WorldWideScience

Sample records for stress process paradigm

  1. Influence of stress on fear memory processes in an aversive differential conditioning paradigm in humans.

    Science.gov (United States)

    Bentz, Dorothée; Michael, Tanja; Wilhelm, Frank H; Hartmann, Francina R; Kunz, Sabrina; von Rohr, Isabelle R Rudolf; de Quervain, Dominique J-F

    2013-07-01

    It is widely assumed that learning and memory processes play an important role in the pathogenesis, expression, maintenance and therapy of anxiety disorders, such as phobias or post-traumatic stress disorder (PTSD). Memory retrieval is involved in symptom expression and maintenance of these disorders, while memory extinction is believed to be the underlying mechanism of behavioral exposure therapy of anxiety disorders. There is abundant evidence that stress and stress hormones can reduce memory retrieval of emotional information, whereas they enhance memory consolidation of extinction training. In this study we aimed at investigating if stress affects these memory processes in a fear conditioning paradigm in healthy human subjects. On day 1, fear memory was acquired through a standard differential fear conditioning procedure. On day 2 (24h after fear acquisition), participants either underwent a stressful cold pressor test (CPT) or a control condition, 20 min before memory retrieval testing and extinction training. Possible prolonged effects of the stress manipulation were investigated on day 3 (48 h after fear acquisition), when memory retrieval and extinction were tested again. On day 2, men in the stress group showed a robust cortisol response to stress and showed lower unconditioned stimulus (US) expectancy ratings than men in the control group. This reduction in fear memory retrieval was maintained on day 3. In women, who showed a significantly smaller cortisol response to stress than men, no stress effects on fear memory retrieval were observed. No group differences were observed with respect to extinction. In conclusion, the present study provides evidence that stress can reduce memory retrieval of conditioned fear in men. Our findings may contribute to the understanding of the effects of stress and glucocorticoids on fear symptoms in anxiety disorders and suggest that such effects may be sex-specific. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. The corruption process of a law enforcement officer: a paradigm of occupational stress and deviancy.

    Science.gov (United States)

    McCafferty, F L; Souryal, S; McCafferty, M A

    1998-01-01

    The public does not want all laws enforced. In the closed society of law enforcement institutions, police discretion, the conspiracy of silence, the lack of an administration with integrity, and susceptible law enforcement officers contribute to the development of corruption from occupational deviance. Corruption in law enforcement agencies may have similar roots in business, law, medicine, and other professions. Understanding the law enforcement corruption paradigm may therefore be helpful in correcting and curbing corruption in other professions.

  3. Hearing impairment, social support, and depressive symptoms among U.S. adults: A test of the stress process paradigm.

    Science.gov (United States)

    West, Jessica S

    2017-11-01

    Hearing impairment is a growing physical disability affecting older adults and is an important physical health stressor, but few studies have examined it in relation to mental health outcomes and even fewer have considered the role of social support in buffering this relationship. The current study builds on the stress process framework and uses longitudinal data from three waves of the Health and Retirement Study (2006, 2010, 2014) to examine the relationship between hearing impairment and depressive symptoms among U.S. adults aged 50 and older (n = 6075). The analysis uses fixed-effects models to assess this relationship and examine the extent to which social support mediates (buffers) or moderates (interaction) the association. The results found that worse self-rated hearing was associated with a significant increase in depressive symptoms, even after controlling for sociodemographic factors. Social support did not buffer this relationship. Instead, social support interacted with hearing impairment: low levels of social support were associated with more depressive symptoms but only among people with poor self-rated hearing. Among those with excellent self-rated hearing, low levels of social support did not increase depressive symptoms. Moreover, high levels of social support reduced depressive symptoms for those with poor hearing. These findings suggest that hearing impairment is a chronic stressor in individuals' lives, and that responses to this stressor vary by the availability of social resources. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Information processing as a paradigm for decision making.

    Science.gov (United States)

    Oppenheimer, Daniel M; Kelso, Evan

    2015-01-03

    For decades, the dominant paradigm for studying decision making--the expected utility framework--has been burdened by an increasing number of empirical findings that question its validity as a model of human cognition and behavior. However, as Kuhn (1962) argued in his seminal discussion of paradigm shifts, an old paradigm cannot be abandoned until a new paradigm emerges to replace it. In this article, we argue that the recent shift in researcher attention toward basic cognitive processes that give rise to decision phenomena constitutes the beginning of that replacement paradigm. Models grounded in basic perceptual, attentional, memory, and aggregation processes have begun to proliferate. The development of this new approach closely aligns with Kuhn's notion of paradigm shift, suggesting that this is a particularly generative and revolutionary time to be studying decision science.

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

    Science.gov (United States)

    Neckameyer, Wendi S; Nieto-Romero, Andres R

    2015-01-01

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

  6. Stress effects on mood, HPA axis, and autonomic response: comparison of three psychosocial stress paradigms.

    Directory of Open Access Journals (Sweden)

    Grace E Giles

    Full Text Available Extensive experimental psychology research has attempted to parse the complex relationship between psychosocial stress, mood, cognitive performance, and physiological changes. To do so, it is necessary to have effective, validated methods to experimentally induce psychosocial stress. The Trier Social Stress Test (TSST is the most commonly used method of experimentally inducing psychosocial stress, but it is resource intensive. Less resource intense psychosocial stress tasks include the Socially Evaluative Cold Pressor Task (SECPT and a computerized mental arithmetic task (MAT. These tasks effectively produce a physiological and psychological stress response and have the benefits of requiring fewer experimenters and affording data collection from multiple participants simultaneously. The objective of this study was to compare the magnitude and duration of these three experimental psychosocial stress induction paradigms. On each of four separate days, participants completed either a control non-stressful task or one of the three experimental stressors: the TSST, SECPT, or MAT. We measured mood, working memory performance, salivary cortisol and alpha-amylase (AA, and heart rate. The TSST and SECPT exerted the most robust effects on mood and physiological measures. TSST effects were generally evident immediately post-stress as well as 10- and 20-minutes after stress cessation, whereas SECPT effects were generally limited to the duration of the stressor. The stress duration is a key determinant when planning a study that utilizes an experimental stressor, as researchers may be interested in collecting dependent measures prior to stress cessation. In this way, the TSST would allow the investigator a longer window to administer tasks of interest.

  7. Comparison of fMRI paradigms assessing visuospatial processing: Robustness and reproducibility.

    Directory of Open Access Journals (Sweden)

    Verena Schuster

    , when being interested in effects at the single-voxel level. Notably, however, when focusing on the reliability of measures of hemispheric lateralization (which was the main goal of study 2, we show that hemispheric dominance (quantified by the lateralization index, LI, with |LI| >0.4 of the evoked activation could be robustly determined in more than 62% and, if considering only two categories (i.e., left, right, in more than 93% of our subjects. Furthermore, the reliability of the lateralization strength (LI was "fair" to "good". In conclusion, our results suggest that the degree of right-hemispheric dominance during visuospatial processing can be reliably determined using the Landmark task, both at the group and single-subject level, while at the same time stressing the need for future refinements of experimental paradigms and more sophisticated fMRI data acquisition techniques.

  8. fMRI paradigm designing and post-processing tools

    International Nuclear Information System (INIS)

    James, Jija S; Rajesh, PG; Chandran, Anuvitha VS; Kesavadas, Chandrasekharan

    2014-01-01

    In this article, we first review some aspects of functional magnetic resonance imaging (fMRI) paradigm designing for major cognitive functions by using stimulus delivery systems like Cogent, E-Prime, Presentation, etc., along with their technical aspects. We also review the stimulus presentation possibilities (block, event-related) for visual or auditory paradigms and their advantage in both clinical and research setting. The second part mainly focus on various fMRI data post-processing tools such as Statistical Parametric Mapping (SPM) and Brain Voyager, and discuss the particulars of various preprocessing steps involved (realignment, co-registration, normalization, smoothing) in these software and also the statistical analysis principles of General Linear Modeling for final interpretation of a functional activation result

  9. The Predictive Processing Paradigm Has Roots in Kant.

    Science.gov (United States)

    Swanson, Link R

    2016-01-01

    Predictive processing (PP) is a paradigm in computational and cognitive neuroscience that has recently attracted significant attention across domains, including psychology, robotics, artificial intelligence and philosophy. It is often regarded as a fresh and possibly revolutionary paradigm shift, yet a handful of authors have remarked that aspects of PP seem reminiscent of the work of 18th century philosopher Immanuel Kant. To date there have not been any substantive discussions of how exactly PP links back to Kant. In this article, I argue that several core aspects of PP were anticipated by Kant (1996/1787) in his works on perception and cognition. Themes from Kant active in PP include: (1) the emphasis on "top-down" generation of percepts; (2) the role of "hyperpriors"; (3) the general function of "generative models"; (4) the process of "analysis-by-synthesis"; and (5) the crucial role of imagination in perception. In addition to these, I also point out that PP echoes Kant's general project in that it aims to explain how minds track causal structure in the world using only sensory data, and that it uses a reverse-engineer or "top-down" method of analysis. I then locate a possible source of Kant's influence on PP by tracing the paradigm back to Hermann von Helmholtz, who saw himself as providing a scientific implementation of Kant's conclusions. I conclude by arguing that PP should not be regarded as a new paradigm, but is more appropriately understood as the latest incarnation of an approach to perception and cognition initiated by Kant and refined by Helmholtz.

  10. The Predictive Processing Paradigm Has Roots in Kant

    Science.gov (United States)

    Swanson, Link R.

    2016-01-01

    Predictive processing (PP) is a paradigm in computational and cognitive neuroscience that has recently attracted significant attention across domains, including psychology, robotics, artificial intelligence and philosophy. It is often regarded as a fresh and possibly revolutionary paradigm shift, yet a handful of authors have remarked that aspects of PP seem reminiscent of the work of 18th century philosopher Immanuel Kant. To date there have not been any substantive discussions of how exactly PP links back to Kant. In this article, I argue that several core aspects of PP were anticipated by Kant (1996/1787) in his works on perception and cognition. Themes from Kant active in PP include: (1) the emphasis on “top-down” generation of percepts; (2) the role of “hyperpriors”; (3) the general function of “generative models”; (4) the process of “analysis-by-synthesis”; and (5) the crucial role of imagination in perception. In addition to these, I also point out that PP echoes Kant’s general project in that it aims to explain how minds track causal structure in the world using only sensory data, and that it uses a reverse-engineer or “top-down” method of analysis. I then locate a possible source of Kant’s influence on PP by tracing the paradigm back to Hermann von Helmholtz, who saw himself as providing a scientific implementation of Kant’s conclusions. I conclude by arguing that PP should not be regarded as a new paradigm, but is more appropriately understood as the latest incarnation of an approach to perception and cognition initiated by Kant and refined by Helmholtz. PMID:27777555

  11. The new risk paradigm for chemical process security and safety.

    Science.gov (United States)

    Moore, David A

    2004-11-11

    The world of safety and security in the chemical process industries has certainly changed since 11 September, but the biggest challenges may be yet to come. This paper will explain that there is a new risk management paradigm for chemical security, discuss the differences in interpreting this risk versus accidental risk, and identify the challenges we can anticipate will occur in the future on this issue. Companies need to be ready to manage the new chemical security responsibilities and to exceed the expectations of the public and regulators. This paper will outline the challenge and a suggested course of action.

  12. OSO paradigm--A rapid behavioral screening method for acute psychosocial stress reactivity in mice.

    Science.gov (United States)

    Brzózka, M M; Unterbarnscheidt, T; Schwab, M H; Rossner, M J

    2016-02-09

    Chronic psychosocial stress is an important environmental risk factor for the development of psychiatric diseases. However, studying the impact of chronic psychosocial stress in mice is time consuming and thus not optimally suited to 'screen' increasing numbers of genetically manipulated mouse models for psychiatric endophenotypes. Moreover, many studies focus on restraint stress, a strong physical stressor with limited relevance for psychiatric disorders. Here, we describe a simple and a rapid method based on the resident-intruder paradigm to examine acute effects of mild psychosocial stress in mice. The OSO paradigm (open field--social defeat--open field) compares behavioral consequences on locomotor activity, anxiety and curiosity before and after exposure to acute social defeat stress. We first evaluated OSO in male C57Bl/6 wildtype mice where a single episode of social defeat reduced locomotor activity, increased anxiety and diminished exploratory behavior. Subsequently, we applied the OSO paradigm to mouse models of two schizophrenia (SZ) risk genes. Transgenic mice with neuronal overexpression of Neuregulin-1 (Nrg1) type III showed increased risk-taking behavior after acute stress exposure suggesting that NRG1 dysfunction is associated with altered affective behavior. In contrast, Tcf4 transgenic mice displayed a normal stress response which is in line with the postulated predominant contribution of TCF4 to cognitive deficits of SZ. In conclusion, the OSO paradigm allows for rapid screening of selected psychosocial stress-induced behavioral endophenotypes in mouse models of psychiatric diseases. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  13. The Trier Social Stress Test as a paradigm to study how people respond to threat in social interactions

    Science.gov (United States)

    Frisch, Johanna U.; Häusser, Jan A.; Mojzisch, Andreas

    2015-01-01

    In our lives, we face countless situations in which we are observed and evaluated by our social interaction partners. Social-evaluative threat is frequently associated with strong neurophysiological stress reactions, in particular, an increase in cortisol levels. Yet, social variables do not only cause stress, but they can also buffer the neurophysiological stress response. Furthermore, social variables can themselves be affected by the threat or the threat-induced neurophysiological stress response. In order to study this complex interplay of social-evaluative threat, social processes and neurophysiological stress responses, a paradigm is needed that (a) reliably induces high levels of social-evaluative threat and (b) is extremely adaptable to the needs of the researcher. The Trier Social Stress Test (TSST) is a well-established paradigm in biopsychology that induces social-evaluative threat in the laboratory by subjecting participants to a mock job-interview. In this review, we aim at demonstrating the potential of the TSST for studying the complex interplay of social-evaluative threat, social processes and neurophysiological stress responses. PMID:25698987

  14. Update in the methodology of the chronic stress paradigm: internal control matters

    Directory of Open Access Journals (Sweden)

    Boyks Marco

    2011-04-01

    Full Text Available Abstract To date, the reliability of induction of a depressive-like state using chronic stress models is confronted by many methodological limitations. We believe that the modifications to the stress paradigm in mice proposed herein allow some of these limitations to be overcome. Here, we discuss a variant of the standard stress paradigm, which results in anhedonia. This anhedonic state was defined by a decrease in sucrose preference that was not exhibited by all animals. As such, we propose the use of non-anhedonic, stressed mice as an internal control in experimental mouse models of depression. The application of an internal control for the effects of stress, along with optimized behavioural testing, can enable the analysis of biological correlates of stress-induced anhedonia versus the consequences of stress alone in a chronic-stress depression model. This is illustrated, for instance, by distinct physiological and molecular profiles in anhedonic and non-anhedonic groups subjected to stress. These results argue for the use of a subgroup of individuals who are negative for the induction of a depressive phenotype during experimental paradigms of depression as an internal control, for more refined modeling of this disorder in animals.

  15. Update in the methodology of the chronic stress paradigm: internal control matters.

    Science.gov (United States)

    Strekalova, Tatyana; Couch, Yvonne; Kholod, Natalia; Boyks, Marco; Malin, Dmitry; Leprince, Pierre; Steinbusch, Harry Mw

    2011-04-27

    To date, the reliability of induction of a depressive-like state using chronic stress models is confronted by many methodological limitations. We believe that the modifications to the stress paradigm in mice proposed herein allow some of these limitations to be overcome. Here, we discuss a variant of the standard stress paradigm, which results in anhedonia. This anhedonic state was defined by a decrease in sucrose preference that was not exhibited by all animals. As such, we propose the use of non-anhedonic, stressed mice as an internal control in experimental mouse models of depression. The application of an internal control for the effects of stress, along with optimized behavioural testing, can enable the analysis of biological correlates of stress-induced anhedonia versus the consequences of stress alone in a chronic-stress depression model. This is illustrated, for instance, by distinct physiological and molecular profiles in anhedonic and non-anhedonic groups subjected to stress. These results argue for the use of a subgroup of individuals who are negative for the induction of a depressive phenotype during experimental paradigms of depression as an internal control, for more refined modeling of this disorder in animals.

  16. A new paradigm of quantifying ecosystem stress through chemical signatures

    Energy Technology Data Exchange (ETDEWEB)

    Kravitz, Ben [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, P.O. Box 999, MSIN K9-30 Richland Washington 99352 USA; Guenther, Alex B. [Department of Earth System Science, University of California Irvine, 3200 Croul Hall Street Irvine California 92697 USA; Gu, Lianhong [Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge Tennessee 37831 USA; Karl, Thomas [Institute of Atmospheric and Crysopheric Sciences, University of Innsbruck, Innrain 52f A-6020 Innsbruck Austria; Kaser, Lisa [National Center for Atmospheric Research, P.O. Box 3000 Boulder Colorado 80307 USA; Pallardy, Stephen G. [Department of Forestry, University of Missouri, 203 Anheuser-Busch Natural Resources Building Columbia Missouri 65211 USA; Peñuelas, Josep [CREAF, Cerdanyola del Vallès 08193 Catalonia Spain; Global Ecology Unit CREAF-CSIC-UAB, CSIC, Cerdanyola del Vallès 08193 Catalonia Spain; Potosnak, Mark J. [Department of Environmental Science and Studies, DePaul University, McGowan South, Suite 203 Chicago Illinois 60604 USA; Seco, Roger [Department of Earth System Science, University of California Irvine, 3200 Croul Hall Street Irvine California 92697 USA

    2016-11-01

    Stress-induced emissions of biogenic volatile organic compounds (VOCs) from terrestrial ecosystems may be one of the dominant sources of VOC emissions world-wide. Understanding the ecosystem stress response could reveal how ecosystems will respond and adapt to climate change and, in turn, quantify changes in the atmospheric burden of VOC oxidants and secondary organic aerosols. Here we argue, based on preliminary evidence from several opportunistic measurement sources, that chemical signatures of stress can be identified and quantified at the ecosystem scale. We also outline future endeavors that we see as next steps toward uncovering quantitative signatures of stress, including new advances in both VOC data collection and analysis of "big data."

  17. Teaching Introductory Geology by a Paradigm, Process and Product Approach

    Science.gov (United States)

    Reams, M.

    2008-12-01

    Students in introductory geology courses can easily become lost in the minutiae of terms and seemingly random ideas and theories. One way to avoid this and provide a holistic picture of each major subject area in a beginning course is to introduce, at the start of each section, the ruling paradigm, the processes, and resultant products. By use of these three Ps: paradigm, processes, and products, students have a reasonably complete picture of the subject area. If they knew nothing more than this simple construct, they would have an excellent perspective of the subject area. This provides a jumping off point for the instructor to develop the details. The three Ps can make course construction much more straightforward and complete. Students benefit since they have a clearer idea of what the subject is about and its importance. Retention may be improved and carryover to advanced courses may be aided. For faculty, the use of these three P's makes organizing a course more straightforward. Additionally, the instructor benefits include: 1. The main points are clearly stated, thus avoiding the problem of not covering the essential concepts. 2. The course topics hold together, pedagogically. There is significant opportunity for continuity of thought. 3. An outline is developed that is easily analyzed for holes or omissions. 4. A course emerges with a balance of topics, permitting appropriate time to be devoted to significant subject matter. 5. If a course is shared between faculty or passes from one faculty to another by semester or quarter, there is greater assurance that topics and concepts everyone agrees on can be adequately covered. 6. There is less guesswork involved in planning a course. New faculty have an approach that will make sense and allow them to feel less awash and more focused. In summary, taking time to construct a course utilizing the important paradigms, processes, and products can provide significant benefits to the instructor and the student. Material

  18. The Support-Stress Paradigm and Faculty Research Publication.

    Science.gov (United States)

    Neumann, Yorem; Finaly-Neumann, Edith

    1990-01-01

    A study developed and tested a model that examines the relative powers of support and work stress indicators in explaining faculty research productivity. Empirical examination indicates the model is most influential in physics, least in education, and that different indicators are significant in determining publication in hard and soft sciences.…

  19. Probabilities, beliefs, and dual processing: The paradigm shift in the psychology of reasoning

    OpenAIRE

    Elqayam, Shira; Over, D. E

    2012-01-01

    In recent years, the psychology of reasoning has been undergoing a paradigm shift, with general Bayesian, probabilistic approaches replacing the older, much more restricted binary logic paradigm. At the same time, dual processing theories have been gaining influence. We argue that these developments should be integrated and moreover that such integration is already underway. The new reasoning paradigm should be grounded in dual processing for its algorithmic level of analysis just as it uses ...

  20. The Eustress Paradigm: A Strategy for Decreasing Stress in Wilderness Adventure Programming.

    Science.gov (United States)

    Estrellas, Anjanette

    This essay proposes that stress has been misused in traditional adventure education and presents a new model of risk taking based on the literature on stress and feminist perspectives in adventure education. Proponents of the traditional adventure perspective state that the intentional use of stress is central to the change process in wilderness…

  1. Information processing psychology: A promising paradigm for research in science teaching

    Science.gov (United States)

    Stewart, James H.; Atkin, Julia A.

    Three research paradigms, those of Ausubel, Gagné and Piaget, have received a great deal of attention in the literature of science education. In this article a fourth paradigm is presented - an information processing psychology paradigm. The article is composed of two sections. The first section describes a model of memory developed by information processing psychologists. The second section describes how such a model could be used to guide science education research on learning and problem solving.Received: 19 October 1981

  2. Optimizing laboratory animal stress paradigms: The H-H* experimental design.

    Science.gov (United States)

    McCarty, Richard

    2017-01-01

    Major advances in behavioral neuroscience have been facilitated by the development of consistent and highly reproducible experimental paradigms that have been widely adopted. In contrast, many different experimental approaches have been employed to expose laboratory mice and rats to acute versus chronic intermittent stress. An argument is advanced in this review that more consistent approaches to the design of chronic intermittent stress experiments would provide greater reproducibility of results across laboratories and greater reliability relating to various neural, endocrine, immune, genetic, and behavioral adaptations. As an example, the H-H* experimental design incorporates control, homotypic (H), and heterotypic (H*) groups and allows for comparisons across groups, where each animal is exposed to the same stressor, but that stressor has vastly different biological and behavioral effects depending upon each animal's prior stress history. Implementation of the H-H* experimental paradigm makes possible a delineation of transcriptional changes and neural, endocrine, and immune pathways that are activated in precisely defined stressor contexts. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Paradigms of forensic science and legal process: a critical diagnosis.

    Science.gov (United States)

    Roberts, Paul

    2015-08-05

    This article reconsiders the relationship between criminal adjudication and forensic expertise in the light of 'new paradigms' of forensic practice and recent law reform. It briefly summarizes conventional wisdom on the typical shortcomings of forensic science and other expert evidence, as a springboard for a more searching critical diagnosis of longstanding maladies. The fundamentally jurisdictional nature of law is emphasized, and some implications for expert testimony noted. English law's traditionally adversarial model of criminal procedure is then reassessed, taking account of a proper understanding of its normative structure and modern development, and drawing on comparative legal research and theorizing to obtain a more rounded second opinion. In conclusion, some avenues for intelligent prescription are canvassed, highlighting the importance of promoting and facilitating effective communication between experts, lawyers and courts, and prioritizing modest practical remedies over radical surgery. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  4. Early life stress paradigms in rodents: potential animal models of depression?

    Science.gov (United States)

    Schmidt, Mathias V; Wang, Xiao-Dong; Meijer, Onno C

    2011-03-01

    While human depressive illness is indeed uniquely human, many of its symptoms may be modeled in rodents. Based on human etiology, the assumption has been made that depression-like behavior in rats and mice can be modulated by some of the powerful early life programming effects that are known to occur after manipulations in the first weeks of life. Here we review the evidence that is available in literature for early life manipulation as risk factors for the development of depression-like symptoms such as anhedonia, passive coping strategies, and neuroendocrine changes. Early life paradigms that were evaluated include early handling, separation, and deprivation protocols, as well as enriched and impoverished environments. We have also included a small number of stress-related pharmacological models. We find that for most early life paradigms per se, the actual validity for depression is limited. A number of models have not been tested with respect to classical depression-like behaviors, while in many cases, the outcome of such experiments is variable and depends on strain and additional factors. Because programming effects confer vulnerability rather than disease, a number of paradigms hold promise for usefulness in depression research, in combination with the proper genetic background and adult life challenges.

  5. Navon's classical paradigm concerning local and global processing relates systematically to visual object classification performance.

    Science.gov (United States)

    Gerlach, Christian; Poirel, Nicolas

    2018-01-10

    Forty years ago David Navon tried to tackle a central problem in psychology concerning the time course of perceptual processing: Do we first see the details (local level) followed by the overall outlay (global level) or is it rather the other way around? He did this by developing a now classical paradigm involving the presentation of compound stimuli; large letters composed of smaller letters. Despite the usefulness of this paradigm it remains uncertain whether effects found with compound stimuli relate directly to visual object recognition. It does so because compound stimuli are not actual objects but rather formations of elements and because the elements that form the global shape of compound stimuli are not features of the global shape but rather objects in their own right. To examine the relationship between performance on Navon's paradigm and visual object processing we derived two indexes from Navon's paradigm that reflect different aspects of the relationship between global and local processing. We find that individual differences on these indexes can explain a considerable amount of variance in two standard object classification paradigms; object decision and superordinate categorization, suggesting that Navon's paradigm does relate to visual object processing.

  6. Acute Stress Influences Neural Circuits of Reward Processing

    Directory of Open Access Journals (Sweden)

    Anthony John Porcelli

    2012-11-01

    Full Text Available People often make decisions under aversive conditions such as acute stress. Yet, less is known about the process in which acute stress can influence decision-making. A growing body of research has established that reward-related information associated with the outcomes of decisions exerts a powerful influence over the choices people make and that an extensive network of brain regions, prominently featuring the striatum, is involved in the processing of this reward-related information. Thus, an important step in research on the nature of acute stress’ influence over decision-making is to examine how it may modulate responses to rewards and punishments within reward-processing neural circuitry. In the current experiment, we employed a simple reward processing paradigm – where participants received monetary rewards and punishments – known to evoke robust striatal responses. Immediately prior to performing each of two task runs, participants were exposed to acute stress (i.e., cold pressor or a no stress control procedure in a between-subjects fashion. No stress group participants exhibited a pattern of activity within the dorsal striatum and orbitofrontal cortex consistent with past research on outcome processing – specifically, differential responses for monetary rewards over punishments. In contrast, acute stress group participants’ dorsal striatum and orbitofrontal cortex demonstrated decreased sensitivity to monetary outcomes and a lack of differential activity. These findings provide insight into how neural circuits may process rewards and punishments associated with simple decisions under acutely stressful conditions.

  7. Stress, cues, and eating behavior. Using drug addiction paradigms to understand motivation for food.

    Science.gov (United States)

    Stojek, Monika Kardacz; Fischer, Sarah; MacKillop, James

    2015-09-01

    Eating patterns that lead to overconsumption of high fat, high sugar (HFHS) foods share similar features with addictive behaviors. Application of addiction paradigms, such as stress inductions, cue reactivity and behavioral economic assessments, to the study of motivation for HFHS food consumption may be a promising means of understanding food consumption. To date, few studies have investigated the interaction of stress and environmental cues on craving, and no study leveraged the state relative reinforcing value of foods (RRVfood) under varying conditions of affective states, the foci of the current study. This study used a mixed factorial design (Mood Induction: Neutral, Stress; Cues: Neutral, Food) with repeated measures on time (Baseline, Post-Mood Induction, Post-Cue Exposure). Participants (N = 133) were community adults who endorsed liking of HFHS snacks but denied eating pathology. The primary DVs were subjective craving and RRVfood. Negative and positive affect (NA, PA), the amount of food consumed, and latency to first bite were also examined. Participants in the Stress condition reported no change in craving or RRVfood. Exposure to food cues significantly increased participants' craving and RRVfood, but an interaction of stress and cues was not present. Participants did not differ on how many calories they consumed based on exposure to stress or food cues, but participants in the food cues condition had a shorter latency to the first bite of food. This study highlights the importance of environmental cues in food motivation. It also demonstrates the utility of using RRVfood to further characterize food motivation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Process for measuring residual stresses

    International Nuclear Information System (INIS)

    Elfinger, F.X.; Peiter, A.; Theiner, W.A.; Stuecker, E.

