. These findings suggest potential mechanisms by which developmental trauma exposure leads to adult PTSD, and which brain mechanisms are associated with the emergence of PTSD symptoms. © 2014 Wiley Periodicals, Inc.

What employers may learn from English higher education institutions: A fortigenic approach to occupational stress

Directory of Open Access Journals (Sweden)

M. Y. Tytherleigh

2003-10-01

Full Text Available Whilst there is no denying that levels of occupational stress in staff working in universities and colleges are increasing, academic staff, in particular, continue to maintain a level of satisfaction from their jobs. A stratified random sample of staff working in 14 higher education institutions in England was used. The results showed that, whilst commitment was lower and levels of occupational stress were significantly higher with regard to work relationships, control and resources and communication, compared to the normative data, staff reported significantly lower levels of stress relating to work-life balance, overload, and job dissatisfaction. Compared to normative data, participants reported significantly lower levels of physical ill-health and psychological outcomes of stress. The results support previous findings identifying a protective effect of job satisfaction against the negative consequences of workplace stress. Opsomming Terwyl dit nie ontken word dat die vlak van werkstres van personeel wat in universiteite en kolleges werk, verhoog nie, ervaar akademiese personeel steeds tevredenheid met hul werk. ’n Gestratifiseerde ewekansige steekproef van personeel wat by 14 hoër opvoedkundige instellings in Engeland werk, is geneem. Die resultate het aangetoon dat hoewel verbondenheid laer en werkstres beduidend hoër was ten opsigte van werksverhoudinge, kontrole en bronne en kommunikasie vergeleke met normatiewe data, personeel beduidend laer vlakke van stres ten opsigte van werklewe balans, oorlading en werkstevredenheid getoon het. Deelnemers het ook beduidend laer vlakke van fisieke ongesondheid en psigologiese uitkomstes van stres gerapporteer. Die resultate ondersteun vorige bevindings wat ’n beskermende effek van werkstevredenheid teen die negatiewe uitkomstes van stres identifiseer.

Finite element analysis for prediction of the residual stresses induced by shot peening II

International Nuclear Information System (INIS)

Kim, Cheol; Seok, Chang Sung; Yang, Won Ho; Ryu, Myung Hai

2002-01-01

Shot peening is a surface impact treatment widely used to improve the performance of metal parts and welded details subjected to fatigue loading, contact fatigue, stress corrosion and other damage mechanisms. The better performance of the peened parts is mainly due to the residual stresses resulting from the plastic deformation of the surface layers of the material caused by the impact of the shot. In this paper the simulation technique is applied to predict the magnitude and distribution of the residual stress and plastic deformation caused by shot peening with the help of finite element analysis

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

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

2003-12-01

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

Prediction of tensile curves, at 673 K, of cold-worked and stress-relieved zircaloy-4 from creep data

International Nuclear Information System (INIS)

Povolo, F.; Buenos Aires Univ. Nacional; Marzocca, A.J.

1986-01-01

A constitutive creep equation, based on jog-drag cell-formation, is used to predict tensile curves from creep data obtained in the same material. The predicted tensile curve are compared with actual stress versus plastic strain data, obtained both in cold-work and stress-relieved specimens. Finally, it is shown that the general features of the tensile curves, at low strain rates, are described by the creep model. (orig.)

Prediction of residual stresses in electron beam welded Ti-6Al-4V plates

Energy Technology Data Exchange (ETDEWEB)

Xu, Lianyong; Ge, Keke; Jing, Hongyang; Zhao, Lei; Lv, Xiaoqing [Tianjin Univ. (China); Han, Yongdian [Tianjin Univ. (China). Key Lab. of Advanced Joining Technology

2017-05-01

A thermo-metallurgical procedure based on the SYSWELD code was developed to predict welding temperature field, microstructure and residual stress in butt-welded Ti-6Al-4V plate taking into account phase transformation. The formation of martensite was confirmed by the CCT diagram and microstructure in the weld joint, which significantly affects the magnitude of residual stress. The hole drilling procedure was utilized to measure the values of residual stress at the top surface of the specimen, which are in well agreement with the numerical results. Both simulated and test results show that the magnitude and distribution of residual stress on the surface of the plate present a large gradient feature from the weld joint to the base metal. Moreover, the distribution law of residual stresses in the plate thickness was further analyzed for better understanding of its generation and evolution.

Predicting the change of child’s behavior problems: sociodemographic and maternal parenting stress factors

OpenAIRE

Viduolienė, Evelina

2013-01-01

Purpose: evaluate 1) whether child’s externalizing problems increase or decrease within 12 months period; 2) the change of externalizing problems with respect to child gender and age, and 3) which maternal parenting stress factors and family sociodemographic characteristics can predict the increase and decrease of child’s externalizing problems. Design/methodology/approach: participants were evaluated 2 times (with the interval of 12 months) with the Parenting Stress Index (Abidin, 1990) and ...

Predicting maternal parenting stress in middle childhood: the roles of child intellectual status, behaviour problems and social skills.

Science.gov (United States)

Neece, C; Baker, B

2008-12-01

Parents of children with intellectual disabilities (ID) typically report elevated levels of parenting stress, and child behaviour problems are a strong predictor of heightened parenting stress. Interestingly, few studies have examined child characteristics beyond behaviour problems that may also contribute to parenting stress. The present longitudinal study examined the contribution of child social skills to maternal parenting stress across middle childhood, as well as the direction of the relationship between child social skills and parenting stress. Families of children with ID (n = 74) or typical development (TD) (n = 115) participated over a 2-year period. Maternal parenting stress, child behaviour problems and child social skills were assessed at child ages six and eight. Child social skills accounted for unique variance in maternal parenting stress above and beyond child intellectual status and child behaviour problems. As the children matured, there was a significant interaction between child social skills and behaviour problems in predicting parenting stress. With respect to the direction of these effects, a cross-lagged panel analysis indicated that early parenting stress contributed to later social skills difficulties for children, but the path from children's early social skills to later parenting stress was not supported, once child behaviour problems and intellectual status were accounted for. When examining parenting stress, child social skills are an important variable to consider, especially in the context of child behaviour problems. Early parenting stress predicted child social skills difficulties over time, highlighting parenting stress as a key target for intervention.

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.

A model to predict multivessel coronary artery disease from the exercise thallium-201 stress test

International Nuclear Information System (INIS)

Pollock, S.G.; Abbott, R.D.; Boucher, C.A.; Watson, D.D.; Kaul, S.

1991-01-01

The aim of this study was to (1) determine whether nonimaging variables add to the diagnostic information available from exercise thallium-201 images for the detection of multivessel coronary artery disease; and (2) to develop a model based on the exercise thallium-201 stress test to predict the presence of multivessel disease. The study populations included 383 patients referred to the University of Virginia and 325 patients referred to the Massachusetts General Hospital for evaluation of chest pain. All patients underwent both cardiac catheterization and exercise thallium-201 stress testing between 1978 and 1981. In the University of Virginia cohort, at each level of thallium-201 abnormality (no defects, one defect, more than one defect), ST depression and patient age added significantly in the detection of multivessel disease. Logistic regression analysis using data from these patients identified three independent predictors of multivessel disease: initial thallium-201 defects, ST depression, and age. A model was developed to predict multivessel disease based on these variables. As might be expected, the risk of multivessel disease predicted by the model was similar to that actually observed in the University of Virginia population. More importantly, however, the model was accurate in predicting the occurrence of multivessel disease in the unrelated population studied at the Massachusetts General Hospital. It is, therefore, concluded that (1) nonimaging variables (age and exercise-induced ST depression) add independent information to thallium-201 imaging data in the detection of multivessel disease; and (2) a model has been developed based on the exercise thallium-201 stress test that can accurately predict the probability of multivessel disease in other populations

Early Prediction of Student Dropout and Performance in MOOCSs Using Higher Granularity Temporal Information

Science.gov (United States)

Ye, Cheng; Biswas, Gautam

2014-01-01

Our project is motivated by the early dropout and low completion rate problem in MOOCs. We have extended traditional features for MOOC analysis with richer and higher granularity information to make more accurate predictions of dropout and performance. The results show that finer-grained temporal information increases the predictive power in the…

Stress sensitivity interacts with depression history to predict depressive symptoms among youth: prospective changes following first depression onset.

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Technow, Jessica R; Hazel, Nicholas A; Abela, John R Z; Hankin, Benjamin L

2015-04-01

Predictors of depressive symptoms may differ before and after the first onset of major depression due to stress sensitization. Dependent stressors, or those to which characteristics of individuals contribute, have been shown to predict depressive symptoms in youth. The current study sought to clarify how stressors' roles may differ before and after the first depressive episode. Adolescents (N = 382, aged 11 to 15 at baseline) were assessed at baseline and every 3 months over the course of 2 years with measures of stressors and depressive symptoms. Semi-structured interviews were conducted every 6 months to assess for clinically significant depressive episodes. Hierarchical linear modeling showed a significant interaction between history of depression and idiographic fluctuations in dependent stressors to predict prospective elevations of symptoms, such that dependent stressors were more predictive of depressive symptoms after onset of disorder. Independent stressors predicted symptoms, but the strength of the association did not vary by depression history. These results suggest a synthesis of dependent stress and stress sensitization processes that might maintain inter-episode depressive symptoms among youth with a history of clinical depression.

The role of early adversity and recent life stress in depression severity in an outpatient sample.

Science.gov (United States)

Vogt, Dominic; Waeldin, Sandra; Hellhammer, Dirk; Meinlschmidt, Gunther

2016-12-01

Pre-, peri-, and postnatal stress have frequently been reported to be associated with negative health outcomes during adult life. However, it is unclear, if these factors independently predict mental health in adulthood. We estimated potential associations between reports of pre-, peri-, and postnatal stress and depression severity in outpatients (N = 473) diagnosed with depression, anxiety or somatoform disorders by their family physician. We retrospectively assessed pre-, peri-, and postnatal stress and measured depression severity as well as recent life stress using questionnaires. First, we estimated if depression severity was predicted by pre-, peri- and/or postnatal stress using multiple regression models. Second, we compared pre- and postnatal stress levels between patient subgroups of different degrees of depression severity, performing multilevel linear modeling. Third, we analyzed if an association between postnatal stress and current depression severity was mediated by recent life stress. We found no associations of pre-, or perinatal stress with depression severity (all p > 0.05). Higher postnatal stress was associated with higher depression severity (p stress as compared to patients with none to minimal, or mild depression (all p life stress of the association between postnatal stress and depression severity (p stress predicted depression severity in adult life. This association was mediated by recent life stress. Copyright © 2016 Elsevier Ltd. All rights reserved.

Trauma, stress, and self-care in clinical training: Predictors of burnout, decline in health status, secondary traumatic stress symptoms, and compassion satisfaction.

Science.gov (United States)

Butler, Lisa D; Carello, Janice; Maguin, Eugene

2017-07-01

[Correction Notice: An Erratum for this article was reported in Vol 9(4) of Psychological Trauma: Theory, Research, Practice, and Policy (see record 2016-54155-001). In the article, there was an error in Table 4 of the Results. The Outcomes and Predictors columns were not clearly categorized from one another. The corrected table is present in the erratum.] Objective: Courtois and Gold (2009) have called for the inclusion of trauma in the curriculum for all mental health training programs. The present study investigated the impact of trauma-related content, stress, and self-care (SC) on trainees in such a program. Method: The study examined potential risk factors (trauma exposures in training [being faced with or reacting to trauma-related field work experiences and course content] and perceptions of stress in field and coursework) and protective factors (SC effort and importance) in relation to burnout (BO), health status (HS), secondary traumatic stress symptoms (STSS), and compassion satisfaction (CS) among 195 students in a graduate social work training program. Results: All students reported trauma exposures in their field placements and/or coursework, including retraumatization experiences that were associated with higher STSS and BO. Field stress and SC effort were both consistent predictors across outcomes. Higher field stress levels predicted higher BO and STSS, a greater likelihood of decline in HS, and lower CS. Lower SC effort was also associated with higher BO and STSS, and a greater likelihood of decline in HS, while higher SC effort predicted higher CS. Older students, those with traumatized field clients, and those whose field work addressed trauma, also reported higher CS. Conclusions: These findings suggest that clinical training involving trauma content can be both rewarding and stressful, and may evoke distress in some trainees. Given that learning about and working with trauma are essential to adequate clinical training, the authors suggest

Leveraging knowledge from physiological data: on-body heat stress risk prediction with sensor networks.

Science.gov (United States)

Gaura, Elena; Kemp, John; Brusey, James

2013-12-01

The paper demonstrates that wearable sensor systems, coupled with real-time on-body processing and actuation, can enhance safety for wearers of heavy protective equipment who are subjected to harsh thermal environments by reducing risk of Uncompensable Heat Stress (UHS). The work focuses on Explosive Ordnance Disposal operatives and shows that predictions of UHS risk can be performed in real-time with sufficient accuracy for real-world use. Furthermore, it is shown that the required sensory input for such algorithms can be obtained with wearable, non-intrusive sensors. Two algorithms, one based on Bayesian nets and another on decision trees, are presented for determining the heat stress risk, considering the mean skin temperature prediction as a proxy. The algorithms are trained on empirical data and have accuracies of 92.1±2.9% and 94.4±2.1%, respectively when tested using leave-one-subject-out cross-validation. In applications such as Explosive Ordnance Disposal operative monitoring, such prediction algorithms can enable autonomous actuation of cooling systems and haptic alerts to minimize casualties.

Predicting violence in veterans with posttraumatic stress disorder

Directory of Open Access Journals (Sweden)

Jovanović Aleksandar A.

2009-01-01

Full Text Available Background/Aim. Frequent expression of negative affects, hostility and violent behavior in individuals suffering from posttraumatic stress disorder (PTSD were recognized long ago, and have been retrospectively well documented in war veterans with PTSD who were shown to have an elevated risk for violent behavior when compared to both veterans without PTSD and other psychiatric patients. The aim of this study was to evaluate the accuracy of clinical prediction of violence in combat veterans suffering from PTSD. Methods. The subjects of this study, 104 male combat veterans with PTSD were assessed with the Historical, Clinical and Risk Management 20 (HCR-20, a 20-item clinicianrated instrument for assessing the risks for violence, and their acts of violence during one-year follow-up period were registered based on bimonthly check-up interviews. Results. Our findings showed that the HCR-20, as an actuarial measure, had good internal consistency reliability (α = 0.82, excellent interrater reliability (Interaclass Correlation ICC = 0.85, as well as excellent predictive validity for acts of any violence, non-physical violence or physical violence in the follow-up period (AUC = 0.82-0.86. The HCR-20 also had good interrater reliability (Cohen's kappa = 0.74, and acceptable predictive accuracy for each outcome criterion (AUC = 0.73-0.79. Conclusion. The results of this research confirm that the HCR-20 may also be applied in prediction of violent behavior in the population of patients suffering from PTSD with reliability and validity comparable with the results of previous studies where this instrument was administered to other populations of psychiatric patients.

Personality, psychological stress, and self-reported influenza symptomatology

Directory of Open Access Journals (Sweden)

Croon Marcel A

2007-11-01

Full Text Available Abstract Background Psychological stress and negative mood have been related to increased vulnerability to influenza-like illness (ILI. This prospective study re-evaluated the predictive value of perceived stress for self-reported ILI. We additionally explored the role of the negative affectivity and social inhibition traits. Methods In this study, 5,404 respondents from the general population were assessed in terms of perceived stress, personality, and control variables (vaccination, vitamin use, exercise, etc.. ILI were registered weekly using self-report measures during a follow-up period of four weeks. Results Multivariable logistic regression analysis on ILI was performed to test the predictive power of stress and personality. In this model, negative affectivity (OR = 1.05, p = 0.009, social inhibition (OR = 0.97, p = 0.011, and perceived stress (OR = 1.03, p = 0.048 predicted ILI reporting. Having a history of asthma (OR = 2.33, p = Conclusion Elderly and socially inhibited persons tend to report less ILI as compared to their younger and less socially inhibited counterparts. In contrast, asthma, trait negative affectivity, and perceived stress were associated with higher self-report of ILI. Our results demonstrate the importance of including trait markers in future studies examining the relation between stress and self-report symptom measures.

Predictive role of stress echocardiography before carotid endarterectomy in patients with coronary artery disease.

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Galyfos, George; Tsioufis, Constantinos; Theodorou, Dimitris; Katsaragakis, Stilianos; Zografos, Georgios; Filis, Konstantinos

2015-07-01

Our aim was to examine the predictive value of preoperative stress echocardiography regarding early myocardial ischemia and late cardiac events after carotid endarterectomy (CEA). Patients with coronary artery disease undergoing CEA were prospectively included in this study. All patients (n = 162) were classified into low, medium, and high cardiac risk group, according to preoperative stress echocardiography. Classification was based on the criteria of the American Society of Echocardiography. For all patients, cTnI was measured before surgery and on postoperative days 1, 3, and 7. Postoperative cTnI values ranging from 0.05 to 0.5 ng/mL were classified as myocardial ischemia; values >0.5 ng/mL were classified as myocardial infarction. Cardiac damage was defined as either myocardial ischemia or infarction. No deaths, strokes, or symptomatic coronary events were observed during the early postoperative period. There were 112 low cardiac risk patients, 42 medium-risk patients, and 8 high-risk patients, according to stress echocardiography findings. Overall, there were 22 patients (14%) that increased their cTnI values postoperatively (12 of low cardiac risk and 10 of medium cardiac risk), and all of them were asymptomatic. None of the high-risk patients showed any troponin increase. Late cardiac events were associated with cTnI increase, although no high-risk patients showed any late event. Preoperative stress echocardiography does not seem to independently recognize patients in high risk for asymptomatic cardiac damage after CEA. Postoperative troponin elevation seems to be more predictive for late adverse cardiac events than preoperative stress echocardiography. © 2014, Wiley Periodicals, Inc.

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.

Measuring stress in medical education: validation of the Korean version of the higher education stress inventory with medical students

OpenAIRE

Eun-Jung Shim; Hong Jin Jeon; Hana Kim; Kwang-Min Lee; Dooyoung Jung; Hae-Lim Noh; Myoung-Sun Roh; Bong-Jin Hahm

2016-01-01

Abstract Background Medical students face a variety of stressors associated with their education; if not promptly identified and adequately dealt with, it may bring about several negative consequences in terms of mental health and academic performance. This study examined psychometric properties of the Korean version of the Higher Education Stress Inventory (K-HESI). Methods The reliability and validity of the K-HESI were examined in a large scale multi-site survey involving 7110 medical stud...

Teacher Role Stress, Higher Order Needs and Work Outcomes.

Science.gov (United States)

Conley, Sharon; Woosley, Sherry A.

2000-01-01

Using a sample of 371 elementary and secondary teachers, this study examined whether three role stresses (role ambiguity, conflict, and overload) are related to two individually and organizationally related values and how teachers moderated stresses. Organizational commitment is affected by role stress. Teaming might increase role ambiguity.…

Factors Influencing the Organizational Stress among Teachers Working in Higher Education Sector in Kerala: An Empirical Analysis

Science.gov (United States)

Areekkuzhiyil, Santhosh

2014-01-01

The study aims to explore the various factors that influence the organizational stress of teachers working in higher education sector in the state of Kerala. The data required for the study has been conveniently collected from 200 teachers working in higher education sector. Exploratory factor analysis revealed nine factors, which significantly…

Interface stresses in fiber-reinforced materials with regular fiber arrangements

Science.gov (United States)

Mueller, W. H.; Schmauder, S.

The theory of linear elasticity is used here to analyze the stresses inside and at the surface of fiber-reinforced composites. Plane strain, plane stress, and generalized plane strain are analyzed using the shell model and the BHE model and are numerically studied using finite element analysis. Interface stresses are shown to depend weakly on Poisson's ratio. For equal values of the ratio, generalized plane strain and plane strain results are identical. For small volume fractions up to 40 vol pct of fibers, the shell and the BHE models predict the interface stresses very well over a wide range of elastic mismatches and for different fiber arrangements. At higher volume fractions the stresses are influenced by interactions with neighboring fibers. Introducing an external pressure into the shell model allows the prediction of interface stresses in real composite with isolated or regularly arranged fibers.

An analytical model to predict and minimize the residual stress of laser cladding process

Science.gov (United States)

Tamanna, N.; Crouch, R.; Kabir, I. R.; Naher, S.

2018-02-01

Laser cladding is one of the advanced thermal techniques used to repair or modify the surface properties of high-value components such as tools, military and aerospace parts. Unfortunately, tensile residual stresses generate in the thermally treated area of this process. This work focuses on to investigate the key factors for the formation of tensile residual stress and how to minimize it in the clad when using dissimilar substrate and clad materials. To predict the tensile residual stress, a one-dimensional analytical model has been adopted. Four cladding materials (Al2O3, TiC, TiO2, ZrO2) on the H13 tool steel substrate and a range of preheating temperatures of the substrate, from 300 to 1200 K, have been investigated. Thermal strain and Young's modulus are found to be the key factors of formation of tensile residual stresses. Additionally, it is found that using a preheating temperature of the substrate immediately before laser cladding showed the reduction of residual stress.

Prediction of residual stress distributions due to surface machining and welding and crack growth simulation under residual stress distribution

International Nuclear Information System (INIS)

Ihara, Ryohei; Katsuyama, JInya; Onizawa, Kunio; Hashimoto, Tadafumi; Mikami, Yoshiki; Mochizuki, Masahito

2011-01-01

Research highlights: → Residual stress distributions due to welding and machining are evaluated by XRD and FEM. → Residual stress due to machining shows higher tensile stress than welding near the surface. → Crack growth analysis is performed using calculated residual stress. → Crack growth result is affected machining rather than welding. → Machining is an important factor for crack growth. - Abstract: In nuclear power plants, stress corrosion cracking (SCC) has been observed near the weld zone of the core shroud and primary loop recirculation (PLR) pipes made of low-carbon austenitic stainless steel Type 316L. The joining process of pipes usually includes surface machining and welding. Both processes induce residual stresses, and residual stresses are thus important factors in the occurrence and propagation of SCC. In this study, the finite element method (FEM) was used to estimate residual stress distributions generated by butt welding and surface machining. The thermoelastic-plastic analysis was performed for the welding simulation, and the thermo-mechanical coupled analysis based on the Johnson-Cook material model was performed for the surface machining simulation. In addition, a crack growth analysis based on the stress intensity factor (SIF) calculation was performed using the calculated residual stress distributions that are generated by welding and surface machining. The surface machining analysis showed that tensile residual stress due to surface machining only exists approximately 0.2 mm from the machined surface, and the surface residual stress increases with cutting speed. The crack growth analysis showed that the crack depth is affected by both surface machining and welding, and the crack length is more affected by surface machining than by welding.

Stress at work: Differential experiences of high versus low SES workers.

