WorldWideScience

Sample records for stress clash environments

  1. CLASH

    DEFF Research Database (Denmark)

    Grillo, C.; Gobat, R.; Presotto, V.

    2014-01-01

    We present a strong lensing system in which a double source is imaged 5 times by 2 early-type galaxies. We take advantage in this target of the multi-band photometry obtained as part of the CLASH program, complemented by the spectroscopic data of the VLT/VIMOS and FORS2 follow-up campaign. We use...... fractions projected within the effective radii of 0.51 +/- 0.21 and 0.80 +/- 0.32. With these lenses we can extend the analysis of the mass properties of lens early-type galaxies by factors that are about 2 and 3 times smaller than previously done with regard to, respectively, velocity dispersion...

  2. Clash of Ignorance

    Directory of Open Access Journals (Sweden)

    Mahmoud Eid

    2012-06-01

    Full Text Available The clash of ignorance thesis presents a critique of the clash of civilizations theory. It challenges the assumptions that civilizations are monolithic entities that do not interact and that the Self and the Other are always opposed to each other. Despite some significantly different values and clashes between Western and Muslim civilizations, they overlap with each other in many ways and have historically demonstrated the capacity for fruitful engagement. The clash of ignorance thesis makes a significant contribution to the understanding of intercultural and international communication as well as to the study of inter-group relations in various other areas of scholarship. It does this by bringing forward for examination the key impediments to mutually beneficial interaction between groups. The thesis directly addresses the particular problem of ignorance that other epistemological approaches have not raised in a substantial manner. Whereas the critique of Orientalism deals with the hegemonic construction of knowledge, the clash of ignorance paradigm broadens the inquiry to include various actors whose respective distortions of knowledge symbiotically promote conflict with each other. It also augments the power-knowledge model to provide conceptual and analytical tools for understanding the exploitation of ignorance for the purposes of enhancing particular groups’ or individuals’ power. Whereas academics, policymakers, think tanks, and religious leaders have referred to the clash of ignorance concept, this essay contributes to its development as a theory that is able to provide a valid basis to explain the empirical evidence drawn from relevant cases.

  3. Stress corrosion in gaseous environment

    International Nuclear Information System (INIS)

    Miannay, Dominique.

    1980-06-01

    The combined influences of a stress and a gaseous environment on materials can lead to brittleness and to unexpected delayed failure by stress corrosion cracking, fatigue cracking and creep. The most important parameters affering the material, the environment, the chemical reaction and the stress are emphasized and experimental works are described. Some trends for further research are given [fr

  4. Clashing world views

    International Nuclear Information System (INIS)

    Lagassa, G.

    1992-01-01

    This article examines how politics, economics, and an increasing awareness of environmental and societal impacts are affecting the market for new hydroelectric projects. The topics of the article include border conflicts, new opposition, resettlement issues, the problems and benefits of hydroelectric projects, taking action, and a clash of world views

  5. Clash of the Titans

    Science.gov (United States)

    Subramaniam, Karthigeyan

    2010-01-01

    WebQuests and the 5E learning cycle are titans of the science classroom. These popular inquiry-based strategies are most often used as separate entities, but the author has discovered that using a combined WebQuest and 5E learning cycle format taps into the inherent power and potential of both strategies. In the lesson, "Clash of the Titans,"…

  6. The stress and underground environment

    Science.gov (United States)

    Chama, A.

    2009-04-01

    Currently,the program of prevention in occupational health needs mainly to identify occupational hazards and strategy of their prevention.Among these risks,the stress represents an important psycho-social hazard in mental health,which unfortunately does not spare no occupation.My Paper attempts to highlight and to develop this hazard in its different aspects even its regulatory side in underground environment as occupational environment.In the interest of better prevention ,we consider "the information" about the impact of stress as the second prevention efficient and no expensive to speleologists,hygienists and workers in the underground areas. In this occasion of this event in Vienna,we also highlight the scientific works on the stress of the famous viennese physician and endocrinologist Doctor Hans Selye (1907-1982),nicknamed "the father of stress" and note on relation between biological rhythms in this underground area and psychological troubles (temporal isolation) (Jurgen Aschoff’s works and experiences out-of time).

  7. CLASH

    DEFF Research Database (Denmark)

    Coe, D.; Postman, M.; Bradley, L.

    2013-01-01

    We present a candidate for the most distant galaxy known to date with a photometric redshift of z = 10.7 (95% confidence limits; with z <9.5 galaxies of known types ruled out at 7.2s). This J-dropout Lyman break galaxy, named MACS0647-JD, was discovered as part of the Cluster Lensing and Supernov...

  8. Stress training and the new military environment

    NARCIS (Netherlands)

    Delahaij, R.; Gaillard, A.W.K.; Soeters, J.M.L.M.

    2006-01-01

    The new environment in which current military operations take place is often characterized by unpredictable and ambiguous situations. This places new demands on military personnel. In combination with high levels of violence and threat, these situations will elicit acute stress reactions, which can

  9. Youth Smoking in Stressed Environments : Determinants and ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    This grant will support three case studies of young people in extremely stressful environments in Medellin (Colombia), the West Bank (Palestine) and northern Argentina, respectively. In the last case, the young people in question will be displaced aboriginal youth. Researchers will examine the role of both classical and ...

  10. Stress Hormones mediated by the Built Environment

    DEFF Research Database (Denmark)

    Fich, Lars Brorson; Wallergård, Mattias; Hansen, Åse Marie

    2017-01-01

    Due to the aging society, dementia is one of the major challenges to the health care systems all over the world. The growing number of patients, the long process and intensive need for care, especially in the later stages of the disease, make the growth in human as well as socioeconomic costs huge....... The development of design strategies for nursing homes and other health care facilities such as day care centers addressing the needs of dementia patients is therefore very important. The vast majority of dementia cases is Alzheimer’s Disease, representing approximately 70% of all cases. Alzheimer’s disease...... of the hippocampus’ function in the stress system, as the lack of control of cortisol levels during stress can lead to further degradation of the hippocampus. We refer to a stress experiment suggesting that is possible through the built environment to influence the release of cortisol during stress. This again...

  11. The Abundance of Large Arcs From CLASH

    Science.gov (United States)

    Xu, Bingxiao; Postman, Marc; Meneghetti, Massimo; Coe, Dan A.; Clash Team

    2015-01-01

    We have developed an automated arc-finding algorithm to perform a rigorous comparison of the observed and simulated abundance of large lensed background galaxies (a.k.a arcs). We use images from the CLASH program to derive our observed arc abundance. Simulated CLASH images are created by performing ray tracing through mock clusters generated by the N-body simulation calibrated tool -- MOKA, and N-body/hydrodynamic simulations -- MUSIC, over the same mass and redshift range as the CLASH X-ray selected sample. We derive a lensing efficiency of 15 ± 3 arcs per cluster for the X-ray selected CLASH sample and 4 ± 2 arcs per cluster for the simulated sample. The marginally significant difference (3.0 σ) between the results for the observations and the simulations can be explained by the systematically smaller area with magnification larger than 3 (by a factor of ˜4) in both MOKA and MUSIC mass models relative to those derived from the CLASH data. Accounting for this difference brings the observed and simulated arc statistics into full agreement. We find that the source redshift distribution does not have big impact on the arc abundance but the arc abundance is very sensitive to the concentration of the dark matter halos. Our results suggest that the solution to the "arc statistics problem" lies primarily in matching the cluster dark matter distribution.

  12. Oxidative stress and the high altitude environment

    Directory of Open Access Journals (Sweden)

    Jakub Krzeszowiak

    2013-03-01

    Full Text Available In the recent years there has been considerable interest in mountain sports, including mountaineering, owing to the general availability of climbing clothing and equipment as well trainings and professional literature. This raised a new question for the environmental and mountain medicine: Is mountaineering harmful to health? Potential hazards include the conditions existing in the alpine environment, i.e. lower atmospheric pressure leading to the development of hypobaric hypoxia, extreme physical effort, increased UV radiation, lack of access to fresh food, and mental stress. A reasonable measure of harmfulness of these factors is to determine the increase in the level of oxidative stress. Alpine environment can stimulate the antioxidant enzyme system but under specific circumstances it may exceed its capabilities with simultaneous consumption of low-molecular antioxidants resulting in increased generation of reactive oxygen species (ROS. This situation is referred to as oxidative stress. Rapid and uncontrolled proliferation of reactive oxygen species leads to a number of adverse changes, resulting in the above-average damage to the lipid structures of cell membranes (peroxidation, proteins (denaturation, and nucleic acids. Such situation within the human body cannot take place without resultant systemic consequences. This explains the malaise of people returning from high altitude and a marked decrease in their physical fitness. In addition, a theory is put forward that the increase in the level of oxidative stress is one of the factors responsible for the onset of acute mountain sickness (AMS. However, such statement requires further investigation because the currently available literature is inconclusive. This article presents the causes and effects of development of oxidative stress in the high mountains.

  13. Liquid salt environment stress-rupture testing

    Science.gov (United States)

    Ren, Weiju; Holcomb, David E.; Muralidharan, Govindarajan; Wilson, Dane F.

    2016-03-22

    Disclosed herein are systems, devices and methods for stress-rupture testing selected materials within a high-temperature liquid salt environment. Exemplary testing systems include a load train for holding a test specimen within a heated inert gas vessel. A thermal break included in the load train can thermally insulate a load cell positioned along the load train within the inert gas vessel. The test specimen can include a cylindrical gage portion having an internal void filled with a molten salt during stress-rupture testing. The gage portion can have an inner surface area to volume ratio of greater than 20 to maximize the corrosive effect of the molten salt on the specimen material during testing. Also disclosed are methods of making a salt ingot for placement within the test specimen.

  14. Does the Environment Exacerbate Effects of Stress on Black ...

    African Journals Online (AJOL)

    the food environment have emerged as two potentially important influences on black women's ... Keywords: black women, USA, stress, environment, diet, obesity, non-communicable .... In this sample we found no association between ei-.

  15. Stress Training and the New Military Environment

    National Research Council Canada - National Science Library

    Delahaij, R; Soeters, J. M

    2006-01-01

    .... This places new demands on military personnel. In combination with high levels of violence and threat, these situations will elicit acute stress reactions, which can impair performance and the ability to operate effectively...

  16. Clash of Desires: Detective vs. Femme Fatale

    Directory of Open Access Journals (Sweden)

    Veronika Pituková

    2013-06-01

    Full Text Available This article discusses the theme of desire presented in American hard-boiled detective fiction and its subsequent transformation on the screen in form of films noir of the 1940’s. The works in focus are novels The Maltese Falcon by Dashiell Hammett, Farewell, My Lovely by Raymond Chandler and Build My Gallows High by Daniel Mainwaring and their film noir adaptations – The Maltese Falcon (1941, Murder, My Sweet (1944 and Out of the Past (1947. The proposed paper seeks to offer a contrastive analysis of the novels and the films and situate them in their respective social and cultural contexts. The central conflict of this article is presented by the clash between the femme fatale’s and detective’s desires. Hard-boiled novels present femme fatale as a dame with a past, a spider woman, and the detective as a hero with no future, caught in her web of intrigues. The only way out for the detective is to suppress the sexual desire for the woman and hold strong to his professional code. The femme fatale’s desire for more and for better is deadly and dangerous for those who succumb to her lure, but the detective’s desire for truth can be fatal for the dark lady too.  This clash presented in the novels is confronted with the 1940’s Hollywood production. When the detective frees himself from the sexual lure of the fatal woman he has a chance to live and even bring her to justice, but she can still escape or decide herself what to do with her destiny. Both, the dame and the hero are victims of their desires. The 1940’s films noir’s femme fatales have to pay for their crimes, no matter how crafty, seductive or manipulative they are.  Thus these films present the masculine dominance as strong and undefeated.

  17. Heat stress protection in abnormally hot environments.

    CSIR Research Space (South Africa)

    Schutte, PC

    1994-11-01

    Full Text Available The present report presents the findings of SIMRAC project GAP 045 entitled ‘Heat stress protection in abnormally hot environments’. It is intended as a reference to develop guidelines which, in turn would assist mine management in establishing safe...

  18. Marriage ceremony: The clash between traditional marriage rites ...

    African Journals Online (AJOL)

    Marriage ceremony: The clash between traditional marriage rites and ... and a woman who has agreed to marry, be socially described as a married couple ... People agreed that traditional marriage rites should be compulsory but performance ...

  19. Stress Management of Library and Information Professionals in Digital Environment

    OpenAIRE

    Routray, Bijayalaxmi; Satpathy, Sunil

    2007-01-01

    Stress is the changes which our bodies experience as we adjust to our continually changing environment. It has been an integral part of our daily life since prehistoric times and Library & Information science personnel are not exception to this. Thus we cannot avoid stress in our life; rather the best policy is to manage it properly to increase our efficiency. This article attempts to define stress in the light of LIS profession. It describes about the types of stress in libraries and its rea...

  20. Work environment, job satisfaction, stress and burnout among haemodialysis nurses.

    Science.gov (United States)

    Hayes, Bronwyn; Douglas, Clint; Bonner, Ann

    2015-07-01

    To examine the relationships among nurse and work characteristics, job satisfaction, stress, burnout and the work environment of haemodialysis nurses. Haemodialysis nursing is characterised by frequent and intense contact with patients in a complex and intense environment. A cross-sectional online survey of 417 haemodialysis nurses that included nurse and work characteristics, the Brisbane Practice Environment Measure, Index of Work Satisfaction, Nursing Stress Scale and the Maslach Burnout Inventory. Haemodialysis nurses reported an acceptable level of job satisfaction and perceived their work environment positively, although high levels of burnout were found. Nurses who were older and had worked in haemodialysis the longest had higher satisfaction levels, experienced less stress and lower levels of burnout than younger nurses. The in-centre type of haemodialysis unit had greater levels of stress and burnout than home training units. Greater satisfaction with the work environment was strongly correlated with job satisfaction, lower job stress and emotional exhaustion. Haemodialysis nurses experienced high levels of burnout even though their work environment was favourable and they had acceptable levels of job satisfaction. Targeted strategies are required to retain and avoid burnout in younger and less experienced nurses in this highly specialised field of nursing. © 2013 John Wiley & Sons Ltd.

  1. Controlling Social Stress in Virtual Reality Environments

    Science.gov (United States)

    Hartanto, Dwi; Kampmann, Isabel L.; Morina, Nexhmedin; Emmelkamp, Paul G. M.; Neerincx, Mark A.; Brinkman, Willem-Paul

    2014-01-01

    Virtual reality exposure therapy has been proposed as a viable alternative in the treatment of anxiety disorders, including social anxiety disorder. Therapists could benefit from extensive control of anxiety eliciting stimuli during virtual exposure. Two stimuli controls are studied in this study: the social dialogue situation, and the dialogue feedback responses (negative or positive) between a human and a virtual character. In the first study, 16 participants were exposed in three virtual reality scenarios: a neutral virtual world, blind date scenario, and job interview scenario. Results showed a significant difference between the three virtual scenarios in the level of self-reported anxiety and heart rate. In the second study, 24 participants were exposed to a job interview scenario in a virtual environment where the ratio between negative and positive dialogue feedback responses of a virtual character was systematically varied on-the-fly. Results yielded that within a dialogue the more positive dialogue feedback resulted in less self-reported anxiety, lower heart rate, and longer answers, while more negative dialogue feedback of the virtual character resulted in the opposite. The correlations between on the one hand the dialogue stressor ratio and on the other hand the means of SUD score, heart rate and audio length in the eight dialogue conditions showed a strong relationship: r(6) = 0.91, p = 0.002; r(6) = 0.76, p = 0.028 and r(6) = −0.94, p = 0.001 respectively. Furthermore, more anticipatory anxiety reported before exposure was found to coincide with more self-reported anxiety, and shorter answers during the virtual exposure. These results demonstrate that social dialogues in a virtual environment can be effectively manipulated for therapeutic purposes. PMID:24671006

  2. Controlling social stress in virtual reality environments.

    Directory of Open Access Journals (Sweden)

    Dwi Hartanto

    Full Text Available Virtual reality exposure therapy has been proposed as a viable alternative in the treatment of anxiety disorders, including social anxiety disorder. Therapists could benefit from extensive control of anxiety eliciting stimuli during virtual exposure. Two stimuli controls are studied in this study: the social dialogue situation, and the dialogue feedback responses (negative or positive between a human and a virtual character. In the first study, 16 participants were exposed in three virtual reality scenarios: a neutral virtual world, blind date scenario, and job interview scenario. Results showed a significant difference between the three virtual scenarios in the level of self-reported anxiety and heart rate. In the second study, 24 participants were exposed to a job interview scenario in a virtual environment where the ratio between negative and positive dialogue feedback responses of a virtual character was systematically varied on-the-fly. Results yielded that within a dialogue the more positive dialogue feedback resulted in less self-reported anxiety, lower heart rate, and longer answers, while more negative dialogue feedback of the virtual character resulted in the opposite. The correlations between on the one hand the dialogue stressor ratio and on the other hand the means of SUD score, heart rate and audio length in the eight dialogue conditions showed a strong relationship: r(6 = 0.91, p = 0.002; r(6 = 0.76, p = 0.028 and r(6 = -0.94, p = 0.001 respectively. Furthermore, more anticipatory anxiety reported before exposure was found to coincide with more self-reported anxiety, and shorter answers during the virtual exposure. These results demonstrate that social dialogues in a virtual environment can be effectively manipulated for therapeutic purposes.

  3. Controlling social stress in virtual reality environments.

    Science.gov (United States)

    Hartanto, Dwi; Kampmann, Isabel L; Morina, Nexhmedin; Emmelkamp, Paul G M; Neerincx, Mark A; Brinkman, Willem-Paul

    2014-01-01

    Virtual reality exposure therapy has been proposed as a viable alternative in the treatment of anxiety disorders, including social anxiety disorder. Therapists could benefit from extensive control of anxiety eliciting stimuli during virtual exposure. Two stimuli controls are studied in this study: the social dialogue situation, and the dialogue feedback responses (negative or positive) between a human and a virtual character. In the first study, 16 participants were exposed in three virtual reality scenarios: a neutral virtual world, blind date scenario, and job interview scenario. Results showed a significant difference between the three virtual scenarios in the level of self-reported anxiety and heart rate. In the second study, 24 participants were exposed to a job interview scenario in a virtual environment where the ratio between negative and positive dialogue feedback responses of a virtual character was systematically varied on-the-fly. Results yielded that within a dialogue the more positive dialogue feedback resulted in less self-reported anxiety, lower heart rate, and longer answers, while more negative dialogue feedback of the virtual character resulted in the opposite. The correlations between on the one hand the dialogue stressor ratio and on the other hand the means of SUD score, heart rate and audio length in the eight dialogue conditions showed a strong relationship: r(6) = 0.91, p = 0.002; r(6) = 0.76, p = 0.028 and r(6) = -0.94, p = 0.001 respectively. Furthermore, more anticipatory anxiety reported before exposure was found to coincide with more self-reported anxiety, and shorter answers during the virtual exposure. These results demonstrate that social dialogues in a virtual environment can be effectively manipulated for therapeutic purposes.

  4. Deconditioning and Reconditioning: Humans in Stressful Environments

    Science.gov (United States)

    Greenleaf, John E. (Editor); Dalton, Bonnie (Technical Monitor)

    2000-01-01

    -homeostatic state. This state occurs in response to the mutually interactive effects of the change in bodily position (hydrostatic pressure), to the virtual elimination of longitudinal pressure on the bones, to the increased confinement with possible reduction in total daily energy (exercise) expenditure, to the reorientation of stimuli within the vestibular organs, and (often) to altered socio-psychological conditions. The exercise-training (reconditioning) syndrome affects total body homeostasis by facilitating increases in work capacity and endurance, whereas deconditioning decreases physical performance. There are many interrelated factors that influence the control parameters that seek to maintain the adaptive conditioning-deconditioning syndrome. These control parameters can be better elucidated by subjecting otherwise healthy ambulatory people to various stresses, such as exercise training and prolonged spaceflight, bed rest, water immersion, hyperbaria, and isolation and confinement. Changes in control parameters will be manifested in muscle function, orthostatic tolerance, cardiorespiratory responses, musculo-skeletal systems, free-radical processes, and body thermoregulation with overarching effects on the subjects' psycho-sociological states. A discussion of these factors and the control parameters constitutes the substance of this volume. Special emphasis is placed on delineating practical applications of the findings that will be of special interest to physicians, nurses, and other health-care workers.

  5. The genetics of aging in optimal and stressful environments

    International Nuclear Information System (INIS)

    Parsons, P.A.

    1978-01-01

    The genetic basis of aging in Drosophila varies according to environment, as shown by variations in temperatures and levels of 60 Co-γ irradiation. Under conditions of extreme stress large additive differences occur not found under less acute stresses. In addition, longevities of strains are not necessarily correlated across levels of 60 C0-γ irradiation or temperatures, so that studies of the genetics of aging are not only relevant to the environment selected. Given these results on experimental animals, it appears impossible to separate clearly genetic and environmental factors determining longevity in man - a conclusion that in any case appears likely from human studies. In experimental organisms such as Drosophila, differences between genotypes for longevity are magnified under stress compared with optimal environments. Hybrid and heterozygote superiority frequently occur for density-independent physical stresses of the environment as well as density-dependent behavioral stresses due to crowding levels. It is argued that these conclusions apply to man, so that for maximum longevity genotypes are likely to be highly heterozygous. (author)

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

    Directory of Open Access Journals (Sweden)

    Jos F. Brosschot

    2018-03-01

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

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

    Science.gov (United States)

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

    2018-03-07

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

  8. Does the Environment Exacerbate Effects of Stress on Black ...

    African Journals Online (AJOL)

    Diet and obesity are major risk factors for a large number of non-communicable diseases, for which black women experience disproportionately high morbidity and mortality. Psychosocial stress and the food environment have emerged as two potentially important influences on black women's food choices. The combination ...

  9. Genetic erosion impedes adaptive responses to stressful environments

    NARCIS (Netherlands)

    Bijlsma, R.; Loeschcke, Volker

    Biodiversity is increasingly subjected to human-induced changes of the environment. To persist, populations continually have to adapt to these often stressful changes including pollution and climate change. Genetic erosion in small populations, owing to fragmentation of natural habitats, is expected

  10. Enriched environment at work: Disassociated from stress and burnout.

    Science.gov (United States)

    Rodriguez, Francisca S; Luck, Tobias; Riedel-Heller, Steffi G

    2018-05-22

    Enriched environment at work (EEW), in terms of high mental demands at work, may be of great relevance for preventative efforts against cognitive decline and dementia as previous studies have shown. Yet, there is the concern that high EEW mental demands may accelerate stress and cause burnout. The aim of our study was to investigate how EEW mental demands are related to stress and burnout. A convenience sample of employees in the city area of Leipzig, Germany, was asked to fill out the Copenhagen Burnout Inventory and indicate for each EEW mental demand the level experienced, demandingness, and stressfulness. Multivariate linear regression and structural equation modelling suggested that only some EEW mental demands were perceived as stressful when the level of the respective EEW mental demand was high. Higher stressfulness was associated with burnout symptoms - however, high levels of EEW mental demands were not significantly associated with burnout (neither directly nor indirectly). Our findings implied that subjectively perceived stressfulness seems to be a more relevant aspect than the actual level of the demand itself. However, further studies are necessary to validate our findings.

  11. Stress-reducing preventive maintenance model for a unit under stressful environment

    International Nuclear Information System (INIS)

    Park, J.H.; Chang, Woojin; Lie, C.H.

    2012-01-01

    We develop a preventive maintenance (PM) model for a unit operated under stressful environment. The PM model in this paper consists of a failure rate model and two cost models to determine the optimal PM scheduling which minimizes a cost rate. The assumption for the proposed model is that stressful environment accelerates the failure of the unit and periodic maintenances reduce stress from outside. The failure rate model handles the maintenance effect of PM using improvement and stress factors. The cost models are categorized into two failure recognition cases: immediate failure recognition and periodic failure detection. The optimal PM scheduling is obtained by considering the trade-off between the related cost and the lifetime of a unit in our model setting. The practical usage of our proposed model is tested through a numerical example.

  12. THE NEW RIGHT WING IN DENMARK AND THE CULTURE CLASH

    Directory of Open Access Journals (Sweden)

    Tomasz Archutowski

    2011-01-01

    Full Text Available Just within sixteen years since its emergence the Danish People’s Party (Dansk Folkeparti has reached the status of the third biggest political party in Denmark. Gaining such considerable voter’s support by a new far-right, populist party in Denmark, a country having a reputation of a stable, well-established democracy provokes a broader analysis of this phenomenon. The main goal of the paper is therefore to fi nd an answer to the question about possible factors that have contributed to the popularity of the new far-right in Denmark. In the paper I make an effort to prove that an essential influence on the popularity of the new far-right has the culture clash. I analyse the term culture clash on two planes – as a clash of the ideas of postmaterialism with the traditional sociocultural values and as a clash between Western culture and the values represented by immigrants coming to Denmark from mostly muslim countries.

  13. Beyond the Social Imaginary of "Clash of Civilizations"?

    Science.gov (United States)

    Rizvi, Fazal

    2011-01-01

    In recent years, the notion of a "clash of civilizations", first put forward by Samuel Huntington (1996), has been widely used to explain the contemporary dynamics of geo-political conflict. It has been argued that the fundamental source of conflict is no longer primarily ideological, or even economic, but cultural. Despite many trenchant and…

  14. CLASH: Climate (change) and cultural evolution of intergroup conflict

    NARCIS (Netherlands)

    van Lange, Paul A.M.; Rinderu, Maria I.; Bushman, Brad J.

    Aggression and violence levels generally increase as one moves closer to the equator, but why? We developed a new theoretical model, CLimate, Aggression, and Self-control in Humans (CLASH; van Lange, Rinderu, & Bushman, 2017b, 2017c), to understand differences within and between countries in

  15. Local Government Administration and Communal Clashes in Nigeria

    African Journals Online (AJOL)

    This paper notes that the increasing communal clashes in local areas are not caused by prevailing disputes such as land disputes, ethnic intolerance, cultural or religious extremism but persistent anomalies, inconsistencies in service delivery performance that have been continued over the years. It is quite an irony that in an ...

  16. Exploring athletes' perceptions of coach stress in elite sport environments.

    Science.gov (United States)

    Thelwell, Richard C; Wagstaff, Christopher R D; Rayner, Adam; Chapman, Michael; Barker, Jamie

    2017-01-01

    The present study aimed to extend research that has focused on the identification of stressors associated with coaching practice by systematically evaluating how such stressors effect athletes, and more broadly, the coach-athlete relationship. A total of 13 professional- and national-level athletes were interviewed to address the three study aims: how they detect when a coach is encountering stressors, how coach experiences of stress effects them as an athlete, and how effective the coach is when experiencing stress. Following content analysis, the data suggested athletes were able to detect when a coach was experiencing stress and this was typically via a variety of verbal and behavioural cues. Despite some positive effects of the coach experiencing stress, the majority were negative and varied across a range of personal influences on the athlete, and effects on the general coaching environment. It was also the broad view of the athletes that coaches were less effective when stressed, and this was reflected in performance expectations, perceptions of competence, and lack of awareness. The findings are discussed in relation to the existing theory and with reference to their implications for applied practice, future research, and development of the coach-athlete relationship.

  17. The relative impact of work-related stress, life stress and driving environment stress on driving outcomes.

    Science.gov (United States)

    Rowden, Peter; Matthews, Gerald; Watson, Barry; Biggs, Herbert

    2011-07-01

    Previous research has shown the association between stress and crash involvement. The impact of stress on road safety may also be mediated by behaviours including cognitive lapses, errors, and intentional traffic violations. This study aimed to provide a further understanding of the impact that stress from different sources may have upon driving behaviour and road safety. It is asserted that both stress extraneous to the driving environment and stress directly elicited by driving must be considered part of a dynamic system that may have a negative impact on driving behaviours. Two hundred and forty-seven public sector employees from Queensland, Australia, completed self-report measures examining demographics, subjective work-related stress, daily hassles, and aspects of general mental health. Additionally, the Driver Behaviour Questionnaire (DBQ) and the Driver Stress Inventory (DSI) were administered. All participants drove for work purposes regularly, however the study did not specifically focus on full-time professional drivers. Confirmatory factor analysis of the predictor variables revealed three factors: DSI negative affect; DSI risk taking; and extraneous influences (daily hassles, work-related stress, and general mental health). Moderate intercorrelations were found between each of these factors confirming the 'spillover' effect. That is, driver stress is reciprocally related to stress in other domains including work and domestic life. Structural equation modelling (SEM) showed that the DSI negative affect factor influenced both lapses and errors, whereas the DSI risk-taking factor was the strongest influence on violations. The SEMs also confirmed that daily hassles extraneous to the driving environment may influence DBQ lapses and violations independently. Accordingly, interventions may be developed to increase driver awareness of the dangers of excessive emotional responses to both driving events and daily hassles (e.g. driving fast to 'blow off steam

  18. School environments and obesity: The mediating role of personal stress.

    Science.gov (United States)

    Milam, Adam J; Jones, Chandria D; Debnam, Katrina J; Bradshaw, Catherine P

    2017-01-01

    Youth spend a large amount of time in the school environment. Given the multiple influences of teachers, peers, and food and physical activity options, youth are likely to experience stressors that can influence their weight. This study examines the association between school climate and weight status. Students ( n = 28,582; 58 schools) completed an online, anonymous school climate survey as part of the Maryland Safe and Supportive Schools Project. Multilevel structural equation modeling was used to explore the association between school climate, personal stress, and obesity. Analyses were stratified by gender. At the individual level, poor school climate (bullying, physical safety, and lack of whole-school connectedness) was associated with an increased likelihood of being overweight among females ( β =.115, p = .019) but not males ( β = .138; p =.244), after controlling for age, race, and physical activity. There was no association between school climate at the school level and being overweight among males or females. A second model included stress as a potential mediator; stress attenuated the relationship between poor school-related climate and being overweight ( β = .039; p = .048) among females. Findings suggest that stress related to school climate can play a role in the health and weight status of youth.

  19. Task-dependent cold stress during expeditions in Antarctic environments.

    Science.gov (United States)

    Morris, Drew M; Pilcher, June J; Powell, Robert B

    2017-01-01

    This study seeks to understand the degree of body cooling, cold perception and physical discomfort during Antarctic tour excursions. Eight experienced expedition leaders across three Antarctic cruise voyages were monitored during occupational tasks: kayaking, snorkelling and zodiac outings. Subjective cold perception and discomfort were recorded using a thermal comfort assessment and skin temperature was recorded using a portable data logger. Indoor cabin temperature and outdoor temperature with wind velocity were used as measures of environmental stress. Physical activity level and clothing insulation were estimated using previous literature. Tour leaders experienced a 6°C (2°C wind chill) environment for an average of 6 hours each day. Leaders involved in kayaking reported feeling colder and more uncomfortable than other leaders, but zodiac leaders showed greater skin temperature cooling. Occupational experience did not predict body cooling or cold stress perception. These findings indicate that occupational cold stress varies by activity and measurement methodology. The current study effectively used objective and subjective measures of cold-stress to identify factors which can contribute to risk in the Antarctic tourism industry. Results suggest that the type of activity may moderate risk of hypothermia, but not discomfort, potentially putting individuals at risk for cognitive related mistakes and cold injuries.

  20. Stressful work environment and wellbeing: What comes first?

    Science.gov (United States)

    Elovainio, Marko; Heponiemi, Tarja; Jokela, Markus; Hakulinen, Christian; Presseau, Justin; Aalto, Anna-Mari; Kivimäki, Mika

    2015-07-01

    The association between the psychosocial work environment, including job demands, job control, and organizational justice, and employee wellbeing has been well established. However, the exposure to adverse work environments is typically measured only using self-reported measures that are vulnerable to reporting bias, and thus any associations found may be explained by reverse causality. Using linear regression models and cross-lagged structural equation modeling (SEM), we tested the direction of the association between established job stress models (job demand control and organizational justice models) and 3 wellbeing indicators (psychological distress, sleeping problems, and job satisfaction) among 1524 physicians in a 4-year follow-up. Results from the longitudinal cross-lagged analyses showed that the direction of the association was from low justice to decreasing wellbeing rather than the reverse. Although the pattern was similar in job demands and job control, a reciprocal association was found between job control and psychological distress. (c) 2015 APA, all rights reserved).

  1. The work environment, stress and well-being.

    Science.gov (United States)

    Wadsworth, E J K; Chaplin, K S; Smith, A P

    2010-12-01

    Much recent work extending the field of job characteristics to include positive aspects of work makes the implicit assumption that the absence of negative work characteristics is equivalent to the presence of positive work characteristics. To consider the effect sizes seen at different ends of job characteristic dimensions and to compare the impact of the presence and absence of job characteristics in association with mental health and well-being outcomes. Data from 8755 workers were analysed to compare the impacts of the presence or absence of job characteristics (job demand, extrinsic effort and social support) in associations with both positive (job satisfaction) and negative (work-related stress) outcome measures. Comparable presence and absence impacts were apparent for extrinsic effort in association with work-related stress. However, in the association between job demand and work-related stress, the presence of high levels of job demand had a significantly greater impact than the absence of high levels of job demand; while in the association between social support and job satisfaction, the absence of high levels of social support had a significantly greater impact than the presence of high levels of social support. It is not always appropriate to assume that the absence of negative aspects of the work environment is equivalent to the presence of positive aspects.

  2. THE DETECTION AND STATISTICS OF GIANT ARCS BEHIND CLASH CLUSTERS

    International Nuclear Information System (INIS)

    Xu, Bingxiao; Zheng, Wei; Postman, Marc; Bradley, Larry; Meneghetti, Massimo; Koekemoer, Anton; Seitz, Stella; Zitrin, Adi; Merten, Julian; Maoz, Dani; Frye, Brenda; Umetsu, Keiichi; Vega, Jesus

    2016-01-01

    We developed an algorithm to find and characterize gravitationally lensed galaxies (arcs) to perform a comparison of the observed and simulated arc abundance. Observations are from the Cluster Lensing And Supernova survey with Hubble (CLASH). Simulated CLASH images are created using the MOKA package and also clusters selected from the high-resolution, hydrodynamical simulations, MUSIC, over the same mass and redshift range as the CLASH sample. The algorithm's arc elongation accuracy, completeness, and false positive rate are determined and used to compute an estimate of the true arc abundance. We derive a lensing efficiency of 4 ± 1 arcs (with length ≥6″ and length-to-width ratio ≥7) per cluster for the X-ray-selected CLASH sample, 4 ± 1 arcs per cluster for the MOKA-simulated sample, and 3 ± 1 arcs per cluster for the MUSIC-simulated sample. The observed and simulated arc statistics are in full agreement. We measure the photometric redshifts of all detected arcs and find a median redshift z s = 1.9 with 33% of the detected arcs having z s  > 3. We find that the arc abundance does not depend strongly on the source redshift distribution but is sensitive to the mass distribution of the dark matter halos (e.g., the c–M relation). Our results show that consistency between the observed and simulated distributions of lensed arc sizes and axial ratios can be achieved by using cluster-lensing simulations that are carefully matched to the selection criteria used in the observations

  3. THE DETECTION AND STATISTICS OF GIANT ARCS BEHIND CLASH CLUSTERS

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Bingxiao; Zheng, Wei [Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Postman, Marc; Bradley, Larry [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21208 (United States); Meneghetti, Massimo; Koekemoer, Anton [INAF, Osservatorio Astronomico di Bologna, and INFN, Sezione di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Seitz, Stella [Universitaets-Sternwarte, Fakultaet fuer Physik, Ludwig-Maximilians Universitaet Muenchen, Scheinerstr. 1, D-81679 Muenchen (Germany); Zitrin, Adi [California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States); Merten, Julian [University of Oxford, Department of Physics, Denys Wilkinson Building, Keble Road, Oxford, OX1 3RH (United Kingdom); Maoz, Dani [School of Physics and Astronomy, Tel Aviv University, Tel-Aviv 69978 (Israel); Frye, Brenda [Steward Observatory/Department of Astronomy, University of Arizona, 933 N. Cherry Ave., Tucson, AZ 85721 (United States); Umetsu, Keiichi [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Vega, Jesus, E-mail: bxu6@jhu.edu [Universidad Autonoma de Madrid, Ciudad Universitaria de Cantoblanco, E-28049 Madrid (Spain)

    2016-02-01

    We developed an algorithm to find and characterize gravitationally lensed galaxies (arcs) to perform a comparison of the observed and simulated arc abundance. Observations are from the Cluster Lensing And Supernova survey with Hubble (CLASH). Simulated CLASH images are created using the MOKA package and also clusters selected from the high-resolution, hydrodynamical simulations, MUSIC, over the same mass and redshift range as the CLASH sample. The algorithm's arc elongation accuracy, completeness, and false positive rate are determined and used to compute an estimate of the true arc abundance. We derive a lensing efficiency of 4 ± 1 arcs (with length ≥6″ and length-to-width ratio ≥7) per cluster for the X-ray-selected CLASH sample, 4 ± 1 arcs per cluster for the MOKA-simulated sample, and 3 ± 1 arcs per cluster for the MUSIC-simulated sample. The observed and simulated arc statistics are in full agreement. We measure the photometric redshifts of all detected arcs and find a median redshift z{sub s} = 1.9 with 33% of the detected arcs having z{sub s} > 3. We find that the arc abundance does not depend strongly on the source redshift distribution but is sensitive to the mass distribution of the dark matter halos (e.g., the c–M relation). Our results show that consistency between the observed and simulated distributions of lensed arc sizes and axial ratios can be achieved by using cluster-lensing simulations that are carefully matched to the selection criteria used in the observations.

  4. The Detection and Statistics of Giant Arcs behind CLASH Clusters

    Science.gov (United States)

    Xu, Bingxiao; Postman, Marc; Meneghetti, Massimo; Seitz, Stella; Zitrin, Adi; Merten, Julian; Maoz, Dani; Frye, Brenda; Umetsu, Keiichi; Zheng, Wei; Bradley, Larry; Vega, Jesus; Koekemoer, Anton

    2016-02-01

    We developed an algorithm to find and characterize gravitationally lensed galaxies (arcs) to perform a comparison of the observed and simulated arc abundance. Observations are from the Cluster Lensing And Supernova survey with Hubble (CLASH). Simulated CLASH images are created using the MOKA package and also clusters selected from the high-resolution, hydrodynamical simulations, MUSIC, over the same mass and redshift range as the CLASH sample. The algorithm's arc elongation accuracy, completeness, and false positive rate are determined and used to compute an estimate of the true arc abundance. We derive a lensing efficiency of 4 ± 1 arcs (with length ≥6″ and length-to-width ratio ≥7) per cluster for the X-ray-selected CLASH sample, 4 ± 1 arcs per cluster for the MOKA-simulated sample, and 3 ± 1 arcs per cluster for the MUSIC-simulated sample. The observed and simulated arc statistics are in full agreement. We measure the photometric redshifts of all detected arcs and find a median redshift zs = 1.9 with 33% of the detected arcs having zs > 3. We find that the arc abundance does not depend strongly on the source redshift distribution but is sensitive to the mass distribution of the dark matter halos (e.g., the c-M relation). Our results show that consistency between the observed and simulated distributions of lensed arc sizes and axial ratios can be achieved by using cluster-lensing simulations that are carefully matched to the selection criteria used in the observations.

  5. Narcissistic Force Meets Systemic Resistance: The Energy Clash Model.

    Science.gov (United States)

    Sedikides, Constantine; Campbell, W Keith

    2017-05-01

    This article focuses on the interplay between narcissistic leaders and organizations. It attempts to capture the gist of this interplay with a model outlining the narcissistic organizational trajectory. The Energy Clash Model borrows and adapts a phase/state physics metaphor to conceptualize narcissism as a force that enters or emerges in a stable system (i.e., organization) as a leader, destabilizes it, and stabilizes it at a different state or is expelled. The model consists of three time-contingent phases: perturbation, conflict, and resolution. Narcissists create instability through waves of excitement, proposed reforms, and an inspiring vision for organization's future ( perturbation). With the passage of time, though, systemic awareness and alertness intensify, as organizational costs-in terms of human resources and monetary losses-accrue. Narcissistic energy clashes directly with the organization ( conflict), a clash likely to restabilize the system eventually. The conflict may provoke the exit of the narcissistic leader or his or her accommodation, that is, steps or controls negotiated between the system and the leader ( resolution). Although narcissism is subject to organizational liability, narcissistic energy, when managed and directed properly, may contribute to organizational innovation and evolution. Thus, several interventions for working with narcissistic leaders are discussed.

  6. Calibrating the Planck cluster mass scale with CLASH

    Science.gov (United States)

    Penna-Lima, M.; Bartlett, J. G.; Rozo, E.; Melin, J.-B.; Merten, J.; Evrard, A. E.; Postman, M.; Rykoff, E.

    2017-08-01

    We determine the mass scale of Planck galaxy clusters using gravitational lensing mass measurements from the Cluster Lensing And Supernova survey with Hubble (CLASH). We have compared the lensing masses to the Planck Sunyaev-Zeldovich (SZ) mass proxy for 21 clusters in common, employing a Bayesian analysis to simultaneously fit an idealized CLASH selection function and the distribution between the measured observables and true cluster mass. We used a tiered analysis strategy to explicitly demonstrate the importance of priors on weak lensing mass accuracy. In the case of an assumed constant bias, bSZ, between true cluster mass, M500, and the Planck mass proxy, MPL, our analysis constrains 1-bSZ = 0.73 ± 0.10 when moderate priors on weak lensing accuracy are used, including a zero-mean Gaussian with standard deviation of 8% to account for possible bias in lensing mass estimations. Our analysis explicitly accounts for possible selection bias effects in this calibration sourced by the CLASH selection function. Our constraint on the cluster mass scale is consistent with recent results from the Weighing the Giants program and the Canadian Cluster Comparison Project. It is also consistent, at 1.34σ, with the value needed to reconcile the Planck SZ cluster counts with Planck's base ΛCDM model fit to the primary cosmic microwave background anisotropies.

  7. THE DYNAMIC INTERCONNECTION BETWEEN MAN AND ENVIRONMENT, A FACTOR OF STRESS AND ECO STRESS

    Directory of Open Access Journals (Sweden)

    SIMIONESCU (BARBU IRINA

    2014-05-01

    Full Text Available The reason for writing this paper is the omnipresence but also the impact of stress in our times. In order to explain why stress has gained an important place in modern history, we need to understand the evolution of medical science and technology, which over the last decades, have taken important steps towards establishing the biological links between stress and human behaviour but also the political and cultural contexts that have endowed with meaning and authority the scientific knowledge. In the same time, we must concentrate on the interaction between the individual and his social and physical environment from a holistic perspective, surpassing the interdisciplinary limits. The term ‘stress’ is used as a metaphor for disasters at a macroeconomic level, when national economies are destabilized and recently it has been associated with the idea of environmental damage. All natural disasters are environmental events, and their impact on human beings (from a psychological, physical, economic and social point of view can be seen as a major eco-stress. It’s essential to understand man`s influence on the environment in order to review the attitude of communities that, under the pretext of modernity, continue to exert destructive actions

  8. Public Diplomacy and the Clash of Satellites

    OpenAIRE

    Marwa Fikry Abdel Samei

    2016-01-01

    The communication revolution has shifted the paradigm of diplomacy by emphasizing the role of public diplomacy, at the same time complicating the environment within which state-managed public diplomacy is conducted. The rise of regional media has provided weaker states with opportunities to challenge the monopoly of information on the part of the more powerful states. Al-Hurra, the American sponsored channel to the Arab World, stands as evidence of the challenges facing US policies in thi...

  9. Does spending time outdoors reduce stress? A review of real-time stress response to outdoor environments

    Science.gov (United States)

    Michelle C. Kondo; Sara F. Jacoby; Eugenia C. South

    2018-01-01

    Everyday environmental conditions impact human health. One mechanism underlying this relationship is the experience of stress. Through systematic review of published literature, we explore how stress has been measured in real-time non-laboratory studies of stress responses to deliberate exposure to outdoor environments. The types of exposures evaluated in this review...

  10. Infectious Disease risks associated with exposure to stressful environments

    Science.gov (United States)

    Meehan, Ichard T.; Smith, Morey; Sams, Clarence

    1993-01-01

    Multiple environmental factors asociated with space flight can increase the risk of infectious illness among crewmembers thereby adversely affecting crew health and mission success. Host defences can be impaired by multiple physiological and psychological stressors including: sleep deprivation, disrupted circadian rhythms, separation from family, perceived danger, radiation exposure, and possibly also by the direct and indirect effects of microgravity. Relevant human immunological data from isolated or stressful environments including spaceflight will be reviewed. Long-duration missions should include reliable hardware which supports sophisticated immunodiagnostic capabilities. Future advances in immunology and molecular biology will continue to provide therapeutic agents and biologic response modifiers which should effectively and selectively restore immune function which has been depressed by exposure to environmental stressors.

  11. Public Diplomacy and the Clash of Satellites

    Directory of Open Access Journals (Sweden)

    Marwa Fikry Abdel Samei

    2016-05-01

    Full Text Available The communication revolution has shifted the paradigm of diplomacy by emphasizing the role of public diplomacy, at the same time complicating the environment within which state-managed public diplomacy is conducted. The rise of regional media has provided weaker states with opportunities to challenge the monopoly of information on the part of the more powerful states. Al-Hurra, the American sponsored channel to the Arab World, stands as evidence of the challenges facing US policies in this part of the world because of the influential role of regional media. It was particularly Al-Jazeera that transformed the media sphere in the Arab World as well as globally in what became known as “Al-Jazeera effect”. The paper argues that identity presentation plays a major role in determining performance of the public diplomacy of the media.

  12. The End of Politics, or the Clash of Civilizations

    OpenAIRE

    Fišer Bohumil

    2012-01-01

    The text The End of Politics or Clash of Civilizations is a part of a essy Politics from the Viewpoint of a Natural Scientist. The essay is in the book Úvahy o politice, Joštova akademie Brno 2011. Text je závěrečnou kapitolou eseje Politika z pohledu přírodovědce, který vyšel v knize Úvahy o politice, Joštova akademie Brno 2011.

  13. [Appraisal of occupational stress and its influential factors in nurses].

    Science.gov (United States)

    Yang, Xin-wei; Wang, Zhi-ming; Wang, Mian-zhen; Lan, Ya-jia

    2004-04-01

    To assess the occupational stress and its influential factors in nurses. A test of occupational stress, its influential factors, work ability were carried out for 248 nurses and 319 controls with revised occupational stress inventory (OSI-R) and work ability index (WAI). The scores of personal cope resource (131.266 +/- 17.176) and work ability index (32.581 +/- 3.158) in nurse group were significantly higher than those in control group (126.931 +/- 19.108, 31.840 +/- 4.069) (P < 0.05). The main occupational stressors scores (role insufficiency, role clash, and responsibility) in nurses were higher than those in controls (P < 0.05). The stress response of interpersonal relationship in nurses was also higher. The items of personal cope resource, such as recreation, self-care and social support of nurses were superior to those of controls (P < 0.05). Stress response was positively correlated with occupational role (r = 0.512, P < 0.01), and negatively correlated with the personal cope resource (r = -0.475, P < 0.01). The primary influential factors of personal stress were recreation, social support, rational conduct, role insufficiency, role clash, responsibility, and poor work environment. To strengthen social support, to improve work condition for nurses, so as to reduce the occupational stress and to enhance the work ability of nurses are important task in occupational health field.

  14. Women in Business Environment: Types of Stress Women Are Exposed

    OpenAIRE

    Mirjana Radovic-Markovic

    2014-01-01

    Time management is a skill that all people, regardless of age, gender and job, can benefit from. This article is aimed at studying the causes and effects of stress and how to manage stress effectively with a focus on women. First, a study was done to examine the causes why stress occurs and the potential consequences of stress. This is followed by a search on methods to manage stress by managing a work-life balance and by effective time-management. The desire to succeed does make people prone...

  15. The influence of the social environment context in stress and coping in sport

    NARCIS (Netherlands)

    Kerdijk, Carlijn; van der Kamp, John; Polman, Remco

    2016-01-01

    Lazarus (1999) model of stress and coping is based on the reciprocal interaction between the person and the environment. The aim of this study therefore was to examine whether the social environment (significant others) are of influence on the stress and coping of team athletes. The study consisted

  16. Strong facilitation in mild environments: the stress gradient hypothesis revisited

    NARCIS (Netherlands)

    Holmgren, M.; Scheffer, M.

    2010-01-01

    1. The idea that the role of facilitative interactions increases as environmental conditions become more stressful has become a ruling paradigm in ecology. Here, we review three reasons why positive interactions may actually be more prominent than generally thought under moderately stressful rather

  17. Understanding and determining the variability of the primitive stress environment.

    CSIR Research Space (South Africa)

    Sellers, EJ

    2002-10-01

    Full Text Available The primitive stress state is an important input into the design of underground excavations. However, it is well known that the stress state varies considerably from place to place. The aim of this project was to determine the main causes...

  18. Family Environments and Children's Executive Function: The Mediating Role of Children's Affective State and Stress.

    Science.gov (United States)

    He, Zhong-Hua; Yin, Wen-Gang

    2016-09-01

    There is increasing evidence that inadequate family environments (family material environment and family psychosocial environment) are not only social problems but also factors contributing to adverse neurocognitive outcomes. In the present study, the authors investigated the relationship among family environments, children's naturalistic affective state, self-reported stress, and executive functions in a sample of 157 Chinese families. These findings revealed that in inadequate family material environments, reduced children's cognitive flexibility is associated with increased naturalistic negative affectivity and self-reported stress. In addition, naturalistic negative affectivity mediated the association between family expressiveness and children's cognitive flexibility. The authors used a structural equation model to examine the mediation model hypothesis, and the results confirmed the mediating roles of naturalistic negative affectivity and self-reported stress between family environments and the cognitive flexibility of Chinese children. These findings indicate the importance of reducing stress and negative emotional state for improving cognitive functions in children of low socioeconomic status.

  19. Predicted thermal and stress environments in the vicinity of repository openings

    International Nuclear Information System (INIS)

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

    1991-01-01

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

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

    Science.gov (United States)

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

    2017-04-01

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

  1. On the asserted clash between the Freud and the Bianchi identities

    Science.gov (United States)

    Antoci, S.

    1995-09-01

    Through a constructive method it is shown that the claim advanced in recent times about a clash that should occur between the Freud and the Bianchi identities in Einstein's general theory of relativity is based on a faulty argument.

  2. Exploring the Role of the Built and Social Neighborhood Environment in Moderating Stress and Health

    Science.gov (United States)

    Yang, Tse-Chuan

    2014-01-01

    Background Health researchers have explored how different aspects of neighborhood characteristics contribute to health and well-being, but current understanding of built environment factors is limited. Purpose This study explores whether the association between stress and health varies by residential neighborhood, and if yes, whether built and social neighborhood environment characteristics act as moderators. Methods This study uses multilevel modeling and variables derived from geospatial data to explore the role of neighborhood environment in moderating the association of stress with health. Individual-level data (N=4,093) were drawn from residents of 45 neighborhoods within Philadelphia County, PA, collected as part of the 2006 Philadelphia Health Management Corporation's Household Health Survey. Results We find that the negative influence of high stress varied by neighborhood, that residential stability and affluence (social characteristics) attenuated the association of high stress with health, and that the presence of hazardous waste facilities (built environment characteristics) moderated health by enhancing the association with stress. Conclusions Our findings suggest that neighborhood environment has both direct and moderating associations with health, after adjusting for individual characteristics. The use of geospatial data could broaden the scope of stress–health research and advance knowledge by untangling the intertwined relationship between built and social environments, stress, and health. In particular, future studies should integrate built environment characteristics in health-related research; these characteristics are modifiable and can facilitate health promotion policies. PMID:20300905

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

    DEFF Research Database (Denmark)

    Annerstedt, Matilda; Jönsson, Peter; Wallergård, Mattias

    2013-01-01

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

  4. Star Formation Activity in CLASH Brightest Cluster Galaxies

    Science.gov (United States)

    Fogarty, Kevin; Postman, Marc; Connor, Thomas; Donahue, Megan; Moustakas, John

    2015-11-01

    The CLASH X-ray selected sample of 20 galaxy clusters contains 10 brightest cluster galaxies (BCGs) that exhibit significant (>5σ) extinction-corrected star formation rates (SFRs). Star formation activity is inferred from photometric estimates of UV and Hα+[N ii] emission in knots and filaments detected in CLASH Hubble Space Telescope ACS and WFC3 observations. UV-derived SFRs in these BCGs span two orders of magnitude, including two with a SFR ≳ 100 M⊙ yr-1. These measurements are supplemented with [O ii], [O iii], and Hβ fluxes measured from spectra obtained with the SOAR telescope. We confirm that photoionization from ongoing star formation powers the line emission nebulae in these BCGs, although in many BCGs there is also evidence of a LINER-like contribution to the line emission. Coupling these data with Chandra X-ray measurements, we infer that the star formation occurs exclusively in low-entropy cluster cores and exhibits a correlation with gas properties related to cooling. We also perform an in-depth study of the starburst history of the BCG in the cluster RXJ1532.9+3021, and create 2D maps of stellar properties on scales down to ˜350 pc. These maps reveal evidence for an ongoing burst occurring in elongated filaments, generally on ˜0.5-1.0 Gyr timescales, although some filaments are consistent with much younger (≲100 Myr) burst timescales and may be correlated with recent activity from the active galactic nucleus. The relationship between BCG SFRs and the surrounding intracluster medium gas properties provide new support for the process of feedback-regulated cooling in galaxy clusters and is consistent with recent theoretical predictions. Based on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel

  5. CLASH-VLT: testing the nature of gravity with galaxy cluster mass profiles

    Energy Technology Data Exchange (ETDEWEB)

    Pizzuti, L.; Sartoris, B.; Borgani, S.; Girardi, M. [Dipartimento di Fisica, Sezione di Astronomia, Università di Trieste, Via Tiepolo 11, I-34143 Trieste (Italy); Amendola, L. [Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 16, D-69120 Heidelberg (Germany); Umetsu, K. [5 Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Biviano, A.; Balestra, I.; Nonino, M. [INAF—Osservatorio Astronomico di Trieste, Via Tiepolo 11, I-34143 Trieste (Italy); Rosati, P. [University Observatory Munich, Scheinerstrasse 1, D-81679 Mu\\' nchen (Germany); Caminha, G.B. [Dipartimento di Fisica e Scienze della Terra, Università di Ferrara, Via Saragat 1, I-44122 Ferrara (Italy); Frye, B. [Steward Observatory/Department of Astronomy, University of Arizona, 933 N Cherry Ave, Tucson, AZ 85721 (United States); Koekemoer, A. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Grillo, C. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Lombardi, M. [Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, I-20133 Milan (Italy); Mercurio, A., E-mail: pizzuti@oats.inaf.it, E-mail: barbara.sartoris@gmail.com, E-mail: borgani@oats.inaf.it, E-mail: l.amendola@thphys.uniheidelberg.de [Osservatorio Astronomico di Capodimonte, Via Moiariello 16, I-80131 Napoli (Italy)

    2016-04-01

    We use high-precision kinematic and lensing measurements of the total mass profile of the dynamically relaxed galaxy cluster MACS J1206.2-0847 at z=0.44 to estimate the value of the ratio η=Ψ/Φ between the two scalar potentials in the linear perturbed Friedmann-Lemaitre-Robertson-Walker metric. An accurate measurement of this ratio, called anisotropic stress, could show possible, interesting deviations from the predictions of the theory of General Relativity, according to which Ψ should be equal to Φ. Complementary kinematic and lensing mass profiles were derived from exhaustive analyses using the data from the Cluster Lensing And Supernova survey with Hubble (CLASH) and the spectroscopic follow-up with the Very Large Telescope (CLASH-VLT). Whereas the kinematic mass profile tracks only the time-time part of the perturbed metric (i.e. only Φ), the lensing mass profile reflects the contribution of both time-time and space-space components (i.e. the sum Φ+Ψ). We thus express η as a function of the mass profiles and perform our analysis over the radial range 0.5 Mpc≤ r≤ r{sub 200}=1.96 Mpc. Using a spherical Navarro-Frenk-White mass profile, which well fits the data, we obtain η(r{sub 200})=1.01 {sub −0.28}{sup +0.31} at the 68% C.L. We discuss the effect of assuming different functional forms for mass profiles and of the orbit anisotropy in the kinematic reconstruction. Interpreting this result within the well-studied f(R) modified gravity model, the constraint on η translates into an upper bound to the interaction length (inverse of the scalaron mass) smaller than 2 Mpc. This tight constraint on the f(R) interaction range is however substantially relaxed when systematic uncertainties in the analysis are considered. Our analysis highlights the potential of this method to detect deviations from general relativity, while calling for the need of further high-quality data on the total mass distribution of clusters and improved control on systematic

  6. Conflict management style, supportive work environments and the experience of work stress in emergency nurses.

    Science.gov (United States)

    Johansen, Mary L; Cadmus, Edna

    2016-03-01

    To examine the conflict management style that emergency department (ED) nurses use to resolve conflict and to determine whether their style of managing conflict and a supportive work environment affects their experience of work stress. Conflict is a common stressor that is encountered as nurses strive to achieve patient satisfaction goals while delivering quality care. How a nurse perceives support may impact work stress levels and how they deal with conflict. A correlational design examined the relationship between supportive work environment, and conflict management style and work stress in a sample of 222 ED nurses using the expanded nurse work stress scale; the survey of perceived organisational support; and the Rahim organisational conflict inventory-II. Twenty seven percent of nurses reported elevated levels of work stress. A supportive work environment and avoidant conflict management style were significant predictors of work stress. Findings suggest that ED nurses' perception of a supportive work environment and their approach to resolving conflict may be related to their experience of work stress. Providing opportunities for ED nurses in skills training in constructive conflict resolution may help to reduce work stress and to improve the quality of patient care. © 2015 John Wiley & Sons Ltd.

  7. Neighborhood food environment role in modifying psychosocial stress-diet relationships.

    Science.gov (United States)

    Zenk, Shannon N; Schulz, Amy J; Izumi, Betty T; Mentz, Graciela; Israel, Barbara A; Lockett, Murlisa

    2013-06-01

    Exposure to highly palatable foods may increase eating in response to stress, but this behavioral response has not been examined in relation to the neighborhood food environment. This study examined whether the neighborhood food environment modified relationships between psychosocial stress and dietary behaviors. Probability-sample survey (n=460) and in-person food environment audit data were used. Dietary behaviors were measured using 17 snack food items and a single eating-out-of-home item. Chronic stress was derived from five subscales; major life events was a count of nine items. The neighborhood food environment was measured as availability of large grocery stores, small grocery stores, and convenience stores, as well as proportion of restaurants that were fast food. Two-level hierarchical regression models were estimated. Snack food intake was positively associated with convenience store availability and negatively associated with large grocery store availability. The measures of chronic stress and major life events were generally not associated with either dietary behavior overall, although Latinos were less likely to eat out at high levels of major life events than African Americans. Stress-neighborhood food environment interactions were not statistically significant. Important questions remain regarding the role of the neighborhood food environment in the stress-diet relationship that warrant further investigation. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Induced Stress, Artificial Environment, Simulated Tactical Operations Center Model

    Science.gov (United States)

    1973-06-01

    hiebman, Stress Situations (Philadelphia: J. Is. IJ iui ott CO., .lqý1.), pp. ’ - 6. ’ | ;* .- -~~~~~~~~. , ’ • :• ",. . .... . , • . 33 provides one or...April 1964, pp. 545-556. ~ .~:.;a-d K. " -Iu: izodoiog;ical Ls;suL5- in Experiuienting, withi Sil-.ISiilatý’ionS of Lusincss Pim ~"paper presentecd at

  9. Stress corrosion cracking behavior of zircaloy-2 in iodine environment

    International Nuclear Information System (INIS)

    Ikeda, Seiichi

    1983-01-01

    The effects of strain rates, iodine partial pressure and testing temperature on SCC behavior of zircaloy-2 in iodine environment were studied by means of slow strain rate technique (SSRT). SCC behavior of recrystallized specimens in iodine environment was remarkably influenced by the testing temperatures, and the susceptibility to SCC of specimens tested at 623 K was higher than that at 573 K. The susceptibility to SCC of recrystallized specimens increased with increasing iodine partial pressure at the lower strain rates of 4.2 x 10 -6 s -1 and 8.3 x 10 -7 s -1 . Cold worked specimens indicate no SCC failure in iodine environment regardless of strain rates, although those were tested only at 573 K. Fractographic observation revealed that SCC features of recrystallized specimens can be classified into two groups. One group, mostly specimens tested at 573 K, are characterized by the fact that cracks are initiated from corrosion pits. The other group are characterized by transgranuler SCC in the absence of pitting. This type of crack is found on specimens tested in environments containing more than 570 Pa iodine and seems to be produced by iodine embrittlement. (author)

  10. Structural Model for the Effects of Perceived Indoor Work Environment on Sick Building Syndrome and Stress

    Directory of Open Access Journals (Sweden)

    Abdullah Nor Hazana

    2016-01-01

    Full Text Available Sick Building syndrome (SBS and stress have a prevalent influence on organizational productivity and competitiveness. Unhealthy employees not only tend to have high medical leaves but also low productivity due to ailments and discomforts. Studies that investigate the effects of indoor work environment on Sick Building Syndrome (SBS have yielded mixed results while their effect on stress has not been empirically established. Furthermore, studies that simultaneously investigate both SBS and stress are almost non-existent. Thus, this study aimed to study the effects of perceived indoor work environment on SBS and stress and the link between SBS and stress. A cross-sectional survey participated by 598 employees from various industries was conducted from September to October 2015. Data were analyzed using Partial Least Square Structural Equation Modeling (PLS-SEM to assess both the measurement model and the path structure. The results suggest that indoor work environment has significant yet the weak effect on SBS while it has no effect on stress. However, SBS has a strong significant relationship with stress. The implication of this study on the importance of conducive indoor work environment is discussed with suggestions for future studies.

  11. Multi-environment QTL mixed models for drought stress adaptation in wheat

    NARCIS (Netherlands)

    Mathews, K.L.; Malosetti, M.; Chapman, S.; McIntyre, L.; Reynolds, M.; Shorter, R.; Eeuwijk, van F.A.

    2008-01-01

    Many quantitative trait loci (QTL) detection methods ignore QTL-by-environment interaction (QEI) and are limited in accommodation of error and environment-specific variance. This paper outlines a mixed model approach using a recombinant inbred spring wheat population grown in six drought stress

  12. Effects of Gender on Teachers' Perceptions of School Environment, Teaching Efficacy, Stress and Job Satisfaction

    Science.gov (United States)

    Tran, Van Dat

    2015-01-01

    This study investigates how teachers' perceptions of school environment factors, teaching efficacy, teacher stress and job satisfaction, and to determine whether gender was a differentiating factor. A total of 387 Vietnamese junior high school teachers completed one questionnaire for four sections about school-level environment, teaching efficacy,…

  13. The STRIVE-ONR Project: Stress Resistance in Virtual Environments

    Science.gov (United States)

    2015-07-29

    from the Virtual Iraq/Afghanistan Virtual Reality Exposure Therapy (VRET) system at the University of Southern California Institute for Creative...better sense of health outcomes; that is, "how the social environment exerts a cumulative impact on the physical and mental well being of individuals...levels with functional decline in elderly men and women. Geriatrics & gerontology international, 9 3, 282-289. Goldman, N., Turra, C. M., Glei, D

  14. Home care nurses' experience of job stress and considerations for the work environment.

    Science.gov (United States)

    Samia, Linda W; Ellenbecker, Carol Hall; Friedman, Donna Haig; Dick, Karen

    2012-01-01

    Home care nurses report increased stress in their jobs due to work environment characteristics that impact professional practice. Stressors and characteristics of the professional practice environment that moderate nurses' experience of job stress were examined in this embedded multiple case study. Real life experiences within a complex environment were drawn from interviews and observations with 29 participants across two home care agencies from one eastern U.S. state. Findings suggest that role overload, role conflict, and lack of control can be moderated in agencies where there are meaningful opportunities for shared decision making and the nurse-patient relationship is supported.

  15. Growth reponses of eggplant and soybean seedlings to mechanical stress in greenhouse and outdoor environments

    Science.gov (United States)

    Latimer, J. G.; Pappas, T.; Mitchell, C. A.

    1986-01-01

    Eggplant (Solanum melongena L. var. esculentum 'Burpee's Black Beauty') and soybean [Glycine max (L.) Merr. 'Wells II'] seedlings were assigned to a greenhouse or a windless or windy outdoor environment. Plants within each environment received either periodic seismic (shaking) or thigmic (flexing or rubbing) treatment, or were left undisturbed. Productivity (dry weight) and dimensional (leaf area and stem length) growth parameters generally were reduced more by mechanical stress in the greenhouse (soybean) or outdoor-windless environment (eggplant) than in the outdoor windy environment. Outdoor exposure enhanced both stem and leaf specific weights, whereas mechanical stress enhanced only leaf specific weight. Although both forms of controlled mechanical stress tended to reduce node and internode diameters of soybean, outdoor exposure increased stem diameter.

  16. Clashing of risers due to vortex induced vibrations

    Energy Technology Data Exchange (ETDEWEB)

    Teissier, D. [Ecole Superieure d' Ingenieurs de Marseille (ESIM), 13 - Marseille (France)]|[Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France); Scolan, Y.M. [Ecole Superieure d' Ingenieurs de Marseille (ESIM), 13 - Marseille (France); Fontaine, E. [Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France)

    2004-07-01

    Phenomena such as Vortex Induced Vibrations can potentially damage offshore risers, especially in ar ay configurations. Due to wake interferences, amplification of VIV is observed leading to large displacements which are no more self limited to one di meter as in the case of VIV. In this context, clash ng becomes also an issue. In order to study this problems, Institut Francais du Petrole is developing a Computational Fluid Dynamics code, DeepFlow, devoted to the simulation of two-dimensional flows around risers. The extension to three-dimensional configurations follows from a strip theory for the fluid flow, coupled to a structural model for flexible pipes (DeepLines). The numerical method (Etienne s 1999) developed in DeepFlow allows to solve the two-dimensional Reynolds Averaged Navier-Stokes equations through a mixed representation (Eulerian and Lagrangian) of the flow properties: vorticity and turbulence. The Eulerian method is necessary in the close vicinity of the bodies in order to capture the boundary layer effects with accuracy, whereas the Lagrangian representation, based on a grid-less method is suitable for the flow in the wake. In the present pa-per, this approach is applied to study the flow around two freely moving cylinders. For this test case, there are some numerical results (Sagatum et al, 2002), however instabilities have been experimentally identified (Paidoussis et al, 1998; Zdravkovich, 1985, 2003). The approach has also been improved to solve accurately the interstitial flow when the bodies are very close to each other. Results from a Chimera approach are presented. (authors)

  17. Fast, clash-free RNA conformational morphing using molecular junctions.

    Science.gov (United States)

    Héliou, Amélie; Budday, Dominik; Fonseca, Rasmus; van den Bedem, Henry

    2017-07-15

    Non-coding ribonucleic acids (ncRNA) are functional RNA molecules that are not translated into protein. They are extremely dynamic, adopting diverse conformational substates, which enables them to modulate their interaction with a large number of other molecules. The flexibility of ncRNA provides a challenge for probing their complex 3D conformational landscape, both experimentally and computationally. Despite their conformational diversity, ncRNAs mostly preserve their secondary structure throughout the dynamic ensemble. Here we present a kinematics-based procedure to morph an RNA molecule between conformational substates, while avoiding inter-atomic clashes. We represent an RNA as a kinematic linkage, with fixed groups of atoms as rigid bodies and rotatable bonds as degrees of freedom. Our procedure maintains RNA secondary structure by treating hydrogen bonds between base pairs as constraints. The constraints define a lower-dimensional, secondary-structure constraint manifold in conformation space, where motions are largely governed by molecular junctions of unpaired nucleotides. On a large benchmark set, we show that our morphing procedure compares favorably to peer algorithms, and can approach goal conformations to within a low all-atom RMSD by directing fewer than 1% of its atoms. Our results suggest that molecular junctions can modulate 3D structural rearrangements, while secondary structure elements guide large parts of the molecule along the transition to the correct final conformation. The source code, binaries and data are available at https://simtk.org/home/kgs . amelie.heliou@polytechnique.edu or vdbedem@stanford.edu. Supplementary data are available at Bioinformatics online. © The Author (2017). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  18. Women's perceived work environment after stress-related rehabilitation: experiences from the ReDO project.

    Science.gov (United States)

    Wästberg, Birgitta A; Erlandsson, Lena-Karin; Eklund, Mona

    2016-01-01

    The study aimed to investigate (a) if women's perceptions of their work environment changed during a 16-week rehabilitation period and at a 12-month follow-up; (b) whether such changes were related to outcomes in terms of return to work, well-being and valued occupations. Eighty-four gainfully employed women on sick-leave due to stress-related disorders responded to instruments assessing perceptions of the work environment, well-being (self-esteem, self-mastery, quality of life, perceived stress, self-rated health) and perceived occupational value. Data about return to work were collected from registers. Non-parametric statistics were used. The increase in the women's ratings of their work environment was non-significant between baseline and completed rehabilitation but was statistically significant between baseline and the 12-month follow-up. No relationships were found between changes in perceptions of the work environment and outcomes after the rehabilitation. At the follow-up, however, there were associations between perceived work environment changes in a positive direction and return to work; improved self-esteem, self-mastery, quality of life, perceived occupational value and self-rated health; and reduced stress. It seems important to consider the work environment in rehabilitation for stress-related problems, and a follow-up appears warranted to detect changes and associations not visible immediately after rehabilitation. Work environment Perceptions of the work environment seem important for return to work, although other factors are likely to contribute as well. Perceptions of the work environment are associated with several aspects of well-being. When developing rehabilitation interventions a focus on the clients' perceptions of their work environment seems vital.

  19. A simplified method of evaluating the stress wave environment of internal equipment

    Science.gov (United States)

    Colton, J. D.; Desmond, T. P.

