Mixed models and reduction method for dynamic analysis of anisotropic shells

NASA Technical Reports Server (NTRS)

Noor, A. K.; Peters, J. M.

1985-01-01

A time-domain computational procedure is presented for predicting the dynamic response of laminated anisotropic shells. The two key elements of the procedure are: (1) use of mixed finite element models having independent interpolation (shape) functions for stress resultants and generalized displacements for the spatial discretization of the shell, with the stress resultants allowed to be discontinuous at interelement boundaries; and (2) use of a dynamic reduction method, with the global approximation vectors consisting of the static solution and an orthogonal set of Lanczos vectors. The dynamic reduction is accomplished by means of successive application of the finite element method and the classical Rayleigh-Ritz technique. The finite element method is first used to generate the global approximation vectors. Then the Rayleigh-Ritz technique is used to generate a reduced system of ordinary differential equations in the amplitudes of these modes. The temporal integration of the reduced differential equations is performed by using an explicit half-station central difference scheme (Leap-frog method). The effectiveness of the proposed procedure is demonstrated by means of a numerical example and its advantages over reduction methods used with the displacement formulation are discussed.

The role of nociceptive input and tissue injury on stress regulation in borderline personality disorder.

PubMed

Willis, Franziska; Kuniss, Sarah; Kleindienst, Nikolaus; Naoum, Janina; Reitz, Sarah; Boll, Sabrina; Bohus, Martin; Treede, Rolf-Detlef; Baumgärtner, Ulf; Schmahl, Christian

2017-03-01

Approximately 60% to 90% of patients with borderline personality disorder (BPD) show nonsuicidal self-injurious behavior (NSSI) with cutting being the most frequently applied method. One of NSSI's functions is to reduce aversive tension. Previous studies have found a tension-reducing effect of painful tissue injury by an incision. It is still unclear whether this effect is based on the effect of tissue injury or the effect of pain experience, or both. The aim of this study was to determine whether tissue injury leads to a stronger stress reduction than a sole pain stimulus in patients with BPD. After stress induction, 57 BPD patients and 60 healthy controls (HCs) received either an incision or a non-tissue-injuring mechanical nociceptive stimulus ("blade") typically perceived as painful or a non-nociceptive tactile sham stimulus (blunt end of scalpel). Participants were unaware of which procedure was applied. For stress assessment, subjective and objective parameters were measured. As immediate response to the stimulus application, we found greater stress reduction after both painful stimuli (incision and blade) in BPD patients but no difference in stress decrease between the tissue-injuring incision and the non-tissue-injuring pain stimulus (blade). Compared with HCs, incision and blade were followed by greater immediate decrease of arousal in BPD patients. Our findings confirm that among BPD patients, the nociceptive input leads to stress reduction. In contrast, the impact of tissue damage on stress reduction was relatively small. In addition, the results suggest that painful stimuli lead to a greater stress reduction in BPD patients compared with HCs.

The effects of different methods of emotional disclosure: differentiating post-traumatic growth from stress symptoms.

PubMed

Slavin-Spenny, Olga M; Cohen, Jay L; Oberleitner, Lindsay M; Lumley, Mark A

2011-10-01

Research on emotional disclosure should test the effects of different disclosure methods and whether symptoms are affected differently than post-traumatic growth. We randomized 214 participants with unresolved stressful experiences to four disclosure conditions (written, private spoken, talking to a passive listener, talking to an active facilitator) or two control conditions. All groups had one 30-minute session. After 6 weeks, disclosure groups reported more post-traumatic growth than controls, and disclosure conditions were similar in this effect. All groups decreased in stress symptoms (intrusions, avoidance, psychological and physical symptoms), but disclosure did not differ from control. We conclude that 30 minutes of disclosure leads to post-traumatic growth but not necessarily symptom reduction, and various disclosure methods have similar effects. Research on the effects of disclosure should focus on the benefits of growth as well as symptom reduction. © 2010 Wiley Periodicals, Inc.

A pilot randomized trial teaching mindfulness-based stress reduction to traumatized youth in foster care.

PubMed

Jee, Sandra H; Couderc, Jean-Philippe; Swanson, Dena; Gallegos, Autumn; Hilliard, Cammie; Blumkin, Aaron; Cunningham, Kendall; Heinert, Sara

2015-08-01

This article presents a pilot project implementing a mindfulness-based stress reduction program among traumatized youth in foster and kinship care over 10 weeks. Forty-two youth participated in this randomized controlled trial that used a mixed-methods (quantitative, qualitative, and physiologic) evaluation. Youth self-report measuring mental health problems, mindfulness, and stress were lower than anticipated, and the relatively short time-frame to teach these skills to traumatized youth may not have been sufficient to capture significant changes in stress as measured by electrocardiograms. Main themes from qualitative data included expressed competence in managing ongoing stress, enhanced self-awareness, and new strategies to manage stress. We share our experiences and recommendations for future research and practice, including focusing efforts on younger youth, and using community-based participatory research principles to promote engagement and co-learning. CLINICALTRIALS.GOV: Protocol Registration System ID NCT01708291. Copyright © 2015 Elsevier Ltd. All rights reserved.

Stress and Fatigue Management Using Balneotherapy in a Short-Time Randomized Controlled Trial.

PubMed

Rapolienė, Lolita; Razbadauskas, Artūras; Sąlyga, Jonas; Martinkėnas, Arvydas

2016-01-01

Objective. To investigate the influence of high-salinity geothermal mineral water on stress and fatigue. Method. 180 seamen were randomized into three groups: geothermal (65), music (50), and control (65). The geothermal group was administered 108 g/L salinity geothermal water bath for 2 weeks five times a week. Primary outcome was effect on stress and fatigue. Secondary outcomes were the effect on cognitive function, mood, and pain. Results. The improvements after balneotherapy were a reduction in the number and intensity of stress-related symptoms, a reduction in pain and general, physical, and mental fatigue, and an improvement in stress-related symptoms management, mood, activation, motivation, and cognitive functions with effect size from 0.8 to 2.3. In the music therapy group, there were significant positive changes in the number of stress symptoms, intensity, mood, pain, and activity with the effect size of 0.4 to 1.1. The researchers did not observe any significant positive changes in the control group. The comparison between the groups showed that balneotherapy was superior to music therapy and no treatment group. Conclusions. Balneotherapy is beneficial for stress and fatigue reduction in comparison with music or no therapy group. Geothermal water baths have a potential as an efficient approach to diminish stress caused by working or living conditions.

Stress and Fatigue Management Using Balneotherapy in a Short-Time Randomized Controlled Trial

PubMed Central

Razbadauskas, Artūras; Sąlyga, Jonas; Martinkėnas, Arvydas

2016-01-01

Objective. To investigate the influence of high-salinity geothermal mineral water on stress and fatigue. Method. 180 seamen were randomized into three groups: geothermal (65), music (50), and control (65). The geothermal group was administered 108 g/L salinity geothermal water bath for 2 weeks five times a week. Primary outcome was effect on stress and fatigue. Secondary outcomes were the effect on cognitive function, mood, and pain. Results. The improvements after balneotherapy were a reduction in the number and intensity of stress-related symptoms, a reduction in pain and general, physical, and mental fatigue, and an improvement in stress-related symptoms management, mood, activation, motivation, and cognitive functions with effect size from 0.8 to 2.3. In the music therapy group, there were significant positive changes in the number of stress symptoms, intensity, mood, pain, and activity with the effect size of 0.4 to 1.1. The researchers did not observe any significant positive changes in the control group. The comparison between the groups showed that balneotherapy was superior to music therapy and no treatment group. Conclusions. Balneotherapy is beneficial for stress and fatigue reduction in comparison with music or no therapy group. Geothermal water baths have a potential as an efficient approach to diminish stress caused by working or living conditions. PMID:27051455

Reduction in perceived stress as a migraine trigger

PubMed Central

Lipton, Richard B.; Hall, Charles B.; Tennen, Howard; DeFreitas, Tiffani A.; Borkowski, Thomas M.; Grosberg, Brian M.; Haut, Sheryl R.

2014-01-01

Objective: To test whether level of perceived stress and reductions in levels of perceived stress (i.e., “let-down”) are associated with the onset of migraine attacks in persons with migraine. Methods: Patients with migraine from a tertiary headache center were invited to participate in a 3-month electronic diary study. Participants entered data daily regarding migraine attack experience, subjective stress ratings, and other data. Stress was assessed using 2 measures: the Perceived Stress Scale and the Self-Reported Stress Scale. Logit-normal, random-effects models were used to estimate the odds ratio for migraine occurrence as a function of level of stress over several time frames. Results: Of 22 enrolled participants, 17 (median age 43.8 years) completed >30 days of diaries, yielding 2,011 diary entries including 110 eligible migraine attacks (median 5 attacks per person). Level of stress was not generally associated with migraine occurrence. However, decline in stress from one evening diary to the next was associated with increased migraine onset over the subsequent 6, 12, and 18 hours, with odds ratios ranging from 1.5 to 1.9 (all p values < 0.05) for the Perceived Stress Scale. Decline in stress was associated with migraine onset after controlling for level of stress for all time points. Findings were similar using the Self-Reported Stress Scale. Conclusions: Reduction in stress from one day to the next is associated with migraine onset the next day. Decline in stress may be a marker for an impending migraine attack and may create opportunities for preemptive pharmacologic or behavioral interventions. PMID:24670889

A simplified method for prediction of long-term prestress loss in post-tensioned concrete bridges.

DOT National Transportation Integrated Search

2006-07-01

Creep and shrinkage of concrete and relaxation of prestressing steel cause time-dependent changes in : the stresses and strains of concrete structures. These changes result in continuous reduction in the : concrete compression stresses and in the ten...

A Mixed-Methods Pilot Study of Mindfulness-Based Stress Reduction for HIV-Associated Chronic Pain.

PubMed

George, Mary Catherine; Wongmek, Arada; Kaku, Michelle; Nmashie, Alexandra; Robinson-Papp, Jessica

2017-01-01

Treatment guidelines for chronic pain recommend nonpharmacologic modalities as part of a comprehensive management plan. Chronic pain is common among people living with HIV/AIDS, but there is little data to guide the choice of nonpharmacologic therapies in this complex population. We performed a mixed-methods feasibility study of Mindfulness-Based Stress Reduction (MBSR) versus health education control with 32 inner city, HIV-infected participants. Outcome measures included: the Brief Pain Inventory, Perceived Stress Scale, HIV Symptoms Index, autonomic function testing, and audiotaped focus groups. Post-intervention, participants reported modest improvements in pain measures and perceived stress, but no effect of group assignment was observed. At 3-month follow-up, 79% of MBSR participants were still practicing, and pain intensity was improved, whereas in the control group pain intensity had worsened. Qualitative analysis revealed a strong sense of community in both groups, but only MBSR was perceived as useful for relaxation and pain relief.

Comparison of Efficacy of Eye Movement, Desensitization and Reprocessing and Cognitive Behavioral Therapy Therapeutic Methods for Reducing Anxiety and Depression of Iranian Combatant Afflicted by Post Traumatic Stress Disorder

NASA Astrophysics Data System (ADS)

Narimani, M.; Sadeghieh Ahari, S.; Rajabi, S.

This research aims to determine efficacy of two therapeutic methods and compare them; Eye Movement, Desensitization and Reprocessing (EMDR) and Cognitive Behavioral Therapy (CBT) for reduction of anxiety and depression of Iranian combatant afflicted with Post traumatic Stress Disorder (PTSD) after imposed war. Statistical population of current study includes combatants afflicted with PTSD that were hospitalized in Isar Hospital of Ardabil province or were inhabited in Ardabil. These persons were selected through simple random sampling and were randomly located in three groups. The method was extended test method and study design was multi-group test-retest. Used tools include hospital anxiety and depression scale. This survey showed that exercise of EMDR and CBT has caused significant reduction of anxiety and depression.

Amigas Latinas Motivando el ALMA (ALMA): Development and Pilot Implementation of a Stress Reduction Promotora Intervention

PubMed Central

Green, Melissa A.; Perez, Georgina; Ornelas, India J.; Tran, Anh N.; Blumenthal, Connie; Lyn, Michelle; Corbie-Smith, Giselle

2014-01-01

Use of mental health care services for psychological distress is limited among Latino immigrants. In geographic areas where migration has been rapid, mental health systems possess limited capacity to provide bilingual and bicultural assistance. The development of a bilingual and bicultural workforce is a necessary yet long-term solution. More immediate strategies, however, are needed to meet the needs of immigrant Latinos. This paper describes the development of a stress-reduction focused, lay health advisor training that targets individual behavior change among Latina immigrants. The theoretical foundation, curriculum components, and pilot implementation of the training are discussed. As natural leaders, Latina promotoras disseminated learned strategies and resources within their communities. The lay health advisor model is a salient method for disseminating information regarding mental health and stress reduction among Latinas. PMID:25364312

The effects of compensatory workplace exercises to reduce work-related stress and musculoskeletal pain1

PubMed Central

de Freitas-Swerts, Fabiana Cristina Taubert; Robazzi, Maria Lúcia do Carmo Cruz

2014-01-01

OBJECTIVES: to assess the effect of a compensatory workplace exercise program on workers with the purpose of reducing work-related stress and musculoskeletal pain. METHOD: quasi-experimental research with quantitative analysis of the data, involving 30 administrative workers from a Higher Education Public Institution. For data collection, questionnaires were used to characterize the workers, as well as the Workplace Stress Scale and the Corlett Diagram. The research took place in three stages: first: pre-test with the application of the questionnaires to the subjects; second: Workplace Exercise taking place twice a week, for 15 minutes, during a period of 10 weeks; third: post-test in which the subjects answered the questionnaires again. For data analysis, the descriptive statistics and non-parametric statistics were used through the Wilcoxon Test. RESULTS: work-related stress was present in the assessed workers, but there was no statistically significant reduction in the scores after undergoing Workplace Exercise. However, there was a statistically significant pain reduction in the neck, cervical, upper, middle and lower back, right thigh, left leg, right ankle and feet. CONCLUSION: the Workplace Exercise promoted a significant pain reduction in the spine, but did not result in a significant reduction in the levels of work-related stress. PMID:25296147

Stress corrosion evaluation of powder metallurgy aluminum alloy 7091 with the breaking load test method

NASA Technical Reports Server (NTRS)

Domack, Marcia S.

1987-01-01

The stress corrosion behavior of the P/M aluminum alloy 7091 is evaluated in two overaged heat treatment conditions, T7E69 and T7E70, using an accelerated test technique known as the breaking load test method. The breaking load data obtained in this study indicate that P/M 7091 alloy is highly resistant to stress corrosion in both longitudinal and transverse orientations at stress levels up to 90 percent of the material yield strength. The reduction in mean breaking stress as a result of corrosive attack is smallest for the more overaged T7E70 condition. Details of the test procedure are included.

Designing, Prototyping and Evaluating Digital Mindfulness Applications: A Case Study of Mindful Breathing for Stress Reduction

PubMed Central

Hedman, Anders; Feng, Shuo; Li, Haibo; Osika, Walter

2017-01-01

Background During the past decade, there has been a rapid increase of interactive apps designed for health and well-being. Yet, little research has been published on developing frameworks for design and evaluation of digital mindfulness facilitating technologies. Moreover, many existing digital mindfulness applications are purely software based. There is room for further exploration and assessment of designs that make more use of physical qualities of artifacts. Objective The study aimed to develop and test a new physical digital mindfulness prototype designed for stress reduction. Methods In this case study, we designed, developed, and evaluated HU, a physical digital mindfulness prototype designed for stress reduction. In the first phase, we used vapor and light to support mindful breathing and invited 25 participants through snowball sampling to test HU. In the second phase, we added sonification. We deployed a package of probes such as photos, diaries, and cards to collect data from users who explored HU in their homes. Thereafter, we evaluated our installation using both self-assessed stress levels and heart rate (HR) and heart rate variability (HRV) measures in a pilot study, in order to measure stress resilience effects. After the experiment, we performed a semistructured interview to reflect on HU and investigate the design of digital mindfulness apps for stress reduction. Results The results of the first phase showed that 22 of 25 participants (88%) claimed vapor and light could be effective ways of promoting mindful breathing. Vapor could potentially support mindful breathing better than light (especially for mindfulness beginners). In addition, a majority of the participants mentioned sound as an alternative medium. In the second phase, we found that participants thought that HU could work well for stress reduction. We compared the effect of silent HU (using light and vapor without sound) and sonified HU on 5 participants. Subjective stress levels were statistically improved with both silent and sonified HU. The mean value of HR using silent HU was significantly lower than resting baseline and sonified HU. The mean value of root mean square of differences (RMSSD) using silent HU was significantly higher than resting baseline. We found that the differences between our objective and subjective assessments were intriguing and prompted us to investigate them further. Conclusions Our evaluation of HU indicated that HU could facilitate relaxed breathing and stress reduction. There was a difference in outcome between the physiological measures of stress and the subjective reports of stress, as well as a large intervariability among study participants. Our conclusion is that the use of stress reduction tools should be customized and that the design work of mindfulness technology for stress reduction is a complex process, which requires cooperation of designers, HCI (Human-Computer Interaction) experts and clinicians. PMID:28615157

Massage and Reiki used to reduce stress and anxiety: Randomized Clinical Trial

PubMed Central

Kurebayashi, Leonice Fumiko Sato; Turrini, Ruth Natalia Teresa; de Souza, Talita Pavarini Borges; Takiguchi, Raymond Sehiji; Kuba, Gisele; Nagumo, Marisa Toshi

2016-01-01

ABTRACT Objective: to evaluate the effectiveness of massage and reiki in the reduction of stress and anxiety in clients at the Institute for Integrated and Oriental Therapy in Sao Paulo (Brazil). Method: clinical tests randomly done in parallel with an initial sample of 122 people divided into three groups: Massage + Rest (G1), Massage + Reiki (G2) and a Control group without intervention (G3). The Stress Systems list and the Trace State Anxiety Inventory were used to evaluate the groups at the start and after 8 sessions (1 month), during 2015. Results: there were statistical differences (p = 0.000) according to the ANOVA (Analysis of Variance) for the stress amongst the groups 2 and 3 (p = 0.014) with a 33% reductions and a Cohen of 0.78. In relation to anxiety-state, there was a reduction in the intervention groups compared with the control group (p < 0.01) with a 21% reduction in group 2 (Cohen of 1.18) and a 16% reduction for group 1 (Cohen of 1.14). Conclusion: Massage + Reiki produced better results amongst the groups and the conclusion is for further studies to be done with the use of a placebo group to evaluate the impact of the technique separate from other techniques. RBR-42c8wp PMID:27901219

A Small Randomized Pilot Study of a Workplace Mindfulness-Based Intervention for Surgical Intensive Care Unit Personnel: Effects on Salivary α-Amylase Levels

PubMed Central

Duchemin, Anne-Marie; Steinberg, Beth A.; Marks, Donald R.; Vanover, Kristin; Klatt, Maryanna

2015-01-01

Objective To determine if a workplace stress-reduction intervention decreases reactivity to stress among personnel exposed to a highly stressful occupational environment. Methods Personnel from a surgical intensive care unit (SICU) were randomized to a stress reduction intervention or a wait-list control group. The 8-week group mindfulness-based intervention (MBI) included mindfulness, gentle yoga and music. Psychological and biological markers of stress were measured one week before and one week after the intervention. Results Levels of salivary α-amylase, an index of sympathetic activation, were significantly decreased between the 1st and 2nd assessments in the intervention group with no changes in the control group. There was a positive correlation between salivary α-amylase levels and burnout scores. Conclusions These data suggest that this type of intervention could not only decrease reactivity to stress, but also decrease the risk of burnout. PMID:25629803

Pollen selection under acid rain stress

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Y.

To investigate whether acid rain stress induces pollen selection in nature, three different approaches were used, based on the assumption that the response of pollen grains to acid rain is controlled by an acid sensitive gene product. Germination of pollen from homozygous and heterozygous individuals under acid rain stress was examined to detect any differences in rate of germination between populations of homogeneous and heterogeneous pollen grains. In vitro and in vivo bulked segregant analysis using RAPDs was used to search for differences in DNA constitution between the survivors of acid rain stressed and non-acid rain stressed pollen populations inmore » vitro and between the progenies of acid rain stressed and non-acid rain stressed populations during pollination, respectively. No evidence for the pollen selection under acid rain stress was obtained in any of the test systems. Inhibition of protein synthesis using cycloheximide led to significant reduction of tube elongation at 4 hr and had no effect on pollen germination at any time interval tested. Total proteins extracted from control and acid rain stressed pollen grain populations exhibited no differences. The reduction of corn pollen germination in vitro under acid rain stress was mainly due to pollen rupture. The present data indicates the reduction of pollen germination and tube growth under acid rain stress may be a physiological response rather than a genetic response. A simple, nontoxic, and effective method to separate germinated from ungerminated pollen grains has been developed using pollen from corn (Zea mays, L. cv. Pioneer 3747). The separated germinated pollen grains retained viability and continued tube growth when placed in culture medium.« less

Effects of Mindfulness-Based Stress Reduction Intervention on Psychological Well-being and Quality of Life: Is Increased Mindfulness Indeed the Mechanism?

PubMed Central

Kuijpers, Karlijn F.

2008-01-01

Background Although several studies have reported positive effects of mindfulness-based stress reduction (MBSR) intervention on psychological well-being, it is not known whether these effects are attributable to a change in mindfulness. Purpose The aim of this study is to compare the effects of MBSR to a waiting-list control condition in a randomized controlled trial while examining potentially mediating effects of mindfulness. Methods Forty women and 20 men from the community with symptoms of distress (mean age 43.6 years, SD = 10.1) were randomized into a group receiving MBSR or a waiting-list control group. Before and after the intervention period, questionnaires were completed on psychological well-being, quality of life, and mindfulness. Results Repeated measures multiple analysis of variance (MANCOVAs) showed that, compared with the control group, the intervention resulted in significantly stronger reductions of perceived stress (p = 0.016) and vital exhaustion (p = 0.001) and stronger elevations of positive affect (p = 0.006), quality of life (p = .009), as well as mindfulness (p = 0.001). When mindfulness was included as a covariate in the MANCOVA, the group effects on perceived stress and quality of life were reduced to nonsignificance. Conclusion Increased mindfulness may, at least partially, mediate the positive effects of mindfulness-based stress reduction intervention. PMID:18535870

Specific reduction in cortisol stress reactivity after social but not attention-based mental training.

PubMed

Engert, Veronika; Kok, Bethany E; Papassotiriou, Ioannis; Chrousos, George P; Singer, Tania

2017-10-01

Psychosocial stress is a public health burden in modern societies. Chronic stress-induced disease processes are, in large part, mediated via the activation of the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic-adrenal-medullary system. We asked whether the contemplative mental training of different practice types targeting attentional, socio-affective (for example, compassion), or socio-cognitive abilities (for example, perspective-taking) in the context of a 9-month longitudinal training study offers an effective means for psychosocial stress reduction. Using a multimethod approach including subjective, endocrine, autonomic, and immune markers and testing 313 participants in a standardized psychosocial laboratory stressor, we show that all three practice types markedly reduced self-reported stress reactivity in healthy participants. However, only the training of intersubjective skills via socio-affective and socio-cognitive routes attenuated the physiological stress response, specifically the secretion of the HPA axis end-product cortisol, by up to 51%. The assessed autonomic and innate immune markers were not influenced by any practice type. Mental training focused on present-moment attention and interoceptive awareness as implemented in many mindfulness-based intervention programs was thus limited to stress reduction on the level of self-report. However, its effectiveness was equal to that of intersubjective practice types in boosting the association between subjective and endocrine stress markers. Our results reveal a broadly accessible low-cost approach to acquiring psychosocial stress resilience. Short daily intersubjective practice may be a promising method for minimizing the incidence of chronic social stress-related disease, thereby reducing individual suffering and relieving a substantial financial burden on society.

Mindfulness-based stress reduction in middle-aged and older adults with memory complaints: a mixed-methods study.

PubMed

Berk, Lotte; Hotterbeekx, Rafke; van Os, Jim; van Boxtel, Martin

2017-07-19

In a rapidly aging world population, an increasingly large group faces age-related decline in cognitive functioning. Cognitive complaints of older adults are often related to worries and concerns associated with age-related functional decline. Mindfulness-Based Stress Reduction (MBSR) can successfully target stress, worry and ruminative thinking, but the applicability of this method in middle-aged and older adults with memory complaints is unclear. Patients of a university hospital memory clinic (n = 13), aged 45-85 years, with memory complaints but no diagnosis of cognitive disorder, participated in a standard 8-week MBSR program, consisting of weekly group meetings and a one-day silent retreat. After completion, semi-structured qualitative interviews were conducted. Questionnaires (administered before, one week after and five weeks after the intervention) assessed quality of life, psychological distress (stress, anxiety and depressive symptoms), mindfulness, self-compassion, and subjective memory functioning. Neurocognitive functioning was assessed online, before and after the intervention. The qualitative analysis showed positive effects of the training (e.g. increased serenity), many participants worrying less about memory complaints. The self-reported measures were in line with the results of the qualitative analysis. This exploratory mixed-methods study suggests that MBSR is feasible and well received among older individuals with cognitive complaints.

A fluid--structure interaction finite element analysis of pulsatile blood flow through a compliant stenotic artery

NASA Technical Reports Server (NTRS)

Bathe, M.; Kamm, R. D.

1999-01-01

A new model is used to analyze the fully coupled problem of pulsatile blood flow through a compliant, axisymmetric stenotic artery using the finite element method. The model uses large displacement and large strain theory for the solid, and the full Navier-Stokes equations for the fluid. The effect of increasing area reduction on fluid dynamic and structural stresses is presented. Results show that pressure drop, peak wall shear stress, and maximum principal stress in the lesion all increase dramatically as the area reduction in the stenosis is increased from 51 to 89 percent. Further reductions in stenosis cross-sectional area, however, produce relatively little additional change in these parameters due to a concomitant reduction in flow rate caused by the losses in the constriction. Inner wall hoop stretch amplitude just distal to the stenosis also increases with increasing stenosis severity, as downstream pressures are reduced to a physiological minimum. The contraction of the artery distal to the stenosis generates a significant compressive stress on the downstream shoulder of the lesion. Dynamic narrowing of the stenosis is also seen, further augmenting area constriction at times of peak flow. Pressure drop results are found to compare well to an experimentally based theoretical curve, despite the assumption of laminar flow.

Adaptation of the Levee Erosional Equivalence Method for the Hurricane Storm Damage Risk Reduction System (HSDRRS)

DTIC Science & Technology

2011-05-01

ER D C/ CH L TR -1 1- 3 Flood and Coastal Storm Damage Reduction R& D Program Adaptation of the Levee Erosional Equivalence Method for the...of vertical wall [-] γw Specific weight of water [kN/m3] γβ Reduction factor for influence of angle of wave attack [-] θ Landward-side levee ...stress multiplied by the flow velocity. Thus, from Equation (4) stream power has the form ERDC/CHL TR-11-3 9 S o D D dW P τ u ρ f u u ρ f u dt

Novel Interventions to Reduce Stress and Overeating in Overweight Pregnant Women: A Feasibility Study.

PubMed

Laraia, B A; Adler, N E; Coleman-Phox, K; Vieten, C; Mellin, L; Kristeller, J L; Thomas, M; Stotland, N E; Lustig, R H; Dallman, M F; Hecht, F M; Bush, N R; de Groat, C L; Epel, E

2018-05-01

Background High stress and depression during pregnancy are risk factors for worsened health trajectories for both mother and offspring. This is also true for pre-pregnancy obesity and excessive gestational weight gain. Reducing stress and depression may be one path to prevent excessive caloric intake and gestational weight gain. Study Purpose We tested the feasibility of two novel interventions aimed at reducing stress and overeating during pregnancy. Reflecting different theoretical underpinnings, the interventions target different mechanisms. Mindful Moms Training (MMT) uses mindfulness to improve awareness and acceptance of experiences and promote conscious rather than automatic behavior choices. Emotional Brain Training (EBT) uses active coping to change perceptions of negative experience and promote positive affective states. Methods Forty-six overweight/obese low-income women were assigned to either MMT (n = 24) or EBT (n = 22) for an 8-week feasibility study. Pre-post changes in perceived stress, eating and presumed mechanisms were assessed. Results Women reported high levels of stress at baseline. Both interventions were well attended and demonstrated clinically significant pre-post reductions in stress, depressive symptoms, and improved eating behaviors. MMT significantly decreased experiential avoidance, whereas EBT significantly increased positive reappraisal; these changes were marginally significantly different by group. Conclusions This feasibility study found that both interventions promoted meaningful reductions in stress and depressive symptoms and improved reported eating behaviors in a high-risk group of pregnant women. Each intervention has a potentially different pathway-acceptance for MMT and reappraisal for EBT. Larger studies are needed to test efficacy on longer term reductions in stress and overeating.

Primary teachers' knowledge and acquisition of stress relieving strategies.

PubMed

Cockburn, A D

1996-09-01

Over the last 20 years there have been numerous studies of teacher stress but little is known of how teachers acquire coping strategies; their knowledge of those available to them and their opinion of these techniques. A total of 335 Norfolk primary teachers responded to a postal questionnaire providing biographical details; levels of job satisfaction and work related stress; responses to a range of commonly advocated techniques to reduce teacher stress and their opinion on who-if anyone-should take more responsibility for reducing teacher stress. On average the respondents were aware of 35 stress reduction strategies. The most effective strategies were ensuring that one understood what one was about to teach and thorough lesson preparation. A significant proportion of practitioners said that they would not consider seeking expert sources of advice. A total of 89 per cent of practitioners reported that they acquired at least some strategies through their own experience. It was concluded that the issue of teacher stress needs to be considered at governmental, school and individual levels. In the light of some resistance to traditional methods of stress reduction, the implications for initial and in-service training were explored.

The effect of yoga in stress reduction for dental students performing their first periodontal surgery: A randomized controlled study

PubMed Central

Shankarapillai, Rajesh; Nair, Manju Anathakrishnan; George, Roy

2012-01-01

Context: The dental students experience a lot of stress, which increase when they perform their first surgical procedure. Yoga as an anxiolytic tool in anxiety reduction has been practiced over centuries in India. Aim: To assess the efficacy of yoga in reducing the state trait anxiety of dental students before their first periodontal surgery performance. Settings and Design: A randomized controlled study using a two-way split plot design (pre-post-test) was conducted in the department of periodontics, Pacific Dental College, Udaipur, India. Materials and Methods: One hundred clinical dental students who were ready to perform their first periodontal surgery were selected. Students were randomly assigned to two groups and were given a 60-min session on stress reduction. Group A, yogic intervention group, were instructed to do yoga and their performances were monitored for a period of one week and Group B, control group, were given a lecture on stress reduction without any yoga instructions. The investigator who was unaware of the groups had taken the state trait anxiety score of the students three times a) before assigning them to each group, b) prior to the surgical procedure and c) immediately after the performance of surgery. Statistical Analysis Used: Analyses of variance (ANOVA) by SPSS V.16. Results: The statistical results showed a significant reduction in the VAS and state trait anxiety of Group A compared to Group B (ANOVA; P<0.001). Conclusions: This study concludes that Yogic breathing has a significant effect on the reduction of state trait anxiety level of dental students. PMID:22346066

Load reduction test method of similarity theory and BP neural networks of large cranes

NASA Astrophysics Data System (ADS)

Yang, Ruigang; Duan, Zhibin; Lu, Yi; Wang, Lei; Xu, Gening

2016-01-01

Static load tests are an important means of supervising and detecting a crane's lift capacity. Due to space restrictions, however, there are difficulties and potential danger when testing large bridge cranes. To solve the loading problems of large-tonnage cranes during testing, an equivalency test is proposed based on the similarity theory and BP neural networks. The maximum stress and displacement of a large bridge crane is tested in small loads, combined with the training neural network of a similar structure crane through stress and displacement data which is collected by a physics simulation progressively loaded to a static load test load within the material scope of work. The maximum stress and displacement of a crane under a static load test load can be predicted through the relationship of stress, displacement, and load. By measuring the stress and displacement of small tonnage weights, the stress and displacement of large loads can be predicted, such as the maximum load capacity, which is 1.25 times the rated capacity. Experimental study shows that the load reduction test method can reflect the lift capacity of large bridge cranes. The load shedding predictive analysis for Sanxia 1200 t bridge crane test data indicates that when the load is 1.25 times the rated lifting capacity, the predicted displacement and actual displacement error is zero. The method solves the problem that lifting capacities are difficult to obtain and testing accidents are easily possible when 1.25 times related weight loads are tested for large tonnage cranes.

Interventions: Employees' Perceptions of What Reduces Stress

PubMed Central

Boyd, Carolyn M.; Provis, Chris

2017-01-01

Objective To build upon research evaluating stress interventions, this qualitative study tests the framework of the extended Job Demands-Resources model to investigate employees' perceptions of the stress-reduction measures implemented at 13 Australian universities. Methods In a cross-sectional survey design, tenured and contract staff indicated whether their overall level of stress had changed during the previous three-four years, and, if so, they described the major causes. A total of 462 staff reported that their level of stress had decreased; the study examines commentary from 115 academic and 304 nonacademic staff who provided details of what they perceived to be effective in reducing stress. Results Thematic analyses show that the key perceived causes were changes in job or work role, new heads of departments or supervisors, and the use of organizational strategies to reduce or manage stress. A higher percentage of academic staff reported reduced stress due to using protective coping strategies or their increased recognition and/or success, whereas a higher percentage of nonacademic staff reported reduced stress due to increases in staffing resources and/or systems. Conclusion These results identify the importance of implementing multilevel strategies to enhance employees' well-being. Nonacademic staff, in particular, specified a variety of organizational stress-reduction interventions. PMID:29318146

Preclinical evaluation of the effect of the combined use of the Ethicon Securestrap® Open Absorbable Strap Fixation Device and Ethicon Physiomesh™ Open Flexible Composite Mesh Device on surgeon stress during ventral hernia repair

PubMed Central

Sutton, Nadia; MacDonald, Melinda H; Lombard, John; Ilie, Bodgan; Hinoul, Piet; Granger, Douglas A

2018-01-01

Aim To evaluate whether performing ventral hernia repairs using the Ethicon Physiomesh™ Open Flexible Composite Mesh Device in conjunction with the Ethicon Securestrap® Open Absorbable Strap Fixation Device reduces surgical time and surgeon stress levels, compared with traditional surgical repair methods. Methods To repair a simulated ventral incisional hernia, two surgeries were performed by eight experienced surgeons using a live porcine model. One procedure involved traditional suture methods and a flat mesh, and the other procedure involved a mechanical fixation device and a skirted flexible composite mesh. A Surgery Task Load Index questionnaire was administered before and after the procedure to establish the surgeons’ perceived stress levels, and saliva samples were collected before, during, and after the surgical procedures to assess the biologically expressed stress (cortisol and salivary alpha amylase) levels. Results For mechanical fixation using the Ethicon Physiomesh Open Flexible Composite Mesh Device in conjunction with the Ethicon Securestrap Open Absorbable Strap Fixation Device, surgeons reported a 46.2% reduction in perceived workload stress. There was also a lower physiological reactivity to the intraoperative experience and the total surgical procedure time was reduced by 60.3%. Conclusions This study provides preliminary findings suggesting that the combined use of a mechanical fixation device and a skirted flexible composite mesh in an open intraperitoneal onlay mesh repair has the potential to reduce surgeon stress. Additional studies are needed to determine whether a reduction in stress is observed in a clinical setting and, if so, confirm that this results in improved clinical outcomes. PMID:29296101

Effects of Lifestyle Modification on Telomerase Gene Expression in Hypertensive Patients: A Pilot Trial of Stress Reduction and Health Education Programs in African Americans

PubMed Central

Duraimani, Shanthi; Schneider, Robert H.; Randall, Otelio S.; Nidich, Sanford I.; Xu, Shichen; Ketete, Muluemebet; Rainforth, Maxwell A.; Gaylord-King, Carolyn; Salerno, John W.; Fagan, John

2015-01-01

Background African Americans suffer from disproportionately high rates of hypertension and cardiovascular disease. Psychosocial stress, lifestyle and telomere dysfunction contribute to the pathogenesis of hypertension and cardiovascular disease. This study evaluated effects of stress reduction and lifestyle modification on blood pressure, telomerase gene expression and lifestyle factors in African Americans. Methods Forty-eight African American men and women with stage I hypertension who participated in a larger randomized controlled trial volunteered for this substudy. These subjects participated in either stress reduction with the Transcendental Meditation technique and a basic health education course (SR) or an extensive health education program (EHE) for 16 weeks. Primary outcomes were telomerase gene expression (hTERT and hTR) and clinic blood pressure. Secondary outcomes included lifestyle-related factors. Data were analyzed for within-group and between-group changes. Results Both groups showed increases in the two measures of telomerase gene expression, hTR mRNA levels (SR: p< 0.001; EHE: p< 0.001) and hTERT mRNA levels (SR: p = 0.055; EHE: p< 0.002). However, no statistically significant between-group changes were observed. Both groups showed reductions in systolic BP. Adjusted changes were SR = -5.7 mm Hg, p< 0.01; EHE = -9.0 mm Hg, p < 0.001 with no statistically significant difference between group difference. There was a significant reduction in diastolic BP in the EHE group (-5.3 mm Hg, p< 0.001) but not in SR (-1.2 mm Hg, p = 0.42); the between-group difference was significant (p = 0.04). The EHE group showed a greater number of changes in lifestyle behaviors. Conclusion In this pilot trial, both stress reduction (Transcendental Meditation technique plus health education) and extensive health education groups demonstrated increased telomerase gene expression and reduced BP. The association between increased telomerase gene expression and reduced BP observed in this high-risk population suggest hypotheses that telomerase gene expression may either be a biomarker for reduced BP or a mechanism by which stress reduction and lifestyle modification reduces BP. Trial Registration ClinicalTrials.gov NCT00681200 PMID:26571023

Evaluation of a Web-Based Holistic Stress Reduction Pilot Program Among Nurse-Midwives.

PubMed

Wright, Erin M

2018-06-01

Work-related stress among midwives results in secondary traumatic stress, posttraumatic stress disorder, and job attrition. The purpose of this pilot project was to evaluate the effectiveness of a holistic, web-based program using holistic modalities for stress reduction and improved coping among certified nurse-midwives. A convenience sample of 10 midwives participated in a web-based holistic stress reduction intervention using yoga, mindfulness-based stress reduction, and meditation for four days each week over 4 weeks. Participants completed pre- and postintervention questionnaires (Perceived Stress Scale [PSS] and the Coping Self-Efficacy Scale [CSES]) for evaluation of effectiveness. The PSS means showed improvement in midwives' stress (16.4-12.3). The CSES means showed improvement in coping (174.8-214.5). Improvement was shown in each subscale of the CSES ("uses problem-focused coping": 19.2%; "stops unpleasant thoughts and emotions": 20.3%; and "gets support from family and friends": 16.6%). Findings suggest the potential for stress reduction and improved coping skills after using holistic techniques in a web-based format within a cohort of nurse-midwives. Further research of web-based, holistic intervention for stress reduction among midwives is warranted.

Recruiting and retaining family caregivers to a randomized controlled trial on mindfulness-based stress reduction.

PubMed

Whitebird, Robin R; Kreitzer, Mary Jo; Lewis, Beth A; Hanson, Leah R; Crain, A Lauren; Enstad, Chris J; Mehta, Adele

2011-09-01

Caregivers for a family member with dementia experience chronic long-term stress that may benefit from new complementary therapies such as mindfulness-based stress reduction. Little is known however, about the challenges of recruiting and retaining family caregivers to research on mind-body based complementary therapies. Our pilot study is the first of its kind to successfully recruit caregivers for a family member with dementia to a randomized controlled pilot study of mindfulness-based stress reduction. The study used an array of recruitment strategies and techniques that were tailored to fit the unique features of our recruitment sources and employed retention strategies that placed high value on establishing early and ongoing communication with potential participants. Innovative recruitment methods including conducting outreach to health plan members and generating press coverage were combined with standard methods of community outreach and paid advertising. We were successful in exceeding our recruitment goal and retained 92% of the study participants at post-intervention (2 months) and 90% at 6 months. Recruitment and retention for family caregiver interventions employing mind-body based complementary therapies can be successful despite many challenges. Barriers include cultural perceptions about the use and benefit of complementary therapies, cultural differences with how the role of family caregiver is perceived, the use of group-based designs requiring significant time commitment by participants, and travel and respite care needs for busy family caregivers. Copyright © 2011 Elsevier Inc. All rights reserved.

Multi-objective shape optimization of plate structure under stress criteria based on sub-structured mixed FEM and genetic algorithms

NASA Astrophysics Data System (ADS)

Garambois, Pierre; Besset, Sebastien; Jézéquel, Louis

2015-07-01

This paper presents a methodology for the multi-objective (MO) shape optimization of plate structure under stress criteria, based on a mixed Finite Element Model (FEM) enhanced with a sub-structuring method. The optimization is performed with a classical Genetic Algorithm (GA) method based on Pareto-optimal solutions and considers thickness distributions parameters and antagonist objectives among them stress criteria. We implement a displacement-stress Dynamic Mixed FEM (DM-FEM) for plate structure vibrations analysis. Such a model gives a privileged access to the stress within the plate structure compared to primal classical FEM, and features a linear dependence to the thickness parameters. A sub-structuring reduction method is also computed in order to reduce the size of the mixed FEM and split the given structure into smaller ones with their own thickness parameters. Those methods combined enable a fast and stress-wise efficient structure analysis, and improve the performance of the repetitive GA. A few cases of minimizing the mass and the maximum Von Mises stress within a plate structure under a dynamic load put forward the relevance of our method with promising results. It is able to satisfy multiple damage criteria with different thickness distributions, and use a smaller FEM.

Mindfulness-Based Stress Reduction

MedlinePlus

... U V W X Y Z Mindfulness-Based Stress Reduction (MBSR) Information 6 Things You Should Know: ... Dementia (12/20/13) Research Spotlights Mindfulness-Based Stress Reduction, Cognitive-Behavioral Therapy Shown To Be Cost ...

Specific reduction in cortisol stress reactivity after social but not attention-based mental training

PubMed Central

Engert, Veronika; Kok, Bethany E.; Papassotiriou, Ioannis; Chrousos, George P.; Singer, Tania

2017-01-01

Psychosocial stress is a public health burden in modern societies. Chronic stress–induced disease processes are, in large part, mediated via the activation of the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic-adrenal-medullary system. We asked whether the contemplative mental training of different practice types targeting attentional, socio-affective (for example, compassion), or socio-cognitive abilities (for example, perspective-taking) in the context of a 9-month longitudinal training study offers an effective means for psychosocial stress reduction. Using a multimethod approach including subjective, endocrine, autonomic, and immune markers and testing 313 participants in a standardized psychosocial laboratory stressor, we show that all three practice types markedly reduced self-reported stress reactivity in healthy participants. However, only the training of intersubjective skills via socio-affective and socio-cognitive routes attenuated the physiological stress response, specifically the secretion of the HPA axis end-product cortisol, by up to 51%. The assessed autonomic and innate immune markers were not influenced by any practice type. Mental training focused on present-moment attention and interoceptive awareness as implemented in many mindfulness-based intervention programs was thus limited to stress reduction on the level of self-report. However, its effectiveness was equal to that of intersubjective practice types in boosting the association between subjective and endocrine stress markers. Our results reveal a broadly accessible low-cost approach to acquiring psychosocial stress resilience. Short daily intersubjective practice may be a promising method for minimizing the incidence of chronic social stress–related disease, thereby reducing individual suffering and relieving a substantial financial burden on society. PMID:28983508

Direct method of design and stress analysis of rotating disks with temperature gradient

NASA Technical Reports Server (NTRS)

Manson, S S

1950-01-01

A method is presented for the determination of the contour of disks, typified by those of aircraft gas turbines, to incorporate arbitrary elastic-stress distributions resulting from either centrifugal or combined centrifugal and thermal effects. The specified stress may be radial, tangential, or any combination of the two. Use is made of the finite-difference approach in solving the stress equations, the amount of computation necessary in the evolution of a design being greatly reduced by the judicious selection of point stations by the aid of a design chart. Use of the charts and of a preselected schedule of point stations is also applied to the direct problem of finding the elastic and plastic stress distribution in disks of a given design, thereby effecting a great reduction in the amount of calculation. Illustrative examples are presented to show computational procedures in the determination of a new design and in analyzing an existing design for elastic stress and for stresses resulting from plastic flow.

Effect of Trailing Intensive Cooling on Residual Stress and Welding Distortion of Friction Stir Welded 2060 Al-Li Alloy

NASA Astrophysics Data System (ADS)

Ji, Shude; Yang, Zhanpeng; Wen, Quan; Yue, Yumei; Zhang, Liguo

2018-04-01

Trailing intensive cooling with liquid nitrogen has successfully applied to friction stir welding of 2 mm thick 2060 Al-Li alloy. Welding temperature, plastic strain, residual stress and distortion of 2060 Al-Li alloy butt-joint are compared and discussed between conventional cooling and trailing intensive cooling using experimental and numerical simulation methods. The results reveal that trailing intensive cooling is beneficial to shrink high temperature area, reduce peak temperature and decrease plastic strain during friction stir welding process. In addition, the reduction degree of plastic strain outside weld is smaller than that inside weld. Welding distortion presents an anti-saddle shape. Compared with conventional cooling, the reductions of welding distortion and longitudinal residual stresses of welding joint under intense cooling reach 47.7 % and 23.8 %, respectively.

New concept for treating female stress urinary incontinence with radiofrequency

PubMed Central

Lordelo, Patrícia; Boas, Andrea Vilas; Sodré, Danielle; Lemos, Amanda; Tozetto, Sibele; Brasil, Cristina

2017-01-01

ABSTRACT Purpose: To evaluate the clinical response and adverse effects of radiofrequency on the urethral meatus in the treatment of stress urinary incontinence in women. Materials and Methods: This phase one study included ten women with Stress Urinary Incontinence (SUI). The evaluation consisted of 1 hour Pad tests to quantify urine loss and to assess the degree of procedure satisfaction by using the Likert scale. To evaluate safety, we observed the number of referred side effects. Results: Average age was 53.10 years±7.08 years. In assessing the final Pad Test, 70% showed a reduction and 30% a worsening of urinary loss. Using the Pad Test one month later, there was a reduction in all patients (p=0.028). The degree of satisfaction was 90% and no side effects have been observed. One patient reported burning sensation. Conclusion: The treatment of SUI with radiofrequency on the urethral meatus has no adverse effects, being a low risk method that reduces urinary loss in women. However, to increase the validity of the study, larger clinical trials are warranted. PMID:28727373

Adolescents' sleep in low-stress and high-stress (exam) times: a prospective quasi-experiment.

PubMed

Dewald, Julia F; Meijer, Anne Marie; Oort, Frans J; Kerkhof, Gerard A; Bögels, Susan M

2014-01-01

This prospective quasi-experiment (N = 175; mean age = 15.14 years) investigates changes in adolescents' sleep from low-stress (regular school week) to high-stress times (exam week), and examines the (moderating) role of chronic sleep reduction, baseline stress, and gender. Sleep was monitored over three consecutive weeks using actigraphy. Adolescents' sleep was more fragmented during the high-stress time than during the low-stress time, meaning that individuals slept more restless during stressful times. However, sleep efficiency, total sleep time, and sleep onset latency remained stable throughout the three consecutive weeks. High chronic sleep reduction was related to later bedtimes, later sleep start times, later sleep end times, later getting up times, and more time spent in bed. Furthermore, low chronic sleep reduction and high baseline stress levels were related to more fragmented sleep during stressful times. This study shows that stressful times can have negative effects on adolescents' sleep fragmentation, especially for adolescents with low chronic sleep reduction or high baseline stress levels.

Combining classifiers to predict gene function in Arabidopsis thaliana using large-scale gene expression measurements.

PubMed

Lan, Hui; Carson, Rachel; Provart, Nicholas J; Bonner, Anthony J

2007-09-21

Arabidopsis thaliana is the model species of current plant genomic research with a genome size of 125 Mb and approximately 28,000 genes. The function of half of these genes is currently unknown. The purpose of this study is to infer gene function in Arabidopsis using machine-learning algorithms applied to large-scale gene expression data sets, with the goal of identifying genes that are potentially involved in plant response to abiotic stress. Using in house and publicly available data, we assembled a large set of gene expression measurements for A. thaliana. Using those genes of known function, we first evaluated and compared the ability of basic machine-learning algorithms to predict which genes respond to stress. Predictive accuracy was measured using ROC50 and precision curves derived through cross validation. To improve accuracy, we developed a method for combining these classifiers using a weighted-voting scheme. The combined classifier was then trained on genes of known function and applied to genes of unknown function, identifying genes that potentially respond to stress. Visual evidence corroborating the predictions was obtained using electronic Northern analysis. Three of the predicted genes were chosen for biological validation. Gene knockout experiments confirmed that all three are involved in a variety of stress responses. The biological analysis of one of these genes (At1g16850) is presented here, where it is shown to be necessary for the normal response to temperature and NaCl. Supervised learning methods applied to large-scale gene expression measurements can be used to predict gene function. However, the ability of basic learning methods to predict stress response varies widely and depends heavily on how much dimensionality reduction is used. Our method of combining classifiers can improve the accuracy of such predictions - in this case, predictions of genes involved in stress response in plants - and it effectively chooses the appropriate amount of dimensionality reduction automatically. The method provides a useful means of identifying genes in A. thaliana that potentially respond to stress, and we expect it would be useful in other organisms and for other gene functions.

The Story of Ferris Urbanowski: California, Here We Come!

PubMed Central

Zwelling, Elaine

2001-01-01

Although childbirth educators may not all have known her by name, the lovely redhead who was the star childbirth educator in the 1970s film The Story of Eric was a familiar face. After viewing the film numerous times in our classes, early childbirth educators all felt that we knew her. Ferris Urbanowski was an early crusader for the Lamaze method of childbirth preparation in California in the 1960s. She worked to convince physicians in the Los Angeles area of the merits of the method, to establish classes for expectant parents, and to start a chapter of ASPO (now, Lamaze International, Inc.) in Los Angeles. Her book about yoga illustrated how additional methods of relaxation could benefit pregnant women. Today, Urbanowski attributes her past involvement in childbirth education to her current professional role as a teacher and counselor in the field of stress reduction at the Stress Reduction Clinic at the University of Massachusetts Medical Center. PMID:17273248

Piloting a stress management and mindfulness program for undergraduate nursing students: student feedback and lessons learned.

PubMed

van der Riet, Pamela; Rossiter, Rachel; Kirby, Dianne; Dluzewska, Teresa; Harmon, Charles

2015-01-01

Widespread reports of high stress levels and mental health problems among university student populations indicate the use of interventions to facilitate stress reduction and support student resilience and wellbeing. There is growing evidence that regular mindfulness practice may confer positive health benefits and reduced stress levels. The aim of this pilot project was to explore the impact of a seven-week stress management and mindfulness program as a learning support and stress reduction method for nursing and midwifery students. The program was conducted at a large regional university in Australia. Fourteen first-year undergraduate nursing and midwifery students agreed to attend the program and to participate in a follow-up focus group. A descriptive qualitative design was utilised to examine the impact of the program. A semi-structured focus group interview was conducted with a thematic analysis undertaken of the transcript and process notes. Ten students completed the research component of this project by participating in the focus group interview. Three main themes capture the participants' experience: attending to self, attending to others and attending to program related challenges. Data indicate a positive impact on sleep, concentration, clarity of thought and a reduction in negative cognitions. Participants also identified challenges related to timetabling, program structure and venue. Overall, this pilot program enhanced the participants' sense of well-being. Despite the challenges, benefits were identified on a personal and professional level. Valuable feedback was provided that will be used to further develop and expand stress management and mindfulness programs offered to students attending this university. Copyright © 2014. Published by Elsevier Ltd.

Aromatherapy Benefits Autonomic Nervous System Regulation for Elementary School Faculty in Taiwan

PubMed Central

Chang, Kang-Ming; Shen, Chuh-Wei

2011-01-01

Workplace stress-related illness is a serious issue, and consequently many stress reduction methods have been investigated. Aromatherapy is especially for populations that work under high stress. Elementary school teachers are a high-stress working population in Taiwan. In this study, fifty-four elementary school teachers were recruited to evaluate aromatherapy performance on stress reduction. Bergamot essential oil was used for aromatherapy spray for 10 minutes. Blood pressure and autonomic nervous system parameters were recorded 5 minutes before and after the application of the aroma spray. Results showed that there were significant decreases in blood pressure, heart rate, LF power percentage, and LF/HF while there were increases in heart rate variability and HF power percentage (P < .001∗∗∗) after application of the aromatherapy spray. Further analysis was investigated by dividing subjects into three background variables (position variables, age variables, gender variables) and anxiety degree groups. All parameters were significantly different for most subgroups, except for the substitute teachers and the light-anxiety group. Parasympathetic nervous system activation was measured after aromatherapy in this study. It encouraged further study for other stress working population by aromatherapy. PMID:21584196

Aromatherapy benefits autonomic nervous system regulation for elementary school faculty in taiwan.

PubMed

Chang, Kang-Ming; Shen, Chuh-Wei

2011-01-01

Workplace stress-related illness is a serious issue, and consequently many stress reduction methods have been investigated. Aromatherapy is especially for populations that work under high stress. Elementary school teachers are a high-stress working population in Taiwan. In this study, fifty-four elementary school teachers were recruited to evaluate aromatherapy performance on stress reduction. Bergamot essential oil was used for aromatherapy spray for 10 minutes. Blood pressure and autonomic nervous system parameters were recorded 5 minutes before and after the application of the aroma spray. Results showed that there were significant decreases in blood pressure, heart rate, LF power percentage, and LF/HF while there were increases in heart rate variability and HF power percentage (P < .001(∗∗∗)) after application of the aromatherapy spray. Further analysis was investigated by dividing subjects into three background variables (position variables, age variables, gender variables) and anxiety degree groups. All parameters were significantly different for most subgroups, except for the substitute teachers and the light-anxiety group. Parasympathetic nervous system activation was measured after aromatherapy in this study. It encouraged further study for other stress working population by aromatherapy.

Reduced Order Methods for Prediction of Thermal-Acoustic Fatigue

NASA Technical Reports Server (NTRS)

Przekop, A.; Rizzi, S. A.

2004-01-01

The goal of this investigation is to assess the quality of high-cycle-fatigue life estimation via a reduced order method, for structures undergoing random nonlinear vibrations in a presence of thermal loading. Modal reduction is performed with several different suites of basis functions. After numerically solving the reduced order system equations of motion, the physical displacement time history is obtained by an inverse transformation and stresses are recovered. Stress ranges obtained through the rainflow counting procedure are used in a linear damage accumulation method to yield fatigue estimates. Fatigue life estimates obtained using various basis functions in the reduced order method are compared with those obtained from numerical simulation in physical degrees-of-freedom.

A Nonlinear Reduced Order Method for Prediction of Acoustic Fatigue

NASA Technical Reports Server (NTRS)

Przekop, Adam; Rizzi, Stephen A.

2006-01-01

The goal of this investigation is to assess the quality of high-cycle-fatigue life estimation via a reduced order method, for structures undergoing geometrically nonlinear random vibrations. Modal reduction is performed with several different suites of basis functions. After numerically solving the reduced order system equations of motion, the physical displacement time history is obtained by an inverse transformation and stresses are recovered. Stress ranges obtained through the rainflow counting procedure are used in a linear damage accumulation method to yield fatigue estimates. Fatigue life estimates obtained using various basis functions in the reduced order method are compared with those obtained from numerical simulation in physical degrees-of-freedom.

Estimates of leaf area index from spectral reflectance of wheat under different cultural practices and solar angle

NASA Technical Reports Server (NTRS)

Asrar, G.; Kanemasu, E. T.; Yoshida, M.

1985-01-01

The influence of management practices and solar illumination angle on the leaf area index (LAI) was estimated from measurements of wheat canopy reflectance evaluated by two methods, a regression formula and an indirect technique. The date of planting and the time of irrigation in relation to the stage of plant growth were found to have significant effects on the development of leaves in spring wheat. A reduction in soil moisture adversely affected both the duration and magnitude of the maximum LAI for late planting dates. In general, water stress during vegetative stages resulted in a reduction in maximum LAI, while water stress during the reproductive period shortened the duration of green LAI in spring wheat. Canopy geometry and solar angle also affected the spectral properties of the canopies, and hence the estimated LAI. Increase in solar zenith angles resulted in a general increase in estimated LAI obtained from both methods.

Anelasticity of olivine single crystals investigated by stress-reduction tests and high-angular resolution electron backscatter diffraction

NASA Astrophysics Data System (ADS)

Wallis, D.; Hansen, L. N.; Kempton, I.; Wilkinson, A. J.

2017-12-01

Geodynamic phenomena, including glacial isostatic adjustment and postseismic deformation, can involve transient deformation in response to changes in differential stress acting on mantle rocks. As such, rheological models of transient deformation are incorporated in predictions of associated processes, including sea-level rise and stress redistribution after earthquakes. However, experimental constraints on rheological models for transient deformation of mantle materials are sparse. In particular, experiments involving stress reductions have been lacking. Moreover, a material's response to a reduction in stress can provide clues to the microphysical processes controlling deformation. To constrain models of transient deformation of mantle rocks we performed stress-reduction tests on single crystals of olivine at 1250-1300°C. Mechanical and piezoelectric actuators controlled constant initial stress during creep. At various strain intervals stress was reduced near-instantaneously using the piezoelectric actuator, inducing both elastic and anelastic (time-dependent) lengthening of the samples. A range of magnitudes of stress reduction were applied, typically unloading 10-90% of the initial stress. High-angular resolution electron backscatter diffraction (HR-EBSD), based on cross-correlation of diffraction patterns, was used to map dislocation density and elastic strain distributions in the recovered samples. Magnitudes of anelastic back-strain increase with increasing magnitudes of stress reduction and show a marked increase when stress reductions exceed 50% of the initial stress, consistent with previous observations in metals and alloys. This observation is inconsistent with the Burgers rheological model commonly used to describe transient behaviour and suggests that the style of rheological behaviour depends on the magnitude of stress change. HR-EBSD maps reveal that the crystal lattices are smoothly curved and generally lack subgrain boundaries and elastic strain heterogeneities. The dependence of the anelastic behaviour on the initial stress, combined with the lack of subgrain boundaries, suggest that the anelastic behaviour is controlled by local interactions between dislocations, rather than resistance imposed by the lattice or subgrain boundaries.

Diamond heteroepitaxial lateral overgrowth

DOE PAGES

Tang, Y. -H.; Bi, B.; Golding, B.

2015-02-24

A method of diamond heteroepitaxial lateral overgrowth is demonstrated which utilizes a photolithographic metal mask to pattern a thin (001) epitaxial diamond surface. Significant structural improvement was found, with a threading dislocation density reduced by two orders of magnitude at the top surface of a thick overgrown diamond layer. In the initial stage of overgrowth, a reduction of diamond Raman linewidth in the overgrown area was also realized. Thermally-induced stress and internal stress were determined by Raman spectroscopy of adhering and delaminated diamond films. As a result, the internal stress is found to decrease as sample thickness increases.

Intraoperative CT in the assessment of posterior wall acetabular fracture stability.

PubMed

Cunningham, Brian; Jackson, Kelly; Ortega, Gil

2014-04-01

Posterior wall acetabular fractures that involve 10% to 40% of the posterior wall may or may not require an open reduction and internal fixation. Dynamic stress examination of the acetabular fracture under fluoroscopy has been used as an intraoperative method to assess joint stability. The aim of this study was to demonstrate the value of intraoperative ISO computed tomography (CT) examination using the Siemens ISO-C imaging system (Siemens Corp, Malvern, Pennsylvania) in the assessment of posterior wall acetabular fracture stability during stress examination under anesthesia. In 5 posterior wall acetabular fractures, standard fluoroscopic images (including anteroposterior pelvis and Judet radiographs) with dynamic stress examinations were compared with the ISO-C CT imaging system to assess posterior wall fracture stability during stress examination. After review of standard intraoperative fluoroscopic images under dynamic stress examination, all 5 cases appeared to demonstrate posterior wall stability; however, when the intraoperative images from the ISO-C CT imaging system demonstrated that 1 case showed fracture instability of the posterior wall segment during stress examination, open reduction and internal fixation was performed. The use of intraoperative ISO CT imaging has shown an initial improvement in the surgeon's ability to assess the intraoperative stability of posterior wall acetabular fractures during stress examination when compared with standard fluoroscopic images. Copyright 2014, SLACK Incorporated.

Transcendental meditation, hypertension and heart disease.

PubMed

King, Michael S; Carr, Tim; D'Cruz, Cathryn

2002-02-01

Accumulating evidence that stress contributes to the pathogenesis and expression of coronary heart disease has led to the increasing use of stress reduction techniques in its prevention and treatment. The most widely used and tested technique is transcendental meditation. To describe transcendental meditation and review research on its use in the treatment and prevention of coronary heart disease. Transcendental meditation shows promise as a preventive and treatment method for coronary heart disease. Transcendental meditation is associated with decreased hypertension and atherosclerosis, improvements in patients with heart disease, decreased hospitalisation rates and improvements in other risk factors including decreased smoking and cholesterol. These findings cannot be generalised to all meditation and stress reduction techniques as each technique differs in its effects. Further research is needed to delineate the mechanisms involved and to verify preliminary findings concerning atherosclerosis and heart disease and the findings of short term hypertension studies.

Therapeutic touch and post-Hurricane Hugo stress.

PubMed

Olson, M; Sneed, N; Bonadonna, R; Ratliff, J; Dias, J

1992-06-01

This repeated-session design sought to answer questions about the effectiveness of therapeutic touch in reduction of stress for 23 individuals following a natural disaster. In addition, methodological issues related to the average length of time for a therapeutic-touch treatment and a method of documenting the nonverbal interaction between subject and toucher were investigated. Findings indicate that stressed people report themselves to be less stressed following therapeutic touch (p = .05). Time of therapeutic-touch intervention varied significantly between the touchers, with a range of 6.8 to 20 minutes. Qualitative data examining the interaction of toucher and subject raised a number of questions that require further study.

Artistic Tasks Outperform Nonartistic Tasks for Stress Reduction

ERIC Educational Resources Information Center

Abbott, Kayleigh A.; Shanahan, Matthew J.; Neufeld, Richard W. J.

2013-01-01

Art making has been documented as an effective stress reduction technique. In this between-subjects experimental study, possible mechanisms of stress reduction were examined in a sample of 52 university students randomly assigned to one of four conditions generated by factorially crossing Activity Type (artistic or nonartistic) with Coping…

Mapping of power consumption and friction reduction in piezoelectrically-assisted ultrasonic lubrication

NASA Astrophysics Data System (ADS)

Dong, Sheng; Dapino, Marcelo J.

2015-04-01

Ultrasonic lubrication has been proven effective in reducing dynamic friction. This paper investigates the relationship between friction reduction, power consumption, linear velocity, and normal stress. A modified pin-on-disc tribometer was adopted as the experimental set-up, and a Labview system was utilized for signal generation and data acquisition. Friction reduction was quantified for 0.21 to 5.31 W of electric power, 50 to 200 mm/s of linear velocity, and 23 to 70 MPa of normal stress. Friction reduction near 100% can be achieved under certain conditions. Lower linear velocity and higher electric power result in greater friction reduction, while normal stress has little effect on friction reduction. Contour plots of friction reduction, power consumption, linear velocity, and normal stress were created. An efficiency coefficient was proposed to calculate power requirements for a certain friction reduction or reduced friction for a given electric power.

[Mind-body approach in the area of preventive medicine: focusing on relaxation and meditation for stress management].

PubMed

Kang, Yunesik

2010-09-01

Emotional support and a stress management program should be simultaneously provided to clients as effective preventive services for healthy behavioral change. This study was conducted to review various relaxation and meditation intervention methods and their applicability for a preventive service program. The author of this paper tried to find various relaxation and meditation programs through a literature review and program searching and to introduce them. The 'Relaxation Response' and 'Mindfulness Based Stress Reduction (MBSR)' are the most the widely used meditative programs in mainstream medical systems. Abdominal breathing, Progressive Musclular Relaxation (PMR), Relaxative Imagery, Autogenic Training (AT) and Biofeedback are other well-known techniques for relaxation and stress management. I have developed and implemented some programs using these methods. Relaxation and meditation classes for cancer patients and a meditation based stress coping workshop are examples of this program. Relaxation and meditation seem to be good and effective methods for primary, secondary and tertiary preventive service programs. Program development and standardization and further study are needed for more and wider use of the mind-body approach in the preventive service area of medicine.

The Consequences of Nursing Stress and Need for Integrated Solutions

PubMed Central

Roberts, Rashaun K.; Grubb, Paula L.

2015-01-01

Purpose In a 2011 survey sponsored by the American Nurses Association (ANA), nurses identified the acute and chronic effects of stress and overwork as one of their two top safety and health concerns. Design/Methods A review of the literature was conducted to investigate the impact that job stress has on the health and safety of nursing professionals and the role that working conditions and job characteristics play in fostering job stress. Findings Strong evidence supporting links between job stress, safety and health in general and within different types of nursing populations exists. Working conditions also contribute to the development of job stress. Conclusion Combining and integrating “person-focused” strategies designed to build nurses’ ability to manage stress at the individual level with “organization-focused” strategies that eliminate stressful working conditions is critical to the reduction and prevention of job stress among nursing professionals. PMID:23696492

Residual stress evaluation of components produced via direct metal laser sintering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kemerling, Brandon; Lippold, John C.; Fancher, Christopher M.

Direct metal laser sintering is an additive manufacturing process which is capable of fabricating three-dimensional components using a laser energy source and metal powder particles. Despite the numerous benefits offered by this technology, the process maturity is low with respect to traditional subtractive manufacturing methods. Relationships between key processing parameters and final part properties are generally lacking and require further development. In this study, residual stresses were evaluated as a function of key process variables. The variables evaluated included laser scan strategy and build plate preheat temperature. Residual stresses were measured experimentally via neutron diffraction and computationally via finite elementmore » analysis. Good agreement was shown between the experimental and computational results. Results showed variations in the residual stress profile as a function of laser scan strategy. Compressive stresses were dominant along the build height (z) direction, and tensile stresses were dominant in the x and y directions. Build plate preheating was shown to be an effective method for alleviating residual stress due to the reduction in thermal gradient.« less

Residual stress evaluation of components produced via direct metal laser sintering

DOE PAGES

Kemerling, Brandon; Lippold, John C.; Fancher, Christopher M.; ...

2018-03-22

Direct metal laser sintering is an additive manufacturing process which is capable of fabricating three-dimensional components using a laser energy source and metal powder particles. Despite the numerous benefits offered by this technology, the process maturity is low with respect to traditional subtractive manufacturing methods. Relationships between key processing parameters and final part properties are generally lacking and require further development. In this study, residual stresses were evaluated as a function of key process variables. The variables evaluated included laser scan strategy and build plate preheat temperature. Residual stresses were measured experimentally via neutron diffraction and computationally via finite elementmore » analysis. Good agreement was shown between the experimental and computational results. Results showed variations in the residual stress profile as a function of laser scan strategy. Compressive stresses were dominant along the build height (z) direction, and tensile stresses were dominant in the x and y directions. Build plate preheating was shown to be an effective method for alleviating residual stress due to the reduction in thermal gradient.« less

Decreased plasma ghrelin contributes to anorexia following novelty stress.

PubMed

Saegusa, Yayoi; Takeda, Hiroshi; Muto, Shuichi; Nakagawa, Koji; Ohnishi, Shunsuke; Sadakane, Chiharu; Nahata, Miwa; Hattori, Tomohisa; Asaka, Masahiro

2011-10-01

We hypothesized that anorexia induced by novelty stress caused by exposure to a novel environment may be due to activation of corticotropin-releasing factor (CRF) and subsequently mediated by decreasing peripheral ghrelin concentration via serotonin (5-HT) and melanocortin-4 receptors (MC4R). Each mouse was transferred from group-housed cages to individual cages to establish the novelty stress. We observed the effect of changes in feeding behavior in a novel environment using the method of transferring group-housed mice to individual cages. We investigated the effect of an intracerebroventricular injection of antagonists/agonists of CRF1/2 receptors (CRF1/2Rs), 5-HT(1B)/(2C) receptors (5-HT(1B)/(2C)R), and MC4R to clarify the role of each receptor on the decrease in food intake. Plasma ghrelin levels were also measured. The novelty stress caused a reduction in food intake that was abolished by administering a CRF1R antagonist. Three hours after the novelty stress, appetite reduction was associated with reduced levels of neuropeptide Y/agouti-related peptide mRNA, increased levels of proopiomelanocortin mRNA in the hypothalamus, and a decrease in plasma ghrelin level. Administering a CRF1R antagonist, a 5-HT(1B)/(2C)R antagonist, an MC4R antagonist, exogenous ghrelin, and an enhancer of ghrelin secretion, rikkunshito, resolved the reduction in food intake 3 h after the novelty stress by enhancing circulating ghrelin concentrations. We showed that anorexia during a novelty stress is a process in which CRF1R is activated at the early stage of appetite loss and is subsequently activated by a 5-HT(1B)/(2C)R and MC4R stimulus, leading to decreased peripheral ghrelin concentrations.

Reducing Distress in Mothers of Children With Autism and Other Disabilities: A Randomized Trial

PubMed Central

Fisher, Marisa H.; Taylor, Julie Lounds; Lambert, Warren; Miodrag, Nancy

2014-01-01

BACKGROUND: Compared with other parents, mothers of children with autism spectrum disorder or other neurodevelopmental disabilities experience more stress, illness, and psychiatric problems. Although the cumulative stress and disease burden of these mothers is exceptionally high, and associated with poorer outcomes in children, policies and practices primarily serve the identified child with disabilities. METHODS: A total of 243 mothers of children with disabilities were consented and randomized into either Mindfulness-Based Stress Reduction (mindfulness practice) or Positive Adult Development (positive psychology practice). Well-trained, supervised peer mentors led 6 weeks of group treatments in 1.5-hour weekly sessions, assessing mothers 6 times before, during, and up to 6 months after treatment. Mothers had children with autism (65%) or other disabilities (35%). At baseline, 85% of this community sample had significantly elevated stress, 48% were clinically depressed, and 41% had anxiety disorders. RESULTS: Using slopes-as-outcomes, mixed random effects models, both treatments led to significant reductions in stress, depression, and anxiety, and improved sleep and life satisfaction, with large effects in depression and anxiety. Mothers in Mindfulness-Based Stress Reduction versus Positive Adult Development had greater improvements in anxiety, depression, sleep, and well-being. Mothers of children with autism spectrum disorder improved less in anxiety, but did not otherwise differ from their counterparts. CONCLUSIONS: Future studies are warranted on how trained mentors and professionals can address the unmet mental health needs of mothers of children with developmental disabilities. Doing so improves maternal well-being and furthers their long-term caregiving of children with complex developmental, physical, and behavioral needs. PMID:25049350

A new method for long-term storage of titred microbial standard solutions suitable for microbiologic quality control activities of pharmaceutical companies.

PubMed

Chiellini, Carolina; Mocali, Stefano; Fani, Renato; Ferro, Iolanda; Bruschi, Serenella; Pinzani, Alessandro

2016-08-01

Commercially available lyophilized microbial standards are expensive and subject to reduction in cell viability due to freeze-drying stress. Here we introduce an inexpensive and straightforward method for in-house microbial standard preparation and cryoconservation that preserves constant cell titre and cell viability over 14 months.

Salivary Cortisol as a Biomarker of Stress in Mothers and their Low Birth Weight Infants and Sample Collecting Challenges

PubMed Central

Vujičić, Ana Đorđević; Đukić, Svjetlana Maglajić

2016-01-01

Summary Background Salivary cortisol measurement is a non-invasive method suitable for use in neonatal research. Mother-infant separation after birth represents stress and skin-to-skin contact (SSC) has numerous benefits. The aim of the study was to measure salivary cortisol in mothers and newborns before and after SSC in order to assess the effect of SSC on mothers’ and infants’ stress and to estimate the efficacy of collecting small saliva samples in newborns. Methods Salivary cortisol was measured in 35 mother-infant pairs before and after the first and the fifth SSC in small saliva samples (50 μL) using the high sensitivity Quantitative ELISA-Kit (0.0828 nmol/L) for low cortisol levels detection. Samples were collected with eye sponge during 3 to 5 minutes. Results Cortisol level in mothers decreased after SSC: the highest levels were measured before and the lowest after SSC and the differences in values were significant during both the first (p<0.001) and the fifth SSC (p<0.001). During the first SSC the cortisol level decrease was detected in 14 (40%) and an increase in 21 (60%) newborns, and during the fifth SSC a decrease was detected in 16 (45.7%) and an increase in 19 (54.3%) newborns, without confirmed significance of the difference. Saliva sampling efficacy using eye sponge was 75%. Conclusions Cortisol level decrease in mothers proves the stress reduction during SSC, while variable cortisol levels in infants do not indicate stress reduction and imply the need for further research. The used sampling method appeared to be one of the most optimal considering the sample volume, sampling time and efficacy. PMID:28356870

Research on the fiber Bragg grating sensor for the shock stress measurement

PubMed Central

Deng, Xiangyang; Chen, Guanghua; Peng, Qixian; Li, Zeren; Meng, Jianhua; Liu, Jun

2011-01-01

A fiber Bragg grating (FBG) sensor with an unbalanced Mach-Zehnder fiber interferometer for the shock stress measurement is proposed and demonstrated. An analysis relationship between the shock stress and the central reflection wavelength shift of the FBG is firstly derived. In this sensor, the optical path difference of the unbalanced Mach-Zehnder fiber interferometer is ∼3.1 mm and the length of the FBG is 2 mm. An arctangent function reduction method, which can avoid sine function's insensitive zone where the shock stress measurement has a reduced accuracy, is presented. A shock stress measurement of water driven by one stage gun (up to 1.4 GPa), with good theoretical accuracy (∼10%), is launched. PMID:22047282

Catalan speakers' perception of word stress in unaccented contexts.

PubMed

Ortega-Llebaria, Marta; del Mar Vanrell, Maria; Prieto, Pilar

2010-01-01

In unaccented contexts, formant frequency differences related to vowel reduction constitute a consistent cue to word stress in English, whereas in languages such as Spanish that have no systematic vowel reduction, stress perception is based on duration and intensity cues. This article examines the perception of word stress by speakers of Central Catalan, in which, due to its vowel reduction patterns, words either alternate stressed open vowels with unstressed mid-central vowels as in English or contain no vowel quality cues to stress, as in Spanish. Results show that Catalan listeners perceive stress based mainly on duration cues in both word types. Other cues pattern together with duration to make stress perception more robust. However, no single cue is absolutely necessary and trading effects compensate for a lack of differentiation in one dimension by changes in another dimension. In particular, speakers identify longer mid-central vowels as more stressed than shorter open vowels. These results and those obtained in other stress-accent languages provide cumulative evidence that word stress is perceived independently of pitch accents by relying on a set of cues with trading effects so that no single cue, including formant frequency differences related to vowel reduction, is absolutely necessary for stress perception.

Effect of pertussis toxin pretreated centrally on blood glucose level induced by stress.

PubMed

Suh, Hong-Won; Sim, Yun-Beom; Park, Soo-Hyun; Sharma, Naveen; Im, Hyun-Ju; Hong, Jae-Seung

2016-09-01

In the present study, we examined the effect of pertussis toxin (PTX) administered centrally in a variety of stress-induced blood glucose level. Mice were exposed to stress after the pretreatment of PTX (0.05 or 0.1 µg) i.c.v. or i.t. once for 6 days. Blood glucose level was measured at 0, 30, 60 and 120 min after stress stimulation. The blood glucose level was increased in all stress groups. The blood glucose level reached at maximum level after 30 min of stress stimulation and returned to a normal level after 2 h of stress stimulation in restraint stress, physical, and emotional stress groups. The blood glucose level induced by cold-water swimming stress was gradually increased up to 1 h and returned to the normal level. The intracerebroventricular (i.c.v.) or intrathecal (i.t.) pretreatment with PTX, a Gi inhibitor, alone produced a hypoglycemia and almost abolished the elevation of the blood level induced by stress stimulation. The central pretreatment with PTX caused a reduction of plasma insulin level, whereas plasma corticosterone level was further up-regulated in all stress models. Our results suggest that the hyperglycemia produced by physical stress, emotional stress, restraint stress, and the cold-water swimming stress appear to be mediated by activation of centrally located PTX-sensitive G proteins. The reduction of blood glucose level by PTX appears to due to the reduction of plasma insulin level. The reduction of blood glucose level by PTX was accompanied by the reduction of plasma insulin level. Plasma corticosterone level up-regulation by PTX in stress models may be due to a blood glucose homeostatic mechanism.