Science.gov (United States)

Damaske, Sarah; Zawadzki, Matthew J; Smyth, Joshua M

2016-05-01

This paper asks whether workers with higher socioeconomic status (SES) experience different levels of stress at work than workers with lower SES and, if so, what might explain these differences. We collected innovative assessments of immediate objective and subjective measures of stress at multiple time points across consecutive days from 122 employed men and women. We find that in comparison to higher SES individuals, those with lower SES reported greater happiness at work, less self-reported stress, and less perceived stress; cortisol, a biological marker of stress, was unrelated to SES. Worker's momentary perceptions of the workplace were predicted by SES, with higher SES individuals more commonly reporting feeling unable to meet work demands, fewer work resources, and less positive work appraisals. In turn, perceptions of the workplace had a generally consistent and robust effect on positive mood, subjective stress, and cortisol. Copyright © 2016 Elsevier 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.

Predicting Academic Success in Higher Education: What's More Important than Being Smart?

Science.gov (United States)

Kappe, Rutger; van der Flier, Henk

2012-01-01

This study investigated the combined predictive validity of intelligence and personality factors on multiple measures of academic achievement. Students in a college of higher education in the Netherlands (N = 137) completed a survey that measured intelligence, the Big Five personality traits, motivation, and four specific personality traits.…

The Cyclic Stress-Strain Curve of Polycrystals

DEFF Research Database (Denmark)

Pedersen, Ole Bøcker; Rasmussen, K. V.; Winter, A. T.

1982-01-01

The internal stresses implied by the Sachs model are estimated for individual PSBs at low plastic strain amplitudes and for homogeneously sheared grains at higher plastic strain amplitudes. The analysis shows that the Sachs model can account semi-quantitatively for experimentally measured cyclic...... stress-strain curves for copper. A similar approximative analysis of the Taylor model cannot account for the data. An interesting feature of the Sachs model is that, although it is assumed that the flow condition is entirely controlled by the PSBs. the predicted cyclic stress-strain curve displays...

Neurobiological stress responses predict aggression in boys with oppositional defiant disorder/conduct disorder: a 1-year follow-up intervention study.

Science.gov (United States)

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

2017-07-01

To improve outcome for children with antisocial and aggressive behavior, it is important to know which individual characteristics contribute to reductions in problem behavior. The predictive value of a parent training (Parent Management Training Oregon; PMTO), parenting practices (monitoring, discipline, and punishment), and child neurobiological function (heart rate, cortisol) on the course of aggression was investigated. 64 boys with oppositional defiant disorder or conduct disorder (8-12 years) participated; parents of 22 boys took part in PMTO. All data were collected before the start of the PMTO, and aggression ratings were collected three times, before PMTO, and at 6 and 12 month follow-up. Parent training predicted a decline in aggression at 6 and 12 months. Child neurobiological variables, i.e., higher cortisol stress reactivity and better cortisol recovery, also predicted a decline in aggression at 6 and 12 months. Heart rate and parenting practices were not related to the course of aggression. These results indicate that child neurobiological factors can predict persistence or reduction of aggression in boys with ODD/CD, and have unique prognostic value on top of the parent training effects.

Intraplaque hemorrhage is associated with higher structural stresses in human atherosclerotic plaques: an in vivo MRI-based 3D fluid-structure interaction study.

Science.gov (United States)

Huang, Xueying; Teng, Zhongzhao; Canton, Gador; Ferguson, Marina; Yuan, Chun; Tang, Dalin

2010-12-31

Studies using medical images have shown that intraplaque hemorrhage may accelerate plaque progression and may produce a stimulus for atherosclerosis development by increasing lipid core and plaque volume and creating new destabilizing factors. Image-based 3D computational models with fluid-structure interactions (FSI) will be used to perform plaque mechanical analysis and investigate possible associations between intraplaque hemorrhage and both plaque wall stress (PWS) and flow shear stress (FSS). In vivo MRI data of carotid plaques from 5 patients with intraplaque hemorrhage confirmed by histology were acquired. 3D multi-component FSI models were constructed for each plaque to obtain mechanical stresses. Plaque Wall Stress (PWS) and Flow Shear Stress (FSS) were extracted from all nodal points on the lumen surface of each plaque for analysis. The mean PWS value from all hemorrhage nodes of the 5 plaques combined was higher than that from non-hemorrhage nodes (75.6 versus 68.1 kPa, P = 0.0003). The mean PWS values from hemorrhage nodes for each of the 5 plaques were all significantly higher (5 out of 5) than those from non-hemorrhage nodes (P shear stress values from individual cases showed mixed results: only one out of five plaques showed mean FSS value from hemorrhage nodes was higher than that from non-hemorrhage nodes; three out of five plaques showed that their mean FSS values from hemorrhage nodes were lower than those from non-hemorrhage nodes; and one plaque showed that the difference had no statistical significance. The results of this study suggested that intraplaque hemorrhage nodes were associated with higher plaque wall stresses. Compared to flow shear stress, plaque wall stress has a better correlation with plaque component feature (hemorrhage) linked to plaque progression and vulnerability. With further validation, plaque stress analysis may provide additional stress indicators for image-based vulnerability assessment.

Predicting the stability of horizontal wells and multi-laterals - the role of in situ stress and rock properties

Energy Technology Data Exchange (ETDEWEB)

Moos, A.; Peska, P. [GeoMechanics International (United States); Zoback, M. D. [Stanford Univ., CA (United States)

1998-12-31

A new suite of software tools, developed to study wellbore stability in a wide variety of geologic environments is introduced as means by which to accurately predict optimally-stable wellbore trajectories from knowledge of the stress tensor. In step one of the process stress, is determined from observations of failure in existing wells; in step two, this knowledge is applied to predict the stability of proposed wells while drilling, as well as later during production. Three case studies are presented to illustrate use of this approach. The examples concentrate on issues related to the stability of highly inclined wells, but the approach can be used to determine the state of stress for other purposes as well. 21 refs., 8 figs.

Predictive maintenance policy for a gradually deteriorating system subject to stress

Energy Technology Data Exchange (ETDEWEB)

Deloux, E. [IRCCyN/Ecole des Mines de Nantes, Nantes (France); Castanier, B. [IRCCyN/Ecole des Mines de Nantes, Nantes (France)], E-mail: bruno.castanier@emn.fr; Berenguer, C. [Universite de Technologie de Troyes/CNRS, Troyes (France)

2009-02-15

This paper deals with a predictive maintenance policy for a continuously deteriorating system subject to stress. We consider a system with two failure mechanisms which are, respectively, due to an excessive deterioration level and a shock. To optimize the maintenance policy of the system, an approach combining statistical process control (SPC) and condition-based maintenance (CBM) is proposed. CBM policy is used to inspect and replace the system according to the observed deterioration level. SPC is used to monitor the stress covariate. In order to assess the performance of the proposed maintenance policy and to minimize the long-run expected maintenance cost per unit of time, a mathematical model for the maintained system cost is derived. Analysis based on numerical results are conducted to highlight the properties of the proposed maintenance policy in respect to the different maintenance parameters.

Predictive maintenance policy for a gradually deteriorating system subject to stress

International Nuclear Information System (INIS)

Deloux, E.; Castanier, B.; Berenguer, C.

2009-01-01

This paper deals with a predictive maintenance policy for a continuously deteriorating system subject to stress. We consider a system with two failure mechanisms which are, respectively, due to an excessive deterioration level and a shock. To optimize the maintenance policy of the system, an approach combining statistical process control (SPC) and condition-based maintenance (CBM) is proposed. CBM policy is used to inspect and replace the system according to the observed deterioration level. SPC is used to monitor the stress covariate. In order to assess the performance of the proposed maintenance policy and to minimize the long-run expected maintenance cost per unit of time, a mathematical model for the maintained system cost is derived. Analysis based on numerical results are conducted to highlight the properties of the proposed maintenance policy in respect to the different maintenance parameters

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.

Workplace Deviance: A Predictive study of Occupational Stress and Emotional Intelligence among Secondary School teachers

OpenAIRE

Oguegbe Tochukwu Matthew; Uzoh Bonaventure Chigozie; Anyikwa Kosiso

2014-01-01

The study investigated workplace deviance:A predictive study of Occupational stress and Emotional intelligence among secondary school teachers. A total number of 198 teachers from Nigeria served as participants with the mean age of 32.98,standarddeviation 0f 9.26 and age range of 22 to 54years. Three instruments were used in the study: Workplace deviance scale, Occupational stress inventory and Emotional intelligence scale. The study adopted a correlational design with Pearson Product Moment ...

Predicting academic success in higher education: what’s more important than being smart?

NARCIS (Netherlands)

Kappe, F.R.; van der Flier, H.

2012-01-01

This study investigated the combined predictive validity of intelligence and personality factors on multiple measures of academic achievement. Students in a college of higher education in the Netherlands (N0137) completed a survey that measured intelligence, the Big Five personality traits,

Screening and Predicting Posttraumatic Stress and Depression in Children Following Single-Incident Trauma

Science.gov (United States)

Nixon, Reginald D. V.; Ellis, Alicia A.; Nehmy, Thomas J.; Ball, Shelley-Anne

2010-01-01

Three screening methods to predict posttraumatic stress disorder (PTSD) and depression symptoms in children following single-incident trauma were tested. Children and adolescents (N = 90; aged 7-17 years) were assessed within 4 weeks of an injury that led to hospital treatment and followed up 3 and 6 months later. Screening methods were adapted…

Predictive value of age for coping: the role of self-efficacy, social support satisfaction and perceived stress.

Science.gov (United States)

Trouillet, Raphaël; Gana, Kamel; Lourel, Marcel; Fort, Isabelle

2009-05-01

The present study was prompted by the lack of agreement on how coping changes with age. We postulate that the effect of age on coping is mediated by coping resources, such as self-efficacy, perceived stress and social support satisfaction. The participants in the study were community dwelling and aged between 22 and 88 years old. Data were collected using the General Self Efficacy Scale, the Social Support Questionnaire, the Perceived Stress Scale, the Geriatric Depression Scale, the Social Readjustment Rating Scale (life-events) and the Way of Coping Checklist. We performed path analyses for two competitive structural models: M1 (age does not directly affect coping processes) and M2 (age directly affects coping processes). Our results supported a modified version of M2. Age was not found to predict either of two coping strategies: problem-focused coping is predicted by self-efficacy and social support satisfaction; emotion-focused coping is predicted by social support satisfaction and perceived stress. Changes in coping over the lifespan reflect the effectiveness with which a person's adaptive processes deal with age-associated changes in self-referred beliefs and environment perception.

The Relationship between Irritable Bowel Syndrome, Depression, Anxiety, and Stress among Sample of Irritable Bowel Patients - Predictive Study

OpenAIRE

Osama Hasan Gaber

2016-01-01

This study aimed to examine the relationship of irritable bowel syndrome, anxiety, depression and stress among a sample of78 IBS patients (Rome III Diagnostic Criteria for Irritable Bowel Syndrome), anxiety symptoms scale, Depression symptoms scale, and stress scale (prepared by the researcher) were used Pearson Correlation Coefficient showed that there are statistically significant relationship between IBS and Anxiety, Depression and Stress (P?=0.01). The Regression and Prediction Coefficien...

Occupational stress, organisational commitment and ill-health of employees at a higher education institution in South Africa

Directory of Open Access Journals (Sweden)

S. E. Coetzee

2005-10-01

Full Text Available The objectives of this study were to assess the indicators and moderators of occupational stress at a higher education institution in South Africa, as well as differences based on language and years of experience at the institution. A cross-sectional survey design was used. The participants included academic and support staff at a higher education institution (N = 372. An Organisational Stress Screening Tool (ASSET and a biographical questionnaire were administered. Workload, control, work-relationships and pay and benefits were the major occupational stressors in the institution. Compared to the international norm, participants reported higher levels of physical and psychological ill-health and perceived lack of commitment from the organisation. Analysis of variance revealed differences in occupational stress levels for all the biographical variables tested. Organisational commitment moderated the effect of occupational stress on ill-health. Opsomming Die doelstellings van hierdie studie was om die aanwysers en verligtende faktore van beroepstres in ’n hoëronderwysinstansie in Suid-Afrika te identifiseer, asook moontlike verskille gebaseer op taal en jare ervaring by die instansie te bepaal. ’n Dwarsdeursnee-opnameontwerp is gebruik. Die deelnemers het bestaan uit akademiese en ondersteuningspersoneel verbonde aan ’n hoëronderwysinstansie (N = 372. ’n Organisasiestresgraderingsinstrument (ASSET en ’n biografiese vraelys is afgeneem. Oorlading, kontrole, werksverhoudinge en salaris en byvoordele was die vernaamste stressore in die instelling. Vergeleke met die internasionale norm, het deelnemers hoër vlakke van fisieke en psigologiese ongesondheid gerapporteer, en ook ’n gebrek aan verbondenheid komende van die werkgewer ervaar. Variansieanalise het verskille in werkstresvlakke uitgewys vir al die biografiese veranderlikes wat getoets is. Organisasieverbondenheid het die effek van beroepstres op ongesondheid gematig.

It Is Not Just Stress: Parent Personality in Raising a Deaf Child

Science.gov (United States)

Plotkin, Rachael M.; Brice, Patrick J.; Reesman, Jennifer H.

2014-01-01

This study examined the impact and predictive ability of parental personality and perceived stress on behavior problems of their deaf child. One hundred and fourteen parents with a deaf child completed measures of personality, parenting stress, and child behavioral functioning. Higher parental neuroticism, which reflects a susceptibility to…

Stress in the City: Influence of Urban Social Stress and Violence on Pregnancy and Postpartum Quality of Life among Adolescent and Young Mothers.

Science.gov (United States)

Willie, Tiara C; Powell, Adeya; Kershaw, Trace

2016-02-01

Adolescent and young mothers transitioning from pregnancy to postpartum need to maintain an optimal quality of life. Stress and exposure to violence (e.g., intimate partner violence (IPV), nonpartner violence) are predictors of poor quality of life for adult women; however, these associations remain understudied among adolescent and young mothers in urban areas. Guided by the social ecological model, the current study created a latent variable, urban social stress, to examine the impact of the urban social environment (i.e., stressful life events, discrimination, family stress, and neighborhood problems) on the quality of life of adolescent and young mothers during both pregnancy and postpartum. The current study is a secondary data analysis of a prospective cohort study of 296 expectant young mothers recruited at obstetrics and gynecology clinics. Results from structural equation and multigroup models found that higher urban social stress predicted lower mental and physical quality of life during pregnancy, but these associations were significantly stronger for IPV-exposed and nonpartner violence-exposed mothers. In the postpartum period, higher urban social stress predicted lower mental and physical quality of life, but these associations were significantly stronger for IPV-unexposed and nonpartner violence-exposed mothers. Stress reduction programs need to help adolescent and young mothers in urban areas develop stress management skills specific to urban social stress. Pregnancy and parenting programs need to be tailored to the specific needs of young mothers in urban areas by becoming sensitive to the role of IPV and nonpartner violence in these young women's lives.

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

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.

Latino parent acculturation stress: Longitudinal effects on family functioning and youth emotional and behavioral health.

Science.gov (United States)

Lorenzo-Blanco, Elma I; Meca, Alan; Unger, Jennifer B; Romero, Andrea; Gonzales-Backen, Melinda; Piña-Watson, Brandy; Cano, Miguel Ángel; Zamboanga, Byron L; Des Rosiers, Sabrina E; Soto, Daniel W; Villamar, Juan A; Lizzi, Karina M; Pattarroyo, Monica; Schwartz, Seth J

2016-12-01

Latino parents can experience acculturation stressors, and according to the Family Stress Model (FSM), parent stress can influence youth mental health and substance use by negatively affecting family functioning. To understand how acculturation stressors come together and unfold over time to influence youth mental health and substance use outcomes, the current study investigated the trajectory of a latent parent acculturation stress factor and its influence on youth mental health and substance use via parent-and youth-reported family functioning. Data came from a 6-wave, school-based survey with 302 recent (stress loaded onto a latent factor of acculturation stress at each of the first 4 time points. Earlier levels of and increases in parent acculturation stress predicted worse youth-reported family functioning. Additionally, earlier levels of parent acculturation stress predicted worse parent-reported family functioning and increases in parent acculturation stress predicted better parent-reported family functioning. While youth-reported positive family functioning predicted higher self-esteem, lower symptoms of depression, and lower aggressive and rule-breaking behavior in youth, parent-reported family positive functioning predicted lower youth alcohol and cigarette use. Findings highlight the need for Latino youth preventive interventions to target parent acculturation stress and family functioning. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Compassion satisfaction, burnout, and secondary traumatic stress in UK therapists who work with adult trauma clients

Directory of Open Access Journals (Sweden)

Ekundayo A. Sodeke-Gregson

2013-12-01

Full Text Available Background: Therapists who work with trauma clients are impacted both positively and negatively. However, most studies have tended to focus on the negative impact of the work, the quantitative evidence has been inconsistent, and the research has primarily been conducted outside the United Kingdom. Objectives: This study aimed to assess the prevalence of, and identify predictor variables for, compassion satisfaction, burnout, and secondary traumatic stress in a group of UK therapists (N=253 working with adult trauma clients. Method: An online questionnaire was developed which used The Professional Quality of Life Scale (Version 5 to assess compassion satisfaction, burnout, and secondary traumatic stress and collect demographics and other pertinent information. Results: Whilst the majority of therapists scored within the average range for compassion satisfaction and burnout, 70% of scores indicated that therapists were at high risk of secondary traumatic stress. Maturity, time spent engaging in research and development activities, a higher perceived supportiveness of management, and supervision predicted higher potential for compassion satisfaction. Youth and a lower perceived supportiveness of management predicted higher risk of burnout. A higher risk of secondary traumatic stress was predicted in therapists engaging in more individual supervision and self-care activities, as well as those who had a personal trauma history. Conclusions: UK therapists working with trauma clients are at high risk of being negatively impacted by their work, obtaining scores which suggest a risk of developing secondary traumatic stress. Of particular note was that exposure to trauma stories did not significantly predict secondary traumatic stress scores as suggested by theory. However, the negative impact of working with trauma clients was balanced by the potential for a positive outcome from trauma work as a majority indicated an average potential for compassion

Compassion satisfaction, burnout, and secondary traumatic stress in UK therapists who work with adult trauma clients.

Science.gov (United States)

Sodeke-Gregson, Ekundayo A; Holttum, Sue; Billings, Jo

2013-01-01

Therapists who work with trauma clients are impacted both positively and negatively. However, most studies have tended to focus on the negative impact of the work, the quantitative evidence has been inconsistent, and the research has primarily been conducted outside the United Kingdom. This study aimed to assess the prevalence of, and identify predictor variables for, compassion satisfaction, burnout, and secondary traumatic stress in a group of UK therapists (N=253) working with adult trauma clients. An online questionnaire was developed which used The Professional Quality of Life Scale (Version 5) to assess compassion satisfaction, burnout, and secondary traumatic stress and collect demographics and other pertinent information. Whilst the majority of therapists scored within the average range for compassion satisfaction and burnout, 70% of scores indicated that therapists were at high risk of secondary traumatic stress. Maturity, time spent engaging in research and development activities, a higher perceived supportiveness of management, and supervision predicted higher potential for compassion satisfaction. Youth and a lower perceived supportiveness of management predicted higher risk of burnout. A higher risk of secondary traumatic stress was predicted in therapists engaging in more individual supervision and self-care activities, as well as those who had a personal trauma history. UK therapists working with trauma clients are at high risk of being negatively impacted by their work, obtaining scores which suggest a risk of developing secondary traumatic stress. Of particular note was that exposure to trauma stories did not significantly predict secondary traumatic stress scores as suggested by theory. However, the negative impact of working with trauma clients was balanced by the potential for a positive outcome from trauma work as a majority indicated an average potential for compassion satisfaction.

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.

Does unconscious stress play a role in prolonged cardiovascular stress recovery?

Science.gov (United States)

Brosschot, J F; Geurts, S A E; Kruizinga, I; Radstaak, M; Verkuil, B; Quirin, M; Kompier, M A J

2014-08-01

According to recent insights, humans might not be aware of a substantial part of their cognitive stress representations while these still have prolonged physiological effects. 'Unconscious stress' can be measured by implicit affect (IA) tests. It was shown that IA predicts physiological stress responses, in fact better than explicit ('conscious') affect. It is not known yet whether IA is associated with concurrent prolonged stress responses. In two studies (n = 62 and 123), anger harassment was used to induce stress. Blood pressure (BP) and heart rate (HR) were measured continuously. During BP and HR recovery, IA was measured by an 'anger' version of the implicit association test (IAT) or the implicit positive and negative affect test (IPANAT). Blood pressure and HR increased during anger harassment and recovery afterwards. When using the IPANAT BP recovery levels were lower when positive IA was high and higher when negative IA was high, independent of explicit affect and rumination. These results were not found using the IAT. These results provide preliminary evidence that physiological stress recovery is associated with IA. This is in line with the theory that unconscious stress is responsible for a-possibly considerable-part of unhealthy prolonged stress-related physiological activity. Copyright © 2014 John Wiley & Sons, Ltd.

Stress and Coping in Higher Education: A Case Study of a Haitian American Woman Administrator

Science.gov (United States)

Wolfgang, Jeff Drayton; West-Olatunji, Cirecie A.; Overton, Jeanine; Shah, Bindi; Coral, Cristina

2015-01-01

The authors applied Relational-Cultural Theory (RCT) to conduct a case study of an Afro-Caribbean woman administrator to explore her perceptions of stress and coping in higher education. While much has been written about the challenges facing Black faculty and students, this study focused on the experiences of a Black woman administrator in a…

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

Science.gov (United States)

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

2017-03-01

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 which are largely unknown. This study aimed at improving PTSD treatment for adult refugees by identifying PTSD treatment response predictors. A prospective longitudinal multilevel modelling design was used to predict PTSD severity scores over time. We analysed data from a randomized controlled trial with pre-, post-, and follow-up measurements of the safety and efficacy of eye movement desensitization and reprocessing and stabilization in asylum seekers and refugees suffering from PTSD. Lack of refugee status, comorbid depression, demographic, trauma-related and treatment-related variables were analysed as potential predictors of PTSD treatment outcome. Treatment outcome data from 72 participants were used. The presence (B = 6.5, p = .03) and severity (B = 6.3, p disorder predicted poor treatment response and explained 39% of the variance between individuals. Refugee patients who suffer from PTSD and severe comorbid depression benefit less from treatment aimed at alleviating PTSD. Results highlight the need for treatment adaptations for PTSD and comorbid severe depression in traumatized refugees, including testing whether initial targeting of severe depressive symptoms increases PTSD treatment effectiveness. There are differences in post-traumatic stress disorder (PTSD) treatment response between traumatized refugees. Comorbid depressive disorder and depression severity predict poor PTSD response. Refugees with PTSD and severe depression may not benefit from PTSD treatment. Targeting comorbid severe depression before PTSD treatment is warranted. This study did not correct for multiple hypothesis testing. Comorbid depression may differentially impact alternative PTSD treatments

Intraplaque hemorrhage is associated with higher structural stresses in human atherosclerotic plaques: an in vivo MRI-based 3d fluid-structure interaction study

Directory of Open Access Journals (Sweden)

Canton Gador

2010-12-01

Full Text Available Abstract Background Studies using medical images have shown that intraplaque hemorrhage may accelerate plaque progression and may produce a stimulus for atherosclerosis development by increasing lipid core and plaque volume and creating new destabilizing factors. Image-based 3D computational models with fluid-structure interactions (FSI will be used to perform plaque mechanical analysis and investigate possible associations between intraplaque hemorrhage and both plaque wall stress (PWS and flow shear stress (FSS. Methods In vivo MRI data of carotid plaques from 5 patients with intraplaque hemorrhage confirmed by histology were acquired. 3D multi-component FSI models were constructed for each plaque to obtain mechanical stresses. Plaque Wall Stress (PWS and Flow Shear Stress (FSS were extracted from all nodal points on the lumen surface of each plaque for analysis. Results The mean PWS value from all hemorrhage nodes of the 5 plaques combined was higher than that from non-hemorrhage nodes (75.6 versus 68.1 kPa, P = 0.0003. The mean PWS values from hemorrhage nodes for each of the 5 plaques were all significantly higher (5 out of 5 than those from non-hemorrhage nodes (P 2, P = 0.0002. However, the mean flow shear stress values from individual cases showed mixed results: only one out of five plaques showed mean FSS value from hemorrhage nodes was higher than that from non-hemorrhage nodes; three out of five plaques showed that their mean FSS values from hemorrhage nodes were lower than those from non-hemorrhage nodes; and one plaque showed that the difference had no statistical significance. Conclusion The results of this study suggested that intraplaque hemorrhage nodes were associated with higher plaque wall stresses. Compared to flow shear stress, plaque wall stress has a better correlation with plaque component feature (hemorrhage linked to plaque progression and vulnerability. With further validation, plaque stress analysis may provide

Predictors of responses to stress among families coping with poverty-related stress.