    1982-01-01

    No single process can at present solve all problems. The complete destructive processes only have a limited field of application, as the component cannot be reused. However, they are essential for the basic determination of stress distributions in the field of research and development. Destructive and non-destructive processes are mainly used if investigations have to be carried out on original components. With increasing component size, the part of destructive tests becomes smaller. The main applications are: quality assurance, testing of manufactured parts and characteristics of components. Among the non-destructive test procedures, X-raying has been developed most. It gives residual stresses on the surface and on surface layers near the edges. Further development is desirable - in assessment - in measuring techniques. Ultrasonic and magnetic crack detection processes are at present mainly used in research and development, and also in quality assurance. Because of the variable depth of penetration and the possibility of automation they are gaining in importance. (orig./RW) [de

  9. Logistic paradigm for industrial solid waste treatment processes

    Directory of Open Access Journals (Sweden)

    Janusz Grabara

    2014-12-01

    Full Text Available Due to the fact that industrial waste are a growing problem, both economic and environmental as their number is increasing every year, it is important to take measures to correctly dealing wi th industrial waste. This article presents the descriptive model of logistics processes concerning the management of industrial waste. In this model the flow of waste begins in the place of production and ends at their disposal. The article presents the concept of logistics model in graphical form together with an analysis of individual processes and their linkages, and opportunities to improve flow of industrial waste streams. Furthermore, the model allows for justification of the relevance of use logistics and its processes for waste management

  10. Business Process Management Systems: Hype or New Paradigm.

    NARCIS (Netherlands)

    J.P.P. Ravesteijn

    2007-01-01

    Business Process Management Systems (BPMSs) are increasingly implemented in and across organizations. There is much talk on BPMSs, and software vendors and IT-consultancy companies are leveraging this. In this paper we provide an investigation on the originality of BPMSs. We identify concepts,

  11. On stress/strain shielding and the material stiffness paradigm for dental implants.

    Science.gov (United States)

    Korabi, Raoof; Shemtov-Yona, Keren; Rittel, Daniel

    2017-10-01

    Stress shielding considerations suggest that the dental implant material's compliance should be matched to that of the host bone. However, this belief has not been confirmed from a general perspective, either clinically or numerically. To characterize the influence of the implant stiffness on its functionality using the failure envelope concept that examines all possible combinations of mechanical load and application angle for selected stress, strain and displacement-based bone failure criteria. Those criteria represent bone yielding, remodeling, and implant primary stability, respectively MATERIALS AND METHODS: We performed numerical simulations to generate failure envelopes for all possible loading configurations of dental implants, with stiffness ranging from very low (polymer) to extremely high, through that of bone, titanium, and ceramics. Irrespective of the failure criterion, stiffer implants allow for improved implant functionality. The latter reduces with increasing compliance, while the trabecular bone experiences higher strains, albeit of an overall small level. Micromotions remain quite small irrespective of the implant's stiffness. The current paradigm favoring reduced implant material's stiffness out of concern for stress or strain shielding, or even excessive micromotions, is not supported by the present calculations, that point exactly to the opposite. © 2017 Wiley Periodicals, Inc.

  12. Logistic paradigm for industrial solid waste treatment processes

    OpenAIRE

    Janusz Grabara; Ioan Constantin Dima

    2014-01-01

    Due to the fact that industrial waste are a growing problem, both economic and environmental as their number is increasing every year, it is important to take measures to correctly dealing wi th industrial waste. This article presents the descriptive model of logistics processes concerning the management of industrial waste. In this model the flow of waste begins in the place of production and ends at their disposal. The article presents the concept of logistics model in graphical form...

  13. Priming paradigm reveals harmonic structure processing in congenital amusia.

    Science.gov (United States)

    Tillmann, Barbara; Gosselin, Nathalie; Bigand, Emmanuel; Peretz, Isabelle

    2012-09-01

    Deficits for pitch structure processing in congenital amusia has been mostly reported for melodic stimuli and explicit judgments. The present study investigated congenital amusia with harmonic stimuli and a priming task. Amusic and control participants performed a speeded phoneme discrimination task on sung chord sequences. The target phoneme was sung either on a functionally important chord (tonic chord, referred to as "related target") or a less important one (subdominant chord, referred to as "less-related target"). Correct response times were faster when the target phoneme was sung on tonic chords rather than on subdominant chords, and this effect was less pronounced, albeit significant, in amusic participants. These data report for the first time a deficit in congenital amusia for chord processing, but also provide evidence that, despite this deficit, amusic individuals have internalized sophisticated syntactic-like functions of chords in the Western tonal musical system. This finding suggests that thanks to this musical knowledge, amusic individuals could develop expectancies for musical events, and, presumably, follow the tension-relaxation schemas in Western tonal music, which also influence emotional responses to music. Copyright © 2012 Elsevier Srl. All rights reserved.

  14. Lexical influence on stress processing in a fixed-stress language.

    Science.gov (United States)

    Garami, Linda; Ragó, Anett; Honbolygó, Ferenc; Csépe, Valéria

    2017-07-01

    In the present study, we investigate how lexicality affects the processing of suprasegmental features at the word level. In contrast to earlier studies which analyzed the role of either segmental or suprasegmental feature in language processing our aim was to investigate the effect of the lexical status on the processing of violated stress pattern defined by linguistic rules. We have conducted a passive oddball ERP experiment, presenting a frequent CVCV word with legal (familiar) and illegal (unfamiliar) stress patterns. Former results obtained with pseudo-words in a similar paradigm enabled to assess the influence of lexical information on stress processing. The presence of lexically relevant information resulted in different ERP patterns compared to those obtained with pseudo-words. We obtained two consecutive MMN responses to the illegally stressed words while violating the illegal stress pattern with a legal one the deviant stimulus elicited two consecutive MMN responses as well. In the latter condition lexicality clearly enhanced the comparison of prosodic information between standard and deviant stimuli, as these components very completely missing when presenting pseudo-words. We interpret the results that lexicality acts as a filter since in the absence of lexical familiarity unfamiliar stress patterns are discriminated better. Our results highlight that even when stress is fully predictable, it is taken into account during pre-attentive processing of linguistic input. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Process versus outcome: challenges of the chiropractic wellness paradigm

    Science.gov (United States)

    Russell, Eric G.

    2010-01-01

    Objective The purpose of this article is to discuss the term wellness in the context of the philosophy of chiropractic. Discussion PubMed and Index to Chiropractic Literature show an upward trend in use of the term wellness. Wellness may be used differently depending upon the profession and may be considered a process by some and an outcome by others. Conclusion There appears to be no consensus on the definition of wellness or how it is being used. Wellness is not exclusive to chiropractic, and wellness is not synonymous with health, although is often used that way. Wellness is a societal trend, and chiropractic as a health care profession may be a good fit for this concept. PMID:22693468

  16. The Viewpoint Paradigm: a semiotic based approach for the intelligibility of a cooperative designing process

    Directory of Open Access Journals (Sweden)

    Pierre-Jean Charrel

    2002-11-01

    Full Text Available The concept of viewpoint is studied in the field of the modelling and the knowledge management concerned in the upstream phases of a designing process. The concept is approached by semiotics, i.e. in dealing with the requirements so that an actor gives sense to an object. This gives means to transform the intuitive concepts of viewpoint and relation between viewpoints into the Viewpoint Paradigm: the sense of an object is the integration of the viewpoints which exert on it. The elements of this paradigm are integrated in a general model, which defines two concepts formally: Viewpoint and Correlation of viewpoints. The Viewpoint Paradigm is then implemented in operational concerns which are related with the intelligibility of the designing process. Two models of viewpoint and correlation are proposed. They raise of viewpoints management such as one can identify them in the written documents of a project.

  17. Exact Dynamics via Poisson Process: a unifying Monte Carlo paradigm

    Science.gov (United States)

    Gubernatis, James

    2014-03-01

    A common computational task is solving a set of ordinary differential equations (o.d.e.'s). A little known theorem says that the solution of any set of o.d.e.'s is exactly solved by the expectation value over a set of arbitary Poisson processes of a particular function of the elements of the matrix that defines the o.d.e.'s. The theorem thus provides a new starting point to develop real and imaginary-time continous-time solvers for quantum Monte Carlo algorithms, and several simple observations enable various quantum Monte Carlo techniques and variance reduction methods to transfer to a new context. I will state the theorem, note a transformation to a very simple computational scheme, and illustrate the use of some techniques from the directed-loop algorithm in context of the wavefunction Monte Carlo method that is used to solve the Lindblad master equation for the dynamics of open quantum systems. I will end by noting that as the theorem does not depend on the source of the o.d.e.'s coming from quantum mechanics, it also enables the transfer of continuous-time methods from quantum Monte Carlo to the simulation of various classical equations of motion heretofore only solved deterministically.

  18. Perceived workplace harassment experiences and problem drinking among physicians: broadening the stress/alienation paradigm.

    Science.gov (United States)

    Richman, J A; Flaherty, J A; Rospenda, K M

    1996-03-01

    Sociologists who embrace the stress or alienation paradigms generally focus on explaining problem drinking in low status occupations. By contrast, this paper argues that a broadened conceptualization of stress and alienation which incorporates abusive work relationships has utility for explaining male and female drinking outcomes in both high and low status occupations. We provide empirical data on the relationship between perceived abusive experiences and drinking outcomes in a cohort of male and female physicians in their internship year of training. The data show that perceived sexual harassment, discriminatory treatment and psychological humiliation relate to various drinking outcomes in men and women, controlling for drinking prior to the internship year. While females were more likely to report experiencing abuse, these perceived experiences had deleterious effects on drinking outcomes for both genders. Personal vulnerability (narcissism) brought into the training environment somewhat influenced the later reporting of abusive experiences by males but not by females. Regression analyses showed that, for both males and females, work-place abusive experiences in interaction with personality vulnerability best explained drinking outcomes. The implications of these results for the design of future alcohol-related work-place studies are discussed.

  19. Whole-word frequency and inflectional paradigm size facilitate Estonian case-inflected noun processing.

    Science.gov (United States)

    Lõo, Kaidi; Järvikivi, Juhani; Baayen, R Harald

    2018-06-01

    Estonian is a morphologically rich Finno-Ugric language with nominal paradigms that have at least 28 different inflected forms but sometimes more than 40. For languages with rich inflection, it has been argued that whole-word frequency, as a diagnostic of whole-word representations, should not be predictive for lexical processing. We report a lexical decision experiment, showing that response latencies decrease both with frequency of the inflected form and its inflectional paradigm size. Inflectional paradigm size was also predictive of semantic categorization, indicating it is a semantic effect, similar to the morphological family size effect. These findings fit well with the evidence for frequency effects of word n-grams in languages with little inflectional morphology, such as English. Apparently, the amount of information on word use in the mental lexicon is substantially larger than was previously thought. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Stress as a one-armed bandit: Differential effects of stress paradigms on the morphology, neurochemistry and behavior in the rodent amygdala

    Science.gov (United States)

    Wilson, Marlene A.; Grillo, Claudia A.; Fadel, Jim R.; Reagan, Lawrence P.

    2015-01-01

    Neuroplasticity may be defined as the ability of the central nervous system (CNS) to respond to changes in the internal and external environment and it is well established that some stimuli have the ability to facilitate or impair neuroplasticity depending on the pre-existing milieu. A classic example of a stimulus that can both facilitate and impair neuroplasticity is stress. Indeed, the ability of CNS to respond to acute stress is often dependent upon the prior stress history of the individual. While responses to acute stress are often viewed as adaptive in nature, stress reactivity in subjects with prior chronic stress experiences are often linked to neuropsychiatric disorders, including major depressive disorder, post-traumatic stress disorder (PTSD) and anxiety. In rodent studies, chronic stress exposure produces structural and functional alterations in the hippocampus and medial prefrontal cortex that are consistent across different types of stress paradigms. Conversely, the amygdala appears to exhibit differential structural and functional responses to stress that are dependent on a variety of factors, including the type of stressor performed and the duration of the stress paradigm. This is most evident in output measures including morphological analysis of amygdala neurons, measurement of glutamatergic tone in amygdalar subdivisions and the analysis of amygdala-centric behaviors. Accordingly, this review will provide an overview of the effects of stress on the structural and functional plasticity of the rodent amygdala, especially in relation to the differential effects of repeated or chronic stress paradigms on dendritic architecture, neurochemistry of the glutamatergic system and behavior. PMID:26844236

  1. Stress as a one-armed bandit: Differential effects of stress paradigms on the morphology, neurochemistry and behavior in the rodent amygdala

    Directory of Open Access Journals (Sweden)

    Marlene A. Wilson

    2015-01-01

    Full Text Available Neuroplasticity may be defined as the ability of the central nervous system (CNS to respond to changes in the internal and external environment and it is well established that some stimuli have the ability to facilitate or impair neuroplasticity depending on the pre-existing milieu. A classic example of a stimulus that can both facilitate and impair neuroplasticity is stress. Indeed, the ability of CNS to respond to acute stress is often dependent upon the prior stress history of the individual. While responses to acute stress are often viewed as adaptive in nature, stress reactivity in subjects with prior chronic stress experiences are often linked to neuropsychiatric disorders, including major depressive disorder, post-traumatic stress disorder (PTSD and anxiety. In rodent studies, chronic stress exposure produces structural and functional alterations in the hippocampus and medial prefrontal cortex that are consistent across different types of stress paradigms. Conversely, the amygdala appears to exhibit differential structural and functional responses to stress that are dependent on a variety of factors, including the type of stressor performed and the duration of the stress paradigm. This is most evident in output measures including morphological analysis of amygdala neurons, measurement of glutamatergic tone in amygdalar subdivisions and the analysis of amygdala-centric behaviors. Accordingly, this review will provide an overview of the effects of stress on the structural and functional plasticity of the rodent amygdala, especially in relation to the differential effects of repeated or chronic stress paradigms on dendritic architecture, neurochemistry of the glutamatergic system and behavior.

  2. Resident intruder paradigm-induced aggression relieves depressive-like behaviors in male rats subjected to chronic mild stress

    Science.gov (United States)

    Wei, Sheng; Ji, Xiao-wei; Wu, Chun-ling; Li, Zi-fa; Sun, Peng; Wang, Jie-qiong; Zhao, Qi-tao; Gao, Jie; Guo, Ying-hui; Sun, Shi-guang; Qiao, Ming-qi

    2014-01-01

    Background Accumulating epidemiological evidence shows that life event stressors are major vulnerability factors for psychiatric diseases such as major depression. It is also well known that the resident intruder paradigm (RIP) results in aggressive behavior in male rats. However, it is not known how resident intruder paradigm-induced aggression affects depressive-like behavior in isolated male rats subjected to chronic mild stress (CMS), which is an animal model of depression. Material/Methods Male Wistar rats were divided into 3 groups: non-stressed controls, isolated rats subjected to the CMS protocol, and resident intruder paradigm-exposed rats subjected to the CMS protocol. Results In the sucrose intake test, ingestion of a 1% sucrose solution by rats in the CMS group was significantly lower than in control and CMS+RIP rats after 3 weeks of stress. In the open-field test, CMS rats had significantly lower open-field scores compared to control rats. Furthermore, the total scores given the CMS group were significantly lower than in the CMS+RIP rats. In the forced swimming test (FST), the immobility times of CMS rats were significantly longer than those of the control or CMS+RIP rats. However, no differences were observed between controls and CMS+RIP rats. Conclusions Our data show that aggressive behavior evoked by the resident intruder paradigm could relieve broad-spectrum depressive-like behaviors in isolated adult male rats subjected to CMS. PMID:24911067

  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. THE STRESS RESISTANCE OF STUDENTS. THE PARADIGM OF SUBJECT PERSONALITY SELF- ORGANIZATION

    Directory of Open Access Journals (Sweden)

    Sergey I. Dyakov

    2016-01-01

    Full Text Available The aim of the investigation is to consider a problem of stress resistance of students in the context of subject self-organization of the personality. Methods. The following methods of research are used: questioning; psychological and diagnostic tests «Tolerance of Uncertainty» (NTN and «Personal Factors of Decisions» (PFD by T. V. Kornilova; original experimental experiences – «Coding», a technique of a self-assessment (scaling and «A locus control». While data processing the methods of mathematical statistics (SPSS 12 package – the correlation analysis of Pearson and the factorial analysis with rotation use a component by «verimax» method are applied. Results and scientific novelty. Types of subjectivity and strategy of stress resistance are allocated. The nature and a role of the emotional and stressful mechanism having information and semantic properties in its basis are disclosed. Communication of irresponsible mechanisms of mentality with the sphere of consciousness in the context of subjectivity of the personality is shown. Mechanisms of emotional and rational self-control of system of mental self-organization of the person are presented. The statistical and qualitative data opening communications between properties of subjectivity and stress resistance of the personality are empirically obtained. Variation of the relations and also types of subjectivity and stress resistance emphasized based on the results of the presented research. Original (author’s methods of studying of subjectivity and factors of stress resistance are presented. Practical significance. The revealed factors of subject self-organization reveal the stress-producing directions of the environment and the relation of the personality to situations of changes and uncertainty: and also indicate subject properties of resistance to stress which need to be developed to increase the level of health of students, to reduce risk of deviance and delinquency of

  5. Anhedonia but not passive floating is an indicator of depressive-like behavior in two chronic stress paradigms.

    Science.gov (United States)

    Stepanichev, Mikhail Yu; Tishkina, Anna O; Novikova, Margarita R; Levshina, Irina P; Freiman, Sofiya V; Onufriev, Mikhail V; Levchenko, Olga A; Lazareva, Natalia A; Gulyaeva, Natalia V

    2016-01-01

    Depression is the most common form of mental disability in the world. Depressive episodes may be precipitated by severe acute stressful events or by mild chronic stressors. Studies on the mechanisms of depression require both appropriate experimental models (most of them based on the exposure of animals to chronic stressors), and appropriate tests for assessment of depressive states. In this study male Wistar rats were exposed to two different chronic stress paradigms: an eight-week chronic unpredictable mild stress or a two-week combined chronic stress. The behavioral effects of stress were evaluated using sucrose preference, forced swim and open field tests. After the exposure to chronic unpredictable mild stress, anhedonia was developed, activity in the open field increased, while no changes in the duration of passive floating could be detected. After chronic combined stress, anhedonia was also evident, whereas behavior in the open field and forced swim test did not change. The levels of corticosterone in the blood and brain structures involved in stress-response did not differ from control in both experiments. The absence of significant changes in corticosterone levels and passive floating may be indicative of the adaptation of animals to chronic stress. Anhedonia appears to be a more sensitive indicator of depressive-like behavioral effects of chronic stress as compared to behavior in the forced swim or open field tests.

  6. Are Children's Memory Illusions Created Differently from Those of Adults? Evidence from Levels-of-Processing and Divided Attention Paradigms

    Science.gov (United States)

    Wimmer, Marina C.; Howe, Mark L.

    2010-01-01

    In two experiments, we investigated the robustness and automaticity of adults' and children's generation of false memories by using a levels-of-processing paradigm (Experiment 1) and a divided attention paradigm (Experiment 2). The first experiment revealed that when information was encoded at a shallow level, true recognition rates decreased for…

  7. The resident-intruder paradigm : a standardized test for aggression, violence and social stress

    NARCIS (Netherlands)

    Koolhaas, Jacob; Coppens, Caroline M.; de Boer, Sietse F.; Buwalda, Bauke; Meerlo, Peter; Timmermans, Paul J. A.

    2013-01-01

    This video publication explains in detail the experimental protocol of the resident-intruder paradigm in rats. This test is a standardized method to measure offensive aggression and defensive behavior in a semi natural setting. The most important behavioral elements performed by the resident and the

  8. Stress and Arousal Symptoms in Individuals and Groups - Persian Gulf War Symptoms as a Paradigm

    National Research Council Canada - National Science Library

    Dine, Sarah

    1999-01-01

    ... and other stresses of military life. It is our conclusion that the time has come to move away from the general and only partially meaningful definitions of "stress" to more tightly operational and measurable ones...

  9. Stress and Arousal Symptoms in Individuals and Groups - Persian Gulf War Symptoms as a Paradigm

    National Research Council Canada - National Science Library

    Dine, Sarah

    1999-01-01

    .... This report makes a series of recommendations, some general, and some quasi-specific for future patterns of research into the somatic and other consequences of combat stress, deployment stress...

  10. Effects of post-encoding stress on performance in the DRM false memory paradigm

    OpenAIRE

    Pardilla-Delgado, Enmanuelle; Alger, Sara E.; Cunningham, Tony J.; Kinealy, Brian; Payne, Jessica D.

    2016-01-01

    Numerous studies have investigated how stress impacts veridical memory, but how stress influences false memory formation remains poorly understood. In order to target memory consolidation specifically, a psychosocial stress (TSST) or control manipulation was administered following encoding of 15 neutral, semantically related word lists (DRM false memory task) and memory was tested 24 h later. Stress decreased recognition of studied words, while increasing false recognition of semantically rel...

  11. Stress and Arousal Symptoms in Individuals and Groups - Persian Gulf War Symptoms as a Paradigm.

    Science.gov (United States)

    1999-09-01

    Symptoms." Psychological Medicine, 1991:21: 1029-1045, quotation from pp. 1040-1041. 18Kellner R., "Functional Somatic Symptoms and Hypochondriasis ...quasi-specific for future patterns of research into the somatic and other consequences of combat stress, deployment stress and other stresses of...psychiatric folklore. Much of the earlier research into the somatic consequences of stress and indeed into medicine as a whole, was correlational in

  12. Effects of Post-Encoding Stress on Performance in the DRM False Memory Paradigm

    Science.gov (United States)

    Pardilla-Delgado, Enmanuelle; Alger, Sara E.; Cunningham, Tony J.; Kinealy, Brian; Payne, Jessica D.

    2016-01-01

    Numerous studies have investigated how stress impacts veridical memory, but how stress influences false memory formation remains poorly understood. In order to target memory consolidation specifically, a psychosocial stress (TSST) or control manipulation was administered following encoding of 15 neutral, semantically related word lists (DRM false…

  13. Levels of processing influences both recollection and familiarity: evidence from a modified remember-know paradigm.

    Science.gov (United States)

    Sheridan, Heather; Reingold, Eyal M

    2012-03-01

    A modified Remember/Know (RK) paradigm was used to investigate reported subjective awareness during retrieval. Levels of processing (shallow vs. deep) was manipulated at study. Word pairs (old/new or new/new) were presented during test trials, and participants were instructed to respond "remember" if they recollected one of the two words, "know" if the word was familiar in the absence of recollection, or "new" if they judged both words to be new. Participants were then required to indicate which of the 2 words was old (2AFC recognition). With the standard RK proportions, deeper processing at study increased remember proportions and decreased know proportions, but this dissociation was not shown with the 2AFC proportion correct measure which instead demonstrated robust LOP effects for both remember and know trials, suggesting that the know proportion measure severely distorts the nature of LOP effects on familiarity. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. Learning about Expectation Violation from Prediction Error Paradigms – A Meta-Analysis on Brain Processes Following a Prediction Error

    Directory of Open Access Journals (Sweden)

    Lisa D’Astolfo

    2017-07-01

    Full Text Available Modifying patients’ expectations by exposing them to expectation violation situations (thus maximizing the difference between the expected and the actual situational outcome is proposed to be a crucial mechanism for therapeutic success for a variety of different mental disorders. However, clinical observations suggest that patients often maintain their expectations regardless of experiences contradicting their expectations. It remains unclear which information processing mechanisms lead to modification or persistence of patients’ expectations. Insight in the processing could be provided by Neuroimaging studies investigating prediction error (PE, i.e., neuronal reactions to non-expected stimuli. Two methods are often used to investigate the PE: (1 paradigms, in which participants passively observe PEs (”passive” paradigms and (2 paradigms, which encourage a behavioral adaptation following a PE (“active” paradigms. These paradigms are similar to the methods used to induce expectation violations in clinical settings: (1 the confrontation with an expectation violation situation and (2 an enhanced confrontation in which the patient actively challenges his expectation. We used this similarity to gain insight in the different neuronal processing of the two PE paradigms. We performed a meta-analysis contrasting neuronal activity of PE paradigms encouraging a behavioral adaptation following a PE and paradigms enforcing passiveness following a PE. We found more neuronal activity in the striatum, the insula and the fusiform gyrus in studies encouraging behavioral adaptation following a PE. Due to the involvement of reward assessment and avoidance learning associated with the striatum and the insula we propose that the deliberate execution of action alternatives following a PE is associated with the integration of new information into previously existing expectations, therefore leading to an expectation change. While further research is needed

  15. Biogeochemical processes on tree islands in the greater everglades: Initiating a new paradigm

    Science.gov (United States)

    Wetzel, P.R.; Sklar, Fred H.; Coronado, C.A.; Troxler, T.G.; Krupa, S.L.; Sullivan, P.L.; Ewe, S.; Price, R.M.; Newman, S.; Orem, W.H.

    2011-01-01

    Scientists' understanding of the role of tree islands in the Everglades has evolved from a plant community of minor biogeochemical importance to a plant community recognized as the driving force for localized phosphorus accumulation within the landscape. Results from this review suggest that tree transpiration, nutrient infiltration from the soil surface, and groundwater flow create a soil zone of confluence where nutrients and salts accumulate under the head of a tree island during dry periods. Results also suggest accumulated salts and nutrients are flushed downstream by regional water flows during wet periods. That trees modulate their environment to create biogeochemical hot spots and strong nutrient gradients is a significant ecological paradigm shift in the understanding of the biogeochemical processes in the Everglades. In terms of island sustainability, this new paradigm suggests the need for distinct dry-wet cycles as well as a hydrologic regime that supports tree survival. Restoration of historic tree islands needs further investigation but the creation of functional tree islands is promising. Copyright ?? 2011 Taylor & Francis Group, LLC.

  16. Stress modulation of cognitive and affective processes

    Science.gov (United States)

    CAMPEAU, SERGE; LIBERZON, ISRAEL; MORILAK, DAVID; RESSLER, KERRY

    2012-01-01

    This review summarizes the major discussion points of a symposium on stress modulation of cognitive and affective processes, which was held during the 2010 workshop on the neurobiology of stress (Boulder, CO, USA). The four discussants addressed a number of specific cognitive and affective factors that are modulated by exposure to acute or repeated stress. Dr David Morilak discussed the effects of various repeated stress situations on cognitive flexibility, as assessed with a rodent model of attentional set-shifting task, and how performance on slightly different aspects of this test is modulated by different prefrontal regions through monoaminergic neurotransmission. Dr Serge Campeau summarized the findings of several studies exploring a number of factors and brain regions that regulate habituation of various autonomic and neuroendocrine responses to repeated audiogenic stress exposures. Dr Kerry Ressler discussed a body of work exploring the modulation and extinction of fear memories in rodents and humans, especially focusing on the role of key neurotransmitter systems including excitatory amino acids and brain-derived neurotrophic factor. Dr Israel Liberzon presented recent results on human decision-making processes in response to exogenous glucocorticoid hormone administration. Overall, these discussions are casting a wider framework on the cognitive/affective processes that are distinctly regulated by the experience of stress and some of the brain regions and neurotransmitter systems associated with these effects. PMID:21790481

  17. Exogenous daytime melatonin modulates response of adolescent mice in a repeated unpredictable stress paradigm.

    Science.gov (United States)

    Onaolapo, Adejoke Yetunde; Adebayo, Ajibola Nurudeen; Onaolapo, Olakunle James

    2017-02-01

    The immediate and short-term behavioural and physiological implications of exposure to stressful scenarios in the adolescent period are largely unknown; however, increases in occurrence of stress-related physiological and psychological disorders during puberty highlight the need to study substances that may modulate stress reactivity during a crucial stage of maturation. Seven groups of mice (12-15 g each) were administered distilled water (DW) (non-stressed and stressed controls), sertraline (10 mg/kg), diazepam (2 mg/kg) or one of three doses of melatonin (5, 10 and 15 mg/kg). Mice were exposed to 30 min of chronic mild stress (25 min of cage shaking, cage tilting, handling and 5 min of forced swimming in tepid warm water at 25 °C, in a random order) after administration of DW or drugs, daily for 21 days. Behavioural assessments were conducted on day 1 and day 21 (after which mice were sacrificed, blood taken for estimation of corticosterone levels and brain homogenates used for estimation of antioxidant activities). Administration of melatonin resulted in an increase in horizontal locomotion and self-grooming, while rearing showed a time-dependent increase, compared to non-stress and stress controls. Working memory improved with increasing doses of melatonin (compared to controls and diazepam); in comparison to setraline however, working memory decreased. A dose-related anxiolytic effect is seen when melatonin is compared to non-stressed and stressed controls. Melatonin administration reduced the systemic/oxidant response to repeated stress. Administration of melatonin in repeatedly stressed adolescent mice was associated with improved central excitation, enhancement of working memory, anxiolysis and reduced systemic response to stress.

  18. DEFINITION AND DEVELOPMENT OF COMPETENCES: A PARADIGM IN THE STRATEGIC PROCESS

    Directory of Open Access Journals (Sweden)

    Glauco Corbari Corrêa

    2015-09-01

    Full Text Available This study aims to examine the issue of defining and developing of competences and their definitive insertion in the strategic process of organizations. The relevance is evident, since in the globalized world of the twenty-first century new skills are being required of workers, employers and citizens in general. The understanding of the current dynamics of competence-based management becomes important, since it can be approached as a set of knowledge, skills and attitudes that accredit an individual to perform a certain function or, on the other hand, as achievements of the citizen in his/her work, i.e., the first definition focuses on the acquired potential and the second one lies in the effected performance. The paper also identifies the methods and techniques for assessing competences, in order to obtain a more objective view of human potential that exists in certain company and what are the needs for updating. Moreover, it attempts to present the importance of emotional competence in the strategic process and its close links with the concept of emotional intelligence, as well as it aims to demonstrate the importance of the irrevocable insertion of competences as a paradigm in the strategic process. Keywords: Competences. Management. Organizations. Globalization. Strategic Process.