Effect of stress ratio on the fatigue behaviour of glass/epoxy composite

NASA Astrophysics Data System (ADS)

Syayuthi, A. R. A.; Majid, M. S. Abdul; Ridzuan, M. J. M.; Basaruddin, K. S.; Peng, T. L.

2017-10-01

The effect of stress ratio on the fatigue behaviour of the GFRE composite has been investigated. The glass fibre reinforced epoxy (GFRE) composite plates were fabricated using vacuum infusion method. Static tensile was performed in accordance with the ASTM D5766 standard, and the cyclic test was conducted according to ASTM D3479 with three different stress ratio, R = 0, 0.5, -1. Static tensile tests were carried out to determine the ultimate strength of this composite. Subsequently, fatigue tests loads ranging from 30% to 90% of the ultimate load were applied to each specimen. The S-N curve of different stress ratio loading of fibreglass/epoxy composites was then established. The results show that the number of cycles to failure increases as the loading is decreased. The specimens for fatigue tests loads 30% at R = 0 and -1 recorded the highest number of cycles at 2 million cycles. The results obtained from this test indicated a significant life reduction for R = -1 compared with the tension-tension loading, with the life reduction for R = -1 being greatest. The fatigue behaviour of the GFRE composite materials is not only influenced by the percentage of fatigue tests load but with different of stress ratio.

MORIN MITIGATES OXIDATIVE STRESS, APOPTOSIS AND INFLAMMATION IN CEREBRAL ISCHEMIC RATS

PubMed Central

Chen, Yanrong; Li, Yanke; Xu, Huali; Li, Gang; Ma, Yunxia; Pang, Yu Jun

2017-01-01

Background: Morin is a flavanoid which exhibits potent antioxidant activity in various oxidative stress related diseases. The current study was attempted to scrutinize the preclinical bio-efficacy of morin on focal ischemia. Methods: The animal model of focal cerebral ischemic injury was done by midbrain carotid artery occlusion (MCAO) method, followed by Morin (30mg/kg) administration for seven days. Results: The outcome of the study showed that treatment with morin displayed positive effects in reducing the focal cerebral ischemia. This effect was evident with the improvements in neurological deficits, reduction in MDA content and elevation of antioxidant levels (SOD, GSH and Gpx). Furthermore, protein expression of Bax and caspase-3 were effectively down-regulated, whilst the expression of Bcl-2 was significantly elevated. On the other hand, the mRNA expression of proinflammatory cytokines was significantly reduced in focal cerebral ischemic rats upon morin intervention. Conclusion: Thus, the beneficial effects of morin on cerebral ischemia assault may result from the reduction of oxidative stress, inhibition of apoptosis and inflammation. The neuroprotective effects of morin supplement may serve as potent adjuvant in the amelioration of ischemic stroke. PMID:28573251

Induction of Intracellular Reductive Stress with a Photoactivatable Phosphine Probe.

PubMed

Tirla, Alina; Rivera-Fuentes, Pablo

2018-04-25

Reductive stress is a condition present in cells that have an increased concentration of reducing species, and it has been associated with a number of pathologies, such as neurodegenerative diseases and cancer. The tools available to study reductive stress lack both in selectivity and specific targeting and some of these shortcomings can be addressed by using photoactivatable compounds. We developed a photoactivatable phosphonium probe, which upon irradiation releases a fluorescent molecule and a trialkyphosphine. The probes can permeate through the plasma membrane and the photoreleased phosphine can induce intracellular reductive stress as proven by the detection of protein aggregates.

[Mechanism of the dentino-enamel junction on the resist-crack propagation of human teeth by the finite element method].

PubMed

Jingjing, Zheng; Tiezhou, Hou; Hong, Tao; Xueyan, Guo; Cui, Wu

2014-10-01

This study aims to identify the crack tip stress intensity factor of the propagation process, crack propagation path, and the changes in the shape of the crack tip by the finite element method. The finite element model of dentino-enamel junction was established with ANSYS software, and the length of the initial crack in the single edge was set to 0.1 mm. The lower end of the sample was fixed. The tensile load of 1 MPa with frequency of 5 Hz was applied to the upper end. The stress intensity factor, deflection angle, and changes in the shape of the crack tip in the crack propagation were calculated by ANSYS. The stress intensity factor suddenly and continuously decreased in dentino-enamel junction as the crack extended. A large skewed angle appeared, and the stress on crack tip was reduced. The dentino-enamel junction on human teeth may resist crack propagation through stress reduction.

Further investigation of relationships between membrane fluidity and ethanol tolerance in Saccharomyces cerevisiae.

PubMed

Ishmayana, Safri; Kennedy, Ursula J; Learmonth, Robert P

2017-11-27

Membrane lipid unsaturation index and membrane fluidity have been related to yeast ethanol stress tolerance in published studies, however findings have been inconsistent. In this study, viability reduction on exposure to 18% (v/v) ethanol was compared to membrane fluidity determined by laurdan generalized polarization. Furthermore, in the determination of viability reduction, we examined the effectiveness of two methods, namely total plate count and methylene violet staining. We found a strong negative correlation between ethanol tolerance and membrane fluidity, indicated by negative Pearson correlation coefficients of - 0.79, - 0.65 and - 0.69 for Saccharomyces cerevisiae strains A12, PDM and K7, respectively. We found that lower membrane fluidity leads to higher ethanol tolerance, as indicated by decreased viability reduction and higher laurdan generalized polarization in respiratory phase compared to respiro-fermentative phase cells. Total plate count better differentiated ethanol tolerance of yeast cells in different growth phases, while methylene violet staining was better to differentiate ethanol tolerance of the different yeast strains at a particular culture phase. Hence, both viability assessment methods have their own advantages and limitations, which should be considered when comparing stress tolerance in different situations.

A pilot study on mindfulness based stress reduction for smokers

PubMed Central

Davis, James M; Fleming, Michael F; Bonus, Katherine A; Baker, Timothy B

2007-01-01

Background Mindfulness means paying attention in the present moment, non-judgmentally, without commentary or decision-making. We report results of a pilot study designed to test the feasibility of using Mindfulness Based Stress Reduction (MBSR) (with minor modifications) as a smoking intervention. Methods MBSR instructors provided instructions in mindfulness in eight weekly group sessions. Subjects attempted smoking cessation during week seven without pharmacotherapy. Smoking abstinence was tested six weeks after the smoking quit day with carbon monoxide breath test and 7-day smoking calendars. Questionnaires were administered to evaluate changes in stress and affective distress. Results 18 subjects enrolled in the intervention with an average smoking history of 19.9 cigarettes per day for 26.4 years. At the 6-week post-quit visit, 10 of 18 subjects (56%) achieved biologically confirmed 7-day point-prevalent smoking abstinence. Compliance with meditation was positively associated with smoking abstinence and decreases in stress and affective distress. Discussions and conclusion The results of this study suggest that mindfulness training may show promise for smoking cessation and warrants additional study in a larger comparative trial. PMID:17254362

Reduction of Cancer-Specific Thought Intrusions and Anxiety Symptoms With a Stress Management Intervention Among Women Undergoing Treatment for Breast Cancer

PubMed Central

Antoni, Michael H.; Wimberly, Sarah R.; Lechner, Suzanne C.; Kazi, Aisha; Sifre, Tammy; Urcuyo, Kenya R.; Phillips, Kristin; Smith, Roselyn G.; Petronis, Vida M.; Guellati, Sophie; Wells, Kurrie A.; Blomberg, Bonnie; Carver, Charles S.

2017-01-01

Objective After surgery for breast cancer, many women experience anxiety relating to the cancer that can adversely affect quality of life and emotional functioning during the year postsurgery. Symptoms such as intrusive thoughts may be ameliorated during this period with a structured, group-based cognitive behavior intervention. Method A 10-week group cognitive behavior stress management intervention that included anxiety reduction (relaxation training), cognitive restructuring, and coping skills training was tested among 199 women newly treated for stage 0-III breast cancer. They were then followed for 1 year after recruitment. Results The intervention reduced reports of thought intrusion, interviewer ratings of anxiety, and emotional distress across 1 year significantly more than was seen with the control condition. The beneficial effects were maintained well past the completion of adjuvant therapy. Conclusions Structured, group-based cognitive behavior stress management may ameliorate cancer-related anxiety during active medical treatment for breast cancer and for 1 year following treatment. Group-based cognitive behavior stress management is a clinically useful adjunct to offer to women treated for breast cancer. PMID:17012691

Mind magic: a pilot study of preventive mind-body-based stress reduction in behaviorally inhibited and activated children.

PubMed

Jellesma, Francine C; Cornelis, Janine

2012-03-01

The aim of this pilot study was to examine a mind-body-based preventive intervention program and to determine relationships between children's behavioral inhibition system (BIS) and behavioral activation system, stress, and stress reduction after the program. Children participated in the program (n=30) or in a control condition (n=24). They filled out questionnaires before and after the program and reported their levels of stress before and after each of the five sessions. The program consisted of weekly sessions. Each session incorporated yoga postures, visualization, and social exercises. Breathing techniques were integrated. Stress reductions were only seen in the intervention group and mainly in children with high BIS--irrespective of their behavioral activation system. The results demonstrate that children with high BIS may benefit from a mind-body-based stress reduction program.

Investigation of high-speed free shear flows using improved pressure-strain correlated Reynolds stress turbulence model

NASA Technical Reports Server (NTRS)

Tiwari, S. N.; Lakshmanan, B.

1993-01-01

A high-speed shear layer is studied using compressibility corrected Reynolds stress turbulence model which employs newly developed model for pressure-strain correlation. MacCormack explicit prediction-corrector method is used for solving the governing equations and the turbulence transport equations. The stiffness arising due to source terms in the turbulence equations is handled by a semi-implicit numerical technique. Results obtained using the new model show a sharper reduction in growth rate with increasing convective Mach number. Some improvements were also noted in the prediction of the normalized streamwise stress and Reynolds shear stress. The computed results are in good agreement with the experimental data.

Social support moderates the effects of stress on sleep in adolescents.

PubMed

van Schalkwijk, Frank J; Blessinga, Agaath N; Willemen, Agnes M; Van Der Werf, Ysbrand D; Schuengel, Carlo

2015-08-01

Academic expectations and demands become primary sources of stress during adolescence, negatively affecting sleep. To cope with stress, adolescents may turn to social support figures. The present study tested the extent of main and moderating effects of various sources of social support on the association between stress and sleep. Adolescents (n = 202, meanage 14.6 years, standard deviation = 0.71) reported on academic stress, sleep, and support using questionnaires during a low- and high-stress period, defined by the absence or presence of examinations, respectively. Inquiries were made regarding social support from parents, friends, and class supervisor. During both stress periods, academic stress was associated negatively with sleep quality and positively with sleep reduction. Social support increased sleep quality and lowered sleep reduction. In addition, social support moderated the effects of academic stress on sleep, thus improving sleep quality and lowering sleep reduction. Moderating effects were stronger during a period of high stress. The present study showed that adolescents can benefit from stress moderation through social support by improvements of sleep quality and sleep reduction. Such moderating effects should be taken into account when studying stress and sleep. Implications and recommendations based on these findings are discussed. © 2015 European Sleep Research Society.

Reduction of stresses on buried rigid highway structures using the imperfect ditch method and expanded polystyrene (Geofoam).

DOT National Transportation Integrated Search

2005-04-01

The study of earth pressure distribution on buried structures has a great practical importance in constructing highway embankments above pipes and culverts. Based on Spanglers research, the supporting strength of a conduit depends primarily on thr...

Psychological effects of forest environments on healthy adults: Shinrin-yoku (forest-air bathing, walking) as a possible method of stress reduction.

PubMed

Morita, E; Fukuda, S; Nagano, J; Hamajima, N; Yamamoto, H; Iwai, Y; Nakashima, T; Ohira, H; Shirakawa, T

2007-01-01

Shinrin-yoku (walking and/or staying in forests in order to promote health) is a major form of relaxation in Japan; however, its effects have yet to be completely clarified. The aims of this study were: (1) to evaluate the psychological effects of shinrin-yoku in a large number of participants; and (2) to identify the factors related to these effects. Four hundred and ninety-eight healthy volunteers took part in the study. Surveys were conducted twice in a forest on the same day (forest day) and twice on a control day. Outcome measures were evaluated using the Multiple Mood Scale-Short Form (hostility, depression, boredom, friendliness, wellbeing and liveliness) and the State-Trait Anxiety Inventory A-State Scale. Statistical analyses were conducted using analysis of variance and multiple regression analyses. Hostility (P<0.001) and depression (P<0.001) scores decreased significantly, and liveliness (P=0.001) scores increased significantly on the forest day compared with the control day. The main effect of environment was also observed with all outcomes except for hostility, and the forest environment was advantageous. Stress levels were shown to be related to the magnitude of the shinrin-yoku effect; the higher the stress level, the greater the effect. This study revealed that forest environments are advantageous with respect to acute emotions, especially among those experiencing chronic stress. Accordingly, shinrin-yoku may be employed as a stress reduction method, and forest environments can be viewed as therapeutic landscapes. Therefore, customary shinrin-yoku may help to decrease the risk of psychosocial stress-related diseases, and evaluation of the long-term effects of shinrin-yoku is warranted.

Effect of Mindfulness-Based Stress Reduction on Anxiety, Depression and Stress in Women With Multiple Sclerosis

PubMed Central

Kolahkaj, Bentolhoda; Zargar, Fatemeh

2015-01-01

Background: Studies suggest that mindfulness-based interventions can improve anxiety, depression and stress in patients with multiple sclerosis (MS). However, no study investigated the effectiveness of this method in patients with a combination of problems such as depression, anxiety and stress simultaneously. However, comorbidities of depression and anxiety in MS are prevalent. Objectives: This study aimed to assess the effects of mindfulness-based stress reduction (MBRS) on anxiety, depression and stress in women with multiple sclerosis. Patients and Methods: This randomized controlled clinical trial was performed in 2013 in Ahvaz MS Society. Forty eight patients were selected by convenient sampling and randomly assigned in experimental and control groups. The patients in the two groups filled out depression, anxiety and stress scale (DASS-21) at initiation of study, 8 weeks later and 1 month after the end of intervention. The experimental group received 8 sessions of MBRS, while the control group treated as usual. Finally, data of 40 patients analyzed using t-test, chi square and repeated measures analysis of variance. Results: In the MBSR group, the mean depression, anxiety and stress were reduced significantly (P < 0.001). The mean depression score was 8.35 ± 1.78 before the intervention and reduced to 4.80 ± 0.83 and 4.45 ± 0.60 after the intervention and follow-up (P < 0.001). Also the mean anxiety score was 8.90 ± 1.97 before the intervention, which was significantly reduced to 4.70 ± 1.38 and 4.55 ± 0.99 after the intervention and follow-up (P < 0.001). The mean stress score was also 8.80 ± 2.35 before treatment and 4.80 ± 1.67 and 4.70 ± 1.34 after the intervention and follow-up (P < 0.001). Conclusions: This study showed that MBSR training can reduce mean depression, anxiety and stress scores in patients with MS. These findings suggest that MBSR is useful for psychological problems such as depression, anxiety and stress in patients with MS. PMID:26835467

Positive Effects of a Stress Reduction Program Based on Mindfulness Meditation in Brazilian Nursing Professionals: Qualitative and Quantitative Evaluation.

PubMed

dos Santos, Teresa Maria; Kozasa, Elisa Harumi; Carmagnani, Isabel Sampaio; Tanaka, Luiza Hiromi; Lacerda, Shirley Silva; Nogueira-Martins, Luiz Antonio

2016-01-01

Mindfulness meditation has been shown to effectively mitigate the negative effects of stress among nursing professionals, but in countries like Brazil, these practices are relatively unexplored. To evaluate the effects of a Stress Reduction Program (SRP) including mindfulness and loving kindness meditation among nursing professionals working in a Brazilian hospital setting. Pilot study with a mixed model using quantitative and qualitative methods was used to evaluate a group of participants. The quantitative data were analyzed at three different time points: pre-intervention, post-intervention, and follow-up. The qualitative data were analyzed at post-intervention. Hospital São Paulo (Brazil). Sample 13 nursing professionals, including nurses, technicians, and nursing assistants working in a hospital. Participants underwent mindfulness and loving kindness meditation during a period of six weeks. Perceived Stress Scale (PSS), Maslach Burnout Inventory (MBI), Beck Depression Inventory (BDI), State-Trait Anxiety Inventory (STAI), Satisfaction With Life Scale (SWLS), Self-Compassion Scale (SCS), WHOQOL-BREF quality of life assessment, and Work Stress Scale (WSS). Qualitative data were collected via a group interview following six weeks participation in the SRP. The quantitative analyses revealed a significant reduction (P < .05) between pre-intervention and post-intervention scores for perceived stress, burnout, depression, and anxiety (trait). These variables showed no significant differences between post-intervention and follow-up scores. The WHOQOL-BREF revealed significant increase (P < .05) just in the physical and psychological domains at post-intervention scores, which remained at the follow-up. Qualitative results showed improvement in the reactivity to inner experience; a more attentive perception of internal and external experiences; greater attention and awareness of actions and attitudes at every moment; and a positive influence of the SRP in nursing activities. Copyright © 2016 Elsevier Inc. All rights reserved.

Optimization of the Mechanical Properties and Residual Stresses in 2024 Aluminum Alloy Through Heat Treatment

NASA Astrophysics Data System (ADS)

Araghchi, M.; Mansouri, H.; Vafaei, R.; Guo, Y.

2018-05-01

Residual stresses induced during quenching of aluminum alloys cause dimensional instability and distortion. In this study, the effects of different concentrations of polyalkylene glycol (PAG) quenchants on residual stresses and mechanical properties of 2024 aluminum alloy were investigated. Surface residual stresses were measured by using hole-drilling strain-gauge method. Also, mechanical properties and microstructure of the heat-treated samples were analyzed using hardness measurements, tensile tests, and transmission electron microscopy. Results showed that quenching into a 15% polymeric solution and aging at 190 °C for 12 h cause 50% reduction in residual stress as compared with quenching in water at 20 °C and naturally aging. Moreover, tensile strength decreased by 104 MPa ( 20%) in compared with the T6 sample.

Transverse cracking and stiffness reduction in composite laminates

NASA Technical Reports Server (NTRS)

Yuan, F. G.; Selek, M. C.

1993-01-01

A study of transverse cracking mechanism in composite laminates is presented using a singular hybrid finite element model. The model provides the global structural response as well as the precise local crack-tip stress fields. An elasticity basis for the problem is established by employing Lekhnitskii's complex variable potentials and method of eigenfunction expansion. Stress singularities associated with the transverse crack are obtained by decomposing the deformation into the symmetric and antisymmetric modes and proper boundary conditions. A singular hybrid element is thereby formulated based on the variational principle of a modified hybrid functional to incorporate local crack singularities. Axial stiffness reduction due to transverse cracking is studied. The results are shown to be in very good agreement with the existing experimental data. Comparison with simple shear lag analysis is also given. The effects of stress intensity factors and strain energy density on the increase of crack density are analyzed. The results reveal that the parameters approach definite limits when crack densities are saturated, an evidence of the existence of characteristic damage state.

Model-Constrained Optimization Methods for Reduction of Parameterized Large-Scale Systems

DTIC Science & Technology

2007-05-01

advices on my newborn baby and for delicious Vietnamese food . Thanks to Chu Thim Ba Van for their hospitality that makes me feel at home whenever I...looking forward to enjoying the delicious food which she has cooked for me with all her love. More importantly, I would like to thank my wife for...working due to the intensive stress in finishing the thesis. It is amazing how a little three-month-old son can help his Dad release stress . Whenever I

Fatigue Behavior of an Advanced SiC/SiC Composite at Elevated Temperature in Air and in Steam

DTIC Science & Technology

2009-12-01

specimens tested in salt fog achieved fatigue run-out. However, a significant decrease in fatigue life was observed for fatigue stresses ≥ 100 MPa...fatigue stress level approached the proportional limit. The reduction is fatigue life was attributed to the increased matrix cracking near the...oxidation of any free silicon remaining after production using methods such as melt infiltration, and the SiC itself as temperatures near 1000 ºC. These

Reduction in plasma vasopressin levels of dehydrated rats following acute stress

NASA Technical Reports Server (NTRS)

Keil, L. C.; Severs, W. B.

1977-01-01

Results are presented for an investigation directed to substantiate and extend preliminary findings of stress-induced reduction in plasma arginine vasopressin (pAVP). Since normally hydrated rats have very low levels of pAVP, it is difficult to measure reliably any decrease in pAVP that may result from stress. To overcome this problem, the pAVP levels of the tested rats were raised by dehydration prior to application of stress. A radioimmunoassay for pAVP is described and used to determine the levels of vasopressin in the plasma of nondehydrated and dehydrated rats after exposure to ether or acceleration stress. Plasma pAVP is also determined in rats following nicotine administration. It is shown that exposure of nondehydrated rats to ether or acceleration stress does not elicit any significant alterations in circulating pAVP levels while nicotine injections stimulate a marked increase. In particular, ether and acceleration stress produce a rapid reduction in the pAVP level of dehydrated rats, the decrease being observed in both large and small animals. The mechanism for this reduction in pAVP level following stress is yet unknown.

Stress reduction programs in patients with elevated blood pressure: a systematic review and meta-analysis.

PubMed

Rainforth, Maxwell V; Schneider, Robert H; Nidich, Sanford I; Gaylord-King, Carolyn; Salerno, John W; Anderson, James W

2007-12-01

Substantial evidence indicates that psychosocial stress contributes to hypertension and cardiovascular disease (CVD). Previous meta-analyses of stress reduction and high blood pressure (BP) were outdated and/or methodologically limited. Therefore, we conducted an updated systematic review of the published literature and identified 107 studies on stress reduction and BP. Seventeen trials with 23 treatment comparisons and 960 participants with elevated BP met criteria for well-designed randomized controlled trials and were replicated within intervention categories. Meta-analysis was used to calculate BP changes for biofeedback, -0.8/-2.0 mm Hg (P = NS); relaxation-assisted biofeedback, +4.3/+2.4 mm Hg (P = NS); progressive muscle relaxation, -1.9/-1.4 mm Hg (P = NS); stress management training, -2.3/-1.3 mm (P = NS); and the Transcendental Meditation program, -5.0/-2.8 mm Hg (P = 0.002/0.02). Available evidence indicates that among stress reduction approaches, the Transcendental Meditation program is associated with significant reductions in BP. Related data suggest improvements in other CVD risk factors and clinical outcomes.

Stress Reduction Programs in Patients with Elevated Blood Pressure: A Systematic Review and Meta-analysis

PubMed Central

Rainforth, Maxwell V.; Schneider, Robert H.; Nidich, Sanford I.; Gaylord-King, Carolyn; Salerno, John W.; Anderson, James W.

2007-01-01

Substantial evidence indicates that psychosocial stress contributes to hypertension and cardiovascular disease (CVD). Previous meta-analyses of stress reduction and high blood pressure (BP) were outdated and/or methodologically limited. Therefore, we conducted an updated systematic review of the published literature and identified 107 studies on stress reduction and BP. Seventeen trials with 23 treatment comparisons and 960 participants with elevated BP met criteria for well-designed randomized controlled trials and were replicated within intervention categories. Meta-analysis was used to calculate BP changes for biofeedback, −0.8/−2.0 mm Hg (P = NS); relaxation-assisted biofeedback, +4.3/+2.4 mm Hg (P = NS); progressive muscle relaxation, −1.9/−1.4 mm Hg (P = NS); stress management training, −2.3/−1.3 mm (P = NS); and the Transcendental Meditation program, −5.0/−2.8 mm Hg (P = 0.002/0.02). Available evidence indicates that among stress reduction approaches, the Transcendental Meditation program is associated with significant reductions in BP. Related data suggest improvements in other CVD risk factors and clinical outcomes. PMID:18350109

Reduction of gas flow nonuniformity in gas turbine engines by means of gas-dynamic methods

NASA Astrophysics Data System (ADS)

Matveev, V.; Baturin, O.; Kolmakova, D.; Popov, G.

2017-08-01

Gas flow nonuniformity is one of the main sources of rotor blade vibrations in the gas turbine engines. Usually, the flow circumferential nonuniformity occurs near the annular frames, located in the flow channel of the engine. This leads to the increased dynamic stresses in blades and as a consequence to the blade damage. The goal of the research was to find an acceptable method of reducing the level of gas flow nonuniformity as the source of dynamic stresses in the rotor blades. Two different methods were investigated during this research. Thus, this study gives the ideas about methods of improving the flow structure in gas turbine engine. On the basis of existing conditions (under development or existing engine) it allows the selection of the most suitable method for reducing gas flow nonuniformity.

Heavy drinking from the freshman year into early young adulthood: the roles of stress, tension-reduction drinking motives, gender and personality.

PubMed

Rutledge, P C; Sher, K J

2001-07-01

This study investigated the relationship between stress (defined alternatively as negative life events and emotional distress) and heavy drinking across late adolescence and early young adulthood, as well as the roles of tension-reduction drinking motives and gender as moderators of that relationship. The role of personality variables (neuroticism, behavioral undercontrol and extraversion) as moderators also was explored. The data were obtained from 485 individuals (255 women) participating in a five-wave longitudinal study that spanned 7 years. The effects on heavy drinking of stress (either negative life events or emotional distress), tension-reduction drinking motives, gender and personality were analyzed each year with hierarchical multiple regression. Stress (negative life events) was positively related to heavy drinking, but only for men with stronger tension-reduction drinking motives at Year 4 (age 21). The relationship between tension-reduction drinking motives and heavy drinking was positive, developmentally graded, and moderated by gender, after the freshman year, the role of tension-reduction drinking motives in heavy drinking became less important for women, relative to men, a trend that grew stronger after the college years. Behavioral undercontrol played a limited role in the relationship of gender and tension-reduction drinking motives to heavy drinking. The findings have implications for theories of stress-related and stress-motivated drinking. Such theories should consider developmental processes, particularly the transition to adult drinking status at age 21 and the roles of tension-reduction drinking motives, gender and behavioral undercontrol.

Method to Determine the Stress-Strain Response of As-Formed Thin-Walled Tubular Structures Using a Flaring Apparatus

NASA Astrophysics Data System (ADS)

Jurendic, S.; Anderson, D.

2017-09-01

Finite element simulations are used extensively to refine the forming steps of draw and wall iron (DWI) aluminum bottles; therefore, accurate material data is required Unfortunately, the material properties of the base sheet cannot presently be used for simulation of the later forming stages due to preceding significant deformation (ironing) and thermal treatments. Measuring the stress-strain response using traditional methods (e.g. tensile test) becomes increasingly difficult at later stages of the bottle forming process due to a significant diameter reduction of the bottle neck from successive die-necking stages. Moreover, failure during forming tends to occur in the final deformation stages when the bottle opening is rolled over, creating a brim roll, at which point brim roll splits may occur. Knowledge of the stress-strain response prior to the roll over may lead to improved product design, reduced waste, and an optimized product. Therefore, this work details a flaring apparatus and data analysis method to determine the stress-strain response in the die-necked region of thin-walled aluminum bottles fabricated from AA3104 sheet metal.

Noninvasive assessment of altered activity following restraint in mice using an automated physiological monitoring system.

PubMed

Spiers, Jereme G; Chen, Hsiao-Jou Cortina; Steyn, Frederik J; Lavidis, Nickolas A; Woodruff, Trent M; Lee, John D

2017-01-01

In the laboratory setting, typical endocrine and targeted behavioral tests are limited in their ability to provide a direct assessment of stress in animals housed in undisturbed conditions. We hypothesized that an automated phenotyping system would allow the detection of subtle stress-related behavioral changes well beyond the time-frames examined using conventional methods. In this study, we have utilized the TSE PhenoMaster system to continuously record basal behaviors and physiological parameters including activity, body weight, food intake and oxygen consumption in undisturbed and stressed C57Bl/6J male mice (n = 12/group), with a pharmacological intervention using the conventional anxiolytic, diazepam (5 mg kg -1 i.p.; n = 8/group). We observed significant 20-30% reductions in locomotor activity in the dark phase, with subtle reductions in light phase activity for up to 96 h following a single 2 h episode of restraint stress. A single administration of diazepam reduced plasma corticosterone concentrations by 30-35% during stress exposure when compared to mice treated with vehicle. This treatment did not result in significantly different locomotor activity compared to vehicle within the first 48 h following restraint stress. However, diazepam treatment facilitated restoration of locomotor activity at 72 and 96 h after restraint stress exposure in comparison to vehicle-treated mice. Hence, the use of an automated phenotyping system allows a real time assessment of basal behaviors and empirical metabolism following exposure to restraint stress and demonstrates major and subtle changes in activity persist for several days after stress exposure.

The Effect of Composite Thickness on the Stress Distribution Pattern of Restored Premolar Teeth with Cusp Reduction.

PubMed

Panahandeh, Narges; Torabzadeh, Hassan; Ziaee, Nargess; Mahdian, Mina; Tootiaee, Bahman; Ghasemi, Amir

2017-07-01

Different thicknesses of restorative material can alter the stress distribution pattern in remaining tooth structure. The assumption is that a thicker composite restoration will induce a higher fracture resistance. Therefore, the present study evaluated the effect of composite thickness on stress distribution in a restored premolar with cusp reduction. A 3D solid model of a maxillary second premolar was prepared and meshed. MOD cavities were designed with different cusp reduction thicknesses (0, 0.5, 1, 1.5, 2.5 mm). Cavities were restored with Valux Plus composite. They were loaded with 200 N force on the occlusal surface in the direction of the long axis. Von Mises stresses were evaluated with Abaqus software. Stress increased from occlusal to gingival and was maximum in the cervical region. The stressed area in the palatal cusp was more than that of the buccal cusp. Increasing the thickness of composite altered the shear stress to compressive stress in the occlusal area of the teeth. The model with 2.5 mm cusp reduction exhibited the most even stress distribution. © 2015 by the American College of Prosthodontists.

Evaluation of the effect of narrative writing on the stress sources of the parents of preterm neonates admitted to the NICU.

PubMed

Kadivar, Maliheh; Seyedfatemi, Naiemeh; Akbari, Negarin; Haghani, Hamid; Fayaz, Mahsa

2017-07-01

Identification of the nurses' and families' understanding of the stresses in the facilitates nursing interventions and increases parental satisfaction. The quasiexperimental study with pretest and posttest was administered to a sample size of 70 mothers with preterm neonates hospitalized in the NICUs of two teaching hospitals of Tehran University of Medical during 6 months. The Parental Stressor Scale (PSS) was used. The data were analyzed using descriptive and analytical statistical methods. Evaluation of the differences in the domains of the questionnaire between the 3rd and 10th day of admission using a multivariate analysis showed that narrative writing had significant effects on all three domains (Roys' largest root = 2.141, F = 47.11, p values < 0.001). The results showed that the highest stress reduction was observed in Infant Behavior and Appearance (-11.847) followed by Sights and Sounds of the Unit (-11.352) while the lowest stress reduction was observed in the Parental Role Alterations (-6.149) in the intervention group, while the control mothers experienced a stress increase in all domains. According to the findings, narrative writing may be considered an efficient supportive intervention to reduce the maternal stress Infant behavior and appearance in the NICUs. However, more research is needed to justify its implementation.

Foot Massage and Physiological Stress in People with Dementia: A Randomized Controlled Trial

PubMed Central

Cooke, Marie Louise; Beattie, Elizabeth; Shum, David H.K.; O'Dwyer, Siobhan T.; Barrett, Sue; Sung, Billy

2014-01-01

Abstract Background: The anxiety associated with unfamiliar surroundings, the disorientation and mental confusion, and the social isolation that accompanies dementia can often create increased stress for people living in long-term care settings. Such a response is thought to affect the autonomic nervous system and result in emotional and physical symptoms of distress that may be manifested as agitation. There is the potential for such distress to influence the physiological response and in particular Blood Pressure and Heart Rate. A relaxation intervention such as massage may influence the physiological stress response. Methods: This randomized controlled trial aimed to compare the effect of foot massage (FM) versus a control activity (quiet presence, QP) on physiological stress response (i.e., blood pressure [BP] and heart rate [HR]) in people living with moderate-to-severe dementia in long-term-care settings. Results: Fifty-three residents were randomized to intervention (10-minute FM) or control group (QP). While the FM group experienced a greater reduction in HR than the control group, these reductions were not significantly different between groups (p=0.83; see Table 1), or across time (p=0.46). Both groups experienced a reduction in systolic BP and diastolic BP, while the mean reduction in systolic BP was greater for those in the FM group. Conclusions: While the findings do not provide strong support for FM, the finding that both conditions allowed the person with dementia to rest in the presence of another human being is of importance in the care of people with dementia. The close presence of another person may in fact promote relaxation and therefore improve BP and HR measures. PMID:24047244

Mindfulness based stress reduction for medical students: optimising student satisfaction and engagement.

PubMed

Aherne, Declan; Farrant, Katie; Hickey, Louise; Hickey, Emma; McGrath, Lisa; McGrath, Deirdre

2016-08-18

Medical practitioners and students are at increased risk of a number of personal and psychological problems. Stress and anxiety due to work-load and study requirements are common and self-care methods are important in maintaining well-being. The current study examines perceptions of and satisfaction ratings with a mindfulness based stress reduction (MBSR) programme for 1(st) year (compulsory) and 2(nd) year (optional) Graduate Entry Medical School students. A mixed method pre and post study of Year 1 (n = 140) and Year 2 (n = 88) medical students completing a 7 week MBSR course compared student satisfaction ratings. Thematic analysis of feedback from the students on their perception of the course was also carried out. Year 1 students (compulsory course) were less satisfied with content and learning outcomes than Year 2 students (optional course) (p < .0005). Thematic analysis of year 1 student feedback identified themes including great concept, poorly executed; and less discussion, more practice. Year 2 themes included session environment and satisfaction with tutors. The MBSR course was associated with high levels of satisfaction and positive feedback when delivered on an optional basis. Catering for the individual needs of the participant and promoting a safe environment are core elements of a successful self-care programme.

Estimation of Stress Concentration Factor of Plate with Hole using Piezoelectric Actuator and Finite Element Method

NASA Astrophysics Data System (ADS)

Abuzaid, A.; Hrairi, M.; Shaik Dawood, M. S. I.

2017-03-01

In this paper, the effect of piezoelectric actuators placed above a circular hole of a rectangular plate subjected to uniform uniaxial tension is studied. The core idea is to investigate the stress (compression/tension) produced by the piezoelectric actuators on the stress distribution around the hole and along the width of the host plate. For this purpose, Finite Element Analysis (FEA) was carried out through parametric study in ANSYS software. The results demonstrated that the positive electric field would decrease and change the state of the stress distribution along the width of the host plate in contrast to the negative applied electric filed which increases the stress distribution smoothly without affecting its behaviour. The results also indicated that the reduction of the stress concentration factor increases with the decrease of the ratio (D/W) for the same applied positive electric field.

INFLUENCE OF RETIREMENT AND WORK STRESS ON HEADACHE PREVALENCE: A LONGITUDINAL MODELLING STUDY FROM THE GAZEL COHORT

PubMed Central

Sjösten, Noora; Nabi, Hermann; Westerlund, Hugo; Singh-Manoux, Archana; Dartigues, Jean-François; Goldberg, Marcel; Zins, Marie; Oksanen, Tuula; Salo, Paula; Pentti, Jaana; Kivimäki, Mika; Vahtera, Jussi

2012-01-01

Aims To examine trajectories of headache in relation to retirement and to clarify the role of work stress and stress-prone personality. Methods Headache prevalence during seven years before and after retirement was measured by annual questionnaires from GAZEL cohort comprising French national gas and electricity company employees (N=12,913). Odds ratios and 95% confidence intervals for headache during pre- peri- and post-retirement were calculated. The role of effect modifiers (work stress, type A or hostile personality) was tested by multiplicative interactions and synergy indices. Results 11%-13% reduction in headache prevalence was found during pre- and post-retirement, whereas decline was much steeper (46%) during the retirement transition. In absolute terms, the decline was greater among persons with high work stress or stress-prone personality than among other participants. Conclusions Retirement is associated with a decrease in headache prevalence, particularly among persons with high amount of work stress or proneness to overreact to stress. PMID:21220374

Work-home interface stress: an important predictor of emotional exhaustion 15 years into a medical career.

PubMed

Hertzberg, Tuva Kolstad; Rø, Karin Isaksson; Vaglum, Per Jørgen Wiggen; Moum, Torbjørn; Røvik, Jan Ole; Gude, Tore; Ekeberg, Øivind; Tyssen, Reidar

2016-01-01

The importance of work-home interface stress can vary throughout a medical career and between genders. We studied changes in work-home interface stress over 5 yr, and their prediction of emotional exhaustion (main dimension of burn-out), controlled for other variables. A nationwide doctor cohort (NORDOC; n=293) completed questionnaires at 10 and 15 yr after graduation. Changes over the period were examined and predictors of emotional exhaustion analyzed using linear regression. Levels of work-home interface stress declined, whereas emotional exhaustion stayed on the same level. Lack of reduction in work-home interface stress was an independent predictor of emotional exhaustion in year 15 (β=-0.21, p=0.001). Additional independent predictors were reduction in support from colleagues (β=0.11, p=0.04) and emotional exhaustion at baseline (β=0.62, p<0.001). Collegial support was a more important predictor for men than for women. In separate analyses, significant adjusted predictors were lack of reduction in work-home interface stress among women, and reduction of collegial support and lack of reduction in working hours among men. Thus, change in work-home interface stress is a key independent predictor of emotional exhaustion among doctors 15 yr after graduation. Some gender differences in predictors of emotional exhaustion were found.

Impact of a Stress Management Intervention Program on Sexual Functioning and Stress Reduction in Women with Breast Cancer

PubMed Central

Shayan, Arezoo; Jamshidi, Farkhondeh; Tahmasebiboldaji, Vahid; Khani, Somayeh; Babaei, Maryam; Havasian, Mohamad Reza; Masoumi, Seyedeh Zahra

2017-01-01

Breast cancer as the most common cancer among women endangers various aspects of their sexual lives and is a major culprit regarding health impairment and low life quality. The aim of this study was to examine the effect of a stress management intervention program on sexual functioning and stress reduction in women with breast cancer. This study employed a quasi-experimental pre-test, post-test design which included follow-up checks and a control group. To this end, 104 women with breast cancer referring to Hamadan’s Mahdiyeh MRI Center at the time of data collection were conventionally selected in 2015. Using permuted blocks, they were randomly divided into experimental and control groups (n= 52), only the former receiving stress management counseling for 18 hours. Data were collected through a demographic questionnaire, the Female Sexual Function Index (FSFI) questionnaire, and Harry’s stress questionnaire, filled out by patients before and after the intervention. To analyze the data, descriptive statistics and two-way ANOVA were used. The results showed that cognitive - behavioral stress management group therapy improved total sexual functioning and its subscales. After the treatment, there was a significant difference in mean scores between the groups (p=0.01). Moreover, significant differences were observed in the mean scores for stress with improvement in the experimental group in post-test results. Cognitive - behavioral group therapy for stress management was thuis found to improve total sexual functioning and its subscales and reduce the level of stress in the experimental group after the intervention and follow-up period with an interval of two weeks. Therefore, this method can be used as a complementary therapy along with medical treatment in oncology centers. PMID:29072415

Personal Approaches to Stress Reduction: A Workshop.

ERIC Educational Resources Information Center

Remer, Rory

1984-01-01

Seven topic areas which may be variously combined to comprise a workshop in personal stress reduction are outlined. They include definitions and types of stress, life style planning, nutrition, exercise, networking/social support system, relaxation and other trophotropic interventions, and communication skills. Suggestions are included for…

Soil Oxidation-Reduction in Wetlands and Its Impact on Plant Functioning

PubMed Central

Pezeshki, S. R.; DeLaune, R. D.

2012-01-01

Soil flooding in wetlands is accompanied by changes in soil physical and chemical characteristics. These changes include the lowering of soil redox potential (Eh) leading to increasing demand for oxygen within the soil profile as well as production of soil phytotoxins that are by-products of soil reduction and thus, imposing potentially severe stress on plant roots. Various methods are utilized for quantifying plant responses to reducing soil conditions that include measurement of radial oxygen transport, plant enzymatic responses, and assessment of anatomical/morphological changes. However, the chemical properties and reducing nature of soil environment in which plant roots are grown, including oxygen demand, and other associated processes that occur in wetland soils, pose a challenge to evaluation and comparison of plant responses that are reported in the literature. This review emphasizes soil-plant interactions in wetlands, drawing attention to the importance of quantifying the intensity and capacity of soil reduction for proper evaluation of wetland plant responses, particularly at the process and whole-plant levels. Furthermore, while root oxygen-deficiency may partially account for plant stress responses, the importance of soil phytotoxins, produced as by-products of low soil Eh conditions, is discussed and the need for development of methods to allow differentiation of plant responses to reduced or anaerobic soil conditions vs. soil phytotoxins is emphasized. PMID:24832223

Evaluation of a Passive Nature Viewing Program Set to Music.

PubMed

Cadman, Sally J

2014-09-01

Research has revealed that passive nature viewing (viewing nature scenes without actually being in nature) has many health benefits but little is known about the best method of offering this complementary modality. The purpose of this pilot program was to evaluate the impact of a passive nature viewing program set to music on stress reduction in adults living in the community. A pre- and postsurvey design along with weekly recordings of stress and relaxation levels were used to evaluate the effect of this passive nature viewing program on stress reduction. Participants watched one of three preselected nature scenes for 5 minutes a day over 1 month and rated their stress and relaxation levels weekly on a 100-mm Visual Analogue Scale before and after viewing the nature DVD. Quantitative analysis were not performed because of the less number of subjects (n = 10) completing the study. Qualitative analysis found five key categories that have an impact on program use: (a) technology, (b) personal preferences, (c) time, (d) immersion, and (e) use of the program. Holistic nurses may consider integrating patient preferences and immersion strategies in the design of future passive nature viewing programs to reduce attrition and improve success. © The Author(s) 2013.

Incorporating Scale-Dependent Fracture Stiffness for Improved Reservoir Performance Prediction

NASA Astrophysics Data System (ADS)

Crawford, B. R.; Tsenn, M. C.; Homburg, J. M.; Stehle, R. C.; Freysteinson, J. A.; Reese, W. C.

2017-12-01

We present a novel technique for predicting dynamic fracture network response to production-driven changes in effective stress, with the potential for optimizing depletion planning and improving recovery prediction in stress-sensitive naturally fractured reservoirs. A key component of the method involves laboratory geomechanics testing of single fractures in order to develop a unique scaling relationship between fracture normal stiffness and initial mechanical aperture. Details of the workflow are as follows: tensile, opening mode fractures are created in a variety of low matrix permeability rocks with initial, unstressed apertures in the micrometer to millimeter range, as determined from image analyses of X-ray CT scans; subsequent hydrostatic compression of these fractured samples with synchronous radial strain and flow measurement indicates that both mechanical and hydraulic aperture reduction varies linearly with the natural logarithm of effective normal stress; these stress-sensitive single-fracture laboratory observations are then upscaled to networks with fracture populations displaying frequency-length and length-aperture scaling laws commonly exhibited by natural fracture arrays; functional relationships between reservoir pressure reduction and fracture network porosity, compressibility and directional permeabilities as generated by such discrete fracture network modeling are then exported to the reservoir simulator for improved naturally fractured reservoir performance prediction.

Examining mindfulness-based stress reduction: Perceptions from minority older adults residing in a low-income housing facility

PubMed Central

2011-01-01

Background Mindfulness-based stress reduction (MBSR) programs are becoming increasingly common, but have not been studied in low income minority older populations. We sought to understand which parts of MBSR were most important to practicing MBSR members of this population, and to understand whether they apply their training to daily challenges. Methods We conducted three focus groups with 13 current members of an MBSR program. Participants were African American women over the age of 60 in a low-income housing residence. We tape recorded each session and subsequently used inductive content analysis to identify primary themes. Results and discussion Analysis of the focus group responses revealed three primary themes stress management, applying mindfulness, and the social support of the group meditation. The stressors they cited using MBSR with included growing older with physical pain, medical tests, financial strain, and having grandchildren with significant mental, physical, financial or legal hardships. We found that participants particularly used their MBSR training for coping with medical procedures, and managing both depression and anger. Conclusion A reflective stationary intervention delivered in-residence could be an ideal mechanism to decrease stress in low-income older adult's lives and improve their health. PMID:21627807

Explant culture: An advantageous method for isolation of mesenchymal stem cells from human tissues.

PubMed

Hendijani, Fatemeh

2017-04-01

Mesenchymal stem cell (MSC) research progressively moves towards clinical phases. Accordingly, a wide range of different procedures were presented in the literature for MSC isolation from human tissues; however, there is not yet any close focus on the details to offer precise information for best method selection. Choosing a proper isolation method is a critical step in obtaining cells with optimal quality and yield in companion with clinical and economical considerations. In this concern, current review widely discusses advantages of omitting proteolysis step in isolation process and presence of tissue pieces in primary culture of MSCs, including removal of lytic stress on cells, reduction of in vivo to in vitro transition stress for migrated/isolated cells, reduction of price, processing time and labour, removal of viral contamination risk, and addition of supporting functions of extracellular matrix and released growth factors from tissue explant. In next sections, it provides an overall report of technical highlights and molecular events of explant culture method for isolation of MSCs from human tissues including adipose tissue, bone marrow, dental pulp, hair follicle, cornea, umbilical cord and placenta. Focusing on informative collection of molecular and methodological data about explant methods can make it easy for researchers to choose an optimal method for their experiments/clinical studies and also stimulate them to investigate and optimize more efficient procedures according to clinical and economical benefits. © 2017 John Wiley & Sons Ltd.

Stress predicts brain changes in children: a pilot longitudinal study on youth stress, posttraumatic stress disorder, and the hippocampus.

PubMed

Carrion, Victor G; Weems, Carl F; Reiss, Allan L

2007-03-01

Does stress damage the brain? Studies of adults with posttraumatic stress disorder have demonstrated smaller hippocampal volumes when compared with the volumes of adults with no posttraumatic stress disorder. Studies of children with posttraumatic stress disorder have not replicated the smaller hippocampal findings in adults, which suggests that smaller hippocampal volume may be caused by neurodevelopmental experiences with stress. Animal research has demonstrated that the glucocorticoids secreted during stress can be neurotoxic to the hippocampus, but this has not been empirically demonstrated in human samples. We hypothesized that cortisol volumes would predict hippocampal volume reduction in patients with posttraumatic symptoms. We report data from a pilot longitudinal study of children (n = 15) with history of maltreatment who underwent clinical evaluation for posttraumatic stress disorder, cortisol, and neuroimaging. Posttraumatic stress disorder symptoms and cortisol at baseline predicted hippocampal reduction over an ensuing 12- to 18-month interval. Results from this pilot study suggest that stress is associated with hippocampal reduction in children with posttraumatic stress disorder symptoms and provide preliminary human evidence that stress may indeed damage the hippocampus. Additional studies seem to be warranted.

Effectiveness of a smartphone-based worry-reduction training for stress reduction: A randomized-controlled trial.

PubMed

Versluis, Anke; Verkuil, Bart; Spinhoven, Philip; F Brosschot, Jos

2018-04-03

Perseverative cognition (e.g. worry) and unconscious stress are suggested to be important mediators in the relation between stressors and physiological health. We examined whether a smartphone-based worry-reduction training improved a physiological marker of stress (i.e. increased heart rate variability [HRV]) and unconscious stress. Randomised-controlled trial was conducted with individuals reporting work stress (n = 136). Participants were randomised to the experimental, control or waitlist condition (resp. EC, CC, WL). The EC and CC registered emotions five times daily for four weeks. The EC additionally received a worry-reduction training with mindfulness exercises. Primary outcome was 24-h assessments of HRV measured at pre-, mid- and post-intervention. Secondary outcomes were implicit affect and stress. Effects on heart rate and other psychological outcomes were explored. A total of 118 participants completed the study. No change from pre- to post-intervention was observed for the primary or secondary outcomes. The change over time was not different between conditions. Findings suggest that the training was ineffective for improving HRV or psychological stress. Future studies may focus on alternative smartphone-based stress interventions, as stress levels are high in society. There is need for easy interventions and smartphones offer possibilities for this.

The effects of country-level population policy for enhancing adaptation to climate change

NASA Astrophysics Data System (ADS)

Gunasekara, N. K.; Kazama, S.; Yamazaki, D.; Oki, T.

2013-11-01

The effectiveness of population policy in reducing the combined impacts of population change and climate change on water resources is explored. One no-policy scenario and two scenarios with population policy assumptions are employed in combination with water availability under the SRES scenarios A1b, B1 and A2 for the impact analysis. The population data used are from the World Bank. The river discharges per grid of horizontal resolution 0.5° are obtained from the Total Runoff Integrating Pathways (TRIP) of the University of Tokyo, Japan. Unlike the population scenarios utilized in the SRES emission scenarios and the newest representative concentration pathways, the scenarios employed in this research are based, even after 2050, on country-level rather than regional-level growth assumptions. Our analysis implies that the heterogeneous pattern of population changes across the world is the dominant driver of water stress, irrespective of future greenhouse gas emissions, with highest impacts occurring in the already water-stressed low latitudes. In 2100, Africa, Middle East and parts of Asia are under extreme water stress under all scenarios. The sensitivity analysis reveals that a small reduction in populations over the region could relieve a large number of people from high water stress, while a further increase in population from the assumed levels (SC1) might not increase the number of people under high water stress considerably. Most of the population increase towards 2100 occurs in the already water-stressed lower latitudes. Therefore, population reduction policies are recommended for this region as a method of adaptation to the future water stress conditions. Population reduction policies will facilitate more control over their future development pathways, even if these countries were not able to contribute significantly to greenhouse gas (GHG) emission cuts due to economic constraints. However, for the European region, the population living in water-stressed regions is almost 20 times lower than that in the lower latitudes. For countries with high population momentum, the population policy scenario with fertility-reduction assumptions gained a maximum of 6.1 times the water availability in Niger and 5.3 times that in Uganda compared with the no-policy scenario. Most of these countries are in sub-Saharan Africa. These countries represent 24.5% of the global population in the no-policy scenario, and the scenario with fertility-reduction assumptions reduces it to 8.7% by 2100. This scenario is also effective in reducing the area under extreme water stress in these countries. However, the policy scenario with assumptions of population stabilization at the replacement fertility rate increases the water stress in high-latitude countries. Nevertheless, the impact is low due to the high per capita water availability in the region. This research is expected to widen the understanding of the combined impacts of climate change in the future and of the strategies needed to enhance the space for adaptation.

Cognitive behavioural therapy and mindfulness based stress reduction may be equally effective in reducing anxiety and depression in adults with autism spectrum disorders.

PubMed

Sizoo, Bram B; Kuiper, Erik

2017-05-01

Anxiety and depression co-occur in 50-70% of adults with autism spectrum disorder (ASD) but treatment methods for these comorbid problems have not been systematically studied. Recently, two ASD-tailored protocols were published: mindfulness based stress reduction (MBSR) and cognitive behavioural therapy (CBT). We wanted to investigate if both methods are equally effective in reducing anxiety and depression symptoms among adults with ASD. 59 adults with ASD and anxiety or depression scores above 7 on the Hospital Anxiety and Depression Scale, gave informed consent to participate; 27 followed the CBT protocol, and 32 the MBSR treatment protocol. Anxiety and depression scores, autism symptoms, rumination, and global mood were registered at the start, at the end of the 13-week treatment period, and at 3-months follow-up. Irrational beliefs and mindful attention awareness were used as process measures during treatment and at follow-up. Results indicate that both MBSR and CBT are associated with a reduction in anxiety and depressive symptoms among adults with ASD, with a sustained effect at follow-up, but without a main effect for treatment group. A similar pattern was seen for the reduction of autistic symptoms, rumination and the improvement in global mood. There are some indications that MBSR may be preferred over CBT with respect to the treatment effect on anxiety when the scores on measures of irrational beliefs or positive global mood at baseline are high. Mindfulness and cognitive behavioral therapies are both promising treatment methods for reducing comorbid anxiety and depression in adults with ASD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ultimate pier and contraction scour prediction in cohesive soils at selected bridges in Illinois

USGS Publications Warehouse

Straub, Timothy D.; Over, Thomas M.; Domanski, Marian M.

2013-01-01

The Scour Rate In COhesive Soils-Erosion Function Apparatus (SRICOS-EFA) method includes an ultimate scour prediction that is the equilibrium maximum pier and contraction scour of cohesive soils over time. The purpose of this report is to present the results of testing the ultimate pier and contraction scour methods for cohesive soils on 30 bridge sites in Illinois. Comparison of the ultimate cohesive and noncohesive methods, along with the Illinois Department of Transportation (IDOT) cohesive soil reduction-factor method and measured scour are presented. Also, results of the comparison of historic IDOT laboratory and field values of unconfined compressive strength of soils (Qu) are presented. The unconfined compressive strength is used in both ultimate cohesive and reduction-factor methods, and knowing how the values from field methods compare to the laboratory methods is critical to the informed application of the methods. On average, the non-cohesive method results predict the highest amount of scour, followed by the reduction-factor method results; and the ultimate cohesive method results predict the lowest amount of scour. The 100-year scour predicted for the ultimate cohesive, noncohesive, and reduction-factor methods for each bridge site and soil are always larger than observed scour in this study, except 12% of predicted values that are all within 0.4 ft of the observed scour. The ultimate cohesive scour prediction is smaller than the non-cohesive scour prediction method for 78% of bridge sites and soils. Seventy-six percent of the ultimate cohesive predictions show a 45% or greater reduction from the non-cohesive predictions that are over 10 ft. Comparing the ultimate cohesive and reduction-factor 100-year scour predictions methods for each bridge site and soil, the scour predicted by the ultimate cohesive scour prediction method is less than the reduction-factor 100-year scour prediction method for 51% of bridge sites and soils. Critical shear stress remains a needed parameter in the ultimate scour prediction for cohesive soils. The unconfined soil compressive strength measured by IDOT in the laboratory was found to provide a good prediction of critical shear stress, as measured by using the erosion function apparatus in a previous study. Because laboratory Qu analyses are time-consuming and expensive, the ability of field-measured Rimac data to estimate unconfined soil strength in the critical shear–soil strength relation was tested. A regression analysis was completed using a historic IDOT dataset containing 366 data pairs of laboratory Qu and field Rimac measurements from common sites with cohesive soils. The resulting equations provide a point prediction of Qu, given any Rimac value with the 90% confidence interval. The prediction equations are not significantly different from the identity Qu = Rimac. The alternative predictions of ultimate cohesive scour presented in this study assume Qu will be estimated using Rimac measurements that include computed uncertainty. In particular, the ultimate cohesive predicted scour is greater than observed scour for the entire 90% confidence interval range for predicting Qu at the bridges and soils used in this study, with the exception of the six predicted values that are all within 0.6 ft of the observed scour.

78 FR 39190 - Airworthiness Directives; Airbus Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-01

... could lead to a local stress concentration resulting in possible reduction of the fatigue life of the... lead to a local stress concentration which may reduce the fatigue life of the jack fitting, possibly... could lead to a local stress concentration resulting in possible reduction of the fatigue life of the...

Calcium ion involvement in growth inhibition of mechanically stressed soybean (Glycine max) seedlings

NASA Technical Reports Server (NTRS)

Jones, R. S.; Mitchell, C. A.

1989-01-01

A 40-50% reduction in soybean [Glycine max (L.) Merr. cv. Century 84] hypocotyl elongation occurred 24 h after application of mechanical stress. Exogenous Ca2+ at 10 mM inhibited growth by 28% if applied with the Ca2+ ionophore A23187 to the zone of maximum hypocotyl elongation. La3+ was even more inhibitory than Ca2+, especially above 5 mM. Treatment with ethyleneglycol-bis-(beta-aminoethylether)-N, N, N', N'-tetraacetic acid (EGTA) alone had no effect on growth of non-stressed seedlings at the concentrations used but negated stress-induced growth reduction by 36% at 4 mM when compared to non-treated, stressed controls. Treatment with EDTA was ineffective in negating stress-induced growth inhibition. Calmodulin antagonists calmidazolium, chlorpromazine, and 48/80 also negated stress-induced growth reduction by 23, 50, and 35%, respectively.

Shirodhara: A psycho-physiological profile in healthy volunteers

PubMed Central

Dhuri, Kalpana D.; Bodhe, Prashant V.; Vaidya, Ashok B.

2013-01-01

Background: Shirodhara is a classical and a well-established ayurvedic procedure of slowly and steadily dripping medicated oil or other liquids on the forehead. This procedure induces a relaxed state of awareness that results in a dynamic psycho-somatic balance. Objectives: The objective of the study is to evaluate the psychological and physiological effects of Shirodhara in healthy volunteers by monitoring the rating of mood and levels of stress, electrocardiogram (ECG), electroencephalogram (EEG), and selected biochemical markers of stress. Materials and Methods: The study was conducted in the human pharmacology laboratory. The study design was open labeled, comparing the baseline variables with values after Shirodhara. The subjects (n = 16) chosen were healthy human volunteers who gave an informed consent. Shirodhara was preceded by Abhyanga – whole body massage. The Shirodhara method was standardized for rate of dripping with peristaltic pump and temperature was controlled with a thermostat. Mood and stress levels were assessed by validated rating scales. The pre- and post-Shirodhara ECG and EEG records were evaluated. Results: Student's paired “t” test was applied to the means + SE of the variables to calculate statistical significance at P <0.05. There was a significant improvement in mood scores and the level of stress (P <0.001). These changes were accompanied by significant decrease in rate of breathing and reduction in diastolic blood pressure along with reduction in heart rate. The relaxed alert state, after Shirodhara, was co-related with an increase in alfa rhythm in EEG. Conclusion: A standardized Shirodhara leads to a state of alert calmness similar to the relaxation response observed in meditation. The clinical benefits observed with Shirodhara in anxiety neurosis, hypertension, and stress aggravation due to chronic degenerative diseases could be mediated through these adaptive physiological effects. PMID:23741161

An adaptogenic role for omega-3 fatty acids in stress; a randomised placebo controlled double blind intervention study (pilot) [ISRCTN22569553

PubMed Central

Bradbury, Joanne; Myers, Stephen P; Oliver, Chris

2004-01-01

Background There is evidence for an adaptive role of the omega -3 fatty acid, docosahexaenoic acid (DHA) during stress. Mechanisms of action may involve regulation of stress mediators, such as the catecholamines and proinflammatory cytokines. Prevention of stress-induced aggression and hostility were demonstrated in a series of clinical trials. This study investigates whether perceived stress is ameliorated by DHA in stressed university staff. Methods Subjects that scored ≥ 17 on the Perceived Stress Scale were randomised into a 6-week pilot intervention study. The diet reactive group was supplemented with 6 g of fish oil containing 1.5 g per day DHA, while the placebo group was supplemented with 6 g a day of olive oil. The groups were compared with each other and a wider cross sectional study population that did not receive either active or placebo intervention. Results There was a significant reduction in perceived stress in both the fish oil and the placebo group from baseline. There was also a significant between-group difference between the fish oil group and the no-treatment controls in the rate of stress reduction (p < 0.05). However, there was not a significant between-group difference between the fish oil and the placebo group, nor the placebo group and the control group. These results are discussed in the context of several methodological limitations. The significant stress reductions in both the fish oil and the placebo group are considered in view of statistical regression, an effect likely to have been exaggerated by the time course of the study, a large placebo effect and the possibility of an active effect from the placebo. Conclusion There were significant differences (p < 0.05) in the fish oil group compared with no-treatment controls. This effect was not demonstrated in the placebo group. As a pilot study, it was not sufficiently powered to find the difference between the fish oil group and the placebo group significant. Further work needs to be undertaken to conclusively demonstrate these data trends. However, the findings from this research support the literature in finding a protective or 'adaptogenic' role for omega-3 fatty acids in stress. PMID:15566625

Thick photosensitive polyimide film side wall angle variability and scum improvement for IC packaging stress control

NASA Astrophysics Data System (ADS)

Mehta, Sohan Singh; Yeung, Marco; Mirza, Fahad; Raman, Thiagarajan; Longenbach, Travis; Morgan, Justin; Duggan, Mark; Soedibyo, Rio A.; Reidy, Sean; Rabie, Mohamed; Cho, Jae Kyu; Premachandran, C. S.; Faruqui, Danish

2018-03-01

In this paper, we demonstrate photosensitive polyimide (PSPI) profile optimization to effectively reduce stress concentrations and enable PSPI as protection package-induced stress. Through detailed package simulation, we demonstrate 45% reduction in stress as the sidewall angle (SWA) of PSPI is increased from 45 to 80 degrees in Cu pillar package types. Through modulation of coating and develop multi-step baking temperature and time, as well as dose energy and post litho surface treatments, we demonstrate a method for reliably obtaining PSPI sidewall angle >75 degree. Additionally, we experimentally validate the simulation findings that PSPI sidewall angle impacts chip package interaction (CPI). Finally, we conclude this paper with PSPI material and tool qualification requirements for future technology node based on current challenges.

The axisymmetric elasticity problem for a laminated plate containing a circular hole

NASA Technical Reports Server (NTRS)

Delale, F.; Erdogan, F.

1981-01-01

The elasticity problem for a laminated thick plate which consists of two bonded dissimilar layers and which contains a circular hole is considered. The problem is formulated for arbitrary axisymmetric tractions on the hole surface by using the Love strain function. Through the expansion of the boundary conditions into Fourier series the problem is reduced to an infinite system of algebraic equations which is solved by the method of reduction. Of particular interest in the problem are the stresses along the interface as they relate to the question of delamination failure of the composite plate. These stresses are calculated and are observed to become unbounded at the hole boundary. An approximate treatment of the singular behavior of the stress state is presented and the stress intensity factors are calculated.

A probabilistic damage model of stress-induced permeability anisotropy during cataclastic flow

NASA Astrophysics Data System (ADS)

Zhu, Wenlu; MontéSi, Laurent G. J.; Wong, Teng-Fong

2007-10-01

A fundamental understanding of the effect of stress on permeability evolution is important for many fault mechanics and reservoir engineering problems. Recent laboratory measurements demonstrate that in the cataclastic flow regime, the stress-induced anisotropic reduction of permeability in porous rocks can be separated into 3 different stages. In the elastic regime (stage I), permeability and porosity reduction are solely controlled by the effective mean stress, with negligible permeability anisotropy. Stage II starts at the onset of shear-enhanced compaction, when a critical yield stress is attained. In stage II, the deviatoric stress exerts primary control over permeability and porosity evolution. The increase in deviatoric stress results in drastic permeability and porosity reduction and considerable permeability anisotropy. The transition from stage II to stage III takes place progressively during the development of pervasive cataclastic flow. In stage III, permeability and porosity reduction becomes gradual again, and permeability anisotropy diminishes. Microstructural observations on deformed samples using laser confocal microscopy reveal that stress-induced microcracking and pore collapse are the primary forms of damage during cataclastic flow. A probabilistic damage model is formulated to characterize the effects of stress on permeability and its anisotropy. In our model, the effects of both effective mean stress and differential stress on permeability evolution are calculated. By introducing stress sensitivity coefficients, we propose a first-order description of the dependence of permeability evolution on different loading paths. Built upon the micromechanisms of deformation in porous rocks, this unified model provides new insight into the coupling of stress and permeability.

Application of Guided Imagery to Facilitate the Transition of New Graduate Registered Nurses

PubMed Central

Boehm, Laura B.; Tse, Alice M.

2016-01-01

Traditionally, the new graduate registered nurse (RN) transition has included a didactic and skills-based orientation accompanied by a period of preceptored practice. However, these methods do not ensure that new RNs are in a state of reduced anxiety to fully interact with their new environment. Transition to practice may cause anxiety, and the new graduate RN may perceive moderate to severe stress. One method of stress reduction is the use of guided imagery, which has shown strong potential with a variety of populations undergoing stressful events. Today, new graduate RNs expect institutions to facilitate orientation to their new employment settings and assist in the transition to their role as a professional nurse. This article proposes a model that incorporates guided imagery for refining the new graduate RN transition process. The model can be adapted for use in the context of orienting other adult learners to unfamiliar practice situations. PMID:23330588

Stress distribution characteristics in the vicinity of coal seam floor

NASA Astrophysics Data System (ADS)

Cui, Zimo; Chanda, Emmanuel; Zhao, Jingli; Wang, Zhihe

2018-01-01

Although longwall top-coal caving (LTCC) has been a popular, more productive and cost-effective method in recent years, roadway floor heave and rock bursts frequently appear when exploiting such coal seams with large dip angle. This paper proposes addressing this problem by adopting three-dimensional roadway layout of stagger arrangement (3-D RLSA). In this study, the first step was to analyse the stress distribution characteristics in the vicinity of coal seam floor based on the stress slip line field theory. In the second step, numerical calculation using FLAC3D was conducted. Finally, an evaluation of the 3-D RLSA for solving this particular issue was given. Results indicate that for this particular mine the proposed 3-D RLSA results in 24% increase in the coal recovery ratio and a modest reduction in excavation and maintenance costs compared to the conventional LTCC method.

Finite element analysis of chip formation usingale method

NASA Astrophysics Data System (ADS)

Jayaprakash, V.

2017-05-01

In recent times, many studies made in FEM on plain isotropic metal plate formulation. The stress analysis plays the significant role in the stability of structural safety and system. The stress and distortion estimation is very helpful for designing and manufacturing product well. Usually the residual stress and plastic strain determine the fatigue life of structure, it also plays the significant role in designing and choosing material. When the load magnitude increases the crack starts to form, decreasing the work load and the residual stress reduces the damage of the metal. The manufacturing process is a key parameter in process and forming the part of any system. However, machining operation involves complex thing like hot development, material property and other estimates based on transition of the plastic strain and residual stress. The reduction of residual stress plays the complexity role in the finite element study. This paper deals with the manufacturing process with less residual stress and strain. The results shows that, by applying the ALE method in machining we can reduce the load on the work piece hence the life type of the work piece can be increased. We also investigate the cutting tool wear and there efficiency since it is a essential machine member in fabrication technology. ABAQUS platform used to solve the machining operation

Diabetes Empowerment Council: Integrative Pilot Intervention for Transitioning Young Adults With Type 1 Diabetes

PubMed Central

Weigensberg, Marc J; Vigen, Cheryl; Sequeira, Paola; Spruijt-Metz, Donna; Juarez, Magaly; Florindez, Daniella; Peters, Anne; Pyatak, Elizabeth A

2018-01-01

Background The transition of young adults with type 1 diabetes (T1D) from pediatric to adult care is challenging and frequently accompanied by worsening of diabetes-related health. To date, there are no reports which prospectively assess the effects of theory-based psycho-behavioral interventions during the transition period neither on glycemic control nor on psychosocial factors that contribute to poor glycemic control. Therefore, the overall aim of this study was to develop and pilot test an integrative group intervention based on the underlying principles of self-determination theory (SDT), in young adults with T1D. Methods Fifty-one young adults with T1D participated in an education and case management-based transition program, of which 9 took part in the Diabetes Empowerment Council (DEC), a 12-week holistic, multimodality facilitated group intervention consisting of “council” process based on indigenous community practices, stress-reduction guided imagery, narrative medicine modalities, simple ritual, and other integrative modalities. Feasibility, acceptability, potential mechanism of effects, and bio-behavioral outcomes were determined using mixed qualitative and quantitative methods. Results The intervention was highly acceptable to participants, though presented significant feasibility challenges. Participants in DEC showed significant reductions in perceived stress and depression, and increases in general well-being relative to other control participants. Reduction in perceived stress, independent of intervention group, was associated with reductions in hemoglobin A1C. A theoretical model explaining the effects of the intervention included the promotion of relatedness and autonomy support, 2 important aspects of SDT. Conclusions The DEC is a promising group intervention for young adults with T1D going through transition to adult care. Future investigations will be necessary to resolve feasibility issues, optimize the multimodality intervention, determine full intervention effects, and fully test the role of the underlying theoretical model of action. ClinicalTrials.gov Registration Number NCT02807155; Registration date: June 15, 2016 (retrospectively registered) PMID:29552422

Work-home interface stress: an important predictor of emotional exhaustion 15 years into a medical career

PubMed Central

HERTZBERG, Tuva Kolstad; RØ, Karin Isaksson; VAGLUM, Per Jørgen Wiggen; MOUM, Torbjørn; RØVIK, Jan Ole; GUDE, Tore; EKEBERG, Øivind; TYSSEN, Reidar

2015-01-01

The importance of work-home interface stress can vary throughout a medical career and between genders. We studied changes in work-home interface stress over 5 yr, and their prediction of emotional exhaustion (main dimension of burn-out), controlled for other variables. A nationwide doctor cohort (NORDOC; n=293) completed questionnaires at 10 and 15 yr after graduation. Changes over the period were examined and predictors of emotional exhaustion analyzed using linear regression. Levels of work-home interface stress declined, whereas emotional exhaustion stayed on the same level. Lack of reduction in work-home interface stress was an independent predictor of emotional exhaustion in year 15 (β=−0.21, p=0.001). Additional independent predictors were reduction in support from colleagues (β=0.11, p=0.04) and emotional exhaustion at baseline (β=0.62, p<0.001). Collegial support was a more important predictor for men than for women. In separate analyses, significant adjusted predictors were lack of reduction in work-home interface stress among women, and reduction of collegial support and lack of reduction in working hours among men. Thus, change in work-home interface stress is a key independent predictor of emotional exhaustion among doctors 15 yr after graduation. Some gender differences in predictors of emotional exhaustion were found. PMID:26538002

Behavioral interventions as a treatment for epilepsy: A multicenter randomized controlled trial.

PubMed

Haut, Sheryl R; Lipton, Richard B; Cornes, Susannah; Dwivedi, Alok K; Wasson, Rachel; Cotton, Sian; Strawn, Jeffrey R; Privitera, Michael

2018-03-13

To evaluate the effect of a stress-reduction intervention in participants with medication-resistant epilepsy. Adults with medication-resistant focal epilepsy (n = 66) were recruited from 3 centers and randomized to 1 of 2 interventions: (1) progressive muscle relaxation (PMR) with diaphragmatic breathing, or (2) control focused-attention activity with extremity movements. Following an 8-week baseline period, participants began 12 weeks of double-blind treatment. Daily self-reported mood and stress ratings plus seizure counts were completed by participants using an electronic diary, and no medication adjustments were permitted. The primary outcome was percent reduction in seizure frequency per 28 days comparing baseline and treatment; secondary outcomes included stress reduction and stress-seizure interaction. In the 66 participants in the intention-to-treat analysis, seizure frequency was reduced from baseline in both treatment groups (PMR: 29%, p < 0.05; focused attention: 25%, p < 0.05). PMR and focused attention did not differ in seizure reduction ( p = 0.38), although PMR was associated with stress reduction relative to focused attention ( p < 0.05). Daily stress was not a predictor of seizures. Both PMR and the focused-attention groups showed reduced seizure frequency compared to baseline in participants with medication-resistant focal seizures, although the 2 treatments did not differ. PMR was more effective than focused attention in reducing self-reported stress. NCT01444183. © 2018 American Academy of Neurology.

Reduction of stresses on buried rigid highway structures using the imperfect ditch method and expanded polysterene : geofoam.

DOT National Transportation Integrated Search

2009-01-01

This study provides strong evidences from both numerical model analysis and in-situ test data to indicate that geofoam is an ideal elasto-plastic material to reduce vertical load on top of rigid culvert resting on a rigid foundation. The load on the ...

Stressed to death: implication of lymphocyte apoptosis for psychoneuroimmunology

NASA Technical Reports Server (NTRS)

Shi, Yufang; Devadas, Satish; Greeneltch, Kristy M.; Yin, Deling; Allan Mufson, R.; Zhou, Jian-nian

2003-01-01

Psychological and physical stressors best exemplify the intercommunication of the immune and the nervous systems. It has been shown that stress significantly impacts leukocyte cellularity and immune responses and alters susceptibility to various diseases. While acute stress has been shown to enhance immune responses, chronic stress often leads to immunosuppression. Among many criteria examined upon exposure to chronic stress, the reduction in lymphocyte mitogenic response and lymphocyte cellularity are commonly assessed. We have reported that chronic restraint stress could induce lymphocyte reduction, an effect dependent on endogenous opioids. Interestingly, the effect of endogenous opioids was found to be exerted through increasing the expression of a cell death receptor, Fas, and an increased sensitivity of lymphocytes to apoptosis. Stress-induced lymphocyte reduction was not affected by adrenalectomy. In this review, based on available literature and our recent data, we will discuss the role of the hypothalamic-pituitary-adrenal axis and endogenous opioids and examine the mechanisms by which chronic stress modulates lymphocyte apoptosis.

A case study of multi-seam coal mine entry stability analysis with strength reduction method

PubMed Central

Tulu, Ihsan Berk; Esterhuizen, Gabriel S; Klemetti, Ted; Murphy, Michael M.; Sumner, James; Sloan, Michael

2017-01-01

In this paper, the advantage of using numerical models with the strength reduction method (SRM) to evaluate entry stability in complex multiple-seam conditions is demonstrated. A coal mine under variable topography from the Central Appalachian region is used as a case study. At this mine, unexpected roof conditions were encountered during development below previously mined panels. Stress mapping and observation of ground conditions were used to quantify the success of entry support systems in three room-and-pillar panels. Numerical model analyses were initially conducted to estimate the stresses induced by the multiple-seam mining at the locations of the affected entries. The SRM was used to quantify the stability factor of the supported roof of the entries at selected locations. The SRM-calculated stability factors were compared with observations made during the site visits, and the results demonstrate that the SRM adequately identifies the unexpected roof conditions in this complex case. It is concluded that the SRM can be used to effectively evaluate the likely success of roof supports and the stability condition of entries in coal mines. PMID:28239503

A case study of multi-seam coal mine entry stability analysis with strength reduction method.

PubMed

Tulu, Ihsan Berk; Esterhuizen, Gabriel S; Klemetti, Ted; Murphy, Michael M; Sumner, James; Sloan, Michael

2016-03-01

In this paper, the advantage of using numerical models with the strength reduction method (SRM) to evaluate entry stability in complex multiple-seam conditions is demonstrated. A coal mine under variable topography from the Central Appalachian region is used as a case study. At this mine, unexpected roof conditions were encountered during development below previously mined panels. Stress mapping and observation of ground conditions were used to quantify the success of entry support systems in three room-and-pillar panels. Numerical model analyses were initially conducted to estimate the stresses induced by the multiple-seam mining at the locations of the affected entries. The SRM was used to quantify the stability factor of the supported roof of the entries at selected locations. The SRM-calculated stability factors were compared with observations made during the site visits, and the results demonstrate that the SRM adequately identifies the unexpected roof conditions in this complex case. It is concluded that the SRM can be used to effectively evaluate the likely success of roof supports and the stability condition of entries in coal mines.

Effect of Canine Play Interventions as a Stress Reduction Strategy in College Students.

PubMed

Delgado, Cheryl; Toukonen, Margaret; Wheeler, Corinne

Forty-eight students engaged with a therapy dog for 15 minutes during finals week to evaluate the effect on stress. Psychological (Perceived Stress Scale, visual analog scales) and physiologic stress (vital signs, salivary cortisol) measures were collected before and after the intervention. Paired t tests showed significant reductions in all psychological and physiologic measures except diastolic blood pressure. This supports animal-assisted therapy as an effective stress management strategy for nursing and other college students.

A sexual risk and stress reduction intervention designed for HIV-positive bisexual African American men with childhood sexual abuse histories.