Science.gov (United States)

Santiago, Catherine DeCarlo; Etter, Erica Moran; Wadsworth, Martha E; Raviv, Tali

2012-05-01

This study tested how poverty-related stress (PRS), psychological distress, and responses to stress predicted future effortful coping and involuntary stress responses one year later. In addition, we explored age, sex, ethnicity, and parental influences on responses to stress over time. Hierarchical linear modeling analyses conducted with 98 low-income families (300 family members: 136 adults, 82 school-aged children, 82 adolescents) revealed that primary control coping, secondary control coping, disengagement, involuntary engagement, and involuntary disengagement each significantly predicted future use of that response. Primary and secondary control coping also predicted less maladaptive future responses to stress, while involuntary responses to stress undermined the development of adaptive responding. Age, sex, and interactions among PRS and prior coping were also found to predict certain responses to stress. In addition, child subgroup analyses demonstrate the importance of parental modeling of coping and involuntary stress responses, and warmth/nurturance and monitoring practices. Results are discussed with regard to the implications for preventive interventions with families in poverty.

The predicting roles of reasons for living and social support on depression, anxiety and stress among young people in Malaysia.

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Amit, N; Ibrahim, N; Aga Mohd Jaladin, R; Che Din, N

2017-10-01

This research examined the predicting roles of reasons for living and social support on depression, anxiety and stress in Malaysia. This research was carried out on a sample of 263 participants (age range 12-24 years old), from Klang Valley, Selangor. The survey package comprises demographic information, a measure of reasons for living, social support, depression, anxiety and stress. To analyse the data, correlation analysis and a series of linear multiple regression analysis were carried out. Findings showed that there were low negative relationships between all subdomains and the total score of reasons for living and depression. There were also low negative relationships between domain-specific of social support (family and friends) and total social support and depression. In terms of the family alliance, self-acceptance and total score of reasons for living, they were negatively associated with anxiety, whereas family social support was negatively associated with stress. The linear regression analysis showed that only future optimism and family social support found to be the significant predictors for depression. Family alliance and total reasons for living were significant in predicting anxiety, whereas family social support was significant in predicting stress. These findings have the potential to promote awareness related to depression, anxiety, and stress among youth in Malaysia.

The organization of irrational beliefs in posttraumatic stress symptomology: testing the predictions of REBT theory using structural equation modelling.

Science.gov (United States)

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

2014-01-01

This study directly tests a central prediction of rational emotive behaviour therapy (REBT) that has received little empirical attention regarding the core and intermediate beliefs in the development of posttraumatic stress symptoms. A theoretically consistent REBT model of posttraumatic stress disorder (PTSD) was examined using structural equation modelling techniques among a sample of 313 trauma-exposed military and law enforcement personnel. The REBT model of PTSD provided a good fit of the data, χ(2) = 599.173, df = 356, p depreciation beliefs. Results were consistent with the predictions of REBT theory and provides strong empirical support that the cognitive variables described by REBT theory are critical cognitive constructs in the prediction of PTSD symptomology. © 2013 Wiley Periodicals, Inc.

Prediction of process induced shape distortions and residual stresses in large fibre reinforced composite laminates

DEFF Research Database (Denmark)

Nielsen, Michael Wenani

to their accuracy in predicting process induced strain and stress development in thick section laminates during curing, and more precisely regarding the evolution of the composite thermoset polymer matrix mechanical behaviour during the phase transitions experienced during curing. The different constitutive...

Economic Stress and Cortisol Among Postpartum Low-Income Mexican American Women: Buffering Influence of Family Support.

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Jewell, Shannon L; Luecken, Linda J; Gress-Smith, Jenna; Crnic, Keith A; Gonzales, Nancy A

2015-01-01

Low-income Mexican American women experience significant health disparities during the postpartum period. Contextual stressors, such as economic stress, are theorized to affect health via dysregulated cortisol output. However, cultural protective factors including strong family support may buffer the impact of stress. In a sample of 322 low-income Mexican American women (mother age 18-42; 82% Spanish-speaking; modal family income $10,000-$15,000), we examined the interactive influence of economic stress and family support at 6 weeks postpartum on maternal cortisol output (AUCg) during a mildly challenging mother-infant interaction task at 12 weeks postpartum, controlling for 6-week maternal cortisol and depressive symptoms. The interaction significantly predicted cortisol output such that higher economic stress predicted higher cortisol only among women reporting low family support. These results suggest that family support is an important protective resource for postpartum Mexican American women experiencing elevated economic stress.

Noise, stress, and annoyance in a pediatric intensive care unit.

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Morrison, Wynne E; Haas, Ellen C; Shaffner, Donald H; Garrett, Elizabeth S; Fackler, James C

2003-01-01

To measure and describe hospital noise and determine whether noise can be correlated with nursing stress measured by questionnaire, salivary amylase, and heart rate. Cohort observational study. Tertiary care center pediatric intensive care unit. Registered nurses working in the unit. None. Eleven nurse volunteers were recruited. An audiogram, questionnaire data, salivary amylase, and heart rate were collected in a quiet room. Each nurse was observed for a 3-hr period during patient care. Heart rate and sound level were recorded continuously; saliva samples and stress/annoyance ratings were collected every 30 mins. Variables assessed as potential confounders were years of nursing experience, caffeine intake, patients' Pediatric Risk of Mortality Score, shift assignment, and room assignment. Data were analyzed by random effects multiple linear regression using Stata 6.0. The average daytime sound level was 61 dB(A), nighttime 59 dB(A). Higher average sound levels significantly predicted higher heart rates (p =.014). Other significant predictors of tachycardia were higher caffeine intake, less nursing experience, and daytime shift. Ninety percent of the variability in heart rate was explained by the regression equation. Amylase measurements showed a large variability and were not significantly affected by noise levels. Higher average sound levels were also predictive of greater subjective stress (p =.021) and annoyance (p =.016). In this small study, noise was shown to correlate with several measures of stress including tachycardia and annoyance ratings. Further studies of interventions to reduce noise are essential.

Measuring stress in medical education: validation of the Korean version of the higher education stress inventory with medical students.

Science.gov (United States)

Shim, Eun-Jung; Jeon, Hong Jin; Kim, Hana; Lee, Kwang-Min; Jung, Dooyoung; Noh, Hae-Lim; Roh, Myoung-Sun; Hahm, Bong-Jin

2016-11-24

Medical students face a variety of stressors associated with their education; if not promptly identified and adequately dealt with, it may bring about several negative consequences in terms of mental health and academic performance. This study examined psychometric properties of the Korean version of the Higher Education Stress Inventory (K-HESI). The reliability and validity of the K-HESI were examined in a large scale multi-site survey involving 7110 medical students. The K-HESI, Beck Depression Inventory (BDI) and questions regarding quality of life (QOL) and self-rated physical health (SPH) were administered. Exploratory factor analysis of the K-HESI identified seven factors: Low commitment; financial concerns; teacher-student relationship; worries about future profession; non-supportive climate; workload; and dissatisfaction with education. A subsequent confirmatory factor analysis supported the 7-factor model. Internal consistency of the K-HESI was satisfactory (Cronbach's α = .78). Convergent validity was demonstrated by its positive association with the BDI. Known group validity was supported by the K-HESI's ability to detect significant differences on the overall and subscale scores of K-HESI according to different levels of QOL and SPH. The K-HESI is a psychometrically valid tool that comprehensively assesses various relevant stressors related to medical education. Evidence-based stress management in medical education empirically guided by the regular assessment of stress using reliable and valid measure is warranted.

Pressure and Stress Prediction in the Nankai Accretionary Prism: A Critical State Soil Mechanics Porosity-Based Approach

Science.gov (United States)

Flemings, Peter B.; Saffer, Demian M.

2018-02-01

We predict pressure and stress from porosity in the Nankai accretionary prism with a critical state soil model that describes porosity as a function of mean stress and maximum shear stress, and assumes Coulomb failure within the wedge and uniaxial burial beneath it. At Ocean Drilling Program Sites 1174 and 808, we find that pore pressure in the prism supports 70% to 90% of the overburden (λu = 0.7 to 0.9), for a range of assumed friction angles (5-30°). The prism pore pressure is equal to or greater than that in the underthrust sediments even though the porosity is lower within the prism. The high pore pressures lead to a mechanically weak wedge that supports low maximum shear stress, and this in turn requires very low basal traction to remain consistent with the observed narrowly tapered wedge geometry. We estimate the décollement friction coefficient (μb) to be 0.08-0.38 (ϕb' = 4.6°-21°). Our approach defines a pathway to predict pressure in a wide range of environments from readily observed quantities (e.g., porosity and seismic velocity). Pressure and stress control the form of the Earth's collisional continental margins and play a key role in its greatest earthquakes. However, heretofore, there has been no systematic approach to relate material state (e.g., porosity), pore pressure, and stress in these systems.

Higher cortisol is associated with poorer executive functioning in preschool children: The role of parenting stress, parent coping and quality of daycare

Science.gov (United States)

Wagner, Shannon L.; Cepeda, Ivan; Krieger, Dena; Maggi, Stefania; D’Angiulli, Amedeo; Weinberg, Joanne; Grunau, Ruth E.

2016-01-01

Child executive functions (cognitive flexibility, inhibitory control, working memory) are key to success in school. Cortisol, the primary stress hormone, is known to affect cognition; however, there is limited information about how child cortisol levels, parenting factors and child care context relate to executive functions in young children. The aim of this study was to examine relationships between child cortisol, parenting stress, parent coping, and daycare quality in relation to executive functions in children aged 3–5 years. We hypothesized that (1) poorer executive functioning would be related to higher child cortisol and higher parenting stress, and (2) positive daycare quality and positive parent coping style would buffer the effects of child cortisol and parenting stress on executive functions. A total of 101 children (53 girls, 48 boys, mean age 4.24 years ±0.74) with complete data on all measures were included. Three saliva samples to measure cortisol were collected at the child’s daycare/preschool in one morning. Parents completed the Behavior Rating Inventory of Executive Function – Preschool Version (BRIEF-P), Parenting Stress Index (PSI), and Ways of Coping Questionnaire (WCQ). The Early Childhood Environment Rating Scale – Revised (ECERS-R) was used to measure the quality of daycare. It was found that children with poorer executive functioning had higher levels of salivary cortisol, and their parents reported higher parenting stress. However, parent coping style and quality of daycare did not modulate these relationships. Identifying ways to promote child executive functioning is an important direction for improving school readiness. PMID:26335047

The finite element analysis for prediction of residual stresses induced by shot peening

International Nuclear Information System (INIS)

Kim, Cheol; Yang, Won Ho; Sung, Ki Deug; Cho, Myoung Rae; Ko, Myung Hoon

2000-01-01

The shot peening is largely used for a surface treatment in which small spherical parts called shots are blasted on a surface of a metallic components with velocities up to 100m/s. This treatment leads to an improvement of fatigue behavior due to the developed compressive residual stresses, and so it has gained widespread acceptance in the automobile and aerospace industries. The residual stress profile on surface layer depends on the parameters of shot peening, which are, shot velocity, shot diameter, coverage, impact angle, material properties etc. and the method to confirm this profile is only measurement by X-ray diffractometer. Despite its importance to automobile and aerospace industries, little attention has been devoted to the accurate modeling of the process. In this paper, the simulation technique is applied to predict the magnitude and distribution of the residual stress and plastic deformation caused by shot peening with the help of the finite element analysis

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.

Patients with Posttraumatic Stress Disorder with Comorbid Major Depressive Disorder Require a Higher Dose of Psychotropic Drugs.

Science.gov (United States)

Chiba, Hiromi; Oe, Misari; Uchimura, Naohisa

2016-01-01

Major depressive disorder (MDD) has been associated with stressful life events and with posttraumatic stress disorder (PTSD). PTSD and MDD comorbidity was also reported to be associated with greater symptom severity and lower levels of functioning. However, the characteristics of pharmacotherapy for PTSD with MDD are not fully understood. To understand this relationship, we conducted a retrospective review using medical charts at the Department of Neuropsychiatry, Kurume University Hospital. Information from 55 patients with PTSD was analyzed. Five cases were excluded after re-evaluation of the PTSD diagnosis. A higher rate of type II trauma was observed in the PTSD with MDD group (50.0%) than in the PTSD-only group [13.6%; χ(2) (1, n =50) = 7.26, p<0.01]. Patients with comorbid MDD were significantly older, had more severe PTSD symptomatology, and a longer duration of treatment. They also received higher doses of psychotropic drugs, regardless of the type (antidepressants, antipsychotics, benzodiazepines), than the PTSD-only group. Our results showed that comorbid MDD is associated with higher doses of psychotropic drugs, suggesting difficulties in treatment.

Race and gender matter: a multidimensional approach to conceptualizing and measuring stress in African American women.

Science.gov (United States)

Woods-Giscombé, Cheryl L; Lobel, Marci

2008-07-01

Based on prior research and theory, the authors constructed a multidimensional model of stress in African American women comprised of race-related, gender-related, and generic stress. Exposure to and appraisal of these three types of stress were combined into a higher-order global stress factor. Using structural equation modeling, the fit of this stress factor and its ability to predict distress symptoms were examined in 189 socioeconomically diverse African American women aged 21 to 78. Results support the multidimensional conceptualization and operationalization of stress. Race-related, gender-related, and generic stress contributed equally to the global stress factor, and global stress predicted a significant amount of variance in distress symptoms and intensity. This model exhibited better fit than a model without a global stress factor, in which each stress component predicted distress directly. Furthermore, race-related, gender-related, and generic stress did not contribute to distress beyond their representation in the global stress factor. These findings illustrate that stress related to central elements of identity, namely race and gender, cohere with generic stress to define the stress experience of African American women. Copyright (c) 2008 APA, all rights reserved.

Emotional memory consolidation under lower versus higher stress conditions

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Inna eKogan

2010-12-01

Full Text Available An exposure to stress can enhance memory for emotionally arousing experiences. The phenomenon is suggested to be amygdala-dependent and in accordance with that view the amygdala was found to modulate mnemonic processes in other brain regions. Previously, we illustrated increased amygdala activation and reduced activation of CA1 following spatial learning under high versus low emotionality conditions. When spatial learning was followed by reversal training interference, impaired retention was detected only under high emotionality conditions. Here we further evaluate the potential implications of the difference in the level of amygdala activation on the quality of the memory formed under these stress conditions. We attempted to affect spatial memory consolidation under low or high stress conditions by either introducing a foot shock interference following massed training in the water maze; by manipulating the threshold for acquisition employing either brief (3 trials or full (12 trials training sessions; or by employing a spaced training (over three days rather than massed training protocol. The current findings reveal that under heightened emotionality, the process of consolidation seems to become less effective and more vulnerable to interference; however, when memory consolidation is not interrupted, retention is improved. These differential effects might underlie the complex interactions of stress, and, particularly, of traumatic stress with memory formation processes.

The Factors Predicting Stress, Anxiety and Depression in the Parents of Children with Autism

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Falk, Nicholas Henry; Norris, Kimberley; Quinn, Michael G.

2014-01-01

The factors predicting stress, anxiety and depression in the parents of children with autism remain poorly understood. In this study, a cohort of 250 mothers and 229 fathers of one or more children with autism completed a questionnaire assessing reported parental mental health problems, locus of control, social support, perceived parent-child…

Risk factors predict post-traumatic stress disorder differently in men and women

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Elklit Ask

2008-11-01

Full Text Available Abstract Background About twice as many women as men develop post-traumatic stress disorder (PTSD, even though men as a group are exposed to more traumatic events. Exposure to different trauma types does not sufficiently explain why women are more vulnerable. Methods The present work examines the effect of age, previous trauma, negative affectivity (NA, anxiety, depression, persistent dissociation, and social support on PTSD separately in men and women. Subjects were exposed to either a series of explosions in a firework factory near a residential area or to a high school stabbing incident. Results Some gender differences were found in the predictive power of well known risk factors for PTSD. Anxiety predicted PTSD in men, but not in women, whereas the opposite was found for depression. Dissociation was a better predictor for PTSD in women than in men in the explosion sample but not in the stabbing sample. Initially, NA predicted PTSD better in women than men in the explosion sample, but when compared only to other significant risk factors, it significantly predicted PTSD for both men and women in both studies. Previous traumatic events and age did not significantly predict PTSD in either gender. Conclusion Gender differences in the predictive value of social support on PTSD appear to be very complex, and no clear conclusions can be made based on the two studies included in this article.

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

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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

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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.

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

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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.

The role of social support, family identification, and family constraints in predicting posttraumatic stress after cancer.

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Swartzman, Samantha; Sani, Fabio; Munro, Alastair J

2017-09-01

We compared social support with other potential psychosocial predictors of posttraumatic stress after cancer. These included family identification, or a sense of belonging to and commonality with family members, and family constraints, or the extent to which family members are closed, judgmental, or unreceptive in conversations about cancer. We also tested the hypothesis that family constraints mediate the relationship between family identification and cancer-related posttraumatic stress. We used a cross-sectional design. Surveys were collected from 205 colorectal cancer survivors in Tayside, Scotland. Both family identification and family constraints were stronger independent predictors of posttraumatic stress than social support. In multivariate analyses, social support was not a significant independent predictor of posttraumatic stress. In addition, there was a significant indirect effect of family identification on posttraumatic stress through family constraints. Numerous studies demonstrate a link between social support and posttraumatic stress. However, experiences within the family may be more important in predicting posttraumatic stress after cancer. Furthermore, a sense of belonging to and commonality with the family may reduce the extent to which cancer survivors experience constraints on conversations about cancer; this may, in turn, reduce posttraumatic stress. Copyright © 2016 John Wiley & Sons, Ltd.

Prediction of wall motion improvement after coronary revascularization in patients with postmyocardial infarction. Diagnostic value of dobutamine stress echocardiography and myocardial contrast echocardiography

International Nuclear Information System (INIS)

Waku, Sachiko; Ohkubo, Tomoyuki; Takada, Kiyoshi; Ishihara, Tadashi; Ohsawa, Nakaaki; Adachi, Itaru; Narabayashi, Isamu

1997-01-01

The diagnostic value of dobutamine stress echocardiography, myocardial contrast echocardiography and dipyridamole stress thallium-201 single photon emission computed tomography (SPECT) for predicting recovery of wall motion abnormality after revascularization was evaluated in 13 patients with postmyocardial infarction. Seventeen segments showed severe wall motion abnormalities before revascularization. Nine segments which had relatively good Tl uptake on delayed SPECT images despite severely abnormal wall motion were opacified during myocardial contrast echocardiography, and showed improved wall motion after revascularization. In contrast, three segments which had poor Tl uptake and severely abnormal wall motion were not opacified during myocardial contrast echocardiography, and showed no improvement in wall motion during dobutamine stress echocardiography and after revascularization. The following three findings were assumed to be signs of myocardial viability: good Tl uptake on delayed SPECT images, improved wall motion by dobutamine stress echocardiography, and positive opacification of the myocardium by myocardiai contrast echocardiography. Myocardial contrast echocardiography had the highest sensitivity (100%) and negative predictive value (100%). Delayed SPECT images had the highest specificity (100%) and positive predictive value (100%). Dobutamine stress echocardiography had a sensitivity of 83.0%, specificity of 80.0%, positive predictive value of 90.9%, and negative predictive value of 66.7%, respectively. Myocardial contrast echocardiography showed the lowest specificity (60.0%). The techniques of dobutamine stress echocardiography and SPECT, though noninvasive, may underestimate wall motion improvement after revascularization. Further examination by myocardial contrast echocardiography is recommended to assess myocardial viability for determining the indications for coronary revascularization in spite of its invasiveness. (author)

Bioinformatics analysis of the predicted polyprenol reductase genes in higher plants

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Basyuni, M.; Wati, R.

2018-03-01

The present study evaluates the bioinformatics methods to analyze twenty-four predicted polyprenol reductase genes from higher plants on GenBank as well as predicted the structure, composition, similarity, subcellular localization, and phylogenetic. The physicochemical properties of plant polyprenol showed diversity among the observed genes. The percentage of the secondary structure of plant polyprenol genes followed the ratio order of α helix > random coil > extended chain structure. The values of chloroplast but not signal peptide were too low, indicated that few chloroplast transit peptide in plant polyprenol reductase genes. The possibility of the potential transit peptide showed variation among the plant polyprenol reductase, suggested the importance of understanding the variety of peptide components of plant polyprenol genes. To clarify this finding, a phylogenetic tree was drawn. The phylogenetic tree shows several branches in the tree, suggested that plant polyprenol reductase genes grouped into divergent clusters in the tree.

Prediction method of long-term reliability in improving residual stresses by means of surface finishing

International Nuclear Information System (INIS)

Sera, Takehiko; Hirano, Shinro; Chigusa, Naoki; Okano, Shigetaka; Saida, Kazuyoshi; Mochizuki, Masahito; Nishimoto, Kazutoshi

2012-01-01

Surface finishing methods, such as Water Jet Peening (WJP), have been applied to welds in some major components of nuclear power plants as a counter measure to Primary Water Stress Corrosion Cracking (PWSCC). In addition, the methods of surface finishing (buffing treatment) is being standardized, and thus the buffing treatment has been also recognized as the well-established method of improving stress. On the other hand, the long-term stability of peening techniques has been confirmed by accelerated test. However, the effectiveness of stress improvement by surface treatment is limited to thin layers and the effect of complicated residual stress distribution in the weld metal beneath the surface is not strictly taken into account for long-term stability. This paper, therefore, describes the accelerated tests, which confirmed that the long-term stability of the layer subjected to buffing treatment was equal to that subjected to WJP. The long-term reliability of very thin stress improved layer was also confirmed through a trial evaluation by thermal elastic-plastic creep analysis, even if the effect of complicated residual stress distribution in the weld metal was excessively taken into account. Considering the above findings, an approach is proposed for constructing the prediction method of the long-term reliability of stress improvement by surface finishing. (author)

"Trauma, stress, and self-care in clinical training: Predictors of burnout, decline in health status, secondary traumatic stress symptoms, and compassion satisfaction": Correction to Butler, Carello, and Maguin (2016).