  19. Paradigm shifts: using a participatory leadership process to redesign health systems.

    Science.gov (United States)

    Saleeby, Erin; Holschneider, Christine H; Singhal, Rita

    2014-12-01

    Physicians have increasingly given up private practices to become members of, and key stakeholders in, large healthcare systems. These systems are currently transforming to meet the Triple Aim: guaranteeing the equitable provision of high-quality, evidence-based care at a reasonable cost. Participatory leadership is an organizational change theory that engages key stakeholders as architects in the transformation process. This review highlights the utility of this leadership strategy in designing care for women's health. Our blueprint describing participatory leadership theory in women's health systems change is discussed in three case studies, highlighting what we call the six Ps of participatory leadership: participants, principles, purpose, process, and power. The 'sixth P', product, can then be substantially influential in changing the paradigm of care. Obstetrics and gynecology is increasingly practiced in large health systems responsible for the health of populations. Innovations in clinical practice impact care at the level of the individual. In order for advances in clinical practice to reach broad populations of women, they must be integrated into a delivery system. Physician engagement in leadership during this time of system transformation is of critical importance.

  20. Effects of acute psychosocial stress on neural activity to emotional and neutral faces in a face recognition memory paradigm.

    Science.gov (United States)

    Li, Shijia; Weerda, Riklef; Milde, Christopher; Wolf, Oliver T; Thiel, Christiane M

    2014-12-01

    Previous studies have shown that acute psychosocial stress impairs recognition of declarative memory and that emotional material is especially sensitive to this effect. Animal studies suggest a central role of the amygdala which modulates memory processes in hippocampus, prefrontal cortex and other brain areas. We used functional magnetic resonance imaging (fMRI) to investigate neural correlates of stress-induced modulation of emotional recognition memory in humans. Twenty-seven healthy, right-handed, non-smoker male volunteers performed an emotional face recognition task. During encoding, participants were presented with 50 fearful and 50 neutral faces. One hour later, they underwent either a stress (Trier Social Stress Test) or a control procedure outside the scanner which was followed immediately by the recognition session inside the scanner, where participants had to discriminate between 100 old and 50 new faces. Stress increased salivary cortisol, blood pressure and pulse, and decreased the mood of participants but did not impact recognition memory. BOLD data during recognition revealed a stress condition by emotion interaction in the left inferior frontal gyrus and right hippocampus which was due to a stress-induced increase of neural activity to fearful and a decrease to neutral faces. Functional connectivity analyses revealed a stress-induced increase in coupling between the right amygdala and the right fusiform gyrus, when processing fearful as compared to neutral faces. Our results provide evidence that acute psychosocial stress affects medial temporal and frontal brain areas differentially for neutral and emotional items, with a stress-induced privileged processing of emotional stimuli.

  1. Electrophysiological evidence for temporal dynamics associated with attentional processing in the zoom lens paradigm

    Directory of Open Access Journals (Sweden)

    Qing Zhang

    2018-04-01

    expansion of the attentional focus, suggesting that observers might further redistribute attentional resources according to the increased task difficulty. Conclusion These findings provide electrophysiological evidence that the neural activity of the N1 generator is the earliest marker of the zoom lens effect of visual spatial attention. Furthermore, evidence from N2pc shows that there is also a redistribution of attentional resources after the action of the zoom lens mechanism, which allows for better perform of the search task in the context of low attentional resolution. On the basis of the timing of P1, N1, and N2pc, our findings provide compelling evidence that visuospatial attention processing in the zoom lens paradigm involves multi-stage dynamic processing.

  2. [New paradigm for soil and water conservation: a method based on watershed process modeling and scenario analysis].

    Science.gov (United States)

    Zhu, A-Xing; Chen, La-Jiao; Qin, Cheng-Zhi; Wang, Ping; Liu, Jun-Zhi; Li, Run-Kui; Cai, Qiang-Guo

    2012-07-01

    With the increase of severe soil erosion problem, soil and water conservation has become an urgent concern for sustainable development. Small watershed experimental observation is the traditional paradigm for soil and water control. However, the establishment of experimental watershed usually takes long time, and has the limitations of poor repeatability and high cost. Moreover, the popularization of the results from the experimental watershed is limited for other areas due to the differences in watershed conditions. Therefore, it is not sufficient to completely rely on this old paradigm for soil and water loss control. Recently, scenario analysis based on watershed modeling has been introduced into watershed management, which can provide information about the effectiveness of different management practices based on the quantitative simulation of watershed processes. Because of its merits such as low cost, short period, and high repeatability, scenario analysis shows great potential in aiding the development of watershed management strategy. This paper elaborated a new paradigm using watershed modeling and scenario analysis for soil and water conservation, illustrated this new paradigm through two cases for practical watershed management, and explored the future development of this new soil and water conservation paradigm.

  3. Reliability of an fMRI Paradigm for Emotional Processing in a Multisite Longitudinal Study

    Science.gov (United States)

    Gee, Dylan G.; McEwen, Sarah C.; Forsyth, Jennifer K.; Haut, Kristen M.; Bearden, Carrie E.; Addington, Jean; Goodyear, Bradley; Cadenhead, Kristin S.; Mirzakhanian, Heline; Cornblatt, Barbara A.; Olvet, Doreen; Mathalon, Daniel H.; McGlashan, Thomas H.; Perkins, Diana O.; Belger, Aysenil; Seidman, Larry J.; Thermenos, Heidi; Tsuang, Ming T.; van Erp, Theo G.M.; Walker, Elaine F.; Hamann, Stephan; Woods, Scott W.; Constable, Todd; Cannon, Tyrone D.

    2015-01-01

    Multisite neuroimaging studies can facilitate the investigation of brain-related changes in many contexts, including patient groups that are relatively rare in the general population. Though multisite studies have characterized the reliability of brain activation during working memory and motor functional magnetic resonance imaging tasks, emotion processing tasks, pertinent to many clinical populations, remain less explored. A traveling participants study was conducted with eight healthy volunteers scanned twice on consecutive days at each of the eight North American Longitudinal Prodrome Study sites. Tests derived from generalizability theory showed excellent reliability in the amygdala (Eρ2=0.82), inferior frontal gyrus (IFG;Eρ2=0.83), anterior cingulate cortex (ACC;Eρ2=0.76), insula (Eρ2=0.85), and fusiform gyrus (Eρ2=0.91) for maximum activation and fair to excellent reliability in the amygdala (Eρ2=0.44), IFG (Eρ2=0.48), ACC (Eρ2=0.55), insula (Eρ2=0.42), and fusiform gyrus (Eρ2=0.83) for mean activation across sites and test days. For the amygdala, habituation (Eρ2=0.71) was more stable than mean activation. In a second investigation, data from 111 healthy individuals across sites were aggregated in a voxelwise, quantitative meta-analysis. When compared with a mixed effects model controlling for site, both approaches identified robust activation in regions consistent with expected results based on prior single-site research. Overall, regions central to emotion processing showed strong reliability in the traveling participants study and robust activation in the aggregation study. These results support the reliability of blood oxygen level-dependent signal in emotion processing areas across different sites and scanners and may inform future efforts to increase efficiency and enhance knowledge of rare conditions in the population through multisite neuroimaging paradigms. PMID:25821147

  4. The gap-startle paradigm to assess auditory temporal processing: Bridging animal and human research.

    Science.gov (United States)

    Fournier, Philippe; Hébert, Sylvie

    2016-05-01

    The gap-prepulse inhibition of the acoustic startle (GPIAS) paradigm is the primary test used in animal research to identify gap detection thresholds and impairment. When a silent gap is presented shortly before a loud startling stimulus, the startle reflex is inhibited and the extent of inhibition is assumed to reflect detection. Here, we applied the same paradigm in humans. One hundred and fifty-seven normal-hearing participants were tested using one of five gap durations (5, 25, 50, 100, 200 ms) in one of the following two paradigms-gap-embedded in or gap-following-the continuous background noise. The duration-inhibition relationship was observable for both conditions but followed different patterns. In the gap-embedded paradigm, GPIAS increased significantly with gap duration up to 50 ms and then more slowly up to 200 ms (trend only). In contrast, in the gap-following paradigm, significant inhibition-different from 0--was observable only at gap durations from 50 to 200 ms. The finding that different patterns are found depending on gap position within the background noise is compatible with distinct mechanisms underlying each of the two paradigms. © 2016 Society for Psychophysiological Research.

  5. Advances in Reasoning-Based Image Processing Intelligent Systems Conventional and Intelligent Paradigms

    CERN Document Server

    Nakamatsu, Kazumi

    2012-01-01

    The book puts special stress on the contemporary techniques for reasoning-based image processing and analysis: learning based image representation and advanced video coding; intelligent image processing and analysis in medical vision systems; similarity learning models for image reconstruction; visual perception for mobile robot motion control, simulation of human brain activity in the analysis of video sequences; shape-based invariant features extraction; essential of paraconsistent neural networks, creativity and intelligent representation in computational systems. The book comprises 14 chapters. Each chapter is a small monograph, representing resent investigations of authors in the area. The topics of the chapters cover wide scientific and application areas and complement each-other very well. The chapters’ content is based on fundamental theoretical presentations, followed by experimental results and comparison with similar techniques. The size of the chapters is well-ballanced which permits a thorough ...

  6. Design optimization of single mixed refrigerant natural gas liquefaction process using the particle swarm paradigm with nonlinear constraints

    International Nuclear Information System (INIS)

    Khan, Mohd Shariq; Lee, Moonyong

    2013-01-01

    The particle swarm paradigm is employed to optimize single mixed refrigerant natural gas liquefaction process. Liquefaction design involves multivariable problem solving and non-optimal execution of these variables can waste energy and contribute to process irreversibilities. Design optimization requires these variables to be optimized simultaneously; minimizing the compression energy requirement is selected as the optimization objective. Liquefaction is modeled using Honeywell UniSim Design ™ and the resulting rigorous model is connected with the particle swarm paradigm coded in MATLAB. Design constraints are folded into the objective function using the penalty function method. Optimization successfully improved efficiency by reducing the compression energy requirement by ca. 10% compared with the base case. -- Highlights: ► The particle swarm paradigm (PSP) is employed for design optimization of SMR NG liquefaction process. ► Rigorous SMR process model based on UniSim is connected with PSP coded in MATLAB. ► Stochastic features of PSP give more confidence in the optimality of complex nonlinear problems. ► Optimization with PSP notably improves energy efficiency of the SMR process.

  7. Visuo-spatial processing in a dynamic and a static working memory paradigm in schizophrenia

    DEFF Research Database (Denmark)

    Cocchi, Luca; Schenk, Françoise; Volken, Henri

    2007-01-01

    patients with schizophrenia and matched controls in a new working memory paradigm involving dynamic (the Ball Flight Task - BFT) or static (the Static Pattern Task - SPT) visual stimuli. In the BFT, the responses of the patients were apparently based on the retention of the last set of segments...... that visuo-spatial working memory can simply be dissociated into visual and spatial sub-components....

  8. Linguistic & Rhetorical Paradigm as Innovative Theoretical Methodological Platform of Studying Discursive Processes of East Slavic and Western Cultures

    Directory of Open Access Journals (Sweden)

    Аlexandra A. Vorozhbitova

    2013-01-01

    Full Text Available The paper suggests studying conceptual models and mechanisms of linguistic consciousness of East Slavic and Western cultures with the application of the theoretical methodological approach of Linguistic & Rhetorical (L&R Paradigm as an integrative philological trend of an innovative type. The L&R Paradigm rests on the intersection of three categorical dimensions: ideological aspects of a speech event (ethos, logos, pathos; stages of universal cycle of idea-into-speech transformation (invention, disposition, elocution as a technology of discursive processes; levels of the structure of a linguistic personality as a discourse producer and ideology bearer (associative verbal network, thesaurus, pragmatic field. Hence, the article proposes three groups of L&R parameters of studying speech and thinking phenomena: ethos-motivational-dispositional; logos-thesaurus-inventional; pathos-verbal-elocutionary.

  9. Ecosystem services: developing sustainable management paradigms based on wetland functions and processes

    Science.gov (United States)

    Euliss, Ned H.; Mushet, David M.; Smith, Loren M.; Conner, William H.; Burkett, Virginia R.; Wilcox, Douglas A.; Hester, Mark W.; Zheng, Haochi

    2013-01-01

    In the late nineteenth century and twentieth century, there was considerable interest and activity to develop the United States for agricultural, mining, and many other purposes to improve the quality of human life standards and prosperity. Most of the work to support this development was focused along disciplinary lines with little attention focused on ecosystem service trade-offs or synergisms, especially those that transcended boundaries of scientific disciplines and specific interest groups. Concurrently, human population size has increased substantially and its use of ecosystem services has increased more than five-fold over just the past century. Consequently, the contemporary landscape has been highly modified for human use, leaving behind a fragmented landscape where basic ecosystem functions and processes have been broadly altered. Over this period, climate change also interacted with other anthropogenic effects, resulting in modern environmental problems having a complexity that is without historical precedent. The challenge before the scientific community is to develop new science paradigms that integrate relevant scientific disciplines to properly frame and evaluate modern environmental problems in a systems-type approach to better inform the decision-making process. Wetland science is a relatively new discipline that grew out of the conservation movement of the early twentieth century. In the United States, most of the conservation attention in the earlier days was on wildlife, but a growing human awareness of the importance of the environment led to the passage of the National Environmental Policy Act in 1969. Concurrently, there was a broadening interest in conservation science, and the scientific study of wetlands gradually gained acceptance as a scientific discipline. Pioneering wetland scientists became formally organized when they formed The Society of Wetland Scientists in 1980 and established a publication outlet to share wetland research

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

    Science.gov (United States)

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

    2016-04-01

    Stress exposure is known to precipitate psychological disorders. However, large differences exist in how individuals respond to stressful situations. A major marker for stress sensitivity is hypothalamus-pituitary-adrenal (HPA)-axis function. Here, we studied how interindividual variance in both basal cortisol levels and stress-induced cortisol responses predicts differences in neural vigilance processing during stress exposure. Implementing a randomized, counterbalanced, crossover design, 120 healthy male participants were exposed to a stress-induction and control procedure, followed by an emotional perception task (viewing fearful and happy faces) during fMRI scanning. Stress sensitivity was assessed using physiological (salivary cortisol levels) and psychological measures (trait questionnaires). High stress-induced cortisol responses were associated with increased stress sensitivity as assessed by psychological questionnaires, a stronger stress-induced increase in medial temporal activity and greater differential amygdala responses to fearful as opposed to happy faces under control conditions. In contrast, high basal cortisol levels were related to relative stress resilience as reflected by higher extraversion scores, a lower stress-induced increase in amygdala activity and enhanced differential processing of fearful compared with happy faces under stress. These findings seem to reflect a critical role for HPA-axis signaling in stress coping; higher basal levels indicate stress resilience, whereas higher cortisol responsivity to stress might facilitate recovery in those individuals prone to react sensitively to stress. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  11. Paradigms for Assessing Hedonic Processing and Motivation in Humans: Relevance to Understanding Negative Symptoms in Psychopathology.

    Science.gov (United States)

    Barch, Deanna M; Gold, James M; Kring, Ann M

    2017-07-01

    Clinicians and researchers have long known that one of the debilitating aspects of psychotic disorders is the presence of "negative symptoms," which involve impairments in hedonic and motivational function, and/or alterations in expressive affect. We have a number of excellent clinical tools available for assessing the presence and severity of negative symptoms. However, to better understand the mechanisms that may give rise to negative symptoms, we need tools and methods that can help distinguish among different potential contributing causes, as a means to develop more targeted intervention pathways. Using such paradigms is particularly important if we wish to understand whether the causes are the same or different across disorders that may share surface features of negative symptoms. This approach is in line with the goals of the Research Diagnostic Criteria Initiative, which advocates understanding the nature of core dimensions of brain-behavior relationships transdiagnostically. Here we highlight some of the emerging measures and paradigms that may help us to parse the nature and causes of negative symptoms, illustrating both the research approaches from which they emerge and the types of constructs that they can help elucidate. © The Author 2017. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  12. Nondestructive control of residual stresses during welding and recharge processes

    International Nuclear Information System (INIS)

    Suarez, J.C.; Fernandez, L.M.; Cruz, C.; Merino, F.; Aragon, B.

    1993-01-01

    In this work, the stress state of material during welding and recharge processes is controlled with the help of Barkhausen effect. The changes, occurred in the longitudinal and transversal stress profile are show during deposition of welding rings. It is proved that the stress state of the base-material depends on the amount of recharge layers, deposited on it

  13. Attributional processes in the learned helplessness paradigm: behavioral effects of global attributions.

    Science.gov (United States)

    Mikulincer, M

    1986-12-01

    Following the learned helplessness paradigm, I assessed in this study the effects of global and specific attributions for failure on the generalization of performance deficits in a dissimilar situation. Helplessness training consisted of experience with noncontingent failures on four cognitive discrimination problems attributed to either global or specific causes. Experiment 1 found that performance in a dissimilar situation was impaired following exposure to globally attributed failure. Experiment 2 examined the behavioral effects of the interaction between stable and global attributions of failure. Exposure to unsolvable problems resulted in reduced performance in a dissimilar situation only when failure was attributed to global and stable causes. Finally, Experiment 3 found that learned helplessness deficits were a product of the interaction of global and internal attribution. Performance deficits following unsolvable problems were recorded when failure was attributed to global and internal causes. Results were discussed in terms of the reformulated learned helplessness model.

  14. Visuo-spatial processing in a dynamic and a static working memory paradigm in schizophrenia

    DEFF Research Database (Denmark)

    Cocchi, Luca; Schenk, Françoise; Volken, Henri

    2007-01-01

    patients with schizophrenia and matched controls in a new working memory paradigm involving dynamic (the Ball Flight Task - BFT) or static (the Static Pattern Task - SPT) visual stimuli. In the BFT, the responses of the patients were apparently based on the retention of the last set of segments...... that visuo-spatial working memory can simply be dissociated into visual and spatial sub-components....... of the perceived trajectory, whereas control subjects relied on a more global strategy. We assume that the patients' performances are the result of a reduced capacity in chunking visual information since they relied mainly on the retention of the last set of segments. This assumption is confirmed by the poor...

  15. Limited evidence of individual differences in holistic processing in different versions of the part-whole paradigm.

    Science.gov (United States)

    Sunday, Mackenzie A; Richler, Jennifer J; Gauthier, Isabel

    2017-07-01

    The part-whole paradigm was one of the first measures of holistic processing and it has been used to address several topics in face recognition, including its development, other-race effects, and more recently, whether holistic processing is correlated with face recognition ability. However the task was not designed to measure individual differences and it has produced measurements with low reliability. We created a new holistic processing test designed to measure individual differences based on the part-whole paradigm, the Vanderbilt Part Whole Test (VPWT). Measurements in the part and whole conditions were reliable, but, surprisingly, there was no evidence for reliable individual differences in the part-whole index (how well a person can take advantage of a face part presented within a whole face context compared to the part presented without a whole face) because part and whole conditions were strongly correlated. The same result was obtained in a version of the original part-whole task that was modified to increase its reliability. Controlling for object recognition ability, we found that variance in the whole condition does not predict any additional variance in face recognition over what is already predicted by performance in the part condition.

  16. Reactivity to interpersonal stress in patients with eating disorders: A systematic review and meta-analysis of studies using an experimental paradigm.

    Science.gov (United States)

    Monteleone, Alessio Maria; Treasure, Janet; Kan, Carol; Cardi, Valentina

    2018-04-01

    Reactivity to interpersonal stress in patients with eating disorders: A systematic review and meta-analysis of studies using an experimental paradigm. NEUROSCI BIOBEHAV REV XXX-XXX, 2018.- Social difficulties have been implicated in the development and maintenance of eating disorder symptoms. The aim of this work was to conduct a systematic review and meta-analysis of experimental studies testing patientsö reactivity to interpersonal stress, compared to healthy controls. Thirty-four studies were included. Meta-analyses were conducted on 16 studies and on following outcomes: attention bias and interference to threatening faces, cortisol, heart rate and negative affect before and after exposure to interpersonal stress. Patients showed heightened attention bias and interference to threatening faces. Lower heart rate after exposure to interpersonal stress and greater negative affect before and after interpersonal stress were observed in the clinical group compared to controls. Surprisingly, only a small minority of studies included measures of abnormal eating behaviour and attitudes. This seems a missed opportunity for testing the causal and maintaining role that abnormalities in interpersonal stress response play in eating disorders. Nonetheless, findings corroborate the hypothesis that patients' response to interpersonal stress differs from that of healthy controls. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. Single-process versus multiple-strategy models of decision making: evidence from an information intrusion paradigm.

    Science.gov (United States)

    Söllner, Anke; Bröder, Arndt; Glöckner, Andreas; Betsch, Tilmann

    2014-02-01

    When decision makers are confronted with different problems and situations, do they use a uniform mechanism as assumed by single-process models (SPMs) or do they choose adaptively from a set of available decision strategies as multiple-strategy models (MSMs) imply? Both frameworks of decision making have gathered a lot of support, but only rarely have they been contrasted with each other. Employing an information intrusion paradigm for multi-attribute decisions from givens, SPM and MSM predictions on information search, decision outcomes, attention, and confidence judgments were derived and tested against each other in two experiments. The results consistently support the SPM view: Participants seemingly using a "take-the-best" (TTB) strategy do not ignore TTB-irrelevant information as MSMs would predict, but adapt the amount of information searched, choose alternative choice options, and show varying confidence judgments contingent on the quality of the "irrelevant" information. The uniformity of these findings underlines the adequacy of the novel information intrusion paradigm and comprehensively promotes the notion of a uniform decision making mechanism as assumed by single-process models. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

  18. Procedure versus process: ethical paradigms and the conduct of qualitative research.

    Science.gov (United States)

    Pollock, Kristian

    2012-09-27

    Research is fundamental to improving the quality of health care. The need for regulation of research is clear. However, the bureaucratic complexity of research governance has raised concerns that the regulatory mechanisms intended to protect participants now threaten to undermine or stifle the research enterprise, especially as this relates to sensitive topics and hard to reach groups. Much criticism of research governance has focused on long delays in obtaining ethical approvals, restrictions imposed on study conduct, and the inappropriateness of evaluating qualitative studies within the methodological and risk assessment frameworks applied to biomedical and clinical research. Less attention has been given to the different epistemologies underlying biomedical and qualitative investigation. The bioethical framework underpinning current regulatory structures is fundamentally at odds with the practice of emergent, negotiated micro-ethics required in qualitative research. The complex and shifting nature of real world settings delivers unanticipated ethical issues and (occasionally) genuine dilemmas which go beyond easy or formulaic 'procedural' resolution. This is not to say that qualitative studies are 'unethical' but that their ethical nature can only be safeguarded through the practice of 'micro-ethics' based on the judgement and integrity of researchers in the field. This paper considers the implications of contrasting ethical paradigms for the conduct of qualitative research and the value of 'empirical ethics' as a means of liberating qualitative (and other) research from an outmoded and unduly restrictive research governance framework based on abstract prinicipalism, divorced from real world contexts and values.

  19. Acute stress-induced cortisol elevations mediate reward system activity during subconscious processing of sexual stimuli.

    Science.gov (United States)

    Oei, Nicole Y L; Both, Stephanie; van Heemst, Diana; van der Grond, Jeroen

    2014-01-01

    Stress is thought to alter motivational processes by increasing dopamine (DA) secretion in the brain's "reward system", and its key region, the nucleus accumbens (NAcc). However, stress studies using functional magnetic resonance imaging (fMRI), mainly found evidence for stress-induced decreases in NAcc responsiveness toward reward cues. Results from both animal and human PET studies indicate that the stress hormone cortisol may be crucial in the interaction between stress and dopaminergic actions. In the present study we therefore investigated whether cortisol mediated the effect of stress on DA-related responses to -subliminal-presentation of reward cues using the Trier Social Stress Test (TSST), which is known to reliably enhance cortisol levels. Young healthy males (n = 37) were randomly assigned to the TSST or control condition. After stress induction, brain activation was assessed using fMRI during a backward-masking paradigm in which potentially rewarding (sexual), emotionally negative and neutral stimuli were presented subliminally, masked by pictures of inanimate objects. A region of interest analysis showed that stress decreased activation in the NAcc in response to masked sexual cues (voxel-corrected, pcortisol levels were related to stronger NAcc activation, showing that cortisol acted as a suppressor variable in the negative relation between stress and NAcc activation. The present findings indicate that cortisol is crucially involved in the relation between stress and the responsiveness of the reward system. Although generally stress decreases activation in the NAcc in response to rewarding stimuli, high stress-induced cortisol levels suppress this relation, and are associated with stronger NAcc activation. Individuals with a high cortisol response to stress might on one hand be protected against reductions in reward sensitivity, which has been linked to anhedonia and depression, but they may ultimately be more vulnerable to increased reward

  20. Procedure versus process: ethical paradigms and the conduct of qualitative research

    Science.gov (United States)

    2012-01-01

    Background Research is fundamental to improving the quality of health care. The need for regulation of research is clear. However, the bureaucratic complexity of research governance has raised concerns that the regulatory mechanisms intended to protect participants now threaten to undermine or stifle the research enterprise, especially as this relates to sensitive topics and hard to reach groups. Discussion Much criticism of research governance has focused on long delays in obtaining ethical approvals, restrictions imposed on study conduct, and the inappropriateness of evaluating qualitative studies within the methodological and risk assessment frameworks applied to biomedical and clinical research. Less attention has been given to the different epistemologies underlying biomedical and qualitative investigation. The bioethical framework underpinning current regulatory structures is fundamentally at odds with the practice of emergent, negotiated micro-ethics required in qualitative research. The complex and shifting nature of real world settings delivers unanticipated ethical issues and (occasionally) genuine dilemmas which go beyond easy or formulaic ‘procedural’ resolution. This is not to say that qualitative studies are ‘unethical’ but that their ethical nature can only be safeguarded through the practice of ‘micro-ethics’ based on the judgement and integrity of researchers in the field. Summary This paper considers the implications of contrasting ethical paradigms for the conduct of qualitative research and the value of ‘empirical ethics’ as a means of liberating qualitative (and other) research from an outmoded and unduly restrictive research governance framework based on abstract prinicipalism, divorced from real world contexts and values. PMID:23016663

  1. Stress Fracture and Nonunion of Coronoid Process in a Gymnast

    Directory of Open Access Journals (Sweden)

    T. Hetling

    2016-01-01

    Full Text Available Background. Gymnasts have high mechanical loading forces of up to 14 times body weight. Overuse lesions are typical in wrists and stress fractures in the olecranon, while isolated fractures of the coronoid process are uncommon. We present a case of retraumatized nonunion stress fracture of the ulnar coronoid process. Case Description. A 19-year-old gymnast presented with elbow pain after training. Imaging confirmed an old fracture of the coronoid process. We describe a 6-month multiphase return to competition rehabilitation program, which allowed him to compete pain-freely. Literature Review. Acute and overuse injuries in gymnasts are known but no nonunion of the coronoid process has been described before. Only one case of stress fracture of coronoid process in a gymnast was reported. Purpose and Clinical Relevance. We could successfully and conservatively return to sport a reactivated nonunion of a stress fracture of the coronoid process.

  2. The behaviorist the historical-cultural: The effectiveness of Aulic Teaching Process under two paradigms dimension

    Directory of Open Access Journals (Sweden)

    Modesta Moreno Iglesias

    2005-03-01

    Full Text Available The article presents an approach to the analysis of the definition of Aulic Teaching Process with its dimensions, focusing on the effectiveness of that process and the actions to be undertaken for evaluation, from a humanist perspective and develope.

  3. Perceived stress predicts altered reward and loss feedback processing in medial prefrontal cortex

    Directory of Open Access Journals (Sweden)

    Michael T Treadway

    2013-05-01

    Full Text Available Stress is significant risk factor for the development of psychopathology, particularly symptoms related to reward processing. Importantly, individuals display marked variation in how they perceive and cope with stressful events, and such differences are strongly linked to risk for developing psychiatric symptoms following stress exposure. However, many questions remain regarding the neural architecture that underlies inter-subject variability in perceptions of stressors. Using functional magnetic resonance imaging (fMRI during a monetary incentive delay paradigm, we examined the effects of self-reported perceived stress levels on neural activity during reward anticipation and feedback in a sample of healthy individuals. We found that subjects reporting more uncontrollable and overwhelming stressors displayed blunted neural responses in medial prefrontal cortex (mPFC following feedback related to monetary gains as well monetary losses. This is consistent with preclinical models that implicate the mPFC as a key site of vulnerability to the noxious effects of uncontrollable stressors. Our data help translate these findings to humans, and elucidate some of the neural mechanisms that may underlie stress-linked risk for developing reward-related psychiatric symptoms.