PubMed

Williams, John K; Glover, Dorie A; Wyatt, Gail E; Kisler, Kimberly; Liu, Honghu; Zhang, Muyu

2013-08-01

HIV transmission risk is high among men who have sex with men and women (MSMW), and it is further heightened by a history of childhood sexual abuse (CSA) and current traumatic stress or depression. Yet, traumatic stress is rarely addressed in HIV interventions. We tested a stress-focused sexual risk reduction intervention for African American MSMW with CSA histories. This randomized controlled trial compared a stress-focused sexual risk reduction intervention with a general health promotion intervention. Sexual risk behaviors, psychological symptoms, stress biomarkers (urinary cortisol and catecholamines), and neopterin (an indicator of HIV progression) were assessed at baseline and at 3- and 6-month follow-ups. Both interventions decreased and sustained reductions in sexual risk and psychological symptoms. The stress-focused intervention was more efficacious than the general health promotion intervention in decreasing unprotected anal insertive sex and reducing depression symptoms. Despite randomization, baseline group differences in CSA severity, psychological symptoms, and biomarkers were found and linked to subsequent intervention outcomes. Although interventions designed specifically for HIV-positive African American MSMW can lead to improvements in health outcomes, future research is needed to examine factors that influence intervention effects.

Effects of Low-Dose Mindfulness-Based Stress Reduction (MBSR-ld) on Working Adults

ERIC Educational Resources Information Center

Klatt, Maryanna D.; Buckworth, Janet; Malarkey, William B.

2009-01-01

Mindfulness-based stress reduction (MBSR) has produced behavioral, psychological, and physiological benefits, but these programs typically require a substantial time commitment from the participants. This study assessed the effects of a shortened (low-dose [ld]) work-site MBSR intervention (MBSR-ld) on indicators of stress in healthy working…

Adolescents' Perceptions of Smoking and Stress Reduction

ERIC Educational Resources Information Center

Scales, Monica B.; Monahan, Jennifer L.; Rhodes, Nancy; Roskos-Ewoldsen, David; Johnson-Turbes, Ashani

2009-01-01

The present study examined how adolescents perceive the relationship between smoking and stress and where they learn that smoking cigarettes may be an effective stress-reduction mechanism. Eight focus groups were conducted with low-income African American and European American 14- to 16-year-olds in urban and rural locations, in which they…

Numerical and Experimental Evaluation on the Residual Stresses of Welded Joints

NASA Astrophysics Data System (ADS)

Huh, Sun Chul; Park, Wonjo; Yang, Haesug; Jung, Haeyoung; Kim, Chuyoung

Wings for the defense industry such as fighters, missiles, and rockets should show no deformation or damage on the structure. The structures of existing wings had holes for weight reduction. The plates and frames were fixed with rivets or screws, which limited the weight reduction possible. In this study, an improvement was made in jointing methods through EB welding and laser welding. Welding strength was measured through tension testing. In addition, finite element analysis was performed for the welding process so as to deduce the optimum welding condition.

Imposed Environmental Stresses Facilitate Cell-Free Nanoparticle Formation by Deinococcus radiodurans

PubMed Central

2017-01-01

ABSTRACT The biological synthesis of metal nanoparticles has been examined in a wide range of organisms, due to increased interest in green synthesis and environmental remediation applications involving heavy metal ion contamination. Deinococcus radiodurans is particularly attractive for environmental remediation involving metal reduction, due to its high levels of resistance to radiation and other environmental stresses. However, few studies have thoroughly examined the relationships between environmental stresses and the resulting effects on nanoparticle biosynthesis. In this work, we demonstrate cell-free nanoparticle production and study the effects of metal stressor concentrations and identity, temperature, pH, and oxygenation on the production of extracellular silver nanoparticles by D. radiodurans R1. We also report the synthesis of bimetallic silver and gold nanoparticles following the addition of a metal stressor (silver or gold), highlighting how production of these particles is enabled through the application of environmental stresses. Additionally, we found that both the morphology and size of monometallic and bimetallic nanoparticles were dependent on the environmental stresses imposed on the cells. The nanoparticles produced by D. radiodurans exhibited antimicrobial activity comparable to that of pure silver nanoparticles and displayed catalytic activity comparable to that of pure gold nanoparticles. Overall, we demonstrate that biosynthesized nanoparticle properties can be partially controlled through the tuning of applied environmental stresses, and we provide insight into how their application may affect nanoparticle production in D. radiodurans during bioremediation. IMPORTANCE Biosynthetic production of nanoparticles has recently gained prominence as a solution to rising concerns regarding increased bacterial resistance to antibiotics and a desire for environmentally friendly methods of bioremediation and chemical synthesis. To date, a range of organisms have been utilized for nanoparticle formation. The extremophile D. radiodurans, which can withstand significant environmental stresses and therefore is more robust for metal reduction applications, has yet to be exploited for this purpose. Thus, this work improves our understanding of the impact of environmental stresses on biogenic nanoparticle morphology and composition during metal reduction processes in this organism. This work also contributes to enhancing the controlled synthesis of nanoparticles with specific attributes and functions using biological systems. PMID:28687649

Imposed Environmental Stresses Facilitate Cell-Free Nanoparticle Formation by Deinococcus radiodurans.

PubMed

Chen, Angela; Contreras, Lydia M; Keitz, Benjamin K

2017-09-15

The biological synthesis of metal nanoparticles has been examined in a wide range of organisms, due to increased interest in green synthesis and environmental remediation applications involving heavy metal ion contamination. Deinococcus radiodurans is particularly attractive for environmental remediation involving metal reduction, due to its high levels of resistance to radiation and other environmental stresses. However, few studies have thoroughly examined the relationships between environmental stresses and the resulting effects on nanoparticle biosynthesis. In this work, we demonstrate cell-free nanoparticle production and study the effects of metal stressor concentrations and identity, temperature, pH, and oxygenation on the production of extracellular silver nanoparticles by D. radiodurans R1. We also report the synthesis of bimetallic silver and gold nanoparticles following the addition of a metal stressor (silver or gold), highlighting how production of these particles is enabled through the application of environmental stresses. Additionally, we found that both the morphology and size of monometallic and bimetallic nanoparticles were dependent on the environmental stresses imposed on the cells. The nanoparticles produced by D. radiodurans exhibited antimicrobial activity comparable to that of pure silver nanoparticles and displayed catalytic activity comparable to that of pure gold nanoparticles. Overall, we demonstrate that biosynthesized nanoparticle properties can be partially controlled through the tuning of applied environmental stresses, and we provide insight into how their application may affect nanoparticle production in D. radiodurans during bioremediation. IMPORTANCE Biosynthetic production of nanoparticles has recently gained prominence as a solution to rising concerns regarding increased bacterial resistance to antibiotics and a desire for environmentally friendly methods of bioremediation and chemical synthesis. To date, a range of organisms have been utilized for nanoparticle formation. The extremophile D. radiodurans , which can withstand significant environmental stresses and therefore is more robust for metal reduction applications, has yet to be exploited for this purpose. Thus, this work improves our understanding of the impact of environmental stresses on biogenic nanoparticle morphology and composition during metal reduction processes in this organism. This work also contributes to enhancing the controlled synthesis of nanoparticles with specific attributes and functions using biological systems. Copyright © 2017 American Society for Microbiology.

Two BASIC computer programs for the determination of in situ stresses using the CSIRO hollow inclusion stress cell and the USBM borehole deformation gage

USGS Publications Warehouse

Smith, W.K.

1982-01-01

The mathematical method of determining in-situ stresses by overcoring, using either the U.S. Bureau of Mines Borehole Deformation Gage or the Commonwealth Scientific and Industrial Research Organisation Hollow Inclusion Stress Cell, is summarized, and data reduction programs for each type of instrument, written in BASIC, are presented. The BASIC programs offer several advantages over previously available FORTRAN programs. They can be executed on a desk-top microcomputer at or near the field site, allowing the investigator to assess the quality of the data and make decisions on the need for additional testing while the crew is still in the field. Also, data input is much simpler than with currently available FORTRAN programs; either English or SI units can be used; and standard deviations of the principal stresses are computed as well as those of the geographic components.

Improvements in Resilience, Stress, and Somatic Symptoms Following Online Resilience Training

PubMed Central

Smith, Brad; Shatté, Andrew; Perlman, Adam; Siers, Michael; Lynch, Wendy D.

2018-01-01

Objective: To determine if participation in an online resilience program impacts resilience, stress, and somatic symptoms. Methods: Approximately 600 enrollees in the meQuilibrium resilience program received a series of brief, individually prescribed video, and text training modules in a user-friendly format. Regression models tested how time in the program affected change in resilience from baseline and how changes in resilience affected change in stress and reported symptoms. Results: A significant dose–response was detected, where increases in the time spent in training corresponded to greater improvements in resilience. Degree of change in resilience predicted the magnitude of reduction in stress and symptoms. Participants with the lowest resilience level at baseline experienced greater improvements. Conclusion: Interaction with the online resilience training program had a positive effect on resilience, stress, and symptoms in proportion to the time of use. PMID:28820863

Stress management for adult survivors of childhood sexual abuse: a holistic inquiry.

PubMed

Wilson, Debra Rose

2010-02-01

Among the many sequelae of childhood sexual abuse is a maladaptive response to stress. Stress has been linked to a reduction in the immune system's ability to resist disease. The purpose of this exploratory mixed-method study is to examine the experience of stress management training for 35 adult survivors of childhood sexual abuse. Data gathered for analysis include pre- and postintervention saliva samples for sIgA, Ways of Coping Questionnaire, and a postintervention qualitative interview. Stress management strategies enhance immunity (increase in salivary immunoglobulin A, p < .05) and coping (less distancing, p < .001; less escape-avoidance, p < .001; more planful problem solving, p < .01; and more positive reappraisal, p < .001). Grounded theory analysis finds three themes emerging: hypervigilance , an outward-focused hyperawareness; somatic detachment, a lack of inward focus on self; and healing pathway, the process of healing from the abuse. Healing is possible.

Ad lib smoking in post-traumatic stress disorder: an electronic diary study.

PubMed

Beckham, Jean C; Wiley, Matthew T; Miller, Susannah C; Dennis, Michelle F; Wilson, Sarah M; McClernon, F Joseph; Calhoun, Patrick S

2008-07-01

Using ambulatory methods for 1 week of monitoring, this study investigated the association between smoking and situational cues in 22 smokers with post-traumatic stress disorder (PTSD) and 23 smokers without PTSD. Generalized estimating equations contrasted 1,759 smoking and 1,088 nonsmoking situations by group status controlling for multiple covariates. PTSD smokers reported higher stress and PTSD symptoms across daily activities. For all smokers, higher nicotine dependence, craving, food and caffeine consumption, and being outside were related to smoking. PTSD smokers were more likely to smoke when experiencing PTSD symptoms, anxiety, and stress. Following smoking, smokers with PTSD reported a significant reduction in negative affect. These results are consistent with previous ambulatory findings regarding mood in smokers, and underscore that in smokers with PTSD, PTSD symptom variables as well as stress and anxiety are significantly associated with ad lib smoking.

New concept for treating female stress urinary incontinence with radiofrequency.

PubMed

Lordelo, Patrícia; Vilas Boas, Andrea; Sodré, Danielle; Lemos, Amanda; Tozetto, Sibele; Brasil, Cristina

2017-01-01

To evaluate the clinical response and adverse effects of radiofrequency on the urethral meatus in the treatment of stress urinary incontinence in women. This phase one study included ten women with Stress Urinary Incontinence (SUI). The evaluation consisted of 1 hour Pad tests to quantify urine loss and to assess the degree of procedure satisfaction by using the Likert scale. To evaluate safety, we observed the number of referred side effects. Average age was 53.10 years±7.08 years. In assessing the final Pad Test, 70% showed a reduction and 30% a worsening of urinary loss. Using the Pad Test one month later, there was a reduction in all patients (p=0.028). The degree of satisfaction was 90% and no side effects have been observed. One patient reported burning sensation. The treatment of SUI with radiofrequency on the urethral meatus has no adverse effects, being a low risk method that reduces urinary loss in women. However, to increase the validity of the study, larger clinical trials are warranted. Copyright® by the International Brazilian Journal of Urology.

Cognitive Behavioral Group Therapy Reduces Stress and Improves the Quality of Life in Patients with Parkinson's Disease.

PubMed

Hadinia, Anousha; Meyer, Antonia; Bruegger, Viviane; Hatz, Florian; Nowak, Karolina; Taub, Ethan; Nyberg, Elisabeth; Stieglitz, Rolf-Dieter; Fuhr, Peter; Gschwandtner, Ute

2016-01-01

Objective: The aim of this study is to compare a cognitive behavioral group therapy (CBT) with a health enhancement program (HEP) for stress reduction and the impact on quality of life (QoL) in patients with Parkinson's disease (PD). Method : Thirty patients with PD participated in the study: 16 received CBT including stress-reducing elements and 14 took part in a HEP. The two groups did not differ significantly in their baseline demographic characteristics. The patients in both groups underwent weekly sessions of 2 h duration for 9 weeks. The Parkinson's Disease Questionnaire with 39 items (PDQ-39), the Burden Questionnaire for Parkinson's Disease (translated from the original German: Belastungsfragebogen für Parkinsonpatienten (BELA) and the Disease-Related Questionnaire [ Fragebogen zur krankheitsbezogenen Kommunikation (FKK)] were used for assessment. Ratings were completed at baseline and after 9 weeks (immediately after the last treatment session). Results : The patients in the CBT group achieved significantly better BELA, FKK and PDQ-39 scores ( p < 0.05). Subscale analysis revealed that the scores on the BELA subscales "emotional well-being" and "somatic motor function" contributed significantly to stress reduction ( p < 0.05). The FKK revealed significant improvement in social skills in the CBT group ( p < 0.05). Conclusion : Cognitive Behavioral Group Therapy appears to be an effective way for patients with PD to lessen stress and improve their quality of life.

Effects of a Brief Qigong-based Stress Reduction Program (BQSRP) in a distressed Korean population: a randomized trial

PubMed Central

2013-01-01

Background Distressed individuals in Korea may benefit from the practice of mind–body exercises such as Qigong. However, the effectiveness of such techniques needs to be investigated. Methods Fifty participants who were eligible to this study were randomized into a group receiving a 4-week intervention of a brief Qigong-based stress reduction program (BQSRP) or a wait-list control group. Before and after the intervention period, saliva samples were collected and questionnaires were completed on perceived stress, anxiety, “Hwa-Byung” (anger syndrome), and quality of life. Salivary cortisol has emerged in mind-body therapy research as an easy-to-collect, relatively inexpensive, biologic marker of stress. Salivary corisol were collected to evaluate physiological effect of BQSRP. Between-group comparisons of change from baseline to study completion were analyzed by analysis of covariance for the Perceived Stress Scale and independent two sample t-tests for other measures. Results Compared with the control group, the BQSRP intervention group displayed significantly larger decreases in Perceived Stress Scale scores (p = 0.0006), State Anxiety scores (p = 0.0028), Trait Anxiety scores (p < 0.0001), personality subscale scores of the Hwa-Byung Scale (p = 0.0321), symptoms scores of the Hwa-Byung Scale (p = 0.0196), and a significantly larger increase in World Health Organization Quality of Life Abbreviated version scores (ps < .05). Salivary cortisol levels were not changed. Conclusions The BQSRP appears to be effective in reducing stress perception, anxiety, anger, and improving quality of life (KCT0000056). PMID:23705963

Xylary pH and Reduction Potential Levels of Iron-stressed Silver Maple (Acer saccharinum L.) 1

PubMed Central

Morris, Robert L.; Swanson, Bert T.

1980-01-01

Xylary fluid pH and reduction potentials were measured on silver maple (Acer saccharinum L.) grown under Fe and pH stress. Although pH and reduction potential (millivolt/59.2) varied significantly in the nutrient solution, xylary pH and reduction potential remained constant. It was concluded that changes in the pH and reduction potential in the xylary fluid of silver maple are not responsible for iron chlorosis. PMID:16661196

Stress reduction at the work-family interface: positive parenting and self-efficacy as mechanisms of change in Workplace Triple P.

PubMed

Hartung, Doreen; Hahlweg, Kurt

2011-01-01

Workplace Triple P (WPTP) is a group-based parenting skills training specifically designed to meet the needs of employed parents. Several randomized controlled trials have demonstrated the training's efficacy. This study examined possible mechanisms of change that account for the stress reduction effects of this parenting skills training at the work-family interface. It was hypothesized that reductions in dysfunctional parenting (DP) behavior and increases in parental self-efficacy would mediate the stress-reducing effects of WPTP. The mediator effects were analyzed in a German pre- and postcompleter sample (N = 97 parents; 74 mothers and 23 fathers; treatment condition: n = 42 parents; waitlist-control condition n = 55 parents). The results indicate that individual stress- (IS) level reductions were mediated by decreased levels of DP. In addition, changes in IS levels mediated the effects of the training on work-related stress. The discussion focuses on the importance of understanding mechanisms of change to effectively implement interventions at the work-family interface.

The use of self-Reiki for stress reduction and relaxation.

PubMed

Bukowski, Elaine L

2015-09-01

More than one-third of college students reported the desire for stress reduction techniques and education. The purpose of this study was to determine the effects of a 20-week structured self-Reiki program on stress reduction and relaxation in college students. Students were recruited from Stockton University and sessions were conducted in the privacy of their residence. Twenty students completed the entire study consisting of 20 weeks of self-Reiki done twice weekly. Each participant completed a Reiki Baseline Credibility Scale, a Reiki Expectancy Scale, and a Perceived Stress Scale (PSS) after acceptance into the study. The PSS was completed every four weeks once the interventions were initiated. A global assessment questionnaire was completed at the end of the study. Logs summarizing the outcome of each session were submitted at the end of the study. With the exception of three participants, participants believed that Reiki is a credible technique for reducing stress levels. Except for two participants, participants agreed that Reiki would be effective in reducing stress levels. All participants experienced stress within the month prior to completing the initial PSS. There was a significant reduction in stress levels from pre-study to post-study. There was a correlation between self-rating of improvement and final PSS scores. With one exception, stress levels at 20 weeks did not return to pre-study stress levels. This study supports the hypothesis that the calming effect of Reiki may be achieved through the use of self-Reiki.

Hypertension Analysis of stress Reduction using Mindfulness meditatiON and Yoga (The HARMONY Study): study protocol of a randomised control trial

PubMed Central

How, Maxine; Dai, Monica; Baker, Brian; Irvine, Jane; Abbey, Susan; Abramson, Beth L; Myers, Martin; Perkins, Nancy; Tobe, Sheldon W

2012-01-01

Introduction Hypertension (HTN) is a leading risk factor for preventable cardiovascular disease, with over one in five adults affected worldwide. Lifestyle modification is a key strategy for the prevention and treatment of HTN. Stress has been associated with greater cardiovascular risk, and stress management is a recommended intervention for hypertensives. Stress reduction through relaxation therapies has been shown to have an effect on human physiology, including lowering blood pressure (BP). However, individualised behavioural interventions are resource intensive, and group stress management approaches have not been validated for reducing HTN. The HARMONY Study is a pilot randomised controlled trial designed to determine if mindfulness-based stress reduction (MBSR), a standardised group therapy, is an effective intervention for lowering BP in stage 1 unmedicated hypertensives. Methods and analysis Men and women unmedicated for HTN with mean daytime ambulatory blood pressure (ABP) ≥135/85 mm Hg or 24 h ABP ≥130/80 mm Hg are included in the study. Subjects are randomised to receive MBSR immediately or after a wait-list control period. The primary outcome measure is mean awake and 24 h ABP. The primary objective of the HARMONY Study is to compare ABP between the treatment and wait-list control arm at the 12-week primary assessment period. Results from this study will determine if MBSR is an effective intervention for lowering BP in early unmedicated hypertensives. Ethics and dissemination This research project was approved by the Sunnybrook Research Ethics Board and the University Health Network Research Ethics Board (Toronto, Canada). Planned analyses are in full compliance with the principles of the Declaration of Helsinki. Data collection will be completed by early spring 2012. Primary and secondary analysis will commence immediately after data monitoring is completed; dissemination plans include preparing publications for submission during the summer of 2012. Trial registration number This study is registered with http://clinicaltrials.gov (NCT00825526). PMID:22396225

Mindfulness meditation-based stress reduction: experience with a bilingual inner-city program.

PubMed

Roth, B; Creaser, T

1997-03-01

This article describes a bilingual mindfulness meditation-based stress reduction program in an inner-city setting. Mindfulness meditation is defined, and the practices of breathing meditation, eating meditation, walking meditation, and mindful yoga are described. Data analysis examined compliance, medical and psychologic symptom reduction, and changes in self-esteem, of English- and Spanish-speaking patients who completed the 8-week Stress Reduction and Relaxation Program at the Community Health Center in Meriden, Conn. Statistically significant decreases in medical and psychologic symptoms and improvement in self-esteem were found. Many program completers reported dramatic changes in attitudes, beliefs, habits, and behaviors. Despite the limitations of the research design, these findings suggest that a mindfulness meditation course can be an effective health care intervention when utilized by English- and Spanish-speaking patients in an inner-city community health center. The article includes a discussion of factors to be considered when establishing a mindfulness meditation-based stress reduction program in a health care setting.

Stress, stress reduction, and hypertension in African Americans: an updated review.

PubMed

Barnes, V; Schneider, R; Alexander, C; Staggers, F

1997-07-01

This is a comprehensive and integrative review of multiple factors underlying the greater prevalence of hypertension in African Americans compared with whites. Evidence linking stress with hypertension and cardiovascular disease in African Americans is reviewed. A survey of mechanisms of hypertension in African Americans and existing behavioral strategies for the treatment of hypertension is presented. Given that the excess of hypertension may be mediated in part by behavioral factors operating through biological mechanisms, a case is presented for behavioral stress reduction measures. This review of stress reduction techniques especially the Transcendental Mediation program for the treatment of hypertension in African Americans highlights current issues facing the field. New information is provided to help direct future nonpharmacological research and practice in hypertension to prevent morbidity and premature mortality in this underserved population.

Experimental evaluation of stresses in spherically hollow balls

NASA Technical Reports Server (NTRS)

Nypan, L. J.

1974-01-01

An analysis was undertaken to evaluate stresses within spherically hollow ball bearings proportioned for 40, 50, and 60% mass reductions. Strain gage rosettes were used to determine principal strains and stresses in the steel ball models statically loaded in various orientations. Dimensionless results are reported for the balls under flate plate contact loads. Similitude considerations permit these results to be applied to calculate stresses in hollow ball bearings proportioned to these mass reductions.

VR Mobile Solutions For Chronic Stress Reduction in Young Adults.

PubMed

Gao, Kenneth; Boyd, Chelsie; Wiederhold, Mark D; Wiederhold, Brenda K

2014-01-01

Chronic stress in young adults has become a growing problem within recent decades and many are unable to find cost-effective and accessible treatment for psychological stress in their daily lives. We analyze the market of using a mobile application, Positive Technology, as a solution. Eleven participants, aged between 18 and 24, participated in the exercise. Self-reported stress reduction was measured via an online marketing survey, while physiological measurements were monitored via peripheral devices. Secondary goals assessed the app's ease-of-use, accessibility, and cost. Results indicate that participants enjoyed the availability of the mobile solution and found the app to be fun and easy to learn. Stress levels were reduced in 73% of the participants, with higher effects in females and in participants aged 18-24. We conclude that the mobile platform is an effective means of delivering psychological stress reduction, and could provide an accessible, cost-effective solution.

A systematic methodology for creep master curve construction using the stepped isostress method (SSM): a numerical assessment

NASA Astrophysics Data System (ADS)

Miranda Guedes, Rui

2018-02-01

Long-term creep of viscoelastic materials is experimentally inferred through accelerating techniques based on the time-temperature superposition principle (TTSP) or on the time-stress superposition principle (TSSP). According to these principles, a given property measured for short times at a higher temperature or higher stress level remains the same as that obtained for longer times at a lower temperature or lower stress level, except that the curves are shifted parallel to the horizontal axis, matching a master curve. These procedures enable the construction of creep master curves with short-term experimental tests. The Stepped Isostress Method (SSM) is an evolution of the classical TSSP method. Higher reduction of the required number of test specimens to obtain the master curve is achieved by the SSM technique, since only one specimen is necessary. The classical approach, using creep tests, demands at least one specimen per each stress level to produce a set of creep curves upon which TSSP is applied to obtain the master curve. This work proposes an analytical method to process the SSM raw data. The method is validated using numerical simulations to reproduce the SSM tests based on two different viscoelastic models. One model represents the viscoelastic behavior of a graphite/epoxy laminate and the other represents an adhesive based on epoxy resin.

Reduction in the cumulative effect of stress-induced inbreeding depression due to intragenerational purging in Drosophila melanogaster.

PubMed

Enders, L S; Nunney, L

2016-03-01

Environmental stress generally exacerbates the harmful effects of inbreeding and it has been proposed that this could be exploited in purging deleterious alleles from threatened inbred populations. However, understanding what factors contribute to variability in the strength of inbreeding depression (ID) observed across adverse environmental conditions remains a challenge. Here, we examined how the nature and timing of stress affects ID and the potential for purging using inbred and outbred Drosophila melanogaster larvae exposed to biotic (larval competition, bacteria infection) and abiotic (ethanol, heat) stressors compared with unstressed controls. ID was measured during (larval survival) and after (male mating success) stress exposure. The level of stress imposed by each stressor was approximately equal, averaging a 42% reduction in outbred larval survival relative to controls. All stressors induced on average the same ID, causing a threefold increase in lethal equivalents for larval survival relative to controls. However, stress-induced ID in larval success was followed by a 30% reduction in ID in mating success of surviving males. We propose that this fitness recovery is due to 'intragenerational purging' whereby fitness correlations facilitate stress-induced purging that increases the average fitness of survivors in later life history stages. For biotic stressors, post-stress reductions in ID are consistent with intragenerational purging, whereas for abiotic stressors, there appeared to be an interaction between purging and stress-induced physiological damage. For all stressors, there was no net effect of stress on lifetime ID compared with unstressed controls, undermining the prediction that stress enhances the effectiveness of population-level purging across generations.

Reduction in the cumulative effect of stress-induced inbreeding depression due to intragenerational purging in Drosophila melanogaster

PubMed Central

Enders, L S; Nunney, L

2016-01-01

Environmental stress generally exacerbates the harmful effects of inbreeding and it has been proposed that this could be exploited in purging deleterious alleles from threatened inbred populations. However, understanding what factors contribute to variability in the strength of inbreeding depression (ID) observed across adverse environmental conditions remains a challenge. Here, we examined how the nature and timing of stress affects ID and the potential for purging using inbred and outbred Drosophila melanogaster larvae exposed to biotic (larval competition, bacteria infection) and abiotic (ethanol, heat) stressors compared with unstressed controls. ID was measured during (larval survival) and after (male mating success) stress exposure. The level of stress imposed by each stressor was approximately equal, averaging a 42% reduction in outbred larval survival relative to controls. All stressors induced on average the same ID, causing a threefold increase in lethal equivalents for larval survival relative to controls. However, stress-induced ID in larval success was followed by a 30% reduction in ID in mating success of surviving males. We propose that this fitness recovery is due to ‘intragenerational purging' whereby fitness correlations facilitate stress-induced purging that increases the average fitness of survivors in later life history stages. For biotic stressors, post-stress reductions in ID are consistent with intragenerational purging, whereas for abiotic stressors, there appeared to be an interaction between purging and stress-induced physiological damage. For all stressors, there was no net effect of stress on lifetime ID compared with unstressed controls, undermining the prediction that stress enhances the effectiveness of population-level purging across generations. PMID:26604190

Mouse handling limits the impact of stress on metabolic endpoints.

PubMed

Ghosal, Sriparna; Nunley, Amanda; Mahbod, Parinaz; Lewis, Alfor G; Smith, Eric P; Tong, Jenny; D'Alessio, David A; Herman, James P

2015-10-15

Studies focused on end-points that are confounded by stress are best performed under minimally stressful conditions. The objective of this study was to demonstrate the impact of handling designed to reduce animal stress on measurements of glucose tolerance. A cohort of mice (CD1.C57BL/6) naïve to any specific handling was subjected to either a previously described "cup" handling method, or a "tail-picked" method in which the animals were picked up by the tail (as is common for metabolic studies). Following training, an elevated plus maze (EPM) test was performed followed by measurement of blood glucose and plasma corticosterone. A second cohort (CD1.C57BL/6) was rendered obese by exposure to a high fat diet, handled with either the tail-picked or cup method and subjected to an intraperitoneal glucose tolerance test. A third cohort of C57BL/6 mice was exposed to a cup regimen that included a component of massage and was subjected to tests of anxiety-like behavior, glucose homeostasis, and corticosterone secretion. We found that the cup mice showed reduced anxiety-like behaviors in the EPM coupled with a reduction in blood glucose levels compared to mice handled by the tail-picked method. Additionally, cup mice on the high fat diet exhibited improved glucose tolerance compared to tail-picked controls. Finally, we found that the cup/massage group showed lower glucose levels following an overnight fast, and decreased anxiety-like behaviors associated with lower stress-induced plasma corticosterone concentration compared to tail-picked controls. These data demonstrate that application of handling methods that reduce anxiety-like behaviors in mice mitigates the confounding contribution of stress to interpretation of metabolic endpoints (such as glucose tolerance). Copyright © 2015 Elsevier Inc. All rights reserved.

Mouse Handling Limits the Impact of Stress on Metabolic Endpoints

PubMed Central

Ghosal, Sriparna; Nunley, Amanda; Mahbod, Parinaz; Lewis, Alfor G.; Smith, Eric P.; Tong, Jenny; D’Alessio, David A.; Herman, James P.

2015-01-01

Studies focused on end-points that are confounded by stress are best performed under minimally stressful conditions. The objective of this study was to demonstrate the impact of handling designed to reduce animal stress on measurements of glucose tolerance. A cohort of mice (CD1.C57BL/6) naïve to any specific handling were subjected to either a previously described “cup” handling method, or a “tail-picked” method in which the animals were picked up by the tail (as is common for metabolic studies). Following training, an elevated plus maze (EPM) test was performed followed by measurement of blood glucose and plasma corticosterone. A second cohort (CD1.C57BL/6) was rendered obese by exposure to a high fat diet, handled with either the tail-picked or cup method and subjected to an intraperitoneal glucose tolerance test. A third cohort of C57BL/6 mice was exposed to a cup regimen that included a component of massage and was subjected to tests of anxiety-like behavior, glucose homeostasis, and corticosterone secretion. We found that the cup mice showed reduced anxiety-like behaviors in the EPM coupled with a reduction in blood glucose levels compared to mice handled by the tail-picked method. Additionally, cup mice on the high fat diet exhibited improved glucose tolerance compared to tail-picked controls. Finally, we found that the cup/massage group showed lower glucose levels following an overnight fast, and decreased anxiety-like behaviors associated with lower stress-induced plasma corticosterone concentration compared to tail-picked controls. These data demonstrate that application of handling methods that reduce anxiety-like behaviors in mice mitigates the confounding contribution of stress to interpretation of metabolic endpoints (such as glucose tolerance). PMID:26079207

Pre-treatment Social Anxiety Severity Moderates the Impact of Mindfulness-Based Stress Reduction and Aerobic Exercise

PubMed Central

Jazaieri, Hooria; Lee, Ihno A.; Goldin, Philippe R.; Gross, James J.

2015-01-01

We examined whether social anxiety severity at pre-treatment would moderate the impact of Mindfulness-Based Stress Reduction (MBSR) or Aerobic Exercise (AE) for generalized social anxiety disorder. MBSR and AE produced equivalent reductions in weekly social anxiety symptoms. Improvements were moderated by pre-treatment social anxiety severity. PMID:25684277

Anti-Inflammatory and Antioxidative Stress Effects of Oryzanol in Glaucomatous Rabbits.

PubMed

Panchal, Shital S; Patidar, Rajesh K; Jha, Abhishek B; Allam, Ahmed A; Ajarem, Jamaan; Butani, Shital B

2017-01-01

Purpose . γ -Oryzanol works by anti-inflammatory and radical scavenging activity as a neuroprotective, anticancer, antiulcer, and immunosuppressive agent. The present study was conducted to investigate effect of oryzanol in acute and chronic experimental glaucoma in rabbits. Methods . Effect of oryzanol was evaluated in 5% dextrose induced acute model of ocular hypertension in rabbit eye. Chronic model of glaucoma was induced with subconjunctival injection of 5% of 0.3 ml phenol. Treatment with oryzanol was given for next two weeks after induction of glaucoma. From anterior chamber of rabbit eye aqueous humor was collected to assess various oxidative stress parameters like malondialdehyde, superoxide dismutase, glutathione peroxidase, catalase, nitric oxide, and inflammatory parameters like TNF- α and IL-6. Structural damage in eye was examined by histopathological studies. Results . In acute model of ocular hypertension oryzanol did not alter raised intraocular pressure. In chronic model of glaucoma oryzanol exhibited significant reduction in oxidative stress followed by reduction in intraocular pressure. Oryzanol treatment reduced level of TNF- α and IL-6. Histopathological studies revealed decreased structural damage of trabecular meshwork, lamina cribrosa, and retina with oryzanol treatment. Conclusions . Oryzanol showed protective effect against glaucoma by its antioxidative stress and anti-inflammatory property. Treatment with oryzanol can reduce optic nerve damage.

Paraquat-Melanin Redox-Cycling: Evidence from Electrochemical Reverse Engineering.

PubMed

Kim, Eunkyoung; Leverage, W Taylor; Liu, Yi; Panzella, Lucia; Alfieri, Maria Laura; Napolitano, Alessandra; Bentley, William E; Payne, Gregory F

2016-08-17

Parkinson's disease is a neurodegenerative disorder associated with oxidative stress and the death of melanin-containing neurons of the substantia nigra. Epidemiological evidence links exposure to the pesticide paraquat (PQ) to Parkinson's disease, and this link has been explained by a redox cycling mechanism that induces oxidative stress. Here, we used a novel electrochemistry-based reverse engineering methodology to test the hypothesis that PQ can undergo reductive redox cycling with melanin. In this method, (i) an insoluble natural melanin (from Sepia melanin) and a synthetic model melanin (having a cysteinyldopamine-melanin core and dopamine-melanin shell) were entrapped in a nonconducting hydrogel film adjacent to an electrode, (ii) the film-coated electrode was immersed in solutions containing PQ (putative redox cycling reductant) and a redox cycling oxidant (ferrocene dimethanol), (iii) sequences of input potentials (i.e., voltages) were imposed to the underlying electrode to systematically engage reductive and oxidative redox cycling, and (iv) output response currents were analyzed for signatures of redox cycling. The response characteristics of the PQ-melanin systems to various input potential sequences support the hypothesis that PQ can directly donate electrons to melanin. This observation of PQ-melanin redox interactions demonstrates an association between two components that have been individually linked to oxidative stress and Parkinson's disease. Potentially, melanin's redox activity could be an important component in understanding the etiology of neurological disorders such as Parkinson's disease.

Vibration and stress analysis of soft-bonded shuttle insulation tiles. Modal analysis with compact widely space stringers

NASA Technical Reports Server (NTRS)

Ojalvo, I. U.; Austin, F.; Levy, A.

1974-01-01

An efficient iterative procedure is described for the vibration and modal stress analysis of reusable surface insulation (RSI) of multi-tiled space shuttle panels. The method, which is quite general, is rapidly convergent and highly useful for this application. A user-oriented computer program based upon this procedure and titled RESIST (REusable Surface Insulation Stresses) has been prepared for the analysis of compact, widely spaced, stringer-stiffened panels. RESIST, which uses finite element methods, obtains three dimensional tile stresses in the isolator, arrestor (if any) and RSI materials. Two dimensional stresses are obtained in the tile coating and the stringer-stiffened primary structure plate. A special feature of the program is that all the usual detailed finite element grid data is generated internally from a minimum of input data. The program can accommodate tile idealizations with up to 850 nodes (2550 degrees-of-freedom) and primary structure idealizations with a maximum of 10,000 degrees-of-freedom. The primary structure vibration capability is achieved through the development of a new rapid eigenvalue program named ALARM (Automatic LArge Reduction of Matrices to tridiagonal form).

Designing, Prototyping and Evaluating Digital Mindfulness Applications: A Case Study of Mindful Breathing for Stress Reduction.

PubMed

Zhu, Bin; Hedman, Anders; Feng, Shuo; Li, Haibo; Osika, Walter

2017-06-14

During the past decade, there has been a rapid increase of interactive apps designed for health and well-being. Yet, little research has been published on developing frameworks for design and evaluation of digital mindfulness facilitating technologies. Moreover, many existing digital mindfulness applications are purely software based. There is room for further exploration and assessment of designs that make more use of physical qualities of artifacts. The study aimed to develop and test a new physical digital mindfulness prototype designed for stress reduction. In this case study, we designed, developed, and evaluated HU, a physical digital mindfulness prototype designed for stress reduction. In the first phase, we used vapor and light to support mindful breathing and invited 25 participants through snowball sampling to test HU. In the second phase, we added sonification. We deployed a package of probes such as photos, diaries, and cards to collect data from users who explored HU in their homes. Thereafter, we evaluated our installation using both self-assessed stress levels and heart rate (HR) and heart rate variability (HRV) measures in a pilot study, in order to measure stress resilience effects. After the experiment, we performed a semistructured interview to reflect on HU and investigate the design of digital mindfulness apps for stress reduction. The results of the first phase showed that 22 of 25 participants (88%) claimed vapor and light could be effective ways of promoting mindful breathing. Vapor could potentially support mindful breathing better than light (especially for mindfulness beginners). In addition, a majority of the participants mentioned sound as an alternative medium. In the second phase, we found that participants thought that HU could work well for stress reduction. We compared the effect of silent HU (using light and vapor without sound) and sonified HU on 5 participants. Subjective stress levels were statistically improved with both silent and sonified HU. The mean value of HR using silent HU was significantly lower than resting baseline and sonified HU. The mean value of root mean square of differences (RMSSD) using silent HU was significantly higher than resting baseline. We found that the differences between our objective and subjective assessments were intriguing and prompted us to investigate them further. Our evaluation of HU indicated that HU could facilitate relaxed breathing and stress reduction. There was a difference in outcome between the physiological measures of stress and the subjective reports of stress, as well as a large intervariability among study participants. Our conclusion is that the use of stress reduction tools should be customized and that the design work of mindfulness technology for stress reduction is a complex process, which requires cooperation of designers, HCI (Human-Computer Interaction) experts and clinicians. ©Bin Zhu, Anders Hedman, Shuo Feng, Haibo Li, Walter Osika. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 14.06.2017.

Three Dimensional Constraint Effects on the Estimated (Delta)CTOD during the Numerical Simulation of Different Fatigue Threshold Testing Techniques

NASA Technical Reports Server (NTRS)

Seshadri, Banavara R.; Smith, Stephen W.

2007-01-01

Variation in constraint through the thickness of a specimen effects the cyclic crack-tip-opening displacement (DELTA CTOD). DELTA CTOD is a valuable measure of crack growth behavior, indicating closure development, constraint variations and load history effects. Fatigue loading with a continual load reduction was used to simulate the load history associated with fatigue crack growth threshold measurements. The constraint effect on the estimated DELTA CTOD is studied by carrying out three-dimensional elastic-plastic finite element simulations. The analysis involves numerical simulation of different standard fatigue threshold test schemes to determine how each test scheme affects DELTA CTOD. The American Society for Testing and Materials (ASTM) prescribes standard load reduction procedures for threshold testing using either the constant stress ratio (R) or constant maximum stress intensity (K(sub max)) methods. Different specimen types defined in the standard, namely the compact tension, C(T), and middle cracked tension, M(T), specimens were used in this simulation. The threshold simulations were conducted with different initial K(sub max) values to study its effect on estimated DELTA CTOD. During each simulation, the DELTA CTOD was estimated at every load increment during the load reduction procedure. Previous numerical simulation results indicate that the constant R load reduction method generates a plastic wake resulting in remote crack closure during unloading. Upon reloading, this remote contact location was observed to remain in contact well after the crack tip was fully open. The final region to open is located at the point at which the load reduction was initiated and at the free surface of the specimen. However, simulations carried out using the constant Kmax load reduction procedure did not indicate remote crack closure. Previous analysis results using various starting K(sub max) values and different load reduction rates have indicated DELTA CTOD is independent of specimen size. A study of the effect of specimen thickness and geometry on the measured DELTA CTOD for various load reduction procedures and its implication in the estimation of fatigue crack growth threshold values is discussed.

The measurement and facilitation of cooperative task performance. [reactions of humans to stress exposure

NASA Technical Reports Server (NTRS)

Hutchinson, R. R.

1975-01-01

Experiments were conducted to determine under what conditions jaw clenching will occur in humans as a response to stress exposure. The method for measuring reactions to stress involves a series of electrical recordings of the masseter and temporalis muscles. A high fixed-ratio response requirement in the first series of experiments shows that jaw clenching in humans occurs in situations analogous to those which produce biting in infrahuman subjects. In the second series, reduction in the amounts of money recieved by subjects is shown to cause increases in the jaw clench response and other negative effect motor behaviors. The third series demonstrates that perception of more favorable conditions existing for another person can increase anger and hostility in the subject.

Quantitative determination of superoxide in plant leaves using a modified NBT staining method.

PubMed

Bournonville, Carlos F Grellet; Díaz-Ricci, Juan Carlos

2011-01-01

In plants, the ROS (reactive oxygen species) level is tightly regulated because their accumulation produces irreversible damage leading to cell death. However, ROS accumulation plays a key role in plant signaling under biotic or abiotic stress. Although various methods were reported to evaluate ROS accumulation, they are restricted to model plants or provide only qualitative information. Develop a simple method to quantify superoxide radicals produced in plant tissues, based on the selective extraction of the formazan produced after nitroblue tetrazolium (NBT) reduction in histochemical staining. Plant leaves were stained with a standard NBT method and the formazan precipitated in tissues was selectively extracted using chloroform. The organic phase was dried and formazan residue dissolved in dimethylsulfoxide-potassium hydroxide and quantified by spectrophotometry. The method was tested in strawberry plant leaves under different stressing conditions. Formazan extracted from leaves subjected to stress conditions showed similar absorption spectra to those obtained from standard solutions using pure formazan. Calibration curves showed a linear relationship between absorbance and formazan amounts, within the range 0.5-8 µg. Outcomes suggested that formazan was retained in the solid residue of leaf tissues. This protocol allowed us to quantify superoxide radicals produced under different stress conditions. Chloroform allowed a selective formazan extraction and removal of potential endogenous, exogenous or procedural artefacts that may interfere with the quantitative determination. This protocol can be used to quantify the superoxide produced in plant tissues using any traditional qualitative NBT histochemical staining method. Copyright © 2011 John Wiley & Sons, Ltd.

Stress, stress reduction, and hypertension in African Americans: an updated review.

PubMed Central

Barnes, V.; Schneider, R.; Alexander, C.; Staggers, F.

1997-01-01

This is a comprehensive and integrative review of multiple factors underlying the greater prevalence of hypertension in African Americans compared with whites. Evidence linking stress with hypertension and cardiovascular disease in African Americans is reviewed. A survey of mechanisms of hypertension in African Americans and existing behavioral strategies for the treatment of hypertension is presented. Given that the excess of hypertension may be mediated in part by behavioral factors operating through biological mechanisms, a case is presented for behavioral stress reduction measures. This review of stress reduction techniques especially the Transcendental Mediation program for the treatment of hypertension in African Americans highlights current issues facing the field. New information is provided to help direct future nonpharmacological research and practice in hypertension to prevent morbidity and premature mortality in this underserved population. PMID:9220696

The impact of stress and psychosocial interventions on assisted reproductive technology outcome.

PubMed

Morreale, Mary; Balon, Richard; Tancer, Manuel; Diamond, Michael

2011-01-01

In natural cycles of attempted conception, stress has been shown to predict lower conception rates. The objective of this article is to determine whether stress affects the outcome of assisted reproductive technology (ART) as well. In addition, this article analyzes the effect that psychosocial interventions targeting the reduction of stress have on ART outcomes. This review examined available PubMed articles published in the past 15 years, and 28 articles were included. Looking specifically at numbers of women studied, stress appears to negatively affect ART outcome; interventions targeting stress reduction appear beneficial. Because stress appears to negatively affect ART outcome, and psychosocial interventions do not have detrimental effects, screening for stress should occur and some type of intervention considered during the ART process.

The role of streamline curvature in sand dune dynamics: evidence from field and wind tunnel measurements

NASA Astrophysics Data System (ADS)

Wiggs, Giles F. S.; Livingstone, Ian; Warren, Andrew

1996-09-01

Field measurements on an unvegetated, 10 m high barchan dune in Oman are compared with measurements over a 1:200 scale fixed model in a wind tunnel. Both the field and wind tunnel data demonstrate similar patterns of wind and shear velocity over the dune, confirming significant flow deceleration upwind of and at the toe of the dune, acceleration of flow up the windward slope, and deceleration between the crest and brink. This pattern, including the widely reported upwind reduction in shear velocity, reflects observations of previous studies. Such a reduction in shear velocity upwind of the dune should result in a reduction in sand transport and subsequent sand deposition. This is not observed in the field. Wind tunnel modelling using a near-surface pulse-wire probe suggests that the field method of shear velocity derivation is inadequate. The wind tunnel results exhibit no reduction in shear velocity upwind of or at the toe of the dune. Evidence provided by Reynolds stress profiles and turbulence intensities measured in the wind tunnel suggest that this maintenance of upwind shear stress may be a result of concave (unstable) streamline curvature. These additional surface stresses are not recorded by the techniques used in the field measurements. Using the occurrence of streamline curvature as a starting point, a new 2-D model of dune dynamics is deduced. This model relies on the establishment of an equilibrium between windward slope morphology, surface stresses induced by streamline curvature, and streamwise acceleration. Adopting the criteria that concave streamline curvature and streamwise acceleration both increase surface shear stress, whereas convex streamline curvature and deceleration have the opposite effect, the relationships between form and process are investigated in each of three morphologically distinct zones: the upwind interdune and concave toe region of the dune, the convex portion of the windward slope, and the crest-brink region. The applicability of the model is supported by measurements of the rate of sand transport and the change of the dune surface in the field.

A method to separate and quantify the effects of indentation size, residual stress and plastic damage when mapping properties using instrumented indentation

NASA Astrophysics Data System (ADS)

Hou, X. D.; Jennett, N. M.

2017-11-01

Instrumented indentation is a convenient and increasingly rapid method of high resolution mapping of surface properties. There is, however, significant untapped potential for the quantification of these properties, which is only possible by solving a number of serious issues that affect the absolute values for mechanical properties obtained from small indentations. The three most pressing currently are the quantification of: the indentation size effect (ISE), residual stress, and pile-up and sink-in—which is itself affected by residual stress and ISE. Hardness based indentation mapping is unable to distinguish these effects. We describe a procedure that uses an elastic modulus as an internal reference and combines the information available from an indentation modulus map, a hardness map, and a determination of the ISE coefficient (using self-similar geometry indentation) to correct for the effects of stress, pile up and the indentation size effect, to leave a quantified map of plastic damage and grain refinement hardening in a surface. This procedure is used to map the residual stress in a cross-section of the machined surface of a previously stress free metal. The effect of surface grinding is compared to milling and is shown to cause different amounts of work hardening, increase in residual stress, and surface grain size reduction. The potential use of this procedure for mapping coatings in cross-section is discussed.

Return to work outcomes of the Redesigning Daily Occupations (ReDO) program for women with stress-related disorders--a comparative study.

PubMed

Eklund, Mona; Erlandsson, Lena-Karin

2011-11-01

Stress-related disorders are a frequent cause for sick leave, with consequences such as great distress and adverse economic effects for the affected person and substantial costs for society. Identifying effective interventions that facilitate return to work is thus important. The aim of this study was to evaluate the effectiveness of the 16-week Redesigning Daily Occupations program as a work rehabilitation method for Swedish women with stress-related disorders. The authors of this study hypothesized that, compared to women who got Care as Usual, 12 months after completed rehabilitation a larger proportion of the Redesigning Daily Occupations women would have returned to work, and they would have less sick leave, perceive less stress, and have greater self-esteem. Forty-two women entered the Redesigning Daily Occupations intervention and a matched comparison group received Care as Usual. The data, collected between 2007 and 2010, consisted of registry information and questionnaires targeting socio-demographics, perceived stress, and self-esteem. The findings partly verified the hypotheses. A larger proportion of the Redesigning Daily Occupations women returned to work and they decreased their sick leave and increased their self-esteem more than the Care as Usual group, but the groups did not differ in stress reduction. Thus, the Redesigning Daily Occupations seems to be a promising work rehabilitation method for women with stress-related disorders.

Alteration in Memory and Electroencephalogram Waves with Sub-acute Noise Stress in Albino Rats and Safeguarded by Scoparia dulcis

PubMed Central

Loganathan, Sundareswaran; Rathinasamy, Sheeladevi

2016-01-01

Background: Noise stress has different effects on memory and novelty and the link between them with an electroencephalogram (EEG) has not yet been reported. Objective: To find the effect of sub-acute noise stress on the memory and novelty along with EEG and neurotransmitter changes. Materials and Methods: Eight-arm maze (EAM) and Y-maze to analyze the memory and novelty by novel object test. Four groups of rats were used: Control, control treated with Scoparia dulcis extract, noise exposed, and noise exposed which received Scoparia extract. Results: The results showed no marked difference observed between control and control treated with Scoparia extract on EAM, Y-maze, novel object test, and EEG in both prefrontal and occipital region, however, noise stress exposed rats showed significant increase in the reference memory and working memory error in EAM and latency delay, triad errors in Y-maze, and prefrontal and occipital EEG frequency rate with the corresponding increase in plasma corticosterone and epinephrine, and significant reduction in the novelty test, and significant reduction in the novelty test, amplitude of prefrontal, occipital EEG, and acetylcholine. Conclusion: These noise stress induced changes in EAM, Y-maze, novel object test, and neurotransmitters were significantly prevented when treated with Scoparia extract and these changes may be due to the normalizing action of Scoparia extract on the brain, which altered due to noise stress. SUMMARY Noise stress exposure causes EEG, behavior, and neurotransmitter alteration in the frontoparietal and occipital regions mainly involved in planning and recognition memoryOnly the noise stress exposed animals showed the significant alteration in the EEG, behavior, and neurotransmittersHowever, these noise stress induced changes in EEG behavior and neurotransmitters were significantly prevented when treated with Scoparia extractThese changes may be due to the normalizing action of Scoparia dulcis (adoptogen) on the brain which altered by noise stress. Abbreviations used: EEG: Electroencephalogram, dB: Decibel, EPI: Epinephrine, ACH: Acetylcholine, EAM: Eight-arm maze PMID:27041862

Combined Effects of Acamprosate and Escitalopram on Ethanol Consumption in Mice

PubMed Central

Ho, Ada Man-Choi; Qiu, Yanyan; Jia, Yun-Fang; Aguiar, Felipe S.; Hinton, David J.; Karpyak, Victor M.; Weinshilboum, Richard M.; Choi, Doo-Sup

2016-01-01

Background Major depression is one of the most prevalent psychiatry comorbidities of alcohol use disorders (AUD). Since negative emotions can trigger craving and increase the risk of relapse, treatments that target both conditions simultaneously may augment treatment success. Previous studies showed a potential synergist effect of FDA approved medication for AUD acamprosate and the antidepressant escitalopram. In this study, we investigated the effects of combining acamprosate and escitalopram on ethanol consumption in stress-induced depressed mice. Methods Forty singly-housed C57BL/6J male mice were subjected to chronic unpredictable stress. In parallel, 40 group-housed male mice were subjected to normal husbandry. After 3 weeks, depressive- and anxiety-like behaviors and ethanol consumption were assessed. For the next 7 days, mice were injected with saline, acamprosate (200 mg/kg; twice/day), escitalopram (5 mg/kg; twice/day), or their combination (n = 9–11/drug group/stress group). Two-bottle choice limited access drinking of 15% ethanol and tap water was performed 3 hours into dark phase for 2 hours immediately after the dark phase daily injection. Ethanol drinking was monitored for another 7 days without drug administration. Results Mice subjected to the chronic unpredictable stress paradigm for 3 weeks showed apparent depression- and anxiety-like behaviors compared to their non-stressed counterparts including longer immobility time in the forced swim test and lower sucrose preference. Stressed mice also displayed higher ethanol consumption and preference in a 2-bottle choice drinking test. During the drug administration period, the escitalopram-only and combined drug groups showed significant reduction in ethanol consumption in non-stressed mice, while only the combined drug group showed significantly reduced consumption in stressed mice. However, such reduction did not persist into the post-drug administration period. Conclusions The combination of acamprosate and escitalopram suppressed ethanol intake in both non-stressed and stressed mice, hence this combination is potentially helpful for AUD individuals with or without comorbid depression to reduce alcohol use. PMID:27184383

Pre-treatment social anxiety severity moderates the impact of mindfulness-based stress reduction and aerobic exercise.

PubMed

Jazaieri, Hooria; Lee, Ihno A; Goldin, Philippe R; Gross, James J

2016-06-01

We examined whether social anxiety severity at pre-treatment would moderate the impact of mindfulness-based stress reduction (MBSR) or aerobic exercise (AE) for generalized social anxiety disorder. MBSR and AE produced equivalent reductions in weekly social anxiety symptoms. Improvements were moderated by pre-treatment social anxiety severity. Mindfulness-based stress reduction (MBSR) and aerobic exercise (AE) are effective in reducing symptoms of social anxiety. Pre-treatment social anxiety severity can be used to inform treatment recommendations. Both MBSR and AE produced equivalent reductions in weekly levels of social anxiety symptoms. MBSR appears to be most effective for patients with lower pre-treatment social anxiety symptom severity. AE appears to be most effective for patients with higher pre-treatment social anxiety symptom severity. © 2015 The British Psychological Society.

Recovery of Work-Related Stress: Complaint Reduction and Work-Resumption are Relatively Independent Processes.

PubMed

de Vente, Wieke; Kamphuis, Jan Henk; Blonk, Roland W B; Emmelkamp, Paul M G

2015-09-01

The process of recovery from work-related stress, consisting of complaint reduction and work-resumption, is not yet fully understood. The aim of this study was to investigate predictors of complaint reduction and work-resumption, as well as testing complaint reduction as a mediator in the association between predictors and work-resumption. Seventy-one patients on sickness-leave because of work-related stress complaints were followed over a period of 13 months. Predictors comprised personal (demographics, coping, cognitions), work-related (job-characteristics, social support), and illness-related (complaint duration, absence duration) variables. Dependent variables were distress complaints, burnout complaints, and work-resumption. Complaints reduced considerably over time to borderline clinical levels and work-resumption increased to 68% at 13 months. Predictors of stronger reduction of distress complaints were male gender, less working hours, less decision authority, more co-worker support, and shorter absence duration. Predictors of stronger reduction of burnout complaints were male gender, lower age, high education, less avoidant coping, less decision authority, more job security, and more co-worker support. Predictors of work-resumption were lower age and stronger reduction of burnout complaints. No indication for a mediating role of burnout complaints between the predictor age and work-resumption was found. Complaint reduction and work-resumption are relatively independent processes. Symptom reduction is influenced by individual and work-related characteristics, which holds promise for a multidisciplinary treatment approach for work-related stress.

Utility of cement injection to stabilize split-depression tibial plateau fracture by minimally invasive methods: A finite element analysis.

PubMed

Belaid, D; Vendeuvre, T; Bouchoucha, A; Brémand, F; Brèque, C; Rigoard, P; Germaneau, A

2018-05-08

Treatment for fractures of the tibial plateau is in most cases carried out by stable fixation in order to allow early mobilization. Minimally invasive technologies such as tibioplasty or stabilization by locking plate, bone augmentation and cement filling (CF) have recently been used to treat this type of fracture. The aim of this paper was to determine the mechanical behavior of the tibial plateau by numerically modeling and by quantifying the mechanical effects on the tibia mechanical properties from injury healing. A personalized Finite Element (FE) model of the tibial plateau from a clinical case has been developed to analyze stress distribution in the tibial plateau stabilized by balloon osteoplasty and to determine the influence of the cement injected. Stress analysis was performed for different stages after surgery. Just after surgery, the maximum von Mises stresses obtained for the fractured tibia treated with and without CF were 134.9 MPa and 289.9 MPa respectively on the plate. Stress distribution showed an increase of values in the trabecular bone in the treated model with locking plate and CF and stress reduction in the cortical bone in the model treated with locking plate only. The computed results of stresses or displacements of the fractured models show that the cement filling of the tibial depression fracture may increase implant stability, and decrease the loss of depression reduction, while the presence of the cement in the healed model renders the load distribution uniform. Copyright © 2018 Elsevier Ltd. All rights reserved.

Interference-Fit Life Factors for Roller Bearings

NASA Technical Reports Server (NTRS)

Oswald, Fred B.; Zaretsky, Erwin V.; Poplawski, Joseph V.

2009-01-01

The effect of hoop stresses in reducing cylindrical roller bearing fatigue life was determined for various classes of inner-ring interference fit. Calculations were performed for up to 7 fit classes for each of 10 bearing sizes. The hoop stresses were superimposed on the Hertzian principal stresses created by the applied radial load to calculate roller bearing fatigue life. A method was developed through a series of equations to calculate the life reduction for cylindrical roller bearings. All calculated lives are for zero initial internal clearance. Any reduction in bearing clearance due to interference fit would be compensated by increasing the initial (unmounted) clearance. Results are presented as tables and charts of life factors for bearings with light, moderate, and heavy loads and interference fits ranging from extremely light to extremely heavy for bearing accuracy class RBEC-5 (ISO class 5). Interference fits on the inner ring of a cylindrical roller bearing can significantly reduce bearing fatigue life. In general, life factors are smaller (lower life) for bearings running under light load where the unfactored life is highest. The various bearing series within a particular bore size had almost identical interference-fit life factors for a particular fit. The tightest fit at the high end of the tolerance band produces a life factor of approximately 0.40 for an inner-race maximum Hertz stress of 1200 MPa (175 ksi) and a life factor of 0.60 for an inner-race maximum Hertz stress of 2200 MPa (320 ksi). Interference fits also impact the maximum Hertz stress-life relation.

Evaluation of the Effect of Surface Finish on High-Cycle Fatigue of SLM-IN718

NASA Technical Reports Server (NTRS)

Lambert, D. M.

2016-01-01

The surface finish of parts produced by additive manufacturing processes is much rougher than the surface finish generated by machining processes, and a rougher surface can reduce the fatigue strength of a part. This paper discusses an effort to quantify that reduction of strength in high-cycle fatigue for selective laser melt (SLM) coupons. A high-cycle fatigue (HCF) knockdown factor was estimated for Inconel 718, manufactured with the SLM process. This factor is the percentage reduction from the maximum stress in fatigue for low-stress ground (LSG) specimens to the maximum stress of those left with the original surface condition at the same fatigue life. Specimens were provided by a number of vendors, free to use their "best practice"; only one heat treat condition was considered; and several test temperatures were characterized, including room temperature, 800F, 1000F, and 1200F. The 1000F data had a large variance, and was omitted from consideration in this document. A first method used linear approximations extracted from the graphs, and only where data was available for both. A recommended knockdown factor of the as-built surface condition (average roughness of approximately 245 micro-inches/inch) versus low-stress ground condition (roughness no more than 4 micro-inches/inch) was established at approximately 1/3 or 33%. This is to say that for the as-built surface condition, a maximum stress of 2/3 of the stress for LSG can be expected to produce a similar life in the as-built surface condition. In this first evaluation, the knockdown factor did not appear to be a function of temperature. A second approach, the "KP method", incorporated the surface finish measure into a new parameter termed the pseudo-stress intensity factor, Kp, which was formulated to be similar to the fracture mechanics stress intensity factor. Using Kp, the variance seemed to be reduced across all sources, and knockdown factors were estimated using Kp over the range where data occurred. A plot of the results suggests that the knockdown factor is a function of temperature, and that for low lives the knockdown might be lower than the knockdown observed above about one million cycles, where it tended to stabilize. This was not universal for all temperatures tested. The higher temperature tests are thought to be influenced by the test temperature, which perhaps continued the aging process. Further evaluation of the method is suggested.

Enhancing Cardiac Rehabilitation With Stress Management Training: A Randomized Clinical Efficacy Trial

PubMed Central

Blumenthal, James A.; Sherwood, Andrew; Smith, Patrick J.; Watkins, Lana; Mabe, Stephanie; Kraus, William E.; Ingle, Krista; Miller, Paula; Hinderliter, Alan

2016-01-01

Background Cardiac rehabilitation (CR) is the standard of care for patients with coronary heart disease (CHD). Despite considerable epidemiologic evidence that high stress is associated with worse health outcomes, stress management training (SMT) is not included routinely as a component of CR. Methods and Results 151 outpatients with CHD aged 36 to 84 years were randomized to 12-weeks of comprehensive CR or comprehensive CR combined with SMT (CR+SMT), with assessments of stress and CHD biomarkers obtained before and after treatment. A matched sample of CR-eligible patients who did not receive CR comprised a No-CR comparison group. All participants were followed for up to 5.3 years (median = 3.2 years) for clinical events. Patients randomized to CR+SMT exhibited greater reductions in composite stress levels compared with those randomized to CR alone (P = 0.022), an effect that was driven primarily by improvements in anxiety, distress, and perceived stress. Both CR groups achieved significant, and comparable, improvements in CHD biomarkers. Participants in the CR+SMT group exhibited lower rates of clinical events compared with CR alone (18% vs. 33%, HR = 0.49 [0.25, 0.95], P = 0.035) and both CR groups had lower event rates compared to the No-CR group (47%, HR = 0.44 [0.27, 0.71], P < .001). Conclusions CR enhanced by SMT produced significant reductions in stress and greater improvements in medical outcomes compared with standard CR. Our findings indicate that SMT may provide incremental benefit when combined with comprehensive CR and suggest that SMT should be incorporated routinely into CR. Clinical Trial Registration Information www.Clinicaltrials.gov. Identifier: NCT00981253. PMID:27045127

Health Hazard Appraisal Counseling—Continuing Evaluation

PubMed Central

LaDou, Joseph; Sherwood, John N.; Hughes, Lewis

1979-01-01

A program of annual health examinations was expanded to include counseling based on a computerized appraisal of individual patients' specific health risk factors. Data obtained from a specially designed questionnaire, laboratory tests and a physical examination yielded a health hazard appraisal showing a number of weighted risk factors and their relation to ten leading causes of death as determined for that patient. From all of this information, a “risk age” was developed which could then be compared with the patient's “true age.” The results were reviewed with each patient, and methods of correcting health hazards were stressed. The first annual retesting of a group of 107 examinees showed a net risk age reduction of 1.4 years (formerly reported in this journal). The longer term follow-up reported in this paper showed a net risk reduction of 2.38 years in a group of 26 examinees. The net risk age reduction in the two groups represented 32 and 40 percent, respectively, of the achievable risk age reduction when patients comply with suggestions made during risk reduction counseling. These findings indicate that health hazard appraisal counseling is an effective method of altering priorities of health practices. PMID:425518

An Experimental Investigation into Additive Manufacturing-Induced Residual Stresses in 316L Stainless Steel

NASA Astrophysics Data System (ADS)

Wu, Amanda S.; Brown, Donald W.; Kumar, Mukul; Gallegos, Gilbert F.; King, Wayne E.

2014-12-01

Additive manufacturing (AM) technology provides unique opportunities for producing net-shape geometries at the macroscale through microscale processing. This level of control presents inherent trade-offs necessitating the establishment of quality controls aimed at minimizing undesirable properties, such as porosity and residual stresses. Here, we perform a parametric study into the effects of laser scanning pattern, power, speed, and build direction in powder bed fusion AM on residual stress. In an effort to better understand the factors influencing macroscale residual stresses, a destructive surface residual stress measurement technique (digital image correlation in conjunction with build plate removal and sectioning) has been coupled with a nondestructive volumetric evaluation method ( i.e., neutron diffraction). Good agreement between the two measurement techniques is observed. Furthermore, a reduction in residual stress is obtained by decreasing scan island size, increasing island to wall rotation to 45 deg, and increasing applied energy per unit length (laser power/speed). Neutron diffraction measurements reveal that, while in-plane residual stresses are affected by scan island rotation, axial residual stresses are unchanged. We attribute this in-plane behavior to misalignment between the greatest thermal stresses (scan direction) and largest part dimension.

Effect of Inflammatory and Noninflammatory Stress on Beta-Hydroxybutyrate and Free Fatty Acids in Rat Blood.

DTIC Science & Technology

fasting plus screen-restraint and fasting plus femoral fracture. Inflammatory stresses caused a marked inhibition of the normal fasting-induced ketosis ...and a reduction in the level of circulating free fatty acids. Noninflammatory stresses caused no inhibition of the normal fasting-induced ketosis but did cause a reduction in the level of circulating free fatty acids. (Author)

Mindfulness-Based Stress Reduction for Low-Income, Predominantly African American Women with PTSD and a History of Intimate Partner Violence

ERIC Educational Resources Information Center

Dutton, Mary Ann; Bermudez, Diana; Matas, Armely; Majid, Haseeb; Myers, Neely L.

2013-01-01

In this article, we consider the use of Mindfulness-Based Stress Reduction (MBSR; Kabat-Zinn, 1991) as a community-based intervention for posttraumatic stress disorder (PTSD) among low-income, predominantly African American women with a history of intimate partner violence (IPV). The results of a pilot randomized clinical trial (RCT) of MBSR as an…

Behavioral interventions for coronary heart disease patients.

PubMed

Orth-Gomér, Kristina

2012-02-02

There is a strong clinical need to provide effective stress reduction programs for patients with an acute coronary syndrome. Such programs for men have been implemented and their cardiovascular health benefit documented. For women such programs are scarce.In this report, The feasibility of a cognitive method that was recently demonstrated to prolong lives of women is tested. A setting with gender segregated groups was applied. The principles of a behavioural health educational program originally designed to attenuate the stress of patients with coronary prone behaviours were used as a basis for the intervention method. For the groups of female patients this method was tailored according to female stressors and for the groups of men according to male stressors. The same core stress reduction program was used for women and men, but the contents of discussions and responses to the pre planned program varied. These were continuously monitored throughout the fifteen sessions. Implementation group: Thirty consecutive patients, eleven women and nineteen men, hospitalized for an acute coronary syndrome were included in this intervention. All expressed their need to learn how to cope with stress in daily life and were highly motivated. Five groups, three groups of men and two groups of women were formed. Psychological assessments were made immediately before and after completion of the program. No gender differences in the pre planned programs were found, but discussion styles varied between the women and men, Women were more open and more personal. Family issues were more frequent than job issues, although all women were employed outside their homes. Men talked about concrete and practical things, mostly about their jobs, and not directly about their feelings. Daily stresses of life decreased significantly for both men and women, but more so for women. Depressive thoughts were low at baseline, and there was no change over time. In contrast, anxiety scores were high at baseline and decreased significantly, but more so for women than for men. Women are likely to benefit from women's groups. Men may prefer to have one or two women in the group, but women fare better in gender segregated groups.

Interference-Fit Life Factors for Ball Bearings

NASA Technical Reports Server (NTRS)

Oswald, Fred B.; Zaretsky, Erwin V.; Poplawski, Joseph V.

2010-01-01

The effect of hoop stresses on the rolling-element fatigue life of angular-contact and deep-groove ball bearings was determined for common inner-ring interference fits at the ABEC-5 tolerance level. The analysis was applied to over 1150 bearing configurations and load cases. Hoop stresses were superimposed on the Hertzian principal stresses created by the applied bearing load to calculate the inner-race maximum shearing stress. The resulting fatigue life of the bearing was recalculated through a series of equations. The reduction in the fatigue life is presented as life factors that are applied to the unfactored bearing life. The life factors found in this study ranged from 1.00 (no life reduction)--where there was no net interface pressure--to a worst case of 0.38 (a 62-percent life reduction). For a given interference fit, the reduction in life is different for angular-contact and deep-groove ball bearings. Interference fits also affect the maximum Hertz stress-life relation. Experimental data of Czyzewski, showing the effect of interference fit on rolling-element fatigue life, were reanalyzed to determine the shear stress-life exponent. The Czyzewski data shear stress-life exponent c equals 8.77, compared with the assumed value of 9. Results are presented as tables and charts of life factors for angular-contact and deep-groove ball bearings with light, normal, and heavy loads and interference fits ranging from extremely light to extremely heavy.

Evaluating bump control techniques through convergence monitoring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Campoli, A.A.

1987-07-01

A coal mine bump is the violent failure of a pillar or pillars due to overstress. Retreat coal mining concentrates stresses on the pillars directly outby gob areas, and the situation becomes critical when mining a coalbed encased in rigid associated strata. Bump control techniques employed by the Olga Mine, McDowell County, WV, were evaluated through convergence monitoring in a Bureau of Mines study. Olga uses a novel pillar splitting mining method to extract 55-ft by 70-ft chain pillars, under 1,100 to 1,550 ft of overburden. Three rows of pillars are mined simultaneously to soften the pillar line and reducemore » strain energy storage capacity. Localized stress reduction (destressing) techniques, auger drilling and shot firing, induced approximately 0.1 in. of roof-to-floor convergence in ''high'' -stress pillars near the gob line. Auger drilling of a ''low''-stress pillar located between two barrier pillars produced no convergence effects.« less

Moment tensor inversion of ground motion from mining-induced earthquakes, Trail Mountain, Utah

USGS Publications Warehouse

Fletcher, Joe B.; McGarr, A.

2005-01-01

A seismic network was operated in the vicinity of the Trail Mountain mine, central Utah, from the summer of 2000 to the spring of 2001 to investigate the seismic hazard to a local dam from mining-induced events that we expect to be triggered by future coal mining in this area. In support of efforts to develop groundmotion prediction relations for this situation, we inverted ground-motion recordings for six mining-induced events to determine seismic moment tensors and then to estimate moment magnitudes M for comparison with the network coda magnitudes Mc. Six components of the tensor were determined, for an assumed point source, following the inversion method of McGarr (1992a), which uses key measurements of amplitude from obvious features of the displacement waveforms. When the resulting moment tensors were decomposed into implosive and deviatoric components, we found that four of the six events showed a substantial volume reduction, presumably due to coseismic closure of the adjacent mine openings. For these four events, the volume reduction ranges from 27% to 55% of the shear component (fault area times average slip). Radiated seismic energy, computed from attenuation-corrected body-wave spectra, ranged from 2.4 ?? 105 to 2.4 ?? 106 J for events with M from 1.3 to 1.8, yielding apparent stresses from 0.02 to 0.06 MPa. The energy released for each event, approximated as the product of volume reduction and overburden stress, when compared with the corresponding seismic energies, revealed seismic efficiencies ranging from 0.5% to 7%. The low apparent stresses are consistent with the shallow focal depths of 0.2 to 0.6 km and rupture in a low stress/low strength regime compared with typical earthquake source regions at midcrustal depths.

Prevention of psychological stress-induced immune suppression by aged garlic extract.

PubMed

Kyo, E; Uda, N; Ushijima, M; Kasuga, S; Itakura, Y

1999-11-01

We determined the effect of Aged Garlic Extract (AGE) on damage caused to immune function by a psychological stress using a communication box. After four days of a psychological stress, a decrease in spleen weight and spleen cells was observed in the psychological stress-exposed mice as compared normal mice (non-stress). AGE significantly prevented the decreases in spleen weight and cells. Additionally, AGE significantly prevented the reduction of hemolytic plaque-forming-cells in spleen cells and anti-SRBC antibody titer in serum caused by this psychological stress. Moreover, a reduction in NK activities was observed in the psychological stress-exposed mice as compared with normal mice (non-stress), whereas NK activities in the AGE administered mice were almost the same as normal mice (non-stress). These results indicate that psychological stress qualitatively and quantitatively impairs immune function, and that AGE is extremely useful for preventing psychologically-induced damage.

Expectancy of Stress-Reducing Aromatherapy Effect and Performance on a Stress-Sensitive Cognitive Task

PubMed Central

Chamine, Irina; Oken, Barry S.

2015-01-01

Objective. Stress-reducing therapies help maintain cognitive performance during stress. Aromatherapy is popular for stress reduction, but its effectiveness and mechanism are unclear. This study examined stress-reducing effects of aromatherapy on cognitive function using the go/no-go (GNG) task performance and event related potentials (ERP) components sensitive to stress. The study also assessed the importance of expectancy in aromatherapy actions. Methods. 81 adults were randomized to 3 aroma groups (active experimental, detectable, and undetectable placebo) and 2 prime subgroups (prime suggesting stress-reducing aroma effects or no-prime). GNG performance, ERPs, subjective expected aroma effects, and stress ratings were assessed at baseline and poststress. Results. No specific aroma effects on stress or cognition were observed. However, regardless of experienced aroma, people receiving a prime displayed faster poststress median reaction times than those receiving no prime. A significant interaction for N200 amplitude indicated divergent ERP patterns between baseline and poststress for go and no-go stimuli depending on the prime subgroup. Furthermore, trends for beneficial prime effects were shown on poststress no-go N200/P300 latencies and N200 amplitude. Conclusion. While there were no aroma-specific effects on stress or cognition, these results highlight the role of expectancy for poststress response inhibition and attention. PMID:25802539

Survival of Escherichia coli and Salmonella spp. in estuarine environments.

PubMed Central

Rhodes, M W; Kator, H

1988-01-01

Survival of Escherichia coli and Salmonella spp. in estuarine waters was compared over a variety of seasonal temperatures during in situ exposure in diffusion chambers. Sublethal stress was measured by both selective-versus-resuscitative enumeration procedures and an electrochemical detection method. E. coli and Salmonella spp. test suspensions, prepared to minimize sublethal injury, were exposed in a shallow tidal creek and at a site 7.1 km further downriver. Bacterial die-off and sublethal stress in filtered estuarine water were inversely related to water temperature. Salmonella spp. populations exhibited significantly less die-off and stress than did E. coli at water temperatures of less than 10 degrees C. Although the most pronounced reductions (ca. 3 log units) in test bacteria occurred during seasonally warm temperatures in the presence of the autochthonous microbiota, 10(2) to 10(4) test cells per ml remained after 2 weeks of exposure to temperatures of greater than 15 degrees C. Reductions in test bacteria were associated with increases in the densities of microflagellates and plaque-forming microorganisms. These studies demonstrated the survival potential of enteric bacteria in estuarine waters and showed that survival was a function of interacting biological and physical factors. PMID:3066291

Internal structural changes in keratin fibres resulting from combined hair waving and stress relaxation treatments: a Raman spectroscopic investigation.

PubMed

Kuzuhara, A

2016-04-01

The objective of our research was to investigate the influence of chemical treatments (reduction, stress relaxation and oxidation) on hair keratin fibres. The structure of cross-sections at various depths of virgin white human hair resulting from permanent waving treatments with stress relaxation process was directly analysed at a molecular level using Raman spectroscopy. In particular, the three disulphide (-SS-) conformations in human hair were compared by S-S band analysis. The gauche-gauche-gauche (GGG) and gauche-gauche-trans (GGT) contents of -SS- groups remarkably decreased, while the trans-gauche-trans (TGT) content was not changed by performing the reduction process with thioglycolic acid. In addition, the high-temperature stress relaxation process after reduction accelerated the disconnection of -SS- (GGG and GGT) groups in the human hair, while the low-temperature stress relaxation process after reduction accelerated the reconnection of -SS- (GGG and GGT) groups. Moreover, the S-O band intensity at 1042 cm(-1) , assigned to cysteic acid, existing in the cuticle region and the surface of the cortex region increased, while the GGG content significantly decreased by performing the oxidation process after the reduction and the high-temperature stress relaxation processes. The author concluded that the high-temperature relaxation process after reduction accelerated the disconnection of -SS- (GGG and GGT) groups, thereby leading to the remarkable local molecular disorganization (an increase in the cysteic acid content and a decrease in the GGG content) on the cuticle and cortex cells during the oxidation process. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Long-Term Effectiveness of Stress Management at Work: Effects of the Changes in Perceived Stress Reactivity on Mental Health and Sleep Problems Seven Years Later

PubMed Central

Barrech, Amira; Riedel, Natalie; Gündel, Harald; Angerer, Peter; Li, Jian

2018-01-01

The reduction of stress reactivity resulting from stress management interventions prevents disorders and improves mental health, however, its long-term sustainability has been little examined. The objective of this study was, therefore, to determine the effectiveness of a stress management intervention, designed to improve stress reactivity, for mental health and sleep problems seven years later, using longitudinal data from 101 male industrial workers. Linear regressions estimated the adjusted effects of the changes in stress reactivity in general as well as in its six subdimensions (work overload, social conflict, social stress, failure at work, and anticipatory and prolonged reactivity) on depression, anxiety, and sleep problems seven years later. The improvement of the prolonged reactivity had positive effects on depression, anxiety, and sleep problems (unstandardized regression coefficients [Bs] ≥ 0.35, all p-values ≤ 0.01). Depression and sleep problems were further improved by a reduction of the reactivity to social conflicts (Bs ≥ 0.29, p-values < 0.05), and an improvement in the overall reactivity score positively influenced sleep problems (B = 0.07, p = 0.017). In conclusion, the improvement of stress reactivity resulting from a work stress intervention was effective and generally long-lasting in preventing mental health and sleep problems. The reduction of the prolonged reactivity seems of particular importance and efficient in inhibiting negative stress manifestations. PMID:29401657

Long-Term Effectiveness of Stress Management at Work: Effects of the Changes in Perceived Stress Reactivity on Mental Health and Sleep Problems Seven Years Later.