    1979-01-01

    A simplified method called the transfer function technique (TFT) was devised for evaluating the stress wave environment in a structure containing internal equipment. The TFT consists of following the initial in-plane stress wave that propagates through a structure subjected to a dynamic load and characterizing how the wave is altered as it is transmitted through intersections of structural members. As a basis for evaluating the TFT, impact experiments and detailed stress wave analyses were performed for structures with two or three, or more members. Transfer functions that relate the wave transmitted through an intersection to the incident wave were deduced from the predicted wave response. By sequentially applying these transfer functions to a structure with several intersections, it was found that the environment produced by the initial stress wave propagating through the structure can be approximated well. The TFT can be used as a design tool or as an analytical tool to determine whether a more detailed wave analysis is warranted.

  20. Does Psychosocial Work Environment Factors Predict Stress and Mean Arterial Pressure in the Malaysian Industry Workers?

    OpenAIRE

    Javaid, Muhammad Umair; Isha, Ahmad Shahrul Nizam; Sabir, Asrar Ahmed; Ghazali, Zulkipli; Nübling, Matthias

    2018-01-01

    Psychosocial risks are considered as a burning issue in the Asia-Pacific region. The aim of this study was to investigate the impact of psychosocial work environment factors on health of petrochemical industry workers of Malaysia. In lieu to job demands-resources theory, significant positive associations were found between quantitative demands, work-family conflict, and job insecurity with stress, while a significant negative association of role clarity as a resource factor with stress was de...

  1. Stress Response and Cognitive Performance Modulation in Classroom versus Natural Environments

    DEFF Research Database (Denmark)

    Mygind, Lærke; Stevenson, Matt P; Liebst, Lasse S

    2018-01-01

    explores the impact of natural environments on stress response during rest and mental load and cognitive performance in 47 children aged 10⁻12 years in a school context. Heart rate variability measures indexing tonic, event, and phasic vagal tone and attention scores were compared across classroom...... and natural environments. Tonic vagal tone was higher in the natural environment than the classrooms, but no differences were found in event or phasic vagal tone or cognitive performance measures. These findings suggest a situational aspect of the conditions under which natural environments may give rise...

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

    Directory of Open Access Journals (Sweden)

    M. Dalband

    2007-01-01

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

  3. [Psychosocial stress environment and health workers in public health: Differences between primary and hospital care].

    Science.gov (United States)

    García-Rodríguez, Antonio; Gutiérrez-Bedmar, Mario; Bellón-Saameño, Juan Ángel; Muñoz-Bravo, Carlos; Fernández-Crehuet Navajas, Joaquín

    2015-01-01

    To describe the psychosocial environment of health professionals in public health in primary and hospital care, and compare it with that of the general Spanish working population, as well as to evaluate the effect of psychosocial risk factors on symptoms related to perceived stress. Cross-sectional study with stratified random sampling. Health care workers in the province of Granada, distributed in 5 hospitals and 4 health districts. A total of 738 employees (medical and nursing staff) of the Andalusian Health Service (SAS) were invited to take part. CopSoQ/Istas21 questionnaire developed for the multidimensional analysis of the psychosocial work environment. Stress symptoms were measured with the Stress Profile questionnaire. The response rate was 67.5%. Compared with the Spanish workforce, our sample showed high cognitive, emotional, and sensory psychological demands, possibilities for development and sense of direction in their work. Primary care physicians were the group with a worse psychosocial work environment. All the groups studied showed high levels of stress symptoms. Multivariate analysis showed that variables associated with high levels of stress symptom were younger and with possibilities for social relations, role conflict, and higher emotional demands, and insecurity at work. Our findings support that the psychosocial work environment of health workers differs from that of the Spanish working population, being more unfavorable in general practitioners. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  4. The measurement of in-situ stress in near surface environments

    International Nuclear Information System (INIS)

    Garritty, P.; Irvin, R.A.

    1984-04-01

    One of the major unknowns affecting aspects of underground construction and the geohydrology of rock masses is the magnitude and direction of the geostatic principal stresses in the earth's crust. This is particularly the case in near surface rocks where there are indications that high horizontal stresses may exist. The measurement of stress in near surface environments is particularly difficult. The techniques, experience and results of a geostatic stress measurement programme using four commercially available devices at shallow depth in the Carnmenellis Granite are critically discussed and compared. This report also brings together some of the conclusions of two previous reports in the series, Garritty (1983) and Garritty and Irvin (1983), and emphasises the fundamental relationship between the state of stress in the earth's crust and the geohydrology of rock masses. (author)

  5. The music of clash: predictions on the concentration-mass relation

    Energy Technology Data Exchange (ETDEWEB)

    Meneghetti, M. [INAF, Osservatorio Astronomico di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Rasia, E. [Physics Department, University of Michigan, 450 Church Avenue, Ann Arbor, MI 48109 (United States); Vega, J.; Yepes, G.; Sembolini, F. [Departamento de Fsica Terica, Universidad Autnoma de Madrid, Cantoblanco, E-28049 Madrid (Spain); Merten, J.; Ettori, S. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Postman, M.; Coe, D. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21208 (United States); Donahue, M. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Umetsu, K.; Czakon, N. [Institute of Astronomy and Astrophysics, Academia Sinica, PO Box 23-141, Taipei 10617, Taiwan (China); Balestra, I. [INAF-Osservatorio Astronomico di Capodimonte, Via Moiariello 16, I-80131 Napoli (Italy); Bartelmann, M. [Institut fur Theoretische Astrophysik, Universität Heidelberg, Zentrum für Astronomie, Philosophenweg 12, D-69120 Heidelberg (Germany); Benítez, N. [Instituto de Astrofísica de Andalucía (CSIC), E-18080 Granada (Spain); Biviano, A. [INAF/Osservatorio Astronomico di Trieste, via G. B. Tiepolo 11, I-34143 Trieste (Italy); Bouwens, R. [Leiden Observatory, Leiden University, PO Box 9513, NL-2333 Leiden (Netherlands); Bradley, L. [Department of Physics and Astronomy, The Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States); Broadhurst, T. [Department of Theoretical Physics and History of Science, University of the Basque Country UPV/EHU, PO Box 644, E-48080 Bilbao (Spain); De Petris, M. [Dipartimento di Fisica, Sapienza Universit di Roma, Piazzale Aldo Moro 5, I-00185 Roma (Italy); and others

    2014-12-10

    We present an analysis of the MUSIC-2 N-body/hydrodynamical simulations aimed at estimating the expected concentration-mass relation for the CLASH (Cluster Lensing and Supernova Survey with Hubble) cluster sample. We study nearly 1,400 halos simulated at high spatial and mass resolution. We study the shape of both their density and surface-density profiles and fit them with a variety of radial functions, including the Navarro-Frenk-White (NFW), the generalized NFW, and the Einasto density profiles. We derive concentrations and masses from these fits. We produce simulated Chandra observations of the halos, and we use them to identify objects resembling the X-ray morphologies and masses of the clusters in the CLASH X-ray-selected sample. We also derive a concentration-mass relation for strong-lensing clusters. We find that the sample of simulated halos that resembles the X-ray morphology of the CLASH clusters is composed mainly of relaxed halos, but it also contains a significant fraction of unrelaxed systems. For such a heterogeneous sample we measure an average two-dimensional concentration that is ∼11% higher than is found for the full sample of simulated halos. After accounting for projection and selection effects, the average NFW concentrations of CLASH clusters are expected to be intermediate between those predicted in three dimensions for relaxed and super-relaxed halos. Matching the simulations to the individual CLASH clusters on the basis of the X-ray morphology, we expect that the NFW concentrations recovered from the lensing analysis of the CLASH clusters are in the range [3-6], with an average value of 3.87 and a standard deviation of 0.61.

  6. The music of clash: predictions on the concentration-mass relation

    International Nuclear Information System (INIS)

    Meneghetti, M.; Rasia, E.; Vega, J.; Yepes, G.; Sembolini, F.; Merten, J.; Ettori, S.; Postman, M.; Coe, D.; Donahue, M.; Umetsu, K.; Czakon, N.; Balestra, I.; Bartelmann, M.; Benítez, N.; Biviano, A.; Bouwens, R.; Bradley, L.; Broadhurst, T.; De Petris, M.

    2014-01-01

    We present an analysis of the MUSIC-2 N-body/hydrodynamical simulations aimed at estimating the expected concentration-mass relation for the CLASH (Cluster Lensing and Supernova Survey with Hubble) cluster sample. We study nearly 1,400 halos simulated at high spatial and mass resolution. We study the shape of both their density and surface-density profiles and fit them with a variety of radial functions, including the Navarro-Frenk-White (NFW), the generalized NFW, and the Einasto density profiles. We derive concentrations and masses from these fits. We produce simulated Chandra observations of the halos, and we use them to identify objects resembling the X-ray morphologies and masses of the clusters in the CLASH X-ray-selected sample. We also derive a concentration-mass relation for strong-lensing clusters. We find that the sample of simulated halos that resembles the X-ray morphology of the CLASH clusters is composed mainly of relaxed halos, but it also contains a significant fraction of unrelaxed systems. For such a heterogeneous sample we measure an average two-dimensional concentration that is ∼11% higher than is found for the full sample of simulated halos. After accounting for projection and selection effects, the average NFW concentrations of CLASH clusters are expected to be intermediate between those predicted in three dimensions for relaxed and super-relaxed halos. Matching the simulations to the individual CLASH clusters on the basis of the X-ray morphology, we expect that the NFW concentrations recovered from the lensing analysis of the CLASH clusters are in the range [3-6], with an average value of 3.87 and a standard deviation of 0.61.

  7. The MUSIC of CLASH: Predictions on the Concentration-Mass Relation

    Science.gov (United States)

    Meneghetti, M.; Rasia, E.; Vega, J.; Merten, J.; Postman, M.; Yepes, G.; Sembolini, F.; Donahue, M.; Ettori, S.; Umetsu, K.; Balestra, I.; Bartelmann, M.; Benítez, N.; Biviano, A.; Bouwens, R.; Bradley, L.; Broadhurst, T.; Coe, D.; Czakon, N.; De Petris, M.; Ford, H.; Giocoli, C.; Gottlöber, S.; Grillo, C.; Infante, L.; Jouvel, S.; Kelson, D.; Koekemoer, A.; Lahav, O.; Lemze, D.; Medezinski, E.; Melchior, P.; Mercurio, A.; Molino, A.; Moscardini, L.; Monna, A.; Moustakas, J.; Moustakas, L. A.; Nonino, M.; Rhodes, J.; Rosati, P.; Sayers, J.; Seitz, S.; Zheng, W.; Zitrin, A.

    2014-12-01

    We present an analysis of the MUSIC-2 N-body/hydrodynamical simulations aimed at estimating the expected concentration-mass relation for the CLASH (Cluster Lensing and Supernova Survey with Hubble) cluster sample. We study nearly 1,400 halos simulated at high spatial and mass resolution. We study the shape of both their density and surface-density profiles and fit them with a variety of radial functions, including the Navarro-Frenk-White (NFW), the generalized NFW, and the Einasto density profiles. We derive concentrations and masses from these fits. We produce simulated Chandra observations of the halos, and we use them to identify objects resembling the X-ray morphologies and masses of the clusters in the CLASH X-ray-selected sample. We also derive a concentration-mass relation for strong-lensing clusters. We find that the sample of simulated halos that resembles the X-ray morphology of the CLASH clusters is composed mainly of relaxed halos, but it also contains a significant fraction of unrelaxed systems. For such a heterogeneous sample we measure an average two-dimensional concentration that is ~11% higher than is found for the full sample of simulated halos. After accounting for projection and selection effects, the average NFW concentrations of CLASH clusters are expected to be intermediate between those predicted in three dimensions for relaxed and super-relaxed halos. Matching the simulations to the individual CLASH clusters on the basis of the X-ray morphology, we expect that the NFW concentrations recovered from the lensing analysis of the CLASH clusters are in the range [3-6], with an average value of 3.87 and a standard deviation of 0.61.

  8. Competition and facilitation structure plant communities under nurse tree canopies in extremely stressful environments.

    Science.gov (United States)

    Al-Namazi, Ali A; El-Bana, Magdy I; Bonser, Stephen P

    2017-04-01

    Nurse plant facilitation in stressful environments can produce an environment with relatively low stress under its canopy. These nurse plants may produce the conditions promoting intense competition between coexisting species under the canopy, and canopies may establish stress gradients, where stress increases toward the edge of the canopy. Competition and facilitation on these stress gradients may control species distributions in the communities under canopies. We tested the following predictions: (1) interactions between understory species shift from competition to facilitation in habitats experiencing increasing stress from the center to the edge of canopy of a nurse plant, and (2) species distributions in understory communities are controlled by competitive interactions at the center of canopy, and facilitation at the edge of the canopy. We tested these predictions using a neighbor removal experiment under nurse trees growing in arid environments. Established individuals of each of four of the most common herbaceous species in the understory were used in the experiment. Two species were more frequent in the center of the canopy, and two species were more frequent at the edge of the canopy. Established individuals of each species were subjected to neighbor removal or control treatments in both canopy center and edge habitats. We found a shift from competitive to facilitative interactions from the center to the edge of the canopy. The shift in the effect of neighbors on the target species can help to explain species distributions in these canopies. Canopy-dominant species only perform well in the presence of neighbors in the edge microhabitat. Competition from canopy-dominant species can also limit the performance of edge-dominant species in the canopy microhabitat. The shift from competition to facilitation under nurse plant canopies can structure the understory communities in extremely stressful environments.

  9. Predictors of nurse manager stress: a dominance analysis of potential work environment stressors.

    Science.gov (United States)

    Kath, Lisa M; Stichler, Jaynelle F; Ehrhart, Mark G; Sievers, Andree

    2013-11-01

    Nurse managers have important but stressful jobs. Clinical or bedside nurse predictors of stress have been studied more frequently, but less has been done on work environment predictors for those in this first-line leadership role. Understanding the relative importance of those work environment predictors could be used to help identify the most fruitful areas for intervention, potentially improving recruitment and retention for nurse managers. Using Role Stress Theory and the Job Demands-Resources Theory, a model was tested examining the relative importance of five potential predictors of nurse manager stress (i.e., stressors). The work environment stressors included role ambiguity, role overload, role conflict, organizational constraints, and interpersonal conflict. A quantitative, cross-sectional survey study was conducted with a convenience sample of 36 hospitals in the Southwestern United States. All nurse managers working in these 36 hospitals were invited to participate. Of the 636 nurse managers invited, 480 responded, for a response rate of 75.5%. Questionnaires were distributed during nursing leadership meetings and were returned in person (in sealed envelopes) or by mail. Because work environment stressors were correlated, dominance analysis was conducted to examine which stressors were the most important predictors of nurse manager stress. Role overload was the most important predictor of stress, with an average of 13% increase in variance explained. The second- and third-most important predictors were organizational constraints and role conflict, with an average of 7% and 6% increase in variance explained, respectively. Because other research has shown deleterious effects of nurse manager stress, organizational leaders are encouraged to help nurse managers reduce their actual and/or perceived role overload and organizational constraints. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Laboratory results of stress corrosion cracking of steam generator tubes in a complex environment - An update

    Energy Technology Data Exchange (ETDEWEB)

    Horner, Olivier; Pavageau, Ellen-Mary; Vaillant, Francois [EDF R and D, Materials and Mechanics of Components Department, 77818 Moret-sur-Loing (France); Bouvier, Odile de [EDF Nuclear Engineering Division, Centre d' Expertise et d' Inspection dans les Domaines de la Realisation et de l' Exploitation, 93206 Saint Denis (France)

    2004-07-01

    Stress corrosion cracking occurs in the flow-restricted areas on the secondary side of steam generator tubes of Pressured Water Reactors (PWR), where water pollutants are likely to concentrate. Chemical analyses carried out during the shutdowns gave some insight into the chemical composition of these areas, which has evolved during these last years (i.e. less sodium as pollutants). It has been modeled in laboratory by tests in two different typical environments: the sodium hydroxide and the sulfate environments. These models satisfactorily describe the secondary side corrosion of steam generator tubes for old plant units. Furthermore, a third typical environment - the complex environment - which corresponds to an All Volatile Treatment (AVT) environment containing alumina, silica, phosphate and acetic acid has been recently studied. This particular environment satisfactorily reproduces the composition of the deposits observed on the surface of the steam generator tubes as well as the degradation of the tubes. A review of the recent laboratory results obtained by considering the complex environment are presented here. Several tests have been carried out in order to study initiation and propagation of secondary side corrosion cracking for some selected materials in such an environment. 600 Thermally Treated (TT) alloy reveals to be less sensitive to secondary side corrosion cracking than 600 Mill Annealed (MA) alloy. Finally, the influence of some related factors like stress, temperature and environmental factors are discussed. (authors)

  11. Laboratory results of stress corrosion cracking of steam generator tubes in a complex environment - An update

    International Nuclear Information System (INIS)

    Horner, Olivier; Pavageau, Ellen-Mary; Vaillant, Francois; Bouvier, Odile de

    2004-01-01

    Stress corrosion cracking occurs in the flow-restricted areas on the secondary side of steam generator tubes of Pressured Water Reactors (PWR), where water pollutants are likely to concentrate. Chemical analyses carried out during the shutdowns gave some insight into the chemical composition of these areas, which has evolved during these last years (i.e. less sodium as pollutants). It has been modeled in laboratory by tests in two different typical environments: the sodium hydroxide and the sulfate environments. These models satisfactorily describe the secondary side corrosion of steam generator tubes for old plant units. Furthermore, a third typical environment - the complex environment - which corresponds to an All Volatile Treatment (AVT) environment containing alumina, silica, phosphate and acetic acid has been recently studied. This particular environment satisfactorily reproduces the composition of the deposits observed on the surface of the steam generator tubes as well as the degradation of the tubes. A review of the recent laboratory results obtained by considering the complex environment are presented here. Several tests have been carried out in order to study initiation and propagation of secondary side corrosion cracking for some selected materials in such an environment. 600 Thermally Treated (TT) alloy reveals to be less sensitive to secondary side corrosion cracking than 600 Mill Annealed (MA) alloy. Finally, the influence of some related factors like stress, temperature and environmental factors are discussed. (authors)

  12. Human Thermal Comfort and Heat Stress in an Outdoor Urban Arid Environment: A Case Study

    Directory of Open Access Journals (Sweden)

    A. M. Abdel-Ghany

    2013-01-01

    Full Text Available To protect humans from heat stress risks, thermal comfort and heat stress potential were evaluated under arid environment, which had never been made for such climate. The thermal indices THI, WBGT, PET, and UTCI were used to evaluate thermal comfort and heat stress. RayMan software model was used to estimate the PET, and the UTCI calculator was used for UTCI. Dry and wet bulb temperatures (Td, Tw, natural wet bulb temperature (Tnw, and globe temperature (Tg were measured in a summer day to be used in the calculation. The results showed the following. (i The thermal sensation and heat stress levels can be evaluated by either the PET or UTCI scales, and both are valid for extremely high temperature in the arid environment. (ii In the comfort zone, around 75% of individuals would be satisfied with the surrounding environment and feel comfortable during the whole day. (iii Persons are exposed to strong heat stress and would feel uncomfortable most of the daytime in summer. (iv Heat fatigue is expected with prolonged exposure to sun light and activity. (v During the daytime, humans should schedule their activities according to the highest permissible values of the WBGT to avoid thermal shock.

  13. Stressful Psychosocial Work Environment, Poor Sleep, and Depressive Symptoms among Primary School Teachers

    Science.gov (United States)

    Gluschkoff, Kia; Elovainio, Marko; Keltikangas-Järvinen, Liisa; Hintsanen, Mirka; Mullola, Sari; Hintsa, Taina

    2016-01-01

    Introduction: We examined the associations and proportionate contributions of three well-validated models of stressful psychosocial work environment (job strain, effort-reward imbalance, and organizational injustice) in explaining depressive symptoms among primary school teachers. In addition, we tested the mediating role of different types of…

  14. Dealing Collectively with Critical Incident Stress Reactions in High Risk Work Environments

    DEFF Research Database (Denmark)

    Müller-Leonhardt, Alice; Strøbæk, Pernille Solveig; Vogt, joachim

    2015-01-01

    organisations. Indeed, we found that the CISM programme once integrated within the socio-cultural patterns of this specific working environment enhanced not only individual feelings of being supported but also organisational safety culture. Keywords: coping; safety culture; critical incident stress management......aim of this paper is to shift the representation of coping patterns within high risk occupations to an existential part of cultural pattern and social structure, which characterises high reliability organisations. Drawing upon the specific peer model of critical incident stress management (CISM......), in which qualified operational peers support colleagues who experienced critical incident stress, the paper discusses critical incident stress management in air traffic control. Our study revealed coping patterns that co-vary with the culture that the CISM programme fostered within this specific high...

  15. The Positive Effect of Resilience on Stress and Business Outcomes in Difficult Work Environments.

    Science.gov (United States)

    Shatté, Andrew; Perlman, Adam; Smith, Brad; Lynch, Wendy D

    2017-02-01

    To examine whether resilience has a protective effect in difficult work environments. A survey of 2063 individuals measured individual resilience, stress, burnout, sleep problems, likelihood of depression, job satisfaction, intent to quit, absences, and productivity. It also measured work characteristics: job demands, job influence, and social support. Multivariate and logistic regression models examined the main effects and interactions of resilience and job characteristics. High strain work environments (high demand, low influence, and low support) have an unfavorable effect on all outcomes. Resilience has a protective effect on all outcomes. For stress, burnout, and sleep, higher resilience has a more protective effect under low-strain conditions. For depression, absence and productivity, resilience has a more protective effect when job strain is high. Workers with high resilience have better outcomes in difficult work environments.

  16. Tax evasion in transition: Outcome of an institutional clash? - Testing Feige's conjecture

    NARCIS (Netherlands)

    Gërxhani, K.

    2003-01-01

    A field survey of households was conducted in Tirana, Albania in 2000. A response rate of 89.3% yielded 1.340 valid questionnaires, allowing us to test Feige’s (1997) conjecture that more tax evasion will be observed, when formal and informal institutions clash. Respondents’ attitudes towards formal

  17. Clashes of discourses: Humanists and Calvinists in seventeenth-century academic Leiden

    NARCIS (Netherlands)

    Kromhout, D.

    2016-01-01

    Using Michel Foucault's concept of discursive change and Stephen Greenblatt's ideas about social poetics and self-fashioning, 'Clashes of Discourses: Calvinists and Humanists in Seventeenth-Century Academic Leiden' explains developments in the literary works of leading Leiden humanists against the

  18. A Clash Between Traditional African Value and Modern Africa in the ...

    African Journals Online (AJOL)

    A Clash Between Traditional African Value and Modern Africa in the Play, The Broken Calabash by Tess Osonye Onwueme. ... She is expected not to be married out but to remain at home to propagate their lineage. However, she has the choice of marrying another female into the family to take up her role of child bearing.

  19. Maps of Clash of Opinions – Classification of Geological Conditions in Karviná Region

    Czech Academy of Sciences Publication Activity Database

    Lednická, Markéta; Kaláb, Zdeněk

    2008-01-01

    Roč. 283, č. 1781 (2008), s. 139-147 ISSN 0372-9508 Institutional research plan: CEZ:AV0Z30860518 Keywords : maps sof clash of opinions * geological conditions Subject RIV: DC - Siesmology, Volcanology, Earth Structure www.wydawnictvopolitechniki.pl

  20. Clashes between or within civilizations? Meeting of cultures in Anatolia and Western Europe

    NARCIS (Netherlands)

    Bruinessen, M.M. van

    2003-01-01

    Samuel Huntington’s thesis of a clash of civilizations, formulated in the early 1990s, has gained renewed popularity in the wake of September 11 and America’s declaration of war on terror. This thesis came out of a research project that aimed to search for the likely sources of major conflict

  1. The Creation of 'German Danes' in England - The social dynamics of cultural clashes

    DEFF Research Database (Denmark)

    Lauring, Jakob

    2004-01-01

    Cultural conflicts and clashes have often been described and analyzed through the work of Geert Hofstede. Actions and reaction, however, cannot always be approached through the concept of static dimensions of cultural differences. This paper describes a situation that led to the creation of mutual...

  2. Why the CLASH model is an unconvincing evolutionary theory of crime.

    Science.gov (United States)

    Boutwell, Brian B; Winegard, Bo

    2017-01-01

    The CLASH model is not convincing for two reasons. First, it ignores prior research proposing very similar ideas in a more compelling fashion. Second, it dismisses the role of genetic factors in shaping criminal propensities across population groups, opting for a facultative view of life history evolution that does not seem to square with current evidence.

  3. The osmotic stress response of split influenza vaccine particles in an acidic environment.

    Science.gov (United States)

    Choi, Hyo-Jick; Kim, Min-Chul; Kang, Sang-Moo; Montemagno, Carlo D

    2014-12-01

    Oral influenza vaccine provides an efficient means of preventing seasonal and pandemic disease. In this work, the stability of envelope-type split influenza vaccine particles in acidic environments has been investigated. Owing to the fact that hyper-osmotic stress can significantly affect lipid assembly of vaccine, osmotic stress-induced morphological change of split vaccine particles, in conjunction with structural change of antigenic proteins, was investigated by the use of stopped-flow light scattering (SFLS), intrinsic fluorescence, transmission electron microscopy (TEM), and hemagglutination assay. Split vaccine particles were found to exhibit a step-wise morphological change in response to osmotic stress due to double-layered wall structure. The presence of hyper-osmotic stress in acidic medium (0.3 osmolarity, pH 2.0) induced a significant level of membrane perturbation as measured by SFLS and TEM, imposing more damage to antigenic proteins on vaccine envelope than can be caused by pH-induced conformational change at acidic iso-osmotic condition. Further supports were provided by the intrinsic fluorescence and hemagglutinin activity measurements. Thus, hyper-osmotic stress becomes an important factor for determining stability of split vaccine particles in acidic medium. These results are useful in better understanding the destabilizing mechanism of split influenza vaccine particles in gastric environment and in designing oral influenza vaccine formulations.

  4. The Influence of the Social Environment Context in Stress and Coping in Sport.

    Science.gov (United States)

    Kerdijk, Carlijn; van der Kamp, John; Polman, Remco

    2016-01-01

    Lazarus (1999) model of stress and coping is based on the reciprocal interaction between the person and the environment. The aim of this study therefore was to examine whether the social environment (significant others) are of influence on the stress and coping of team athletes. The study consisted of two separate studies in which a total of 12 team athletes participated. First, six field hockey players (two males, four females) aged 18-29 years (M = 23.0 years) participated in a diary study. Second, six team athletes of different sports (two males, four females) aged 24-29 years (M = 25.8 years) were interviewed. The results showed that in particular teammates are important for the appraisal of stress and coping in team sports. For over half (i.e., 51.5%) of the reported stressors in the diary study the participants felt that others were of influence on their coping. Team athletes experienced the highest stress intensity during competition, or when they appraised the situation as a threat. When others were of influence the team athletes were most likely to appraise the situation as a challenge and use problem- or emotion-focused coping strategies. These finding might provide a new portal for intervention to enhance coping with stress in sport and enhance performance and satisfaction.

  5. Evolution of genomic diversity and sex at extreme environments: Fungal life under hypersaline Dead Sea stress

    Science.gov (United States)

    Kis-Papo, Tamar; Kirzhner, Valery; Wasser, Solomon P.; Nevo, Eviatar

    2003-01-01

    We have found that genomic diversity is generally positively correlated with abiotic and biotic stress levels (1–3). However, beyond a high-threshold level of stress, the diversity declines to a few adapted genotypes. The Dead Sea is the harshest planetary hypersaline environment (340 g·liter–1 total dissolved salts, ≈10 times sea water). Hence, the Dead Sea is an excellent natural laboratory for testing the “rise and fall” pattern of genetic diversity with stress proposed in this article. Here, we examined genomic diversity of the ascomycete fungus Aspergillus versicolor from saline, nonsaline, and hypersaline Dead Sea environments. We screened the coding and noncoding genomes of A. versicolor isolates by using >600 AFLP (amplified fragment length polymorphism) markers (equal to loci). Genomic diversity was positively correlated with stress, culminating in the Dead Sea surface but dropped drastically in 50- to 280-m-deep seawater. The genomic diversity pattern paralleled the pattern of sexual reproduction of fungal species across the same southward gradient of increasing stress in Israel. This parallel may suggest that diversity and sex are intertwined intimately according to the rise and fall pattern and adaptively selected by natural selection in fungal genome evolution. Future large-scale verification in micromycetes will define further the trajectories of diversity and sex in the rise and fall pattern. PMID:14645702

  6. Psychosocial Work Environment, Stress Factors and Individual Characteristics among Nursing Staff in Psychiatric In-Patient Care

    Directory of Open Access Journals (Sweden)

    Tuvesson Hanna

    2014-01-01

    Full Text Available The psychosocial work environment is an important factor in psychiatric in-patient care, and knowing more of its correlates might open up new paths for future workplace interventions. Thus, the aims of the present study were to investigate perceptions of the psychosocial work environment among nursing staff in psychiatric in-patient care and how individual characteristics—Mastery, Moral Sensitivity, Perceived Stress, and Stress of Conscience—are related to different aspects of the psychosocial work environment. A total of 93 nursing staff members filled out five questionnaires: the QPSNordic 34+, Perceived Stress Scale, Stress of Conscience Questionnaire, Moral Sensitivity Questionnaire, and Mastery scale. Multivariate analysis showed that Perceived Stress was important for Organisational Climate perceptions. The Stress of Conscience subscale Internal Demands and Experience in current units were indicators of Role Clarity. The other Stress of Conscience subscale, External Demands and Restrictions, was related to Control at Work. Two types of stress, Perceived Stress and Stress of Conscience, were particularly important for the nursing staff’s perception of the psychosocial work environment. Efforts to prevent stress may also contribute to improvements in the psychosocial work environment.

  7. Fibrocartilage tissue engineering: the role of the stress environment on cell morphology and matrix expression.

    Science.gov (United States)

    Thomopoulos, Stavros; Das, Rosalina; Birman, Victor; Smith, Lester; Ku, Katherine; Elson, Elliott L; Pryse, Kenneth M; Marquez, Juan Pablo; Genin, Guy M

    2011-04-01

    Although much is known about the effects of uniaxial mechanical loading on fibrocartilage development, the stress fields to which fibrocartilaginous regions are subjected to during development are mutiaxial. That fibrocartilage develops at tendon-to-bone attachments and in compressive regions of tendons is well established. However, the three-dimensional (3D) nature of the stresses needed for the development of fibrocartilage is not known. Here, we developed and applied an in vitro system to determine whether fibrocartilage can develop under a state of periodic hydrostatic tension in which only a single principal component of stress is compressive. This question is vital to efforts to mechanically guide morphogenesis and matrix expression in engineered tissue replacements. Mesenchymal stromal cells in a 3D culture were exposed to compressive and tensile stresses as a result of an external tensile hydrostatic stress field. The stress field was characterized through mechanical modeling. Tensile cyclic stresses promoted spindle-shaped cells, upregulation of scleraxis and type one collagen, and cell alignment with the direction of tension. Cells experiencing a single compressive stress component exhibited rounded cell morphology and random cell orientation. No difference in mRNA expression of the genes Sox9 and aggrecan was observed when comparing tensile and compressive regions unless the medium was supplemented with the chondrogenic factor transforming growth factor beta3. In that case, Sox9 was upregulated under static loading conditions and aggrecan was upregulated under cyclic loading conditions. In conclusion, the fibrous component of fibrocartilage could be generated using only mechanical cues, but generation of the cartilaginous component of fibrocartilage required biologic factors in addition to mechanical cues. These studies support the hypothesis that the 3D stress environment influences cell activity and gene expression in fibrocartilage development.

  8. Stress corrosion cracking of the tubing materials for nuclear steam generators in an environment containing lead

    International Nuclear Information System (INIS)

    Kim, Kyung Mo; Kim, Uh Chul; Lee, Eun Hee; Hwang, Seong Sik

    2004-01-01

    Steam generator tube materials show a high susceptibility to stress corrosion cracking (SCC) in an environment containing lead species and some nuclear power plants currently have degradation problems associated with lead-induced stress corrosion cracking in a caustic solution. Effects of an applied potential on SCC is tested for middle-annealed Alloy 600 specimens since their corrosion potential can be changed when lead oxide coexists with other oxidizing species like copper oxide in the sludge. In addition, all the steam generator tubing materials used for nuclear power plants being operated and currently under construction in Korea are tested in a caustic solution with lead oxide. (author)

  9. Stress-reducing effects of indoor plants in the built healthcare environment: The mediating role of perceived attractiveness

    NARCIS (Netherlands)

    Dijkstra, K.; Pieterse, Marcel E.; Pruyn, Adriaan T.H.

    2008-01-01

    Objective: Natural elements in the built healthcare environment have shown to hold potential stress-reducing properties. In order to shed light on the underlying mechanism of stress-reducing effects of nature, the present study investigates whether the stress-reducing effects of indoor plants occur

  10. Stress-reducing effects of indoor plants in the built healthcare environment : The mediating role of perceived attractiveness

    NARCIS (Netherlands)

    Dijkstra, K.; Pieterse, Marcel E.; Pruyn, A.Th.

    Objective: Natural elements in the built healthcare environment have shown to hold potential stress-reducing properties. In order to shed light on the underlying mechanism of stress-reducing effects of nature, the present study investigates whether the stress-reducing effects of indoor plants occur

  11. Haemodialysis work environment contributors to job satisfaction and stress: a sequential mixed methods study.

    Science.gov (United States)

    Hayes, Bronwyn; Bonner, Ann; Douglas, Clint

    2015-01-01

    Haemodialysis nurses form long term relationships with patients in a technologically complex work environment. Previous studies have highlighted that haemodialysis nurses face stressors related to the nature of their work and also their work environments leading to reported high levels of burnout. Using Kanters (1997) Structural Empowerment Theory as a guiding framework, the aim of this study was to explore the factors contributing to satisfaction with the work environment, job satisfaction, job stress and burnout in haemodialysis nurses. Using a sequential mixed-methods design, the first phase involved an on-line survey comprising demographic and work characteristics, Brisbane Practice Environment Measure (B-PEM), Index of Work Satisfaction (IWS), Nursing Stress Scale (NSS) and the Maslach Burnout Inventory (MBI). The second phase involved conducting eight semi-structured interviews with data thematically analyzed. From the 417 nurses surveyed the majority were female (90.9 %), aged over 41 years of age (74.3 %), and 47.4 % had worked in haemodialysis for more than 10 years. Overall the work environment was perceived positively and there was a moderate level of job satisfaction. However levels of stress and emotional exhaustion (burnout) were high. Two themes, ability to care and feeling successful as a nurse, provided clarity to the level of job satisfaction found in phase 1. While two further themes, patients as quasi-family and intense working teams, explained why working as a haemodialysis nurse was both satisfying and stressful. Nurse managers can use these results to identify issues being experienced by haemodialysis nurses working in the unit they are supervising.

  12. Parental employment and work-family stress: Associations with family food environments

    Science.gov (United States)

    Bauer, Katherine W.; Hearst, Mary O.; Escoto, Kamisha; Berge, Jerica M.; Neumark-Sztainer, Dianne

    2013-01-01

    Parental employment provides many benefits to children's health. However, an increasing number of studies have observed associations between mothers' full-time employment and less healthful family food environments. Few studies have examined other ways in which parental employment may be associated with the family food environment, including the role of fathers' employment and parents' stress balancing work and home obligations. This study utilized data from Project F-EAT, a population-based study of a socio-demographically diverse sample of 3709 parents of adolescents living in a metropolitan area in the Midwestern United States, to examine cross-sectional associations between mothers' and fathers' employment status and parents' work-life stress with multiple aspects of the family food environment. Among parents participating in Project F-EAT, 64% of fathers and 46% of mothers were full-time employed, while 25% of fathers and 37% of mothers were not employed. Results showed that full-time employed mothers reported fewer family meals, less frequent encouragement of their adolescents' healthful eating, lower fruit and vegetable intake, and less time spent on food preparation, compared to part-time and not-employed mothers, after adjusting for socio-demographics. Full-time employed fathers reported significantly fewer hours of food preparation; no other associations were seen between fathers' employment status and characteristics of the family food environment. In contrast, higher work-life stress among both parents was associated with less healthful family food environment characteristics including less frequent family meals and more frequent sugar-sweetened beverage and fast food consumption by parents. Among dual-parent families, taking into account the employment characteristics of the other parent did not substantially alter the relationships between work-life stress and family food environment characteristics. While parental employment is beneficial for many

  13. Parental employment and work-family stress: associations with family food environments.

    Science.gov (United States)

    Bauer, Katherine W; Hearst, Mary O; Escoto, Kamisha; Berge, Jerica M; Neumark-Sztainer, Dianne

    2012-08-01

    Parental employment provides many benefits to children's health. However, an increasing number of studies have observed associations between mothers' full-time employment and less healthful family food environments. Few studies have examined other ways in which parental employment may be associated with the family food environment, including the role of fathers' employment and parents' stress balancing work and home obligations. This study utilized data from Project F-EAT, a population-based study of a socio-demographically diverse sample of 3709 parents of adolescents living in a metropolitan area in the Midwestern United States, to examine cross-sectional associations between mothers' and fathers' employment status and parents' work-life stress with multiple aspects of the family food environment. Among parents participating in Project F-EAT, 64% of fathers and 46% of mothers were full-time employed, while 25% of fathers and 37% of mothers were not employed. Results showed that full-time employed mothers reported fewer family meals, less frequent encouragement of their adolescents' healthful eating, lower fruit and vegetable intake, and less time spent on food preparation, compared to part-time and not-employed mothers, after adjusting for socio-demographics. Full-time employed fathers reported significantly fewer hours of food preparation; no other associations were seen between fathers' employment status and characteristics of the family food environment. In contrast, higher work-life stress among both parents was associated with less healthful family food environment characteristics including less frequent family meals and more frequent sugar-sweetened beverage and fast food consumption by parents. Among dual-parent families, taking into account the employment characteristics of the other parent did not substantially alter the relationships between work-life stress and family food environment characteristics. While parental employment is beneficial for many

  14. Effect of Environment on the Stress- Rupture Behavior of a C/SiC Composite Studied

    Science.gov (United States)

    Verrilli, Michael J.; Kiser, J. Douglas; Opila, Elizabeth J.; Calomino, Anthony M.

    2002-01-01

    Advanced reusable launch vehicles will likely incorporate fiber-reinforced ceramic matrix composites (CMC's) in critical propulsion and airframe components. The use of CMC's is highly desirable to save weight, improve reuse capability, and increase performance. One of the candidate CMC materials is carbon-fiber-reinforced silicon carbide (C/SiC). In potential propulsion applications, such as turbopump rotors and nozzle exit ramps, C/SiC components will be subjected to a service cycle that includes mechanical loading under complex, high-pressure environments containing hydrogen, oxygen, and steam. Degradation of both the C fibers and the SiC matrix are possible in these environments. The objective of this effort was to evaluate the mechanical behavior of C/SiC in various environments relevant to reusable launch vehicle applications. Stress-rupture testing was conducted at the NASA Glenn Research Center on C/SiC specimens in air and steam-containing environments. Also, the oxidation kinetics of the carbon fibers that reinforce the composite were monitored by thermogravimetric analysis in the same environments and temperatures used for the stress-rupture tests of the C/SiC composite specimens. The stress-rupture lives obtained for C/SiC tested in air and in steam/argon mixtures are shown in the following bar chart. As is typical for most materials, lives obtained at the lower temperature (600 C) are longer than for the higher temperature (1200 C). The effect of environment was most pronounced at the lower temperature, where the average test duration in steam at 600 C was at least 30 times longer than the lives obtained in air. The 1200 C data revealed little difference between the lives of specimens tested in air and steam at atmospheric pressure.

  15. Does Psychosocial Work Environment Factors Predict Stress and Mean Arterial Pressure in the Malaysian Industry Workers?

    Directory of Open Access Journals (Sweden)

    Muhammad Umair Javaid

    2018-01-01

    Full Text Available Psychosocial risks are considered as a burning issue in the Asia-Pacific region. The aim of this study was to investigate the impact of psychosocial work environment factors on health of petrochemical industry workers of Malaysia. In lieu to job demands-resources theory, significant positive associations were found between quantitative demands, work-family conflict, and job insecurity with stress, while a significant negative association of role clarity as a resource factor with stress was detected. We also found that quantitative demands were significantly associated with the mean arterial pressure (MAP. Multistage sampling procedure was used to collect study sample. Structural Equation Modeling was used to identify relationship between the endogenous and exogenous variables. Finally, the empirically tested psychosocial work environment model will further help in providing a better risk assessment in different industries and enterprises.

  16. Does Psychosocial Work Environment Factors Predict Stress and Mean Arterial Pressure in the Malaysian Industry Workers?

    Science.gov (United States)

    Javaid, Muhammad Umair; Isha, Ahmad Shahrul Nizam; Sabir, Asrar Ahmed; Ghazali, Zulkipli; Nübling, Matthias

    2018-01-01

    Psychosocial risks are considered as a burning issue in the Asia-Pacific region. The aim of this study was to investigate the impact of psychosocial work environment factors on health of petrochemical industry workers of Malaysia. In lieu to job demands-resources theory, significant positive associations were found between quantitative demands, work-family conflict, and job insecurity with stress, while a significant negative association of role clarity as a resource factor with stress was detected. We also found that quantitative demands were significantly associated with the mean arterial pressure (MAP). Multistage sampling procedure was used to collect study sample. Structural Equation Modeling was used to identify relationship between the endogenous and exogenous variables. Finally, the empirically tested psychosocial work environment model will further help in providing a better risk assessment in different industries and enterprises.

  17. Stress corrosion cracking resistance of 22% Cr duplex stainless steel in simulated sour environments

    International Nuclear Information System (INIS)

    Kudo, T.; Tsuge, H.; Moroishi, T.

    1989-01-01

    This paper reports the effect of nickel and nitrogen contents on stress corrosion cracking (SCC) of 22%Cr - 3%Mo-base duplex stainless steel investigated in simulated sour environments with respect to both the base metal and the heat-affected zone (HAZ) of welding. The threshold stress and the critical chloride concentration for SCC were evaluated as a function of the ferrite content (α-content) in the alloy. The threshold stress is highest at the α-content of 40 to 45%, and is lowered with decreasing and increasing the α-content from its value. The alloy whose α-content exceeds 80% at the HAZ has also high susceptibilities to pitting corrosion and intergranular corrosion (ICG). The critical chloride concentration for cracking increases with the decrease in the α-content. Moreover, the contents of chromium, nickel and molybdenum in the α-phase are considered to be an important factor for determining the critical chloride concentration

  18. Standard practice for determining cracking susceptibility of metals exposed under stress to a hot salt environment

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1990-01-01

    1.1 This practice covers procedures for testing metals for embrittlement and cracking susceptibility when exposed under stress to a hot salt environment. This practice can be used for testing all metals for which service conditions dictate the need for such information. The test procedures described herein are generally applicable to all metal alloys; required adjustments in environmental variables (temperature, stress) to characterize a given materials system should be made. This practice describes the environmental conditions and degree of control required, and suggests means for obtaining this desired control. 1.2 This practice can be used both for alloy screening for determination of relative susceptibility to embrittlement and cracking, and for the determination of time-temperature-stress threshold levels for onset of embrittlement and cracking. However, certain specimen types are more suitable for each of these two types of characterizations. Note 1 This practice relates solely to the performance of ...

  19. Some phonetic experiments on : Double stress and rhythmic variation in R.P. English

    NARCIS (Netherlands)

    Heuven, van V.J.J.P.

    1974-01-01

    This thesis examines the phonetic nature of so-called double-stressed words in English (also called equal- stressed or even-stressed), and the susceptibility of these words to rhythmic adjustment (stress clash avoidance). An acoustic analysis of stress correlates was made of disyllabic words

  20. Oxidative stress in pied flycatcher (Ficedula hypoleuca) nestlings from metal contaminated environments in northern Sweden

    International Nuclear Information System (INIS)

    Berglund, A.M.M.; Sturve, J.; Foerlin, L.; Nyholm, N.E.I.

    2007-01-01

    Metals have been shown to induce oxidative stress in animals. One of the most metal polluted terrestrial environments in Sweden is the surroundings of a sulfide ore smelter plant located in the northern part of the country. Pied flycatcher nestlings (Ficedula hypoleuca) that grew up close to the industry had accumulated amounts of arsenic, cadmium, mercury, lead, iron and zinc in their liver tissue. The aim of this study was to investigate if pied flycatcher nestlings in the pollution gradient of the industry were affected by oxidative stress using antioxidant molecules and enzyme activities. The antioxidant assays were also evaluated in search for useful biomarkers in pied flycatchers. This study indicated that nestlings in metal contaminated areas showed signs of oxidative stress evidenced by up regulated hepatic antioxidant defense given as increased glutathione reductase (GR) and catalase (CAT) activities and slightly but not significantly elevated lipid peroxidation and glutathione-S-transferase (GST) activities. Stepwise linear regression indicated that lipid peroxidation and CAT activities were influenced mostly by iron, but iron and lead influenced the CAT activity to a higher degree. Positive relationships were found between GST and lead as well as GR activities and cadmium. We conclude that GR, CAT, GST activities and lipid peroxidation levels may function as useful biomarkers for oxidative stress in free-living pied flycatcher nestlings exposed to metal contaminated environments

  1. Profiling nurses' job satisfaction, acculturation, work environment, stress, cultural values and coping abilities: A cluster analysis.

    Science.gov (United States)

    Goh, Yong-Shian; Lee, Alice; Chan, Sally Wai-Chi; Chan, Moon Fai

    2015-08-01

    This study aimed to determine whether definable profiles existed in a cohort of nursing staff with regard to demographic characteristics, job satisfaction, acculturation, work environment, stress, cultural values and coping abilities. A survey was conducted in one hospital in Singapore from June to July 2012, and 814 full-time staff nurses completed a self-report questionnaire (89% response rate). Demographic characteristics, job satisfaction, acculturation, work environment, perceived stress, cultural values, ways of coping and intention to leave current workplace were assessed as outcomes. The two-step cluster analysis revealed three clusters. Nurses in cluster 1 (n = 222) had lower acculturation scores than nurses in cluster 3. Cluster 2 (n = 362) was a group of younger nurses who reported higher intention to leave (22.4%), stress level and job dissatisfaction than the other two clusters. Nurses in cluster 3 (n = 230) were mostly Singaporean and reported the lowest intention to leave (13.0%). Resources should be allocated to specifically address the needs of younger nurses and hopefully retain them in the profession. Management should focus their retention strategies on junior nurses and provide a work environment that helps to strengthen their intention to remain in nursing by increasing their job satisfaction. © 2014 Wiley Publishing Asia Pty Ltd.

  2. The Legionella pneumophila kai operon is implicated in stress response and confers fitness in competitive environments

    Science.gov (United States)

    Loza-Correa, Maria; Sahr, Tobias; Rolando, Monica; Daniels, Craig; Petit, Pierre; Skarina, Tania; Valero, Laura Gomez; Dervins-Ravault, Delphine; Honoré, Nadine; Savchenko, Aleksey; Buchrieser, Carmen

    2014-01-01

    Summary Legionella pneumophila uses aquatic protozoa as replication niche and protection from harsh environments. Although L. pneumophila is not known to have a circadian clock, it encodes homologues of the KaiBC proteins of Cyanobacteria that regulate circadian gene expression. We show that L. pneumophila kaiB, kaiC and the downstream gene lpp1114, are transcribed as a unit under the control of the stress sigma factor RpoS. KaiC and KaiB of L. pneumophila do not interact as evidenced by yeast and bacterial two-hybrid analyses. Fusion of the C-terminal residues of cyanobacterial KaiB to Legionella KaiB restores their interaction. In contrast, KaiC of L. pneumophila conserved autophosphorylation activity, but KaiB does not trigger the dephosphorylation of KaiC like in Cyanobacteria. The crystal structure of L. pneumophila KaiB suggests that it is an oxidoreductase-like protein with a typical thioredoxin fold. Indeed, mutant analyses revealed that the kai operon-encoded proteins increase fitness of L. pneumophila in competitive environments, and confer higher resistance to oxidative and sodium stress. The phylogenetic analysis indicates that L. pneumophila KaiBC resemble Synechosystis KaiC2B2 and not circadian KaiB1C1. Thus, the L. pneumophila Kai proteins do not encode a circadian clock, but enhance stress resistance and adaption to changes in the environments. PMID:23957615

  3. Stress-corrosion cracks behavior under underground disposal environment of radioactive wastes

    International Nuclear Information System (INIS)

    Isei, Takehiro; Seto, Masahiro; Ogata, Yuji; Wada, Yuji; Utagawa, Manabu; Kosugi, Masayuki

    2000-01-01

    This study is composed by two sub-theme of study on stress-corrosion cracking under an environment of disposal on radioactive wastes and control technique on microscopic crack around the disposal cavity, and aims at experimental elucidation on forming mechanism of stress-corrosion cracking phenomenon on rocks and establishment of its control technique. In 1998 fiscal year, together with an investigation on effect of temperature on fracture toughness and on stress-corrosion cracks performance of sedimentary rocks (sandy rocks), an investigation on limit of the stress-corrosion cracking by addition of chemicals and on crack growth in a rock by in-situ observation using SEM were carried out. As a result, it was formed that fracture toughness of rocks reduced at more than 100 centigrade of temperature, that a region showing an equilibrium between water supply to crack end and crack speed appeared definitely, that a limit of stress-corrosion cracking appeared by addition of chemicals, and that as a result of observing crack advancement of saturated rock by in-situ observation of crack growth using SEM, a process zone was formed at the front of main crack due to grain boundary fracture. (G.K.)

  4. Roots Withstanding their Environment: Exploiting Root System Architecture Responses to Abiotic Stress to Improve Crop Tolerance

    Science.gov (United States)

    Koevoets, Iko T.; Venema, Jan Henk; Elzenga, J. Theo. M.; Testerink, Christa

    2016-01-01

    To face future challenges in crop production dictated by global climate changes, breeders and plant researchers collaborate to develop productive crops that are able to withstand a wide range of biotic and abiotic stresses. However, crop selection is often focused on shoot performance alone, as observation of root properties is more complex and asks for artificial and extensive phenotyping platforms. In addition, most root research focuses on development, while a direct link to the functionality of plasticity in root development for tolerance is often lacking. In this paper we review the currently known root system architecture (RSA) responses in Arabidopsis and a number of crop species to a range of abiotic stresses, including nutrient limitation, drought, salinity, flooding, and extreme temperatures. For each of these stresses, the key molecular and cellular mechanisms underlying the RSA response are highlighted. To explore the relevance for crop selection, we especially review and discuss studies linking root architectural responses to stress tolerance. This will provide a first step toward understanding the relevance of adaptive root development for a plant’s response to its environment. We suggest that functional evidence on the role of root plasticity will support breeders in their efforts to include root properties in their current selection pipeline for abiotic stress tolerance, aimed to improve the robustness of crops. PMID:27630659

  5. Genotype x environment interaction for grain yield of wheat genotypes tested under water stress conditions

    International Nuclear Information System (INIS)

    Sail, M.A.; Dahot, M.U.; Mangrio, S.M.; Memon, S.

    2007-01-01

    Effect of water stress on grain yield in different wheat genotypes was studied under field conditions at various locations. Grain yield is a complex polygenic trait influenced by genotype, environment and genotype x environment (GxE) interaction. To understand the stability among genotypes for grain yield, twenty-one wheat genotypes developed Through hybridization and radiation-induced mutations at Nuclear Institute of Agriculture (NIA) TandoJam were evaluated with four local check varieties (Sarsabz, Thori, Margalla-99 and Chakwal-86) in multi-environmental trails (MET/sub s/). The experiments were conducted over 5 different water stress environments in Sindh. Data on grain yield were recorded from each site and statistically analyzed. Combined analysis of variance for all the environments indicated that the genotype, environment and genotype x environment (GxE) interaction were highly significant (P greater then 0.01) for grain yield. Genotypes differed in their response to various locations. The overall highest site mean yield (4031 kg/ha) recorded at Moro and the lowest (2326 kg/ha) at Thatta. Six genotypes produced significantly (P=0.01) the highest grain yield overall the environments. Stability analysis was applied to estimate stability parameters viz., regression coefficient (b), standard error of regression coefficient and variance due to deviation from regression (S/sub 2/d) genotypes 10/8, BWS-78 produced the highest mean yield over all the environments with low regression coefficient (b=0.68, 0.67 and 0.63 respectively and higher S/sup 2/ d value, showing specific adaptation to poor (un favorable) environments. Genotype 8/7 produced overall higher grain yield (3647 kg/ha) and ranked as third high yielding genotype had regression value close to unity (b=0.9) and low S/sup d/ value, indicating more stability and wide adaptation over the all environments. The knowledge of the presence and magnitude of genotype x environment (GE) interaction is important to

  6. Person-environment fit: using commensurate scales to predict student stress.

    Science.gov (United States)

    Puccio, G J; Talbot, R J; Joniak, A J

    1993-11-01

    The relationship between person-environment fit and stress was examined for two samples of university students (N = 55 and 79). The Kirton Adaption-Innovation Inventory (KAI) was modified to assess the students' perceptions of the adaptor-innovator style required by their course, the styles they exhibited in the course, and their ideal style preferences. To ascertain fit, the KAI total scores and subscale scores (Originality, Efficiency, and Rule/Group Conformity) were used to classify students on three dimensions: (1) perception of what style their course required, adaptive or innovative; (2) congruence between the style the course required and the style they exhibited in the course; and (3) the magnitude of the difference, if any, between the required style and the exhibited style. Points two and three are measures of fit. The dependent variable was stress. Also the students' ideal style scores, KAI total and subscales, were substituted for the exhibited scores and the classification and analyses were repeated. Analysis of the total scores revealed that a course requiring adaptive behaviours was perceived as more stressful than a course requiring innovative behaviours. Similarly, an analysis of the Rule/Group Conformity scores revealed that the greater the conformity required the greater the stress. Also the less originality demanded in the course the greater was the perceived stress. For the KAI total scores and Rule/Group Conformity scores, the two measures of fit (incongruity and magnitude of the incongruity) were not related to stress. However, analyses of the Originality and Efficiency subscales supported the importance of the P-E fit position. For both subscales, stress was associated with the magnitude of the difference between what was required in the course and what students exhibited in the course. Educational implications derived from these findings as well as recommendations for future research are discussed.

  7. Crowd behaviour during high-stress evacuations in an immersive virtual environment

    Science.gov (United States)

    Kapadia, Mubbasir; Thrash, Tyler; Sumner, Robert W.; Gross, Markus; Helbing, Dirk; Hölscher, Christoph

    2016-01-01

    Understanding the collective dynamics of crowd movements during stressful emergency situations is central to reducing the risk of deadly crowd disasters. Yet, their systematic experimental study remains a challenging open problem due to ethical and methodological constraints. In this paper, we demonstrate the viability of shared three-dimensional virtual environments as an experimental platform for conducting crowd experiments with real people. In particular, we show that crowds of real human subjects moving and interacting in an immersive three-dimensional virtual environment exhibit typical patterns of real crowds as observed in real-life crowded situations. These include the manifestation of social conventions and the emergence of self-organized patterns during egress scenarios. High-stress evacuation experiments conducted in this virtual environment reveal movements characterized by mass herding and dangerous overcrowding as they occur in crowd disasters. We describe the behavioural mechanisms at play under such extreme conditions and identify critical zones where overcrowding may occur. Furthermore, we show that herding spontaneously emerges from a density effect without the need to assume an increase of the individual tendency to imitate peers. Our experiments reveal the promise of immersive virtual environments as an ethical, cost-efficient, yet accurate platform for exploring crowd behaviour in high-risk situations with real human subjects. PMID:27605166

  8. Simulating extreme environments: Ergonomic evaluation of Chinese pilot performance and heat stress tolerance.

    Science.gov (United States)

    Li, Jing; Tian, Yinsheng; Ding, Li; Zou, Huijuan; Ren, Zhaosheng; Shi, Liyong; Feathers, David; Wang, Ning

    2015-06-05

    High-temperatures in the cockpit environment can adversely influence pilot behavior and performance. To investigate the impact of high thermal environments on Chinese pilot performance in a simulated cockpit environment. Ten subjects volunteered to participate in the tests under 40°C and 45°C high-temperature simulations in an environmentally controlled chamber. Measures such as grip strength, perception, dexterity, somatic sense reaction, and analytical reasoning were taken. The results were compared to the Combined Index of Heat Stress (CIHS). CIHS exceeded the heat stress safety limit after 45 min under 40°C, grip strength decreased by 12% and somatic perception became 2.89 times larger than the initial value. In the case of 45°C, CIHS exceeded the safety limit after only 20 min, while the grip strength decreased just by 3.2% and somatic perception increased to 4.36 times larger than the initial value. Reaction and finger dexterity were not statistically different from baseline measurements, but the error rate of analytical reasoning test rose remarkably. Somatic perception was the most sensitive index to high-temperature, followed by grip strength. Results of this paper may help to improve environmental control design of new fighter cockpit and for pilot physiology and cockpit environment ergonomics research for Chinese pilots.

  9. Crowd behaviour during high-stress evacuations in an immersive virtual environment.

    Science.gov (United States)

    Moussaïd, Mehdi; Kapadia, Mubbasir; Thrash, Tyler; Sumner, Robert W; Gross, Markus; Helbing, Dirk; Hölscher, Christoph

    2016-09-01

    Understanding the collective dynamics of crowd movements during stressful emergency situations is central to reducing the risk of deadly crowd disasters. Yet, their systematic experimental study remains a challenging open problem due to ethical and methodological constraints. In this paper, we demonstrate the viability of shared three-dimensional virtual environments as an experimental platform for conducting crowd experiments with real people. In particular, we show that crowds of real human subjects moving and interacting in an immersive three-dimensional virtual environment exhibit typical patterns of real crowds as observed in real-life crowded situations. These include the manifestation of social conventions and the emergence of self-organized patterns during egress scenarios. High-stress evacuation experiments conducted in this virtual environment reveal movements characterized by mass herding and dangerous overcrowding as they occur in crowd disasters. We describe the behavioural mechanisms at play under such extreme conditions and identify critical zones where overcrowding may occur. Furthermore, we show that herding spontaneously emerges from a density effect without the need to assume an increase of the individual tendency to imitate peers. Our experiments reveal the promise of immersive virtual environments as an ethical, cost-efficient, yet accurate platform for exploring crowd behaviour in high-risk situations with real human subjects. © 2016 The Authors.

  10. The change in body stressed to relaxed body through breathing, visualization and a protective environment together

    Directory of Open Access Journals (Sweden)

    Evelyn I. Rodríguez Morrill

    2009-11-01

    Full Text Available This work shows several ways to meet and relax the body through personal knowledge and techniques encounter with nature. Modern life and fast, the constant pressure from childhood to adulthood, in the modes of interaction between individuals and groups, they lead to construction of bodies that reflect emotional anatomy visible loss of balance, contractures, inflammation, multiple imbalances by lack of knowledge and awareness especially being in the world fully, the person has moved away from its ecological relationship with itself and the environment. Methods are shown to positively change a condition of constant stress and chronic discomfort, a learned condition of physical and psychological wellbeing, with a series of movements, recovering the body through exercise, to tend to personal balance, obtaining a positive relationship with the environment and the people attended. The proposal starts promoting new habits that can be saved in consciousness. Partly, mainly of breath, alignment with the music and the environment and personal and group work

  11. Quantitative genetic analysis of life-history traits of Caenorhabditis elegans in stressful environments

    Directory of Open Access Journals (Sweden)

    Shorto Alison

    2008-01-01

    Full Text Available Abstract Background Organisms live in environments that vary. For life-history traits that vary across environments, fitness will be maximised when the phenotype is appropriately matched to the environmental conditions. For the free-living nematode Caenorhabditis elegans, we have investigated how two major life-history traits, (i the development of environmentally resistant dauer larvae and (ii reproduction, respond to environmental stress (high population density and low food availability, and how these traits vary between lines and the genetic basis of this variation. Results We found that lines of C. elegans vary in their phenotypic plasticity of dauer larva development, i.e. there is variation in the likelihood of developing into a dauer larva for the same environmental change. There was also variation in how lifetime fecundity and the rate of reproduction changed under conditions of environmental stress. These traits were related, such that lines that are highly plastic for dauer larva development also maintain a high population growth rate when stressed. We identified quantitative trait loci (QTL on two chromosomes that control the dauer larva development and population size phenotypes. The QTLs affecting the dauer larva development and population size phenotypes on chromosome II are closely linked, but are genetically separable. This chromosome II QTL controlling dauer larva development does not encompass any loci previously identified to control dauer larva development. This chromosome II region contains many predicted 7-transmembrane receptors. Such proteins are often involved in information transduction, which is clearly relevant to the control of dauer larva development. Conclusion C. elegans alters both its larval development and adult reproductive strategy in response to environmental stress. Together the phenotypic and genotypic data suggest that these two major life-history traits are co-ordinated responses to environmental stress

  12. Investigation of smooth specimen scc test procedures; variations in environment, specimen size, stressing frame, and stress state. [for high strength aluminum alloys

    Science.gov (United States)

    Lifka, B. W.; Sprowls, D. O.; Kelsey, R. A.

    1975-01-01

    The variables studied in the stress-corrosion cracking performance of high strength aluminum alloys were: (1) corrosiveness of the environment, (2) specimen size and stiffness of the stressing system, (3) interpretation of transgranular cracking, and (4) interaction of the state of stress and specimen orientation in a product with an anisotropic grain structure. It was shown that the probability of failure and time to fracture for a specimen loaded in direct tension are influenced by corrosion pattern, the stressing assembly stiffness, and the notch tensile strength of the alloy. Results demonstrate that the combination of a normal tension stress and a shear stress acting on the plane of maximum susceptibility in a product with a highly directional grain cause the greatest tendency for stress-corrosion cracking.

  13. Impact of imaging room environment: staff job stress and satisfaction, patient satisfaction, and willingness to recommend.

    Science.gov (United States)

    Quan, Xiaobo; Joseph, Anjali; Ensign, Janet C

    2012-01-01

    The built environment significantly affects the healthcare experiences of patients and staff. Healthcare administrators and building designers face the opportunity and challenge of improving healthcare experience and satisfaction through better environmental design. The purpose of the study was to evaluate how a novel environmental intervention for imaging rooms, which integrated multiple elements of healing environments including positive distractions and personal control over environment, affects the perceptions and satisfactions of its primary users-patients and staff. Anonymous questionnaire surveys were conducted to compare patient and staff perceptions of the physical environment, satisfaction, and stress in two types of imaging rooms: imaging rooms with the intervention installed (intervention rooms) and traditionally designed rooms without the intervention (comparison rooms). Imaging technologists and patients perceived the intervention rooms to be significantly more pleasant-looking. Patients in the intervention rooms reported significantly higher levels of environmental control and were significantly more willing to recommend the intervention rooms to others. The environmental intervention was effective in improving certain aspects of the imaging environment: pleasantness and environmental control. Further improvement of the imaging environment is needed to address problematic areas such as noise.

  14. Sex and Trait Anxiety Differences in Psychological Stress are Modified by Environment.

    Science.gov (United States)

    Liu, James; Scira, John; Donaldson, Simone; Kajiji, Nina; Dash, Gordon H; Donaldson, S Tiffany

    2018-05-09

    Evidence-based research has revealed how physiological and emotional responses to acute stress are adaptive. However, under conditions of unpredictable or protracted stress, health and drug vulnerability can be compromised. In this study, we examined anxiety-like behavioral responses of 4th generation adolescent male and female Long Evans rats selectively bred for high (HAn) and low (LAn) anxiety-like behavior when housed in an isolated environment (IE) versus a social environment (SE). After 35 days in IE or SE, animals were tested in the elevated plus maze (EPM), injected with amphetamine (AMPH: 0.5 mg/kg, IP) in the locomotor activity (LMA) chamber, measured for basal and post air puff-stressor core body temperature and blood pressure. Following select rearing, SE reduced the anxiogenic response in HAn rats with females displaying the lowest anxiety-like behavior in the EPM. During habituation in the LMA, IE rats remained active, while post-AMPH injection HAn females were hyperactive, followed closely by LAn females. Our findings from the post-stressor physiological measurements indicate that temperature differences due to environment are observed only in the SE females. We also observed group differences for diastolic (DBP) and systolic (SBP) blood pressure. HAn IE males experienced higher DBP and SBP but LAn IE females only experienced higher SBP. Not only do our findings corroborate earlier work on HAn/LAn lines but the findings obtained from this research offer new insights about the role of environment and the role of sex in (1) modulation of anxiety-like behavior, (2) AMPH sensitivity, and (3) basal and stress-induced physiological changes. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

  15. Cotton proteomics for deciphering the mechanism of environment stress response and fiber development.

    Science.gov (United States)

    Zhou, Meiliang; Sun, Guoqing; Sun, Zhanmin; Tang, Yixiong; Wu, Yanmin

    2014-06-13

    Cotton fiber is considered as the backbone of the textile industry. The productivity of cotton crop is severely hampered by the occurrence of pathogens, pests, and various environmental factors. Nevertheless, cotton plant has developed sophisticated mechanisms to respond to environment stresses to avoid detrimental effects on its growth and development. Therefore, understanding the mechanisms of cotton fiber development and environment stress response is of considerable interest for designing agriculture breeding strategies to ensure sustainable productivity. The application of proteomics technologies to advance our knowledge in cotton fiber development and abiotic/biotic stress tolerance has increased dramatically in the last 5years as evidenced by the large amount of publications in this area. This review summarizes the work which has been reported for cotton proteomics and evaluates the findings in context of the approaches that are widely employed with the aim to generate novel insight useful for cotton improvement. Cotton (Gossypium spp.) is considered as the foremost commercially important fiber crop grown all over the world and is deemed as the backbone of the textile industry. Cotton is also an important source of edible oil seed and a nutrient-rich food crop as cottonseed contains high-quality protein and oil. The growth and productivity of cotton crop are often hampered by various biotic stress factors, such as insect pests and pathogens. In addition, cotton plants are frequently subjected to unavoidable environmental factors that cause abiotic stress, such as salt, heat and drought. Proteomic techniques provide one of the best options for understanding the gene function and phenotypic changes during cotton fiber development and stress response. This review first summarizes the work which has been reported for cotton proteomics about cotton fiber development and abiotic/biotic stress tolerance, and also evaluates the findings in context of the approaches

  16. The Morphologies and Alignments of Gas, Mass, and the Central Galaxies of CLASH Clusters of Galaxies

    Science.gov (United States)

    Donahue, Megan; Ettori, Stefano; Rasia, Elena; Sayers, Jack; Zitrin, Adi; Meneghetti, Massimo; Voit, G. Mark; Golwala, Sunil; Czakon, Nicole; Yepes, Gustavo; Baldi, Alessandro; Koekemoer, Anton; Postman, Marc

    2016-03-01

    Morphology is often used to infer the state of relaxation of galaxy clusters. The regularity, symmetry, and degree to which a cluster is centrally concentrated inform quantitative measures of cluster morphology. The Cluster Lensing and Supernova survey with Hubble Space Telescope (CLASH) used weak and strong lensing to measure the distribution of matter within a sample of 25 clusters, 20 of which were deemed to be “relaxed” based on their X-ray morphology and alignment of the X-ray emission with the Brightest Cluster Galaxy. Toward a quantitative characterization of this important sample of clusters, we present uniformly estimated X-ray morphological statistics for all 25 CLASH clusters. We compare X-ray morphologies of CLASH clusters with those identically measured for a large sample of simulated clusters from the MUSIC-2 simulations, selected by mass. We confirm a threshold in X-ray surface brightness concentration of C ≳ 0.4 for cool-core clusters, where C is the ratio of X-ray emission inside 100 h70-1 kpc compared to inside 500 {h}70-1 kpc. We report and compare morphologies of these clusters inferred from Sunyaev-Zeldovich Effect (SZE) maps of the hot gas and in from projected mass maps based on strong and weak lensing. We find a strong agreement in alignments of the orientation of major axes for the lensing, X-ray, and SZE maps of nearly all of the CLASH clusters at radii of 500 kpc (approximately 1/2 R500 for these clusters). We also find a striking alignment of clusters shapes at the 500 kpc scale, as measured with X-ray, SZE, and lensing, with that of the near-infrared stellar light at 10 kpc scales for the 20 “relaxed” clusters. This strong alignment indicates a powerful coupling between the cluster- and galaxy-scale galaxy formation processes.

  17. Service experience and stress corrosion of Inconel 600 bellows expansion joints in turbine steam environments

    International Nuclear Information System (INIS)

    Kramer, L.D.; Michael, S.T.; Pement, F.W.

    The purpose of this paper is to discuss the service history of Inconel 600 expansion bellows, to illustrate a typical case of failure, propose S.C.C. mechanisms, and to rationalize the most probable mechanism. Inconel 600 is fully resistant to high-purity power plant steam (720 deg F maximum) for on-going service lifetimes which greatly exceed the incubation periods which are reported or postulated in the literature for delayed stress corrosion cracking in high-purity water tests (630-660 deg F). The only observed stress corrosion environments which are sufficiently rapidly deleterious to be consistent with failure lifetimes are molten NaOH in superheated steam or a very concentrated aqueous caustic solution containing silica contamination. (author)

  18. Adaptive Role of Inversion Polymorphism of Drosophila subobscura in Lead Stressed Environment.

    Science.gov (United States)

    Kenig, Bojan; Kurbalija Novičić, Zorana; Patenković, Aleksandra; Stamenković-Radak, Marina; Anđelković, Marko

    2015-01-01

    Local adaptation to environmental stress at different levels of genetic polymorphism in various plants and animals has been documented through evolution of heavy metal tolerance. We used samples of Drosophila subobscura populations from two differently polluted environments to analyze the change of chromosomal inversion polymorphism as genetic marker during laboratory exposure to lead. Exposure to environmental contamination can affect the genetic content within a particular inversion and produce targets for selection in populations from different environments. The aims were to discover whether the inversion polymorphism is shaped by the local natural environments, and if lead as a selection pressure would cause adaptive divergence of two populations during the multigenerational laboratory experiment. The results showed that populations retain signatures from past contamination events, and that heavy metal pollution can cause adaptive changes in population. Differences in inversion polymorphism between the two populations increased over generations under lead contamination in the laboratory. The inversion polymorphism of population originating from the more polluted natural environment was more stable during the experiment, both under conditions with and without lead. Therefore, results showed that inversion polymorphism as a genetic marker reflects a strong signature of adaptation to the local environment, and that historical demographic events and selection are important for both prediction of evolutionary potential and long-term viability of natural populations.