  4. The impact of acute stress on the neural processing of food cues in bulimia nervosa: Replication in two samples.

    Science.gov (United States)

    Collins, Brittany; Breithaupt, Lauren; McDowell, Jennifer E; Miller, L Stephen; Thompson, James; Fischer, Sarah

    2017-07-01

    The impact of acute stress on the neural processing of food cues in bulimia nervosa (BN) is unknown, despite theory that acute stress decreases cognitive control over food and hence increases vulnerability to environmental triggers for binge eating. Thus, the goals of this manuscript were to explore the impact of acute stress on the neural processing of food cues in BN. In Study 1, 10 women with Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5; American Psychiatric Association, 2013) BN and 10 healthy controls participated in an fMRI paradigm examining the neural correlates of visual food cue processing pre and post an acute stress induction. Whole brain analysis indicated that women with BN exhibited significant decreases in activation in the precuneus, associated with self-referential processing, the paracingulate gyrus, and the anterior vermis of the cerebellum. Healthy controls exhibited increased activation in these regions in response to food cues poststress. In Study 2, 17 women with DSM-5 BN or otherwise specified feeding and eating disorder with BN symptoms participated in the same paradigm. A region of interest analysis replicated findings from Study 1. Replication of imaging findings in 2 different samples suggests the potential importance of these regions in relation to BN. Decreased activation in the precuneus, specifically, is consistent with models of BN that posit that binge eating serves as a concrete distraction from aversive internal stimuli. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  5. Towards a New Paradigm of Software Development: an Ambassador Driven Process in Distributed Software Companies

    Science.gov (United States)

    Kumlander, Deniss

    The globalization of companies operations and competitor between software vendors demand improving quality of delivered software and decreasing the overall cost. The same in fact introduce a lot of problem into software development process as produce distributed organization breaking the co-location rule of modern software development methodologies. Here we propose a reformulation of the ambassador position increasing its productivity in order to bridge communication and workflow gap by managing the entire communication process rather than concentrating purely on the communication result.

  6. The Rubber Hand Illusion paradigm as a sensory learning process in patients with schizophrenia.

    Science.gov (United States)

    Lev-Ari, L; Hirschmann, S; Dyskin, O; Goldman, O; Hirschmann, I

    2015-10-01

    The Rubber Hand Illusion (RHI) has previously been used to depict the hierarchy between visual, tactile and perceptual stimuli. Studies on schizophrenia inpatients (SZs) have found mixed results in the ability to first learn the illusion, and have yet to explain the learning process involved. This study's aim was two-fold: to examine the learning process of the RHI in SZs and healthy controls over time, and to better understand the relationship between psychotic symptoms and the RHI. Thirty schizophrenia inpatients and 30 healthy controls underwent five different trials of the RHI over a two-week period. As has been found in previous studies, SZs felt the initial illusion faster than healthy controls did, but their learning process throughout the trials was inconsistent. Furthermore, for SZs, no correlations between psychotic symptoms and the learning of the illusion emerged. Healthy individuals show a delayed reaction to first feeling the illusion (due to latent inhibition), but easily learn the illusion over time. For SZs, both strength of the illusion and the ability to learn the illusion over time are inconsistent. The cognitive impairment in SZ impedes the learning process of the RHI, and SZs are unable to utilize the repetition of the process as healthy individuals can. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  7. Hydrography for the non-Hydrographer: A Paradigm shift in Data Processing

    Science.gov (United States)

    Malzone, C.; Bruce, S.

    2017-12-01

    Advancements in technology have led to overall systematic improvements including; hardware design, software architecture, data transmission/ telepresence. Historically, utilization of this technology has required a high knowledge level obtained with many years of experience, training and/or education. High training costs are incurred to achieve and maintain an acceptable level proficiency within an organization. Recently, engineers have developed off-the-shelf software technology called Qimera that has simplified the processing of hydrographic data. The core technology is centered around the isolation of tasks within the work- flow to capitalize on the technological advances in computing technology to automate the mundane error prone tasks to bring more value to the stages in which the human brain brings value. Key design features include: guided workflow, transcription automation, processing state management, real-time QA, dynamic workflow for validation, collaborative cleaning and production line processing. Since, Qimera is designed to guide the user, it allows expedition leaders to focus on science while providing an educational opportunity for students to quickly learn the hydrographic processing workflow including ancillary data analysis, trouble-shooting, calibration and cleaning. This paper provides case studies on how Qimera is currently implemented in scientific expeditions, benefits of implementation and how it is directing the future of on-board research for the non-hydrographer.

  8. Ewan and Cooper processes unite in 'paradigm shifting' patent

    Energy Technology Data Exchange (ETDEWEB)

    Tang, R.; Sanyal, P. [International Environmental and Energy Consultants (United States)

    2010-11-15

    A freshly patented technology aimed at removing over 99% of the flue emissions and over 90% of CO{sub 2}, the CEFCO process, is being presented as a comprehensive maximum achievable control technology (MACT) solution to enable coal and oil fired plants to meet tightening US emission standards. 3 figs.

  9. Effects of acute alcohol intoxication on automated processing: evidence from the double-step paradigm.

    Science.gov (United States)

    Vorstius, Christian; Radach, Ralph; Lang, Alan R

    2012-02-01

    Reflexive and voluntary levels of processing have been studied extensively with respect to possible impairments due to alcohol intoxication. This study examined alcohol effects at the 'automated' level of processing essential to many complex visual processing tasks (e.g., reading, visual search) that involve ongoing modifications or reprogramming of well-practiced routines. Data from 30 participants (16 male) were collected in two counterbalanced sessions (alcohol vs. no-alcohol control; mean breath alcohol concentration = 68 mg/dL vs. 0 mg/dL). Eye movements were recorded during a double-step task where 75% of trials involved two target stimuli in rapid succession (inter-stimulus interval [ISI]=40, 70, or 100 ms) so that they could elicit two distinct saccades or eye movements (double steps). On 25% of trials a single target appeared. Results indicated that saccade latencies were longer under alcohol. In addition, the proportion of single-step responses and the mean saccade amplitude (length) of primary saccades decreased significantly with increasing ISI. The key novel finding, however, was that the reprogramming time needed to cancel the first saccade and adjust saccade amplitude was extended significantly by alcohol. The additional time made available by prolonged latencies due to alcohol was not utilized by the saccade programming system to decrease the number of two-step responses. These results represent the first demonstration of specific alcohol-induced programming deficits at the automated level of oculomotor processing.

  10. Navon's classical paradigm concerning local and global processing relates systematically to visual object classification performance

    DEFF Research Database (Denmark)

    Gerlach, Christian; Poirel, Nicolas

    2018-01-01

    Forty years ago David Navon tried to tackle a central problem in psychology concerning the time course of perceptual processing: Do we first see the details (local level) followed by the overall outlay (global level) or is it rather the other way around? He did this by developing a now classical ...

  11. Output Position and Word Relatedness Effects in a DRM Paradigm: Support for a Dual-Retrieval Process Theory of Free Recall and False Memories

    Science.gov (United States)

    Barnhardt, T. M.; Choi, H.; Gerkens, D. R.; Smith, S. M.

    2006-01-01

    Five experiments investigated predictions--derived from a dual-retrieval process approach to free recall (Brainerd, C. J., Wright, R., Reyna, V. F., & Payne, D. G. (2002). Dual-retrieval processes in free and associative recall. Journal of Memory and Language, 46, 120-152.)--about false memories in a DRM-like paradigm. In all the experiments, the…

  12. The Processing Using Memory Paradigm:In-DRAM Bulk Copy, Initialization, Bitwise AND and OR

    OpenAIRE

    Seshadri, Vivek; Mutlu, Onur

    2016-01-01

    In existing systems, the off-chip memory interface allows the memory controller to perform only read or write operations. Therefore, to perform any operation, the processor must first read the source data and then write the result back to memory after performing the operation. This approach consumes high latency, bandwidth, and energy for operations that work on a large amount of data. Several works have proposed techniques to process data near memory by adding a small amount of compute logic...

  13. Neurocognitive correlates of processing food-related stimuli in a Go/No-go paradigm.

    Science.gov (United States)

    Watson, Todd D; Garvey, Katherine T

    2013-12-01

    We examined the neurocognitive correlates of processing food-related stimuli in healthy young adults. Event-related potential (ERP) data were collected while 48 participants completed a computerized Go/No-go task consisting of food and nonfood images. Separately, we assessed participants' self-reported levels of external, restrained, and emotional eating behaviors as well as trait impulsivity, behavioral activation/inhibition, and performance on the Stroop Color-Word Test. We found that across participants, food images elicited significantly enhanced P3(00) and slow-wave ERP components. The difference in slow-wave components elicited by food and nonfood images was correlated with Stroop interference scores. Food images also elicited significantly enhanced N2(00) components, but only in female participants. The difference between N2 components elicited by food and nonfood images was related to body mass index and scores of external eating in females. Overall, these data suggest that processing food-related stimuli recruits distinct patterns of cortical activity, that the magnitude of these effects is related to behavioral and cognitive variables, and that the neurocognitive correlates of processing food-cues may be at least partly dissociable between males and females. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Investigating Resulting Residual Stresses during Mechanical Forming Process

    Science.gov (United States)

    Akinlabi, Stephen A.; Fatoba, Olawale S.; Mashinini, Peter M.; Akinlabi, Esther T.

    2018-03-01

    Most manufacturing processes such as machining, welding, heat treatment, laser forming, laser cladding and, laser metal deposition, etc. are subjected to a form of heat or energy to change the geometrical shape thus changing the inherent engineering and structural properties of the material. These changes often cause the development of locked up stresses referred to as residual stresses as a result of these activities. This study reports on the residual stresses developed due to the mechanical forming process to maintain a suitable structural integrity for the formed components. The result of the analysis through the X-ray diffraction confirmed that residual stresses were induced in the manufactured parts and further revealed that residual stresses were compressive in nature as found in the parent material but with values less than the parent material.

  15. Model and system learners, optimal process constructors and kinetic theory-based goal-oriented design: A new paradigm in materials and processes informatics

    Science.gov (United States)

    Abisset-Chavanne, Emmanuelle; Duval, Jean Louis; Cueto, Elias; Chinesta, Francisco

    2018-05-01

    Traditionally, Simulation-Based Engineering Sciences (SBES) has relied on the use of static data inputs (model parameters, initial or boundary conditions, … obtained from adequate experiments) to perform simulations. A new paradigm in the field of Applied Sciences and Engineering has emerged in the last decade. Dynamic Data-Driven Application Systems [9, 10, 11, 12, 22] allow the linkage of simulation tools with measurement devices for real-time control of simulations and applications, entailing the ability to dynamically incorporate additional data into an executing application, and in reverse, the ability of an application to dynamically steer the measurement process. It is in that context that traditional "digital-twins" are giving raise to a new generation of goal-oriented data-driven application systems, also known as "hybrid-twins", embracing models based on physics and models exclusively based on data adequately collected and assimilated for filling the gap between usual model predictions and measurements. Within this framework new methodologies based on model learners, machine learning and kinetic goal-oriented design are defining a new paradigm in materials, processes and systems engineering.

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

    Science.gov (United States)

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

    2017-07-01

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

  17. Risk-based Process Development of Biosimilars as Part of the Quality by Design Paradigm.

    Science.gov (United States)

    Zalai, Dénes; Dietzsch, Christian; Herwig, Christoph

    2013-01-01

    In the last few years, several quality by design (QbD) studies demonstrated the benefit of systematic approaches for biopharmaceutical development. However, only very few studies identified biosimilars as a special case of product development. The targeted quality profile of biosimilars is strictly defined by the originator's product characteristic. Moreover, the major source of prior knowledge is the experience with the originator product itself. Processing this information in biosimilar development has a major effect on risk management and process development strategies. The main objective of this contribution is to demonstrate how risk management can facilitate the implementation of QbD in early-stage product development with special emphasis on fitting the reported approaches to biosimilars. Risk assessments were highlighted as important tools to integrate prior knowledge in biosimilar development. The risk assessment process as suggested by the International Conference on Harmonization (ICH Q9) was reviewed and three elements were identified to play a key role in targeted risk assessment approaches: proper understanding of target linkage, risk assessment tool compliance, and criticality threshold value. Adjusting these steps to biosimilar applications helped to address some unique challenges of these products such as a strictly defined quality profile or a lack of process knowledge. This contribution demonstrates the need for tailored risk management approaches for the risk-based development of biosimilars and provides novel tools for the integration of additional knowledge available for these products. The pharmaceutical industry is facing challenges such as profit loss and price competition. Companies are forced to rationalize business models and to cut costs in development as well as manufacturing. These trends recently hinder the implementation of any concepts that do not offer certain financial benefit or promise a long return of investment. Quality by

  18. L1 and L2 Spoken Word Processing: Evidence from Divided Attention Paradigm.

    Science.gov (United States)

    Shafiee Nahrkhalaji, Saeedeh; Lotfi, Ahmad Reza; Koosha, Mansour

    2016-10-01

    The present study aims to reveal some facts concerning first language (L 1 ) and second language (L 2 ) spoken-word processing in unbalanced proficient bilinguals using behavioral measures. The intention here is to examine the effects of auditory repetition word priming and semantic priming in first and second languages of these bilinguals. The other goal is to explore the effects of attention manipulation on implicit retrieval of perceptual and conceptual properties of spoken L 1 and L 2 words. In so doing, the participants performed auditory word priming and semantic priming as memory tests in their L 1 and L 2 . In a half of the trials of each experiment, they carried out the memory test while simultaneously performing a secondary task in visual modality. The results revealed that effects of auditory word priming and semantic priming were present when participants processed L 1 and L 2 words in full attention condition. Attention manipulation could reduce priming magnitude in both experiments in L 2 . Moreover, L 2 word retrieval increases the reaction times and reduces accuracy on the simultaneous secondary task to protect its own accuracy and speed.

  19. Competing reaction processes on a lattice as a paradigm for catalyst deactivation

    Science.gov (United States)

    Abad, E.; Kozak, J. J.

    2015-02-01

    We mobilize both a generating function approach and the theory of finite Markov processes to compute the probability of irreversible absorption of a randomly diffusing species on a lattice with competing reaction centers. We consider an N-site lattice populated by a single deep trap, and N -1 partially absorbing traps (absorption probability 0 characteristic Ω =0 and Ω =2 . The results obtained allow a characterization of catalyst deactivation processes on planar surfaces and on catalyst pellets where only a single catalytic site remains fully active (deep trap), the other sites being only partially active as a result of surface poisoning. The central result of our study is that the predicted dependence of the reaction efficiency on system size N and on s is in qualitative accord with previously reported experimental results, notably catalysts exhibiting selective poisoning due to surface sites that have different affinities for chemisorption of the poisoning agent (e.g., acid zeolite catalysts). Deviations from the efficiency of a catalyst with identical sites are quantified, and we find that such deviations display a significant dependence on the topological details of the surface (for fixed values of N and s we find markedly different results for, say, a planar surface and for the polyhedral surface of a catalyst pellet). Our results highlight the importance of surface topology for the efficiency of catalytic conversion processes on inhomogeneous substrates, and in particular for those aimed at industrial applications. From our exact analysis we extract results for the two limiting cases s ≈1 and s ≈0 , corresponding respectively to weak and strong catalyst poisoning (decreasing s leads to a monotonic decrease in the efficiency of catalytic conversion). The results for the s ≈0 case are relevant for the dual problem of light-energy conversion via trapping of excitations in the chlorophyll antenna network. Here, decreasing the probability of excitation

  20. Process induced residual stresses and distortions in pultrusion

    DEFF Research Database (Denmark)

    Baran, Ismet; Tutum, Cem Celal; Nielsen, Michael Wenani

    2013-01-01

    In the present study, a coupled 3D transient Eulerian thermo-chemical analysis together with a 2D plane strain Lagrangian mechanical analysis of the pultrusion process, which has not been considered until now, is carried out. The development of the process induced residual stresses and strains...... together with the distortions are predicted during the pultrusion in which the cure hardening instantaneous linear elastic (CHILE) approach is implemented. At the end of the process, tension stresses prevail for the inner region of the composite since the curing rate is higher here as compared to the outer...... regions where compression stresses are obtained. The separation between the heating die and the part due to shrinkage is also investigated using a mechanical contact formulation at the die-part interface. The proposed approach is found to be efficient and fast for the calculation of the residual stresses...

  1. Exploring a post-traumatic stress disorder paradigm in Flinders sensitive line rats to model treatment-resistant depression I: bio-behavioural validation and response to imipramine.

    Science.gov (United States)

    Brand, Sarel Jacobus; Harvey, Brian Herbert

    2017-08-01

    Co-morbid depression with post-traumatic stress disorder (PTSD) is often treatment resistant. In developing a preclinical model of treatment-resistant depression (TRD), we combined animal models of depression and PTSD to produce an animal with more severe as well as treatment-resistant depressive-like behaviours. Male Flinders sensitive line (FSL) rats, a genetic animal model of depression, were exposed to a stress re-stress model of PTSD [time-dependent sensitisation (TDS)] and compared with stress-naive controls. Seven days after TDS stress, depressive-like and coping behaviours as well as hippocampal and cortical noradrenaline (NA) and 5-hydroxyindoleacetic acid (5HIAA) levels were analysed. Response to sub-chronic imipramine treatment (IMI; 10 mg/kg s.c.×7 days) was subsequently studied. FSL rats demonstrated bio-behavioural characteristics of depression. Exposure to TDS stress in FSL rats correlated negatively with weight gain, while demonstrating reduced swimming behaviour and increased immobility versus unstressed FSL rats. IMI significantly reversed depressive-like (immobility) behaviour and enhanced active coping behaviour (swimming and climbing) in FSL rats. The latter was significantly attenuated in FSL rats exposed to TDS versus unstressed FSL rats. IMI reversed reduced 5HIAA levels in unstressed FSL rats, whereas exposure to TDS negated this effect. Lowered NA levels in FSL rats were sustained after TDS with IMI significantly reversing this in the hippocampus. Combining a gene-X-environment model of depression with a PTSD paradigm produces exaggerated depressive-like symptoms that display an attenuated response to antidepressant treatment. This work confirms combining FSL rats with TDS exposure as a putative animal model of TRD.

  2. Information processing biases in spider phobia: application of the Stroop and "White Noise" Paradigm.

    Science.gov (United States)

    Olatunji, Bunmi O; Sawchuk, Craig N; Lee, Thomas C; Lohr, Jeffrey M; Tolin, David F

    2008-06-01

    The present study examines attentional and implicit memory biases in spider phobic and nonphobic participants. The results showed that spider phobics demonstrated increased interference for neutral, negative, and spider-relevant words on a computerized Stroop task. However, no group differences emerged when adjusting for differences in color-naming speed. Prior exposure to a dead spider did result in higher overall Stroop interference in spider phobics and this appeared to be mostly pronounced for spider-relevant words. Implicit memory bias for threat was examined with a noise judgment task. Participants first heard neutral and spider-relevant sentences and implicit memory for these sentences was evaluated by having participants rate the volume of noise accompanying the presentation of old sentences intermixed with new sentences. An implicit memory bias is indicated if participants rate noise accompanying old sentences as less loud than noise accompanying new sentences. No evidence was found for an implicit memory bias in spider phobics. These findings are discussed in relation to the role of information processing biases in spider phobia.

  3. Interaction between behavioral inhibition and emotional processing in borderline personality disorder using a pictorial emotional go/no-go paradigm.

    Science.gov (United States)

    Sinke, Christopher; Wollmer, M Axel; Kneer, Jonas; Kahl, Kai G; Kruger, Tillmann H C

    2017-10-01

    Borderline personality disorder (BPD) is characterized by difficulties in emotional regulation and impulse control. In this study, we presented a novel picture-based emotional go/no-go task with distracting emotional faces in the background, which was administered to 16 patients with BPD and 16 age-matched healthy controls. The faces displayed different emotional content (angry, neutral, or happy). Results showed differences in sensitivity between patients and the control group, with patients exhibiting less sensitivity in the task, and also showed influences of emotional content represented in the distracting faces in both groups. Specifically, happy faces decreased sensitivity compared to angry faces. It seemed as though processing of a positive emotional stimulus led to a more relaxed state and thereby to decreased sensitivity, while a negative emotional stimulus induced more alertness and tension, leading to higher sensitivity. Thus, this paradigm is suitable to investigate the interplay between emotion processing and impulse control in patients with BPD. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Social Movements Facing the Processes of Globalization: Beyond the Paradigms of Class and Identity

    Directory of Open Access Journals (Sweden)

    Verónica Alfaro

    2004-08-01

    Full Text Available This essay focuses on a particular expression of globalization and regionalization that entails social, political, cultural and economic dimensions: social movements. I argue that current social movements are not necessarily articulated only in terms of class struggle-as the major labor movements were for the last two centuries. Neither do they articulate their protests only in terms of identity and recognition-such as women's movements did in the 1960s. Social movements are now most commonly organized around a discourse that combines those two dimensions. Contemporary social movements are expanding from the structural economic and industrial system (and thus abandoning the form of traditional class struggles to cultural and identity grounds. New social movements are now seen more and more as symbolic challengers, because power-that affects everyday life and tries to manipulate and give social meaning to things-is being contested by individuals in both the public and private spheres. Thus movements have a more symbolic function: they are a new kind of media, fighting for symbolic and cultural stakes, and for a different meaning and orientation of social action. However, constructing a collective identity within a social movement is not definitive. A movement's identity is constructed on an everyday basis, and within the process of globalization, the contact and social interaction with others -with the other, which allows the definition of one's own identity-is not only possible but also necessary. This paper considers the Zapatista rebellion in Chiapas as an empirical approach to social movements expanding from regional, local mobilizations and discourse, to more global oriented contentious activities. I argue that the Zapatista movement's identity in 1994 was quite different from the one it has now: the Ejército Zapatista de Liberación Nacional (EZLN, or Zapatista National Liberation Army discourse has been transformed, from having an ethnic

  5. Processing grounded-wire TEM signal in time-frequency-pseudo-seismic domain: A new paradigm

    Science.gov (United States)

    Khan, M. Y.; Xue, G. Q.; Chen, W.; Huasen, Z.

    2017-12-01

    Grounded-wire TEM has received great attention in mineral, hydrocarbon and hydrogeological investigations for the last several years. Conventionally, TEM soundings have been presented as apparent resistivity curves as function of time. With development of sophisticated computational algorithms, it became possible to extract more realistic geoelectric information by applying inversion programs to 1-D & 3-D problems. Here, we analyze grounded-wire TEM data by carrying out analysis in time, frequency and pseudo-seismic domain supported by borehole information. At first, H, K, A & Q type geoelectric models are processed using a proven inversion program (1-D Occam inversion). Second, time-to-frequency transformation is conducted from TEM ρa(t) curves to magneto telluric MT ρa(f) curves for the same models based on all-time apparent resistivity curves. Third, 1-D Bostick's algorithm was applied to the transformed resistivity. Finally, EM diffusion field is transformed into propagating wave field obeying the standard wave equation using wavelet transformation technique and constructed pseudo-seismic section. The transformed seismic-like wave indicates that some reflection and refraction phenomena appear when the EM wave field interacts with geoelectric interface at different depth intervals due to contrast in resistivity. The resolution of the transformed TEM data is significantly improved in comparison to apparent resistivity plots. A case study illustrates the successful hydrogeophysical application of proposed approach in recovering water-filled mined-out area in a coal field located in Ye county, Henan province, China. The results support the introduction of pseudo-seismic imaging technology in short-offset version of TEM which can also be an useful aid if integrated with seismic reflection technique to explore possibilities for high resolution EM imaging in future.

  6. Stress hormones link food availability and population processes in seabirds

    Science.gov (United States)

    Kitaysky, A.S.; Piatt, John F.; Wingfield, J.C.

    2007-01-01

    Catastrophic population declines in marine top predators in the northern Pacific have been hypothesized to result from nutritional stress affecting reproduction and survival of individuals. However, empirical evidence for food-related stress in wild animals is frequently lacking or inconclusive. We used a field endocrinology approach to measure stress, identify its causes, and examine a link between stress and population processes in the common murre Uria aalge. We tested the empirical relationship between variations in the stress hormone corticosterone (CORT) and food abundance, reproduction, and persistence of individuals at declining and increasing colonies in Cook Inlet, Alaska, from 1996 to 2001. We found that CORT secretion in murres is independent of colony, reproductive stage effects, and gender of individuals, but is directly negatively correlated with abundance of their food. Baseline CORT reflected current food abundance, whereas acute stress-induced CORT reflected food abundance in the previous month. As food supply diminished, increased CORT secretion predicted a decrease in reproductive performance. At a declining colony, increased baseline levels of CORT during reproduction predicted disappearance of individuals from the population. Persistence of individuals in a growing colony was independent of CORT during reproduction. The obtained results support the hypothesis that nutritional stress during reproduction affects reproduction and survival in seabirds. This study provides the first unequivocal evidence for CORT secretion as a mechanistic link between fluctuations in food abundance and population processes in seabirds. ?? Inter-Research 2007.

  7. Posttraumatic Stress and Cognitive Processes in Patients with Burns

    OpenAIRE

    Sveen, Josefin

    2011-01-01

    A severe burn is one of the most traumatic injuries a person can experience. Posttraumatic stress disorder (PTSD) is relatively common after burns, and can be devastating for the individual’s possibilities for recovery. The principal aims were to gain knowledge regarding posttraumatic stress symptoms and cognitive processes after burn and to evaluate methods for assessing symptoms of PTSD up to one year after burn. The psychometric properties of a Swedish version of the Impact of Event Scale-...

  8. Translational Rodent Paradigms to Investigate Neuromechanisms Underlying Behaviors Relevant to Amotivation and Altered Reward Processing in Schizophrenia.

    Science.gov (United States)

    Young, Jared W; Markou, Athina

    2015-09-01

    Amotivation and reward-processing deficits have long been described in patients with schizophrenia and considered large contributors to patients' inability to integrate well in society. No effective treatments exist for these symptoms, partly because the neuromechanisms mediating such symptoms are poorly understood. Here, we propose a translational neuroscientific approach that can be used to assess reward/motivational deficits related to the negative symptoms of schizophrenia using behavioral paradigms that can also be conducted in experimental animals. By designing and using objective laboratory behavioral tools that are parallel in their parameters in rodents and humans, the neuromechanisms underlying behaviors with relevance to these symptoms of schizophrenia can be investigated. We describe tasks that measure the motivation of rodents to expend physical and cognitive effort to gain rewards, as well as probabilistic learning tasks that assess both reward learning and feedback-based decision making. The latter tasks are relevant because of demonstrated links of performance deficits correlating with negative symptoms in patients with schizophrenia. These tasks utilize operant techniques in order to investigate neural circuits targeting a specific domain across species. These tasks therefore enable the development of insights into altered mechanisms leading to negative symptom-relevant behaviors in patients with schizophrenia. Such findings will then enable the development of targeted treatments for these altered neuromechanisms and behaviors seen in schizophrenia. © The Author 2015. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  9. The influence of stress on fear memory processes

    Directory of Open Access Journals (Sweden)

    I.D. Martijena

    2012-04-01

    Full Text Available It is well recognized that stressful experiences promote robust emotional memories, which are well remembered. The amygdaloid complex, principally the basolateral complex (BLA, plays a pivotal role in fear memory and in the modulation of stress-induced emotional responses. A large number of reports have revealed that GABAergic interneurons provide a powerful inhibitory control of the activity of projecting glutamatergic neurons in the BLA. Indeed, a reduced GABAergic control in the BLA is essential for the stress-induced influence on the emergence of associative fear memory and on the generation of long-term potentiation (LTP in BLA neurons. The extracellular signal-regulated kinase (ERK subfamily of the mitogen-activated protein kinase (MAPK signaling pathway in the BLA plays a central role in the consolidation process and synaptic plasticity. In support of the view that stress facilitates long-term fear memory, stressed animals exhibited a phospho-ERK2 (pERK2 increase in the BLA, suggesting the involvement of this mechanism in the promoting influence of threatening stimuli on the consolidation fear memory. Moreover, the occurrence of reactivation-induced lability is prevented when fear memory is encoded under intense stressful conditions since the memory trace remains immune to disruption after recall in previously stressed animals. Thus, the underlying mechanism in retrieval-induced instability seems not to be functional in memories formed under stress. All these findings are indicative that stress influences both the consolidation and reconsolidation fear memory processes. Thus, it seems reasonable to propose that the emotional state generated by an environmental challenge critically modulates the formation and maintenance of long-term fear memory.

  10. Electronic processes in uniaxially stressed p-type germanium

    Energy Technology Data Exchange (ETDEWEB)

    Dubon, Jr., Oscar Danilo [Univ. of California, Berkeley, CA (United States)

    1996-02-01

    Effect of uniaxial stress on acceptor-related electronic processes in Ge single crystals doped with Ga, Be, and Cu were studied by Hall and photo-Hall effect measurements in conjunction with infrared spectroscopy. Stress dependence of hole lifetime in p-type Ge single crystals is used as a test for competing models of non-radiative capture of holes by acceptors. Photo-Hall effect shows that hole lifetime in Ga- and Be-doped Ge increases by over one order of magnitude with uniaxial stress at liq. He temps. Photo-Hall of Ge:Be shows a stress-induced change in the temperature dependence of hole lifetime. This is consistent with observed increase of responsivity of Ge:Ga detectors with uniaxial stress. Electronic properties of Ge:Cu are shown to change dramatically with uniaxial stress; the results provide a first explanation for the performance of uniaxially stressed, Cu-diffused Ge:Ga detectors which display a high conductivity in absence of photon signal and therefore have poor sensitivity.

  11. NMDA receptor modulation by dextromethorphan and acute stress selectively alters electroencephalographic indicators of partial report processing.