PubMed

Herr, Raphael M; Barrech, Amira; Riedel, Natalie; Gündel, Harald; Angerer, Peter; Li, Jian

2018-02-03

The reduction of stress reactivity resulting from stress management interventions prevents disorders and improves mental health, however, its long-term sustainability has been little examined. The objective of this study was, therefore, to determine the effectiveness of a stress management intervention, designed to improve stress reactivity, for mental health and sleep problems seven years later, using longitudinal data from 101 male industrial workers. Linear regressions estimated the adjusted effects of the changes in stress reactivity in general as well as in its six subdimensions (work overload, social conflict, social stress, failure at work, and anticipatory and prolonged reactivity) on depression, anxiety, and sleep problems seven years later. The improvement of the prolonged reactivity had positive effects on depression, anxiety, and sleep problems (unstandardized regression coefficients [ Bs ] ≥ 0.35, all p -values ≤ 0.01). Depression and sleep problems were further improved by a reduction of the reactivity to social conflicts ( Bs ≥ 0.29, p -values < 0.05), and an improvement in the overall reactivity score positively influenced sleep problems ( B = 0.07, p = 0.017). In conclusion, the improvement of stress reactivity resulting from a work stress intervention was effective and generally long-lasting in preventing mental health and sleep problems. The reduction of the prolonged reactivity seems of particular importance and efficient in inhibiting negative stress manifestations.

A comparison of mindfulness-based stress reduction and an active control in modulation of neurogenic inflammation

PubMed Central

Rosenkranz, Melissa A.; Davidson, Richard J.; MacCoon, Donal G.; Sheridan, John F.; Kalin, Ned H.; Lutz, Antoine

2012-01-01

Psychological stress is a major provocative factor of symptoms in chronic inflammatory conditions. In recent years, interest in addressing stress responsivity through meditation training in health-related domains has increased astoundingly, despite a paucity of evidence that reported benefits are specific to meditation practice. We designed the present study to rigorously compare an 8-week Mindfulness-Based Stress Reduction (MBSR) intervention to a well-matched active control intervention, the Health Enhancement Program (HEP) in ability to reduce psychological stress and experimentally-induced inflammation. The Trier Social Stress Test (TSST) was used to induce psychological stress and inflammation was produced using topical application of capsaicin cream to forearm skin. Immune and endocrine measures of inflammation and stress were collected both before and after MBSR training. Results show those randomized to MBSR and HEP training had comparable post-training stress-evoked cortisol responses, as well as equivalent reductions in self-reported psychological distress and physical symptoms. However, MBSR training resulted in a significantly smaller post-stress inflammatory response compared to HEP, despite equivalent levels of stress hormones. These results suggest behavioral interventions designed to reduce emotional reactivity may be of therapeutic benefit in chronic inflammatory conditions. Moreover, mindfulness practice, in particular, may be more efficacious in symptom relief than the well-being promoting activities cultivated in the HEP program. PMID:23092711

Spatial and Temporal Variations in Earthquake Stress Drop on Gofar Transform Fault, East Pacific Rise: Implications for Fault Strength

NASA Astrophysics Data System (ADS)

Moyer, P. A.; Boettcher, M. S.; McGuire, J. J.; Collins, J. A.

2017-12-01

During the last five seismic cycles on Gofar transform fault on the East Pacific Rise, the largest earthquakes (6.0 ≤ Mw ≤ 6.2) have repeatedly ruptured the same fault segment (rupture asperity), while intervening fault segments host swarms of microearthquakes. Previous studies on Gofar have shown that these segments of low (≤10%) seismic coupling contain diffuse zones of seismicity and P-wave velocity reduction compared with the rupture asperity; suggesting heterogeneous fault properties control earthquake behavior. We investigate the role systematic differences in material properties have on earthquake rupture along Gofar using waveforms from ocean bottom seismometers that recorded the end of the 2008 Mw 6.0 seismic cycle.We determine stress drop for 117 earthquakes (2.4 ≤ Mw ≤ 4.2) that occurred in and between rupture asperities from corner frequency derived using an empirical Green's function spectral ratio method and seismic moment obtained by fitting the omega-square source model to the low frequency amplitude of earthquake spectra. We find stress drops from 0.03 to 2.7 MPa with significant spatial variation, including 2 times higher average stress drop in the rupture asperity compared to fault segments with low seismic coupling. We interpret an inverse correlation between stress drop and P-wave velocity reduction as the effect of damage on earthquake rupture. Earthquakes with higher stress drops occur in more intact crust of the rupture asperity, while earthquakes with lower stress drops occur in regions of low seismic coupling and reflect lower strength, highly fractured fault zone material. We also observe a temporal control on stress drop consistent with log-time healing following the Mw 6.0 mainshock, suggesting a decrease in stress drop as a result of fault zone damage caused by the large earthquake.

The von Mises stress distribution on the surface of UHMWPE with texture-shaped variation in the presence of normal load and dry sliding contact

NASA Astrophysics Data System (ADS)

Lestari, W. D.; Jamari, J.; Bayuseno, A. P.

2017-04-01

The texture shapes play a key role in the tribological performance of the surface material. This paper presents a study on the use of the 3D finite element method for surface stress analysis on the different texture shape under load and dry sliding contact. The five texture-shaped model was investigated in this work, namely square, circle, ellipse, triangle, and chevron. The result shown that the square shape has the highest value of von Mises resultant stress under static load. In contrast, the dry sliding contact on the triangle shape provided the highest von Mises stress distribution. The lowest value of von Mises stress can be found in the texture pattern of circle, square, and chevron under influence of load for 17 N, 30 N, and 50 N, respectively. Those texture patterns applied to surface of Ultra High Molecular Weight Polyethylene (UHMWPE) may have a strong effect on the reduction of wear rate and enhance tribological performance.

[Mindfulness training for psychiatrists in residency: a pilot study].

PubMed

Hoenders, H J R; Booij, S H; Knegtering, H; van den Brink, H

Medical students and psychiatrists in residency run a high risk for burnout. Furthermore, while at medical school, students seem to experience a reduction in empathy; this seems to be linked to a high level of stress. Interventions based on mindfulness training appear to reduce stress and increase empathy in medical students. Trainees in psychiatric residency might also benefit from mindfulness training.
AIM: To assess the effects that a mindfulness course has on perceived stress and empathy in psychiatrists in residency.
METHOD: In this pilot study 13 trainees in psychiatric residency participated in an eight-week course in mindfulness. Before and after the training, 11 of the participants completed questionnaires relating to their empathy, perceived stress and mindfulness.
RESULTS: Participants reported experiencing considerably more empathy after their course than before it. Perceived stress also diminished, but not significantly.
CONCLUSION: The results support our suggestion that mindfulness training can be a valuable part of the curriculum for trainees in psychiatric residency.

Numerical modeling of the effect of heat and mass transfer in porous low-temperature heat insulation in composite material structures on the magnitude of stresses which develop

NASA Astrophysics Data System (ADS)

Kuznetsov, G. V.; Rudzinskaya, N. V.

1997-05-01

The stressed state of multilayer low-temperature heat insulation for a cryogenic fuel tank is considered. Account is taken of heat and mass transfer in foam plastic (the main heat insulation material) occurring at cryogenic temperatures. A method is developed for solving a set of differential equations and boundary conditions. Numerical studies of the main features of these processes are performed. It is established that below 200 K the stresses which arise in foam plastic markedly exceed the ultimate strength for this material. Stresses develop as a result of both a reduction in temperature and a drop in pressure in the foam plastic pores connected with material cooling. On the basis of the results obtained it is established that the combination of thermophysical processes which occur in foam plastic during cooling to cryogenic temperatures leads to changes in the stress-strained state of structure, which should be considered in planning aerospace technology.

A Web-Based Mindfulness Stress Management Program in a Corporate Call Center

PubMed Central

Allexandre, Didier; Bernstein, Adam M.; Walker, Esteban; Hunter, Jennifer; Roizen, Michael F.; Morledge, Thomas J.

2016-01-01

Objective: The objective of this study is to determine the effectiveness of an 8-week web-based, mindfulness stress management program (WSM) in a corporate call center and added benefit of group support. Methods: One hundred sixty-one participants were randomized to WSM, WSM with group support, WSM with group and expert clinical support, or wait-list control. Perceived stress, burnout, emotional and psychological well-being, mindfulness, and productivity were measured at baseline, weeks 8 and 16, and 1 year. Results: Online usage was low with participants favoring CD use and group practice. All active groups demonstrated significant reductions in perceived stress and increases in emotional and psychological well-being compared with control. Group support improved participation, engagement, and outcomes. Conclusion: A self-directed mindfulness program with group practice and support can provide an affordable, effective, and scalable workplace stress management solution. Engagement may also benefit from combining web-based and traditional CD delivery. PMID:26949875

Protocol: a multi-level intervention program to reduce stress in 9-1-1 telecommunicators.

PubMed

Meischke, Hendrika; Lilly, Michelle; Beaton, Randal; Calhoun, Rebecca; Tu, Ann; Stangenes, Scott; Painter, Ian; Revere, Debra; Baseman, Janet

2018-05-02

Nationwide, emergency response systems depend on 9-1-1 telecommunicators to prioritize, triage, and dispatch assistance to those in distress. 9-1-1 call center telecommunicators (TCs) are challenged by acute and chronic workplace stressors: tense interactions with citizen callers in crisis; overtime; shift-work; ever-changing technologies; and negative work culture, including co-worker conflict. This workforce is also subject to routine exposures to secondary traumatization while handling calls involving emergency situations and while making time urgent, high stake decisions over the phone. Our study aims to test the effectiveness of a multi-part intervention to reduce stress in 9-1-1 TCs through an online mindfulness training and a toolkit containing workplace stressor reduction resources. The study employs a randomized controlled trial design with three data collection points. The multi-part intervention includes an individual-level online mindfulness training and a call center-level organizational stress reduction toolkit. 160 TCs will be recruited from 9-1-1 call centers, complete a baseline survey at enrollment, and are randomly assigned to an intervention or a control group. Intervention group participants will start a 7-week online mindfulness training developed in-house and tailored to 9-1-1 TCs and their call center environment; control participants will be "waitlisted" and start the training after the study period ends. Following the intervention group's completion of the mindfulness training, all participants complete a second survey. Next, the online toolkit with call-center wide stress reduction resources is made available to managers of all participating call centers. After 3 months, a third survey will be completed by all participants. The primary outcome is 9-1-1 TCs' self-reported symptoms of stress at three time points as measured by the C-SOSI (Calgary Symptoms of Stress Inventory). Secondary outcomes will include: perceptions of social work environment (measured by metrics of social support and network conflict); mindfulness; and perceptions of social work environment and mindfulness as mediators of stress reduction. This study will evaluate the effectiveness of an online mindfulness training and call center-wide stress reduction toolkit in reducing self-reported stress in 9-1-1 TCs. The results of this study will add to the growing body of research on worksite stress reduction programs. ClinicalTrials.gov Registration Number: NCT02961621 Registered on November 7, 2016 (retrospectively registered).

Effects of behavioral stress reduction Transcendental Meditation intervention in Persons with HIV

PubMed Central

Chhatre, Sumedha; Metzger, David S.; Frank, Ian; Boyer, Jean; Thompson, Edward; Nidich, Sanford; Montaner, Luis J.; Jayadevappa, Ravishankar

2013-01-01

Stress is implicated in the pathogenesis and progression of HIV. The Transcendental Meditation is a behavioral stress reduction program that incorporates mind-body approach, and has demonstrated effectiveness in improving outcomes via stress reduction. We evaluated the feasibility of implementing Transcendental Meditation and its effects on outcomes in persons with HIV. In this community based single blinded Phase-I, randomized controlled trial, outcomes (psychological and physiological stress, immune activation, generic and HIV-specific health related quality of life, depression and quality of well-being) were assessed at baseline and at six months, and were compared using parametric and non-parametric tests. Twenty two persons with HIV were equally randomized to Transcendental Meditation intervention or healthy eating (HE) education control group. Retention was 100% in Transcendental Meditation group and 91% in healthy eating control group. The Transcendental Meditation group exhibited significant improvement in vitality. Significant between group differences were observed for generic and HIV-specific health related quality of life.. Small sample size may possibly limit the ability to observe significant differences in some outcomes. Transcendental Meditation stress reduction intervention in community dwelling adults with HIV is viable and can enhance health related quality of life. Further research with large sample and longer follow-up is needed to validate our results. PMID:23394825

Time Savings and Surgery Task Load Reduction in Open Intraperitoneal Onlay Mesh Fixation Procedure.

PubMed

Roy, Sanjoy; Hammond, Jeffrey; Panish, Jessica; Shnoda, Pullen; Savidge, Sandy; Wilson, Mark

2015-01-01

This study assessed the reduction in surgeon stress associated with savings in procedure time for mechanical fixation of an intraperitoneal onlay mesh (IPOM) compared to a traditional suture fixation in open ventral hernia repair. Nine general surgeons performed 36 open IPOM fixation procedures in porcine model. Each surgeon conducted two mechanical (using ETHICON SECURESTRAP ™ Open) and two suture fixation procedures. Fixation time was measured using a stopwatch, and related surgeon stress was assessed using the validated SURG-TLX questionnaire. T-tests were used to compare between-group differences, and a two-sided 95% confidence interval for the difference in stress levels was established using nonparametric methodology. The mechanical fixation group demonstrated an 89.1% mean reduction in fixation time, as compared to the suture group (p < 0.00001). Surgeon stress scores measured using SURG-TLX were 55.5% lower in the mechanical compared to the suture fixation group (p < 0.001). Scores in five of the six sources of stress were significantly lower for mechanical fixation. Mechanical fixation with ETHICON SECURESTRAP ™ Open demonstrated a significant reduction in fixation time and surgeon stress, which may translate into improved operating efficiency, improved performance, improved surgeon quality of life, and reduced overall costs of the procedure.

Time Savings and Surgery Task Load Reduction in Open Intraperitoneal Onlay Mesh Fixation Procedure

PubMed Central

Roy, Sanjoy; Hammond, Jeffrey; Panish, Jessica; Shnoda, Pullen; Savidge, Sandy; Wilson, Mark

2015-01-01

Background. This study assessed the reduction in surgeon stress associated with savings in procedure time for mechanical fixation of an intraperitoneal onlay mesh (IPOM) compared to a traditional suture fixation in open ventral hernia repair. Study Design. Nine general surgeons performed 36 open IPOM fixation procedures in porcine model. Each surgeon conducted two mechanical (using ETHICON SECURESTRAPTM Open) and two suture fixation procedures. Fixation time was measured using a stopwatch, and related surgeon stress was assessed using the validated SURG-TLX questionnaire. T-tests were used to compare between-group differences, and a two-sided 95% confidence interval for the difference in stress levels was established using nonparametric methodology. Results. The mechanical fixation group demonstrated an 89.1% mean reduction in fixation time, as compared to the suture group (p < 0.00001). Surgeon stress scores measured using SURG-TLX were 55.5% lower in the mechanical compared to the suture fixation group (p < 0.001). Scores in five of the six sources of stress were significantly lower for mechanical fixation. Conclusions. Mechanical fixation with ETHICON SECURESTRAPTM Open demonstrated a significant reduction in fixation time and surgeon stress, which may translate into improved operating efficiency, improved performance, improved surgeon quality of life, and reduced overall costs of the procedure. PMID:26240834

Comparison of the effects of Korean mindfulness-based stress reduction, walking, and patient education in diabetes mellitus.

PubMed

Jung, Hee Young; Lee, Haejung; Park, Jina

2015-12-01

The purpose of this study was to compare the effects of Korean mindfulness-based stress reduction (K-MBSR), walking, and patient education regarding diabetes mellitus (DM) on stress response, glycemic control, and vascular inflammation in patients with diabetes mellitus. A cluster randomized trial including 56 adults with diabetes mellitus (K-MBSR group = 21, walking group = 18, patient education group = 17) was conducted between 13 July and 14 September 2012. The questionnaire included the Diabetes Distress Scale and Perceived Stress Response Inventory. Fasting blood samples were used to measure levels of cortisol, blood glucose, plasminogen activator inhibitor-1 (PAI-1), and tissue plasminogen activator (t-PA). There were no statistically significant differences between the effects of K-MBSR, walking, and patient education on stress, glycemic control, or vascular inflammation. However, in the K-MBSR and walking groups, significant reductions in the levels of serum cortisol and PAI-1 were observed. A significant reduction in psychological responses to stress was observed in the walking and patient education groups. Longitudinal studies could provide better insight into the impact of K-MBSR, walking, and patient education on health outcomes in adults with diabetes mellitus. © 2015 Wiley Publishing Asia Pty Ltd.

Discrete element analysis is a valid method for computing joint contact stress in the hip before and after acetabular fracture.

PubMed

Townsend, Kevin C; Thomas-Aitken, Holly D; Rudert, M James; Kern, Andrew M; Willey, Michael C; Anderson, Donald D; Goetz, Jessica E

2018-01-23

Evaluation of abnormalities in joint contact stress that develop after inaccurate reduction of an acetabular fracture may provide a potential means for predicting the risk of developing post-traumatic osteoarthritis. Discrete element analysis (DEA) is a computational technique for calculating intra-articular contact stress distributions in a fraction of the time required to obtain the same information using the more commonly employed finite element analysis technique. The goal of this work was to validate the accuracy of DEA-computed contact stress against physical measurements of contact stress made in cadaveric hips using Tekscan sensors. Four static loading tests in a variety of poses from heel-strike to toe-off were performed in two different cadaveric hip specimens with the acetabulum intact and again with an intentionally malreduced posterior wall acetabular fracture. DEA-computed contact stress was compared on a point-by-point basis to stress measured from the physical experiments. There was good agreement between computed and measured contact stress over the entire contact area (correlation coefficients ranged from 0.88 to 0.99). DEA-computed peak contact stress was within an average of 0.5 MPa (range 0.2-0.8 MPa) of the Tekscan peak stress for intact hips, and within an average of 0.6 MPa (range 0-1.6 MPa) for fractured cases. DEA-computed contact areas were within an average of 33% of the Tekscan-measured areas (range: 1.4-60%). These results indicate that the DEA methodology is a valid method for accurately estimating contact stress in both intact and fractured hips. Copyright © 2017 Elsevier Ltd. All rights reserved.

Assessment of current state of the art in modeling techniques and analysis methods for large space structures

NASA Technical Reports Server (NTRS)

Noor, A. K.

1983-01-01

Advances in continuum modeling, progress in reduction methods, and analysis and modeling needs for large space structures are covered with specific attention given to repetitive lattice trusses. As far as continuum modeling is concerned, an effective and verified analysis capability exists for linear thermoelastic stress, birfurcation buckling, and free vibration problems of repetitive lattices. However, application of continuum modeling to nonlinear analysis needs more development. Reduction methods are very effective for bifurcation buckling and static (steady-state) nonlinear analysis. However, more work is needed to realize their full potential for nonlinear dynamic and time-dependent problems. As far as analysis and modeling needs are concerned, three areas are identified: loads determination, modeling and nonclassical behavior characteristics, and computational algorithms. The impact of new advances in computer hardware, software, integrated analysis, CAD/CAM stems, and materials technology is also discussed.

The Feasibility and Impact of Delivering a Mind-Body Intervention in a Virtual World

PubMed Central

Hoch, Daniel B.; Watson, Alice J.; Linton, Deborah A.; Bello, Heather E.; Senelly, Marco; Milik, Mariola T.; Baim, Margaret A.; Jethwani, Kamal; Fricchione, Gregory L.; Benson, Herbert; Kvedar, Joseph C.

2012-01-01

Introduction Mind-body medical approaches may ameliorate chronic disease. Stress reduction is particularly helpful, but face-to-face delivery systems cannot reach all those who might benefit. An online, 3-dimensional virtual world may be able to support the rich interpersonal interactions required of this approach. In this pilot study, we explore the feasibility of translating a face-to-face stress reduction program into an online virtual setting and estimate the effect size of the intervention. Methods and Findings Domain experts in virtual world technology joined with mind body practitioners to translate an existing 8 week relaxation response-based resiliency program into an 8-week virtual world-based program in Second Life™ (SL). Twenty-four healthy volunteers with at least one month's experience in SL completed the program. Each subject filled out the Perceived Stress Scale (PSS) and the Symptom Checklist 90- Revised (SCL-90-R) before and after taking part. Participants took part in one of 3 groups of about 10 subjects. The participants found the program to be helpful and enjoyable. Many reported that the virtual environment was an excellent substitute for the preferred face-to-face approach. On quantitative measures, there was a general trend toward decreased perceived stress, (15.7 to 15.0), symptoms of depression, (57.6 to 57.0) and anxiety (56.8 to 54.8). There was a significant decrease of 2.8 points on the SCL-90-R Global Severity Index (p<0.05). Conclusions This pilot project showed that it is feasible to deliver a typical mind-body medical intervention through a virtual environment and that it is well received. Moreover, the small reduction in psychological distress suggests further research is warranted. Based on the data collected for this project, a randomized trial with less than 50 subjects would be appropriately powered if perceived stress is the primary outcome. PMID:22470483

5 Things You Should Know: The Science of Chronic Pain and Complementary Health Practices

MedlinePlus

... some evidence that mindfulness-based stress reduction and cognitive-behavioral therapy improves pain and functional limitation compared to usual ... pain found that mindfulness-based stress reduction and cognitive-behavioral therapy resulted in greater improvement in pain and functional ...

Long-Term Occupational Stress Is Associated with Regional Reductions in Brain Tissue Volumes

PubMed Central

Blix, Eva; Perski, Aleksander; Berglund, Hans; Savic, Ivanka

2013-01-01

There are increasing reports of cognitive and psychological declines related to occupational stress in subjects without psychiatric premorbidity or major life trauma. The underlying neurobiology is unknown, and many question the notion that the described disabilities represent a medical condition. Using PET we recently found that persons suffering from chronic occupational stress had limbic reductions in the 5-HT1A receptor binding potential. Here we examine whether chronic work-related stress is also associated with changes in brain structure. We performed MRI-based voxel-based morphometry and structural volumetry in stressed subjects and unstressed controls focusing on gray (GM) and white matter (WM) volumes, and the volumes of hippocampus, caudate, and putamen – structures known to be susceptible to neurotoxic changes. Stressed subjects exhibited significant reductions in the GM volumes of the anterior cingulate cortex and the dorsolateral prefrontal cortex. Furthermore, their caudate and putamen volumes were reduced, and the volumes correlated inversely to the degree of perceived stress. Our results add to previous data on chronic psychosocial stress, and indicate a morphological involvement of the frontostriatal circuits. The present findings of morphological changes in these regions confirm our previous conclusion that symptoms from occupational stress merit careful investigations and targeted treatment. PMID:23776438

A Stress Management Primer for College Administrators.

ERIC Educational Resources Information Center

Cloud, Robert C.

1991-01-01

A discussion of stress and college administrators looks at two types of stress (eustress and distress), stress and the autonomic nervous system, the need for regular exercise as well as stress reduction activities, the influence of personality on stress, the sources and stages of burnout, and stress management for administrators. (MSE)

Executive Well-Being: Stress and Administrators.

ERIC Educational Resources Information Center

Giammatteo, Michael C.; Giammatteo, Dolores M.

This booklet explains the meaning and sources of stress, presents a model differentiating among several approaches to dealing with stress, and offers advice and self-help exercises to aid in alleviating the causes of stress. Each chapter topic is a component of the stress alleviation model: stress awareness, tolerance, stress reduction, and stress…

Stress reduction in an isotropic plate with a hole by applied induced strains

NASA Technical Reports Server (NTRS)

Sensharma, Pradeep K.; Palantera, Markku J.; Haftka, Raphael T.

1992-01-01

Recently there has been much interest in adaptive structures that can respond to a varying environment by changing their properties. Shape memory alloys and piezoelectric materials can be used as induced strain actuators to reduce stresses in the regions of stress concentration. The objective of the work was to find the maximum possible reduction in the stress concentration factor in an isotropic plate with a hole by applying induced strains in a small area near the hole. Induced strains were simulated by thermal expansion.

Conductivity Evolution of Fracture Proppant in Partial Monolayers and Multilayers

NASA Astrophysics Data System (ADS)

Fan, M.; Han, Y.; McClure, J. E.; Chen, C.

2017-12-01

Proppant is a granular material, typically sand, coated sand, or man-made ceramic materials, which is widely used in hydraulic fracturing to keep the induced fractures open. Optimization of proppant placement in a hydraulic fracture, as well as its role on the fracture's conductivity, is vital for effective and economical production of petroleum hydrocarbons. In this research, a numerical modeling approach, combining Discrete Element Method (DEM) with lattice Boltzmann (LB) method, was adopted to advance the understanding of fracture conductivity as function of proppant concentration under various effective stresses. DEM was used to simulate effective stress increase and the resultant proppant particle compaction and rearrangement during the process of reservoir depletion due to hydrocarbon extraction. DEM-simulated pore structure was extracted and imported into the LB simulator as boundary conditions to calculate the time-dependent permeability of the proppant pack. We first validated the DEM-LB coupling workflow; the simulated proppant pack permeabilities as functions of effective stress were in good agreement with laboratory measurements. Next, several proppant packs were generated with various proppant concentrations, ranging from partial-monolayer to multilayer structures. Proppant concentration is defined as proppant mass per unit fracture face area. Fracture conductivity as function of proppant concentration was measured in LB simulations. It was found that a partial-monolayer proppant pack with large-diameter particles was optimal in maintaining sufficient conductivity while lowering production costs. Three proppant packs with the same average diameter but different diameter distributions were generated. Specifically, we used the coefficient of variation (COV) of diameter, defined as the ratio of standard deviation of diameter to mean diameter, to characterize the heterogeneity in particle size. We obtained proppant pack porosity, permeability, and fracture width reduction as functions of effective stress. Under the same effective stress, a proppant pack with a smaller diameter COV had higher porosity and permeability and smaller fracture width reduction, which are all favorable for maintaining the fracture conductivity during the process of hydrocarbon extraction.

Microstructural evolutions and stress studies of titania films derived by "spin-deposition" methods

NASA Astrophysics Data System (ADS)

Eun, Tai Hee

Titania (TiO2) films were fabricated by a "spin-deposition" process. Titanium alkoxides react with moisture in the air, leading to the formation of metal hydroxides which subsequently form an oxide network during deposition. The microstructure of film is easily controlled by the selection of titanium alkoxides and solvents. Films from titanium n-butoxide (Ti(OC 4H9n)4) in toluene exhibited a dense microstructure devoid of cracks. In contrast, films produced from titanium isopropoxide (Ti(OC3H7i)4) in the toluene regularly contained micro-cracks. Titanium isopropoxide in either isopropanol or n-propanol produces highly porous films. After annealing at 300°C, the film derived from titanium n-butoxide in toluene possessed 2˜3 nm nanocrystallites of titanium monoxide (TiO, cubic) in amorphous matrices. TEM and FTIR investigations indicate that the intermediates formed from the oligomers of titanium n-butoxide lead to the formation of the TiO. By annealing at 400°C, the TiO nanoparticles transformed to the TiO2 (anatase). At annealing higher than 450°C, the film was completely crystallized into a polycrystalline of ˜5 nm anatase. In water-rich environments, all amorphous titania films crystallized within 24 hours at 100°C. The crystallization of films is confirmed by XRD and FTIR studies. Amorphous titania films have remnant bridging and terminal hydroxy groups. Removal of these hydroxy groups is promoted by water vapor, which induces the crystallization of amorphous titania to anatase. The mechanism of crystallization in a water-rich environment was proposed based on the FTIR study. Stress evolution in titania films spin-deposited on silicon with solutions of titanium n-butoxide in toluene was investigated by an in-situ wafer curvature method. Tensile stresses were induced due to the densification by removal of water molecules attached to Ti-O-Ti linkages from 200°C to 300°C. The effect of crystallization on stress in the film was studied by comparing results of oxygen and nitrogen anneals. Compositional stress in anatase (a non-stoichiometric oxide) was measured by cyclic reduction-oxidation experiments performed at 700°C. The state of stress observed under reduction conditions was tensile in nature while compressive stresses evolved under oxidizing conditions. The measured value of the compositional stress of the film is 29.6 MPa.

Experimental analysis and application of the effect of stress on continental shale reservoir brittleness

NASA Astrophysics Data System (ADS)

Yin, Shuai; Lv, Dawei; Jin, Lin; Ding, Wenlong

2018-04-01

Hydraulic fracturing is an effective measure of reservoir modification for the development of shale gas. The evaluation of rock brittleness can provide a basis for the optimization of fracturing. In this paper, the effect of stress on the brittleness of shale is systematically analyzed by designing triaxial mechanics tests. The strain analysis method was used to evaluate the shale brittleness. The research indicates that, with the increase of effective confining pressure, the value of the brittleness index (B 1) decreases. There is a linear and positive correlation between the average reduction ratio of B 1 and the buried depth. The stress has a significant effect on the shale brittleness. Therefore, the rock brittleness can be overestimated without considering the influence of the buried depth or the stress of formation when using the mineral composition method. Being affected by the stress, when the brittle mineral content of the shale reservoir is 70%, 65%, 60%, and 55%, the lower limit depth of the shale gas development is 5000 m, 4400 m, 3000 m, and 1800 m, respectively. However, when the brittle mineral content of the shale is less than 50%, the brittleness index is less than 50% in all of the buried depths. In this case, the shale will not have any commercial development potential. The logging interpretation results of the brittleness index conducted with stress correction are more consistent with the real situation, and thus, this method can be better used to help the optimization of the fracturing intervals of shale gas.

Parks, Recreation and Public Health.

ERIC Educational Resources Information Center

Ho, Ching-Hua; Payne, Laura; Orsega-Smith, Elizabeth; Godbey, Geoffrey

2003-01-01

Reviews what current research says about the holistic health benefits of park and recreation services, focusing on: health benefits according to park users; physical activities in parks; stress reduction benefits of park use; social support, self-determination, and stress reduction; observing nature in parks and associated benefits; and the…

Gear tooth stress measurements of two helicopter planetary stages

NASA Technical Reports Server (NTRS)

Krantz, Timothy L.

1992-01-01

Two versions of the planetary reduction stages from U.S. Army OH-58 helicopter main rotor transmissions were tested at NASA Lewis. One sequential and one nonsequential planetary were tested. Sun gear and ring gear teeth strains were measured, and stresses were calculated from the strains. The alternating stress at the fillet of both the loaded and unloaded sides of the teeth and at the root of the sun gear teeth are reported. Typical stress variations as the gear tooth moves through mesh are illustrated. At the tooth root location of the thin rimmed sun gear, a significant stress was produced by a phenomenon other than the passing of a planet gear. The load variation among the planets was studied. Each planet produced its own distinctive load distribution on the ring and sun gears. The load variation was less for a three planet, nonsequential design as compared to that of a four planet, sequential design. The reported results enhance the data base for gear stress levels and provide data for the validation of analytical methods.

Stress ratio effects in fatigue of lost foam cast aluminum alloy 356

NASA Astrophysics Data System (ADS)

Palmer, David E.

Lost foam casting is a highly versatile metalcasting process that offers significant benefits in terms of design flexibility, energy consumption, and environmental impact. In the present work, the fatigue behavior of lost foam cast aluminum alloy 356, in conditions T6 and T7, was investigated, under both zero and non-zero mean stress conditions, with either as-cast or machined surface finish. Scanning electron microscopy was used to identify and measure the defect from which fatigue fracture initiated. Based on the results, the applicability of nine different fatigue mean stress equations was compared. The widely-used Goodman equation was found to be highly non-conservative, while the Stulen, Topper-Sandor, and Walker equations performed reasonably well. Each of these three equations includes a material-dependent term for stress ratio sensitivity. The stress ratio sensitivity was found to be affected by heat treatment, with the T6 condition having greater sensitivity than the T7 condition. The surface condition (as-cast vs. machined) did not significantly affect the stress ratio sensitivity. The fatigue life of as-cast specimens was found to be approximately 60--70% lower than that of machined specimens at the same equivalent stress. This reduction could not be attributed to pore size alone, and is suspected to be due to the greater concentration of pyrolysis products at the as-cast surface. Directions for future work, including improved testing methods and some possible methods of improving the properties of lost foam castings, are discussed.

Hypnosis in patients with perceived stress - a systematic review.

PubMed

Fisch, S; Brinkhaus, B; Teut, M

2017-06-19

Although hypnosis and hypnotherapy have become more popular in recent years, the evidence for hypnosis to influence perceived stress is unclear. In this systematic review we searched and evaluated randomized clinical studies investigating the effect of hypnosis on perceived stress reduction and coping. The Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, the Database of Abstracts of Review of Effects, EMBASE, Medline, PsycINFO, PSYNDEX and PubMed were systematically screened from their inception until December 2015 for randomized controlled trials (RCTs) reporting about hypnosis or hypnotherapy for stress reduction in healthy participants. Risk of Bias was assessed according the Cochrane Collaboration recommendations. Nine RCTs with a total of 365 participants met the inclusion criteria and were included in this review. Most included participants were medical students, predominantly female (n = 211). Mean age of participants ranged in most studies between 20 and 25 years, in three studies the mean ages were between 30 and 42 years. Perceived stress was measured by a wide range of psychological questionnaires including Face Valid Stress Test, Stress Thermometer, and immunological data was collected. All nine included studies used explorative designs and showed a high risk of bias. Six out of nine studies reported significant positive effects of hypnosis for stress reduction in the main outcome parameter compared to control groups (3 active controls, 3 no therapy controls). Immunological outcomes were assessed in six studies, the results were inconclusive. Due to exploratory designs and high risk of bias, the effectiveness of hypnosis or hypnotherapy in stress reduction remains still unclear. More high quality clinical research is urgently needed.

Influence of external mechanical stress on electrical properties of single-crystal n-3C-SiC/p-Si heterojunction diode

NASA Astrophysics Data System (ADS)

Qamar, Afzaal; Veit Dao, Dzung; Tanner, Philip; Phan, Hoang-Phuong; Dinh, Toan; Dimitrijev, Sima

2015-06-01

This article reports for the first time the electrical properties of fabricated n-3C-SiC/p-Si heterojunction diodes under external mechanical stress in the [110] direction. An anisotype heterojunction diode of n-3C-SiC/p-Si was fabricated by depositing 3C-SiC onto the Si substrate by low-pressure chemical vapor deposition. The mechanical stress significantly affected the scaling current density of the heterojunction. The scaling current density increases with stress and is explained in terms of a band offset reduction at the SiC/Si interface under applied stress. A reduction in the barrier height across the junction owing to applied stress is also explained quantitatively.

Strain Rate Behavior of HTPB-Based Magnetorheological Materials

NASA Astrophysics Data System (ADS)

Stoltz, Chad; Seminuk, Kenneth; Joshi, Vasant

2013-06-01

It is of particular interest to determine whether the mechanical properties of binder systems can be manipulated by adding ferrous or Magnetostrictive particulates. Strain rate response of two HTPB/Fe (Hydroxyl-terminated Polybutadiene/Iron) compositions under electromagnetic fields has been investigated using a Split Hopkinson Pressure bar arrangement equipped with aluminum bars. Two HTPB/Fe compositions were developed, the first without plasticizer and the second containing plasticizer. Samples were tested with and without the application of a 0.01 Tesla magnetic field coil. Strain gauge data taken from the Split Hopkinson Pressure bar has been used to determine what mechanical properties were changed by inducing a mild electromagnetic field onto each sample. The data reduction method to obtain stress-strain plots included dispersion corrections for deciphering minute changes due to compositional alterations. Data collected from the Split Hopkinson Pressure bar indicate changes in the Mechanical Stress-Strain curves and suggest that the impedance of a binder system can be altered by means of a magnetic field. We acknowledge the Defense Threat Reduction Agency for funding.

Urban Teacher Stress: A Critical Literature Review.

ERIC Educational Resources Information Center

Goodman, Victor Brian

This review of literature on stress among teachers in urban schools examines the stress concept as it is defined in medicine, psychology, and teaching; causes of teacher stress; the nature of the stress response in teachers; ways of coping with stress and the effects of various stress reduction techniques; economic and educational costs of teacher…

Wall relaxation in growing stems: comparison of four species and assessment of measurement techniques

NASA Technical Reports Server (NTRS)

Cosgrove, D. J.

1987-01-01

This study was carried out to develop improved methods for measuring in-vivo stress relaxation of growing tissues and to compare relaxation in the stems of four different species. When water uptake by growing tissue is prevented, in-vivo stress relaxation occurs because continued wall loosening reduces wall stress and cell turgor pressure. With this procedure one may measure the yield threshold for growth (Y), the turgor pressure in excess of the yield threshold (P-Y), and the physiological wall extensibility (phi). Three relaxation techniques proved useful: "turgor-relaxation", "balance-pressure" and "pressure-block". In the turgor-relaxation method, water is withheld from growing tissue and the reduction in turgor is measured directly with the pressure probe. This technique gives absolute values for P and Y, but requires tissue excision. In the balance-pressure technique, the excised growing region is sealed in a pressure chamber, and the subsequent reduction in water potential is measured as the applied pressure needed to return xylem sap to the cut surface. This method is simple, but only measures (P-Y), not the individual values of P and Y. In the pressure-block technique, the growing tissue is sealed into a pressure chamber, growth is monitored continuously, and just sufficient pressure is applied to the chamber to block growth. The method gives high-resolution kinetics of relaxation and does not require tissue excision, but only measures (P-Y). The three methods gave similar results when applied to the growing stems of pea (Pisum sativum L.), cucumber (Cucumis sativus L.), soybean (Glycine max (L.) Merr.) and zucchini (Curcubita pepo L.) seedlings. Values for (P-Y) averaged between 1.4 and 2.7 bar, depending on species. Yield thresholds averaged between 1.3 and 3.0 bar. Compared with the other methods, relaxation by pressure-block was faster and exhibited dynamic changes in wall-yielding properties. The two pressure-chamber methods were also used to measure the internal water-potential gradient (between the xylem and the epidermis) which drives water uptake for growth. For the four species it was small, between 0.3 and 0.6 bar, and so did not limit growth substantially.

Mechanical and hydraulic properties of Nankai accretionary prism sediments: Effect of stress path

NASA Astrophysics Data System (ADS)

Kitajima, Hiroko; Chester, Frederick M.; Biscontin, Giovanna

2012-10-01

We have conducted triaxial deformation experiments along different loading paths on prism sediments from the Nankai Trough. Different load paths of isotropic loading, uniaxial strain loading, triaxial compression (at constant confining pressure, Pc), undrained Pc reduction, drained Pc reduction, and triaxial unloading at constant Pc, were used to understand the evolution of mechanical and hydraulic properties under complicated stress states and loading histories in accretionary subduction zones. Five deformation experiments were conducted on three sediment core samples for the Nankai prism, specifically from older accreted sediments at the forearc basin, underthrust slope sediments beneath the megasplay fault, and overthrust Upper Shikoku Basin sediments along the frontal thrust. Yield envelopes for each sample were constructed based on the stress paths of Pc-reduction using the modified Cam-clay model, and in situ stress states of the prism were constrained using the results from the other load paths and accounting for horizontal stress. Results suggest that the sediments in the vicinity of the megasplay fault and frontal thrust are highly overconsolidated, and thus likely to deform brittle rather than ductile. The porosity of sediments decreases as the yield envelope expands, while the reduction in permeability mainly depends on the effective mean stress before yield, and the differential stress after yield. An improved understanding of sediment yield strength and hydromechanical properties along different load paths is necessary to treat accurately the coupling of deformation and fluid flow in accretionary subduction zones.

The contribution of changes in diet, exercise, and stress management to changes in coronary risk in women and men in the multisite cardiac lifestyle intervention program.

PubMed

Daubenmier, Jennifer J; Weidner, Gerdi; Sumner, Michael D; Mendell, Nancy; Merritt-Worden, Terri; Studley, Joli; Ornish, Dean

2007-02-01

The relative contribution of health behaviors to coronary risk factors in multicomponent secondary coronary heart disease (CHD) prevention programs is largely unknown. Our purpose is to evaluate the additive and interactive effects of 3-month changes in health behaviors (dietary fat intake, exercise, and stress management) on 3-month changes in coronary risk and psychosocial factors among 869 nonsmoking CHD patients (34% female) enrolled in the health insurance-based Multisite Cardiac Lifestyle Intervention Program. Analyses of variance for repeated measures were used to analyze health behaviors, coronary risk factors, and psychosocial factors at baseline and 3 months. Multiple regression analyses evaluated changes in dietary fat intake and hours per week of exercise and stress management as predictors of changes in coronary risk and psychosocial factors. Significant overall improvement in coronary risk was observed. Reductions in dietary fat intake predicted reductions in weight, total cholesterol, low-density lipoprotein cholesterol, and interacted with increased exercise to predict reductions in perceived stress. Increases in exercise predicted improvements in total cholesterol and exercise capacity (for women). Increased stress management was related to reductions in weight, total cholesterol/high-density lipoprotein cholesterol (for men), triglycerides, hemoglobin A1c (in patients with diabetes), and hostility. Improvements in dietary fat intake, exercise, and stress management were individually, additively and interactively related to coronary risk and psychosocial factors, suggesting that multicomponent programs focusing on diet, exercise, and stress management may benefit patients with CHD.

Combining walking and relaxation for stress reduction-A randomized cross-over trial in healthy adults.

PubMed

Matzer, Franziska; Nagele, Eva; Lerch, Nikolaus; Vajda, Christian; Fazekas, Christian

2018-04-01

Both physical activity and relaxation have stress-relieving potential. This study investigates their combined impact on the relaxation response while considering participants' initial stress level. In a randomized cross-over trial, 81 healthy adults completed 4 types of short-term interventions for stress reduction, each lasting for 1 hr: (1) physical activity (walking) combined with resting, (2) walking combined with balneotherapy, (3) combined resting and balneotherapy, and (4) resting only. Saliva cortisol, blood pressure, state of mood, and relaxation were measured preintervention and postintervention. Stress levels were determined by validated questionnaires. All interventions were associated with relaxation responses in the variables saliva cortisol, blood pressure, state of mood, and subjective relaxation. No significant differences were found regarding the reduction of salivary cortisol (F = 1.30; p = .281). The systolic blood pressure was reduced best when walking was combined with balneotherapy or resting (F = 7.34; p < .001). Participants with high stress levels (n = 25) felt more alert after interventions including balneotherapy, whereas they reported an increase of tiredness when walking was combined with resting (F = 3.20; p = .044). Results suggest that combining physical activity and relaxation (resting or balneotherapy) is an advantageous short-term strategy for stress reduction as systolic blood pressure is reduced best while similar levels of relaxation can be obtained. Copyright © 2017 John Wiley & Sons, Ltd.

Effectiveness of Mindfulness-Based Stress Reduction Bibliotherapy: A Preliminary Randomized Controlled Trial.

PubMed

Hazlett-Stevens, Holly; Oren, Yelena

2017-06-01

This randomized controlled investigation examined the effectiveness of a self-help bibliotherapy format of the evidence-based mindfulness-based stress reduction (MBSR) intervention. College students seeking stress reduction were randomly assigned to a 10-week MBSR bibliotherapy intervention group (n = 47) or a no-treatment control group (n = 45). Self-report measures were collected at baseline and postintervention. A total of 25 bibliotherapy and 43 control group participants provided final data following the intervention period. Compared to the control group, bibliotherapy participants reported increased mindfulness following the intervention. Significant decreases on measures of depression, anxiety, stress, perceived stress, and anxiety sensitivity also were reported postintervention as well as increased quality of life in physical health, psychological, and environmental domains. No statistically significant group effects were found for social relationships quality of life domain, worry, and experiential avoidance measures. This MBSR workbook may provide an acceptable and effective alternative for motivated individuals seeking to reduce stress, at least for a select group of individuals who are willing and able to sustain participation in the intervention. © 2016 Wiley Periodicals, Inc.

Interference Fit Life Factors for Roller Bearings

NASA Technical Reports Server (NTRS)

Oswald, Fred B.; Zaretsky, Erwin V.; Poplawski, Joseph V.

2008-01-01

The effect of hoop stresses in reducing cylindrical roller bearing fatigue life was determined for various classes of inner ring interference fit. Calculations were performed for up to seven interference fit classes for each of ten bearing sizes. Each fit was taken at tightest, average and loosest values within the fit class for RBEC-5 tolerance, thus requiring 486 separate analyses. The hoop stresses were superimposed on the Hertzian principal stresses created by the applied radial load to calculate roller bearing fatigue life. The method was developed through a series of equations to calculate the life reduction for cylindrical roller bearings based on interference fit. All calculated lives are for zero initial bearing internal clearance. Any reduction in bearing clearance due to interference fit was compensated by increasing the initial (unmounted) clearance. Results are presented as tables and charts of life factors for bearings with light, moderate and heavy loads and interference fits ranging from extremely light to extremely heavy and for bearing accuracy class RBEC 5 (ISO class 5). Interference fits on the inner bearing ring of a cylindrical roller bearing can significantly reduce bearing fatigue life. In general, life factors are smaller (lower life) for bearings running under light load where the unfactored life is highest. The various bearing series within a particular bore size had almost identical interference fit life factors for a particular fit. The tightest fit at the high end of the RBEC-5 tolerance band defined in ANSI/ABMA shaft fit tables produces a life factor of approximately 0.40 for an inner-race maximum Hertz stress of 1200 MPa (175 ksi) and a life factor of 0.60 for an inner-race maximum Hertz stress of 2200 MPa (320 ksi). Interference fits also impact the maximum Hertz stress-life relation.

Z-Guggulsterone Produces Antidepressant-Like Effects in Mice through Activation of the BDNF Signaling Pathway

PubMed Central

Liu, Feng-Guo; Hu, Wen-Feng; Wang, Ji-Li; Wang, Peng; Gong, Yu; Tong, Li-Juan; Jiang, Bo; Zhang, Wei; Qin, Yi-Bin; Chen, Zhuo

2017-01-01

Abstract Background: Z-guggulsterone, an active compound extracted from the gum resin of the tree Commiphora mukul, has been shown to improve animal memory deficits via activating the brain-derived neurotrophic factor signaling pathway. Here, we investigated the antidepressant-like effect of Z-guggulsterone in a chronic unpredictable stress mouse model of depression. Methods: The effects of Z-guggulsterone were assessed in mice with the tail suspension test and forced swimming test. Z-guggulsterone was also investigated in the chronic unpredictable stress model of depression with fluoxetine as the positive control. Changes in hippocampal neurogenesis as well as the brain-derived neurotrophic factor signaling pathway after chronic unpredictable stress/Z-guggulsterone treatment were investigated. The tryptophan hydroxylase inhibitor and the tyrosine kinase B inhibitor were also used to explore the antidepressant-like mechanisms of Z-guggulsterone. Results: Z-guggulsterone (10, 30 mg/kg) administration protected the mice against the chronic unpredictable stress-induced increases in the immobile time in the tail suspension test and forced swimming test and also reversed the reduction in sucrose intake in sucrose preference experiment. Z-guggulsterone (10, 30 mg/kg) administration prevented the reductions in brain-derived neurotrophic factor protein expression levels as well as the phosphorylation levels of cAMP response element binding protein, extracellular signal-regulated kinase 1/2, and protein kinase B in the hippocampus and cortex induced by chronic unpredictable stress. Z-guggulsterone (10, 30 mg/kg) treatment also improved hippocampal neurogenesis in chronic unpredictable stress-treated mice. Blockade of the brain-derived neurotrophic factor signal, but not the monoaminergic system, attenuated the antidepressant-like effects of Z-guggulsterone. Conclusions: Z-guggulsterone exhibits antidepressant activity via activation of the brain-derived neurotrophic factor signaling pathway and upregulation of hippocampal neurogenesis. PMID:28339691

Increased reactive oxygen species production during reductive stress: The roles of mitochondrial glutathione and thioredoxin reductases.

PubMed

Korge, Paavo; Calmettes, Guillaume; Weiss, James N

2015-01-01

Both extremes of redox balance are known to cause cardiac injury, with mounting evidence revealing that the injury induced by both oxidative and reductive stress is oxidative in nature. During reductive stress, when electron acceptors are expected to be mostly reduced, some redox proteins can donate electrons to O2 instead, which increases reactive oxygen species (ROS) production. However, the high level of reducing equivalents also concomitantly enhances ROS scavenging systems involving redox couples such as NADPH/NADP+ and GSH/GSSG. Here our objective was to explore how reductive stress paradoxically increases net mitochondrial ROS production despite the concomitant enhancement of ROS scavenging systems. Using recombinant enzymes and isolated permeabilized cardiac mitochondria, we show that two normally antioxidant matrix NADPH reductases, glutathione reductase and thioredoxin reductase, generate H2O2 by leaking electrons from their reduced flavoprotein to O2 when electron flow is impaired by inhibitors or because of limited availability of their natural electron acceptors, GSSG and oxidized thioredoxin. The spillover of H2O2 under these conditions depends on H2O2 reduction by peroxiredoxin activity, which may regulate redox signaling in response to endogenous or exogenous factors. These findings may explain how ROS production during reductive stress overwhelms ROS scavenging capability, generating the net mitochondrial ROS spillover causing oxidative injury. These enzymes could potentially be targeted to increase cancer cell death or modulate H2O2-induced redox signaling to protect the heart against ischemia/reperfusion damage. Copyright © 2015 Elsevier B.V. All rights reserved.

Evaluation of the Effect of Surface Finish on High-Cycle Fatigue for SLM-IN718

NASA Technical Reports Server (NTRS)

Lambert, Dennis M.

2016-01-01

A high-cycle fatigue (HCF) knockdown factor was estimated for Inconel 718, manufactured with the selective laser melt (SLM) process. This factor is the reduction at a common fatigue life from the maximum stress in fatigue for low-stress ground (LSG) specimens to the maximum stress of those left with the original surface condition. Various vendors provided specimens. To reduce the number of degrees-of-freedom, only one heat treat condition was evaluated. Testing temperatures included room temperature, 800F, 1000F, and 1200F. The two surface conditions were compared at constant lives, where data was available. The recommended knockdown factor of the as-built surface condition (average roughness of approximately 245 micro-inches/inch) versus low-stress ground condition (roughness <= 4 micro-inches/inch) is approximately 1/3 or 33%. This is to say that for the as-built surface condition, a maximum stress of 2/3 of the stress for LSG can be expected to produce the same life in the as built surface condition. As an alternative method, the surface finish was incorporated into a new parameter with the maximum stress. The new parameter was formulated to be similar to the fracture mechanics stress intensity factor, and it was named the pseudo stress intensity factor, Kp. Using Kp, the variance seemed acceptable across all sources, and the knockdown factor was estimated over the range of data identified by Kp where data occurred. A plot of the results suggests that the knockdown factor is a function of temperature, and that for low lives the knockdown is greater than the knockdown observed above about one million cycles, where it stabilizes. One data point at room temperature was clearly different, and the sparsity of data in the higher life region reduces the value of these results. The method does appear to provide useful results, and further characterization of the method is suggested.

Role of leaf hydraulic conductance in the regulation of stomatal conductance in almond and olive in response to water stress.

PubMed

Hernandez-Santana, Virginia; Rodriguez-Dominguez, Celia M; Fernández, J Enrique; Diaz-Espejo, Antonio

2016-06-01

The decrease of stomatal conductance (gs) is one of the prime responses to water shortage and the main determinant of yield limitation in fruit trees. Understanding the mechanisms related to stomatal closure in response to imposed water stress is crucial for correct irrigation management. The loss of leaf hydraulic functioning is considered as one of the major factors triggering stomatal closure. Thus, we conducted an experiment to quantify the dehydration response of leaf hydraulic conductance (Kleaf) and its impact on gs in two Mediterranean fruit tree species, one deciduous (almond) and one evergreen (olive). Our hypothesis was that a higher Kleaf would be associated with a higher gs and that the reduction in Kleaf would predict the reduction in gs in both species. We measured Kleaf in olive and almond during a cycle of irrigation withholding. We also compared the results of two methods to measure Kleaf: dynamic rehydration kinetics and evaporative flux methods. In addition, determined gs, leaf water potential (Ψleaf), vein density, photosynthetic capacity and turgor loss point. Results showed that gs was higher in almond than in olive and so was Kleaf (Kmax = 4.70 and 3.42 mmol s(-1) MPa(-1) m(-2), in almond and olive, respectively) for Ψleaf > -1.2 MPa. At greater water stress levels than -1.2 MPa, however, Kleaf decreased exponentially, being similar for both species, while gs was still higher in almond than in olive. We conclude that although the Kleaf decrease with increasing water stress does not drive unequivocally the gs response to water stress, Kleaf is the variable most strongly related to the gs response to water stress, especially in olive. Other variables such as the increase in abscisic acid (ABA) may be playing an important role in gs regulation, although in our study the gs-ABA relationship did not show a clear pattern. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Children with medical complexity: a scoping review of interventions to support caregiver stress.

PubMed

Edelstein, H; Schippke, J; Sheffe, S; Kingsnorth, S

2017-05-01

Caring for children with chronic and complex medical needs places extraordinary stress on parents and other family members. A scoping review was undertaken to identify and describe the full range of current interventions for reducing caregiver stress. Applying a broad definition of caregiver stress, a systematic search of three scientific databases (CINAHL, Embase and Ovid Medline), a general internet search and hand searching of key peer-reviewed articles were conducted. Inclusion criteria were as follows: (i) published in English between 2004-2016; (ii) focused on familial caregivers, defined as parents, siblings or extended family; (iii) targeted children/youth with medical complexity between the ages of 1-24 years; and (iv) described an intervention and impact on caregiver stress. Data on type of intervention, study design and methods, measures and overall findings were extracted. Forty-nine studies were included from a list of 22 339 unique titles. Six domains of interventions were found: care coordination models (n = 23); respite care (n = 8); telemedicine (n = 5); peer and emotional support (n = 6); insurance and employment benefits (n = 4); and health and related supports (n = 3). Across studies, there was a wide variety of designs, outcomes and measures used. Positive findings of reductions in caregiver stress were noted within an emerging body of evidence on effective interventions for families of children with medical complexity. A commonality across domains was a significant focus on streamlining services and reducing the burden of care related to varied pressures experienced, including time, finances, care needs and service access, among others. There was non-conclusive evidence however around which of the six identified intervention domains or combination thereof are most effective for reducing stress. These promising findings demonstrate that stress reduction is possible with the right support and that multiple interventions may be effective in reducing burdens of care experienced by families of children with medical complexity. © 2016 John Wiley & Sons Ltd.

Photosynthesis and yield reductions from wheat stem sawfly (Hymenoptera: Cephidae): interactions with wheat solidness, water stress, and phosphorus deficiency.

PubMed

Delaney, Kevin J; Weaver, David K; Peterson, Robert K D

2010-04-01

The impact of herbivory on plants is variable and influenced by several factors. The current study examined causes of variation in the impact of larval stem mining by the wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), on spring wheat, Triticum aestivum L. We performed greenhouse experiments over 2 yr to (1) study whether biotic (hollow versus solid stemmed host wheat) and abiotic (water, phosphorus stress) factors interact with C. cinctus stem mining to influence degree of mined stem physiological (photosynthesis) and yield (grain weight) reductions; and (2) determine whether whole plant yield compensatory responses occur to offset stem-mining reductions. Flag leaf photosynthetic reduction was not detected 16-20 d after infestation, but were detected at 40-42 d and doubled from water or phosphorus stresses. Main stem grain weight decreased from 10 to 25% from stem mining, largely due to reductions in grain size, with greater reductions under low phosphorus and/or water levels. Phosphorus-deficient plants without water stress were most susceptible to C. cinctus, more than doubling the grain weight reduction due to larval feeding relative to other water and phosphorus treatments. Two solid stemmed varieties with stem mining had less grain weight loss than a hollow stemmed variety, so greater internal mechanical resistance may reduce larval stem mining and plant yield reductions. Our results emphasize the importance of sufficient water and macronutrients for plants grown in regions impacted by C. cinctus. Also, solid stemmed varieties not only reduce wheat lodging from C. cinctus, they may reduce harvested grain losses from infested stems.

Complementary and Alternative Therapies as Treatment Approaches for Interstitial Cystitis

PubMed Central

Whitmore, Kristene E

2002-01-01

The management of interstitial cystitis (IC) is predominantly the reduction of the symptoms of frequency, urgency, and pain. Multimodal treatment approaches for IC are helpful in customizing therapy for individual patients. Complementary and alternative therapies are a quintessential addition to the therapeutic armamentarium and frequently include dietary modification, nutraceuticals, bladder training, neuromodulation, stress reduction, and sex therapy. Dietary modification involves elimination of bladder irritants, fluid regulation, and a bowel regimen. Nutraceuticals studied for the treatment of IC include calcium glycerophosphate, L-arginine, mucopolysaccharides, bioflavinoids, and Chinese herbs. Bladder training is effective after pain reduction. The neuromodulation of high-tone pelvic-floor muscle dysfunction is achieved with physical therapy and acupuncture. Stress reduction and sex therapy are best administered by a qualified stress manager and sex therapist. Multimodal, nonconventional management may add efficacy to the treatment of IC. PMID:16986031

Posttraumatic stress symptoms and tobacco abstinence effects in a non-clinical sample: evaluating the mediating role of negative affect reduction smoking expectancies.

PubMed

Langdon, Kirsten J; Leventhal, Adam M

2014-11-01

The relation between posttraumatic stress symptoms and smoking is well documented but poorly understood. The present investigation sought to evaluate the impact of posttraumatic stress symptoms on subjective and behavioral tobacco abstinence effects both directly and indirectly through negative affect reduction smoking outcome expectancies. Participants included 275 (68.7% male; Mage =43.9, 10+ cig/day) adult non-treatment seeking smokers, who attended two counterbalanced laboratory sessions (16 h of smoking deprivation vs ad libitum smoking), during which they completed self-report measures of withdrawal symptoms and mood followed by a smoking lapse task in which they could earn money for delaying smoking and purchase cigarettes to smoke. Results supported a mediational pathway whereby higher baseline symptoms of posttraumatic stress predicted greater endorsement of expectancies that smoking will effectively reduce negative affect, which in turn predicted greater abstinence-provoked exacerbations in nicotine withdrawal symptoms and negative affect. Posttraumatic stress symptoms also predicted number of cigarettes purchased independent of negative affect reduction expectancies, but did not predict delaying smoking for money. Findings highlight tobacco abstinence effects as a putative mechanism underlying posttraumatic stress disorder (PTSD)-smoking comorbidity, indicate an important mediating role of beliefs for smoking-induced negative affect reduction, and shed light on integrated treatment approaches for these two conditions. © The Author(s) 2014.

Numerical Study on Stress Heterogeneity Development in Two-Phase Rocks with Large Rheological Contrast and Implications in the Lower Crust

NASA Astrophysics Data System (ADS)

Xu, Junshan; Zhang, Baohua

2018-03-01

Development of stress heterogeneity in two-phase rocks was investigated via a finite element method at 1000-1200 K and 100 MPa. Two groups of rock models were considered: anorthite-diopside and anorthite-clinopyroxene, with a phase volume ratio of 1:1 in each group and different dislocation creep rates between phases ( 4-8 orders of magnitude). Our numerical results indicate that the stress inside the model can be several times higher than the differential stress applied to the model and stress will tend to concentrate in hard phase, especially near the sharp boundaries with soft phase. Moreover, large stress gradient in hard phase and nearly homogeneous stress in soft phase will lead to the initialization of localized dynamic recrystallization or fracture. These numerical observations suggest that the rheological contrast between two phases plays a crucial role in stress heterogeneity rather than other factors (such as grain size, the boundary conditions or mesh density), which may eventually accelerate development of stress heterogeneity in the lower crust. Our study provides new insights into the dynamic processes of grain size reduction in the lower crust, which may cause the transformation from dislocation creep to diffusion creep and enable the weakened shear zones.

The effects of aromatherapy in relieving symptoms related to job stress among nurses.

PubMed

Chen, Miao-Chuan; Fang, Shu-Hui; Fang, Li

2015-02-01

Workplace-related stress has become today's most serious occupational hazard. Aromatherapy is a simple, convenient and non-invasive method of stress relief. There is little research regarding the efficacy of aromatherapy by means of inhaling essential oil in reducing workplace stress-related symptoms among nurses. Therefore, this study was to examine the effectiveness of lavender oil inhalation in reducing job stress-related symptoms among nurses. The 53 nurses in the experimental group pinned small bottles containing 3% lavender oil on the clothes of their right chests, whereas 57 participants in the control group pinned bottles with no lavender oil. Aromatherapy was shown to be effective in the reduction of the number of stress symptoms for 3 or 4 days. The stress symptoms of the experimental group decreased from 6.1 to 2.8 after aromatherapy was carried out (P = 0.126, 0.159, 0.035 and 0.026). This represented a significant decrease in stress, whereas the stress symptoms in the control group increased from 5.6 to 5.8. Hospital staff managers are still encouraged to include aromatherapy concepts and techniques in the continuing education of nursing staff. Concurrently, future research should focus on the possible side effects of aromatherapy to assure safety. © 2013 Wiley Publishing Asia Pty Ltd.

Growth and yield of patchouli (Pogostemon cablin, Benth) due to mulching and method of fertilizer on rain-fed land

NASA Astrophysics Data System (ADS)

Nasruddin; Harahap, E. M.; Hanum, C.; Siregar, L. A. M.

2018-02-01

The drought stress that occurs during growth results in a drastic reduction in growth and yield. This study was aimed to study the effect of mulching and method of fertilizer application in reducing the impact of drought stress on patchouli plants. The experiment was conducted from July to December 2016 using a split plot design into three replications with two treatment factors. The first factor was mulch factor with three levels, i.e. M0 (without mulch), M1 (rice straw mulch) and M2 (silver black plastic mulch). The second factor was the method of fertilizer application consisting of three stages: C1 (once), C2 (twice), C3 (three times). The parameters included plant height, number of branches, number of leaves, root length, wet weight of plant, root canopy ratio, total of chlorophyll, soil temperature and soil moisture content. The results showed the use of straw mulch reduce the impact of drought stress on patchouli plants. Two times fertilizer application gave better growth and yield. The use of straw mulch produced lower temperature degrees and maintained soil moisture content.

Effect of a stress management program on subjects with neck pain: A pilot randomized controlled trial.

PubMed

Metikaridis, T Damianos; Hadjipavlou, Alexander; Artemiadis, Artemios; Chrousos, George; Darviri, Christina

2016-05-20

Studies have shown that stress is implicated in the cause of neck pain (NP). The purpose of this study is to examine the effect of a simple, zero cost stress management program on patients suffering from NP. This study is a parallel-type randomized clinical study. People suffering from chronic non-specific NP were chosen randomly to participate in an eight week duration program of stress management (N= 28) (including diaphragmatic breathing, progressive muscle relaxation) or in a no intervention control condition (N= 25). Self-report measures were used for the evaluation of various variables at the beginning and at the end of the eight-week monitoring period. Descriptive and inferential statistic methods were used for the statistical analysis. At the end of the monitoring period, the intervention group showed a statistically significant reduction of stress and anxiety (p= 0.03, p= 0.01), report of stress related symptoms (p= 0.003), percentage of disability due to NP (p= 0.000) and NP intensity (p= 0.002). At the same time, daily routine satisfaction levels were elevated (p= 0.019). No statistically significant difference was observed in cortisol measurements. Stress management has positive effects on NP patients.

Polymer flexibility and turbulent drag reduction.

PubMed

Gillissen, J J J

2008-10-01

Polymer-induced drag reduction is the phenomenon by which the friction factor of a turbulent flow is reduced by the addition of small amounts of high-molecular-weight linear polymers, which conformation in solution at rest can vary between randomly coiled and rodlike. It is well known that drag reduction is positively correlated to viscous stresses, which are generated by extended polymers. Rodlike polymers always assume this favorable conformation, while randomly coiling chains need to be unraveled by fluid strain rate in order to become effective. The coiling and stretching of flexible polymers in turbulent flow produce an additional elastic component in the polymer stress. The effect of the elastic stresses on drag reduction is unclear. To study this issue, we compare direct numerical simulations of turbulent drag reduction in channel flow using constitutive equations describing solutions of rigid and flexible polymers. When compared at constant phi r2, both simulations predict the same amount of drag reduction. Here phi is the polymer volume fraction and r is the polymer aspect ratio, which for flexible polymers is based on average polymer extension at the channel wall. This demonstrates that polymer elasticity plays a marginal role in the mechanism for drag reduction.

Study of mechanism of stress-induced threshold voltage shift and recovery in top-gate amorphous-InGaZnO4 thin-film transistors with source- and drain-offsets

NASA Astrophysics Data System (ADS)

Mativenga, Mallory; Kang, Dong Han; Lee, Ung Gi; Jang, Jin

2012-09-01

Bias instability of top-gate amorphous-indium-gallium-zinc-oxide thin-film transistors with source- and drain-offsets is reported. Positive and negative gate bias-stress (VG_STRESS) respectively induce reversible negative threshold-voltage shift (ΔVTH) and reduction in on-current. Migration of positive charges towards the offsets lowers the local resistance of the offsets, resulting in the abnormal negative ΔVTH under positive VG_STRESS. The reduction in on-current under negative VG_STRESS is due to increase in resistance of the offsets when positive charges migrate away from the offsets. Appropriate drain and source bias-stresses applied simultaneously with VG_STRESS either suppress or enhance the instability, verifying lateral ion migration to be the instability mechanism.

Structural optimization of dental restorations using the principle of adaptive growth.

PubMed

Couegnat, Guillaume; Fok, Siu L; Cooper, Jonathan E; Qualtrough, Alison J E

2006-01-01

In a restored tooth, the stresses that occur at the tooth-restoration interface during loading could become large enough to fracture the tooth and/or restoration and it has been estimated that 92% of fractured teeth have been previously restored. The tooth preparation process for a dental restoration is a classical optimization problem: tooth reduction must be minimized to preserve tooth tissue whilst stress levels must be kept low to avoid fracture of the restored unit. The objective of the present study was to derive alternative optimized designs for a second upper premolar cavity preparation by means of structural shape optimization based on the finite element method and biological adaptive growth. Three models of cavity preparations were investigated: an inlay design for preparation of a premolar tooth, an undercut cavity design and an onlay preparation. Three restorative materials and several tooth/restoration contact conditions were utilized to replicate the in vitro situation as closely as possible. The optimization process was run for each cavity geometry. Mathematical shape optimization based on biological adaptive growth process was successfully applied to tooth preparations for dental restorations. Significant reduction in stress levels at the tooth-restoration interface where bonding is imperfect was achieved using optimized cavity or restoration shapes. In the best case, the maximum stress value was reduced by more than 50%. Shape optimization techniques can provide an efficient and effective means of reducing the stresses in restored teeth and hence has the potential of prolonging their service lives. The technique can easily be adopted for optimizing other dental restorations.

Social isolation stress and chronic glutathione deficiency have a common effect on the glutamine-to-glutamate ratio and myo-inositol concentration in the mouse frontal cortex.

PubMed

Corcoba, Alberto; Gruetter, Rolf; Do, Kim Q; Duarte, João M N

2017-09-01

Environmental stress can interact with genetic predisposition to increase the risk of developing psychopathology. In this work, we tested the hypothesis that social isolation stress interacts with impaired glutathione synthesis and have cumulative effects on the neurochemical profile of the frontal cortex. A mouse model with chronic glutathione deficit induced by knockout (-/-) of the glutamate-cysteine ligase modulatory subunit (Gclm) was exposed to social isolation stress from weaning to post-natal day 65. Using magnetic resonance methods at high-field (14.1 T), we analysed the neurochemical profile in the frontal cortex, brain size and ventricular volume of adult animals. Glutathione deficit was accompanied by elevated concentrations of N-acetylaspartate, alanine, and glutamine, as well as the ratio of glutamine-to-glutamate (Gln/Glu), and by a reduction in levels of myo-inositol and choline-containing compounds in the frontal cortex of -/- animals with respect to wild-type littermates. Although there was no significant interaction between social isolation stress and glutathione deficiency, mice reared in isolation displayed lower myo-inositol concentration (-8.4%, p < 0.05) and larger Gln/Glu (+7.6%, p < 0.05), relative to those in group housing. Furthermore, glutathione deficiency caused a reduction in whole brain volume and enlargement of ventricles, but social isolation had no effect on these parameters. We conclude that social isolation caused neurochemical alterations that may add to those associated to impaired glutathione synthesis. © 2017 International Society for Neurochemistry.

The influence of crop management on banana weevil, Cosmopolites sordidus (Coleoptera: Curculionidae) populations and yield of highland cooking banana (cv. Atwalira) in Uganda.

PubMed

Rukazambuga, N D T M; Gold, C S; Gowen, S R; Ragama, P

2002-10-01

A field study was undertaken in Uganda using highland cooking banana (cv. Atwalira) to test the hypothesis that bananas grown under stressed conditions are more susceptible to attack by Cosmopolites sordidus (Germar). Four banana treatments were employed to create different levels of host-plant vitality: (1) high stress: intercrop with finger millet; (2) moderate stress: monoculture without soil amendments; (3) low stress: monoculture with manure; (4) high vigour: monoculture with continuous mulch and manure. Adult C. sordidus were released at the base of banana mats 11 months after planting and populations were monitored for three years using mark and recapture methods. Cosmopolites sordidus density was greatest in the mulched plots which may have reflected increased longevity and/or longer tenure time in moist soils. Lowest C. sordidus numbers were found in intercropped banana. Damage, estimated as percentage corm tissue consumed by larvae, was similar among treatments. However, the total amount of tissue consumed was greater in mulched banana than in other systems. Plants supporting the heaviest levels of C. sordidus damage displayed bunch size reductions of 40-55%. Banana yield losses ranged from 14-20% per plot with similar levels in the intercropped and mulched systems. Yield reductions, reported as t ha-1, were twice as high in the mulched system as in the intercrop. The results from this study indicate that C. sordidus problems are not confined to stressed banana systems or those with low levels of management, but that the weevil can also attain pest status in well-managed and productive banana stands.

Comparisons of Photosynthetic Responses of Xanthium strumarium and Helianthus annuus to Chronic and Acute Water Stress in Sun and Shade 1

PubMed Central

Ben, Gui-Ying; Osmond, C. Barry; Sharkey, Thomas D.

1987-01-01

We have examined the effects of mild, chronic water stress and acute water stress on two water stress sensitive plants, Xanthium strumarium and Helianthus annuus. Using a combination of the leaf disc O2 electrode to measure the light responses of photosynthesis and 77 K fluorescence to monitor damage to the primary photochemistry, we have found the following: (a) The CO2 saturated rate of photosynthesis at high light is the most water stress sensitive parameter measured. (b) The apparent quantum yield (moles O2 per mole photons) was slightly, if at all, affected by mild water stress (>−1.5 megapascals). (c) Severe water stress (<−1.5 megapascals) reduced the quantum yield of photosynthesis regardless of whether the stress was applied in sun or shade. The light independent reduction of quantum yield was not associated with a reduction in 77 K fluorescence (Fv/Fm) indicating that the quantum yield reduction was not the result of damage to primary photochemistry. (d) The diel fluctuation in 77 K fluorescence seen in sun-exposed control leaves was greatly exaggerated in water stressed leaves because of enhanced decline in 77 K fluorescence in the morning. The rate of recovery was similar in both control and water stressed leaves. Shaded leaves showed no change in 77 K fluorescence regardless of whether water stress was imposed or not. (e) The water stress sensitive plants used in these experiments did not recover from acute water stress severe enough to reduce the quantum yield or chronic water stress which lasted long enough that light dependent damage to primary photochemistry occurred. PMID:16665465

Comparisons of Photosynthetic Responses of Xanthium strumarium and Helianthus annuus to Chronic and Acute Water Stress in Sun and Shade.

PubMed

Ben, G Y; Osmond, C B; Sharkey, T D

1987-06-01

We have examined the effects of mild, chronic water stress and acute water stress on two water stress sensitive plants, Xanthium strumarium and Helianthus annuus. Using a combination of the leaf disc O(2) electrode to measure the light responses of photosynthesis and 77 K fluorescence to monitor damage to the primary photochemistry, we have found the following: (a) The CO(2) saturated rate of photosynthesis at high light is the most water stress sensitive parameter measured. (b) The apparent quantum yield (moles O(2) per mole photons) was slightly, if at all, affected by mild water stress (>-1.5 megapascals). (c) Severe water stress (<-1.5 megapascals) reduced the quantum yield of photosynthesis regardless of whether the stress was applied in sun or shade. The light independent reduction of quantum yield was not associated with a reduction in 77 K fluorescence (F(v)/F(m)) indicating that the quantum yield reduction was not the result of damage to primary photochemistry. (d) The diel fluctuation in 77 K fluorescence seen in sun-exposed control leaves was greatly exaggerated in water stressed leaves because of enhanced decline in 77 K fluorescence in the morning. The rate of recovery was similar in both control and water stressed leaves. Shaded leaves showed no change in 77 K fluorescence regardless of whether water stress was imposed or not. (e) The water stress sensitive plants used in these experiments did not recover from acute water stress severe enough to reduce the quantum yield or chronic water stress which lasted long enough that light dependent damage to primary photochemistry occurred.

A Tolerant Behavior in Salt-Sensitive Tomato Plants can be Mimicked by Chemical Stimuli

PubMed Central

Flors, Víctor; Paradís, Mercedes; García-Andrade, Javier; Cerezo, Miguel; González-Bosch, Carmen

2007-01-01

Lycopersicon esculentum plants exhibit increased salt stress tolerance following treatment with adipic acid monoethylester and 1,3-diaminepropane (DAAME), known as an inducer of resistance against biotic stress in tomato and pepper. For an efficient water and nutrient uptake, plants should adapt their water potential to compensate a decrease in water soil potential produced by salt stress. DAAME-treated plants showed a faster and stronger water potential reduction and an enhanced proline accumulation. Salinity-induced oxidative stress was also ameliorated by DAAME treatments. Oxidative membrane damage and ethylene emission were both reduced in DAAME-treated plants. This effect is probably a consequence of an increase of both non-enzymatic antioxidant activity as well as peroxidase activity. DAAME-mediated tolerance resulted in an unaltered photosynthetic rate and a stimulation of the decrease in transpiration under stress conditions without a cost in growth due to salt stress. The reduction in transpiration rate was concomitant with a reduction in phytotoxic Na+ and Cl− accumulation under saline stress. Interestingly, the ABA deficient tomato mutant sitiens was insensitive to DAAME-induced tolerance following NaCl stress exposure. Additionally, DAAME treatments increased the ABA content of leaves, therefore, an intact ABA signalling pathway seems to be important to express DAAME-induced salt tolerance. Here, we show a possibility of enhance tomato stress tolerance by chemical induction of the major plant defences against salt stress. DAAME-induced tolerance against salt stress could be complementary to or share elements with induced resistance against biotic stress. This might be the reason for the observed wide spectrum of effectiveness of this compound. PMID:19516968

Mindfulness Based Stress Reduction for Academic Evaluation Anxiety: A Naturalistic Longitudinal Study.