Science.gov (United States)

2017-07-01

Reports an error in "Trauma, stress, and self-care in clinical training: Predictors of burnout, decline in health status, secondary traumatic stress symptoms, and compassion satisfaction" by Lisa D. Butler, Janice Carello and Eugene Maguin ( Psychological Trauma: Theory, Research, Practice, and Policy , Advanced Online Publication, Sep 12, 2016, np). In the article, there was an error in Table 4 of the Results. The Outcomes and Predictors columns were not clearly categorized from one another. The corrected table is present in the erratum. (The following abstract of the original article appeared in record 2016-43766-001.) Objective: Courtois and Gold (2009) have called for the inclusion of trauma in the curriculum for all mental health training programs. The present study investigated the impact of trauma-related content, stress, and self-care (SC) on trainees in such a program. Method: The study examined potential risk factors (trauma exposures in training [being faced with or reacting to trauma-related field work experiences and course content] and perceptions of stress in field and coursework) and protective factors (SC effort and importance) in relation to burnout (BO), health status (HS), secondary traumatic stress symptoms (STSS), and compassion satisfaction (CS) among 195 students in a graduate social work training program. Results: All students reported trauma exposures in their field placements and/or coursework, including retraumatization experiences that were associated with higher STSS and BO. Field stress and SC effort were both consistent predictors across outcomes. Higher field stress levels predicted higher BO and STSS, a greater likelihood of decline in HS, and lower CS. Lower SC effort was also associated with higher BO and STSS, and a greater likelihood of decline in HS, while higher SC effort predicted higher CS. Older students, those with traumatized field clients, and those whose field work addressed trauma, also reported higher CS. Conclusions

Hormonal modulation of the heat shock response: insights from fish with divergent cortisol stress responses

DEFF Research Database (Denmark)

LeBlanc, Sacha; Höglund, Erik; Gilmour, Kathleen M.

2012-01-01

shock response, we capitalized on two lines of rainbow trout specifically bred for their high (HR) and low (LR) cortisol response to stress. We predicted that LR fish, with a low cortisol but high catecholamine response to stress, would induce higher levels of HSPs after acute heat stress than HR trout....... We found that HR fish have significantly higher increases in both catecholamines and cortisol compared with LR fish, and LR fish had no appreciable stress hormone response to heat shock. This unexpected finding prevented further interpretation of the hormonal modulation of the heat shock response...

A critical analysis of the Mises stress criterion used in frequency domain fatigue life prediction

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Adam Niesłony

2016-10-01

Full Text Available Multiaxial fatigue failure criteria are formulated in time and frequency domain. The number of frequency domain criteria is rather small and the most popular one is the equivalent von Mises stress criterion. This criterion was elaborated by Preumont and Piefort on the basis of well-known von Mises stress concept, first proposed by Huber in 1907, and well accepted by the scientific community and engineers. It is important to know, that the criterion was developed to determine the yield stress and material effort under static load. Therefore the direct use of equivalent von Mises stress criterion for fatigue life prediction can lead to some incorrectness of theoretical and practical nature. In the present study four aspects were discussed: influence of the value of fatigue strength of tension and torsion, lack of parallelism of the SN curves, abnormal behaviour of the criterion under biaxial tensioncompression and influence of phase shift between particular stress state components. Information contained in this article will help to prevent improper use of this criterion and contributes to its better understanding

Exposure to stressful life events during pregnancy predicts psychotic experiences via behaviour problems in childhood.

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Betts, Kim S; Williams, Gail M; Najman, Jakob M; Scott, James; Alati, Rosa

2014-12-01

Exposure to stressful life events during pregnancy has been associated with later schizophrenia in offspring. We explore how prenatal stress and neurodevelopmental abnormalities in childhood associate to increase the risk of later psychotic experiences. Participants from the Mater University Study of Pregnancy (MUSP), an Australian based, pre-birth cohort study were examined for lifetime DSM-IV positive psychotic experiences at 21 years by a semi-structured interview (n = 2227). Structural equation modelling suggested psychotic experiences were best represented with a bifactor model including a general psychosis factor and two group factors. We tested for an association between prenatal stressful life events with the psychotic experiences, and examined for potential moderation and mediation by behaviour problems and cognitive ability in childhood. Prenatal stressful life events predicted psychotic experiences indirectly via behaviour problems at child age five years, and this relationship was not confounded by maternal stressful life events at child age five. We found no statistical evidence for an interaction between prenatal stressful life events and behaviour problems or cognitive ability. The measurable effect of prenatal stressful life events on later psychotic experiences in offspring manifested as behaviour problems by age 5. By identifying early abnormal behavioural development as an intermediary, this finding further confirms the role of prenatal stress to later psychotic disorders. Copyright © 2014 Elsevier Ltd. All rights reserved.

Non-standard work schedules, gender, and parental stress

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Mariona Lozano

2016-02-01

predictability is more important than flexibility. Workers with non-standard predictable schedules exhibit a lower risk of being stressed than those with non-standard unpredictable hours. Work flexibility does not seem to bring any additional advantage to women. However, it is linked to higher odds of being stressed for fathers, particularly among those having non-standard schedules.

Prenatal Stress due to a Natural Disaster Predicts Adiposity in Childhood: The Iowa Flood Study

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Kelsey N. Dancause

2015-01-01

Full Text Available Prenatal stress can affect lifelong physical growth, including increased obesity risk. However, human studies remain limited. Natural disasters provide models of independent stressors unrelated to confounding maternal characteristics. We assessed degree of objective hardship and subjective distress in women pregnant during severe flooding. At ages 2.5 and 4 years we assessed body mass index (BMI, subscapular plus triceps skinfolds (SS + TR, an index of total adiposity, and SS : TR ratio (an index of central adiposity in their children (n=106. Hierarchical regressions controlled first for several potential confounds. Controlling for these, flood exposure during early gestation predicted greater BMI increase from age 2.5 to 4, as well as total adiposity at 2.5. Greater maternal hardship and distress due to the floods, as well as other nonflood life events during pregnancy, independently predicted greater increase in total adiposity between 2.5 and 4 years. These results support the hypothesis that prenatal stress increases adiposity beginning in childhood and suggest that early gestation is a sensitive period. Results further highlight the additive effects of maternal objective and subjective stress, life events, and depression, emphasizing the importance of continued studies on multiple, detailed measures of maternal mental health and experience in pregnancy and child growth.

Attitudes to emotional expression and personality in predicting post-traumatic stress disorder.

Science.gov (United States)

Nightingale, J; Williams, R M

2000-09-01

To test hypotheses derived from a suggestion of Williams (1989) that negative attitudes towards emotional expression act as a predisposing or maintaining factor for post-traumatic stress reactions following a traumatic event. The study employed a prospective design in which attitudes to emotional expression, the 'Big Five' personality factors (Costa & McCrae, 1992a) and initial symptoms and injury severity within 1 week of a road traffic accident were used to predict the development of post-traumatic stress disorder 6 weeks post-accident. Sixty victims of road traffic accidents randomly selected from attenders at a large A&E department were assessed by questionnaire and interview. Measures comprised a 4-item scale relating to emotional expression, standardized scales for intrusion and avoidance features of traumatic experiences, and for anxiety and depression and the NEO-FFI Five Factor Personality Inventory. Forty-five of these participants responded to a postal questionnaire follow-up. In this survey the battery was repeated and also included a self-report diagnostic measure of post-traumatic stress disorder (PTSD). The percentage of the sample meeting DSM-IV diagnostic criteria for PTSD at 6 weeks post-trauma was 30.8%. A small but significant relationship was found for negative attitudes to emotional expression at 1 week to predict intrusive symptoms and diagnosis at 6 weeks, over and above the independent relationships of initial symptoms, initial injury severity, personality and coping. The emotional expression measure was largely stable between the two points of measurement. More negative attitudes to emotional expression were related to less openness, extraversion and agreeableness personality domains. Some support for the hypotheses was found in relation to the development of PTSD and for the status of attitudes to emotion as a stable trait related to personality factors. The potential importance of attitudes to emotional expression in therapy and other

A longitudinal examination of the Adaptation to Poverty-Related Stress Model: predicting child and adolescent adjustment over time.

Science.gov (United States)

Wadsworth, Martha E; Rindlaub, Laura; Hurwich-Reiss, Eliana; Rienks, Shauna; Bianco, Hannah; Markman, Howard J

2013-01-01

This study tests key tenets of the Adaptation to Poverty-related Stress Model. This model (Wadsworth, Raviv, Santiago, & Etter, 2011 ) builds on Conger and Elder's family stress model by proposing that primary control coping and secondary control coping can help reduce the negative effects of economic strain on parental behaviors central to the family stress model, namely, parental depressive symptoms and parent-child interactions, which together can decrease child internalizing and externalizing problems. Two hundred seventy-five co-parenting couples with children between the ages of 1 and 18 participated in an evaluation of a brief family strengthening intervention, aimed at preventing economic strain's negative cascade of influence on parents, and ultimately their children. The longitudinal path model, analyzed at the couple dyad level with mothers and fathers nested within couple, showed very good fit, and was not moderated by child gender or ethnicity. Analyses revealed direct positive effects of primary control coping and secondary control coping on mothers' and fathers' depressive symptoms. Decreased economic strain predicted more positive father-child interactions, whereas increased secondary control coping predicted less negative mother-child interactions. Positive parent-child interactions, along with decreased parent depression and economic strain, predicted child internalizing and externalizing over the course of 18 months. Multiple-group models analyzed separately by parent gender revealed, however, that child age moderated father effects. Findings provide support for the adaptation to poverty-related stress model and suggest that prevention and clinical interventions for families affected by poverty-related stress may be strengthened by including modules that address economic strain and efficacious strategies for coping with strain.

Dual-hormone stress reactivity predicts downstream war-zone stress-evoked PTSD.

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Josephs, Robert A; Cobb, Adam R; Lancaster, Cynthia L; Lee, Han-Joo; Telch, Michael J

2017-04-01

The crucial role of the hypothalamic-pituitary-adrenal axis (HPA) in stress-related homeostasis suggests dysregulated HPA involvement in the pathogenesis of post-traumatic stress disorder (PTSD), yet most studies examining linkages between HPA axis measures and PTSD have yielded null findings. One untested explanation for this inconsistency is a failure to account for simultaneous adrenal and gonadal influence. Here we tested the singular and interactive effects of cortisol (C R ) and testosterone (T R ) reactivity as moderators of war-zone stress evoked PTSD emergence in the war-zone. U.S. soldiers (N=120) scheduled for deployment to Iraq completed pre-deployment measures of C R and T R stress reactivity to a CO 2 inhalation challenge. Once deployed, monthly assessments of exposure to traumatic war-zone stressors and PTSD symptoms were collected via a web-based assessment system. Cortisol hypo-reactivity potentiated the pathogenic impact of war-zone stressors only in soldiers for whom the CO 2 challenge did not elevate testosterone, suggesting that the dual hormone stress reactivity profile of blunted cortisol and testosterone may confer increased risk for PTSD emergence by potentiating the pathogenic effects of war-zone stressors. Findings underscore the utility of assessing both HPA and HPG stress reactivity when assessing PTSD vulnerability and may help inform efforts for enhanced soldier screening and inoculation to war-zone stressors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluating stress, burnout and job satisfaction in New Zealand radiation oncology departments.

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Jasperse, M; Herst, P; Dungey, G

2014-01-01

This research aimed to determine the levels of occupational stress, burnout and job satisfaction among radiation oncology workers across New Zealand. All oncology staff practising in all eight radiation oncology departments in New Zealand were invited to participate anonymously in a questionnaire, which consisted of the Maslach Burnout Inventory and measures of stress intensity associated with specific occupational stressors, stress reduction strategies and job satisfaction. A total of 171 (out of 349) complete responses were analysed using spss 19; there were 23 oncologists, 111 radiation therapists, 22 radiation nurses and 15 radiation physicists. All participants, regardless of profession, reported high stress levels associated with both patient-centred and organisational stressors. Participants scored high in all three domains of burnout: emotional exhaustion, depersonalisation and personal accomplishment. Interestingly, although organisational stressors predicted higher emotional exhaustion and emotional exhaustion predicted lower job satisfaction, patient stressors were associated with higher job satisfaction. Job satisfaction initiatives such as ongoing education, mentoring and role extension were supported by many participants as was addressing organisational stressors, such as lack of recognition and support from management and unrealistic expectations and demands. New Zealand staff exhibit higher levels of burnout than Maslach Burnout Inventory medical norms and oncology workers in previous international studies. © 2013 John Wiley & Sons Ltd.

Measuring stress in medical education: validation of the Korean version of the higher education stress inventory with medical students

Directory of Open Access Journals (Sweden)

Eun-Jung Shim

2016-11-01

Full Text Available Abstract Background Medical students face a variety of stressors associated with their education; if not promptly identified and adequately dealt with, it may bring about several negative consequences in terms of mental health and academic performance. This study examined psychometric properties of the Korean version of the Higher Education Stress Inventory (K-HESI. Methods The reliability and validity of the K-HESI were examined in a large scale multi-site survey involving 7110 medical students. The K-HESI, Beck Depression Inventory (BDI and questions regarding quality of life (QOL and self-rated physical health (SPH were administered. Results Exploratory factor analysis of the K-HESI identified seven factors: Low commitment; financial concerns; teacher-student relationship; worries about future profession; non-supportive climate; workload; and dissatisfaction with education. A subsequent confirmatory factor analysis supported the 7-factor model. Internal consistency of the K-HESI was satisfactory (Cronbach’s α = .78. Convergent validity was demonstrated by its positive association with the BDI. Known group validity was supported by the K-HESI’s ability to detect significant differences on the overall and subscale scores of K-HESI according to different levels of QOL and SPH. Conclusions The K-HESI is a psychometrically valid tool that comprehensively assesses various relevant stressors related to medical education. Evidence-based stress management in medical education empirically guided by the regular assessment of stress using reliable and valid measure is warranted.

Prediction of thermal and mechanical stress-strain responses of TMC's subjected to complex TMF histories

Science.gov (United States)

Johnson, W. S.; Mirdamadi, M.

1994-01-01

This paper presents an experimental and analytical evaluation of cross-plied laminates of Ti-15V-3Cr-3Al-3Sn (Ti-15-3) matrix reinforced with continuous silicon-carbide fibers (SCS-6) subjected to a complex TMF loading profile. Thermomechanical fatigue test techniques were developed to conduct a simulation of a generic hypersonic flight profile. A micromechanical analysis was used. The analysis predicts the stress-strain response of the laminate and of the constituents in each ply during thermal and mechanical cycling by using only constituent properties as input. The fiber was modeled as elastic with transverse orthotropic and temperature-dependent properties. The matrix was modeled using a thermoviscoplastic constitutive relation. The fiber transverse modulus was reduced in the analysis to simulate the fiber-matrix interface failures. Excellent correlation was found between measured and predicted laminate stress-strain response due to generic hypersonic flight profile when fiber debonding was modeled.

Higher levels of masculine gender role stress in masculine than in feminine nations. A thirteen-nations study

NARCIS (Netherlands)

Arrindell, W.A.; van Well, S.; Kolk, A.M.; Barelds, D.P.H.; Oei, T.P.S.; Lau, P.Y.

2013-01-01

It was hypothesized that societies that put greater emphasis on men being rigidly committed to culturally accepted models of masculinity (nations with high Hofstede MASculinity scores) would report higher mean national levels of masculine gender role stress (MGRS) than societies that emphasize such

Higher Levels of Masculine Gender Role Stress in Masculine than in Feminine Nations : A Thirteen-Nations Study

NARCIS (Netherlands)

Arrindell, W. A.; van Well, Sonja; Kolk, Annemarie M.; Barelds, Dick P. H.; Oei, Tian P. S.; Lau, Pui Yi

It was hypothesized that societies that put greater emphasis on men being rigidly committed to culturally accepted models of masculinity (nations with high Hofstede MASculinity scores) would report higher mean national levels of masculine gender role stress (MGRS) than societies that emphasize such

Damage assessment of low-cycle fatigue by crack growth prediction. Fatigue life under cyclic thermal stress

International Nuclear Information System (INIS)

Kamaya, Masayuki

2013-01-01

The number of cycles to failure of specimens in fatigue tests can be estimated by predicting crack growth. Under a cyclic thermal stress caused by fluctuation of fluid temperature, due to the stress gradient in the thickness direction, the estimated fatigue life differs from that estimated for mechanical fatigue tests. In this paper, the influence of crack growth under cyclic thermal loading on the fatigue life was investigated. First, the thermal stress was derived by superposing analytical solutions, and then, the stress intensity factor was obtained by the weight function method. It was shown that the thermal stress depended not on the rate of the fluid temperature change but on the rise time, and the magnitude of the stress was increased as the rise time was decreased. The stress intensity factor under the cyclic thermal stress was smaller than that under the uniform stress distribution. The change in the stress intensity factor with the crack depth was almost the same regardless of the rise time. The estimated fatigue life under the cyclic thermal loading could be 1.6 times longer than that under the uniform stress distribution. The critical size for the fatigue life determination was assumed to be 3 mm for fatigue test specimens of 10 mm diameter. By evaluating the critical size by structural integrity analyses, the fatigue life was increased and the effect of the critical size on the fatigue life was more pronounced for the cyclic thermal stress. (author)

Higher emotional intelligence is related to lower test anxiety among students

Science.gov (United States)

Ahmadpanah, Mohammad; Keshavarz, Mohammadreza; Haghighi, Mohammad; Jahangard, Leila; Bajoghli, Hafez; Sadeghi Bahmani, Dena; Holsboer-Trachsler, Edith; Brand, Serge

2016-01-01

Background For students attending university courses, experiencing test anxiety (TA) dramatically impairs cognitive performance and success at exams. Whereas TA is a specific case of social phobia, emotional intelligence (EI) is an umbrella term covering interpersonal and intrapersonal skills, along with positive stress management, adaptability, and mood. In the present study, we tested the hypothesis that higher EI and lower TA are associated. Further, sex differences were explored. Method During an exam week, a total of 200 university students completed questionnaires covering sociodemographic information, TA, and EI. Results Higher scores on EI traits were associated with lower TA scores. Relative to male participants, female participants reported higher TA scores, but not EI scores. Intrapersonal and interpersonal skills and mood predicted low TA, while sex, stress management, and adaptability were excluded from the equation. Conclusion The pattern of results suggests that efforts to improve intrapersonal and interpersonal skills, and mood might benefit students with high TA. Specifically, social commitment might counteract TA. PMID:26834474

Testing predictive models of positive and negative affect with psychosocial, acculturation, and coping variables in a multiethnic undergraduate sample.

Science.gov (United States)

Kuo, Ben Ch; Kwantes, Catherine T

2014-01-01

Despite the prevalence and popularity of research on positive and negative affect within the field of psychology, there is currently little research on affect involving the examination of cultural variables and with participants of diverse cultural and ethnic backgrounds. To the authors' knowledge, currently no empirical studies have comprehensively examined predictive models of positive and negative affect based specifically on multiple psychosocial, acculturation, and coping variables as predictors with any sample populations. Therefore, the purpose of the present study was to test the predictive power of perceived stress, social support, bidirectional acculturation (i.e., Canadian acculturation and heritage acculturation), religious coping and cultural coping (i.e., collective, avoidance, and engagement coping) in explaining positive and negative affect in a multiethnic sample of 301 undergraduate students in Canada. Two hierarchal multiple regressions were conducted, one for each affect as the dependent variable, with the above described predictors. The results supported the hypotheses and showed the two overall models to be significant in predicting affect of both kinds. Specifically, a higher level of positive affect was predicted by a lower level of perceived stress, less use of religious coping, and more use of engagement coping in dealing with stress by the participants. Higher level of negative affect, however, was predicted by a higher level of perceived stress and more use of avoidance coping in responding to stress. The current findings highlight the value and relevance of empirically examining the stress-coping-adaptation experiences of diverse populations from an affective conceptual framework, particularly with the inclusion of positive affect. Implications and recommendations for advancing future research and theoretical works in this area are considered and presented.

Prediction of residual stress for dissimilar metals welding at nuclear power plants using fuzzy neural network models

International Nuclear Information System (INIS)

Na, Man Gyun; Kim, Jin Weon; Lim, Dong Hyuk

2007-01-01

A fuzzy neural network model is presented to predict residual stress for dissimilar metal welding under various welding conditions. The fuzzy neural network model, which consists of a fuzzy inference system and a neuronal training system, is optimized by a hybrid learning method that combines a genetic algorithm to optimize the membership function parameters and a least squares method to solve the consequent parameters. The data of finite element analysis are divided into four data groups, which are split according to two end-section constraints and two prediction paths. Four fuzzy neural network models were therefore applied to the numerical data obtained from the finite element analysis for the two end-section constraints and the two prediction paths. The fuzzy neural network models were trained with the aid of a data set prepared for training (training data), optimized by means of an optimization data set and verified by means of a test data set that was different (independent) from the training data and the optimization data. The accuracy of fuzzy neural network models is known to be sufficiently accurate for use in an integrity evaluation by predicting the residual stress of dissimilar metal welding zones

Burnout in radiation therapists: the predictive value of selected stressors

International Nuclear Information System (INIS)

Akroyd, Duane; Caison, Amy; Adams, Robert D.

2002-01-01

Purpose: As cancer caregivers, radiation therapists experience a variety of stresses that may develop into burnout, which has been demonstrated to impact patient care, employee health, and organizational effectiveness. The purpose of the study was to assess the levels of radiation therapists' burnout at three stages. Additionally, the ability of selected workplace variables to predict each of the three stages of burnout was examined. Methods and Materials: We used descriptive and inferential statistical analyses on reliable and valid instruments, which measured stress, burnout, and social support. Results: Radiation therapists have high levels of the first two stages of burnout: emotional exhaustion and depersonalization. Although personal stress, organizational stress, guidance, reassurance of worth, and work load predicted 50% or more of the variance in emotional exhaustion and depersonalization, their predictive ability for personal accomplishment was low. Conclusion: Efforts to alleviate burnout among radiation therapists within an organization should have positive effects, including increased quality of patient care, improved quality of work life, higher levels of job satisfaction, and commitment and lower staff turnover

Thermal stress prediction in mirror and multilayer coatings.