  19. Galvanic and stress corrosion of copper canisters in repository environment. A short review

    International Nuclear Information System (INIS)

    Hermansson, H.P.; Koenig, M.

    2001-02-01

    The Swedish Nuclear Power Inspectorate, SKI, has studied different aspects of canister and copper corrosion as part of the general improvement of the knowledge base within the area. General and local corrosion has earlier been treated by experiments as well as by thermodynamic calculations. For completeness also galvanic and stress corrosion should be treated. The present work is a short review, intended to indicate areas needing further focus. The work consists of two parts, the first of which contains a judgement of statements concerning risk of galvanic corrosion of copper in the repository. The second part concerns threshold values for the stress intensity factor of stress corrosion in copper. A suggestion is given on how such values possibly could be measured for copper at repository conditions. In early investigations by SKB, galvanic corrosion is not mentioned or at least not treated. In later works it is treated but often in a theoretical way without indications of any further treatment or investigation. Several pieces of work indicate that further investigations are required to ensure that different types of corrosion, like galvanic, cannot occur in the repository environment. There are for example effects of grain size, grain boundary conditions, impurities and other factors that could influence the appearance of galvanic corrosion that are not treated. Those factors have to be considered to be completely sure that galvanic corrosion and related effects does not occur for the actual canister in the specific environment of the repository. The circumstances are so specific, that a rather general discussion indicating that galvanic corrosion is not probable just is not enough. Experiments should also be performed for verification. It is concluded that the following specific areas, amongst others, could benefit from further consideration. Galvanic corrosion of unbreached copper by inhomogeneities in the environment and in the copper metal should be addressed

  20. Galvanic and stress corrosion of copper canisters in repository environment. A short review

    Energy Technology Data Exchange (ETDEWEB)

    Hermansson, H.P.; Koenig, M. [Studsvik Nuclear AB, Nykoeping (Sweden)

    2001-02-01

    The Swedish Nuclear Power Inspectorate, SKI, has studied different aspects of canister and copper corrosion as part of the general improvement of the knowledge base within the area. General and local corrosion has earlier been treated by experiments as well as by thermodynamic calculations. For completeness also galvanic and stress corrosion should be treated. The present work is a short review, intended to indicate areas needing further focus. The work consists of two parts, the first of which contains a judgement of statements concerning risk of galvanic corrosion of copper in the repository. The second part concerns threshold values for the stress intensity factor of stress corrosion in copper. A suggestion is given on how such values possibly could be measured for copper at repository conditions. In early investigations by SKB, galvanic corrosion is not mentioned or at least not treated. In later works it is treated but often in a theoretical way without indications of any further treatment or investigation. Several pieces of work indicate that further investigations are required to ensure that different types of corrosion, like galvanic, cannot occur in the repository environment. There are for example effects of grain size, grain boundary conditions, impurities and other factors that could influence the appearance of galvanic corrosion that are not treated. Those factors have to be considered to be completely sure that galvanic corrosion and related effects does not occur for the actual canister in the specific environment of the repository. The circumstances are so specific, that a rather general discussion indicating that galvanic corrosion is not probable just is not enough. Experiments should also be performed for verification. It is concluded that the following specific areas, amongst others, could benefit from further consideration. Galvanic corrosion of unbreached copper by inhomogeneities in the environment and in the copper metal should be addressed

  1. CLASH-VLT: constraints on f (R) gravity models with galaxy clusters using lensing and kinematic analyses

    Energy Technology Data Exchange (ETDEWEB)

    Pizzuti, L.; Sartoris, B.; Borgani, S.; Girardi, M., E-mail: pizzuti@oats.inaf.it, E-mail: sartoris@oats.inaf.it, E-mail: borgani@oats.inaf.it, E-mail: girardi@oats.inaf.it [Dipartimento di Fisica, Sezione di Astronomia, Università di Trieste, Via Tiepolo 11, I-34143 Trieste (Italy); and others

    2017-07-01

    We perform a maximum likelihood kinematic analysis of the two dynamically relaxed galaxy clusters MACS J1206.2-0847 at z =0.44 and RXC J2248.7-4431 at z =0.35 to determine the total mass profile in modified gravity models, using a modified version of the MAMPOSSt code of Mamon, Biviano and Bou and apos;e. Our work is based on the kinematic and lensing mass profiles derived using the data from the Cluster Lensing And Supernova survey with Hubble (hereafter CLASH) and the spectroscopic follow-up with the Very Large Telescope (hereafter CLASH-VLT). We assume a spherical Navarro-Frenk-White (NFW hereafter) profile in order to obtain a constraint on the fifth force interaction range λ for models in which the dependence of this parameter on the environment is negligible at the scale considered (i.e. λ= const ) and fixing the fifth force strength to the value predicted in f (R) gravity. We then use information from lensing analysis to put a prior on the other NFW free parameters. In the case of MACSJ 1206 the joint kinematic+lensing analysis leads to an upper limit on the effective interaction range λ≤1.61 mpc at Δχ{sup 2}=2.71 on the marginalized distribution. For RXJ 2248 instead a possible tension with the ΛCDM model appears when adding lensing information, with a lower limit λ≥0.14 mpc at Δχ{sup 2}=2.71. This is consequence of the slight difference between the lensing and kinematic data, appearing in GR for this cluster, that could in principle be explained in terms of modifications of gravity. We discuss the impact of systematics and the limits of our analysis as well as future improvements of the results obtained. This work has interesting implications in view of upcoming and future large imaging and spectroscopic surveys, that will deliver lensing and kinematic mass reconstruction for a large number of galaxy clusters.

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

    Science.gov (United States)

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

    2010-01-01

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

  3. Critical study of test methods in stress corrosion cracking. Application to stainless steels in chloride environment

    International Nuclear Information System (INIS)

    Ajana, Lotfi

    1985-01-01

    The transposition of results obtained in laboratory to the prediction of in-service material resistance is a crucial problem in the case of stress corrosion cracking (SCC). The search for a SCC test which allows a reliable and realistic classification of stainless steels in chloride environments requires a choice of adequate electrolytes and of mechanical solicitation mode. In this research, the author first justifies the choice of an environment which could be representative of actual service conditions in the case of 5 grades of austenitic steels and 1 grade of austeno-ferric steel. Using a computerized data acquisition and processing system, the author compares the information obtained with two types of test: under constant load and under slow strain rate [fr

  4. Stress-corrosion behavior of aluminum-lithium alloys in aqueous salt environments

    Science.gov (United States)

    Pizzo, P. P.; Galvin, R. P.; Nelson, H. G.

    1984-01-01

    The stress corrosion susceptibility of two powder metallurgy (P/M) alloys, Al-Li-Cu and Al-Li-Cu-Mg; two mechanically attrited (M/A) alloys, Al-Li-Cu and Al-Li-Mg; and two wrought, ingot alloys, X-2020 and AA7475, are compared. Time-dependent fracture in an aqueous sodium chloride environment under alternate immersion condition was found to vary significantly between alloys. The stress corrosion behavior of the two powder metallurgy processed alloys was studied in detail under conditions of crack initiation, static crack growth, and fatigue crack growth. A variety of stress corrosion tests were performed including smooth surface, time-to-failure tests; potentiostatic tests on smooth surfaces exposed to constant applied strain rates; and fracture mechanics-type tests under static and cyclic loads. Both alloys show surface pitting and subsequent intergranular corrosion. Pitting is more severe in the magnesium-bearing alloy and is associated with stringer particles strung along the extrusion direction as a result of P/M processing.

  5. Stress-corrosion behavior of aluminum-lithium alloys in aqueous environments

    Science.gov (United States)

    Pizzo, P. P.; Galvin, R. P.; Nelson, H. G.

    1983-01-01

    The stress corrosion susceptibility of two powder metallurgy (P/M) alloys, Al-Li-Cu and Al-Li-Cu-Mg two mechanically attrited (M/A) alloys, Al-Li-Cu and Al-Li-Mg; and two wrought, ingot alloys, X-2020 and AA7475, are compared. Time-dependent fracture in an aqueous sodium chloride environment under alternate immersion condition was found to vary significantly between alloys. The stress corrosion behavior of the two powder metallurgy processed alloys was studied in detail under conditions of crack initiation, static crack growth, and fatigue crack growth. A variety of stress corrosion tests were performed including smooth surface, time-to-failure tests; potentiostatic tests on smooth surfaces exposed to constant applied strain rates; and fracture mechanics-type tests under static and cyclic loads. Both alloys show surface pitting and subsequent intergranular corrosion. Pitting is more severe in the magnesium-bearing alloy and is associated with stringer particles strung along the extrusion direction as a result of P/M processing.

  6. Natural outdoor environments and mental health: Stress as a possible mechanism.

    Science.gov (United States)

    Triguero-Mas, Margarita; Donaire-Gonzalez, David; Seto, Edmund; Valentín, Antònia; Martínez, David; Smith, Graham; Hurst, Gemma; Carrasco-Turigas, Glòria; Masterson, Daniel; van den Berg, Magdalena; Ambròs, Albert; Martínez-Íñiguez, Tania; Dedele, Audrius; Ellis, Naomi; Grazulevicius, Tomas; Voorsmit, Martin; Cirach, Marta; Cirac-Claveras, Judith; Swart, Wim; Clasquin, Eddy; Ruijsbroek, Annemarie; Maas, Jolanda; Jerret, Michael; Gražulevičienė, Regina; Kruize, Hanneke; Gidlow, Christopher J; Nieuwenhuijsen, Mark J

    2017-11-01

    Better mental health has been associated with exposure to natural outdoor environments (NOE). However, comprehensive studies including several indicators of exposure and outcomes, potential effect modifiers and mediators are scarce. We used novel, objective measures to explore the relationships between exposure to NOE (i.e. residential availability and contact) and different indicators of mental health, and possible modifiers and mediators. A nested cross-sectional study was conducted in: Barcelona, Spain; Stoke-on-Trent, United Kingdom; Doetinchem, Netherlands; Kaunas, Lithuania. Participants' exposure to NOE (including both surrounding greenness and green and/or blue spaces) was measured in terms of (a) amount in their residential environment (using Geographical Information Systems) and (b) their contact with NOE (using smartphone data collected over seven days). Self-reported information was collected for mental health (psychological wellbeing, sleep quality, vitality, and somatisation), and potential effect modifiers (gender, age, education level, and city) and mediators (perceived stress and social contacts), with additional objective NOE physical activity (potential mediator) derived from smartphone accelerometers. Analysis of data from 406 participants showed no statistically significant associations linking mental health and residential NOE exposure. However, NOE contact, especially surrounding greenness, was statistically significantly tied to better mental health. There were indications that these relationships were stronger for males, younger people, low-medium educated, and Doetinchem residents. Perceived stress was a mediator of most associations, and physical activity and social contacts were not. Our findings indicate that contact with NOE benefits mental health. Our results also suggest that having contact with NOE that can facilitate stress reduction could be particularly beneficial. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Period 3 gene polymorphism and sleep adaptation to stressful urban environments.

    Science.gov (United States)

    Anderson, Maxwell R; Akeeb, Ameenat; Lavela, Joseph; Chen, Yuanxiu; Mellman, Thomas A

    2017-02-01

    This study's objective was to investigate the relationship between a variable-number tandem-repeat (VNTR) Period 3 gene (PER3) polymorphism and sleep adaptation to stressful urban environments. Seventy-five (49 female) African American participants (ages 18-35 years) living in neighbourhoods with high rates of violent crime were selected for the study based on converging criteria for good or poor sleep. Categorization of sleep quality was based on the Insomnia Severity Index (ISI), estimates of typical sleep duration and sleep efficiency. Other assessments included the Fear of Sleep Index (FOSI) and City Stress Inventory (CSI). Whole blood DNA was analysed for the 4 and 5 VNTR alleles using polymerase chain reaction (PCR) and restrictive enzyme digestion. Fifty-seven per cent of those who were homo- or heterozygous for the 4-repeat allele were poor sleepers versus 25% of those homozygous for the 5-repeat allele; χ 2  = 4.17, P = 0.041. In a logistic regression model with all the variables with significant bivariate relationships to sleep quality group, FOSI was the only significant predictor (χ 2  = 5.68, P = 0.017). FOSI scores were higher among those with the 4-repeat allele (t = 2.66, P = 0.013). The PER3 4 and 5 VNTR polymorphisms appear to influence sensitivity to the effects of stressful urban environments on sleep. While FOSI was the only variable associated independently with sleep quality category, the candidate vulnerability allele was also associated with greater 'fear of sleep'. © 2016 European Sleep Research Society.

  8. Timing of favorable conditions, competition and fertility interact to govern recruitment of invasive Chinese tallow tree in stressful environments.

    Directory of Open Access Journals (Sweden)

    Christopher A Gabler

    Full Text Available The rate of new exotic recruitment following removal of adult invaders (reinvasion pressure influences restoration outcomes and costs but is highly variable and poorly understood. We hypothesize that broad variation in average reinvasion pressure of Triadica sebifera (Chinese tallow tree, a major invader arises from differences among habitats in spatiotemporal availability of realized recruitment windows. These windows are periods of variable duration long enough to permit establishment given local environmental conditions. We tested this hypothesis via a greenhouse mesocosm experiment that quantified how the duration of favorable moisture conditions prior to flood or drought stress (window duration, competition and nutrient availability influenced Triadica success in high stress environments. Window duration influenced pre-stress seedling abundance and size, growth during stress and final abundance; it interacted with other factors to affect final biomass and germination during stress. Stress type and competition impacted final size and biomass, plus germination, mortality and changes in size during stress. Final abundance also depended on competition and the interaction of window duration, stress type and competition. Fertilization interacted with competition and stress to influence biomass and changes in height, respectively, but did not affect Triadica abundance. Overall, longer window durations promoted Triadica establishment, competition and drought (relative to flood suppressed establishment, and fertilization had weak effects. Interactions among factors frequently produced different effects in specific contexts. Results support our 'outgrow the stress' hypothesis and show that temporal availability of abiotic windows and factors that influence growth rates govern Triadica recruitment in stressful environments. These findings suggest that native seed addition can effectively suppress superior competitors in stressful environments. We also

  9. A clash of gods – Conceptualising space in Daniel 1

    Directory of Open Access Journals (Sweden)

    J. Jacobus de Bruyn

    2014-02-01

    Full Text Available Applying cognitive linguistics to the text of Daniel 1 is a useful exegetical aid for a better understanding of the narrative. Studying the author’s use of ‘spatial markers’ such as ‘Jerusalem’, ‘Babylon’, ‘temple’ and some other spatial features, makes it possible to reconstruct the narrative into a ‘cognitive spatial frameset’. In this particular exegetical frameset, Daniel 1 can be described as a narrated confrontation between Yahweh and the gods of Babylon. Within this conflict between deities, Daniel, the divine agent becomes a spatial embodiment of Yahweh’s power and authority to act inside a hostile, non-Israelite environment and at the same time undermines the authority of the Babylonian gods.

  10. Usability and user driven innovation - unity or clash?

    DEFF Research Database (Denmark)

    Fronczek-Munter, Aneta

    2011-01-01

    Aim: To present different understandings of the concepts ‗usability‘ and ‗user driven innovation‘ and discuss if and how the built environment can benefit from these concepts and the unity of them. Approach and methodology: The paper is based on literature reviews of scientific journals and other...... influential publications within the academic fields of Facilities Management, Architecture and Engineering, Participatory Design and Software design. Outline: The paper will discuss different understandings of the concept ‗usability‘ and its relation to ‗user driven innovation‘, which depends on the academic...... field and area of professional application. The concept of usability has its roots in evaluations of consumer products and user interfaces of computer software. During the last 5-10 years there has been a new development of research in usability of buildings and workplaces. Recently researchers have...

  11. Stress-induced ECM alteration modulates cellular microRNAs that feedback to readjust the extracellular environment and cell behaviour

    Directory of Open Access Journals (Sweden)

    Halyna R Shcherbata

    2013-12-01

    Full Text Available The extracellular environment is a complex entity comprising of the extracellular matrix (ECM and regulatory molecules. It is highly dynamic and under cell-extrinsic stress, transmits the stressed organism’s state to each individual ECM-connected cell. microRNAs (miRNAs are regulatory molecules involved in virtually all the processes in the cell, especially under stress. In this review, we analyse how microRNA expression is regulated downstream of various signal transduction pathways induced by changes in the extracellular environment. In particular, we focus on the muscular dystrophy-associated cell adhesion molecule dystroglycan capable of signal transduction. Then we show how exactly the same miRNAs feedback to regulate the extracellular environment. The ultimate goal of this bi-directional signal transduction process is to change cell behaviour under cell-extrinsic stress in order to respond to it accordingly.

  12. Impact of domestic care environment on trauma and posttraumatic stress disorder among orphans in western Kenya.

    Directory of Open Access Journals (Sweden)

    Lukoye Atwoli

    Full Text Available The aim of this study was to determine the impact of the domestic care environment on the prevalence of potentially traumatic events (PTEs and posttraumatic stress disorder (PTSD among orphaned and separated children in Uasin Gishu County, western Kenya.A total of 1565 (55.5% male orphaned and separated adolescents aged 10-18 years (mean 13.8 years, sd 2.2, were assessed for PTSD and PTEs including bullying, physical abuse and sexual abuse. In this sample, 746 lived in extended family households, 746 in Charitable Children's Institutions (CCIs, and 73 on the street. Posttraumatic stress symptom (PTSS scores and PTSD were assessed using the Child PTSD Checklist.Bullying was the commonest PTE in all domestic care environments, followed by physical and sexual abuse. All PTEs were commonest among the street youth followed by CCIs. However, sexual abuse was more prevalent in households than in CCIs. Prevalence of PTSD was highest among street youth (28.8%, then households (15.0% and CCIs (11.5%. PTSS scores were also highest among street youth, followed by CCIs and households. Bullying was associated with higher PTSS scores and PTSD odds than either sexual or physical abuse.This study demonstrated differences in distribution of trauma and PTSD among orphaned and separated children in different domestic care environments, with street youth suffering more than those in CCIs or households. Interventions are needed to address bullying and sexual abuse, especially in extended family households. Street youth, a heretofore neglected population, are urgently in need of dedicated mental health services and support.

  13. Data from: Effects of multi-generational stress exposure and offspring environment on the expression and persistence of transgenerational effects in Arabidopsis thaliana

    NARCIS (Netherlands)

    Groot, M.; Kooke, R.; Knoben, Nieke; Vergeer, P.; Keurentjes, J.J.B.; Ouborg, N.J.; Verhoeven, Koen J.F.

    2016-01-01

    Phenotype data of A. thaliana plants grown in either a field environment or in a climate chamber environment. In the climate chamber environment plants were grown under control conditions or salt stress.

  14. Submillimeter Observations of CLASH 2882 and the Evolution of Dust in this Galaxy

    Science.gov (United States)

    Dwek, Eli; Staguhn, Johannes; Arendt, Richard G; Kovacs, Attila; Decarli, Roberto; Egami, Eiichi; Michalowski, Michal J.; Rawle, Timothy D.; Toft, Sune; Walter, Fabian

    2015-01-01

    Two millimeter observations of the MACS J1149.6+2223 cluster have detected a source that was consistent with the location of the lensed MACS 1149-JD galaxy at z = 9.6. A positive identification would have rendered this galaxy as the youngest dust forming galaxy in the universe. Follow up observation with the AzTEC 1.1 mm camera and the IRAM NOrthern Extended Millimeter Array (NOEMA) at 1.3 mm have not confirmed this association. In this paper we show that the NOEMA observations associate the 2 mm source with [PCB2012] 2882,12 source number 2882 in the Cluster Lensing And Supernova survey with Hubble (CLASH) catalog of MACS J1149.6 +2223. This source, hereafter referred to as CLASH 2882, is a gravitationally lensed spiral galaxy at z = 0.99. We combine the Goddard IRAM Superconducting 2-Millimeter Observer (GISMO) 2 mm and NOEMA 1.3 mm fluxes with other (rest frame) UV to far-IR observations to construct the full spectral energy distribution of this galaxy, and derive its star formation history, and stellar and interstellar dust content. The current star formation rate of the galaxy is 54/mu/Solar Mass/yr, and its dust mass is about 5 × 10(exp 7)/mu Solar Mass, where mu is the lensing magnification factor for this source, which has a mean value of 2.7. The inferred dust mass is higher than the maximum dust mass that can be produced by core collapse supernovae and evolved AGB stars. As with many other star forming galaxies, most of the dust mass in CLASH 2882 must have been accreted in the dense phases of the interstellar medium.

  15. When we test, do we stress? Impact of the testing environment on cortisol secretion and memory performance in older adults.

    Science.gov (United States)

    Sindi, Shireen; Fiocco, Alexandra J; Juster, Robert-Paul; Pruessner, Jens; Lupien, Sonia J

    2013-08-01

    The majority of studies find that older adults have worse memory performance than young adults. However, contextual features in the testing environment may be perceived as stressful by older adults, increasing their stress hormone levels. Given the evidence that older adults are highly sensitive to the effects of stress hormones (cortisol) on memory performance, it is postulated that a stressful testing environment in older adults can lead to an acute stress response and to memory impairments. The current study compared salivary cortisol levels and memory performance in young and older adults tested in environments manipulated to be stressful (unfavourable condition) or not stressful (favourable condition) for each age group. 28 young adults and 32 older adults were tested in two testing conditions: (1) a condition favouring young adults (constructed to be less stressful for young adults), and (2) a condition favouring older adults (constructed to be less stressful for older adults). The main outcome measure was salivary cortisol levels. Additionally, immediate and delayed memory performances were assessed during each condition. In older adults only, we found significantly high cortisol levels and low memory performance in the condition favouring young adults. In contrast, cortisol levels were lower and memory performance was better when older adults were tested in conditions favouring them. There was no effect of testing condition in young adults. The results demonstrate that older adults' memory performance is highly sensitive to the testing environment. These findings have important implications for both research and clinical settings in which older adults are tested for memory performance. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Intergranular stress corrosion cracking of ion irradiated 304L stainless steel in PWR environment

    International Nuclear Information System (INIS)

    Gupta, Jyoti

    2016-01-01

    IASCC is irradiation - assisted enhancement of intergranular stress corrosion cracking susceptibility of austenitic stainless steel. It is a complex degrading phenomenon which can have a significant influence on maintenance time and cost of PWRs' core internals and hence, is an issue of concern. Recent studies have proposed using ion irradiation (to be specific, proton irradiation) as an alternative of neutron irradiation to improve the current understanding of the mechanism. The objective of this study was to investigate the cracking susceptibility of irradiated SA 304L and factors contributing to cracking, using two different ion irradiations; iron and proton irradiations. Both resulted in generation of point defects in the microstructure and thereby causing hardening of the SA 304L. Material (unirradiated and iron irradiated) showed no susceptibility to intergranular cracking on subjection to SSRT with a strain rate of 5 * 10 -8 s -1 up to 4 % plastic strain in inert environment. But, irradiation (iron and proton) was found to increase intergranular cracking severity of material on subjection to SSRT in simulated PWR primary water environment at 340 C. Correlation between the cracking susceptibility and degree of localization was studied. Impact of iron irradiation on bulk oxidation of SA 304L was studied as well by conducting an oxidation test for 360 h in simulated PWR environment at 340 C. The findings of this study indicate that the intergranular cracking of 304L stainless steel in PWR environment can be studied using Fe irradiation despite its small penetration depth in material. Furthermore, it has been shown that the cracking was similar in both iron and proton irradiated samples despite different degrees of localization. Lastly, on establishing iron irradiation as a successful tool, it was used to study the impact of surface finish and strain paths on intergranular cracking susceptibility of the material. (author) [fr

  17. Evaluation of the cracking by stress corrosion in nuclear reactor environments type BWR

    International Nuclear Information System (INIS)

    Arganis J, C. R.

    2010-01-01

    The stress corrosion cracking susceptibility was studied in sensitized, solution annealed 304 steel, and in 304-L welded with a heat treatment that simulated the radiation induced segregation, by the slow strain rate test technique, in a similar environment of a boiling water reactor (BWR), 288 C, 8 MPa, low conductivity and a electrochemical corrosion potential near 200 mV. vs. standard hydrogen electrode (She). The electrochemical noise technique was used for the detection of the initiation and propagation of the cracking. The steels were characterized by metallographic studies with optical and scanning electronic microscopy and by the electrochemical potentiodynamic reactivation of single loop and double loop. In all the cases, the steels present delta ferrite. The slow strain rate tests showed that the 304 steel in the solution annealed condition is susceptible to transgranular stress corrosion cracking (TGSCC), such as in a normalized condition showed granulated. In the sensitized condition the steel showed intergranular stress corrosion cracking, followed by a transition to TGSCC. The electrochemical noise time series showed that is possible associated different time sequences to different modes of cracking and that is possible detect sequentially cracking events, it is means, one after other, supported by the fractographic studies by scanning electron microscopy. The parameter that can distinguish between the different modes of cracking is the re passivation rate, obtained by the current decay rate -n- in the current transients. This is due that the re passivation rate is a function of the microstructure and the sensitization. Other statistic parameters like the localized index, Kurtosis, Skew, produce results that are related with mixed corrosion. (Author)

  18. Irradiation-Assisted Stress Corrosion Cracking of Austenitic Stainless Steels in BWR Environments

    International Nuclear Information System (INIS)

    Chen, Y.; Chopra, O. K.; Gruber, Eugene E.; Shack, William J.

    2010-01-01

    The internal components of light water reactors are exposed to high-energy neutron irradiation and high-temperature reactor coolant. The exposure to neutron irradiation increases the susceptibility of austenitic stainless steels (SSs) to stress corrosion cracking (SCC) because of the elevated corrosion potential of the reactor coolant and the introduction of new embrittlement mechanisms through radiation damage. Various nonsensitized SSs and nickel alloys have been found to be prone to intergranular cracking after extended neutron exposure. Such cracks have been seen in a number of internal components in boiling water reactors (BWRs). The elevated susceptibility to SCC in irradiated materials, commonly referred to as irradiation-assisted stress corrosion cracking (IASCC), is a complex phenomenon that involves simultaneous actions of irradiation, stress, and corrosion. In recent years, as nuclear power plants have aged and irradiation dose increased, IASCC has become an increasingly important issue. Post-irradiation crack growth rate and fracture toughness tests have been performed to provide data and technical support for the NRC to address various issues related to aging degradation of reactor-core internal structures and components. This report summarizes the results of the last group of tests on compact tension specimens from the Halden-II irradiation. The IASCC susceptibility of austenitic SSs and heat-affected-zone (HAZ) materials sectioned from submerged arc and shielded metal arc welds was evaluated by conducting crack growth rate and fracture toughness tests in a simulated BWR environment. The fracture and cracking behavior of HAZ materials, thermally sensitized SSs and grain-boundary engineered SSs was investigated at several doses (3 dpa). These latest results were combined with previous results from Halden-I and II irradiations to analyze the effects of neutron dose, water chemistry, alloy compositions, and welding and processing conditions on IASCC. The

  19. Designing automation for complex work environments under different levels of stress.

    Science.gov (United States)

    Sauer, Juergen; Nickel, Peter; Wastell, David

    2013-01-01

    This article examines the effectiveness of different forms of static and adaptable automation under low- and high-stress conditions. Forty participants were randomly assigned to one of four experimental conditions, comparing three levels of static automation (low, medium and high) and one level of adaptable automation, with the environmental stressor (noise) being varied as a within-subjects variable. Participants were trained for 4 h on a simulation of a process control environment, called AutoCAMS, followed by a 2.5-h testing session. Measures of performance, psychophysiology and subjective reactions were taken. The results showed that operators preferred higher levels of automation under noise than under quiet conditions. A number of parameters indicated negative effects of noise exposure, such as performance impairments, physiological stress reactions and higher mental workload. It also emerged that adaptable automation provided advantages over low and intermediate static automation, with regard to mental workload, effort expenditure and diagnostic performance. The article concludes that for the design of automation a wider range of operational scenarios reflecting adverse as well as ideal working conditions needs to be considered. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  20. Detection of Stress Levels from Biosignals Measured in Virtual Reality Environments Using a Kernel-Based Extreme Learning Machine.

    Science.gov (United States)

    Cho, Dongrae; Ham, Jinsil; Oh, Jooyoung; Park, Jeanho; Kim, Sayup; Lee, Nak-Kyu; Lee, Boreom

    2017-10-24

    Virtual reality (VR) is a computer technique that creates an artificial environment composed of realistic images, sounds, and other sensations. Many researchers have used VR devices to generate various stimuli, and have utilized them to perform experiments or to provide treatment. In this study, the participants performed mental tasks using a VR device while physiological signals were measured: a photoplethysmogram (PPG), electrodermal activity (EDA), and skin temperature (SKT). In general, stress is an important factor that can influence the autonomic nervous system (ANS). Heart-rate variability (HRV) is known to be related to ANS activity, so we used an HRV derived from the PPG peak interval. In addition, the peak characteristics of the skin conductance (SC) from EDA and SKT variation can also reflect ANS activity; we utilized them as well. Then, we applied a kernel-based extreme-learning machine (K-ELM) to correctly classify the stress levels induced by the VR task to reflect five different levels of stress situations: baseline, mild stress, moderate stress, severe stress, and recovery. Twelve healthy subjects voluntarily participated in the study. Three physiological signals were measured in stress environment generated by VR device. As a result, the average classification accuracy was over 95% using K-ELM and the integrated feature (IT = HRV + SC + SKT). In addition, the proposed algorithm can embed a microcontroller chip since K-ELM algorithm have very short computation time. Therefore, a compact wearable device classifying stress levels using physiological signals can be developed.

  1. Stress

    Science.gov (United States)

    ... can be life-saving. But chronic stress can cause both physical and mental harm. There are at least three different types of stress: Routine stress related to the pressures of work, family, and other daily responsibilities Stress brought about ...

  2. Conflicts and politics in the Tana Delta, Kenya : an analysis of the 2012-2013 clashes and the general and presidential elections 2013

    NARCIS (Netherlands)

    Kirchner, K.

    2013-01-01

    This study connects the topic of natural resource conflicts with political elements, especially elections and looks into clashes between a pastoralist (Orma) and an agricultural (Pokomo) community in Kenya. It analyses the clashes in the Tana delta which escalated in August 2012 from a political

  3. [Person-organization fit as a mediator of relationship between work environment and stress among social workers].

    Science.gov (United States)

    Waszkowska, Małlgorzata; Andysz, Aleksandra; Merecz, Dorota

    2014-01-01

    Occupational stress of social workers is associated with various psychosocial hazards in the work environment. Some of them affect person-organization fit (P-O fit). The aim of the study was to verify a hypothesis on the mediating role of P-O fit in the relationship between work environment and stress. The research was based on a sample of 500 social workers directly involved in social work. The data were obtained using the Person-Organization Fit Questionnaire by Czarnota-Bojarska, the Work Environment Questionnaire developed by the Department of Occupational Psychology, Nofer Institute of Occupational Medicine, Łódź, and the Perceived Stress Scale (PSS-10) by Cohen et al. As revealed by the regression analysis of the 4 analyzed work environment factors, only organizational politics was significantly related with perceived stress. Complementary and supplementary dimensions of P-O fit and identification with organization were the mediators of the relationship between organizational policies and stress, but only complementary fit proved to be a total mediator. The results of the study suggest that person-organization fit, especially its complementary aspect, is an essential determinant of accomplishing the core functions of social work and good practice among social workers.

  4. Person-organization fit as a mediator of relationship between work environment and stress among social workers

    Directory of Open Access Journals (Sweden)

    Małgorzata Waszkowska

    2014-04-01

    Full Text Available Background: Occupational stress of social workers is associated with various psychosocial hazards in the work environment. Some of them affect person-organization fit (P-O fit. The aim of the study was to verify a hypothesis on the mediating role of P-O fit in the relationship between work environment and stress. Material and Methods: The research was based on a sample of 500 social workers directly involved in social work. The data were obtained using the Person-Organization Fit Questionnaire by Czarnota-Bojarska, the Work Environment Questionnaire developed by the Department of Occupational Psychology, Nofer Institute of Occupational Medicine, Łódź, and the Perceived Stress Scale (PSS-10 by Cohen et al. Results: As revealed by the regression analysis of the 4 analyzed work environment factors, only organizational politics was significantly related with perceived stress. Complementary and supplementary dimensions of P-O fit and identification with organization were the mediators of the relationship between organizational policies and stress, but only complementary fit proved to be a total mediator. Conclusions: The results of the study suggest that person-organization fit, especially its complementary aspect, is an essential determinant of accomplishing the core functions of social work and good practice among social workers. Med Pr 2014;65(2:219–228

  5. Being Edward James Olmos: Culture Clash and the Portrayal of Chicano Masculinity

    Directory of Open Access Journals (Sweden)

    Nohemy Solózano-Thompson

    2008-06-01

    Full Text Available This paper analyzes how Culture Clash problematizes Chicano masculinity through the manipulation of two iconic Chicano characters originally popularized by two films starring Edward James Olmos - the pachuco from Luis Valdez’s Zoot Suit (1981 and the portrayal of real-life math teacher Jaime Escalante in Stand and Deliver (1988. In “Stand and Deliver Pizza” (from A Bowl of Beings, 1992, Culture Clash tries to introduce new Chicano characters that can be read as masculine, and who at the same time, display alternative behaviors and characteristics, including homosexual desire. The three characters in “Stand and Deliver Pizza” represent stock icons of Chicano masculinity. In the skit, these icons are forced to interact with each other and through this process become more complex and accessible representatives of Chicano masculinity. They are able to communicate with each other to create something tangible. The pizza of course is a comedic metaphor for contemporary American society—the new melting pot.

  6. Modelling Titanic and Clash of Clans Games: Theoretical Definition and Application in Current Social Systems

    Directory of Open Access Journals (Sweden)

    Jan Mertl

    2017-12-01

    Full Text Available This article develops research into Titanic games and the associated concepts anchored in game theory. It defines the conditions under which a Titanic game transitions into a Clash of Clans game and discusses the degree of punishment and its consequences for the nature of the game and the positions of the individual players. The game is analysed in significant detail, clearly showing what happens when diff erent strategies are chosen. At the same time, the article also looks at the context of social policy and social systems, where the application of the analysed games is very beneficial, and points to the example of the situation in the Czech health insurance system between 2000 and 2010. The identification of the proposed concepts and their possible existence in socio-economic reality enables us to substantially better see what games are being played or can be played, and as such to gain an understanding of what is happening. The article shows the diff erences between Titanic and Clash of Clans games and their possible application in current social systems.

  7. The critical role of personality and organizational factors as determinants of reactions to restricted and stressful environments. [undersea habitats

    Science.gov (United States)

    Helmreich, Robert L.

    1987-01-01

    Research into the impact of personality factors on groups in various settings is reviewed as an introduction to a brief discussion of personality and group behavior research needs relevant to the space program. Significant findings of some earlier research are summarized, and methodological problems are touched on. The study of intergroup and intragroup conflict in a stressful environment, as exemplified particularly by undersea habitats, is seen as being of consequence for long-term space missions. It is concluded that adequate research can only be conducted as an adjunct to data collection from operational stressful environments, and not from laboratory experiments.

  8. Stress and stressors in the clinical environment: a comparative study of fourth-year student nurses and newly qualified general nurses in Ireland.

    LENUS (Irish Health Repository)

    Suresh, Patricia

    2013-03-01

    To measure and compare the perceived levels of job-related stress and stressors of newly qualified nurses and fourth-year student nurses in the clinical environment and to explore the participants\\' views on stress and stressors.

  9. Hydrogen Peroxide Cycling in Acidic Geothermal Environments and Potential Implications for Oxidative Stress

    Science.gov (United States)

    Mesle, M.; Beam, J.; Jay, Z.; Bodle, B.; Bogenschutz, E.; Inskeep, W.

    2014-12-01

    Hydrogen peroxide (H2O2) may be produced in natural waters via photochemical reactions between dissolved oxygen, organic carbon and light. Other reactive oxygen species (ROS) such as superoxide and hydroxyl radicals are potentially formed in environments with high concentrations of ferrous iron (Fe(II), ~10-100 μM) by reaction between H2O2 and Fe(II) (i.e., Fenton chemistry). Thermophilic archaea and bacteria inhabiting acidic iron-oxide mats have defense mechanisms against both extracellular and intracellular peroxide, such as peroxiredoxins (which can degrade H2O2) and against other ROS, such as superoxide dismutases. Biological cycling of H2O2 is not well understood in geothermal ecosystems, and geochemical measurements combined with molecular investigations will contribute to our understanding of microbial response to oxidative stress. We measured H2O2 and other dissolved compounds (Fe(II), Fe(III), H2S, O2), as well as photon flux, pH and temperature, over time in surface geothermal waters of several acidic springs in Norris Geyser Basin, Yellowstone National Park, WY (Beowulf Spring and One Hundred Spring Plain). Iron-oxide mats were sampled in Beowulf Spring for on-going analysis of metatranscriptomes and RT-qPCR assays of specific stress-response gene transcription (e.g., superoxide dismutases, peroxiredoxins, thioredoxins, and peroxidases). In situ analyses show that H2O2 concentrations are lowest in the source waters of sulfidic systems (ca. 1 μM), and increase by two-fold in oxygenated waters corresponding to Fe(III)-oxide mat formation (ca. 2 - 3 μM). Channel transects confirm increases in H2O2 as a function of oxygenation (distance). The temporal dynamics of H2O2, O2, Fe(II), and H2S in Beowulf geothermal waters were also measured during a diel cycle, and increases in H2O2 were observed during peak photon flux. These results suggest that photochemical reactions may contribute to changes in H2O2. We hypothesize that increases in H2O2 and O2

  10. Estimated work ability in warm outdoor environments depends on the chosen heat stress assessment metric.

    Science.gov (United States)

    Bröde, Peter; Fiala, Dusan; Lemke, Bruno; Kjellstrom, Tord

    2018-03-01

    With a view to occupational effects of climate change, we performed a simulation study on the influence of different heat stress assessment metrics on estimated workability (WA) of labour in warm outdoor environments. Whole-day shifts with varying workloads were simulated using as input meteorological records for the hottest month from four cities with prevailing hot (Dallas, New Delhi) or warm-humid conditions (Managua, Osaka), respectively. In addition, we considered the effects of adaptive strategies like shielding against solar radiation and different work-rest schedules assuming an acclimated person wearing light work clothes (0.6 clo). We assessed WA according to Wet Bulb Globe Temperature (WBGT) by means of an empirical relation of worker performance from field studies (Hothaps), and as allowed work hours using safety threshold limits proposed by the corresponding standards. Using the physiological models Predicted Heat Strain (PHS) and Universal Thermal Climate Index (UTCI)-Fiala, we calculated WA as the percentage of working hours with body core temperature and cumulated sweat loss below standard limits (38 °C and 7.5% of body weight, respectively) recommended by ISO 7933 and below conservative (38 °C; 3%) and liberal (38.2 °C; 7.5%) limits in comparison. ANOVA results showed that the different metrics, workload, time of day and climate type determined the largest part of WA variance. WBGT-based metrics were highly correlated and indicated slightly more constrained WA for moderate workload, but were less restrictive with high workload and for afternoon work hours compared to PHS and UTCI-Fiala. Though PHS showed unrealistic dynamic responses to rest from work compared to UTCI-Fiala, differences in WA assessed by the physiological models largely depended on the applied limit criteria. In conclusion, our study showed that the choice of the heat stress assessment metric impacts notably on the estimated WA. Whereas PHS and UTCI-Fiala can account for

  11. Estimated work ability in warm outdoor environments depends on the chosen heat stress assessment metric

    Science.gov (United States)

    Bröde, Peter; Fiala, Dusan; Lemke, Bruno; Kjellstrom, Tord

    2018-03-01

    With a view to occupational effects of climate change, we performed a simulation study on the influence of different heat stress assessment metrics on estimated workability (WA) of labour in warm outdoor environments. Whole-day shifts with varying workloads were simulated using as input meteorological records for the hottest month from four cities with prevailing hot (Dallas, New Delhi) or warm-humid conditions (Managua, Osaka), respectively. In addition, we considered the effects of adaptive strategies like shielding against solar radiation and different work-rest schedules assuming an acclimated person wearing light work clothes (0.6 clo). We assessed WA according to Wet Bulb Globe Temperature (WBGT) by means of an empirical relation of worker performance from field studies (Hothaps), and as allowed work hours using safety threshold limits proposed by the corresponding standards. Using the physiological models Predicted Heat Strain (PHS) and Universal Thermal Climate Index (UTCI)-Fiala, we calculated WA as the percentage of working hours with body core temperature and cumulated sweat loss below standard limits (38 °C and 7.5% of body weight, respectively) recommended by ISO 7933 and below conservative (38 °C; 3%) and liberal (38.2 °C; 7.5%) limits in comparison. ANOVA results showed that the different metrics, workload, time of day and climate type determined the largest part of WA variance. WBGT-based metrics were highly correlated and indicated slightly more constrained WA for moderate workload, but were less restrictive with high workload and for afternoon work hours compared to PHS and UTCI-Fiala. Though PHS showed unrealistic dynamic responses to rest from work compared to UTCI-Fiala, differences in WA assessed by the physiological models largely depended on the applied limit criteria. In conclusion, our study showed that the choice of the heat stress assessment metric impacts notably on the estimated WA. Whereas PHS and UTCI-Fiala can account for

  12. Environment

    DEFF Research Database (Denmark)

    Valentini, Chiara

    2017-01-01

    The term environment refers to the internal and external context in which organizations operate. For some scholars, environment is defined as an arrangement of political, economic, social and cultural factors existing in a given context that have an impact on organizational processes and structures....... For others, environment is a generic term describing a large variety of stakeholders and how these interact and act upon organizations. Organizations and their environment are mutually interdependent and organizational communications are highly affected by the environment. This entry examines the origin...... and development of organization-environment interdependence, the nature of the concept of environment and its relevance for communication scholarships and activities....

  13. Saccharomyces interspecies hybrids as model organisms for studying yeast adaptation to stressful environments.

    Science.gov (United States)

    Lopandic, Ksenija

    2018-01-01

    The strong development of molecular biology techniques and next-generation sequencing technologies in the last two decades has significantly improved our understanding of the evolutionary history of Saccharomyces yeasts. It has been shown that many strains isolated from man-made environments are not pure genetic lines, but contain genetic materials from different species that substantially increase their genome complexity. A number of strains have been described as interspecies hybrids, implying different yeast species that under specific circumstances exchange and recombine their genomes. Such fusing usually results in a wide variety of alterations at the genetic and chromosomal levels. The observed changes have suggested a high genome plasticity and a significant role of interspecies hybridization in the adaptation of yeasts to environmental stresses and industrial processes. There is a high probability that harsh wine and beer fermentation environments, from which the majority of interspecies hybrids have been isolated so far, influence their selection and stabilization as well as their genomic and phenotypic heterogeneity. The lessons we have learned about geno- and phenotype plasticity and the diversity of natural and commercial yeast hybrids have already had a strong impact on the development of artificial hybrids that can be successfully used in the fermentation-based food and beverage industry. The creation of artificial hybrids through the crossing of strains with desired attributes is a possibility to obtain a vast variety of new, but not genetically modified yeasts with a range of improved and beneficial traits. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  14. Aerobic lineage of the oxidative stress response protein rubrerythrin emerged in an ancient microaerobic, (hyperthermophilic environment

    Directory of Open Access Journals (Sweden)

    Juan Pablo Cardenas

    2016-11-01

    Full Text Available Rubrerythrins (RBRs are non-heme di-iron proteins belonging to the ferritin-like superfamily (FLSF. They are involved in oxidative stress defense as peroxide scavengers in a wide range of organisms. The vast majority of RBRs, including classical forms of this protein, contain a C-terminal rubredoxin-like domain involved in electron transport that is used during catalysis in anaerobic conditions. Rubredoxin is an ancient and large protein family of short length (<100 residues that contains a Fe-S center involved in electron transfer. However, functional forms of the enzyme lacking the rubredoxin-like domain have been reported (e.g., sulerythrin and ferriperoxin. In this study, phylogenomic evidence is presented that suggests that a complete lineage of rubrerythrins, lacking the rubredoxin-like domain, arose in an ancient microaerobic and (hyperthermophilic environments in the ancestors of the Archaea Thermoproteales and Sulfolobales. This lineage (termed the aerobic-type lineage subsequently evolved to become adapted to environments with progressively lower temperatures and higher oxygen concentrations via the acquisition of two co-localized genes, termed DUF3501 and RFO, encoding a conserved protein of unknown function and a predicted Fe-S oxidoreductase respectively. Proposed Horizontal Gene Transfer (HGT events from these archaeal ancestors to Bacteria expanded the opportunities for further evolution of this RBR including adaption to lower temperatures. The second lineage (termed the cyanobacterial lineage is proposed to have evolved in cyanobacterial ancestors, maybe in direct response to the production of oxygen via oxygenic photosynthesis during the Great Oxygen Event (GOE. It is hypothesized that both lineages of RBR emerged in a largely anaerobic world with whiffs of oxygen and that their subsequent independent evolutionary trajectories allowed microorganisms to transition from this anaerobic world to an aerobic one.

  15. Remote Sensing Plant Stress Using Combined Fluorescence and Reflectance Measurements for Early Detection of Defoliants within the Battlefield Environment

    Science.gov (United States)

    2012-10-02

    Sensing Imagery, Instituto de Agricultura Sostenible, Córdoba, Spain Young, D.R. 2007. Leaf to landscape in a barrier island environment.” Workshop...on Vegetation Stress Detection with Remote Sensing Imagery, Instituto de Agricultura Sostenible, Córdoba, Spain Young, D.R. and J.C. Naumann. 2007

  16. Stress responsiveness and anxiety-like behavior: The early social environment differentially shapes stability over time in a small rodent.

    Science.gov (United States)

    Sangenstedt, Susanne; Jaljuli, Iman; Sachser, Norbert; Kaiser, Sylvia

    2017-04-01

    The early social environment can profoundly affect behavioral and physiological phenotypes. We investigated how male wild cavy offspring, whose mothers had either lived in a stable (SE) or an unstable social environment (UE) during pregnancy and lactation, differed in their anxiety-like behavior and stress responsiveness. At two different time points in life, we tested the offspring's anxiety-like behavior in a dark-light test and their endocrine reaction to challenge in a cortisol reactivity test. Furthermore, we analyzed whether individual traits remained stable over time. There was no effect of the early social environment on anxiety-like behavior and stress responsiveness. However, at an individual level, anxiety-like behavior was stable over time in UE- but not in SE-sons. Stress responsiveness, in turn, was rather inconsistent in UE-sons and temporally stable in SE-sons. Conclusively, we showed for the first time that the early social environment differentially shapes the stability of behavioral and endocrine traits. At first glance, these results may be surprising, but they can be explained by the different functions anxiety-like behavior and stress responsiveness have. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. The Social Construction of the Dutch Air Quality Clash : How Road Expansions Bit the Dust Against Particulate Matter

    NARCIS (Netherlands)

    N.T. Arnoldussen (Tobias)

    2016-01-01

    markdownabstractFrom a small policy issue in the 1990s, air quality became a hotly debated public problem in Dutch law and politics in 2004. During the political and legal clash over air quality in the years 2004 - 2010, Dutch infrastructure development and road expansion grinded to all but a halt

  18. Early Triassic wrinkle structures on land: stressed environments and oases for life

    Science.gov (United States)

    Chu, Daoliang; Tong, Jinnan; Song, Haijun; Benton, Michael J.; Bottjer, David J.; Song, Huyue; Tian, Li

    2015-06-01

    Wrinkle structures in rocks younger than the Permian-Triassic (P-Tr) extinction have been reported repeatedly in marine strata, but rarely mentioned in rocks recording land. Here, three newly studied terrestrial P-Tr boundary rock succession in North China have yielded diverse wrinkle structures. All of these wrinkles are preserved in barely bioturbated shore-shallow lacustrine siliciclastic deposits of the Liujiagou Formation. Conversely, both the lacustrine siliciclastic deposits of the underlying Sunjiagou Formation and the overlying Heshanggou Formation show rich bioturbation, but no wrinkle structures or other microbial-related structures. The occurrence of terrestrial wrinkle structures in the studied sections reflects abnormal hydrochemical and physical environments, presumably associated with the extinction of terrestrial organisms. Only very rare trace fossils occurred in the aftermath of the P-Tr extinction, but most of them were preserved together with the microbial mats. This suggests that microbial mats acted as potential oases for the surviving aquatic animals, as a source of food and oxygen. The new finds suggests that extreme environmental stresses were prevalent both in the sea and on land through most of the Early Triassic.

  19. Occupational Stress Management and Burnout Interventions in Nursing and Their Implications for Healthy Work Environments: A Literature Review.

    Science.gov (United States)

    Nowrouzi, Behdin; Lightfoot, Nancy; Larivière, Michael; Carter, Lorraine; Rukholm, Ellen; Schinke, Robert; Belanger-Gardner, Diane

    2015-07-01

    This article reports on a literature review of workplace interventions (i.e., creating healthy work environments and improving nurses' quality of work life [QWL]) aimed at managing occupational stress and burnout for nurses. A literature search was conducted using the keywords nursing, nurses, stress, distress, stress management, burnout, and intervention. All the intervention studies included in this review reported on workplace intervention strategies, mainly individual stress management and burnout interventions. Recommendations are provided to improve nurses' QWL in health care organizations through workplace health promotion programs so that nurses can be recruited and retained in rural and northern regions of Ontario. These regions have unique human resources needs due to the shortage of nurses working in primary care. © 2015 The Author(s).

  20. Use of the RoboFlag synthetic task environment to investigate workload and stress responses in UAV operation.

    Science.gov (United States)

    Guznov, Svyatoslav; Matthews, Gerald; Funke, Gregory; Dukes, Allen

    2011-09-01

    Use of unmanned aerial vehicles (UAVs) is an increasingly important element of military missions. However, controlling UAVs may impose high stress and workload on the operator. This study evaluated the use of the RoboFlag simulated environment as a means for profiling multiple dimensions of stress and workload response to a task requiring control of multiple vehicles (robots). It tested the effects of two workload manipulations, environmental uncertainty (i.e., UAV's visual view area) and maneuverability, in 64 participants. The findings confirmed that the task produced substantial workload and elevated distress. Dissociations between the stress and performance effects of the manipulations confirmed the utility of a multivariate approach to assessment. Contrary to expectations, distress and some aspects of workload were highest in the low-uncertainty condition, suggesting that overload of information may be an issue for UAV interface designers. The strengths and limitations of RoboFlag as a methodology for investigating stress and workload responses are discussed.

  1. Academics Job Satisfaction and Job Stress across Countries in the Changing Academic Environments

    Science.gov (United States)

    Shin, Jung Cheol; Jung, Jisun

    2014-01-01

    This study examined job satisfaction and job stress across 19 higher education systems. We classified the 19 countries according to their job satisfaction and job stress and applied regression analysis to test whether new public management has impacts on either or both job satisfaction and job stress. According to this study, strong market driven…

  2. Application of indirect stress measurement techniques (non strain gauge based technology) to quantify stress environments in mines

    CSIR Research Space (South Africa)

    Stacey, TR

    2002-03-01

    Full Text Available Reliable values of in situ stress are essential for the valid modelling of mine layouts. Available non-strain gauge methods are reviewed as potential practical techniques for South African mines. From this review it is concluded that the most...

  3. Stress-Preventive Management Competencies, Psychosocial Work Environments, and Affective Well-Being: A Multilevel, Multisource Investigation

    Science.gov (United States)

    Balducci, Cristian

    2018-01-01

    The Management Competencies for Preventing and Reducing Stress at Work framework represents one of the few tailored models of leadership for work stress prevention purposes, but it has never been empirically evaluated. The aim of this study was to investigate whether supervisors’ stress-preventive management competencies, as measured by the Stress Management Competencies Indicator Tool (SMCIT), are related to employees’ affective well-being through psychosocial work environmental factors. To this end, multilevel structural equation modelling (MSEM) was developed and tested, including data provided by both supervisors and employees. Supervisors (n = 84) self-assessed their stress-preventive management competencies (i.e., being respectful and responsible, managing and communicating existing and future work, reasoning and managing difficult situations, and managing the individual within the team) with a previously validated reduced version of the SMCIT. The supervised employees (n = 584) rated job content (e.g., job demands) and work context (e.g., role clarity) psychosocial factors and their job-related affective well-being. Supervisors’ job-related affective well-being was also included in the tested model. The results revealed that the stress-preventive competencies factor was related to employees’ affective well-being through the psychosocial work environment only when the latter was operationalized by means of contextual work factors. Supervisors’ affective well-being was related to their stress-preventive competencies, but it was not related to employees’ affective well-being. We discuss the implications of the results obtained. PMID:29495360

  4. Stress-Preventive Management Competencies, Psychosocial Work Environments, and Affective Well-Being: A Multilevel, Multisource Investigation.

    Science.gov (United States)

    Toderi, Stefano; Balducci, Cristian

    2018-02-26

    The Management Competencies for Preventing and Reducing Stress at Work framework represents one of the few tailored models of leadership for work stress prevention purposes, but it has never been empirically evaluated. The aim of this study was to investigate whether supervisors' stress-preventive management competencies, as measured by the Stress Management Competencies Indicator Tool (SMCIT), are related to employees' affective well-being through psychosocial work environmental factors. To this end, multilevel structural equation modelling (MSEM) was developed and tested, including data provided by both supervisors and employees. Supervisors ( n = 84) self-assessed their stress-preventive management competencies (i.e., being respectful and responsible, managing and communicating existing and future work, reasoning and managing difficult situations, and managing the individual within the team) with a previously validated reduced version of the SMCIT. The supervised employees ( n = 584) rated job content (e.g., job demands) and work context (e.g., role clarity) psychosocial factors and their job-related affective well-being. Supervisors' job-related affective well-being was also included in the tested model. The results revealed that the stress-preventive competencies factor was related to employees' affective well-being through the psychosocial work environment only when the latter was operationalized by means of contextual work factors. Supervisors' affective well-being was related to their stress-preventive competencies, but it was not related to employees' affective well-being. We discuss the implications of the results obtained.

  5. The catholic thought in the context of political clashes of 1930s in Brazil

    Directory of Open Access Journals (Sweden)

    Aline Christine de Souza

    2017-11-01

    Full Text Available The production of this article results from studies realized in the scope of a research of scientific initiation which the object is the Catholic Thought in Brazil in the context of the clashes with the so-called “Pioneers of New Education” that preceded the elaboration of the Constitution of 1934. It is a bibliographic research that prioritized the study, on the one hand, of the fundamentals of Catholic Thought in ecclesiastic documents and, on the other hand, of its manifestation in Brazil through “A Ordem” magazine, its mainly public expression. It is concluded that the Catholic Thought constitute an important ideological ingredient in the context in question and develops in accord with the class struggle in Europe and the fractions of the dominant class in Brazil, expressing the resistance of the Catholic Church to the republican model of school and to the ideal, also republican, of State secularism.

  6. When ideal and real culture clash - trust, infidelity and condom use

    Directory of Open Access Journals (Sweden)

    L Ackermann

    2003-09-01

    Full Text Available With high rates of HIV transmission in South Africa, the correct and consistent use of condoms has become critically important. The findings reported in this article form part of a larger study that investigated the vulnerability of women to HIV infection. This article concentrates on one dimension of the study: how a clash between real and ideal culture negatively impacts upon condom use. This study, conducted in Bloemfontein, revealed that an ideal culture of trust, resulted in non condom use. On the other hand, this study also revealed that despite the emphasis on an ideal culture of trust, a real culture of infidelity exists. This places individuals at risk of contracting HIV, as condom use is guided by ideal rather than real culture.

  7. When ideal and real culture clash--trust, infidelity and condom use.

    Science.gov (United States)

    Ackermann, L; de Klerk, G W

    2003-08-01

    With high rates of HIV transmission in South Africa, the correct and consistent use of condoms has become critically important. The findings reported in this article form part of a larger study that investigated the vulnerability of women to HIV infection. This article concentrates on one dimension of the study: how a clash between real and ideal culture negatively impacts upon condom use. This study, conducted in Bloemfontein, revealed that an ideal culture of trust, resulted in non condom use. On the other hand, this study also revealed that despite the emphasis on an ideal culture of trust, a real culture of infidelity exists. This places individuals at risk of contracting HIV, as condom use is guided by ideal rather than real culture.

  8. Clashing and Emerging Genres: The interplay of knowledge forms in educational gaming

    Directory of Open Access Journals (Sweden)

    Thorkhild Hanghøj

    2011-09-01

    Full Text Available Based upon a series of design interventions with the educational computer game series Global Conflicts at various secondary schools, this article explores how educational gaming can be understood as a complex interplay between four knowledge forms – i.e. students’ everyday knowledge (non-specialised knowledge, the institutionalised knowledge forms of schooling, teachers’ subject-specific knowledge (specialised knowledge forms, and game-specific knowledge forms such as professional journalism, which is one of the inspirations for the game scenario. Depending on how the GC series was enacted by different teachers and students, these knowledge forms were brought into play rather differently. More specifically, several students experienced genre clashes in relation to their expectations of what it means to play a computer game, whereas other students experienced emerging genres – e.g. when one student was able to transform the game experience into a journalistic article that challenged her classmates’ understanding of journalistic writing.

  9. A clash of civilizations? Examining liberal-democratic values in Turkey and the European Union.

    Science.gov (United States)

    Dixon, Jeffrey C

    2008-12-01

    Turkey's proposed entry into the European Union (EU) has been undermined by Europeans' perceptions of Turkish-European cultural differences, particularly regarding the liberal-democratic values that the EU promotes (democracy, rule of law, and respect for and appreciation of minority/human rights). Yet, cross-national research on values has not focused on Turkey, the EU, and these liberal-democratic values, leaving assumptions of cultural differences and their explanations untested. Through analyses of World and European Values Survey data (1999-2002), this article asks whether people in Turkey have the same values regarding democracy, rule of law (versus religious and authoritarian rule), and minority/human rights as people in EU member and candidate states (as of 2000)? What factors explain these values? I find that people in Turkey support democracy to the same extent as people in EU member and candidate states, but people in Turkey are more supportive of religious and authoritarian rule and are less tolerant of minorities. Although the 'clash of civilizations' thesis expects liberal values to be ordered according to countries' religious traditions, with western Christian the most supportive and Islamic the least, only for tolerance of minorities values is this pattern found. Instead, economic development most consistently explains differences between Turkey and EU member and candidate states in support for these values. I conclude with calls for theoretical refinement, particularly of the clash of civilizations thesis, along with suggestions for future research to examine more Muslim and Orthodox countries; I discuss the debate over Turkey's EU entry.

  10. Adaptive value of phenological traits in stressful environments: predictions based on seed production and laboratory natural selection.

    Directory of Open Access Journals (Sweden)

    Benjamin Brachi

    Full Text Available Phenological traits often show variation within and among natural populations of annual plants. Nevertheless, the adaptive value of post-anthesis traits is seldom tested. In this study, we estimated the adaptive values of pre- and post-anthesis traits in two stressful environments (water stress and interspecific competition, using the selfing annual species Arabidopsis thaliana. By estimating seed production and by performing laboratory natural selection (LNS, we assessed the strength and nature (directional, disruptive and stabilizing of selection acting on phenological traits in A. thaliana under the two tested stress conditions, each with four intensities. Both the type of stress and its intensity affected the strength and nature of selection, as did genetic constraints among phenological traits. Under water stress, both experimental approaches demonstrated directional selection for a shorter life cycle, although bolting time imposes a genetic constraint on the length of the interval between bolting and anthesis. Under interspecific competition, results from the two experimental approaches showed discrepancies. Estimation of seed production predicted directional selection toward early pre-anthesis traits and long post-anthesis periods. In contrast, the LNS approach suggested neutrality for all phenological traits. This study opens questions on adaptation in complex natural environment where many selective pressures act simultaneously.

  11. Two Hymenophyllaceae species from contrasting natural environments exhibit a homoiochlorophyllous strategy in response to desiccation stress.

    Science.gov (United States)

    Flores-Bavestrello, Alejandra; Król, Marianna; Ivanov, Alexander G; Hüner, Norman P A; García-Plazaola, José Ignacio; Corcuera, Luis J; Bravo, León A

    2016-02-01

    Hymenophyllaceae is a desiccation tolerant family of Pteridophytes which are poikilohydric epiphytes. Their fronds are composed by a single layer of cells and lack true mesophyll cells and stomata. Although they are associated with humid and shady environments, their vertical distribution varies along the trunk of the host plant with some species inhabiting the drier sides with a higher irradiance. The aim of this work was to compare the structure and function of the photosynthetic apparatus during desiccation and rehydration in two species, Hymenophyllum dentatum and Hymenoglossum cruentum, isolated from a contrasting vertical distribution along the trunk of their hosts. Both species were subjected to desiccation and rehydration kinetics to analyze frond phenotypic plasticity, as well as the structure, composition and function of the photosynthetic apparatus. Minimal differences in photosynthetic pigments were observed upon dehydration. Measurements of ϕPSII (effective quantum yield of PSII), ϕNPQ (quantum yield of the regulated energy dissipation of PSII), ϕNO (quantum yield of non-regulated energy dissipation of PSII), and TL (thermoluminescence) indicate that both species convert a functional photochemical apparatus into a structure which exhibits maximum quenching capacity in the dehydrated state with minimal changes in photosynthetic pigments and polypeptide compositions. This dehydration-induced conversion in the photosynthetic apparatus is completely reversible upon rehydration. We conclude that H. dentatum and H. cruentum are homoiochlorophyllous with respect to desiccation stress and exhibited no correlation between inherent desiccation tolerance and the vertical distribution along the host tree trunk. Copyright © 2015 Elsevier GmbH. All rights reserved.

  12. Viability and Stress Response of Putative Probiotic Lactobacillus plantarum Strains in Honey Environment.

    Science.gov (United States)

    Landry, Bemmo Kamdem Ulrich; François, Zambou Ngoufack; Wang, Rui-Yan; Taicheng, Zhu; Li, Yin

    2017-12-01

    Due to problem of preservation of dairy products which serve as a matrix for probiotics, it is challenging to use these probiotics as food supplements in many developing countries. To determine the suitability of the Lactobacillus strains for exploitation as probiotics in honey, we investigated the effect of their storage on the viability, functionality, and the mechanism associated with their protective effect. Three isolates obtained from our laboratory collection were identified through amplification of the 16S rRNA gene. The viability of the strains in honey at different storage conditions was studied. Three genes (hdc, gtf, and clpL) responsible for the resistance of bacteria in acidic environments were screened. SDS-PAGE analysis of total protein was performed to observe protein profile changes of the strains after exposure to honey. All the three isolates, namely, GGU, GLA51, and GLP56, were identified as Lactobacillus plantarum strains. After 28 days of storage in honey at 4 °C, viable cell concentrations of the three strains were higher than 2.04 × 10 6  CFU/ml. During the same period at room temperature, only the Lactobacillus plantarum GLP56 strain remained viable with a cell concentration of 1.86 × 10 4  CFU/ml. The clpL gene coding for ATPase was detected in all the three strains. The protein of molecular weight ~ 50 kDa was absent in the protein profile of Lactobacillus plantarum GGU after 60 days of storage in honey at 4 °C. The Lactobacillus plantarum GLP56, Lactobacillus plantarum GLA51, and Lactobacillus plantarum GGU strains exposed to honey can withstand acidic environmental stress but their viability declines over time.

  13. STRIVE: Stress Resilience In Virtual Environments: a pre-deployment VR system for training emotional coping skills and assessing chronic and acute stress responses.

    Science.gov (United States)

    Rizzo, Albert; Buckwalter, J Galen; John, Bruce; Newman, Brad; Parsons, Thomas; Kenny, Patrick; Williams, Josh

    2012-01-01

    The incidence of posttraumatic stress disorder (PTSD) in returning OEF/OIF military personnel is creating a significant healthcare challenge. This has served to motivate research on how to better develop and disseminate evidence-based treatments for PTSD. One emerging form of treatment for combat-related PTSD that has shown promise involves the delivery of exposure therapy using immersive Virtual Reality (VR). Initial outcomes from open clinical trials have been positive and fully randomized controlled trials are currently in progress to further validate this approach. Based on our research group's initial positive outcomes using VR to emotionally engage and successfully treat persons undergoing exposure therapy for PTSD, we have begun development in a similar VR-based approach to deliver stress resilience training with military service members prior to their initial deployment. The Stress Resilience In Virtual Environments (STRIVE) project aims to create a set of combat simulations (derived from our existing Virtual Iraq/Afghanistan exposure therapy system) that are part of a multi-episode narrative experience. Users can be immersed within challenging combat contexts and interact with virtual characters within these episodes as part of an experiential learning approach for training a range of psychoeducational and cognitive-behavioral emotional coping strategies believed to enhance stress resilience. The STRIVE project aims to present this approach to service members prior to deployment as part of a program designed to better prepare military personnel for the types of emotional challenges that are inherent in the combat environment. During these virtual training experiences users are monitored physiologically as part of a larger investigation into the biomarkers of the stress response. One such construct, Allostatic Load, is being directly investigated via physiological and neuro-hormonal analysis from specimen collections taken immediately before and after

  14. The effect of social environment on markers of vascular oxidative stress and inflammation in the Watanabe heritable hyperlipidemic rabbit.

    Science.gov (United States)

    Nation, Daniel A; Gonzales, Julie A; Mendez, Armando J; Zaias, Julia; Szeto, Angela; Brooks, Larry G; Paredes, Jamespaul; D'Angola, Alyssa; Schneiderman, Neil; McCabe, Philip M

    2008-04-01

    Previous research demonstrated that social environment can influence progression of atherosclerosis in the Watanabe Heritable Hyperlipidemic (WHHL) rabbit. This study examined the effect of social environment on markers of oxidative stress and inflammation to clarify the physiological pathways potentially responsible for the influence of social environment on disease. WHHL rabbits were assigned to 1 of 3 social groups: an unstable group, in which unfamiliar rabbits were paired daily, with the pairing switched each week; a stable group, in which littermates were paired daily; and an individually-caged group. The stable group engaged in more affiliative social behavior than the unstable group. The unstable group showed more agonistic behavior compared with the stable group and higher C-reactive protein levels than the individually caged group. The individually caged group was behaviorally sedentary, had higher 24-hour urinary catecholamine levels than the other groups, and exhibited higher NAD(P)H-oxidase activity in the aortic arch relative to the stable group. The results suggest that social environment creates distinct behavioral contexts that can affect markers of inflammation and oxidative stress early in the development of atherosclerosis. Specifically, physical inactivity associated with individual caging affects indices of oxidative stress and inflammation. These pathophysiological markers may help to explain behaviorally related differences in the extent of atherosclerosis observed in prior studies.

  15. Can reactivity to stress and family environment explain memory and executive function performance in early and middle childhood?

    Science.gov (United States)

    Piccolo, Luciane da Rosa; Salles, Jerusa Fumagalli de; Falceto, Olga Garcia; Fernandes, Carmen Luiza; Grassi-Oliveira, Rodrigo

    2016-01-01

    According to the literature, children's overall reactivity to stress is associated with their socioeconomic status and family environment. In turn, it has been shown that reactivity to stress is associated with cognitive performance. However, few studies have systematically tested these three constructs together. To investigate the relationship between family environment, salivary cortisol measurements and children's memory and executive function performance. Salivary cortisol levels of 70 children aged 9 or 10 years were measured before and after performing tasks designed to assess memory and executive functions. Questionnaires on socioeconomic issues, family environment and maternal psychopathologies were administered to participants' families during the children's early childhood and again when they reached school age. Data were analyzed by calculating correlations between variables and conducting hierarchical regression. High cortisol levels were associated with poorer working memory and worse performance in tasks involving executive functions, and were also associated with high scores for maternal psychopathology (during early childhood and school age) and family dysfunction. Family environment variables and changes in cortisol levels explain around 20% of the variance in performance of cognitive tasks. Family functioning and maternal psychopathology in early and middle childhood and children's stress levels were associated with children's working memory and executive functioning.

  16. Stress corrosion cracking of Ni-Fe-Cr alloys in acid sulfate environments relevant to CANDU steam generators

    Energy Technology Data Exchange (ETDEWEB)

    Persaud, S.Y.; Carcea, A.G., E-mail: suraj.persaud@mail.utoronto.ca [Univ. of Toronto, Toronto, ON (Canada); Huang, J.; Korinek, A.; Botton, G.A. [McMaster Univ., Hamilton, ON (Canada); Newman, R.C. [Univ. of Toronto, Toronto, ON (Canada)

    2014-07-01

    Ni-Fe-Cr alloys used in nuclear plants have been found susceptible to stress corrosion cracking (SCC) in acid sulfate environments. Electrochemical measurements and SCC tests were done using Ni, Alloy 600, and Alloy 800 in acid sulfate solutions at 315 {sup o}C. Electrochemical measurements suggested that sulfate is a particularly aggressive anion in mixed chloride systems. Cracks with lengths in excess of 300 μm were present on stressed Alloy 800 samples after 60 hours. High resolution analytical electron microscopy was used to extract a crack tip from an Alloy 800 sample and draw final conclusions with respect to the mechanism of SCC. (author)

  17. Minority stress and college persistence attitudes among African American, Asian American, and Latino students: perception of university environment as a mediator.

    Science.gov (United States)

    Wei, Meifen; Ku, Tsun-Yao; Liao, Kelly Yu-Hsin

    2011-04-01

    We examined whether perception of university environment mediated the association between minority status stress and college persistence attitudes after controlling for perceived general stress. Participants were 160 Asian American, African American, and Latino students who attended a predominantly White university. Results of a path model analysis showed that university environment was a significant mediator for the association between minority status stress and college persistence attitudes. Additionally, minority status stress was distinct from perceived general stress. Finally, the results from a multiple-group comparison indicated that the magnitude of the mediation effect was invariant across Asian American, African American, and Latino college students, thus supporting the generalizability of the mediation model.

  18. Short-term exposure to enriched environment rescues chronic stress-induced impaired hippocampal synaptic plasticity, anxiety, and memory deficits.