PubMed

Dundas, Ingrid; Thorsheim, Torbjørn; Hjeltnes, Aslak; Binder, Per Einar

2016-04-02

Mindfulness based stress reduction (MBSR) for academic evaluation anxiety and self-confidence in 70 help-seeking bachelor's and master's students was examined. A repeated measures analysis of covariance on the 46 students who completed pretreatment and posttreatment measures (median age = 24 years, 83% women) showed that evaluation anxiety and self-confidence improved. A growth curve analysis with all 70 original participants showed reductions in both cognitive and emotional components of evaluation anxiety, and that reduction continued postintervention. Although more research is needed, this study indicates that MBSR may reduce evaluation anxiety.

Mindfulness Based Stress Reduction for Academic Evaluation Anxiety: A Naturalistic Longitudinal Study

PubMed Central

Dundas, Ingrid; Thorsheim, Torbjørn; Hjeltnes, Aslak; Binder, Per Einar

2016-01-01

ABSTRACT Mindfulness based stress reduction (MBSR) for academic evaluation anxiety and self-confidence in 70 help-seeking bachelor’s and master’s students was examined. A repeated measures analysis of covariance on the 46 students who completed pretreatment and posttreatment measures (median age = 24 years, 83% women) showed that evaluation anxiety and self-confidence improved. A growth curve analysis with all 70 original participants showed reductions in both cognitive and emotional components of evaluation anxiety, and that reduction continued postintervention. Although more research is needed, this study indicates that MBSR may reduce evaluation anxiety. PMID:27227169

Mindfulness-based stress reduction: an intervention to enhance the effectiveness of nurses' coping with work-related stress.

PubMed

Smith, Sarah A

2014-06-01

This critical literature review explored the current state of the science regarding mindfulness-based stress reduction (MBSR) as a potential intervention to improve the ability of nurses to effectively cope with stress. Literature sources include searches from EBSCOhost, Gale PowerSearch, ProQuest, PubMed Medline, Google Scholar, Online Journal of Issues in Nursing, and reference lists from relevant articles. Empirical evidence regarding utilizing MBSR with nurses and other healthcare professionals suggests several positive benefits including decreased stress, burnout, and anxiety; and increased empathy, focus, and mood. Nurse use of MBSR may be a key intervention to help improve nurses' ability to cope with stress and ultimately improve the quality of patient care provided. © 2014 NANDA International, Inc.

Examining the Efficacy of a Brief Mindfulness-Based Stress Reduction (Brief MBSR) Program on Psychological Health

ERIC Educational Resources Information Center

Bergen-Cico, Dessa; Possemato, Kyle; Cheon, Sanghyeon

2013-01-01

Objective: The purpose of the study was to examine potential psychological health benefits of participating in a brief (5-week) mindfulness-based stress reduction (brief MBSR) program integrated into an academic course. Participants: Participants were 119 undergraduate students (treatment: "n" = 72; control: "n" = 47) enrolled…

Simple and rapid LC-MS method for the determination of circulating albumin microheterogeneity in veal calves exposed to heat stress.

PubMed

Baldassarre, Maurizio; Naldi, Marina; Domenicali, Marco; Volo, Sabrina; Pietra, Marco; Dondi, Francesco; Caraceni, Paolo; Peli, Angelo

2017-09-10

Heat stress has a major impact on veal calves welfare and productivity. Prolonged exposure to warm temperature is associated with several alterations of physiologic processes and increased systemic inflammation and oxidative stress. Bovine serum albumin (BSA) is the most abundant plasma protein and, besides the regulation of osmotic pressure, carries several additional functions, including antioxidant, immunomodulatory, binding and transport activities. Such non-oncotic properties are closely related to structural integrity of the circulating molecule and may be compromised in stressful microenvironments as it occurs in heat stressed animals. Thus, in the present study we developed and validated an LC-MS analytical technique for the characterization of circulating BSA microheterogeneity in veal calves exposed to heat stress. The method was specifically tailored to the structural characteristics of the BSA molecule as well as to the complexity of the biological samples, allowing the identification of several BSA isoforms, each characterized by a specific structural defect. The mass spectrometry based approach enabled the identification of BSA isoforms with reversible and irreversible oxidation and/or glycation and the native BSA, the only isoform endowed with structural and functional integrity. We found that, in veal calves, heat stress is associated to a significant reduction of the native BSA and to a significant increment of the reversibly and irreversibly oxidized BSA. Then, by monitoring the BSA microheterogeneity over a period of moderate heat stress, we found that the native BSA as well as the glycated BSA increased significantly during the recovery period. Based on our results the analysis of the BSA microheterogeneity could represent a novel biomarker for the assessment of animal welfare during environmental stressful conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

Study of water stress effects in different growth stages on yield and yield components of different rice (Oryza sativa L.) cultivars.

PubMed

Sarvestani, Zinolabedin Tahmasebi; Pirdashti, Hemmatollah; Sanavy, Seyed Ali Mohammad Modarres; Balouchi, Hamidreza

2008-05-15

A field experiment was conducted during 2001-2003 to evaluate the effect of water stress on the yield and yield components of four rice cultivars commonly grown in Mazandaran province, Iran. In northern Iran irrigated lowland rice usually experiences water deficit during the growing season include of land preparation time, planting, tillering stage, flowering and grain filing period. Recently drought affected 20 of 28 provinces in Iran; with the southeastern, central and eastern parts of the country being most severely affected. The local and improved cultivars used were Tarom, Khazar, Fajr and Nemat. The different water stress conditions were water stress during vegetative, flowering and grain filling stages and well watered was the control. Water stress at vegetative stage significantly reduced plant height of all cultivars. Water stress at flowering stage had a greater grain yield reduction than water stress at other times. The reduction of grain yield largely resulted from the reduction in fertile panicle and filled grain percentage. Water deficit during vegetative, flowering and grain filling stages reduced mean grain yield by 21, 50 and 21% on average in comparison to control respectively. The yield advantage of two semidwarf varieties, Fajr and Nemat, were not maintained under drought stress. Total biomass, harvest index, plant height, filled grain, unfilled grain and 1000 grain weight were reduced under water stress in all cultivars. Water stress at vegetative stage effectively reduced total biomass due to decrease of photosynthesis rate and dry matter accumulation.

Management of occult stress urinary incontinence with prolapse surgery.

PubMed

Al-Mandeel, H; Al-Badr, A

2013-08-01

Pelvic organ prolapse (POP) and stress urinary incontinence (SUI), are two common health-related conditions, each affecting up to 50% women worldwide. Stress urinary incontinence only observed after the reduction of co-existent prolapse is called occult SUI (OSUI), and is found in up to 80% of women with advanced POP. Although there is no consensus on how to diagnose OSUI, there are several reported methods to better diagnose. Counseling symptomatically continent women with POP concerning the potential risk for developing SUI postoperatively cannot be overstated. Evidence suggests that positive OSUI in symptomatically continent women who are planning to have POP repair is associated with a high risk of POSUI, furthermore, adding continence procedure is found to reduce postoperative SUI. Therefore, adding continence surgery at the time of POP surgery in patients who are found to have OSUI preoperatively is advocated.

On the computational aspects of comminution in discrete element method

NASA Astrophysics Data System (ADS)

Chaudry, Mohsin Ali; Wriggers, Peter

2018-04-01

In this paper, computational aspects of crushing/comminution of granular materials are addressed. For crushing, maximum tensile stress-based criterion is used. Crushing model in discrete element method (DEM) is prone to problems of mass conservation and reduction in critical time step. The first problem is addressed by using an iterative scheme which, depending on geometric voids, recovers mass of a particle. In addition, a global-local framework for DEM problem is proposed which tends to alleviate the local unstable motion of particles and increases the computational efficiency.

Monitoring reservoir response to earthquakes and fluid extraction, Salton Sea geothermal field, California

PubMed Central

Taira, Taka’aki; Nayak, Avinash; Brenguier, Florent; Manga, Michael

2018-01-01

Continuous monitoring of in situ reservoir responses to stress transients provides insights into the evolution of geothermal reservoirs. By exploiting the stress dependence of seismic velocity changes, we investigate the temporal evolution of the reservoir stress state of the Salton Sea geothermal field (SSGF), California. We find that the SSGF experienced a number of sudden velocity reductions (~0.035 to 0.25%) that are most likely caused by openings of fractures due to dynamic stress transients (as small as 0.08 MPa and up to 0.45 MPa) from local and regional earthquakes. Depths of velocity changes are estimated to be about 0.5 to 1.5 km, similar to the depths of the injection and production wells. We derive an empirical in situ stress sensitivity of seismic velocity changes by relating velocity changes to dynamic stresses. We also observe systematic velocity reductions (0.04 to 0.05%) during earthquake swarms in mid-November 2009 and late-December 2010. On the basis of volumetric static and dynamic stress changes, the expected velocity reductions from the largest earthquakes with magnitude ranging from 3 to 4 in these swarms are less than 0.02%, which suggests that these earthquakes are likely not responsible for the velocity changes observed during the swarms. Instead, we argue that velocity reductions may have been induced by poroelastic opening of fractures due to aseismic deformation. We also observe a long-term velocity increase (~0.04%/year) that is most likely due to poroelastic contraction caused by the geothermal production. Our observations demonstrate that seismic interferometry provides insights into in situ reservoir response to stress changes. PMID:29326977

Monitoring reservoir response to earthquakes and fluid extraction, Salton Sea geothermal field, California.

PubMed

Taira, Taka'aki; Nayak, Avinash; Brenguier, Florent; Manga, Michael

2018-01-01

Continuous monitoring of in situ reservoir responses to stress transients provides insights into the evolution of geothermal reservoirs. By exploiting the stress dependence of seismic velocity changes, we investigate the temporal evolution of the reservoir stress state of the Salton Sea geothermal field (SSGF), California. We find that the SSGF experienced a number of sudden velocity reductions (~0.035 to 0.25%) that are most likely caused by openings of fractures due to dynamic stress transients (as small as 0.08 MPa and up to 0.45 MPa) from local and regional earthquakes. Depths of velocity changes are estimated to be about 0.5 to 1.5 km, similar to the depths of the injection and production wells. We derive an empirical in situ stress sensitivity of seismic velocity changes by relating velocity changes to dynamic stresses. We also observe systematic velocity reductions (0.04 to 0.05%) during earthquake swarms in mid-November 2009 and late-December 2010. On the basis of volumetric static and dynamic stress changes, the expected velocity reductions from the largest earthquakes with magnitude ranging from 3 to 4 in these swarms are less than 0.02%, which suggests that these earthquakes are likely not responsible for the velocity changes observed during the swarms. Instead, we argue that velocity reductions may have been induced by poroelastic opening of fractures due to aseismic deformation. We also observe a long-term velocity increase (~0.04%/year) that is most likely due to poroelastic contraction caused by the geothermal production. Our observations demonstrate that seismic interferometry provides insights into in situ reservoir response to stress changes.

Awareness of Stress-reduction Interventions: The Impact on Employees' Well-being and Organizational Attitudes.

PubMed

Pignata, Silvia; Boyd, Carolyn; Gillespie, Nicole; Provis, Christopher; Winefield, Anthony H

2016-08-01

Employing the social-exchange theoretical framework, we examined the effect of employees' awareness of stress-reduction interventions on their levels of psychological strain, job satisfaction, organizational commitment, perceptions of senior management trustworthiness and procedural justice. We present longitudinal panel data from 869 employees who completed questionnaires at two time points at 13 Australian universities. Our results show that employees who reported an awareness of stress-reduction interventions undertaken at their university scored lower on psychological strain and higher on job satisfaction and commitment than those who were unaware of the interventions. The results suggest that simply the awareness of stress interventions can be linked to positive employee outcomes. The study further revealed that senior management trustworthiness and procedural justice mediate the relationship between awareness and employee outcomes. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

Parent Perspectives of Applying Mindfulness-Based Stress Reduction Strategies to Special Education.

PubMed

Burke, Meghan M; Chan, Neilson; Neece, Cameron L

2017-06-01

Parents of children with (versus without) intellectual and developmental disabilities report greater stress; such stress may be exacerbated by dissatisfaction with school services, poor parent-school partnerships, and the need for parent advocacy. Increasingly, mindfulness interventions have been used to reduce parent stress. However, it is unclear whether parents apply mindfulness strategies during the special education process to reduce school-related stress. To investigate whether mindfulness may reduce school-related stress, interviews were conducted with 26 parents of children with intellectual and developmental disabilities who completed a mindfulness-based stress reduction intervention. Participants were asked about their stress during meetings with the school, use of mindfulness strategies in communicating with the school, and the impact of such strategies. The majority of parent participants reported: special education meetings were stressful; they used mindfulness strategies during IEP meetings; and such strategies affected parents' perceptions of improvements in personal well-being, advocacy, family-school relationships, and access to services for their children. Implications for future research, policy, and practice are discussed.

Critical soil conditions for oxygen stress to plant roots: Substituting the Feddes-function by a process-based model

NASA Astrophysics Data System (ADS)

Bartholomeus, Ruud P.; Witte, Jan-Philip M.; van Bodegom, Peter M.; van Dam, Jos C.; Aerts, Rien

2008-10-01

SummaryEffects of insufficient soil aeration on the functioning of plants form an important field of research. A well-known and frequently used utility to express oxygen stress experienced by plants is the Feddes-function. This function reduces root water uptake linearly between two constant pressure heads, representing threshold values for minimum and maximum oxygen deficiency. However, the correctness of this expression has never been evaluated and constant critical values for oxygen stress are likely to be inappropriate. On theoretical grounds it is expected that oxygen stress depends on various abiotic and biotic factors. In this paper, we propose a fundamentally different approach to assess oxygen stress: we built a plant physiological and soil physical process-based model to calculate the minimum gas filled porosity of the soil ( ϕgas_min) at which oxygen stress occurs. First, we calculated the minimum oxygen concentration in the gas phase of the soil needed to sustain the roots through (micro-scale) diffusion with just enough oxygen to respire. Subsequently, ϕgas_min that corresponds to this minimum oxygen concentration was calculated from diffusion from the atmosphere through the soil (macro-scale). We analyzed the validity of constant critical values to represent oxygen stress in terms of ϕgas_min, based on model simulations in which we distinguished different soil types and in which we varied temperature, organic matter content, soil depth and plant characteristics. Furthermore, in order to compare our model results with the Feddes-function, we linked root oxygen stress to root water uptake (through the sink term variable F, which is the ratio of actual and potential uptake). The simulations showed that ϕgas_min is especially sensitive to soil temperature, plant characteristics (root dry weight and maintenance respiration coefficient) and soil depth but hardly to soil organic matter content. Moreover, ϕgas_min varied considerably between soil types and was larger in sandy soils than in clayey soils. We demonstrated that F of the Feddes-function indeed decreases approximately linearly, but that actual oxygen stress already starts at drier conditions than according to the Feddes-function. How much drier is depended on the factors indicated above. Thus, the Feddes-function might cause large errors in the prediction of transpiration reduction and growth reduction through oxygen stress. We made our method easily accessible to others by implementing it in SWAP, a user-friendly soil water model that is coupled to plant growth. Since constant values for ϕgas_min in plant and hydrological modeling appeared to be inappropriate, an integrated approach, including both physiological and physical processes, should be used instead. Therefore, we advocate using our method in all situations where oxygen stress could occur.

Clinical and Biochemical Outcomes Following EEG Neurofeedback Training in Traumatic Brain Injury in the Context of Spontaneous Recovery.

PubMed

Bennett, Cathlyn N; Gupta, Rajnish K; Prabhakar, Puttachandra; Christopher, Rita; Sampath, Somanna; Thennarasu, K; Rajeswaran, Jamuna

2017-12-01

It has been found that reduction of posttraumatic stress symptoms is positively associated with the reduction of postconcussive symptoms. Cortisol is commonly used as a biomarker of stress. Understanding the role of posttraumatic stress and cortisol in symptom reduction has implication for neuropsychological rehabilitation particularly in the context of spontaneous recovery. The aim of the research was to study the effectiveness of EEG neurofeedback training on clinical symptoms, perceived stress, and cortisol in traumatic brain injury (TBI) patients in the context of spontaneous recovery. The design was an experimental longitudinal design with the pre-post comparison. The sample comprised 60 patients with the diagnosis of TBI-30 patients in the neurofeedback training (NFT) group and 30 patients in the treatment as usual group (TAU) group. Half of the patients were recruited within 6 months of injury to study the role of spontaneous recovery and the other half were recruited in the 12 to 18 months postinjury phase. Alpha-theta training was given to the NFT group over 20 sessions. Pre and post comparisons were made on clinical symptom rating, perceived stress, and serum cortisol levels. The results indicate significant differences in symptom reporting and perceived stress between the NFT and TAU groups. Significant differences were also seen in cortisol levels with implications for the acute recovery phase. Alpha-theta NFT has a beneficial effect on symptom reduction as well as perceived stress. It also has a beneficial effect on levels of serum cortisol, corroborating these findings.

Cryogenic Treatment of Al-Li Alloys for Improved Weldability, Repairability, and Reduction of Residual Stresses

NASA Technical Reports Server (NTRS)

Malone, Tina W.; Graham, Benny F.; Gentz, Steven J. (Technical Monitor)

2001-01-01

Service performance has shown that cryogenic treatment of some metals provides improved strength, fatigue life, and wear resistance to the processed material. Effects such as these were initially discovered by NASA engineers while evaluating spacecraft that had returned from the cold vacuum of space. Factors such as high cost, poor repairability, and poor machinability are currently prohibitive for wide range use of some aerospace aluminum alloys. Application of a cryogenic treatment process to these alloys is expected provide improvements in weldability and weld properties coupled with a reduction in repairs resulting in a significant reduction in the cost to manufacture and life cycle cost of aerospace hardware. The primary purpose of this effort was to evaluate the effects of deep cryogenic treatment of some aluminum alloy plate products, welds, and weld repairs, and optimize a process for the treatment of these materials. The optimized process is being evaluated for improvements in properties of plate and welds, improvements in weldability and repairability of treated materials, and as an alternative technique for the reduction of residual stresses in repaired welds. This paper will present the results of testing and evaluation conducted in this effort. These results will include assessments of changes in strength, toughness, stress corrosion susceptability, weldability, repairability, and reduction in residual stresses of repaired welds.

Integrating social capacity into risk reduction strategies

NASA Astrophysics Data System (ADS)

Schneiderbauer, S.; Pedoth, L.; Zebisch, M.

2012-04-01

The reduction of risk to impacts from external stresses and shocks is an important task in communities worldwide at all government levels and independent of the development status. The importance of building social capacity as part of risk reduction strategies is increasingly recognized. However, there is space for improvement to incorporate related activities into a holistic risk governance approach. Starting point for such enhancements is to promote and improve assessments of what is called 'sensitivity' or 'adaptive capacity' in the climate change community and what is named 'vulnerability' or 'resilience' in the hazard risk community. Challenging issues that need to be tackled in this context are the integration of concepts and method as well as the fusion of data. Against this background we introduce a method to assess regional adaptive capacity to climate change focusing on mountain areas accounting for sector specific problems. By considering three levels of specificity as base for the selection of most appropriate indicators the study results have the potential to support decision making regarding most appropriate adaptation actions. Advantages and shortcomings of certain aspects of adaptive capacity assessment in general and of the proposed method in particular are presented.

Thermally tailored gradient topography surface on elastomeric thin films.

PubMed

Roy, Sudeshna; Bhandaru, Nandini; Das, Ritopa; Harikrishnan, G; Mukherjee, Rabibrata

2014-05-14

We report a simple method for creating a nanopatterned surface with continuous variation in feature height on an elastomeric thin film. The technique is based on imprinting the surface of a film of thermo-curable elastomer (Sylgard 184), which has continuous variation in cross-linking density introduced by means of differential heating. This results in variation of viscoelasticity across the length of the surface and the film exhibits differential partial relaxation after imprinting with a flexible stamp and subjecting it to an externally applied stress for a transient duration. An intrinsic perfect negative replica of the stamp pattern is initially created over the entire film surface as long as the external force remains active. After the external force is withdrawn, there is partial relaxation of the applied stresses, which is manifested as reduction in amplitude of the imprinted features. Due to the spatial viscoelasticity gradient, the extent of stress relaxation induced feature height reduction varies across the length of the film (L), resulting in a surface with a gradient topography with progressively varying feature heights (hF). The steepness of the gradient can be controlled by varying the temperature gradient as well as the duration of precuring of the film prior to imprinting. The method has also been utilized for fabricating wettability gradient surfaces using a high aspect ratio biomimetic stamp. The use of a flexible stamp allows the technique to be extended for creating a gradient topography on nonplanar surfaces as well. We also show that the gradient surfaces with regular structures can be used in combinatorial studies related to pattern directed dewetting.

Reduced Slc6a15 in Nucleus Accumbens D2-Neurons Underlies Stress Susceptibility.

PubMed

Chandra, Ramesh; Francis, T Chase; Nam, Hyungwoo; Riggs, Lace M; Engeln, Michel; Rudzinskas, Sarah; Konkalmatt, Prasad; Russo, Scott J; Turecki, Gustavo; Iniguez, Sergio D; Lobo, Mary Kay

2017-07-05

Previous research demonstrates that Slc6a15, a neutral amino acid transporter, is associated with depression susceptibility. However, no study examined Slc6a15 in the ventral striatum [nucleus accumbens (NAc)] in depression. Given our previous characterization of Slc6a15 as a striatal dopamine receptor 2 (D2)-neuron-enriched gene, we examined the role of Slc6a15 in NAc D2-neurons in mediating susceptibility to stress in male mice. First, we showed that Slc6a15 mRNA was reduced in NAc of mice susceptible to chronic social defeat stress (CSDS), a paradigm that produces behavioral and molecular adaptations that resemble clinical depression. Consistent with our preclinical data, we observed Slc6a15 mRNA reduction in NAc of individuals with major depressive disorder (MDD). The Slc6a15 reduction in NAc occurred selectively in D2-neurons. Next, we used Cre-inducible viruses combined with D2-Cre mice to reduce or overexpress Slc6a15 in NAc D2-neurons. Slc6a15 reduction in D2-neurons caused enhanced susceptibility to a subthreshold social defeat stress (SSDS) as observed by reduced social interaction, while a reduction in social interaction following CSDS was not observed when Slc6a15 expression in D2-neurons was restored. Finally, since both D2-medium spiny neurons (MSNs) and D2-expressing choline acetyltransferase (ChAT) interneurons express Slc6a15, we examined Slc6a15 protein in these interneurons after CSDS. Slc6a15 protein was unaltered in ChAT interneurons. Consistent with this, reducing Slc5a15 selectively in NAc D2-MSNs, using A2A-Cre mice that express Cre selectively in D2-MSNs, caused enhanced susceptibility to SSDS. Collectively, our data demonstrate that reduced Slc6a15 in NAc occurs in MDD individuals and that Slc6a15 reduction in NAc D2-neurons underlies stress susceptibility. SIGNIFICANCE STATEMENT Our study demonstrates a role for reduced Slc6a15, a neutral amino acid transporter, in nucleus accumbens (NAc) in depression and stress susceptibility. The reduction of Slc6a15 occurs selectively in the NAc D2-neurons. Genetic reduction of Slc6a15 induces susceptibility to a subthreshold stress, while genetic overexpression in D2-neurons prevents social avoidance after chronic social defeat stress. Copyright © 2017 the authors 0270-6474/17/376527-12$15.00/0.

Reduced Slc6a15 in Nucleus Accumbens D2-Neurons Underlies Stress Susceptibility

PubMed Central

Nam, Hyungwoo; Engeln, Michel; Konkalmatt, Prasad; Iniguez, Sergio D.

2017-01-01

Previous research demonstrates that Slc6a15, a neutral amino acid transporter, is associated with depression susceptibility. However, no study examined Slc6a15 in the ventral striatum [nucleus accumbens (NAc)] in depression. Given our previous characterization of Slc6a15 as a striatal dopamine receptor 2 (D2)-neuron-enriched gene, we examined the role of Slc6a15 in NAc D2-neurons in mediating susceptibility to stress in male mice. First, we showed that Slc6a15 mRNA was reduced in NAc of mice susceptible to chronic social defeat stress (CSDS), a paradigm that produces behavioral and molecular adaptations that resemble clinical depression. Consistent with our preclinical data, we observed Slc6a15 mRNA reduction in NAc of individuals with major depressive disorder (MDD). The Slc6a15 reduction in NAc occurred selectively in D2-neurons. Next, we used Cre-inducible viruses combined with D2-Cre mice to reduce or overexpress Slc6a15 in NAc D2-neurons. Slc6a15 reduction in D2-neurons caused enhanced susceptibility to a subthreshold social defeat stress (SSDS) as observed by reduced social interaction, while a reduction in social interaction following CSDS was not observed when Slc6a15 expression in D2-neurons was restored. Finally, since both D2-medium spiny neurons (MSNs) and D2-expressing choline acetyltransferase (ChAT) interneurons express Slc6a15, we examined Slc6a15 protein in these interneurons after CSDS. Slc6a15 protein was unaltered in ChAT interneurons. Consistent with this, reducing Slc5a15 selectively in NAc D2-MSNs, using A2A-Cre mice that express Cre selectively in D2-MSNs, caused enhanced susceptibility to SSDS. Collectively, our data demonstrate that reduced Slc6a15 in NAc occurs in MDD individuals and that Slc6a15 reduction in NAc D2-neurons underlies stress susceptibility. SIGNIFICANCE STATEMENT Our study demonstrates a role for reduced Slc6a15, a neutral amino acid transporter, in nucleus accumbens (NAc) in depression and stress susceptibility. The reduction of Slc6a15 occurs selectively in the NAc D2-neurons. Genetic reduction of Slc6a15 induces susceptibility to a subthreshold stress, while genetic overexpression in D2-neurons prevents social avoidance after chronic social defeat stress. PMID:28576941

Dependency of the injection induced seismicity b-value on the stress state of existing fractures

NASA Astrophysics Data System (ADS)

Mukuhira, Y.; Fehler, M. C.; Ito, T.; Asanuma, H.; Häring, M. O.

2017-12-01

The Gutenberg-Richter distribution of earthquake is a power law relationship and it holds for laboratory scale earthquakes (acoustic emission) to subduction zone earthquakes as well as induced seismicity. The gradient of the power law is known as the b-value, which can be considered the ratio of the number of the larger earthquakes to small ones. Larger earthquakes are often observed in low b-value regions, or alternatively a b-value reduction has been observed before some main shocks. Some authors have argued that b-value is negatively correlated with differential stress level. Therefore, a b-value anomaly found in time-space analysis may be used for detection of an area of stress concentration and used for earthquake prediction or hazard risk assessment. In the field of induced seismicity where b-value reduction has also been observed, the physical mechanism of b-value reduction has not been understood well. Since induced seismicity related with fluid injection usually occurs at depths around 1000 5000 m, a significant tectonic mechanism to cause a stress concentration during a short time of hydraulic stimulation might not be expected. We used borehole analysis and focal mechanism information to investigate the stress state on the existing fractures that caused induced seismicity. Then we divide the catalog into the groups with varying normalized shear stress threshold and estimated the b-value. We found that b-value for the events that occurred along higher shear stress fractures were significantly lower (figure 1a) than those from the moderate/lower shear stress fractures (figure 1b). Thus, b-value dependency on the shear stress can be observed for induced seismicity on a reservoir scale. Therefore, we propose that the reason for the observed b-value reductions in induced seismicity on a reservoir scale is the events that occur along higher shear stress fractures. Supposing that the earthquakes occurs along well-orientated fractures, the b-value dependence on differential stress can be translated to dependence on increasing shear stress. Thus, our observations about b-value are consistent with the conventional interpretations of b-value.

Effects of Lifestyle Modification on Telomerase Gene Expression in Hypertensive Patients: A Pilot Trial of Stress Reduction and Health Education Programs in African Americans.

PubMed

Duraimani, Shanthi; Schneider, Robert H; Randall, Otelio S; Nidich, Sanford I; Xu, Shichen; Ketete, Muluemebet; Rainforth, Maxwell A; Gaylord-King, Carolyn; Salerno, John W; Fagan, John

2015-01-01

African Americans suffer from disproportionately high rates of hypertension and cardiovascular disease. Psychosocial stress, lifestyle and telomere dysfunction contribute to the pathogenesis of hypertension and cardiovascular disease. This study evaluated effects of stress reduction and lifestyle modification on blood pressure, telomerase gene expression and lifestyle factors in African Americans. Forty-eight African American men and women with stage I hypertension who participated in a larger randomized controlled trial volunteered for this substudy. These subjects participated in either stress reduction with the Transcendental Meditation technique and a basic health education course (SR) or an extensive health education program (EHE) for 16 weeks. Primary outcomes were telomerase gene expression (hTERT and hTR) and clinic blood pressure. Secondary outcomes included lifestyle-related factors. Data were analyzed for within-group and between-group changes. Both groups showed increases in the two measures of telomerase gene expression, hTR mRNA levels (SR: p< 0.001; EHE: p< 0.001) and hTERT mRNA levels (SR: p = 0.055; EHE: p< 0.002). However, no statistically significant between-group changes were observed. Both groups showed reductions in systolic BP. Adjusted changes were SR = -5.7 mm Hg, p< 0.01; EHE = -9.0 mm Hg, p < 0.001 with no statistically significant difference between group difference. There was a significant reduction in diastolic BP in the EHE group (-5.3 mm Hg, p< 0.001) but not in SR (-1.2 mm Hg, p = 0.42); the between-group difference was significant (p = 0.04). The EHE group showed a greater number of changes in lifestyle behaviors. In this pilot trial, both stress reduction (Transcendental Meditation technique plus health education) and extensive health education groups demonstrated increased telomerase gene expression and reduced BP. The association between increased telomerase gene expression and reduced BP observed in this high-risk population suggest hypotheses that telomerase gene expression may either be a biomarker for reduced BP or a mechanism by which stress reduction and lifestyle modification reduces BP. ClinicalTrials.gov NCT00681200.

Metabolomics of Oxidative Stress in Recent Studies of Endogenous and Exogenously Administered Intermediate Metabolites

PubMed Central

Liu, Jia; Litt, Lawrence; Segal, Mark R.; Kelly, Mark J. S.; Pelton, Jeffrey G.; Kim, Myungwon

2011-01-01

Aerobic metabolism occurs in a background of oxygen radicals and reactive oxygen species (ROS) that originate from the incomplete reduction of molecular oxygen in electron transfer reactions. The essential role of aerobic metabolism, the generation and consumption of ATP and other high energy phosphates, sustains a balance of approximately 3000 essential human metabolites that serve not only as nutrients, but also as antioxidants, neurotransmitters, osmolytes, and participants in ligand-based and other cellular signaling. In hypoxia, ischemia, and oxidative stress, where pathological circumstances cause oxygen radicals to form at a rate greater than is possible for their consumption, changes in the composition of metabolite ensembles, or metabolomes, can be associated with physiological changes. Metabolomics and metabonomics are a scientific disciplines that focuse on quantifying dynamic metabolome responses, using multivariate analytical approaches derived from methods within genomics, a discipline that consolidated innovative analysis techniques for situations where the number of biomarkers (metabolites in our case) greatly exceeds the number of subjects. This review focuses on the behavior of cytosolic, mitochondrial, and redox metabolites in ameliorating or exacerbating oxidative stress. After reviewing work regarding a small number of metabolites—pyruvate, ethyl pyruvate, and fructose-1,6-bisphosphate—whose exogenous administration was found to ameliorate oxidative stress, a subsequent section reviews basic multivariate statistical methods common in metabolomics research, and their application in human and preclinical studies emphasizing oxidative stress. Particular attention is paid to new NMR spectroscopy methods in metabolomics and metabonomics. Because complex relationships connect oxidative stress to so many physiological processes, studies from different disciplines were reviewed. All, however, shared the common goal of ultimately developing “omics”-based, diagnostic tests to help influence therapies. PMID:22072900

Mindfulness-based stress reduction, mindfulness-based cognitive therapy, and Zen meditation for depression, anxiety, pain, and psychological distress.

PubMed

Marchand, William R

2012-07-01

Mindfulness has been described as a practice of learning to focus attention on moment-bymoment experience with an attitude of curiosity, openness, and acceptance. Mindfulness practices have become increasingly popular as complementary therapeutic strategies for a variety of medical and psychiatric conditions. This paper provides an overview of three mindfulness interventions that have demonstrated effectiveness for psychiatric symptoms and/or pain. The goal of this review is to provide a synopsis that practicing clinicians can use as a clinical reference concerning Zen meditation, mindfulness-based stress reduction (MBSR), and mindfulness-based cognitive therapy (MBCT). All three approaches originated from Buddhist spiritual practices, but only Zen is an actual Buddhist tradition. MBSR and MBCT are secular, clinically based methods that employ manuals and standardized techniques. Studies indicate that MBSR and MBCT have broad-spectrum antidepressant and antianxiety effects and decrease general psychological distress. MBCT is strongly recommended as an adjunctive treatment for unipolar depression. The evidence suggests that both MBSR and MBCT have efficacy as adjunctive interventions for anxiety symptoms. MBSR is beneficial for general psychological health and stress management in those with medical and psychiatric illness as well as in healthy individuals. Finally, MBSR and Zen meditation have a role in pain management.

An Experimental Evaluation of Adaptogenic Potential of Standardized Epipremnum Aureum Leaf Extract.

PubMed

Das, Sreemoy Kanti; Sengupta, Pinaki; Mustapha, Mohd Shahimi; Sarker, Md Moklesur Rahman

2017-01-01

Stress is a normal part of everyday life but chronic stress can lead to a variety of stress-related illnesses including hypertension, anxiety, and depression. In the present investigation, standardized leaf extract of Epipremnumaureum was evaluated for its anti-stress potential. For the evaluation of anti-stress activity, groups of mice ( n = 6) were subjected to forced swim stress and anoxic stress tolerance test in mice 1h after daily treatment of E.aureumextract . Diazepam (5 mg/kg) was taken as a reference standard. Urinary vanillylmandelic acid (VMA) and ascorbic acid were selected as noninvasive biomarkers to assess the anti-stress activity and plasma cortisol, blood ascorbic acid, and weight of adrenal were measured. The 24 h urinary excretion of VMA and ascorbic acid were determined by spectrophotometric methods in all groups under normal and stressed conditions. The hematological parameters (neutrophils, lymphocytes, and eosinophils) were also determined. Administration of E.aureumat doses of 400 and 600 mg/kg wasfound to be effective in inhibiting the stress induced urinary biochemical changes in a dose-dependent manner. Treatment with E. aureum extract prevents the rise in blood ascorbic acid and plasma cortisol. Moreover, the extract prevented the increase in weight of adrenal gland also significantly increased the anoxia stress tolerance time. Dose-dependent significant reduction in white blood cell count was observed in anoxic stress tolerance test as compared to stressed group. Hence, the present study provides scientific support for the positiveadaptogenic effect of E. aureum extract.

Numerical study of effect of elastomeric stress absorbers on stress reduction in bone-dental implant interface.

PubMed

Mehdi, Ghalem; Belarbi, Abderrahmane; Mansouri, Bensmaine; Azari, Zitouni

2015-01-01

This paper focused on optimal stress distribution in the mandibular bone surrounding a dental implant and is devoted to the development of a modified Osteoplant® implant type in order to minimize stress concentration in the bone-implant interface. This study investigated 0.4 mm thick layers of two elastomeric stress barriers incorporated into the dental implant using 3-D finite element analysis. Overall, this proposed implant provoked lower load transfer in bone-implant interface due to the effect of the elastomers as stress absorbers. The stress level in the bone was reduced between 28% and 42% for three load cases: 75 N, 60 N and 27 N in corono-apical, linguo-buccal and disto-mesial direction, respectively. The proposed model provided an acceptable solution for load transfer reduction to the mandible. This investigation also permitted to choose how to incorporate two elastomers into the Osteoplant® implant system.

Stress corrosion study of PH13-8Mo stainless steel using the Slow Strain Rate Technique

NASA Technical Reports Server (NTRS)

Torres, Pablo D.

1989-01-01

The need for a fast and reliable method to study stress corrosion in metals has caused increased interest in the Slow Strain Rate Technique (SSRT) during the last few decades. PH13-8MoH950 and H1000 round tensile specimens were studied by this method. Percent reduction-in-area, time-to-failure, elongation at fracture, and fracture energy were used to express the loss in ductility, which has been used to indicate susceptibility to stress corrosion cracking (SCC). Results from a 3.5 percent salt solution (corrosive medium) were compared to those in air (inert medium). A tendency to early failure was found when testing in the vicinity of 1.0 x 10(-6) mm/mm/sec in the 3.5 percent salt solution. PH13-8Mo H1000 was found to be less likely to suffer SCC than PH13-8Mo H950. This program showed that the SSRT is promising for the SCC characterization of metals and results can be obtained in much shorter times (18 hr for PH steels) than those required using conventional techniques.

An analysis of thermal stress and gas bending effects on vibrations of compressor rotor stages. [blade torsional rigidity

NASA Technical Reports Server (NTRS)

Chen, L.-T.; Dugundji, J.

1979-01-01

A preliminary study conducted by Kerrebrock et al. (1976) has shown that the torsional rigidity of untwisted thin blades of a transonic compressor can be reduced significantly by transient thermal stresses. The aerodynamic loads have various effects on blade vibration. One effect is that gas bending loads may result in a bending-torsion coupling which may change the characteristics of the torsion and bending vibration of the blade. For a general study of transient-temperature distribution within a rotor stage, a finite-element heat-conduction analysis was developed. The blade and shroud are divided into annular elements. With a temperature distribution obtained from the heat-conduction analysis and a prescribed gas bending load distribution along the blade span, the static deformation and moment distributions of the blade can be solved iteratively using the finite-element method. The reduction of the torsional rigidity of pretwisted blades caused by the thermal stress effect is then computed. The dynamic behavior of the blade is studied by a modified Galerkin's method.

Decoupling thermal, chemical, and mechanical strain components in thin films

NASA Astrophysics Data System (ADS)

Silberstein, Meredith; Crumlin, Ethan; Shao-Horn, Yang; Boyce, Mary

2011-03-01

Many electrochemical systems have performance which is affected by internal strains due to thermal and/or chemical stimuli. The bi-material curvature method is a means to quantify these thermal and chemical strains and their coupling with mechanical stress. In this method, a thin layer of the material of interest is deposited on a substrate of intermediate thickness. The composite assumes a curvature that depends on the mismatch strains between the substrate and film. The Stoney formula provides an explicit expression for the film stress as a function of the elastic substrate properties, film and substrate thickness, and curvature. Here we study two distinct materials systems: Nafion used as the polymer electrolyte in low temperature fuel cells, and epitaxial perovskite thin films used as a catalyst for the oxygen reduction reaction in solid oxide fuel cells. The thermal, chemical, and mechanical strains are quantitatively determined as functions of temperature and atmospheric conditions by monitoring the curvature evolution with changes in these parameters. The extent of coupling of the thermal and chemical strains with mechanical stress is evaluated by conducting the experiment at multiple substrate thicknesses.

Mindfulness-based stress reduction for people living with HIV/AIDS: preliminary review of intervention trial methodologies and findings.

PubMed

Riley, Kristen E; Kalichman, Seth

2015-01-01

In the context of successful antiretroviral therapy (ART) for the management of HIV infection, the harmful effects of stress remain a significant threat. Stress may increase viral replication, suppress immune response, and impede adherence to ART. Stressful living conditions of poverty, facing a chronic life-threatening illness and stigma all exacerbate chronic stress in HIV-affected populations. Stress-reduction interventions are urgently needed for the comprehensive care of people living with HIV. Mindfulness-based stress reduction (MBSR) is one approach that has shown promise as an intervention for patients facing other medical conditions for reducing disease progression, psychological distress and maladaptive behaviours. In this systematic review, we identified 11 studies that have examined MBSR as an intervention for HIV-positive populations. Of the studies, six were randomised designs, one was a quasi-experimental design, and the remaining four were pre- and post-test designs. The preliminary outcomes support MBSR to decrease emotional distress with mixed evidence for impact on disease progression. Effect sizes were generally small to moderate in magnitude. The early findings from this emerging literature must be considered preliminary and support moving forward with more rigorous controlled trials, evaluated with objective assessments in longer-term follow-ups to determine the efficacy of MBSR for people living with HIV.

Two-Dimensional Sequential and Concurrent Finite Element Analysis of Unstiffened and Stiffened Aluminum and Composite Panels with Hole

NASA Technical Reports Server (NTRS)

Razzaq, Zia; Prasad, Venkatesh

1988-01-01

The results of a detailed investigation of the distribution of stresses in aluminum and composite panels subjected to uniform end shortening are presented. The focus problem is a rectangular panel with two longitudinal stiffeners, and an inner stiffener discontinuous at a central hole in the panel. The influence of the stiffeners on the stresses is evaluated through a two-dimensional global finite element analysis in the absence or presence of the hole. Contrary to the physical feel, it is found that the maximum stresses from the glocal analysis for both stiffened aluminum and composite panels are greater than the corresponding stresses for the unstiffened panels. The inner discontinuous stiffener causes a greater increase in stresses than the reduction provided by the two outer stiffeners. A detailed layer-by-layer study of stresses around the hole is also presented for both unstiffened and stiffened composite panels. A parallel equation solver is used for the global system of equations since the computational time is far less than that using a sequential scheme. A parallel Choleski method with up to 16 processors is used on Flex/32 Multicomputer at NASA Langley Research Center. The parallel computing results are summarized and include the computational times, speedups, bandwidths, and their inter-relationships for the panel problems. It is found that the computational time for the Choleski method decreases with a decrease in bandwidth, and better speedups result as the bandwidth increases.

Effectiveness of a Comprehensive Stress Management Program to Reduce Work-Related Stress in a Medium-Sized Enterprise

PubMed Central

2014-01-01

Objectives To assess the effectiveness of a comprehensive workplace stress management program consisting of participatory action-oriented training (PAOT) and individual management. Methods A comprehensive workplace stress management program was conducted in a medium-sized enterprise. The baseline survey was conducted in September 2011, using the Korean Occupational Stress Scale (KOSS) and Worker’s Stress Response Inventory (WSRI). After implementing both organizational and individual level interventions, the follow up evaluation was conducted in November 2011. Results Most of the workers participated in the organizational level PAOT and made Team-based improvement plans. Based on the stress survey, 24 workers were interviewed by a researcher. After the organizational and individual level interventions, there was a reduction of several adverse psychosocial factors and stress responses. In the case of blue-collar workers, psychosocial factors such as the physical environment, job demands, organizational system, lack of rewards, and occupational climate were significantly improved; in the case of white-collar workers, the occupational climate was improved. Conclusions In light of these results, we concluded that the comprehensive stress management program was effective in reducing work-related stress in a short-term period. A persistent long-term follow up is necessary to determine whether the observed effects are maintained over time. Both team-based improvement activities and individual interviews have to be sustainable and complementary to each other under the long-term plan. PMID:24524591

Finite element analysis of thrust angle contact ball slewing bearing

NASA Astrophysics Data System (ADS)

Deng, Biao; Guo, Yuan; Zhang, An; Tang, Shengjin

2017-12-01

In view of the large heavy slewing bearing no longer follows the rigid ring hupothesis under the load condition, the entity finite element model of thrust angular contact ball bearing was established by using finite element analysis software ANSYS. The boundary conditions of the model were set according to the actual condition of slewing bearing, the internal stress state of the slewing bearing was obtained by solving and calculation, and the calculated results were compared with the numerical results based on the rigid ring assumption. The results show that more balls are loaded in the result of finite element method, and the maximum contact stresses between the ball and raceway have some reductions. This is because the finite element method considers the ferrule as an elastic body. The ring will produce structure deformation in the radial plane when the heavy load slewing bearings are subjected to external loads. The results of the finite element method are more in line with the actual situation of the slewing bearing in the engineering.

Effects of Mindfulness-Based Stress Reduction on employees’ mental health: A systematic review

PubMed Central

Heerkens, Yvonne; Kuijer, Wietske; van der Heijden, Beatrice; Engels, Josephine

2018-01-01

Objectives The purpose of this exploratory study was to obtain greater insight into the effects of Mindfulness-Based Stress Reduction (MBSR) and Mindfulness-Based Cognitive Therapy (MBCT) on the mental health of employees. Methods Using PsycINFO, PubMed, and CINAHL, we performed a systematic review in October 2015 of studies investigating the effects of MBSR and MBCT on various aspects of employees’ mental health. Studies with a pre-post design (i.e. without a control group) were excluded. Results 24 articles were identified, describing 23 studies: 22 on the effects of MBSR and 1 on the effects of MBSR in combination with some aspects of MBCT. Since no study focused exclusively on MBCT, its effects are not described in this systematic review. Of the 23 studies, 2 were of high methodological quality, 15 were of medium quality and 6 were of low quality. A meta-analysis was not performed due to the emergent and relatively uncharted nature of the topic of investigation, the exploratory character of this study, and the diversity of outcomes in the studies reviewed. Based on our analysis, the strongest outcomes were reduced levels of emotional exhaustion (a dimension of burnout), stress, psychological distress, depression, anxiety, and occupational stress. Improvements were found in terms of mindfulness, personal accomplishment (a dimension of burnout), (occupational) self-compassion, quality of sleep, and relaxation. Conclusion The results of this systematic review suggest that MBSR may help to improve psychological functioning in employees. PMID:29364935

Reduced Stress Tensor and Dissipation and the Transport of Lamb Vector

NASA Technical Reports Server (NTRS)

Wu, Jie-Zhi; Zhou, Ye; Wu, Jian-Ming

1996-01-01

We develop a methodology to ensure that the stress tensor, regardless of its number of independent components, can be reduced to an exactly equivalent one which has the same number of independent components as the surface force. It is applicable to the momentum balance if the shear viscosity is constant. A direct application of this method to the energy balance also leads to a reduction of the dissipation rate of kinetic energy. Following this procedure, significant saving in analysis and computation may be achieved. For turbulent flows, this strategy immediately implies that a given Reynolds stress model can always be replaced by a reduced one before putting it into computation. Furthermore, we show how the modeling of Reynolds stress tensor can be reduced to that of the mean turbulent Lamb vector alone, which is much simpler. As a first step of this alternative modeling development, we derive the governing equations for the Lamb vector and its square. These equations form a basis of new second-order closure schemes and, we believe, should be favorably compared to that of traditional Reynolds stress transport equation.

Analysis of the stress field and strain rate in Zagros-Makran transition zone

NASA Astrophysics Data System (ADS)

Ghorbani Rostam, Ghasem; Pakzad, Mehrdad; Mirzaei, Noorbakhsh; Sakhaei, Seyed Reza

2018-01-01

Transition boundary between Zagros continental collision and Makran oceanic-continental subduction can be specified by two wide limits: (a) Oman Line is the seismicity boundary with a sizeable reduction in seismicity rate from Zagros in the west to Makran in the east; and (b) the Zendan-Minab-Palami (ZMP) fault system is believed to be a prominent tectonic boundary. The purpose of this paper is to analyze the stress field in the Zagros-Makran transition zone by the iterative joint inversion method developed by Vavrycuk (Geophysical Journal International 199:69-77, 2014). The results suggest a rather uniform pattern of the stress field around these two boundaries. We compare the results with the strain rates obtained from the Global Positioning System (GPS) network stations. In most cases, the velocity vectors show a relatively good agreement with the stress field except for the Bandar Abbas (BABS) station which displays a relatively large deviation between the stress field and the strain vector. This deviation probably reflects a specific location of the BABS station being in the transition zone between Zagros continental collision and Makran subduction zones.

On the performance of the moment approximation for the numerical computation of fiber stress in turbulent channel flow

NASA Astrophysics Data System (ADS)

Gillissen, J. J. J.; Boersma, B. J.; Mortensen, P. H.; Andersson, H. I.

2007-03-01

Fiber-induced drag reduction can be studied in great detail by means of direct numerical simulation [J. S. Paschkewitz et al., J. Fluid Mech. 518, 281 (2004)]. To account for the effect of the fibers, the Navier-Stokes equations are supplemented by the fiber stress tensor, which depends on the distribution function of fiber orientation angles. We have computed this function in turbulent channel flow, by solving the Fokker-Planck equation numerically. The results are used to validate an approximate method for calculating fiber stress, in which the second moment of the orientation distribution is solved. Since the moment evolution equations contain higher-order moments, a closure relation is required to obtain as many equations as unknowns. We investigate the performance of the eigenvalue-based optimal fitted closure scheme [J. S. Cintra and C. L. Tucker, J. Rheol. 39, 1095 (1995)]. The closure-predicted stress and flow statistics in two-way coupled simulations are within 10% of the "exact" Fokker-Planck solution.

Protection of ultrastructure in chilling-stressed banana leaves by salicylic acid*

PubMed Central

Kang, Guo-zhang; Wang, Zheng-xun; Xia, Kuai-fei; Sun, Gu-chou

2007-01-01

Objective: Chilling tolerance of salicylic acid (SA) in banana seedlings (Musa acuminata cv., Williams 8818) was investigated by changes in ultrastructure in this study. Methods: Light and electron microscope observation. Results: Pretreatment with 0.5 mmol/L SA under normal growth conditions (30/22 °C) by foliar spray and root irrigation resulted in many changes in ultrastructure of banana cells, such as cells separation from palisade parenchymas, the appearance of crevices in cell walls, the swelling of grana and stromal thylakoids, and a reduction in the number of starch granules. These results implied that SA treatment at 30/22 °C could be a type of stress. During 3 d of exposure to 7 °C chilling stress under low light, however, cell ultrastructure of SA-pretreated banana seedlings showed less deterioration than those of control seedlings (distilled water-pretreated). Conclusion: SA could provide some protection for cell structure of chilling-stressed banana seedling. PMID:17444604

Efficacy of Chinese auriculotherapy for stress in nursing staff: a randomized clinical trial

PubMed Central

Kurebayashi, Leonice Fumiko Sato; da Silva, Maria Júlia Paes

2014-01-01

Objective this randomized single blind clinical study aimed to evaluate the efficacy of auriculotherapy with and without a protocol for reducing stress levels among nursing staff. Method a total of 175 nursing professionals with medium and high scores according to Vasconcelos' Stress Symptoms List were divided into 3 groups: Control (58), Group with protocol (58), Group with no protocol (59). They were assessed at the baseline, after 12 sessions, and at the follow-up (30 days). Results in the analysis of variance, statistically significant differences between the Control and Intervention groups were found in the two evaluations (p<0.05) with greater size of effect indices (Cohen) for the No protocol group. The Yang Liver 1 and 2, Kidney, Brain Stem and Shen Men were the points most used. Conclusion individualized auriculotherapy, with no protocol, could expand the scope of the technique for stress reduction compared with auriculotherapy with a protocol. NCT: 01420835 PMID:25029046

The stress-reducing effects of art in pediatric health care: art preferences of healthy children and hospitalized children.

PubMed

Eisen, Sarajane L; Ulrich, Roger S; Shepley, Mardelle M; Varni, James W; Sherman, Sandra

2008-09-01

Art is assumed to possess therapeutic benefits of healing for children, as part of patient-focused design in health care. Since the psychological and physiological well-being of children in health care settings is extremely important in contributing to the healing process, it is vitally important to identify what type of art supports stress reduction. Based on adult studies, nature art was anticipated to be the most preferred and to have stress-reducing effects on pediatric patients. Nature art refers to art images dominated by natural vegetation, flowers or water. The objective of this study was to investigate what type of art image children prefer, and what type of art image has potentially stress-reducing effects on children in hospitals. This study used a three-phase, multi-method approach with children aged 5-17 years: a focus group study (129 participants), a randomized study (48 participants), and a quasi-experimental study design (48 participants). Findings were evaluated from three phases.

Effects of Participation in a Mindfulness-Based Stress Reduction Program on College Students' Psychological Well-Being

ERIC Educational Resources Information Center

Trotter, Michelle Judith

2009-01-01

The present study utilized a pre-test, post-test comparison group design to examine effects of participation in a twelve-week Mindfulness-based Stress Reduction (MBSR) course on college students' psychological well-being (Ryff Psychological Well-Being Scale, Medium Form; Ryff, 1989, 1995, 1996), psychological distress (Hopkins Symptom…

Taming the Anxious Mind: An 8-Week Mindfulness Meditation Group at a University Counseling Center

ERIC Educational Resources Information Center

Murphy, Michael C.

2006-01-01

This article describes an eight-week mindfulness meditation-based group that took place at a university counseling center. The group is patterned after the Mindfulness-Based Stress Reduction (MBSR) program developed by Dr. Jon Kabat-Zinn at the Stress Reduction Clinic at the University of Massachusetts Medical Center. Group members are taught…

Experiencing the restorative components of wilderness environments: Does congestion interfere and does length of exposure matter?

Treesearch

David N. Cole; Troy E. Hall

2010-01-01

Wilderness should provide opportunities for stress reduction and restoration of mental fatigue. Visitors, surveyed as they exited wilderness trailheads, were asked for self-assessments of stress reduction and mental rejuvenation and the extent to which they experienced various restorative components of the environment-attributes deemed by attention restorative theory...

Inquiry-Based Stress Reduction Meditation Technique for Teacher Burnout: A Qualitative Study

ERIC Educational Resources Information Center

Schnaider-Levi, Lia; Mitnik, Inbal; Zafrani, Keren; Goldman, Zehavit; Lev-Ari, Shahar

2017-01-01

An inquiry-based intervention has been found to have a positive effect on burnout and mental well-being parameters among teachers. The aim of the current study was to qualitatively evaluate the effect of the inquiry-based stress reduction (IBSR) meditation technique on the participants. Semi-structured interviews were conducted before and after…

Mindfulness Based Stress Reduction for Academic Evaluation Anxiety: A Naturalistic Longitudinal Study

ERIC Educational Resources Information Center

Dundas, Ingrid; Thorsheim, Torbjørn; Hjeltnes, Aslak; Binder, Per Einar

2016-01-01

Mindfulness based stress reduction (MBSR) for academic evaluation anxiety and self-confidence in 70 help-seeking bachelor's and master's students was examined. A repeated measures analysis of covariance on the 46 students who completed pretreatment and posttreatment measures (median age = 24 years, 83% women) showed that evaluation anxiety and…

Type-A Personality and Stress Reduction Training Based on Transpersonal Psychology with Biofeedback and Computers.

ERIC Educational Resources Information Center

Cassel, Russell N.; Sumantardja, Elmira N.

1982-01-01

Describes Type-A personality as the result of mad pursuit for excellence, characteristic in Western Culture. Relaxation training and stress reduction in management, combined with careful ordering of priorities for single goal attainment, results in Type-C personalities, which implies the development of coping skills for achieving goals.…

Stress, self-esteem and well-being among female health professionals: A randomized clinical trial on the impact of a self-care intervention mediated by the senses

PubMed Central

Dal Fabbro, Daniela Reis; de Oliveira, Rebeca Barqueiro; dos Santos, Ingrid Ribeiro; Victor, Elivane da Silva; Aquarone, Rita Lacerda; Andrade, Cristiane Benvenuto; Ribeiro, Vivian Finotti; de Oliveira, Roselaine Coelho; Friedlander, Rosa; Ferreira, Daniela Santos

2017-01-01

Background Stress levels are evident among health professionals. However, there are few studies on sensory-based self-care aimed at stress management, self-esteem and subjective well-being in this group of professionals. Objective To assess the impact of a self-care intervention mediated by the senses on the stress levels, self-esteem and well-being of health professionals in a hospital environment. Methods A total of 93 health professionals participated in an unblinded clinical trial, randomized into four groups: 1) control (no intervention); 2) Monosensory—daily body moisturizing (DBM) with odorless cream; 3) Bisensory—DBM with scented cream; 4) Multisensory—DBM with scented cream associated with audiovisual material. Participants answered specific questionnaires to assess stress, self-esteem and well-being and cortisol samples were collected at baseline, 15 and 30 days following intervention, and at the 30-day follow-up. Results Self-care was characterized as neglected, with most participants reporting inadequate hours of sleep (74%), irregular physical activity (68%), and inadequate nutrition (45%). Compared to the other groups, the Bisensory group had lower stress on all three assessments (p = 0.017; 0.012; 0.036), a life satisfaction 8% higher at follow-up than at baseline (95% CI: 2% to 15%, p = 0.016), a 10% increase in positive affect (95% CI: 2% to 19%, p = 0.011) and a 12% reduction in negative affect (95% CI: 3% to 21% less, p = 0.014) after 30 days. The Multisensory group showed improvement in self-esteem (p = 0.012) and reduced cortisol (p = 0.036) after 30 days of intervention. The control group showed no changes in the variables studied, except for cortisol: an increase at the 15-day evaluation (denoting higher risk for stress, p = 0.009) and a reduction at follow-up (p = 0.028), which was nevertheless within normal levels. Trial registration Clinicaltrials.gov NCT02406755 PMID:28241070

Reduction in Left Ventricular Wall Stress and Improvement in Function in Failing Hearts using Algisyl-LVR

PubMed Central

Lee, Lik Chuan; Zhihong, Zhang; Hinson, Andrew; Guccione, Julius M.

2013-01-01

Injection of Algisyl-LVR, a treatment under clinical development, is intended to treat patients with dilated cardiomyopathy. This treatment was recently used for the first time in patients who had symptomatic heart failure. In all patients, cardiac function of the left ventricle (LV) improved significantly, as manifested by consistent reduction of the LV volume and wall stress. Here we describe this novel treatment procedure and the methods used to quantify its effects on LV wall stress and function. Algisyl-LVR is a biopolymer gel consisting of Na+-Alginate and Ca2+-Alginate. The treatment procedure was carried out by mixing these two components and then combining them into one syringe for intramyocardial injections. This mixture was injected at 10 to 19 locations mid-way between the base and apex of the LV free wall in patients. Magnetic resonance imaging (MRI), together with mathematical modeling, was used to quantify the effects of this treatment in patients before treatment and at various time points during recovery. The epicardial and endocardial surfaces were first digitized from the MR images to reconstruct the LV geometry at end-systole and at end-diastole. Left ventricular cavity volumes were then measured from these reconstructed surfaces. Mathematical models of the LV were created from these MRI-reconstructed surfaces to calculate regional myofiber stress. Each LV model was constructed so that 1) it deforms according to a previously validated stress-strain relationship of the myocardium, and 2) the predicted LV cavity volume from these models matches the corresponding MRI-measured volume at end-diastole and end-systole. Diastolic filling was simulated by loading the LV endocardial surface with a prescribed end-diastolic pressure. Systolic contraction was simulated by concurrently loading the endocardial surface with a prescribed end-systolic pressure and adding active contraction in the myofiber direction. Regional myofiber stress at end-diastole and end-systole was computed from the deformed LV based on the stress-strain relationship. PMID:23608998

Novel orally active epoxyeicosatrienoic acid (EET) analogs attenuate cisplatin nephrotoxicity

PubMed Central

Khan, Md. Abdul Hye; Liu, Jing; Kumar, Ganesh; Skapek, Stephen X.; Falck, John R.; Imig, John D.

2013-01-01

Nephrotoxicity severely limits the use of the anticancer drug cisplatin. Oxidative stress, inflammation, and endoplasmic reticulum (ER) stress contribute to cisplatin-induced nephrotoxicity. We developed novel orally active epoxyeicosatrienoic acid (EET) analogs and investigated their prophylactic effect in cisplatin-induced nephrotoxicity in rats. Cisplatin-induced nephrotoxicity was manifested by increases in blood urea nitrogen, plasma creatinine, urinary N-acetyl-β-(d)-glucosaminidase activity, kidney injury molecule 1, and histopathology. EET analogs (10 mg/kg/d) attenuated cisplatin-induced nephrotoxicity by reducing these renal injury markers by 40–80% along with a 50–70% reduction in renal tubular cast formation. This attenuated renal injury is associated with reduced oxidative stress, inflammation, and ER stress evident from reduction in related biomarkers and in the renal expression of genes involved in these pathways. Moreover, we demonstrated that the attenuated nephrotoxicity correlated with decreased apoptosis that is associated with 50–90% reduction in Bcl-2 protein family mediated proapoptotic signaling, reduced renal caspase-12 expression, and a 50% reduction in renal caspase-3 activity. We further demonstrated in vitro that the protective activity of EET analogs does not compromise the anticancer effects of cisplatin. Collectively, our data provide evidence that EET analogs attenuate cisplatin-induced nephrotoxicity by reducing oxidative stress, inflammation, ER stress, and apoptosis without affecting the chemotherapeutic effects of cisplatin.—Khan, Md. A. H., Liu, J., Kumar, G., Skapek, S. X., Falck, J. R., Imig, J. D. Novel orally active epoxyeicosatrienoic acid (EET) analogs attenuate cisplatin nephrotoxicity. PMID:23603837

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhou, A.; He, Z.; Redding-Johanson, A.M.

2010-07-01

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

Global fit concept in revision hip arthroplasty for cementless press-fit femoral stems.

PubMed

Canovas, F; LeBeguec, P; Batard, J; Gaillard, F; Dagneaux, L

2017-06-01

A revision stem may be required after a femoral extended trochanteric osteotomy (ETO) is made during revision hip arthroplasty. The two main complications of straight cementless femoral stems are subsidence due to inadequate osteointegration and stress-shielding. We will describe an original revision method with ETO that uses a straight cementless stem. The goal of this method was to achieve the most extensive press-fit possible during stem implantation to improve the transmission of stresses to the bone and to prevent reduction in bone density. The intramedullary preparation was done after closure and fixation of the ETO, which allows impaction of the revision stem with metaphyseal and diaphyseal press-fit. We report encouraging results with preservation of periprosthetic bone stock and good osteointegration of these revision stems at the final follow-up. Pronounced sagittal curvature or large bone defects are contraindications for this technique. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Polymer-surfactant complex formation and its effect on turbulent wall shear stress.

PubMed

Suksamranchit, Siriluck; Sirivat, Anuvat; Jamieson, Alexander M

2006-02-01

Turbulent drag reduction in Couette flow was investigated in terms of a decrease in wall shear stress for aqueous solutions of a nonionic polymer, poly(ethylene oxide) (PEO), a cationic surfactant, hexadecyltrimethylammonium chloride (HTAC), and their mixtures. Consistent with literature data, drag reduction was observed for PEO solutions above a critical molecular weight, 0.91 x 10(5) < Mc < 3.04 x 10(5) g/mol. Maximum drag reduction occurred at an optimum concentration, c(PEO)*, which scales inversely with molecular weight, and the % maximum drag reduction increases with molecular weight. For aqueous HTAC solutions, wall shear stress decreased with increasing HTAC concentration and leveled off at an optimum concentration, c(HTAC)*, comparable to the critical micelle concentration. For HTAC/PEO mixtures, the critical PEO molecular weight for drag reduction decreases, interpreted as due to an increase in hydrodynamic volume because of binding of HTAC micelles to PEO. Consistent with this interpretation, at fixed PEO concentration, maximum drag reduction was observed at an optimum HTAC concentration, c(HTAC/PEO)*, comparable to the maximum binding concentration, MBC. Also, with HTAC concentration fixed at the MBC, the optimum PEO concentration for drag reduction, c(PEO/HTAC)*, decreases relative to that, c(PEO)*, in the absence of HTAC.

Reducing Nurses’ Stress: A Randomized Controlled Trial of a Web-Based Stress Management Program for Nurses

PubMed Central

Hersch, Rebekah K.; Cook, Royer F.; Deitz, Diane K.; Kaplan, Seth; Hughes, Daniel; Friesen, Mary Ann; Vezina, Maria

2016-01-01

Background Nursing is a notoriously high-stress occupation emotionally taxing and physically draining, with a high incidence of burnout. In addition to the damaging effects of stress on nurses’ health and well being, stress is also a major contributor to attrition and widespread shortages in the nursing profession. Although there exist promising in-person interventions for addressing the problem of stress among nurses, the experience of our group across multiple projects in hospitals has indicated that the schedules and workloads of nurses can pose problems for implementing in-person interventions, and that web-based interventions might be ideally suited to addressing the high levels of stress among nurses. Purpose The purpose of this study was to evaluate the effectiveness of the web-based BREATHE: Stress Management for Nurses program. Methods The randomized controlled trial was conducted with 104 nurses in five hospitals in Virginia and one hospital in New York. The primary outcome measure was perceived nursing-related stress. Secondary measures included symptoms of distress, coping, work limitations, job satisfaction, use of substances to relieve stress, alcohol consumption, and understanding depression and anxiety. Results Program group participants experienced significantly greater reductions than the control group on the full Nursing Stress Scale, and six of the seven subscales. No other significant results were found. Moderator analysis found that nurses with greater experience benefitted more. Conclusion Using a web-based program holds tremendous promise for providing nurses with the tools they need to address nursing related stress. PMID:27969025

Effect of Kampo medicine "Dai-kenchu-to" on microbiome in the intestine of the rats with fast stress.

PubMed

Yoshikawa, Kozo; Shimada, Mitsuo; Kuwahara, Tomomi; Hirakawa, Hideki; Kurita, Nobuhiro; Sato, Hirohiko; Utsunomiya, Tohru; Iwata, Takashi; Miyatani, Tomohiko; Higashijima, Jun; Kashihara, Hideya; Takasu, Chie; Matsumoto, Noriko; Nakayama-Imaohji, Haruyuki

2013-01-01

Diversity of gut microbiome has been recently reported to be lost in inflammatory bowel disease. We have previously reported that the Dai-kenchu-to (DKT) prevented the bacterial translocation through suppression of cytokine and apoptosis in rat's fast stress model. The aim of this study was to evaluate the effect of DKT on maintenance of microbial diversity in rat's intestine with inflammation. Wister rats were received the fast stress for 5 days. In DKT group, rats were administered with DKT (300 mg/kg/day) during the fast stress (DKT-group). The gut microbiomes were analyzed at before- and after- fast stress, and the effect of DKT for on microbial diversities of the gut were evaluated by the PCR-clone library method targeting the 16 S ribosomal RNA gene. In Control-group, Erysipelotrichaceae increased to 86% in after fast stress, OTU of before-fast stress was 111 and after fast stress was only 9 (changing rate: 58%). The diversity of microbiome was severely decreased. On the other hand, in DKT-group, diversity of microbiome was kept after fast stress (Lachnospiraceae: Ruminococcaceae: Coriobacteriales 54%, 22%, 5%), Operational taxonomic units of before fast stress was 52 and after fast stress was 55 (changing rate: 6%). Family Lachnospiraceae which includes butyrate-producing Clostridia (Clostridium IV and XIVa). DKT prevented the reduction of diversity of microbiome in rat's fast stress model. Our data suggested the new anti-inflammatory mechanism of DKT through gut microbiome.

Psychosocial correlates of perceived stress among undergraduate medical students in Nigeria

PubMed Central

Thomas, Ibironke F.; Omoaregba, Joyce O.; Okogbenin, Esther O.; Okonoda, Kingsley M.; Ibrahim, Abdu W.; Salihu, Auwal S.; Oshodi, Yewande O.; Orovwigho, Andrew; Odinka, Paul C.; Eze, George O.; Onyebueke, Godwin C.; Aweh, Benjamin E.

2017-01-01

Objectives To assess the prevalence and factors associated with perceived stress among medical students. Methods A cross-sectional study of students (n=623) selected across eight medical schools in Nigeria. A structured questionnaire obtained socio-demographic characteristics, alcohol use (Alcohol Use Disorders Identification Test), other psychoactive drug use (Drug Abuse Screening Test), anxiety/depression symptoms (Hospital Anxiety Depression Scale) and stress (Perceived Medical School Stress Scale). We performed bivariate analysis using the chi-squared test, t-test and one-way ANOVA, with multiple regression analysis for multivariate testing in analysing the data.  Results Most students reported experiencing medical school stress. Female participants were more likely to perceive medical school as competitive (t(621)=1.17, p=0.003), less likely to see medical school as a threat (t(621)=-2.70, p=0.01) or worry about finances (t(621)=-4.80, p=0.001). Nearly a quarter; 21.3% (n=133) and 28.6% (n=178) reported depression and anxiety symptoms respectively. Approximately 4.2% (n=26) were dependent on alcohol, while 14.1% (n=88) had ‘low-risk use’ for other psychoactive substances. In the multiple regression model, lack of finance (B=2.881, p=0.001), weak adherence to religious faith (B=2.376, p=0.001), anxiety symptoms (B=-2.231, p=0.002), problematic alcohol use (B=5.196, p=0.001) and choice of study influenced by parents (B=-3.105, p=0.001) were predictors of greater perceived stress. Conclusions Medical students in Nigeria report high levels of stress. Incorporating stress reduction strategies in the medical curriculum, and the input of students in providing feedback regarding the methods and styles of undergraduate medical education is required.  PMID:29083991

Selenium Nanoparticles for Stress-Resilient Fish and Livestock

NASA Astrophysics Data System (ADS)

Sarkar, Biplab; Bhattacharjee, Surajit; Daware, Akshay; Tribedi, Prosun; Krishnani, K. K.; Minhas, P. S.

2015-09-01

The fisheries and livestock sectors capture the highest share of protein-rich animal food and demonstrate accelerated growth as an agriculture subsidiary. Environmental pollution, climate change, as well as pathogenic invasions exert increasing stress impacts that lead the productivity momentum at a crossroads. Oxidative stress is the most common form of stress phenomenon responsible for the retardation of productivity in fisheries and livestock. Essential micronutrients play a determinant role in combating oxidative stress. Selenium, one of the essential micronutrients, appears as a potent antioxidant with reduced toxicity in its nanoscale form. In the present review, different methods of synthesis and characterization of nanoscale selenium have been discussed. The functional characterization of nano-selenium in terms of its effect on growth patterns, feed digestibility, and reproductive system has been discussed to elucidate the mechanism of action. Moreover, its anti-carcinogenic and antioxidant potentiality, antimicrobial and immunomodulatory efficacy, and fatty acid reduction in liver have been deciphered as the new phenomena of nano-selenium application. Biologically synthesized nano-selenium raises hope for pharmacologically enriched, naturally stable nanoscale selenium with high ecological viability. Hence, nano-selenium can be administered with commercial feeds for improvising stress resilience and productivity of fish and livestock.

Defensive freezing links Hypothalamic-Pituitary-Adrenal-axis activity and internalizing symptoms in humans.

PubMed

Niermann, Hannah C M; Figner, Bernd; Tyborowska, Anna; van Peer, Jacobien M; Cillessen, Antonius H N; Roelofs, Karin

2017-08-01

The Hypothalamic-Pituitary-Adrenal (HPA)-axis plays an important role in the expression of defensive freezing. Adaptive freezing reactivity, characterized by an immediate increase in acute stress and timely termination upon threat offset or need to act, is essential for adequate stress coping. Blunted HPA-axis activity in animals is associated with blunted freezing reactivity and internalizing symptoms. Despite their potential relevance, it remains unknown whether these mechanisms apply to humans and human psychopathology. Using a well-established method combining electrocardiography and posturography, we assessed freezing before, immediately after, and one hour after a stress induction in 92 human adolescents. In line with animal models, human adolescents showed stress-induced freezing, as quantified by relative reductions in heart rate and body sway after, as compared to before, stress. Moreover, relatively lower basal cortisol was associated with reduced stress-induced freezing reactivity (i.e., less immediate freezing and less recovery). Path analyses showed that decreased freezing recovery in individuals with reduced cortisol levels was associated with increased levels of internalizing symptoms. These findings suggest that reduced freezing recovery may be a promising marker for the etiology of internalizing symptoms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Selenium Nanoparticles for Stress-Resilient Fish and Livestock.

PubMed

Sarkar, Biplab; Bhattacharjee, Surajit; Daware, Akshay; Tribedi, Prosun; Krishnani, K K; Minhas, P S

2015-12-01

The fisheries and livestock sectors capture the highest share of protein-rich animal food and demonstrate accelerated growth as an agriculture subsidiary. Environmental pollution, climate change, as well as pathogenic invasions exert increasing stress impacts that lead the productivity momentum at a crossroads. Oxidative stress is the most common form of stress phenomenon responsible for the retardation of productivity in fisheries and livestock. Essential micronutrients play a determinant role in combating oxidative stress. Selenium, one of the essential micronutrients, appears as a potent antioxidant with reduced toxicity in its nanoscale form. In the present review, different methods of synthesis and characterization of nanoscale selenium have been discussed. The functional characterization of nano-selenium in terms of its effect on growth patterns, feed digestibility, and reproductive system has been discussed to elucidate the mechanism of action. Moreover, its anti-carcinogenic and antioxidant potentiality, antimicrobial and immunomodulatory efficacy, and fatty acid reduction in liver have been deciphered as the new phenomena of nano-selenium application. Biologically synthesized nano-selenium raises hope for pharmacologically enriched, naturally stable nanoscale selenium with high ecological viability. Hence, nano-selenium can be administered with commercial feeds for improvising stress resilience and productivity of fish and livestock.

The effect of Mindfulness-Based Stress Reduction on wound healing: a preliminary study.

PubMed

Meesters, Astrid; den Bosch-Meevissen, Yvo M C In; Weijzen, Chantal A H; Buurman, Wim A; Losen, Mario; Schepers, Jan; Thissen, Monique R T M; Alberts, Hugo J E M; Schalkwijk, Casper G; Peters, Madelon L

2018-06-01

Psychological factors have been shown to influence the process of wound healing. This study examined the effect of Mindfulness-Based Stress Reduction (MBSR) on the speed of wound healing. The local production of pro-inflammatory cytokines and growth factors was studied as potential underlying mechanism. Forty-nine adults were randomly allocated to a waiting-list control group (n = 26) or an 8-week MBSR group (n = 23). Pre- and post-intervention/waiting period assessment for both groups consisted of questionnaires. Standardized skin wounds were induced on the forearm using a suction blister method. Primary outcomes were skin permeability and reduction in wound size monitored once a day at day 3, 4, 5, 6, 7, and 10 after injury. Secondary outcomes were cytokines and growth factors and were measured in wound exudates obtained at 3, 6, and 22 h after wounding. Although there was no overall condition effect on skin permeability or wound size, post hoc analyses indicated that larger increases in mindfulness were related to greater reductions in skin permeability 3 and 4 days after wound induction. In addition, MBSR was associated with lower levels of interleukin (IL)-8 and placental growth factor in the wound fluid 22 h after wound induction. These outcomes suggest that increasing mindfulness by MBSR might have beneficial effects on early stages of wound healing. Trial Registration NTR3652, http://www.trialregister.nl.

Mindfulness-based stress reduction for treating chronic headache: A systematic review and meta-analysis.

PubMed

Anheyer, Dennis; Leach, Matthew J; Klose, Petra; Dobos, Gustav; Cramer, Holger

2018-01-01

Background Mindfulness-based stress reduction/cognitive therapy are frequently used for pain-related conditions, but their effects on headache remain uncertain. This review aimed to assess the efficacy and safety of mindfulness-based stress reduction/cognitive therapy in reducing the symptoms of chronic headache. Data sources and study selection MEDLINE/PubMed, Scopus, CENTRAL, and PsychINFO were searched to 16 June 2017. Randomized controlled trials comparing mindfulness-based stress reduction/cognitive therapy with usual care or active comparators for migraine and/or tension-type headache, which assessed headache frequency, duration or intensity as a primary outcome, were eligible for inclusion. Risk of bias was assessed using the Cochrane Tool. Results Five randomized controlled trials (two on tension-type headache; one on migraine; two with mixed samples) with a total of 185 participants were included. Compared to usual care, mindfulness-based stress reduction/cognitive therapy did not improve headache frequency (three randomized controlled trials; standardized mean difference = 0.00; 95% confidence interval = -0.33,0.32) or headache duration (three randomized controlled trials; standardized mean difference = -0.08; 95% confidence interval = -1.03,0.87). Similarly, no significant difference between groups was found for pain intensity (five randomized controlled trials; standardized mean difference = -0.78; 95% confidence interval = -1.72,0.16). Conclusions Due to the low number, small scale and often high or unclear risk of bias of included randomized controlled trials, the results are imprecise; this may be consistent with either an important or negligible effect. Therefore, more rigorous trials with larger sample sizes are needed.

Responses to reductive stress in the cardiovascular system.