    Science.gov (United States)

    Weckesser, Lisa J; Enge, Sören; Riedel, Philipp; Kirschbaum, Clemens; Miller, Robert

    2017-10-01

    Proceeding from a biophysical network model, the present study hypothesized that glutamatergic neurotransmission across the NMDA receptor (NMDAR) plays a key role in visual perception and its modulation by acute stress. To investigate these hypotheses, behavioral and electroencephalographic (EEG) indicators of partial report task processing were assessed in twenty-four healthy young men who randomly received a non-competitive NMDAR antagonist (0.8 mg/kg dextromethorphan, DXM) or a placebo, and concurrently accomplished a stress-induction (MAST) or control protocol in three consecutive sessions. Saliva samples served to quantify cortisol responses to the MAST, whereas a passive auditory oddball paradigm was implemented to verify the impact of DXM on the EEG-derived mismatch negativity component (MMN). DXM administration significantly increased MMN amplitudes but not salivary cortisol concentrations. By contrast, concurrent MAST exposure significantly reduced MMN latencies but also increased cortisol concentrations. With regard to EEG indicators, DXM administration reduced visually "evoked" (30Hz to 50Hz) and "induced" occipital gamma-band activity (70Hz to 100Hz), which was partly compensated by additional MAST exposure. However, neither the interventions nor EEG activity were significantly associated with behavioral partial report sensitivities. In summary, the present data suggest that glutamatergic neurotransmission across the NMDAR is only one among many determinants of intact visual perception. Accordingly, therapeutic doses of DXM and their inhibitory modulation by stress probably yield more pronounced electroencephalographic as compared with behavioural effects. Copyright © 2017 Elsevier B.V. and ECNP. All rights reserved.

  12. Good, bad and ugly word stress--fMRI evidence for foot structure driven processing of prosodic violations.

    Science.gov (United States)

    Domahs, Ulrike; Klein, Elise; Huber, Walter; Domahs, Frank

    2013-06-01

    Using a stress violation paradigm, we investigated whether metrical feet constrain the way prosodic patterns are processed and evaluated. Processing of correctly versus incorrectly stressed words was associated with activation in left posterior angular and retrosplenial cortex, indicating the recognition of an expected and familiar pattern, whereas the inverse contrast yielded enhanced bilateral activation in the superior temporal gyrus, reflecting higher costs in auditory (re-)analysis. More fine-grained analyses of severe versus mild stress violations revealed activations of the left superior temporal and left anterior angular gyrus whereas the opposite contrast led to frontal activations including Broca's area and its right-hemisphere homologue, suggesting that detection of mild violations lead to increased effort in working memory and deeper phonological processing. Our results provide first evidence that different incorrect stress patterns are processed in a qualitatively different way and that the underlying foot structure seems to determine potential stress positions in German words. Copyright © 2013 Elsevier Inc. All rights reserved.

  13. Psychological wellbeing of Turkish university students with physical impairments: an evaluation within the stress-vulnerability paradigm.

    Science.gov (United States)

    Koca-Atabey, Mujde; Karanci, A Nuray; Dirik, Gulay; Aydemir, Deniz

    2011-04-01

    Generally, universities in developing countries offer little in the way of provisions and support (material, emotional, etc.) for disabled students. Therefore, disabled students experience considerable burdens and barriers in their educational life. This study investigated the psychological wellbeing of disabled Turkish university students by examining influences on stress-related growth and psychological distress. Disability is defined within the framework of a social model. According to this view, impairment refers to the functional limitation(s) that affect(s) a person's body, whereas disability refers to the loss or limitation of opportunities owing to social, physical or psychological obstacles. Seventy disabled university students with physical impairments were administered a questionnaire package, including a sociodemographic information sheet, Ways of Coping Questionnaire, Stress-Related Growth Scale, Multidimensional Scale of Social Support, Life Events Inventory, and Brief Symptom Inventory. Snowball sampling was used and voluntary participation was essential. The results showed that disability burden, daily hassles, and helplessness coping were significant predictors of psychological symptoms. For stress-related growth the only variable that appeared significant was problem-solving coping. The results pointed out that there may be different pathways to distress and growth. In order to decrease psychological distress and enhance growth in disabled university students, disability awareness programs, changes in the barriers in the academic and physical environments of the university campuses, and coping skills training to increase problem-focused coping and to combat helplessness may prove to be effective. Reducing daily hassles for the disabled students is likely to contribute to their wellbeing by decreasing their burdens. Also, a more disability-friendly environment is likely to be empowering for disabled university students.

  14. Hardiness and the response to stressful situations: Investigating mediating processes

    NARCIS (Netherlands)

    Delahaij, R.; Gaillard, A.W.K.; Dam, K. van

    2010-01-01

    The present study investigated mediating processes that explain how hardiness influences the way people respond to a stressful situation. Coping style and coping self-efficacy were investigated as mediating variables. Using a longitudinal design, hardiness, coping style and coping self-efficacy, and

  15. Process-induced viscoelastic stress in composite laminates

    International Nuclear Information System (INIS)

    Stango, R.J.

    1985-01-01

    In recent years, considerable interest has developed in evaluating the stress response of composite laminates which is associated with cooling the material system from the cure temperature to room temperature. This research examines the fundamental nature of time-dependent residual-thermal stresses in composite laminates which are caused by the extreme temperature reduction encountered during the fabrication process. Viscoelastic stress in finite-width, symmetric composite laminates is examined on the basis of a formulation that employs an incremental hereditary integral approach in conjunction with a quasi-three dimensional finite element analysis. A consistent methodology is developed and employed for the characterization of lamina material properties. Special attention is given to the time-dependent stress response at ply-interface locations near the free-edge. In addition, the influence of cooling path on stress history is examined. Recently published material property data for graphite-epoxy lamina is employed in the analysis. Results of the investigation generally indicate that nominal differences between the thermoelastic and viscoelastic solutions are obtained. Slight changes of the final stress state are observed to result when different cooling paths are selected for the temperature history. The methodology employed is demonstrated to result in an accurate, efficient, and consistent approach for the viscoelastic analysis of advanced composite laminates

  16. Re-appraisal of the Magma-rich versus Magma-poor Paradigm at Rifted Margins: consequences for breakup processes

    Science.gov (United States)

    Tugend, J.; Gillard, M.; Manatschal, G.; Nirrengarten, M.; Harkin, C. J.; Epin, M. E.; Sauter, D.; Autin, J.; Kusznir, N. J.; McDermott, K.

    2017-12-01

    Rifted margins are often classified based on their magmatic budget only. Magma-rich margins are commonly considered to have excess decompression melting at lithospheric breakup compared with steady state seafloor spreading while magma-poor margins have suppressed melting. New observations derived from high quality geophysical data sets and drill-hole data have revealed the diversity of rifted margin architecture and variable distribution of magmatism. Recent studies suggest, however, that rifted margins have more complex and polyphase tectono-magmatic evolutions than previously assumed and cannot be characterized based on the observed volume of magma alone. We compare the magmatic budget related to lithospheric breakup along two high-resolution long-offset deep reflection seismic profiles across the SE-Indian (magma-poor) and Uruguayan (magma-rich) rifted margins. Resolving the volume of magmatic additions is difficult. Interpretations are non-unique and several of them appear plausible for each case involving variable magmatic volumes and mechanisms to achieve lithospheric breakup. A supposedly 'magma-poor' rifted margin (SE-India) may show a 'magma-rich' lithospheric breakup whereas a 'magma-rich' rifted margin (Uruguay) does not necessarily show excess magmatism at lithospheric breakup compared with steady-state seafloor spreading. This questions the paradigm that rifted margins can be subdivided in either magma-poor or magma-rich margins. The Uruguayan and other magma-rich rifted margins appear characterized by an early onset of decompression melting relative to crustal breakup. For the converse, where the onset of decompression melting is late compared with the timing of crustal breakup, mantle exhumation can occur (e.g. SE-India). Our work highlights the difficulty in determining a magmatic budget at rifted margins based on seismic reflection data alone, showing the limitations of margin classification based solely on magmatic volumes. The timing of

  17. Membrane paradigm

    International Nuclear Information System (INIS)

    Price, R.H.; Thorne, K.S.

    1986-01-01

    The membrane paradigm is a modified frozen star approach to modeling black holes, with particles and fields assuming a complex, static, boundary-layer type structure (membrane) near the event horizon. The membrane has no effects on the present or future evolution of particles and fields above itself. The mathematical representation is a combination of a formalism containing terms for the shear and bulk viscosity, surface pressure, momentum, temperature, entropy, etc., of the horizon and the 3+1 formalism. The latter model considers a family of three-dimensional spacelike hypersurfaces in one-dimensional time. The membrane model considers a magnetic field threading the hole and undergoing torque from the hole rotation. The field is cleaned by the horizon and distributed over the horizon so that ohmic dissipation is minimized. The membrane paradigm is invalid inside the horizon, but is useful for theoretically probing the properties of slowly evolving black holes

  18. Information-Processing Alternatives to Holistic Perception: Identifying the Mechanisms of Secondary-Level Holism within a Categorization Paradigm

    Science.gov (United States)

    Fific, Mario; Townsend, James T.

    2010-01-01

    Failure to selectively attend to a facial feature, in the part-to-whole paradigm, has been taken as evidence of holistic perception in a large body of face perception literature. In this article, we demonstrate that although failure of selective attention is a necessary property of holistic perception, its presence alone is not sufficient to…

  19. Modular Energy-Efficient and Robust Paradigms for a Disaster-Recovery Process over Wireless Sensor Networks.

    Science.gov (United States)

    Razaque, Abdul; Elleithy, Khaled

    2015-07-06

    Robust paradigms are a necessity, particularly for emerging wireless sensor network (WSN) applications. The lack of robust and efficient paradigms causes a reduction in the provision of quality of service (QoS) and additional energy consumption. In this paper, we introduce modular energy-efficient and robust paradigms that involve two archetypes: (1) the operational medium access control (O-MAC) hybrid protocol and (2) the pheromone termite (PT) model. The O-MAC protocol controls overhearing and congestion and increases the throughput, reduces the latency and extends the network lifetime. O-MAC uses an optimized data frame format that reduces the channel access time and provides faster data delivery over the medium. Furthermore, O-MAC uses a novel randomization function that avoids channel collisions. The PT model provides robust routing for single and multiple links and includes two new significant features: (1) determining the packet generation rate to avoid congestion and (2) pheromone sensitivity to determine the link capacity prior to sending the packets on each link. The state-of-the-art research in this work is based on improving both the QoS and energy efficiency. To determine the strength of O-MAC with the PT model; we have generated and simulated a disaster recovery scenario using a network simulator (ns-3.10) that monitors the activities of disaster recovery staff; hospital staff and disaster victims brought into the hospital. Moreover; the proposed paradigm can be used for general purpose applications. Finally; the QoS metrics of the O-MAC and PT paradigms are evaluated and compared with other known hybrid protocols involving the MAC and routing features. The simulation results indicate that O-MAC with PT produced better outcomes.

  20. Modular Energy-Efficient and Robust Paradigms for a Disaster-Recovery Process over Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Abdul Razaque

    2015-07-01

    Full Text Available Robust paradigms are a necessity, particularly for emerging wireless sensor network (WSN applications. The lack of robust and efficient paradigms causes a reduction in the provision of quality of service (QoS and additional energy consumption. In this paper, we introduce modular energy-efficient and robust paradigms that involve two archetypes: (1 the operational medium access control (O-MAC hybrid protocol and (2 the pheromone termite (PT model. The O-MAC protocol controls overhearing and congestion and increases the throughput, reduces the latency and extends the network lifetime. O-MAC uses an optimized data frame format that reduces the channel access time and provides faster data delivery over the medium. Furthermore, O-MAC uses a novel randomization function that avoids channel collisions. The PT model provides robust routing for single and multiple links and includes two new significant features: (1 determining the packet generation rate to avoid congestion and (2 pheromone sensitivity to determine the link capacity prior to sending the packets on each link. The state-of-the-art research in this work is based on improving both the QoS and energy efficiency. To determine the strength of O-MAC with the PT model; we have generated and simulated a disaster recovery scenario using a network simulator (ns-3.10 that monitors the activities of disaster recovery staff; hospital staff and disaster victims brought into the hospital. Moreover; the proposed paradigm can be used for general purpose applications. Finally; the QoS metrics of the O-MAC and PT paradigms are evaluated and compared with other known hybrid protocols involving the MAC and routing features. The simulation results indicate that O-MAC with PT produced better outcomes.

  1. Numerical analysis of stress fields generated by quenching process

    Directory of Open Access Journals (Sweden)

    A. Bokota

    2011-04-01

    Full Text Available In work the presented numerical models of tool steel hardening processes take into account mechanical phenomena generated by thermalphenomena and phase transformations. In the model of mechanical phenomena, apart from thermal, plastic and structural strain, alsotransformations plasticity was taken into account. The stress and strain fields are obtained using the solution of the Finite Elements Method of the equilibrium equation in rate form. The thermophysical constants occurring in constitutive relation depend on temperature and phase composite. For determination of plastic strain the Huber-Misses condition with isotropic strengthening was applied whereas fordetermination of transformation plasticity a modified Leblond model was used. In order to evaluate the quality and usefulness of thepresented models a numerical analysis of stresses and strains associated hardening process of a fang lathe of cone shaped made of tool steel was carried out.

  2. Information Processing Bias in Post-traumatic Stress Disorder

    OpenAIRE

    Weber, Darren L

    2008-01-01

    This review considers theory and evidence for abnormal information processing in post-traumatic stress disorder (PTSD). Cognitive studies have indicated sensitivity in PTSD for traumatic information, more so than general emotional information. These findings were supported by neuroimaging studies that identify increased brain activity during traumatic cognition, especially in affective networks (including the amygdala, orbitofrontal and anterior cingulate cortex). In theory, it is proposed th...

  3. Abnormal emotional processing in maltreated children diagnosed of Complex Posttraumatic Stress Disorder.

    Science.gov (United States)

    Bertó, Clara; Ferrin, Maite; Barberá, María; Livianos, Lorenzo; Rojo, Luis; García-Blanco, Ana

    2017-11-01

    Maltreated children usually show a specific pattern of emotional and behavioral symptoms that exceed those relating to posttraumatic stress disorder (PTSD). These symptoms have been defined as Complex PTSD (CPTSD). The underlying attentional mechanisms of abnormal emotional processing and their relation to the clinical presentation of CPTSD are not well understood. A visual dot-probe paradigm involving pre-attentive (i.e., 500ms) and attentive (i.e., 1500ms) presentation rates of neutral versus emotional (i.e., angry, happy or sad) facial expressions was applied. Twenty-one maltreated CPTSD children were compared with twenty-six controls. The results are as follows: an attention bias away from threatening faces and an attentional bias towards sad faces were observed in maltreated CPTSD children during pre-attentive and attentive processing. Whereas the attentional bias away from angry faces was associated with social problems, the attentional bias towards sad faces was associated with depressive and withdrawn symptoms. Therefore, CPTSD children develop maladaptive negative cognitive styles, which may underlie not only social problems (by a cognitive avoidance of threatening stimuli) but also depressive symptoms (by a cognitive approach to sad stimuli). Attention processing abnormalities should be considered as therapeutic targets for new treatment approaches in this population. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. STRESS AND NEURODEVELOPMENTAL PROCESSES IN THE EMERGENCE OF PSYCHOSIS

    Science.gov (United States)

    Holtzman, C. W.; Trotman, H. D.; Goulding, S. M.; Ryan, A. T.; Macdonald, A. N.; Shapiro, D. I.; Brasfield, J. L.; Walker, E. F.

    2014-01-01

    The notion that stress plays a role in the etiology of psychotic disorders, especially schizophrenia, is longstanding. However, it is only in recent years that the potential neural mechanisms mediating this effect have come into sharper focus. The introduction of more sophisticated models of the interplay between psychosocial factors and brain function has expanded our opportunities for conceptualizing more detailed psychobiological models of stress in psychosis. Further, scientific advances in our understanding of adolescent brain development have shed light on a pivotal question that has challenged researchers; namely, why the first episode of psychosis typically occurs in late adolescence/young adulthood. In this paper, we begin by reviewing the evidence supporting associations between psychosocial stress and psychosis in diagnosed patients as well as individuals at clinical high risk for psychosis. We then discuss biological stress systems and examine changes that precede and follow psychosis onset. Next, research findings on structural and functional brain characteristics associated with psychosis are presented; these findings suggest that normal adolescent neuromaturational processes may go awry, thereby setting the stage for the emergence of psychotic syndromes. Finally, a model of neural mechanisms underlying the pathogenesis of psychosis is presented and directions for future research strategies are explored. PMID:23298853

  5. Delayed memory effects after intense stress in Special Forces candidates: exploring path processes between cortisol secretion and memory recall.

    Science.gov (United States)

    Taverniers, John; Taylor, Marcus K; Smeets, Tom

    2013-05-01

    The aim of this paper is twofold. First, it explores delayed effects of high endogenously evoked cortisol concentrations on visuo-spatial declarative memory. Subsequently, it applies multiple mediation (MM) analyses to reveal path processes between stress and cognitive performance in a sample of 24 male Special Forces (SF) candidates (mean age = 27.0 years, SD = 4.1). The SF candidates were randomly assigned to a control (n = 12) or an intense stress group (n = 12), and cortisol secretion for the intense stress condition was triggered by a brusque 60 min prisoner of war exercise. Stress exposure provoked robust increases in cortisol concentrations and a significant decline in immediate recall performance, measured with the Rey-Osterrieth Complex Figure (ROCF). The relative retrieval differences in regard to the ROCF persisted even after a recovery period of 24 h, as both groups showed similar levels of memory decline over 24 h. Next, the study applied a MM design that involved distribution-independent asymptotic and resampling strategies to extend traditional bivariate analyses. MM results showed that ROCF performance was mediated by increases in cortisol concentrations. Considering the studied variables, the current analysis was the first to provide statistical support for the generally accepted thesis that cortisol secretion in itself, rather than subjective strain or the experimental treatment, affects cognitive performance. The revelation of such path processes is important because it establishes process identification and may refine existing paradigms.

  6. NUMERICAL SIMULATION OF RESIDUAL STRESSES GENERATED IN THE WIRE DRAWING PROCESS FOR DIFFERENT PROCESS PARAMETERS

    Directory of Open Access Journals (Sweden)

    Juliana Zottis

    2014-03-01

    Full Text Available The drawing process of steel bars is usually used to check better dimensional accuracy and mechanical properties to the material. In the other hand, the major concern found in manufacturing axes through this process is the appearance of distortion of shape. Such distortions are directly linked to the accumulation of residual stresses generated during the processes. As a result, this paper aims to study the influence of process parameters such as shape of puller, speed and lubrication used in wire drawing analyzing the accumulation of residual stress after the process. The stress analysis was performed by FEM being used two simulation software: Simufact.formingGP and DeformTM. Through these analyzes, it was found that the shape of how the bar is pulled causes a reduction of up to 100 MPa in residual stresses in the center of the bar, which represents an important factor in the study of the possible causes of the distortion. As well as factors speed and homogeneity of lubrication significantly altered the profile of residual stresses in the bar.

  7. Modelling Of Residual Stresses Induced By High Speed Milling Process

    International Nuclear Information System (INIS)

    Desmaison, Olivier; Mocellin, Katia; Jardin, Nicolas

    2011-01-01

    Maintenance processes used in heavy industries often include high speed milling operations. The reliability of the post-process material state has to be studied. Numerical simulation appears to be a very interesting way to supply an efficient residual stresses (RS) distribution prediction.Because the adiabatic shear band and the serrated chip shaping are features of the austenitic stainless steel high speed machining, a 2D high speed orthogonal cutting model is briefly presented. This finite element model, developed on Forge registered software, is based on data taken from Outeiro and al.'s paper [1]. A new behaviour law fully coupling Johnson-Cook's constitutive law and Latham and Cockcroft's damage model is detailed in this paper. It ensures results that fit those found in literature.Then, the numerical tools used on the 2D model are integrated to a 3D high speed milling model. Residual stresses distribution is analysed, on the surface and into the depth of the material. Various revolutions and passes of the two teeth hemispheric mill on the workpiece are simulated. Thus the sensitivity of the residual stresses generation to the cutting conditions can be discussed. In order to validate the 3D model, a comparison of the cutting forces measured by EDF R and D to those given by numerical simulations is achieved.

  8. PARADIGMS IN CONSUMER BEHAVIOR

    OpenAIRE

    Sabrina Oktoria Sihombing

    2011-01-01

    A paradigm influences what we see and conceive about certain facts. Paradigm can also influence what we accept as a truth. Yet, the debate over which paradigm and methodology is best suit for marketing and consumer behavior has begun since 1980s. Many researchers criticized the domination of logical empiricism paradigm and offered alternative paradigm to understand marketing and consumer behavior. This article discusses several paradigms and methodology, which are part of qualitative paradigm...

  9. Examining distinct working memory processes in children and adolescents using fMRI: Results and validation of a modified Brown-Peterson paradigm.

    Science.gov (United States)

    Siffredi, Vanessa; Barrouillet, Pierre; Spencer-Smith, Megan; Vaessen, Maarten; Anderson, Vicki; Vuilleumier, Patrik

    2017-01-01

    Verbal working memory (WM) comprises different processes (encoding, maintenance, retrieval) that are often compromised in brain diseases, but their neural correlates have not yet been examined in childhood and adolescence. To probe WM processes and associated neural correlates in developmental samples, and obtain comparable effects across different ages and populations, we designed an adapted Brown-Peterson task (verbal encoding and retrieval combined with verbal and visual concurrent tasks during maintenance) to implement during functional magnetic resonance imaging (fMRI). In a sample of typically developing children and adolescents (n = 16), aged 8 to 16 years, our paradigm successfully identified distinct patterns of activation for encoding, maintenance, and retrieval. While encoding activated perceptual systems in posterior and ventral visual regions, retrieval activated fronto-parietal regions associated with executive control and attention. We found a different impact of verbal versus visual concurrent processing during WM maintenance: at retrieval, the former condition evoked greater activations in visual cortex, as opposed to selective involvement of language-related areas in left temporal cortex in the latter condition. These results are in accord with WM models, suggesting greater competition for processing resources when retrieval follows within-domain compared with cross-domain interference. This pattern was found regardless of age. Our study provides a novel paradigm to investigate distinct WM brain systems with reliable results across a wide age range in developmental populations, and suitable for participants with different WM capacities.

  10. Examining distinct working memory processes in children and adolescents using fMRI: Results and validation of a modified Brown-Peterson paradigm.

    Directory of Open Access Journals (Sweden)

    Vanessa Siffredi

    Full Text Available Verbal working memory (WM comprises different processes (encoding, maintenance, retrieval that are often compromised in brain diseases, but their neural correlates have not yet been examined in childhood and adolescence. To probe WM processes and associated neural correlates in developmental samples, and obtain comparable effects across different ages and populations, we designed an adapted Brown-Peterson task (verbal encoding and retrieval combined with verbal and visual concurrent tasks during maintenance to implement during functional magnetic resonance imaging (fMRI. In a sample of typically developing children and adolescents (n = 16, aged 8 to 16 years, our paradigm successfully identified distinct patterns of activation for encoding, maintenance, and retrieval. While encoding activated perceptual systems in posterior and ventral visual regions, retrieval activated fronto-parietal regions associated with executive control and attention. We found a different impact of verbal versus visual concurrent processing during WM maintenance: at retrieval, the former condition evoked greater activations in visual cortex, as opposed to selective involvement of language-related areas in left temporal cortex in the latter condition. These results are in accord with WM models, suggesting greater competition for processing resources when retrieval follows within-domain compared with cross-domain interference. This pattern was found regardless of age. Our study provides a novel paradigm to investigate distinct WM brain systems with reliable results across a wide age range in developmental populations, and suitable for participants with different WM capacities.

  11. Numerical modelling of stresses and deformations in casting processes

    DEFF Research Database (Denmark)

    Hattel, Jesper Henri

    1997-01-01

    Keywords: Stresses and deformations, casting, governing equations, thermal strain, control volume method......Keywords: Stresses and deformations, casting, governing equations, thermal strain, control volume method...

  12. PARADIGMS IN CONSUMER BEHAVIOR

    Directory of Open Access Journals (Sweden)

    Sabrina Oktoria Sihombing

    2011-05-01

    Full Text Available A paradigm influences what we see and conceive about certain facts. Paradigm can also influence what we accept as a truth. Yet, the debate over which paradigm and methodology is best suit for marketing and consumer behavior has begun since 1980s. Many researchers criticized the domination of logical empiricism paradigm and offered alternative paradigm to understand marketing and consumer behavior. This article discusses several paradigms and methodology, which are part of qualitative paradigm, and compares them with positivism paradigm. This article will also point to the importance of reconciliation between qualitative and quantitative paradigm in order to improve marketing and consumer behavior studies.

  13. Aberrant Neural Connectivity during Emotional Processing Associated with Posttraumatic Stress.

    Science.gov (United States)

    Sadeh, Naomi; Spielberg, Jeffrey M; Warren, Stacie L; Miller, Gregory A; Heller, Wendy

    2014-11-01

    Given the complexity of the brain, characterizing relations among distributed brain regions is likely essential to describing the neural instantiation of posttraumatic stress symptoms. This study examined patterns of functional connectivity among key brain regions implicated in the pathophysiology of posttraumatic stress disorder (PTSD) in 35 trauma-exposed adults using an emotion-word Stroop task. PTSD symptom severity (particularly hyperarousal symptoms) moderated amygdala-mPFC coupling during the processing of unpleasant words, and this moderation correlated positively with reported real-world impairment and amygdala reactivity. Reexperiencing severity moderated hippocampus-insula coupling during pleasant and unpleasant words. Results provide evidence that PTSD symptoms differentially moderate functional coupling during emotional interference and underscore the importance of examining network connectivity in research on PTSD. They suggest that hyperarousal is associated with negative mPFC-amygdala coupling and that reexperiencing is associated with altered insula-hippocampus function, patterns of connectivity that may represent separable indicators of dysfunctional inhibitory control during affective processing.

  14. Mediating processes between stress and problematic marijuana use.

    Science.gov (United States)

    Ketcherside, Ariel; Filbey, Francesca M

    2015-06-01

    The literature widely reports that stress is associated with marijuana use, yet, to date, the path from stress to marijuana-related problems has not been tested. In this study, we evaluated whether negative affect mediates the relationship between stress and marijuana use. To that end, we tested models to determine mediators between problems with marijuana use (via Marijuana Problem Scale), stress (via Early Life Stress Questionnaire, Perceived Stress Scale), and negative affect (via Beck Depression Inventory; Beck Anxiety Inventory) in 157 current heavy marijuana users. Mediation tests and bootstrap confidence intervals were carried out via the "Mediation" package in R. Depression and anxiety scores both significantly mediated the relationship between perceived stress and problematic marijuana use. Only depression significantly mediated the relationship between early life stress and problematic marijuana use. Early life stress, perceived stress and problematic marijuana use were significant only as independent variables and dependent variables. These findings demonstrate that (1) depression mediated both early life stress and perceived stress, and problematic marijuana use, and, (2) anxiety mediated perceived stress and problematic marijuana use. This mediation analysis represents a strong first step toward understanding the relationship between these variables; however, longitudinal studies are needed to determine causality between these variables. To conclude, addressing concomitant depression and anxiety in those who report either perceived stress or early life stress is important for the prevention of cannabis use disorders. Copyright © 2015. Published by Elsevier Ltd.

  15. The role of stressors and psychosocial variables in the stress process: a study of chronic caregiver stress.

    Science.gov (United States)

    Vedhara, K; Shanks, N; Anderson, S; Lightman, S

    2000-01-01

    An investigation was conducted 1) to examine the relative importance of stressor types (ie, daily hassles, caregiving-specific stressors, and life events) on the stress response, 2) to assess the stability of relationships between psychosocial variables and stress over a 6-month period, and 3) to explore how the nature and magnitude of the contributions made by stressors and psychosocial factors to the stress process varied according to the qualitative characteristics of the stress response (ie, anxiety, depression, and stress). Fifty spousal caregivers of patients with dementia were recruited and asked to participate in a detailed psychosocial evaluation at 3-month intervals; the evaluation involved measurement of stressor frequency, psychosocial variables, and indices of the stress response (ie, anxiety, depression, and stress). The data revealed that the effects of stressors and psychosocial factors on the stress response were considerable (accounting for 49-63% of the variance in stress response measures). Furthermore, there was some evidence of stability in the effects of the stressor and mediator variables on the stress response. Specifically, the contributions of life events and caregiver difficulties were largely consistent at both 3 and 6 months, and the psychosocial factor of "reactive coping and self-appraisal" influenced all three stress response indices at both 3 and 6 months. There is some evidence of stability in the effects of stressors and psychosocial variables on the stress process over a 6-month period. However, it would also seem that the nature of the stress process differs according to the qualitative characteristics of the stress response.