    Science.gov (United States)

    Bhagya, Venkanna Rao; Srikumar, Bettadapura N; Veena, Jayagopalan; Shankaranarayana Rao, Byrathnahalli S

    2017-08-01

    Exposure to prolonged stress results in structural and functional alterations in the hippocampus including reduced long-term potentiation (LTP), neurogenesis, spatial learning and working memory impairments, and enhanced anxiety-like behavior. On the other hand, enriched environment (EE) has beneficial effects on hippocampal structure and function, such as improved memory, increased hippocampal neurogenesis, and progressive synaptic plasticity. It is unclear whether exposure to short-term EE for 10 days can overcome restraint stress-induced cognitive deficits and impaired hippocampal plasticity. Consequently, the present study explored the beneficial effects of short-term EE on chronic stress-induced impaired LTP, working memory, and anxiety-like behavior. Male Wistar rats were subjected to chronic restraint stress (6 hr/day) over a period of 21 days, and then they were exposed to EE (6 hr/day) for 10 days. Restraint stress reduced hippocampal CA1-LTP, increased anxiety-like symptoms in elevated plus maze, and impaired working memory in T-maze task. Remarkably, EE facilitated hippocampal LTP, improved working memory performance, and completely overcame the effect of chronic stress on anxiety behavior. In conclusion, exposure to EE can bring out positive effects on synaptic plasticity in the hippocampus and thereby elicit its beneficial effects on cognitive functions. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  19. Stress

    Science.gov (United States)

    ... taking care of an aging parent. With mental stress, the body pumps out hormones to no avail. Neither fighting ... with type 1 diabetes. This difference makes sense. Stress blocks the body from releasing insulin in people with type 2 ...

  20. Psychometric Properties of the Croatian Language Version of the Dental Environment Stress Questionnaire on Dental Medicine Students.

    Science.gov (United States)

    Laktić, Martina; Kuftinec, Krešimir; Čelebić, Asja; Kovačić, Ines; Alhajj, Mohamed Nasser; Kiršić, Sanja Peršić

    2017-09-01

    To develop the Croatian version of the 41-item Dental Environment Stress questionnaire (DES) for stress assessment of dental students in both, preclinical and clinical years of study and to test its psychometric properties in Croatian dental student population. The English version of the 41-Item DES questionnaire was first translated into the Croatian language. Subsequently, it was set on the google drive and filled out by a total of 202 students from the School of Dental Medicine, University of Zagreb and 30 additional students from other Faculties. Students also assessed their overall level of stress on the Likert scale (1=no stress, 5=highest level of stress). Internal consistency was tested on 202 dental students; test-retest reliability on 30 dental students who filled out the same questionnaire twice; convergent validity on 202 dental students; and divergent validity on 202 dental students and 30 students from faculties not belonging to the biomedicine group. Internal consistency showed high Cronbach alpha coefficient (0.9) and test-retest reliability showed no significant difference (P>0.05) within the period of 14 days when stress level had not changed (vacation). Convergent validity was confirmed by the significant association between the DES summary scores and the self- perceived level of stress (Spearman's rho=0.881; P <0.001). Divergent validity was confirmed by significantly lower DES summary scores in students not belonging to the Biomedicine group (t=7.5, P<0.001). Excellent psychometric properties of the Croatian version of the DES questionnaire enable its utilization for assessment of stress level in Croatian dental students.

  1. Psychometric Properties of the Croatian Language Version of the Dental Environment Stress Questionnaire on Dental Medicine Students

    Directory of Open Access Journals (Sweden)

    Martina Laktić

    2017-01-01

    Full Text Available Objective: To develop the Croatian version of the 41-item Dental Environment Stress questionnaire (DES for stress assessment of dental students in both, preclinical and clinical years of study and to test its psychometric properties in Croatian dental student population. Materials and Methods: The English version of the 41-Item DES questionnaire was first translated into the Croatian language. Subsequently, it was set on the google drive and filled out by a total of 202 students from the School of Dental Medicine, University of Zagreb and 30 additional students from other Faculties. Students also assessed their overall level of stress on the Likert scale (1=no stress, 5=highest level of stress. Internal consistency was tested on 202 dental students; test-retest reliability on 30 dental students who filled out the same questionnaire twice; convergent validity on 202 dental students; and divergent validity on 202 dental students and 30 students from faculties not belonging to the biomedicine group. Results: Internal consistency showed high Cronbach alpha coefficient (0.9 and test-retest reliability showed no significant difference (P>0.05 within the period of 14 days when stress level had not changed (vacation. Convergent validity was confirmed by the significant association between the DES summary scores and the self- perceived level of stress (Spearman’s rho=0.881; P<0.001. Divergent validity was confirmed by significantly lower DES summary scores in students not belonging to the Biomedicine group (t=7.5, P<0.001. Conclusion: Excellent psychometric properties of the Croatian version of the DES questionnaire enable its utilization for assessment of stress level in Croatian dental students.

  2. The Role of Perception in the Typology of Geminate Consonants: Effects of Manner of Articulation, Segmental Environment, Position, and Stress.

    Science.gov (United States)

    Dmitrieva, Olga

    2018-03-01

    The present study seeks to answer the question of whether consonant duration is perceived differently across consonants of different manners of articulation and in different contextual environments and whether such differences may be related to the typology of geminates. The results of the cross-linguistic identification experiment suggest higher perceptual acuity in labeling short and long consonants in sonorants than in obstruents. Duration categories were also more consistently and clearly labeled in the intervocalic than in the preconsonantal environment, in the word-initial than in the word-final position, and after stressed vowels than between unstressed vowels. These perceptual asymmetries are in line with some typological tendencies, such as the cross-linguistic preference for intervocalic and post-stress geminates, but contradict other proposed cross-linguistic patterns, such as the preference for obstruent geminates and the abundance of word-final geminates.

  3. Expanding the psychosocial work environment: workplace norms and work-family conflict as correlates of stress and health.

    Science.gov (United States)

    Hammer, Tove Helland; Saksvik, Per Øystein; Nytrø, Kjell; Torvatn, Hans; Bayazit, Mahmut

    2004-01-01

    This study examined the contributions of organizational level norms about work requirements and social relations, and work-family conflict, to job stress and subjective health symptoms, controlling for Karasek's job demand-control-support model of the psychosocial work environment, in a sample of 1,346 employees from 56 firms in the Norwegian food and beverage industry. Hierarchical linear modeling analyses showed that organizational norms governing work performance and social relations, and work-to-family and family-to-work conflict, explained significant amounts of variance for job stress. The cross-level interaction between work performance norms and work-to-family conflict was also significantly related to job stress. Work-to-family conflict was significantly related to health symptoms, but family-to-work conflict and organizational norms were not.

  4. 6th COSTAM/SFRR (ASEAN/Malaysia) International Workshop on Micronutrients, Oxidative Stress, and the Environment.

    Science.gov (United States)

    Nesaretnam, Kalanithi; Sies, Helmut

    2006-01-01

    The 6(th) COSTAM/SFRR (ASEAN/Malaysia) workshop, "Micronutrients, Oxidative Stress, and the Environment," was held from June 29 to July 2 at Holiday Inn Damai Beach Resort in Kuching, Sarawak. Two hundred twenty participants from 17 countries presented recent advances on natural antioxidants in the area of oxidative stress and molecular aspects of nutrition. Natural products and research are an important program in academic institutions and are experiencing unprecedented interest and growth by the scientific community and public health authorities. Progress is being driven by better understanding of the molecular mechanisms of the relation between oxidative stress and micronutrient action. The gathering of scientists from around the world was fruitful, and we hope that future work will be developed by the formal and informal interactions that took place in this beautiful tropical setting.

  5. Separating the Influence of Environment from Stress Relaxation Effects on Dwell Fatigue Crack Growth

    Science.gov (United States)

    Telesman, Jack; Gabb, Tim; Ghosn, Louis J.

    2016-01-01

    Seven different microstructural variations of LSHR were produced by controlling the cooling rate and the subsequent aging and thermal exposure heat treatments. Through cyclic fatigue crack growth testing performed both in air and vacuum, it was established that four out of the seven LSHR heat treatments evaluated, possessed similar intrinsic environmental resistance to cyclic crack growth. For these four heat treatments, it was further shown that the large differences in dwell crack growth behavior which still persisted, were related to their measured stress relaxation behavior. The apparent differences in their dwell crack growth resistance were attributed to the inability of the standard linear elastic fracture mechanics (LEFM) stress intensity parameter to account for visco-plastic behavior. Crack tip stress relaxation controls the magnitude of the remaining local tensile stresses which are directly related to the measured dwell crack growth rates. It was hypothesized that the environmentally weakened grain boundary crack tip regions fail during the dwells when their strength is exceeded by the remaining local crack tip tensile stresses. It was shown that the classical creep crack growth mechanisms such as grain boundary sliding did not contribute to crack growth, but the local visco-plastic behavior still plays a very significant role by determining the crack tip tensile stress field which controls the dwell crack growth behavior. To account for the influence of the visco-plastic behavior on the crack tip stress field, an empirical modification to the LEFM stress intensity parameter, Kmax, was developed by incorporating into the formulation the remaining stress level concept as measured by simple stress relaxation tests. The newly proposed parameter, Ksrf, did an excellent job in correlating the dwell crack growth rates for the four heat treatments which were shown to have similar intrinsic environmental cyclic fatigue crack growth resistance.

  6. The impact of match-play tennis in a hot environment on indirect markers of oxidative stress and antioxidant status

    Science.gov (United States)

    Knez, Wade L; Périard, JP

    2014-01-01

    Objectives The purpose of this study was to determine the impact of changes in oxidative stress and antioxidant status in response to playing tennis in HOT (∼36°C and 35% relative humidity (RH)) and COOL (∼22°C and 70% RH) conditions. Methods 10 male tennis players undertook two matches for an effective playing time (ie, ball in play) of 20 min, corresponding to ∼122 and ∼107 min of total play in HOT and COOL conditions, respectively. Core body temperature, body mass and indirect markers of oxidative stress (diacrons reactive oxygen metabolic test) and antioxidant status (biological antioxidant potential test) were assessed immediately prematch, midmatch and postmatch, and 24 and 48 h into recovery. Results Regardless of the condition, oxidative stress remained similar throughout play and into recovery. Likewise, match-play tennis in the COOL had no impact on antioxidant status. However, antioxidants status increased significantly in the HOT compared with COOL environment (pantioxidant status. These data suggest that the heat stress observed in the HOT environment may provide a necessary signal for the upregulation of antioxidant defence, dampening cellular damage. PMID:24668382

  7. Mitigating Stress and Supporting Health in Deprived Urban Communities: The Importance of Green Space and the Social Environment.

    Science.gov (United States)

    Ward Thompson, Catharine; Aspinall, Peter; Roe, Jenny; Robertson, Lynette; Miller, David

    2016-04-22

    Environment-health research has shown significant relationships between the quantity of green space in deprived urban neighbourhoods and people's stress levels. The focus of this paper is the nature of access to green space (i.e., its quantity or use) necessary before any health benefit is found. It draws on a cross-sectional survey of 406 adults in four communities of high urban deprivation in Scotland, United Kingdom. Self-reported measures of stress and general health were primary outcomes; physical activity and social wellbeing were also measured. A comprehensive, objective measure of green space quantity around each participant's home was also used, alongside self-report measures of use of local green space. Correlated Component Regression identified the optimal predictors for primary outcome variables in the different communities surveyed. Social isolation and place belonging were the strongest predictors of stress in three out of four communities sampled, and of poor general health in the fourth, least healthy, community. The amount of green space in the neighbourhood, and in particular access to a garden or allotment, were significant predictors of stress. Physical activity, frequency of visits to green space in winter months, and views from the home were predictors of general health. The findings have implications for public health and for planning of green infrastructure, gardens and public open space in urban environments.

  8. Gene-Environment Interaction Effects of Peer Deviance, Parental Knowledge and Stressful Life Events on Adolescent Alcohol Use.

    Science.gov (United States)

    Cooke, Megan E; Meyers, Jacquelyn L; Latvala, Antti; Korhonen, Tellervo; Rose, Richard J; Kaprio, Jaakko; Salvatore, Jessica E; Dick, Danielle M

    2015-10-01

    The purpose of this study was to address two methodological issues that have called into question whether previously reported gene-environment interaction (GxE) effects for adolescent alcohol use are 'real'. These issues are (1) the potential correlation between the environmental moderator and the outcome across twins and (2) non-linear transformations of the behavioral outcome. Three environments that have been previously studied (peer deviance, parental knowledge, and potentially stressful life events) were examined here. For each moderator (peer deviance, parental knowledge, and potentially stressful life events), a series of models was fit to both a raw and transformed measure of monthly adolescent alcohol use in a sample that included 825 dizygotic (DZ) and 803 monozygotic (MZ) twin pairs. The results showed that the moderating effect of peer deviance was robust to transformation, and that although the significance of moderating effects of parental knowledge and potentially stressful life events were dependent on the scale of the adolescent alcohol use outcome, the overall results were consistent across transformation. In addition, the findings did not vary across statistical models. The consistency of the peer deviance results and the shift of the parental knowledge and potentially stressful life events results between trending and significant, shed some light on why previous findings for certain moderators have been inconsistent and emphasize the importance of considering both methodological issues and previous findings when conducting and interpreting GxE analyses.

  9. Mitigating Stress and Supporting Health in Deprived Urban Communities: The Importance of Green Space and the Social Environment

    Directory of Open Access Journals (Sweden)

    Catharine Ward Thompson

    2016-04-01

    Full Text Available Environment-health research has shown significant relationships between the quantity of green space in deprived urban neighbourhoods and people’s stress levels. The focus of this paper is the nature of access to green space (i.e., its quantity or use necessary before any health benefit is found. It draws on a cross-sectional survey of 406 adults in four communities of high urban deprivation in Scotland, United Kingdom. Self-reported measures of stress and general health were primary outcomes; physical activity and social wellbeing were also measured. A comprehensive, objective measure of green space quantity around each participant’s home was also used, alongside self-report measures of use of local green space. Correlated Component Regression identified the optimal predictors for primary outcome variables in the different communities surveyed. Social isolation and place belonging were the strongest predictors of stress in three out of four communities sampled, and of poor general health in the fourth, least healthy, community. The amount of green space in the neighbourhood, and in particular access to a garden or allotment, were significant predictors of stress. Physical activity, frequency of visits to green space in winter months, and views from the home were predictors of general health. The findings have implications for public health and for planning of green infrastructure, gardens and public open space in urban environments.

  10. Mitigating Stress and Supporting Health in Deprived Urban Communities: The Importance of Green Space and the Social Environment

    Science.gov (United States)

    Ward Thompson, Catharine; Aspinall, Peter; Roe, Jenny; Robertson, Lynette; Miller, David

    2016-01-01

    Environment-health research has shown significant relationships between the quantity of green space in deprived urban neighbourhoods and people’s stress levels. The focus of this paper is the nature of access to green space (i.e., its quantity or use) necessary before any health benefit is found. It draws on a cross-sectional survey of 406 adults in four communities of high urban deprivation in Scotland, United Kingdom. Self-reported measures of stress and general health were primary outcomes; physical activity and social wellbeing were also measured. A comprehensive, objective measure of green space quantity around each participant’s home was also used, alongside self-report measures of use of local green space. Correlated Component Regression identified the optimal predictors for primary outcome variables in the different communities surveyed. Social isolation and place belonging were the strongest predictors of stress in three out of four communities sampled, and of poor general health in the fourth, least healthy, community. The amount of green space in the neighbourhood, and in particular access to a garden or allotment, were significant predictors of stress. Physical activity, frequency of visits to green space in winter months, and views from the home were predictors of general health. The findings have implications for public health and for planning of green infrastructure, gardens and public open space in urban environments. PMID:27110803

  11. BDNF Val66Met polymorphism, life stress and depression: A meta-analysis of gene-environment interaction.

    Science.gov (United States)

    Zhao, Mingzhe; Chen, Lu; Yang, Jiarun; Han, Dong; Fang, Deyu; Qiu, Xiaohui; Yang, Xiuxian; Qiao, Zhengxue; Ma, Jingsong; Wang, Lin; Jiang, Shixiang; Song, Xuejia; Zhou, Jiawei; Zhang, Jian; Chen, Mingqi; Qi, Dong; Yang, Yanjie; Pan, Hui

    2018-02-01

    Depression is thought to be multifactorial in etiology, including genetic and environmental components. While a number of gene-environment interaction studies have been carried out, meta-analyses are scarce. The present meta-analysis aimed to quantify evidence on the interaction between brain-derived neurotrophic factor (BDNF) Val66Met polymorphism and stress in depression. Included were 31 peer-reviewed with a pooled total of 21060 participants published before October 2016 and literature searches were conducted using PubMed, Wolters Kluwer, Web of Science, EBSCO, Elsevier Science Direct and Baidu Scholar databases. The results indicated that the Met allele of BDNF Val66Met polymorphism significantly moderated the relationship between stress and depression (Z=2.666, p = 0.003). The results of subgroup analysis concluded that stressful life events and childhood adversity separately interacted with the Met allele of BDNF Val66Met polymorphism in depression (Z = 2.552, p = 0.005; Z = 1.775, p = 0.03). The results could be affected by errors or bias in primary studies which had small sample sizes with relatively lower statistic power. We could not estimate how strong the interaction effect between gene and environment was. We found evidence that supported the hypothesis that BDNF Val66Met polymorphism moderated the relationship between stress and depression, despite the fact that many included individual studies did not show this effect. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Age Dependent Hypothalamic and Pituitary Responses to Novel Environment Stress or Lipopolysaccharide in Rats

    Directory of Open Access Journals (Sweden)

    Sandy Koenig

    2018-03-01

    Full Text Available Previously, we have shown that the transcription factor nuclear factor interleukin (NF-IL6 can be used as an activation marker for inflammatory lipopolysaccharide (LPS-induced and psychological novel environment stress (NES in the rat brain. Here, we aimed to investigate age dependent changes of hypothalamic and pituitary responses to NES (cage switch or LPS (100 μg/kg in 2 and 24 months old rats. Animals were sacrificed at specific time points, blood and brains withdrawn and analyzed using immunohistochemistry, RT-PCR and bioassays. In the old rats, telemetric recording revealed that NES-induced hyperthermia was enhanced and prolonged compared to the young group. Plasma IL-6 levels remained unchanged and hypothalamic IL-6 mRNA expression was increased in the old rats. Interestingly, this response was accompanied by a significant upregulation of corticotropin-releasing hormone mRNA expression only in young rats after NES and overall higher plasma corticosterone levels in all aged animals. Immunohistochemical analysis revealed a significant upregulation of NF-IL6-positive cells in the pituitary after NES or LPS-injection. In another important brain structure implicated in immune-to-brain communication, namely, in the median eminence (ME, NF-IL6-immunoreactivity was increased in aged animals, while the young group showed just minor activation after LPS-stimulation. Interestingly, we found a higher amount of NF-IL6-CD68-positive cells in the posterior pituitary of old rats compared to the young counterparts. Moreover, aging affected the regulation of cytokine interaction in the anterior pituitary lobe. LPS-treatment significantly enhanced the secretion of the cytokines IL-6 and TNFα into supernatants of primary cell cultures of the anterior pituitary. Furthermore, in the young rats, incubation with IL-6 and IL-10 antibodies before LPS-stimulation led to a robust decrease of IL-6 production and an increase of TNFα production by the pituitary

  13. Effects of strain rate, stress condition and environment on iodine embrittlement of Ziracloy-2

    International Nuclear Information System (INIS)

    Une, K.

    1979-01-01

    Iodine stress corrosion cracking (SCC) susceptibility of Zircaloy became higher with decreasing strain rate. Critical strain rate, below which high SCC severity was observed, substantially depended on Zircaloy stress condition. This strain rate (7 x 10 -3 min -1 ) under plane strain condition was about 3.5 times as fast as that (2 x 10 -3 min -1 ) under uniaxial condition. The maximum iodine embrittlement in Zircaloy was found in stress ratio α (axial/tangential stress) range of 0.5 to 0.7. No embrittlement occurred at α = infinity because of its texture effect. The SCC fracture stresses were about 39 kg/mm 2 for unirradiated and stress-relieved material, and about 34 kg/mm 2 for recrystallized material, whose ratios to yield strength of each material were 0.8 and 1.2. Impurity gases of oxygen and moisture in the iodine had the effects of reducing Zircaloy SCC susceptibility. Stress-relieved material was more sensitive to environmental impurities than recrystallized material

  14. CLASH-VLT: The stellar mass function and stellar mass density profile of the z=0.44 cluster of galaxies MACS J1206.2-0847

    CERN Document Server

    Annunziatella, M; Mercurio, A.; Nonino, M.; Rosati, P.; Balestra, I.; Presotto, V.; Girardi, M.; Gobat, R.; Grillo, C.; Medezinski, E.; Kelson, D.; Postman, M.; Scodeggio, M.; Brescia, M.; Sartoris, B.; Demarco, R.; Fritz, A.; Koekemoer, A.; Lemze, D.; Lombardi, M.; Bradley, L.; Coe, D.; Donahue, M.; Regös, E.; Umetsu, K.; Vanzella, E.; Infante, L.; Kuchner, U.; Maier, C.; Verdugo, M.; Ziegler, B.

    2014-01-01

    Context. The study of the galaxy stellar mass function (SMF) in relation to the galaxy environment and the stellar mass density profile, rho(r), is a powerful tool to constrain models of galaxy evolution. Aims. We determine the SMF of the z=0.44 cluster of galaxies MACS J1206.2-0847 separately for passive and star-forming (SF) galaxies, in different regions of the cluster, from the center out to approximately 2 virial radii. We also determine rho(r) to compare it to the number density and total mass density profiles. Methods. We use the dataset from the CLASH-VLT survey. Stellar masses are obtained by SED fitting on 5-band photometric data obtained at the Subaru telescope. We identify 1363 cluster members down to a stellar mass of 10^9.5 Msolar. Results. The whole cluster SMF is well fitted by a double Schechter function. The SMFs of cluster SF and passive galaxies are statistically different. The SMF of the SF cluster galaxies does not depend on the environment. The SMF of the passive population has a signif...

  15. Effects of Occurrence of Drought Stress in Maternal Environment on Cardinal Temperatures and Germination Responses of Carthamus Species

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Nazari

    2018-02-01

    Full Text Available Safflower (Carthamustinctorius L. is one of the oldest domesticated crops, mainly grown as an oilseed in the arid and semiarid regions of the world. This study was conducted to investigate the Cardinal temperatures and to identify the effects of occurrence of drought stress in maternal environment on seed germination aspects of some Carthamus species according to a completely randomized design in 2014. To accomplish this, seeds of 13 genotypes from C. tinctorius, C. palaestinus, C. oxyacanthus, C. glaucus and C. lanatus were used which had been harvested from plants grown at normal and drought stress conditions. Seeds were subjected to 9 fixed temperatures (5, 10, 15, 20, 25, 30, 35, 40 and 45°C for germination in the growth chamber according to a factorial experiment. Results showed that the effects of genotype, species, temperature, pretreatment drought stress and some of their interactions were significant for certain germination characteristics at 0.05% probability level. Significant reductions occurred in the germination rate of seeds at temperatures below 10°C and above 30°C. Although there were significant differences in percent of seed germination among species, seeds harvested from drought stressed plants were not significantly different from the ones harvested from non-stressed plants in terms of cardinal temperatures. Hence, it is more likely that cardinal temperatures will not cause difficulties in the case of inter-specific breeding programs for drought tolerant safflower cultivar development.

  16. Influence of Tensile Stresses on α+β – Titanium Alloy VT22 Corrosion Resistance in Marine Environment

    Directory of Open Access Journals (Sweden)

    Yu. A. Puchkov

    2015-01-01

    Full Text Available Tensile stresses and hydrogen render strong influence on the titanic alloys propensity for delayed fracture. The protective film serves аs a barrier for penetration in hydrogen alloy. Therefore to study the stress effect on its structure and protective properties is of significant interest.The aim of this work is to research the tensile stress influence on the passivation, indexes of corrosion, protective film structure and reveal reasons for promoting hydrogenation and emerging propensity for delayed fracture of titanium alloy VТ22 in the marine air atmosphere.The fulfillеd research has shown that:- there is а tendency to reduce the passivation abilities of the alloy VТ22 in synthetic marine water (3 % solution of NaCl with increasing tensile stresses up to 1170 МPа, namely to reduce the potential of free corrosion and the rate of its сhange, thus the alloy remains absolutely (rather resistant;- the protective film consists of a titanium hydroxide layer under which there is the titanium oxide layer adjoining to the alloy, basically providing the corrosion protection.- the factors providing hydrogenation of titanium alloys and formation in their surface zone fragile hydrides, causing the appearing propensity for delayed fracture, alongside with tensile stresses are:- substances promoting chemisorbtion of hydrogen available in the alloy and on its surface;- the cathodic polarization caused by the coupling;- the presence of the structural defects promoting the formation of pitting and local аcidifying of the environment surrounding the alloy.

  17. Effect of yield strength on stress corrosion crack propagation under PWR and BWR environments of hardened stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Castano, M.L.; Garcia, M.S.; Diego, G. de; Gomez-Briceno, D. [CIEMAT, Nuclear Fission Department, Structural Materials Program, Avda. Complutense 22, 28040 Madrid (Spain)

    2004-07-01

    Core components of light water reactor (LWR), mainly made of austenitic stainless steels (SS), subjected to stress and exposed to relatively high fast neutron flux may suffer a cracking process termed as Irradiation Assisted Stress Corrosion Cracking (IASCC). Neutron radiation leads to critical modifications in material characteristics, which can modify their stress corrosion cracking (SCC) response. Current knowledge highlights three fundamental factors, induced by radiation, as primary contributors to IASCC of core materials: Radiation Induced Segregation (RIS) at grain boundaries, Radiation Hardening and Radiolysis. Most of the existing literature on IASCC is focussed on the influence of RIS, mainly chromium depletion, which can promote IASCC in oxidizing environments, such a Boiling Water Reactor (BWR) under normal water chemistry. However, in non-oxidizing environments, such as primary water of Pressurized Water Reactor (PWR) or BWR hydrogen water chemistry, the role played by chromium depletion at grain boundary on IASCC behaviour of highly irradiated material is irrelevant. One important issue with limited study is the effect of radiation induced hardening. The role of hardening on IASCC is became stronger considered, especially for environments where other factors, like micro-chemistry, have no significant influence. To formulate the mechanism of IASCC, a well-established method is to isolate and quantify the effect of individual parameters. The use of unirradiated material and the simulation of the irradiation effects is a procedure used with success for evaluating the influence of irradiation effects. Radiation hardening can be simulated by mechanical deformation and, although some differences exist in the types of defects produced, it is believed that the study of the SCC behaviour of unirradiated materials with different hardening levels would contribute to the understanding of IASCC mechanism. In order to evaluate the influence of hardening on the

  18. Improvement of the Work Environment and Work-Related Stress: A Cross-Sectional Multilevel Study of a Nationally Representative Sample of Japanese Workers.

    Science.gov (United States)

    Watanabe, Kazuhiro; Tabuchi, Takahiro; Kawakami, Norito

    2017-03-01

    This cross-sectional multilevel study aimed to investigate the relationship between improvement of the work environment and work-related stress in a nationally representative sample in Japan. The study was based on a national survey that randomly sampled 1745 worksites and 17,500 nested employees. The survey asked the worksites whether improvements of the work environment were conducted; and it asked the employees to report the number of work-related stresses they experienced. Multilevel multinominal logistic and linear regression analyses were conducted. Improvement of the work environment was not significantly associated with any level of work-related stress. Among men, it was significantly and negatively associated with the severe level of work-related stress. The association was not significant among women. Improvements to work environments may be associated with reduced work-related stress among men nationwide in Japan.

  19. Coping with a changing environment: The effects of early life stress

    DEFF Research Database (Denmark)

    Vindas, Marco A.; Madaro, Angelico; Fraser, Thomas W.K.

    2016-01-01

    to environmental changes is particularly evident at early life stages. We investigated the performance of salmon, previously subjected to an unpredictable chronic stress (UCS) treatment at an early age (10 month old parr), over several months and life stages. The UCS fish showed overall higher specific growth...... rates compared with unstressed controls after smoltification, a particularly challenging life stage, and after seawater transfer. Furthermore, subjecting fish to acute stress at the end of the experiment, we found that UCS groups had an overall lower hypothalamic catecholaminergic and brain stem...... serotonergic response to stress compared with control groups. In addition, serotonergic activity was negatively correlated with final growth rates,which implies that serotonin responsive individuals have growth disadvantages. Altogether, our results may imply that a subduedmonoaminergic response in stressful...

  20. The Relation of Work Environment and Stress in Classroom Management among Preschool Teachers

    Directory of Open Access Journals (Sweden)

    Abdul Said Ambotang

    2011-10-01

    Full Text Available The purpose of this research is to observe how far preschool teachers endure stress in carrying out their job which is influenced by the work climate including the management of classroom. This research is carried out by choosing a group of 55 preschool teachers as respondents in the district of Keningau Sabah. Data is analyzed using descriptive method (mean, inferential (T-test Statistic, one way ANOVA and Pearson correlation. Result showed that there were high positive relationships between the work climate with stress level among the teachers. (r = 0.807, p<0.01 and classroom management with level of stress (r = 0.770, p< 0.01. It is hoped that with the information obtained by this research will assist the Malaysian Ministry of Education in planning and designing a suitable programme to overcome the stress problem faced by teachers especially preschool teachers towards improving the teaching profession quality in the near future.

  1. CLASH: THREE STRONGLY LENSED IMAGES OF A CANDIDATE z Almost-Equal-To 11 GALAXY

    Energy Technology Data Exchange (ETDEWEB)

    Coe, Dan; Postman, Marc; Bradley, Larry; Koekemoer, Anton [Space Telescope Science Institute, Baltimore, MD (United States); Zitrin, Adi; Carrasco, Mauricio [Institut fuer Theoretische Astrophysik, Zentrum fuer Astronomie, Institut fuer Theoretische Astrophysik, Albert-Ueberle-Str. 2, D-29120 Heidelberg (Germany); Shu, Xinwen [Department of Astronomy, University of Science and Technology of China, Hefei (China); Zheng, Wei; Ford, Holland; Rodney, Steven A. [Department of Physics and Astronomy, The Johns Hopkins University, Baltimore, MD (United States); Bouwens, Rychard [Leiden Observatory, Leiden University, NL-2333 Leiden (Netherlands); Broadhurst, Tom [Department of Theoretical Physics, University of the Basque Country UPV/EHU, E-48080 Bilbao (Spain); Monna, Anna [Instituts fuer Astronomie und Astrophysik, Universitaes-Sternwarte Muenchen, D-81679 Muenchen (Germany); Host, Ole; Jouvel, Stephanie [Department of Physics and Astronomy, University College London, London (United Kingdom); Moustakas, Leonidas A. [Jet Propulsion Laboratory, California Institute of Technology, La Canada Flintridge, CA (United States); Moustakas, John [Department of Physics and Astronomy, Siena College, Loudonville, NY (United States); Van der Wel, Arjen [Max-Planck-Institut fuer Astronomie (MPIA), D-69117 Heidelberg (Germany); Donahue, Megan [Department of Physics and Astronomy, Michigan State University, East Lansing, MI (United States); Benitez, Narciso, E-mail: DCoe@STScI.edu [Instituto de Astrofisica de Andalucia (IAA-CSIC), E-18008 Granada (Spain); and others

    2013-01-01

    We present a candidate for the most distant galaxy known to date with a photometric redshift of z = 10.7{sup +0.6} {sub -0.4} (95% confidence limits; with z < 9.5 galaxies of known types ruled out at 7.2{sigma}). This J-dropout Lyman break galaxy, named MACS0647-JD, was discovered as part of the Cluster Lensing and Supernova survey with Hubble (CLASH). We observe three magnified images of this galaxy due to strong gravitational lensing by the galaxy cluster MACSJ0647.7+7015 at z = 0.591. The images are magnified by factors of {approx}80, 7, and 2, with the brighter two observed at {approx}26th magnitude AB ({approx}0.15 {mu}Jy) in the WFC3/IR F160W filter ({approx}1.4-1.7 {mu}m) where they are detected at {approx}>12{sigma}. All three images are also confidently detected at {approx}>6{sigma} in F140W ({approx}1.2-1.6 {mu}m), dropping out of detection from 15 lower wavelength Hubble Space Telescope filters ({approx}0.2-1.4 {mu}m), and lacking bright detections in Spitzer/IRAC 3.6 {mu}m and 4.5 {mu}m imaging ({approx}3.2-5.0 {mu}m). We rule out a broad range of possible lower redshift interlopers, including some previously published as high-redshift candidates. Our high-redshift conclusion is more conservative than if we had neglected a Bayesian photometric redshift prior. Given CLASH observations of 17 high-mass clusters to date, our discoveries of MACS0647-JD at z {approx} 10.8 and MACS1149-JD at z {approx} 9.6 are consistent with a lensed luminosity function extrapolated from lower redshifts. This would suggest that low-luminosity galaxies could have reionized the universe. However, given the significant uncertainties based on only two galaxies, we cannot yet rule out the sharp drop-off in number counts at z {approx}> 10 suggested by field searches.

  2. Deformation stresses and mechanical behaviour of engineered barriers in the repository environment

    International Nuclear Information System (INIS)

    Ipatti, A.; Majamaeki, O.

    1991-12-01

    The report surveys functioning of the engineered barriers in the Loviisa repository under deformation stresses of the solidification product and the concrete filling material. The survey is based on the latest estimates of the waste amounts and the corresponding repository plans, and on solidification product compositions and properties. The IVOFEM and NASTRAN software was used in the structural analyses. The materials were supposed to be homogeneous and linearly elastic and dislocations small. Accordingly, the design loads were chosen conservatively so that the impacts of deformation stresses are sufficiently overestimated. A reinforced concrete container lined with cellular plastic remains a watertight structure, meeting the requirements set in view of expansion of a solidification product. In view of the stresses, the decisive time is the intermediate storage stage. The greatest stresses are found in junctions between the container wall and the bottom and cover. The concrete filling between the waste packages cannot resist the drying shrinkage and wetting expansion stresses without cracking. Concrete walls of the repository can withstand the stress caused by wetting expansion of the waste packages only when strongly reinforced. However, the forces against the walls are so big that if cracks in the concrete walls are desired to be restricted, due to reinforcement steel corrosion or wall tightness, the present type of filling material between the waste packages is not necessarily technically the best alternative

  3. The clash of rural-urban migrants and real estate investors on Phnom Penh's housing market: Prospects for garment workers

    OpenAIRE

    Buttmann, Vera

    2017-01-01

    Housing markets of large cities around the world, particularly in so-called developing and emerging countries, are currently experiencing a clash: On the one hand, large numbers of labour migrants arrive from rural areas and need cheap rental housing. On the other hand, international real estate investment, particularly in the upper market segment, is strong. The resulting mismatch of housing demand and supply increases segregation, marginalises the vulnerable and leads to massive urban devel...

  4. Dissecting long-term adjustments of photoprotective and photo-oxidative stress acclimation occurring in dynamic light environments

    Directory of Open Access Journals (Sweden)

    Shizue Matsubara

    2016-11-01

    Full Text Available Changes in light intensity directly affect the performance of the photosynthetic apparatus. Light energy absorbed in excess of cells’ needs leads to production of reactive oxygen species and photo-oxidative damage. Excess light in both constant and dynamic environments induces photoprotective acclimation in plants. Distinct sets of signals and regulatory mechanisms are involved in acclimatory adjustment of photoprotection and photosynthesis under constant and dynamic (fluctuating light conditions. We are still far away from drawing a comprehensive picture of acclimatory signal transduction pathways, particularly in dynamic environments. In this perspective article, we propose the use of Arabidopsis plants that produce H2O2 in chloroplasts (GO plants under atmospheric CO2 levels as a tool to study the mechanisms of long-term acclimation to photo-oxidative stress. In our opinion there are new avenues to future investigations on acclimatory adjustments and signal transduction occurring in plants under dynamic light environments.

  5. The Impact of Stress and the Working Environment on Job Satisfaction and Decision-Making among Women Entrepreneurs in Mexico

    Directory of Open Access Journals (Sweden)

    Jose-Melchor Medina

    2013-07-01

    Full Text Available The world is changing and these changes have deeply affected the status of women as entrepreneurs; women’s working force is growing by the day along with their entrepreneurship, forcing women to find a balance between their jobs and their personal lives. This research analyses the degree of the impact of stress and the working environment on women entrepreneurs’ efficient decision-making and job satisfaction. An empirical investigation is carry out in four states in the Mexican Republic. It is using multiple regression analyses in SPSS. Results show that working environment impacts positively on women entrepreneurs’ efficient decision-making. This means that by having a good working environment, women entrepreneurs are able to have good relationships with workers in order to face decision.

  6. Aggression and violence around the world: A model of CLimate, Aggression, and Self-control in Humans (CLASH).

    Science.gov (United States)

    Van Lange, Paul A M; Rinderu, Maria I; Bushman, Brad J

    2017-01-01

    Worldwide there are substantial differences within and between countries in aggression and violence. Although there are various exceptions, a general rule is that aggression and violence increase as one moves closer to the equator, which suggests the important role of climate differences. While this pattern is robust, theoretical explanations for these large differences in aggression and violence within countries and around the world are lacking. Most extant explanations focus on the influence of average temperature as a factor that triggers aggression (The General Aggression Model), or the notion that warm temperature allows for more social interaction situations (Routine Activity Theory) in which aggression is likely to unfold. We propose a new model, CLimate, Aggression, and Self-control in Humans (CLASH), that helps us to understand differences within and between countries in aggression and violence in terms of differences in climate. Lower temperatures, and especially larger degrees of seasonal variation in climate, call for individuals and groups to adopt a slower life history strategy, a greater focus on the future (vs. present), and a stronger focus on self-control. The CLASH model further outlines that slow life strategy, future orientation, and strong self-control are important determinants of inhibiting aggression and violence. We also discuss how CLASH differs from other recently developed models that emphasize climate differences for understanding conflict. We conclude by discussing the theoretical and societal importance of climate in shaping individual and societal differences in aggression and violence.

  7. Enhancing water stress tolerance improves fitness in biological control strains of Lactobacillus plantarum in plant environments.

    Science.gov (United States)

    Daranas, Núria; Badosa, Esther; Francés, Jesús; Montesinos, Emilio; Bonaterra, Anna

    2018-01-01

    Lactobacillus plantarum strains PM411 and TC92 can efficiently control bacterial plant diseases, but their fitness on the plant surface is limited under unfavourable low relative humidity (RH) conditions. To increase tolerance of these strains to water stress, an adaptive strategy was used consisting of hyperosmotic and acidic conditions during growth. Adapted cells had higher survival rates under desiccation than non-adapted cells. Transcript levels and patterns of general stress-related genes increased immediately after the combined-stress adaptation treatment, and remained unaltered or repressed during the desiccation challenge. However, there were differences between strains in the transcription patterns that were in agreement with a better performance of adapted cells of PM411 than TC92 in plant surfaces under low RH environmental conditions. The combined-stress adaptation treatment increased the survival of PM411 cells consistently in different plant hosts in the greenhouse and under field conditions. Stress-adapted cells of PM411 had similar biocontrol potential against bacterial plant pathogens than non-adapted cells, but with less variability within experiments.

  8. Enhancing water stress tolerance improves fitness in biological control strains of Lactobacillus plantarum in plant environments.

    Directory of Open Access Journals (Sweden)

    Núria Daranas

    Full Text Available Lactobacillus plantarum strains PM411 and TC92 can efficiently control bacterial plant diseases, but their fitness on the plant surface is limited under unfavourable low relative humidity (RH conditions. To increase tolerance of these strains to water stress, an adaptive strategy was used consisting of hyperosmotic and acidic conditions during growth. Adapted cells had higher survival rates under desiccation than non-adapted cells. Transcript levels and patterns of general stress-related genes increased immediately after the combined-stress adaptation treatment, and remained unaltered or repressed during the desiccation challenge. However, there were differences between strains in the transcription patterns that were in agreement with a better performance of adapted cells of PM411 than TC92 in plant surfaces under low RH environmental conditions. The combined-stress adaptation treatment increased the survival of PM411 cells consistently in different plant hosts in the greenhouse and under field conditions. Stress-adapted cells of PM411 had similar biocontrol potential against bacterial plant pathogens than non-adapted cells, but with less variability within experiments.

  9. Correlated-Data Fusion and Cooperative Aiding in GNSS-Stressed or Denied Environments

    Science.gov (United States)

    Mokhtarzadeh, Hamid

    A growing number of applications require continuous and reliable estimates of position, velocity, and orientation. Price requirements alone disqualify most traditional navigation or tactical-grade sensors and thus navigation systems based on automotive or consumer-grade sensors aided by Global Navigation Satellite Systems (GNSS), like the Global Positioning System (GPS), have gained popularity. The heavy reliance on GPS in these navigation systems is a point of concern and has created interest in alternative or back-up navigation systems to enable robust navigation through GPS-denied or stressed environments. This work takes advantage of current trends for increased sensing capabilities coupled with multilayer connectivity to propose a cooperative navigation-based aiding system as a means to limit dead reckoning error growth in the absence of absolute measurements like GPS. Each vehicle carries a dead reckoning navigation system which is aided by relative measurements, like range, to neighboring vehicles together with information sharing. Detailed architectures and concepts of operation are described for three specific applications: commercial aviation, Unmanned Aerial Vehicles (UAVs), and automotive applications. Both centralized and decentralized implementations of cooperative navigation-based aiding systems are described. The centralized system is based on a single Extended Kalman Filter (EKF). A decentralized implementation suited for applications with very limited communication bandwidth is discussed in detail. The presence of unknown correlation between the a priori state and measurement errors makes the standard Kalman filter unsuitable. Two existing estimators for handling this unknown correlation are Covariance Intersection (CI) and Bounded Covariance Inflation (BCInf) filters. A CI-based decentralized estimator suitable for decentralized cooperative navigation implementation is proposed. A unified derivation is presented for the Kalman filter, CI filter

  10. The Clash of Interests: An Explanation of the World [Dis]order

    Directory of Open Access Journals (Sweden)

    Ahmet Davutoğlu

    1994-12-01

    Full Text Available The paper is a critical re-examination of the Post-Cold War theories– especially Fukuyama's "End of History" and Huntington's "Clash of Civilizations"– and aims to provide an alternative explanation for the global political crisis and instabilities during this era. It is argued that the end of the Cold War strategic balance based on bipolarity has created sensitive regions on a large geopolitical and geoeconomic zone, because there is a vacuum of power to control the strategic capabilities of the geopolitical core areas as well as the vast resource-production-trade capabilities of international political economy. The revival of cultural and civilizational identities after the collapse of the ideological identities of the bipolar Cold War era has been exploited to justify the intra-civilizational strategic competition among the systemic power centers in order to control these sensitive geopolitical and geoeconomic zones. The Eurasian component of the Muslim world, which became the intersectional arena of these two phenomena, civilizational revival and strategic competition, appears as the focal point in international relations.

  11. The clash of Gods: changes in a patient's use of God representations.

    Science.gov (United States)

    Lamothe, Ryan

    2009-01-01

    In this article, I argue that manifest and latent intrapsychic and interpersonal clashes of god representations, which are inextricably yoked to transference and countertransference communications, signify the patient's and therapist's personal realities and histories. More specifically, the therapist's conscious (relatively speaking) commitment to a god representation will not only shape his/her analytic attitude-as well as interpretations and noninterpretive interventions-it may also be implicated in a patient altering his/her use of god representations. I suggest further that one way to understand the process of psychoanalytic therapy is how both analyst and analysand tacitly face and answer the following questions: What God(s) orients my life and relationships? What God(s) represents subjugation, fear, and the loss of freedom? What God(s) have I repressed? What God(s) represents the possibility and experience of being alive and real with others? In the end, what God(s) will I choose to serve, to surrender to?

  12. When Religion and Medicine Clash: Non-beneficial Treatments and Hope for a Miracle.

    Science.gov (United States)

    Rosoff, Philip M

    2018-06-07

    Patient and family demands for the initiation or continuation of life-sustaining medically non-beneficial treatments continues to be a major issue. This is especially relevant in intensive care units, but is also a challenge in other settings, most notably with cardiopulmonary resuscitation. Differences of opinion between physicians and patients/families about what are appropriate interventions in specific clinical situations are often fraught with highly strained emotions, and perhaps none more so when the family bases their desires on religious belief. In this essay, I discuss non-beneficial treatments in light of these sorts of disputes, when there is a clash between the nominally secular world of fact- and evidence-based medicine and the faith-based world of hope for a miraculous cure. I ask the question whether religious belief can justify providing treatment that has either no or a vanishly small chance of restoring meaningful function. I conclude that non-beneficial therapy by its very definition cannot be helpful, and indeed is often harmful, to patients and hence cannot be justified no matter what the source or kind of reasons used to support its use. Therefore, doctors may legitimately refuse to provide such treatments, so long as they do so for acceptable clinical reasons. They must also offer alternatives, including second (and third) opinions, as well the option of transferring the care of the patient to a more accommodating physician or institution.

  13. The Clash of Discourses Regarding Relations with Russia: New Fault Lines in the European Union?

    Directory of Open Access Journals (Sweden)

    Valentin Naumescu

    2017-12-01

    Full Text Available Following the annexation of Crimea and the secession war in Eastern Ukraine, the topic of European security has returned as a major benchmark for a number of EU and non-EU countries. For a couple of years, in 2014-2015, the discourse of condemnation and international sanctions against the Russian regime dominated the agenda of the European-Russian relations. Nevertheless, the economic considerations and the ascension of right-wing or left-wing populism(s in the European Union acted as a drag on European unity and solidarity. Thereby a series of political leaders in the EU and its Eastern Neighbourhood began to ask for economic rapprochement with Russia, while others remained very cautious. Based on a comparative qualitative method, this paper explores the clashing discourses about relations with Russia, in light of the discourse theory. The dynamics of divergent positioning regarding Russia after 2016 led to the question of possible new fault lines in the European Union. Inconsistencies on this topic can be seen between West and East, between post-communist countries on the Eastern Flank with Poland, Romania and the Baltic States, on one side, and Hungary, Bulgaria, Slovakia and the Czech Republic on the other side, and between Western chancelleries with rather different views such as Berlin, London or Rome. The aim of this article is to explore the increasing differences and clarify whether conflicting approaches regarding relations with Russia could create real cleavages between EU Member States and threaten European unity.

  14. Intra Cluster Light properties in the CLASH-VLT cluster MACS J1206.2-0847

    CERN Document Server

    Presotto, V; Nonino, M; Mercurio, A; Grillo, C; Rosati, P; Biviano, A; Annunziatella, M; Balestra, I; Cui, W; Sartoris, B; Lemze, D; Ascaso, B; Moustakas, J; Ford, H; Fritz, A; Czoske, O; Ettori, S; Kuchner, U; Lombardi, M; Maier, C; Medezinski, E; Molino, A; Scodeggio, M; Strazzullo, V; Tozzi, P; Ziegler, B; Bartelmann, M; Benitez, N; Bradley, L; Brescia, M; Broadhurst, T; Coe, D; Donahue, M; Gobat, R; Graves, G; Kelson, D; Koekemoer, A; Melchior, P; Meneghetti, M; Merten, J; Moustakas, L; Munari, E; Postman, M; Regős, E; Seitz, S; Umetsu, K; Zheng, W; Zitrin, A

    2014-01-01

    We aim at constraining the assembly history of clusters by studying the intra cluster light (ICL) properties, estimating its contribution to the fraction of baryons in stars, f*, and understanding possible systematics/bias using different ICL detection techniques. We developed an automated method, GALtoICL, based on the software GALAPAGOS to obtain a refined version of typical BCG+ICL maps. We applied this method to our test case MACS J1206.2-0847, a massive cluster located at z=0.44, that is part of the CLASH sample. Using deep multi-band SUBARU images, we extracted the surface brightness (SB) profile of the BCG+ICL and we studied the ICL morphology, color, and contribution to f* out to R500. We repeated the same analysis using a different definition of the ICL, SBlimit method, i.e. a SB cut-off level, to compare the results. The most peculiar feature of the ICL in MACS1206 is its asymmetric radial distribution, with an excess in the SE direction and extending towards the 2nd brightest cluster galaxy which i...

  15. Work Environment, Stress, and Driving Anger: A Structural Equation Model for Predicting Traffic Sanctions of Public Transport Drivers

    Science.gov (United States)

    2018-01-01

    Public transport is an effective and sustainable alternative to private vehicle usage, also helping to reduce the environmental impact of driving. However, the work environment of public transport operators is full of adverse conditions, which, together with their high mileage, may increase the occurrence of negative safety outcomes such as traffic accidents, often preceded by risky road behaviors enhanced by stress, anger, and difficult operating conditions. The aims of this study were, first, to determine the association between work-related psychosocial factors and individual characteristics of public transport drivers and the rate of traffic sanctions they are subject to; and second, to assess the mediation of driving anger in this relationship. A sample of professional drivers (57.4% city bus, 17.6% taxi, and 25% inter-urban bus male operators) was used for this cross-sectional study, responding to a five-section survey including demographic data and driving-related factors, psychosocial work factors including job stress, driving stress, risk predisposition, and driving anger. The results of this study showed significant associations between work-related factors: measures of stress and self-reported rates of traffic fines. Second, it was found that driving anger mediates the associations between driving stress, risk predisposition, and traffic sanctions; and partially mediates the association between driving experience, hourly intensity, and job stress. This study supports the idea that traffic penalties reported by public transport rates are preceded by work-related, personality, and other individual factors that, when combined with driving anger, enhance the occurrence of road misbehavior that may affect overall road safety. PMID:29534530

  16. Work Environment, Stress, and Driving Anger: A Structural Equation Model for Predicting Traffic Sanctions of Public Transport Drivers

    Directory of Open Access Journals (Sweden)

    Luis Montoro

    2018-03-01

    Full Text Available Public transport is an effective and sustainable alternative to private vehicle usage, also helping to reduce the environmental impact of driving. However, the work environment of public transport operators is full of adverse conditions, which, together with their high mileage, may increase the occurrence of negative safety outcomes such as traffic accidents, often preceded by risky road behaviors enhanced by stress, anger, and difficult operating conditions. The aims of this study were, first, to determine the association between work-related psychosocial factors and individual characteristics of public transport drivers and the rate of traffic sanctions they are subject to; and second, to assess the mediation of driving anger in this relationship. A sample of professional drivers (57.4% city bus, 17.6% taxi, and 25% inter-urban bus male operators was used for this cross-sectional study, responding to a five-section survey including demographic data and driving-related factors, psychosocial work factors including job stress, driving stress, risk predisposition, and driving anger. The results of this study showed significant associations between work-related factors: measures of stress and self-reported rates of traffic fines. Second, it was found that driving anger mediates the associations between driving stress, risk predisposition, and traffic sanctions; and partially mediates the association between driving experience, hourly intensity, and job stress. This study supports the idea that traffic penalties reported by public transport rates are preceded by work-related, personality, and other individual factors that, when combined with driving anger, enhance the occurrence of road misbehavior that may affect overall road safety.

  17. Work Environment, Stress, and Driving Anger: A Structural Equation Model for Predicting Traffic Sanctions of Public Transport Drivers.

    Science.gov (United States)

    Montoro, Luis; Useche, Sergio; Alonso, Francisco; Cendales, Boris

    2018-03-12

    Public transport is an effective and sustainable alternative to private vehicle usage, also helping to reduce the environmental impact of driving. However, the work environment of public transport operators is full of adverse conditions, which, together with their high mileage, may increase the occurrence of negative safety outcomes such as traffic accidents, often preceded by risky road behaviors enhanced by stress, anger, and difficult operating conditions. The aims of this study were, first, to determine the association between work-related psychosocial factors and individual characteristics of public transport drivers and the rate of traffic sanctions they are subject to; and second, to assess the mediation of driving anger in this relationship. A sample of professional drivers (57.4% city bus, 17.6% taxi, and 25% inter-urban bus male operators) was used for this cross-sectional study, responding to a five-section survey including demographic data and driving-related factors, psychosocial work factors including job stress, driving stress, risk predisposition, and driving anger. The results of this study showed significant associations between work-related factors: measures of stress and self-reported rates of traffic fines. Second, it was found that driving anger mediates the associations between driving stress, risk predisposition, and traffic sanctions; and partially mediates the association between driving experience, hourly intensity, and job stress. This study supports the idea that traffic penalties reported by public transport rates are preceded by work-related, personality, and other individual factors that, when combined with driving anger, enhance the occurrence of road misbehavior that may affect overall road safety.

  18. Preliminary assessment of stress corrosion cracking of nickel based alloy 182 in nuclear reactor environment

    International Nuclear Information System (INIS)

    Lima, Luciana Iglesias Lourenco; Bracarense, Alexandre Queiroz; Schvartzman, Monica Maria de Abreu Mendonca; Quinan, Marco Antonio Dutra

    2010-01-01

    Stress corrosion crack (SCC) in a primary circuit of a nuclear pressurized water reactor consists of a degradation process in which aggressive media, stress and material susceptibility are present. Over the last thirty years, SCC has been observed in dissimilar metal welds. This study presents a comparative work between the SCC in the alloy 182 filler metal weld in two different hydrogen concentrations (25 e 50 cm 3 H 2 /kg H 2 O) in primary water. The susceptibility to stress corrosion cracking was assessed using the slow strain rate tensile (SSRT) test. The results of the SSRT test indicated that the material is more susceptible to SCC at 25 cm 3 H 2 /kg H 2 O. (author)

  19. Physiological characteristics under the influence of heat stress working in the hot environment, (4)

    International Nuclear Information System (INIS)

    Nagasaka, Akihiko; Yoshino, Kenji; Takano, Ken-ichi

    1987-01-01

    There is a possibility that physical and mental stress appears under hot environmental condition for the cause of wearing protection suits on reactor maintenance work. It is important to reduce heat stress rapidly and effectively. This paper mentioned following about the results of static state and simulation work done by testees with or without protection suits under 25 kinds of temperatures and wind velocities in a artificial climate chamber. (1) the correlation between ambient temperatures or wind velocities and subjective symptoms without protection suits. (2) the correlation between ambient temperatures or wind velocities and skin temperatures without protection suits. (3) investigation of the parts of body affecting subjective symptoms. (4) the correlation between ambient temperatures or wind velocities and skin temperatures at working with protection suits. (5) working out countermeasures of recovery from heat stress with the index of skin temperatures and subjective symptoms. (author)

  20. Complex-Spectrum Magnetic Environment enhances and/or modifies Bioeffects of Hypokinetic Stress Condition: an Animal Study

    Science.gov (United States)

    Temuriantz, N. A.; Martinyuk, V. S.; Ptitsyna, N. G.; Villoresi, G.; Iucci, N.; Tyasto, M. I.; Dorman, L. I.

    During last decades it was shown by many authors that ultra-low and extremely low frequency electric and magnetic fields ULF 0-10 Hz ELF 10-1000 Hz may produce biological effects and consequently may be a possible source for health problems Spaceflight electric and magnetic environments are characterized by complex combination of static and time-varying components in ULF-ELF range and by high variability The objective of this study was to investigate the possible influence of such magnetic fields on rats to understand the pathway regarding functional state of cardiovascular system Magnetic field MF pattern with variable complex spectra in 0-150 Hz frequency range was simulated using 3-axial Helmholtz coils and special computer-based equipment The effect of the real world MF exposure on rats was also tested in combination with hypokinetic stress condition which is typical for spaceflights It was revealed that variable complex-spectrum MF acts as a weak or moderate stress-like factor which amplifies and or modifies the functional shifts caused by other stress-factors The value and direction of the functional shifts caused by MF exposure significantly depend on gender individual-typological constitutional features and also on the physiological state norm stress of organism Our results support the idea that variable complex-spectrum MF action involves sympathetic activation overload in cholesterol transport in blood and also secretor activation of tissue basophyls mast cells that can influence the regional haemodynamics These

  1. Standard test method for determining a threshold stress intensity factor for environment-assisted cracking of metallic materials

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2003-01-01

    1.1 This test method covers the determination of the environment-assisted cracking threshold stress intensity factor parameters, KIEAC and KEAC, for metallic materials from constant-force testing of fatigue precracked beam or compact fracture specimens and from constant-displacement testing of fatigue precracked bolt-load compact fracture specimens. 1.2 This test method is applicable to environment-assisted cracking in aqueous or other aggressive environments. 1.3 Materials that can be tested by this test method are not limited by thickness or by strength as long as specimens are of sufficient thickness and planar size to meet the size requirements of this test method. 1.4 A range of specimen sizes with proportional planar dimensions is provided, but size may be variable and adjusted for yield strength and applied force. Specimen thickness is a variable independent of planar size. 1.5 Specimen configurations other than those contained in this test method may be used, provided that well-established stress ...

  2. Remote sensing of gene expression in Planta: transgenic plants as monitors of exogenous stress perception in extraterrestrial environments

    Science.gov (United States)

    Manak, Michael S.; Paul, Anna-Lisa; Sehnke, Paul C.; Ferl, Robert J.

    2002-01-01

    Transgenic arabidopsis plants containing the alcohol dehydrogenase (Adh) gene promoter fused to the green fluorescent protein (GFP) reporter gene were developed as biological sensors for monitoring physiological responses to unique environments. Plants were monitored in vivo during exposure to hypoxia, high salt, cold, and abcissic acid in experiments designed to characterize the utility and responses of the Adh/GFP biosensors. Plants in the presence of environmental stimuli that induced the Adh promoter responded by expressing GFP, which in turn generated a detectable fluorescent signal. The GFP signal degraded when the inducing stimulus was removed. Digital imaging of the Adh/GFP plants exposed to each of the exogenous stresses demonstrated that the stress-induced gene expression could be followed in real time. The experimental results established the feasibility of using a digital monitoring system for collecting gene expression data in real time from Transgenic Arabidopsis Gene Expression System (TAGES) biosensor plants during space exploration experiments.

  3. Tensile Stress Rupture Behavior of a Woven Ceramic Matrix Composite in Humid Environments at Intermediate Temperature

    National Research Council Canada - National Science Library

    LaRochelle, Kevin J

    2005-01-01

    Stress rupture tests on the Sylramic(TM) fiber with an in-situ layer of boron nitride, boron nitride interphase, and SiC matrix ceramic matrix composite were performed at 550 degrees C and 750 degrees C with 0.0, 0.2...

  4. Roots withstanding their environment : Exploiting root system architecture responses to abiotic stress to improve crop tolerance

    NARCIS (Netherlands)

    Koevoets, Iko T; Venema, Jan Henk; Elzenga, J Theo M; Testerink, Christa

    2016-01-01

    To face future challenges in crop production dictated by global climate changes, breeders and plant researchers collaborate to develop productive crops that are able to withstand a wide range of biotic and abiotic stresses. However, crop selection is often focused on shoot performance alone, as

  5. PGPR Potentially Improve Growth of Tomato Plants in Salt-Stressed Environment

    Directory of Open Access Journals (Sweden)

    Mariam Zameer

    2016-06-01

    Full Text Available Plant growth promoting rhizobacteria are colonized bacterial species that has the capability to improve plant growth by certain direct and indirect means. Environmental factors including both biotic and abiotic stresses are among the major constraints to crop production. In the current study, the effectiveness of microbial inoculation (Bacillus megaterium for enhancing growth of tomato plants under salt stress conditions has been investigated. Significant improvement in shoot length, root length, leaf surface area, number of leaves, total weight of the shoot and root was observed in tomato plants inoculated with zm7 strain post 15 and 30 days of its application. Zm3, Zm4 and Zm6 strains improved the morphological parameters as compared to the control. Chlorophyll content a, chlorophyll content b, anthocyanin and carotenoid content was increased in tomato plants subjected to Zm7, Zm6 and Zm4 strains. Stress responsive genes; metallothionein and glutothion gene were found highly expressed in Zm7 treated tomato plants as compared to control, untreated plants. Significant correlation of anthocyanin was reported for carotenoids, chlorophyll-b, shoot weight and total weight of seedling while carotenoids were significantly correlated with leaf surface area, root length, chlorophyll-b and anthocyanin. Overall, Zm7 strain proved best for improvement in salt stressed plant’s morphological parameters and biochemical parameters as compared to control, untreated plants.

  6. Evaluation of Transient Pin-Stress Requirements for Spacecraft Launching in Lightning Environments. Pain Free Analysis to Alleviate Those Pin Stress Headaches

    Science.gov (United States)

    Edwards, Paul; Terseck, Alex; Trout, Dawn

    2016-01-01

    Spacecraft are generally protected from direct lightning attachment by encapsulation within the payload fairing of a launch vehicle and the ground structures that exist at the launch site. Regardless of where lightning strikes, potentially damaging indirect effects prevail from the coupling of electromagnetic fields into a loop created by outer shield of the payload umbilical. The energy coupled into individual spacecraft circuits is dependent on the umbilical current drive, the cable transfer impedance and the source/ load circuitry, and the reference potential used. Lightning induced transient susceptibility of the spacecraft avionics needs to be fully understood in order to define realistic re-test criteria in the event of a lightning occurrence during the launch campaign. Use of standards such as RTCA/DO-160 & SAE 5412 has some applicability but do not represent the indirect environment adequately. This paper evaluates the launch pad environments, the measurement data available, and computer simulations to provide pain-free analysis to alleviate the transient pin-stress headaches for spacecraft launching in Lightning environments.

  7. Modified single prolonged stress reduces cocaine self-administration during acquisition regardless of rearing environment.

    Science.gov (United States)

    Hofford, Rebecca S; Prendergast, Mark A; Bardo, Michael T

    2018-02-15

    Until recently, there were few rodent models available to study the interaction of post-traumatic stress disorder (PTSD) and drug taking. Like PTSD, single prolonged stress (SPS) produces hypothalamic-pituitary-adrenal (HPA) axis dysfunction and alters psychostimulant self-administration. Other stressors, such as isolation stress, also alter psychostimulant self-administration. However, it is currently unknown if isolation housing combined with SPS can alter the acquisition or maintenance of cocaine self-administration. The current study applied modified SPS (modSPS; two hours restraint immediately followed by cold swim stress) to rats raised in an isolation condition (Iso), enrichment condition (Enr), or standard condition (Std) to measure changes in cocaine self-administration and HPA markers. Regardless of rearing condition, rats exposed to modSPS had greater corticosterone (CORT) release and reduced cocaine self-administration during initial acquisition compared to non-stressed controls. In addition, during initial acquisition, rats that received both Iso rearing and modSPS showed a more rapid increase in cocaine self-administration across sessions compared to Enr and Std rats exposed to modSPS. Following initial acquisition, a dose response analysis showed that Iso rats were overall most sensitive to changes in cocaine unit dose; however, modSPS had no effect on the cocaine dose response curve. Further, there was no effect of either modSPS or differential rearing on expression of glucocorticoid receptor (GR) in hypothalamus, medial prefrontal cortex, amygdala, or nucleus accumbens. By using modSPS in combination with Iso housing, this study identified unique contributions of each stressor to acquisition of cocaine self-administration. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Breeding approaches in simultaneous selection for multiple stress tolerance of maize in tropical environments

    Directory of Open Access Journals (Sweden)

    Denić M.

    2007-01-01

    Full Text Available Maize is the principal crop and major staple food in the most countries of Sub-Saharan Africa. However, due to the influence of abiotic and biotic stress factors, maize production faces serious constraints. Among the agro-ecological conditions, the main constraints are: lack and poor distribution of rainfall; low soil fertility; diseases (maize streak virus, downy mildew, leaf blights, rusts, gray leaf spot, stem/cob rots and pests (borers and storage pests. Among the socio-economic production constraints are: poor economy, serious shortage of trained manpower; insufficient management expertise, lack of use of improved varieties and poor cultivation practices. To develop desirable varieties, and thus consequently alleviate some of these constraints, appropriate breeding approaches and field-based methodologies in selection for multiple stress tolerance, were implemented. These approaches are mainly based on: a Crossing selected genotypes with more desirable stress tolerant and other agronomic traits; b Using the disease/pest spreader row method, combined with testing and selection of created progenies under strong to intermediate pressure of drought and low soil fertility in nurseries; and c Evaluation of the varieties developed in multi-location trials under low and "normal" inputs. These approaches provide testing and selection of large number of progenies, which is required for simultaneous selection for multiple stress tolerance. Data obtained revealed that remarkable improvement of the traits under selection was achieved. Biggest progress was obtained in selection for maize streak virus and downy mildew resistance, flintiness and earliness. In the case of drought stress, statistical analyses revealed significant negative correlation between yield and anthesis-silking interval, and between yield and days to silk, but positive correlation between yield and grain weight per ear.

  9. Assessment of susceptibility of Type 304 stainless steel to intergranular stress corrosion cracking in simulated Savannah River Reactor environments

    International Nuclear Information System (INIS)

    Ondrejcin, R.S.; Caskey, C.R. Jr.

    1989-01-01

    Intergranular stress corrosion cracking (IGSCC) of Type 304 stainless steel rate tests (CERT) of specimens machined was evaluated by constant extension from Savannah River Plant (SRP) decontaminated process water piping. Results from 12 preliminary CERT tests verified that IGSCC occurred over a wide range of simulated SRP envirorments. 73 specimens were tested in two statistical experimental designs of the central composite class. In one design, testing was done in environments containing hydrogen peroxide; in the other design, hydrogen peroxide was omitted but oxygen was added to the environment. Prediction equations relating IGSCC to temperature and environmental variables were formulated. Temperature was the most important independent variable. IGSCC was severe at 100 to 120C and a threshold temperature between 40C and 55C was identified below which IGSCC did not occur. In environments containing hydrogen peroxide, as in SRP operation, a reduction in chloride concentration from 30 to 2 ppB also significantly reduced IGSCC. Reduction in sulfate concentration from 50 to 7 ppB was effective in reducing IGSCC provided the chloride concentration was 30 ppB or less and temperature was 95C or higher. Presence of hydrogen peroxide in the environment increased IGSCC except when chloride concentration was 11 ppB or less. Actual concentrations of hydrogen peroxide, oxygen and carbon dioxide did not affect IGSCC. Large positive ECP values (+450 to +750 mV Standard Hydrogen Electrode (SHE)) in simulated SRP environments containing hydrogen peroxide and were good agreement with ECP measurements made in SRP reactors, indicating that the simulated environments are representative of SRP reactor environments. Overall CERT results suggest that the most effective method to reduce IGSCC is to reduce chloride and sulfate concentrations

  10. Methodology to evaluate the crack growth rate by stress corrosion cracking in dissimilar metals weld in simulated environment of PWR nuclear reactor

    International Nuclear Information System (INIS)

    Paula, Raphael G.; Figueiredo, Celia A.; Rabelo, Emerson G.

    2013-01-01

    Inconel alloys weld metal is widely used to join dissimilar metals in nuclear reactors applications. It was recently observed failures of weld components in plants, which have triggered an international effort to determine reliable data on the stress corrosion cracking behavior of this material in reactor environment. The objective of this work is to develop a methodology to determine the crack growth rate caused by stress corrosion in Inconel alloy 182, using the specimen (Compact Tensile) in simulated PWR environment. (author)

  11. Stress

    DEFF Research Database (Denmark)

    Keller, Hanne Dauer

    2015-01-01

    Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb.......Kapitlet handler om stress som følelse, og det trækker primært på de få kvalitative undersøgelser, der er lavet af stressforløb....

  12. Stress !!!

    OpenAIRE

    Fledderus, M.

    2012-01-01

    Twee op de vijf UT-studenten hebben last van ernstige studiestress, zo erg zelfs dat het ze in hun privéleven belemmert. Die cijfers komen overeen met het landelijk beeld van stress onder studenten. Samen met 14 andere universiteits- en hogeschoolbladen enquêteerde UT Nieuws bijna 5500 studenten. Opvallend is dat mannelijke studenten uit Twente zich veel minder druk lijken te maken over hun studie. Onder vrouwen ligt de stress juist erg hoog ten opzichte van het landelijk gemiddelde.

  13. Comparative study on the stress corrosion cracking of X70 pipeline steel in simulated shallow and deep sea environments

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Feilong [Corrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083 (China); Key Laboratory of Corrosion and Protection of Ministry of Education, Beijing 100083 (China); China Building Material Test & Certification Group Co. Ltd., Beijing 100024 (China); Ren, Shuai [Corrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083 (China); Key Laboratory of Corrosion and Protection of Ministry of Education, Beijing 100083 (China); Li, Zhong [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada T6G 2G6 (Canada); Liu, Zhiyong, E-mail: liuzhiyong7804@ustb.edu.cn [Corrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083 (China); Key Laboratory of Corrosion and Protection of Ministry of Education, Beijing 100083 (China); Li, Xiaogang; Du, Cuiwei [Corrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083 (China); Key Laboratory of Corrosion and Protection of Ministry of Education, Beijing 100083 (China)

    2017-02-08

    The stress corrosion cracking (SCC) behavior of X70 steel in simulated shallow and deep sea environments was studied using potentiodynamic polarization measurement, a slow strain rate tensile (SSRT) test and scanning electron microscopy (SEM). The results indicate that the predominant cathodic reaction changes from an oxygen reduction reaction to the hydrogen evolution reaction as the dissolved oxygen (DO) content decreases. In the simulated deep sea environment, the SCC susceptibility of X70 steel decreased first, reached its lowest point at 15 MPa and then increased as the simulated sea hydrostatic pressure (HP) further increased. This is consistent with the regularity for the change of the cathodic hydrogen evolution reaction current density i{sub H} at E{sub corr}, which indicates that the HP may influence the SCC susceptibility of X70 steel by changing the permeated hydrogen concentration.

  14. Stress corrosion cracking tests on high-level-waste container materials in simulated tuff repository environments

    International Nuclear Information System (INIS)

    Abraham, T.; Jain, H.; Soo, P.

    1986-06-01

    Types 304L, 316L, and 321 austenitic stainless steel and Incoloy 825 are being considered as candidate container materials for emplacing high-level waste in a tuff repository. The stress corrosion cracking susceptibility of these materials under simulated tuff repository conditions was evaluated by using the notched C-ring method. The tests were conducted in boiling synthetic groundwater as well as in the steam/air phase above the boiling solutions. All specimens were in contact with crushed Topopah Spring tuff. The investigation showed that microcracks are frequently observed after testing as a result of stress corrosion cracking or intergranular attack. Results showing changes in water chemistry during test are also presented

  15. Constant load and constant displacement stress corrosion in simulated water reactor environments

    International Nuclear Information System (INIS)

    Lloyd, G.J.