PubMed

Handy, Diane E; Loscalzo, Joseph

2017-08-01

There is a growing appreciation that reductive stress represents a disturbance in the redox state that is harmful to biological systems. On a cellular level, the presence of increased reducing equivalents and the lack of beneficial fluxes of reactive oxygen species can prevent growth factor-mediated signaling, promote mitochondrial dysfunction, increase apoptosis, and decrease cell survival. In this review, we highlight the importance of redox balance in maintaining cardiovascular homeostasis and consider the tenuous balance between oxidative and reductive stress. We explain the role of reductive stress in models of protein aggregation-induced cardiomyopathies, such as those caused by mutations in αB-crystallin. In addition, we discuss the role of NADPH oxidases in models of heart failure and ischemia-reperfusion to illustrate how oxidants may mediate the adaptive responses to injury. NADPH oxidase 4, a hydrogen peroxide generator, also has a major role in promoting vascular homeostasis through its regulation of vascular tone, angiogenic responses, and effects on atherogenesis. In contrast, the lack of antioxidant enzymes that reduce hydrogen peroxide, such as glutathione peroxidase 1, promotes vascular remodeling and is deleterious to endothelial function. Thus, we consider the role of oxidants as necessary signals to promote adaptive responses, such as the activation of Nrf2 and eNOS, and the stabilization of Hif1. In addition, we discuss the adaptive metabolic reprogramming in hypoxia that lead to a reductive state, and the subsequent cellular redistribution of reducing equivalents from NADH to other metabolites. Finally, we discuss the paradoxical ability of excess reducing equivalents to stimulate oxidative stress and promote injury. Copyright © 2017 Elsevier Inc. All rights reserved.

A Case Study on Engineering Failure Analysis of Link Chain

PubMed Central

Lee, Seong-Beom; Lee, Hong-Chul

2010-01-01

Objectives The objective of this study was to investigate the effect of chain installation condition on stress distribution that could eventually cause disastrous failure from sudden deformation and geometric rupture. Methods Fractographic method used for the failed chain indicates that over-stress was considered as the root cause of failure. 3D modeling and finite element analysis for the chain, used in a crane hook, were performed with a three-dimensional interactive application program, CATIA, commercial finite element analysis and computational fluid dynamic software, ANSYS. Results The results showed that the state of stress was changed depending on the initial position of the chain that was installed in the hook. Especially, the magnitude of the stress was strongly affected by the bending forces, which are 2.5 times greater (under the simulation condition currently investigated) than that from the plain tensile load. Also, it was noted that the change of load state is strongly related to the failure of parts. The chain can hold an ultimate load of about 8 tons with only the tensile load acting on it. Conclusion The conclusions of this research clearly showed that a reduction of the loss from similar incidents can be achieved when an operator properly handles the installation of the chain. PMID:22953162

Stopping the tsunami of stress in primary care.

PubMed

Pearson, Tamera

2015-12-12

This article provides an overview of the psychoneuroimmunologic impact of stress on illness along with a review of mind/body therapies to counteract the effects of stress. Primary care providers are encouraged to promote stress reduction and translate evidence into practice by recommending mind/body therapies.

A three-year cohort study of the relationships between coping, job stress and burnout after a counselling intervention for help-seeking physicians.

PubMed

Isaksson Ro, Karin E; Tyssen, Reidar; Hoffart, Asle; Sexton, Harold; Aasland, Olaf G; Gude, Tore

2010-04-27

Knowledge about important factors in reduction of burnout is needed, but there is a dearth of burnout intervention program studies and their effects among physicians. The present three-year follow-up study aimed to investigate the roles of coping strategies, job stress and personality traits in burnout reduction after a counselling intervention for distressed physicians. 227 physicians who attended a counselling intervention for burnout at the Resource Centre Villa Sana, Norway in 2003-2005, were followed with self-report assessments at baseline, one-year, and three-year follow-up. Main outcome measures were emotional exhaustion (one dimension of burnout), job stress, coping strategies and neuroticism. Changes in these measures were analyzed with repeated measures ANOVA. Temporal relationships between changes were examined using structural modelling with cross-lagged and synchronous panel models. 184 physicians (81%, 83 men, 101 women) completed the three-year follow-up assessment. Significantly reduced levels of emotional exhaustion, job stress, and emotion-focused coping strategies from baseline to one year after the intervention, were maintained at three-year follow-up.Panel modelling indicated that changes in emotion-focused coping (z = 4.05, p < 0.001) and job stress (z = 3.16, p < 0.01) preceded changes in emotional exhaustion from baseline to three-year follow-up. A similar pattern was found from baseline to one-year follow-up. A sequential relationship indicated that reduction in emotion-focused coping and in job stress preceded reduction in emotional exhaustion. As a consequence, coping strategies and job stress could be important foci in intervention programs that aim to reduce or prevent burnout in help-seeking physicians.

Stress Reduction at the Work-Family Interface: Positive Parenting and Self-Efficacy as Mechanisms of Change in Workplace Triple P

ERIC Educational Resources Information Center

Hartung, Doreen; Hahlweg, Kurt

2011-01-01

Workplace Triple P (WPTP) is a group-based parenting skills training specifically designed to meet the needs of employed parents. Several randomized controlled trials have demonstrated the training's efficacy. This study examined possible mechanisms of change that account for the stress reduction effects of this parenting skills training at the…

Shirodhara: A psycho-physiological profile in healthy volunteers.

PubMed

Dhuri, Kalpana D; Bodhe, Prashant V; Vaidya, Ashok B

2013-01-01

Shirodhara is a classical and a well-established ayurvedic procedure of slowly and steadily dripping medicated oil or other liquids on the forehead. This procedure induces a relaxed state of awareness that results in a dynamic psycho-somatic balance. The objective of the study is to evaluate the psychological and physiological effects of Shirodhara in healthy volunteers by monitoring the rating of mood and levels of stress, electrocardiogram (ECG), electroencephalogram (EEG), and selected biochemical markers of stress. The study was conducted in the human pharmacology laboratory. The study design was open labeled, comparing the baseline variables with values after Shirodhara. The subjects (n = 16) chosen were healthy human volunteers who gave an informed consent. Shirodhara was preceded by Abhyanga - whole body massage. The Shirodhara method was standardized for rate of dripping with peristaltic pump and temperature was controlled with a thermostat. Mood and stress levels were assessed by validated rating scales. The pre- and post-Shirodhara ECG and EEG records were evaluated. Student's paired "t" test was applied to the means + SE of the variables to calculate statistical significance at P <0.05. There was a significant improvement in mood scores and the level of stress (P <0.001). These changes were accompanied by significant decrease in rate of breathing and reduction in diastolic blood pressure along with reduction in heart rate. The relaxed alert state, after Shirodhara, was co-related with an increase in alfa rhythm in EEG. A standardized Shirodhara leads to a state of alert calmness similar to the relaxation response observed in meditation. The clinical benefits observed with Shirodhara in anxiety neurosis, hypertension, and stress aggravation due to chronic degenerative diseases could be mediated through these adaptive physiological effects.

Numerical simulation of damage and progressive failures in composite laminates using the layerwise plate theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reddy, Y.S.

1992-01-01

The failure behavior of composite laminates is modeled numerically using the Generalized Layerwise Plate Theory (GLPT) of Reddy and a progressive failure algorithm. The Layerwise Theory of Reddy assumes a piecewise continuous displacement field through the thickness of the laminate and therefore has the ability to capture the interlaminar stress fields near the free edges and cut outs more accurately. The progressive failure algorithm is based on the assumption that the material behaves like a stable progressively fracturing solid. A three-dimensional stiffness reduction scheme is developed and implemented to study progressive failures in composite laminates. The effect of various parametersmore » such as out-of-plane material properties, boundary conditions, and stiffness reduction methods on the failure stresses and strains of a quasi-isotropic composite laminate with free edges subjected to tensile loading is studied. The ultimate stresses and strains predicted by the Generalized Layerwise Plate Theory (GLPT) and the more widely used First Order Shear Deformation Theory (FSDT) are compared with experimental results. The predictions of the GLPT are found to be in good agreement with the experimental results both qualitatively and quantitatively, while the predictions of FSDT are found to be different from experimental results both qualitatively and quantitatively. The predictive ability of various phenomenological failure criteria is evaluated with reference to the experimental results available in the literature. The effect of geometry of the test specimen and the displacement boundary conditions at the grips on the ultimate stresses and strains of a composite laminate under compressive loading is studied. The ultimate stresses and strains are found to be quite sensitive to the geometry of the test specimen and the displacement boundary conditions at the grips. The degree of sensitivity is observed to depend strongly on the lamination sequence.« less

Wrinkling reduction of membrane structure by trimming edges

NASA Astrophysics Data System (ADS)

Liu, Mingjun; Huang, Jin; Liu, Mingyue

2017-05-01

Thin membranes have negligible bending stiffness, compressive stresses inevitably lead to wrinkling. Therefore, it is important to keep the surface of membrane structures flat in order to guarantee high precision. Edge-trimming is an effective method to passively diminish wrinkles, however a key difficulty in this process is the determination of the optimal trimming level. In this paper, regular polygonal membrane structures subjected to equal radial forces were analyzed, and a new stress field distribution model for arc-edge square membrane structure was proposed to predict the optimal trimming level. This model is simple and applicable to any polygonal membrane structures. Comparison among the results of the finite element analysis, and the experimental and analytical results showed that the proposed model accurately described the stress field distribution and guaranteed that there are no wrinkles appear inside the effective inscribed circle region for the optimal trimming level.

A coupled thermo-mechanical pseudo inverse approach for preform design in forging

NASA Astrophysics Data System (ADS)

Thomas, Anoop Ebey; Abbes, Boussad; Li, Yu Ming; Abbes, Fazilay; Guo, Ying-Qiao; Duval, Jean-Louis

2017-10-01

Hot forging is a process used to form difficult to form materials as well as to achieve complex geometries. This is possible due to the reduction of yield stress at high temperatures and a subsequent increase in formability. Numerical methods have been used to predict the material yield and the stress/strain states of the final product. Pseudo Inverse Approach (PIA) developed in the context of cold forming provides a quick estimate of the stress and strain fields in the final product for a given initial shape. In this paper, PIA is extended to include the thermal effects on the forging process. A Johnson-Cook thermo-viscoplastic material law is considered and a staggered scheme is employed for the coupling between the mechanical and thermal problems. The results are compared with available commercial codes to show the efficiency and the limitations of PIA.

Polarization independent thermally tunable erbium-doped fiber amplifier gain equalizer using a cascaded Mach-Zehnder coupler.

PubMed

Sahu, P P

2008-02-10

A thermally tunable erbium-doped fiber amplifier (EDFA) gain equalizer filter based on compact point symmetric cascaded Mach-Zehnder (CMZ) coupler is presented with its mathematical model and is found to be polarization dependent due to stress anisotropy caused by local heating for thermo-optic phase change from its mathematical analysis. A thermo-optic delay line structure with a stress releasing groove is proposed and designed for the reduction of polarization dependent characteristics of the high index contrast point symmetric delay line structure of the device. It is found from thermal analysis by using an implicit finite difference method that temperature gradients of the proposed structure, which mainly causes the release of stress anisotropy, is approximately nine times more than that of the conventional structure. It is also seen that the EDFA gain equalized spectrum by using the point symmetric CMZ device based on the proposed structure is almost polarization independent.

Face Gear Drive with Spur Involute Pinion: Geometry, Generation by a Worm, Stress Analysis

NASA Technical Reports Server (NTRS)

Litvin, Faydor L.; Fuentes, Alfonso; Zanzi, Claudio; Pontiggia, Matteo; Handschuh, Robert F. (Technical Monitor)

2002-01-01

A face gear drive with a spur involute pinion is considered. The generation of the face gear is based on application of a grinding or cutting worm whereas the conventional method of generation is based on application of an involute shaper. An analytical approach is proposed for the determination of: (1) the worm thread surface; (2) avoidance of singularities of the worm thread surface, (air) dressing of the worm; and (3) determination of stresses of the face-gear drive. A computer program for simulation of meshing and contact of the pinion and face-gear has been developed. Correction of machine-tool settings is proposed for reduction of the shift of the bearing contact caused by misalignment. An automatic development of the model of five contacting teeth has been proposed for stress analysis. Numerical examples for illustration of the developed theory are provided.

A Randomized Controlled Trial of Stress Reduction in African Americans Treated for Hypertension for Over One Year

PubMed Central

Schneider, Robert H.; Alexander, Charles N.; Staggers, Frank; Orme-Johnson, David W.; Rainforth, Maxwell; Salerno, John W.; Sheppard, William; Castillo-Richmond, Amparo; Barnes, Vernon A.; Nidich, Sanford I.

2007-01-01

Background Psychosocial stress has been implicated in the disproportionately higher rates of hypertension among African Americans. This randomized controlled trial compared the effects of two stress reduction techniques and a health education control program on hypertension during a period of 1 year in African-American men and women (N = 150, mean age 49 ± 10 years, mean blood pressure (BP) = 142/95 mm Hg) at an urban community health center. Methods Interventions included 20 min twice a day of Transcendental Meditation (TM) or progressive muscle relaxation (PMR), or participation in conventional health education (HE) classes. All subjects continued usual medical care. Outcomes assessed were systolic BP and diastolic BP at 3, 6, 9, and 12 months after treatment, analyzed by repeated measures ANCOVA. Results The TM group showed decreases in systolic BP/diastolic BP of −3.1/−5.7 mm Hg compared to −0.5/−2.9 mm Hg for PMR or HE, (P = .12 to .17 for systolic BP, P = .01 for diastolic BP). In addition the TM group demonstrated reduced use of antihypertensive medication relative to increases for PMR (P = .001) and HE (P = .09) groups. Group analysis by gender showed that women practicing TM had decreased BP (−7.3/−6.9 mm Hg) significantly more than women practicing PMR (0.7/−2.7 mm Hg) or HE (−.07/−3.0 mm Hg) (P .01 to .03). The change in men praticing TM (0.2/−4.7 mm Hg) was greater than men practicing HE (−0.9/−2.0 mm Hg) for diastolic BP only (P = .09,) and not different from PMR men (−2.0/−3.1). Conclusions A selected stress reduction approach, the Transcendental Meditation program, may be useful as an adjunct in the long-term treatment of hypertension in African Americans. PMID:15691622

A pilot study: the effect of healing touch on anxiety, stress, pain, pain medication usage, and physiological measures in hospitalized sickle cell disease adults experiencing a vaso-occlusive pain episode.

PubMed

Thomas, Linda S; Stephenson, Nancy; Swanson, Mel; Jesse, D Elizabeth; Brown, Sylvia

2013-12-01

This pilot study was conducted to determine the effectiveness of Healing Touch on anxiety, stress, pain, pain medication usage, and selected physiological measures of hospitalized adults with sickle cell disease experiencing a vaso-occlusive pain episode. Healing Touch sessions were administered for 30 minutes on four consecutive days, and the self-reported data on anxiety, stress, pain, and the selected physiological data were collected while controlling for music and presence. A parallel-group randomized control trial comparing the effects of Healing Touch with Music (HTM) to Attention Control with Music (ACM). Due to the small sample size, there were no statistically significant changes in any between-group comparisons, except for present pain on Day 4 for the ACM group. For both groups, the within-group comparison showed a nonsignificant reduction in physiological parameters, a statistically significant reduction in anxiety and stress for the ACM group after Day 4, and a statistically significant reduction in stress in the HTM group after Days 2 and 4. The pre- to postintervention reductions in present pain were greater in the HTM group across all 4 days, but the only statistically significant within groups findings were in the HTM group (p < .01) on Day 1. Further research is needed.

Towards multilevel mental stress assessment using SVM with ECOC: an EEG approach.

PubMed

Al-Shargie, Fares; Tang, Tong Boon; Badruddin, Nasreen; Kiguchi, Masashi

2018-01-01

Mental stress has been identified as one of the major contributing factors that leads to various diseases such as heart attack, depression, and stroke. To avoid this, stress quantification is important for clinical intervention and disease prevention. This study aims to investigate the feasibility of exploiting electroencephalography (EEG) signals to discriminate between different stress levels. We propose a new assessment protocol whereby the stress level is represented by the complexity of mental arithmetic (MA) task for example, at three levels of difficulty, and the stressors are time pressure and negative feedback. Using 18-male subjects, the experimental results showed that there were significant differences in EEG response between the control and stress conditions at different levels of MA task with p values < 0.001. Furthermore, we found a significant reduction in alpha rhythm power from one stress level to another level, p values < 0.05. In comparison, results from self-reporting questionnaire NASA-TLX approach showed no significant differences between stress levels. In addition, we developed a discriminant analysis method based on multiclass support vector machine (SVM) with error-correcting output code (ECOC). Different stress levels were detected with an average classification accuracy of 94.79%. The lateral index (LI) results further showed dominant right prefrontal cortex (PFC) to mental stress (reduced alpha rhythm). The study demonstrated the feasibility of using EEG in classifying multilevel mental stress and reported alpha rhythm power at right prefrontal cortex as a suitable index.

Proposal for a model to assess the effect of seismic activity on the triggering of debris flows

NASA Astrophysics Data System (ADS)

Vidar Vangelsten, Bjørn; Liu, Zhongqiang; Eidsvig, Unni; Luna, Byron Quan; Nadim, Farrokh

2013-04-01

Landslide triggered by earthquakes is a serious threat for many communities around the world, and in some cases is known to have caused 25-50% of the earthquake fatalities. Seismic shaking can contribute to the triggering of debris flows either during the seismic event or indirectly by increasing the susceptibility of the slope to debris flow during intense rainfall in a period after the seismic event. The paper proposes a model to quantify both these effects. The model is based on an infinite slope formulation where precipitation and earthquakes influence the slope stability as follows: (1) During the shaking, the factor of safety is reduced due to cyclic pore pressure build-up where the cyclic pore pressure is modelled as a function of earthquake duration and intensity (measured as number of equivalent shear stress cycles and cyclic shear stress magnitude) and in-situ soil conditions (measured as average normalised shear stress). The model is calibrated using cyclic triaxial and direct simple shear (DSS) test data on clay and sand. (2) After the shaking, the factor of safety is modified using a combined empirical and analytical model that links observed earthquake induced changes in rainfall thresholds for triggering of debris flow to an equivalent reduction in soil shear strength. The empirical part uses data from past earthquakes to propose a conceptual model linking a site-specific reduction factor for rainfall intensity threshold (needed to trigger debris flows) to earthquake magnitude, distance from the epicentre and time period after the earthquake. The analytical part is a hydrological model for transient rainfall infiltration into an infinite slope in order to translate the change in rainfall intensity threshold into an equivalent reduction in soil shear strength. This is generalised into a functional form giving a site-specific shear strength reduction factor as function of earthquake history and soil conditions. The model is suitable for hazard and risk assessment at local and regional scale for earthquake and rainfall induced landslide. The research leading to these results has received funding from the European Community's Seventh Framework Programme [FP7/2007-2013] under grant agreement No 265138 New Multi-HAzard and MulTi-RIsK Assessment MethodS for Europe (MATRIX).

Physical activity, mindfulness meditation, or heart rate variability biofeedback for stress reduction: a randomized controlled trial.

PubMed

van der Zwan, Judith Esi; de Vente, Wieke; Huizink, Anja C; Bögels, Susan M; de Bruin, Esther I

2015-12-01

In contemporary western societies stress is highly prevalent, therefore the need for stress-reducing methods is great. This randomized controlled trial compared the efficacy of self-help physical activity (PA), mindfulness meditation (MM), and heart rate variability biofeedback (HRV-BF) in reducing stress and its related symptoms. We randomly allocated 126 participants to PA, MM, or HRV-BF upon enrollment, of whom 76 agreed to participate. The interventions consisted of psycho-education and an introduction to the specific intervention techniques and 5 weeks of daily exercises at home. The PA exercises consisted of a vigorous-intensity activity of free choice. The MM exercises consisted of guided mindfulness meditation. The HRV-BF exercises consisted of slow breathing with a heart rate variability biofeedback device. Participants received daily reminders for their exercises and were contacted weekly to monitor their progress. They completed questionnaires prior to, directly after, and 6 weeks after the intervention. Results indicated an overall beneficial effect consisting of reduced stress, anxiety and depressive symptoms, and improved psychological well-being and sleep quality. No significant between-intervention effect was found, suggesting that PA, MM, and HRV-BF are equally effective in reducing stress and its related symptoms. These self-help interventions provide easily accessible help for people with stress complaints.

Salivary Testosterone Levels Under Psychological Stress and Its Relationship with Rumination and Five Personality Traits in Medical Students

PubMed Central

Afrisham, Reza; Sadegh-Nejadi, Sahar; SoliemaniFar, Omid; Kooti, Wesam; Ashtary-Larky, Damoon; Alamiri, Fatima; Najjar-Asl, Sedigheh; Khaneh-Keshi, Ali

2016-01-01

Objective The purpose of this study was to evaluate the salivary testosterone levels under psychological stress and its relationship with rumination and five personality traits in medical students. Methods A total of 58 medical students, who wanted to participate in the final exam, were selected by simple random sampling. Two months before the exam, in the basal conditions, the NEO Inventory short form, and the Emotional Control Questionnaire (ECQ) were completed. Saliva samples were taken from students in both the basal conditions and under exam stress. Salivary testosterone was measured by ELISA. Data was analyzed using multivariate analysis of variance with repeated measures, paired samples t-test, Pearson correlation and stepwise regression analysis. Results Salivary testosterone level of men showed a significant increase under exam stress (p<0.05). However, a non-significant although substantial reduction observed in women. A significant correlation was found between extroversion (r=-0.33) and openness to experience (r=0.30) with salivary testosterone (p<0.05). Extraversion, aggression control and emotional inhibition predicted 28% of variance of salivary testosterone under stress. Conclusion Salivary testosterone reactivity to stress can be determined by sexual differences, personality traits, and emotional control variables which may decrease or increase stress effects on biological responses, especially the salivary testosterone. PMID:27909455

Biofeedback Intervention for Stress and Anxiety among Nursing Students: A Randomized Controlled Trial

PubMed Central

Ratanasiripong, Paul; Ratanasiripong, Nop; Kathalae, Duangrat

2012-01-01

Purpose. It has been well documented that nursing students across the world experience stress and anxiety throughout their education and training. The purpose of this randomized controlled study is to investigate the impact of biofeedback intervention program on nursing students' levels of stress and anxiety during their first clinical training. Methods. Participants consisted of 60 second-year baccalaureate nursing students. The 30 participants in the biofeedback group received training on how to use the biofeedback device to assist in stress and anxiety management for 5 weeks while the 30 in the control group did not receive any training. Findings. Results indicated that the biofeedback group was able to maintain the stress level while the control group had a significant increase in the stress level over the 5-week period of clinical training. Additionally, the biofeedback group had a significant reduction in anxiety, while the control group had a moderate increase in anxiety. Conclusions. The better the nursing students can manage their stress and anxiety, the more successful they can be in their clinical training. Ultimately, the more psychologically healthy the nursing students are, the more likely they will flourish and graduate to become productive and contributing members of the nursing profession. PMID:22811932

Radiation-induced reductive modifications of sulfur-containing amino acids within peptides and proteins.

PubMed

Chatgilialoglu, Chryssostomos; Ferreri, Carla; Torreggiani, Armida; Salzano, Anna Maria; Renzone, Giovanni; Scaloni, Andrea

2011-10-19

The complex scenario of radical stress reactions affecting peptides/proteins can be better elucidated through the design of biomimetic studies simulating the consequences of the different free radicals attacking amino acids. In this context, ionizing radiations allowed to examine the specific damages caused by H-atoms and electrons coupled with protons, thus establishing the molecular basis of reductive radical stress. This is an innovative concept that complements the well-known oxidative stress also in view of a complete understanding of the global consequences of radical species reactivities on living systems. This review summarizes the knowledge of the chemical changes present in sulfur-containing amino acids occurring in polypeptides under reductive radical conditions, in particular the transformation of Met and Cys residues into α-amino butyric acid and alanine, respectively. Reductive radical stress causing a desulfurization process, is therefore coupled with the formation of S-centered radicals, which in turn can diffuse apart and become responsible of the damage transfer from proteins to lipids. These reductive modifications assayed in different peptide/protein sequences constitute an integration of the molecular inventories that up to now take into account only oxidative transformations. They can be useful to achieve an integrated vision of the free radical reactivities in a multifunctional system and, overall, for wider applications in the redox proteomics field. Copyright © 2011 Elsevier B.V. All rights reserved.

Diabetes Empowerment Council: Integrative Pilot Intervention for Transitioning Young Adults With Type 1 Diabetes.

PubMed

Weigensberg, Marc J; Vigen, Cheryl; Sequeira, Paola; Spruijt-Metz, Donna; Juarez, Magaly; Florindez, Daniella; Provisor, Joseph; Peters, Anne; Pyatak, Elizabeth A

2018-01-01

The transition of young adults with type 1 diabetes (T1D) from pediatric to adult care is challenging and frequently accompanied by worsening of diabetes-related health. To date, there are no reports which prospectively assess the effects of theory-based psycho-behavioral interventions during the transition period neither on glycemic control nor on psychosocial factors that contribute to poor glycemic control. Therefore, the overall aim of this study was to develop and pilot test an integrative group intervention based on the underlying principles of self-determination theory (SDT), in young adults with T1D. Fifty-one young adults with T1D participated in an education and case management-based transition program, of which 9 took part in the Diabetes Empowerment Council (DEC), a 12-week holistic, multimodality facilitated group intervention consisting of "council" process based on indigenous community practices, stress-reduction guided imagery, narrative medicine modalities, simple ritual, and other integrative modalities. Feasibility, acceptability, potential mechanism of effects, and bio-behavioral outcomes were determined using mixed qualitative and quantitative methods. The intervention was highly acceptable to participants, though presented significant feasibility challenges. Participants in DEC showed significant reductions in perceived stress and depression, and increases in general well-being relative to other control participants. Reduction in perceived stress, independent of intervention group, was associated with reductions in hemoglobin A1C. A theoretical model explaining the effects of the intervention included the promotion of relatedness and autonomy support, 2 important aspects of SDT. The DEC is a promising group intervention for young adults with T1D going through transition to adult care. Future investigations will be necessary to resolve feasibility issues, optimize the multimodality intervention, determine full intervention effects, and fully test the role of the underlying theoretical model of action.ClinicalTrials.gov Registration Number NCT02807155; Registration date: June 15, 2016 (retrospectively registered).

Effect of obesity reduction on preservation of heart function and attenuation of left ventricular remodeling, oxidative stress and inflammation in obese mice

PubMed Central

2012-01-01

Background Obesity is an important cardiovascular risk factor. This study tested the effect of obesity reduction on preserving left ventricular ejection fraction (LVEF) and attenuating inflammation, oxidative stress and LV remodeling in obese mice. Methods and results Eight-week-old C57BL/6 J mice (n=24) were equally divided into control (fed a control diet for 22 weeks), obesity (high-fat diet, 22 weeks), and obese reduction (OR) (high-fat diet, 14 weeks; then control diet, 8 weeks). Animals were sacrificed at post 22-week high-fat diet and the LV myocardium collected. Heart weight, body weight, abdominal-fat weight, total cholesterol level and fasting blood glucose were higher in obesity than in control and OR (all p<0.001). Inflammation measured by mRNA expressions of IL-6, MMP-9, PAI-1 and leptin and protein expression of NF-κB was higher, whereas anti-inflammation measured by mRNA expressions of adiponectin and INF-γ was lower in obesity than in control and OR (all p<0.003). Oxidative protein expressions of NOX-1, NOX-2 and oxidized protein were higher, whereas expression of anti-oxidant markers HO-1 and NQO-1 were lower (all p<0.01); and apoptosis measured by Bax and caspase 3 was higher, whereas anti-apoptotic Bcl-2 was lower in obesity as compared with control and OR (all p<0.001). The expressions of fibrotic markers phosphorylated Smad3 and TGF-β were higher, whereas expression of anti-fibrotic phosphorylated Smad1/5 and BMP-2 were lower (all p<0.02); and LVEF was lower, whereas the LV remodeling was higher in obesity than in control and OR (all p<0.001). Conclusion Impaired LVEF, enhanced LV remodeling, inflammation, fibrosis, oxidative stress and apoptosis were reversed by reduction in mouse obesity. PMID:22784636

Scaling, elasticity, and CLPT

NASA Technical Reports Server (NTRS)

Brunelle, Eugene J.

1994-01-01

The first few viewgraphs describe the general solution properties of linear elasticity theory which are given by the following two statements: (1) for stress B.C. on S(sub sigma) and zero displacement B.C. on S(sub u) the altered displacements u(sub i)(*) and the actual stresses tau(sub ij) are elastically dependent on Poisson's ratio nu alone: thus the actual displacements are given by u(sub i) = mu(exp -1)u(sub i)(*); and (2) for zero stress B.C. on S(sub sigma) and displacement B.C. on S(sub u) the actual displacements u(sub i) and the altered stresses tau(sub ij)(*) are elastically dependent on Poisson's ratio nu alone: thus the actual stresses are given by tau(sub ij) = E tau(sub ij)(*). The remaining viewgraphs describe the minimum parameter formulation of the general classical laminate theory plate problem as follows: The general CLT plate problem is expressed as a 3 x 3 system of differential equations in the displacements u, v, and w. The eighteen (six each) A(sub ij), B(sub ij), and D(sub ij) system coefficients are ply-weighted sums of the transformed reduced stiffnesses (bar-Q(sub ij))(sub k); the (bar-Q(sub ij))(sub k) in turn depend on six reduced stiffnesses (Q(sub ij))(sub k) and the material and geometry properties of the k(sup th) layer. This paper develops a method for redefining the system coefficients, the displacement components (u,v,w), and the position components (x,y) such that a minimum parameter formulation is possible. The pivotal steps in this method are (1) the reduction of (bar-Q(sub ij))(sub k) dependencies to just two constants Q(*) = (Q(12) + 2Q(66))/(Q(11)Q(22))(exp 1/2) and F(*) - (Q(22)/Q(11))(exp 1/2) in terms of ply-independent reference values Q(sub ij); (2) the reduction of the remaining portions of the A, B, and D coefficients to nondimensional ply-weighted sums (with 0 to 1 ranges) that are independent of Q(*) and F(*); and (3) the introduction of simple coordinate stretchings for u, v, w and x,y such that the process is neatly completed.

Imagine HEALTH: results from a randomized pilot lifestyle intervention for obese Latino adolescents using Interactive Guided ImagerySM

PubMed Central

2014-01-01

Background There is an urgent need for innovative and developmentally appropriate lifestyle interventions to promote healthy lifestyle behaviors and to prevent the early onset of type 2 diabetes and cardiovascular disease risk in obese Latino adolescents. Guided imagery offers promise to reduce stress and promote lifestyle behavior change to reduce disease risk in obese adolescents. Our objectives were: 1) To pilot test a new 12-wk lifestyle intervention using a randomized trial design in obese Latino adolescents, in order to determine the effects of the mind-body modality of Interactive Guided ImagerySM (IGI), over and above those of a didactic lifestyle education, on insulin resistance, eating and physical activity behaviors, stress and stress biomarkers; and 2) To explore the role of intervention-related changes in stress and stress biomarkers on changes in metabolic outcomes, particularly insulin resistance. Methods Obese (BMI > 95th percentile), Latino adolescents (n = 35, age 14-17) were randomized to receive either 12 weekly sessions of a lifestyle education plus guided imagery program (GI), or lifestyle education plus a digital storytelling computer program (DS). Between-group differences in behavioral, biological, and psychological outcomes were assessed using unpaired T-tests and ANCOVA in the 29 subjects who completed the intervention. Results The GI group demonstrated significant reductions in leisure sedentary behavior (p < .05) and increases in moderate physical activity (p < .05) compared to DS group, and a trend toward reduced caloric intake in GI vs DS (p = .09). Salivary cortisol was acutely reduced by stress-reduction guided imagery (p < .01). There were no group differences in adiposity, insulin resistance, perceived stress, or stress biomarkers across the 12-week intervention, though decrease in serum cortisol over the course of the intervention was associated with improved insulin sensitivity (p = .03) independent of intervention group and other relevant co-variates. Conclusions The improvements in physical activity and stress biomarkers following this pilot intervention support the role of guided imagery in promoting healthy lifestyle behavior change and reducing metabolic disease risk in obese Latino adolescent populations. Future investigations will be needed to determine the full effects of the Imagine HEALTH intervention on insulin resistance, stress, and stress biomarkers. Trial registration Clinicaltrials.gov Registry #: NCT01895595 PMID:24433565

Steps To Beat Stress.

ERIC Educational Resources Information Center

Shelton, Michael

1998-01-01

Explains techniques for reducing stress: diaphragmatic breathing, relaxation, progressive muscle relaxation, and meditation. Two sidebars define the fight-or-flight response and the camp administration's role in helping to lower stress through staff training and reduction of camp-wide stressors. (SAS)

A small randomized pilot study of a workplace mindfulness-based intervention for surgical intensive care unit personnel: effects on salivary α-amylase levels.

PubMed

Duchemin, Anne-Marie; Steinberg, Beth A; Marks, Donald R; Vanover, Kristin; Klatt, Maryanna

2015-04-01

To determine whether a workplace stress-reduction intervention decreases reactivity to stress among personnel exposed to a highly stressful occupational environment. Personnel from a surgical intensive care unit were randomized to a stress-reduction intervention or a waitlist control group. The 8-week group mindfulness-based intervention included mindfulness, gentle yoga, and music. Psychological and biological markers of stress were measured 1 week before and 1 week after the intervention. Levels of salivary α-amylase, an index of sympathetic activation, were significantly decreased between the first and second assessments in the intervention group with no changes in the control group. There was a positive correlation between salivary α-amylase levels and burnout scores. These data suggest that this type of intervention could decrease not only reactivity to stress but also the risk of burnout.

An epigenetic intervention interacts with genetic strain differences to modulate the stress-induced reduction of flurazepam's antiseizure efficacy in the mouse.

PubMed

Deutsch, Stephen I; Mastropaolo, John; Burket, Jessica A; Rosse, Richard B

2009-06-01

Stress induces changes in the endogenous tone of both GABA and NMDA receptor-mediated neurotransmission in the intact mouse. Because changes are observed 24 h after stress, epigenetically-regulated alterations in gene expression may mediate these effects. In earlier work, sodium butyrate, a centrally-active histone deacetylase inhibitor that promotes gene expression, was shown to modulate the stress-induced reduction of the ability of MK-801 (dizocilpine), a noncompetitive NMDA receptor antagonist, to antagonize electrically-precipitated seizures. In the current study, we extended this work to look at sodium butyrate's modulatory effect on stress-induced changes in the antiseizure efficacy of flurazepam, a benzodiazepine receptor agonist, in two strains of mice. Epigenetic mechanisms, genetic strain differences and a standard stress interacted to alter flurazepam's antiseizure efficacy. These data support examination and development of epigenetic treatment strategies.

Posttraumatic Stress Symptom Severity and Cognitive-Based Smoking Processes Among Trauma-Exposed Treatment-Seeking Smokers: The Role of Perceived Stress

PubMed Central

Garey, Lorra; Bakhshaie, Jafar; Vujanovic, Anka A.; Reitzel, Lorraine R.; Schmidt, Norman B.; Zvolensky, Michael J.

2016-01-01

Trauma exposure and smoking co-occur at an alarmingly high rate. However, there is little understanding of the mechanisms underlying this clinically significant relation. The present study examined perceived stress as an explanatory mechanism linking posttraumatic stress symptom severity and smoking-specific avoidance/inflexibility, perceived barriers to smoking cessation, and negative affect reduction/negative reinforcement expectancies from smoking among trauma-exposed smokers. Participants were trauma-exposed, treatment-seeking daily cigarette smokers (n = 179; 48.0% female; Mage = 41.17; SD = 12.55). Results indicated that posttraumatic stress symptom severity had an indirect significant effect on each of the dependent variables via perceived stress. The present results provide empirical support that perceived stress may be an underlying mechanism that indirectly explains posttraumatic symptoms relation to smoking-specific avoidance/inflexibility, perceived barriers to smoking cessation, and negative affect reduction/negative reinforcement expectancies among trauma-exposed smokers. These findings suggest that there may be clinical utility in targeting perceived stress among trauma-exposed smokers via stress management psychoeducation and skills training. PMID:27100473

Between harm reduction, loss and wellness: on the occupational hazards of work

PubMed Central

2013-01-01

Those working in the fields of harm reduction, healthcare, and human services must cope with a range of stresses, including post traumatic stress and vicarious trauma. Pain and loss are just a part of the job. So is dealing with premature death as a result of HIV, hypertension, and even overdose. Faced with a range of challenges, some workers in the field even turn to self-medication. For some, it is about pleasure; for others it is about alleviating suffering. In recent years, several leaders in the AIDS and harm reduction fields have died ahead of their time. Some stopped taking their medications; others overdosed. Rather than weakness or pathology, French sociologist Emile Durkheim saw self-destructive behavior as a byproduct of social disorganization and isolation, as a way of contending with a breakdown of social bonds and alienation. There are any number of reasons why such behavior becomes part of work for those involved with battling the dueling epidemics of Hepatitis C, HIV, and related concerns. Forms of stress related to this work include secondary trauma, compassion fatigue, organizational conflict, burnout, complications of direct services, and lack of funding. Faced with day-to- day struggles over poverty, punitive welfare systems, drug use, the war on drugs, high risk behavior, structural violence, and illness, many in the field are left to wonder how to strive for wellness when taking on so much pain. For some, self-injury and self-medication are ways of responding. Building on ethnographic methods, this reflective analysis considers the stories of those who have suffered, as well as a few of the ways those in the field cope with harm and pain. The work considers the moral questions we face when we see our friends and colleagues suffer. It asks how we as practitioners strive to create a culture of wellness and support in the fields of harm reduction, healthcare, and human services. Through a brief review of losses and literature thereof, the essay considers models of harm reduction practice that emphasize health, pleasure and sustainability for practitioners. PMID:23548032

Between harm reduction, loss and wellness: on the occupational hazards of work.

PubMed

Shepard, Benjamin C

2013-04-01

Those working in the fields of harm reduction, healthcare, and human services must cope with a range of stresses, including post traumatic stress and vicarious trauma. Pain and loss are just a part of the job. So is dealing with premature death as a result of HIV, hypertension, and even overdose. Faced with a range of challenges, some workers in the field even turn to self-medication. For some, it is about pleasure; for others it is about alleviating suffering. In recent years, several leaders in the AIDS and harm reduction fields have died ahead of their time. Some stopped taking their medications; others overdosed. Rather than weakness or pathology, French sociologist Emile Durkheim saw self-destructive behavior as a byproduct of social disorganization and isolation, as a way of contending with a breakdown of social bonds and alienation. There are any number of reasons why such behavior becomes part of work for those involved with battling the dueling epidemics of Hepatitis C, HIV, and related concerns. Forms of stress related to this work include secondary trauma, compassion fatigue, organizational conflict, burnout, complications of direct services, and lack of funding. Faced with day-to- day struggles over poverty, punitive welfare systems, drug use, the war on drugs, high risk behavior, structural violence, and illness, many in the field are left to wonder how to strive for wellness when taking on so much pain. For some, self-injury and self-medication are ways of responding. Building on ethnographic methods, this reflective analysis considers the stories of those who have suffered, as well as a few of the ways those in the field cope with harm and pain. The work considers the moral questions we face when we see our friends and colleagues suffer. It asks how we as practitioners strive to create a culture of wellness and support in the fields of harm reduction, healthcare, and human services. Through a brief review of losses and literature thereof, the essay considers models of harm reduction practice that emphasize health, pleasure and sustainability for practitioners.

An adapted mindfulness-based stress reduction program for elders in a continuing care retirement community: quantitative and qualitative results from a pilot randomized controlled trial.

PubMed

Moss, Aleezé S; Reibel, Diane K; Greeson, Jeffrey M; Thapar, Anjali; Bubb, Rebecca; Salmon, Jacqueline; Newberg, Andrew B

2015-06-01

The purpose of this study was to test the feasibility and effectiveness of an adapted 8-week Mindfulness-Based Stress Reduction (MBSR) program for elders in a continuing care community. This mixed-methods study used both quantitative and qualitative measures. A randomized waitlist control design was used for the quantitative aspect of the study. Thirty-nine elderly were randomized to MBSR (n = 20) or a waitlist control group (n = 19), mean age was 82 years. Both groups completed pre-post measures of health-related quality of life, acceptance and psychological flexibility, facets of mindfulness, self-compassion, and psychological distress. A subset of MBSR participants completed qualitative interviews. MBSR participants showed significantly greater improvement in acceptance and psychological flexibility and in role limitations due to physical health. In the qualitative interviews, MBSR participants reported increased awareness, less judgment, and greater self-compassion. Study results demonstrate the feasibility and potential effectiveness of an adapted MBSR program in promoting mind-body health for elders. © The Author(s) 2014.

FFR analysis of blood flow through a stenosed Left Anterior Descending Artery

NASA Astrophysics Data System (ADS)

Pasupathi, Jawahar; Arul Prakash, K.

2017-11-01

The numerical analyisis of blood flow through a stenosed tapering Left Anterior Descending (LAD) artery was done using Streamwise Upwind Petrov Galerkin (SUPG) method to obtain the clinical parameters such as Fractional Flow reserve (FFR) and Wall Shear Stress (WSS). The geometry was considered to be a straight tapering cylindrical duct with the severity of stenosis modeled using a curve equation based on the reduction in diameter at the stenosed region. Poiseuille velocity profile was given at the inlet such that at each time step the product of mean velocity and the inlet area gives the realistic flow rate through the LAD. The simulation was done for 30,50 and 70 percent reduction in cross-section of LAD. The average pressure values across the stenosis was used to quantify FFR. The FFR increased with higher pressure ratio across the stenosis, which is a result of increased severity of stenosis. The velocity gradients that are responsible for the shear stress at the walls were found to be dependent on the shape of the stenosis, i.e., the diameter and its length.

Trait Anxiety Reductions in a Substance Abuse Population Trained in Stress Management.

ERIC Educational Resources Information Center

Charlesworth, Edward A.; Dempsey, George

1982-01-01

Investigated a stress management training program for 11 hospitalized drug-abusing patients, compared to a control group in different psychotherapy programs. Results indicated that the stress management treatment group produced significant decreases in trait anxiety. Subjects used the stress management techniques to overcome insomnia, anger, and…

Parent Perspectives of Applying Mindfulness-Based Stress Reduction Strategies to Special Education

ERIC Educational Resources Information Center

Burke, Meghan M.; Chan, Neilson; Neece, Cameron L.

2017-01-01

Parents of children with (versus without) intellectual and developmental disabilities report greater stress; such stress may be exacerbated by dissatisfaction with school services, poor parent-school partnerships, and the need for parent advocacy. Increasingly, mindfulness interventions have been used to reduce parent stress. However, it is…

Neighbourhood parks and reduction in stress among adolescents: Results from Buffalo, New York

USDA-ARS?s Scientific Manuscript database

The presence of green space or parks in adolescents’ built environment may protect against daily psychological stress. Physical activity may also buffer the effects of stress. This study determined the association between objective measures of neighborhood park area and the usual stress of adolesc...

Nonlinear behavior of PP/PS blends with and without clay under large amplitude oscillatory shear (LAOS) flow

NASA Astrophysics Data System (ADS)

Salehiyan, Reza; Song, Hyeong Yong; Hyun, Kyu

2015-05-01

Dynamic oscillatory measurement, i.e., small amplitude oscillatory shear (SAOS) and large amplitude oscillatory shear (LAOS) test was used to investigate linear and non-linear viscoelastic properties of Polypropylene (PP)/Polystyrene (PS) blends with and without 5 wt.% clay (C20A). Fourier transform (FT-Rheology), Lissajous curves and stress decomposition methods were used to analyze non-linear responses under LAOS flow. Composition effects of blends were investigated prior to compatibilization effects. Elevated concentrations of dispersed phase (PS) increased the moduli G'(ω) from SAOS test and G*( γ 0) from LAOS test of the blends as well as strain thinning behavior. Interestingly, addition of 5 wt.% clay (C20A) boosted moduli of the blends as well as led to similar strain thinning behaviors among the PP/PS/C20A blends, except for the (90/10) PP/PS blend. The latter did not show improved rheological properties despite morphological improvements, as shown by SEM. Results from SEM and improved rheological properties of PP/PS/C20A blends revealed the compatibilization effects of clay (C20A) particles regardless of size reduction mechanisms. Third relative intensities ( I 3/1) from FT-rheology were found to be sensitive to clay (C20A) additions for the (70/30) and (30/70) PP/PS blends. Similarly, Lissajous curves could detect changes upon clay (C20A) addition, specifically at lower strain amplitudes whereupon addition of 5 wt.% clay resulted in the closed loops of Lissajous curves showing a more ellipsoidal shape due to increased elasticity in the blends. However, detection of these changes at larger strain amplitudes was more challenging. Therefore, stress decomposition (SD) method was applied for more precise characterization as it decomposes the total stress (σ) into elastic stress (σ') and viscous stress (σ″). Using SD method, elastic stress was more distorted, especially, strain hardening, while the total stress response remained almost unchanged at larger strain amplitudes.

A pilot randomized controlled trial of mindfulness-based stress reduction for caregivers of family members with dementia.

PubMed

Brown, Kirk Warren; Coogle, Constance L; Wegelin, Jacob

2016-11-01

The majority of care for those with Alzheimer's disease and other age-related dementias is provided in the home by family members. To date, there is no consistently effective intervention for reducing the significant stress burden of many family caregivers. The present pilot randomized controlled trial tested the efficacy of an adapted, eight-week mindfulness-based stress reduction (MBSR) program, relative to a near structurally equivalent, standard social support (SS) control condition for reducing caregiver stress and enhancing the care giver-recipient relationship. Thirty-eight family caregivers were randomized to MBSR or SS, with measures of diurnal salivary cortisol, and perceived stress, mental health, experiential avoidance, caregiver burden, and relationship quality collected pre- and post-intervention and at three-month follow-up. MBSR participants reported significantly lower levels of perceived stress and mood disturbance at post-intervention relative to SS participants. At three-month follow-up, participants in both treatment conditions reported improvements on several psychosocial outcomes. At follow-up, there were no condition differences on these outcomes, nor did MBSR and SS participants differ in diurnal cortisol response change over the course of the study. Both MBSR and SS showed stress reduction effects, and MBSR showed no sustained neuroendocrine and psychosocial advantages over SS. The lack of treatment condition differences could be attributable to active ingredients in both interventions, and to population-specific and design factors.

Effects of stress reduction on carotid atherosclerosis in hypertensive African Americans.

PubMed

Castillo-Richmond, A; Schneider, R H; Alexander, C N; Cook, R; Myers, H; Nidich, S; Haney, C; Rainforth, M; Salerno, J

2000-03-01

African Americans suffer disproportionately higher cardiovascular disease mortality rates than do whites. Psychosocial stress influences the development and progression of atherosclerosis. Carotid intima-media thickness (IMT) is a valid surrogate measure for coronary atherosclerosis, is a predictor of coronary outcomes and stroke, and is associated with psychosocial stress factors. Stress reduction with the Transcendental Meditation (TM) program decreases coronary heart disease risk factors and cardiovascular mortality in African Americans. B-mode ultrasound is useful for the noninvasive evaluation of carotid atherosclerosis. This randomized controlled clinical trial evaluated the effects of the TM program on carotid IMT in hypertensive African American men and women, aged >20 years, over a 6- to 9-month period. From the initially enrolled 138 volunteers, 60 subjects completed pretest and posttest carotid IMT data. The assigned interventions were either the TM program or a health education group. By use of B-mode ultrasound, mean maximum IMT from 6 carotid segments was used to determine pretest and posttest IMT values. Regression analysis and ANCOVA were performed. Age and pretest IMT were found to be predictors of posttest IMT values and were used as covariates. The TM group showed a significant decrease of -0.098 mm (95% CI -0. 198 to 0.003 mm) compared with an increase of 0.054 mm (95% CI -0.05 to 0.158 mm) in the control group (P=0.038, 2-tailed). Stress reduction with the TM program is associated with reduced carotid atherosclerosis compared with health education in hypertensive African Americans. Further research with this stress-reduction technique is warranted to confirm these preliminary findings.

Endogenous reward mechanisms and their importance in stress reduction, exercise and the brain.

PubMed

Esch, Tobias; Stefano, George B

2010-06-30

Stress can facilitate disease processes and causes strain on the health care budgets. It is responsible or involved in many human ailments of our time, such as cardiovascular illnesses, particularly related to the psychosocial stressors of daily life, including work. Besides pharmacological or clinical medical treatment options, behavioral stress reduction is much-needed. These latter approaches rely on an endogenous healing potential via life-style modification. Hence, research has suggested different ways and approaches to self-treat stress or buffer against stressors and their impacts. These self-care-centred approaches are sometimes referred to as mind-body medicine or multi-factorial stress management strategies. They consist of various cognitive behavioral techniques, as well as relaxation exercises and nutritional counselling. However, a critical and consistent element of modern effective stress reduction strategies are exercise practices. With regard to underlying neurobiological mechanisms of stress relief, reward and motivation circuitries that are imbedded in the limbic regions of the brain are responsible for the autoregulatory and endogenous processing of stress. Exercise techniques clearly have an impact upon these systems. Thereby, physical activities have a potential to increase mood, i.e., decrease psychological distress by pleasure induction. For doing so, neurobiological signalling molecules such as endogenous morphine and coupled nitric oxide pathways get activated and finely tuned. Evolutionarily, the various activities and autoregulatory pathways are linked together, which can also be demonstrated by the fact that dopamine is endogenously converted into morphine which itself leads to enhanced nitric oxide release by activation of constitutive nitric oxide synthase enzymes. These molecules and mechanisms are clearly stress-reducing.

Wild soybean roots depend on specific transcription factors and oxidation reduction related genesin response to alkaline stress.

PubMed

DuanMu, Huizi; Wang, Yang; Bai, Xi; Cheng, Shufei; Deyholos, Michael K; Wong, Gane Ka-Shu; Li, Dan; Zhu, Dan; Li, Ran; Yu, Yang; Cao, Lei; Chen, Chao; Zhu, Yanming

2015-11-01

Soil alkalinity is an important environmental problem limiting agricultural productivity. Wild soybean (Glycine soja) shows strong alkaline stress tolerance, so it is an ideal plant candidate for studying the molecular mechanisms of alkaline tolerance and identifying alkaline stress-responsive genes. However, limited information is available about G. soja responses to alkaline stress on a genomic scale. Therefore, in the present study, we used RNA sequencing to compare transcript profiles of G. soja root responses to sodium bicarbonate (NaHCO3) at six time points, and a total of 68,138,478 pairs of clean reads were obtained using the Illumina GAIIX. Expression patterns of 46,404 G. soja genes were profiled in all six samples based on RNA-seq data using Cufflinks software. Then, t12 transcription factors from MYB, WRKY, NAC, bZIP, C2H2, HB, and TIFY families and 12 oxidation reduction related genes were chosen and verified to be induced in response to alkaline stress by using quantitative real-time polymerase chain reaction (qRT-PCR). The GO functional annotation analysis showed that besides "transcriptional regulation" and "oxidation reduction," these genes were involved in a variety of processes, such as "binding" and "response to stress." This is the first comprehensive transcriptome profiling analysis of wild soybean root under alkaline stress by RNA sequencing. Our results highlight changes in the gene expression patterns and identify a set of genes induced by NaHCO3 stress. These findings provide a base for the global analyses of G. soja alkaline stress tolerance mechanisms.

Mindfulness-based stress reduction for parents of young children with developmental delays: implications for parental mental health and child behavior problems.

PubMed

Neece, Cameron L

2014-03-01

Parents of children with developmental delays (DD) typically report elevated levels of parental stress compared with parents of typically developing children. Children with DD are also at high risk for exhibiting significant behaviour problems. Parental stress has been shown to impact the development of these behaviour problems; however, it is rarely addressed in interventions aimed at reducing child behaviour problems. The current study examined the efficacy of mindfulness-based stress reduction (MBSR) for parents of children with DD by investigating whether this intervention is effective in reducing parenting stress and whether decreases in parenting stress lead to reductions in behaviour problems among children with DD. Forty six parents of children with DD were randomly assigned to an immediate treatment or wait list-control group. Participants completed questionnaires assessing parental stress and child behaviour problems at intake and at a second assessment, which took place after only the immediate treatment group had received the MBSR. Parents who participated in MBSR reported significantly less stress and depression as well as greater life satisfaction compared with wait list-control parents. Regarding child outcomes, children whose parents participated in MBSR were reported to have fewer behaviour problems following the intervention, specifically in the areas of attention problems and ADHD symptomatology. Results indicated that MBSR may be an effective intervention for ameliorating parental stress and mental health problems among parents of children with DD. Additionally, these benefits may 'spill over' and improve behaviour challenges among these children. © 2013 John Wiley & Sons Ltd.

The controlled growth method - A tool for structural optimization

NASA Technical Reports Server (NTRS)

Hajela, P.; Sobieszczanski-Sobieski, J.

1981-01-01

An adaptive design variable linking scheme in a NLP based optimization algorithm is proposed and evaluated for feasibility of application. The present scheme, based on an intuitive effectiveness measure for each variable, differs from existing methodology in that a single dominant variable controls the growth of all others in a prescribed optimization cycle. The proposed method is implemented for truss assemblies and a wing box structure for stress, displacement and frequency constraints. Substantial reduction in computational time, even more so for structures under multiple load conditions, coupled with a minimal accompanying loss in accuracy, vindicates the algorithm.

Recovery from the impact of light reduction on the seagrass Amphibolis griffithii, insights for dredging management.

PubMed

McMahon, Kathryn; Lavery, Paul S; Mulligan, Michael

2011-02-01

A large-scale, manipulative experiment was conducted to examine the extent and rate of recovery of meadows of the temperate Australian seagrass, Amphibolis griffithii to different light-reduction scenarios typical of dredging operations, and to identify potential indicators of recovery from light reduction stress. Shade cloth was used to mimic different intensities, durations and start times of light reduction, and then was removed to assess the recovery. The meadow could recover from 3 months of light stress (5-18% ambient) following 10 months re-exposure to ambient light, even when up to 72% of leaf biomass was lost, much faster recovery rates than has previously been observed for large seagrasses. However, when the meadow had been shaded for 6-9 months and more than 82% of leaf biomass was lost, no recovery was detected up to 23 months after the light stress had ceased, consistent with other studies. Five potential indicators of recovery were recommended. Copyright © 2010 Elsevier Ltd. All rights reserved.

Effects of roughness height, pressure and streamwise distance on stress profiles in the inner part of turbulent boundary layer over super-hydrophobic surfaces

NASA Astrophysics Data System (ADS)

Ling, Hangjian; Katz, Joseph; Srinivasan, Siddarth; McKinley, Gareth; Golovin, Kevin; Tuteja, Anish; Pillutla, Venkata; Abhijeet, Abhijeet; Choi, Wonjae

2016-11-01

Digital holographic microscopy is used for measuring the mean velocity and stress in the inner part of turbulent boundary layers over sprayed or etched super-hydrophobic surfaces (SHSs). The slip velocity and wall friction are calculated directly from the mean velocity and its gradient along with the Reynolds shear stress at the top of SHSs "roughness". Effects of the normalized rms roughness height krms+, facility pressure p and streamwise distance x from the beginning of SHSs on mean flow are examined. For krms+<1 and pkrms / σ <1 (σ is surface tension), the SHSs show 10-28% wall friction reduction, 15-30% slip velocity and λ+ = 3-10 slip length. Increasing Reynolds number and/or krms to establish krms+>1, and increasing p to achieve pkrms / σ >1 suppress the drag reduction, as roughness effects and associated near wall Reynolds stress increase. When the roughness effect is not dominant, the measurements agree with previous theoretical predictions of the relationships between drag reduction and slip velocity. The significance of spanwise slip relative to streamwise slip varies with the SHSs texture. Transitions from a smooth wall to a SHS involve overshoot of Reynolds stress and undershoot of viscous stress, trends that diminish with x. Sponsored by ONR.

Reductions in labour capacity from heat stress under climate warming

NASA Astrophysics Data System (ADS)

Dunne, John P.; Stouffer, Ronald J.; John, Jasmin G.

2013-06-01

A fundamental aspect of greenhouse-gas-induced warming is a global-scale increase in absolute humidity. Under continued warming, this response has been shown to pose increasingly severe limitations on human activity in tropical and mid-latitudes during peak months of heat stress. One heat-stress metric with broad occupational health applications is wet-bulb globe temperature. We combine wet-bulb globe temperatures from global climate historical reanalysis and Earth System Model (ESM2M) projections with industrial and military guidelines for an acclimated individual's occupational capacity to safely perform sustained labour under environmental heat stress (labour capacity)--here defined as a global population-weighted metric temporally fixed at the 2010 distribution. We estimate that environmental heat stress has reduced labour capacity to 90% in peak months over the past few decades. ESM2M projects labour capacity reduction to 80% in peak months by 2050. Under the highest scenario considered (Representative Concentration Pathway 8.5), ESM2M projects labour capacity reduction to less than 40% by 2200 in peak months, with most tropical and mid-latitudes experiencing extreme climatological heat stress. Uncertainties and caveats associated with these projections include climate sensitivity, climate warming patterns, CO2 emissions, future population distributions, and technological and societal change.

Wall stress reduction in abdominal aortic aneurysms as a result of polymeric endoaortic paving.

PubMed

Ashton, John H; Ayyalasomayajula, Avinash; Simon, Bruce R; Vande Geest, Jonathan P

2011-06-01

Polymeric endoaortic paving (PEAP) may improve endovascular repair of abdominal aortic aneurysms (AAA) since it has the potential to treat patients with complex AAA geometries while reducing the incidence of migration and endoleak. Polycaprolactone (PCL)/polyurethane (PU) blends are proposed as PEAP materials due to their range of mechanical properties, thermoformability, and resistance to biodegradation. In this study, the reduction in AAA wall stress that can be achieved using PEAP was estimated and compared to that resulting from stent-grafts. This was accomplished by mechanically modeling the anisotropic response of PCL/PU blends and implementing these results into finite element model (FEM) simulations. We found that at the maximum diameter of the AAA, the 50/50 and 10/90 PCL/PU blends reduced wall stress by 99 and 98%, respectively, while a stent-graft reduced wall stress by 99%. Our results also show that wall stress reduction increases with increasing PEAP thickness and PCL content in the blend ratio. These results indicate that PEAP can reduce AAA wall stress as effectively as a stent-graft. As such, we propose that PEAP may provide an improved treatment alternative for AAA, since many of the limitations of stent-grafts have the potential to be solved using this approach.

A meteorologically-driven yield reduction model for spring and winter wheat

NASA Technical Reports Server (NTRS)

Ravet, F. W.; Cremins, W. J.; Taylor, T. W.; Ashburn, P.; Smika, D.; Aaronson, A. (Principal Investigator)

1983-01-01

A yield reduction model for spring and winter wheat was developed for large-area crop condition assessment. Reductions are expressed in percentage from a base yield and are calculated on a daily basis. The algorithm contains two integral components: a two-layer soil water budget model and a crop calendar routine. Yield reductions associated with hot, dry winds (Sukhovey) and soil moisture stress are determined. Input variables include evapotranspiration, maximum temperature and precipitation; subsequently crop-stage, available water holding percentage and stress duration are evaluated. No specific base yield is required and may be selected by the user; however, it may be generally characterized as the maximum likely to be produced commercially at a location.

The effects of mindfulness-based stress reduction on cardiac patients' blood pressure, perceived stress, and anger: a single-blind randomized controlled trial.

PubMed

Momeni, Javad; Omidi, Abdollah; Raygan, Fariba; Akbari, Hossein

2016-10-01

This study aimed at assessing the effects of mindfulness-based stress reduction (MBSR) on cardiac patients' blood pressure (BP), perceived stress, and anger. In total, 60 cardiac patients were recruited between April and June 2015 from a specialized private cardiac clinic located in Kashan, Iran. Patients were allocated to the intervention and control groups. Patients in the experimental group received MBSR in eight 2.5-hour sessions, while patients in the control group received no psychological therapy. The main outcomes were BP, perceived stress, and anger. Analysis of covariance revealed a significant difference between the study groups regarding the posttest values of systolic BP, perceived stress, and anger (P < .001). However, the study groups did not differ significantly in terms of diastolic BP (P = .061; P = .17). This study reveals that MBSR is effective in reducing cardiac patients' systolic BP, perceived stress, and anger. Copyright © 2016 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

Improved tolerance to post-anthesis drought stress by pre-drought priming at vegetative stages in drought-tolerant and -sensitive wheat cultivars.

PubMed

Abid, Muhammad; Tian, Zhongwei; Ata-Ul-Karim, Syed Tahir; Liu, Yang; Cui, Yakun; Zahoor, Rizwan; Jiang, Dong; Dai, Tingbo

2016-09-01

Wheat crop endures a considerable penalty of yield reduction to escape the drought events during post-anthesis period. Drought priming under a pre-drought stress can enhance the crop potential to tolerate the subsequent drought stress by triggering a faster and stronger defense mechanism. Towards these understandings, a set of controlled moderate drought stress at 55-60% field capacity (FC) was developed to prime the plants of two wheat cultivars namely Luhan-7 (drought tolerant) and Yangmai-16 (drought sensitive) during tillering (Feekes 2 stage) and jointing (Feekes 6 stage), respectively. The comparative response of primed and non-primed plants, cultivars and priming stages was evaluated by applying a subsequent severe drought stress at 7 days after anthesis. The results showed that primed plants of both cultivars showed higher potential to tolerate the post-anthesis drought stress through improved leaf water potential, more chlorophyll, and ribulose-1, 5-bisphosphate carboxylase/oxygenase contents, enhanced photosynthesis, better photoprotection and efficient enzymatic antioxidant system leading to less yield reductions. The primed plants of Luhan-7 showed higher capability to adapt the drought stress events than Yangmai-16. The positive effects of drought priming to sustain higher grain yield were pronounced in plants primed at tillering than those primed at jointing. In consequence, upregulated functioning of photosynthetic apparatus and efficient enzymatic antioxidant activities in primed plants indicated their superior potential to alleviate a subsequently occurring drought stress, which contributed to lower yield reductions than non-primed plants. However, genotypic and priming stages differences in response to drought stress also contributed to affect the capability of primed plants to tolerate the post-anthesis drought stress conditions in wheat. Copyright © 2016. Published by Elsevier Masson SAS.

Examining the Impact of a University-driven Exercise Programming Event on End-of-semester Stress in Students.

PubMed

Koschel, Tessa L; Young, John C; Navalta, James W

2017-01-01

Stress levels in university students peak during the final exam period. An inverse association exists between Physical Activity (PA) and poor mental health. UNLV has created Fitness4Finals (F4F), an event novel in its approach to academic stress reduction by incorporating both physical activity and mental relaxation. To our knowledge, a university-driven programming event aimed at reducing physiological and psychological stress among students approaching final exams had never been studied. Therefore, the aims of this research were to 1) examine the influence of F4F on physiological stress and perceived psychological stress (PPS) and 2) to examine the relationship between physiological stress and PPS. Fifteen full-time university students were recruited to participate in their choice of one of two groups: F4F or control (NonF4F). Pre-F4F and post-F4F measures of physiological stress, measured by salivary cortisol, and perceived psychological stress, measured by survey were collected. The F4F event was held the week prior to final examinations. Participants in the F4F group engaged in one F4F activity per day for the duration of the 3-day event. Results of the repeated measures MANOVA indicated nonsignificant interaction (p = .864) between F4F participation, physiological stress and PPS. PPS and cortisol were not correlated at the onset of the study (r = -0.18, p = 0.48) or at the last sampling period (r = 0.097, p = 0.73). Preemptive elevated levels of PA in the F4F group may have influenced results. Qualitative data indicates a unanimous perceived reduction in stress from F4F participation. While the physiological measures of stress in the present study were not significantly different, the perceived stress reduction reported by F4F participants is influential. Further investigation with improvements in timing and measurement tools is warranted.

[Criteria for assessing severely hot environments: from the WBGT index to the PHS (predicted heat strain) model].

PubMed

d'Ambrosio, Francesca Romana; Palella, B I; Riccio, G; Alfano, G

2004-01-01

The present study deals with the main methods for assessment of hot environments: i.e., WBGT, SWreq and PHS. It is stressed how the WBGT index, which is strictly empirical, although a very practical tool for the assessment of the hot environments, can only be used for a rough evaluation of heat stress, and especially for a not very high metabolic rate (M<175 W/m2). On the contrary, the SWreq method, which is based on both subject-environment heat exchange and the effect of clothing, allows a better assessment of the work situation with a general reduction of the exposure limits with respect to WBGT, especially in non-uniform environments (ta not equal to tr). However, it should be noted that application of SWreq is required by the ISO standard 7243 when the WBGT limit values are exceeded. In this study interest was extensively focused on the "Predicted Heat Strain" method, highlighting via a special software the differences in heat stress assessment related to this new approach, which will be adopted by the ISO in the next revision of standard 7933. The PHS method, unlike SWreq, allows the prediction of the time-response of the main physiological variables of interest (i.e., skin temperature, core temperature and sweat rate). Moreover thanks to better modelling of heat exchanges, the PHS method allows account to be taken of both movement and clothing effects, resulting in even more reduced exposure.

Mechanics of evolutionary digit reduction in fossil horses (Equidae).

PubMed

McHorse, Brianna K; Biewener, Andrew A; Pierce, Stephanie E

2017-08-30

Digit reduction is a major trend that characterizes horse evolution, but its causes and consequences have rarely been quantitatively tested. Using beam analysis on fossilized centre metapodials, we tested how locomotor bone stresses changed with digit reduction and increasing body size across the horse lineage. Internal bone geometry was captured from 13 fossil horse genera that covered the breadth of the equid phylogeny and the spectrum of digit reduction and body sizes, from Hyracotherium to Equus To account for the load-bearing role of side digits, a novel, continuous measure of digit reduction was also established-toe reduction index (TRI). Our results show that without accounting for side digits, three-toed horses as late as Parahippus would have experienced physiologically untenable bone stresses. Conversely, when side digits are modelled as load-bearing, species at the base of the horse radiation through Equus probably maintained a similar safety factor to fracture stress. We conclude that the centre metapodial compensated for evolutionary digit reduction and body mass increases by becoming more resistant to bending through substantial positive allometry in internal geometry. These results lend support to two historical hypotheses: that increasing body mass selected for a single, robust metapodial rather than several smaller ones; and that, as horse limbs became elongated, the cost of inertia from the side toes outweighed their utility for stabilization or load-bearing. © 2017 The Author(s).

Heat stress, the follicle, and its enclosed oocyte: mechanisms and potential strategies to improve fertility in dairy cows.

PubMed

Roth, Z

2008-07-01

Reduced reproductive performance of lactating cows during the summer is associated with decreased thermoregulatory competence due to intensive genetic selection for high milk production. This review examines the immediate and delayed effects of heat stress on follicular function and describes some potential strategies for their alleviation. It focuses on how heat stress affects the follicle and its enclosed oocyte, suggesting that perturbations in the follicular microenvironment, to which the oocytes are exposed for long periods of development, reduce their developmental competence. Among the potential alterations are reduction in gonadotropin secretion, alteration in follicular growth, attenuation of dominance, and disruption of steroidogenesis. Evaporative cooling methods are the most common strategy used to alleviate the effect of heat stress; however, there is a compelling need to find additional ways to improve fertility during the summer and autumn. Hormonal treatment to enhance removal of the impaired follicles by synchronization of follicular waves with GnRH and PGF2 alpha is suggested. An alternative method is stimulation of follicular growth by a brief treatment with bST or FSH. Other strategies, such as timed AI and embryo transfer, have been recently used, making the optimization of embryo cryopreservation procedures highly relevant. Protection of the ovarian pool of oocytes from thermal stress via nutritional manipulations or administration of antioxidants or other survival factors should also be considered. A better understanding of the underlying mechanisms by which heat stress impairs fertility may lead to the development of additional approaches to alleviate these effects.

Affect systems, changes in body mass index, disordered eating and stress: an 18-month longitudinal study in women

PubMed Central

Kupeli, N.; Norton, S.; Chilcot, J.; Campbell, I. C.; Schmidt, U. H.; Troop, N. A.

2017-01-01

ABSTRACT Background: Evidence suggests that stress plays a role in changes in body weight and disordered eating. The present study examined the effect of mood, affect systems (attachment and social rank) and affect regulatory processes (self-criticism, self-reassurance) on the stress process and how this impacts on changes in weight and disordered eating. Methods: A large sample of women participated in a community-based prospective, longitudinal online study in which measures of body mass index (BMI), disordered eating, perceived stress, attachment, social rank, mood and self-criticism/reassurance were measured at 6-monthly intervals over an 18-month period. Results: Latent Growth Curve Modelling showed that BMI increased over 18 months while stress and disordered eating decreased and that these changes were predicted by high baseline levels of these constructs. Independently of this, however, increases in stress predicted a reduction in BMI which was, itself, predicted by baseline levels of self-hatred and unfavourable social comparison. Conclusions: This study adds support to the evidence that stress is important in weight change. In addition, this is the first study to show in a longitudinal design, that social rank and self-criticism (as opposed to self-reassurance) at times of difficulty predict increases in stress and, thus, suggests a role for these constructs in weight regulation. PMID:28553564

Drag reduction using wrinkled surfaces in high Reynolds number laminar boundary layer flows

NASA Astrophysics Data System (ADS)

Raayai-Ardakani, Shabnam; McKinley, Gareth H.

2017-09-01

Inspired by the design of the ribbed structure of shark skin, passive drag reduction methods using stream-wise riblet surfaces have previously been developed and tested over a wide range of flow conditions. Such textures aligned in the flow direction have been shown to be able to reduce skin friction drag by 4%-8%. Here, we explore the effects of periodic sinusoidal riblet surfaces aligned in the flow direction (also known as a "wrinkled" texture) on the evolution of a laminar boundary layer flow. Using numerical analysis with the open source Computational Fluid Dynamics solver OpenFOAM, boundary layer flow over sinusoidal wrinkled plates with a range of wavelength to plate length ratios ( λ / L ), aspect ratios ( 2 A / λ ), and inlet velocities are examined. It is shown that in the laminar boundary layer regime, the riblets are able to retard the viscous flow inside the grooves creating a cushion of stagnant fluid that the high-speed fluid above can partially slide over, thus reducing the shear stress inside the grooves and the total integrated viscous drag force on the plate. Additionally, we explore how the boundary layer thickness, local average shear stress distribution, and total drag force on the wrinkled plate vary with the aspect ratio of the riblets as well as the length of the plate. We show that riblets with an aspect ratio of close to unity lead to the highest reduction in the total drag, and that because of the interplay between the local stress distribution on the plate and stream-wise evolution of the boundary layer the plate has to exceed a critical length to give a net decrease in the total drag force.

Educational Leaders Describe a Job Too Big for One: Stress Reduction In the Midst of Leading

ERIC Educational Resources Information Center

Wells, Caryn M.

2013-01-01

This conceptual paper reviews research findings about the world of stress of principals and superintendents, focusing on the high levels of stress that the educational leaders report. The literature on occupational stress is also explored for its insights on the medical and psychological results of workplace stress and the relationship to stress…

Creative Arts Interventions for Stress Management and Prevention-A Systematic Review.

PubMed

Martin, Lily; Oepen, Renate; Bauer, Katharina; Nottensteiner, Alina; Mergheim, Katja; Gruber, Harald; Koch, Sabine C

2018-02-22

Stress is one of the world's largest health problems, leading to exhaustion, burnout, anxiety, a weak immune system, or even organ damage. In Germany, stress-induced work absenteeism costs about 20 billion Euros per year. Therefore, it is not surprising that the Central Federal Association of the public Health Insurance Funds in Germany ascribes particular importance to stress prevention and stress management as well as health enhancing measures. Building on current integrative and embodied stress theories, Creative Arts Therapies (CATs) or arts interventions are an innovative way to prevent stress and improve stress management. CATs encompass art, music, dance/movement, and drama therapy as their four major modalities. In order to obtain an overview of CATs and arts interventions' efficacy in the context of stress reduction and management, we conducted a systematic review with a search in the following data bases: Academic Search Complete, ERIC, Medline, Psyndex, PsycINFO and SocINDEX. Studies were included employing the PICOS principle and rated according to their evidence level. We included 37 studies, 73% of which were randomized controlled trials. 81.1% of the included studies reported a significant reduction of stress in the participants due to interventions of one of the four arts modalities.

[Integration of psychodynamic imaginative trauma therapy in a modified psychoanalytic concept of a inpatient psychotherapy unit].

PubMed

Beckrath-Wilking, Ulrike

2004-11-01

Results of latest neurobiological trauma-research suggest that many psychic disorders like personality disorders with complex traumatisation in patient's history and co-morbidities should better be treated as posttraumatic disorders. This is important for any therapy planning: should a modified psychoanalytic approach (like TFP by Kernberg) with emphasis on interpreting the transference-relation be preferred for patients with Borderline personality disorder or - diagnosing the same patients as complex posttraumatic stress disorder - a phase oriented trauma-specific approach. As such PITT combines psychodynamic understanding with hypnotherapeutic and imaginative methods. Crucial points are an active and supporting therapeutic relation, safety and reduction of stress, focus on all individual resources and use of imaginative ways for stabilization and later trauma-confrontation work.

How specialized volatiles respond to chronic and short-term physiological and shock heat stress in Brassica nigra.

PubMed

Kask, Kaia; Kännaste, Astrid; Talts, Eero; Copolovici, Lucian; Niinemets, Ülo

2016-09-01

Brassicales release volatile glucosinolate breakdown products upon tissue mechanical damage, but it is unclear how the release of glucosinolate volatiles responds to abiotic stresses such as heat stress. We used three different heat treatments, simulating different dynamic temperature conditions in the field to gain insight into stress-dependent changes in volatile blends and photosynthetic characteristics in the annual herb Brassica nigra (L.) Koch. Heat stress was applied by either heating leaves through temperature response curve measurements from 20 to 40 °C (mild stress), exposing plants for 4 h to temperatures 25-44 °C (long-term stress) or shock-heating leaves to 45-50 °C. Photosynthetic reduction through temperature response curves was associated with decreased stomatal conductance, while the reduction due to long-term stress and collapse of photosynthetic activity after heat shock stress were associated with non-stomatal processes. Mild stress decreased constitutive monoterpene emissions, while long-term stress and shock stress resulted in emissions of the lipoxygenase pathway and glucosinolate volatiles. Glucosinolate volatile release was more strongly elicited by long-term stress and lipoxygenase product released by heat shock. These results demonstrate that glucosinolate volatiles constitute a major part of emission blend in heat-stressed B. nigra plants, especially upon chronic stress that leads to induction responses. © 2016 John Wiley & Sons Ltd.

A quasi-linear analysis of the impurity effect on turbulent momentum transport and residual stress

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ko, S. H., E-mail: shko@nfri.re.kr; Jhang, Hogun; Singh, R.

2015-08-15

We study the impact of impurities on turbulence driven intrinsic rotation (via residual stress) in the context of the quasi-linear theory. A two-fluid formulation for main and impurity ions is employed to study ion temperature gradient modes in sheared slab geometry modified by the presence of impurities. An effective form of the parallel Reynolds stress is derived in the center of mass frame of a coupled main ion-impurity system. Analyses show that the contents and the radial profile of impurities have a strong influence on the residual stress. In particular, an impurity profile aligned with that of main ions ismore » shown to cause a considerable reduction of the residual stress, which may lead to the reduction of turbulence driven intrinsic rotation.« less

Stress reduction in the secondary prevention of cardiovascular disease: randomized, controlled trial of transcendental meditation and health education in Blacks.

PubMed

Schneider, Robert H; Grim, Clarence E; Rainforth, Maxwell V; Kotchen, Theodore; Nidich, Sanford I; Gaylord-King, Carolyn; Salerno, John W; Kotchen, Jane Morley; Alexander, Charles N

2012-11-01

Blacks have disproportionately high rates of cardiovascular disease. Psychosocial stress may contribute to this disparity. Previous trials on stress reduction with the Transcendental Meditation (TM) program have reported improvements in cardiovascular disease risk factors, surrogate end points, and mortality in blacks and other populations. This was a randomized, controlled trial of 201 black men and women with coronary heart disease who were randomized to the TM program or health education. The primary end point was the composite of all-cause mortality, myocardial infarction, or stroke. Secondary end points included the composite of cardiovascular mortality, revascularizations, and cardiovascular hospitalizations; blood pressure; psychosocial stress factors; and lifestyle behaviors. During an average follow-up of 5.4 years, there was a 48% risk reduction in the primary end point in the TM group (hazard ratio, 0.52; 95% confidence interval, 0.29-0.92; P=0.025). The TM group also showed a 24% risk reduction in the secondary end point (hazard ratio, 0.76; 95% confidence interval, 0.51-0.1.13; P=0.17). There were reductions of 4.9 mmHg in systolic blood pressure (95% confidence interval -8.3 to -1.5 mmHg; P=0.01) and anger expression (P<0.05 for all scales). Adherence was associated with survival. A selected mind-body intervention, the TM program, significantly reduced risk for mortality, myocardial infarction, and stroke in coronary heart disease patients. These changes were associated with lower blood pressure and psychosocial stress factors. Therefore, this practice may be clinically useful in the secondary prevention of cardiovascular disease. Clinical Trial Registration- URL: www.clinicaltrials.gov Unique identifier: NCT01299935.