  16. Examining the aging process through the stress-coping framework: application to driving cessation in later life.

    Science.gov (United States)

    Choi, Moon; Adams, Kathryn Betts; Mezuk, Briana

    2012-01-01

    The aging process is marked by a series of transitions that influence multiple domains of well-being. One important transition for older adults is the process of driving cessation. Numerous studies have examined risk factors for driving cessation among older adults to identify at-risk older drivers for road safety. Recent research has focused on the consequences of driving cessation in later life for health and well-being. However, these reports have been largely empirical and are not drawn from a defined conceptual framework. Establishing a theoretical model of 'how driving cessation interacts with other processes and domains of aging' will promote synthesis of seemingly disparate findings and also link the empirical research on cessation to the broader field of gerontology. This article describes a conceptual model for articulating and examining the components of the driving cessation process based on the stress-coping paradigm. This model situates driving cessation within the context of exogenous stressors, individual vulnerabilities and coping strategies, and environmental hazards and buffers over the lifespan. This model could assist in guiding intervention strategies aimed at reducing premature driving cessation in older drivers with ameliorable impairments while assisting at-risk older drivers to reduce or stop driving in a less stressful way.

  17. Examining the aging process through the stress-coping framework: application to driving cessation in later life

    Science.gov (United States)

    Choi, Moon; Adams, Kathryn Betts; Mezuk, Briana

    2017-01-01

    The aging process is marked by a series of transitions that influence multiple domains of well-being. One important transition for older adults is the process of driving cessation. Numerous studies have examined risk factors for driving cessation among older adults to identify at-risk older drivers for road safety. Recent research has focused on the consequences of driving cessation in later life for health and well-being. However, these reports have been largely empirical and are not drawn from a defined conceptual framework. Establishing a theoretical model of ‘how driving cessation interacts with other processes and domains of aging’ will promote synthesis of seemingly disparate findings and also link the empirical research on cessation to the broader field of gerontology. This article describes a conceptual model for articulating and examining the components of the driving cessation process based on the stress-coping paradigm. This model situates driving cessation within the context of exogenous stressors, individual vulnerabilities and coping strategies, and environmental hazards and buffers over the lifespan. This model could assist in guiding intervention strategies aimed at reducing premature driving cessation in older drivers with ameliorable impairments while assisting at-risk older drivers to reduce or stop driving in a less stressful way. PMID:21702704

  18. Three-dimensional x-ray tomography of crack-resistant composites: New paradigms for process optimization

    Energy Technology Data Exchange (ETDEWEB)

    Kinney, J.H.; Haupt, D.L. [Lawrence Livermore National Laboratory, CA (United States)

    1995-05-01

    The goal of this research is to apply noninvasive, volumetric imaging technology (the x-ray tomographic microscope) to the characterization and process-modeling of ceramic matrix composites. Specifically, we propose to follow the evolution of a composite`s microstructure during chemical vapor infiltration processing, and relate the microstructure to processing parameters and fiber architecture. The results will be used to provide the fundamental and practical understanding necessary for cost-effective intelligent processing of ceramic matrix composites.

  19. Identification and location tasks rely on different mental processes: a diffusion model account of validity effects in spatial cueing paradigms with emotional stimuli.

    Science.gov (United States)

    Imhoff, Roland; Lange, Jens; Germar, Markus

    2018-02-22

    Spatial cueing paradigms are popular tools to assess human attention to emotional stimuli, but different variants of these paradigms differ in what participants' primary task is. In one variant, participants indicate the location of the target (location task), whereas in the other they indicate the shape of the target (identification task). In the present paper we test the idea that although these two variants produce seemingly comparable cue validity effects on response times, they rest on different underlying processes. Across four studies (total N = 397; two in the supplement) using both variants and manipulating the motivational relevance of cue content, diffusion model analyses revealed that cue validity effects in location tasks are primarily driven by response biases, whereas the same effect rests on delay due to attention to the cue in identification tasks. Based on this, we predict and empirically support that a symmetrical distribution of valid and invalid cues would reduce cue validity effects in location tasks to a greater extent than in identification tasks. Across all variants of the task, we fail to replicate the effect of greater cue validity effects for arousing (vs. neutral) stimuli. We discuss the implications of these findings for best practice in spatial cueing research.

  20. The Role of Semantic Processing in Reading Japanese Orthographies: An Investigation Using a Script-Switch Paradigm

    Science.gov (United States)

    Dylman, Alexandra S.; Kikutani, Mariko

    2018-01-01

    Research on Japanese reading has generally indicated that processing of the logographic script Kanji primarily involves whole-word lexical processing and follows a semantics-to-phonology route, while the two phonological scripts Hiragana and Katakana (collectively called Kana) are processed via a sub-lexical route, and more in a…

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

    NARCIS (Netherlands)

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

    2016-01-01

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

  2. Research on Stress Neutral Layer Offset in the Straightening Process

    Directory of Open Access Journals (Sweden)

    Hailian Gui

    2015-01-01

    Full Text Available The stress neutral layer offset is analyzed by theoretical and numerical calculation methods. In traditional straightening theory, the stress neutral layer was consistent with the geometric central layer. However, there is a phenomenon that the stress neutral layer has some offset with the geometric neutral layer. This offset is a very important factor for improving the precision of the straightening force. The formula of the stress neutral layer offset is obtained by a theoretical method and the change law is given by numerical calculation method. The neutral layer offset theory provides the theoretical basis for establishing the model of straightening force precisely.

  3. Aging and magnetism: Presenting a possible new holistic paradigm for ameliorating the aging process and the effects thereof, through externally applied physiologic PicoTesla magnetic fields.

    Science.gov (United States)

    Jacobson, Jerry; Sherlag, Benjamin

    2015-09-01

    A new holistic paradigm is proposed for slowing our genomic-based biological clocks (e.g. regulation of telomere length), and decreasing heat energy exigencies for maintenance of physiologic homeostasis. Aging is considered the result of a progressive slow burn in small volumes of tissues with increase in the quantum entropic states; producing desiccation, microscopic scarring, and disruption of cooperative coherent states. Based upon piezoelectricity, i.e. photon-phonon transductions, physiologic PicoTesla range magnetic fields may decrease the production of excessive heat energy through target specific, bio molecular resonant interactions, renormalization of intrinsic electromagnetic tissue profiles, and autonomic modulation. Prospectively, we hypothesize that deleterious effects of physical trauma, immunogenic microbiological agents, stress, and anxiety may be ameliorated. A particle-wave equation is cited to ascertain magnetic field parameters for application to the whole organism thereby achieving desired homeostasis; secondary to restoration of structure and function on quantum levels. We hypothesize that it is at the atomic level that physical events shape the flow of signals and the transmission of energy in bio molecular systems. References are made to experimental data indicating the aspecific efficacy of non-ionizing physiologic magnetic field profiles for treatment of various pathologic states. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Setting a new paradigm in cognitive science information: contributions to the process of knowing the information professional

    Directory of Open Access Journals (Sweden)

    Paula Regina Dal' Evedove

    2013-05-01

    Full Text Available Introduction: Studies about human cognition represent a relevant perspective in information science, considering the subjective actions of information professionals and dialogic process that should permeate the activity of subjects dealing with the organization and representation of information.Objective: Explore the approach of the cognitive perspective in information science and their new settings by contemporary needs of information to reflect on the process of meeting the professional information through the social reality that permeates the contexts of information.Methodology: Reflection on theoretical aspects that deal with the cognitive development to discuss the implications of the cognitive approach in information science and its evolution in the scope of the representation and processing of information.Results: Research in Information Science must consider issues of cognitive and social order that underlie information processing and the process of knowing the information professional as knowledge structures must be explained from the social context of knowing subjects.Conclusions: There is a need to investigate the process of knowing the information professional in the bias of socio-cognitive approach, targeting new elements for the understanding of the relationship information (cognitive manifestations and its implications on the social dimension.

  5. Stress as a mnemonic filter: Interactions between medial temporal lobe encoding processes and post-encoding stress.

    Science.gov (United States)

    Ritchey, Maureen; McCullough, Andrew M; Ranganath, Charan; Yonelinas, Andrew P

    2017-01-01

    Acute stress has been shown to modulate memory for recently learned information, an effect attributed to the influence of stress hormones on medial temporal lobe (MTL) consolidation processes. However, little is known about which memories will be affected when stress follows encoding. One possibility is that stress interacts with encoding processes to selectively protect memories that had elicited responses in the hippocampus and amygdala, two MTL structures important for memory formation. There is limited evidence for interactions between encoding processes and consolidation effects in humans, but recent studies of consolidation in rodents have emphasized the importance of encoding "tags" for determining the impact of consolidation manipulations on memory. Here, we used functional magnetic resonance imaging in humans to test the hypothesis that the effects of post-encoding stress depend on MTL processes observed during encoding. We found that changes in stress hormone levels were associated with an increase in the contingency of memory outcomes on hippocampal and amygdala encoding responses. That is, for participants showing high cortisol reactivity, memories became more dependent on MTL activity observed during encoding, thereby shifting the distribution of recollected events toward those that had elicited relatively high activation. Surprisingly, this effect was generally larger for neutral, compared to emotionally negative, memories. The results suggest that stress does not uniformly enhance memory, but instead selectively preserves memories tagged during encoding, effectively acting as mnemonic filter. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  6. Modelling health care processes for eliciting user requirements: a way to link a quality paradigm and clinical information system design.

    Science.gov (United States)

    Staccini, P; Joubert, M; Quaranta, J F; Fieschi, D; Fieschi, M

    2001-12-01

    Healthcare institutions are looking at ways to increase their efficiency by reducing costs while providing care services with a high level of safety. Thus, hospital information systems have to support quality improvement objectives. The elicitation of the requirements has to meet users' needs in relation to both the quality (efficacy, safety) and the monitoring of all health care activities (traceability). Information analysts need methods to conceptualise clinical information systems that provide actors with individual benefits and guide behavioural changes. A methodology is proposed to elicit and structure users' requirements using a process-oriented analysis, and it is applied to the blood transfusion process. An object-oriented data model of a process has been defined in order to organise the data dictionary. Although some aspects of activity, such as 'where', 'what else', and 'why' are poorly represented by the data model alone, this method of requirement elicitation fits the dynamic of data input for the process to be traced. A hierarchical representation of hospital activities has to be found for the processes to be interrelated, and for their characteristics to be shared, in order to avoid data redundancy and to fit the gathering of data with the provision of care.

  7. A novel process for introducing a new intraoperative program: a multidisciplinary paradigm for mitigating hazards and improving patient safety.

    Science.gov (United States)

    Rodriguez-Paz, Jose M; Mark, Lynette J; Herzer, Kurt R; Michelson, James D; Grogan, Kelly L; Herman, Joseph; Hunt, David; Wardlow, Linda; Armour, Elwood P; Pronovost, Peter J

    2009-01-01

    Since the Institute of Medicine's report, To Err is Human, was published, numerous interventions have been designed and implemented to correct the defects that lead to medical errors and adverse events; however, most efforts were largely reactive. Safety, communication, team performance, and efficiency are areas of care that attract a great deal of attention, especially regarding the introduction of new technologies, techniques, and procedures. We describe a multidisciplinary process that was implemented at our hospital to identify and mitigate hazards before the introduction of a new technique: high-dose-rate intraoperative radiation therapy, (HDR-IORT). A multidisciplinary team of surgeons, anesthesiologists, radiation oncologists, physicists, nurses, hospital risk managers, and equipment specialists used a structured process that included in situ clinical simulation to uncover concerns among care providers and to prospectively identify and mitigate defects for patients who would undergo surgery using the HDR-IORT technique. We identified and corrected 20 defects in the simulated patient care process before application to actual patients. Subsequently, eight patients underwent surgery using the HDR-IORT technique with no recurrence of simulation-identified or unanticipated defects. Multiple benefits were derived from the use of this systematic process to introduce the HDR-IORT technique; namely, the safety and efficiency of care for this select patient population was optimized, and this process mitigated harmful or adverse events before the inclusion of actual patients. Further work is needed, but the process outlined in this paper can be universally applied to the introduction of any new technologies, treatments, or procedures.

  8. L[subscript 1] and L[subscript 2] Spoken Word Processing: Evidence from Divided Attention Paradigm

    Science.gov (United States)

    Shafiee Nahrkhalaji, Saeedeh; Lotfi, Ahmad Reza; Koosha, Mansour

    2016-01-01

    The present study aims to reveal some facts concerning first language (L[subscript 1]) and second language (L[subscript 2]) spoken-word processing in unbalanced proficient bilinguals using behavioral measures. The intention here is to examine the effects of auditory repetition word priming and semantic priming in first and second languages of…

  9. Methamphetamine Use among Rural White and Native American Adolescents: An Application of the Stress Process Model

    Science.gov (United States)

    Eitle, David J.; Eitle, Tamela McNulty

    2013-01-01

    Methamphetamine use has been identified as having significant adverse health consequences, yet we know little about the correlates of its use. Additionally, research has found that Native Americans are at the highest risk for methamphetamine use. Our exploratory study, informed by the stress process model, examines stress and stress buffering…

  10. Acute stress-induced cortisol elevations mediate reward system activity during subconscious processing of sexual stimuli

    NARCIS (Netherlands)

    Oei, N.Y.L.; Both, S.; van Heemst, D.; van der Grond, J.

    2014-01-01

    Stress is thought to alter motivational processes by increasing dopamine (DA) secretion in the brain's "reward system", and its key region, the nucleus accumbens (NAcc). However, stress studies using functional magnetic resonance imaging (fMRI), mainly found evidence for stress-induced decreases in

  11. Analysis of residual stress state in sheet metal parts processed by single point incremental forming

    Science.gov (United States)

    Maaß, F.; Gies, S.; Dobecki, M.; Brömmelhoff, K.; Tekkaya, A. E.; Reimers, W.

    2018-05-01

    The mechanical properties of formed metal components are highly affected by the prevailing residual stress state. A selective induction of residual compressive stresses in the component, can improve the product properties such as the fatigue strength. By means of single point incremental forming (SPIF), the residual stress state can be influenced by adjusting the process parameters during the manufacturing process. To achieve a fundamental understanding of the residual stress formation caused by the SPIF process, a valid numerical process model is essential. Within the scope of this paper the significance of kinematic hardening effects on the determined residual stress state is presented based on numerical simulations. The effect of the unclamping step after the manufacturing process is also analyzed. An average deviation of the residual stress amplitudes in the clamped and unclamped condition of 18 % reveals, that the unclamping step needs to be considered to reach a high numerical prediction quality.

  12. Sinistrals are rarely ‘right’: evidence from tool­-affordance processing in visual half-­field paradigms

    Directory of Open Access Journals (Sweden)

    Bartosz eMichałowski

    2015-03-01

    Full Text Available Although current neuroscience and behavioral studies provide substantial understanding of tool representations (e.g., the processing of tool-­related affordances in the human brain, most of this knowledge is limited to right-handed individuals with typical organization of cognitive and manual skills. Therefore, any insights from these lines of research may be of little value in rehabilitation of patients with atypical laterality of praxis and/or hand dominance. To fill this gap, we tested perceptual processing of man­-made objects in 18 healthy left-­handers who were likely to show greater incidence of right-sided or bilateral (atypical lateralization of functions. In the two experiments reported here, participants performed a tool vs. non-­tool categorization task. In Exp. 1, target and distracter objects were presented for 200 ms in the left (LVF or right (RVF visual field, followed by 200ms masks. In Exp. 2, the centrally presented targets were preceded by masked primes of 35ms duration, again presented in the LVF or RVF. Based on results from both studies, i.e., response times to correctly discriminated stimuli irrespective of their category, participants were divided into two groups showing privileged processing in either left (N = 9 or right (N = 9 visual field. In Exp. 1, only individuals with RVF advantage showed significantly faster categorization of tools in their dominant visual field, whereas those with LVF advantage revealed merely a trend towards such an effect. In Exp. 2, when targets were preceded by identical primes, the ‘atypical’ group showed significantly facilitated categorization of non­-tools, whereas the ‘typical’ group demonstrated a trend towards faster categorization of tools. These results indicate that in subjects with atypically organized cognitive skills, tool­-related processes are not just mirror reversed. Thus, our outcomes call for particular caution in neurorehabilitation directed at left

  13. Isothermal martensitic transformation as an internal-stress-increasing process

    International Nuclear Information System (INIS)

    Liu, Y.; Xie, Z.L.; Haenninen, H.; Humbeeck, J. van; Pietikaeinen, J.

    1995-01-01

    Based on the results that the magnitude of the stabilization of retained austenite increases with increasing the amount of martensite transformed, it has been assumed that the martensitic transformation is accompanied with an increase in internal resisting stress which subsequently results in the stabilization of retained austenite. By simplifying this internal resisting stress to be a type of hydrostatic compressive stress acting on retained austenite due to surrounding martensite plates, a thermodynamical analysis for an isothermal martensitic transformation under applied hydrostatic pressure has been performed. The calculated results, to some extent, show a good agreement with the experimental data. (orig.)

  14. Time course of syllabic and sub-syllabic processing in Mandarin word production: Evidence from the picture-word interference paradigm.

    Science.gov (United States)

    Wang, Jie; Wong, Andus Wing-Kuen; Chen, Hsuan-Chih

    2017-06-05

    The time course of phonological encoding in Mandarin monosyllabic word production was investigated by using the picture-word interference paradigm. Participants were asked to name pictures in Mandarin while visual distractor words were presented before, at, or after picture onset (i.e., stimulus-onset asynchrony/SOA = -100, 0, or +100 ms, respectively). Compared with the unrelated control, the distractors sharing atonal syllables with the picture names significantly facilitated the naming responses at -100- and 0-ms SOAs. In addition, the facilitation effect of sharing word-initial segments only appeared at 0-ms SOA, and null effects were found for sharing word-final segments. These results indicate that both syllables and subsyllabic units play important roles in Mandarin spoken word production and more critically that syllabic processing precedes subsyllabic processing. The current results lend strong support to the proximate units principle (O'Seaghdha, Chen, & Chen, 2010), which holds that the phonological structure of spoken word production is language-specific and that atonal syllables are the proximate phonological units in Mandarin Chinese. On the other hand, the significance of word-initial segments over word-final segments suggests that serial processing of segmental information seems to be universal across Germanic languages and Chinese, which remains to be verified in future studies.

  15. Acute stress-induced cortisol elevations mediate reward system activity during subconscious processing of sexual stimuli

    OpenAIRE

    Oei, Nicole Y. L.; Both, Stephanie; van Heemst, Diana; van der Grond, Jeroen

    2014-01-01

    Summary Stress is thought to alter motivational processes by increasing dopamine (DA) secretion in the brain’s ‘‘reward system’’, and its key region, the nucleus accumbens (NAcc). However, stress studies using functional magnetic resonance imaging (fMRI), mainly found evidence for stress-induced decreases in NAcc responsiveness toward reward cues. Results from both animal and human PETstudies indicate that the stress hormone cortisol may be crucial in the interaction between st...

  16. Non destructive evaluation of residual stresses in welding and hard-surfacing processes

    International Nuclear Information System (INIS)

    Suarez, J.C.; Fernandez, L.M.; Cruz, C.; Aragon, B.; Merino, F.

    1995-01-01

    In this paper transversal and longitudinal stress profiles in welding and hard-surfacing by welding processes are presented. The stresses were measured by RMS of Barkhausen signal. In this work it is shown that in each case the level of stresses is strongly dependent on the number of weld beads of surfacing layers deposited. The subsequent deposition of new weld beads or surfacing layers produces a stress-relieving effect

  17. Optimization of a Coupling Process for Insulin Degludec According to a Quality by Design (QbD) Paradigm.

    Science.gov (United States)

    Nie, Lei; Hu, Mingming; Yan, Xu; Guo, Tingting; Wang, Haibin; Zhang, Sheng; Qu, Haibin

    2018-05-03

    This case study described a successful application of the quality by design (QbD) principles to a coupling process development of insulin degludec. Failure mode effects analysis (FMEA) risk analysis was first used to recognize critical process parameters (CPPs). Five CPPs, including coupling temperature (Temp), pH of desB30 solution (pH), reaction time (Time), desB30 concentration (Conc), and molar equivalent of ester per mole of desB30 insulin (MolE), were then investigated using a fractional factorial design. The curvature effect was found significant, indicating the requirement of second-order models. Afterwards, a central composite design was built with an augmented star and center points study. Regression models were developed for the CPPs to predict the purity and yield of predegludec using above experimental data. The R 2 and adjusted R 2 were higher than 96 and 93% for the two models respectively. The Q 2 values were more than 80% indicating a good predictive ability of models. MolE was found to be the most significant factor affecting both yield and purity of predegludec. Temp, pH, and Conc were also significant for predegludec purity, while Time appeared to remarkably influence the yield model. The multi-dimensional design space and normal operating region (NOR) with a robust setpoint were determined using a probability-based Monte-Carlo simulation method. The verified experimental results showed that the design space was reliable and effective. This study enriches the understanding of acetylation process and is instructional to other complicated operations in biopharmaceutical engineering.

  18. Biased information processing in the escalation paradigm: information search and information evaluation as potential mediators of escalating commitment.

    Science.gov (United States)

    Schultze, Thomas; Pfeiffer, Felix; Schulz-Hardt, Stefan

    2012-01-01

    Escalation of commitment denotes decision makers' increased reinvestment of resources in a losing course of action. Despite the relevance of this topic, little is known about how information is processed in escalation situations, that is, whether decision makers who receive negative outcome feedback on their initial decision search for and/or process information biasedly and whether these biases contribute to escalating commitment. Contrary to a widely cited study by E. J. Conlon and J. M. Parks (1987), in 3 experiments, the authors found that biases do not occur on the level of information search. Neither in a direct replication and extension of the original study with largely increased test power (Experiment 1) nor under methodologically improved conditions (Experiments 2 and 3) did decision makers responsible for failure differ from nonresponsible decision makers with regards to information search, and no selective search for information supporting the initial decision or voting for further reinvestment was observed. However, Experiments 3 and 4 show that the evaluation of the previously sought information is biased among participants who were responsible for initiating the course of action. Mediation analyses show that this evaluation bias in favor of reinvestment partially mediated the responsibility effect on escalation of commitment.

  19. Towards a sustainable paradigm of waste-to-energy process: Enhanced anaerobic digestion of sludge with woody biochar

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Yanwen; Linville, Jessica L.; Ignacio-de Leon, Patricia Anne A.; Schoene, Robin P.; Urgun-Demirtas, Meltem

    2016-11-01

    This study presents an integrated waste-to-energy process, using two waste streams, sludge generated from the municipal wastewater treatment plants (WWTPs) and biochar generated from the biomass gasification systems, to produce fungible biomethane and nutrient-rich digestate with fertilizer value. Two woody biochar, namely pinewood (PBC) and white oak biochar (WOBC) were used as additives during anaerobic digestion (AD) of WWTP sludge to enhance methane production at mesophilic and thermophilic temperatures. The PBC and WOBC have porous structure, large surface area and desirable chemical properties to be used as AD amendment material to sequester CO2 from biogas in the digester. The biochar-amended digesters achieved average methane content in biogas of up to 92.3% and 79.0%, corresponding to CO2 sequestration by up to 66.2% and 32.4% during mesophilic and thermophilic AD, respectively. Biochar addition enhanced process stability by increasing the alkalinity, but inhibitory effects were observed at high dosage. It also alleviated free ammonia inhibition by up to 10.5%. The biochar-amended digesters generated digestate rich in macro- and micronutrients including K (up to 300 m/L), Ca (up to 750 mg/L), Mg (up to 1800 mg/L) and Fe (up to 390 mg/L), making biochar-amended digestate a potential alternative used as agricultural lime fertilizer.

  20. A functional magnetic resonance imaging study of visuomotor processing in a virtual reality-based paradigm: Rehabilitation Gaming System.

    Science.gov (United States)

    Prochnow, D; Bermúdez i Badia, S; Schmidt, J; Duff, A; Brunheim, S; Kleiser, R; Seitz, R J; Verschure, P F M J

    2013-05-01

    The Rehabilitation Gaming System (RGS) has been designed as a flexible, virtual-reality (VR)-based device for rehabilitation of neurological patients. Recently, training of visuomotor processing with the RGS was shown to effectively improve arm function in acute and chronic stroke patients. It is assumed that the VR-based training protocol related to RGS creates conditions that aid recovery by virtue of the human mirror neuron system. Here, we provide evidence for this assumption by identifying the brain areas involved in controlling the catching of approaching colored balls in the virtual environment of the RGS. We used functional magnetic resonance imaging of 18 right-handed healthy subjects (24 ± 3 years) in both active and imagination conditions. We observed that the imagery of target catching was related to activation of frontal, parietal, temporal, cingulate and cerebellar regions. We interpret these activations in relation to object processing, attention, mirror mechanisms, and motor intention. Active catching followed an anticipatory mode, and resulted in significantly less activity in the motor control areas. Our results provide preliminary support for the hypothesis underlying RGS that this novel neurorehabilitation approach engages human mirror mechanisms that can be employed for visuomotor training. © 2013 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  1. Self-organized criticality paradigm

    International Nuclear Information System (INIS)

    Duran, I.; Stoeckel, J.; Hron, M.; Horacek, J.; Jakubka, K.; Kryska, L.

    2000-01-01

    According to the paradigm of the Self-Organized Criticality (SOC), the anomalous transport in tokamaks is caused by fast transient processes - avalanches. One of the manifestations of these phenomena should be 1/f decay of electrostatic fluctuations power spectra in a certain frequency range. In this paper, the frequency spectra of floating potential, density and fluctuation-induced flux, measured by poloidal and radial arrays of Langmuir probes on the CASTOR tokamak, are presented. The floating potential and the fluctuation-induced flux decay from 30 kHz up to 100 kHz as f -1 . The plasma density decays as f -1 in a more narrow band, 20 to 40 kHz. The possible limitation of SOC behavior for frequencies higher than 100 kHz due to intermittency is stressed. For this reason the Probability Distribution Functions (PDFs) of floating potential fluctuations were computed at different time scales using wavelet transform. A clear departure of the computed PDFs from Gaussianity, which is a classical signature of intermittency, is observed at time scales under 10 μs (100 kHz). (author)

  2. Stress associated with caregiving: an examination of the stress process model among Kenyan Luo elders.

    Science.gov (United States)

    Ice, Gillian H; Sadruddin, Aalyia F A; Vagedes, Amy; Yogo, Jaja; Juma, Elizabeth

    2012-06-01

    Globally, a growing number of grandparents are caring for their grandchildren. The impact and burden associated with increases in custodial grandparenting, however, may differ by culture. In the United States, the caregiving role has been shown to be a significant source of stress for older adults. In cultures in which grandparents are more commonly involved in the care of young children, however, increasing caregiving roles may not be viewed as stressful. This study examines the impact of caregiving on perceived and physiological measures of stress among 640 Luo elders (60+) in western Kenya, where high HIV prevalence among younger-to-middle aged adults has led to a heavy burden of orphan care. Perceived stress levels were measured using the Luo Perceived Stress Scale (LPSS). Salivary cortisol and casual blood pressure were used as biomarkers of stress. Results were analyzed using random mixed effects models. Overall this study showed that caregivers have higher levels of perceived stress than non-caregivers. For women, household composition, including the number of orphans and adults in the homestead impacted perceived stress. Among men, those who perceived caregiving as burdensome had higher perceived stress. Despite the association between caregiving and perceived stress, there was a minimal relationship between caregiving and the two biomarkers of stress. This may be because caregiving is superimposed onto other stressors and therefore has a minimal physiological impact. These results highlight the importance of local context in determining the impact of the caregiving role on older adult well-being. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Variation behavior of residual stress distribution by manufacturing processes in welded pipes of austenitic stainless steel

    International Nuclear Information System (INIS)

    Ihara, Ryohei; Hashimoto, Tadafumi; Mochizuki, Masahito

    2012-01-01

    Stress corrosion cracking (SCC) has been observed near heat affected zone (HAZ) of primary loop recirculation pipes made of low-carbon austenitic stainless steel type 316L in the nuclear power plants. For the non-sensitization material, residual stress is the important factor of SCC, and it is generated by machining and welding. In the actual plants, welding is conducted after machining as manufacturing processes of welded pipes. It could be considered that residual stress generated by machining is varied by welding as a posterior process. This paper presents residual stress variation due to manufacturing processes of pipes using X-ray diffraction method. Residual stress distribution due to welding after machining had a local maximum stress in HAZ. Moreover, this value was higher than residual stress generated by welding or machining. Vickers hardness also had a local maximum hardness in HAZ. In order to clarify hardness variation, crystal orientation analysis with EBSD method was performed. Recovery and recrystallization were occurred by welding heat near the weld metal. These lead hardness decrease. The local maximum region showed no microstructure evolution. In this region, machined layer was remained. Therefore, the local maximum hardness was generated at machined layer. The local maximum stress was caused by the superposition effect of residual stress distributions due to machining and welding. Moreover, these local maximum residual stress and hardness are exceeded critical value of SCC initiation. In order to clarify the effect of residual stress on SCC initiation, evaluation including manufacturing processes is important. (author)

  4. MET Activation and Physical Dynamics of the Metastatic Process: The Paradigm of Cancers of Unknown Primary Origin

    Directory of Open Access Journals (Sweden)

    Giulia M. Stella

    2017-10-01

    Full Text Available The molecular and cellular mechanisms which drive metastatic spread are the topic of constant debate and scientific research due to the potential implications for cancer patients' prognosis. In addition to genetics and environmental factors, mechanics of single cells and physical interaction with the surrounding environment play relevant role in defining invasive phenotype. Reconstructing the physical properties of metastatic clones may help to clarify still open issues in disease progression as well as to lead to new diagnostic and therapeutic approaches. In this perspective cancer of unknown primary origin (CUP identify the ideal model to study physical interactions and forces involved in the metastatic process. We have previously demonstrated that MET oncogene is mutated with unexpected high frequency in CUPs. We here analyze and discuss how the MET activation by somatic mutation may affect physical properties in giving rise to such a highly malignant syndrome, as that defined by CUP.