    1987-02-01

    The stress corrosion behaviour of selected water reactor constructional materials, as determined by constant load or constant displacement test techniques, is reviewed. Experimental results obtained using a very wide range of conditions have been collected in a form for easy reference. A discussion is given of some apparent trends in these data. The possible reasons for these trends are considered together with a discussion of how the observed discrepancies may be resolved. (author)

  16. Effect of Crack Tip Stress Concentration Factor on Fracture Resistance in Vacuum Environment

    Science.gov (United States)

    2015-01-20

    indicate: (1) in all alloys, the fracture resistance is highest for blunt-notches (smaller Kt), and is lowest for fatigue -sharpened precracked...paths are transgranular and the fracture mode is ductile void coalescence in all cases, irrespective of the stress concentration factor. 20-01-2015...because of corrosion and/or various loading conditions such as fatigue , fretting, abrasion, etc. Also, the geometry of the structure may cause an

  17. Physical robustness of canopy temperature models for crop heat stress simulation across environments and production conditions

    DEFF Research Database (Denmark)

    Webber, Heidi; White, Jeffrey W; Kimball, Bruce

    2018-01-01

    to simulate Tc. Model performance in predicting Tc was evaluated for two experiments in continental North America with various water, nitrogen and CO2 treatments. An empirical model fit to one dataset had the best performance, followed by the EBSC models. Stability conditions explained much of the differences...... between modeling approaches. More accurate simulation of heat stress will likely require use of energy balance approaches that consider atmospheric stability conditions....

  18. Stress corrosion cracking of alloy 182 weld in a PWR water environment

    International Nuclear Information System (INIS)

    Lima, Luciana Iglesias Lourenco; Schvartzman, Monica Maria de Abreu Mendonca; Quinan, Marco Antonio Dutra; Soares, Antonio Edicleto Gomes; Piva, Stephano P.T.

    2011-01-01

    The weld used to connect two different metals is known as dissimilar metal welds (DMW). In the nuclear power plant, this weld is used to join stainless steel nipples to low alloy carbon steel components on the nuclear pressurized water reactor (PWR). In most cases, nickel alloys are used to joint these materials. These alloys are known to accommodate the differences in composition and thermal expansion of the two materials. The stress corrosion cracking (SCC) is a phenomenon that occurs in nuclear power plants metallic components where susceptibility materials are subjected to the simultaneously effect of mechanical stress and an aggressive media with different compositions. SCC is one of degradation process that gradually introduces damage of components, change their characteristics with the operation time. The nickel alloy 600, and their weld metals (nickel alloys 82 and 182), originally selected due to its high corrosion resistance, it exhibit after long operation period (20 years), susceptibility to the SCC. This study presents a comparative work between the SCC in the Alloy 182 filler metal weld in two different temperatures (303 deg C and 325 deg C) in primary water. The susceptibility to stress corrosion cracking was assessed using the slow strain rate tensile (SSRT) test. The results of the SSRT tests indicated that SCC is a thermally-activated mechanism and that brittle fracture caused by the corrosion process was observed at 325 deg C. (author)

  19. Settler Colonialism in the Digital Age: Clash of Clans, Territoriality, and the Erasure of the Native

    Directory of Open Access Journals (Sweden)

    Jacob Euteneuer

    2018-03-01

    Full Text Available In the past ten years, two seemingly unconnected fields of study have risen to prominence. Patrick Wolfe’s 2006 theorization of settler colonialism called for the development of a distinct set of literature and analytical tools to analyze the relationship between indigenous peoples and occupying settlers. Meanwhile, Ian Bogost’s 2007 elaboration of the notion of procedural rhetoric provided a theoretical framework to approach the critical analysis of the ideology modeled by a game’s rules and design. While each of these theories have proliferated and prospered within their disciplines, this article seeks to bring the two fields together in order to establish a critical framework that can be used to highlight the presence of settler colonialism in popular mobile videogames, in particular Supercell’s 2012 mobile game 'Clash of Clans'. Within this framework, the essay analyzes how the game engages in a system of play driven by its focus on improvement, progression, and expansion, which ends up operating under the same principles settler colonialism has used to justify the expansion of settler-states and the eradication of indigenous populations. Through an examination of the game’s economy, enemies, maps, and music, the essay connects the game’s systems of play to the embedded nature of settler colonialism in the videogame industry—particularly the mobile or casual scene—and contemporary life in settler-states. The ultimate goal is to explain how social meaning is derived from these types of games and what that means for both players and creators in terms of developing new, progressive opportunities for play.

  20. The Relationship Between Brightest Cluster Galaxy Star Formation and the Intracluster Medium in CLASH

    Science.gov (United States)

    Fogarty, Kevin; Postman, Marc; Larson, Rebecca; Donahue, Megan; Moustakas, John

    2017-09-01

    We study the nature of feedback mechanisms in the 11 CLASH brightest cluster galaxies (BCGs) that exhibit extended ultraviolet and nebular line emission features. We estimate star formation rates (SFRs), dust masses, and starburst durations using a Bayesian photometry-fitting technique that accounts for both stellar and dust emission from the UV through far-IR. By comparing these quantities to intracluster medium (ICM) cooling times and freefall times derived from X-ray observations and lensing estimates of the cluster mass distribution, we discover a tight relationship between the BCG SFR and the ICM cooling time to freefall time ratio, {t}{cool}/{t}{ff}, with an upper limit on the intrinsic scatter of 0.15 dex. Furthermore, starburst durations may correlate with ICM cooling times at a radius of 0.025 {R}500, and the two quantities converge upon reaching the gigayear regime. Our results provide a direct observational link between the thermodynamical state of the ICM and the intensity and duration of BCG star formation activity, and appear consistent with a scenario where active galactic nuclei induce condensation of thermally unstable ICM overdensities that fuel long-duration (>1 Gyr) BCG starbursts. This scenario can explain (a) how gas with a low cooling time is depleted without causing a cooling flow and (b) the scaling relationship between SFR and {t}{cool}/{t}{ff}. We also find that the scaling relation between SFR and dust mass in BCGs with SFRs 100 {M}⊙ yr-1) SFRs have dust masses comparable to extreme starbursts.

  1. Biofilm generation by Piscirickettsia salmonis under growth stress conditions: a putative in vivo survival/persistence strategy in marine environments.

    Science.gov (United States)

    Marshall, Sergio H; Gómez, Fernando A; Ramírez, Ramón; Nilo, Luis; Henríquez, Vitalia

    2012-01-01

    Piscirickettsia salmonis is a bacterial fish pathogen seriously threatening the sustainability of the Chilean salmon industry. The biology and life cycle of this bacterium is not completely understood and there are no reports explaining how it survives or persists in marine environments. This work provides descriptive data of P. salmonis behavior when it is exposed to stress conditions, producing large cell aggregates closely resembling typical biofilm structures. In order to track this putative biofilm, we used indirect fluorescence and scanning electron microscopy. Complex masses were observed over time; the bacteria appear to be embedded within a matrix which disappears when it is exposed to cellulase, suggesting a polysaccharide nature typical of biofilm formation. Two lectins (ConA and WGA) were used to characterize the matrix. Both lectins showed a strong reaction with the structure, validating the exopolysaccharide nature of the matrix. Recently, several studies have demonstrated a correlation between toxin/anti-toxin system expression at initial stages of biofilm formation. In this report, QRT-PCR analysis was used with the P. salmonis toxin/anti-toxin mazEF operon, showing induction of these genes at early stages of biofilm formation, suggesting that said formation may be an adaptive strategy for survival and persistence under stress conditions in marine environments. Copyright © 2012 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  2. Susceptibility of 17-4PH stainless steel to stress corrosion cracking in aqueous environments by electrochemical techniques

    International Nuclear Information System (INIS)

    Diaz S, A.C.

    1997-01-01

    The susceptibility of a 17-4PH type steel to Stress Corrosion Cracking (SCC) in low pressure steam turbine environments was assessed using slow strain rate test at 90 Centigrade and at 1.35x10 -6 seg -1 . Environments tested included different concentrated solutions of NaCl, NaOH and Na 2 SO 4 . It was concluded that this steel is susceptible to SCC in 20 % NaCl and pH=3 and in 20 % NaCl pH=neutral but under cathodic polarisation. The electrochemical potential noise of the specimen was monitored during the test. The naturally fluctuations in potential were arise due to spontaneous brake protective film and were characteristics of the kind of corrosion like pit or stress corrosion cracking. After that using Fast Fourier Transformer (FFT) the noise data set were analyzed to obtain power spectral density plots which showed differences between general corrosion and localized corrosion. Polarization curves were carry out at two different rates and them showed the general behavior of the systems. (Author)

  3. Theoretical and experimental study of stress corrosion cracking of pipeline steel in near neutral pH environment

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, B.; Fan, J.; Chudnovsky, A. [Illinois Univ., Chicago, IL (United States); Gogotsi, Y. [Drexel Univ., Philadelphia, PA (United States); Teitsma, A. [Gas Technology Inst., Chicago, IL (United States)

    2000-07-01

    Field observations indicate that stress corrosion cracking (SCC) in a near neutral pH environment starts with microcracks growing from corrosion pits on the external surface of the buried pipe. A complex phenomenon, SCC combines stochasticity and determinism resulting in the evolution of a SCC colony. The authors proposed a statistical model which generates a random field of corrosion pits and crack initiation at randomly selected pits. Using the framework of the Crack Layer theory, a thermodynamic model of individual stress corrosion growth was also developed recently. Relations between the crack growth, hydrogen diffusion and corrosion rates on one hand and corresponding thermodynamic forces on the other were used to develop the mathematical realization of the stress corrosion crack growth model. Additionally, there is a quick overview of the experimental program for determination of the kinetic coefficients employed in the crack growth equations. A simulation of SCC colony evolution, including a stage of the large-scale crack interaction is provided by applying the individual crack growth law to random configuration of multiple cracks. Finally, the FRANC2D Finite Element Methods resulted in a computer simulation of multi-crack cluster formation within the colony. 14 refs., 15 figs.

  4. Environment

    International Nuclear Information System (INIS)

    McIntyre, A.D.; Turnbull, R.G.H.

    1992-01-01

    The development of the hydrocarbon resources of the North Sea has resulted in both offshore and onshore environmental repercussions, involving the existing physical attributes of the sea and seabed, the coastline and adjoining land. The social and economic repercussions of the industry were equally widespread. The dramatic and speedy impact of the exploration and exploitation of the northern North Sea resources in the early 1970s, on the physical resources of Scotland was quickly realised together with the concern that any environmental and social damage to the physical and social fabric should be kept to a minimum. To this end, a wide range of research and other activities by central and local government, and other interested agencies was undertaken to extend existing knowledge on the marine and terrestrial environments that might be affected by the oil and gas industry. The outcome of these activities is summarized in this paper. The topics covered include a survey of the marine ecosystems of the North Sea, the fishing industry, the impact of oil pollution on seabirds and fish stocks, the ecology of the Scottish coastline and the impact of the petroleum industry on a selection of particular sites. (author)

  5. The Metabolic Syndrome, Oxidative Stress, Environment, and Cardiovascular Disease: The Great Exploration

    Science.gov (United States)

    Hutcheson, Rebecca; Rocic, Petra

    2012-01-01

    The metabolic syndrome affects 30% of the US population with increasing prevalence. In this paper, we explore the relationship between the metabolic syndrome and the incidence and severity of cardiovascular disease in general and coronary artery disease (CAD) in particular. Furthermore, we look at the impact of metabolic syndrome on outcomes of coronary revascularization therapies including CABG, PTCA, and coronary collateral development. We also examine the association between the metabolic syndrome and its individual component pathologies and oxidative stress. Related, we explore the interaction between the main external sources of oxidative stress, cigarette smoke and air pollution, and metabolic syndrome and the effect of this interaction on CAD. We discuss the apparent lack of positive effect of antioxidants on cardiovascular outcomes in large clinical trials with emphasis on some of the limitations of these trials. Finally, we present evidence for successful use of antioxidant properties of pharmacological agents, including metformin, statins, angiotensin II type I receptor blockers (ARBs), and angiotensin II converting enzyme (ACE) inhibitors, for prevention and treatment of the cardiovascular complications of the metabolic syndrome. PMID:22829804

  6. Improvement in the bioenergetics system of plants under metal stress environment via seaweeds

    International Nuclear Information System (INIS)

    Azmat, R.; Askari, S.

    2015-01-01

    The effects of Hg and its remediation through seaweeds on seedlings were escorted in a greenhouse experiment in a randomized block design. The effects of Hg were monitored in relation with bioenergetics system of Trigonella foenumgraecum plant at test site scale. Plants that were exposed to Hg, showed affect in diverse ways, including affinity to suffer in morphological as well as on sugar metabolism. The stress imposed by Hg exposure also extends to chloroplast pigments that lead to the distorted photosynthetic apparatus. The outcomes of reduced contents of photosynthetic machinery related with reduced contents of glucose, sucrose, total soluble sugars and carbohydrate contents of plants. These contents plays vital rule for providing bioenergy to the plant growth regulation. It was suggested that Hg is lethal for plant bioenergetics system due to which plants fail to survive under stress. The lethal effects of Hg were tried to remediate through green seaweeds (Codium iyengrii). It was observed that seaweeds successfully controlled the mobility of Hg metal and improves the plant growth regulatory system at lower applied dose only. While at higher dose of Hg, seaweeds were also effective but to a certain limits. It was established that continuous addition of Hg in soil and aquatic resources execute to the plant productivity. It is demand of time to develop alternative eco-friendly remediation technologies for controlling, cleaning Hg-polluted zones. (author)

  7. Asellus and Gammarus spp. (Crustacea) in changing environments: effects of acid stress and habitat permanence

    Energy Technology Data Exchange (ETDEWEB)

    Hargeby, A.

    1993-03-01

    The research underlying this thesis included laboratory and field studies on how acid stress affects the benthic crustaceans Asellus aquaticus L. and Gammarus pulex (L.). A laboratory chamber was constructed to study growth and survival of G. pulex during acid stress. Low pH (6.0) caused 64-92% mortality within three weeks and reduced growth rate and food conversion efficiency in surviving animals. In a field experiment along a pH gradient, the mortality of G. pulex increased below pH 6. The whole-body content of sodium and potassium was reduced in surviving individuals, indicating osmoregulatory disturbance. In Asellus aquaticus, mortality was not affected by pH within the tested range (4.3-7.5). Laboratory experiments showed that interspecific interactions between A. aquaticus and G. pulex can include both exploitative competition and predation by G. pulex on A. aquaticus. Effects of seasonal habitat alterations was studied in a lake by comparing invertebrate assemblages associated with two species of submerged macroalgae (Characea), one perennial and one senescent during autumn. (28 refs.).

  8. The Metabolic Syndrome, Oxidative Stress, Environment, and Cardiovascular Disease: The Great Exploration

    Directory of Open Access Journals (Sweden)

    Rebecca Hutcheson

    2012-01-01

    Full Text Available The metabolic syndrome affects 30% of the US population with increasing prevalence. In this paper, we explore the relationship between the metabolic syndrome and the incidence and severity of cardiovascular disease in general and coronary artery disease (CAD in particular. Furthermore, we look at the impact of metabolic syndrome on outcomes of coronary revascularization therapies including CABG, PTCA, and coronary collateral development. We also examine the association between the metabolic syndrome and its individual component pathologies and oxidative stress. Related, we explore the interaction between the main external sources of oxidative stress, cigarette smoke and air pollution, and metabolic syndrome and the effect of this interaction on CAD. We discuss the apparent lack of positive effect of antioxidants on cardiovascular outcomes in large clinical trials with emphasis on some of the limitations of these trials. Finally, we present evidence for successful use of antioxidant properties of pharmacological agents, including metformin, statins, angiotensin II type I receptor blockers (ARBs, and angiotensin II converting enzyme (ACE inhibitors, for prevention and treatment of the cardiovascular complications of the metabolic syndrome.

  9. Adapting the Apsim model for assessing maize cultivars performances through European stressing environments

    OpenAIRE

    Lacube, Sébastien; Tardieu, Francois; Parent, Boris; Hammer, Graeme

    2015-01-01

    Genetic progress will largely depend on the adaptation of new genotypes to the diversity of environments, market requirements and types of agriculture. Most experiments for cultivar evaluation use networks of field experiments to assess the suitability of hundreds of genotypes to environmental conditions. In most cases, most of them run for a few years, thereby taking into account a small fraction of the climatic variability. The use of crop models for predicting plant performance under di...

  10. Stress !!!

    NARCIS (Netherlands)

    Fledderus, M.

    2012-01-01

    Twee op de vijf UT-studenten hebben last van ernstige studiestress, zo erg zelfs dat het ze in hun privéleven belemmert. Die cijfers komen overeen met het landelijk beeld van stress onder studenten. Samen met 14 andere universiteits- en hogeschoolbladen enquêteerde UT Nieuws bijna 5500 studenten.

  11. Stress experiences in neighborhood and social environments (SENSE): a pilot study to integrate the quantified self with citizen science to improve the built environment and health.

    Science.gov (United States)

    Chrisinger, Benjamin W; King, Abby C

    2018-06-05

    Identifying elements of one's environment-observable and unobservable-that contribute to chronic stress including the perception of comfort and discomfort associated with different settings, presents many methodological and analytical challenges. However, it also presents an opportunity to engage the public in collecting and analyzing their own geospatial and biometric data to increase community member understanding of their local environments and activate potential environmental improvements. In this first-generation project, we developed a methodology to integrate geospatial technology with biometric sensing within a previously developed, evidence-based "citizen science" protocol, called "Our Voice." Participants used a smartphone/tablet-based application, called the Discovery Tool (DT), to collect photos and audio narratives about elements of the built environment that contributed to or detracted from their well-being. A wrist-worn sensor (Empatica E4) was used to collect time-stamped data, including 3-axis accelerometry, skin temperature, blood volume pressure, heart rate, heartbeat inter-beat interval, and electrodermal activity (EDA). Open-source R packages were employed to automatically organize, clean, geocode, and visualize the biometric data. In total, 14 adults (8 women, 6 men) were successfully recruited to participate in the investigation. Participants recorded 174 images and 124 audio files with the DT. Among captured images with a participant-determined positive or negative rating (n = 131), over half were positive (58.8%, n = 77). Within-participant positive/negative rating ratios were similar, with most participants rating 53.0% of their images as positive (SD 21.4%). Significant spatial clusters of positive and negative photos were identified using the Getis-Ord Gi* local statistic, and significant associations between participant EDA and distance to DT photos, and street and land use characteristics were also observed with linear mixed

  12. Estimation of durability of GFRP laminates under stress-corrosive environments using acoustic emission; AE wo mochiita ouryoku fushoku kankyoka deno GFRP no taikyusei hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Yoshimichi. [Seikow Chemical Engineering and Machinery, Ltd., Hyogo (Japan). Laboratory of Composite Materials; Nishiyabu, Kazuaki. [Osaka Prefectural College of Tehcnology, Osaka (Japan)

    1999-05-15

    The objective of this investigation is to estimate the creep life of glass fiber reinforced plastic (GFRP) under stress-corrosive environments using acoustic emission(AE). The laminates were fabricated using combinations of vinylester resin (R806) and random fiber mat or woven cloth. The creep tests were conducted in 5% nitric acid (HNO{sub 3}) environment. The AE depends on the loading level and the environment condition. For the creep test, the woven cloth reinforced specimens gave higher number of AE counts than the random mat reinforced specimens. The creep life decreased with increasing creep stress, whereas the rate of AE counts increased with increasing creep stress. A linear relationship was found between the creep life and the AE count rate. Using the proposed equation, a prediction of the creep life of GFRP under corrosive environments would presumably be possible. (author)

  13. Octocorals in a changing environment: Seasonal response of stress biomarkers in natural populations of Veretillum cynomorium

    Science.gov (United States)

    Madeira, Carolina; Madeira, Diana; Vinagre, Catarina; Diniz, Mário

    2015-09-01

    Current concerns about climate change emphasize the need for an accurate monitoring of physiological conditions in wild populations. Therefore, the aims of this work were to a) assess the response of the octocoral Veretillum cynomorium to thermal variation in natural populations during low tide, by quantifying several biochemical indicators of thermal and oxidative stress and b) evaluate the effect of seasonality in the results and the adequacy of the use of biochemical indicators of stress in field monitoring studies in octocorals. Sampling took place during spring (April) and summer (June). Heat shock protein (Hsp70) and ubiquitin (Ub) content, enzyme activities - superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST), and lipid peroxidation (LPO) were assessed in rachis and peduncle tissues separately. The results showed significant seasonal fluctuations in the set of biomarkers tested. Differences were detected between spring and summer, with significant decreases in biomarker levels from April to June being a major observed trend. These results suggest that V. cynomorium is thermo-tolerant during summer low tide conditions. Seasonal variation seems to reflect a metabolic suppression strategy and/or may also be related to seasonal changes in food availability and reproductive status. Differences in activity between tissue types were also found significant for GST, LPO and Ub. Biomarker levels were correlated with total protein concentration, but not with wet body weight of the specimens. This study suggests that season influences the expression of biomarkers and must be taken into consideration in the preliminary stages of sampling design for climate change biomonitoring studies. In addition, the results suggest that this octocoral species is likely to survive in future challenging thermal conditions.

  14. Approach to stress tests in SIP environment based on marginal analysis

    OpenAIRE

    Voznak, Miroslav; Rozhon, Jan

    2013-01-01

    In the field of performance metrics and measurements of SIP (Session Initiation Protocol) Proxy and B2BUA (Back-to-Back User Agent) no standardized methodology has been presented yet. This gap results in a problematic determination of a hardware, the performance of which would be cost-effective and sufficient for the running the SIP Server in a given environment. Today practice relies on the administrator’s skills and experience with the needs of the telephony infrastructure. From this and th...

  15. An investigation into the impact of cryogenic environment on mechanical stresses in FRP composites

    Science.gov (United States)

    Fifo, O.; Basu, B.

    2015-07-01

    Fibre reinforced polymer (FRP) composites are fast becoming a highly utilised engineering material for high performance applications due to their light weight and high strength. Carbon fibre and other high strength fibres are commonly used in design of aerospace structures, wind turbine blades, etc. and potentially for propellant tanks of launch vehicles. For the aforementioned fields of application, stability of the material is essential over a wide range of temperature particularly for structures in hostile environments. Many studies have been conducted, experimentally, over the last decade to investigate the mechanical behaviour of FRP materials at varying subzero temperature. Likewise, tests on aging and cycling effect (room to low temperature) on the mechanical response of FRP have been reported. However, a relatively lesser focused area has been the mechanical behaviour of FRP composites under cryogenic environment. This article reports a finite element method of investigating the changes in the mechanical characteristics of an FRP material when temperature based analysis falls below zero. The simulated tests are carried out using a finite element package with close material properties used in the cited literatures. Tensile test was conducted and the results indicate that the mechanical responses agree with those reported in the literature sited.

  16. Index of thermal stress for cows (ITSC) under high solar radiation in tropical environments

    Science.gov (United States)

    Da Silva, Roberto Gomes; Maia, Alex Sandro C.; de Macedo Costa, Leonardo Lelis

    2015-05-01

    This paper presents a new thermal stress index for dairy cows in inter-tropical regions, with special mention to the semi-arid ones. Holstein cows were measured for rectal temperature ( T R), respiratory rate ( F R) and rates of heat exchange by convection ( C), radiation ( R), skin surface evaporation ( E S) and respiratory evaporation ( E R) in the north eastern region of Brazil, after exposure to sun for several hours. Average environmental measurements during the observations were air temperature ( T A) 32.4 °C (24.4-38.9°), wind speed ( U) 1.8 m.s-1 (0.01-11.0), relative humidity 63.6 % (36.8-81.5) and short-wave solar radiation 701.3 W m-2 (116-1,295). The effective radiant heat load (ERHL) was 838.5 ± 4.9 W m-2. Values for the atmospheric transmittance ( τ) were also determined for tropical regions, in order to permit adequate estimates of the solar radiation. The average value was τ = 0.611 ± 0.004 for clear days with some small moving clouds, with a range of 0.32 to 0.91 in the day period from 1000 to 1300 hours. Observed τ values were higher (0.62-0.66) for locations near the seacoast and in those regions well-provided with green fields. Effects of month, location and time of the day were all statistically significant ( P cows exposed for 1 to 8 h to sun during the day; in 7 months (February, March, April, July, August, September and November), 4 days per month on the average. A principal component analysis summarised the T R, F R, C, R, E S and E R measurements into just one synthetic variable ( y 1); several indexes were then obtained by multiple regression of y 1 on the four environmental variables and its combinations, by using Origin 8.1 software (OriginLab Corp.). The chosen equation was the index of thermal stress for cows, ITSC = 77.1747 + 4.8327 T A - 34.8189 U + 1.111 U 2 + 118.6981 P V - 14.7956 P V 2 - 0.1059 ERHL with r 2 = 0.812. The correlations of ITSC with T R, F R, C, E S, R and E R were 0.275, 0.255, -0.493, -0.647, -0.818 and 0

  17. The influence of perceived stress on work-family conflict and mental health: the moderating effect of person-environment fit.

    Science.gov (United States)

    Chu, Li-Chuan

    2014-07-01

    This study examines whether higher perceived stress among female hospital workers can result in more serious work-family conflict (WFC) and poorer mental health, and also identifies the role that person-environment (P-E) fit plays in moderating these relationships. Female hospital workers with higher perceived stress tend to report greater WFC and worse mental health than others with less perceived stress. A better fit between a person and her environment may lead to lower perceived stress. As a result, she may experience less WFC and better mental health. This study adopts a longitudinal design with 273 participants, all of whom are employed by hospitals in Taiwan. All hypotheses are tested using hierarchical regression analyses. The results show that perceived stress is an effective predictor of WFC and mental health status, whereas the P-E fit can moderate these relationships. Hospitals should pay more attention to the negative effects of perceived high stress on the WFC levels and mental health of their female employees. The P-E fit can buffer effectively the impact of perceived stress on both WFC and mental health. If hospitals can adopt appropriate human resource management practices as well as monitor and manage the P-E fit continuously, they can better help their employees to fit into the overall hospital environment. © 2012 John Wiley & Sons Ltd.

  18. Ability of crassulacean acid metabolism plants to overcome interacting stresses in tropical environments.

    Science.gov (United States)

    Lüttge, Ulrich

    2010-01-01

    Single stressors such as scarcity of water and extreme temperatures dominate the struggle for life in severely dry desert ecosystems or cold polar regions and at high elevations. In contrast, stress in the tropics typically arises from a dynamic network of interacting stressors, such as availability of water, CO(2), light and nutrients, temperature and salinity. This requires more plastic spatio-temporal responsiveness and versatility in the acquisition and defence of ecological niches. The mode of photosynthesis of crassulacean acid metabolism (CAM) is described and its flexible expression endows plants with powerful strategies for both acclimation and adaptation. Thus, CAM plants are able to inhabit many diverse habitats in the tropics and are not, as commonly thought, successful predominantly in dry, high-insolation habitats. Typical tropical CAM habitats or ecosystems include exposed lava fields, rock outcrops of inselbergs, salinas, savannas, restingas, high-altitude páramos, dry forests and moist forests. Morphotypical and physiotypical plasticity of CAM phenotypes allow a wide ecophysiological amplitude of niche occupation in the tropics. Physiological and biochemical plasticity appear more responsive by having more readily reversible variations in performance than do morphological adaptations. This makes CAM plants particularly fit for the multi-factor stressor networks of tropical forests. Thus, while the physiognomy of semi-deserts outside the tropics is often determined by tall succulent CAM plants, tropical forests house many more CAM plants in terms of quantity (biomass) and quality (species diversity).

  19. TEM characterisation of stress corrosion cracks in nickel based alloys: effect of chromium content and chemistry of environment

    International Nuclear Information System (INIS)

    Delabrouille, F.

    2004-11-01

    Stress corrosion cracking (SCC) is a damaging mode of alloys used in pressurized water reactors, particularly of nickel based alloys constituting the vapour generator tubes. Cracks appear on both primary and secondary sides of the tubes, and more frequently in locations where the environment is not well defined. SCC sensitivity of nickel based alloys depends of their chromium content, which lead to the replacement of alloy 600 (15 % Cr) by alloy 690 (30 % Cr) but this phenomenon is not yet very well understood. The goal of this thesis is two fold: i) observe the effect of chromium content on corrosion and ii) characterize the effect of environment on the damaging process of GV tubes. For this purpose, one industrial tube and several synthetic alloys - with controlled chromium content - have been studied. Various characterisation techniques were used to study the corrosion products on the surface and within the SCC cracks: SIMS; TEM - FEG: thin foil preparation, HAADF, EELS, EDX. The effect of chromium content and surface preparation on the generalised corrosion was evidenced for synthetic alloys. Moreover, we observed the penetration of oxygen along triple junctions of grain boundaries few micrometers under the free surface. SCC tests show the positive effect of chromium for contents varying from 5 to 30 % wt. Plastic deformation induces a modification of the structure, and thus of the protective character, of the internal chromium rich oxide layer. SCC cracks which developed in different chemical environments were characterised by TEM. The oxides which are formed within the cracks are different from what is observed on the free surface, which reveals a modification of medium and electrochemical conditions in the crack. Finally we were able to evidence some structural characteristics of the corrosion products (in the cracks and on the surface) which turn to be a signature of the chemical environment. (author)

  20. Effect of Environment on Stress-Rupture Behavior of a Carbon Fiber-Reinforced Silicon Carbide (C/SiC) Ceramic Matrix Composite

    Science.gov (United States)

    Verrilli, Michael J.; Opila, Elizabeth J.; Calomino, Anthony; Kiser, J. Douglas

    2002-01-01

    Stress-rupture tests were conducted in air, vacuum, and steam-containing environments to identify the failure modes and degradation mechanisms of a carbon fiber-reinforced silicon carbide (C/SiC) composite at two temperatures, 600 and 1200 C. Stress-rupture lives in air and steam containing environments (50 - 80% steam with argon) are similar for a composite stress of 69 MPa at 1200 C. Lives of specimens tested in a 20% steam/argon environment were about twice as long. For tests conducted at 600 C, composite life in 20% steam/argon was 20 times longer than life in air. Thermogravimetric analysis of the carbon fibers was conducted under similar conditions to the stress-rupture tests. The oxidation rate of the fibers in the various environments correlated with the composite stress-rupture lives. Examination of the failed specimens indicated that oxidation of the carbon fibers was the primary damage mode for specimens tested in air and steam environments at both temperatures.

  1. A Proteome Translocation Response to Complex Desert Stress Environments in Perennial Phragmites Sympatric Ecotypes with Contrasting Water Availability.

    Science.gov (United States)

    Li, Li; Chen, Xiaodan; Shi, Lu; Wang, Chuanjing; Fu, Bing; Qiu, Tianhang; Cui, Suxia

    2017-01-01

    After a long-term adaptation to desert environment, the perennial aquatic plant Phragmites communis has evolved a desert-dune ecotype. The desert-dune ecotype (DR) of Phragmites communis showed significant differences in water activity and protein distribution compared to its sympatric swamp ecotype (SR). Many proteins that were located in the soluble fraction of SR translocated to the insoluble fraction of DR, suggesting that membrane-associated proteins were greatly reinforced in DR. The unknown phenomenon in plant stress physiology was defined as a proteome translocation response. Quantitative 2D-DIGE technology highlighted these 'bound' proteins in DR. Fifty-eight kinds of proteins were identified as candidates of the translocated proteome in Phragmites . The majority were chloroplast proteins. Unexpectedly, Rubisco was the most abundant protein sequestered by DR. Rubisco activase, various chaperons and 2-cysteine peroxiredoxin were major components in the translocation response. Conformational change was assumed to be the main reason for the Rubisco translocation due to no primary sequence difference between DR and SR. The addition of reductant in extraction process partially reversed the translocation response, implying that intracellular redox status plays a role in the translocation response of the proteome. The finding emphasizes the realistic significance of the membrane-association of biomolecule for plant long-term adaptation to complex stress conditions.

  2. Physical activity: does environment make a difference for tension, stress, emotional outlook, and perceptions of health status?

    Science.gov (United States)

    Puett, Robin; Teas, Jane; España-Romero, Vanesa; Artero, Enrique Garcia; Lee, Duck-chul; Baruth, Meghan; Sui, Xuemei; Montresor-López, Jessica; Blair, Steven N

    2014-11-01

    The importance of physical activity for health is well-established. Questions remain whether outdoor exercise additionally benefits overall mental and physical well-being. Using cross-sectional data from the Aerobics Center Longitudinal Study, we examined relationships of physical activity environment (PAE) with reported tension, stress, emotional outlook, and health. 11,649 participants were included. 18% exercised indoors, 54% outdoors, and 28% in both. Participants who exercised partially or entirely outdoors exercised more. In fully adjusted models, for women combined PAE was protective for worse emotional outlook (OR: 0.72; 95% CI: 0.52-0.98). Combined PAE was also protective for reported poor health (OR for women: 0.63; 95% CI: 0.44-0.91; OR for men: 0.75; 95% CI: 0.61-0.92). Amount of physical activity modified PAE relationships with outcomes. Combined and outdoor PAE were more consistently protective for worse outcomes among high activity participants. Regardless of PAE, better outcomes were observed in active versus inactive participants. The current study suggests addition of outdoor PAE may be linked with better stress management, outlook and health perceptions for more active populations, whereas indoor PAE may be more important for low active populations. Further research should examine the order of causation and whether type of outdoor PAE (eg, urban, natural) is important.

  3. Investigation of Bucket Wheel Excavator Lattice Structure Internal Stress in Harsh Environment through a Remote Measurement System

    Science.gov (United States)

    Risteiu, M.; Dobra, R.; Andras, I.; Roventa, M.; Lorincz, A.

    2017-06-01

    The paper shows the results of a lab model for strain gauges based measuring system for multiple measuring heads of the mechanical stress in lattice structures of the bucket wheel excavator for open pit mines-harsh environment. The system is designed around a microcontroller system. Because of specific working conditions, the measuring system sends data to a processing system (a PC with Matlab software), we have implemented a secure communication solution based on ISM standard, by using NRF24L01 module. The transceiver contains a fully integrated frequency synthesizer based on crystal oscillator, and a Enhanced ShockBurst™ protocol engine. The proposed solution has a current consumption around 9.0 mA at an output power of -6dBm and 12.3mA in RX mode. Built-in Power Down and Standby modes makes power saving easily realizable for our solution battery powered. The stress from structures is taken by specific strain gauges adapted to low frequency vibrations. We are using a precision 24-bit analog-to-digital converter (ADC) designed for weigh scales and industrial control applications to interface directly with a bridge sensor-instrumentation device, with low drift voltage, low noise, common mode rejection signal, frequency and temperature stability. As backup implementation for measurements a high speed storage implementation is used.

  4. Stress corrosion cracking of austenitic weld deposits in a salt spray environment

    Energy Technology Data Exchange (ETDEWEB)

    Cai, J.B. [Institute of Materials Engineering, National Taiwan Ocean University, Keelung 202, Taiwan (China); Yu, C.; Shiue, R.K. [Department of Materials Engineering, National Taiwan University, Taipei 106, Taiwan (China); Tsay, L.W., E-mail: b0186@mail.ntou.edu.tw [Institute of Materials Engineering, National Taiwan Ocean University, Keelung 202, Taiwan (China)

    2015-10-15

    ER 308L and 309LMo were utilized as the filler metals for the groove and overlay welds of a 304L stainless steel substrate, which was prepared via a gas tungsten arc-welding process in multiple passes. U-bend and weight-loss tests were conducted by testing the welds in a salt spray containing 10 wt% NaCl at 120 °C. The dissolution of the skeletal structure in the fusion zone (FZ) caused the stress corrosion cracking (SCC) of the weld. The FZ in the cold-rolled condition showed the longest single crack length in the U-bend tests. Moreover, sensitization treatment at 650 °C for 10 h promoted the formation of numerous fine cracks, which resulted in a high SCC susceptibility. The weight loss of the deposits was consistent with the SCC susceptibility of the welds in a salt spray. The 309LMo deposit was superior to the 308L deposit in the salt spray. - Highlights: • ER 308L and 309LMo were utilized as fillers for the groove and overlay welds of a 304L SS. • U-bend and weight-loss tests in a salt spray containing 10 wt% NaCl at 120 °C were performed. • The dissolution of solidified structure caused the SCC of the welds in a salt spray. • Sensitization treatment increased the weight loss and SCC susceptibility of the deposits. • The weight loss of the weld deposits was related to their SCC susceptibility in a salt spray.

  5. Stress corrosion cracking of austenitic weld deposits in a salt spray environment

    International Nuclear Information System (INIS)

    Cai, J.B.; Yu, C.; Shiue, R.K.; Tsay, L.W.

    2015-01-01

    ER 308L and 309LMo were utilized as the filler metals for the groove and overlay welds of a 304L stainless steel substrate, which was prepared via a gas tungsten arc-welding process in multiple passes. U-bend and weight-loss tests were conducted by testing the welds in a salt spray containing 10 wt% NaCl at 120 °C. The dissolution of the skeletal structure in the fusion zone (FZ) caused the stress corrosion cracking (SCC) of the weld. The FZ in the cold-rolled condition showed the longest single crack length in the U-bend tests. Moreover, sensitization treatment at 650 °C for 10 h promoted the formation of numerous fine cracks, which resulted in a high SCC susceptibility. The weight loss of the deposits was consistent with the SCC susceptibility of the welds in a salt spray. The 309LMo deposit was superior to the 308L deposit in the salt spray. - Highlights: • ER 308L and 309LMo were utilized as fillers for the groove and overlay welds of a 304L SS. • U-bend and weight-loss tests in a salt spray containing 10 wt% NaCl at 120 °C were performed. • The dissolution of solidified structure caused the SCC of the welds in a salt spray. • Sensitization treatment increased the weight loss and SCC susceptibility of the deposits. • The weight loss of the weld deposits was related to their SCC susceptibility in a salt spray.

  6. Effects of Cr and Nb contents on the susceptibility of Alloy 600 type Ni-base alloys to stress-corrosion cracking in a simulated BWR environment

    International Nuclear Information System (INIS)

    Akashi, Masatsune

    1995-01-01

    In order to discuss the effects of chromium and niobium contents on the susceptibility of Alloy 600 type nickel-base alloys to stress-corrosion cracking in the BWR primary coolant environment, a series of creviced bent-beam (CBB) tests were conducted in a high-temperature, high-purity water environment. Chromium, niobium, and titanium as alloying elements improved the resistivity to stress-corrosion cracking, whereas carbon enhanced the susceptibility to it. Alloy-chemistry-based correlations have been defined to predict the relative resistances of alloys to stress-corrosion cracking. A strong correlation was found, for several heats of alloys, between grain-boundary chromium depletion and the susceptibility to stress-corrosion cracking

  7. Stress.

    Science.gov (United States)

    Chambers, David W

    2008-01-01

    We all experience stress as a regular, and sometimes damaging and sometimes useful, part of our daily lives. In our normal ups and downs, we have our share of exhaustion, despondency, and outrage--matched with their corresponding positive moods. But burnout and workaholism are different. They are chronic, dysfunctional, self-reinforcing, life-shortening habits. Dentists, nurses, teachers, ministers, social workers, and entertainers are especially susceptible to burnout; not because they are hard-working professionals (they tend to be), but because they are caring perfectionists who share control for the success of what they do with others and perform under the scrutiny of their colleagues (they tend to). Workaholics are also trapped in self-sealing cycles, but the elements are ever-receding visions of control and using constant activity as a barrier against facing reality. This essay explores the symptoms, mechanisms, causes, and successful coping strategies for burnout and workaholism. It also takes a look at the general stress response on the physiological level and at some of the damage American society inflicts on itself.

  8. The effect of the work environment and performance-based self-esteem on cognitive stress symptoms among Danish knowledge workers.

    Science.gov (United States)

    Albertsen, Karen; Rugulies, Reiner; Garde, Anne Helene; Burr, Hermann

    2010-02-01

    Interpersonal relations at work as well as individual factors seem to play prominent roles in the modern labour market, and arguably also for the change in stress symptoms. The aim was to examine whether exposures in the psychosocial work environment predicted symptoms of cognitive stress in a sample of Danish knowledge workers (i.e. employees working with sign, communication or exchange of knowledge) and whether performance-based self-esteem had a main effect, over and above the work environmental factors. 349 knowledge workers, selected from a national, representative cohort study, were followed up with two data collections, 12 months apart. We used data on psychosocial work environment factors and cognitive stress symptoms measured with the Copenhagen Psychosocial Questionnaire (COPSOQ), and a measurement of performance-based self-esteem. Effects on cognitive stress symptoms were analyzed with a GLM procedure with and without adjustment for baseline level. Measures at baseline of quantitative demands, role conflicts, lack of role clarity, recognition, predictability, influence and social support from management were positively associated with cognitive stress symptoms 12 months later. After adjustment for baseline level of cognitive stress symptoms, follow-up level was only predicted by lack of predictability. Performance-based self-esteem was prospectively associated with cognitive stress symptoms and had an independent effect above the psychosocial work environment factors on the level of and changes in cognitive stress symptoms. The results suggest that both work environmental and individual characteristics should be taken into account in order to capture sources of stress in modern working life.

  9. The Influence of Urban Environments on Oxidative Stress Balance: A Case Study on the House Sparrow in the Iberian Peninsula

    Directory of Open Access Journals (Sweden)

    Amparo Herrera-Dueñas

    2017-09-01

    Full Text Available The House Sparrow is a globally distributed species and is closely associated with anthropised environments. They are well-adapted to urban life; therefore the decline of their populations in Europe represents an unexpected event that demands an investigation into its causes. Causes that have promoted this decline are not well-known, but one of the highlighted hypotheses is an increase of oxidative stress linked to the toxicity of pollution in urban areas. From an ecophysiological perspective, oxidative damage, antioxidant defense, and oxidative balance are considered reliable indicators of environmental stressors such as pollutants. To carry out this study, blood samples were collected from House Sparrows in three different habitats that varied in terms of urbanization degree: urban, suburban, and rural; during the winter and breeding season. According to our results, urban sparrows showed higher levels of oxidative damage and higher activity of antioxidant enzymes, but lower antioxidant capacity in comparison with the rural birds; and these differences especially increase during the breeding season. The maintenance of oxidative balance increases in an urban environment in comparison to a rural one; we suggest that the high level of pollution and the poor quality diet linked to urban environments. The breeding season is expected to be particularly challenging for the oxidative balance of urban birds, when the reallocation of resources between self-maintenance and reproduction may be critical due to the scarcity of antioxidants found in urban areas. This study may contribute to determining the causes of the population decrease of House Sparrows in cities.

  10. Species-Dependent Effects of the Urban Environment on Fatty Acid Composition and Oxidative Stress in Birds

    Directory of Open Access Journals (Sweden)

    Caroline Isaksson

    2017-05-01

    Full Text Available Ecological impacts of urbanization include the loss of biodiversity and changes in species composition and population densities. However, how the urban environment affects fundamental physiological parameters is largely unknown. Here, we investigated physiological components related to health and nutrition, namely, plasma fatty acids (FA and lipid peroxidation at inter-habitat and interspecific levels. Specifically, we compared four passerine bird species—the great tit (Parus major, the blue tit (Cyanistes caeruleus, the house sparrow (Passer domesticus, and the tree sparrow (P. montanus—from urban and rural environments. Significant interactions between species and habitat were revealed for the majority of the FAs. Interestingly, the observed inter-habitat variation in FAs was frequently in opposite directions when comparing species from the two families (tits, Paridae; sparrows, Passeridae. These patterns suggest that sparrows and tits feed on different food sources, or modulate their FA metabolism differently, across the urban-rural gradient. By using canonical discriminant analyses (CDA, we further demonstrated species-specific signals in FA composition, with misclassification of species being <1% within habitats and <7% between habitats. Finally, the urban-rural FA differences between species and families were manifested in two indices of health. Firstly, urban blue tits had a higher total ω-6/ω-3 polyunsaturated FA ratio than rural conspecifics, which is believed to increase inflammatory responses. Secondly, urban sparrows of both species showed higher lipid peroxidation indices (indicating a higher susceptibility to lipid peroxidation if exposed to pro-oxidants, and consequently, a higher level of lipid peroxidation compared to their rural conspecifics. Collectively, the species- and habitat-specific differences in plasma FA composition, which are linked to nutrition and metabolism, suggest that the urban environment affect tits and

  11. Drought-tolerance of wheat improved by rhizosphere bacteria from harsh environments: enhanced biomass production and reduced emissions of stress volatiles.

    Directory of Open Access Journals (Sweden)

    Salme Timmusk

    Full Text Available Water is the key resource limiting world agricultural production. Although an impressive number of research reports have been published on plant drought tolerance enhancement via genetic modifications during the last few years, progress has been slower than expected. We suggest a feasible alternative strategy by application of rhizospheric bacteria coevolved with plant roots in harsh environments over millions of years, and harboring adaptive traits improving plant fitness under biotic and abiotic stresses. We show the effect of bacterial priming on wheat drought stress tolerance enhancement, resulting in up to 78% greater plant biomass and five-fold higher survivorship under severe drought. We monitored emissions of seven stress-related volatiles from bacterially-primed drought-stressed wheat seedlings, and demonstrated that three of these volatiles are likely promising candidates for a rapid non-invasive technique to assess crop drought stress and its mitigation in early phases of stress development. We conclude that gauging stress by elicited volatiles provides an effectual platform for rapid screening of potent bacterial strains and that priming with isolates of rhizospheric bacteria from harsh environments is a promising, novel way to improve plant water use efficiency. These new advancements importantly contribute towards solving food security issues in changing climates.

  12. Do neighborhood economic characteristics, racial composition, and residential stability predict perceptions of stress associated with the physical and social environment? Findings from a multilevel analysis in Detroit.

    Science.gov (United States)

    Schulz, Amy J; Zenk, Shannon N; Israel, Barbara A; Mentz, Graciela; Stokes, Carmen; Galea, Sandro

    2008-09-01

    As the body of evidence linking disparities in the health of urban residents to disparate social, economic and environmental contexts grows, efforts to delineate the pathways through which broader social and economic inequalities influence health have burgeoned. One hypothesized pathway connects economic and racial and ethnic inequalities to differentials in stress associated with social and physical environments, with subsequent implications for health. Drawing on data from Detroit, Michigan, we examined contributions of neighborhood-level characteristics (e.g., poverty rate, racial and ethnic composition, residential stability) and individual-level characteristics (e.g., age, gender) to perceived social and physical environmental stress. We found that neighborhood percent African American was positively associated with perceptions of both social and physical environmental stress; neighborhood percent poverty and percent Latino were positively associated with perceived physical environmental stress; and neighborhood residential stability was negatively associated with perceived social environmental stress. At the individual level, whites perceived higher levels of both social and physical environmental stress compared to African American residents of the same block groups, after accounting for other variables included in the models. Our findings suggest the importance of understanding and addressing contributions of neighborhood structural characteristics to perceptions of neighborhood stress. The consistency of the finding that neighborhood racial composition and individual-level race influence perceptions of both social and physical environments suggests the continuing importance of understanding the role played by structural conditions and by personal and collective histories that vary systematically by race and ethnicity within the United States.

  13. "A Clash of Two Worlds"; Disjuncture between the Norms and Values Held by Educational Practitioners and Parents of Children with Behavioural, Emotional and Social Difficulties

    Science.gov (United States)

    Broomhead, Karen

    2014-01-01

    This article, by Karen Broomhead of Liverpool John Moores University, discusses an exploration of the clashing norms, values and expectations of parenting behaviours between parents of children with behavioural, emotional and social difficulties (BESD) and practitioners. Semi-structured interviews with 15 education professionals, employed in both…

  14. Relevance of a Healthy Change Process and Psychosocial Work Environment Factors in Predicting Stress, Health Complaints, and Commitment Among Employees in a Ghanaian Bank

    OpenAIRE

    Quaye, Emmanuel

    2010-01-01

    This thesis was intended to examine the effect of the healthiness of change process and psychosocial work environment factors in predicting job stress, health complaints and commitment among employees in a Ghanaian bank (N=132), undergoing organizational change. The change process was measured in terms of dimensions from the Healthy Change Process Index (HCPI) and the psychosocial work environment was measured by the Demands-Control-Support (DCS) model. Hierarchical regression analyses reveal...

  15. PSYCHOLOGICAL PROBLEMS AND STRESS FACED BY SOLDIERS WHO OPERATE IN ASYMMETRIC WARFARE ENVIRONMENTS: EXPERIENCES IN THE FIELD

    Directory of Open Access Journals (Sweden)

    Giuseppe CAFORIO

    2014-10-01

    Full Text Available This article deals with the problems of anxiety, stress and psychological discomfort that can affect soldiers sent on asymmetric warfare operations. It is based on secondary analysis of the data of two important field researches whose results have recently (2013 been published. Although the two researches adopted different methodologies, the testimonies are fully comparable and show that soldiers from different countries and cultures display common or similar reactions when they are placed in the stress conditions that the asymmetric environment involves. The approach of the paper is drawn up in such a way as to make the reader a participating observer of the reality of such missions. It is therefore centered on the personal testimonies of the soldiers interviewed in the two researches, testimonies reported just as they are, in their simplicity and, often, drama, with comments by the author kept to a minimum in order to give readers ample opportunity to evaluate and interpret the reported texts on their own. The research data, drawn from the declarations of those directly concerned, reveal the existence of a problem of psychological distress resulting from deployment in asymmetric warfare situations that is in part different in the causes of the problems resulting from deployment in traditional combat and affects percentages of participating soldiers that are not high but definitely significant. The highest incidence appears to be constituted by problems relating to reintegration into normal social and working life upon returning from the mission. This is followed in percentage terms by anxiety situations relating to life far from the family, due in large part to a sense of powerlessness for the scant possibility of managing family situations that may have cropped up or already existed beforehand.

  16. Genetic liability, prenatal health, stress and family environment: risk factors in the Harvard Adolescent Family High Risk for schizophrenia study.

    Science.gov (United States)

    Walder, Deborah J; Faraone, Stephen V; Glatt, Stephen J; Tsuang, Ming T; Seidman, Larry J

    2014-08-01

    The familial ("genetic") high-risk (FHR) paradigm enables assessment of individuals at risk for schizophrenia based on a positive family history of schizophrenia in first-degree, biological relatives. This strategy presumes genetic transmission of abnormal traits given high heritability of the illness. It is plausible, however, that adverse environmental factors are also transmitted in these families. Few studies have evaluated both biological and environmental factors within a FHR study of adolescents. We conceptualize four precursors to psychosis pathogenesis: two biological (genetic predisposition, prenatal health issues (PHIs)) and two environmental (family environment, stressful life events (SLEs)). Participants assessed between 1998 and 2007 (ages 13-25) included 40 (20F/20M) adolescents at FHR for schizophrenia (FHRs) and 55 (31F/24M) community controls. 'Genetic load' indexed number of affected family members relative to pedigree size. PHI was significantly greater among FHRs, and family cohesion and expressiveness were less (and family conflict was higher) among FHRs; however, groups did not significantly differ in SLE indices. Among FHRs, genetic liability was significantly associated with PHI and family expressiveness. Prenatal and family environmental disruptions are elevated in families with a first-degree relative with schizophrenia. Findings support our proposed 'polygenic neurodevelopmental diathesis-stress model' whereby psychosis susceptibility (and resilience) involves the independent and synergistic confluence of (temporally-sensitive) biological and environmental factors across development. Recognition of biological and social environmental influences across critical developmental periods points to key issues relevant for enhanced identification of psychosis susceptibility, facilitation of more precise models of illness risk, and development of novel prevention strategies. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. H3K27me3 and H3K4me3 chromatin environment at super-induced dehydration stress memory genes of Arabidopsis thaliana.

    Science.gov (United States)

    Liu, Ning; Fromm, Michael; Avramova, Zoya

    2014-03-01

    Pre-exposure to a stress may alter the plant's cellular, biochemical, and/or transcriptional responses during future encounters as a 'memory' from the previous stress. Genes increasing transcription in response to a first dehydration stress, but producing much higher transcript levels in a subsequent stress, represent the super-induced 'transcription memory' genes in Arabidopsis thaliana. The chromatin environment (histone H3 tri-methylations of Lys 4 and Lys 27, H3K4me3, and H3K27me3) studied at five dehydration stress memory genes revealed existence of distinct memory-response subclasses that responded differently to CLF deficiency and displayed different transcriptional activities during the watered recovery periods. Among the most important findings is the novel aspect of the H3K27me3 function observed at specific dehydration stress memory genes. In contrast to its well-known role as a chromatin repressive mechanism at developmentally regulated genes, H3K27me3 did not prevent transcription from the dehydration stress-responding genes. The high H3K27me3 levels present during transcriptionally inactive states did not interfere with the transition to active transcription and with H3K4me3 accumulation. H3K4me3 and H3K27me3 marks function independently and are not mutually exclusive at the dehydration stress-responding memory genes.

  18. Stress and stressors in the clinical environment: a comparative study of fourth-year student nurses and newly qualified general nurses in Ireland.

    Science.gov (United States)

    Suresh, Patricia; Matthews, Anne; Coyne, Imelda

    2013-03-01

    To measure and compare the perceived levels of job-related stress and stressors of newly qualified nurses and fourth-year student nurses in the clinical environment and to explore the participants' views on stress and stressors. Stress in the nursing workplace has significant consequences for the person, the patient and the organisation, such as psychological and physical health deterioration and impaired professional practice. To address this problem, stress and stressors need to be measured and identified. This study used a cross-sectional survey design and self-reporting questionnaires to measure and compare levels of stress in both groups. Convenience sampling involved all newly qualified nurses (n = 120) and fourth-year student nurses (n = 128) in Dublin North-East region in Ireland. The instrument used was 'The Nursing Stress Scale' (Gray-Toft & Anderson 1981, Journal of Behavioral Assessment 3, 11-23). Descriptive, qualitative analysis was conducted on an open-ended question. Data were obtained from newly qualified nurses (n = 31) and fourth-year student nurses (n = 40) in six acute hospital sites. Levels of perceived stress and stressors were high in both groups. Themes identified from the responses to the open question by both groups included excessive workload, difficult working relationships and unmet clinical learning needs. Student nurses also reported the combination of academic demands with clinical placement as a major stressor. There was no significant difference between each group. Stress continues to be a problem for nurses in the clinical setting. Excessive workload requires urgent attention by hospital managers in view of widespread retention difficulties. Themes identified could provide a framework for possible interventions for improving the clinical environment for nurses. These results can help stakeholders in nurse education and practice to develop interventions to reduce stress for both groups and to ease the transition from student to

  19. Revealing Pesticide Residues Under High Pesticide Stress in Taiwan's Agricultural Environment Probed by Fresh Honey Bee (Hymenoptera: Apidae) Pollen.

    Science.gov (United States)

    Nai, Yu-Shin; Chen, Tsui-Yao; Chen, Yi-Cheng; Chen, Chun-Ting; Chen, Bor-Yann; Chen, Yue-Wen

    2017-10-01

    Significant pesticide residues are among the most serious problems for sustainable agriculture. In the beekeeping environment, pesticides not only impact a honey bee's survival, but they also contaminate bee products. Taiwan's agricultural environment has suffered from pesticide stress that was higher than that found in Europe and America. This study deciphered problems of pesticide residues in fresh honey bee pollen samples collected from 14 monitoring apiaries in Taiwan, which reflected significant contaminations within the honey bee population. In total, 155 pollen samples were screened for 232 pesticides, and 56 pesticides were detected. Among the residues, fluvalinate and chlorpyrifos showed the highest concentrations, followed by carbendazim, carbaryl, chlorfenapyr, imidacloprid, ethion, and flufenoxuron. The average frequency of pesticide residues detected in pollen samples was ca. 74.8%. The amounts and types of pesticides were higher in winter and in southwestern Taiwan. Moreover, five of these pollen samples were contaminated with 11-15 pesticides, with average levels between 1,560 and 6,390 μg/kg. Compared with the literature, this study emphasized that pollen gathered by honey bee was highly contaminated with more pesticides in Taiwan than in the America, France, and Spain. The ubiquity of pesticides in the pollen samples was likely due to the field applications of common pesticides. Recently, the Taiwanese government began to improve the pesticide policy. According to the resurvey data in 2016, there were reductions in several pesticide contamination parameters in pollen samples from west to southwest Taiwan. A long-term investigation of pollen pesticide residues should be conducted to inspect pesticides usage in Taiwan's agriculture. © The Author 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Daily and Momentary Mood and Stress Are Associated with Binge Eating and Vomiting in Bulimia Nervosa Patients in the Natural Environment

    Science.gov (United States)

    Smyth, Joshua M.; Wonderlich, Stephen A.; Heron, Kristin E.; Sliwinski, Martin J.; Crosby, Ross D.; Mitchell, James E.; Engel, Scott G.

    2007-01-01

    The relation of mood and stress to binge eating and vomiting in the natural environments of patients with bulimia nervosa (BN) was examined using real-time data collection. Women (n = 131; mean age = 25.3 years) with BN carried a palmtop computer for 2 weeks and completed ratings of positive affect (PA), negative affect (NA), anger/hostility (AH),…

  1. Analysis of 3D models of octopus estrogen receptor with estradiol: evidence for steric clashes that prevent estrogen binding.

    Science.gov (United States)

    Baker, Michael E; Chandsawangbhuwana, Charlie

    2007-09-28

    Relatives of the vertebrate estrogen receptor (ER) are found in Aplysia californica, Octopus vulgaris, Thais clavigera, and Marisa cornuarietis. Unlike vertebrate ERs, invertebrate ERs are constitutively active and do not bind estradiol. To investigate the molecular basis of the absence of estrogen binding, we constructed a 3D model of the putative steroid-binding domain on octopus ER. Our 3D model indicates that binding of estradiol to octopus ER is prevented by steric clashes between estradiol and amino acids in the steroid-binding pocket. In this respect, octopus ER resembles vertebrate estrogen-related receptors (ERR), which have a ligand-binding pocket that cannot accommodate estradiol. Like ERR, octopus ER also may have the activation function 2 domain (AF2) in a configuration that can bind to coactivators in the absence of estrogens, which would explain constitutive activity of octopus ER.

  2. Cold Stress

    Science.gov (United States)

    ... Publications and Products Programs Contact NIOSH NIOSH COLD STRESS Recommend on Facebook Tweet Share Compartir Workers who ... cold environments may be at risk of cold stress. Extreme cold weather is a dangerous situation that ...

  3. Heat Stress

    Science.gov (United States)

    ... Publications and Products Programs Contact NIOSH NIOSH HEAT STRESS Recommend on Facebook Tweet Share Compartir OSHA-NIOSH ... hot environments may be at risk of heat stress. Exposure to extreme heat can result in occupational ...

  4. Pitting and Stress Corrosion Cracking Susceptibility of Nanostructured Al-Mg Alloys in Natural and Artificial Environments

    Science.gov (United States)

    Sharma, Mala M.; Ziemian, Constance W.

    2008-12-01

    The stress corrosion cracking (SCC) behavior of two developmental nanocrystalline 5083 alloys with varied composition and processing conditions was studied. The results were compared to a commercial aluminum AA 5083 (H111) alloy. The pitting densities, size and depths, and residual tensile strengths were measured after alternate immersion in artificial seawater and atmospheric exposure under different loading conditions. Optical and scanning electron microscopy (SEM) with EDX was used to analyze the fracture surfaces of failed specimen after removal at selected intervals and tensile testing. One of the nanostructured Al-Mg alloys exhibited significantly superior pitting resistance when compared to conventional microstructured AA 5083. Under conditions where pitting corrosion showed up as local tunnels toward phase inclusions, transgranular cracking was observed, whereas under conditions when pitting corrosion evolved along grain boundaries, intergranular cracking inside the pit was observed. Pit initiation resistance of the nano alloys appears to be better than that of the conventional alloys. However, long-term pit propagation is a concern and warrants further study. The objective of this investigation was to obtain information regarding the role that ultra-fine microstructures play in their degradation in marine environments and to provide insight into the corrosion mechanisms and damage processes of these alloys.

  5. Adaptation of children to the new environment as a stress factor in the work of teachers in nursery school

    OpenAIRE

    Vondrová, Terezie

    2018-01-01

    The topic of the bachelor thesis is children's adaptation to the nursery school education as a stress factor for the teachers. The thesis examines five areas which may cause stress to the teachers working with newly come children during the adaptation period and describes strategies teachers employ in order to cope with the stress. The expected stress factors are: children's problematic behavior, school management, colleague and parental pressure exacting fast and smooth adaptation process an...

  6. Relative Humidity and the Susceptibility of Austenitic Stainless Steel to Stress Corrosion Cracking in an impure Plutonium Oxide Environment

    Energy Technology Data Exchange (ETDEWEB)

    Zapp, P.; Duffey, J.; Lam, P.; Dunn, K.

    2010-05-05

    Laboratory tests to investigate the corrosivity of moist plutonium oxide/chloride salt mixtures on 304L and 316L stainless steel coupons showed that corrosion occurred in selected samples. The tests exposed flat coupons for pitting evaluation and 'teardrop' stressed coupons for stress corrosion cracking (SCC) evaluation at room temperature to various mixtures of PuO{sub 2} and chloride-bearing salts for periods up to 500 days. The exposures were conducted in sealed containers in which the oxide-salt mixtures were loaded with about 0.6 wt % water from a humidified helium atmosphere. Observations of corrosion ranged from superficial staining to pitting and SCC. The extent of corrosion depended on the total salt concentration, the composition of the salt and the moisture present in the test environment. The most significant corrosion was found in coupons that were exposed to 98 wt % PuO{sub 2}, 2 wt % chloride salt mixtures that contained calcium chloride and 0.6 wt% water. SCC was observed in two 304L stainless steel teardrop coupons exposed in solid contact to a mixture of 98 wt % PuO{sub 2}, 0.9 wt % NaCl, 0.9 wt % KCl, and 0.2 wt % CaCl{sub 2}. The cracking was associated with the heat-affected zone of an autogenous weld that ran across the center of the coupon. Cracking was not observed in coupons exposed to the headspace gas above the solid mixture, or in coupons exposed to other mixtures with either no CaCl{sub 2} or 0.92 wt% CaCl{sub 2}. SCC was present where the 0.6 wt % water content exceeded the value needed to fully hydrate the available CaCl{sub 2}, but was absent where the water content was insufficient. These results reveal the significance of the relative humidity in the austenitic stainless steels environment to their susceptibility to corrosion. The relative humidity in the test environment was controlled by the water loading and the concentration of the hydrating salts such as CaCl{sub 2}. For each salt or salt mixture there is a threshold

  7. Comparison of Effect of Two-Hour Exposure to Forest and Urban Environments on Cytokine, Anti-Oxidant, and Stress Levels in Young Adults.

    Science.gov (United States)

    Im, Su Geun; Choi, Han; Jeon, Yo-Han; Song, Min-Kyu; Kim, Won; Woo, Jong-Min

    2016-06-23

    The purpose of this study was to investigate the effect of two-hour exposure to a forest environment on cytokine, anti-oxidant and stress levels among university students and to compare the results to those measured in urban environments. Forty-one subjects were recruited. For our crossover design, subjects were divided into two groups based on similar demographic characteristics. Group A remained in the urban environment and was asked to perform regular breathing for 2 h. Blood samples were collected and the serum levels of cytokines including interleukin-6 (IL-6), IL-8, tumor necrosis factor-α (TNF-α), and glutathione peroxidase (GPx) were examined. Subjects were moved to a small town in a rural area for an equal amount of time to exclude carryover effects, and then remained for another 2 h in a forest environment. The second set of blood samples was collected to assess the effect of exposure to the forest environment. Using the same method, Group B was first exposed to the forest environment, followed by exposure to the urban environment. Blood samples collected after the subjects were exposed to the forest environment showed significantly lower levels of IL-8 and TNF-α compared to those in samples collected after urban environment exposure (10.76 vs. 9.21, t = 4.559, p forest environment (LnGPx = 5.09 vs. LnGPx = 5.21, t = -2.039, p < 0.05).

  8. Effect of nitrogen in austenitic stainless steel on deformation behavior and stress corrosion cracking susceptibility in BWR simulated environment

    International Nuclear Information System (INIS)

    Roychowdhury, S.; Kain, V.; Dey, G.K.

    2012-01-01

    Intergranular stress corrosion cracking (IGSCC) of austenitic stainless steel (SS) components in boiling water reactor (BWR has been a serious issue and is generic in nature. Initial cracking incidences were attributed to weld induced sensitisation and low temperature sensitisation which was mitigated by the use of low carbon grade of SS and molybdenum and nitrogen containing nuclear grade SS. However, IGSCC has occurred in these SS in the non-sensitised condition which was attributed to residual weld induced strain. Strain hardening in SS has been identified as a major cause for enhanced IGSCC susceptibility in BWR environment. Nitrogen in SS has a significant effect on the strain hardening characteristics and has potential to affect the IGSCC susceptibility in BWR environment. Type 304LN stainless steel is a candidate material for use in future reactors with long design life like the Advanced Heavy Water Reactor (AHWR), in which the operating conditions are similar to BWR. This study reports the effect of nitrogen in type 304LN stainless steel on the strain hardening behaviour and deformation characteristics and its effect on the IGSCC susceptibility in BWR/AHWR environment. Two heats of type 304LN stainless steel were used containing different levels of nitrogen, 0.08 and 0.16 wt % (SS alloys A and B, respectively). Both the SS was strain hardened by cross rolling at 200℃ to simulate the strain hardened regions having higher IGSCC susceptibility in BWRs. Tensile testing was done at both room temperature and 288℃(temperature simulating operating BWR conditions) and the effect of nitrogen on the tensile properties were established. Tensile testing was done at strain rates similar to the crack tip strain rates associated with a growing IGSCC in SS. Detailed transmission electron microscopic (TEM) studies were done to establish the effect of nitrogen on the deformation modes. Results indicated twinning was the major mode of deformation during cross rolling while

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

    Directory of Open Access Journals (Sweden)

    Harsh Chauhan

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

  10. Mindfulness in Motion (MIM): An Onsite Mindfulness Based Intervention (MBI) for Chronically High Stress Work Environments to Increase Resiliency and Work Engagement

    Science.gov (United States)

    Klatt, Maryanna; Steinberg, Beth; Duchemin, Anne-Marie

    2015-01-01

    A pragmatic mindfulness intervention to benefit personnel working in chronically high-stress environments, delivered onsite during the workday, is timely and valuable to employee and employer alike. Mindfulness in Motion (MIM) is a Mindfulness Based Intervention (MBI) offered as a modified, less time intensive method (compared to Mindfulness-Based Stress Reduction), delivered onsite, during work, and intends to enable busy working adults to experience the benefits of mindfulness. It teaches mindful awareness principles, rehearses mindfulness as a group, emphasizes the use of gentle yoga stretches, and utilizes relaxing music in the background of both the group sessions and individual mindfulness practice. MIM is delivered in a group format, for 1 hr/week/8 weeks. CDs and a DVD are provided to facilitate individual practice. The yoga movement is emphasized in the protocol to facilitate a quieting of the mind. The music is included for participants to associate the relaxed state experienced in the group session with their individual practice. To determine the intervention feasibility/efficacy we conducted a randomized wait-list control group in Intensive Care Units (ICUs). ICUs represent a high-stress work environment where personnel experience chronic exposure to catastrophic situations as they care for seriously injured/ill patients. Despite high levels of work-related stress, few interventions have been developed and delivered onsite for such environments. The intervention is delivered on site in the ICU, during work hours, with participants receiving time release to attend sessions. The intervention is well received with 97% retention rate. Work engagement and resiliency increase significantly in the intervention group, compared to the wait-list control group, while participant respiration rates decrease significantly pre-post in 6/8 of the weekly sessions. Participants value institutional support, relaxing music, and the instructor as pivotal to program success

  11. Potential Foraging Decisions by a Desert Ungulate to Balance Water and Nutrient Intake in a Water-Stressed Environment.

    Science.gov (United States)

    Gedir, Jay V; Cain, James W; Krausman, Paul R; Allen, Jamison D; Duff, Glenn C; Morgart, John R

    2016-01-01

    Arid climates have unpredictable precipitation patterns, and wildlife managers often provide supplemental water to help desert ungulates endure the hottest, driest periods. When surface water is unavailable, the only source of water for ungulates comes from the forage they consume, and they must make resourceful foraging decisions to meet their requirements. We compared two desert bighorn sheep (Ovis canadensis nelsoni) populations in Arizona, USA: a treatment population with supplemental water removed during treatment, and a control population. We examined whether sheep altered their seasonal diets without supplemental water. We calculated water and nutrient intake and metabolic water production from dry matter intake and forage moisture and nitrogen content, to determine whether sheep could meet their seasonal daily water and nutrient requirements solely from forage. Diets of sheep were higher in protein (all seasons) and moisture (autumn and winter) during treatment compared to pretreatment. During treatment, sheep diet composition was similar between the treatment and control populations, which suggests, under the climatic conditions of this study, water removal did not influence sheep diets. We estimated that under drought conditions, without any surface water available (although small ephemeral potholes would contain water after rains), female and male sheep would be unable to meet their daily water requirements in all seasons, except winter, when reproductive females had a nitrogen deficit. We determined that sheep could achieve water and nutrient balances in all seasons by shifting their total diet proportions by 8-55% from lower to higher moisture and nitrogen forage species. We elucidate how seasonal forage quality and foraging decisions by desert ungulates allow them to cope with their xeric and uncertain environment, and suggest that, with the forage conditions observed in our study area during this study period, providing supplemental water during

  12. Potential Foraging Decisions by a Desert Ungulate to Balance Water and Nutrient Intake in a Water-Stressed Environment.