The integration of studio cycling into a worksite stress management programme.

PubMed

Clark, Matthew M; Soyring, Jason E; Jenkins, Sarah M; Daniels, Denise C; Berkland, Bridget E; Werneburg, Brooke L; Hagen, Philip T; Lopez-Jimenez, Francisco; Warren, Beth A; Olsen, Kerry D

2014-04-01

High stress is a prevalent problem in the worksite. To reduce stress, improve productivity, reduce absenteeism, and lower healthcare costs, many companies offer exercise classes or stress management programmes. Although physical activity is an important component of stress management, few worksites have integrated physical activity into their comprehensive stress reduction programmes. The purpose of this single-arm pilot project was to examine the potential effectiveness of an integrated exercise (studio cycling) and cognitive-behavioural stress management programme. Eighty-four adults, 75% female, mostly aged 40+ years, participated in an integrated 12-week cycling studio and cognitive-behavioural stress management programme. Participants experienced a significant and clinically meaningful reduction on the Perceived Stress Scale (p < 0.01), rating of current stress level and confidence to manage stress at the programme's end and at a 1-month follow-up. Participants also reported having significantly improved overall health, improved nutritional habits, higher physical activity level, greater confidence in their ability to follow a healthy diet, higher spiritual well-being, improved sleep, receiving more support for maintaining healthy living and improved quality of life at the completion of the 12-week programme and 1-month follow-up. These findings provide further support for an integrated exercise and stress management programme. © 2013 John Wiley & Sons, Ltd.

Academic Stress and Prevalence of Stress-Related Self-Medication among Undergraduate Female Students of Health and Non-Health Cluster Colleges of a Public Sector University in Dammam, Saudi Arabia

PubMed Central

Al Rasheed, Fatima; Naqvi, Atta Abbas; Ahmad, Rizwan; Ahmad, Niyaz

2017-01-01

Objective: The objective was to report academic stress and prevalence of stress-related self-medication among undergraduate female students of health and nonhealth cluster colleges at a public sector university in Dammam, Saudi Arabia. Materials and Methods: A 5-month cross-sectional survey was conducted in the university. The survey included the English version of 10-item Perceived Stress Scale (PSS) to report self-perceived stress. Student responses were analyzed by SPSS version 22 software. Results: The majority of students (85%) perceived examinations as a stressor. Most of the students (64%) had perceived moderate stress that increased as students progressed from preparatory year to 4th year. It declined in students of 5th and 6th year. The prevalence of stress related was reported at 39.58%. Highest prevalence of stress-induced self-medication was reported from College of Nursing (59.09%) and lowest (29.69%) from clinical pharmacy. Most common drug used to self-medicate during stress was caffeine (49.5%). The PSS score was significantly associated with colleges and study levels. Conclusion: Students studying in health cluster colleges reported high academic stress and self-medication practice. The major stressors identified were examination and course load. Student counseling sessions and counseling by pharmacists regarding self-care may help in the reduction of such stressors and may promote responsible self-medication. Self-evaluation and quality assurance process of curriculum may highlight areas for improvement in the courses. This may help in lowering academic stress among students. PMID:29456376

Stress Prevention and Mindfulness: A Psychoeducational and Support Group for Teachers

ERIC Educational Resources Information Center

Reiser, Jenson E.; Murphy, Susan L.; McCarthy, Christopher J.

2016-01-01

A stress prevention and mindfulness (SPAM) group is described, which is a 6-week psychoeducational and support group for teachers. The group incorporated psychoeducation about stress and utilized elements of Mindfulness-Based Stress Reduction (MBSR). The group was implemented in a public charter school in the Southwest. Preliminary evaluation…

Examination of Broad Symptom Improvement Resulting From Mindfulness-Based Stress Reduction in Breast Cancer Survivors: A Randomized Controlled Trial

PubMed Central

Reich, Richard R.; Paterson, Carly L.; Ramesar, Sophia; Park, Jong Y.; Alinat, Carissa; Johnson-Mallard, Versie; Moscoso, Manolete; Budhrani-Shani, Pinky; Miladinovic, Branko; Jacobsen, Paul B.; Cox, Charles E.; Goodman, Matthew; Kip, Kevin E.

2016-01-01

Purpose The purpose of this randomized trial was to evaluate the efficacy of the Mindfulness-Based Stress Reduction for Breast Cancer (MBSR[BC]) program in improving psychological and physical symptoms and quality of life among breast cancer survivors (BCSs) who completed treatment. Outcomes were assessed immediately after 6 weeks of MBSR(BC) training and 6 weeks later to test efficacy over an extended timeframe. Patients and Methods A total of 322 BCSs were randomly assigned to either a 6-week MBSR(BC) program (n = 155) or a usual care group (n = 167). Psychological (depression, anxiety, stress, and fear of recurrence) and physical symptoms (fatigue and pain) and quality of life (as related to health) were assessed at baseline and at 6 and 12 weeks. Linear mixed models were used to assess MBSR(BC) effects over time, and participant characteristics at baseline were also tested as moderators of MBSR(BC) effects. Results Results demonstrated extended improvement for the MBSR(BC) group compared with usual care in both psychological symptoms of anxiety, fear of recurrence overall, and fear of recurrence problems and physical symptoms of fatigue severity and fatigue interference (P < .01). Overall effect sizes were largest for fear of recurrence problems (d = 0.35) and fatigue severity (d = 0.27). Moderation effects showed BCSs with the highest levels of stress at baseline experienced the greatest benefit from MBSR(BC). Conclusion The MBSR(BC) program significantly improved a broad range of symptoms among BCSs up to 6 weeks after MBSR(BC) training, with generally small to moderate overall effect sizes. PMID:27247219

Mindfulness-based stress reduction for overweight/obese women with and without polycystic ovary syndrome: design and methods of a pilot randomized controlled trial.

PubMed

Raja-Khan, Nazia; Agito, Katrina; Shah, Julie; Stetter, Christy M; Gustafson, Theresa S; Socolow, Holly; Kunselman, Allen R; Reibel, Diane K; Legro, Richard S

2015-03-01

Mindfulness-based stress reduction (MBSR) may be beneficial for overweight/obese women, including women with polycystic ovary syndrome (PCOS), as it has been shown to reduce psychological distress and improve quality of life in other patient populations. Preliminary studies suggest that MBSR may also have salutary effects on blood pressure and blood glucose. This paper describes the design and methods of an ongoing pilot randomized controlled trial evaluating the feasibility and effects of MBSR in PCOS and non-PCOS women who are overweight or obese (NCT01464398). Eighty six (86) women with body mass index ≥ 25 kg/m(2), including 31 women with PCOS, have been randomized to 8 weeks of MBSR or health education control, and followed for 16 weeks. The primary outcome is mindfulness assessed with the Toronto Mindfulness Scale. Secondary outcomes include measures of blood pressure, blood glucose, quality of life, anxiety and depression. Our overall hypothesis is that MBSR will increase mindfulness and ultimately lead to favorable changes in blood pressure, blood glucose, psychological distress and quality of life in PCOS and non-PCOS women. This would support the integration of MBSR with conventional medical treatments to reduce psychological distress, cardiovascular disease and diabetes in PCOS and non-PCOS women who are overweight or obese. Copyright © 2015 Elsevier Inc. All rights reserved.

Mindfulness-Based Stress Reduction for Overweight/Obese Women With and Without Polycystic Ovary Syndrome: Design and Methods of a Pilot Randomized Controlled Trial

PubMed Central

Raja-Khan, Nazia; Agito, Katrina; Shah, Julie; Stetter, Christy M.; Gustafson, Theresa S.; Socolow, Holly; Kunselman, Allen R.; Reibel, Diane K.; Legro, Richard S.

2015-01-01

Mindfulness-based stress reduction (MBSR) may be beneficial for overweight/obese women, including women with polycystic ovary syndrome (PCOS), as it has been shown to reduce psychological distress and improve quality of life in other patient populations. Preliminary studies suggest that MBSR may also have salutary effects on blood pressure and blood glucose. This paper describes the design and methods of an ongoing pilot randomized controlled trial evaluating the feasibility and effects of MBSR in PCOS and non-PCOS women who are overweight or obese. Eighty six (86) women with body mass index ≥25 kg/m2, including 31 women with PCOS, have been randomized to 8 weeks of MBSR or health education control, and followed for 16 weeks. The primary outcome is mindfulness assessed with the Toronto Mindfulness Scale. Secondary outcomes include measures of blood pressure, blood glucose, quality of life, anxiety and depression. Our overall hypothesis is that MBSR will increase mindfulness and ultimately lead to favorable changes in blood pressure, blood glucose, psychological distress and quality of life in PCOS and non-PCOS women. This would support the integration of MBSR with conventional medical treatments to reduce psychological distress, cardiovascular disease and diabetes in PCOS and non-PCOS women who are overweight or obese. PMID:25662105

Study of occupational stress among railway engine pilots

PubMed Central

Kumar, Devesh; Singh, Jai Vir; Kharwar, Poonam S.

2011-01-01

Background: Traffic volume and speed is going to be increased in Indian Railways successively, leading to higher stress in staff connected with train operations. The jobs of railway engine pilots come under the category of high-strain jobs, necessitating a need to conduct multicentric study to unfold the factors associated with occupational stress and organizational strategies. Materials and Methods: Present study covered 185 railway engine pilots and office clerks working in various railway zones by incidental method. Occupational Stress Index (OSI) test developed by Srivastva and Singh, questionnaire of specific stressors constructed by authors and laboratory test battery for psychological screening of high-speed train pilots were used as tools. Results: Means of OSI and all the 12 occupational stressors of railway engine pilots were found significantly higher to that of office clerks. Means of OSI and occupational stressors of goods train pilots were significantly higher in comparison to high-speed train pilots and passenger train pilots. Study revealed positive correlation of speed perception and complex reaction time tests and negative correlation of other constituent tests of laboratory test battery to OSI test. Highest subgroup of stressor observedwas role overload followed by role conflict. Conclusions: These findings provide a prima facie evidence of higher occupational stress among railway engine pilots because of identified specific stressors prevalent in their job and explore the possible intervention strategies for its reduction. Significant correlation is noticed between OSI and laboratory test results, indicating its relevant utility in preliminary psychological screening. PMID:21808497

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

PubMed Central

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 (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). Conclusions 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. PMID:28349668

Effect of Acute Psychological Stress on Prefrontal GABA Concentration Determined by Proton Magnetic Resonance Spectroscopy

PubMed Central

Hasler, Gregor; van der Veen, Jan Willem; Grillon, Christian; Drevets, Wayne C.; Shen, Jun

2011-01-01

Objective Impaired function of the central gamma-aminobutyric acid (GABA) system, which provides the brain’s major inhibitory pathways, is thought to play an important role in the pathophysiology of anxiety disorders. The effect of acute psychological stress on the human GABA-ergic system is still unknown, however. The purpose of this study was to determine the effect of acute stress on prefrontal GABA levels. Method A recently developed noninvasive magnetic resonance spectroscopy method was used to measure changes in the GABA concentration of the prefrontal cortex in 10 healthy human subjects during a threat-of-shock condition and during a safe condition (two sessions on different days). The main outcome measure was the mean GABA concentration within a 3×3×2-cm3 voxel selected from the medial prefrontal cortex. Results Prefrontal GABA decreased by approximately 18% in the threat-of-shock condition relative to the safe condition. This reduction was specific to GABA, since the concentrations of N-acetyl-aspartate, choline-containing compounds, and glutamate/glutamine levels obtained in the same spectra did not change significantly. Conclusions This result appeared compatible with evidence from preclinical studies in rodents, which showed rapid presynaptic down-regulation of GABA-ergic neurotransmission in response to acute psychological stress. The molecular mechanism and functional significance of this reduced inhibitory effect of acute psychological stress in relation to impaired GABA-ergic function in anxiety disorders merit further investigation. PMID:20634372

Oxidative stress measured in vivo without an exogenous contrast agent using QUEST MRI

NASA Astrophysics Data System (ADS)

Berkowitz, Bruce A.

2018-06-01

Decades of experimental studies have implicated excessive generation of reactive oxygen species (ROS) in the decline of tissue function during normal aging, and as a pathogenic factor in a vast array of fatal or debilitating morbidities. This massive body of work has important clinical implications since many antioxidants are FDA approved, readily cross blood-tissue barriers, and are effective at improving disease outcomes. Yet, the potential benefits of antioxidants have remained largely unrealized in patients because conventional methods cannot determine the dose, timing, and drug combinations to be used in clinical trials to localize and decrease oxidative stress. To address this major problem and improve translational success, new methods are urgently needed that non-invasively measure the same ROS biomarker both in animal models and patients with high spatial resolution. Here, we summarize a transformative solution based on a novel method: QUEnch-assiSTed MRI (QUEST MRI). The QUEST MRI index is a significant antioxidant-induced improvement in pathophysiology, or a reduction in 1/T1 (i.e., R1). The latter form of QUEST MRI provides a unique measure of uncontrolled production of endogenous, paramagnetic reactive oxygen species (ROS). QUEST MRI results to-date have been validated by gold standard oxidative stress assays. QUEST MRI has high translational potential because it does not use an exogenous contrast agent and requires only standard MRI equipment. Summarizing, QUEST MRI is a powerful non-invasive approach with unprecedented potential for (i) bridging antioxidant treatment in animal models and patients, (ii) identifying tissue subregions exhibiting oxidative stress, and (iii) coupling oxidative stress localization with behavioral dysfunction, disease pathology, and genetic vulnerabilities to serve as a marker of susceptibility.

Mobile app self-care versus in-office care for stress reduction: a cost minimization analysis.

PubMed

Luxton, David D; Hansen, Ryan N; Stanfill, Katherine

2014-12-01

We calculated the cost of providing stress reduction care with a mobile phone app (Breathe2Relax) in comparison with normal in-person care, the standard method for managing stress in military and civilian populations. We conducted a cost-minimization analysis. The total cost to the military healthcare system of treating 1000 patients with the app was $106,397. Treating 1000 patients with in-office care cost $68,820. Treatment using the app became less expensive than in-office treatment at approximately 1600 users. From the perspective of the civilian healthcare system, treatment using the app became less expensive than in-office treatment at approximately 1500 users. An online tool was used to obtain data about the number of app downloads and usage sessions. A total of 47,000 users had accessed the app for 10-30 min sessions in the 2.5 years since the release of the app. Assuming that all 47,000 users were military beneficiaries, the savings to the military healthcare system would be $2.7 million; if the 47,000 users were civilian, the savings to the civilian healthcare system would be $2.9 million. Because of the large number of potential users, the total societal savings resulting from self-care using the app may be considerable. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Strength Estimation for Hydrate-Bearing Sediments From Direct Shear Tests of Hydrate-Bearing Sand and Silt

NASA Astrophysics Data System (ADS)

Liu, Zhichao; Dai, Sheng; Ning, Fulong; Peng, Li; Wei, Houzhen; Wei, Changfu

2018-01-01

Safe and economic methane gas production, as well as the replacement of methane while sequestering carbon in natural hydrate deposits, requires enhanced geomechanical understanding of the strength and volume responses of hydrate-bearing sediments during shear. This study employs a custom-made apparatus to investigate the mechanical and volumetric behaviors of carbon dioxide hydrate-bearing sediments subjected to direct shear. The results show that both peak and residual strengths increase with increased hydrate saturation and vertical stress. Hydrate contributes mainly the cohesion and dilatancy constraint to the peak strength of hydrate-bearing sediments. The postpeak strength reduction is more evident and brittle in specimens with higher hydrate saturation and under lower stress. Significant strength reduction after shear failure is expected in silty sediments with high hydrate saturation Sh ≥ 0.65. Hydrate contribution to the residual strength is mainly by increasing cohesion at low hydrate saturation and friction at high hydrate saturation. Stress state and hydrate saturation are dominating both the stiffness and the strength of hydrate-bearing sediments; thus, a wave velocity-based peak strength prediction model is proposed and validated, which allows for precise estimation of the shear strength of hydrate-bearing sediments through acoustic logging data. This method is advantageous to geomechanical simulators, particularly when the experimental strength data of natural samples are not available.

The effect of oblique angle of sound incidence, realistic edge conditions, curvature and in-plane panel stresses on the noise reduction characteristics of general aviation type panels

NASA Technical Reports Server (NTRS)

Grosveld, F.; Lameris, J.; Dunn, D.

1979-01-01

Experiments and a theoretical analysis were conducted to predict the noise reduction of inclined and curved panels. These predictions are compared to the experimental results with reasonable agreement between theory and experiment for panels under an oblique angle of sound incidence. Theoretical as well as experimental results indicate a big increase in noise reduction when a flat test panel is curved. Further curving the panel slightly decreases the noise reduction. Riveted flat panels are shown to give a higher noise reduction in the stiffness-controlled frequency region, while bonded panels are superior in this region when the test panel is curved. Experimentally measured noise reduction characteristics of flat aluminum panels with uniaxial in-plane stresses are presented and discussed. These test results indicate an important improvement in the noise reduction of these panels in the frequency range below the fundamental panel/cavity frequency.

Method of thermal strain hysteresis reduction in metal matrix composites

NASA Technical Reports Server (NTRS)

Dries, Gregory A. (Inventor); Tompkins, Stephen S. (Inventor)

1987-01-01

A method is disclosed for treating graphite reinforced metal matrix composites so as to eliminate thermal strain hysteresis and impart dimensional stability through a large thermal cycle. The method is applied to the composite post fabrication and is effective on metal matrix materials using graphite fibers manufactured by both the hot roll bonding and diffusion bonding techniques. The method consists of first heat treating the material in a solution anneal oven followed by a water quench and then subjecting the material to a cryogenic treatment in a cryogenic oven. This heat treatment and cryogenic stress reflief is effective in imparting a dimensional stability and reduced thermal strain hysteresis in the material over a -250.degree. F. to +250.degree. F. thermal cycle.

Reductions in Traumatic Stress Following a Coping Intervention Were Mediated by Decreases in Avoidant Coping for People Living with HIV/AIDS and Childhood Sexual Abuse

ERIC Educational Resources Information Center

Sikkema, Kathleen J.; Ranby, Krista W.; Meade, Christina S.; Hansen, Nathan B.; Wilson, Patrick A.; Kochman, Arlene

2013-01-01

Objective: To examine whether (a) Living in the Face of Trauma (LIFT), a group intervention to address coping with HIV and childhood sexual abuse (CSA), significantly reduced traumatic stress over a 1-year follow-up period more than an attention-matched support group comparison intervention; and (b) reductions in avoidant coping over time mediated…

Gas dynamic improvement of the axial compressor design for reduction of the flow non-uniformity level

NASA Astrophysics Data System (ADS)

Matveev, V. N.; Baturin, O. V.; Kolmakova, D. A.; Popov, G. M.

2017-01-01

Circumferential nonuniformity of gas flow is one of the main problems in the gas turbine engine. Usually, the flow circumferential nonuniformity appears near the annular frame located in the flow passage of the engine. The presence of circumferential nonuniformity leads to the increased dynamic stresses in the blade rows and the blade damage. The goal of this research was to find the ways of the flow non-uniformity reduction, which would not require a fundamental changing of the engine design. A new method for reducing the circumferential nonuniformity of the gas flow was proposed that allows the prediction of the pressure peak values of the rotor blades without computationally expensive CFD calculations.

Analog VLSI system for active drag reduction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, B.; Goodman, R.; Jiang, F.

1996-10-01

In today`s cost-conscious air transportation industry, fuel costs are a substantial economic concern. Drag reduction is an important way to reduce costs. Even a 5% reduction in drag translates into estimated savings of millions of dollars in fuel costs. Drawing inspiration from the structure of shark skin, the authors are building a system to reduce drag along a surface. Our analog VLSI system interfaces with microfabricated, constant-temperature shear stress sensors. It detects regions of high shear stress and outputs a control signal to activate a microactuator. We are in the process of verifying the actual drag reduction by controlling microactuatorsmore » in wind tunnel experiments. We are encouraged that an approach similar to one that biology employs provides a very useful contribution to the problem of drag reduction. 9 refs., 21 figs.« less

Experimental study on titanium wire drawing with ultrasonic vibration.

PubMed

Liu, Shen; Shan, Xiaobiao; Guo, Kai; Yang, Yuancai; Xie, Tao

2018-02-01

Titanium and its alloys have been widely used in aerospace and biomedical industries, however, they are classified as difficult-to-machine materials. In this paper, ultrasonic vibration is imposed on the die to overcome the difficulties during conventional titanium wire drawing processes at the room temperature. Numerical simulations were performed to investigate the variation of axial stress within the contacting region and study the change of the drawing stress with several factors in terms of the longitudinal amplitude and frequency of the applied ultrasonic vibration, the diameter reduction ratio, and the drawing force. An experimental testing equipment was established to measure the drawing torque and rotational velocity of the coiler drum during the wire drawing process. The result indicates the drawing force increases with the growth of the drawing velocity and the reduction ratio, whether with or without vibrations. Application of either form of ultrasonic vibrations contributes to the further decrease of the drawing force, especially the longitudinal vibration with larger amplitude. SEM was employed to detect the surface morphology of the processed wires drawn under the three circumstances. The surface quality of the drawn wires with ultrasonic vibrations was apparently improved compared with those using conventional method. In addition, the longitudinal and torsional composite vibration was more effective for surface quality improvement than pure longitudinal vibration, however, at the cost of weakened drawing force reduction effect. Copyright © 2017 Elsevier B.V. All rights reserved.

A controlled study of the effect of a mindfulness-based stress reduction technique in women with multiple chemical sensitivity, chronic fatigue syndrome, and fibromyalgia

PubMed Central

Sampalli, Tara; Berlasso, Elizabeth; Fox, Roy; Petter, Mark

2009-01-01

Background: The objective of this study was to examine the effect of a mindfulness-based stress reduction (MBSR) program on women diagnosed with conditions such as multiple chemical sensitivity (MCS), chronic fatigue syndrome (CFS), and fibromyalgia (FM). Methods: The intervention group underwent a 10-week MBSR program. Symptoms Checklist Inventory (SCL-90R) was used as outcome measure and was administered before the start of the program (pre-), immediately upon completion (post-) and at three-month follow-up. Women on the wait list to receive treatment at the Nova Scotia Environmental Health Centre were used as control subjects for the study. Results: A total of 50 participants in the intervention group and 26 in the wait-list controls group were recruited for this study. Global scores in the intervention group reached statistical significance pre-post (<0.0001) and at pre-follow-up (<0.0001) while the global scores in the control group remained the same. Five of nine and eight of nine subscales of the SCL-90R showed improvement of statistical significance in MBSR group following treatment and at three-month follow-up. Conclusions: The study showed the importance of complementary interventions such as MBSR techniques in the reduction of psychological distress in women with chronic conditions. PMID:21197347

Finite Element Study into the effect of footwear temperature on the Forces transmitted to the foot during quasi- static compression loading

NASA Astrophysics Data System (ADS)

Shariatmadari, M. R.; English, R.; Rothwell, G.

2010-06-01

The determination of plantar stresses using computational footwear models which include temperature effects are crucial to predict foam performance in service and to aid material development and product design. Finite Element Method (FEM) provides an efficient computational framework to investigate the foot-footwear interaction. The aim of this research is to use FEM to investigate the effect of varying footwear temperature on plantar stresses. The results obtained will provide data which can be used to help optimise shoe design in terms of minimising damaging stresses in the foot particularly for individuals with diabetes who are susceptible to lower extremity complications. The FE simulation results showed significant reductions in foot stresses with the modifications from FE model (1) without footwear to model (2) with midsole only and to model (3) with midsole and insole. In summary, insole and midsole layers made from various foam materials aim to reduce the Ground Reaction Forces (GRF's) and foot stresses considerably and temperature variation can affect their cushioning and consequently the shock attenuation properties. The loss of footwear cushioning effect can have important clinical implications for those individuals with a history of lower limb overuse injuries or diabetes.

Stress evolution during caldera collapse

NASA Astrophysics Data System (ADS)

Holohan, E. P.; Schöpfer, M. P. J.; Walsh, J. J.

2015-07-01

The mechanics of caldera collapse are subject of long-running debate. Particular uncertainties concern how stresses around a magma reservoir relate to fracturing as the reservoir roof collapses, and how roof collapse in turn impacts upon the reservoir. We used two-dimensional Distinct Element Method models to characterise the evolution of stress around a depleting sub-surface magma body during gravity-driven collapse of its roof. These models illustrate how principal stress orientations rotate during progressive deformation so that roof fracturing transitions from initial reverse faulting to later normal faulting. They also reveal four end-member stress paths to fracture, each corresponding to a particular location within the roof. Analysis of these paths indicates that fractures associated with ultimate roof failure initiate in compression (i.e. as shear fractures). We also report on how mechanical and geometric conditions in the roof affect pre-failure unloading and post-failure reloading of the reservoir. In particular, the models show how residual friction within a failed roof could, without friction reduction mechanisms or fluid-derived counter-effects, inhibit a return to a lithostatically equilibrated pressure in the magma reservoir. Many of these findings should be transferable to other gravity-driven collapse processes, such as sinkhole formation, mine collapse and subsidence above hydrocarbon reservoirs.

Growth stage-based modulation in physiological and biochemical attributes of two genetically diverse wheat (Triticum aestivum L.) cultivars grown in salinized hydroponic culture.

PubMed

Ashraf, Muhammad Arslan; Ashraf, Muhammad

2016-04-01

Hydroponic experiment was conducted to appraise variation in the salt tolerance potential of two wheat cultivars (salt tolerant, S-24, and moderately salt sensitive, MH-97) at different growth stages. These two wheat cultivars are not genetically related as evident from randomized polymorphic DNA analysis (random amplified polymorphic DNA (RAPD)) which revealed 28% genetic diversity. Salinity stress caused a marked reduction in grain yield of both wheat cultivars. However, cv. S-24 was superior to cv. MH-97 in maintaining grain yield under saline stress. Furthermore, salinity caused a significant variation in different physiological attributes measured at different growth stages. Salt stress caused considerable reduction in different water relation attributes of wheat plants. A significant reduction in leaf water, osmotic, and turgor potentials was recorded in both wheat cultivars at different growth stages. Maximal reduction in leaf water potential was recorded at the reproductive stage in both wheat cultivars. In contrast, maximal turgor potential was observed at the boot stage. Salt-induced adverse effects of salinity on different water relation attributes were more prominent in cv. MH-97 as compared to those in cv. S-24. Salt stress caused a substantial decrease in glycine betaine and alpha tocopherols. These biochemical attributes exhibited significant salt-induced variation at different growth stages in both wheat cultivars. For example, maximal accumulation of glycine betaine was evident at the early growth stages (vegetative and boot). However, cv. S-24 showed higher accumulation of this organic osmolyte, and this could be the reason for maintenance of higher turgor than that of cv. MH-97 under stress conditions. Salt stress significantly increased the endogenous levels of toxic ions (Na(+) and Cl(-)) and decreased essential cations (K(+) and Ca(2+)) in both wheat cultivars at different growth stages. Furthermore, K(+)/Na(+) and Ca(2+)/Na(+) ratios decreased markedly due to salt stress in both wheat cultivars at different growth stages, and this salt-induced reduction was more prominent in cv. MH-97. Moreover, higher K(+)/Na(+) and Ca(2+)/Na(+) ratios were recorded at early growth stages in both wheat cultivars. It can be inferred from the results that wheat plants are more prone to adverse effects of salinity stress at early growth stages than that at the reproductive stage.

A Diet, Physical Activity, and Stress Reduction Intervention in Men with Rising Prostate-Specific Antigen (PSA) after Treatment for Prostate Cancer

PubMed Central

Hébert, James R.; Hurley, Thomas G.; Harmon, Brook E.; Heiney, Sue; Hebert, Christine J.; Steck, Susan E.

2011-01-01

Background Nearly 35% of men treated for prostate cancer (PrCA) will experience biochemically defined recurrence, noted by a rise in PSA, within ten years of definitive therapy. Diet, physical activity, and stress reduction may affect tumor promotion and disease progression. Methods A randomized trial of an intensive diet, physical activity, and meditation intervention was conducted in men with rising post-treatment PSA after definitive treatment for PrCA. Intention-to-treat methods were used to compare usual care to the intervention in 47 men with complete data. Signal detection methods were used to identify dietary factors associated with PSA change. Results The intervention and control groups did not differ statistically on any demographic or disease-related factor. Although the intervention group experienced decreases of 39% in intakes of saturated fatty acid (SFA as percent of total calories) (p<0.0001) and 12% in total energy intake (218 kcal/day p<0.05)], no difference in PSA change was observed by intervention status. Signal detection methods indicated that in men increasing their consumption of fruit, 56% experienced no rise in PSA (vs. 29% in men who did not increase their fruit intake). Among men who increased fruit and fiber intakes, PSA increased in 83% of participants who also increased saturated fatty acid intake (vs. 44% in participants who decreased or maintained saturated fatty acid intake). Conclusion Results are discussed in the context of conventional treatment strategies that were more aggressive when this study was being conducted in the mid-2000s. Positive health changes in a number of lifestyle parameters were observed with the intervention, and both increased fruit and reduced saturated fat intakes were associated with maintaining PSA levels in men with biochemically recurrent disease. PMID:22018935

Posterior papillary muscle anchoring affects remote myofiber stress and pump function: finite element analysis.

PubMed

Pantoja, Joe Luis; Ge, Liang; Zhang, Zhihong; Morrel, William G; Guccione, Julius M; Grossi, Eugene A; Ratcliffe, Mark B

2014-10-01

The role of posterior papillary muscle anchoring (PPMA) in the management of chronic ischemic mitral regurgitation (CIMR) is controversial. We studied the effect of anchoring point direction and relocation displacement on left ventricular (LV) regional myofiber stress and pump function. Previously described finite element models of sheep 16 weeks after posterolateral myocardial infarction (MI) were used. True-sized mitral annuloplasty (MA) ring insertion plus different PPM anchoring techniques were simulated. Anchoring points tested included both commissures and the central anterior mitral annulus; relocation displacement varied from 10% to 40% of baseline diastolic distance from the PPM to the anchor points on the annulus. For each reconstruction scenario, myofiber stress in the MI, border zone, and remote myocardium as well as pump function were calculated. PPMA caused reductions in myofiber stress at end-diastole and end-systole in all regions of the left ventricle that were proportional to the relocation displacement. Although stress reduction was greatest in the MI region, it also occurred in the remote region. The maximum 40% displacement caused a slight reduction in LV pump function. However, with the correction of regurgitation by MA plus PPMA, there was an overall increase in forward stroke volume. Finally, anchoring point direction had no effect on myofiber stress or pump function. PPMA reduces remote myofiber stress, which is proportional to the absolute distance of relocation and independent of anchoring point. Aggressive use of PPMA techniques to reduce remote myofiber stress may accelerate reverse LV remodeling without impairing LV function. Copyright © 2014 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

Drag reduction in hydrocarbon-aluminum soap polymer systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zakin, J.L.; Lee, K.C.

1972-01-01

While the drag-reducing capability of solutions of aluminum soap in hydrocarbons in turbulent flow has been known for over 20 yr, investigations of the effects of concentration, soap type, and aging on drag reduction have only recently begun. The effects of aging, shear stress, and the presence of peptizers on drag reduction of hydrocarbon dispersions of aluminum soaps at relatively low concentrations were studied. These systems showed an apparent upper critical shear stress above which drag reduction was gradually lost. Degradation of the soap micelle structure occurred relatively rapidly above this point and recovery was slow. The effect of peptizersmore » is complex. In some situations, it enhanced and in others reduced the drag-reducing ability of the soap polymers. (13 refs.)« less

Mindfulness and meditation: treating cognitive impairment and reducing stress in dementia.

PubMed

Russell-Williams, Jesse; Jaroudi, Wafa; Perich, Tania; Hoscheidt, Siobhan; El Haj, Mohamad; Moustafa, Ahmed A

2018-02-21

This study investigates the relationship between mindfulness, meditation, cognition and stress in people with Alzheimer's disease (AD), dementia, mild cognitive impairment and subjective cognitive decline. Accordingly, we explore how the use of meditation as a behavioural intervention can reduce stress and enhance cognition, which in turn ameliorates some dementia symptoms. A narrative review of the literature was conducted with any studies using meditation as an intervention for dementia or dementia-related memory conditions meeting inclusion criteria. Studies where moving meditation was the main intervention were excluded due to the possible confounding of exercise. Ten papers were identified and reviewed. There was a broad use of measures across all studies, with cognitive assessment, quality of life and perceived stress being the most common. Three studies used functional magnetic resonance imaging to measure functional changes to brain regions during meditation. The interventions fell into the following three categories: mindfulness, most commonly mindfulness-based stress reduction (six studies); Kirtan Kriya meditation (three studies); and mindfulness-based Alzheimer's stimulation (one study). Three of these studies were randomised controlled trials. All studies reported significant findings or trends towards significance in a broad range of measures, including a reduction of cognitive decline, reduction in perceived stress, increase in quality of life, as well as increases in functional connectivity, percent volume brain change and cerebral blood flow in areas of the cortex. Limitations and directions for future studies on meditation-based treatment for AD and stress management are suggested.

Changes in translation rate modulate stress-induced damage of diverse proteins

PubMed Central

Kim, Heejung

2013-01-01

Proteostasis is the maintenance of the proper function of cellular proteins. Hypertonic stress disrupts proteostasis and causes rapid and widespread protein aggregation and misfolding in the nematode Caenorhabditis elegans. Optimal survival in hypertonic environments requires degradation of damaged proteins. Inhibition of protein synthesis occurs in response to diverse environmental stressors and may function in part to minimize stress-induced protein damage. We recently tested this idea directly and demonstrated that translation inhibition by acute exposure to cycloheximide suppresses hypertonicity-induced aggregation of polyglutamine::YFP (Q35::YFP) in body wall muscle cells. In this article, we further characterized the relationship between protein synthesis and hypertonic stress-induced protein damage. We demonstrate that inhibition of translation reduces hypertonic stress-induced formation and growth of Q35::YFP, Q44::YFP, and α-synuclein aggregates; misfolding of paramyosin and ras GTPase; and aggregation of multiple endogenous proteins expressed in diverse cell types. Activation of general control nonderepressible-2 (GCN-2) kinase signaling during hypertonic stress inhibits protein synthesis via phosphorylation of eukaryotic initiation factor-2α (eIF-2α). Inhibition of GCN-2 activation prevents the reduction in translation rate and greatly exacerbates the formation and growth of Q35::YFP aggregates and the aggregation of endogenous proteins. The current studies together with our previous work provide the first direct demonstration that hypertonic stress-induced reduction in protein synthesis minimizes protein aggregation and misfolding. Reduction in translation rate also serves as a signal that activates osmoprotective gene expression. The cellular proteostasis network thus plays a critical role in minimizing hypertonic stress-induced protein damage, in degrading stress-damaged proteins, and in cellular osmosensing and signaling. PMID:24153430

Strength and gas dynamic methods of development of the axial turbine turbocharger

NASA Astrophysics Data System (ADS)

Baturin, O. V.; Popov, G. M.; Kolmakova, D. A.; Goryachkin, E. S.

2017-01-01

The results of strength and gas dynamic improvement of the turbocharger TK-32 axial turbine are presented. The turbocharger is manufactured by LLC “Penzadieselmash” (Penza, Russian) and is used as unit boost for a diesel locomotive. The aim of this work was to ensure the turbine work capacity when the rotor speed is increased by 10% without efficiency reduction. The strain-stress state analysis indicated the region of high stresses on the rotor blade body at the level of 2/3 of root. These stresses exceed allowable values when the rotor speed increased. The variant of tangential displacement of the peripheral rotor blade section, allowing reducing the level of stress by 20%, was found. Gas dynamic calculation showed that the variant of rotor blade modernization results in an increase of efficiency by 0.4%. Also it was shown that the increase in turbine efficiency by 1% can be reached if the number of rotor blades is reduced by 13%. This recommendation was implemented and confirmed experimentally by the example of mass turbocharger TK-32 [1].

Glycation & Insulin Resistance: Novel Mechanisms and Unique Targets?

PubMed Central

Song, Fei; Schmidt, Ann Marie

2012-01-01

Objectives Multiple biochemical, metabolic and signal transduction pathways contribute to insulin resistance. In this review, we present the evidence that the post-translational process of protein glycation may play role in insulin resistance. The post-translational modifications, the advanced glycation endproducts (AGEs), are formed and accumulate by endogenous and exogenous mechanisms. Methods and Results AGEs may contribute to insulin resistance by a variety of mechanisms, including generation of tumor necrosis factor-alpha, direct modification of the insulin molecule thereby leading to its impaired action, generation of oxidative stress, and impairment of mitochondrial function, as examples. AGEs may stimulate signal transduction via engagement of cellular receptors, such as RAGE, or receptor for AGE. AGE-RAGE interaction perpetuates AGE formation and cellular stress via induction of inflammation, oxidative stress and reduction in the expression and activity of the enzyme, glyoxalase I that detoxifies the AGE precursor, methylglyoxal, or MG. Conclusions Once set in motion, glycation-promoting mechanisms may stimulate ongoing AGE production and target tissue stresses that reduce insulin responsiveness. Strategies to limit AGE accumulation and action may contribute to prevention of insulin resistance and its consequences. PMID:22815341

Evidence against a direct role for oxidative stress in cadmium-induced axial malformation in the chick embryo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thompson, Jennifer, E-mail: jennifer.thompson@ucd.i; Doi, Takashi; The Children's Research Centre, Our Lady's Children's Hospital, Dublin 12

Cadmium (Cd) is a powerful inducer of oxidative stress. It also causes ventral body wall defects in chick embryos treated at Hamburger-Hamilton stages 16-17. By measuring malondialdehyde levels (TBARS method) and cotreating with antioxidants (tempol, ascorbate, and N-acetylcysteine), we sought to determine if oxidative stress were directly related to teratogenesis. We also investigated the expression of mRNAs for antioxidant enzymes superoxide dismutase (SOD) -1 and -2, catalase (CAT), and glutathione peroxidase (GPx). RT-PCR showed reductions in SOD-1, SOD-2, and CAT 1 hour after treatment with Cd. MDA levels increased 4 hours after Cd, and remained elevated 24 hours after treatment.more » Of the antioxidants, only N-acetylcysteine reduced MDA levels to control values. Nonetheless, no antioxidant could reduce embryo lethality or malformation rates. Furthermore, MDA levels 24 hours after treatment were identical in malformed and normal embryos exposed to Cd. Hence, we conclude that oxidative stress may not have a direct role in Cd teratogenesis.« less

78 FR 65173 - Airworthiness Directives; Airbus Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-31

... washers, which could lead to a local stress concentration resulting in possible reduction of the fatigue... installation. This condition, if not detected and corrected, could lead to a local stress concentration which... incorrectly manufactured special washers, which could lead to a local stress concentration resulting in...

Leadership behavior and subordinate stress: a 360 degrees view.

PubMed

Offermann, L R; Hellmann, P S

1996-10-01

Relationships between leader behavior and subordinate work stress were examined from the perspectives of 343 leaders, their bosses, and their subordinates. Leader behaviors did relate to stress experienced by staff; however, leaders' views of what related to subordinate stress did not always coincide with the factors that subordinates themselves associated with stress. The relationships of leader delegation and subordinate participation to lower subordinate reports of stress were particularly underestimated by leaders. Implications for developing leaders as agents for employee stress reduction are discussed.

Stress on external hexagon and Morse taper implants submitted to immediate loading

PubMed Central

Odo, Caroline H.; Pimentel, Marcele J.; Consani, Rafael L.X.; Mesquita, Marcelo F.; Nóbilo, Mauro A.A.

2015-01-01

Background/Aims This study aimed to evaluate the stress distribution around external hexagon (EH) and Morse taper (MT) implants with different prosthetic systems of immediate loading (distal bar (DB), casting technique (CT), and laser welding (LW)) by using photoelastic method. Methods Three infrastructures were manufactured on a model simulating an edentulous lower jaw. All models were composed by five implants (4.1 mm × 13.0 mm) simulating a conventional lower protocol. The samples were divided into six groups. G1: EH implants with DB and acrylic resin; G2: EH implants with titanium infrastructure CT; G3: EH implants with titanium infrastructure attached using LW; G4: MT implants with DB and acrylic resin; G5: MT implants with titanium infrastructure CT; G6: MT implants with titanium infrastructure attached using LW. After the infrastructures construction, the photoelastic models were manufactured and a loading of 4.9 N was applied in the cantilever. Five pre-determined points were analyzed by Fringes software. Results Data showed significant differences between the connection types (p < 0.0001), and there was no significant difference among the techniques used for infrastructure. Conclusion The reduction of the stress levels was more influenced by MT connection (except for CT). Different bar types submitted to immediate loading not influenced stress concentration. PMID:26605142

Time-dependent rheological behavior of natural polysaccharide xanthan gum solutions in interrupted shear and step-incremental/reductional shear flow fields

NASA Astrophysics Data System (ADS)

Lee, Ji-Seok; Song, Ki-Won

2015-11-01

The objective of the present study is to systematically elucidate the time-dependent rheological behavior of concentrated xanthan gum systems in complicated step-shear flow fields. Using a strain-controlled rheometer (ARES), step-shear flow behaviors of a concentrated xanthan gum model solution have been experimentally investigated in interrupted shear flow fields with a various combination of different shear rates, shearing times and rest times, and step-incremental and step-reductional shear flow fields with various shearing times. The main findings obtained from this study are summarized as follows. (i) In interrupted shear flow fields, the shear stress is sharply increased until reaching the maximum stress at an initial stage of shearing times, and then a stress decay towards a steady state is observed as the shearing time is increased in both start-up shear flow fields. The shear stress is suddenly decreased immediately after the imposed shear rate is stopped, and then slowly decayed during the period of a rest time. (ii) As an increase in rest time, the difference in the maximum stress values between the two start-up shear flow fields is decreased whereas the shearing time exerts a slight influence on this behavior. (iii) In step-incremental shear flow fields, after passing through the maximum stress, structural destruction causes a stress decay behavior towards a steady state as an increase in shearing time in each step shear flow region. The time needed to reach the maximum stress value is shortened as an increase in step-increased shear rate. (iv) In step-reductional shear flow fields, after passing through the minimum stress, structural recovery induces a stress growth behavior towards an equilibrium state as an increase in shearing time in each step shear flow region. The time needed to reach the minimum stress value is lengthened as a decrease in step-decreased shear rate.

Stress at Work and Its Subsequent Problems among Teachers of the Public Schools Which Operate the School-Based Violence Reduction Program (VRP) in Tulkarm Governorate

ERIC Educational Resources Information Center

Oteer, Rabee

2015-01-01

This study aimed to identify the work-related stress and its subsequent problems among teachers of the public schools which operated the school-based Violence Reduction Program (VRP) in the governorate of Tulkarm during the second semester of 2015-2016. Besides, it aimed to identify the effect of specific variables, such as gender, specialization,…

Temperature stress and plant sexual reproduction: uncovering the weakest links.

PubMed

Zinn, Kelly E; Tunc-Ozdemir, Meral; Harper, Jeffrey F

2010-04-01

The reproductive (gametophytic) phase in flowering plants is often highly sensitive to hot or cold temperature stresses, with even a single hot day or cold night sometimes being fatal to reproductive success. This review describes studies of temperature stress on several crop plants, which suggest that pollen development and fertilization may often be the most sensitive reproductive stage. Transcriptome and proteomic studies on several plant species are beginning to identify stress response pathways that function during pollen development. An example is provided here of genotypic differences in the reproductive stress tolerance between two ecotypes of Arabidopsis thaliana Columbia (Col) and Hilversum (Hi-0), when reproducing under conditions of hot days and cold nights. Hi-0 exhibited a more severe reduction in seed set, correlated with a reduction in pollen tube growth potential and tropism defects. Hi-0 thus provides an Arabidopsis model to investigate strategies for improved stress tolerance in pollen. Understanding how different plants cope with stress during reproductive development offers the potential to identify genetic traits that could be manipulated to improve temperature tolerance in selected crop species being cultivated in marginal climates.

Trauma-Informed Mindfulness-Based Stress Reduction for Female Survivors of Interpersonal Violence: Results From a Stage I RCT.

PubMed

Kelly, Amber; Garland, Eric L

2016-04-01

This pilot randomized controlled trial evaluated a novel trauma-informed model of mindfulness-based stress reduction (TI-MBSR) as a phase I trauma intervention for female survivors of interpersonal violence (IPV). A community-based sample of women (mean age = 41.5, standard deviation = 14.6) with a history of IPV was randomly assigned to an 8-week TI-MBSR intervention (n = 23) or a waitlist control group (n = 22). Symptoms of posttraumatic stress disorder (PTSD) and depression as well as anxious and avoidant attachment were assessed pre- and postintervention. Relative to the control group, participation in TI-MBSR was associated with statistically and clinically significant decreases in PTSD and depressive symptoms and significant reductions in anxious attachment. Retention in the intervention was high, with most participants completing at least 5 of the 8 sessions for the intervention. Minutes of mindfulness practice per week significantly predicted reductions in PTSD symptoms. TI-MBSR appears to be a promising and feasible phase I intervention for female survivors of interpersonal trauma. © 2016 Wiley Periodicals, Inc.

Creative Arts Interventions for Stress Management and Prevention—A Systematic Review

PubMed Central

Martin, Lily; Bauer, Katharina; Nottensteiner, Alina; Mergheim, Katja

2018-01-01

Stress is one of the world’s largest health problems, leading to exhaustion, burnout, anxiety, a weak immune system, or even organ damage. In Germany, stress-induced work absenteeism costs about 20 billion Euros per year. Therefore, it is not surprising that the Central Federal Association of the public Health Insurance Funds in Germany ascribes particular importance to stress prevention and stress management as well as health enhancing measures. Building on current integrative and embodied stress theories, Creative Arts Therapies (CATs) or arts interventions are an innovative way to prevent stress and improve stress management. CATs encompass art, music, dance/movement, and drama therapy as their four major modalities. In order to obtain an overview of CATs and arts interventions’ efficacy in the context of stress reduction and management, we conducted a systematic review with a search in the following data bases: Academic Search Complete, ERIC, Medline, Psyndex, PsycINFO and SocINDEX. Studies were included employing the PICOS principle and rated according to their evidence level. We included 37 studies, 73% of which were randomized controlled trials. 81.1% of the included studies reported a significant reduction of stress in the participants due to interventions of one of the four arts modalities. PMID:29470435

Tualang Honey Attenuates Noise Stress-Induced Memory Deficits in Aged Rats

PubMed Central

Azman, Khairunnuur Fairuz; Abdul Aziz, Che Badariah; Othman, Zahiruddin

2016-01-01

Ageing and stress exposure may lead to memory impairment while oxidative stress is thought to be one of the underlying mechanisms involved. This study aimed to investigate the potential protective effects of Tualang honey supplementation on memory performance in aged rats exposed to noise stress. Tualang honey supplementation was given orally, 200 mg/kg body weight for 28 days. Rats in the stress group were subjected to loud noise, 100 dB(A), 4 hours daily for 14 days. All rats were subjected to novel object recognition test for evaluation of memory performance. It was observed that the rats subjected to noise stress exhibited significantly lower memory performance and higher oxidative stress as evident by elevated malondialdehyde and protein carbonyl levels and reduction of antioxidant enzymes activities compared to the nonstressed rats. Tualang honey supplementation was able to improve memory performance, decrease oxidative stress levels, increase brain-derived neurotrophic factor (BDNF) concentration, decrease acetylcholinesterase activity, and enhance neuronal proliferation in the medial prefrontal cortex (mPFC) and hippocampus. In conclusion, Tualang honey protects against memory decline due to stress exposure and/or ageing via enhancement of mPFC and hippocampal morphology possibly secondary to reduction in brain oxidative stress and/or upregulation of BDNF concentration and cholinergic system. PMID:27119005

Mindfulness in Academia: Considerations for Administrative Preparation

ERIC Educational Resources Information Center

Wells, Caryn M.

2013-01-01

This conceptual paper presents a synthesis of information about the workload stress of educational administrators. Currently, there are few programs designed to assist educational leaders to deal with stress (Hawk & Martin, 2011). Stress reduction programs may include mindfulness, a widely used practice of meditation. Mindfulness is used in…

Combined micromechanical and fabrication process optimization for metal-matrix composites

NASA Technical Reports Server (NTRS)

Morel, M.; Saravanos, D. A.; Chamis, C. C.

1991-01-01

A method is presented to minimize the residual matrix stresses in metal matrix composites. Fabrication parameters such as temperature and consolidation pressure are optimized concurrently with the characteristics (i.e., modulus, coefficient of thermal expansion, strength, and interphase thickness) of a fiber-matrix interphase. By including the interphase properties in the fabrication process, lower residual stresses are achievable. Results for an ultra-high modulus graphite (P100)/copper composite show a reduction of 21 percent for the maximum matrix microstress when optimizing the fabrication process alone. Concurrent optimization of the fabrication process and interphase properties show a 41 percent decrease in the maximum microstress. Therefore, this optimization method demonstrates the capability of reducing residual microstresses by altering the temperature and consolidation pressure histories and tailoring the interphase properties for an improved composite material. In addition, the results indicate that the consolidation pressures are the most important fabrication parameters, and the coefficient of thermal expansion is the most critical interphase property.

Concurrent micromechanical tailoring and fabrication process optimization for metal-matrix composites

NASA Technical Reports Server (NTRS)

Morel, M.; Saravanos, D. A.; Chamis, Christos C.

1990-01-01

A method is presented to minimize the residual matrix stresses in metal matrix composites. Fabrication parameters such as temperature and consolidation pressure are optimized concurrently with the characteristics (i.e., modulus, coefficient of thermal expansion, strength, and interphase thickness) of a fiber-matrix interphase. By including the interphase properties in the fabrication process, lower residual stresses are achievable. Results for an ultra-high modulus graphite (P100)/copper composite show a reduction of 21 percent for the maximum matrix microstress when optimizing the fabrication process alone. Concurrent optimization of the fabrication process and interphase properties show a 41 percent decrease in the maximum microstress. Therefore, this optimization method demonstrates the capability of reducing residual microstresses by altering the temperature and consolidation pressure histories and tailoring the interphase properties for an improved composite material. In addition, the results indicate that the consolidation pressures are the most important fabrication parameters, and the coefficient of thermal expansion is the most critical interphase property.

Rennet-induced gelation of concentrated milk in the presence of sodium caseinate: differences between milk concentration using ultrafiltration and osmotic stressing.

PubMed

Krishnankutty Nair, P; Corredig, M

2015-01-01

Concentrating milk is a common unit operation in the dairy industry. With the reduction of water, the particles interact more frequently with each other and the functionality of the casein micelles may depend on the interactions occurring during concentration. The objective of this research was to investigate the effect of concentration on the renneting properties of the casein micelles by comparing 2 concentration methods: ultrafiltration and osmotic stressing. Both methods selectively concentrate the protein fraction of milk, while the composition of the soluble phase is unaltered. To evaluate possible differences in the rearrangements of the casein micelles during concentration, renneting properties were evaluated with or without the addition of soluble caseins, added either before or after concentration. The results indicate that casein micelles undergo rearrangements during concentration and that shear during membrane filtration may play a role in affecting the final properties of the milk. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

[In-patient hypnotherapeutic trauma exposure for posttraumatic stress disorder: a case report].

PubMed

Elsig, Claudia; Schopper, Christian; Anthony, Marion; Gramigna, Ronald; Böker, Heinz

2002-03-01

This paper describes the treatment of a patient with the diagnoses of a borderline personality disorder and posttraumatic stress disorder (DSM-IV and ICD-10) within the setting of a psychiatric ward spezializing in depression. For purposes of controlled re-exposure to the patient's trauma, a hypnotherapeutic method was chosen. A significant reduction of symptoms, in particular the intrusions and the hyperarousal, was observed. Of great importance in the successful outcome of this case is the integration of hypnotherapy into a multi-dimensional treatment concept including group therapy, physical therapy and anxiety-reducing self-management therapy. This approach facilitated the development of trust and security in the patient required for the hypnotherapeutic intervention and minimized the splitting tendencies specific to borderline patients. Further discussion is centered on the difficulties arising in the context of an emergency ward setting with its high intensity atmosphere encompassing the danger of retraumatization of this special group of patients. Finally several aspects of the clinical implications of this method are addressed.

Using RNA interference to knock down the adhesion protein TES.

PubMed

Griffith, Elen

2007-01-01

RNA interference (RNAi) is a specific and efficient method to knock down protein levels using small interfering RNAs (siRNAs), which target mRNA degradation. RNAi can be used in mammalian cell culture systems to target any protein of interest, and several studies have used this method to knock down adhesion proteins. We used siRNAs to knock down the levels of TES, a focal adhesion protein, in HeLa cells. We demonstrated knockdown of both TES mRNA and TES protein. Although total knockdown of TES was not achieved, the observed reduction in TES protein was sufficient to result in a cellular phenotype of reduced actin stress fibers.

The Driving Behavior Survey as a Measure of Behavioral Stress Responses to MVA-related PTSD

PubMed Central

Baker, Aaron S.; Litwack, Scott D.; Clapp, Joshua D.; Beck, J. Gayle; Sloan, Denise M.

2014-01-01

Numerous treatments are available that address the core symptoms of posttraumatic stress disorder (PTSD). However, there are a number of related behavioral stress responses that are not assessed with PTSD measures, yet these behavioral stress responses affect quality of life. The goal of the current study was to investigate whether a recently developed measure of behavioral stress response, the Driving Behavior Survey (DBS), was sensitive to change associated with treatment among a group of participants diagnosed with PTSD. The DBS indexes anxious driving behavior, which is frequently observed among individuals with motor vehicle accident-related PTSD. Participants (n = 40) were racially-diverse adults (M age =40.78, 63% women) who met diagnostic criteria for motor vehicle accident-related PTSD. Hierarchical linear modeling analyses indicated that participants who were assigned to a brief, exposure-based intervention displayed significant reductions on the DBS subscales relative to participants assigned to the waitlist control condition (r = .41-.43). Moreover, meditational analyses indicated that the observed reductions on the DBS subscales were not better accounted for by reductions in PTSD. Taken together, these findings suggest that the DBS subscales are sensitive to changes associated with PTSD treatment and can be used to augment outcome measures in PTSD treatment trials PMID:24491201

The Driving Behavior Survey as a Measure of Behavioral Stress Responses to MVA-Related PTSD

PubMed Central

Baker, Aaron S.; Litwack, Scott D.; Clapp, Joshua D.; Beck, J. Gayle; Sloan, Denise M.

2014-01-01

Numerous treatments are available that address the core symptoms of posttraumatic stress disorder (PTSD). However, there are a number of related behavioral stress responses that are not assessed with PTSD measures, yet these behavioral stress responses affect quality of life. The goal of the current study was to investigate whether a recently developed measure of behavioral stress response, the Driving Behavior Survey (DBS), was sensitive to change associated with treatment among a group of participants diagnosed with PTSD. The DBS indexes anxious driving behavior, which is frequently observed among individuals with motor vehicle accident-related PTSD. Participants (n = 40) were racially diverse adults (M age = 40.78, 63% women) who met diagnostic criteria for motor vehicle accident-related PTSD. Hierarchical linear modeling analyses indicated that participants who were assigned to a brief, exposure-based intervention displayed significant reductions on the DBS subscales relative to participants assigned to the wait-list control condition (r = .41–.43). Moreover, mediational analyses indicated that the observed reductions on the DBS subscales were not better accounted for by reductions in PTSD. Taken together, these findings suggest that the DBS subscales are sensitive to changes associated with PTSD treatment and can be used to augment outcome assessment in PTSD treatment trials. PMID:24800313

Reducing heat stress under thermal insulation in protective clothing: microclimate cooling by a 'physiological' method.

PubMed

Glitz, K J; Seibel, U; Rohde, U; Gorges, W; Witzki, A; Piekarski, C; Leyk, D

2015-01-01

Heat stress caused by protective clothing limits work time. Performance improvement of a microclimate cooling method that enhances evaporative and to a minor extent convective heat loss was tested. Ten male volunteers in protective overalls completed a work-rest schedule (130 min; treadmill: 3 × 30 min, 3 km/h, 5% incline) with or without an additional air-diffusing garment (climatic chamber: 25°C, 50% RH, 0.2 m/s wind). Heat loss was supported by ventilating the garment with dry air (600 l/min, ≪5% RH, 25°C). Ventilation leads (M ± SD, n = 10, ventilated vs. non-ventilated) to substantial strain reduction (max. HR: 123 ± 12 b/min vs. 149 ± 24 b/min) by thermal relief (max. core temperature: 37.8 ± 0.3°C vs. 38.4 ± 0.4°C, max. mean skin temperature: 34.7 ± 0.8°C vs. 37.1 ± 0.3°C) and offers essential extensions in performance and work time under thermal insulation. Heat stress caused by protective clothing limits work time. Performance can be improved by a microclimate cooling method that supports evaporative and to a minor extent convective heat loss. Sweat evaporation is the most effective thermoregulatory mechanism for heat dissipation and can be enhanced by insufflating dry air into clothing.

Effects of Passive Hydrotherapy WATSU (WaterShiatsu) in the Third Trimester of Pregnancy: Results of a Controlled Pilot Study.

PubMed

Schitter, Agnes M; Nedeljkovic, Marko; Baur, Heiner; Fleckenstein, Johannes; Raio, Luigi

2015-01-01

Background. WATSU (WaterShiatsu) is a complementary therapeutic treatment method comprising passive stretches and massage techniques administered in 35°C warm water. Pregnant women claim safe methods to reduce pain, stress, and fatigue. Therefore, we conducted a pilot study evaluating the effects of WATSU on pregnancy-related complaints in third trimester pregnant women. Methods. Nine healthy pregnant women at gestational week ≥34 were included in an intervention group (receiving WATSU) and compared to eight women in a passive control group (receiving no treatment). WATSU was performed on days 1 and 4 of the study, accompanied by ultrasound examinations. Outcomes include physiological and psychometric as well as qualitative data. Participants in the control group completed questionnaires only. Results. WATSU was found to significantly lower participants' levels of stress and pain and to improve their mental health-related quality of life and mood. In comparison to the passive control group, participants in the intervention group reported reduction in perceived stress from day 1 to day 8 (P = 0.036, Cohen's f = 0.57). Qualitative data indicate that WATSU was appreciated as enjoyable and deeply relaxing. No negative side effects were reported. Conclusion. Our findings support the notion that WATSU yields therapeutic benefits for pregnant women and warrant further research. This study has been registered at ClinicalTrials.gov: NCT01708018.

Effects of Passive Hydrotherapy WATSU (WaterShiatsu) in the Third Trimester of Pregnancy: Results of a Controlled Pilot Study

PubMed Central

Schitter, Agnes M.

2015-01-01

Background. WATSU (WaterShiatsu) is a complementary therapeutic treatment method comprising passive stretches and massage techniques administered in 35°C warm water. Pregnant women claim safe methods to reduce pain, stress, and fatigue. Therefore, we conducted a pilot study evaluating the effects of WATSU on pregnancy-related complaints in third trimester pregnant women. Methods. Nine healthy pregnant women at gestational week ≥34 were included in an intervention group (receiving WATSU) and compared to eight women in a passive control group (receiving no treatment). WATSU was performed on days 1 and 4 of the study, accompanied by ultrasound examinations. Outcomes include physiological and psychometric as well as qualitative data. Participants in the control group completed questionnaires only. Results. WATSU was found to significantly lower participants' levels of stress and pain and to improve their mental health-related quality of life and mood. In comparison to the passive control group, participants in the intervention group reported reduction in perceived stress from day 1 to day 8 (P = 0.036, Cohen's f = 0.57). Qualitative data indicate that WATSU was appreciated as enjoyable and deeply relaxing. No negative side effects were reported. Conclusion. Our findings support the notion that WATSU yields therapeutic benefits for pregnant women and warrant further research. This study has been registered at ClinicalTrials.gov: NCT01708018. PMID:25815033

A dose of nature: Tree cover, stress reduction, and gender differences

Treesearch

Bin Jiang; Chun-Yen Chang; William C. Sullivan

2014-01-01

Although it is well established that exposure to nearby nature can help reduce stress in individuals, the shape of the dose-response curve is entirely unclear. To establish this dose-response curve, we recruited 160 individuals for a laboratory experiment. Participants engaged in the Trier Social Stress Test (TSST) to induce psychological stress, and were then randomly...

Nurses and stress: recognizing causes and seeking solutions.

PubMed

Happell, Brenda; Dwyer, Trudy; Reid-Searl, Kerry; Burke, Karena J; Caperchione, Cristina M; Gaskin, Cadeyrn J

2013-05-01

To identify, from the perspectives of nurses, occupational stressors and ways in which they may be reduced. Nurses commonly experience high levels of occupational stress, with negative consequences for their physical and psychological health, health-care organisations and community. There is minimal research on reducing occupational stress. Six focus groups were conducted with 38 registered nurses using a qualitative exploratory approach. Participants were asked to identify sources of occupational stress and possible workplace initiatives to reduce stress. Sources of occupational stress were: high workloads, unavailability of doctors, unsupportive management, human resource issues, interpersonal issues, patients' relatives, shift work, car parking, handover procedures, no common area for nurses, not progressing at work and patient mental health. Suggestions for reduction included: workload modification, non-ward-based initiatives, changing shift hours, forwarding suggestions for change, music, special events, organisational development, ensuring nurses get breaks, massage therapists, acknowledgement from management and leadership within wards. The findings highlight the need to understand local perspectives and the importance of involving nurses in identifying initiatives to reduce occupational stress. Health-care environments can be enhanced through local understanding of the occupational stressors and productively engaging nurses in developing stress reduction initiatives. Nurse managers must facilitate such processes. © 2013 Blackwell Publishing Ltd.

The role of the endoplasmic reticulum stress response following cerebral ischemia.

PubMed

Hadley, Gina; Neuhaus, Ain A; Couch, Yvonne; Beard, Daniel J; Adriaanse, Bryan A; Vekrellis, Kostas; DeLuca, Gabriele C; Papadakis, Michalis; Sutherland, Brad A; Buchan, Alastair M

2018-06-01

Background Cornu ammonis 3 (CA3) hippocampal neurons are resistant to global ischemia, whereas cornu ammonis (CA1) 1 neurons are vulnerable. Hamartin expression in CA3 neurons mediates this endogenous resistance via productive autophagy. Neurons lacking hamartin demonstrate exacerbated endoplasmic reticulum stress and increased cell death. We investigated endoplasmic reticulum stress responses in CA1 and CA3 regions following global cerebral ischemia, and whether pharmacological modulation of endoplasmic reticulum stress or autophagy altered neuronal viability . Methods In vivo: male Wistar rats underwent sham or 10 min of transient global cerebral ischemia. CA1 and CA3 areas were microdissected and endoplasmic reticulum stress protein expression quantified at 3 h and 12 h of reperfusion. In vitro: primary neuronal cultures (E18 Wistar rat embryos) were exposed to 2 h of oxygen and glucose deprivation or normoxia in the presence of an endoplasmic reticulum stress inducer (thapsigargin or tunicamycin), an endoplasmic reticulum stress inhibitor (salubrinal or 4-phenylbutyric acid), an autophagy inducer ([4'-(N-diethylamino) butyl]-2-chlorophenoxazine (10-NCP)) or autophagy inhibitor (3-methyladenine). Results In vivo, decreased endoplasmic reticulum stress protein expression (phospho-eIF2α and ATF4) was observed at 3 h of reperfusion in CA3 neurons following ischemia, and increased in CA1 neurons at 12 h of reperfusion. In vitro, endoplasmic reticulum stress inducers and high doses of the endoplasmic reticulum stress inhibitors also increased cell death. Both induction and inhibition of autophagy also increased cell death. Conclusion Endoplasmic reticulum stress is associated with neuronal cell death following ischemia. Neither reduction of endoplasmic reticulum stress nor induction of autophagy demonstrated neuroprotection in vitro, highlighting their complex role in neuronal biology following ischemia.

Somatic Symptoms Evoked by Exam Stress in University Students: The Role of Alexithymia, Neuroticism, Anxiety and Depression

PubMed Central

Zunhammer, Matthias; Eberle, Hanna; Eichhammer, Peter; Busch, Volker

2013-01-01

Objective The etiology of somatization is incompletely understood, but could be elucidated by models of psychosocial stress. Academic exam stress has effectively been applied as a naturalistic stress model, however its effect on somatization symptoms according to ICD-10 and DSM-IV criteria has not been reported so far. Baseline associations between somatization and personality traits, such as alexithymia, have been studied exhaustively. Nevertheless, it is largely unknown if personality traits have an explanatory value for stress induced somatization. Methods This longitudinal, quasi-experimental study assessed the effects of university exams on somatization — and the reversal of effects after an exam-free period. Repeated-observations were obtained within 150 students, measuring symptom intensity before, during and after an exam period, according to the Screening for Somatoform Symptoms 7-day (SOMS-7d). Additionally, self-reports on health status were used to differentiate between medically explained and medically unexplained symptoms. Alexithymia, neuroticism, trait-anxiety and baseline depression were surveyed using the Toronto-Alexithymia Scale (TAS-20), the Big-Five Personality Interview (NEO-FFI), the State Trait Anxiety Inventory (STAI) and Beck’s Depression Inventory (BDI-II). These traits were competitively tested for their ability to explain somatization increases under exam stress. Results Somatization significantly increased across a wide range of symptoms under exam stress, while health reports pointed towards a reduction in acute infections and injuries. Neuroticism, alexithymia, trait anxiety and depression explained variance in somatization at baseline, but only neuroticism was associated with symptom increases under exam stress. Conclusion Exam stress is an effective psychosocial stress model inducing somatization. A comprehensive quantitative description of bodily symptoms under exam stress is supplied. The results do not support the stress-alexithymia hypothesis, but favor neuroticism as a personality trait of importance for somatization. PMID:24367700

E-cigarette aerosols induce lower oxidative stress in vitro when compared to tobacco smoke.

PubMed

Taylor, Mark; Carr, Tony; Oke, Oluwatobiloba; Jaunky, Tomasz; Breheny, Damien; Lowe, Frazer; Gaça, Marianna

2016-07-01

Tobacco smoking is a risk factor for various diseases. The underlying cellular mechanisms are not fully characterized, but include oxidative stress, apoptosis, and necrosis. Electronic-cigarettes (e-cigarettes) have emerged as an alternative to and a possible means to reduce harm from tobacco smoking. E-cigarette vapor contains significantly lower levels of toxicants than cigarette smoke, but standardized methods to assess cellular responses to exposure are not well established. We investigated whether an in vitro model of the airway epithelium (human bronchial epithelial cells) and commercially available assays could differentiate cellular stress responses to aqueous aerosol extracts (AqE) generated from cigarette smoke and e-cigarette aerosols. After exposure to AqE concentrations of 0.063-0.500 puffs/mL, we measured the intracellular glutathione ratio (GSH:GSSG), intracellular generation of oxidant species, and activation of the nuclear factor erythroid-related factor 2 (Nrf2)-controlled antioxidant response elements (ARE) to characterize oxidative stress. Apoptotic and necrotic responses were characterized by increases in caspase 3/7 activity and reductions in viable cell protease activities. Concentration-dependent responses indicative of oxidative stress were obtained for all endpoints following exposure to cigarette smoke AqE: intracellular generation of oxidant species increased by up to 83%, GSH:GSSG reduced by 98.6% and transcriptional activation of ARE increased by up to 335%. Caspase 3/7 activity was increased by up to 37% and the viable cell population declined by up to 76%. No cellular stress responses were detected following exposure to e-cigarette AqE. The methods used were suitably sensitive to be employed for comparative studies of tobacco and nicotine products.

Nitrogen Starvation Acclimation in Synechococcus elongatus: Redox-Control and the Role of Nitrate Reduction as an Electron Sink

PubMed Central

Klotz, Alexander; Reinhold, Edgar; Doello, Sofía; Forchhammer, Karl

2015-01-01

Nitrogen starvation acclimation in non-diazotrophic cyanobacteria is characterized by a process termed chlorosis, where the light harvesting pigments are degraded and the cells gradually tune down photosynthetic and metabolic activities. The chlorosis response is governed by a complex and poorly understood regulatory network, which converges at the expression of the nblA gene, the triggering factor for phycobiliprotein degradation. This study established a method that allows uncoupling metabolic and redox-signals involved in nitrogen-starvation acclimation. Inhibition of glutamine synthetase (GS) by a precise dosage of l-methionine-sulfoximine (MSX) mimics the metabolic situation of nitrogen starvation. Addition of nitrate to such MSX-inhibited cells eliminates the associated redox-stress by enabling electron flow towards nitrate/nitrite reduction and thereby, prevents the induction of nblA expression and the associated chlorosis response. This study demonstrates that nitrogen starvation is perceived not only through metabolic signals, but requires a redox signal indicating over-reduction of PSI-reduced electron acceptors. It further establishes a cryptic role of nitrate/nitrite reductases as electron sinks to balance conditions of over-reduction. PMID:25780959

The impacts of effective stress and CO 2 sorption on the matrix permeability of shale reservoir rocks [The impacts of CO 2 sorption and effective stress on the matrix permeability of shale reservoir rocks

DOE PAGES

Wu, Wei; Zoback, Mark D.; Kohli, Arjun H.

2017-05-02

We assess the impacts of effective stress and CO 2 sorption on the bedding-parallel matrix permeability of the Utica shale through pressure pulse-decay experiments. We first measure permeability using argon at relatively high (14.6 MPa) and low (2.8 MPa) effective stresses to assess both pressure dependence and recoverability. We subsequently measure permeability using supercritical CO 2 and again using argon to assess changes due to CO 2 sorption. We find that injection of both argon and supercritical CO 2 reduces matrix permeability in distinct fashion. Samples with permeability higher than 10 –20 m 2 experience a large permeability reduction aftermore » treatment with argon, but a minor change after treatment with supercritical CO 2. However, samples with permeability lower than this threshold undergo a slight change after treatment with argon, but a dramatic reduction after treatment with supercritical CO 2. These results indicate that effective stress plays an important role in the evolution of relatively permeable facies, while CO 2 sorption dominates the change of ultra-low permeability facies. The permeability reduction due to CO 2 sorption varies inversely with initial permeability, which suggests that increased surface area from hydraulic stimulation with CO 2 may be counteracted by sorption effects in ultra-low permeability facies. As a result, we develop a conceptual model to explain how CO 2 sorption induces porosity reduction and volumetric expansion to constrict fluid flow pathways in shale reservoir rocks.« less

The impacts of effective stress and CO 2 sorption on the matrix permeability of shale reservoir rocks [The impacts of CO 2 sorption and effective stress on the matrix permeability of shale reservoir rocks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Wei; Zoback, Mark D.; Kohli, Arjun H.

We assess the impacts of effective stress and CO 2 sorption on the bedding-parallel matrix permeability of the Utica shale through pressure pulse-decay experiments. We first measure permeability using argon at relatively high (14.6 MPa) and low (2.8 MPa) effective stresses to assess both pressure dependence and recoverability. We subsequently measure permeability using supercritical CO 2 and again using argon to assess changes due to CO 2 sorption. We find that injection of both argon and supercritical CO 2 reduces matrix permeability in distinct fashion. Samples with permeability higher than 10 –20 m 2 experience a large permeability reduction aftermore » treatment with argon, but a minor change after treatment with supercritical CO 2. However, samples with permeability lower than this threshold undergo a slight change after treatment with argon, but a dramatic reduction after treatment with supercritical CO 2. These results indicate that effective stress plays an important role in the evolution of relatively permeable facies, while CO 2 sorption dominates the change of ultra-low permeability facies. The permeability reduction due to CO 2 sorption varies inversely with initial permeability, which suggests that increased surface area from hydraulic stimulation with CO 2 may be counteracted by sorption effects in ultra-low permeability facies. As a result, we develop a conceptual model to explain how CO 2 sorption induces porosity reduction and volumetric expansion to constrict fluid flow pathways in shale reservoir rocks.« less

Posttraumatic Stress Disorder and Depression Symptom Severities Are Differentially Associated With Hippocampal Subfield Volume Loss in Combat Veterans.

PubMed

Averill, Christopher L; Satodiya, Ritvij M; Scott, J Cobb; Wrocklage, Kristen M; Schweinsburg, Brian; Averill, Lynnette A; Akiki, Teddy J; Amoroso, Timothy; Southwick, Steven M; Krystal, John H; Abdallah, Chadi G

2017-01-01

Two decades of human neuroimaging research have associated volume reductions in the hippocampus with posttraumatic stress disorder. However, little is known about the distribution of volume loss across hippocampal subfields. Recent advances in neuroimaging methods have made it possible to accurately delineate 10 gray matter hippocampal subfields. Here, we apply a volumetric analysis of hippocampal subfields to data from a group of combat-exposed Veterans. Veterans (total, n = 68, posttraumatic stress disorder, n = 36; combat control, n = 32) completed high-resolution structural magnetic resonance imaging. Based on previously validated methods, hippocampal subfield volume measurements were conducted using FreeSurfer 6.0. The Clinician-Administered PTSD Scale assessed posttraumatic stress disorder symptom severity; Beck Depression Inventory assessed depressive symptom severity. Controlling for age and intracranial volume, partial correlation analysis examined the relationship between hippocampal subfields and symptom severity. Correction for multiple comparisons was performed using false discovery rate. Gender, intelligence, combat severity, comorbid anxiety, alcohol/substance use disorder, and medication status were investigated as potential confounds. In the whole sample, total hippocampal volume negatively correlated with Clinician-Administered PTSD Scale and Beck Depression Inventory scores. Of the 10 hippocampal subfields, Clinician-Administered PTSD Scale symptom severity negatively correlated with the hippocampus-amygdala transition area (HATA). Beck Depression Inventory scores negatively correlated with dentate gyrus, cornu ammonis 4 (CA4), HATA, CA2/3, molecular layer, and CA1. Follow-up analysis limited to the posttraumatic stress disorder group showed a negative correlation between Clinician-Administered PTSD Scale symptom severity and each of HATA, CA2/3, molecular layer, and CA4. This study provides the first evidence relating posttraumatic stress disorder and depression symptoms to abnormalities in the HATA, an anterior hippocampal region highly connected to prefrontal-amygdala circuitry. Notably, dentate gyrus abnormalities were associated with depression severity but not posttraumatic stress disorder symptoms. Future confirmatory studies should determine the extent to which dentate gyrus volume can differentiate between posttraumatic stress disorder- and depression-related pathophysiology.

Development, implementation, and evaluation of a mental rehearsal strategy to improve clinical performance and reduce stress: A mixed methods study.

PubMed

Ignacio, Jeanette; Dolmans, Diana; Scherpbier, Albert; Rethans, Jan-Joost; Lopez, Violeta; Liaw, Sok Ying

2016-02-01

Mental rehearsal is a form of mental training that has been used by physicians and nurses to improve performance of clinical skills, and as a vital component of stress management training. To help novice nurses deal with often stressful clinical events that require the processing of information essential to patient management, a mental rehearsal strategy was developed and implemented in a Year 3 nursing simulation program. Inherent to mental rehearsal is imagery, which facilitates cognitive and affective modification, and reduction of extraneous cognitive load. As such, it was expected that the mental rehearsal strategy would improve students' performance and reduce stress in managing deteriorating patients. The study used a mixed methods design. Eighteen Year 3 nursing students participated in the pre- and post-design study, which consisted of the development and implementation of a mental rehearsal strategy. The Rescuing A Patient In Deteriorating Situations (RAPIDS) tool was used to assess performance. Heart rates and systolic blood pressures were used to measure stress. The State-Trait Anxiety Inventory (STAI) was used as a psychological measure of stress/anxiety. Five participants were involved in a focus group discussion that evaluated the usefulness of the mental rehearsal strategy. There was a significant improvement in performance (P<0.05). However, post-test heart rate and systolic blood pressure were not significantly different from pre-test measures. A comparison of STAI results did not show significant differences between pre- and post-test state anxiety and pre- and post-test trait anxiety. Three themes emerged from the focus group interview: managing stress, using a mental framework, and integrating realistic simulations with the mental rehearsal strategy. The mental rehearsal strategy for deteriorating patient management can be valuable based on the findings on performance and based on the participants' feedback. Its role in reducing stress, however, needs further evaluation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Should fertilization treatment start with reducing stress?