  5. The ATLAS Production System Evolution: New Data Processing and Analysis Paradigm for the LHC Run2 and High-Luminosity

    Science.gov (United States)

    Barreiro, F. H.; Borodin, M.; De, K.; Golubkov, D.; Klimentov, A.; Maeno, T.; Mashinistov, R.; Padolski, S.; Wenaus, T.; ATLAS Collaboration

    2017-10-01

    The second generation of the ATLAS Production System called ProdSys2 is a distributed workload manager that runs daily hundreds of thousands of jobs, from dozens of different ATLAS specific workflows, across more than hundred heterogeneous sites. It achieves high utilization by combining dynamic job definition based on many criteria, such as input and output size, memory requirements and CPU consumption, with manageable scheduling policies and by supporting different kind of computational resources, such as GRID, clouds, supercomputers and volunteer-computers. The system dynamically assigns a group of jobs (task) to a group of geographically distributed computing resources. Dynamic assignment and resources utilization is one of the major features of the system, it didn’t exist in the earliest versions of the production system where Grid resources topology was predefined using national or/and geographical pattern. Production System has a sophisticated job fault-recovery mechanism, which efficiently allows to run multi-Terabyte tasks without human intervention. We have implemented “train” model and open-ended production which allow to submit tasks automatically as soon as new set of data is available and to chain physics groups data processing and analysis with central production by the experiment. We present an overview of the ATLAS Production System and its major components features and architecture: task definition, web user interface and monitoring. We describe the important design decisions and lessons learned from an operational experience during the first year of LHC Run2. We also report the performance of the designed system and how various workflows, such as data (re)processing, Monte-Carlo and physics group production, users analysis, are scheduled and executed within one production system on heterogeneous computing resources.

  6. On-line Processing of German Number-marked Relative Clauses in the Visual-world Paradigm

    Directory of Open Access Journals (Sweden)

    Anne Adelt

    2014-04-01

    (3 Filler: Wo ist das Schwein mit dem Ballon? (Where is the pig with the balloon? All sentences are randomized and presented auditorily. Simultaneously, colored illustrations of animals performing an action are shown on a computer screen (see Figure 1. Participants have to identify via button press (left/right the target animal to which the question refers. During this task, eye movements are collected as an on-line measure of sentence processing. Off-line comprehension is measured in terms of accuracy of target identification. Ten IWAs with sentence comprehension deficits and 30 healthy controls are tested. Discussion Following Burchert et al. (2003, we expect the IWA’s off-line comprehension of SRCs and ORCs to be at chance level, while controls make hardly any errors. In the on-line data, the number of fixations to the target picture are supposed to increase only at the verb or shortly after the sentence offset, since disambiguation occurs sentence finally at the verb. Controls are expected to show faster or longer fixations to the target in SRCs compared to ORCs (Caplan et al., 2007. In line with Hanne, Sekerina, Vasishth, Burchert, and De Bleser (2011, IWA’s fixations to the target should not differ qualitatively from those of controls, at least for correct responses, but eye gaze patterns may be delayed. Data collection and analysis is still ongoing. Results will be ready by October and presented and discussed at the Academy of Aphasia conference.

  7. The impact of training process on the stress tests results of women cross country skiing representation.

    OpenAIRE

    Fusková, Dana

    2015-01-01

    Title: The impact of training process on the stress tests results of women cross country skiing representation. Aim: The aim of this thesis is the comparison of the results of stress tests carried out preparatory period before and after the preparation period and whether the results were influenced by the applied training process. Methods: In this thesis was used background research of professional publications, content analyzes of documents and comparison of the results of stress tests and c...

  8. New energy paradigm?

    International Nuclear Information System (INIS)

    Goldoni, Giovanni

    2007-01-01

    The rise of oil prices, the difficulties in markets liberalization, and the poor results of competition have convinced many that a new energy paradigm is necessary. Taking the original definition of scientific paradigm, it doesn't seem that a practical solution could be found outside the present paradigm of energy policy, made of privatisation, liberalisation and competition [it

  9. [Personality and occupation stress of workers in processing line in Guangzhou].

    Science.gov (United States)

    Lin, Qiu-hong; Zhang, Wei-sen; Zhou, Jing-dong; Fan, Yuan-yu; Liu, Li-fen; Li, Jian-lin; Liu, Wei-wei

    2009-12-01

    To study relationships between personality and occupational stress of workers in processing line in Guangzhou. 452 workers in processing line in Guangzhou were investigated by the Eysenck Personality Questionnaire (EPQ) and Occupational Stress Indicator (OSI). N scores and P scores of EPQ were positively correlated with the occupational stress and the poor physical fitness status (r value was 0.196, 0.128, 0.202, 0.218, respectively) (P stress coping ability(r value was -0.146, -0.140, respectively) (P stress coping ability (r = 0.176, P stress, the poor physical fitness status and the explanation to vicinity event (r value was -0.139, -0.140, -0.111, respectively) (P related to the occupational stress, the sense of job satisfaction and unhealthy mental reaction.

  10. ENVIRONMENTALISM AND CLASSIC PARADIGMS OF INTERNATIONAL RELATIONS

    OpenAIRE

    D. D. Miniaeva

    2014-01-01

    This article examines an environmentalism integration process into Three classical paradigms of international relations theory (Liberalism, Realism and Marxism) into Three classical paradigms of international relations theory (Liberalism, Realism and Marxism). The main purpose of this study is to reveal the result of this integration. Methods used in this article include analysis and comparison of "ecological" paradigms on selected parameters (the nature of international relations, actors, ta...

  11. Residual stresses generated in F-522 steel by different machining processes

    International Nuclear Information System (INIS)

    Gracia-Navas, V.; Ferreres, I.; Maranon, J. A.; Garcia-Rosales, C.; Gil-Sevillano, J.

    2005-01-01

    Machining operations induce plastic deformation and heat generation in the near surface area of the machined part, giving rise to residual stresses. Depending on their magnitude and sign, these stresses can be detrimental or beneficial to the service life of the part. The final stress state depends on the machining process applied, as well as on the machining parameters. Therefore, the establishment of adequate machining guidelines requires the measurement of the residual stresses generated both at the surface and inside the material. in this work, the residual stresses generated in F-522 steel by two hard turning (conventional and laser assisted) and two grinding (production and finishing) processes were measured by X-ray diffraction. Additionally, depth profiles of the volume fraction of retained austenite, microstructure and nano hardness were obtained in order to correlate those results with the residual stress state obtained for each machining process. It has been observed that turning generates tensile stresses in the surface while grinding causes compressive stresses. Below the surface grinding generates weak tensile or nearly null stresses whereas turning generates strong compressive stresses. These results show that the optimum mechanising process (disregarding economical considerations) implies the combination of turning plus elimination of a small thickness by final grinding. (Author) 19 refs

  12. The effect of initial stress induced during the steel manufacturing process on the welding residual stress in multi-pass butt welding

    Directory of Open Access Journals (Sweden)

    Jeong-ung Park

    2018-03-01

    Full Text Available A residual stress generated in the steel structure is broadly categorized into initial residual stress during manufacturing steel material, welding residual stress caused by welding, and heat treatment residual stress by heat treatment. Initial residual stresses induced during the manufacturing process is combined with welding residual stress or heat treatment residual stress, and remained as a final residual stress. Because such final residual stress affects the safety and strength of the structure, it is of utmost importance to measure or predict the magnitude of residual stress, and to apply this point on the design of the structure. In this study, the initial residual stress of steel structures having thicknesses of 25 mm and 70 mm during manufacturing was measured in order to investigate initial residual stress (hereinafter, referred to as initial stress. In addition, thermal elastic plastic FEM analysis was performed with this initial condition, and the effect of initial stress on the welding residual stress was investigated. Further, the reliability of the FE analysis result, considering the initial stress and welding residual stress for the steel structures having two thicknesses, was validated by comparing it with the measured results. In the vicinity of the weld joint, the initial stress is released and finally controlled by the weld residual stress. On the other hand, the farther away from the weld joint, the greater the influence of the initial stress. The range in which the initial stress affects the weld residual stress was not changed by the initial stress. However, in the region where the initial stress occurs in the compressive stress, the magnitude of the weld residual compressive stress varies with the compression or tension of the initial stress. The effect of initial stress on the maximum compression residual stress was far larger when initial stress was considered in case of a thickness of 25 mm with a value of 180

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

    Science.gov (United States)

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

    2015-01-01

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

  14. NORMAL PRESSURE AND FRICTION STRESS MEASUREMENT IN ROLLING PROCESSES

    DEFF Research Database (Denmark)

    Henningsen, Poul; Arentoft, Mogens; Lagergren, Jonas

    2005-01-01

    the output from the transducer, the friction stress and normal pressure in the contact zone can be determined. The new concept differs from existing pin designs by a lower disturbance of lubricant film and material flow and limited penetration of material between transducer and roll. Aluminum, cupper...

  15. Differential Effects of Acute Stress on Anticipatory and Consummatory Phases of Reward Processing

    Science.gov (United States)

    Kumar, Poornima; Berghorst, Lisa H.; Nickerson, Lisa D.; Dutra, Sunny J.; Goer, Franziska; Greve, Douglas; Pizzagalli, Diego A.

    2014-01-01

    Anhedonia is one of the core symptoms of depression and has been linked to blunted responses to rewarding stimuli in striatal regions. Stress, a key vulnerability factor for depression, has been shown to induce anhedonic behavior, including reduced reward responsiveness in both animals and humans, but the brain processes associated with these effects remain largely unknown in humans. Emerging evidence suggests that stress has dissociable effects on distinct components of reward processing, as it has been found to potentiate motivation/‘wanting’ during the anticipatory phase but reduce reward responsiveness/‘liking’ during the consummatory phase. To examine the impact of stress on reward processing, we used a monetary incentive delay (MID) task and an acute stress manipulation (negative performance feedback) in conjunction with functional magnetic resonance imaging (fMRI). Fifteen healthy participants performed the MID task under no-stress and stress conditions. We hypothesized that stress would have dissociable effects on the anticipatory and consummatory phases in reward-related brain regions. Specifically, we expected reduced striatal responsiveness during reward consumption (mirroring patterns previously observed in clinical depression) and increased striatal activation during reward anticipation consistent with non-human findings. Supporting our hypotheses, significant Phase (Anticipation/Consumption) x Stress (Stress/No-stress) interactions emerged in the putamen, nucleus accumbens, caudate and amygdala. Post-hoc tests revealed that stress increased striatal and amygdalar activation during anticipation but decreased striatal activation during consumption. Importantly, stress-induced striatal blunting was similar to the profile observed in clinical depression under baseline (no-stress) conditions in prior studies. Given that stress is a pivotal vulnerability factor for depression, these results offer insight to better understand the etiology of this

  16. Snap your fingers! An ERP/sLORETA study investigating implicit processing of self- vs. other-related movement sounds using the passive oddball paradigm

    Directory of Open Access Journals (Sweden)

    Christoph Justen

    2016-10-01

    Full Text Available So far, neurophysiological studies have investigated implicit and explicit self-related processing particularly for self-related stimuli such as the own face or name. The present study extends previous research to the implicit processing of self-related movement sounds and explores their spatiotemporal dynamics. Event-related potentials (ERPs were assessed while participants (N = 12 healthy subjects listened passively to previously recorded self- and other-related finger snapping sounds, presented either as deviants or standards during an oddball paradigm. Passive listening to low (500 Hz and high (1000 Hz pure tones served as additional control. For self- vs. other-related finger snapping sounds, analysis of ERPs revealed significant differences in the time windows of the N2a/MMN and P3. An subsequent source localization analysis with standardized low resolution brain electromagnetic tomography (sLORETA revealed increased cortical activation in distinct motor areas such as the supplementary motor area (SMA in the N2a/mismatch negativity (MMN as well as the P3 time window during processing of self- and other-related finger snapping sounds. In contrast, brain regions associated with self-related processing (e.g., right anterior/posterior cingulate cortex (ACC/PPC as well as the right inferior parietal lobule (IPL showed increased activation particularly during processing of self- vs. other-related finger snapping sounds in the time windows of the N2a/MMN (ACC/PCC or the P3 (IPL. None of these brain regions showed enhanced activation while listening passively to low (500 Hz and high (1000 Hz pure tones. Taken together, the current results indicate (1 a specific role of motor regions such as SMA during auditory processing of movement-related information, regardless of whether this information is self- or other-related, (2 activation of neural sources such as the ACC/PCC and the IPL during implicit processing of self-related movement stimuli, and (3

  17. Snap Your Fingers! An ERP/sLORETA Study Investigating Implicit Processing of Self- vs. Other-Related Movement Sounds Using the Passive Oddball Paradigm

    Science.gov (United States)

    Justen, Christoph; Herbert, Cornelia

    2016-01-01

    So far, neurophysiological studies have investigated implicit and explicit self-related processing particularly for self-related stimuli such as the own face or name. The present study extends previous research to the implicit processing of self-related movement sounds and explores their spatio-temporal dynamics. Event-related potentials (ERPs) were assessed while participants (N = 12 healthy subjects) listened passively to previously recorded self- and other-related finger snapping sounds, presented either as deviants or standards during an oddball paradigm. Passive listening to low (500 Hz) and high (1000 Hz) pure tones served as additional control. For self- vs. other-related finger snapping sounds, analysis of ERPs revealed significant differences in the time windows of the N2a/MMN and P3. An subsequent source localization analysis with standardized low-resolution brain electromagnetic tomography (sLORETA) revealed increased cortical activation in distinct motor areas such as the supplementary motor area (SMA) in the N2a/mismatch negativity (MMN) as well as the P3 time window during processing of self- and other-related finger snapping sounds. In contrast, brain regions associated with self-related processing [e.g., right anterior/posterior cingulate cortex (ACC/PPC)] as well as the right inferior parietal lobule (IPL) showed increased activation particularly during processing of self- vs. other-related finger snapping sounds in the time windows of the N2a/MMN (ACC/PCC) or the P3 (IPL). None of these brain regions showed enhanced activation while listening passively to low (500 Hz) and high (1000 Hz) pure tones. Taken together, the current results indicate (1) a specific role of motor regions such as SMA during auditory processing of movement-related information, regardless of whether this information is self- or other-related, (2) activation of neural sources such as the ACC/PCC and the IPL during implicit processing of self-related movement stimuli, and (3

  18. 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 ...

  19. CNN a paradigm for complexity

    CERN Document Server

    Chua, Leon O

    1998-01-01

    Revolutionary and original, this treatise presents a new paradigm of EMERGENCE and COMPLEXITY, with applications drawn from numerous disciplines, including artificial life, biology, chemistry, computation, physics, image processing, information science, etc.CNN is an acronym for Cellular Neural Networks when used in the context of brain science, or Cellular Nonlinear Networks, when used in the context of emergence and complexity. A CNN is modeled by cells and interactions: cells are defined as dynamical systems and interactions are defined via coupling laws. The CNN paradigm is a universal Tur

  20. Cognitive processes in post-traumatic stress disorder

    OpenAIRE

    Yıldırımlı, Gamze; Tosun, Ahmet

    2012-01-01

    Post-Traumatic Stress Disorder (PTSD) consists of a pattern of symptoms that include cognitive, affective, sensory and behavioral systems. In PTSD, the individual experiences disturbing emotions and sensations such as anxiety, panic, depression, anger, tension, high startle response and hyper-vigilance as a result of re-experiencing traumatic memories, flashbacks, attention difficulties, memory loss, nightmares and intrusive thoughts. To get rid of these emotions, he avoids all stimuli that r...

  1. Intraindividual change and variability in daily stress processes: Findings from two measurement-burst diary studies

    Science.gov (United States)

    Sliwinski, Martin J.; Almeida, David M.; Smyth, Joshua; Stawski, Robert S.

    2010-01-01

    There is little longitudinal information on aging-related changes in emotional responses to negative events. The present manuscript examined intraindividual change and variability in the within-person coupling of daily stress and negative affect (NA) using data from two-measurement burst daily diary studies. Three main findings emerged. First, average reactivity to daily stress increased longitudinally, and this increase was evident across most the adult lifespan. Second, individual differences in emotional reactivity to daily stress exhibited long-term temporal stability, but this stability was greatest in midlife and decreased in old age. And third, reactivity to daily stress varied reliably within-persons (across-time), with individual exhibiting higher levels of reactivity during times when reporting high levels of global subject stress in previous month. Taken together, the present results emphasize the importance of modeling dynamic psychosocial and aging processes that operate across different time scales for understanding age-related changes in daily stress processes. PMID:20025399

  2. Residual Stress Evaluation of Weld Inlay Process on Reactor Vessel Nozzles

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Kihyun; Cho, Hong Seok [KEPCO KPS, Naju (Korea, Republic of)

    2015-10-15

    Weld overlay, weld inlay and stress improvement are mitigation technologies for butt joints. Weld overlay is done on pressurizer nozzles which are the highest potential locations occurring PWSCC due to high temperature in Korea. Reactor vessel nozzles are other big safety concerns for butt joints. Weld overlay and stress improvement should be so difficult to apply to those locations because space is too limited. Weld inlay should be one of the solutions. KEPCO KPS has developed laser welding system and process for reactor nozzles. Welding residual stress analysis is necessary for flaw evaluation. United States nuclear regulatory commission has calculated GTAW(Gas Tungsten Arc Welding) residual stress using ABAQUS. To confirm effectiveness of weld inlay process, welding residual stress analysis was performed. and difference between GTAW and LASER welding process was compared. Evaluation of weld inlay process using ANSYS and ABAQUS is performed. All of the both results are similar. The residual stress generated after weld inlay was on range of 450-500 MPa. Welding residual stresses are differently generated by GTAW and LASER welding. But regardless of welding process type, residual tensile stress is generated on inside surface.

  3. Stress and organisational citizenship behaviours in Indian business process outsourcing organisations

    Directory of Open Access Journals (Sweden)

    Ajay K. Jain

    2012-09-01

    Full Text Available This study investigates the direct effect of organisational stress (as measured through ASSET on organisational citizenship behaviours (OCBs. A sample of 402 operators was taken from business process outsourcing (BPO organisations located in northern India. The authors hypothesised that there is a negative relationship between organisational stress and OCBs. Results of multiple regression analysis showed that stress had significant negative impact on OCBs. The implications for managers are discussed.

  4. Residual stress evaluation and curvature behavior of aluminium 7050 peen forming processed

    International Nuclear Information System (INIS)

    Oliveira, R.R. de; Lima, N.B.; Braga, A.P.V.; Goncalves, M.

    2010-01-01

    Shot peening is a superficial cold work process used to increase the fatigue life evaluated by residual stress measurements. The peen forming process is a variant of the shot peening process, where a curvature in the plate is obtained by the compression of the grains near to the surface. In this paper, the influence of the parameters such as: pressure of shot, ball shot size and thickness of aluminum 7050 samples with respect to residual stress profile and resulting arc height was studied. The evaluation of the residual stress profile was obtained by sin 2 Ψ method. (author)

  5. Processing of syllable stress is functionally different from phoneme processing and does not profit from literacy acquisition

    Directory of Open Access Journals (Sweden)

    Ulrike eSchild

    2014-06-01

    Full Text Available Speech is characterized by phonemes and prosody. Neurocognitive evidence supports the separate processing of each type of information. Therefore, one might suggest individual development of both pathways. In this study, we examine literacy acquisition in middle childhood. Children become aware of the phonemes in speech at that time and refine phoneme processing when they acquire an alphabetic writing system. We test whether an enhanced sensitivity to phonemes in middle childhood extends to other aspects of the speech signal, such as prosody. To investigate prosodic processing, we used stress priming. Spoken stressed and unstressed syllables (primes preceded spoken German words with stress on the first syllable (targets. We orthogonally varied stress overlap and phoneme overlap between the primes and onsets of the targets. Lexical decisions and Event-Related Potentials (ERPs for the targets were obtained for pre-reading preschoolers, reading pupils and adults. The behavioral and ERP results were largely comparable across all groups. The fastest responses were observed when the first syllable of the target word shared stress and phonemes with the preceding prime. ERP stress priming and ERP phoneme priming started 200 ms after the target word onset. Bilateral ERP stress priming was characterized by enhanced ERP amplitudes for stress overlap. Left-lateralized ERP phoneme priming replicates previously observed reduced ERP amplitudes for phoneme overlap. Groups differed in the strength of the behavioral phoneme priming and in the late ERP phoneme priming effect. The present results show that enhanced phonological processing in middle childhood is restricted to phonemes and does not extend to prosody. These results are indicative of two parallel processing systems for phonemes and prosody that might follow different developmental trajectories in middle childhood as a function of alphabetic literacy.

  6. How does context affect intimate relationships? linking external stress and cognitive processes within marriage.

    Science.gov (United States)

    Neff, Lisa A; Karney, Benjamin R

    2004-02-01

    Stressors external to the marriage frequently affect the way spouses evaluate their marital quality. To date, however, understanding of the interplay between external stress and internal relationship processes has been limited in two ways. First, research has generally examined only the short-term consequences of stress. Second, the mechanisms through which external stressors influence relationship outcomes are unclear. This study addressed both limitations by examining relationship cognitions that may mediate the effects of external stress throughout 4 years of marriage. Analyses confirmed that stressful experiences were associated with the trajectory of marital quality overtime. Furthermore, both the content and the organization of spouses' specific relationship cognitions mediated this effect. That is, stress negatively influenced the nature of spouses' marital perceptions as well as the way spouses interpreted and processed those perceptions. These findings draw attention to ways that the context of relationships shapes and constrains relationship processes.

  7. On the importance of being bilingual: word stress processing in a context of segmental variability.

    Science.gov (United States)

    Abboub, Nawal; Bijeljac-Babic, Ranka; Serres, Josette; Nazzi, Thierry

    2015-04-01

    French-learning infants have language-specific difficulties in processing lexical stress due to the lack of lexical stress in French. These difficulties in discriminating between words with stress-initial (trochaic) and stress-final (iambic) patterns emerge by 10months of age in the easier context of low variability (using a single item pronounced with a trochaic pattern vs. an iambic pattern) as well as in the more challenging context of high segmental variability (using lists of segmentally different trochaic and iambic items). These findings raise the question of stress pattern perception in simultaneous bilinguals learning French and a second language using stress at the lexical level. Bijeljac-Babic, Serres, Höhle, and Nazzi (2012) established that at 10 months of age, in the simpler context of low variability, such bilinguals have better stress discrimination abilities than French-learning monolinguals. The current study explored whether this advantage extends to the more challenging context of high segmental variability. Results first establish stress pattern discrimination in a group of bilingual 10-month-olds learning French and one language with (variable) lexical stress, but not in French-learning 10-month-old monolinguals. Second, discrimination in bilinguals appeared not to be affected by the language balance of the infants, suggesting that sensitivity to stress patterns might be maintained in these bilingual infants provided that they hear at least 30% of a language with lexical stress. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. The Next Paradigm

    Directory of Open Access Journals (Sweden)

    Bernardo Kastrup

    2018-04-01

    Full Text Available In order to perceive the world, we need more than just raw sensory input: a subliminal paradigm of thought is required to interpret raw sensory data and, thereby, create the objects and events we perceive around ourselves. As such, the world we see reflects our own unexamined, culture-bound assumptions and expectations, which explains why every generation in history has believed that it more or less understood the world. Today, we perceive a world of objects and events outside and independent of mind, which merely reflects our current paradigm of thought. Anomalies that contradict this paradigm have been accumulated by physicists over the past couple of decades, which will eventually force our culture to move to a new paradigm. Under this new paradigm, a form of universal mind will be viewed as nature’s sole fundamental entity. In this paper, I offer a sketch of what the new paradigm may look like.

  9. Effects of Stress and Working Memory Capacity on Foreign Language Readers' Inferential Processing during Comprehension

    Science.gov (United States)

    Rai, Manpreet K.; Loschky, Lester C.; Harris, Richard Jackson; Peck, Nicole R.; Cook, Lindsay G.

    2011-01-01

    Although stress is frequently claimed to impede foreign language (FL) reading comprehension, it is usually not explained how. We investigated the effects of stress, working memory (WM) capacity, and inferential complexity on Spanish FL readers' inferential processing during comprehension. Inferences, although necessary for reading comprehension,…

  10. Employee Communication during Crises: The Effects of Stress on Information Processing.

    Science.gov (United States)

    Pincus, J. David; Acharya, Lalit

    Based on multidisciplinary research findings, this report proposes an information processing model of employees' response to highly stressful information environments arising during organizational crises. The introduction stresses the importance of management's handling crisis communication with employees skillfully. The second section points out…

  11. Financial Stress, Parental Depressive Symptoms, Parenting Practices, and Children's Externalizing Problem Behaviors: Underlying Processes

    Science.gov (United States)

    Lee, Chih-Yuan Steven; Lee, Jaerim; August, Gerald J.

    2011-01-01

    This study examined the relationships among financial stress encountered by families, parents' social support, parental depressive symptoms, parenting practices, and children's externalizing problem behaviors to advance our understanding of the processes by which family financial stress is associated with children's problem behaviors. We also…

  12. Together in Pain: Attachment-Related Dyadic Processes and Posttraumatic Stress Disorder

    Science.gov (United States)

    Ein-Dor, Tsachi; Doron, Guy; Solomon, Zahava; Mikulincer, Mario; Shaver, Phillip R.

    2010-01-01

    We used actor-partner interdependence modeling to explore associations among attachment-related dyadic processes, posttraumatic stress disorder (PTSD) in war veterans, and secondary traumatic stress (STS) in their wives. A sample of 157 Israeli couples (85 former prisoners of war and their wives and a comparison group of 72 veterans not held…

  13. Cemented carbide cutting tool: Laser processing and thermal stress analysis

    Energy Technology Data Exchange (ETDEWEB)

    Yilbas, B.S. [Mechanical Engineering Department, KFUPM, Box 1913, Dhahran 31261 (Saudi Arabia)]. E-mail: bsyilbas@kfupm.edu.sa; Arif, A.F.M. [Mechanical Engineering Department, KFUPM, Box 1913, Dhahran 31261 (Saudi Arabia); Karatas, C. [Engineering Faculty, Hacettepe University, Ankara (Turkey); Ahsan, M. [Mechanical Engineering Department, KFUPM, Box 1913, Dhahran 31261 (Saudi Arabia)

    2007-04-15

    Laser treatment of cemented carbide tool surface consisting of W, C, TiC, TaC is examined and thermal stress developed due to temperature gradients in the laser treated region is predicted numerically. Temperature rise in the substrate material is computed numerically using the Fourier heating model. Experiment is carried out to treat the tool surfaces using a CO{sub 2} laser while SEM, XRD and EDS are carried out for morphological and structural characterization of the treated surface. Laser parameters were selected include the laser output power, duty cycle, assisting gas pressure, scanning speed, and nominal focus setting of the focusing lens. It is found that temperature gradient attains significantly high values below the surface particularly for titanium and tantalum carbides, which in turn, results in high thermal stress generation in this region. SEM examination of laser treated surface and its cross section reveals that crack initiation below the surface occurs and crack extends over the depth of the laser treated region.

  14. Acute stress shifts the balance between controlled and automatic processes in prospective memory.

    Science.gov (United States)

    Möschl, Marcus; Walser, Moritz; Plessow, Franziska; Goschke, Thomas; Fischer, Rico

    2017-10-01

    In everyday life we frequently rely on our abilities to postpone intentions until later occasions (prospective memory; PM) and to deactivate completed intentions even in stressful situations. Yet, little is known about the effects of acute stress on these abilities. In the present work we investigated the impact of acute stress on PM functioning under high task demands. (1) Different from previous studies, in which intention deactivation required mostly low processing demands, we used salient focal PM cues to induce high processing demands during intention-deactivation phases. (2) We systematically manipulated PM-monitoring demands in a nonfocal PM task that required participants to monitor for either one or six specific syllables that could occur in ongoing-task words. Eighty participants underwent the Trier Social Stress Test, a standardized stress induction protocol, or a standardized control situation, before performing a computerized PM task. Our primary interests were whether PM performance, PM-monitoring costs, aftereffects of completed intentions and/or commission-error risk would differ between stressed and non-stressed individuals and whether these effects would differ under varying task demands. Results revealed that PM performance and aftereffects of completed intentions during subsequent performance were not affected by acute stress induction, replicating previous findings. Under high demands on intention deactivation (focal condition), however, acute stress produced a nominal increase in erroneous PM responses after intention completion (commission errors). Most importantly, under high demands on PM monitoring (nonfocal condition), acute stress led to a substantial reduction in PM-monitoring costs. These findings support ideas of selective and demand-dependent effects of acute stress on cognitive functioning. Under high task demands, acute stress might induce a shift in processing strategy towards resource-saving behavior, which seems to increase the

  15. Didaktiske paradigmer og refleksion

    DEFF Research Database (Denmark)

    Christensen, Torben Spanget

    2014-01-01

    analysis of subject didactics by Sigmund Ongstad. The two positions offer fundamentally different insights into didactics. Nielsen’s position establishes didactics as a knowledge domain and Ongstad’s position points to the dynamics of subject didactics by analyzing communication as a basic aspect. Krogh...... this article. A possible utilitarian didactical paradigm, already indicated by Krogh as a historical paradigm prominent in our time, is also discussed. It is suggested that reflection could be seen as a normative response to the utilitarian paradigm, and not as a paradigm in its own right. It is concluded...