    Directory of Open Access Journals (Sweden)

    Jay V Gedir

    Full Text Available Arid climates have unpredictable precipitation patterns, and wildlife managers often provide supplemental water to help desert ungulates endure the hottest, driest periods. When surface water is unavailable, the only source of water for ungulates comes from the forage they consume, and they must make resourceful foraging decisions to meet their requirements. We compared two desert bighorn sheep (Ovis canadensis nelsoni populations in Arizona, USA: a treatment population with supplemental water removed during treatment, and a control population. We examined whether sheep altered their seasonal diets without supplemental water. We calculated water and nutrient intake and metabolic water production from dry matter intake and forage moisture and nitrogen content, to determine whether sheep could meet their seasonal daily water and nutrient requirements solely from forage. Diets of sheep were higher in protein (all seasons and moisture (autumn and winter during treatment compared to pretreatment. During treatment, sheep diet composition was similar between the treatment and control populations, which suggests, under the climatic conditions of this study, water removal did not influence sheep diets. We estimated that under drought conditions, without any surface water available (although small ephemeral potholes would contain water after rains, female and male sheep would be unable to meet their daily water requirements in all seasons, except winter, when reproductive females had a nitrogen deficit. We determined that sheep could achieve water and nutrient balances in all seasons by shifting their total diet proportions by 8-55% from lower to higher moisture and nitrogen forage species. We elucidate how seasonal forage quality and foraging decisions by desert ungulates allow them to cope with their xeric and uncertain environment, and suggest that, with the forage conditions observed in our study area during this study period, providing supplemental

  13. Potential foraging decisions by a desert ungulate to balance water and nutrient intake in a water-stressed environment

    Science.gov (United States)

    Gedir, Jay V.; Cain, James W.; Krausman, Paul R.; Allen, Jamison D.; Duff, Glenn C.; Morgart, John R.

    2016-01-01

    Arid climates have unpredictable precipitation patterns, and wildlife managers often provide supplemental water to help desert ungulates endure the hottest, driest periods. When surface water is unavailable, the only source of water for ungulates comes from the forage they consume, and they must make resourceful foraging decisions to meet their requirements. We compared two desert bighorn sheep (Ovis canadensis nelsoni) populations in Arizona, USA: a treatment population with supplemental water removed during treatment, and a control population. We examined whether sheep altered their seasonal diets without supplemental water. We calculated water and nutrient intake and metabolic water production from dry matter intake and forage moisture and nitrogen content, to determine whether sheep could meet their seasonal daily water and nutrient requirements solely from forage. Diets of sheep were higher in protein (all seasons) and moisture (autumn and winter) during treatment compared to pretreatment. During treatment, sheep diet composition was similar between the treatment and control populations, which suggests, under the climatic conditions of this study, water removal did not influence sheep diets. We estimated that under drought conditions, without any surface water available (although small ephemeral potholes would contain water after rains), female and male sheep would be unable to meet their daily water requirements in all seasons, except winter, when reproductive females had a nitrogen deficit. We determined that sheep could achieve water and nutrient balances in all seasons by shifting their total diet proportions by 8–55% from lower to higher moisture and nitrogen forage species. We elucidate how seasonal forage quality and foraging decisions by desert ungulates allow them to cope with their xeric and uncertain environment, and suggest that, with the forage conditions observed in our study area during this study period, providing supplemental water during

  14. Effect of temperature and humidity on post-gel shrinkage, cusp deformation, bond strength and shrinkage stress - Construction of a chamber to simulate the oral environment.

    Science.gov (United States)

    Bicalho, Aline Aredes; de Souza, Silas Júnior Boaventura; de Rosatto, Camila Maria Peres; Tantbirojn, Daranee; Versluis, Antheunis; Soares, Carlos José

    2015-12-01

    Evaluate the effect of environment on post-gel shrinkage (Shr), cuspal strains (CS), microtensile bond strength (μTBS), elastic modulus (E) and shrinkage stress in molars with large class II restorations. Sixty human molars received standardized Class II mesio-oclusal-distal cavity preparations. Restorations were made with two composites (CHA, Charisma Diamond, Heraus Kulzer and IPS Empress Direct, Ivoclar-Vivadent) using three environment conditions (22°C/50% humidity, 37°C/50% humidity and 37°C/90% humidity) simulated in custom developed chamber. Shr was measured using the strain gauge technique (n=10). CS was measured using strain gauges. Half of the teeth (n=5) were used to assess the elastic modulus (E) and Knoop hardness (KHN) at different depths using microhardness indentation. The other half (n=5) was used to measure the μTBS. The composites and environment conditions were simulated in a two-dimensional finite element analysis of a tooth restoration. Polymerization shrinkage was modeled using Shr data. The Shr, CS, μTBS, KHN and E data were statistically analyzed using two-way ANOVA and Tukey test (significance level: 0.05). Both composites had similar Shr, CS, μTBS and shrinkage stress. CHA had higher elastic modulus than IPS. Increasing temperature and humidity significantly increased Shr, CS and shrinkage stress. μTBS were similar for groups with lower humidity, irrespective of temperature, and higher with higher humidity. E and KHN were constant through the depth for CHA. E and KHN values were affected by environment only for IPS, mainly deeper in the cavity. Shrinkage stress at dentin/composite interface had high inverse correlation with μTBS. Shrinkage stress in enamel had high correlation with CS. Increasing temperature and humidity caused higher post-gel shrinkage and cusp deformation with higher shrinkage stresses in the tooth structure and tooth/restoration interface for both composites tested. The chamber developed for simulating the

  15. Tailored Fitness: Culture Clash in the Quest for Combat-Fit Airmen

    Science.gov (United States)

    2014-06-01

    standardized number of failures for discharge recommendation, established a Fitness Assessment Cell (FAC) to centralize and standardize the...of the mental and physical stamina challenges of flying, but does so within a climate-controlled room with less physiological stress. This is not

  16. Effect of multiple stress factors (thermal, nutritional and pregnancy type) on adaptive capability of native ewes under semi-arid environment.

    Science.gov (United States)

    Dias E Silva, Tairon Pannunzio; Costa Torreão, Jacira Neves da; Torreão Marques, Carlo Aldrovandi; de Araújo, Marcos Jácome; Bezerra, Leílson Rocha; Kumar Dhanasekaran, Dinesh; Sejian, Veerasamy

    2016-07-01

    This study was conducted to evaluate the effect of multiple stress factors (thermal, nutritional and pregnancy type) on two different native track breeds of ewes as reflected by their adaptive capability under semi-arid environment. The multiple stressor experiment was conducted in twenty-four ewes (12 Santa Inês and 12 Morada Nova ewes). Both heat stress and pregnancy stress was common to all four groups. However, the animals were divided into further two groups within each breed on the basis of nutrition regimen. According the groupings were: Group 1 (Six Santa Ines ewes; heat stress; nutrition at 0.5% of BW; single pregnancy); Group 2 (Six Santa Ines ewes; heat stress; nutrition at 1.5% BW; twin pregnancy); groups Group 3 (Six Morada Nova ewes; heat stress; nutrition at 0.5% of BW; single pregnancy); Group 4 (Six Morada Nova ewes; heat stress; nutrition at 1.5% BW; twin pregnancy). All the animals in the experiment were pregnant. Heat stress was induced by exposing all animals to summer heat stress in outside environment while the nutritional regimen followed was at 0.5% and 1.5% level of body weight (BW) respectively in each breed. The experiment was conducted in a completely randomized design with two breeds, two nutritional treatments and two pregnancy types, 10 repetitions for physiological parameters and six for blood parameters, with repeated measures over time. Physiological parameters (respiratory rate, pulse rate and rectal temperature) were measured with the animals at rest in the morning and afternoon, 0600-0700 and 1300-1400h, respectively, every seven days. Blood samples were collected every 14d for determination of serum glucose, triglycerides, cholesterol, urea and creatinine. We found interaction effect between breed and pregnancy type on respiratory rate and rectal temperature with greater values in Santa Inês ewes than Morada Nova ewes. However, there was no significant fixed effect of pregnancy type and supplementation level on physiological

  17. Alcohol consumption as a predictor of reactivity to smoking and stress cues presented in the natural environment of smokers.

    Science.gov (United States)

    Tomko, Rachel L; Saladin, Michael E; McClure, Erin A; Squeglia, Lindsay M; Carpenter, Matthew J; Tiffany, Stephen T; Baker, Nathaniel L; Gray, Kevin M

    2017-02-01

    The high prevalence of co-occurring alcohol and tobacco use underscores the importance of understanding the influence of alcohol consumption on risk factors for smoking and relapse. Alcohol has been shown to impact reactivity to smoking and stress-related cues, both of which are common antecedents to smoking and smoking relapse. The objective of the current study is to examine associations between alcohol use, cigarette craving, and stress reactivity following exposure to smoking and stress cues delivered in participants' daily lives. Using cue-reactivity ecological momentary assessment (CREMA), adult smokers (n = 138) reported cigarette craving, stress, and past hour alcohol use on a mobile device four times per day for 2 weeks, resulting in a range of 4493-5983 data points per analysis. Questions were followed by exposure to pictorial neutral, stressful, or smoking cues delivered via the mobile device. Craving and affect were re-assessed following cue exposure. Results showed that recent (past hour) alcohol use was significantly associated with increases in the following: (a) tonic (non-cue-elicited) cigarette craving, (b) stress cue-elicited cigarette craving, and (c) stress cue-elicited stress reactivity, in the context of high-baseline stress. There was no significant association between alcohol use and smoking cue-elicited craving. Alcohol use may increase risk for smoking and relapse to smoking by increasing cigarette craving and, in certain contexts, stress following stress cue exposure. Though alcohol is known for its anxiolytic properties, under some conditions, it may increase reactivity to stress cues.

  18. Phreatophytes under stress: transpiration and stomatal conductance of saltcedar (Tamarix spp.) in a high-salinity environment

    Science.gov (United States)

    Glenn, Edward P.; Nagler, Pamela L.; Morino, Kiyomi; Hultine, Kevin

    2013-01-01

    Background and aims: We sought to understand the environmental constraints on an arid-zone riparian phreatophtye, saltcedar (Tamarix ramosissima and related species and hybrids), growing over a brackish aquifer along the Colorado River in the western U.S. Depth to groundwater, meteorological factors, salinity and soil hydraulic properties were compared at stress and non-stressed sites that differed in salinity of the aquifer, soil properties and water use characteristics, to identify the factors depressing water use at the stress site.

  19. The Virginian's Cultural Clashes: A Study of Cultural Representation in Owen Wister's novel The Virginian

    OpenAIRE

    Aksnes, Karoline

    2012-01-01

    This thesis is a cultural study of Owen Wister's novel The Virginian. Its main focus is on the ways in which cultural differences between East and West are staged and acted out in the novel's depiction of a culturally diverse frontier environment in nineteenth century Wyoming, USA. Central in this study are the story's three main characters as they represent different cultural backgrounds, and, by their personal experiences with the Western environment as well as wi...

  20. Prenatal Stress, Methylation in Inflammation-Related Genes, and Adiposity Measures in Early Childhood: the Programming Research in Obesity, Growth Environment and Social Stress Cohort Study.

    Science.gov (United States)

    Wu, Shaowei; Gennings, Chris; Wright, Rosalind J; Wilson, Ander; Burris, Heather H; Just, Allan C; Braun, Joseph M; Svensson, Katherine; Zhong, Jia; Brennan, Kasey J M; Dereix, Alexandra; Cantoral, Alejandra; Schnaas, Lourdes; Téllez-Rojo, Martha Maria; Wright, Robert O; Baccarelli, Andrea A

    2018-01-01

    Maternal stress during pregnancy may influence childhood growth and adiposity, possibly through immune/inflammatory programming. We investigated whether exposure to prenatal stress and methylation in inflammation-related genes were associated with childhood adiposity in 424 mother-child pairs in Mexico City, Mexico. A stress index was created based on four prenatally administered stress-related scales (Exposure to Violence, Crisis in Family Systems, State-Trait Anxiety Inventory, and Edinburgh Postnatal Depression Scale). We measured weight, height, body fat mass (BFM), percentage body fat (PBF), and waist circumference in early childhood (age range, 4-6 years). Body mass index (BMI) z scores were calculated according to World Health Organization standards. DNA methylation in gene promoters of tumor necrosis factor α, interleukin 8, and interleukin 6 (IL6) in umbilical cord blood were determined by pyrosequencing. An interquartile range increase in stress index (27.3) was associated with decreases of 0.14 unit in BMI z score (95% confidence interval [CI] = -0.28 to -0.005), 5.6% in BFM (95% CI = -9.7 to -1.4), 3.5% in PBF (95% CI = -6.3 to -0.5), and 1.2% in waist circumference (95% CI = -2.4 to -0.04) in multivariable-adjusted models. An interquartile range increase in IL6 methylation (3.9%) was associated with increases of 0.23 unit in BMI z score (95% CI = 0.06-0.40), 8.1% (95% CI = 2.3-14.3) in BFM, 5.5% (95% CI = 1.7-9.5) in PBF, and 1.7% (95% CI = 0.2-3.3) in waist circumference. Prenatal stress was associated with decreased childhood adiposity, whereas cord blood IL6 methylation was associated with increased childhood adiposity in Mexican children.

  1. Corticosterone levels and behavioral changes induced by simultaneous exposure to chronic social stress and enriched environments in NMRI male mice.

    Science.gov (United States)

    Mesa-Gresa, Patricia; Ramos-Campos, Marta; Redolat, Rosa

    2016-05-01

    Environmental enrichment (EE) is an experimental model which is believed to counteract some of the effects induced by stressors, although few studies have exposed rodents simultaneously to EE and stress. Our aim was to compare the short- and long-term effects of different housing conditions in mice submitted to chronic stress. 128 NMRI male mice arrived at our laboratory on postnatal day (PND) 21. During Phase I (PND 28), animals were randomly assigned to four experimental conditions: 1) EE+STRESS: mice housed in EE and submitted to social stress (n=32); 2) EE+NO STRESS: mice housed in EE without stress (n=32); 3) SE+STRESS: mice maintained in standard conditions (SE) and submitted to social stress (n=32); and 4) SE+NO STRESS (n=32). At the end of Phase I (PND 77), one cohort of 32 animals was used for behavioral assessment whereas another cohort of 32 was sacrificed for corticosterone analysis. Results indicated that EE animals showed less body weight, higher water and food intake, diminished anxiety response and decreased motor and exploratory behavior than SE mice. Mice exposed to stress gained less body weight, showed higher food and fluid intake and displayed decreased exploratory behavior than non-stressed mice. Furthermore, EE+STRESS group displayed significantly higher corticosterone levels than EE+NO STRESS group whereas EE+NO STRESS group showed lower levels than SE+NO STRESS. On PND 83, Phase II of the study began. Animals (n=96) were assigned to two different housing conditions: EE (n=48) and SE (n=48). On PND 112, corticosterone analysis (n=32) and behavioral study (n=64) were done. The factor "Housing Phase II" reached statistical significance. Results indicated that EE animals showed lower body weight and higher fluid intake than SE group, as well as decreased anxiety. No clear effects on motor and exploratory behavior or learning were observed. When long-term effects were analyzed, results indicated that "Initial Housing" condition was significant

  2. Creating creationists: The influence of 'issues framing' on our understanding of public perceptions of clash narratives between evolutionary science and belief.

    Science.gov (United States)

    Elsdon-Baker, Fern

    2015-05-01

    Clash narratives relating to evolutionary science and personal belief are a recurrent theme in media or public space discourse. However, a 2009 British Council poll undertaken in 10 countries worldwide shows that the perception of a necessary clash between evolutionary worldviews and belief in a God is a minority viewpoint. How then does the popular conception that there is an ongoing conflict between evolution and belief in God arise? One contributing factor is the framing and categorization of creationism and evolutionism within large-scale surveys for use within media campaigns. This article examines the issue framing within four polls conducted in the United Kingdom and internationally between 2008 and 2013. It argues that by ignoring the complexity and range of perspectives individuals hold, or by framing evolutionary science as atheistic, we are potentially creating 'creationists' - including 'Islamic creationists' - both figuratively and literally. © The Author(s) 2015.

  3. Retarding effect of prior-overloading on stress corrosion cracking of cold rolled 316L SS in simulated PWR water environment

    Science.gov (United States)

    Chen, Junjie; Lu, Zhanpeng; Xiao, Qian; Ru, Xiangkun; Ma, Jiarong; Shoji, Tetsuo

    2017-12-01

    The effect of prior single tensile overloading on the stress corrosion cracking behavior of cold rolled 316L in a simulated PWR water environment at 310 °C was investigated. SCC growth retardation by overloading was observed in cold rolled 316L specimens in both the T-L and L-T orientations. The stretch zone observed on the fracture surfaces of the overloaded specimens affected SCC propagation. The compressive residual stress induced by overloading process reduced the effective driving force of SCC propagation. The negative dK/da effect ahead of the crack tip likely contributes to the retardation of SCC growth. The duration of overloading is dependent on water chemistry and the local stress conditions.

  4. Prenatal stress induces depressive-like behavior in a sex-specific manner; impact of familiar versus novel environments

    DEFF Research Database (Denmark)

    Sickmann, Helle Mark; Arentzen, Tine S; Kristensen, Morten Pilgaard

    in dams exposed to PS. Locomotor activity in a familiar environment (housing cage) during the rodent inactive phase was significantly enhanced in PS females compared to controls (Δ= 49 %, n = 15-37; p ...-15; p familiar environment whereas male offspring seems vulnerable in a novel environment. The central...

  5. The Urban Environment Can Modify Drought Stress of Small-Leaved Lime (Tilia cordata Mill. and Black Locust (Robinia pseudoacacia L.

    Directory of Open Access Journals (Sweden)

    Astrid Moser

    2016-03-01

    Full Text Available The urban environment characterized by various stresses poses challenges to trees. In particular, water deficits and high temperatures can cause immense drought stress to urban trees, resulting in reduced growth and die-off. Drought-tolerant species are expected to be resilient to these conditions and are therefore advantageous over other, more susceptible species. However, the drought tolerance of urban trees in relation to the specific growth conditions in urban areas remains poorly researched. This study aimed to analyze the annual growth and drought tolerance of two common urban tree species, namely small-leaved lime (Tilia cordata Mill. (T. cordata and black locust (Robinia pseudoacacia L. (R. pseudoacacia, in two cities in southern Germany in relation to their urban growing conditions. Marked growth reductions during drought periods and subsequent fast recovery were found for R. pseudoacacia, whereas T. cordata exhibited continued reduced growth after a drought event, although these results were highly specific to the analyzed city. We further show that individual tree characteristics and environmental conditions significantly influence the growth of urban trees. Canopy openness and other aspects of the surrounding environment (water supply and open surface area of the tree pit, tree size, and tree species significantly affect urban tree growth and can modify the ability of trees to tolerate the drought stress in urban areas. Sustainable tree planting of well adapted tree species to their urban environment ensures healthy trees providing ecosystem services for a high quality of life in cities.

  6. Initial laboratory experience with a novel ultrasound probe for standard and single-port robotic kidney surgery: increasing console surgeon autonomy and minimizing instrument clashing.

    Science.gov (United States)

    Yakoubi, Rachid; Autorino, Riccardo; Laydner, Humberto; Guillotreau, Julien; White, Michael A; Hillyer, Shahab; Spana, Gregory; Khanna, Rakesh; Isaac, Wahib; Haber, Georges-Pascal; Stein, Robert J; Kaouk, Jihad H

    2012-06-01

    The aim of this study was to evaluate a novel ultrasound probe specifically developed for robotic surgery by determining its efficiency in identifying renal tumors. The study was carried out using the Da Vinci™ surgical system in one female pig. Renal tumor targets were created by percutaneous injection of a tumor mimic mixture. Single-port and standard robotic partial nephrectomy were performed. Intraoperative ultrasound was performed using both standard laparoscopic probe and the new ProART™ Robotic probe. Probe maneuverability and ease of handling for tumor localization were recorded. The standard laparoscopic probe was guided by the assistant. Significant clashing with robotic arms was noted during the single-port procedure. The novel robotic probe was easily introduced through the assistant trocar, and held by the console surgeon using the robotic Prograsp™ with no registered clashing in the external operative field. The average time for grasping the new robotic probe was less than 10 s. Once inserted and grasped, no limitation was found in terms of instrument clashing during the single-port procedure. This novel ultrasound probe developed for robotic surgery was noted to be user-friendly when performing porcine standard and especially single-port robotic partial nephrectomy. Copyright © 2011 John Wiley & Sons, Ltd.

  7. Comparison of Effect of Two-Hour Exposure to Forest and Urban Environments on Cytokine, Anti-Oxidant, and Stress Levels in Young Adults

    Directory of Open Access Journals (Sweden)

    Su Geun Im

    2016-06-01

    Full Text Available The purpose of this study was to investigate the effect of two-hour exposure to a forest environment on cytokine, anti-oxidant and stress levels among university students and to compare the results to those measured in urban environments. Forty-one subjects were recruited. For our crossover design, subjects were divided into two groups based on similar demographic characteristics. Group A remained in the urban environment and was asked to perform regular breathing for 2 h. Blood samples were collected and the serum levels of cytokines including interleukin-6 (IL-6, IL-8, tumor necrosis factor-α (TNF-α, and glutathione peroxidase (GPx were examined. Subjects were moved to a small town in a rural area for an equal amount of time to exclude carryover effects, and then remained for another 2 h in a forest environment. The second set of blood samples was collected to assess the effect of exposure to the forest environment. Using the same method, Group B was first exposed to the forest environment, followed by exposure to the urban environment. Blood samples collected after the subjects were exposed to the forest environment showed significantly lower levels of IL-8 and TNF-α compared to those in samples collected after urban environment exposure (10.76 vs. 9.21, t = 4.559, p < 0.001, and 0.97 vs. 0.87, t = 4.130, p < 0.001. The GPx concentration increased significantly after exposure to the forest environment (LnGPx = 5.09 vs. LnGPx = 5.21, t = −2.039, p < 0.05.

  8. Stress corrosion crack initiation of Zircaloy-4 cladding tubes in an iodine vapor environment during creep, relaxation, and constant strain rate tests

    Science.gov (United States)

    Jezequel, T.; Auzoux, Q.; Le Boulch, D.; Bono, M.; Andrieu, E.; Blanc, C.; Chabretou, V.; Mozzani, N.; Rautenberg, M.

    2018-02-01

    During accidental power transient conditions with Pellet Cladding Interaction (PCI), the synergistic effect of the stress and strain imposed on the cladding by thermal expansion of the fuel, and corrosion by iodine released as a fission product, may lead to cladding failure by Stress Corrosion Cracking (SCC). In this study, internal pressure tests were conducted on unirradiated cold-worked stress-relieved Zircaloy-4 cladding tubes in an iodine vapor environment. The goal was to investigate the influence of loading type (constant pressure tests, constant circumferential strain rate tests, or constant circumferential strain tests) and test temperature (320, 350, or 380 °C) on iodine-induced stress corrosion cracking (I-SCC). The experimental results obtained with different loading types were consistent with each other. The apparent threshold hoop stress for I-SCC was found to be independent of the test temperature. SEM micrographs of the tested samples showed many pits distributed over the inner surface, which tended to coalesce into large pits in which a microcrack could initiate. A model for the time-to-failure of a cladding tube was developed using finite element simulations of the viscoplastic mechanical behavior of the material and a modified Kachanov's damage growth model. The times-to-failure predicted by this model are consistent with the experimental data.

  9. Phenotypic effects of repeated psychosocial stress during adolescence in mice mutant for the schizophrenia risk gene neuregulin-1: a putative model of gene × environment interaction.

    Science.gov (United States)

    Desbonnet, Lieve; O'Tuathaigh, Colm; Clarke, Gerard; O'Leary, Claire; Petit, Emilie; Clarke, Niamh; Tighe, Orna; Lai, Donna; Harvey, Richard; Cryan, John F; Dinan, Timothy G; Waddington, John L

    2012-05-01

    There is a paucity of animal models by which the contributions of environmental and genetic factors to the pathobiology of psychosis can be investigated. This study examined the individual and combined effects of chronic social stress during adolescence and deletion of the schizophrenia risk gene neuregulin-1 (NRG1) on adult mouse phenotype. Mice were exposed to repeated social defeat stress during adolescence and assessed for exploratory behaviour, working memory, sucrose preference, social behaviour and prepulse inhibition in adulthood. Thereafter, in vitro cytokine responses to mitogen stimulation and corticosterone inhibition were assayed in spleen cells, with measurement of cytokine and brain-derived neurotrophic factor (BDNF) mRNA in frontal cortex, hippocampus and striatum. NRG1 mutants exhibited hyperactivity, decreased anxiety, impaired sensorimotor gating and reduced preference for social novelty. The effects of stress on exploratory/anxiety-related parameters, spatial working memory, sucrose preference and basal cytokine levels were modified by NRG1 deletion. Stress also exerted varied effect on spleen cytokine response to concanavalin A and brain cytokine and BDNF mRNA expression in NRG1 mutants. The experience of psychosocial stress during adolescence may trigger further pathobiological features that contribute to the development of schizophrenia, particularly in those with underlying NRG1 gene abnormalities. This model elaborates the importance of gene × environment interactions in the etiology of schizophrenia. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. The effects of cold rolling orientation and water chemistry on stress corrosion cracking behavior of 316L stainless steel in simulated PWR water environments

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Junjie [Institute of Materials Science, School of Materials Science and Engineering, Shanghai University, Mailbox 269, 149 Yanchang Road, Shanghai, 200072 (China); Lu, Zhanpeng, E-mail: zplu@t.shu.edu.cn [Institute of Materials Science, School of Materials Science and Engineering, Shanghai University, Mailbox 269, 149 Yanchang Road, Shanghai, 200072 (China); State Key Laboratory of Advanced Special Steels, Shanghai University, 149 Yanchang Road, Shanghai, 200072 (China); Xiao, Qian; Ru, Xiangkun; Han, Guangdong; Chen, Zhen [Institute of Materials Science, School of Materials Science and Engineering, Shanghai University, Mailbox 269, 149 Yanchang Road, Shanghai, 200072 (China); Zhou, Bangxin [Institute of Materials Science, School of Materials Science and Engineering, Shanghai University, Mailbox 269, 149 Yanchang Road, Shanghai, 200072 (China); State Key Laboratory of Advanced Special Steels, Shanghai University, 149 Yanchang Road, Shanghai, 200072 (China); Shoji, Tetsuo [New Industry Creation Hatchery Center, Tohoku University, Sendai 980-8579 (Japan)

    2016-04-15

    Stress corrosion cracking behaviors of one-directionally cold rolled 316L stainless steel specimens in T–L and L–T orientations were investigated in hydrogenated and deaerated PWR primary water environments at 310 °C. Transgranular cracking was observed during the in situ pre-cracking procedure and the crack growth rate was almost not affected by the specimen orientation. Locally intergranular stress corrosion cracks were found on the fracture surfaces of specimens in the hydrogenated PWR water. Extensive intergranular stress corrosion cracks were found on the fracture surfaces of specimens in deaerated PWR water. More extensive cracks were found in specimen T–L orientation with a higher crack growth rate than that in the specimen L–T orientation with a lower crack growth rate. Crack branching phenomenon found in specimen L–T orientation in deaerated PWR water was synergistically affected by the applied stress direction as well as the preferential oxidation path along the elongated grain boundaries, and the latter was dominant. - Highlights: • Transgranular fatigue crack growth rate was not affected by the cold rolling orientation. • Locally intergranular SCC was found in the hydrogenated PWR water. • Extensive intergranular SCC cracks were found in deaerated PWR water. • T–L specimen showed more extensive SCC cracks and a higher crack growth rate. • Crack branching related to the applied stress and the preferential oxidation path.

  11. Impact of variation in the BDNF gene on social stress sensitivity and the buffering impact of positive emotions: replication and extension of a gene-environment interaction.

    Science.gov (United States)

    van Winkel, Mark; Peeters, Frenk; van Winkel, Ruud; Kenis, Gunter; Collip, Dina; Geschwind, Nicole; Jacobs, Nele; Derom, Catherine; Thiery, Evert; van Os, Jim; Myin-Germeys, Inez; Wichers, Marieke

    2014-06-01

    A previous study reported that social stress sensitivity is moderated by the brain-derived-neurotrophic-factor(Val66Met) (BDNF rs6265) genotype. Additionally, positive emotions partially neutralize this moderating effect. The current study aimed to: (i) replicate in a new independent sample of subjects with residual depressive symptoms the moderating effect of BDNF(Val66Met) genotype on social stress sensitivity, (ii) replicate the neutralizing impact of positive emotions, (iii) extend these analyses to other variations in the BDNF gene in the new independent sample and the original sample of non-depressed individuals. Previous findings were replicated in an experience sampling method (ESM) study. Negative Affect (NA) responses to social stress were stronger in "Val/Met" carriers of BDNF(Val66Met) compared to "Val/Val" carriers. Positive emotions neutralized the moderating effect of BDNF(Val66Met) genotype on social stress sensitivity in a dose-response fashion. Finally, two of four additional BDNF SNPs (rs11030101, rs2049046) showed similar moderating effects on social stress-sensitivity across both samples. The neutralizing effect of positive emotions on the moderating effects of these two additional SNPs was found in one sample. In conclusion, ESM has important advantages in gene-environment (GxE) research and may attribute to more consistent findings in future GxE research. This study shows how the impact of BDNF genetic variation on depressive symptoms may be explained by its impact on subtle daily life responses to social stress. Further, it shows that the generation of positive affect (PA) can buffer social stress sensitivity and partially undo the genetic susceptibility. Copyright © 2014 Elsevier B.V. and ECNP. All rights reserved.

  12. Random regression models to account for the effect of genotype by environment interaction due to heat stress on the milk yield of Holstein cows under tropical conditions.

    Science.gov (United States)

    Santana, Mário L; Bignardi, Annaiza Braga; Pereira, Rodrigo Junqueira; Menéndez-Buxadera, Alberto; El Faro, Lenira

    2016-02-01

    The present study had the following objectives: to compare random regression models (RRM) considering the time-dependent (days in milk, DIM) and/or temperature × humidity-dependent (THI) covariate for genetic evaluation; to identify the effect of genotype by environment interaction (G×E) due to heat stress on milk yield; and to quantify the loss of milk yield due to heat stress across lactation of cows under tropical conditions. A total of 937,771 test-day records from 3603 first lactations of Brazilian Holstein cows obtained between 2007 and 2013 were analyzed. An important reduction in milk yield due to heat stress was observed for THI values above 66 (-0.23 kg/day/THI). Three phases of milk yield loss were identified during lactation, the most damaging one at the end of lactation (-0.27 kg/day/THI). Using the most complex RRM, the additive genetic variance could be altered simultaneously as a function of both DIM and THI values. This model could be recommended for the genetic evaluation taking into account the effect of G×E. The response to selection in the comfort zone (THI ≤ 66) is expected to be higher than that obtained in the heat stress zone (THI > 66) of the animals. The genetic correlations between milk yield in the comfort and heat stress zones were less than unity at opposite extremes of the environmental gradient. Thus, the best animals for milk yield in the comfort zone are not necessarily the best in the zone of heat stress and, therefore, G×E due to heat stress should not be neglected in the genetic evaluation.

  13. Spectral entropy as a mean to quantify water stress history for natural vegetation and irrigated agriculture in a water-stressed tropical environment

    Science.gov (United States)

    Kim, Y.; Johnson, M. S.

    2017-12-01

    Spectral entropy (Hs) is an index which can be used to measure the structural complexity of time series data. When a time series is made up of one periodic function, the Hs value becomes smaller, while Hs becomes larger when a time series is composed of several periodic functions. We hypothesized that this characteristic of the Hs could be used to quantify the water stress history of vegetation. For the ideal condition for which sufficient water is supplied to an agricultural crop or natural vegetation, there should be a single distinct phenological cycle represented in a vegetation index time series (e.g., NDVI and EVI). However, time series data for a vegetation area that repeatedly experiences water stress may include several fluctuations that can be observed in addition to the predominant phenological cycle. This is because the process of experiencing water stress and recovering from it generates small fluctuations in phenological characteristics. Consequently, the value of Hs increases when vegetation experiences several water shortages. Therefore, the Hs could be used as an indicator for water stress history. To test this hypothesis, we analyzed Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) data for a natural area in comparison to a nearby sugarcane area in seasonally-dry western Costa Rica. In this presentation we will illustrate the use of spectral entropy to evaluate the vegetative responses of natural vegetation (dry tropical forest) and sugarcane under three different irrigation techniques (center pivot irrigation, drip irrigation and flood irrigation). Through this comparative analysis, the utility of Hs as an indicator will be tested. Furthermore, crop response to the different irrigation methods will be discussed in terms of Hs, NDVI and yield.

  14. Posttraumatic Stress Symptoms in Preschool Children in Foster Care: The Influence of Placement and Foster Family Environment.

    Science.gov (United States)

    Vasileva, Mira; Petermann, Franz

    2017-10-01

    Children in foster care often experience traumatic events which increase their risk for posttraumatic stress symptoms (PTSS). Until now, no research has investigated the developmentally sensitive PTSS criteria for preschoolers among children in foster care. The current study estimated the prevalence of potentially traumatic experiences and clinical PTSS in German foster care children aged 3 to 7 years. The foster parents of 324 children completed questionnaires about children's PTSS, foster parental stress, parenting, and family functioning. Linear regression models tested trauma-related variables, placement history, and foster family characteristics as predictors of PTSS. Approximately 45.4% of the foster children had experienced at least one traumatic event and 15.4% had clinical PTSS. Physical abuse, β = .34, p < .001; hospitalization, β = -.17, p = .026; witnessing someone being hurt, β = -.15, p = .047; and parental stress, β = .43, p < .001, were significantly associated with PTSS. Results demonstrate the impact the foster family has on children who are coping with trauma, and suggest the necessity of trauma-sensitive trainings for foster parents, with stress management as an important component. Copyright © 2017 International Society for Traumatic Stress Studies.

  15. Ultracoatings: Enabling Energy and Power Solutions in High Contact Stress Environments through next-generation Nanocoatings Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Clifton B. Higdon III

    2012-03-20

    A review of current commercially available, industrial-grade, low friction coatings will show that interfacial contact pressures nearing 1GPa ({approx}150ksi) inherently limit surface engineering solutions like WC, TiN, TiAlN, and so forth. Extremely hard coatings, then, are often pursued as the principle path, although they too are not without significant limitations. A majority of these compounds are inherently brittle in nature or may not pair well with their mating substrate. In either case, their durability in high contact stress environments is compromised. In parallel to thin film coatings, many conventional surface treatments do not yield an interface hard enough to withstand extreme stresses under load. New research into advanced, nanocomposite materials like (Ti, Zr)B2 shows great promise. Bulk compacts of this compound have demonstrated an order of magnitude better wear resistance than current offerings, notably materials like tungsten carbide. At a laboratory level, the (Ti,Zr)B2 nanocomposite material exhibited abrasive and erosive wear resistance nearly ten times better than existing mixed-phase boride systems. In ASTM abrasion and erosion testing, these new compositions exhibit wear resistance superior to other known advanced materials such as RocTec 500 and 'Borazon' cubic boron nitride. Many significant challenges exist for mass production of (Ti, Zr)B2, one of which is the necessary processing technology that is capable of minimizing deleterious impurity phases. Secondly, this material's performance is derived from a synergistic effect of the two materials existing as a single phase structure. While the individual constituents of TiB2 and ZrB2 do yield improvements to wear resistance, their singular effects are not as significant. Lastly, deposition of this material on a commercial level requires thorough knowledge of nanocomposite boride solids; the benefits associated with these innovative new materials are just being realized

  16. The ameliorative effect of ascorbic acid on the oxidative status, live weight and recovery rate in road transport stressed goats in a hot humid tropical environment.

    Science.gov (United States)

    Nwunuji, Tanko Polycarp; Mayowa, Opeyemi Onilude; Yusoff, Sabri Mohd; Bejo, Siti-Khairani; Salisi, Shahrom; Mohd, Effendy Abd Wahid

    2014-05-01

    The ameliorative effect of ascorbic acid (AA) on live weight following transportation is vital in animal husbandry. This study investigated the influence of AA on live weight, rectal temperature (rt), and oxidative status of transport stressed goats in a hot humid tropical environment. Twenty-four goats were divided into four groups, A, B, C and D of six animals each. Group A were administered AA 100 mg/kg intramuscularly 30 min prior to 3.5 h transportation. Group B was administered AA following transportation. Group C were transported but not administered AA as positive controls while group D were not transported but were administered normal saline as negative controls. Live weight, rt and blood samples were collected before, immediately post-transport (pt), 24 h, 3 days, 7 days and 10 days pt. Plasma was used for malondialdehyde (MDA) analysis while hemolysates were used for superoxide dismutase (SOD) analysis. There was minimal live weight loss in group A compared to groups B and C. Group A recorded reduced MDA activities and increased SOD activities compared to groups B and C which recorded significantly high MDA activities. This study revealed that AA administration ameliorated the stress responses induced by transportation in animals in hot humid tropical environments. The administration of AA to goats prior to transportation could ameliorate stress and enhance productivity. © 2014 Japanese Society of Animal Science.

  17. TolC is important for bacterial survival and oxidative stress response in Salmonella enterica serovar Choleraesuis in an acidic environment.

    Science.gov (United States)

    Lee, Jen-Jie; Wu, Ying-Chen; Kuo, Chih-Jung; Hsuan, Shih-Ling; Chen, Ter-Hsin

    2016-09-25

    The outer membrane protein TolC, which is one of the key components of several multidrug efflux pumps, is thought to be involved in various independent systems in Enterobacteriaceae. Since the acidic environment of the stomach is an important protection barrier against foodborne pathogen infections in hosts, we evaluated whether TolC played a role in the acid tolerance of Salmonella enterica serovar Choleraesuis. Comparison of the acid tolerance of the tolC mutant and the parental wild-type strain showed that the absence of TolC limits the ability of Salmonella to sustain life under extreme acidic conditions. Additionally, the mutant exhibited morphological changes during growth in an acidic medium, leading to the conflicting results of cell viability measured by spectrophotometry and colony-forming unit counting. Reverse-transcriptional-PCR analysis indicated that acid-related molecules, apparatus, or enzymes and oxidation-induced factors were significantly affected by the acidic environment in the null-tolC mutant. The elongated cellular morphology was restored by adding antioxidants to the culture medium. Furthermore, we found that increased cellular antioxidative activity provides an overlapping protection against acid killing, demonstrating the complexity of the bacterial acid stress response. Our findings reinforce the multifunctional characteristics of TolC in acid tolerance or oxidative stress resistance and support the correlative protection mechanism between oxygen- and acid-mediated stress responses in Salmonella enterica serovar Choleraesuis. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. Effect of walking stress on growth, physiological adaptability and endocrine responses in Malpura ewes in a semi-arid tropical environment

    Science.gov (United States)

    Sejian, Veerasamy; Maurya, Vijai P.; Naqvi, Syed M. K.

    2012-03-01

    Sheep in hot semi-arid environments are mostly reared using extensive systems. In addition to thermal stress and feed scarcity, the animals need to walk long distances for grazing in this ecological zone. A study was conducted to assess the effect of long-distance walking on adaptive capability in terms of physiological, biochemical and endocrine responses in Malpura ewes. Fourteen adult Malpura non-pregnant ewes weighing between 33 and 35 kg were used in the study. The ewes were randomly allocated into two groups of seven animals each: GI ( n = 7; Control), and GII ( n = 7; walking stress). The animals were stall-fed with a diet consisting of 70% roughage and 30% concentrate. Both GI and GII ewes had uniform access to feed and water. The walking stress group (GII) ewes were made to walk 14 km in two spans between 0900 and 1500 hours with 1 h 30 min for each span (7 km) of walking. The ewes subjected to walking stress (GII) were prevented from grazing by applying a face mask made of cotton thread. The study was conducted for a period of two estrous cycles (35 days) during the autumn season (October-November). Physiological responses were recorded twice daily at 0800 and 1400 hours at weekly intervals. Blood samples were collected from the jugular vein at weekly intervals to study the effects of walking stress on blood biochemical and endocrine parameters. The results indicate that walking stress had significant ( P ewes have the capability to adapt to long-distance walking, and that adrenal and thyroid gland hormones play a significant role in such adaptation.

  19. [Assessment of work environment vs. feeling of threat and aggravation of stress in job of a high risk - An attempt of organizational intervention].

    Science.gov (United States)

    Stasiła-Sieradzka, Marta; Chudzicka-Czupała, Agata; Grabowski, Damian; Dobrowolska, Małgorzata

    2018-01-01

    The main purpose of this article was to examine, whether and to what extend an assessment of work environment and feeling of threat are associated with stress at work performed in health- and life-threatening conditions. Previous studies of the determinants of occupational stress have been carried out in relation to representatives of different occupational groups that are not, however, representatives of one organization. The research was also meant to provide practical guidance for a particular employer. The study was carried out in the factory of explosives. It involved 95 randomly selected employees of the production departments. Subjective evaluation of work was performed by the examined persons in the Areas of Worklife Survey. It allows to assess the functioning of the employee in the workplace and to recognize the discrepancies between the requirements of the organization and the needs, aspirations and abilities of the examined person. Feeling of insecurity at work was defined by using the Feeling of Danger at Work Survey. The level of stress was assessed using the Perceived Stress Scale (PSS-10). The workload and feeling of danger are relevant to the stress felt by the employees. The workload is also the mediator of the relations between the sense of danger and the stress felt by the examined employees. At the level of manufacturing process management in an organization, there is a need to reduce the negative impact of physical and mental strain associated with haste and uncertainty. Med Pr 2018;69(1):45-58. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

  20. Risk assessment of chronic stress at work place and work environment of persons occupationally exposed to ionizing radiation at work

    International Nuclear Information System (INIS)

    Milanovic, S.; Ilic, Z.; Spasojevic-Tisma, V.; Milanovic, S.)

    2007-01-01

    Interactions of factors at work and worker's health have been analyzed through indicators of chronic professional stress. The examinees have been persons working with sealed sources of radiation with various professional risks among which we have stressed exposure to different radiation doses. Health professionals (medical doctors, radiologist, technicians) working in radio diagnostic and radiotherapy of oncology deceases have been examined. It was concluded that examinees among the subgroup 'therapy' has higher values of stress indicators expressed through all examined indicators: work motivation, personal opinion of work load, behavioral dysfunctions (smoking, alcoholism, drug abuse), increase incidence of health dysfunctions and general neuroticism of examinees. Obtained results are values for which statistical significant have not been established, so they have certain theoretical and practical importance in the frame research with descriptive nature [sr

  1. Adaptive evolution of Escherichia coli to Ciprofloxacin in controlled stress environments: emergence of tolerance in spatial and temporal gradients

    Science.gov (United States)

    Deng, J.; Sanford, R. A.; Dong, Y.; Shechtman, L. A.; Zhou, L.; Alcalde, R.; Werth, C. J.; Fouke, B. W.

    2016-12-01

    Microorganisms in nature have evolved in response to a variety of environmental stresses, including gradients of temperature, pH, substrate availability and aqueous chemistry. While environmental stresses are considered to be the driving forces of adaptive evolution, the impact and extent of any specific stress needed to drive such changes has not been well characterized. In this study, the antibiotic Ciprofloxacin was used as a stressor and systematically applied to E. coli st. 307 cells via a spatial gradient in a microfluidic pore network and a temporal gradient in batch cultures. The microfluidic device facilitated in vitro real-time tracking of bacterial abundances and dynamic spatial distributions in response to the gradients of both the antibiotic and nutrients. Cells collected from the microfluidic device showed growth on plates containing up to 10-times the original minimum inhibition concentration (MIC). In batch systems, Ciprofloxacin was used to evaluate adaptive responses via temporal gradients, in which the stressor concentration was incrementally increased over time with each transfer of the culture after 24 hours of growth. Responses of E. coli 307 to these stress patterns were measured by quantifying changes in the MIC for Ciprofloxacin. Over a period of 18 days of step-wise concentration increments, bacterial cells were observed to acquire tolerance gradually and eventually adapt to a 28-fold increase in the original MIC. Samples at different stages within the temporal Ciprofloxacin gradient treatment show different extents of resistance. All samples exhibited resistance exceeding the highest exposure stress concentration. In combination with the spatial and temporal gradient systems, this work provides the first comprehensive measure of the dynamic resistance of E. coli in response to Ciprofloxacin concentration gradients. These will provide invaluable insights to understand the effects of antibiotic stresses on bacterial adaptive evolution in

  2. Stress corrosion cracking of iron-nickel-chromium alloys in primary circuit environment of PWR-type reactors

    International Nuclear Information System (INIS)

    Boursier, Jean-Marie

    1993-01-01

    Stress corrosion cracking of Alloy 600 steam generator tubing is a great concern for pressurized water reactors. The mechanism that controls intergranular stress corrosion cracking of Alloy 600 in primary water (lithiated-borated water) has yet to be clearly identified. A study of stress corrosion cracking behaviour, which can identify the main parameters that control the cracking phenomenon, was so necessary to understand the stress corrosion cracking process. Constant extension rate tests, and constant load tests have evidenced that Alloy 600 stress corrosion cracking involves firstly an initiation period, then a slow propagation stage with crack less than 50 to 80 micrometers, and finally a rapid propagation stage leading to failure. The influence of mechanical parameters have shown the next points: - superficial strain hardening and cold work have a strong effect of stress corrosion cracking resistance (decrease of initiation time and increase of crack growth rate), - strain rate was the most suitable parameter for describing the different stage of propagation. The creep behaviour of alloy 600 has shown an increase of creep rate in primary water compared to air, which implies a local interaction plasticity/corrosion. An assessment of the durations of the initiation and the propagation stages was attempted for the whole uniaxial tensile tests, using the macroscopic strain rate: - the initiation time is less than 100 hours and seems to be an electrochemical process, - the durations of the propagation stage are strongly dependent on the strain rate. The behaviour in high primary water temperature of Alloys 690 and 800, which replace Alloy 600, was studied to appraise their margin, and validate their choice. Then the last chapter has to objective to evaluate the crack tip strain rate, in order to better describe the evolution of the different stages of cracking. (author) [fr

  3. When culture clashes with individual human rights: A practical theological reflection on the dignity of widows

    Directory of Open Access Journals (Sweden)

    Gift T. Baloyi

    2017-01-01

    Full Text Available This article discusses the nature of human beings (men and women as an egalitarian one even beyond cultural expectations. It argues against some cultural practices on women, especially widows, which claim supremacy and bind the widows to its ritual processes among the Tsonga people. It stresses the importance of human individual that overtakes everything from God�s creation, including cultural rituals which are created by human beings. It claims that the existence of culture depends solely on the existence or presence of human beings and their communities. Therefore, culture cannot use humans to shape itself and to transform the community. It is humans themselves who use culture to identify themselves and ultimately change their communities. Although the paper is theological in its approach, it argues for individual human rights to be respected and weighed above all cultural practices. It further concludes that such cultural practices are not static and that they can be removed from the rest of culture.Intradisciplinary and/or interdisciplinary implications: This article, from a practical theological view, challenges the African cultural rituals that claim authority over women�s rights and dignity. The interdisciplinary nature of this article indicates the sanctity of human individuals especially widows and thereby calls for paradigm shift to deconstruct certain oppressive teachings and practices against widows among African women. This article concludes thus, cultural deconstruction is possible.

  4. THE SOMALISATION OF POLITICAL ISLAM: TURNING POINT FOR THE CLASH OF ISLAMISMS IN AFRICA

    Directory of Open Access Journals (Sweden)

    Ignacio Gutiérrez de Terán Gómez-Benita

    2011-04-01

    Full Text Available This article covers – firstly and generally speaking – the gradual process of confrontation between traditional African Islam (and particularly the Sufi brotherhoods and the Salafist tendencies that became established in the continent some time ago. Taking the chronic case of Somalia as an example, the author stresses the fact that in addition to doctrinal differences, it is also important to note that social, economic and cultural factors have also helped to aggravate tensions. These, nevertheless, have even erupted in the heart of organisations backing political Islam, in many cases of Wahhabi origin, owing partly to geostrategic determining factors, and partly to the turbulent debate on the advisability of incorporating processes of national reform and reconciliation. Furthermore, and in a way that is reminiscent of a number of antecedents in countries such as Algeria and Afghanistan, the controversy is focused around which strategy to adopt to fight the local leaders who have been labelled as corrupt, and how to link up with the regional and international powers involved in the conflict. Thus, an extreme Somalisation has also reached African Islamist movements, as can be seen in the current fragmentation of Islamism over much of the continent.

  5. Sample environment for neutron scattering measurements of internal stresses in engineering materials in the temperature range of 6 K to 300 K.

    Science.gov (United States)

    Kirichek, O; Timms, J D; Kelleher, J F; Down, R B E; Offer, C D; Kabra, S; Zhang, S Y

    2017-02-01

    Internal stresses in materials have a considerable effect on material properties including strength, fracture toughness, and fatigue resistance. The ENGIN-X beamline is an engineering science facility at ISIS optimized for the measurement of strain and stress using the atomic lattice planes as a strain gauge. Nowadays, the rapidly rising interest in the mechanical properties of engineering materials at low temperatures has been stimulated by the dynamic development of the cryogenic industry and the advanced applications of the superconductor technology. Here we present the design and discuss the test results of a new cryogenic sample environment system for neutron scattering measurements of internal stresses in engineering materials under a load of up to 100 kN and in the temperature range of 6 K to 300 K. Complete cooling of the system starting from the room temperature down to the base temperature takes around 90 min. Understanding of internal stresses in engineering materials at cryogenic temperatures is vital for the modelling and designing of cutting-edge superconducting magnets and other superconductor based applications.

  6. The working memory stroop effect: when internal representations clash with external stimuli.

    Science.gov (United States)

    Kiyonaga, Anastasia; Egner, Tobias

    2014-08-01

    Working memory (WM) has recently been described as internally directed attention, which implies that WM content should affect behavior exactly like an externally perceived and attended stimulus. We tested whether holding a color word in WM, rather than attending to it in the external environment, can produce interference in a color-discrimination task, which would mimic the classic Stroop effect. Over three experiments, the WM Stroop effect recapitulated core properties of the classic attentional Stroop effect, displaying equivalent congruency effects, additive contributions from stimulus- and response-level congruency, and susceptibility to modulation by the percentage of congruent and incongruent trials. Moreover, WM maintenance was inversely related to attentional demands during the WM delay between stimulus presentation and recall, with poorer memory performance following incongruent than congruent trials. Together, these results suggest that WM and attention rely on the same resources and operate over the same representations. © The Author(s) 2014.

  7. Stress testing of electrically active FlexMEAs with simultaneous electrical recording in fluidic environment: Introduction of a new measurement setup

    Science.gov (United States)

    Westerhausen, Markus; Martin, Tanja; Kappel, Marcel; Hofmann, Boris

    2018-02-01

    We present a measurement setup consisting of two fluid-filled pressure chambers to mimic the mechanical stress likely to that of small body movements on biomedical flexible micro-electrode arrays for the analysis of various degradation mechanisms. Our main goal was the simulation of micro-motions in fluid conditions, while maintaining an electric access to the device. These micro-motions would be likely to those occurring in the human body caused by the intracranial pressure in magnitudes of 7-25 mmHg, which translates to a fluid pressure of 9-33 mbar. Furthermore, severe mechanical stress can be administered to the samples under the previously mentioned environment. Therefore, a flexible, polyimide-based sample with various metal test structures was fabricated and analyzed in the presented measurement setup. A comparison of the elongation of the sample's surface as a function of the applied hydrostatic pressure is given with computer simulations.

  8. Effect of strain-path on stress corrosion cracking of AISI 304L stainless steel in PWR primary environment at 360 deg. C

    International Nuclear Information System (INIS)

    Couvant, T.; Vaillant, F.; Boursier, JM.; Delafosse, D.

    2004-01-01

    Austenitic stainless steels (ASS) are widespread in primary and auxiliary circuits of PWR. Moreover, some components suffer stress corrosion cracking (SCC) under neutron irradiation. This degradation could be the result of the increase of hardness or the modification of chemical composition at the grain boundary by irradiation. In order to avoid complex and costly corrosion facilities, the effects of irradiation on the material are commonly simulated by applying a cold work on non-irradiated material prior to stress corrosion cracking tests. Slow strain rate tests were conducted on an austenitic stainless steel (SS) AISI 304L in PWR environment (360 deg. C). Particular attention was directed towards pre-straining effects on crack growth rate (CGR) and crack growth path (CGP). Results have demonstrated that the susceptibility of 304L to SCC in high-temperature hydrogenated water was enhanced by pre-straining. It seemed that IGSCC was enhanced by complex strain paths. (authors)

  9. Effects of Exercise Training and Social Environment on Stress Resilience in Male and Female Long-Evans Rats

    Science.gov (United States)

    2010-03-15

    Dalla et al., 2005; Marin, Cruz, & Planeta , 2007; Mineur, Belzung, & Crusio, 2006; Padilla et al., 2009; Pohl et al., 2007; Slawecki, 2005...48. 156 Marin, M.T., Cruz, F.C., & Planeta , C.S. (2007). Chronic restraint or variable stresses differently affect the behavior, corticosterone

  10. Nutritional Ketosis Affects Metabolism and Behavior in Sprague-Dawley Rats in Both Control and Chronic Stress Environments

    Directory of Open Access Journals (Sweden)

    Milene L. Brownlow

    2017-05-01

    Full Text Available Nutritional ketosis may enhance cerebral energy metabolism and has received increased interest as a way to improve or preserve performance and resilience. Most studies to date have focused on metabolic or neurological disorders while anecdotal evidence suggests that ketosis may enhance performance in the absence of underlying dysfunction. Moreover, decreased availability of glucose in the brain following stressful events is associated with impaired cognition, suggesting the need for more efficient energy sources. We tested the hypotheses that ketosis induced by endogenous or exogenous ketones could: (a augment cognitive outcomes in healthy subjects; and (b prevent stress-induced detriments in cognitive parameters. Adult, male, Sprague Dawley rats were used to investigate metabolic and behavioral outcomes in 3 dietary conditions: ketogenic (KD, ketone supplemented (KS, or NIH-31 control diet in both control or chronic stress conditions. Acute administration of exogenous ketones resulted in reduction in blood glucose and sustained ketosis. Chronic experiments showed that in control conditions, only KD resulted in pronounced metabolic alterations and improved performance in the novel object recognition test. The hypothalamic-pituitary-adrenal (HPA axis response revealed that KD-fed rats maintained peripheral ketosis despite increases in glucose whereas no diet effects were observed in ACTH or CORT levels. Both KD and KS-fed rats decreased escape latencies on the third day of water maze, whereas only KD prevented stress-induced deficits on the last testing day and improved probe test performance. Stress-induced decrease in hippocampal levels of β-hydroxybutyrate was attenuated in KD group while both KD and KS prevented stress effects on BDNF levels. Mitochondrial enzymes associated with ketogenesis were increased in both KD and KS hippocampal samples and both endothelial and neuronal glucose transporters were affected by stress but only in the

  11. Proposed research on class I components to test a general approach to accelerated aging under combined stress environments

    International Nuclear Information System (INIS)

    Gillen, K.T.; Salazar, E.A.; Frank, C.W.

    1977-04-01

    This report summarizes research on the aging of Class I components in environments representative of nuclear power plants. It discusses Class IE equipment used in nuclear power plants, typical environments encountered by Class IE components, and aging techniques used to qualify this equipment. General discussions of radiation chemistry of polymers and accelerated aging techniques are also included. Based on the inadequacies of present aging techniques for Class IE equipment, a proposal for an experimental program on electrical cables is presented. One of the main purposes of the proposed work is to obtain relevant data in two areas of particular concern--the effect of radiation dose rate on polymer degradation, and the importance of synergism for combined thermal and radiation environments. A new model that allows combined environment accelerated aging to be carried out is introduced, and it is shown how the experimental data to be generated can be used to test this model

  12. Pattern recognition model to estimate intergranular stress corrosion cracking (IGSCC) at crevices and pit sites of 304 SS in BWR environments

    Energy Technology Data Exchange (ETDEWEB)

    Urquidi-Macdonald, Mirna [Penn State University, 212 Earth-Engineering Science Building, University Park, PA 16801 (United States)

    2004-07-01

    Many publications have shown that crack growth rates (CGR) due to intergranular stress corrosion cracking (IGSCC) of metals is dependent on many parameters related to the manufacturing process of the steel and the environment to which the steel is exposed. Those parameters include, but are not restricted to, the concentration of chloride, fluoride, nitrates, and sulfates, pH, fluid velocity, electrochemical potential (ECP), electrolyte conductivity, stress and sensitization applied to the steel during its production and use. It is not well established how combinations of each of these parameters impact the CGR. Many different models and beliefs have been published, resulting in predictions that sometimes disagree with experimental observations. To some extent, the models are the closest to the nature of IGSCC, however, there is not a model that fully describes the entire range of observations, due to the difficulty of the problem. Among the models, the Fracture Environment Model, developed by Macdonald et al., is the most physico-chemical model, accounting for experimental observations in a wide range of environments or ECPs. In this work, we collected experimental data on BWR environments and designed a data mining pattern recognition model to learn from that data. The model was used to generate CGR estimations as a function of ECP on a BWR environment. The results of the predictive model were compared to the Fracture Environment Model predictions. The results from those two models are very close to the experimental observations of the area corresponding to creep and IGSCC controlled by diffusion. At more negative ECPs than the potential corresponding to creep, the pattern recognition predicts an increase of CGR with decreasing ECP, while the Fracture Environment Model predicts the opposite. The results of this comparison confirm that the pattern recognition model covers 3 phenomena: hydrogen embrittlement at very negative ECP, creep at intermediate ECP, and IGSCC

  13. Pattern recognition model to estimate intergranular stress corrosion cracking (IGSCC) at crevices and pit sites of 304 SS in BWR environments

    International Nuclear Information System (INIS)

    Urquidi-Macdonald, Mirna

    2004-01-01

    Many publications have shown that crack growth rates (CGR) due to intergranular stress corrosion cracking (IGSCC) of metals is dependent on many parameters related to the manufacturing process of the steel and the environment to which the steel is exposed. Those parameters include, but are not restricted to, the concentration of chloride, fluoride, nitrates, and sulfates, pH, fluid velocity, electrochemical potential (ECP), electrolyte conductivity, stress and sensitization applied to the steel during its production and use. It is not well established how combinations of each of these parameters impact the CGR. Many different models and beliefs have been published, resulting in predictions that sometimes disagree with experimental observations. To some extent, the models are the closest to the nature of IGSCC, however, there is not a model that fully describes the entire range of observations, due to the difficulty of the problem. Among the models, the Fracture Environment Model, developed by Macdonald et al., is the most physico-chemical model, accounting for experimental observations in a wide range of environments or ECPs. In this work, we collected experimental data on BWR environments and designed a data mining pattern recognition model to learn from that data. The model was used to generate CGR estimations as a function of ECP on a BWR environment. The results of the predictive model were compared to the Fracture Environment Model predictions. The results from those two models are very close to the experimental observations of the area corresponding to creep and IGSCC controlled by diffusion. At more negative ECPs than the potential corresponding to creep, the pattern recognition predicts an increase of CGR with decreasing ECP, while the Fracture Environment Model predicts the opposite. The results of this comparison confirm that the pattern recognition model covers 3 phenomena: hydrogen embrittlement at very negative ECP, creep at intermediate ECP, and IGSCC

  14. Type-Ia supernova rates to redshift 2.4 from clash: The cluster lensing and supernova survey with Hubble

    International Nuclear Information System (INIS)

    Graur, O.; Rodney, S. A.; Riess, A. G.; Medezinski, E.; Maoz, D.; Jha, S. W.; Holoien, T. W.-S.; McCully, C.; Patel, B.; Postman, M.; Dahlen, T.; Strolger, L.-G.; Coe, D.; Bradley, L.; Koekemoer, A.; Benítez, N.; Molino, A.; Jouvel, S.; Nonino, M.; Balestra, I.

    2014-01-01

    We present the supernova (SN) sample and Type-Ia SN (SN Ia) rates from the Cluster Lensing And Supernova survey with Hubble (CLASH). Using the Advanced Camera for Surveys and the Wide Field Camera 3 on the Hubble Space Telescope (HST), we have imaged 25 galaxy-cluster fields and parallel fields of non-cluster galaxies. We report a sample of 27 SNe discovered in the parallel fields. Of these SNe, ∼13 are classified as SN Ia candidates, including four SN Ia candidates at redshifts z > 1.2. We measure volumetric SN Ia rates to redshift 1.8 and add the first upper limit on the SN Ia rate in the range 1.8 < z < 2.4. The results are consistent with the rates measured by the HST/GOODS and Subaru Deep Field SN surveys. We model these results together with previous measurements at z < 1 from the literature. The best-fitting SN Ia delay-time distribution (DTD; the distribution of times that elapse between a short burst of star formation and subsequent SN Ia explosions) is a power law with an index of −1.00 −0.06(0.10) +0.06(0.09) (statistical) −0.08 +0.12 (systematic), where the statistical uncertainty is a result of the 68% and 95% (in parentheses) statistical uncertainties reported for the various SN Ia rates (from this work and from the literature), and the systematic uncertainty reflects the range of possible cosmic star-formation histories. We also test DTD models produced by an assortment of published binary population synthesis (BPS) simulations. The shapes of all BPS double-degenerate DTDs are consistent with the volumetric SN Ia measurements, when the DTD models are scaled up by factors of 3-9. In contrast, all BPS single-degenerate DTDs are ruled out by the measurements at >99% significance level.

  15. Type-Ia Supernova Rates to Redshift 2.4 from Clash: The Cluster Lensing and Supernova Survey with Hubble

    Science.gov (United States)

    Graur, O.; Rodney, S. A.; Maoz, D.; Riess, A. G.; Jha, S. W.; Postman, M.; Dahlen, T.; Holoien, T. W.-S.; McCully, C.; Patel, B.; hide

    2014-01-01

    We present the supernova (SN) sample and Type-Ia SN (SN Ia) rates from the Cluster Lensing And Supernova survey with Hubble (CLASH). Using the Advanced Camera for Surveys and the Wide Field Camera 3 on the Hubble Space Telescope (HST), we have imaged 25 galaxy-cluster fields and parallel fields of non-cluster galaxies. We report a sample of 27 SNe discovered in the parallel fields. Of these SNe, approximately 13 are classified as SN Ia candidates, including four SN Ia candidates at redshifts z greater than 1.2.We measure volumetric SN Ia rates to redshift 1.8 and add the first upper limit on the SN Ia rate in the range z greater than 1.8 and less than 2.4. The results are consistent with the rates measured by the HST/ GOODS and Subaru Deep Field SN surveys.We model these results together with previous measurements at z less than 1 from the literature. The best-fitting SN Ia delay-time distribution (DTD; the distribution of times that elapse between a short burst of star formation and subsequent SN Ia explosions) is a power law with an index of 1.00 (+0.06(0.09))/(-0.06(0.10)) (statistical) (+0.12/-0.08) (systematic), where the statistical uncertainty is a result of the 68% and 95% (in parentheses) statistical uncertainties reported for the various SN Ia rates (from this work and from the literature), and the systematic uncertainty reflects the range of possible cosmic star-formation histories. We also test DTD models produced by an assortment of published binary population synthesis (BPS) simulations. The shapes of all BPS double-degenerate DTDs are consistent with the volumetric SN Ia measurements, when the DTD models are scaled up by factors of 3-9. In contrast, all BPS single-degenerate DTDs are ruled out by the measurements at greater than 99% significance level.

  16. Evaluation of heat stress effects on production traits and somatic cell score of Holsteins in a temperate environment.

    Science.gov (United States)

    Hammami, H; Bormann, J; M'hamdi, N; Montaldo, H H; Gengler, N

    2013-03-01

    This study was aimed to evaluate the degree of thermal stress exhibited by Holsteins under a continental temperate climate. Milk, fat, protein, and somatic cell count test-day records collected between 2000 and 2011 from 23,963 cows in 604 herds were combined with meteorological data from 14 public weather stations in Luxembourg. Daily values of 6 different thermal indices (TI) weighted in term of temperature, relative humidity, solar radiation, and wind speed were calculated by averaging hourly TI over 24h. Heat stress thresholds were first identified by a broken-line regression model. Regression models were thereafter applied to quantify milk production losses due to heat stress. The tipping points at which milk and protein yields declined were effectively identified. For fat yield, no valid threshold was identified for any of the studied TI. Daily fat yields tended to decrease steadily with increasing values of TI. Daily somatic cell score patterns were marked by increased values at both lowest and highest TI ranges, with a more pronounced reaction to cold stress for apparent temperature indices. Thresholds differed between TI and traits. For production traits, they ranged from 62 (TI(1)) to 80 (TI(3)) for temperature-humidity indices (THI) and from 16 (TI(5)) to 20 (TI(6)) for apparent temperature indices. Corresponding somatic cell score thresholds were higher and ranged from 66 (TI(1)) to 82 (TI(3)) and from 20 (TI(5)) to 23 (TI(6)), respectively. The largest milk decline per unit of mild, moderate, and extreme heat stress levels of 0.164, 0.356, and 0.955 kg, respectively, was observed when using the conventional THI (TI(1)). The highest yearly milk, fat, and protein losses of 54, 5.7, and 4.2 kg, respectively, were detected by TI(2), the THI index that is adjusted for wind speed and solar radiation. The latter index could be considered as the best indicator of heat stress to be used for forecast and herd management in a first step in temperate regions under

  17. Determination of the time to failure curve as a function of stress for a highly irradiated AISI 304 stainless steel after constant load tests in simulated PWR water environment

    International Nuclear Information System (INIS)

    Pokor, C.; Massoud, J.P.; Wintergerst, M.; Toivonen, A.; Ehrnsten, U.; Karlsen, W.

    2011-01-01

    The structures of Reactor Pressure Vessel Internals are subjected to an intense neutron flux. Under these operating conditions, the microstructure and the mechanical properties of the austenitic stainless steel components change. In addition, these components are subjected to stress of either manufacturing origin or generated under operation. Cases of baffle bolts cracking have occurred in CP0 Nuclear Power Plant units. The mechanism of degradation of these bolts is Irradiation-Assisted Stress Corrosion Cracking. In order to obtain a better understanding of this mechanism and its principal parameters of influence, a set of stress corrosion tests (mainly constant load tests) were launched within the framework of the EDF project 'PWR Internals' using materials from a Chooz A baffle corner (SA 304). These tests aim to quantify the influence on IASCC of the applied stress, temperature and environment (primary water, higher lithium concentration, inert environment) for an irradiation dose close to 30 dpa. A curve showing time to failure as a function of the stress was determined. The shape of this curve is consistent with the few data that are available in the literature. A stress threshold of about 50 % of the yield strength value at the test temperature has been determined, below which cracking in that environment seems impossible. After irradiation this material is sensitive to intergranular fracture in a primary environment, but also in an inert environment (argon) at 340 C. The tests also showed a negative effect of increased lithium concentration on the time to failure and on the stress threshold. (authors)

  18. Finger Millet: A "Certain" Crop for an "Uncertain" Future and a Solution to Food Insecurity and Hidden Hunger under Stressful Environments.

    Science.gov (United States)

    Gupta, Sanjay Mohan; Arora, Sandeep; Mirza, Neelofar; Pande, Anjali; Lata, Charu; Puranik, Swati; Kumar, J; Kumar, Anil

    2017-01-01

    Crop growth and productivity has largely been vulnerable to various abiotic and biotic stresses that are only set to be compounded due to global climate change. Therefore developing improved varieties and designing newer approaches for crop improvement against stress tolerance have become a priority now-a-days. However, most of the crop improvement strategies are directed toward staple cereals such as rice, wheat, maize etc., whereas attention on minor cereals such as finger millet [ Eleusine coracana (L.) Gaertn.] lags far behind. It is an important staple in several semi-arid and tropical regions of the world with excellent nutraceutical properties as well as ensuring food security in these areas even during harsh environment. This review highlights the importance of finger millet as a model nutraceutical crop. Progress and prospects in genetic manipulation for the development of abiotic and biotic stress tolerant varieties is also discussed. Although limited studies have been conducted for genetic improvement of finger millets, its nutritional significance in providing minerals, calories and protein makes it an ideal model for nutrition-agriculture research. Therefore, improved genetic manipulation of finger millets for resistance to both abiotic and biotic stresses, as well as for enhancing nutrient content will be very effective in millet improvement. Key message: Apart from the excellent nutraceutical value of finger millet, its ability to tolerate various abiotic stresses and resist pathogens make it an excellent model for exploring vast genetic and genomic potential of this crop, which provide us a wide choice for developing strategies for making climate resilient staple crops.

  19. Finger Millet: A “Certain” Crop for an “Uncertain” Future and a Solution to Food Insecurity and Hidden Hunger under Stressful Environments

    Science.gov (United States)

    Gupta, Sanjay Mohan; Arora, Sandeep; Mirza, Neelofar; Pande, Anjali; Lata, Charu; Puranik, Swati; Kumar, J.; Kumar, Anil

    2017-01-01

    Crop growth and productivity has largely been vulnerable to various abiotic and biotic stresses that are only set to be compounded due to global climate change. Therefore developing improved varieties and designing newer approaches for crop improvement against stress tolerance have become a priority now-a-days. However, most of the crop improvement strategies are directed toward staple cereals such as rice, wheat, maize etc., whereas attention on minor cereals such as finger millet [Eleusine coracana (L.) Gaertn.] lags far behind. It is an important staple in several semi-arid and tropical regions of the world with excellent nutraceutical properties as well as ensuring food security in these areas even during harsh environment. This review highlights the importance of finger millet as a model nutraceutical crop. Progress and prospects in genetic manipulation for the development of abiotic and biotic stress tolerant varieties is also discussed. Although limited studies have been conducted for genetic improvement of finger millets, its nutritional significance in providing minerals, calories and protein makes it an ideal model for nutrition-agriculture research. Therefore, improved genetic manipulation of finger millets for resistance to both abiotic and biotic stresses, as well as for enhancing nutrient content will be very effective in millet improvement. Key message: Apart from the excellent nutraceutical value of finger millet, its ability to tolerate various abiotic stresses and resist pathogens make it an excellent model for exploring vast genetic and genomic potential of this crop, which provide us a wide choice for developing strategies for making climate resilient staple crops. PMID:28487720

  20. Finger Millet: A “Certain” Crop for an “Uncertain” Future and a Solution to Food Insecurity and Hidden Hunger under Stressful Environments

    Directory of Open Access Journals (Sweden)

    Anil Kumar

    2017-04-01

    Full Text Available Crop growth and productivity has largely been vulnerable to various abiotic and biotic stresses that are only set to be compounded due to global climate change. Therefore developing improved varieties and designing newer approaches for crop improvement against stress tolerance have become a priority now-a-days. However, most of the crop improvement strategies are directed toward staple cereals such as rice, wheat, maize etc., whereas attention on minor cereals such as finger millet [Eleusine coracana (L. Gaertn.] lags far behind. It is an important staple in several semi-arid and tropical regions of the world with excellent nutraceutical properties as well as ensuring food security in these areas even during harsh environment. This review highlights the importance of finger millet as a model nutraceutical crop. Progress and prospects in genetic manipulation for the development of abiotic and biotic stress tolerant varieties is also discussed. Although limited studies have been conducted for genetic improvement of finger millets, its nutritional significance in providing minerals, calories and protein makes it an ideal model for nutrition-agriculture research. Therefore, improved genetic manipulation of finger millets for resistance to both abiotic and biotic stresses, as well as for enhancing nutrient content will be very effective in millet improvement.Key message: Apart from the excellent nutraceutical value of finger millet, its ability to tolerate various abiotic stresses and resist pathogens make it an excellent model for exploring vast genetic and genomic potential of this crop, which provide us a wide choice for developing strategies for making climate resilient staple crops.