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Cheng, Xianchao; Zhang, Lin; Morawe, Christian; Sanchez Del Rio, Manuel

2015-03-01

Multilayer optics for X-rays typically consist of hundreds of periods of two types of alternating sub-layers which are coated on a silicon substrate. The thickness of the coating is well below 1 µm (tens or hundreds of nanometers). The high aspect ratio (∼10(7)) between the size of the optics and the thickness of the multilayer can lead to a huge number of elements (∼10(16)) for the numerical simulation (by finite-element analysis using ANSYS code). In this work, the finite-element model for thermal-structural analysis of multilayer optics has been implemented using the ANSYS layer-functioned elements. The number of meshed elements is considerably reduced and the number of sub-layers feasible for the present computers is increased significantly. Based on this technique, single-layer coated mirrors and multilayer monochromators cooled by water or liquid nitrogen are studied with typical parameters of heat-load, cooling and geometry. The effects of cooling-down of the optics and heating of the X-ray beam are described. It is shown that the influences from the coating on temperature and deformation are negligible. However, large stresses are induced in the layers due to the different thermal expansion coefficients between the layer and the substrate materials, which is the critical issue for the survival of the optics. This is particularly true for the liquid-nitrogen cooling condition. The material properties of thin multilayer films are applied in the simulation to predict the layer thermal stresses with more precision.

Stress, anxiety, and depression among medical students in a multiethnic setting.

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Kulsoom, Bibi; Afsar, Nasir Ali

2015-01-01

Contemporary literature suggests that medical education might adversely affect students' mental health. Alfaisal University in Riyadh, Saudi Arabia is a developing institution; hence, there has been a concern regarding the mental well-being of the students. This study was designed to assess the traits of depression, anxiety, and stress among students in relation to potential underlying reasons. All 575 medical students across the 5 years of study participated by filling out the Depression, Anxiety, and Stress Scale-21 (DASS-21) questionnaire anonymously twice. Firstly, 2-3 weeks before a major examination (pre-examination), and secondly, during regular classes (post-examination). Correlation was sought regarding sex, year of scholarship, attendance of a premedical university preparatory program (UPP), housing, and smoking. Subjective comments from students were also obtained. A total of 76.8% and 74.9% of students participated in pre-and post-examination groups, respectively. The majority were the children of expatriate workers in Saudi Arabia, and included Arabs, South Asians, and North Americans. Prevalence of depression, anxiety, and stress was high (43%, 63%, and 41%, respectively) which reduced (to 30%, 47%, and 30%, respectively) to some extent after examinations. Saudis and those who had attended UPP had higher DASS-21 scores. Smoking and female sex predicted higher levels of "baseline" depression, anxiety, or stress. The students perceived the curriculum and schedule to be the primary causes of their high DASS-21 scores. The students had high "baseline" traits of depression, anxiety, and stress, and these were higher if an examination was near, especially among Saudis and those who had attended UPP. Smoking and female sex predicted higher levels of "baseline" depression, anxiety, or stress. Students suggested that study burden and a busy schedule were the major reasons for their high DASS-21 scores.

Application of the predicted heat strain model in development of localized, threshold-based heat stress management guidelines for the construction industry.

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Rowlinson, Steve; Jia, Yunyan Andrea

2014-04-01

Existing heat stress risk management guidelines recommended by international standards are not practical for the construction industry which needs site supervision staff to make instant managerial decisions to mitigate heat risks. The ability of the predicted heat strain (PHS) model [ISO 7933 (2004). Ergonomics of the thermal environment analytical determination and interpretation of heat stress using calculation of the predicted heat strain. Geneva: International Standard Organisation] to predict maximum allowable exposure time (D lim) has now enabled development of localized, action-triggering and threshold-based guidelines for implementation by lay frontline staff on construction sites. This article presents a protocol for development of two heat stress management tools by applying the PHS model to its full potential. One of the tools is developed to facilitate managerial decisions on an optimized work-rest regimen for paced work. The other tool is developed to enable workers' self-regulation during self-paced work.

Proband Mental Health Difficulties and Parental Stress Predict Mental Health in Toddlers at High-Risk for Autism Spectrum Disorders.

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Crea, Katherine; Dissanayake, Cheryl; Hudry, Kristelle

2016-10-01

Family-related predictors of mental health problems were investigated among 30 toddlers at familial high-risk for autism spectrum disorders (ASD) and 28 controls followed from age 2- to 3-years. Parents completed the self-report Depression Anxiety Stress Scales and the parent-report Behavior Assessment System for Children. High-risk toddlers were assessed for ASD at 3-years. Parent stress and proband mental health difficulties predicted concurrent toddler mental health difficulties at 2-years, but only baseline proband internalising problems continued to predict toddler internalising problems at 3-years; high-risk status did not confer additional risk. Baseline toddler mental health difficulties robustly predicted later difficulties, while high-risk status and diagnostic outcome conferred no additional risk. A family systems perspective may be useful for understanding toddler mental health difficulties.

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

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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 sensitivity interacts with depression history to predict depressive symptoms among youth: Prospective changes following first depression onset

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Technow, Jessica R.; Hazel, Nicholas A.; Abela, John R. Z.; Hankin, Benjamin L.

2015-01-01

Predictors of depressive symptoms may differ before and after the first onset of major depression due to stress sensitization. Dependent stressors, or those to which characteristics of individuals contribute, have been shown to predict depressive symptoms in youth. The current study sought to clarify how stressors’ roles may differ before and after the first depressive episode. Adolescents (N = 382, aged 11 to 15 at baseline) were assessed at baseline and every three months over the course of two years with measures of stressors and depressive symptoms. Semi-structured interviews were conducted every 6 months to assess for clinically significant depressive episodes. Hierarchical linear modeling showed a significant interaction between history of depression and idiographic fluctuations in dependent stressors to predict prospective elevations of symptoms, such that dependent stressors were more predictive of depressive symptoms after onset of disorder. Independent stressors predicted symptoms, but the strength of the association did not vary by depression history. These results suggest a synthesis of stress sensitization and generation processes that might maintain inter-episode depressive symptoms among youth with a history of clinical depression. PMID:25123081

[Empowerment, stress vulnerability and burnout among Portuguese nursing staff].

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Orgambídez-Ramos, Alejandro; Borrego-Alés, Yolanda; Ruiz-Frutos, Carlos

2018-01-01

The work environment in Portuguese hospitals, characterized by economic cutbacks, can lead to higher levels of burnout experienced by nursing staff. Furthermore, vulnerability to stress can negatively affect the perception of burnout in the workplace. However, structural empowerment is an organizational process that can prevent and decrease burnout among nurses. Consequently, the aim of the study was to examine to what extent structural empowerment and vulnerability to stress can play a predictive role in core burnout in a sample of Portuguese nurses. A convenience sample of 297 nursing staff members from Portuguese hospitals was used in this study. Core burnout was negatively and significantly related to all the dimensions of structural empowerment, and it was positively and significantly related to vulnerability to stress. Regression models showed that core burnout was significantly predicted by access to funds, access to opportunities and vulnerability to stress. Organizational administrations must make every effort in designing interventions focused on structural empowerment, as well as interventions focused on individual interventions that enhance skills for coping with stress.

Stress-related increases in risk taking and attentional failures predict earlier relapse to smoking in young adults: A pilot investigation.

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Schepis, Ty S; Tapscott, Brian E; Krishnan-Sarin, Suchitra

2016-04-01

Substantial evidence links greater impulsivity and stress exposure to poorer smoking cessation outcomes. Results from adolescents also indicate that stress-related change in risk taking can impede cessation attempts. We investigated the effects of stress-related change in impulsivity, risk taking, attention and nicotine withdrawal, and craving in young adult smokers on time to smoking relapse in a relapse analogue paradigm. Twenty-six young adult smokers (50% women; mean age: 20.9 ± 1.8) were exposed to a stress imagery session followed by a contingency management-based relapse analogue paradigm. Participants smoked at least 5 cigarettes daily, with a mean baseline carbon monoxide (CO) level of 13.7 (± 5.1) ppm. Repeated measures analysis of variance (ANOVA) and paired t tests examined stress induction validity and Cox regressions of proportional hazards examined the effects of stress-related changes in nicotine withdrawal, nicotine craving, attention, impulsivity, and risk taking on time to relapse. While stress-related change in impulsivity, nicotine craving and withdrawal did not predict time to relapse (all ps > .10), greater stress-related increases in reaction time (RT) variability (p = .02) were predictive of shorter time to relapse, with trend-level findings for inattention and risk taking. Furthermore, changes in stress-related risk taking affected outcome in women more than in men, with a significant relationship between stress-related change in risk taking only in women (p = .026). Smoking cessation attempts in young adults may be adversely impacted by stress-related increases in risk taking and attentional disruption. Clinicians working with young adults attempting cessation may need to target these stress-related impairments by fostering more adaptive coping and resilience. (c) 2016 APA, all rights reserved).

Perceived Stress, Stressors, and Coping Mechanisms among Doctor of Pharmacy Students

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Jennifer W. Beall

2015-11-01

Full Text Available The primary purpose of this study was to examine perceived stress in doctor of pharmacy students during their first, second, and third years of their program in a fully implemented new curriculum. The secondary objectives were to determine if there is a relationship between perceived stress and certain demographic variables, to compare student pharmacist perceived stress to the perceived stress in the general population, and to examine student reported stressors during pharmacy school and coping strategies employed for those stressors. A previously validated survey (Perceived Stress Scale-10 was given to first, second, and third year student pharmacists. Females exhibited higher mean stress scores than males. The under 22 years and over 32 years age categories exhibited higher mean stress scores than the 22 to 26 year old student population. There was no significant difference in perceived stress scores between classes of the program. Only a portion of the variation in stress scores was predicted by gender, age, marital status, race, and year in curriculum. Stress scores among these student pharmacists are higher overall than those in previously published probability samples in the general population. Class assignments and completing electronic portfolios were the top stressors reported. Spending time with family and friends was the most frequent coping mechanism reported. Programming related to stress reduction (particularly among female and nontraditional age students appears warranted.

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

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

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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.

Social support attenuates the harmful effects of stress in healthy adult women.

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Stein, Elizabeth R; Smith, Bruce W

2015-12-01

The purpose of this study was to test the hypothesis that social support buffers the effects of perceived stress on physical symptoms in healthy women. The study was conducted in the Southwest United States and data were collected from 2006 to 2010. Participants were 52 healthy adult women who completed a baseline questionnaire and a 21-day daily diary. Social support was assessed in the baseline questionnaire and perceived stress and physical symptoms were assessed in the daily diary. Multilevel analyses were used to predict both same day and next day physical symptoms from baseline social support and daily perceived stress. The hypotheses were supported when predicting both same and next day physical symptoms. For the same day, perceived stress and the social support × perceived stress interaction were both related to physical symptoms. For the next day, the social support × perceived stress interaction but not perceived stress was related to physical symptoms when controlling for previous day physical symptoms. The interactions were such that women higher in social support had smaller increases in same and next day physical symptoms on days of higher perceived stress than women lower in social support. Social support may buffer the effects of daily perceived stress on physical symptoms in healthy women. Future research should investigate what aspects and in what contexts social support may reduce the effects of perceived stress on physical symptoms and examine how social support may affect the development of long-term health problems through increases in daily physical symptoms. Copyright © 2015 Elsevier Ltd. All rights reserved.

Teacher drug use: a response to occupational stress.

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Watts, W D; Short, A P

1990-01-01

Work-related stress is predicted to be correlated with wanting to leave the teaching profession and drug use. A stratified random sample of 500 Texas teachers was surveyed (56.5% responded), regarding working conditions, collegial and supervisory relationships, job satisfaction, rigidity of attitudes and drug use. Two-thirds of teachers may want to quit the profession, while 36.4 percent are likely to quit. Teachers report higher rates than a national sample of lifetime alcohol, amphetamine, and tranquilizer use and higher rates of alcohol use in the last year and last month. Selected measures of stress are correlated with drug use, particularly amphetamine use, over the lifetime, last year, and last month.

Testing the adaptation to poverty-related stress model: predicting psychopathology symptoms in families facing economic hardship.

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Wadsworth, Martha E; Raviv, Tali; Santiago, Catherine Decarlo; Etter, Erica M

2011-01-01

This study tested the Adaptation to Poverty-related Stress Model and its proposed relations between poverty-related stress, effortful and involuntary stress responses, and symptoms of psychopathology in an ethnically diverse sample of low-income children and their parents. Prospective Hierarchical Linear Modeling analyses conducted with 98 families (300 family members: 136 adults, 82 adolescents and preadolescents, 82 school-age children) revealed that, consistent with the model, primary and secondary control coping were protective against poverty-related stress primarily for internalizing symptoms. Conversely, disengagement coping exacerbated externalizing symptoms over time. In addition, involuntary engagement stress responses exacerbated the effects of poverty-related stress for internalizing symptoms, whereas involuntary disengagement responses exacerbated externalizing symptoms. Age and gender effects were found in most models, reflecting more symptoms of both types for parents than children and higher levels of internalizing symptoms for girls.

Stress in junior enlisted air force women with and without children.

Science.gov (United States)

Hopkins-Chadwick, Denise L; Ryan-Wenger, Nancy

2009-04-01

The objective was to determine if there are differences between young enlisted military women with and without preschool children on role strain, stress, health, and military career aspiration and to identify the best predictors of these variables. The study used a cross-sectional descriptive design of 50 junior Air Force women with preschool children and 50 women without children. There were no differences between women with and without children in role strain, stress, health, and military career aspiration. In all women, higher stress was moderately predictive of higher role strain (39.9% of variance explained) but a poor predictor of career aspiration (3.8% of variance explained). Lower mental health scores were predicted by high stress symptoms (27.9% of variance explained), low military career aspiration (4.1% of variance explained), high role strain (4.0% of variance explained), and being non-White (3.9% of variance explained). Aspiration for a military career was predicted by high perceived availability of military resources (16.8% of variance explained), low family of origin socioeconomic status (4.5% of variance explained), and better mental health status (3.3% of variance explained). Contrary to theoretical expectations, in this sample, motherhood was not a significant variable. Increased role strain, stress, and decreased health as well as decreased military career aspiration were evident in both groups and may have more to do with individual coping skills and other unmeasured resources. More research is needed to determine what nursing interventions are needed to best support both groups of women.

Adult age differences in prospective memory in the laboratory: are they related to higher stress levels in the elderly?

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Ihle, Andreas; Kliegel, Matthias; Hering, Alexandra; Ballhausen, Nicola; Lagner, Prune; Benusch, Julia; Cichon, Anja; Zergiebel, Annekathrin; Oris, Michel; Schnitzspahn, Katharina M

2014-01-01

To explain age deficits found in laboratory-based prospective memory (PM) tasks, it has recently been suggested that the testing situation per se may be more stressful for older adults, thereby impairing their performance. To test this assumption, subjective and physiological stress levels were assessed at several times during the experiment in 33 younger and 29 older adults. In addition, half of participants were randomized in a condition where they completed a relaxation intervention before performing a time-based PM task. Results confirmed the age deficit in laboratory PM. Subjective and physiological stress levels showed no age difference and no detrimental association with PM. The intervention successfully reduced stress levels in both age groups but had no effect on PM or the age deficit. In conclusion, data suggest that age deficits usually observed in laboratory PM may not be due to higher stress levels in the older adults.

Resources predicting positive and negative affect during the experience of stress: a study of older Asian Indian immigrants in the United States.

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Diwan, Sadhna; Jonnalagadda, Satya S; Balaswamy, Shantha

2004-10-01

Using the life stress model of psychological well-being, in this study we examined risks and resources predicting the occurrence of both positive and negative affect among older Asian Indian immigrants who experienced stressful life events. We collected data through a telephone survey of 226 respondents (aged 50 years and older) in the Southeastern United States. We used hierarchical, negative binomial regression analyses to examine correlates of positive and negative affect. Different coping resources influenced positive and negative affect when stressful life events were controlled for. Being female was a common risk factor for poorer positive and increased negative affect. Satisfaction with friendships and a cultural or ethnic identity that is either bicultural or more American were predictive of greater positive affect. Greater religiosity and increased mastery were resources predicting less negative affect. Cognitive and structural interventions that increase opportunities for social integration, increasing mastery, and addressing spiritual concerns are discussed as ways of coping with stress to improve the well-being of individuals in this immigrant community.

Correlates and predictors of parenting stress among internationally adopting mothers: A longitudinal investigation.

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Viana, Andres G; Welsh, Janet A

2010-07-01

This study examined correlates and predictors of parenting stress among internationally adopting (IA) mothers with the goal of expanding the knowledge base on the experiences of adoptive parents. One hundred and forty-three IA mothers completed pre-adoption (Time 0) and six months post-adoption (Time 1) surveys with questions regarding child-, parent-, and family-related characteristics. Mother reports of higher depression symptoms, higher expectations of child developmental and behavioral/emotional problems, and a greater number of children in the family at pre-adoption were significantly related to higher parenting stress six months post-adoption. In contrast, mother reports of higher expectations for child acceptance and higher perceived social support at pre-adoption were significantly related to lower parenting stress six months post-adoption. Higher maternal depression symptoms, higher expectations of child behavior/emotional problems, and a greater number of children in the family at pre-adoption together accounted for 22% of the variance in parenting stress six months post-adoption. Concurrent higher maternal depression symptoms and higher reports of child behavioral/emotional problems predicted higher parenting stress six months post-adoption over and above pre-adoption predictors, and accounted for an additional 33% of the variance. Results and directions for future research are discussed from a transactional perspective, with particular emphasis on the importance of pre-adoptive information for adoption research and practice.

Damage assessment of low-cycle fatigue by crack growth prediction. Fatigue life under cyclic thermal stress

International Nuclear Information System (INIS)

Kamaya, Masayuki

2013-01-01

The number of cycles to failure of specimens in fatigue tests can be estimated by predicting crack growth. Under a cyclic thermal stress caused by fluctuation of fluid temperature, due to the stress gradient in the thickness direction, the estimated fatigue life differs from that estimated for mechanical fatigue tests. In this paper, the influence of crack growth under cyclic thermal loading on the fatigue life was investigated. First, the thermal stress was derived by superposing analytical solutions, and then, the stress intensity factor was obtained by the weight function method. It was shown that the thermal stress depended not on the rate of the fluid temperature change but on the rise time, and the magnitude of the stress was increased as the rise time was decreased. The stress intensity factor under the cyclic thermal stress was smaller than that under the uniform stress distribution. The change in the stress intensity factor with the crack depth did not depend on the heat transfer coefficient and only slightly depended on the rise time. The estimated fatigue life under the cyclic thermal loading could be 1.6 times longer than that under the uniform stress distribution. The critical size for the fatigue life determination was assumed to be 3 mm for fatigue test specimens of 10 mm diameter. By evaluating the critical size by structural integrity analyses, the fatigue life was increased and the effect of the critical size on the fatigue life was more pronounced for the cyclic thermal stress. (author)

Exoproteome analysis reveals higher abundance of proteins linked to alkaline stress in persistent Listeria monocytogenes strains.

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Rychli, Kathrin; Grunert, Tom; Ciolacu, Luminita; Zaiser, Andreas; Razzazi-Fazeli, Ebrahim; Schmitz-Esser, Stephan; Ehling-Schulz, Monika; Wagner, Martin

2016-02-02

The foodborne pathogen Listeria monocytogenes, responsible for listeriosis a rare but severe infection disease, can survive in the food processing environment for month or even years. So-called persistent L. monocytogenes strains greatly increase the risk of (re)contamination of food products, and are therefore a great challenge for food safety. However, our understanding of the mechanism underlying persistence is still fragmented. In this study we compared the exoproteome of three persistent strains with the reference strain EGDe under mild stress conditions using 2D differential gel electrophoresis. Principal component analysis including all differentially abundant protein spots showed that the exoproteome of strain EGDe (sequence type (ST) 35) is distinct from that of the persistent strain R479a (ST8) and the two closely related ST121 strains 4423 and 6179. Phylogenetic analyses based on multilocus ST genes showed similar grouping of the strains. Comparing the exoproteome of strain EGDe and the three persistent strains resulted in identification of 22 differentially expressed protein spots corresponding to 16 proteins. Six proteins were significantly increased in the persistent L. monocytogenes exoproteomes, among them proteins involved in alkaline stress response (e.g. the membrane anchored lipoprotein Lmo2637 and the NADPH dehydrogenase NamA). In parallel the persistent strains showed increased survival under alkaline stress, which is often provided during cleaning and disinfection in the food processing environments. In addition, gene expression of the proteins linked to stress response (Lmo2637, NamA, Fhs and QoxA) was higher in the persistent strain not only at 37 °C but also at 10 °C. Invasion efficiency of EGDe was higher in intestinal epithelial Caco2 and macrophage-like THP1 cells compared to the persistent strains. Concurrently we found higher expression of proteins involved in virulence in EGDe e.g. the actin-assembly-inducing protein ActA and the

Culture shapes whether the pursuit of happiness predicts higher or lower well-being

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Ford, Brett Q.; Dmitrieva, Julia O.; Heller, Daniel; Chentsova-Dutton, Yulia; Grossmann, Igor; Tamir, Maya; Uchida, Yukiko; Koopmann-Holm, Birgit; Floerke, Victoria A.; Uhrig, Meike; Bokhan, Tatiana; Mauss, Iris B.

2015-01-01

Pursuing happiness can paradoxically impair well-being. Here, we propose the potential downsides to pursuing happiness may be specific to individualistic cultures. In collectivistic (vs. individualistic) cultures, pursuing happiness may be more successful because happiness is viewed – and thus pursued – in relatively socially-engaged ways. In four geographical regions that vary in level of collectivism (U.S., Germany, Russia, East Asia), we assessed participants’ well-being, motivation to pursue happiness, and to what extent they pursued happiness in socially-engaged ways. Motivation to pursue happiness predicted lower well-being in the U.S., did not predict well-being in Germany, and predicted higher well-being in Russia and in East Asia. These cultural differences in the link between motivation to pursue happiness and well-being were explained by cultural differences in the socially-engaged pursuit of happiness. These findings suggest that culture shapes whether the pursuit of happiness is linked with better or worse well-being, perhaps via how people pursue happiness. PMID:26347945

Early life stress predicts negative urgency through brooding, depending on 5-HTTLPR genotype: A pilot study with 6-month follow-up examining suicide ideation.

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Valderrama, Jorge; Miranda, Regina

2017-12-01

The present study examined the interaction between early life stress and 5-HTT genotypes in predicting two risk factors for suicidal behavior - the brooding subtype of rumination and impulsivity, in the form of negative urgency - over time. Furthermore, we examined early life stress, brooding, and impulsivity as predictors of suicidal ideation over time. Participants with and without a history of early life stress were genotyped for the 5-HTTLPR polymorphism and completed assessments assessing brooding and negative urgency at baseline and 6-month follow up. Early life emotional abuse was associated with negative urgency at follow-up. We found an indirect effect of early life emotional abuse on negative urgency through brooding among individuals with 5-HTT low expressing genotypes but not among individuals with 5-HTT high expressing genotypes. Further, a logistic regression analysis revealed that negative urgency was associated with higher odds (O.R. = 16.2) of reporting suicide ideation (versus no ideation) at follow-up. Our findings suggest that brooding and negative urgency may result from the interaction between early life emotional abuse and 5-HTT low expressing genotypes. Further research is necessary to understand how early life stress interacts with 5-HTT genotypes to confer risk for suicidal behavior through psychological mechanisms. Copyright © 2017 Elsevier B.V. All rights reserved.