PubMed

Campagne, Daniel M

2006-07-01

In the past few decades, new and more efficient techniques to help solve fertility problems have become widely available throughout the developed world. These techniques include hormonal stimulation, ICSI, gamete intra-Fallopian transfer (GIFT) and IVF, and their cost is, on average, considerable. There is substantial initial evidence that the psychological disposition of the parents-to-be influences their fertility and thus the outcome of fertilization techniques. Many fertility treatments include consultation with a psychologist and do try to keep the stress produced by the treatment itself to a minimum, using concurrent therapy. However, the accumulating evidence points to the need to program medical fertility treatment, bearing in mind both chronic and acute stress levels, and to treat for their reduction before commencing the (actual) fertility treatment. There is ample evidence that lower stress levels mean better female and male natural fertility, though there is as yet no conclusive experimental evidence that lower stress levels result in better fertility treatment outcome. However, first reducing stress may diminish the number of treatment cycles needed before pregnancy is obtained, may prepare the couple for an initial failure of treatment or even make the more invasive techniques unnecessary. Primary psychological treatment for trait and state stress, being a less invasive method than IVF, ICSI or GIFT, is to be applied whenever indicated. Also, treatment and therapy to reduce stress, and in so doing enhance fertility, do not provoke the ethical and religious objections raised by infertility treatments.

Lack of Effect of Sleep Apnea on Oxidative Stress in Obstructive Sleep Apnea Syndrome (OSAS) Patients

PubMed Central

Simiakakis, M.; Kapsimalis, F.; Chaligiannis, E.; Loukides, S.; Sitaras, N.; Alchanatis, M.

2012-01-01

Purpose The aim of this study was to evaluate markers of systemic oxidative stress and antioxidant capacity in subjects with and without OSAS in order to investigate the most important factors that determine the oxidant–antioxidant status. Methods A total of 66 subjects referred to our Sleep laboratory were examined by full polysomnography. Oxidative stress and antioxidant activity were assessed by measurement of the derivatives of reactive oxygen metabolites (d-ROMs) and the biological antioxidant capacity (BAP) in blood samples taken in the morning after the sleep study. Known risk factors for oxidative stress, such as age, sex, obesity, smoking, hypelipidemia, and hypertension, were investigated as possible confounding factors. Results 42 patients with OSAS (Apnea-Hypopnea index >15 events/hour) were compared with 24 controls (AHI<5). The levels of d-ROMS were significantly higher (p = 0.005) in the control group but the levels of antioxidant capacity were significantly lower (p = 0.004) in OSAS patients. The most important factors predicting the variance of oxidative stress were obesity, smoking habit, and sex. Parameters of sleep apnea severity were not associated with oxidative stress. Minimal oxygen desaturation and smoking habit were the most important predicting factors of BAP levels. Conclusion Obesity, smoking, and sex are the most important determinants of oxidative stress in OSAS subjects. Sleep apnea might enhance oxidative stress by the reduction of antioxidant capacity of blood due to nocturnal hypoxia. PMID:22761732

Potential and Limitations of an Improved Method to Produce Dynamometric Wheels

PubMed Central

García de Jalón, Javier

2018-01-01

A new methodology for the estimation of tyre-contact forces is presented. The new procedure is an evolution of a previous method based on harmonic elimination techniques developed with the aim of producing low cost dynamometric wheels. While the original method required stress measurement in many rim radial lines and the fulfillment of some rigid conditions of symmetry, the new methodology described in this article significantly reduces the number of required measurement points and greatly relaxes symmetry constraints. This can be done without compromising the estimation error level. The reduction of the number of measuring radial lines increases the ripple of demodulated signals due to non-eliminated higher order harmonics. Therefore, it is necessary to adapt the calibration procedure to this new scenario. A new calibration procedure that takes into account angular position of the wheel is completely described. This new methodology is tested on a standard commercial five-spoke car wheel. Obtained results are qualitatively compared to those derived from the application of former methodology leading to the conclusion that the new method is both simpler and more robust due to the reduction in the number of measuring points, while contact forces’ estimation error remains at an acceptable level. PMID:29439427

Strategies for Coping with Stress and Chronic Pain.

ERIC Educational Resources Information Center

Meyer, Genevieve Rogge

This guide presents strategies used in Pain Management and Stress Reduction workshops for helping the elderly cope with stress and chronic pain. Client evaluations of the workshops are given along with an analysis of the clients' presenting problems. Coping strategies described include: the relaxation response, imagery, daily logs, journal…

Educators' Response to Stress: Towards a Coping Taxonomy.

ERIC Educational Resources Information Center

Gmelch, Walter H.

In assessing coping techniques, the individual is the most important variable; no one technique will be successful for an individual in all situations. Also, stress-reduction techniques must be sensitive to individual differences, both culturally and situationally. Consequently, since no one technique will work for everyone, a stress-reduction…

The Mindful Teacher: Translating Research into Daily Well-Being

ERIC Educational Resources Information Center

Eva, Amy L.; Thayer, Natalie M.

2017-01-01

This article features a stress management approach that is becoming increasingly influential in schools: mindfulness-based stress reduction. The authors describe what it is, provide research-based evidence of its usefulness, and highlight mindfulness resources that educators can use to manage stress and improve their well-being (including…

Written Disclosure Treatment for Posttraumatic Stress Disorder in Substance Use Disorder Inpatients

ERIC Educational Resources Information Center

Bragdon, Rodney A.; Lombardo, Thomas W.

2012-01-01

Comprehensive exposure-based approaches to treating posttraumatic stress disorder (PTSD) are effective, but they are time intensive and not widely used because of factors such as client noncompliance and fears of iatrogenic effects. Exposure by writing disclosure (WD), modeled after Pennebaker's brief stress-reduction procedure, may circumvent…

Cognitive-Behavior Therapy for Disaster-Exposed Youth with Posttraumatic Stress: Results from a Multiple-Baseline Examination

ERIC Educational Resources Information Center

Taylor, Leslie K.; Weems, Carl F.

2011-01-01

Youth traumatized by natural disasters report high levels of posttraumatic stress such as symptoms of posttraumatic stress disorder, other anxiety disorders, and depression. Research suggests that cognitive behavioral therapies are promising interventions for symptom reduction; however, few cognitive behavioral treatments have been systematically…

Effects of exercise training on stress-induced vascular reactivity alterations: role of nitric oxide and prostanoids

PubMed Central

Bruder-Nascimento, Thiago; Silva, Samuel T.; Boer, Patrícia A.; Cordellini, Sandra

2015-01-01

Background: Physical exercise may modify biologic stress responses. Objective: To investigate the impact of exercise training on vascular alterations induced by acute stress, focusing on nitric oxide and cyclooxygenase pathways. Method: Wistar rats were separated into: sedentary, trained (60-min swimming, 5 days/week during 8 weeks, carrying a 5% body-weight load), stressed (2 h-immobilization), and trained/stressed. Response curves for noradrenaline, in the absence and presence of L-NAME or indomethacin, were obtained in intact and denuded aortas (n=7-10). Results: None of the procedures altered the denuded aorta reactivity. Intact aortas from stressed, trained, and trained/stressed rats showed similar reduction in noradrenaline maximal responses (sedentary 3.54±0.15, stressed 2.80±0.10*, trained 2.82±0.11*, trained/stressed 2.97± 0.21*, *P<0.05 relate to sedentary). Endothelium removal and L-NAME abolished this hyporeactivity in all experimental groups, except in trained/stressed rats that showed a partial aorta reactivity recovery in L-NAME presence (L-NAME: sedentary 5.23±0,26#, stressed 5.55±0.38#, trained 5.28±0.30#, trained/stressed 4.42±0.41, #P<0.05 related to trained/stressed). Indomethacin determined a decrease in sensitivity (EC50) in intact aortas of trained rats without abolishing the aortal hyporeactivity in trained, stressed, and trained/stressed rats. Conclusions: Exercise-induced vascular adaptive response involved an increase in endothelial vasodilator prostaglandins and nitric oxide. Stress-induced vascular adaptive response involved an increase in endothelial nitric oxide. Beside the involvement of the endothelial nitric oxide pathway, the vascular response of trained/stressed rats involved an additional mechanism yet to be elucidated. These findings advance on the understanding of the vascular processes after exercise and stress alone and in combination. PMID:26083604

In vivo suppression of plasma IL-12 levels by acute and chronic stress paradigms: potential mediating mechanisms and sex differences

PubMed Central

Shaashua, L.; Sominsky, L.; Levi, B.; Sorski, L.; Reznick, M.; Page, G.; Ben-Eliyahu, S.

2012-01-01

Interleukin-12 (IL-12) is a major pro-inflammatory cytokine, which promotes cell-mediated immunity and TH1 differentiation. In vitro studies indicated suppression of IL-12 production by several stress-related factors, but no effects of behavioral stress were shown on plasma IL-12 levels. Therefore, in the current study we (i) examined the in vivo effects of various behavioral and pharmacological stress paradigms on baseline plasma IL-12 levels; (ii) compared these in vivo findings to those obtained following in vitro stimulation of leukocytes from the same rats; and (iii) assessed potential sexual dimorphism in these outcomes. The findings indicated that plasma IL-12 levels were significantly reduced by social confrontation, wet-cage exposure, surgery, and the administration of corticosterone, epinephrine, or prostaglandin-E2. Notably, most in vivo impacts on plasma levels were not evident when assessed in vitro. The IL-12-reducing effects of wet-cage exposure, and of corticosterone and epinephrine administration, were significantly greater in males than in females, although females exhibited greater total corticosterone levels following stress. The duration of acute stressors predicted the degree of IL-12 reduction, but more prolonged stressors did not. Furthermore, seven days of alternating behavioral stressors reduced plasma IL-12 levels more than fourteen days. These findings suggest animals’ behavioral habituation to stress conditions, or a specific immune mechanism restricting the duration of IL-12 reduction. Overall, our findings indicate a generic and robust stress-induced reduction in plasma IL-12 levels, and suggest epinephrine, corticosterone, and prostaglandin-E2, as potential mediators that should be scrutinized in vivo in the context of natural physiological stress responses. PMID:22659252

Plasma-deposited amorphous silicon carbide films for micromachined fluidic channels

NASA Astrophysics Data System (ADS)

Wuu, Dong-Sing; Horng, Ray-Hua; Chan, Chia-Chi; Lee, Yih-Shing

1999-04-01

The stress properties of the a-SiC:H films on Si by plasma-enhanced chemical vapor deposition (PECVD) are investigated. It is found that the stability of the a-SiC:H films relates to Si-H bonds breaking and changes the stress toward tensile. No evident reduction in the content of Si-H bonds after thermal cycles was found in the carbon-rich samples. Moreover, a new method to fabricate microchannels by through-hole etching with subsequent planarization is proposed. The process is based on etching out the deep grooves through a perforated a-SiC:H membrane, where poly-Si is used as a sacrificial layer to define the channel structure, followed by PECVD sealing the SiC:H membrane. In order to improve the etching performance, the agitated KOH etch is performed at low temperatures (<50°C). The process technology is demonstrated on the fabrication of microfluidic channels with the low-stress (<0.1 GPa) a-SiC:H membranes.

Triathletes Lose Their Advantageous Pain Modulation under Acute Psychosocial Stress.

PubMed

Geva, Nirit; Pruessner, Jens; Defrin, Ruth

2017-02-01

Triathletes, who constantly engage in intensely stressful sport, were recently found to exhibit greater pain tolerance and more efficient pain inhibition capabilities than nonathletes. However, pain inhibition correlated negatively with retrospective reports of mental stress during training and competition. The aim of the current study was to test pain inhibition capabilities of triathletes under acute, controlled psychological stress manipulation. Participants were 25 triathletes and ironman triathletes who underwent the measurement of pain threshold, pain intolerance, tonic suprathreshold pain, and conditioned pain modulation before and during exposure to the Montreal Imaging Stress Task (MIST). Perceived ratings of stress and anxiety, autonomic variables, and salivary cortisol levels were obtained as indices of stress. The MIST induced a significant stress reaction manifested in the subjective and objective indices. Overall, a significant reduction in pain threshold and in conditioned pain modulation efficacy was observed after the MIST, which reached the baseline levels observed previously in nonathletes. Paradoxically, the magnitude of this stress-induced hyperalgesia (SIH) correlated negatively with the magnitude of the stress response; low-stress responders exhibited greater SIH than high-stress responders. The results suggest that under acute psychological stress, triathletes not only react with SIH and a reduction in pain modulation but also lose their advantageous pain modulation over nonathletes. The stronger the stress response recorded, the weaker the SIH. It appears that triathletes are not resilient to stress, responding with an increase in the sensitivity to pain as well as a decrease in pain inhibition. The possible effects of athletes' baseline pain profile and stress reactivity on SIH are discussed.

Effect of power history on the shape and the thermal stress of a large sapphire crystal during the Kyropoulos process

NASA Astrophysics Data System (ADS)

Nguyen, Tran Phu; Chuang, Hsiao-Tsun; Chen, Jyh-Chen; Hu, Chieh

2018-02-01

In this study, the effect of the power history on the shape of a sapphire crystal and the thermal stress during the Kyropoulos process are numerically investigated. The simulation results show that the thermal stress is strongly dependent on the power history. The thermal stress distributions in the crystal for all growth stages produced with different power histories are also studied. The results show that high von Mises stress regions are found close to the seed of the crystal, the highly curved crystal surface and the crystal-melt interface. The maximum thermal stress, which occurs at the crystal-melt interface, increases significantly in value as the crystal expands at the crown. After this, there is reduction in the maximum thermal stress as the crystal lengthens. There is a remarkable enhancement in the maximum von Mises stress when the crystal-melt interface is close to the bottom of the crucible. There are two obvious peaks in the maximum Von Mises stress, at the end of the crown stage and in the final stage, when cracking defects can form. To alleviate this problem, different power histories are considered in order to optimize the process to produce the lowest thermal stress in the crystal. The optimal power history is found to produce a significant reduction in the thermal stress in the crown stage.

Oxidative Stress and Inflammation Differentially Elevated in Objective Versus Habitual Subjective Reduced Sleep Duration in Obstructive Sleep Apnea

PubMed Central

DeMartino, Theresanne; Ghoul, Rawad El; Wang, Lu; Bena, James; Hazen, Stanley L.; Tracy, Russel; Patel, Sanjay R.; Auckley, Dennis; Mehra, Reena

2016-01-01

Study Objectives: Data have demonstrated adverse health effects of sleep deprivation. We postulate that oxidative stress and systemic inflammation biomarkers will be elevated in relation to short-term and long-term sleep duration reduction. Methods: We analyzed data from the baseline examination of a randomized controlled trial involving participants with moderate to severe obstructive sleep apnea (OSA). Baseline polysomnography provided the total sleep time (PSG-TST, primary predictor); self-reported habitual sleep duration (SR-HSD) data was collected. Morning measures of oxidative stress and systemic inflammation included: myeloperoxidase (MPO, pmol/L), oxidized low-density lipoprotein (ox-LDL, U/L), F2-isoprostane (ng/mg), paraoxonase 1 (PON1, nmol·min−1·mL−1), and aryl esterase (μmol·min−1·mL−1). Linear models adjusted for age, sex, race, body mass index (BMI), cardiovascular disease (CVD), smoking, statin/anti-inflammatory medications, and apnea-hypopnea index were utilized (beta estimates and 95% confidence intervals). Results: One hundred forty-seven participants comprised the final analytic sample; they were overall middle-aged (51.0 ± 11.7 y), obese (BMI = 37.3 ± 8.1 kg/m2), and 17% had CVD. Multivariable models demonstrated a significant inverse association of PSG-TST and MPO (β [95% CI] = −20.28 [−37.48, −3.08], P = 0.021), i.e., 20.3 pmol/L MPO reduction per hour increase PSG-TST. Alternatively, a significant inverse association with ox-LDL and SR-HSD was observed (β [95% CI] = 0.98 [0.96, 0.99], P = 0.027), i.e., 2% ox-LDL reduction per hour increase SR-HSD. Conclusions: Even after consideration of obesity and OSA severity, inverse significant findings were observed such that reduced PSG-TST was associated with elevated MPO levels and SR-HSD with ox-LDL, suggesting differential up-regulation of oxidative stress and pathways of inflammation in acute versus chronic sleep curtailment. Clinical Trial Registration: NIH clinical trials registry number NCT00607893. Citation: DeMartino T, Ghoul RE, Wang L, Bena J, Hazen SL, Tracy R, Patel SR, Ackley D, Mehra R. Oxidative stress and inflammation differentially elevated in objective versus habitual subjective reduced sleep duration in obstructive sleep apnea. SLEEP 2016;39(7):1361–1369. PMID:27091532

Effects of a multidisciplinary stress treatment programme on patient return to work rate and symptom reduction: results from a randomised, wait-list controlled trial.

PubMed

Netterstrøm, Bo; Friebel, Lene; Ladegaard, Yun

2013-01-01

To evaluate the efficacy of a multidisciplinary stress treatment programme. General practitioners referred 198 employed patients on sick leave with symptoms of persistent work-related stress. Using a waitlisted randomised controlled trial design, the participants were randomly divided into the following three groups: the intervention group (IG, 69 participants); treatment-as-usual control group (TAUCG, 71 participants), which received 12 consultations with a psychologist, and the waitlisted control group (WLCG, 58 participants). The stress treatment intervention consisted of nine 1-hour sessions conducted over 3 months. The goals of the sessions were the following: (1) identifying relevant stressors; (2) changing the participant's coping strategies; (3) adjusting the participant's workload and tasks, and (4) improving workplace dialogue. Each participant also attended a mindfulness-based stress reduction (MBSR) course for 2 h a week over 8 weeks. The IG and TAUCG showed significantly greater symptom level (Symptom Check List 92) reductions compared to the WLCG. Regarding the return to work (RTW) rate, 67% of participants in the IG returned to full-time work after treatment, which was a significantly higher rate than in the TAUCG (36%) and WLCG (24%). Significantly more participants in the IG (97%) increased their working hours during treatment compared with the participants in the control groups, TAUCG (71%) and WLCG (64%). The stress treatment programme--a combination of work place-focused psychotherapy and MBSR--significantly reduced stress symptom levels and increased RTW rates compared with the WLCG and TAUCG. Copyright © 2013 S. Karger AG, Basel.

The management of stress in MOCVD-grown InGaN/GaN LED multilayer structures on Si(1 1 1) substrates

NASA Astrophysics Data System (ADS)

Jiang, Quanzhong; Allsopp, Duncan W. E.; Bowen, Chris R.; Wang, Wang N.

2013-09-01

The tensile stress in light-emitting diode (LED)-on-Si(1 1 1) multilayer structures must be reduced so that it does not compromise the multiple quantum well emission wavelength uniformity and structural stability. In this paper it is shown for non-optimized LED structures grown on Si(1 1 1) substrates that both emission wavelength uniformity and structural stability can be achieved within the same growth process. In order to gain a deeper understanding of the stress distribution within such a structure, cross-sectional Raman and photo-luminescence spectroscopy techniques were developed. It is observed that for a Si:GaN layer grown on a low-temperature (LT) AlN intermediate layer there is a decrease in compressive stress with increasing Si:GaN layer thickness during MOCVD growth which leads to a high level of tensile stress in the upper part of the layer. This may lead to the development of cracks during cooling to room temperature. Such a phenomenon may be associated with annihilation of defects such as dislocations. Therefore, a reduction of dislocation intensity should take place at the early stage of GaN growth on an AlN or AlGaN layer in order to reduce a build up of tensile stress with thickness. Furthermore, it is also shown that a prolonged three dimensional GaN island growth on a LT AlN interlayer for the reduction of dislocations may result in a reduction in the compressive stress in the resulting GaN layer.

An experimental study of the influence of stress history on fault slip during injection of supercritical CO2

NASA Astrophysics Data System (ADS)

Cuss, Robert J.; Wiseall, Andrew C.; Tamayo-Mas, Elena; Harrington, Jon F.

2018-04-01

The injection of super-critical CO2 into a depleted reservoir will alter the pore pressure of the basin, which if sufficiently perturbed could result in fault slip. Therefore, knowledge of the acceptable pressure limits is required in order to maintain fault stability. A two-part laboratory study was conducted on fully saturated kaolinite fault gouge to investigate this issue. Previously, we showed that fault slip occurred once pore-pressure within the gouge was sufficient to overcome the normal stress acting on the fault. For kaolinite, this behaviour occurred at a pressure similar to the yield stress. The current study shows that following a slow-reduction in the maximum principal stress, as would be expected through changes in effective stress, the reactivation pressure shows a stress memory. Consequently, the pressure necessary to initiate fault slip is similar to that required at the maximum stress encountered. Therefore, fault slip is at least partially controlled by the previous maximum stress and not the current stress state. During the slow reduction in normal stress, the flow characteristics of the fault remain unchanged until pore-pressure exceeds shear stress and does not increase significantly until it exceeds normal stress. This results in fault slip, which slows the rate of flow increase as shear is an effective self-sealing mechanism. These observations lead to the conclusion that stress history is a vital parameter when considering fault stability.

Urban Greenspace is Associated with Reduced Psychological Stress among Adolescents: A Geographic Ecological Momentary Assessment (GEMA) Analysis of Activity Space.

PubMed

Mennis, Jeremy; Mason, Michael; Ambrus, Andreea

2018-06-01

This study investigates the momentary association between urban greenspace, captured using Normalized Difference Vegetation Index (NDVI) derived from Landsat imagery, and psychological stress, captured using Geographic Ecological Momentary Assessment (GEMA), in the activity spaces of a sample of primarily African American adolescents residing in Richmond, Virginia. We employ generalized estimating equations (GEE) to estimate the effect of exposure to urban greenspace on stress and test for moderation by sex, emotional dysregulation, season, neighborhood disadvantage, and whether the observation occurs at home or elsewhere. Results indicate that urban greenspace is associated with lower stress when subjects are away from home, which we speculate is due to the properties of stress reduction and attention restoration associated with exposure to natural areas, and to the primacy of other family dynamics mechanisms of stress within the home. Subjects may also seek out urban greenspaces at times of lower stress or explicitly for purposes of stress reduction. The greenspace-stress association away from home did not differ by sex, emotional dysregulation, neighborhood disadvantage, or season, the latter of which suggests that the observed greenspace-stress relationship is associated with being in a natural environment rather than strictly exposure to abundant green vegetation. Given the association of urban greenspace with lower stress found here and in other studies, future research should address the mediated pathways between greenspace, stress, and stress-related negative health outcomes for different population subgroups as a means toward understanding and addressing health disparities.

Reduction of Convection in Closed Tube Vapor Transport Experiments

NASA Technical Reports Server (NTRS)

Naumann, R. J.; Tan, Sarwa Bakti; Shin, In-Seok; Kim, Joo Soo

2002-01-01

The primary objective of this effort was to develop a method for suppressing convective flows during the growth of mercurous chloride crystals by vapor transport in closed tubes to levels approaching those obtained in the microgravity environment. Mercurous chloride was chosen because it is a technologically interesting acoustical optical material whose optical properties are believed to be affected by convective flows. Since the Grashof number scales as the cube of the smallest dimension in the flow system, reduction of the size scale can be extremely effective in reducing unwanted convective flows. However, since materials of practical interest must be grown at least on the cm scale, reduction of the overall growth system is not feasible. But if the region just above the growing crystal could be restricted to a few mm, considerable reduction in flow velocity would result. By suspending an effusive barrier in the growth ampoule just above the growth interface, it should be possible to reduce the convective velocity in this vicinity to levels approaching flows in microgravity. If successful, this growth technique will offer a screening test for proposed space experiments that involve vapor transport to see if reduction of convection will result in improved material and will set a new standard against which the improvements obtained in microgravity may be judged. In addition, it may provide an improved method for preparing materials on Earth whose growth is affected adversely by convection. If the properties of this material can be improved there is a potential commercial interest from Brimrose Inc., who has agreed to fabricate and test devices from the crystals we have grown. This report describes the development of the growth facility, the purification processes developed for preparing the starting material, and the results from growth experiments with and without the effusive baffle. Mercurous chloride turned out to be a more difficult material to deal with than originally anticipated. At growth temperatures, it is extremely sensitive to practically any impurity which causes it to form oxychlorides and/or to decompose into elemental mercury and bichloride of mercury. We were unable to find a suitable method for protecting the magnetic material used to suspend the effusion barrier from the attack of mercurous chloride vapor. Although we were successful in growing single crystals of mercurous chloride without the effusion baffle, they exhibited severe microcracking which we attribute to wall-induced thermal stresses. This leads us to believe that uncontrolled convection may not be the most important problem in the development of this material and a new growth process was attempted that eliminates the wall-induced stress. Unfortunately, the grant ran out before this new method could be adequately tested.

Students and Teachers Benefit from Mindfulness-Based Stress Reduction in a School-Embedded Pilot Study

PubMed Central

Gouda, Sarah; Luong, Minh T.; Schmidt, Stefan; Bauer, Joachim

2016-01-01

Objective: There is a research gap in studies that evaluate the effectiveness of a school-embedded mindfulness-based intervention for both students and teachers. To address this gap, the present pilot study reviews relevant literature and investigates whether students and teachers who participate in separate Mindfulness-Based Stress Reduction (MBSR) courses show improvements across a variety of psychological variables including areas of mental health and creativity. Methods: The study applied a controlled waitlist design with three measurement points. A total of 29 students (n = 15 in the intervention and n = 14 in the waitlist group) and 29 teachers (n = 14 in the intervention and n = 15 in the waitlist group) completed questionnaires before and after the MBSR course. The intervention group was also assessed after a 4-month follow-up period. Results: Relative to the control group, significant improvements in self-reported stress, self-regulation, school-specific self-efficacy and interpersonal problems were found among the students who participated in the MBSR course (p < 0.05, Cohens' d ranges from 0.62 to 0.68). Medium effect sizes on mindfulness, anxiety and creativity indicate a realistic potential in those areas. By contrast, teachers in the intervention group showed significantly higher self-reported mindfulness levels and reduced interpersonal problems compared to the control group(p < 0.05, Cohens' d = 0.66 and 0.42, respectively), with medium effect sizes on anxiety and emotion regulation. Conclusion: The present findings contribute to a growing body of studies investigating mindfulness in schools by discussing the similarities and differences in the effects of MBSR on students and teachers as well as stressing the importance of investigating interpersonal effects. PMID:27199825

Constitutive Modeling of the Flow Stress of GCr15 Continuous Casting Bloom in the Heavy Reduction Process

NASA Astrophysics Data System (ADS)

Ji, Cheng; Wang, Zilin; Wu, Chenhui; Zhu, Miaoyong

2018-04-01

According to the calculation results of a 3D thermomechanical-coupled finite-element (FE) model of GCr15 bearing steel bloom during a heavy reduction (HR) process, the variation ranges in the strain rate and strain under HR were described. In addition, the hot deformation behavior of the GCr15 bearing steel was studied over the temperature range from 1023 K to 1573 K (750 °C to 1300 °C) with strain rates of 0.001, 0.01, and 0.1 s-1 in single-pass thermosimulation compression experiments. To ensure the accuracy of the constitutive model, the temperature range was divided into two temperature intervals according to the fully austenitic temperature of GCr15 steel [1173 K (900 °C)]. Two sets of material parameters for the constitutive model were derived based on the true stress-strain curves of the two temperature intervals. A flow stress constitutive model was established using a revised Arrhenius-type constitutive equation, which considers the relationships among the material parameters and true strain. This equation describes dynamic softening during hot compression processes. Considering the effect of glide and climb on the deformation mechanism, the Arrhenius-type constitutive equation was modified by a physically based approach. This model is the most accurate over the temperatures ranging from 1173 K to 1573 K (900 °C to 1300 °C) under HR deformation conditions (ignoring the range from 1273 K to 1573 K (1000 °C to 1300 °C) with a strain rate of 0.1 s-1). To ensure the convergence of the FE calculation, an approximated method was used to estimate the flow stress at temperatures greater than 1573 K (1300 °C).

Hexapeptides from human milk prevent the induction of oxidative stress from parenteral nutrition in the newborn guinea pig

PubMed Central

Miloudi, Khalil; Tsopmo, Apollinaire; Friel, James K.; Rouleau, Thérèse; Comte, Blandine; Lavoie, Jean-Claude

2016-01-01

INTRODUCTION In preterm neonates, peroxides contaminating total parenteral nutrition (TPN) contribute to oxidative stress, which is suspected to be a strong inducer of hepatic complications related to prematurity. Recently, others reported that hexapeptides derived from human milk (HM) exerted free radical–scavenging activities in vitro. Therefore, the aim of this study was to assess the capacity of these hexapeptides to limit the generation of peroxides in TPN and to prevent TPN-induced hepatic oxidative stress. METHODS At 3 d of life, guinea pigs were infused, through a catheter in jugular vein, with TPN containing or not peptide-A (YGYTGA) or peptide-B (ISELGW). Peroxide concentrations were measured in TPN solutions, whereas glutathione, glutathionyl-1,4-dihydroxynonenal (GS-HNE) and mRNA levels of interleukin-1 (IL-1) and tumor necrosis factor-α (TNFα) were determined in liver after 4 d of infusion. RESULTS The addition of peptide-A to TPN allowed a reduction in peroxide contamination by half. In vivo, peptide-A or peptide-B corrected the hepatic oxidative status induced by TPN. Indeed, both peptides lowered the hepatic redox potential of glutathione and the level of GS-HNE, a marker of lipid peroxidation. As compared with animals infused with TPN without peptide, the hepatic mRNA levels of IL-1 and TNFα were lower in animals infused with TPN containing peptide-A or peptide-B. DISCUSSION These results suggest that the addition of YGYTGA or ISELGW to TPN will reduce oxidative stress in newborns. The reduction in mRNA of two proinflammatory cytokines could be important for the incidence of hepatic complications related to TPN. PMID:22337230

Redox nanoparticles as a novel treatment approach for inflammation and fibrosis associated with nonalcoholic steatohepatitis

PubMed Central

Eguchi, Akiko; Yoshitomi, Toru; Lazic, Milos; Johnson, Casey D; Vong, Long Binh; Wree, Alexander; Povero, Davide; Papouchado, Bettina G; Nagasaki, Yukio; Feldstein, Ariel E

2015-01-01

Aim: Oxidative stress (OS) is largely thought to be a central mechanism responsible for liver damage, inflammation and fibrosis in nonalcoholic steatohepatitis (NASH). Our aim was to investigate whether suppression of OS in the liver via redox nanoparticles (RNPs) reduces liver damage in a mouse model of NASH. Materials & methods: RNPs were prepared by self-assembly of redox polymers possessing antioxidant nitroxide radicals and were orally administered by daily gavage for 4 weeks. Results: The redox polymer was delivered to the liver after disintegration of nanoparticle in the stomach. RNP treatment in NASH mice via gavage led to a reduction of liver OS, improvement of fibrosis, and significant reduction of inflammation. Conclusion: These findings uncover RNP as a novel potential NASH therapy. PMID:26020857

Finite element analysis using NASTRAN applied to helicopter transmission vibration/noise reduction

NASA Technical Reports Server (NTRS)

Howells, R. W.; Sciarra, J. J.

1975-01-01

A finite element NASTRAN model of the complete forward rotor transmission housing for the Boeing Vertol CH-47 helicopter was developed and applied to reduce transmission vibration/noise at its source. In addition to a description of the model, a technique for vibration/noise prediction and reduction is outlined. Also included are the dynamic response as predicted by NASTRAN, test data, the use of strain energy methods to optimize the housing for minimum vibration/noise, and determination of design modifications which will be manufactured and tested. The techniques presented are not restricted to helicopters but are applicable to any power transmission system. The transmission housing model developed can be used further to evaluate static and dynamic stresses, thermal distortions, deflections and load paths, fail-safety/vulnerability, and composite materials.

Reynolds number dependence of large-scale friction control in turbulent channel flow

NASA Astrophysics Data System (ADS)

Canton, Jacopo; Örlü, Ramis; Chin, Cheng; Schlatter, Philipp

2016-12-01

The present work investigates the effectiveness of the control strategy introduced by Schoppa and Hussain [Phys. Fluids 10, 1049 (1998), 10.1063/1.869789] as a function of Reynolds number (Re). The skin-friction drag reduction method proposed by these authors, consisting of streamwise-invariant, counter-rotating vortices, was analyzed by Canton et al. [Flow, Turbul. Combust. 97, 811 (2016), 10.1007/s10494-016-9723-8] in turbulent channel flows for friction Reynolds numbers (Reτ) corresponding to the value of the original study (i.e., 104) and 180. For these Re, a slightly modified version of the method proved to be successful and was capable of providing a drag reduction of up to 18%. The present study analyzes the Reynolds number dependence of this drag-reducing strategy by performing two sets of direct numerical simulations (DNS) for Reτ=360 and 550. A detailed analysis of the method as a function of the control parameters (amplitude and wavelength) and Re confirms, on the one hand, the effectiveness of the large-scale vortices at low Re and, on the other hand, the decreasing and finally vanishing effectiveness of this method for higher Re. In particular, no drag reduction can be achieved for Reτ=550 for any combination of the parameters controlling the vortices. For low Reynolds numbers, the large-scale vortices are able to affect the near-wall cycle and alter the wall-shear-stress distribution to cause an overall drag reduction effect, in accordance with most control strategies. For higher Re, instead, the present method fails to penetrate the near-wall region and cannot induce the spanwise velocity variation observed in other more established control strategies, which focus on the near-wall cycle. Despite the negative outcome, the present results demonstrate the shortcomings of the control strategy and show that future focus should be on methods that directly target the near-wall region or other suitable alternatives.

Method to adjust multilayer film stress induced deformation of optics

DOEpatents

Spiller, Eberhard A.; Mirkarimi, Paul B.; Montcalm, Claude; Bajt, Sasa; Folta, James A.

2000-01-01

Stress compensating systems that reduces/compensates stress in a multilayer without loss in reflectivity, while reducing total film thickness compared to the earlier buffer-layer approach. The stress free multilayer systems contain multilayer systems with two different material combinations of opposite stress, where both systems give good reflectivity at the design wavelengths. The main advantage of the multilayer system design is that stress reduction does not require the deposition of any additional layers, as in the buffer layer approach. If the optical performance of the two systems at the design wavelength differ, the system with the poorer performance is deposited first, and then the system with better performance last, thus forming the top of the multilayer system. The components for the stress reducing layer are chosen among materials that have opposite stress to that of the preferred multilayer reflecting stack and simultaneously have optical constants that allow one to get good reflectivity at the design wavelength. For a wavelength of 13.4 nm, the wavelength presently used for extreme ultraviolet (EUV) lithography, Si and Be have practically the same optical constants, but the Mo/Si multilayer has opposite stress than the Mo/Be multilayer. Multilayer systems of these materials have practically identical reflectivity curves. For example, stress free multilayers can be formed on a substrate using Mo/Be multilayers in the bottom of the stack and Mo/Si multilayers at the top of the stack, with the switch-over point selected to obtain zero stress. In this multilayer system, the switch-over point is at about the half point of the total thickness of the stack, and for the Mo/Be--Mo/Si system, there may be 25 deposition periods Mo/Be to 20 deposition periods Mo/Si.

Interactive Effects of Nutrient and Mechanical Stresses on Plant Morphology

PubMed Central

Puijalon, Sara; Lena, Jean-Paul; Bornette, Gudrun

2007-01-01

Background and Aims Plant species frequently encounter multiple stresses under natural conditions, and the way they cope with these stresses is a major determinant of their ecological breadth. The way mechanical (e.g. wind, current) and resource stresses act simultaneously on plant morphological traits has been poorly addressed, even if both stresses often interact. This paper aims to assess whether hydraulic stress affects plant morphology in the same way at different nutrient levels. Methods An examination was made of morphological variations of an aquatic plant species growing under four hydraulic stress (flow velocity) gradients located in four habitats distributed along a nutrient gradient. Morphological traits covering plant size, dry mass allocation, organ water content and foliage architecture were measured. Key Results Significant interactive effects of flow velocity and nutrient level were observed for all morphological traits. In particular, increased flow velocity resulted in size reductions under low nutrient conditions, suggesting an adaptive response to flow stress (escape strategy). On the other hand, moderate increases in flow velocity resulted in increased size under high nutrient conditions, possibly related to an inevitable growth response to a higher nutrient supply induced by water renewal at the plant surface. For some traits (e.g. dry mass allocation), a consistent sense of variation as a result of increasing flow velocity was observed, but the amount of variation was either reduced or amplified under nutrient-rich compared with nutrient-poor conditions, depending on the traits considered. Conclusions These results suggest that, for a given species, a stress factor may result, in contrasting patterns and hence strategies, depending on a second stress factor. Such results emphasize the relevance of studies on plant responses to multiple stresses for understanding the actual ecological breadth of species. PMID:17913725

The way to a man's heart is through his stomach?: a mixed methods study on causal mechanisms through which cash and in-kind food transfers decreased intimate partner violence.

PubMed

Buller, Ana Maria; Hidrobo, Melissa; Peterman, Amber; Heise, Lori

2016-06-08

Intimate partner violence (IPV) is highly prevalent and has detrimental effects on the physical and mental health of women across the world. Despite emerging evidence on the impacts of cash transfers on intimate partner violence, the pathways through which reductions in violence occur remain under-explored. A randomised controlled trial of a cash and in-kind food transfer programme on the northern border of Ecuador showed that transfers reduced physical or sexual violence by 30 %. This mixed methods study aimed to understand the pathways that led to this reduction. We conducted a mixed methods study that combined secondary analysis from a randomised controlled trial relating to the impact of a transfer programme on IPV with in-depth interviews and focus group discussions with male and female beneficiaries. A sequential analysis strategy was followed, whereby qualitative results guided the choice of variables for the quantitative analysis and qualitative insights were used to help interpret the quantitative findings. We found qualitative and quantitative evidence that the intervention led to reductions in IPV through three pathways operating at the couple, household and individual level: i) reduced day-to-day conflict and stress in the couple; ii) improved household well-being and happiness; and iii) increased women's decision making, self-confidence and freedom of movement. We found little evidence that any type of IPV increased as a result of the transfers. While cash and in-kind transfers can be important programmatic tools for decreasing IPV, the positive effects observed in this study seem to depend on circumstances that may not exist in all settings or programmes, such as the inclusion of a training component. Moreover, the programme built upon rather than challenged traditional gender roles by targeting women as transfer beneficiaries and framing the intervention under the umbrella of food security and nutrition - domains traditionally ascribed to women. Transfers destined for food consumption combined with nutrition training reduced IPV among marginalised households in northern Ecuador. Evidence suggests that these reductions were realised by decreasing stress and conflict, improving household well-being, and enhancing women's decision making, self-confidence and freedom of movement. ClinicalTrials.gov NCT02526147 . Registered 24 August 2015.

Perception of a Naturalistic Stressor Interacts with 5-HTTLPR/rs25531 Genotype and Gender to Impact Reward Responsiveness

PubMed Central

Nikolova, Yuliya; Bogdan, Ryan; Pizzagalli, Diego A.

2011-01-01

Background Stressful life experiences frequently precede the onset of major depression; however, the mechanisms that underlie this link are poorly understood. Importantly, some individuals are more susceptible to the depressogenic effects of stress than others. Carriers of the S or LG allele of the 5-HTTLPR/rs25531 polymorphisms (S’ participants) have been found to be more prone to developing depression under stress relative to L or LA homozygotes (L’ participants). Moreover, emerging evidence indicates that stress-induced anhedonia may be a mechanism underlying links between stress and depression. Given these findings, we hypothesized that exposure to a naturalistic stressor (school final examinations) would disrupt reward responsiveness (a key behavioral component of anhedonia), and that this effect would be strongest in S’ participants. Methods To objectively assess reward responsiveness, we administered a probabilistic reward task to 70 Bulgarian high school students over two sessions in the 6-month period preceding school finals. For each participant, the two sessions were designated as the ‘stress’ and ‘control’ conditions based on self-reported perceived stress. Results A genotype × condition interaction emerged in males, with S’ participants showing larger stress-related reduction in reward responsiveness relative to L’ participants. Conclusion While in need of replication in a larger sample, our results indicate that stress associated with a real-life event is linked to reduced reward responsiveness, the susceptibility to which is modulated by 5-HTTLPR/rs25531 genotype. Although preliminary, these findings identify anhedonia as a promising mechanism linking 5-HTTLPR/rs25531 genotype and stress to depression. PMID:22094432

Beneficial Effects of Simulated Gastro-Intestinal Digests of Fried Egg and Its Fractions on Blood Pressure, Plasma Lipids and Oxidative Stress in Spontaneously Hypertensive Rats

PubMed Central

Chakrabarti, Subhadeep; Morton, Jude S.; Panahi, Sareh; Kaufman, Susan; Davidge, Sandra T.; Wu, Jianping

2014-01-01

Abstract Background We have previously characterized several antihypertensive peptides in simulated digests of cooked eggs and showed blood pressure lowering property of fried whole egg digest. However, the long-term effects of this hydrolysate and its fractions on blood pressure are not known. Therefore, the objectives of the study were to determine the effects of long term administration of fried whole egg hydrolysate and its fractions (i.e. egg white and egg yolk) on regulation of blood pressure and associated factors in cardiovascular disease such as plasma lipid profile and tissue oxidative stress. Methods and Results We used spontaneously hypertensive rats (SHR), an animal model of essential hypertension. Hydrolysates of fried egg and its fractions were prepared by simulated gastro-intestinal digestion with pepsin and pancreatin. 16–17 week old male SHRs were orally administered fried whole egg hydrolysate, non-hydrolyzed fried whole egg, egg white hydrolysate or egg yolk hydrolysates (either defatted, or not) daily for 18 days. Blood pressure (BP) and heart rate were monitored by telemetry. Animals were sacrificed at the end of the treatment for vascular function studies and evaluating plasma lipid profile and tissue oxidative stress. BP was reduced by feeding fried whole egg hydrolysate but not by the non-hydrolyzed product suggesting a critical role for in vitro digestion in releasing anti-hypertensive peptides. Egg white hydrolysate and defatted egg yolk hydrolysate (but not egg yolk hydrolysate) also had similar effects. Reduction in BP was accompanied by the restoration of nitric oxide (NO) dependent vasorelaxation and reduction of plasma angiotensin II. Fried whole egg hydrolysate also reduced plasma levels of triglyceride although it was increased by the non-hydrolyzed sample. Additionally the hydrolyzed preparations attenuated tissue oxidative stress. Conclusion Our results demonstrate that fried egg hydrolysates exert anti-hypertensive effects, improve plasma lipid profile and attenuate tissue oxidative stress in vivo. PMID:25502445

Antioxidant and antidiabetic profiles of two African medicinal plants: Picralima nitida (Apocynaceae) and Sonchus oleraceus (Asteraceae)

PubMed Central

2013-01-01

Background Diabetes mellitus (DM) is a metabolic disease characterized by chronic hyperglycaemia generally associated with oxidative stress. The present study aims at evaluating the antioxidant and antidiabetic potential of methanol and hydroethanol extracts of the stem bark and leaves of Pricralima nitida and the Sonchus oleraceus whole plant respectively. Methods The in vitro antioxidant activity was assessed using 1,1-Diphenyl-2-picrilhydrazyl (DPPH) for free radical-scavenging properties of the extracts, and the Folin-Ciocalteu method in determining their phenol contents. The antidiabetic activity was tested in mice following streptozotocin diabetes induction, and selected oxidative stress markers (Malondialdehyde, Hydrogen peroxides and Catalase) were measured in order to evaluate the level of oxidative stress in treated animals. Results The in vitro antioxidant activity using DPPH showed IC50 ranging from 0.19 ± 0.08 to 1.00 ± 0.06 mg/mL. The highest activity was obtained with the hydroethanol extracts of S. oleraceus (0.19 mg/mL and P. nitida (0.24 mg/mL). Polyphenol contents ranged from 182.25 ± 16.76 to 684.62 ± 46.66 μg Eq Cat/g. The methanol extract of P. nitida showed the highest activity, followed by the hydroethanol extract of S. oleraceus (616.89 ± 19.20 μEq Cat/g). The hydroethanol extract of whole plants (150 mg/Kg) and methanol leave extract of P. nitida (300 mg/Kg) exhibited significant antidiabetic activities with 39.40% and 38.48% glycaemia reduction, respectively. The measurement of stress markers in plasma, liver and kidney after administration of both extracts showed significant reduction in MDA and hydrogen peroxide levels, coupled with a substantial increase in catalase activity. Conclusions These findings suggest that S. oleraceus whole plant and P. nitida leaves possess both antidiabetic and antioxidant properties, and therefore could be used as starting point for the development of herbal medicines and/or source of new drug molecules against diabetes. PMID:23855679

The two facets of species sensitivity: Stress and disturbance on coralligenous assemblages in space and time.

PubMed

Montefalcone, Monica; Morri, Carla; Bianchi, Carlo Nike; Bavestrello, Giorgio; Piazzi, Luigi

2017-04-15

Marine coastal ecosystems are affected by a vast array of human-induced disturbances and stresses, which are often capable of overwhelming the effects of natural changes. Despite the conceptual and practical difficulty in differentiating between disturbance and stress, which are often used interchangeably, the two terms bear different ecological meanings. Both are external agents, but the former causes mortality or physical damage (subtraction of biomass), whereas the latter causes physiological alteration (reduction in productivity). Sensitivity of marine organisms may thus have a dual connotation, being influenced in different ways by disturbance and by stress following major environmental change. Coralligenous assemblages, which shape unique biogenic formations in the Mediterranean Sea, are considered highly sensitive to change. In this paper, we propose a method to differentiate between disturbance and stress to assess the ecological status of the coralligenous assemblages. Disturbance sensitivity level (DSL) and stress sensitivity level (SSL) of the sessile organisms thriving in the coralligenous assemblages were combined into the integrated sensitivity level of coralligenous assemblages (ISLA) index. Changes in the coralligenous status were assessed in space, along a gradient of stress (human-induced pressures) at several sites of the western Mediterranean, and in time, from a long-term series (1961-2008) at Mesco Reef (Ligurian Sea) that encompasses a mass mortality event in the 1990s. The quality of the coralligenous assemblages was lower in highly urbanised sites than that in sites in both marine protected areas and areas with low levels of urbanisation; moreover, the quality of the assemblages at Mesco Reef decreased during the last 50years. Reduction in quality was mainly due to the increase in stress-tolerant and/or opportunist species (e.g. algal turfs, hydroids and encrusting sponges), the disappearance of the most sensitive macroalgae (e.g. Udoteaceae and erect Rhodophyta) and macro-invertebrates (e.g. Savalia savaglia, Alcyonium coralloides and Smittina cervicornis), and the appearance of invasive alien algal species. Although the specific indices of SSL or DSL well illustrated the changes in the spatial or temporal datasets, respectively, their integration in the ISLA index was more effective in measuring the change experienced by the coralligenous assemblages in both space and time. Copyright © 2017 Elsevier Ltd. All rights reserved.

Stressors and Coping Strategies in Community College Students.

ERIC Educational Resources Information Center

Garrido, Marjorie

The document summarizes a study on stress and coping in a group of college students. In this study, 30 community college students, who were enrolled in an experientially taught stress reduction course, completed measures of stress, support, and coping strategies. The purpose of this study was to explore the possible positive effects of…

46 CFR 32.63-20 - Hull structure-B/ALL.

Code of Federal Regulations, 2010 CFR

2010-10-01

... bending stress shall not exceed the following limits: (1) Independent tanks may be installed in such a... stress shall not exceed either 50 percent of the minimum ultimate tensile strength of the material or 70... reduction in hull stress when independent tanks are installed in such a manner as to contribute to the...

A Comprehensive Stress Education and Reduction Program Utilizing a Well-Being Model: Incorporating the ASCA Student Standards

ERIC Educational Resources Information Center

Tarabochia, Dawn S.

2013-01-01

The American School Counselor Association developed national standards for students to provide a framework for a holistic approach to student academic, career, and personal/social development. While the ASCA Student Standards are comprehensive, little attention is given to stress. Adolescents are experiencing greater stress associated with…

46 CFR 32.63-20 - Hull structure-B/ALL.

Code of Federal Regulations, 2012 CFR

2012-10-01

... bending stress shall not exceed the following limits: (1) Independent tanks may be installed in such a... stress shall not exceed either 50 percent of the minimum ultimate tensile strength of the material or 70... reduction in hull stress when independent tanks are installed in such a manner as to contribute to the...

46 CFR 32.63-20 - Hull structure-B/ALL.

Code of Federal Regulations, 2014 CFR

2014-10-01

... bending stress shall not exceed the following limits: (1) Independent tanks may be installed in such a... stress shall not exceed either 50 percent of the minimum ultimate tensile strength of the material or 70... reduction in hull stress when independent tanks are installed in such a manner as to contribute to the...

46 CFR 32.63-20 - Hull structure-B/ALL.

Code of Federal Regulations, 2013 CFR

2013-10-01

... bending stress shall not exceed the following limits: (1) Independent tanks may be installed in such a... stress shall not exceed either 50 percent of the minimum ultimate tensile strength of the material or 70... reduction in hull stress when independent tanks are installed in such a manner as to contribute to the...

Estimating the Return on Investment From a Health Risk Management Program Offered to Small Colorado-Based Employers

PubMed Central

Goetzel, Ron Z.; Tabrizi, Maryam; Henke, Rachel Mosher; Benevent, Richele; Brockbank, Claire v. S.; Stinson, Kaylan; Trotter, Margo; Newman, Lee S.

2015-01-01

Objective To determine whether changes in health risks for workers in small businesses can produce medical and productivity cost savings. Methods A 1-year pre- and posttest study tracked changes in 10 modifiable health risks for 2458 workers at 121 Colorado businesses that participated in a comprehensive worksite health promotion program. Risk reductions were entered into a return-on-investment (ROI) simulation model. Results Reductions were recorded in 10 risk factors examined, including obesity (−2.0%), poor eating habits (−5.8%), poor physical activity (−6.5%), tobacco use (−1.3%), high alcohol consumption (−1.7%), high stress (−3.5%), depression (−2.3%), high blood pressure (−0.3%), high total cholesterol (−0.9%), and high blood glucose (−0.2%). The ROI model estimated medical and productivity savings of $2.03 for every $1.00 invested. Conclusions Pooled data suggest that small businesses can realize a positive ROI from effective risk reduction programs. PMID:24806569

Sleep, Stress & Relaxation: Rejuvenate Body & Mind

Cancer.gov

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Effect of yoga on short-term heart rate variability measure as a stress index in subjunior cyclists: a pilot study.

PubMed

Patil, Satish G; Mullur, Lata M; Khodnapur, Jyoti P; Dhanakshirur, Gopal B; Aithala, Manjunatha R

2013-01-01

Subjunior athletes experience mental stress due to pressure from the coach, teachers and parents for better performance. Stress, if remains for longer period and not managed appropriately can leads to negative physical, mental and cognitive impact on children. The present study was aimed to evaluate the effect of integrated yoga module on heart rate variability (HRV) measure as a stress index in subjunior cyclists. Fast furrier transform technique of frequency domain method was used for the analysis of HRV. We have found a significant increase in high frequency (HF) component by 14.64% (P < 0.05) and decrease in the low frequency component (LF) of HRV spectrum by 5.52% (P < 0.05) and a decrease in LF/HF ratio by 19.63% (P < 0.01) in yoga group. In the control group, there was decrease in the HF component and, no significant difference in the LF component of HRV spectrum and LF/HF ratio. The results show that yoga practice decreases sympathetic activity and causes a shift in the autonomic balance towards parasympathetic dominance indicating a reduction in stress. In conclusion, yoga practice helps to reduce stress by optimizing the autonomic functions. So, it is suggested to incorporate yoga module as a regular feature to keep subjunior athletes both mentally and physically fit.

Response morphology and anatomy of tobacco (Nicotiana tabacum L.) plant on waterlogging

NASA Astrophysics Data System (ADS)

Nurhidayati, Tutik; Wardhani, Selfrina Puri; Purnobasuki, Hery; Hariyanto, Sucipto; Jadid, Nurul; Nurcahyani, Desy Dwi

2017-11-01

This study has conducted research on morphological and anatomical responses of some varieties of tobacco plants to waterlogging stress. Parameters measured were morphology, anatomy, and plants sensitivity index. Results were analyzed using two-way ANOVA followed by the Tukey test. The results show that waterlogging stress can reduce the growth of tobacco plants, including a decrease in plant height with the lowest value of 15.6 cm, root length reduction to the lowest value of 4.6 cm and plant dry weight reduction to the lowest value of 0.26 gr. But waterlogging stress can increase the number of adventitious roots with the highest value of 18.33. In addition, waterlogging stress can lead to the formation of aerenchyma tissue. The sensitivity index showed that plant varieties that are resistant to waterlogging stress are the varieties Kemloko 3 (index value of 0.03), varieties of Paiton 2 (index value of 0.18), and the varieties Kemloko 2 (index value of 0.42).

Fractal structures and fractal functions as disease indicators

USGS Publications Warehouse

Escos, J.M; Alados, C.L.; Emlen, J.M.

1995-01-01

Developmental instability is an early indicator of stress, and has been used to monitor the impacts of human disturbance on natural ecosystems. Here we investigate the use of different measures of developmental instability on two species, green peppers (Capsicum annuum), a plant, and Spanish ibex (Capra pyrenaica), an animal. For green peppers we compared the variance in allometric relationship between control plants, and a treatment group infected with the tomato spotted wilt virus. The results show that infected plants have a greater variance about the allometric regression line than the control plants. We also observed a reduction in complexity of branch structure in green pepper with a viral infection. Box-counting fractal dimension of branch architecture declined under stress infection. We also tested the reduction in complexity of behavioral patterns under stress situations in Spanish ibex (Capra pyrenaica). Fractal dimension of head-lift frequency distribution measures predator detection efficiency. This dimension decreased under stressful conditions, such as advanced pregnancy and parasitic infection. Feeding distribution activities reflect food searching efficiency. Power spectral analysis proves to be the most powerful tool for character- izing fractal behavior, revealing a reduction in complexity of time distribution activity under parasitic infection.

A randomized controlled trial of mindfulness to reduce stress and burnout among intern medical practitioners.

PubMed

Ireland, Michael J; Clough, Bonnie; Gill, Kim; Langan, Fleur; O'Connor, Angela; Spencer, Lyndall

2017-04-01

Stress and burnout are highly prevalent among medical doctors, and are associated with negative consequences for doctors, patients, and organizations. The purpose of the current study was to examine the effectiveness of a mindfulness training intervention in reducing stress and burnout among medical practitioners, by means of a Randomised Controlled Trial design. Participants were 44 intern doctors completing an emergency department rotation in a major Australian hospital. Participants were randomly assigned to either an active control (one hour extra break per week) or the 10-week mindfulness training intervention. Measures of stress and burnout were taken pre-, mid- and post intervention. Participants undergoing the 10-week mindfulness training program reported greater improvements in stress and burnout relative to participants in the control condition. Significant reduction in stress and burnout was observed for participants in the mindfulness condition. No such reductions were observed for participants in the control condition. Mindfulness interventions may provide medical practitioners with skills to effectively manage stress and burnout, thereby reducing their experience of these symptoms. It is likely that doctors would benefit from the inclusion of such a training program as a part of their general medical education.

Cardiorespiratory dynamic response to mental stress: a multivariate time-frequency analysis.

PubMed

Widjaja, Devy; Orini, Michele; Vlemincx, Elke; Van Huffel, Sabine

2013-01-01

Mental stress is a growing problem in our society. In order to deal with this, it is important to understand the underlying stress mechanisms. In this study, we aim to determine how the cardiorespiratory interactions are affected by mental arithmetic stress and attention. We conduct cross time-frequency (TF) analyses to assess the cardiorespiratory coupling. In addition, we introduce partial TF spectra to separate variations in the RR interval series that are linearly related to respiration from RR interval variations (RRV) that are not related to respiration. The performance of partial spectra is evaluated in two simulation studies. Time-varying parameters, such as instantaneous powers and frequencies, are derived from the computed spectra. Statistical analysis is carried out continuously in time to evaluate the dynamic response to mental stress and attention. The results show an increased heart and respiratory rate during stress and attention, compared to a resting condition. Also a fast reduction in vagal activity is noted. The partial TF analysis reveals a faster reduction of RRV power related to (3 s) than unrelated to (30 s) respiration, demonstrating that the autonomic response to mental stress is driven by mechanisms characterized by different temporal scales.

Neural stress reactivity relates to smoking outcomes and differentiates between mindfulness and cognitive-behavioral treatments.

PubMed

Kober, Hedy; Brewer, Judson A; Height, Keri L; Sinha, Rajita

2017-05-01

Stress and negative affect are known contributors to drug use and relapse, and several known treatments for addictions include strategies for managing them. In the current study, we administered a well-established stress provocation during functional magnetic resonance imaging (fMRI) to 23 participants who completed either mindfulness training (MT; N=11) or the American Lung Association's Freedom From Smoking (FFS; N=12), which is a cognitive-behavioral treatment (CBT) for smoking cessation. Across the entire sample, we found that stress reactivity in several brain regions including the amygdala and anterior/mid insula was related to reductions in smoking after treatment, as well as at 3-month post-treatment follow-up. Moreover, conjunction analysis revealed that these same regions also differentiated between treatment groups such that the MT group showed lower stress-reactivity compared to the FFS/CBT group. This suggests that reduction in stress reactivity may be one of the mechanisms that underlie the efficacy of MT in reducing smoking over time. The findings have important implications for our understanding of stress, the neural and psychological mechanisms that underlie mindfulness-based treatments, and for smoking cessation treatments more broadly. Copyright © 2016 Elsevier Inc. All rights reserved.

ChloroSeq, an optimized chloroplast RNA-Seq bioinformatic pipeline, reveals remodeling of the organellar transcriptome under heat stress

DOE PAGES

Castandet, Benoît; Hotto, Amber M.; Strickler, Susan R.; ...

2016-07-06

Although RNA-Seq has revolutionized transcript analysis, organellar transcriptomes are rarely assessed even when present in published datasets. Here, we describe the development and application of a rapid and convenient method, ChloroSeq, to delineate qualitative and quantitative features of chloroplast RNA metabolism from strand-specific RNA-Seq datasets, including processing, editing, splicing, and relative transcript abundance. The use of a single experiment to analyze systematically chloroplast transcript maturation and abundance is of particular interest due to frequent pleiotropic effects observed in mutants that affect chloroplast gene expression and/or photosynthesis. To illustrate its utility, ChloroSeq was applied to published RNA-Seq datasets derived from Arabidopsismore » thaliana grown under control and abiotic stress conditions, where the organellar transcriptome had not been examined. The most appreciable effects were found for heat stress, which induces a global reduction in splicing and editing efficiency, and leads to increased abundance of chloroplast transcripts, including genic, intergenic, and antisense transcripts. Moreover, by concomitantly analyzing nuclear transcripts that encode chloroplast gene expression regulators from the same libraries, we demonstrate the possibility of achieving a holistic understanding of the nucleus-organelle system. In conclusion, ChloroSeq thus represents a unique method for streamlining RNA-Seq data interpretation of the chloroplast transcriptome and its regulators.« less

Hurst exponent: A Brownian approach to characterize the nonlinear behavior of red blood cells deformability

NASA Astrophysics Data System (ADS)

Mancilla Canales, M. A.; Leguto, A. J.; Riquelme, B. D.; León, P. Ponce de; Bortolato, S. A.; Korol, A. M.

2017-12-01

Ektacytometry techniques quantifies red blood cells (RBCs) deformability by measuring the elongation of suspended RBCs subjected to shear stress. Raw shear stress elongation plots are difficult to understand, thus most research papers apply data reduction methods characterizing the relationship between curve fitting. Our approach works with the naturally generated photometrically recorded time series of the diffraction pattern of several million of RBCs subjected to shear stress, and applies nonlinear quantifiers to study the fluctuations of these elongations. The development of new quantitative methods is crucial for restricting the subjectivity in the study of the cells behavior, mainly if they are capable of analyze at the same time biological and mechanical aspects of the cells in flowing conditions and compare their dynamics. A patented optical system called Erythrocyte Rheometer was used to evaluate viscoelastic properties of erythrocytes by Ektacytometry. To analyze cell dynamics we used the technique of Time Delay Coordinates, False Nearest Neighbors, the forecasting procedure proposed by Sugihara and May, and Hurst exponent. The results have expressive meaning on comparing healthy samples with parasite treated samples, suggesting that apparent noise associated with deterministic chaos can be used not only to distinguish but also to characterize biological and mechanical aspects of cells at the same time in flowing conditions.

ChloroSeq, an optimized chloroplast RNA-Seq bioinformatic pipeline, reveals remodeling of the organellar transcriptome under heat stress

DOE Office of Scientific and Technical Information (OSTI.GOV)

Castandet, Benoît; Hotto, Amber M.; Strickler, Susan R.

Although RNA-Seq has revolutionized transcript analysis, organellar transcriptomes are rarely assessed even when present in published datasets. Here, we describe the development and application of a rapid and convenient method, ChloroSeq, to delineate qualitative and quantitative features of chloroplast RNA metabolism from strand-specific RNA-Seq datasets, including processing, editing, splicing, and relative transcript abundance. The use of a single experiment to analyze systematically chloroplast transcript maturation and abundance is of particular interest due to frequent pleiotropic effects observed in mutants that affect chloroplast gene expression and/or photosynthesis. To illustrate its utility, ChloroSeq was applied to published RNA-Seq datasets derived from Arabidopsismore » thaliana grown under control and abiotic stress conditions, where the organellar transcriptome had not been examined. The most appreciable effects were found for heat stress, which induces a global reduction in splicing and editing efficiency, and leads to increased abundance of chloroplast transcripts, including genic, intergenic, and antisense transcripts. Moreover, by concomitantly analyzing nuclear transcripts that encode chloroplast gene expression regulators from the same libraries, we demonstrate the possibility of achieving a holistic understanding of the nucleus-organelle system. In conclusion, ChloroSeq thus represents a unique method for streamlining RNA-Seq data interpretation of the chloroplast transcriptome and its regulators.« less

Which family factors predict children’s externalizing behaviors following discharge from psychiatric inpatient treatment?

PubMed Central

Blader, Joseph C.

2010-01-01

Objective Parents’ behavior management practices, parental stress, and family environment are highly pertinent to children’s conduct problems. Preadolescents’ psychiatric hospitalization usually arises because of severe conduct problems, so the relationships of family-related variables to postdischarge functioning warrant investigation. This study examined postdischarge clinical course and select family factors to model outcomes via a) predictors measured at admission, b) predictors measured concurrently with outcome, and c) changes in predictor values from admission through follow-up. Method In a prospective follow-up of 107 child psychiatry inpatients, caregivers completed rating scales pertaining to their child’s behavior, parenting practices, parenting stress, caregiver strain, and their own psychological distress at admission and three, six, and 12 months after discharge. Results The magnitude of reductions in parenting stress between admission and follow-up bore the strongest relationship to improvements in externalizing behavior. The largest and most sustained decreases in externalizing behavior arose among youngsters whose parents reported high parenting stress at admission and low parenting stress after discharge. By contrast, children whose parents reported low parenting stress at admission and follow-up showed significantly less postdischarge improvement. Parenting stress changes were not attributable to changes in behavioral symptoms. Parenting stress eclipsed relationships between behavior management practices and child outcomes, suggesting that parenting stress might have a mediational role. Conclusions High initial parenting stress disposed to better outcomes over the year of follow-up. Consistently low stress predicted less improvement. Higher stress at admission may imply more advantageous parent–child relationships or motivation for subsequent persistence with treatment. Interventions that ameliorate high stress may warrant further study. Low parenting stress might signify disengagement, or, alternatively, that parents of some chronically impaired children become rather inured to fluctuations in behavioral problems. If confirmed, further examination of these and other accounts for a relationship between low parenting stress and suboptimal child outcome seems warranted. PMID:17076752

Stress engineering of high-quality single crystal diamond by heteroepitaxial lateral overgrowth

DOE PAGES

Tang, Y. -H.; Golding, B.

2016-02-02

Here, we describe a method for lateral overgrowth of low-stress single crystal diamond by chemical vapor deposition (CVD). The process is initiated by deposition of a thin (550 nm) (001) diamond layer on Ir-buffered a-plane sapphire. The diamond is partially masked by periodic thermally evaporated Au stripes using photolithography. Lateral overgrowth of the Au occurs with extremely effective filtering of threading dislocations. Thermal stress resulting from mismatch of the low thermal expansion diamond and the sapphire substrate is largely accommodated by the ductile Au layer. The stress state of the diamond is investigated by Raman spectroscopy for two thicknesses: atmore » 10 μm where the film has just overgrown the Au mask and at 180 μm where the film thickness greatly exceeds the scale of the masking. For the 10-μm film, the Raman linewidth shows spatial oscillations with the period of the Au stripes with a factor of 2 to 3 reduction relative to the unmasked region. In a 180-μm thick diamond film, the overall surface stress was extremely low, 0.00 ± 0.16 GPa, obtained from the Raman shift averaged over the 7.5mm diameter of the crystal at its surface. We conclude that the metal mask protects the overgrown diamond layer from substrate-induced thermal stress and cracking. Lastly, it is also responsible for low internal stress by reducing dislocation density by several orders of magnitude.« less

Pilot study investigating the effects of Ayurvedic Abhyanga massage on subjective stress experience.

PubMed

Basler, Annetrin Jytte

2011-05-01

Many providers of Ayurvedic massage treatments make unsubstantiated claims regarding their potential psychologic and physiologic benefits. While these claims are based on ancient traditions of the Indian medical system as well as personal experience, no attempt had yet been made to verify the effect of Ayurvedic oil massage within the Western-scientific context. This pilot study assessed the single-dose effect of Abhyanga, the classic Ayurvedic oil massage, in terms of its impact on subjective stress experience. Ten (10) healthy women (mean [M] 36.4 years, standard deviation [SD] 4.62) and 10 healthy men (M 37.0 years, SD 3.23) underwent a 1-hour Abhyanga massage treatment. The study employed a repeated-measures design for the collection of stress data using a validated and published questionnaire, as well as for the collection of heart rate (HR) and blood pressure (BP) values, immediately pre- and postintervention. Subjects showed high statistically and clinically significant reductions in subjective stress experience. A consequent analysis of physiologic data indicated likewise reductions in HR, while a BP reduction was not recorded for the total sample, but was only found in the prehypertensive subgroup. Findings indicate that Abhyanga massage is promising in reducing subjective stress experience. It may be beneficial in lowering HR in all, and BP in prehypertensive subjects. The results of this pilot study encourage further research with more stringent methodology.

Health status, job stress and work-related injury among Los Angeles taxi drivers.

PubMed

Wang, Pin-Chieh; Delp, Linda

2014-01-01

Taxi drivers work long hours for low wages and report hypertension, weight gain, and musculoskeletal pain associated with the sedentary nature of their job, stressful working conditions, and poor dietary habits. They also experience a high work-related fatality rate. The objective of this study is to examine the association of taxi drivers' health status and level of job stress with work-related injury and determine if a potential interaction exists. A survey of 309 Los Angeles taxi drivers provides basic data on health status, job stress, and work-related injuries. We further analyzed the data using a Modified Poisson regression approach with a robust error variance to estimate the relative risk (RR) and the 95% confidence intervals (CI) of work-related injuries. Focus group results supplemented and helped interpret the quantitative data. The joint effect of good health and low job stress was associated with a large reduction in the incidence of injuries, consistent with the hypothesis that health status and stress levels modify each other on the risk of work-related injury. These results suggest that the combination of stress reduction and health management programs together with changes in the stressful conditions of the job may provide targeted avenues to prevent injuries.

Ocular-specific ER stress reduction rescues glaucoma in murine glucocorticoid-induced glaucoma

PubMed Central

Zode, Gulab S.; Sharma, Arti B.; Lin, Xiaolei; Searby, Charles C.; Bugge, Kevin; Kim, Gun Hee; Clark, Abbot F.; Sheffield, Val C.

2014-01-01

Administration of glucocorticoids induces ocular hypertension in some patients. If untreated, these patients can develop a secondary glaucoma that resembles primary open-angle glaucoma (POAG). The underlying pathology of glucocorticoid-induced glaucoma is not fully understood, due in part to lack of an appropriate animal model. Here, we developed a murine model of glucocorticoid-induced glaucoma that exhibits glaucoma features that are observed in patients. Treatment of WT mice with topical ocular 0.1% dexamethasone led to elevation of intraocular pressure (IOP), functional and structural loss of retinal ganglion cells, and axonal degeneration, resembling glucocorticoid-induced glaucoma in human patients. Furthermore, dexamethasone-induced ocular hypertension was associated with chronic ER stress of the trabecular meshwork (TM). Similar to patients, withdrawal of dexamethasone treatment reduced elevated IOP and ER stress in this animal model. Dexamethasone induced the transcriptional factor CHOP, a marker for chronic ER stress, in the anterior segment tissues, and Chop deletion reduced ER stress in these tissues and prevented dexamethasone-induced ocular hypertension. Furthermore, reduction of ER stress in the TM with sodium 4-phenylbutyrate prevented dexamethasone-induced ocular hypertension in WT mice. Our data indicate that ER stress contributes to glucocorticoid-induced ocular hypertension and suggest that reducing ER stress has potential as a therapeutic strategy for treating glucocorticoid-induced glaucoma. PMID:24691439

Chronic light reduction reduces overall resilience to additional shading stress in the seagrass Halophila ovalis.

PubMed

Yaakub, Siti M; Chen, Eugene; Bouma, Tjeerd J; Erftemeijer, Paul L A; Todd, Peter A

2014-06-30

Seagrasses have substantial capacity to survive long periods of light reduction, but how acclimation to chronic low light environments may influence their ability to cope with additional stress is poorly understood. This study examines the effect of temporal light reduction by adding two levels of shading to Halophila ovalis plants in two meadows with different light histories, one characterized by a low light (turbid) environment and the other by a relatively high light (clear) environment. Additional shading resulted in complete mortality for both shading treatments at the turbid site while the clear site showed a pattern of decreased shoot density and increased photochemical efficiency (Fv/Fm) with increased shading. These contrasting results for the same species in two different locations indicate that acclimation to chronic low light regimes can affect seagrass resilience and highlights the importance of light history in determining the outcome of exposure to further (short-term) stress. Copyright © 2013 Elsevier Ltd. All rights reserved.

An Efficient Implementation of the GMC Micromechanics Model for Multi-Phased Materials with Complex Microstructures

NASA Technical Reports Server (NTRS)

Pindera, Marek-Jerzy; Bednarcyk, Brett A.

1997-01-01

An efficient implementation of the generalized method of cells micromechanics model is presented that allows analysis of periodic unidirectional composites characterized by repeating unit cells containing thousands of subcells. The original formulation, given in terms of Hill's strain concentration matrices that relate average subcell strains to the macroscopic strains, is reformulated in terms of the interfacial subcell tractions as the basic unknowns. This is accomplished by expressing the displacement continuity equations in terms of the stresses and then imposing the traction continuity conditions directly. The result is a mixed formulation wherein the unknown interfacial subcell traction components are related to the macroscopic strain components. Because the stress field throughout the repeating unit cell is piece-wise uniform, the imposition of traction continuity conditions directly in the displacement continuity equations, expressed in terms of stresses, substantially reduces the number of unknown subcell traction (and stress) components, and thus the size of the system of equations that must be solved. Further reduction in the size of the system of continuity equations is obtained by separating the normal and shear traction equations in those instances where the individual subcells are, at most, orthotropic. The reformulated version facilitates detailed analysis of the impact of the fiber cross-section geometry and arrangement on the response of multi-phased unidirectional composites with and without evolving damage. Comparison of execution times obtained with the original and reformulated versions of the generalized method of cells demonstrates the new version's efficiency.

Sex-dependent effects of larval food stress on adult performance under semi-natural conditions: only a matter of size?

PubMed

Rosa, Elena; Saastamoinen, Marjo

2017-07-01

Organisms with complex life-cycles acquire essential nutrients as juveniles, and hence even a short-term food stress during development can impose serious fitness costs apparent in adults. We used the Glanville fritillary butterfly to investigate the effects of larval food stress on adult performance under semi-natural conditions in a population enclosure. We were specifically interested in whether the negative effects observed were due to body mass reduction only or whether additional effects unrelated to pupal mass were evident. The two sexes responded differently to the larval food stress. In females, larval food stress reduced pupal mass and reproductive performance. The reduced reproductive performance was partially mediated by pupal mass reduction. Food stressed females also had reduced within-patch mobility, and this effect was not dependent on pupal mass. Conversely, food stress had no effect on male pupal mass, suggesting a full compensation via prolonged development time. Nonetheless, food stressed males were less likely to sire any eggs, potentially due to changes in their territorial behavior, as indicated by food stress also increasing male within-patch mobility (i.e., patrolling behavior). When males did sire eggs, the offspring number and viability were unaffected by male food stress treatment. Viability was in general higher for offspring sired by lighter males. Our study highlights how compensatory mechanisms after larval food stress can act in a sex-specific manner and that the alteration in body mass is only partially responsible for the reduced adult performance observed.

Effectiveness of patient empowerment over stress related to knee arthroplasty surgery.

PubMed

Garzón-Rey, Jorge Mario; Arza-Valdés, Adriana; Nuevo-Gayoso, Montserrat; Aguiló, Jordi

This study aims to show evidence of the Empowerment Session's effectiveness through measurements of surgery related emotional stress before and after this session. The study was performed on 41 patients with knee arthroplasty surgery prescription by measuring the evolution of their emotional stress generated by surgery expectative, during the empowerment session. Two sets of measurements per patient were performed, before and after the empowerment session. Each set consisted of recording an electrocardiogram for 10min while the patients were seated and then applying two standard psychometric tests: State-Trait Anxiety Inventory test and Visual Analog Stress test. Differences in emotional stress were analyzed using psychometric tests and heart rate variability (HRV) analysis as stress biomarkers. Psychometric stress measurement shows a 17.8% reduction in stress according to the total stress scale value, and a 41.9% reduction in stress between test results before and after the session. Mean heart rate values increased by 7.4% with respect to the initial values, very low frequency power and total power also change in value suggesting more sympathetic and less parasympathetic activity. Both psychological and physiological measurements suggest the effectiveness of the empowerment session due to a significant increase in the wellness state of patients. Additionally, the correlation between psychometric tests and HRV indices demonstrates that both emotional stress indicators could be used as feedback on the empowerment sessions or as a reference to enhance surgical outcomes. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

Effects of low-modulus coatings on pin-bone contact stresses in external fixation.

PubMed

Manley, M T; Hurst, L; Hindes, R; Dee, R; Chiang, F P

1984-01-01

The intent of this study was to investigate the stress distribution in cortical bone around fracture fixation pins and around pins coated with various polymeric and elastomeric materials. Since these interface stresses cannot be measured directly, a photoelastic technique was employed and stresses were measured in two-dimensional bone models fabricated from sheets of epoxy resin. Our results showed that when a fixation pin was loaded in compression, the compressive stress measured in the model was greatest at the pin-model interface. The magnitude of the compressive stress was found to diminish steeply away from the hole in a log decrement distribution which was asymptotic to the value of the average stress in the model. When polymeric and elastomeric materials were applied as pin coatings and the performance of the coated pins was compared to that of uncoated pins of the same overall diameter, a reduction of the maximum stress in the bone model was demonstrated. Among the coatings tested, we found that of the polymeric materials ultrahigh molecular weight polyethylene (UHMWPE) was most effective at reducing the peak cortical stress magnitude. The most effective coating material overall was found to be silicon elastomer. Computation of stress values in models loaded through stainless-steel pins and through pins coated with 1-mm silicon elastomer showed that the presence of the elastomer layer caused a reduction of about 50% in the maximum compressive stress in the model.