  1. Uptake and allocation of 15N in alpine plants. Implications for the importance of competitive ability in predicting community structure in a stressful environment

    International Nuclear Information System (INIS)

    Theodose, T.A.; Jaeger, C.H.; Bowman, W.D.; Schardt, J.C.

    1996-01-01

    Several potential components of competitive ability were determined for 13 plant species in a N-limited alpine moist meadow community in order to determine if competition had an influence on relative abundance in this stressful environment. The components of competitive ability examined were 15 N uptake rate, 15 N allocation, whole plant biomass, root:shoot ratio, and tissue N concentrations. It was hypothesized that 15 N uptake rate would be the component most correlated with relative abundance. However, 15 N uptake rate was negatively correlated with percent cover in the community. In contrast, whole plant biomass and root:shoot ratio were positively correlated with relative abundance. Tissue N concentrations and 15 N allocation were not important predictors of relative abundance. These results suggest that in a harsh environment, high resource uptake rates are not indicative of competitive ability, but may instead by a mechanism by which rare species are able to coexist with competitive dominants. (au) 47 refs

  2. Clash of kingdoms or why Drosophila larvae positively respond to fungal competitors

    Directory of Open Access Journals (Sweden)

    Rohlfs Marko

    2005-01-01

    Full Text Available Abstract Background Competition with filamentous fungi has been demonstrated to be an important cause of mortality for the vast group of insects that depend on ephemeral resources (e.g. fruit, dung, carrion. Recent data suggest that the well-known aggregation of Drosophila larvae across decaying fruit yields a competitive advantage over mould, by which the larvae achieve a higher survival probability in larger groups compared with smaller ones. Feeding and locomotor behaviour of larger larval groups is assumed to cause disruption of fungal hyphae, leading to suppression of fungal growth, which in turn improves the chances of larval survival to the adult stage. Given the relationship between larval density, mould suppression and larval survival, the present study has tested whether fungal-infected food patches elicit communal foraging behaviour on mould-infected sites by which larvae might hamper mould growth more efficiently. Results Based on laboratory experiments in which Drosophila larvae were offered the choice between fungal-infected and uninfected food patches, larvae significantly aggregated on patches containing young fungal colonies. Grouping behaviour was also visible when larvae were offered only fungal-infected or only uninfected patches; however, larval aggregation was less strong under these conditions than in a heterogeneous environment (infected and uninfected patches. Conclusion Because filamentous fungi can be deadly competitors for insect larvae on ephemeral resources, social attraction of Drosophila larvae to fungal-infected sites leading to suppression of mould growth may reflect an adaptive behavioural response that increases insect larval fitness and can thus be discussed as an anti-competitor behaviour. These observations support the hypothesis that adverse environmental conditions operate in favour of social behaviour. In a search for the underlying mechanisms of communal behaviour in Drosophila, this study highlights

  3. Dementia care worker stress associations with unit type, resident, and work environment characteristics: a cross-sectional secondary data analysis of the Swiss Nursing Homes Human Resources Project (SHURP).

    Science.gov (United States)

    Vogel, Barbara; De Geest, Sabina; Fierz, Katharina; Beckmann, Sonja; Zúñiga, Franziska

    2017-03-01

    Although caring for residents with dementia in nursing homes is associated with various stressors for care workers, the role of the unit type, and particularly the proportion of residents with dementia, remains unclear. This study aimed to explore associations between unit type and care worker stress, taking into account additional potential stressors. This cross-sectional study was a secondary data analysis in the Swiss Nursing Homes Human Resources Project, which included data from 3,922 care workers from 156 Swiss nursing homes. Care workers' stress was measured with a shortened version of the Health Professions Stress Inventory. Generalized estimating equation models were used to assess care worker stress and its relationships with three unit types (special care units and others with high or low proportions of residents with dementia), work environment factors, and aggressive resident behavior. After including all potential stressors in the models, no significant differences between the three unit types regarding care worker stress were found. However, increased care worker stress levels were significantly related to lower ratings of staffing and resources adequacy, the experience of verbal aggression, and the observation of verbal or physical aggression among residents. Although the unit type plays only a minor role regarding care worker stress, this study confirms that work environment and aggressive behavior of residents are important factors associated with work-related stress. To prevent increases of care worker stress, interventions to improve the work environment and strengthen care workers' ability to cope with aggressive behavior are suggested.

  4. Plant survival in a changing environment: the role of nitric oxide in plant responses to abiotic stress

    Directory of Open Access Journals (Sweden)

    Marcela eSimontacchi

    2015-11-01

    Full Text Available Nitric oxide in plants may originate endogenously or come from surrounding atmosphere and soil. Interestingly, this gaseous free radical is far from having a constant level and varies greatly among tissues depending on a given plant´s ontogeny and environmental fluctuations.Proper plant growth, vegetative development, and reproduction require the integration of plant hormonal activity with the antioxidant network, as well as the maintenance of concentration of reactive oxygen and nitrogen species within a narrow range. Plants are frequently faced with abiotic stress conditions such as low nutrient availability, salinity, drought, high ultraviolet (UV radiation and extreme temperatures, which can influence developmental processes and lead to growth restriction making adaptive responses the plant´s priority. The ability of plants to respond and survive under environmental-stress conditions involves sensing and signalling events where nitric oxide becomes a critical component mediating hormonal actions, interacting with reactive oxygen species, and modulating gene expression and protein activity. This review focuses on the current knowledge of the role of nitric oxide in adaptive plant responses to some specific abiotic stress conditions, particularly low mineral nutrient supply, drought, salinity and high UV-B radiation.

  5. Plant Survival in a Changing Environment: The Role of Nitric Oxide in Plant Responses to Abiotic Stress

    Science.gov (United States)

    Simontacchi, Marcela; Galatro, Andrea; Ramos-Artuso, Facundo; Santa-María, Guillermo E.

    2015-01-01

    Nitric oxide in plants may originate endogenously or come from surrounding atmosphere and soil. Interestingly, this gaseous free radical is far from having a constant level and varies greatly among tissues depending on a given plant’s ontogeny and environmental fluctuations. Proper plant growth, vegetative development, and reproduction require the integration of plant hormonal activity with the antioxidant network, as well as the maintenance of concentration of reactive oxygen and nitrogen species within a narrow range. Plants are frequently faced with abiotic stress conditions such as low nutrient availability, salinity, drought, high ultraviolet (UV) radiation and extreme temperatures, which can influence developmental processes and lead to growth restriction making adaptive responses the plant’s priority. The ability of plants to respond and survive under environmental-stress conditions involves sensing and signaling events where nitric oxide becomes a critical component mediating hormonal actions, interacting with reactive oxygen species, and modulating gene expression and protein activity. This review focuses on the current knowledge of the role of nitric oxide in adaptive plant responses to some specific abiotic stress conditions, particularly low mineral nutrient supply, drought, salinity and high UV-B radiation. PMID:26617619

  6. Mapping the diatom redox-sensitive proteome provides insight into response to nitrogen stress in the marine environment.

    Science.gov (United States)

    Rosenwasser, Shilo; Graff van Creveld, Shiri; Schatz, Daniella; Malitsky, Sergey; Tzfadia, Oren; Aharoni, Asaph; Levin, Yishai; Gabashvili, Alexandra; Feldmesser, Ester; Vardi, Assaf

    2014-02-18

    Diatoms are ubiquitous marine photosynthetic eukaryotes responsible for approximately 20% of global photosynthesis. Little is known about the redox-based mechanisms that mediate diatom sensing and acclimation to environmental stress. Here we used a quantitative mass spectrometry-based approach to elucidate the redox-sensitive signaling network (redoxome) mediating the response of diatoms to oxidative stress. We quantified the degree of oxidation of 3,845 cysteines in the Phaeodactylum tricornutum proteome and identified approximately 300 redox-sensitive proteins. Intriguingly, we found redox-sensitive thiols in numerous enzymes composing the nitrogen assimilation pathway and the recently discovered diatom urea cycle. In agreement with this finding, the flux from nitrate into glutamine and glutamate, measured by the incorporation of (15)N, was strongly inhibited under oxidative stress conditions. Furthermore, by targeting the redox-sensitive GFP sensor to various subcellular localizations, we mapped organelle-specific oxidation patterns in response to variations in nitrogen quota and quality. We propose that redox regulation of nitrogen metabolism allows rapid metabolic plasticity to ensure cellular homeostasis, and thus is essential for the ecological success of diatoms in the marine ecosystem.

  7. Relasi Penerapan Elemen Interior Healing Environment Pada Ruang Rawat Inap dalam Mereduksi Stress Psikis Pasien (Studi Kasus: RSUD. Kanjuruhan, Kabupaten Malang

    Directory of Open Access Journals (Sweden)

    Debri Haryndia Putri

    2013-12-01

    Full Text Available The pleasing atmosphere of medical environment is a friendly atmosphere so it can accelerate the adaptation process of patients. However, the medical environment is very often identical with fear, anxiety, and uncertainty that can suppress the immune system so that patients require longer treatment time and even hasten the complications during treatment occur. This study is conducted to analyze how to optimize the application of healing environment interior elements (such: circulation, lighting, color, interior supporting elements: natural elements, the position of social interaction and television inside the treatment room directly affect the patients psychologically. The research is at Kanjuruhan public hospital which has simple and candid interior physical condition. The results demonstrates that the elements of nature and natural lighting are potential to reduce patient stress, given the daily conditions of people who tend to be close to nature. The differences in economic background, culture, and community demographics would produce a different perception in looking at the most ideal and suitable healing elements for their treatment environment.

  8. The Interacting Effect of the BDNF Val66Met Polymorphism and Stressful Life Events on Adolescent Depression Is Not an Artifact of Gene-Environment Correlation: Evidence from a Longitudinal Twin Study

    Science.gov (United States)

    Chen, Jie; Li, Xinying; McGue, Matt

    2013-01-01

    Background: Confounding introduced by gene-environment correlation (rGE) may prevent one from observing a true gene-environment interaction (G × E) effect on psychopathology. The present study investigated the interacting effect of the BDNF Val66Met polymorphism and stressful life events (SLEs) on adolescent depression while controlling for the…

  9. Rock outcrops reduce temperature-induced stress for tropical conifer by decoupling regional climate in the semiarid environment.

    Science.gov (United States)

    Locosselli, Giuliano Maselli; Cardim, Ricardo Henrique; Ceccantini, Gregório

    2016-05-01

    We aimed to understand the effect of rock outcrops on the growth of Podocarpus lambertii within a microrefuge. Our hypothesis holds that the growth and survival of this species depend on the regional climate decoupling provided by rock outcrops. To test this hypothesis, we characterized the microclimate of (1) surrounding vegetation, (2) rock outcrop corridors, and (3) adjacencies. We assessed population structure by collecting data of specimen stem diameter and height. We also assessed differences between vegetation associated or not with outcrops using satellite imaging. For dendrochronological analyses, we sampled 42 individuals. Tree rings of 31 individuals were dated, and climate-growth relationships were tested. Rock outcrops produce a favorable microclimate by reducing average temperature by 4.9 °C and increasing average air humidity by 12 %. They also reduce the variability of atmospheric temperature by 42 % and air humidity by 20 % supporting a vegetation with higher leaf area index. Within this vegetation, specimen height was strongly constrained by the outcrop height. Although temperature and precipitation modulate this species growth, temperature-induced stress is the key limiting growth factor for this population of P. lambertii. We conclude that this species growth and survival depend on the presence of rock outcrops. These topography elements decouple regional climate in a favorable way for this species growth. However, these benefits are restricted to the areas sheltered by rock outcrops. Although this microrefuge supported P. lambertii growth so far, it is unclear whether this protection would be sufficient to withstand the stress of future climate changes.

  10. Hidden realities inside PBL design processes: Is consensus design an impossible clash of interest between the individual and the collective, and is architecture its first victim?

    Directory of Open Access Journals (Sweden)

    Ole Pihl

    2015-06-01

    following points: 1 How can a PBL group-based learning environment based on a dialogical consensus ensure that everyone is working towards the same goal? 2 Does consensus architecture secure a necessary analysis and interpretation of the context, or does it create a grey consensus architecture based on compromises? 3 Does the PBL-method evoke a certain expression in space, form and materiality, but perhaps exclude other (possibly better solutions? 4 Every group’s work depends on the interplay between the personalities of the individuals and the group. How does this interplay affect the creative process? This paper seeks answers to the initial question “Is consensus design an impossible clash of interest between the individual and the collective, and is architecture its first victim?” and suggests new possible methodological tools for the architectural design process that secure the level of quality in design education.

  11. Planktonic foraminiferal abnormalities in coastal and open marine eastern Mediterranean environments: A natural stress monitoring approach in recent and early Holocene marine systems

    Science.gov (United States)

    Antonarakou, A.; Kontakiotis, G.; Zarkogiannis, S.; Mortyn, P. G.; Drinia, H.; Koskeridou, E.; Anastasakis, G.

    2018-05-01

    Marine environmental status can be assessed through the study of bio-indicator species. Here, we monitor natural environmental stress by the occurrence of morphologically abnormal planktonic foraminiferal specimens from a suite of surface sediments in the eastern Mediterranean Sea. We also compare Scanning Electron Microscopy (SEM) abnormality observations from sapropel S1-derived sediments in the Aegean, Libyan and Levantine basins, since they provide a direct record of a natural stress experiment that took place over past time scales. At initial sapropel deposition levels, we observe increased growth asymmetry in Globigerinoides ruber twinned and twisted individuals, possibly associated with eutrophication and anoxia. In modern material, a range of malformations and aberrant morphologies from slight deformity with smaller or overdeveloped chambers to more severe deformity with abnormally protruding or misplaced chambers, distorted spirals, and double tests is also observed, as a result of the hypersaline, oligotrophic and oxygen-depleted nature of the Mediterranean Sea water column. Overall, we highlight the current use of the relative abundance of abnormal tests as a bio-indicator for monitoring natural stress, especially the occurrence of twin specimens as indicative of high-salinity stress conditions, and further illustrate the necessity to map both their spatial and temporal distribution for accurate paleoenvironmental reconstructions. Such an approach presents the advantage to rapidly provide information over wide spatial and temporal scales, extending our ability to monitor a wide variety of environments (from coastal to the open-sea). However, further investigations should extend this approach to test the robustness of our findings in a number of similar oceanic settings.

  12. A cleanroom sleeping environment's impact on markers of oxidative stress, immune dysregulation, and behavior in children with autism spectrum disorders.

    Science.gov (United States)

    Faber, Scott; Zinn, Gregory M; Boggess, Andrew; Fahrenholz, Timothy; Kern, John C; Kingston, H M Skip

    2015-03-19

    An emerging paradigm suggests children with autism display a unique pattern of environmental, genetic, and epigenetic triggers that make them susceptible to developing dysfunctional heavy metal and chemical detoxification systems. These abnormalities could be caused by alterations in the methylation, sulfation, and metalloprotein pathways. This study sought to evaluate the physiological and behavioral effects of children with autism sleeping in an International Organization for Standardization Class 5 cleanroom. Ten children with autism, ages 3-12, slept in a cleanroom for two weeks to evaluate changes in toxin levels, oxidative stress, immune dysregulation, and behavior. Before and after the children slept in the cleanroom, samples of blood and hair and rating scale scores were obtained to assess these changes. Five children significantly lowered their concentration of oxidized glutathione, a biomarker of oxidative stress. The younger cohort, age 5 and under, showed significantly greater mean decreases in two markers of immune dysregulation, CD3% and CD4%, than the older cohort. Changes in serum magnesium, influencing neuronal regulation, correlated negatively while changes in serum iron, affecting oxygenation of tissues, correlated positively with age. Changes in serum benzene and PCB 28 concentrations showed significant negative correlations with age. The younger children demonstrated significant improvements on behavioral rating scales compared to the older children. In a younger pair of identical twins, one twin showed significantly greater improvements in 4 out of 5 markers of oxidative stress, which corresponded with better overall behavioral rating scale scores than the other twin. Younger children who slept in the cleanroom altered elemental levels, decreased immune dysregulation, and improved behavioral rating scales, suggesting that their detoxification metabolism was briefly enhanced. The older children displayed a worsening in behavioral rating scale

  13. effect of extreme seasonal variations and environments on some stress hormones and clotting factors of type 2 diabetics

    International Nuclear Information System (INIS)

    Mohamed, A.I.

    2006-01-01

    the present study aimed to to investigate the effect of seasons (summer and winter) and environments (Cairo and Assiut) on some serum components including fasting and postprandial blood glucose, glycosylated hemoglobin cholesterol and triglycerides in type Il diabetic patients . measure also included prothrombin time, partial thromboplastin time, plasma fibrinogen, factor Vlll and plasminogen . the study also aimed to investigate the effect of season and environments on serum insulin, glucagon, cortisol and prolactin. twenty male diabetics and ten normal control have shared from each governorate during summer and winter. data from this study showed: 1- during summer, there was an increase in postprandial glucose of normal volunteers and in fasting and postprandial glucose in cairo diabetics. 2- normal assiut volunteers experienced increased FBG in summer while diabetics experienced lower postprandial glucose during summer. 3- during winter, cairo diabetics had significantly lower fasting and postprandial glucose than assiut diabetics.4- during summer, cairo diabetics had increased postprandial serum glucose in comparison to assiut. 5-the more the level of glucose the less the effect of seasons on blood glucose. 6- serum triglycerides were higher in cairo during summer, while serum cholesterol was higher in assiut in summer than in winter

  14. Clashing Over the Climate

    Institute of Scientific and Technical Information of China (English)

    HAIDER; RIZVI

    2010-01-01

    At the Copenhagen climate change summit,poor nations challenge Western domination Is the glass half empty or half full? As the year 2009 approached its end,the leaders of developing countries who attended the UN summit on climate left the Danish

  15. Seasonal changes in mRNA encoding for cell stress markers in the oyster Crassostrea gigas exposed to radioactive discharges in their natural environment

    International Nuclear Information System (INIS)

    Farcy, Emilie; Voiseux, Claire; Lebel, Jean-Marc; Fievet, Bruno

    2007-01-01

    The North Cotentin area (Normandy, France) hosts several nuclear facilities among which the AREVA reprocessing plant of La Hague is responsible for controlled discharges of liquid radioactive wastes into the marine environment. The resulting increase in radioactivity is very small compared to natural radioactivity. However, concerns about environment protection prompted the scientific community to focus on the effects of the chronic exposure to low concentrations of radionuclides in non-human biota. This study contributes to the evaluation of the possible impact of radioactive discharges on the oyster Crassostrea gigas in the field. Real-time polymerase chain reaction was used to quantify the expression levels of genes involved in cell stress in the oyster. They included members of the heat shock protein family (Hsp70, Hsc72, Hsp90), superoxide dismutase (SOD) and metallothionein (MT). Times series measurements were built from periodic samplings in the natural environment in order to characterize the natural variability as well as possible seasonal fluctuations. The genes studied exhibited a general seasonal expression pattern with a peak value in winter. The data inversely correlated with seawater temperature and the nature of the relationship between gene expression and temperature is discussed. In parallel, oysters were collected in four locations on the French shores, exposed or not to radioactive liquid wastes from the nuclear facilities hosted in the North Cotentin. The comparison of data obtained in the reference location on the Atlantic coast (not exposed) and data from oysters of the English Channel (exposed) gave no evidence for any statistical difference. However, because of the complexity of the natural environment, we cannot rule out the possibility that other parameters may have masked the impact of radioactive discharges. This dense set of data is a basis for the use of the expression levels of those genes as biomarkers to address the question of the

  16. Influence of sulfur on the passivity of inconel 600 in aqueous environment at 3000C. Relationship with stress corrosion

    International Nuclear Information System (INIS)

    Vancon, D.

    1989-11-01

    Dissolution kinetics and repassivation of inconel 600 in simulated primary coolant circuits of PWR is studied by fast traction experiment under potentiostatic control. The notion of elementary electrochemical transient is introduced. The model of anodic dissolution - film rupture allows the calculation of crack growth in constant deformation rate tests. When sulfur concentration is smaller than 100 micrograms/g the current is low, above the current is high. Calculation of crack growth from high level current are consistent with experimental data. Influence of pH, temperature, solution composition are determined. A Comparative study with nickel, incoloy 690 and a 19% chromium alloy was carried out to understand fast traction phenomena. Chromium plays an important part without pollution a protecting chromium oxide is formed. In polluted environment sulfur prevent nucleation of this compound and chromium hydroxides are precipitated on the surface. With pure nickel there is no passivity in presence of sulfur [fr

  17. Stress corrosion cracking in repair-welded 3.5 NiCrMoV steel in an actual turbine environment

    International Nuclear Information System (INIS)

    Hitomi, Itoh; Takashi, Shige; Takashi, Momoo

    2001-01-01

    Temporary welding repairs are sometimes needed when damage occurs at the teeth of blade grooves in a low-pressure turbine rotor operated at the dry/wet boundary region. When repair welding has been performed for the 3,5 NiCrMoV steel used in low-pressure turbines, the soundness of the weld must be confirmed. For this reason, a laboratory investigation of susceptibility for stress corrosion cracking (SCC) was conducted for test specimens taken from simulated welds, and then an exposure test was conducted in an actual turbine environment for approximately 7,000 hours. As no SCC initiation was detected and also the propagation was extremely small, repair welding is deemed to be applicable. (author)

  18. Crack growth testing of cold worked stainless steel in a simulated PWR primary water environment to assess susceptibility to stress corrosion cracking

    International Nuclear Information System (INIS)

    Tice, D.R.; Stairmand, J.W.; Fairbrother, H.J.; Stock, A.

    2007-01-01

    Although austenitic stainless steels do not show a high degree of susceptibility to stress corrosion cracking (SCC) in PWR primary environments, there is limited evidence from laboratory testing that crack propagation may occur under some conditions for materials in a cold-worked condition. A test program is therefore underway to examine the factors influencing SCC propagation in good quality PWR primary coolant. Type 304 stainless steel was subjected to cold working by either rolling (at ambient or elevated temperature) or fatigue cycling, to produce a range of yield strengths. Compact tension specimens were fabricated from these materials and tested in simulated high temperature (250-300 o C) PWR primary coolant. It was observed that the degree of crack propagation was influenced by the degree of cold work, the crack growth orientation relative to the rolling direction and the method of working. (author)

  19. Effects of body-mapping-designed clothing on heat stress and running performance in a hot environment.

    Science.gov (United States)

    Jiao, Jiao; Li, Yi; Yao, Lei; Chen, Yajun; Guo, Yueping; Wong, Stephen H S; Ng, Frency S F; Hu, Junyan

    2017-10-01

    To investigate clothing-induced differences in human thermal response and running performance, eight male athletes participated in a repeated-measure study by wearing three sets of clothing (CloA, CloB, and CloC). CloA and CloB were body-mapping-designed with 11% and 7% increased capacity of heat dissipation respectively than CloC, the commonly used running clothing. The experiments were conducted by using steady-state running followed by an all-out performance running in a controlled hot environment. Participants' thermal responses such as core temperature (T c ), mean skin temperature ([Formula: see text]), heat storage (S), and the performance running time were measured. CloA resulted in shorter performance time than CloC (323.1 ± 10.4 s vs. 353.6 ± 13.2 s, p = 0.01), and induced the lowest [Formula: see text], smallest ΔT c , and smallest S in the resting and running phases. This study indicated that clothing made with different heat dissipation capacities affects athlete thermal responses and running performance in a hot environment. Practitioner Summary: A protocol that simulated the real situation in running competitions was used to investigate the effects of body-mapping-designed clothing on athletes' thermal responses and running performance. The findings confirmed the effects of optimised clothing with body-mapping design and advanced fabrics, and ensured the practical advantage of developed clothing on exercise performance.

  20. Vitamin C impacts anxiety-like behavior and stress-induced anorexia relative to social environment in SMP30/GNL knockout mice.

    Science.gov (United States)

    Koizumi, Miwako; Kondo, Yoshitaka; Isaka, Ayumi; Ishigami, Akihito; Suzuki, Emiko

    2016-12-01

    The role of endogenous vitamin C (VC) in emotion and psychiatric measures has long been uncertain. We aimed to investigate how an individual's VC status impacts his or her mental health. Our hypothesis is that body VC levels modulate anxiety, anorexia, and depressive phenotypes under the influence of psychosocial rearing environments and sex. The VC status of senescence marker protein-30/gluconolactonase knockout mice, which lack the ability to synthesize VC, were continuously shifted from adequate (VC+) to depleted (VC-) by providing a water with or without VC. Despite weight loss in both sexes, suppressed feeding was specifically seen in males only during the VC- phase. Anxiety responses in the novelty-suppressed feeding paradigm were worse during the VC-, especially in females. Sensitivity to the forced swim test as determined by the initial latency was significantly shorter in the socially stable animals compared with socially unstable animals during the VC+ condition. The stress coping underlying depressive phenotypes was assessed by immobility duration in a series of forced swim tests. No significant differences were apparent between contrasting VC status. Homeostatic symptoms following stressful behavioral tests consisted of a great loss of appetite during the VC-. It should be noted that anorexia is extremely serious for the females. We conclude that endogenous VC status is critical for determining vulnerability to anxiety and anorexia in a sex-specific manner. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Evaluation of the IGSCC(Intergranular Stress Corrosion Cracking) resistance of inconel alloys by static potential method in high temperature and high pressure environment

    International Nuclear Information System (INIS)

    Maeng, Wan Young; Nam, Tae Woon

    1997-01-01

    Inconel alloys which have good high temperature mechanical properties and corrosion resistance have been used extensively as steam generator tube of nuclear power plants. There have been some reports on the intergranular stress corrosion cracking (IGSCC) failure problems in steam generator tubes of nuclear reactors. In order to evaluate the effects of heat treatment and composition on the IGSCC behavior of inconel alloys in simulated nuclear reactor environment, four different specimens (inconel 600 MA, 600 TT, 690 MA and 690 TT) were prepared and tested by eletrochemical method. Static potential tests for stressed C-ring type inconel specimens were carried out in 10% NaOH solution at 300 deg C (75 atm). It was found that IGSCC was initiated in inconel 600 MA specimen, but the other three specimens were not cracked. Based on the gradients of corrosion current density of the four specimens as a function of test time, thermally treated alloys show better IGSCC resistance than mull-annealed alloys, and inconel 690 TT has better passivation characteristic than inconel 600 MA. Inconel 690 TT shows clear periodic passivation that indicates good SCC resistance. The good IGSCC resistance of inconel 690 TT is due to periodic passivation characteristics of surface layer. (author)

  2. Effects of heat stress on the physiological parameters and productivity of hair sheep in tropical and coastal environments

    Directory of Open Access Journals (Sweden)

    Antonio Gesualdi Júnior

    2014-10-01

    Full Text Available The experiment was carried out with sheep during the finishing phase in a partial confinement system to evaluate the following physiological parameters: rectal temperature (RT, respiratory rate (RR, heart rate (HR, productive performance and carcass characteristics. Fourteen uncastrated sheep with an average initial age of 90 days belonging to two genetic groups were used. There were seven Santa Inês animals, whose average initial live weight (ILW was 23.65 kg, and seven F1 Dorper × St. Inês animals, with an ILW of 20.02 kg. The treatments were the two genetic groups and two times for the collection of the physiological parameters, at 09.00 h and 15.00 h. Evaluation took place once a week, in a shared stall, always following a 20-min grazing activity. The animals had daily access to a Megathyrsus maximus(Jacquin pasture, cultivar Masai, from 08.00 h to 17.00 h and their feed was placed in a trough, at a forage:concentrate ratio of 51:49 in the total dry matter. The concentrate consisted of 900 g/kg of ground corn and 100 g/kg of soybean meal, and the roughage supplied was alfalfa hay. There was no interaction between treatments for the studied variables. The physiological parameters were affected only by the time of day. The variables RR and RT were higher at 15.00 h, while the highest HR values were observed at 09.00 h. Neither of the two genetic groups differed for performance and carcass characteristics. Hair sheep belonging to close genetic groups show no differences in performance, carcass characteristics and physiological responses when subjected to heat stress.

  3. Enhancing Butanol Production under the Stress Environments of Co-Culturing Clostridium acetobutylicum/Saccharomyces cerevisiae Integrated with Exogenous Butyrate Addition.

    Directory of Open Access Journals (Sweden)

    Hongzhen Luo

    Full Text Available In this study, an efficient acetone-butanol-ethanol (ABE fermentation strategy integrating Clostridium acetobutylicum/Saccharomyces cerevisiae co-culturing system with exogenous butyrate addition, was proposed and experimentally conducted. In solventogenic phase, by adding 0.2 g-DCW/L-broth viable S. cerevisiae cells and 4.0 g/L-broth concentrated butyrate solution into C. acetobutylicum culture broth, final butanol concentration and butanol/acetone ratio in a 7 L anaerobic fermentor reached the highest levels of 15.74 g/L and 2.83 respectively, with the increments of 35% and 43% as compared with those of control. Theoretical and experimental analysis revealed that, the proposed strategy could, 1 extensively induce secretion of amino acids particularly lysine, which are favorable for both C. acetobutylicum survival and butanol synthesis under high butanol concentration environment; 2 enhance the utilization ability of C. acetobutylicum on glucose and over-produce intracellular NADH for butanol synthesis in C. acetobutylicum metabolism simultaneously; 3 direct most of extra consumed glucose into butanol synthesis route. The synergetic actions of effective amino acids assimilation, high rates of substrate consumption and NADH regeneration yielded highest butanol concentration and butanol ratio in C. acetobutylicum under this stress environment. The proposed method supplies an alternative way to improve ABE fermentation performance by traditional fermentation technology.

  4. Sulfide stress corrosion study of a super martensitic stainless steel in H2S sour environments: Metallic sulfides formation and hydrogen embrittlement

    Science.gov (United States)

    Monnot, Martin; Nogueira, Ricardo P.; Roche, Virginie; Berthomé, Grégory; Chauveau, Eric; Estevez, Rafael; Mantel, Marc

    2017-02-01

    Thanks to their high corrosion resistance, super martensitic stainless steels are commonly used in the oil and gas industry, particularly in sour environments. Some grades are however susceptible to undergo hydrogen and mechanically-assisted corrosion processes in the presence of H2S, depending on the pH. The martensitic stainless steel EN 1.4418 grade exhibits a clear protective passive behavior with no sulfide stress corrosion cracking when exposed to sour environments of pH ≥ 4, but undergoes a steep decrease in its corrosion resistance at lower pH conditions. The present paper investigated this abrupt loss of corrosion resistance with electrochemical measurements as well as different physicochemical characterization techniques. Results indicated that below pH 4.0 the metal surface is covered by a thick (ca 40 μm) porous and defect-full sulfide-rich corrosion products layer shown to be straightforwardly related to the onset of hydrogen and sulfide mechanically-assisted corrosion phenomena.

  5. Changes in oxidative stress parameters in relation to age, growth and reproduction in the short-lived catarina scallop Argopecten ventricosus reared in its natural environment.

    Science.gov (United States)

    Guerra, C; Zenteno-Savín, T; Maeda-Martínez, A N; Philipp, E E R; Abele, D

    2012-08-01

    Increase in oxidative damage and decrease in cellular maintenance is often associated with aging, but, in marine ectotherms, both processes are also strongly influenced by somatic growth, maturation and reproduction. In this study, we used a single cohort of the short-lived catarina scallop Argopecten ventricosus, to investigate the effects of somatic growth, reproduction and aging on oxidative damage parameters (protein carbonyls, TBARS and lipofuscin) and cellular maintenance mechanisms (antioxidant activity and apoptosis) in scallops, caged in their natural environment. The concentrations of protein carbonyls and TBARS increased steeply during the early period of fast growth and during reproduction in one-year-old scallops. However, oxidative damage was transient, and apoptotic cell death played a pivotal role in eliminating damage in gill, mantle and muscle tissues of young scallops. Animals were able to reproduce again in the second year, but the reduced intensity of apoptosis impaired subsequent removal of damaged cells. In late survivors low antioxidant capacity and apoptotic activity together with a fast accumulation of the age pigment lipofuscin was observed. Rates of oxygen consumption and oxidative stress markers were strongly dependent on somatic growth and reproductive state but not on temperature. Compared to longer-lived bivalves, A. ventricosus seems more susceptible to oxidative stress with higher tissue-specific protein carbonyl levels and fast accumulation of lipofuscin in animals surviving the second spawning. Superoxide dismutase activity and apoptotic cell death intensity were however higher in this short-lived scallop than in longer-lived bivalves. The life strategy of this short-lived and intensely predated scallop supports rapid somatic growth and fitness as well as early maturation at young age at the cost of fast cellular degradation in second year scallops. Copyright © 2012 Elsevier Inc. All rights reserved.

  6. Evaluation of Virulence Factors In vitro, Resistance to Osmotic Stress and Antifungal Susceptibility of Candida tropicalis Isolated from the Coastal Environment of Northeast Brazil

    Science.gov (United States)

    Zuza-Alves, Diana L.; de Medeiros, Sayama S. T. Q.; de Souza, Luanda B. F. C.; Silva-Rocha, Walicyranison P.; Francisco, Elaine C.; de Araújo, Maria C. B.; Lima-Neto, Reginaldo G.; Neves, Rejane P.; Melo, Analy S. de Azevedo; Chaves, Guilherme M.

    2016-01-01

    Several studies have been developed regarding human health risks associated with the recreational use of beaches contaminated with domestic sewage. These wastes contain various micro-organisms, including Candida tropicalis. In this context, the objective of this study was to characterize C. tropicalis isolates from the sandy beach of Ponta Negra, Natal, Rio Grande do Norte, Brazil, regarding the expression of in vitro virulence factors, adaptation to osmotic stress and susceptibility to antifungal drugs. We analyzed 62 environmental isolates and observed a great variation among them for the various virulence factors evaluated. In general, environmental isolates were more adherent to human buccal epithelial cells (HBEC) than C. tropicalis ATCC13803 reference strain, and they also showed increased biofilm production. Most of the isolates presented wrinkled phenotypes on Spider medium (34 isolates, 54.8%). The majority of the isolates also showed higher proteinase production than control strains, but low phospholipase activity. In addition, 35 isolates (56.4%) had high hemolytic activity (hemolysis index > 0.55). With regard to C. tropicalis resistance to osmotic stress, 85.4% of the isolates were able to grow in a liquid medium containing 15% sodium chloride. The strains were highly resistant to the azoles tested (fluconazole, voriconazole and itraconazole). Fifteen strains were resistant to the three azoles tested (24.2%). Some strains were also resistant to amphotericin B (14 isolates; 22.6%), while all of them were susceptible for the echinocandins tested, except for a single strain of intermediate susceptibility to micafungin. Our results demonstrate that C. tropicalis isolated from the sand can fully express virulence attributes and showed a high persistence capacity on the coastal environment; in addition of showing high minimal inhibitory concentrations to several antifungal drugs used in current clinical practice, demonstrating that environmental isolates may

  7. Transcriptional and Physiological Characterizations of Escherichia coli MG1655 that have been grown under Low Shear Stress Environment for 1000 Generations

    Science.gov (United States)

    Karouia, Fathi; Tirumalai, Madhan R.; Nelman-Gonzalez, Mayra A.; Sams, Clarence F.; Ott, Mark C.; Pierson, Duane L.; Fofanov, Yuriy; Willson, Richard C.; Fox, George E.

    Human space travelers experience a unique environment that affects homeostasis and physio-logic adaptation. One of the important regulatory biology interactions affected by space flight is the alteration of the immune response. As such, the impairment of the immune system may lead to higher risk of bacterial and/or viral infection during human space flight missions. Mi-crobiological contaminants have been a source of concern over the years for NASA and there is evidence to suggest that microbes in space do not behave like they do on Earth. Previ-ous studies have examined the physiological response of bacteria when exposed to short-term microgravity either during spaceflight or in a Low Shear Modeled Microgravity (LSMMG) en-vironment. Exposure to these environments has been found to induce increased resistance to stresses and antibiotics, and in one case increase of virulence. As NASA increases the duration of space flight missions and is starting to envision human presence on the lunar surface and Mars, it becomes legitimate to question the long-term effects of microgravity on bacteria. The effect of long-term exposure to LSMMG on microbial gene expression and physiology in Escherichia coli (E. coli) is being examined using functional genomics, and molecular tech-niques. In previous E. coli short term studies, reproducible changes in transcription were seen but no direct responses to changes in the gravity vector were identified. Instead, absence of shear and a randomized gravity vector appeared to cause local extra-cellular environmental changes, which elicited cellular responses. In order to evaluate the long-term effects of micro-gravity on bacteria, E. coli was grown under simulated microgravity for 1000 generations and gene expression patterns and cellular physiology were analyzed in comparison with short-term exposure. The analysis revealed that the long-term response differed significantly from the short-term exposure and 357 genes were expressed

  8. Teacher Wellness: Too Stressed for Stress Management?

    Science.gov (United States)

    Kipps-Vaughan, Debi; Ponsart, Tyler; Gilligan, Tammy

    2012-01-01

    Healthier, happier teachers promote healthier, happier, and more effective learning environments. Yet, many teachers experience considerable stress. Studies have found that between one fifth and one fourth of teachers frequently experience a great deal of stress (Kyriacou, 1998). Stress in teaching appears to be universal across nations and…

  9. The challenging environment on board the International Space Station affects endothelial cell function by triggering oxidative stress through thioredoxin interacting protein overexpression: the ESA-SPHINX experiment.

    Science.gov (United States)

    Versari, Silvia; Longinotti, Giulia; Barenghi, Livia; Maier, Jeanette Anne Marie; Bradamante, Silvia

    2013-11-01

    Exposure to microgravity generates alterations that are similar to those involved in age-related diseases, such as cardiovascular deconditioning, bone loss, muscle atrophy, and immune response impairment. Endothelial dysfunction is the common denominator. To shed light on the underlying mechanism, we participated in the Progress 40P mission with Spaceflight of Human Umbilical Vein Endothelial Cells (HUVECs): an Integrated Experiment (SPHINX), which consisted of 12 in-flight and 12 ground-based control modules and lasted 10 d. Postflight microarray analysis revealed 1023 significantly modulated genes, the majority of which are involved in cell adhesion, oxidative phosphorylation, stress responses, cell cycle, and apoptosis. Thioredoxin-interacting protein was the most up-regulated (33-fold), heat-shock proteins 70 and 90 the most down-regulated (5.6-fold). Ion channels (TPCN1, KCNG2, KCNJ14, KCNG1, KCNT1, TRPM1, CLCN4, CLCA2), mitochondrial oxidative phosphorylation, and focal adhesion were widely affected. Cytokine detection in the culture media indicated significant increased secretion of interleukin-1α and interleukin-1β. Nitric oxide was found not modulated. Our data suggest that in cultured HUVECs, microgravity affects the same molecular machinery responsible for sensing alterations of flow and generates a prooxidative environment that activates inflammatory responses, alters endothelial behavior, and promotes senescence.

  10. The Past and Future Trends of Heat Stress Based On Wet Bulb Globe Temperature Index in Outdoor Environment of Tehran City, Iran.

    Science.gov (United States)

    Habibi Mohraz, Majid; Ghahri, Asghar; Karimi, Mehrdad; Golbabaei, Farideh

    2016-06-01

    The workers who are working in the open and warm environments are at risk of health effects of climate and heat changes. It is expected that the risk is increase with global warming. This study aimed to investigate the changes of Wet Bulb Globe Temperature (WBGT) index in the past and to predict their trend of future changes in Tehran, capital of Iran. The meteorological data recorded in Tehran, Iran during the statistical period between 1961 and 2009 were obtained from the Iran Meteorological Organization and based on them, WBGT index was calculated and processed using Man-Kendall correlation test. The results of Man-Kendall correlation test showed that the trend of changes of annual mean WBGT during the statistical period under study (1961-2009) has been significantly increasing. In addition, the result of proposed predictive model estimated that an increase of about 1.55 degree in WBGT index will be seen over 40 years from 2009 to 2050 in Tehran. Climate change in Tehran has had an effect on person's exposure to heat stresses consistent with global warming.

  11. The effect of a single tensile overload on stress corrosion cracking growth of stainless steel in a light water reactor environment

    International Nuclear Information System (INIS)

    Xue He; Li Zhijun; Lu Zhanpeng; Shoji, Tetsuo

    2011-01-01

    Research highlights: → The affect of a single tensile overload on SCC growth rate is investigated. → A single tensile overload would produce a residual plastic strain in the SCC tip. → The residual plastic strain would decrease the plastic strain rate in the SCC tip. → A single tensile overload would cause crack growth rate retardation in the SCC tip. → SCC growth rate in the quasi-stationary crack tip is relatively lower. - Abstract: It has been found that a single tensile overload applied during constant load amplitude might cause crack growth rate retardation in various crack propagating experiments which include fatigue test and stress corrosion cracking (SCC) test. To understand the affecting mechanism of a single tensile overload on SCC growth rate of stainless steel or nickel base alloy in light water reactor environment, based on elastic-plastic finite element method (EPFEM), the residual plastic strain in both tips of stationary and growing crack of contoured double cantilever beam (CDCB) specimen was simulated and analyzed in this study. The results of this investigation demonstrate that a residual plastic strain in the region immediately ahead of the crack tips will be produced when a single tensile overload is applied, and the residual plastic strain will decrease the plastic strain rate level in the growing crack tip, which will causes crack growth rate retardation in the tip of SCC.

  12. Development of crack growth and crack initiation test units for stress corrosion cracking examinations in high-temperature water environments under neutron irradiation (1) (Contract research)

    International Nuclear Information System (INIS)

    Izumo, Hironobu; Ishida, Takuya; Kawamata, Kazuo; Inoue, Shuichi; Ide, Hiroshi; Saito, Takashi; Ishitsuka, Etsuo; Chimi, Yasuhiro; Ise, Hideo; Miwa, Yukio; Ugachi, Hirokazu; Nakano, Junichi; Kaji, Yoshiyuki; Tsukada, Takashi

    2009-04-01

    To evaluate integrity of irradiation-assisted stress corrosion cracking (IASCC) on in-core structural materials used in light water reactors (LWRs), useful knowledge regarding IASCC has been obtained mainly by post-irradiation examinations (PIEs). In the core of commercial LWRs, however, the actual IASCC occurs under the effects of irradiation on both materials and high-temperature water environment. Therefore, it is necessary to confirm the suitability of the knowledge by PIE with comparison to IASCC behaviors during in-core SCC tests. Fundamental techniques for in-core crack growth and crack initiation tests have been developed already at the Japan Materials Testing Reactor (JMTR) of the Japan Atomic Energy Agency (JAEA). For the in-core crack growth test technique, to evaluate the effects of neutron irradiation on stainless steels irradiated to low neutron fluences, it is indispensable to develop new loading technique which is applicable to compact tension (CT) specimens with thickness of 0.5 inch (0.5T), from the viewpoint of validity based on the fracture mechanics. Based on the present technical investigation for the in-core loading technique, it is expected that a target load of 7.6 kN approximately can apply to a 0.5T-CT specimen by adopting a loading unit of a lever type instead of the previous uni-axial tension type. For the in-core crack initiation test technique, moreover, construction of a loading unit adopting linear variable differential transformers (LVDTs) has been investigated and technical issues have examined. (author)

  13. Tang-Luo-Ning, a Traditional Chinese Medicine, Inhibits Endoplasmic Reticulum Stress-Induced Apoptosis of Schwann Cells under High Glucose Environment

    Directory of Open Access Journals (Sweden)

    Weijie Yao

    2017-01-01

    Full Text Available Tang-Luo-Ning (TLN has a definite effect in the clinical treatment of diabetic peripheral neuropathy (DPN. Schwann cells (SCs apoptosis induced by endoplasmic reticulum stress (ER stress is one of the main pathogeneses of DPN. This study investigates whether TLN can inhibit SCs apoptosis by inhibiting ER stress-induced apoptosis. Our previous researches have demonstrated that TLN could increase the expression of ER stress marker protein GRP78 and inhibited the expression of apoptosis marker protein CHOP in ER stress. In this study, the results showed that TLN attenuated apoptosis by decreasing Ca2+ level in SCs and maintaining ER morphology. TLN could decrease downstream proteins of CHOP including GADD34 and Ero1α, while it increased P-eIF2α and decreased the upstream proteins of CHOP including P-IRE1α/IRE1α and XBP-1, thereby reducing ER stress-induced apoptosis.

  14. The Invasion of the Christian West by the Tatars (Mongols. A Clash of Civilizations between Frederick II, Gregory IX and the Tatars

    Directory of Open Access Journals (Sweden)

    Huub Kurstjens

    2017-06-01

    Full Text Available Research objectives: The author of this article wants to show how the clash of two di­f­ferent civilizations, until then practically unaware of the other’s existence, the Tatars and the Christian West, undermined the superior and self-confident position of the latter. In the author’s view, Western Christian Society in the first part of the thirteenth century regarded itself as superior to other civilizations. This article is not focused on either civilization, but tries to unveil motives, background and perspectives from both sides’ attempts to try to be the strongest power and the most important civilization at that time. In the Christian West there was a constant struggle for power between the Pope and the Emperor, going back to the Investiture Controversy of the eleventh and twelfth centuries and culminating in the conflict between Emperor Frederick II and the papacy in the thirteenth century. At the height of that struggle, in 1241, the Tatars (Mongols invaded Hungary and Poland. Western Civilization was threatened, although at first almost nobody realized the danger and underestimated the consequences. It was due to the superior tactics of the Tatars that they surprised the Christian West. The Tatars were far better in their communication, strategy and information than the divided society in the West. The Tatar invasion, through their use of a kind of Tsunami Stra­tegy, had all the necessary ingredients to destroy Western, Christian society. Research materials: By using contemporary sources and books that illuminate the Tatars as well as the Christian West, the character of the conflict that took place becomes clear. Results and novelty of the research: The end result was a clash of civilizations, an exp­losive mixture of a political-cultural conflict, a time-bomb which ultimately, narrowly, failed to explode, thanks to a sudden and somewhat mysterious retreat of the Tatars, but leaving Western Civilization faced with an

  15. CLASH-VLT: INSIGHTS ON THE MASS SUBSTRUCTURES IN THE FRONTIER FIELDS CLUSTER MACS J0416.1–2403 THROUGH ACCURATE STRONG LENS MODELING

    International Nuclear Information System (INIS)

    Grillo, C.; Suyu, S. H.; Umetsu, K.; Rosati, P.; Caminha, G. B.; Mercurio, A.; Balestra, I.; Munari, E.; Nonino, M.; De Lucia, G.; Borgani, S.; Biviano, A.; Girardi, M.; Lombardi, M.; Gobat, R.; Coe, D.; Koekemoer, A. M.; Postman, M.; Zitrin, A.; Halkola, A.

    2015-01-01

    We present a detailed mass reconstruction and a novel study on the substructure properties in the core of the Cluster Lensing And Supernova survey with Hubble (CLASH) and Frontier Fields galaxy cluster MACS J0416.1–2403. We show and employ our extensive spectroscopic data set taken with the VIsible Multi-Object Spectrograph instrument as part of our CLASH-VLT program, to confirm spectroscopically 10 strong lensing systems and to select a sample of 175 plausible cluster members to a limiting stellar mass of log (M * /M ☉ ) ≅ 8.6. We reproduce the measured positions of a set of 30 multiple images with a remarkable median offset of only 0.''3 by means of a comprehensive strong lensing model comprised of two cluster dark-matter halos, represented by cored elliptical pseudo-isothermal mass distributions, and the cluster member components, parameterized with dual pseudo-isothermal total mass profiles. The latter have total mass-to-light ratios increasing with the galaxy HST/WFC3 near-IR (F160W) luminosities. The measurement of the total enclosed mass within the Einstein radius is accurate to ∼5%, including the systematic uncertainties estimated from six distinct mass models. We emphasize that the use of multiple-image systems with spectroscopic redshifts and knowledge of cluster membership based on extensive spectroscopic information is key to constructing robust high-resolution mass maps. We also produce magnification maps over the central area that is covered with HST observations. We investigate the galaxy contribution, both in terms of total and stellar mass, to the total mass budget of the cluster. When compared with the outcomes of cosmological N-body simulations, our results point to a lack of massive subhalos in the inner regions of simulated clusters with total masses similar to that of MACS J0416.1–2403. Our findings of the location and shape of the cluster dark-matter halo density profiles and on the cluster substructures provide intriguing

  16. CLASH-VLT: INSIGHTS ON THE MASS SUBSTRUCTURES IN THE FRONTIER FIELDS CLUSTER MACS J0416.1–2403 THROUGH ACCURATE STRONG LENS MODELING

    Energy Technology Data Exchange (ETDEWEB)

    Grillo, C. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Suyu, S. H.; Umetsu, K. [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); Rosati, P.; Caminha, G. B. [Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Ferrara, Via Saragat 1, I-44122 Ferrara (Italy); Mercurio, A. [INAF - Osservatorio Astronomico di Capodimonte, Via Moiariello 16, I-80131 Napoli (Italy); Balestra, I.; Munari, E.; Nonino, M.; De Lucia, G.; Borgani, S.; Biviano, A.; Girardi, M. [INAF - Osservatorio Astronomico di Trieste, via G. B. Tiepolo 11, I-34143, Trieste (Italy); Lombardi, M. [Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, I-20133 Milano (Italy); Gobat, R. [Laboratoire AIM-Paris-Saclay, CEA/DSM-CNRS-Universitè Paris Diderot, Irfu/Service d' Astrophysique, CEA Saclay, Orme des Merisiers, F-91191 Gif sur Yvette (France); Coe, D.; Koekemoer, A. M.; Postman, M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21208 (United States); Zitrin, A. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States); Halkola, A., E-mail: grillo@dark-cosmology.dk; and others

    2015-02-10

    We present a detailed mass reconstruction and a novel study on the substructure properties in the core of the Cluster Lensing And Supernova survey with Hubble (CLASH) and Frontier Fields galaxy cluster MACS J0416.1–2403. We show and employ our extensive spectroscopic data set taken with the VIsible Multi-Object Spectrograph instrument as part of our CLASH-VLT program, to confirm spectroscopically 10 strong lensing systems and to select a sample of 175 plausible cluster members to a limiting stellar mass of log (M {sub *}/M {sub ☉}) ≅ 8.6. We reproduce the measured positions of a set of 30 multiple images with a remarkable median offset of only 0.''3 by means of a comprehensive strong lensing model comprised of two cluster dark-matter halos, represented by cored elliptical pseudo-isothermal mass distributions, and the cluster member components, parameterized with dual pseudo-isothermal total mass profiles. The latter have total mass-to-light ratios increasing with the galaxy HST/WFC3 near-IR (F160W) luminosities. The measurement of the total enclosed mass within the Einstein radius is accurate to ∼5%, including the systematic uncertainties estimated from six distinct mass models. We emphasize that the use of multiple-image systems with spectroscopic redshifts and knowledge of cluster membership based on extensive spectroscopic information is key to constructing robust high-resolution mass maps. We also produce magnification maps over the central area that is covered with HST observations. We investigate the galaxy contribution, both in terms of total and stellar mass, to the total mass budget of the cluster. When compared with the outcomes of cosmological N-body simulations, our results point to a lack of massive subhalos in the inner regions of simulated clusters with total masses similar to that of MACS J0416.1–2403. Our findings of the location and shape of the cluster dark-matter halo density profiles and on the cluster substructures provide

  17. Self-Care for Nurse Leaders in Acute Care Environment Reduces Perceived Stress: A Mixed-Methods Pilot Study Merits Further Investigation.

    Science.gov (United States)

    Dyess, Susan Mac Leod; Prestia, Angela S; Marquit, Doren-Elyse; Newman, David

    2018-03-01

    Acute care practice settings are stressful. Nurse leaders face stressful demands of numerous competing priorities. Some nurse leaders experience unmanageable stress, but success requires self-care. This article presents a repeated measures intervention design study using mixed methods to investigate a self-care simple meditation practice for nurse leaders. Themes and subthemes emerged in association with the three data collection points: at baseline (pretest), after 6 weeks, and after 12 weeks (posttest) from introduction of the self-care simple meditation practice. An analysis of variance yielded a statistically significant drop in perceived stress at 6 weeks and again at 12 weeks. Conducting future research is merited.

  18. Comparing Dark Energy Survey and HSTCLASH observations of the galaxy cluster RXC J2248.7-4431: implications for stellar mass versus dark matter

    Energy Technology Data Exchange (ETDEWEB)

    Palmese, A.; Lahav, O.; Banerji, M.; Gruen, D.; Jouvel, S.; Melchior, P.; Aleksić, J.; Annis, J.; Diehl, H. T.; Hartley, W. G.; Jeltema, T.; Romer, A. K.; Rozo, E.; Rykoff, E. S.; Seitz, S.; Suchyta, E.; Zhang, Y.; Abbott, T. M. C.; Abdalla, F. B.; Allam, S.; Benoit-Lévy, A.; Bertin, E.; Brooks, D.; Buckley-Geer, E.; Burke, D. L.; Capozzi, D.; Carnero Rosell, A.; Carrasco Kind, M.; Carretero, J.; Crocce, M.; Cunha, C. E.; D' Andrea, C. B.; da Costa, L. N.; Desai, S.; Dietrich, J. P.; Doel, P.; Estrada, J.; Evrard, A. E.; Flaugher, B.; Frieman, J.; Gerdes, D. W.; Goldstein, D. A.; Gruendl, R. A.; Gutierrez, G.; Honscheid, K.; James, D. J.; Kuehn, K.; Kuropatkin, N.; Li, T. S.; Lima, M.; Maia, M. A. G.; Marshall, J. L.; Miller, C. J.; Miquel, R.; Nord, B.; Ogando, R.; Plazas, A. A.; Roodman, A.; Sanchez, E.; Scarpine, V.; Sevilla-Noarbe, I.; Smith, R. C.; Soares-Santos, M.; Sobreira, F.; Swanson, M. E. C.; Tarle, G.; Thomas, D.; Tucker, D.; Vikram, V.

    2016-08-20

    We derive the stellar mass fraction in the galaxy cluster RXC J2248.7-4431 observed with the Dark Energy Survey (DES) during the Science Verification period. We compare the stellar mass results from DES (five filters) with those from the Hubble Space Telescope Cluster Lensing And Supernova Survey (CLASH; 17 filters). When the cluster spectroscopic redshift is assumed, we show that stellar masses from DES can be estimated within 25 per cent of CLASH values. We compute the stellar mass contribution coming from red and blue galaxies, and study the relation between stellar mass and the underlying dark matter using weak lensing studies with DES and CLASH. An analysis of the radial profiles of the DES total and stellar mass yields a stellar-to-total fraction of f(star) = (6.8 +/- 1.7) x 10(-3) within a radius of r(200c) similar or equal to 2 Mpc. Our analysis also includes a comparison of photometric redshifts and star/galaxy separation efficiency for both data sets. We conclude that space-based small field imaging can be used to calibrate the galaxy properties in DES for the much wider field of view. The technique developed to derive the stellar mass fraction in galaxy clusters can be applied to the similar to 100 000 clusters that will be observed within this survey and yield important information about galaxy evolution.

  19. Raising awareness of stress at work in developing countires : a modern hazard in a traditional working environment : advice to employers and worker representatives

    NARCIS (Netherlands)

    Houtman, I.; Jettinghof, K.; Cedillo, L.

    2007-01-01

    Work-related stress is of growing concern in developing countries due to important developments in the modern world; two of the most significant being globalisation and the changing nature of work. Although the emphasis of this booklet is on developing countries, the problem of workrelated stress is

  20. Unexplored regions in QFT: an alternative resolution of the gauge-theoretic clash between localization and the Hilbert space of quantum theory

    International Nuclear Information System (INIS)

    Schroer, Bert; FU-Berlin

    2012-02-01

    Massive quantum matter of prescribed spin permits infinitely many possibilities of covariantization in terms of spinorial (undotted/dotted) pointlike fields, whereas massless nite helicity representations lead to large gap in this spinorial spectrum which for s=1 excludes vector potentials. Since the nonexistence of such pointlike generators is the result of a deep structural clash between modular localization and the Hilbert space setting of QT, there are two ways out: gauge theory which sacrifices the Hilbert space and keeps the pointlike formalism and the use of string like potentials which allows to preserve the Hilbert space. The latter setting contains also string-localized charge-carrying operators whereas the gauge theoretic formulation is limited to point-like generated observables. This description also gives a much better insight into the Higgs mechanism which leads to a revival of the more physical 'Schwinger-Higgs' screening idea. The new formalism is not limited to m=0, s=1, it leads to renormalizable inter- actions in the sense of power-counting for all s in massless representations. The existence of string like vector potentials is preempted by the Aharonov-Bohm effect in QFT; it is well-known that the use of pointlike vector potentials in Stokes theorem would with lead to wrong results. Their use in Maxwell's equations is known to lead to zero Maxwell charge. The role of string-localization in the problem behind the observed invisibility and confinement of gluons and quarks leads to new questions and problems. (author)

  1. Adaptive capability as indicated by endocrine and biochemical responses of Malpura ewes subjected to combined stresses (thermal and nutritional) in a semi-arid tropical environment

    Science.gov (United States)

    Sejian, Veerasamy; Maurya, Vijai P.; Naqvi, Sayeed M. K.

    2010-11-01

    A study was conducted to assess the effect of combined stresses (thermal and nutritional) on endocrine and biochemical responses in Malpura ewes. Twenty eight adult Malpura ewes (average body weight 33.56 kg) were used in the present study. The ewes were divided into four groups viz., GI ( n = 7; control), GII ( n = 7; thermal stress), GIII ( n = 7; nutritional stress) and GIV ( n = 7; combined stress). The animals were stall fed with a diet consisting of 60% roughage and 40% concentrate. GI and GII ewes were provided with ad libitum feeding while GIII and GIV ewes were provided with restricted feed (30% intake of GI ewes) to induce nutritional stress. GII and GIV ewes were kept in climatic chamber at 40°C and 55% RH for 6 h a day between 1000 hours and 1600 hours to induce thermal stress. The study was conducted for a period of two estrus cycles. The parameters studied were Hb, PCV, glucose, total protein, total cholesterol, ACP, ALP, cortisol, T4, T3, and insulin. Combined stress significantly ( P ewes. It can be concluded from this study that two stressors occurring simultaneously may impact severely on the biological functions necessary to maintain homeostasis in sheep.

  2. Separating the Influence of Environment from Stress Relaxation Effects on Dwell Fatigue Crack Growth in a Nickel-Base Disk Alloy

    Science.gov (United States)

    Telesman, J.; Gabb, T. P.; Ghosn, L. J.

    2016-01-01

    Both environmental embrittlement and crack tip visco-plastic stress relaxation play a significant role in determining the dwell fatigue crack growth (DFCG) resistance of nickel-based disk superalloys. In the current study performed on the Low Solvus High Refractory (LSHR) disk alloy, the influence of these two mechanisms were separated so that the effects of each could be quantified and modeled. Seven different microstructural variations of LSHR were produced by controlling the cooling rate and the subsequent aging and thermal exposure heat treatments. Through cyclic fatigue crack growth testing performed both in air and vacuum, it was established that four out of the seven LSHR heat treatments evaluated, possessed similar intrinsic environmental resistance to cyclic crack growth. For these four heat treatments, it was further shown that the large differences in dwell crack growth behavior which still persisted, were related to their measured stress relaxation behavior. The apparent differences in their dwell crack growth resistance were attributed to the inability of the standard linear elastic fracture mechanics (LEFM) stress intensity parameter to account for visco-plastic behavior. Crack tip stress relaxation controls the magnitude of the remaining local tensile stresses which are directly related to the measured dwell crack growth rates. It was hypothesized that the environmentally weakened grain boundary crack tip regions fail during the dwells when their strength is exceeded by the remaining local crack tip tensile stresses. It was shown that the classical creep crack growth mechanisms such as grain boundary sliding did not contribute to crack growth, but the local visco-plastic behavior still plays a very significant role by determining the crack tip tensile stress field which controls the dwell crack growth behavior. To account for the influence of the visco-plastic behavior on the crack tip stress field, an empirical modification to the LEFM stress

  3. Seasonal Dynamics of Stress Proteins in Leaves of Medicinal Plants in a Natural Environment of Irkutsk and on the Shores of the Lake Baikal

    Directory of Open Access Journals (Sweden)

    M.A. Zhivetiev

    2014-12-01

    Full Text Available We study leafs of five plant species, growing in Irkutsk city and on the southeastern shore of Lake Baikal. These species are Achillea asiatica Serg., Taraxacum officinale Wigg., Plantago major L., Veronica chamaedrys L. and Alchemilla subcrenata Buser. In its leafs we identify some types of stress-induced proteins. In autumn, the accumulation of stress proteins in leafs of plants both from shores of Lake Baikal and from Irkutsk have been registered.

  4. Steric Clash in the SET Domain of Histone Methyltransferase NSD1 as a Cause of Sotos Syndrome and Its Genetic Heterogeneity in a Brazilian Cohort

    Directory of Open Access Journals (Sweden)

    Kyungsoo Ha

    2016-11-01

    Full Text Available Most histone methyltransferases (HMTase harbor a predicted Su(var3–9, Enhancer-of-zeste, Trithorax (SET domain, which transfers a methyl group to a lysine residue in their substrates. Mutations of the SET domains were reported to cause intellectual disability syndromes such as Sotos, Weaver, or Kabuki syndromes. Sotos syndrome is an overgrowth syndrome with intellectual disability caused by haploinsufficiency of the nuclear receptor binding SET domain protein 1 (NSD1 gene, an HMTase at 5q35.2–35.3. Here, we analyzed NSD1 in 34 Brazilian Sotos patients and identified three novel and eight known mutations. Using protein modeling and bioinformatic approaches, we evaluated the effects of one novel (I2007F and 21 previously reported missense mutations in the SET domain. For the I2007F mutation, we observed conformational change and loss of structural stability in Molecular Dynamics (MD simulations which may lead to loss-of-function of the SET domain. For six mutations near the ligand-binding site we observed in simulations steric clashes with neighboring side chains near the substrate S-Adenosyl methionine (SAM binding site, which may disrupt the enzymatic activity of NSD1. These results point to a structural mechanism underlying the pathology of the NSD1 missense mutations in the SET domain in Sotos syndrome. NSD1 mutations were identified in only 32% of the Brazilian Sotos patients in our study cohort suggesting other genes (including unknown disease genes underlie the molecular etiology for the majority of these patients. Our studies also found NSD1 expression to be profound in human fetal brain and cerebellum, accounting for prenatal onset and hypoplasia of cerebellar vermis seen in Sotos syndrome.

  5. Professional stress

    Directory of Open Access Journals (Sweden)

    Stanojević Dragana Z.

    2011-01-01

    Full Text Available Job stress is a line, for the person at work hired adverse physiological, psychological and behavioral reactions to situations in which job requirements are not in accordance with its capabilities, abilities and needs. Sources of stress at work are numerous. Personal factors: personality types have been most studied so far, environmental changes and demographic characteristics as well. Interpersonal stress inducing factors act and influence to the occurrence of many psychosomatic diseases. Psychosocial climate and relationships which are prevented or encouraged such as: cooperation and competition, trust and suspicion certainly affect to the appearance of professional stress. The way of leadership is very important. Organizational factors are the type of work, work time, noncompliance of the job, the introduction of new ethnologies, the conflict of personal roles, fear of job loss, bad physical conditions of working environment. The consequences of stress at work are numerous: at the cognitive level, the emotional level, the production plan, the health, plan reduces the immune system that cause a variety of psychosomatic illnesses and accidents at work.

  6. Factors controlling plasticity of leaf morphology in Robinia pseudoacacia L. II: the impact of water stress on leaf morphology of seedlings grown in a controlled environment chamber

    Science.gov (United States)

    M.T. Tyree

    2012-01-01

    Context. The cause of morphological plasticity of leaves within the crowns of tall trees still debated. Whether it is driven by irradiance or hydraulic constraints is inconclusive. In a previous study, we hypothesized that water stress caused between-site and within-tree morphological variability in mature Robinia trees.

  7. Combined effects of CO2 enrichment, changes in diurnal light level and water stress on foliar metabolites of potato plants grown in naturally sunlit controlled environment chambers

    Science.gov (United States)

    Potato plants (Solanum tuberosum L. cv Kennebec) were grown in outdoor, naturally sunlit, soil-plant-atmosphere research (SPAR) chambers. Drought treatments were imposed at post-tuber initiation stage to assess water stress effects on leaf metabolites, and interactions with enriched CO2 concentrati...

  8. Stress Management: Job Stress

    Science.gov (United States)

    Healthy Lifestyle Stress management Job stress can be all-consuming — but it doesn't have to be. Address your triggers, keep perspective and ... stress triggers, it's often helpful to improve time management skills — especially if you tend to feel overwhelmed ...

  9. Canopy temperature for simulation of heat stress in irrigated wheat in a semi-arid environment: A multi-model comparison

    DEFF Research Database (Denmark)

    Webber, Heidi; Martre, Pierre; Asseng, Senthold

    2017-01-01

    Even brief periods of high temperatures occurring around flowering and during grain filling can severely reduce grain yield in cereals. Recently, ecophysiological and crop models have begun to represent such phenomena. Most models use air temperature (Tair) in their heat stress responses despite...... evidence that crop canopy temperature (Tc) better explains grain yield losses. Tc can deviate significantly from Tair based on climatic factors and the crop water status. The broad objective of this study was to evaluate whether simulation of Tc improves the ability of crop models to simulate heat stress...... impacts on wheat under irrigated conditions. Nine process-based models, each using one of three broad approaches (empirical, EMP; energy balance assuming neutral atmospheric stability, EBN; and energy balance correcting for the atmospheric stability conditions, EBSC) to simulate Tc, simulated grain yield...

  10. Impacts of water stress, environment and rootstock on the diurnal behaviour of stem water potential and leaf conductance in pistachio (Pistacia vera L.)

    International Nuclear Information System (INIS)

    Memmi, H.; Couceiro, J.F.; Gijón, C.; Pérez-López, D.

    2016-01-01

    Little information is available on the diurnal behaviour of water potential and leaf conductance on pistachio trees despite their relevance to fine tune irrigation strategies. Mature pistachio trees were subject to simultaneous measurements of stem water potential (Ψx) and leaf conductance (gl) during the day, at three important periods of the irrigation season. Trees were grown on three different rootstocks and water regimes. An initial baseline relating Ψx to air vapor pressure deficit (VPD) is presented for irrigation scheduling in pistachio. Ψx was closely correlated with VPD but with a different fit according to the degree of water stress. No evidence of the variation of Ψx in relation to the phenology of the tree was observed. Furthermore, midday Ψx showed more accuracy to indicate a situation of water stress than predawn water potential. Under well irrigated conditions, gl was positively correlated with VPD during stage II of growth reaching its peak when VPD reached its maximum value (around 4 kPa). This behaviour changed during stage III of fruit growth suggesting a reliance of stomatal behaviour to the phenological stage independently to the tree water status. The levels of water stress reached were translated in a slow recovery of tree water status and leaf conductance (more than 40 days). Regarding rootstocks, P. integerrima showed little adaptation to water shortage compared to the two other rootstocks under the studied conditions. (Author)

  11. Impacts of water stress, environment and rootstock on the diurnal behaviour of stem water potential and leaf conductance in pistachio (Pistacia vera L.

    Directory of Open Access Journals (Sweden)

    Houssem Memmi

    2016-06-01

    Full Text Available Little information is available on the diurnal behaviour of water potential and leaf conductance on pistachio trees despite their relevance to fine tune irrigation strategies. Mature pistachio trees were subject to simultaneous measurements of stem water potential (Ψx and leaf conductance (gl during the day, at three important periods of the irrigation season. Trees were grown on three different rootstocks and water regimes. An initial baseline relating Ψx to air vapor pressure deficit (VPD is presented for irrigation scheduling in pistachio. Ψx was closely correlated with VPD but with a different fit according to the degree of water stress. No evidence of the variation of Ψx in relation to the phenology of the tree was observed. Furthermore, midday Ψx showed more accuracy to indicate a situation of water stress than predawn water potential. Under well irrigated conditions, gl was positively correlated with VPD during stage II of growth reaching its peak when VPD reached its maximum value (around 4 kPa. This behaviour changed during stage III of fruit growth suggesting a reliance of stomatal behaviour to the phenological stage independently to the tree water status. The levels of water stress reached were translated in a slow recovery of tree water status and leaf conductance (more than 40 days. Regarding rootstocks, P. integerrima showed little adaptation to water shortage compared to the two other rootstocks under the studied conditions.

  12. The influence of social environment in early life on the behavior, stress response, and reproductive system of adult male Norway rats selected for different attitudes to humans.

    Science.gov (United States)

    Gulevich, R G; Shikhevich, S G; Konoshenko, M Yu; Kozhemyakina, R V; Herbeck, Yu E; Prasolova, L A; Oskina, I N; Plyusnina, I Z

    2015-05-15

    The influence of social disturbance in early life on behavior, response of blood corticosterone level to restraint stress, and endocrine and morphometric indices of the testes was studied in 2-month Norway rat males from three populations: not selected for behavior (unselected), selected for against aggression to humans (tame), and selected for increased aggression to humans (aggressive). The experimental social disturbance included early weaning, daily replacement of cagemates from days 19 to 25, and subsequent housing in twos till the age of 2months. The social disturbance increased the latent period of aggressive behavior in the social interaction test in unselected males and reduced relative testis weights in comparison to the corresponding control groups. In addition, experimental unselected rats had smaller diameters of seminiferous tubules and lower blood testosterone levels. In the experimental group, tame rats had lower basal corticosterone levels, and aggressive animals had lower hormone levels after restraint stress in comparison to the control. The results suggest that the selection in two directions for attitude to humans modifies the response of male rats to social disturbance in early life. In this regard, the selected rat populations may be viewed as a model for investigation of (1) neuroendocrinal mechanisms responsible for the manifestation of aggression and (2) interaction of the hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal systems in stress. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Impacts of water stress, environment and rootstock on the diurnal behaviour of stem water potential and leaf conductance in pistachio (Pistacia vera L.)