Characteristics of people with self-reported stress-precipitated seizures.

Science.gov (United States)

Privitera, Michael; Walters, Michael; Lee, Ikjae; Polak, Emily; Fleck, Adrienne; Schwieterman, Donna; Haut, Sheryl R

2014-12-01

Stress is the most common patient-reported seizure precipitant. We aimed to determine mood and epilepsy characteristics of people who report stress-precipitated seizures. Sequential patients at a tertiary epilepsy center were surveyed about stress as a seizure precipitant. We asked whether acute (lasting minutes-hours) or chronic (lasting days-months) stress was a seizure precipitant, whether stress reduction had been tried, and what effect stress reduction had on seizure frequency. We collected information on antiepileptic drugs, history of depression and anxiety disorder, prior or current treatment for depression or anxiety, and scores on the Neurological Disorders Depression Inventory (NDDI-E) and Generalized Anxiety Disorders-7 (GAD-7) instruments, which are administered at every visit in our Epilepsy Center. We also asked whether respondents thought that they could predict their seizures to determine if stress as a seizure precipitant was correlated with seizure self-prediction. Two hundred sixty-six subjects were included: 219 endorsed stress as a seizure precipitant [STRESS (+)] and 47 did not [STRESS (-)]. Among STRESS (+) subjects, 85% endorsed chronic stress as a seizure precipitant, and 68% endorsed acute stress as a seizure precipitant. In STRESS (+) subjects, 57% had used some type of relaxation or stress reduction method (most commonly yoga, exercise and meditation), and, of those who tried, 88% thought that these methods improved seizures. Among STRESS (-) subjects, 25% had tried relaxation or stress reduction, and 71% thought that seizures improved. Although univariate analysis showed multiple associations with stress as a seizure precipitant, in the multivariable logistic regression, only the GAD-7 score was associated with STRESS (+) (OR = 1.18 [1.03-1.35], p = 0.017). Subjects who reported stress as a seizure precipitant were more likely to report an ability to self-predict seizures (p < 0.001). Stress-precipitated seizures are commonly reported

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

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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.

Stress, anxiety, and depression among medical students in a multiethnic setting

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Kulsoom B

2015-07-01

Full Text Available Bibi Kulsoom,1 Nasir Ali Afsar2 1Department of Biochemistry, 2Department of Pharmacology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia Background: Contemporary literature suggests that medical education might adversely affect students’ mental health. Alfaisal University in Riyadh, Saudi Arabia is a developing institution; hence, there has been a concern regarding the mental well-being of the students.Objectives: This study was designed to assess the traits of depression, anxiety, and stress among students in relation to potential underlying reasons.Methods: All 575 medical students across the 5 years of study participated by filling out the Depression, Anxiety, and Stress Scale-21 (DASS-21 questionnaire anonymously twice. Firstly, 2–3 weeks before a major examination (pre-examination, and secondly, during regular classes (post-examination. Correlation was sought regarding sex, year of scholarship, attendance of a premedical university preparatory program (UPP, housing, and smoking. Subjective comments from students were also obtained.Results: A total of 76.8% and 74.9% of students participated in pre- and post-examination groups, respectively. The majority were the children of expatriate workers in Saudi Arabia, and included Arabs, South Asians, and North Americans. Prevalence of depression, anxiety, and stress was high (43%, 63%, and 41%, respectively which reduced (to 30%, 47%, and 30%, respectively to some extent after examinations. Saudis and those who had attended UPP had higher DASS-21 scores. Smoking and female sex predicted higher levels of “baseline” depression, anxiety, or stress. The students perceived the curriculum and schedule to be the primary causes of their high DASS-21 scores.Conclusion: The students had high “baseline” traits of depression, anxiety, and stress, and these were higher if an examination was near, especially among Saudis and those who had attended UPP. Smoking and female sex

Fatigue life estimation considering welding residual stress and hot-spot stress of welded components

International Nuclear Information System (INIS)

Han, S. H.; Lee, T. K.; Shin, B. C.

2002-01-01

The fatigue life of welded joints is sensitive to welding residual stress and complexity of their geometric shapes. To predict the fatigue life more reasonably, the effects of welding residual stress and its relaxation have to be considered quantitatively which are equivalent to mean stress by external loads. The hot-spot stress concept should be also adopted which can be reduce the dependence of fatigue strengths for various welding details. Considering the factors mentioned above, a fatigue life prediction model using the modified Goodman's diagram was proposed. In this model, an equivalent stress was introduced which are composed of the mean stress based on the hot-spot stress concept and the relaxed welding residual stress. From the verification of the proposed model to real welding details, it is confirmed that this model can be applied to predict reasonably their fatigue lives

Neural Reactivity to Emotional Stimuli Prospectively Predicts the Impact of a Natural Disaster on Psychiatric Symptoms in Children.

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Kujawa, Autumn; Hajcak, Greg; Danzig, Allison P; Black, Sarah R; Bromet, Evelyn J; Carlson, Gabrielle A; Kotov, Roman; Klein, Daniel N

2016-09-01

Natural disasters expose entire communities to stress and trauma, leading to increased risk for psychiatric symptoms. Yet, the majority of exposed individuals are resilient, highlighting the importance of identifying underlying factors that contribute to outcomes. The current study was part of a larger prospective study of children in Long Island, New York (n = 260). At age 9, children viewed unpleasant and pleasant images while the late positive potential (LPP), an event-related potential component that reflects sustained attention toward salient information, was measured. Following the event-related potential assessment, Hurricane Sandy, the second costliest hurricane in United States history, hit the region. Eight weeks after the hurricane, mothers reported on exposure to hurricane-related stress and children's internalizing and externalizing symptoms. Symptoms were reassessed 8 months after the hurricane. The LPP predicted both internalizing and externalizing symptoms after accounting for prehurricane symptomatology and interacted with stress to predict externalizing symptoms. Among children exposed to higher levels of hurricane-related stress, enhanced neural reactivity to unpleasant images predicted greater externalizing symptoms 8 weeks after the disaster, while greater neural reactivity to pleasant images predicted lower externalizing symptoms. Moreover, interactions between the LPP and stress continued to predict externalizing symptoms 8 months after the hurricane. Results indicate that heightened neural reactivity and attention toward unpleasant information, as measured by the LPP, predispose children to psychiatric symptoms when exposed to higher levels of stress related to natural disasters, while greater reactivity to and processing of pleasant information may be a protective factor. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

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.

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.

Perspectives of Student Combat Veterans Diagnosed with Posttraumatic Stress Disorder (PTSD) on Their Experiences in Higher Education

Science.gov (United States)

Ryder, Richard R., Jr.

2012-01-01

The intention of the this qualitative study was to explore the perceptions of military combat veteran college students (MCVCS) who self-identify as having been diagnosed with Posttraumatic Stress Disorder (PTSD). They were offered the opportunity to answer questions on the experiences they have in higher education. The study inquired on the…

Negative life events and symptoms of depression and anxiety: stress causation and/or stress generation.

Science.gov (United States)

Phillips, Anna C; Carroll, Douglas; Der, Geoff

2015-01-01

Stressful life events are known to contribute to development of depression; however, it is possible this link is bidirectional. The present study examined whether such stress generation effects are greater than the effects of stressful life events on depression, and whether stress generation is also evident with anxiety. Participants were two large age cohorts (N = 732 aged 44 years; N = 705 aged 63 years) from the West of Scotland Twenty-07 study. Stressful life events, depression, and anxiety symptoms were measured twice five years apart. Cross-lagged panel analysis examined the mutual influences of stressful life events on depression and on anxiety over time. Life events predicted later depressive symptomatology (p = .01), but the depression predicting life events relationship was less strong (p = .06), whereas earlier anxiety predicted life events five years later (p = .001). There was evidence of sex differences in the extent to which life events predicted later anxiety. This study provides evidence of stress causation for depression and weaker evidence for stress generation. In contrast, there was strong evidence of stress generation for anxiety but weaker evidence for stress causation, and that differed for men and women.

Wine grape cultivar influence on the performance of models that predict the lower threshold canopy temperature of a water stress index

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The calculation of a thermal based Crop Water Stress Index (CWSI) requires an estimate of canopy temperature under non-water stressed conditions. The objective of this study was to assess the influence of different wine grape cultivars on the performance of models that predict canopy temperature non...

Language Acculturation, Acculturation-Related Stress, and Marital Quality in Chinese American Couples.

Science.gov (United States)

Hou, Yang; Neff, Lisa A; Kim, Su Yeong

2018-04-01

The current study examines the longitudinal indirect pathways linking language acculturation to marital quality. Three waves of data were collected from 416 Chinese American couples over eight years ( M age.wave1 = 48 for husbands, 44 for wives). Actor-partner interdependence model analyses revealed that for both husbands and wives, lower levels of language acculturation were associated with higher levels of stress over being stereotyped as a perpetual foreigner. Individuals' foreigner stress, in turn, was directly related to greater levels of their own and their partners' marital warmth, suggesting that foreigner stress may have some positive relational effects. However, individuals' foreigner stress also was associated with increases in their own depressive symptoms, which predicted higher levels of marital hostility in the partner. Overall, these results underscore the complexity of how language acculturation and foreigner stress relate to marital quality and the importance of considering the interdependence of the marital system.

Higher Temperature at Lower Elevation Sites Fails to Promote Acclimation or Adaptation to Heat Stress During Pollen Germination

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Lluvia Flores-Rentería

2018-04-01

Full Text Available High temperatures associated with climate change are expected to be detrimental for aspects of plant reproduction, such as pollen viability. We hypothesized that (1 higher peak temperatures predicted with climate change would have a minimal effect on pollen viability, while high temperatures during pollen germination would negatively affect pollen viability, (2 high temperatures during pollen dispersal would facilitate acclimation to high temperatures during pollen germination, and (3 pollen from populations at sites with warmer average temperatures would be better adapted to high temperature peaks. We tested these hypotheses in Pinus edulis, a species with demonstrated sensitivity to climate change, using populations along an elevational gradient. We tested for acclimation to high temperatures by measuring pollen viability during dispersal and germination stages in pollen subjected to 30, 35, and 40°C in a factorial design. We also characterized pollen phenology and measured pollen heat tolerance using trees from nine sites along a 200 m elevational gradient that varied 4°C in temperature. We demonstrated that this gradient is biologically meaningful by evaluating variation in vegetation composition and P. edulis performance. Male reproduction was negatively affected by high temperatures, with stronger effects during pollen germination than pollen dispersal. Populations along the elevational gradient varied in pollen phenology, vegetation composition, plant water stress, nutrient availability, and plant growth. In contrast to our hypothesis, pollen viability was highest in pinyons from mid-elevation sites rather than from lower elevation sites. We found no evidence of acclimation or adaptation of pollen to high temperatures. Maximal plant performance as measured by growth did not occur at the same elevation as maximal pollen viability. These results indicate that periods of high temperature negatively affected sexual reproduction, such that

The Usefulness of Assessing and Identifying Workers' Temperaments and Their Effects on Occupational Stress in the Workplace.

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Yasuhiko Deguchi

Full Text Available The relationship between temperaments and mental disorders has been reported in previous studies, but there has been little attention to temperaments in the occupational safety and health research. The aim of this study was to clarify the effects of temperaments on occupational stress among local government employees. The subjects were 145 Japanese daytime workers in local government. Temperaments were assessed by the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego-Auto questionnaire (TEMPS-A. Occupational stress was assessed using the Generic Job Stress Questionnaire (GJSQ. Hierarchical multiple linear regression analysis was used. Hyperthymic temperament predicted a higher level of job control, and a lower level of role ambiguity and job future ambiguity. Irritable temperament predicted a lower level of social support from supervisors and a higher level of role conflict, variance in workload and intragroup conflict. Anxious temperament predicted a lower level of social support from coworkers and a higher level of job future ambiguity. The sample size was small. Only Japanese local government employees were surveyed. Hyperthymic temperament played a protective role, and irritable, anxious temperament played a vulnerable role against one's own occupational stress and recognizing the roles they play in work life would lead to self-insight. Additionally, recognition of the temperaments and temperament-related stressors by one's supervisors or coworkers would facilitate provision of social support.

Slat Noise Predictions Using Higher-Order Finite-Difference Methods on Overset Grids

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Housman, Jeffrey A.; Kiris, Cetin

2016-01-01

Computational aeroacoustic simulations using the structured overset grid approach and higher-order finite difference methods within the Launch Ascent and Vehicle Aerodynamics (LAVA) solver framework are presented for slat noise predictions. The simulations are part of a collaborative study comparing noise generation mechanisms between a conventional slat and a Krueger leading edge flap. Simulation results are compared with experimental data acquired during an aeroacoustic test in the NASA Langley Quiet Flow Facility. Details of the structured overset grid, numerical discretization, and turbulence model are provided.

Post-traumatic stress symptom clusters in acute whiplash associated disorder and their prediction of chronic pain-related disability.

Science.gov (United States)

Maujean, Annick; Gullo, Matthew J; Andersen, Tonny Elmose; Ravn, Sophie Lykkegaard; Sterling, Michele

2017-11-01

The presence of post-traumatic stress disorder (PTSD) symptoms has been found to be associated with an increased risk of persisting neck pain and disability in motor vehicle crash (MVC) survivors with whiplash injuries. The findings are mixed as to which PTSD symptom(s) best predicts recovery in this population. The aims were (1) to explore the factor structure of the Post-traumatic Stress Diagnostic Scale (PDS) in a sample of acute whiplash-injured individuals following a MVC and (2) to identify the PTSD-symptom clusters that best predict long-term neck pain-related disability in this population as measured by the Neck Pain Disability Index (NDI). A sample (N = 146) of whiplash-injured individuals completed the NDI and the PDS at baseline (whiplash-injured individuals following a MVC.

THE RELATIONSHIP BETWEEN MENTAL TOUGHNESS, STRESS, AND BURNOUT AMONG ADOLESCENTS: A LONGITUDINAL STUDY WITH SWISS VOCATIONAL STUDENTS (.).

Science.gov (United States)

Gerber, Markus; Feldmeth, Anne Karina; Lang, Christin; Brand, Serge; Elliot, Catherine; Holsboer-Trachsler, Edith; Pühse, Uwe

2015-12-01

Past research has shown that higher stress is associated with increased burnout symptoms. The purpose of this study was to test whether mental toughness protects against symptoms of burnout and whether mental toughness moderates the relationship between perceived stress and burnout over time. Fifty-four vocational students (M age = 18.1 yr., SD = 1.2; 27 males, 27 females) completed self-report questionnaires twice, 10 mo. apart. Perceived stress, mental toughness, and burnout were measured using the Adolescent Stress Questionnaire (ASQ), the Mental Toughness Questionnaire (MTQ), and the Shirom-Melamed Burnout Measure (SMBM). Students who perceived higher stress and lower mental toughness scores reported higher burnout symptoms. Although no significant interaction effects were found between stress and mental toughness in the prediction of burnout, the graphical inspection of the interactions indicated that among students with high stress, those with high mental toughness remained below the cutoff for mild burnout, whereas an increase in burnout symptoms was observable among peers with low mental toughness.

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

Science.gov (United States)

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.

Simulation of three-dimensional tectonic stress fields and quantitative prediction of tectonic fracture within the Damintun Depression, Liaohe Basin, northeast China

Science.gov (United States)

Guo, Peng; Yao, Leihua; Ren, Desheng

2016-05-01

Tectonic fractures are important factors that influence oil and natural gas migration and accumulation within "buried hill" reservoirs. To obtain a quantitative forecast of the development and distribution of reservoir fractures in the Damintun Depression, we analyzed the characteristics of regional structural evolution and paleotectonic stress field setting. A reasonable geological model of the research area was built based on an interpretation of the geological structure, a test for rock mechanics, and experiment on acoustic emission. Thereafter, a three-dimensional paleotectonic stress field during the Yanshan movement was simulated by the finite element method. Rock failure criterion and comprehensive evaluation coefficient of fractures were used to determine the quantitative development of fractures and predict zones that are prone to fracture development. Under an intense Yanshan movement, high stress strength is distributed in the south and northeast parts of the study area, where stress is extremely high. The fracture development zones are mainly controlled by the tectonic stress field and typically located in the same areas as those of high maximum principal and shear stresses. The predicted areas with developed fractures are consistent with the wells with high fracture linear density and in locations with high-producing oil and gas wells.

Prenatal maternal stress shapes children's theory of mind: the QF2011 Queensland Flood Study.

Science.gov (United States)

Simcock, G; Kildea, S; Elgbeili, G; Laplante, D P; Cobham, V; King, S

2017-08-01

Research shows that stress in pregnancy has powerful and enduring effects on many facets of child development, including increases in behavior problems and neurodevelopmental disorders. Theory of mind is an important aspect of child development that is predictive of successful social functioning and is impaired in children with autism. A number of factors related to individual differences in theory of mind have been identified, but whether theory of mind development is shaped by prenatal events has not yet been examined. In this study we utilized a sudden onset flood that occurred in Queensland, Australia in 2011 to examine whether disaster-related prenatal maternal stress predicts child theory of mind and whether sex of the child or timing of the stressor in pregnancy moderates these effects. Higher levels of flood-related maternal subjective stress, but not objective hardship, predicted worse theory of mind at 30 months (n=130). Further, maternal cognitive appraisal of the flood moderated the effects of stress in pregnancy on girls' theory of mind performance but not boys'. These results illuminate how stress in pregnancy can shape child development and the findings are discussed in relation to biological mechanisms in pregnancy and stress theory.

Culture shapes whether the pursuit of happiness predicts higher or lower well-being.

Science.gov (United States)

Ford, Brett Q; Dmitrieva, Julia O; Heller, Daniel; Chentsova-Dutton, Yulia; Grossmann, Igor; Tamir, Maya; Uchida, Yukiko; Koopmann-Holm, Birgit; Floerke, Victoria A; Uhrig, Meike; Bokhan, Tatiana; Mauss, Iris B

2015-12-01

Pursuing happiness can paradoxically impair well-being. Here, the authors propose the potential downsides to pursuing happiness may be specific to individualistic cultures. In collectivistic (vs. individualistic) cultures, pursuing happiness may be more successful because happiness is viewed--and thus pursued--in relatively socially engaged ways. In 4 geographical regions that vary in level of collectivism (United States, Germany, Russia, East Asia), we assessed participants' well-being, motivation to pursue happiness, and to what extent they pursued happiness in socially engaged ways. Motivation to pursue happiness predicted lower well-being in the United States, did not predict well-being in Germany, and predicted higher well-being in Russia and in East Asia. These cultural differences in the link between motivation to pursue happiness and well-being were explained by cultural differences in the socially engaged pursuit of happiness. These findings suggest that culture shapes whether the pursuit of happiness is linked with better or worse well-being, perhaps via how people pursue happiness. (c) 2015 APA, all rights reserved).

Automatic Earthquake Shear Stress Measurement Method Developed for Accurate Time- Prediction Analysis of Forthcoming Major Earthquakes Along Shallow Active Faults

Science.gov (United States)

Serata, S.

2006-12-01

The Serata Stressmeter has been developed to measure and monitor earthquake shear stress build-up along shallow active faults. The development work made in the past 25 years has established the Stressmeter as an automatic stress measurement system to study timing of forthcoming major earthquakes in support of the current earthquake prediction studies based on statistical analysis of seismological observations. In early 1982, a series of major Man-made earthquakes (magnitude 4.5-5.0) suddenly occurred in an area over deep underground potash mine in Saskatchewan, Canada. By measuring underground stress condition of the mine, the direct cause of the earthquake was disclosed. The cause was successfully eliminated by controlling the stress condition of the mine. The Japanese government was interested in this development and the Stressmeter was introduced to the Japanese government research program for earthquake stress studies. In Japan the Stressmeter was first utilized for direct measurement of the intrinsic lateral tectonic stress gradient G. The measurement, conducted at the Mt. Fuji Underground Research Center of the Japanese government, disclosed the constant natural gradients of maximum and minimum lateral stresses in an excellent agreement with the theoretical value, i.e., G = 0.25. All the conventional methods of overcoring, hydrofracturing and deformation, which were introduced to compete with the Serata method, failed demonstrating the fundamental difficulties of the conventional methods. The intrinsic lateral stress gradient determined by the Stressmeter for the Japanese government was found to be the same with all the other measurements made by the Stressmeter in Japan. The stress measurement results obtained by the major international stress measurement work in the Hot Dry Rock Projects conducted in USA, England and Germany are found to be in good agreement with the Stressmeter results obtained in Japan. Based on this broad agreement, a solid geomechanical

Post-traumatic stress symptom clusters in acute whiplash associated disorder and their prediction of chronic pain-related disability

OpenAIRE

Annick Maujean; Matthew J. Gullo; Tonny Elmose Andersen; Sophie Lykkegaard Ravn; Michele Sterling

2017-01-01

Abstract. Introduction:. The presence of post-traumatic stress disorder (PTSD) symptoms has been found to be associated with an increased risk of persisting neck pain and disability in motor vehicle crash (MVC) survivors with whiplash injuries. The findings are mixed as to which PTSD symptom(s) best predicts recovery in this population. Objectives:. The aims were (1) to explore the factor structure of the Post-traumatic Stress Diagnostic Scale (PDS) in a sample of acute whiplash-injured in...

Predicted tyre-soil interface area and vertical stress distribution based on loading characteristics

DEFF Research Database (Denmark)

Schjønning, Per; Stettler, M.; Keller, Thomas

2015-01-01

The upper boundary condition for all models simulating stress patterns throughout the soil profile is the stress distribution at the tyre–soil interface. The so-called FRIDA model (Schjønning et al., 2008. Biosyst. Eng. 99, 119–133) treats the contact area as a superellipse and has been shown...... of the actual to recommended inflation pressure ratio. We found that VT and Kr accounted for nearly all variation in the data with respect to the contact area. The contact area width was accurately described by a combination of tyre width and Kr, while the superellipse squareness parameter, n, diminished...... slightly with increasing Kr. Estimated values of the contact area length related to observed data with a standard deviation of about 0.06 m. A difference between traction and implement tyres called for separate prediction equations, especially for the contact area. The FRIDA parameters α and β, reflecting...

[Formula: see text]Higher cortisol is associated with poorer executive functioning in preschool children: The role of parenting stress, parent coping and quality of daycare.