    Energy Technology Data Exchange (ETDEWEB)

    Memmi, H.; Couceiro, J.F.; Gijón, C.; Pérez-López, D.

    2016-11-01

    Little information is available on the diurnal behaviour of water potential and leaf conductance on pistachio trees despite their relevance to fine tune irrigation strategies. Mature pistachio trees were subject to simultaneous measurements of stem water potential (Ψx) and leaf conductance (gl) during the day, at three important periods of the irrigation season. Trees were grown on three different rootstocks and water regimes. An initial baseline relating Ψx to air vapor pressure deficit (VPD) is presented for irrigation scheduling in pistachio. Ψx was closely correlated with VPD but with a different fit according to the degree of water stress. No evidence of the variation of Ψx in relation to the phenology of the tree was observed. Furthermore, midday Ψx showed more accuracy to indicate a situation of water stress than predawn water potential. Under well irrigated conditions, gl was positively correlated with VPD during stage II of growth reaching its peak when VPD reached its maximum value (around 4 kPa). This behaviour changed during stage III of fruit growth suggesting a reliance of stomatal behaviour to the phenological stage independently to the tree water status. The levels of water stress reached were translated in a slow recovery of tree water status and leaf conductance (more than 40 days). Regarding rootstocks, P. integerrima showed little adaptation to water shortage compared to the two other rootstocks under the studied conditions. (Author)

  14. Neuroepigenetics of stress.

    Science.gov (United States)

    Griffiths, B B; Hunter, R G

    2014-09-05

    Stress, a common if unpredictable life event, can have pronounced effects on physiology and behavior. Individuals show wide variation in stress susceptibility and resilience, which are only partially explained by variations in coding genes. Developmental programing of the hypothalamic-pituitary-adrenal stress axis provides part of the explanation for this variance. Epigenetic approaches have successfully helped fill the explanatory gaps between the influences of gene and environment on stress responsiveness, and differences in the sequelae of stress across individuals and generations. Stress and the stress axis interacts bi-directionally with epigenetic marks within the brain. It is now clear that exposure to stress, particularly in early life, has both acute and lasting effects on these marks. They in turn influence cognitive function and behavior, as well as the risk for suicide and psychiatric disorders across the lifespan and, in some cases, unto future generations. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

  15. Childhood Stress

    Science.gov (United States)

    ... Safe Videos for Educators Search English Español Childhood Stress KidsHealth / For Parents / Childhood Stress What's in this ... and feel stress to some degree. Sources of Stress Stress is a function of the demands placed ...

  16. GUIDED IMAGERY: KONSEP KONSELING KREATIF UNTUK PENANGGANAN POST TRAUMATIC STRESS DISORDER (PTSD

    Directory of Open Access Journals (Sweden)

    author Yulianto

    2015-01-01

    Full Text Available Everyone has a different reaction in facing the extraordinary events that are triggered by the teribble events. They clash psychic cause post traumatic stress disorder or in Post Traumatic Stress Disorder (PTSD. To solve it can be done through treatment with pharmacotherapy and psychotherapy. In psychotherapy handling, one of the techniques that can be used is the technique of guided imagery as one of the PTSD treatment efforts. This technique is an effort that can be used to deal with a difficult client to communicate verbally. Communication is the basis of the counseling relationship. Implementation of counseling through guided imagery techniques are considered able to help clients resolve client’s problems. In this technique, clients are guided to be able to focus on positive thoughts and imaginations that lead to negative events experienced to be able to create a positive picture of the imagination.Keywords: Guided imagery, post traumatic stress disorder (PTSD, Creative counseling

  17. CLASH: DISCOVERY OF A BRIGHT z {approx_equal} 6.2 DWARF GALAXY QUADRUPLY LENSED BY MACS J0329.6-0211

    Energy Technology Data Exchange (ETDEWEB)

    Zitrin, A. [Institut fuer Theoretische Astrophysik, Universitaet Heidelberg, Heidelberg (Germany); Moustakas, J. [Center for Astrophysics and Space Sciences, University of California, San Diego, CA (United States); Bradley, L.; Coe, D.; Postman, M.; Koekemoer, A. [Space Telescope Science Institute, Baltimore, MD (United States); Moustakas, L. A. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA (United States); Shu, X. [Department of Astronomy, University of Science and Technology of China, Hefei, Anhui (China); Zheng, W.; Ford, H. [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD (United States); Benitez, N. [Instituto de Astrofisica de Andalucia (CSIC), Granada (Spain); Bouwens, R. [Leiden Observatory, University of Leiden, Leiden (Netherlands); Broadhurst, T. [Department of Theoretical Physics, University of Basque Country, Bilbao (Spain); Host, O.; Jouvel, S. [Department of Physics and Astronomy, University College London, London (United Kingdom); Meneghetti, M. [INAF, Osservatorio Astronomico di Bologna, Bologna (Italy); Rosati, P. [European Southern Observatory, Garching bei Muenchen (Germany); Donahue, M. [Physics and Astronomy Department, Michigan State University, East Lansing, MI (United States); Grillo, C. [Excellence Cluster Universe, Technische Universitaet Muenchen, Muenchen (Germany); Kelson, D., E-mail: adizitrin@gmail.com [Observatories of the Carnegie Institution of Washington, Pasadena, CA (United States); and others

    2012-03-15

    We report the discovery of a z{sub phot} = 6.18{sup +0.05}{sub -0.07} (95% confidence level) dwarf galaxy, lensed into four images by the galaxy cluster MACS J0329.6-0211 (z{sub l} = 0.45). The galaxy is observed as a high-redshift dropout in HST/ACS/WFC3 CLASH and Spitzer/IRAC imaging. Its redshift is securely determined due to a clear detection of the Lyman break in the 18-band photometry, making this galaxy one of the highest-redshift multiply lensed objects known to date with an observed magnitude of F125W =24.00 {+-} 0.04 AB mag for its most magnified image. We also present the first strong-lensing analysis of this cluster uncovering 15 additional multiply imaged candidates of five lower-redshift sources spanning the range z{sub s} {approx_equal} 2-4. The mass model independently supports the high photometric redshift and reveals magnifications of 11.6{sup +8.9}{sub -4.1}, 17.6{sup +6.2}{sub -3.9}, 3.9{sup +3.0}{sub -1.7}, and 3.7{sup +1.3}{sub -0.2}, respectively, for the four images of the high-redshift galaxy. By delensing the most magnified image we construct an image of the source with a physical resolution of {approx}200 pc when the universe was {approx}0.9 Gyr old, where the z {approx_equal} 6.2 galaxy occupies a source-plane area of approximately 2.2 kpc{sup 2}. Modeling the observed spectral energy distribution using population synthesis models, we find a demagnified stellar mass of {approx}10{sup 9} M{sub Sun }, subsolar metallicity (Z/Z{sub Sun} {approx} 0.5), low dust content (A{sub V} {approx} 0.1 mag), a demagnified star formation rate (SFR) of {approx}3.2 M{sub Sun} yr{sup -1}, and a specific SFR of {approx}3.4 Gyr{sup -1}, all consistent with the properties of local dwarf galaxies.

  18. CLASH-VLT: DISSECTING THE FRONTIER FIELDS GALAXY CLUSTER MACS J0416.1-2403 WITH ∼800 SPECTRA OF MEMBER GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Balestra, I.; Sartoris, B.; Girardi, M.; Nonino, M.; Biviano, A. [INAF—Osservatorio Astronomico di Trieste, via G. B. Tiepolo 11, I-34131, Trieste (Italy); Mercurio, A. [INAF—Osservatorio Astronomico di Capodimonte, Via Moiariello 16, I-80131 Napoli (Italy); Grillo, C. [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Rosati, P. [Dipartimento di Fisica e Scienze della Terra, Università di Ferrara, Via Saragat 1, I-44122, Ferrara (Italy); Ettori, S.; Vanzella, E. [INAF—Osservatorio Astronomico di Bologna, Via Ranzani 1, I-40127 Bologna (Italy); Forman, W.; Jones, C.; Ogrean, G. A.; Weeren, R. J. van [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Koekemoer, A. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21208 (United States); Medezinski, E.; Zitrin, A. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States); Merten, J. [Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Tozzi, P. [INAF—Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125, Firenze (Italy); Umetsu, K., E-mail: balestra@oats.inaf.it [Institute of Astronomy and Astrophysics, Academia Sinica, P.O. Box 23-141, Taipei 10617, Taiwan (China); and others

    2016-06-01

    We present VIMOS-Very Large Telescope (VLT) spectroscopy of the Frontier Fields cluster MACS J0416.1-2403 ( z  = 0.397). Taken as part of the CLASH-VLT survey, the large spectroscopic campaign provided more than 4000 reliable redshifts over ∼600 arcmin{sup 2}, including ∼800 cluster member galaxies. The unprecedented sample of cluster members at this redshift allows us to perform a highly detailed dynamical and structural analysis of the cluster out to ∼2.2 r {sub 200} (∼4 Mpc). Our analysis of substructures reveals a complex system composed of a main massive cluster ( M {sub 200} ∼ 0.9 × 10{sup 15} M {sub ⊙} and σ{sub V,r200} ∼ 1000 km s{sup −1}) presenting two major features: (i) a bimodal velocity distribution, showing two central peaks separated by Δ V {sub rf} ∼ 1100 km s{sup −1} with comparable galaxy content and velocity dispersion, and (ii) a projected elongation of the main substructures along the NE–SW direction, with a prominent sub-clump ∼600 kpc SW of the center and an isolated BCG approximately halfway between the center and the SW clump. We also detect a low-mass structure at z  ∼ 0.390, ∼10′ south of the cluster center, projected at ∼3 Mpc, with a relative line-of-sight velocity of Δ V{sub rf} ∼ −1700 km s{sup −1}. The cluster mass profile that we obtain through our dynamical analysis deviates significantly from the “universal” NFW, being best fit by a Softened Isothermal Sphere model instead. The mass profile measured from the galaxy dynamics is found to be in relatively good agreement with those obtained from strong and weak lensing, as well as with that from the X-rays, despite the clearly unrelaxed nature of the cluster. Our results reveal an overall complex dynamical state of this massive cluster and support the hypothesis that the two main subclusters are being observed in a pre-collisional phase, in agreement with recent findings from radio and deep X-ray data. In this article, we

  19. Developing a model for effects of climate change on human health and health-environment interactions: Heat stress in Austin, Texas presentation

    Science.gov (United States)

    Background/Question/Methods In December, 2010, a consortium of EPA, Centers for Disease Control, and state and local health officials convened in Austin, Texas for a “participatory modeling workshop” on climate change effects on human health and health-environment int...

  20. Developing a model for effects of climate change on human health and health-environment interactions: Heat stress in Austin, Texas

    Science.gov (United States)

    Background/Question/Methods In December, 2010, a consortium of EPA, Centers for Disease Control, and state and local health officials convened in Austin, Texas for a “participatory modeling workshop” on climate change effects on human health and health-environment interactions. ...

  1. Indices of stress and immune function in Arctic barnacle goslings (Branta leucopsis) were impacted by social isolation but not a contaminated grazing environment

    NARCIS (Netherlands)

    de Jong, Margje E.; Scheiber, Isabella B. R.; van den Brink, Nico W.; Braun, Anna; Matson, Kevin D.; Komdeur, Jan; Loonen, Maarten J. J. E.

    2017-01-01

    In many areas around the Arctic remains and spoil heaps of old mines can be found, which have been abandoned after their heydays. Runoff from tailings of these abandoned mines can directly contaminate the local environment with elevated concentrations of trace metals. Few studies have investigated

  2. Indices of stress and immune function in Arctic barnacle goslings (Branta leucopsis) were impacted by social isolation but not a contaminated grazing environment

    NARCIS (Netherlands)

    Jong, de Margje E.; Scheiber, Isabella B.R.; Brink, van den Nico W.; Braun, Anna; Matson, Kevin D.; Komdeur, Jan; Loonen, Maarten J.J.E.

    2017-01-01

    In many areas around the Arctic remains and spoil heaps of old mines can be found, which have been abandoned after their heydays. Runoff from tailings of these abandoned mines can directly contaminate the local environment with elevated concentrations of trace metals. Few studies have

  3. Susceptibility of 17-4PH stainless steel to stress corrosion cracking in aqueous environments by electrochemical techniques.; Estudio de la corrosion bajo tension del acero 17-4PH en medios acuosos usando tecnicas electroquimicas

    Energy Technology Data Exchange (ETDEWEB)

    Diaz S, A C [Instituto Nacional de Investigaciones Nucleares, Mexico City (Mexico)

    1998-12-31

    The susceptibility of a 17-4PH type steel to Stress Corrosion Cracking (SCC) in low pressure steam turbine environments was assessed using slow strain rate test at 90 Centigrade and at 1.35x10{sup -6} seg{sup -1}. Environments tested included different concentrated solutions of NaCl, NaOH and Na{sub 2}SO{sub 4}. It was concluded that this steel is susceptible to SCC in 20 % NaCl and pH=3 and in 20 % NaCl pH=neutral but under cathodic polarisation. The electrochemical potential noise of the specimen was monitored during the test. The naturally fluctuations in potential were arise due to spontaneous brake protective film and were characteristics of the kind of corrosion like pit or stress corrosion cracking. After that using Fast Fourier Transformer (FFT) the noise data set were analyzed to obtain power spectral density plots which showed differences between general corrosion and localized corrosion. Polarization curves were carry out at two different rates and them showed the general behavior of the systems. (Author).

  4. Effects of divorce on Dutch boys' and girls' externalizing behavior in Gene × Environment perspective: diathesis stress or differential susceptibility in the Dutch Tracking Adolescents' Individual Lives Survey study?

    Science.gov (United States)

    Nederhof, Esther; Belsky, Jay; Ormel, Johan; Oldehinkel, Albertine J

    2012-08-01

    The effects of divorce on children's behavioral development have proven to be quite varied across studies, and most developmental and family scholars today appreciate the great heterogeneity in divorce effects. Thus, this inquiry sought to determine whether select dopaminergic genes previously associated with externalizing behavior and/or found to moderate diverse environmental effects (dopamine receptors D2 and D4, catechol-O-methyltransferase) might moderate divorce effects on adolescent self-reported externalizing problems; and, if so, whether evidence of gene-environment (G × E) interaction would prove consistent with diathesis-stress or differential-susceptibility models of environmental action. Data from the first and third wave of the Dutch Tracking Adolescents' Individual Lives Survey (n = 1,134) revealed some evidence of G × E interaction reflecting diathesis-stress but not differential susceptibility. It is intriguing that some evidence pointed to "vantage sensitivity," which are benefits accruing to those with a specific genotype when their parents remained together, the exact opposite of diathesis-stress. The limits of this work are considered, especially with regard to the conditions for testing differential susceptibility, and future directions are outlined.

  5. Biotransformation and Oxidative Stress Responses in Captive Nile Crocodile (Crocodylus niloticus Exposed to Organic Contaminants from the Natural Environment in South Africa.

    Directory of Open Access Journals (Sweden)

    Augustine Arukwe

    Full Text Available In the present study, the biotransformation and oxidative stress responses in relation to chemical burden in the liver of male and female Nile crocodiles--Crocodylus niloticus--from a commercial crocodile farm passively exposed to various anthropogenic aquatic pollutants was investigated. In general, the data showed that male crocodiles consistently produced higher biotransformation and oxidative stress responses compared to females. Relationships between these responses and concentrations of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs were also observed. Specifically, the catalytic assays for EROD and BROD (not PROD and MROD showed sex-differences between male and female crocodiles and paralleled immunochemically determined CYP1A and CYP3A protein levels; the relatively similar levels of PAHs in both sexes suggest an estrogen-mediated reduction of this pathway in females. The antioxidant system exhibited higher levels in male crocodiles with slight or significant higher values for catalase (CAT, glutathione reductase (GR, glutathione peroxidases-H2O2 (GPx-H2O2, glutathione peroxidases-Cu (GPx-Cu, total antioxidant capacity towards peroxyl radicals (TOSC-ROO and hydroxyl radicals (TOSC-HO, total glutathione (GSH and malondialdehyde (MDA. On the other hand, the activities of acyl-CoA oxidase (AOX and glutathione S-transferases (GST were significantly higher in females. Principal component analysis (PCA produced significant groupings that revealed correlative relationships (both positive and negative between biotransformation/oxidative stress variables and liver PAHs and aliphatic hydrocarbon burden. The overall results suggest that these captive pre-slaughter crocodiles exhibited adverse exposure responses to anthropogenic aquatic contaminants with potentially relevant effects on key cellular pathways, and these responses may be established as relevant species biomarkers of exposure and effects in this endangered species.

  6. Biotransformation and Oxidative Stress Responses in Captive Nile Crocodile (Crocodylus niloticus) Exposed to Organic Contaminants from the Natural Environment in South Africa

    Science.gov (United States)

    Arukwe, Augustine; Røsbak, Randi; Adeogun, Aina O.; Langberg, Håkon A.; Venter, Annette; Myburgh, Jan; Botha, Christo; Benedetti, Maura; Regoli, Francesco

    2015-01-01

    In the present study, the biotransformation and oxidative stress responses in relation to chemical burden in the liver of male and female Nile crocodiles—Crocodylus niloticus—from a commercial crocodile farm passively exposed to various anthropogenic aquatic pollutants was investigated. In general, the data showed that male crocodiles consistently produced higher biotransformation and oxidative stress responses compared to females. Relationships between these responses and concentrations of aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) were also observed. Specifically, the catalytic assays for EROD and BROD (not PROD and MROD) showed sex-differences between male and female crocodiles and paralleled immunochemically determined CYP1A and CYP3A protein levels; the relatively similar levels of PAHs in both sexes suggest an estrogen-mediated reduction of this pathway in females. The antioxidant system exhibited higher levels in male crocodiles with slight or significant higher values for catalase (CAT), glutathione reductase (GR), glutathione peroxidases-H2O2 (GPx-H2O2), glutathione peroxidases-Cu (GPx-Cu), total antioxidant capacity towards peroxyl radicals (TOSC-ROO) and hydroxyl radicals (TOSC-HO), total glutathione (GSH) and malondialdehyde (MDA). On the other hand, the activities of acyl-CoA oxidase (AOX) and glutathione S-transferases (GST) were significantly higher in females. Principal component analysis (PCA) produced significant groupings that revealed correlative relationships (both positive and negative) between biotransformation/oxidative stress variables and liver PAHs and aliphatic hydrocarbon burden. The overall results suggest that these captive pre-slaughter crocodiles exhibited adverse exposure responses to anthropogenic aquatic contaminants with potentially relevant effects on key cellular pathways, and these responses may be established as relevant species biomarkers of exposure and effects in this endangered species. PMID

  7. Adaptive evolution of Escherichia coli to Ciprofloxacin in controlled stress environments: emergence of resistance in continuous and step-wise gradients

    Science.gov (United States)

    Deng, J.; Zhou, L.; Dong, Y.; Sanford, R. A.; Shechtman, L. A.; Alcalde, R.; Werth, C. J.; Fouke, B. W.

    2017-12-01

    Microorganisms in nature have evolved in response to a variety of environmental stresses, including gradients in pH, flow and chemistry. While environmental stresses are generally considered to be the driving force of adaptive evolution, the impact and extent of any specific stress needed to drive such changes has not been well characterized. In this study, a microfluidic diffusion chamber (MDC) and a batch culturing system were used to systematically study the effects of continuous versus step-wise stress increments on adaptation of E. coli to the antibiotic ciprofloxacin. In the MDC, a diffusion gradient of ciprofloxacin was established across a microfluidic well array to microscopically observe changes in Escherichia coli strain 307 replication and migration patterns that would indicate emergence of resistance due to genetic mutations. Cells recovered from the MDC only had resistance of 50-times the original minimum inhibition concentration (MICoriginal) of ciprofloxacin, although minimum exposure concentrations were over 80 × MICoriginal by the end of the experiment. In complementary batch experiments, E. coli 307 were exposed to step-wise daily increases of ciprofloxacin at rates equivalent to 0.1×, 0.2×, 0.4× or 0.8× times MICoriginal/day. Over a period of 18 days, E. coli cells were able to acquire resistance of up to 225 × MICoriginal, with exposure to ciprofloxacin concentration up to only 14.9 × MIC­original. The different levels of acquired resistance in the continuous MDC versus step-wise batch increment experiments suggests that the intrinsic rate of E. coli adaptation was exceeded in the MDC, while the step-wise experiments favor adaptation to the highest ciprofloxacin experiments. Genomic analyses of E. coli DNA extracted from the microfluidic cell and batch cultures indicated four single nucleotide polymorphism (SNP) mutations of amino acid 82, 83 and 87 in the gyrA gene. The progression of adaptation in the step-wise increments of

  8. Effect of Low-Temperature Environment on Stress Corrosion Cracking Behavior of X80 Pipeline Steel in Simulated Alkaline Soil Solution

    Science.gov (United States)

    Xie, Fei; Wang, Dan; Wu, Ming; Yu, Chengxiang; Sun, Dongxu; Yang, Xu; Xu, Changhao

    2018-04-01

    The stress corrosion cracking (SCC) of X80 pipeline steel in simulated alkaline soil solution under different temperatures was investigated by slow-strain-rate testing, scanning electron microscopy and energy-dispersive spectroscopy. Results showed that the fracture was transgranular and brittle at 273 K to 278 K (0 °C to 5 °C), and the metal surface was dissolved by a large number of chloride ions. Furthermore, hydrogen embrittlement was caused by the hydrogen atom extended to the high-stress region. The fracture process was controlled by hydrogen-induced cracking, and SCC was highly sensitive at this stage. At 288 K to 298 K (15 °C to 25 °C), the fracture morphology was attributed to the mixed mode of ductile and brittle fractures, the fracture process was controlled by the mechanism of hydrogen-induced cracking and anodic dissolution, and the susceptibility to SCC decreased. When the temperature reached 308 K to 318 K (35 °C to 45 °C), the fracture was mainly intergranular and ductile, the fracture process was controlled by anodic dissolution, and SCC sensitivity was the smallest in this temperature range.

  9. A comparative study on oxidative stress response in the hepatopancreas and midgut of the white shrimp Litopenaeus vannamei under gradual changes to low or high pH environment.

    Science.gov (United States)

    Han, Si-Yin; Wang, Meng-Qiang; Wang, Bao-Jie; Liu, Mei; Jiang, Ke-Yong; Wang, Lei

    2018-05-01

    White shrimp Litopenaeus vannamei were reared under conditions of gradual changes to a low pH (gradual-low pH, 6.65-8.20) or a high pH (gradual-high pH, 8.20-9.81) versus a normal pH environment (8.14-8.31) during a 28-day period. Survival of shrimp, and ROS production, antioxidant responses and oxidative damage in the hepatopancreas and midgut were investigated. Consequently, shrimp enhanced MnSOD, GPx, and Hsp70 transcripts as early defense mechanism in the hepatopancreas and midgut to scavenge excessive ROS during short-term (≤ 7 days) gradual-low and high pH stress. Meanwhile, the hepatopancreas was more sensitive to ROS than midgut because of earlier ROS production increase, antioxidant response and oxidative damage. Then, suppressed antioxidant response in the hepatopancreas and midgut of shrimp suggested a loss of antioxidant regulatory capacity caused by aggravated oxidative damage after long-term (≥ 14 days) gradual-high pH stress, leading to continuous death. However, enhanced GPx, GST, and Hsp70 transcripts in the hepatopancreas and midgut might be long-term(≥ 14 days) antioxidant adaptation mechanism of shrimp to gradual-low pH stress, which could prevent further ROS perturbation and weaken oxidative damage to achieve a new immune homeostasis, contributing to stable survival rate. Therefore, we have a few insights that it is necessary to protect hepatopancreas for controlling shrimp death under gradual-high pH stress. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Development of a structure-dependent material model for complex, high-temperature environments and stresses. Example: turbine blades, turbine discs

    International Nuclear Information System (INIS)

    Schubert, F.

    1988-01-01

    For the optimum use of new high-temperature superalloys for turbine discs and blades, it is necessary to develop new design concepts which, on the one hand, permit a quantitative allocation of the structural characteristics to the deformation behaviour and damage mechanisms and, on the other hand, take into account the real course of stress. It is planned to use PM-Udinet 700 as material for turbine discs and IN 738 LC with supplementary tests of IN 100 for turbine blades. For turbine discs, a probabilistic model is developed, for turbine blades, cooled at the interior, first a deterministic model is developed and then a probabilistic model is prepared. The concept for the development of the models is dealt with in detail. The project started in April 1987, therefore only first investigation results can be reported. (orig.) [de

  11. Stress corrosion cracking and corrosion fatigue characterisation of MgZn1Ca0.3 (ZX10) in a simulated physiological environment.

    Science.gov (United States)

    Jafari, Sajjad; Raman, R K Singh; Davies, Chris H J; Hofstetter, Joelle; Uggowitzer, Peter J; Löffler, Jörg F

    2017-01-01

    Magnesium (Mg) alloys have attracted great attention as potential materials for biodegradable implants. It is essential that an implant material possesses adequate resistance to cracking/fracture under the simultaneous actions of corrosion and mechanical stresses, i.e., stress corrosion cracking (SCC) and/or corrosion fatigue (CF). This study investigates the deformation behaviour of a newly developed high-strength low-alloy Mg alloy, MgZn1Ca0.3 (ZX10), processed at two different extrusion temperatures of 325 and 400°C (named E325 and E400, respectively), under slow strain tensile and cyclic tension-compression loadings in air and modified simulated body fluid (m-SBF). Extrusion resulted in a bimodal grain size distribution with recrystallised grain sizes of 1.2 μm ± 0.8 μm and 7 ± 5 μm for E325 and E400, respectively. E325 possessed superior tensile and fatigue properties to E400 when tested in air. This is mainly attributed to a grain-boundary strengthening mechanism. However, both E325 and E400 were found to be susceptible to SCC at a strain rate of 3.1×10 -7 s -1 in m-SBF. Moreover, both E325 and E400 showed similar fatigue strength when tested in m-SBF. This is explained on the basis of crack initiation from localised corrosion following tests in m-SBF. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

  12. Combining field performance with controlled environment plant imaging to identify the genetic control of growth and transpiration underlying yield response to water-deficit stress in wheat.

    Science.gov (United States)

    Parent, Boris; Shahinnia, Fahimeh; Maphosa, Lance; Berger, Bettina; Rabie, Huwaida; Chalmers, Ken; Kovalchuk, Alex; Langridge, Peter; Fleury, Delphine

    2015-09-01

    Crop yield in low-rainfall environments is a complex trait under multigenic control that shows significant genotype×environment (G×E) interaction. One way to understand and track this trait is to link physiological studies to genetics by using imaging platforms to phenotype large segregating populations. A wheat population developed from parental lines contrasting in their mechanisms of yield maintenance under water deficit was studied in both an imaging platform and in the field. We combined phenotyping methods in a common analysis pipeline to estimate biomass and leaf area from images and then inferred growth and relative growth rate, transpiration, and water-use efficiency, and applied these to genetic analysis. From the 20 quantitative trait loci (QTLs) found for several traits in the platform, some showed strong effects, accounting for between 26 and 43% of the variation on chromosomes 1A and 1B, indicating that the G×E interaction could be reduced in a controlled environment and by using dynamic variables. Co-location of QTLs identified in the platform and in the field showed a possible common genetic basis at some loci. Co-located QTLs were found for average growth rate, leaf expansion rate, transpiration rate, and water-use efficiency from the platform with yield, spike number, grain weight, grain number, and harvest index in the field. These results demonstrated that imaging platforms are a suitable alternative to field-based screening and may be used to phenotype recombinant lines for positional cloning. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  13. Stress Management

    Science.gov (United States)

    Healthy Lifestyle Stress management By Mayo Clinic Staff Stress basics Stress is a normal psychological and physical reaction to the demands of life. ... some people's alarm systems rarely shut off. Stress management gives you a range of tools to reset ...

  14. Manage Stress

    Science.gov (United States)

    ... Manage Stress Print This Topic En español Manage Stress Browse Sections The Basics Overview Signs and Health ... and Health Effects What are the signs of stress? When people are under stress, they may feel: ...

  15. Stress Incontinence

    Science.gov (United States)

    Stress incontinence Overview Urinary incontinence is the unintentional loss of urine. Stress incontinence happens when physical movement or activity — such ... coughing, sneezing, running or heavy lifting — puts pressure (stress) on your bladder. Stress incontinence is not related ...

  16. The Lipopolysaccharide Lipid A Long-Chain Fatty Acid Is Important for Rhizobium leguminosarum Growth and Stress Adaptation in Free-Living and Nodule Environments.

    Science.gov (United States)

    Bourassa, Dianna V; Kannenberg, Elmar L; Sherrier, D Janine; Buhr, R Jeffrey; Carlson, Russell W

    2017-02-01

    Rhizobium bacteria live in soil and plant environments, are capable of inducing symbiotic nodules on legumes, invade these nodules, and develop into bacteroids that fix atmospheric nitrogen into ammonia. Rhizobial lipopolysaccharide (LPS) is anchored in the bacterial outer membrane through a specialized lipid A containing a very long-chain fatty acid (VLCFA). VLCFA function for rhizobial growth in soil and plant environments is not well understood. Two genes, acpXL and lpxXL, encoding acyl carrier protein and acyltransferase, are among the six genes required for biosynthesis and transfer of VLCFA to lipid A. Rhizobium leguminosarum mutant strains acpXL, acpXL - /lpxXL - , and lpxXL - were examined for LPS structure, viability, and symbiosis. Mutations in acpXL and lpxXL abolished VLCFA attachment to lipid A. The acpXL mutant transferred a shorter acyl chain instead of VLCFA. Strains without lpxXL neither added VLCFA nor a shorter acyl chain. In all strains isolated from nodule bacteria, lipid A had longer acyl chains compared with laboratory-cultured bacteria, whereas mutant strains displayed altered membrane properties, modified cationic peptide sensitivity, and diminished levels of cyclic β-glucans. In pea nodules, mutant bacteroids were atypically formed and nitrogen fixation and senescence were affected. The role of VLCFA for rhizobial environmental fitness is discussed.

  17. Stress and hormones

    Directory of Open Access Journals (Sweden)

    Salam Ranabir

    2011-01-01

    Full Text Available In the modern environment one is exposed to various stressful conditions. Stress can lead to changes in the serum level of many hormones including glucocorticoids, catecholamines, growth hormone and prolactin. Some of these changes are necessary for the fight or flight response to protect oneself. Some of these stressful responses can lead to endocrine disorders like Graves′ disease, gonadal dysfunction, psychosexual dwarfism and obesity. Stress can also alter the clinical status of many preexisting endocrine disorders such as precipitation of adrenal crisis and thyroid storm.

  18. Genetic Gains in Yield and Yield Related Traits under Drought Stress and Favorable Environments in a Maize Population Improved Using Marker Assisted Recurrent Selection

    Directory of Open Access Journals (Sweden)

    Folusho Bankole

    2017-05-01

    Full Text Available The objective of marker assisted recurrent selection (MARS is to increase the frequency of favorable marker alleles in a population before inbred line extraction. This approach was used to improve drought tolerance and grain yield (GY in a biparental cross of two elite drought tolerant lines. The testcrosses of randomly selected 50 S1 lines from each of the three selection cycles (C0, C1, C2 of the MARS population, parental testcrosses and the cross between the two parents (F1 were evaluated under drought stress (DS and well watered (WW well as under rainfed conditions to determine genetic gains in GY and other agronomic traits. Also, the S1 lines derived from each selection types were genotyped with single nucleotide polymorphism (SNP markers. Testcrosses derived from C2 produced significantly higher grain field under DS than those derived from C0 with a relative genetic gain of 7% per cycle. Also, the testcrosses of S1 lines from C2 showed an average genetic gain of 1% per cycle under WW condition and 3% per cycle under rainfed condition. Molecular analysis revealed that the frequency of favorable marker alleles increased from 0.510 at C0 to 0.515 at C2, while the effective number of alleles (Ne per locus decreased from C0 (1.93 to C2 (1.87. Our results underscore the effectiveness of MARS for improvement of GY under DS condition.

  19. Neuropeptide Y and Stress

    Directory of Open Access Journals (Sweden)

    Murat Gulsun

    2012-03-01

    Full Text Available The neurobiological aspects of stress and coping skills has been the focus of interest for many researchers. Some of the studies has shown that there is a significant relationship among genetically variables, stress response and life events. Neuropeptide Y is one of the systems regulating the stress response. Under the prolonged or repeated trauma neuropeptide Y is released from the brain's key areas. This system shows different levels of functioning in individuals with different levels of resilience. There is particular interest in the variations of genes that encode stress-sensitive signaling molecules during gene-environment interaction. This condition may contribute to susceptibility of stress or stress resilience. Neuropeptide Y system plays a key role in the adaptation to behavioral stress. The reduced levels of neuropeptide Y have also been observed in treatment-resistant depression and posttraumatic stress disorder. Lower level of neuropeptide Y expression and dysfunctional neuropeptide Y system in response to stress and resulting decreased stress resilience could increase susceptibility to stress-related disorders.

  20. Staphylococcal response to oxidative stress

    Directory of Open Access Journals (Sweden)

    Rosmarie eGaupp

    2012-03-01

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

  1. Probing Earth's State of Stress

    Science.gov (United States)

    Delorey, A. A.; Maceira, M.; Johnson, P. A.; Coblentz, D. D.

    2016-12-01

    The state of stress in the Earth's crust is a fundamental physical property that controls both engineered and natural systems. Engineered environments including those for hydrocarbon, geothermal energy, and mineral extraction, as well those for storage of wastewater, carbon dioxide, and nuclear fuel are as important as ever to our economy and environment. Yet, it is at spatial scales relevant to these activities where stress is least understood. Additionally, in engineered environments the rate of change in the stress field can be much higher than that of natural systems. In order to use subsurface resources more safely and effectively, we need to understand stress at the relevant temporal and spatial scales. We will present our latest results characterizing the state of stress in the Earth at scales relevant to engineered environments. Two important components of the state of stress are the orientation and magnitude of the stress tensor, and a measure of how close faults are to failure. The stress tensor at any point in a reservoir or repository has contributions from both far-field tectonic stress and local density heterogeneity. We jointly invert seismic (body and surface waves) and gravity data for a self-consistent model of elastic moduli and density and use the model to calculate the contribution of local heterogeneity to the total stress field. We then combine local and plate-scale contributions, using local indicators for calibration and ground-truth. In addition, we will present results from an analysis of the quantity and pattern of microseismicity as an indicator of critically stressed faults. Faults are triggered by transient stresses only when critically stressed (near failure). We show that tidal stresses can trigger earthquakes in both tectonic and reservoir environments and can reveal both stress and poroelastic conditions.

  2. Epibenthic colonization on an artificial reef in a stressed environment off the north coast of the Rio de Janeiro State, Brazil

    Directory of Open Access Journals (Sweden)

    Werther Krohling

    2008-02-01

    Full Text Available The influence of sedimentation and turbidity caused by the pluviometric precipitation and by the Paraiba do Sul River during the summer was investigated on an artificial reef along the north coast of Rio de Janeiro, Brazil. Four recruitment and four cumulative plates were removed monthly (January 2002 to February 2003 from the external surface of the concrete reef modules. Empty space was not a limiting factor the recruitment. Turnover rate and structural difference index were higher in the first months and reflected low change in the species dominance during almost the entire study period. The high correlation between the precipitation and the empty space suggested that rain influence the recruitment and the succession. The recruitment was possible despite stress factors such as sedimentation, turbidity, abrasion, strong bottom currents and a lack of natural consolidated substrate. Changes in the community structure reflected the substrate colonization history of a few resistant species and their subsequent interactions.A influência da sedimentação e da turbidez causadas pela precipitação pluviométrica e vazão do rio Paraíba do Sul nos meses de verão foi investigada em um recife artificial na costa norte do Estado do Rio de Janeiro, Brasil. Quatro placas de recrutamento e quarto placas de sucessão eram retiradas mensalmente (Janeiro de 2002 a Fevereiro de 2003 da superfície externa de módulos recifais de concreto. Espaço vazio não foi um fator limitante para o recrutamento. A taxa de substituição de espécies e o grau de diferença na estrutura da comunidade foram superiores nos meses iniciais, refletindo as reduzidas mudanças na dominância das espécies durante o período de estudo. A alta correlação entre precipitação e espaço vazio sugere a influência da precipitação no recrutamento e sucessão dos organismos. Recrutamento foi possível mesmo com fatores estressantes como sedimentação, turbidez, correntes de fundo

  3. Intercorrelation between immunological biomarkers and job stress indicators among female nurses: A nine-month longitudinal study

    Directory of Open Access Journals (Sweden)

    Hyung-Suk eYoon

    2014-10-01

    Full Text Available Some immunological biomarkers have been reported to be associated with job stress. This study was conducted to explore an intercorrelation between the psychological components of job stress and various immunological biomarkers among female nurses. To assess monthly and weekly job stress, 41 nurses had repeatedly completed the questionnaires such as the GJSQ, the POMS and the CES-D. Using flow cytometry and radioimmunoassay, the number of white blood cells, lymphocytic proliferation to mitogens, and toxoid were measured. Moreover, the levels of hydrocortisol, IL-b, INF-r, and TNF-a and salivary IgA were eveluated by enzyme-linked immunosorbent assay. When the Pearson correlation coefficients between job stress and immunological biomarkers were estimated after adjusting for age and smoking status, Clashes: conflict at work was significantly related to the number of CD4 cells (r = 0.36, p-value < 0.05, CD4 to CD8 ratio (0.35; < 0.05, response to concanavalin A (0.42; < 0.05, and phytohemagglutinin (0.35; < 0.05. Additionally, the level of hydrocortisol was significantly related to seven psychosocial measures; i.e., role conflict (-0.47; < 0.01, role ambiguity (-0.39; < 0.05, clashes at work (-0.38; < 0.05, control & influence at work (0.53; < 0.01, task control (0.55; < 0.001, resources at work (0.35; < 0.05, and skill underutilization (0.43; < 0.05. The results indicate that 1 the psychological job stress is associated with the levels of some immunological biomarkers in nurses; and 2 especially, hydrocortisol shows a remarkable relationship with diverse job stress indicators.

  4. Nuclear stress test

    Science.gov (United States)

    ... Persantine stress test; Thallium stress test; Stress test - nuclear; Adenosine stress test; Regadenoson stress test; CAD - nuclear stress; Coronary artery disease - nuclear stress; Angina - nuclear ...

  5. Effect of coastline properties and wastewater on plankton composition and distribution in a stressed environment on the north coast of Olinda-PE (Brazil

    Directory of Open Access Journals (Sweden)

    Luci Cajueiro Carneiro Pereira

    2005-11-01

    Full Text Available A study of the structure of the plankton community along the coastal zone of the Casa Caiada-Rio Doce area (Pernambuco, Brazil is presented. The results obtained indicated that in the protected zones the water presented high turbidity, high temperature, low salinity and high nutrient and oxygen rates. All of these conditions were responsible for the reduction in plankton diversity and an increase in the biomass of the most opportunistic (r-strategist species e.g. Gyrosigma balticum and Bacillaria paxillifera (Phytoplankton and Euterpina acutifrons (Zooplankton. The differences found with respect to others area studies performed in pristine conditions indicated that plankton structure could be used as an environmental health indicator and that, in this specific area, it was indicative of a poor quality coastal environment.Foi realizado um estudo sobre a estrutura das comunidades planctônicas ao longo das praias de Casa Caiada e Rio Doce (Pernanbuco, Brasil. A área de estudo sofre grande influência antrópica onde as condições ambientais são controladas pela presença de estruturas costeiras, reduzindo a intensidade da circulação neste ambiente; e pelos efluentes clandestinos de esgoto que aportam águas poluídas para dentro do sistema protegido. Os resultados obtidos indicam que nas zonas protegidas as águas apresentam alta turbidez, temperaturas elevadas, salinidades reduzidas e altas concentrações de nutrientes e oxigênio. Estas condições são responsáveis pela redução da diversidade do plâncton e pelo aumento da biomassa das espécies mais resistentes. As diferenças registradas com respeito a áreas similares, porém não impactadas, parecem indicar que a estrutura planctônica pode ser usada como um indicador da qualidade ambiental, sugerindo uma baixa qualidade das praias em estudo.

  6. Deccan volcanism induced high-stress environment during the Cretaceous-Paleogene transition at Zumaia, Spain: Evidence from magnetic, mineralogical and biostratigraphic records

    Science.gov (United States)

    Font, Eric; Adatte, Thierry; Andrade, Mariana; Keller, Gerta; Mbabi Bitchong, André; Carvallo, Claire; Ferreira, Joana; Diogo, Zenaida; Mirão, José

    2018-02-01

    We conducted detailed rock magnetic, mineralogical and geochemical (mercury) analyses spanning the Cretaceous-Paleogene boundary (KPB) at Zumaia, Spain, to unravel the signature of Deccan-induced climate and environmental changes in the marine sedimentary record. Our biostratigraphic results show that Zumaia is not complete, and lacks the typical boundary clay, zone P0 and the base of zone P1a(1) in the basal Danian. Presence of an unusual ∼1m-thick interval spanning the KPB is characterized by very low detrital magnetite and magnetosome (biogenic magnetite) contents and by the occurrence of akaganéite, a very rare mineral on Earth in oxidizing, acidic and hyper-chlorinated environments compatible with volcanic settings. These benchmarks correlate with higher abundance of the opportunist Guembelitria cretacea species. Detrital magnetite depletion is not linked to significant lithological changes, suggesting that iron oxide dissolution by acidification is the most probable explanation. The concomitant decrease in magnetosomes, produced by magnetotactic bacteria at the anoxic-oxic boundary, is interpreted as the result of changes in seawater chemistry induced by surficial ocean acidification. Mercury peaks up to 20-50 ppb are common during the last 100 kyr of the Maastrichtian (zone CF1) but only one significant anomaly is present in the early Danian, which is likely due to the missing interval. Absence of correlation between mercury content (R2 = 0.009) and total organic carbon (R2 = 0.006) suggest that the former originated from the Deccan Traps eruptions. No clear relation between the stratigraphic position of the mercury peaks and the magnetite-depleted interval is observed, although the frequency of the mercury peaks tends to increase close to the KPg boundary. In contrast to Bidart (France) and Gubbio (Italy), where magnetite depletion and akaganéite feature within a ∼50cm-thick interval located 5 cm below the KPg boundary, the same benchmarks are

  7. Stress in College Athletics: Causes, Consequences, Coping.

    Science.gov (United States)

    Humphrey, James H.; Yow, Deborah A.; Bowden, William W.

    This book addresses the causes and consequences of stress in college sports and offers effective coping mechanisms to help individuals understand and control stressors and emotions in their environment. The chapters are: (1) "Understanding Stress"; (2) "Perceptions of Stress in College Athletics"; (3) "Stress among College Athletes"; (4) "Stress…

  8. Physicians' occupational stress, depressive symptoms and work ability in relation to their working environment: a cross-sectional study of differences among medical residents with various specialties working in German hospitals.

    Science.gov (United States)

    Bernburg, Monika; Vitzthum, Karin; Groneberg, David A; Mache, Stefanie

    2016-06-15

    This study aimed to analyse and compare differences in occupational stress, depressive symptoms, work ability and working environment among residents working in various medical specialties. 435 German hospital residents in medical training working in 6 different medical specialties participated in a cross-sectional survey study. Physicians were asked about their working conditions and aspects of mental health and work ability. The Copenhagen Psychosocial Questionnaire, the Work Ability Index, the ICD-10 Symptom Rating and the Perceived Stress Questionnaire were used to measure working conditions, mental health and work ability. Results show that up to 17% of the physicians reported high levels of occupational distress and 9% reported high levels of depressive symptoms. 11% of the hospital physicians scored low in work ability. Significant differences between medical specialties were demonstrated for occupational distress, depressive symptoms, work ability, job demands and job resources. Surgeons showed consistently the highest levels of perceived distress but also the highest levels of work ability and lowest scores for depression. Depressive symptoms were rated with the highest levels by anaesthesiologists. Significant associations between physicians' working conditions, occupational distress and mental health-related aspects are illustrated. Study results demonstrated significant differences in specific job stressors, demands and resources. Relevant relations between work factors and physicians' health and work ability are discussed. These findings should be reinvestigated in further studies, especially with a longitudinal study design. This work suggests that to ensure physicians' health, hospital management should plan and implement suitable mental health promotion strategies. In addition, operational efficiency through resource planning optimisation and work process improvements should be focused by hospital management. Published by the BMJ Publishing Group

  9. The impact of stress on tournament entry

    NARCIS (Netherlands)

    Buser, T.; Dreber, A.; Mollerstrom, J.

    Individual willingness to enter competitive environments predicts career choices and labor market outcomes. Meanwhile, many people experience competitive contexts as stressful. We use two laboratory experiments to investigate whether factors related to stress can help explain individual differences

  10. Perennial Environment Observatory

    International Nuclear Information System (INIS)

    Plas, Frederic

    2014-07-01

    The Perennial Environment Observatory [Observatoire Perenne de l'Environnement - OPE] is a unique approach and infrastructure developed and implemented by ANDRA, the French National Radioactive Waste Management Agency, as part of its overall project of deep geological disposal for radioactive waste. Its current mission is to assess the initial state of the rural (forest, pasture, open-field and aquatic) environment, prior to repository construction. This will be followed in 2017 (pending construction authorizations) and for a period exceeding a century, by monitoring of any impact the repository may have on the environment. In addition to serving its own industrial purpose of environmental monitoring, ANDRA also opens the OPE approach, infrastructure and acquired knowledge (database...) to the scientific community to support further research on long term evolution of the environment subjected to natural and anthropogenic stresses, and to contribute to a better understanding of the interaction between the various compartments of the environment

  11. Combined Effect of Alternating Current Interference and Cathodic Protection on Pitting Corrosion and Stress Corrosion Cracking Behavior of X70 Pipeline Steel in Near-Neutral pH Environment

    Directory of Open Access Journals (Sweden)

    Liwei Wang

    2018-03-01

    Full Text Available Influence of alternating current (AC on pitting corrosion and stress corrosion cracking (SCC behavior of X70 pipeline steel in the near-neutral pH environment under cathodic protection (CP was investigated. Both corrosion and SCC are inhibited by −0.775 VSCE CP without AC interference. With the superimposition of AC current (1–10 mA/cm2, the direct current (DC potential shifts negatively under the CP of −0.775 VSCE and the cathodic DC current decreases and shifts to the anodic direction. Under the CP potential of −0.95 VSCE and −1.2 VSCE, the applied AC current promotes the cathodic reaction and leads to the positive shift of DC potential and increase of cathodic current. Local anodic dissolution occurs attributing to the generated anodic current transients in the positive half-cycle of the AC current, resulting in the initiation of corrosion pits (0.6–2 μm in diameter. AC enhances the SCC susceptibility of X70 steel under −0.775 VSCE CP, attributing to the promotion of anodic dissolution and hydrogen evolution. Even an AC current as low as 1 mA/cm2 can enhance the SCC susceptibility.

  12. Occupational Stress

    OpenAIRE

    Löblová, Klára

    2011-01-01

    The thesis deals with load, stress and related questions of the working life. Work-related stress brings numerous difficulties not only to affected individuals, but as a result also to organizations. The thesis follows symptoms, impacts, somatic and mental aspects of stress, its types and also types of stressors, which cause this problem. It is concentrated on workload as a specific area of work-related stress, individual resistance to the load, factors of workload and work-related stress and...

  13. Controlling social stress in virtual reality environments

    NARCIS (Netherlands)

    Hartanto, D.; Kampmann, I.L.; Morina, N.; Emmelkamp, P.G.M.; Neerincx, M.A.; Brinkman, W.P.

    2014-01-01

    Virtual reality exposure therapy has been proposed as a viable alternative in the treatment of anxiety disorders, including social anxiety disorder. Therapists could benefit from extensive control of anxiety eliciting stimuli during virtual exposure. Two stimuli controls are studied in this study:

  14. Neuronal responses to physiological stress

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  15. STRESS IN ORGANIZATIONS

    Directory of Open Access Journals (Sweden)

    Maria-Elena, GHEORDUNESCU

    2014-11-01

    Full Text Available Taking into account the changes that are currently taking place in our country, it is clear that these changes, which occur in almost all companies, lead to new stress factors for both employees and the organization. Occupational stress is a major problem for employees and managers, but also for the whole society. The issue of stress in organizations has given birth to many debates and studies. It is a common theme that is addressed by managers, employees and consultants from different perspectives. According to a study by the European Agency for Safety and Health at Work, in the European Union, work-related stress is the second work-related health issue after dorsal disorders. It affects 28% of EU employees. The European Parliament is fully involved in addressing issues related to the psychological support of the staff. Preventing work-related stress is one of the objectives set out in the Communique of the European Commission for Employment and Social Affairs regarding their new health and safety at work strategy. Manifestations of stress in organizations are easily observable, being manifested by behaviors such as: difficulties in adapting to the changes required to work or the dramatic drop in labor productivity. Also a double action is met: both the person who passes through the stressful situation and at the organization level on which it is reflected the existence of a stressful environment. This paper aims to address the implications of workplace stress, symptoms of stress in the workplace and strategies to eliminate and prevent stress at work This paper represents an exploratory research based on qualitative methods, being consulted various sources of information: the literature, case studies, media articles, reports of relevant organizations, etc.

  16. Living with urea stress

    Indian Academy of Sciences (India)

    Intracellular organic osmolytes are present in certain organisms adapted to harsh environments. These osmolytes protect intracellular macromolecules against denaturing environmental stress. In contrast to the usually benign effects of most organic osmolytes, the waste product urea is a well-known perturbant of ...

  17. Built environment and diabetes

    Science.gov (United States)

    Pasala, Sudhir Kumar; Rao, Allam Appa; Sridhar, G. R.

    2010-01-01

    Development of type 2 diabetes mellitus is influenced by built environment, which is, ‘the environments that are modified by humans, including homes, schools, workplaces, highways, urban sprawls, accessibility to amenities, leisure, and pollution.’ Built environment contributes to diabetes through access to physical activity and through stress, by affecting the sleep cycle. With globalization, there is a possibility that western environmental models may be replicated in developing countries such as India, where the underlying genetic predisposition makes them particularly susceptible to diabetes. Here we review published information on the relationship between built environment and diabetes, so that appropriate modifications can be incorporated to reduce the risk of developing diabetes mellitus. PMID:20535308

  18. Neuromuscular Stress.

    Science.gov (United States)

    White, Timothy P.; Kern, Marialice

    1994-01-01

    Discusses exercise-induced stress that results from motor unit recruitment, the impact of recruitment on selected systemic support systems, and some of the environmental overlays that affect the degree of physiological stress. Adaptations to sustained changes in physical activity and muscle and myotendinous injury induced by stress are examined.…

  19. Stress Fractures

    Science.gov (United States)

    Stress fractures Overview Stress fractures are tiny cracks in a bone. They're caused by repetitive force, often from overuse — such as repeatedly jumping up and down or running long distances. Stress fractures can also arise from normal use of ...

  20. Features of heat stress control

    International Nuclear Information System (INIS)

    Bernard, T.E.

    1989-01-01

    Heat stress is caused by hot environments and physical demands of work. It is further complicated by protective clothing requirements commonly found in the nuclear power industry. The resulting physiological strain is reflected in increased sweating, heart rate and body temperature. Uncontrolled exposures to heat stress will lead to decreased personnel performance and increased risk of accidents and heat disorders. The article describes major heat disorders, a method of heat stress evaluation, and some basic interventions to reduce the stress and strain of working in the heat

  1. Residual stresses

    International Nuclear Information System (INIS)

    Sahotra, I.M.

    2006-01-01

    The principal effect of unloading a material strained into the plastic range is to create a permanent set (plastic deformation), which if restricted somehow, gives rise to a system of self-balancing within the same member or reaction balanced by other members of the structure., known as residual stresses. These stresses stay there as locked-in stresses, in the body or a part of it in the absence of any external loading. Residual stresses are induced during hot-rolling and welding differential cooling, cold-forming and extruding: cold straightening and spot heating, fabrication and forced fitting of components constraining the structure to a particular geometry. The areas which cool more quickly develop residual compressive stresses, while the slower cooling areas develop residual tensile stresses, and a self-balancing or reaction balanced system of residual stresses is formed. The phenomenon of residual stresses is the most challenging in its application in surface modification techniques determining endurance mechanism against fracture and fatigue failures. This paper discusses the mechanism of residual stresses, that how the residual stresses are fanned and what their behavior is under the action of external forces. Such as in the case of a circular bar under limit torque, rectangular beam under limt moment, reclaiming of shafts welds and peening etc. (author)

  2. Dust in cosmic plasma environments

    International Nuclear Information System (INIS)

    Mendis, D.A.

    1979-01-01

    Cosmic dust is invariably immersed in a plasma and a radiative environment. Consequently, it is charged to some electrostatic potential which depends on the properties of the environment as well as the nature of the dust. This charging affects the physical and dynamical properties of the dust. In this paper the basic aspects of this dust-plasma interaction in several cosmic environments - including planetary magnetospheres, the heliosphere and the interstellar medium - are discussed. The physical and dynamical consequences of the interaction, as well as the pertinent observational evidence, are reviewed. Finally, the importance of the surface charge during the condensation process in plasma environments is stressed. (Auth.)

  3. Sustainability of compressive residual stress by stress improvement processes

    International Nuclear Information System (INIS)

    Nishikawa, Satoru; Okita, Shigeru; Yamaguchi, Atsunori

    2013-01-01

    Stress improvement processes are countermeasures against stress corrosion cracking in nuclear power plant components. It is necessary to confirm whether compressive residual stress induced by stress improvement processes can be sustained under operation environment. In order to evaluate stability of the compressive residual stress in 60-year operating conditions, the 0.07% cyclic strains of 200 times at 593 K were applied to the welded specimens, then a thermal aging treatment for 1.66x10 6 s at 673 K was carried out. As the result, it was confirmed that the compressive residual stresses were sustained on both surfaces of the dissimilar welds of austenitic stainless steel (SUS316L) and nickel base alloy (NCF600 and alloy 182) processed by laser peening (LP), water jet peening (WJP), ultrasonic shot peening (USP), shot peening (SP) and polishing under 60-year operating conditions. (author)

  4. Oxidative stress

    Directory of Open Access Journals (Sweden)

    Osredkar Joško

    2012-05-01

    Full Text Available The human organism is exposed to the influence of various forms of stress, either physical, psychological or chemical, which all have in common that they may adversely affect our body. A certain amount of stress is always present and somehow directs, promotes or inhibits the functioning of the human body. Unfortunately, we are now too many and too often exposed to excessive stress, which certainly has adverse consequences. This is especially true for a particular type of stress, called oxidative stress. All aerobic organisms are exposed to this type of stress because they produce energy by using oxygen. For this type of stress you could say that it is rather imperceptibly involved in our lives, as it becomes apparent only at the outbreak of certain diseases. Today we are well aware of the adverse impact of radicals, whose surplus is the main cause of oxidative stress. However, the key problem remains the detection of oxidative stress, which would allow us to undertake timely action and prevent outbreak of many diseases of our time. There are many factors that promote oxidative stress, among them are certainly a fast lifestyle and environmental pollution. The increase in oxidative stress can also trigger intense physical activity that is directly associated with an increased oxygen consumption and the resulting formation of free radicals. Considering generally positive attitude to physical activity, this fact may seem at first glance contradictory, but the finding has been confimed by several studies in active athletes. Training of a top athlete daily demands great physical effort, which is also reflected in the oxidative state of the organism. However, it should be noted that the top athletes in comparison with normal individuals have a different defense system, which can counteract the negative effects of oxidative stress. Quite the opposite is true for irregular or excessive physical activity to which the body is not adapted.

  5. Encapsulated environment

    NARCIS (Netherlands)

    McLellan, Tom M.; Daanen, Hein A M; Cheung, Stephen S.

    2013-01-01

    In many occupational settings, clothing must be worn to protect individuals from hazards in their work environment. However, personal protective clothing (PPC) restricts heat exchange with the environment due to high thermal resistance and low water vapor permeability. As a consequence, individuals

  6. Encapsulated Environment

    NARCIS (Netherlands)

    McLellan, T.M.; Daanen, H.A.M.; Cheung, S.S.

    2013-01-01

    In many occupational settings, clothing must be worn to protect individuals from hazards in their work environment. However, personal protective clothing (PPC) restricts heat exchange with the environment due to high thermal resistance and low water vapor permeability. As a consequence, individuals

  7. Work Stress

    OpenAIRE

    Roeters, Anne

    2014-01-01

    Most of us agree that stress is a growing problem within organizations. We hear about the postal workers who had killed fellow employees and supervisors, and then hear that a major cause of tension is at work. Friends tell us that they are stressed due to increased workload and he has to work overtime because the company is restructured. We read the polls that employees complain about the stress in trying to balance family life with the work. Stress is a dynamic condition in which an individu...

  8. Stress, catecholaminergic system and cancer.

    Science.gov (United States)

    Krizanova, O; Babula, P; Pacak, K

    2016-07-01

    Stress as a modern civilization factor significantly affects our lives. While acute stress might have a positive effect on the organism, chronic stress is usually detrimental and might lead to serious health complications. It is known that stress induced by the physical environment (temperature-induced cold stress) can significantly impair the efficacy of cytotoxic chemotherapies and the anti-tumor immune response. On the other hand, epidemiological evidence has shown that patients taking drugs known as β-adrenergic antagonists ("β-blockers"), which are commonly prescribed to treat arrhythmia, hypertension, and anxiety, have significantly lower rates of several cancers. In this review, we summarize the current knowledge about catecholamines as important stress hormones in tumorigenesis and discuss the use of β-blockers as the potential therapeutic agents.

  9. Work environment stressors and personnel efficacy in Nigeria's ...

    African Journals Online (AJOL)

    Work environment stressors and personnel efficacy in Nigeria's maritime industry. ... Journal Home > Vol 15, No 1 (2017) > ... employees and corporate organizations need to manage stress by identifying the stressors and stress levels.

  10. Heat Stress Effects on Growing-Finishing Swine

    Science.gov (United States)

    Understanding the factors that create heat stress, the response of the animals while under heat stress, and the signs of heat-stressed swine are essential to making rational decisions for the selection, design, and management of their environments. Heat stressors include combinations of environment...

  11. Social stress models in rodents : Towards enhanced validity

    NARCIS (Netherlands)

    Koolhaas, J M; de Boer, S F; Buwalda, B; Meerlo, P

    Understanding the role of the social environment in the development of stress related diseases requires a more fundamental understanding of stress. Stress includes not only the stimulus and the response but also the individual appraisal of the situation. The social environment is not only essential

  12. Residual stresses

    International Nuclear Information System (INIS)

    Macherauch, E.

    1978-01-01

    Residual stresses are stresses which exist in a material without the influence of external powers and moments. They come into existence when the volume of a material constantly changes its form as a consequence of mechanical, thermal, and/or chemical processes and is hindered by neighbouring volumes. Bodies with residual stress are in mechanical balance. These residual stresses can be manifested by means of all mechanical interventions disturbing this balance. Acoustical, optical, radiological, and magnetical methods involving material changes caused by residual stress can also serve for determining residual stress. Residual stresses have an ambivalent character. In technical practice, they are feared and liked at the same time. They cause trouble because they can be the cause for unexpected behaviour of construction elements. They are feared since they can cause failure, in the worst case with catastrophical consequences. They are appreciated, on the other hand, because, in many cases, they can contribute to improvements of the material behaviour under certain circumstances. But they are especially liked for their giving convenient and (this is most important) mostly uncontrollable explanations. For only in very few cases we have enough knowledge and possibilities for the objective evaluation of residual stresses. (orig.) [de

  13. Geopotential Stress

    DEFF Research Database (Denmark)

    Schiffer, Christian; Nielsen, S.B.

    Density heterogeneity in the Earth’s lithosphere causes lateral pressure variations. Horizontal gradients of the vertically integrated lithostatic pressure, the Geopotential Energy (GPE), are a source of stresses (Geopotential Stress) that contribute to the Earth’s Stress Field. In theory the GPE...... is linearly related to the lithospheric part of the Geoid. The Geopotential Stress can be calculated if either the density structure and as a consequence the GPE or the lithospheric contribution to the Geoid is known. The lithospheric Geoid is usually obtained by short pass filtering of satellite Geoid...... are not entirely suitable for the stress calculations but can be compiled and adjusted. We present an approach in which a global lithospheric density model based on CRUST2.0 is obtained by simultaneously fitting topography and surface heat flow in the presence of isostatic compensation and long-wavelength lateral...

  14. Environmental stress, oxytocin receptor gene (OXTR) polymorphism, and mental health following collective stress.

    Science.gov (United States)

    Lucas-Thompson, Rachel G; Holman, E Alison

    2013-04-01

    We examined whether the oxytocin receptor gene (OXTR) single nucleotide polymorphism (SNP) rs53576 genotype buffers the combined impact of negative social environments (e.g., interpersonal conflict/constraint) and economic stress on post-traumatic stress (PTS) symptoms and impaired daily functioning following collective stress (September 11th terrorist attacks). Saliva was collected by mail and used to genotype 704 respondents. Participants completed Web-based assessments of pre-9/11 mental health, acute stress 9-23 days after 9/11, the quality of social environments 1 year post-9/11, economic stress 18 months post-9/11, and PTS symptoms and impaired functioning 2 and 3 years post-9/11. Interactions between negative social environments and economic stress were examined separately based on OXTR rs53576 genotype (GG vs. any A allele). For individuals with an A allele, a negative social environment significantly increased PTS symptoms without regard to the level of economic stress experienced. However, for respondents with a GG genotype, negative social environments predicted elevated PTS symptoms only for those also experiencing high economic stress. Gender moderated associations between negative social environments, economic stress, and impaired functioning. The functioning of females was most affected by negative social environments regardless of genotype and economic stress, whereas the functioning of males was differentially susceptible to economic stress depending on OXTR genotype and negative social environments. These findings suggest that it is important to consider the combined impact of gender and ongoing stress in different domains as moderators of genetic vulnerability following collective stress. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Robotic environments

    NARCIS (Netherlands)

    Bier, H.H.

    2011-01-01

    Technological and conceptual advances in fields such as artificial intelligence, robotics, and material science have enabled robotic architectural environments to be implemented and tested in the last decade in virtual and physical prototypes. These prototypes are incorporating sensing-actuating

  16. Performative Environments

    DEFF Research Database (Denmark)

    Thomsen, Bo Stjerne

    2008-01-01

    The paper explores how performative architecture can act as a collective environment localizing urban flows and establishing public domains through the integration of pervasive computing and animation techniques. The NoRA project introduces the concept of ‘performative environments,' focusing on ...... of local interactions and network behaviour, building becomes social infrastructure and prompts an understanding of architectural structures as quasiobjects, which can retain both variation and recognisability in changing social constellations.......The paper explores how performative architecture can act as a collective environment localizing urban flows and establishing public domains through the integration of pervasive computing and animation techniques. The NoRA project introduces the concept of ‘performative environments,' focusing...

  17. Learn to manage stress

    Science.gov (United States)

    Stress - managing; Stress - recognizing; Stress - relaxation techniques ... LEARN TO RECOGNIZE STRESS The first step in managing stress is recognizing it in your life. Everyone feels stress in a different way. ...

  18. Stress Effects on Transfer from Virtual Environment Flight Training to Stressful Flight Environments

    Science.gov (United States)

    2009-06-01

    2001; Saunders, Driskell, Hall, & Salas, 1996; Thorndike & Woodworth, 1901). The present research project expands on these findings to further...Similar to Osgood (1949), Thorndike and Woodworth (1901) first demonstrated that training systems and the real world must share identical elements in...shared between the training and transfer task (Rose, Attree, Brooks, Parslow, Penn, & Ambihaipahan, 2000; Thorndike & Woodworth, 1901). When designing

  19. Culture Clash? Investigating constructions of sexual and reproductive health from the perspective of 1.5 generation migrants in Australia using Q methodology.

    Science.gov (United States)

    Dune, T; Perz, J; Mengesha, Z; Ayika, D

    2017-04-04

    In Australia, those who migrate as children or adolescents (1.5 generation migrants) may have entered a new cultural environment at a crucial time in their psychosexual development. These migrants may have to contend with constructions of sexual and reproductive health from at least two cultures which may be at conflict on the matter. This study was designed to investigate the role of culture in constructions of sexual and reproductive health and health care seeking behaviour from the perspective of 1.5 generation migrants. Forty-two adults from various ethno-cultural backgrounds took part in this Q methodological study. Online, participants rank-ordered forty-two statements about constructions of sexual and reproductive health and health seeking behaviours based on the level to which they agreed or disagreed with them. Participants then answered a series of questions about the extent to which their ethnic/cultural affiliations influenced their identity. A by-person factor analysis was then conducted, with factors extracted using the centroid technique and a varimax rotation. A seven-factor solution provided the best conceptual fit for constructions of sexual and reproductive health and help-seeking. Factor A compared progressive and traditional sexual and reproductive health values. Factor B highlighted migrants' experiences through two cultural lenses. Factor C explored migrant understandings of sexual and reproductive health in the context of culture. Factor D explained the role of culture in migrants' intimate relationships, beliefs about migrant sexual and reproductive health and engagement of health care services. Factor E described the impact of culture on sexual and reproductive health related behaviour. Factor F presented the messages migrant youth are given about sexual and reproductive health. Lastly, Factor G compared constructions of sexual and reproductive health across cultures. This study has demonstrated that when the cultural norms of migrants

  20. A Journey into AlaskaWhen I went to Alaska to study humans in nature, I wrote a story to summarize my research. It follows Caleb as he goes through Alaskan wilderness. He contrasts the peaceful ways of the Tlingit. His materialistic motives clash with others. The story ends with him dying in the wild. Caleb symbolizes unrightfully using natural resources.

    Science.gov (United States)

    Hosseini, A.

    2017-12-01

    When I went to Alaska to study humanity's place in nature, I crafted a short piece of writing as a way to summarize what I learned. The story follows the path of Caleb as he goes through the Alaskan wilderness. His actions contrast heavily with the peaceful ways of Alaska's natives, the Tlingit, and his selfish, materialistic motives clash with those of others he meets. The story ends with him dying alone, succumbing to Mother Nature's defeat. Caleb represents those who utilize natural resources at their own gain, and his journey shows the same trap many others have fallen into.

  1. Nanomaterials and the Environment

    International Nuclear Information System (INIS)

    Manzo, Sonia; Rametta, Gabriella; Miglietta Maria Lucia; Di Francia, Girolamo

    2015-01-01

    Nanotechnology intend to engineer the material using the special properties that it exhibits in the nanoscale to create new products. These properties imply a greater chemical reactivity, a higher strength and electrical conductivity and, potentially, a more pronounced biological activity. This can have not only positive valence (antioxidant activity, penetration of cellular barriers to the release of drugs), but also negative (eg. Toxicity, induction of oxidative stress or cellular dysfunction). Therefore, in addition to the great practical interest, nanotechnology has attracted the attention of the scientific community and the legislative authority for the specific interactions that may occur with living beings and the environment [it

  2. Accelerated Stress-Corrosion Testing

    Science.gov (United States)

    1986-01-01

    Test procedures for accelerated stress-corrosion testing of high-strength aluminum alloys faster and provide more quantitative information than traditional pass/fail tests. Method uses data from tests on specimen sets exposed to corrosive environment at several levels of applied static tensile stress for selected exposure times then subsequently tensile tested to failure. Method potentially applicable to other degrading phenomena (such as fatigue, corrosion fatigue, fretting, wear, and creep) that promote development and growth of cracklike flaws within material.

  3. Synthetic environments

    Science.gov (United States)

    Lukes, George E.; Cain, Joel M.

    1996-02-01

    The Advanced Distributed Simulation (ADS) Synthetic Environments Program seeks to create robust virtual worlds from operational terrain and environmental data sources of sufficient fidelity and currency to interact with the real world. While some applications can be met by direct exploitation of standard digital terrain data, more demanding applications -- particularly those support operations 'close to the ground' -- are well-served by emerging capabilities for 'value-adding' by the user working with controlled imagery. For users to rigorously refine and exploit controlled imagery within functionally different workstations they must have a shared framework to allow interoperability within and between these environments in terms of passing image and object coordinates and other information using a variety of validated sensor models. The Synthetic Environments Program is now being expanded to address rapid construction of virtual worlds with research initiatives in digital mapping, softcopy workstations, and cartographic image understanding. The Synthetic Environments Program is also participating in a joint initiative for a sensor model applications programer's interface (API) to ensure that a common controlled imagery exploitation framework is available to all researchers, developers and users. This presentation provides an introduction to ADS and the associated requirements for synthetic environments to support synthetic theaters of war. It provides a technical rationale for exploring applications of image understanding technology to automated cartography in support of ADS and related programs benefitting from automated analysis of mapping, earth resources and reconnaissance imagery. And it provides an overview and status of the joint initiative for a sensor model API.

  4. Potential of elite maize composites for drought tolerance in stress ...

    African Journals Online (AJOL)

    1999-12-11

    Dec 11, 1999 ... Effects due to environment (E), genotype (G) and G x E interaction were highly significant (P<0.01) for grain yield, 50% silk emergence, plant height, lodging, ears per plant, and ear rating in both environments (drought and non-drought stressed). In the stress environment, grain yields of the varieties ranged ...

  5. Enacting Environments

    DEFF Research Database (Denmark)

    Lippert, Ingmar

    2013-01-01

    Enacting Environments is an ethnography of the midst of the encounter between corporations, sustainable development and climate change. At this intersection 'environmental management' and 'carbon accounting' are put into practice. Purportedly, these practices green capitalism. Drawing on fieldwork...... of day-to-day practices of corporate environmental accountants and managers, Ingmar Lippert reconstructs their work as achieving to produce a reality of environment that is simultaneously stable and flexible enough for a particular corporate project: to stage the company, and in consequence capitalism......, as in control over its relations to an antecedent environment. Not confined to mere texts or meetings between shiny stakeholders co-governing the corporation – among them some of the world's biggest auditing firms, an environmental non-governmental organisation (NGO) and standards – cont