Science.gov (United States)

Wagner, Shannon L; Cepeda, Ivan; Krieger, Dena; Maggi, Stefania; D'Angiulli, Amedeo; Weinberg, Joanne; Grunau, Ruth E

2016-01-01

Child executive functions (cognitive flexibility, inhibitory control, working memory) are key to success in school. Cortisol, the primary stress hormone, is known to affect cognition; however, there is limited information about how child cortisol levels, parenting factors and child care context relate to executive functions in young children. The aim of this study was to examine relationships between child cortisol, parenting stress, parent coping, and daycare quality in relation to executive functions in children aged 3-5 years. We hypothesized that (1) poorer executive functioning would be related to higher child cortisol and higher parenting stress, and (2) positive daycare quality and positive parent coping style would buffer the effects of child cortisol and parenting stress on executive functions. A total of 101 children (53 girls, 48 boys, mean age 4.24 years ±0.74) with complete data on all measures were included. Three saliva samples to measure cortisol were collected at the child's daycare/preschool in one morning. Parents completed the Behavior Rating Inventory of Executive Function - Preschool Version (BRIEF-P), Parenting Stress Index (PSI), and Ways of Coping Questionnaire (WCQ). The Early Childhood Environment Rating Scale - Revised (ECERS-R) was used to measure the quality of daycare. It was found that children with poorer executive functioning had higher levels of salivary cortisol, and their parents reported higher parenting stress. However, parent coping style and quality of daycare did not modulate these relationships. Identifying ways to promote child executive functioning is an important direction for improving school readiness.

Coronary vascular age: An alternate means for predicting stress-induced myocardial ischemia in patients with suspected coronary artery disease.

Science.gov (United States)

Nappi, Carmela; Gaudieri, Valeria; Acampa, Wanda; Arumugam, Parthiban; Assante, Roberta; Zampella, Emilia; Mannarino, Teresa; Mainolfi, Ciro Gabriele; Imbriaco, Massimo; Petretta, Mario; Cuocolo, Alberto

2018-01-22

Coronary artery calcium (CAC) can be used to estimate vascular age in adults, providing a convenient transformation of CAC from Agatston units into a year's scale. We investigated the role of coronary vascular age in predicting stress-induced myocardial ischemia in subjects with suspected coronary artery disease (CAD). A total of 717 subjects referred to CAC scoring and 82 Rb PET/CT stress-rest myocardial perfusion imaging for suspected CAD were studied. CAC score was measured according to the Agatston method and coronary vascular age by equating estimated CAD risk for chronological age and CAC using the formula 39.1 + 7.25 × ln(CAC + 1). Stress-induced ischemia was present in 105 (15%) patients. Mean chronological age, CAC score, and coronary vascular age were higher (all P age was added to clinical variables. Including vascular age in the model, the global Chi square further increased from 68.77 to 106.38 (P age to clinical data, continuous net reclassification improvement (cNRI) was 0.57, while adding vascular age to clinical data and chronological age cNRI was 0.62. At decision curve analysis, the model including vascular age was associated with the highest net benefit compared to the model including only clinical data, to the model including chronological age and clinical data, and to a strategy considering that all patients had ischemia. The model including vascular age also showed the largest reduction in false-positive rate without missing any ischemic patients. In subjects with suspected CAD, coronary vascular age is strongly associated with stress-induced ischemia. The communication of a given vascular age would have a superior emotive impact improving observance of therapies and healthier lifestyles.

Higher resting heart rate variability predicts skill in expressing some emotions.

Science.gov (United States)

Tuck, Natalie L; Grant, Rosemary C I; Sollers, John J; Booth, Roger J; Consedine, Nathan S

2016-12-01

Vagally mediated heart rate variability (vmHRV) is a measure of cardiac vagal tone, and is widely viewed as a physiological index of the capacity to regulate emotions. However, studies have not directly tested whether vmHRV is associated with the ability to facially express emotions. In extending prior work, the current report tested links between resting vmHRV and the objectively assessed ability to facially express emotions, hypothesizing that higher vmHRV would predict greater expressive skill. Eighty healthy women completed self-reported measures, before attending a laboratory session in which vmHRV and the ability to express six emotions in the face were assessed. A repeated measures analysis of variance revealed a marginal main effect for vmHRV on skill overall; individuals with higher resting vmHRV were only better able to deliberately facially express anger and interest. Findings suggest that differences in resting vmHRV are associated with the objectively assessed ability to facially express some, but not all, emotions, with potential implications for health and well-being. © 2016 Society for Psychophysiological Research.

Improved prediction of higher heating value of biomass using an artificial neural network model based on proximate analysis.

Science.gov (United States)

Uzun, Harun; Yıldız, Zeynep; Goldfarb, Jillian L; Ceylan, Selim

2017-06-01

As biomass becomes more integrated into our energy feedstocks, the ability to predict its combustion enthalpies from routine data such as carbon, ash, and moisture content enables rapid decisions about utilization. The present work constructs a novel artificial neural network model with a 3-3-1 tangent sigmoid architecture to predict biomasses' higher heating values from only their proximate analyses, requiring minimal specificity as compared to models based on elemental composition. The model presented has a considerably higher correlation coefficient (0.963) and lower root mean square (0.375), mean absolute (0.328), and mean bias errors (0.010) than other models presented in the literature which, at least when applied to the present data set, tend to under-predict the combustion enthalpy. Copyright © 2017 Elsevier Ltd. 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.

Patient-Specific MRI-Based Right Ventricle Models Using Different Zero-Load Diastole and Systole Geometries for Better Cardiac Stress and Strain Calculations and Pulmonary Valve Replacement Surgical Outcome Predictions.

Directory of Open Access Journals (Sweden)

Dalin Tang

Full Text Available Accurate calculation of ventricular stress and strain is critical for cardiovascular investigations. Sarcomere shortening in active contraction leads to change of ventricular zero-stress configurations during the cardiac cycle. A new model using different zero-load diastole and systole geometries was introduced to provide more accurate cardiac stress/strain calculations with potential to predict post pulmonary valve replacement (PVR surgical outcome.Cardiac magnetic resonance (CMR data were obtained from 16 patients with repaired tetralogy of Fallot prior to and 6 months after pulmonary valve replacement (8 male, 8 female, mean age 34.5 years. Patients were divided into Group 1 (n = 8 with better post PVR outcome and Group 2 (n = 8 with worse post PVR outcome based on their change in RV ejection fraction (EF. CMR-based patient-specific computational RV/LV models using one zero-load geometry (1G model and two zero-load geometries (diastole and systole, 2G model were constructed and RV wall thickness, volume, circumferential and longitudinal curvatures, mechanical stress and strain were obtained for analysis. Pairwise T-test and Linear Mixed Effect (LME model were used to determine if the differences from the 1G and 2G models were statistically significant, with the dependence of the pair-wise observations and the patient-slice clustering effects being taken into consideration. For group comparisons, continuous variables (RV volumes, WT, C- and L- curvatures, and stress and strain values were summarized as mean ± SD and compared between the outcome groups by using an unpaired Student t-test. Logistic regression analysis was used to identify potential morphological and mechanical predictors for post PVR surgical outcome.Based on results from the 16 patients, mean begin-ejection stress and strain from the 2G model were 28% and 40% higher than that from the 1G model, respectively. Using the 2G model results, RV EF changes correlated negatively with

A risk score for predicting coronary artery disease in women with angina pectoris and abnormal stress test finding.

Science.gov (United States)

Lo, Monica Y; Bonthala, Nirupama; Holper, Elizabeth M; Banks, Kamakki; Murphy, Sabina A; McGuire, Darren K; de Lemos, James A; Khera, Amit

2013-03-15

Women with angina pectoris and abnormal stress test findings commonly have no epicardial coronary artery disease (CAD) at catheterization. The aim of the present study was to develop a risk score to predict obstructive CAD in such patients. Data were analyzed from 337 consecutive women with angina pectoris and abnormal stress test findings who underwent cardiac catheterization at our center from 2003 to 2007. Forward selection multivariate logistic regression analysis was used to identify the independent predictors of CAD, defined by ≥50% diameter stenosis in ≥1 epicardial coronary artery. The independent predictors included age ≥55 years (odds ratio 2.3, 95% confidence interval 1.3 to 4.0), body mass index stress imaging (odds ratio 2.8, 95% confidence interval 1.5 to 5.5), and exercise capacity statistic of 0.745 (95% confidence interval 0.70 to 0.79), and an optimized cutpoint of a score of ≤2 included 62% of the subjects and had a negative predictive value of 80%. In conclusion, a simple clinical risk score of 7 characteristics can help differentiate those more or less likely to have CAD among women with angina pectoris and abnormal stress test findings. This tool, if validated, could help to guide testing strategies in women with angina pectoris. Copyright © 2013 Elsevier Inc. All rights reserved.

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

Predicting Performance in Higher Education Using Proximal Predictors

Science.gov (United States)

Niessen, A. Susan M.; Meijer, Rob R.; Tendeiro, Jorge N.

2016-01-01

We studied the validity of two methods for predicting academic performance and student-program fit that were proximal to important study criteria. Applicants to an undergraduate psychology program participated in a selection procedure containing a trial-studying test based on a work sample approach, and specific skills tests in English and math. Test scores were used to predict academic achievement and progress after the first year, achievement in specific course types, enrollment, and dropout after the first year. All tests showed positive significant correlations with the criteria. The trial-studying test was consistently the best predictor in the admission procedure. We found no significant differences between the predictive validity of the trial-studying test and prior educational performance, and substantial shared explained variance between the two predictors. Only applicants with lower trial-studying scores were significantly less likely to enroll in the program. In conclusion, the trial-studying test yielded predictive validities similar to that of prior educational performance and possibly enabled self-selection. In admissions aimed at student-program fit, or in admissions in which past educational performance is difficult to use, a trial-studying test is a good instrument to predict academic performance. PMID:27073859

Oxidative stress in birds along a NOx and urbanisation gradient: An interspecific approach.

Science.gov (United States)

Salmón, Pablo; Stroh, Emilie; Herrera-Dueñas, Amparo; von Post, Maria; Isaksson, Caroline

2018-05-01

Urbanisation is regarded as one of the most threatening global issues for wildlife, however, measuring its impact is not always straight forward. Oxidative stress physiology has been suggested to be a useful biomarker of health and therefore, a potentially important indicator of the impact that urban environmental stressors, especially air pollution, can have on wildlife. For example, nitrogen oxides (NO x ), released during incomplete combustion of fossil fuels, are highly potent pro-oxidants, thus predicted to affect either the protective antioxidants and/or cause oxidative damage to bio-molecules. To date, epidemiological modelling of the predicted association between oxidative stress and NO x exposure has not been performed in wild animals. Here, we address this short-coming, by investigating multiple oxidative stress markers in four common passerine bird species, the blue tit (Cyanistes caeruleus), great tit (Parus major), house sparrow (Passer domesticus) and tree sparrow (Passer montanus), living along a gradient of NO x and urbanisation levels in southern Sweden. First of all, the results revealed that long- and medium-term (one month and one week, respectively) NO x levels were highly correlated with the level of urbanisation. This confirms that the commonly used urbanisation index is a reliable proxy for urban air pollution. Furthermore, in accordance to our prediction, individuals exposed to higher long- and medium-term NO x levels/urbanisation had higher plasma antioxidant capacity. However, only tree sparrows showed higher oxidative damage (protein carbonyls) in relation to NO x levels and this association was absent with urbanisation. Lipid peroxidation, glutathione and superoxide dismutase levels did not co-vary with NO x /urbanisation. Given that most oxidative stress biomarkers showed strong species-specificity, independent of variation in NO x /urbanisation, the present study highlights the need to study variation in oxidative stress across

Initialization and Predictability of a Coupled ENSO Forecast Model

Science.gov (United States)

Chen, Dake; Zebiak, Stephen E.; Cane, Mark A.; Busalacchi, Antonio J.

1997-01-01

The skill of a coupled ocean-atmosphere model in predicting ENSO has recently been improved using a new initialization procedure in which initial conditions are obtained from the coupled model, nudged toward observations of wind stress. The previous procedure involved direct insertion of wind stress observations, ignoring model feedback from ocean to atmosphere. The success of the new scheme is attributed to its explicit consideration of ocean-atmosphere coupling and the associated reduction of "initialization shock" and random noise. The so-called spring predictability barrier is eliminated, suggesting that such a barrier is not intrinsic to the real climate system. Initial attempts to generalize the nudging procedure to include SST were not successful; possible explanations are offered. In all experiments forecast skill is found to be much higher for the 1980s than for the 1970s and 1990s, suggesting decadal variations in predictability.

Methodology for formulating predictions of stress corrosion cracking life

International Nuclear Information System (INIS)

Yamauchi, Kiyoshi; Hattori, Shigeo; Shindo, Takenori; Kuniya, Jiro

1994-01-01

This paper presents a methodology for formulating predictions to evaluate the stress corrosion cracking (SCC) potential of each light-water reactor component, where an index is introduced as a life index or F index. The index denotes the SCC time ratio of a given SCC system to be evaluated against a reference SCC system. The life index is expressed by the products of several subdivided life indexes, which correspond to each SCC influencing factor. Each subdivided life index is constructed as a function containing the influencing factor variable, obtained by analyzing experimental SCC life data. The methodology was termed the subdivided factor method. Application of the life index to SCC life data and field data showed that it was effective for evaluating the SCC potential, i.e. the SCC life. Accordingly, the proposed methodology can potentially describe a phenomenon expressed by a function which consists of the variables of several influencing factors whether there are formulae which unite as a physical model or not. ((orig.))

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

Life prediction of steam generator tubing due to stress corrosion crack using Monte Carlo Simulation

International Nuclear Information System (INIS)

Hu Jun; Liu Fei; Cheng Guangxu; Zhang Zaoxiao

2011-01-01

Highlights: → A life prediction model for SG tubing was proposed. → The initial crack length for SCC was determined. → Two failure modes called rupture mode and leak mode were considered. → A probabilistic life prediction code based on Monte Carlo method was developed. - Abstract: The failure of steam generator tubing is one of the main accidents that seriously affects the availability and safety of a nuclear power plant. In order to estimate the probability of the failure, a probabilistic model was established to predict the whole life-span and residual life of steam generator (SG) tubing. The failure investigated was stress corrosion cracking (SCC) after the generation of one through-wall axial crack. Two failure modes called rupture mode and leak mode based on probabilistic fracture mechanics were considered in this proposed model. It took into account the variance in tube geometry and material properties, and the variance in residual stresses and operating conditions, all of which govern the propagations of cracks. The proposed model was numerically calculated by using Monte Carlo Simulation (MCS). The plugging criteria were first verified and then the whole life-span and residual life of the SG tubing were obtained. Finally, important sensitivity analysis was also carried out to identify the most important parameters affecting the life of SG tubing. The results will be useful in developing optimum strategies for life-cycle management of the feedwater system in nuclear power 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).

Relationships Among Nightly Sleep Quality, Daily Stress, and Daily Affect.

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Blaxton, Jessica M; Bergeman, Cindy S; Whitehead, Brenda R; Braun, Marcia E; Payne, Jessic D

2017-05-01

We explored the prospective, microlevel relationship between nightly sleep quality (SQ) and the subsequent day's stress on positive (PA) and negative affect (NA) as well as the moderating relationships between nightly SQ, subsequent stress, and subsequent PA on NA. We investigated whether age moderated these relationships. We collected 56 days of sleep, stress, and affect data using daily diary questionnaires (N = 552). We used multilevel modeling to assess relationships at the between- and within-person levels. Daily increases in SQ and decreases in stress interacted to predict higher daily PA and lower daily NA. Better SQ in older adults enhanced the benefits of PA on the stress-NA relationship more during times of low stress, whereas better sleep in younger adults enhanced the benefits of PA more during times of high stress. Between-person effects were stronger predictors of well-being outcomes than within-person variability. The combination of good SQ and higher PA buffered the impact of stress on NA. The moderating impact of age suggests that sleep and stress play different roles across adulthood. Targeting intervention and prevention strategies to improve SQ and enhance PA could disrupt the detrimental relationship between daily stress and NA. © The Author 2015. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Prediction of functional recovery in patients with myocardial infarction after revascularization. Comparison of low-dose dobutamine stress echocardiography with fluorine-18 fluorodeoxyglucose positron emission tomography

International Nuclear Information System (INIS)

Tani, Tomoko; Teragaki, Masakazu; Watanabe, Hiroyuki; Muro, Takashi; Yamagishi, Hiroyuki; Akioka, Kaname; Takeuchi, Kazuhide; Yoshikawa, Junichi

2001-01-01

The present study investigated the agreement between low-dose dobutamine stress echocardiography (LDDSE) and fluorine-18 fluorodeoxyglusose positron emission tomography (FDG-PET) and compared each technique's ability to detect myocardial viability and predict functional recovery in 30 patients. All patients underwent revascularization, followed by echocardiography 5±3 months. Of the 390 segments analyzed by echocardiography before revascularization, 110 (28%) had abnormal wall motion. LDDSE showed viability in 66 sites of the 110 dyssynergic segments and 58 of these viable segments recovered their wall motion. With FDG-PET, 78 of the 110 dyssynergic segments were diagnosed as viable and 62 of these showed improvement of the wall motion. The sensitivities for LDDSE and FDG-PET to assess functional recovery were 84% and 90%, respectively; specificities were 80% and 64%, respectively. Positive predictive values for LDDSE and FDG-PET were 88% and 79%; negative predictive values were 75% and 78%, respectively. Both methods had good sensitivity for detecting improvement in regional function after revascularization, but LDDSE had a higher specificity for detecting viability and a better positive predictive value for left ventricular functional recovery. (author)

Predictive factors for acute stress disorder and posttraumatic stress disorder after motor vehicle accidents.

Science.gov (United States)

Yaşan, Aziz; Guzel, Aslan; Tamam, Yusuf; Ozkan, Mustafa

2009-01-01

Since traffic accidents are more common in developing countries than in developed countries, we aimed to investigate the association of several factors with the development and persistence of posttraumatic stress disorder (PTSD) after traffic accidents. In the study,95 participants with injuries from traffic accidents were evaluated at 4 different times: in the beginning, and after 3, 6 and 12 months. During the first evaluation, 41.1% (39) of our participants had acute stress disorder (ASD). It was found that lower perceived social support (OR = 0.0908, 95% CI = 0.834-0.989, p = 0.027) and higher peritraumatic dissociative experience scores (OR = 1.332, 95% CI = 1.170-1.516, p accident, we found PTSD affected 29.8, 23.1 and 17.9% of the participants, respectively. Although limitations at work and in social life after a traffic accident were not related to PTSD at 3 months (OR = 122.43, 95% CI = 0.000, p = 0.999) or at 6 months (OR = 63.438, 95% CI = 0.529-76.059, p = 0.089), limitations at work and in social life were predictors of PTSD at 12 months (OR = 155.514, 95% CI = 2.321-104.22, p = 0.019). The persistence of PTSD at the 12-month evaluation is related to ASD, limitations in work and social life, and lower social support scores. In developing countries like Turkey, long-term PTSD is commonly seen after traffic accidents. 2009 S. Karger AG, Basel.

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

OpenAIRE

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 perce...

Friction stress effects on mode I crack growth predictions

NARCIS (Netherlands)

Chen, Q.; Deshpande, V.S.; Giessen, E. van der; Needleman, A.

2003-01-01

The effect of a lattice friction stress on the monotonic growth of a plane strain mode I crack under small-scale yielding conditions is analyzed using discrete dislocation plasticity. When the friction stress is increased from zero to half the dislocation nucleation stress, the crack tip stress

The impact of stress at different life stages on physical health and the buffering effects of maternal sensitivity.

Science.gov (United States)

Farrell, Allison K; Simpson, Jeffry A; Carlson, Elizabeth A; Englund, Michelle M; Sung, Sooyeon

2017-01-01

Many studies indicate that early life stress leads to negative health outcomes in adulthood, and some suggest that high-quality parenting might buffer these effects. Most prior research, however, has relied on cross-sectional retrospective reports of stress and parenting. Our study tests how coder-rated stress and parenting quality assessed at different life stages predict adult health outcomes in a prospective, longitudinal study. Participants were 163 individuals in the Minnesota Longitudinal Study of Risk and Adaptation studied since birth. Physical health was assessed at age 32 with body mass index, self-reports of symptoms and illnesses experienced, and self-ratings of overall physical health. Stress was assessed by coder-rated interviews involving participants or their mothers at 16 time points partitioned into 5 life stages: early childhood, middle childhood, adolescence, young adulthood, and at age 32 (when health was assessed). Parenting quality was measured by coder ratings of each mother's provision of sensitive, responsive support at 7 time points between birth and age 13. Early childhood, adolescent, and concurrent stress predicted adult health outcomes at age 32. Early childhood and adolescent stress, and adolescent and concurrent stress, both showed a "dual-risk" pattern, such that experiencing higher stress at both of these life stages predicted the worst health outcomes. Higher maternal sensitivity, however, buffered these deleterious effects. Our prospective data reveal that early childhood and adolescence are important developmental periods during which stress is influential for adult physical health. However, parenting interventions that promote greater sensitivity may help children in high-stress environments avoid negative adult health outcomes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

The impact of stress at different life stages on physical health and the buffering effects of maternal sensitivity

Science.gov (United States)

Farrell, Allison K.; Simpson, Jeffry A.; Carlson, Elizabeth A.; Englund, Michelle M.; Sung, Sooyeon

2016-01-01

Objective Many studies indicate that early life stress leads to negative health outcomes in adulthood, and some suggest that high-quality parenting might buffer these effects. Most prior research, however, has relied on cross-sectional retrospective reports of stress and parenting. Our study tests how coder-rated stress and parenting quality assessed at different life stages predict adult health outcomes in a prospective, longitudinal study. Methods Participants were 163 individuals in the Minnesota Longitudinal Study of Risk and Adaptation (MLSRA) studied since birth. Physical health was assessed at age 32 with BMI, self-reports of symptoms and illnesses experienced, and self-ratings overall physical health. Stress was assessed by coder-rated interviews involving participants or their mothers at 16 time-points partitioned into five life stages: early childhood, middle childhood, adolescence, young adulthood, and at age 32 (when health was assessed). Parenting quality was measured by coder-ratings of each mother's provision of sensitive, responsive support at 7 time-points between birth and age 13. Results Early childhood, adolescent, and concurrent stress predicted adult health outcomes at age 32. Early childhood and adolescent stress, and adolescent and concurrent stress, both showed a “dual-risk” pattern, such that experiencing higher stress at both of these life stages predicted the worst health outcomes. Higher maternal sensitivity, however, buffered these deleterious effects. Conclusions Our prospective data reveals that early childhood and adolescence are important developmental periods during which stress is influential for adult physical health. However, parenting interventions that promote greater sensitivity may help children in high-stress environments avoid negative adult health outcomes. PMID:27669179

Interindividual differences in stress sensitivity: basal and stress-induced cortisol levels differentially predict neural vigilance processing under stress

NARCIS (Netherlands)

Henckens, Marloes J. A. G.; Klumpers, Floris; Everaerd, Daphne; Kooijman, Sabine C.; van Wingen, Guido A.; Fernández, Guillén

2016-01-01

Stress exposure is known to precipitate psychological disorders. However, large differences exist in how individuals respond to stressful situations. A major marker for stress sensitivity is hypothalamus-pituitary-adrenal (HPA)-axis function. Here, we studied how interindividual variance in both

The role of prenatal, obstetric, and post-partum factors in the parenting stress of mothers and fathers of 9-month old infants.

Science.gov (United States)

Matvienko-Sikar, Karen; Murphy, Gillian; Murphy, Mike

2018-03-01

The aim of this paper was to examine the role of perinatal, obstetric and post partum factors on maternal and paternal stress. It will present the first examination of the role of prenatal, obstetric, post-partum, and demographic variables in parenting stress for mothers and fathers at 9 months. Data from 6821 parental dyads of 9-month-old infants were extracted from the Growing Up in Ireland National Longitudinal Study of Children. Participants completed the Parental Stress Scale, the Dyadic Adjustment Scale, the Quality of Attachment Sub-scale from the Maternal and Paternal Postnatal Attachment Scales, and a single item health status question from the Short Form 12 Health Survey. Information on prenatal care, pregnancy complications, obstetric outcomes, infant health, and participant demographics were also collected. Separate hierarchical linear regressions were conducted for mothers and fathers Results: Mothers reported higher levels of parenting stress than fathers (p stress was predicted by attachment, own health status, average sleep, occupation, household income, and having a very rapid labor. Paternal parenting stress was predicted by attachment and own health status. A range of perinatal factors was associated with an increased risk of higher parenting stress at 9 months post-partum and the roles of these factors differ between mothers and fathers. These findings are important for predicting and reducing risk of parenting stress in both genders.

Stress faced by gifted Vietnamese students: what might contribute to it?

Directory of Open Access Journals (Sweden)

Minh Hang Thi Nguyen

2015-11-01

Full Text Available Background Gifted students might have to face an abundance of stress. Nevertheless, very little evidence in Vietnam indicates how much stress those students are experiencing and what might predict it. This study aims to examine the stress level in students of the High School for Gifted Students in Hanoi and factors that might contribute to the stress. Participants and procedure This is a cross sectional study with the participation of 150 students from the High School for Gifted Students, Hanoi. Data were collected from March to April 2015. The first measure was the “Stress Level Test”, which was adapted to the Vietnamese culture to measure academic stress in students. The second measure examined factors contributing to stress: 1 social life, 2 family, 3 school work, 4 personal relationships, 5 well-being, 6 adapting skills. Results The results showed that 74% of students were experiencing mild to medium stress, which was found to be higher in girls and in students who lived away from home. The six predicting factors significantly contribute 17.30% to students’ stress experience, of which school work (p = .001 and students’ well-being (p = .011 can individually predict stress. These outcomes suggested that more attention should be focused on this specific population and more actions need to be taken to help them perform better at school. Conclusions Students of the High School for Gifted Students definitely experienced a considerable amount of stress which was related to school pressure and their well-being. For them to have a better high school life, more recreational and leisure time activities outside the classroom need to take place. In addition, more approachable and functional advisors and counseling personnel would be an ideal solution to this problem.

Feather corticosterone reveals developmental stress in seabirds.

Science.gov (United States)

Will, Alexis P; Suzuki, Yuya; Elliott, Kyle H; Hatch, Scott A; Watanuki, Yutaka; Kitaysky, Alexander S

2014-07-01

In nest-bound avian offspring, food shortages typically trigger a release of the stress hormone corticosterone (CORT). Recent studies indicate that CORT is passively deposited in the tissue of growing feathers and thus may provide an integrated measure of stress incurred during development in the nest. The current hypothesis predicts that, assuming a constant rate of feather growth, elevated CORT circulating in the blood corresponds to higher levels of CORT in feather tissue, but experimental evidence for nutritionally stressed chicks is lacking. Here, we examined how food limitation affects feather CORT content in the rhinoceros auklet (Cerorhinca moncerata). We (i) used captive chicks reared on control versus restricted diets, and (ii) applied this technique to free-living chicks with unknown nutritional histories that fledged at three separate colonies. We found that (i) feather growth was not affected by experimentally induced nutritional stress; (ii) captive chicks raised on a restricted diet had higher levels of CORT in their primary feathers; (iii) feather CORT deposition is a sensitive method of detecting nutritional stress; and (iv) free-living fledglings from the colony with poor reproductive performance had higher CORT in their primary feathers. We conclude that feather CORT is a sensitive integrated measure revealing the temporal dynamics of food limitations experienced by rhinoceros auklet nestlings. The use of feather CORT may be a powerful endocrine tool in ecological and evolutionary studies of bird species with similar preferential allocation of limited resources to feather development. © 2014. Published by The Company of Biologists Ltd.

Stress Coping Levels and Mental States of Police Vocational School of Higher Education Students

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Arzu Yildirim

2011-06-01

Full Text Available SUMMARY AIM: This study was planned and carried out with the objective of determining stress coping levels and mental state of students attending Police Vocational Schools of Higher Education, in addition to factors effecting these. MATERIAL and METHOD: This desciptive and cross-sectional study consisted of 300 male students enrolled in the 2005-2006 academic year, at Police Vocational School of Higher Education, located in central Erzincan, Turkey. In this study, instead of random sampling, 281 (93.7% students who were present at the school at the time of the study and accepted to partipate in it were included. Data for this study was collected using a desciptive form created by the researchers, Rosenbaum’s Learned Resourcefulness Scale (RLRS and The Symptom Check List-90-R (SCL-90-R. During the data analysis, frequency distributions, Mann-Whitney U, Kruskal-Wallis and analysis of variance (one-way ANOVA were used; and for analysis of independent groups, t-test was used. RESULTS: Among the students, it was determined that 54.8% were 1. grade, 90.7% had their parents living together, 43.5% had a father and 60.5% had a mother who graduated from elementary school, fathers of 23.5% of students were retired, 93.6% of them had mothers who were home makers. In addition, it was found out that 78.6% of students chose their profession willingly, the average family income of 71.5% of students were at medium levels, 82.9% always believed in themselves and 63.3% of students did not smoke. Based on the results obtained, it was observed that second grade students, those with mothers who are highly educated and those who trusted themselved all the time had significantly high stress coping levels; students who chose their own profession, believed in themselves and did not smoke had significantly low levels of mental symptom indications. CONCLUSION: In this study, the students were determined to posess averge levels of stress coping skills and they were found

Stress corrosion cracking of nickel base alloys characterization and prediction

International Nuclear Information System (INIS)

Santarini, G.; Pinard-Legry, G.

1988-01-01

For many years, studies have been carried out in several laboratories to characterize the IGSCC (Intergranular Stress Corrosion Cracking) behaviour of nickel base alloys in aqueous environments. For their relative shortness, CERTs (Constant Extension Rate Tests) have been extensively used, especially at the Corrosion Department of the CEA. However, up to recently, the results obtained with this method remained qualitative. This paper presents a first approach to a quantitative interpretation of CERT results. The basic datum used is the crack trace depth distribution determined on a specimen section at the end of a CERT. It is shown that this information can be used for the calculation of initiation and growth parameters which quantitatively characterize IGSCC phenomenon. Moreover, the rationale proposed should lead to the determination of intrinsic cracking parameters, and so, to in-service behaviour prediction

Prediction by data mining, of suicide attempts in Korean adolescents: a national study

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Bae SM

2015-09-01

Full Text Available Sung Man Bae,1 Seung A Lee,2 Seung-Hwan Lee2,3 1Department of Counseling Psychology, The Cyber University of Korea, Seoul, South Korea; 2Clinical Emotion and Cognition Research Laboratory, Goyang, South Korea; 3Department of Psychiatry, Ilsan Paik Hospital, Inje University College of Medicine, Goyang, South Korea Objective: This study aimed to develop a prediction model for suicide attempts in Korean adolescents.Methods: We conducted a decision tree analysis of 2,754 middle and high school students nationwide. We fixed suicide attempt as the dependent variable and eleven sociodemographic, intrapersonal, and extrapersonal variables as independent variables.Results: The rate of suicide attempts of the total sample was 9.5%, and severity of depression was the strongest variable to predict suicide attempt. The rates of suicide attempts in the depression and potential depression groups were 5.4 and 2.8 times higher than that of the non-depression group. In the depression group, the most powerful factor to predict a suicide attempt was delinquency, and the rate of suicide attempts in those in the depression group with higher delinquency was two times higher than in those in the depression group with lower delinquency. Of special note, the rate of suicide attempts in the depressed females with higher delinquency was the highest. Interestingly, in the potential depression group, the most impactful factor to predict a suicide attempt was intimacy with family, and the rate of suicide attempts of those in the potential depression group with lower intimacy with family was 2.4 times higher than that of those in the potential depression group with higher intimacy with family. And, among the potential depression group, middle school students with lower intimacy with family had a 2.5-times higher rate of suicide attempts than high school students with lower intimacy with family. Finally, in the non-depression group, stress level was the most powerful factor to

Remaining life case history studies for high energy piping systems using equivalent stress

International Nuclear Information System (INIS)

Cohn, M.J.

1987-01-01

As the development of plant life extension for high energy piping systems is progressing, conventional piping system design methodologies are also being reevaluated. Traditional guidelines such as American National Standard Institute/American Society of Mechanical Engineers B31.1 (ANSI/ASME) were developed for plants having design lives in the 25- to 30-year regime based upon relatively short-term base metal creep data. These guidelines use a simplified approach for the piping analysis. Two types of stress criteria must be satisfied. The first type is longitudinal plus torsion stress checks for several types of loading conditions versus the material allowable stresses. The second type is an independent minimum wall thickness check which considers the hoop stress versus the material allowable stress. Seven case histories have been evaluated to estimate the minimum piping system creep life based on the current ANSI/ASME B31.1 finite element type of analysis, which is a traditional approach, versus a multiaxial stress state type of analysis. In nearly every case, the equivalent stress methodology predicted significantly higher stresses. Consequently, the equivalent stress methodology resulted in 11 to 96% lower time to rupture values as compared to the values predicted using ANSI/ASME B31.1 stresses

Pre-diagnosis employment status and financial circumstances predict cancer-related financial stress and strain among breast and prostate cancer survivors.

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Sharp, Linda; Timmons, Aileen

2016-02-01

Cancer may have a significant financial impact on patients, but the characteristics that predispose patients to cancer-related financial hardship are poorly understood. We investigated factors associated with cancer-related financial stress and strain in breast and prostate cancer survivors in Ireland, which has a complex mixed public-private healthcare system. Postal questionnaires were distributed to 1373 people diagnosed with cancer 3-24 months previously identified from the National Cancer Registry Ireland. Outcomes were cancer-related financial stress (impact of cancer diagnosis on household ability to make ends meet) and financial strain (concerns about household financial situation since cancer diagnosis). Modified Poisson regression was used to estimate relative risks (RR) for factors associated with cancer-related financial stress and strain. Seven hundred forty survivors participated (response rate = 54 %). Of the respondents, 48 % reported cancer-related financial stress and 32 % cancer-related financial strain. Compared to those employed at diagnosis, risk of cancer-related financial stress was significantly lower in those not working (RR = 0.71, 95 % CI 0.58-0.86) or retired (RR = 0.48, 95 % CI 0.34-0.68). It was significantly higher in those who had dependents; experienced financial stress pre-diagnosis; had a mortgage/personal loans; had higher direct medical out-of-pocket costs; and had increased household bills post-diagnosis. For cancer-related financial strain, significant associations were found with dependents, pre-diagnosis employment status and pre-diagnosis financial stress; risk was lower in those with higher direct medical out-of-pocket costs. Cancer-related financial stress and strain are common. Pre-diagnosis employment status and financial circumstances are important predictors of post-diagnosis financial wellbeing. These findings could inform development of tools to identify patients/survivors most in need of financial

Fatigue life estimation of welded components considering welding residual stress relaxation and its mean stress effect

International Nuclear Information System (INIS)

Han, Seung Ho; Han, Jeong Woo; Shin, Byung Chun; Kim, Jae Hoon

2003-01-01

The fatigue life of welded joints is sensitive to welding residual stress and complexity of their geometric shapes. To predict the fatigue life more reasonably, the effects of welding residual stress and its relaxation on their fatigue strengths should be considered quantitatively, which are often regarded to be equivalent to the effects of mean stresses by external loads. The hot-spot stress concept should be also adopted which can reduce the dependence of fatigue strengths for various welding details. Considering the factors mentioned above, a fatigue life prediction model using the modified Goodman's diagram was proposed. In this model, an equivalent stress was introduced which is composed of the mean stress based on the hot-spot stress concept and the relaxed welding residual stress. From the verification of the proposed model to real welding details, it is proved that this model can be applied to predict reasonably their fatigue lives

Repeated Predictable Stress Causes Resilience against Colitis-Induced Behavioral Changes in Mice

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Ahmed M Hassan

2014-11-01

Full Text Available Inflammatory bowel disease is associated with an increased risk of mental disorders and can be exacerbated by stress. In this study which was performed with male 10-week old C57Bl/6N mice, we used dextran sulfate sodium (DSS-induced colitis to evaluate behavioral changes caused by intestinal inflammation, to assess the interaction between repeated psychological stress (water avoidance stress, WAS and colitis in modifying behavior, and to analyze neurochemical correlates of this interaction. A 7-day treatment with DSS (2 % in drinking water decreased locomotion and enhanced anxiety-like behavior in the open field test and reduced social interaction. Repeated exposure to WAS for 7 days had little influence on behavior but prevented the DSS-induced behavioral disturbances in the open field and social interaction tests. In contrast, repeated WAS did not modify colon length, colonic myeloperoxidase content and circulating proinflammatory cytokines, parameters used to assess colitis severity. DSS-induced colitis was associated with an increase in circulating neuropeptide Y (NPY, a rise in the hypothalamic expression of cyclooxygenase-2 mRNA and a decrease in the hippocampal expression of NPY mRNA, brain-derived neurotrophic factor mRNA and mineralocorticoid receptor mRNA. Repeated WAS significantly decreased the relative expression of corticotropin-releasing factor mRNA in the hippocampus. The effect of repeated WAS to blunt the DSS-evoked behavioral disturbances was associated with a rise of circulating corticosterone and an increase in the expression of hypothalamic NPY mRNA. These results show that experimental colitis leads to a particular range of behavioral alterations which can be prevented by repeated WAS, a model of predictable chronic stress, while the severity of colitis remains unabated. We conclude that the mechanisms underlying the resilience effect of repeated WAS involves hypothalamic NPY and the hypothalamic-pituitary-adrenal axis.

Stressful life events predict delayed functional recovery following treatment for mania in bipolar disorder.

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Yan-Meier, Leslie; Eberhart, Nicole K; Hammen, Constance L; Gitlin, Michael; Sokolski, Kenneth; Altshuler, Lori

2011-04-30

Identifying predictors of functional recovery in bipolar disorder is critical to treatment efforts to help patients re-establish premorbid levels of role adjustment following an acute manic episode. The current study examined the role of stressful life events as potential obstacles to recovery of functioning in various roles. 65 patients with bipolar I disorder participated in a longitudinal study of functional recovery following clinical recovery from a manic episode. Stressful life events were assessed as predictors of concurrent vs. delayed recovery of role functioning in 4 domains (friends, family, home duties, work/school). Despite clinical recovery, a subset of patients experienced delayed functional recovery in various role domains. Moreover, delayed functional recovery was significantly associated with presence of one or more stressors in the prior 3 months, even after controlling for mood symptoms. Presence of a stressor predicted longer time to functional recovery in life domains, up to 112 days in work/school. Interventions that provide monitoring, support, and problem-solving may be needed to help prevent or mitigate the effects of stress on functional recovery. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Oxidative Stress Predicts All-Cause Mortality in HIV-Infected Patients.

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Mar Masiá

Full Text Available We aimed to assess whether oxidative stress is a predictor of mortality in HIV-infected patients.We conducted a nested case-control study in CoRIS, a contemporary, multicentre cohort of HIV-infected patients, antiretroviral-naïve at entry, launched in 2004. Cases were patients who died with available stored plasma samples collected. Two age and sex-matched controls for each case were selected. We measured F2-isoprostanes (F2-IsoPs and malondialdehyde (MDA plasma levels in the first blood sample obtained after cohort engagement.54 cases and 93 controls were included. Median F2-IsoPs and MDA levels were significantly higher in cases than in controls. When adjustment was performed for age, HIV-transmission category, CD4 cell count and HIV viral load at cohort entry, and subclinical inflammation measured with highly-sensitive C-reactive protein (hsCRP, the association of F2-IsoPs with mortality remained significant (adjusted OR per 1 log10 increase, 2.34 [1.23-4.47], P = 0.009. The association of MDA with mortality was attenuated after adjustment: adjusted OR (95% CI per 1 log10 increase, 2.05 [0.91-4.59], P = 0.080. Median hsCRP was also higher in cases, and it also proved to be an independent predictor of mortality in the adjusted analysis: OR (95% CI per 1 log10 increase, 1.39 (1.01-1.91, P = 0.043; and OR (95% CI per 1 log10 increase, 1.46 (1.07-1.99, P = 0.014, respectively, when adjustment included F2-IsoPs and MDA.Oxidative stress is a predictor of all-cause mortality in HIV-infected patients. For plasma F2-IsoPs, this association is independent of HIV-related factors and subclinical inflammation.

Residual Stress Estimation and Fatigue Life Prediction of an Autofrettaged Pressure Vessel

Energy Technology Data Exchange (ETDEWEB)

Song, Kyung Jin; Kim, Eun Kyum; Koh, Seung Kee [Kunsan Nat’l Univ., Kunsan (Korea, Republic of)

2017-09-15

Fatigue failure of an autofrettaged pressure vessel with a groove at the outside surface occurs owing to the fatigue crack initiation and propagation at the groove root. In order to predict the fatigue life of the autofrettaged pressure vessel, residual stresses in the autofrettaged pressure vessel were evaluated using the finite element method, and the fatigue properties of the pressure vessel steel were obtained from the fatigue tests. Fatigue life of a pressure vessel obtained through summation of the crack initiation and propagation lives was calculated to be 2,598 cycles for an 80% autofrettaged pressure vessel subjected to a pulsating internal pressure of 424 MPa.

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

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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.

The Different Facets of Work Stress: A Latent Profile Analysis of Nurses' Work Demands.

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Jenull, Brigitte B; Wiedermann, Wolfgang

2015-10-01

Work-related stress has been identified as a relevant problem leading to negative effects on health and quality of life. Using data from 844 nurses, latent profile analyses (LPA) were applied to identify distinct patterns of work stress. Several sociodemographic variables, including nurses' working and living conditions, as well as nurses' reactions to workload, were considered to predict respondents' profile membership. LPA revealed three distinct profiles that can be distinguished by a low, moderate, and higher stress level. Being financially secure is positively related to the low stress profile, whereas working in an urban area and having low job satisfaction increases the chance of belonging to the higher stress profile. Our results can be used as a basis to develop interventions to create a healthy nursing home environment by supporting the balance between family and work, providing access to job resources and optimizing recovery opportunities. © The Author(s) 2013.

The effects of a mindfulness meditation-based stress reduction program on mood and symptoms of stress in cancer outpatients: 6-month follow-up.

Science.gov (United States)

Carlson, L E; Ursuliak, Z; Goodey, E; Angen, M; Speca, M

2001-03-01

The goals of this work were to assess the effects of participation in a mindfulness meditation-based stress reduction program on mood disturbance and symptoms of stress in cancer outpatients immediately after and 6 months after program completion. A convenience sample of eligible cancer patients were enrolled after they had given informed consent. All patients completed the Profile of Mood States (POMS) and Symptoms of Stress Inventory (SOSI) both before and after the intervention and 6 months later. The intervention consisted of a mindfulness meditation group lasting 1.5 h each week for 7 weeks, plus daily home meditation practice. A total of 89 patients, average age 51, provided pre-intervention data. Eighty patients provided post-intervention data, and 54 completed the 6-month follow-up The participants were heterogeneous with respect to type and stage of cancer. Patients' scores decreased significantly from before to after the intervention on the POMS and SOSI total scores and most subscales, indicating less mood disturbance and fewer symptoms of stress, and these improvements were maintained at the 6-month follow-up. More advanced stages of cancer were associated with less initial mood disturbance, while more home practice and higher initial POMS scores predicted improvements on the POMS between the pre- and post-intervention scores. Female gender and more education were associated with higher initial SOSI scores, and improvements on the SOSI were predicted by more education and greater initial mood disturbance. This program was effective in decreasing mood disturbance and stress symptoms for up to 6 months in both male and female patients with a wide variety of cancer diagnoses, stages of illness, and educational background, and with disparate ages.

Forecasting Individual Headache Attacks Using Perceived Stress: Development of a Multivariable Prediction Model for Persons With Episodic Migraine.

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Houle, Timothy T; Turner, Dana P; Golding, Adrienne N; Porter, John A H; Martin, Vincent T; Penzien, Donald B; Tegeler, Charles H

2017-07-01

To develop and validate a prediction model that forecasts future migraine attacks for an individual headache sufferer. Many headache patients and physicians believe that precipitants of headache can be identified and avoided or managed to reduce the frequency of headache attacks. Of the numerous candidate triggers, perceived stress has received considerable attention for its association with the onset of headache in episodic and chronic headache sufferers. However, no evidence is available to support forecasting headache attacks within individuals using any of the candidate headache triggers. This longitudinal cohort with forecasting model development study enrolled 100 participants with episodic migraine with or without aura, and N = 95 contributed 4626 days of electronic diary data and were included in the analysis. Individual headache forecasts were derived from current headache state and current levels of stress using several aspects of the Daily Stress Inventory, a measure of daily hassles that is completed at the end of each day. The primary outcome measure was the presence/absence of any headache attack (head pain > 0 on a numerical rating scale of 0-10) over the next 24 h period. After removing missing data (n = 431 days), participants in the study experienced a headache attack on 1613/4195 (38.5%) days. A generalized linear mixed-effects forecast model using either the frequency of stressful events or the perceived intensity of these events fit the data well. This simple forecasting model possessed promising predictive utility with an AUC of 0.73 (95% CI 0.71-0.75) in the training sample and an AUC of 0.65 (95% CI 0.6-0.67) in a leave-one-out validation sample. This forecasting model had a Brier score of 0.202 and possessed good calibration between forecasted probabilities and observed frequencies but had only low levels of resolution (ie, sharpness). This study demonstrates that future headache attacks can be forecasted for a diverse group of

The parenting attitudes and the stress of mothers predict the asthmatic severity of their children: a prospective study.

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Nagano, Jun; Kakuta, Chikage; Motomura, Chikako; Odajima, Hiroshi; Sudo, Nobuyuki; Nishima, Sankei; Kubo, Chiharu

2010-10-07

To examine relationships between a mother's stress-related conditions and parenting attitudes and their children's asthmatic status. 274 mothers of an asthmatic child 2 to 12 years old completed a questionnaire including questions about their chronic stress/coping behaviors (the "Stress Inventory"), parenting attitudes (the "Ta-ken Diagnostic Test for Parent-Child Relationship, Parent Form"), and their children's disease status. One year later, a follow-up questionnaire was mailed to the mothers that included questions on the child's disease status. 223 mothers (81%) responded to the follow-up survey. After controlling for non-psychosocial factors including disease severity at baseline, multiple linear regression analysis followed by multiple logistic regression analysis found chronic irritation/anger and emotional suppression to be aggravating factors for children aged types of parental stress/coping behaviors and parenting styles may differently predict their children's asthmatic status, and such associations may change as children grow.