  16. Understanding psychological stress, its biological processes, and impact on primary headache.

    Science.gov (United States)

    Nash, Justin M; Thebarge, Ronald W

    2006-10-01

    Psychological stress is generally acknowledged to be a central contributor to primary headache. Stress results from any challenge or threat, either real or perceived, to normal functioning. The stress response is the body's activation of physiological systems, namely the hypothalamic-pituitary-adrenal axis, to protect and restore functioning. Chronic activation of the stress response can lead to wear and tear that eventually can predispose an individual to disease. There are multiple ways that stress and headache are closely related. Stress can (a) be a predisposing factor that contributes to headache disorder onset, (b) accelerate the progression of the headache disorder into a chronic condition, and (c) precipitate and exacerbate individual headache episodes. How stress impacts headache is not often understood. However, stress is assumed to affect primary headache by directly impacting pain production and modulation processes at both the peripheral and central levels. Stress can also independently worsen headache-related disability and quality of life. Finally, the headache experience itself can serve as a stressor that compromises an individual's health and well-being. With the prominent role that stress plays in headache, there are implications for the evaluation of stress and the use of stress reduction strategies at the various stages of headache disorder onset and progression. Future directions can help to develop a better empirical understanding of the pattern of the stress and headache connections and the mechanisms that explain the connections. Further research can also examine the interactive effects of stress and other factors that impact headache disorder onset, course, and adjustment.

  17. Information processing speed as a mediator between psychosocial stress and global cognition in older adults.

    Science.gov (United States)

    Foong, Hui F; Hamid, Tengku A; Ibrahim, Rahimah; Haron, Sharifah A

    2018-01-01

    The link between psychosocial stress and cognitive function is complex, and previous studies have indicated that it may be mediated by processing speed. Therefore, the main aim of this study was to examine whether processing speed mediates the association between psychosocial stress and global cognition in older adults. Moreover, the moderating role of gender in this model is examined as well. The study included 2322 community-dwelling older adults in Malaysia who were randomly selected through a multistage proportional cluster random sampling technique. Global cognition construct was measured by the Mini-Mental State Examination and Montreal Cognitive Assessment; psychosocial stress construct was measured by perceived stress, depression, loneliness, and neuroticism; and processing speed was assessed by the Digit Symbol Substitution Test. Structural equation modelling was used to analyze the mediation and moderation tests. Processing speed was found to partially mediate the relationship between psychosocial stress and global cognition (β in the direct model = -0.15, P cognition was found to be significant in men only, whereas the association between processing speed and global cognition was significant in men and women. Psychosocial stress may increase the likelihood that older adults will experience poor processing capacity, which could reduce their higher level cognition. Results indicate that there is a need to develop processing capacity intervention programmes for psychologically distressed older adults to prevent them from suffering cognitive decline. © 2018 Japanese Psychogeriatric Society.

  18. Dynamic paradigm of turbulence

    International Nuclear Information System (INIS)

    Mukhamedov, Alfred M.

    2006-01-01

    In this paper a dynamic paradigm of turbulence is proposed. The basic idea consists in the novel definition of chaotic structure given with the help of Pfaff system of PDE associated with the turbulent dynamics. A methodological analysis of the new and the former paradigm is produced

  19. An Integrative Paradigm

    Science.gov (United States)

    Hammack, Phillip L.

    2005-01-01

    Through the application of life course theory to the study of sexual orientation, this paper specifies a new paradigm for research on human sexual orientation that seeks to reconcile divisions among biological, social science, and humanistic paradigms. Recognizing the historical, social, and cultural relativity of human development, this paradigm…

  20. The Role of Oxidative Stress in the Aging Process

    Directory of Open Access Journals (Sweden)

    Barbara F. Oliveira

    2010-01-01

    Full Text Available The aging of organisms is characterized by a gradual functional decline of all organ systems. An appropriate theory must explain four main characteristics of aging: it is progressive, endogenous, irreversible, and deleterious for the individual. The aging of the immune system, or immunosenescence, is manifested by an increased susceptibility to infections with increased morbidity and mortality. Phagocytic capacity, synthesis of reactive oxygen intermediaries, and the intracellular killing efficiency of neutrophils are impaired in the elderly. Among all aging theories, the most updated one describes the free radicals. It implies that progressive aging is associated with higher levels of oxidative biomolecules reacted with free radicals. Although reactive oxygen species (ROS are predominantly implicated in causing cell damage, they also play a major physiological role in several aspects of intracellular signaling and regulation. ROS include a number of chemically reactive molecules derived from oxygen. Not only oxygen, but also nitrogen can be deleterious species. The overproduction of reactive nitrogen species (RNS is called nitrosative stress. ROS/RNS are known to play a dual role in biological systems since they can be either harmful or beneficial to living systems.

  1. Oak kombucha protects against oxidative stress and inflammatory processes.

    Science.gov (United States)

    Vázquez-Cabral, B D; Larrosa-Pérez, M; Gallegos-Infante, J A; Moreno-Jiménez, M R; González-Laredo, R F; Rutiaga-Quiñones, J G; Gamboa-Gómez, C I; Rocha-Guzmán, N E

    2017-06-25

    Black tea infusion is the common substrate for preparing kombucha; however other sources such as oak leaves infusions can be used for the same purpose. Almost any white oak species have been used for medicinal applications by some ethnic groups in Mexico and could be also suitable for preparing kombucha analogues from oak (KAO). The objective of this research was to investigate the antioxidant activity and anti-inflammatory effects of KAO by examining its modulation ability on macrophage-derived TNF-alpha and IL-6. Herbal infusions from oak and black tea were fermented by kombucha consortium during seven days at 28 °C. Chemical composition was determined by LC-ESI-MS/MS. The antioxidant activity of samples against oxidative damage caused by H 2 O 2 in monocytes activated (macrophages) was explored. Additionally, it was determined the anti-inflammatory activity using lipopolysaccharide (LPS) - stimulated macrophages; in particular, the nitric oxide (NO), TNF-alpha, and IL-6 production was assessed. Levels of pro-inflammatory cytokines IL-6 and TNF-alpha were significantly reduced by the sample treatment. Likewise, NO production was lower in treatment with kombucha and KAO compared with LPS-stimulated macrophages. Fermented beverages of oak effectively down-regulated the production of NO, while pro-inflammatory cytokines (TNF-alpha and IL-6) in macrophages were stimulated with LPS. Additionally, phytochemical compounds present in KAO decrease oxidative stress. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Thermomechanical Stresses Analysis of a Single Event Burnout Process

    Science.gov (United States)

    Tais, Carlos E.; Romero, Eduardo; Demarco, Gustavo L.

    2009-06-01

    This work analyzes the thermal and mechanical effects arising in a power Diffusion Metal Oxide Semiconductor (DMOS) during a Single Event Burnout (SEB) process. For studying these effects we propose a more detailed simulation structure than the previously used by other authors, solving the mathematical models by means of the Finite Element Method. We use a cylindrical heat generation region, with 5 W, 10 W, 50 W and 100 W for emulating the thermal phenomena occurring during SEB processes, avoiding the complexity of the mathematical treatment of the ion-semiconductor interaction.

  3. Psychological Processes for Achieving and Coping with Stress in Sport.

    Science.gov (United States)

    Rotella, Robert J.

    Several exploratory studies have begun to look at the role of cognition on sport performance. An enriched understanding of the mental aspects of sport is emerging. Recently a team composed of researchers and a coach has attempted a closer understanding of the cognitive processes involved in the development of young athletes to their performance…

  4. Stress and reward processing in bipolar disorder: an fMRI study

    Science.gov (United States)

    Berghorst, Lisa H; Kumar, Poornima; Greve, Doug N; Deckersbach, Thilo; Ongur, Dost; Dutra, Sunny; Pizzagalli, Diego A

    2016-01-01

    Objectives A link between negative life stress and the onset of mood episodes in bipolar disorder (BD) has been established, but processes underlying such a link remain unclear. Growing evidence suggests that stress can negatively affect reward processing and related neurobiological substrates, indicating that a dysregulated reward system may provide a partial explanation. The aim of this study was to test the impact of stress on reward-related neural functioning in BD. Methods Thirteen euthymic or mildly depressed individuals with BD and 15 controls performed a Monetary Incentive Delay task while undergoing functional magnetic resonance imaging during no-stress and stress (negative psychosocial stressor involving poor performance feedback and threat of monetary deductions) conditions. Results In hypothesis-driven region-of- interest-based analyses, a significant group by condition interaction emerged in the amygdala during reward anticipation. Relative to controls, while anticipating a potential reward, subjects with BD were characterized by amygdalar hyperactivation in the no-stress condition but hypoactivation during stress. Moreover, relative to controls, subjects with BD had significantly larger amygdala volumes. After controlling for structural differences, the effects of stress on amygdalar function remained, whereas groups no longer differed during the no-stress condition. During reward consumption, a group by condition interaction emerged in the putamen due to increased putamen activation to rewards in participants with BD during stress, but an opposite pattern in controls. Conclusions Overall, findings highlight possible impairments in using reward-predicting cues to adaptively engage in goal-directed actions in BD, combined with stress-induced hypersensitivity to reward consumption. Potential clinical implications are discussed. PMID:27870507

  5. Investigation of Thermal Stress Distribution in Laser Spot Welding Process

    OpenAIRE

    Osamah F. Abdulateef

    2009-01-01

    The objective of this paper was to study the laser spot welding process of low carbon steel sheet. The investigations were based on analytical and finite element analyses. The analytical analysis was focused on a consistent set of equations representing interaction of the laser beam with materials. The numerical analysis based on 3-D finite element analysis of heat flow during laser spot welding taken into account the temperature dependence of the physical properties and latent heat of transf...

  6. Analytical study of residual stress improvement method, delta-T process for small-diameter pipe

    International Nuclear Information System (INIS)

    Tsuruki, Masaki; Aoike, Satoru; Okido, Shinobu; Fukuda, Yuka; Oritani, Naohiko

    2012-01-01

    In order to prevent initiation of stress corrosion cracking (SCC) at the inner surface of the butt-weld region of a small-diameter pipe, a residual stress improvement process called delta-T process has been developed. During delta-T process, the outer surface of pipe is heated by an external device and the inner surface is rapidly cooled by flashing water. The large thermal stress due to temperature difference between outer and inner surface could improve tensile stress to compressive one at inner surface. In this paper, the thermal elasto-plastic finite element analysis (FEA) was conducted to clarify the mechanism of delta-T process for piping system with 50A schedule 80 in nominal pipe size. The FEA results showed good agreements with experimentally measurements of temperature and residual stress in delta-T process. In addition, the management criterion to verify the application of delta-T process to piping system by measurement of temperature at outer surface of pipe was discussed by various parametric numerical analyses. (author)

  7. Honey Bee Antiviral Immune Barriers as Affected by Multiple Stress Factors: A Novel Paradigm to Interpret Colony Health Decline and Collapse

    Directory of Open Access Journals (Sweden)

    Francesco Nazzi

    2018-03-01

    Full Text Available Any attempt to outline a logical framework in which to interpret the honey bee health decline and its contribution to elevated colony losses should recognize the importance of the multifactorial nature of the responsible syndrome and provide a functional model as a basis for defining and testing working hypotheses. We propose that covert infections by deformed wing virus (DWV represent a sword of Damocles permanently threatening the survival of honey bee colonies and suggest that any factor affecting the honey bee’s antiviral defenses can turn this pathogen into a killer. Here we discuss the available experimental evidence in the framework of a model based on honey bee immune competence as affected by multiple stress factors that is proposed as a conceptual tool for analyzing bee mortality and its underlying mechanisms.

  8. Of Paradigms and Power

    DEFF Research Database (Denmark)

    Carstensen, Martin B.; Matthijs, Matthias

    in the study of policy paradigms. To demonstrate the general applicability of our framework, the paper examines the evolution of British macroeconomic policy making since 1990. We show that various Prime Ministers and their Chancellors were able to reinterpret and redefine the dominant neoliberal understanding......? Despite the profound impact of Peter Hall’s approach to policy paradigms and social learning, there is a burgeoning consensus that transposing a rudimentary ‘Kuhnian’ understanding of paradigms into the context of public policy making leads to a notion of punctuated equilibrium style shifts as the only...

  9. A dyadic analysis of stress processes in Latinas with breast cancer and their family caregivers.

    Science.gov (United States)

    Segrin, Chris; Badger, Terry A; Sikorskii, Alla; Crane, Tracy E; Pace, Thaddeus W W

    2018-03-01

    Breast cancer diagnosis and treatment negatively affect quality of life for survivors and their family caregivers. The stress process model has been useful for describing the cascade of social and psychological experiences that culminate in degraded quality of life for both survivors and their family caregivers. This study is designed to test theoretically specified predictors of negative psychosocial outcomes in a dyadic context. Participants were 230 dyads composed of Latinas recently diagnosed with breast cancer and their primary family caregiver, who completed measures of socioeconomic status, stress, family conflict, depression, and anxiety. Data were analyzed following the Actor-Partner Interdependence Mediation Model in structural equation modeling. For both survivors and caregivers, there were significant direct and indirect actor effects (through family conflict) of perceived stress on depression and anxiety. Several indirect partner effects were also evident in this sample. Specifically, caregivers' stress was predictive of survivors' depression and anxiety through survivors' increased perceptions of family conflict. As predicted by the stress process model, stress and family conflict were predictive of psychological distress in breast cancer survivors and their family caregivers. Significant partner effects in the Actor-Partner Interdependence Mediation Model suggest that there are some dyadic influences, particularly from caregivers' stress to survivors' perceptions of exacerbated family conflict. These findings show how strained family relationships can aggravate the well-being of cancer survivors and their family caregivers through this challenging experience. Copyright © 2017 John Wiley & Sons, Ltd.

  10. Coupling image processing and stress analysis for damage identification in a human premolar tooth.

    Science.gov (United States)

    Andreaus, U; Colloca, M; Iacoviello, D

    2011-08-01

    Non-carious cervical lesions are characterized by the loss of dental hard tissue at the cement-enamel junction (CEJ). Exceeding stresses are therefore generated in the cervical region of the tooth that cause disruption of the bonds between the hydroxyapatite crystals, leading to crack formation and eventual loss of enamel and the underlying dentine. Damage identification was performed by image analysis techniques and allowed to quantitatively assess changes in teeth. A computerized two-step procedure was generated and applied to the first left maxillary human premolar. In the first step, dental images were digitally processed by a segmentation method in order to identify the damage. The considered morphological properties were the enamel thickness and total area, the number of fragments in which the enamel is chipped. The information retrieved by the data processing of the section images allowed to orient the stress investigation toward selected portions of the tooth. In the second step, a three-dimensional finite element model based on CT images of both the tooth and the periodontal ligament was employed to compare the changes occurring in the stress distributions in normal occlusion and malocclusion. The stress states were analyzed exclusively in the critical zones designated in the first step. The risk of failure at the CEJ and of crack initiation at the dentin-enamel junction through the quantification of first and third principal stresses, von Mises stress, and normal and tangential stresses, were also estimated. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  11. Flow and Stress Field Analysis of Different Fluids and Blades for Fermentation Process

    Directory of Open Access Journals (Sweden)

    Cheng-Chi Wang

    2014-02-01

    Full Text Available Fermentation techniques are applied for the biotechnology and are widely used for food manufacturing, materials processing, chemical reaction, and so forth. Different fluids and types of blades in the tank for fermentation cause distinct flow and stress field distributions on the surface between fluid and blade and various flow reactions in the tank appear. This paper is mainly focused on the analysis of flow field with different fluid viscosities and also studied the stress field acting on the blades with different scales and shapes of them under specific rotational speed. The results show that the viscosity of fluid influences the flow field and stress distributions on the blades. The maximum stress that acts on the blade is increased with the increasing of viscosity. On the other hand, the ratio of blade length to width influences stress distributions on the blade. At the same time, the inclined angle of blade is also the key parameter for the consideration of design and appropriate inclined angle of blade will decrease the maximum stress. The results provide effective means of gaining insights into the flow and stress distribution of fermentation process.

  12. A New Test Device for Characterization of Mechanical Stress Caused by Packaging Processes

    International Nuclear Information System (INIS)

    Hirsch, Soeren; Doerner, Steffen; Hauptmann, Peter; Schmidt, Bertram

    2006-01-01

    This paper reports on a new method for estimation and minimization of mechanical stress on MEMS sensor and actuator structures due to packaging processes based on flip chip technology. For studying mechanical stress a test chip with silicon membranes was fabricated. A network of piezo-resistive solid state resistors created by diffusion was used to measure the surface tension pattern between adjacent membranes. Finite element method simulation was used to calculate the stress profile and to determine the optimum positions for placing the resistive network

  13. Identifying blood biomarkers and physiological processes that distinguish humans with superior performance under psychological stress.

    Directory of Open Access Journals (Sweden)

    Amanda M Cooksey

    2009-12-01

    Full Text Available Attrition of students from aviation training is a serious financial and operational concern for the U.S. Navy. Each late stage navy aviator training failure costs the taxpayer over $1,000,000 and ultimately results in decreased operational readiness of the fleet. Currently, potential aviators are selected based on the Aviation Selection Test Battery (ASTB, which is a series of multiple-choice tests that evaluate basic and aviation-related knowledge and ability. However, the ASTB does not evaluate a person's response to stress. This is important because operating sophisticated aircraft demands exceptional performance and causes high psychological stress. Some people are more resistant to this type of stress, and consequently better able to cope with the demands of naval aviation, than others.Although many psychological studies have examined psychological stress resistance none have taken advantage of the human genome sequence. Here we use high-throughput -omic biology methods and a novel statistical data normalization method to identify plasma proteins associated with human performance under psychological stress. We identified proteins involved in four basic physiological processes: innate immunity, cardiac function, coagulation and plasma lipid physiology.The proteins identified here further elucidate the physiological response to psychological stress and suggest a hypothesis that stress-susceptible pilots may be more prone to shock. This work also provides potential biomarkers for screening humans for capability of superior performance under stress.

  14. Stress evolution in elastic-plastic electrodes during electrochemical processes: A numerical method and its applications

    Science.gov (United States)

    Wen, Jici; Wei, Yujie; Cheng, Yang-Tse

    2018-07-01

    Monitoring in real time the stress state in high capacity electrodes during charge-discharge processes is pivotal to the performance assessment and structural optimization of advanced batteries. The wafer curvature measurement technique broadly employed in thin-film industry, together with stress analysis using the Stoney equation, has been successfully adopted to measure in situ the stress in thin film electrodes. How large plastic deformation or interfacial delamination during electrochemical cycles in such electrodes affects the applicability of Stoney equation remains unclear. Here we develop a robust electrochemical-mechanical coupled numerical procedure to investigate the influence of large plastic deformation and interfacial failure on the measured stress in thin film electrodes. We identify how the constitutive behavior of electrode materials and film-substrate interfacial properties affect the measured stress-capacity curves of electrodes, and hence establish the relationship of electrode material parameters with the characteristics of stress-capacity curves. Using Li-ions batteries as examples, we show that plastic deformation and interfacial delamination account for the asymmetric stress-capacity loops seen in in situ stress measurements. The methods used here, along with the finite-element code in the supplementary material, may be used to model the electrode behavior as a function of the state of charge.

  15. Realignment process of actin stress fibers in single living cells studied by focused femtosecond laser irradiation

    OpenAIRE

    Yasukuni, Ryohei; Spitz, Jean-Alexis; Meallet-Renault, Rachel; Negishi, Takayuki; Tada, Takuji; Hosokawa, Yoichiroh; Asahi, Tsuyoshi; Shukunami, Chisa; Hiraki, Yuji; Masuhara, Hiroshi

    2007-01-01

    Three-dimensional dissection of a single actin stress fiber in a living cell was performed based on multi-photon absorption of a focused femtosecond laser pulse. The realignment process of an actin stress fiber was investigated after its direct cutting by a single-shot femtosecond laser pulse irradiation by high-speed transmission and fluorescence imaging methods. It was confirmed that mechanical force led by the femtosecond laser cutting propagates to entire cell through the cytockelton in a...

  16. Effects of advanced laser processing on the microstructure and residual stresses of H13 tool steel

    OpenAIRE

    Trojan, Karel; Ocelík, Václav; Ganev, Nikolaj; Němeček, Stanislav; Čapek, Jiří

    2017-01-01

    The aim of this paper is to describe the effects of laser processing on the microstructure and residual stresses of laser cladded H13 tool steel on the classical construct steel S355 substrate. This research paper concludes that in this case of laser cladding, phase transformation and not shrinkage is likely to be a dominant effect on the formation of compressive residual stresses along the clad. Furthermore, martensitic structure and unequal concentration of alloying elements was observed on...

  17. Flow and Stress Field Analysis of Different Fluids and Blades for Fermentation Process

    OpenAIRE

    Cheng-Chi Wang; Po-Jen Cheng; Kuo-Chi Liu; Ming-Yi Tsai

    2014-01-01

    Fermentation techniques are applied for the biotechnology and are widely used for food manufacturing, materials processing, chemical reaction, and so forth. Different fluids and types of blades in the tank for fermentation cause distinct flow and stress field distributions on the surface between fluid and blade and various flow reactions in the tank appear. This paper is mainly focused on the analysis of flow field with different fluid viscosities and also studied the stress field acting on t...

  18. Numerical simulation of residual stress in laser based additive manufacturing process

    Science.gov (United States)

    Kalyan Panda, Bibhu; Sahoo, Seshadev

    2018-03-01

    Minimizing the residual stress build-up in metal-based additive manufacturing plays a pivotal role in selecting a particular material and technique for making an industrial part. In beam-based additive manufacturing, although a great deal of effort has been made to minimize the residual stresses, it is still elusive how to do so by simply optimizing the processing parameters, such as beam size, beam power, and scan speed. Amid different types of additive manufacturing processes, Direct Metal Laser Sintering (DMLS) process uses a high-power laser to melt and sinter layers of metal powder. The rapid solidification and heat transfer on powder bed endows a high cooling rate which leads to the build-up of residual stresses, that will affect the mechanical properties of the build parts. In the present work, the authors develop a numerical thermo-mechanical model for the measurement of residual stress in the AlSi10Mg build samples by using finite element method. Transient temperature distribution in the powder bed was assessed using the coupled thermal to structural model. Subsequently, the residual stresses were estimated with varying laser power. From the simulation result, it found that the melt pool dimensions increase with increasing the laser power and the magnitude of residual stresses in the built part increases.

  19. Programming Language Paradigms

    OpenAIRE

    Felician ALECU

    2013-01-01

    This paper's goal is to briefly explain the basic theory behind programming languages and their history while taking a close look at different programming paradigms that are used today as well as describing their differences, benefits, and drawbacks

  20. Manufacturing work and organizational stresses in export processing zones.

    Science.gov (United States)

    Lu, Jinky Leilanie

    2009-10-01

    In the light of global industrialization, much attention has been focused on occupational factors and their influence on the health and welfare of workers. This was a cross sectional study using stratified sampling technique based on industry sizes. The study sampled 24 industries, 6 were small scale industries and 9 each for medium and large scale industries. From the 24 industries, a total of 500 respondents for the questionnaire was taken. For occupational health and safety standards that industries have to comply with, there was low compliance among small-scale industries relative to the medium and large scale industries. Only one industry had an air cleaning device for cleaning contaminated air prior to emission into the external community. Among the 500 respondents, majority were female (88.8%), single (69.6%) and worked in the production or assembly-line station (87.4%). Sickness absenteeism was relative high among the workers in this study accounting for almost 54% among females and 48% among males. Many of the workers also reported of poor performance at work, boredom, tardiness and absenteeism. For association between work factors and personal factors, the following were found to be statistically significant at p=0.05. Boredom was associated with lack of skills training, lack of promotion, disincentives for sick leaves, poor relationship with boss and poor relationships with employers. On the other hand, poor performance was also associated with lack of skills training, lack of promotions, job insecurity, and poor relationship with employers. From the data generated, important issues that must be dealt with in work organizations include the quality of work life, and health and safety issues. Based on these findings, we can conclude that there are still issues on occupational health and safety (OHS) in the target site of export processing zones in the Philippines. There must be an active campaign for OHS in industries that are produce for the global market

  1. 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 ...

  2. Hemispheric asymmetry in stress processing in rat prefrontal cortex and the role of mesocortical dopamine.

    Science.gov (United States)

    Sullivan, R M

    2004-06-01

    The prefrontal cortex (PFC) is known to play an important role not only in the regulation of emotion, but in the integration of affective states with appropriate modulation of autonomic and neuroendocrine stress regulatory systems. The present review highlights findings in the rat which helps to elucidate the complex nature of prefrontal involvement in emotion and stress regulation. The medial PFC is particularly important in this regard and while dorsomedial regions appear to play a suppressive role in such regulation, the ventromedial (particularly infralimbic) region appears to activate behavioral, neuroendocrine and sympathetic autonomic systems in response to stressful situations. This may be especially true of spontaneous stress-related behavior or physiological responses to relatively acute stressors. The role of the medial PFC is somewhat more complex in conditions involving learned adjustments to stressful situations, such as the extinction of conditioned fear responses, but it is clear that the medial PFC is important in incorporating stressful experience for future adaptive behavior. It is also suggested that mesocortical dopamine plays an important adaptive role in this region by preventing excessive behavioral and physiological stress reactivity. The rat brain shows substantial hemispheric specialization in many respects, and while the right PFC is normally dominant in the activation of stress-related systems, the left may play a role in countering this activation through processes of interhemispheric inhibition. This proposed basic template for the lateralization of stress regulatory systems is suggested to be associated with efficient stress and emotional self-regulation, and also to be shaped by both early postnatal experience and gender differences.

  3. How Accumulated Real Life Stress Experience and Cognitive Speed Interact on Decision-Making Processes.

    Science.gov (United States)

    Friedel, Eva; Sebold, Miriam; Kuitunen-Paul, Sören; Nebe, Stephan; Veer, Ilya M; Zimmermann, Ulrich S; Schlagenhauf, Florian; Smolka, Michael N; Rapp, Michael; Walter, Henrik; Heinz, Andreas

    2017-01-01

    and slower information processing capacities, however, might favor model-free strategies. Thus, the valence and preference of either system strongly depends on stressful experiences and individual cognitive capacities.

  4. Black hole evaporation: a paradigm

    International Nuclear Information System (INIS)

    Ashtekar, Abhay; Bojowald, Martin

    2005-01-01

    A paradigm describing black hole evaporation in non-perturbative quantum gravity is developed by combining two sets of detailed results: (i) resolution of the Schwarzschild singularity using quantum geometry methods and (ii) time evolution of black holes in the trapping and dynamical horizon frameworks. Quantum geometry effects introduce a major modification in the traditional spacetime diagram of black hole evaporation, providing a possible mechanism for recovery of information that is classically lost in the process of black hole formation. The paradigm is developed directly in the Lorentzian regime and necessary conditions for its viability are discussed. If these conditions are met, much of the tension between expectations based on spacetime geometry and structure of quantum theory would be resolved

  5. Contrasting Effects of Dual-task Paradigm and of Timing Interruption Paradigm in Interval Timing of the Context of Culti-modal Processing%跨通道情境下双任务范式与计时中断范式中的效应比较*

    Institute of Scientific and Technical Information of China (English)

    尹华站; 李丹; 袁祥勇; 黄希庭

    2013-01-01

    为了探讨跨通道情境下同一种刺激序列中双任务范式与计时中断范式中位置效应和间断效应的异同,研究设计了实验1和实验2。实验1以2500 ms和4500 ms为目标时距,采用相同的刺激序列(视觉呈现时距信号,听觉呈现干扰信号或中断信号),要求3组被试分别在控制、干扰及中断条件下完成相应任务,结果发现不管2500 ms或4500 ms时,中断条件较干扰条件和控制条件的间断效应更明显;同时发现在2500 ms时,不管控制、干扰还是中断条件下均发现了位置效应,而4500 ms时仅在中断条件下出现了位置效应,这可能由于实验1的控制及干扰任务中的4500 ms时的“晚”位置的时间确定性较高,以致掩盖了位置效应。为了降低“晚”位置出现的确定性,更好地对比两种范式中的效应,实验2将目标时距设置为1500 ms和2500 ms,结果发现在1500 ms或2500 ms时,不管控制、干扰还是中断条件下均发现了位置效应,且中断条件较干扰条件和控制条件下间断效应更明显。上述结果意味着跨通道情境下同一种刺激序列中双任务范式与计时中断范式中位置效应是否相同局限在一定时间范畴;计时中断范式中的中断效应对计时的消弱较双任务范式干扰效应更显著。%Distribution of attention in time information processing is one of the hot areas of research science, and the dual-task paradigm is one of the most common ways to study distribution of attention. It requires an individual to perform two tasks simultaneously, the less the attention allocated to a temporal interval, the shorter it is judged(Brown, 1997). The attention sharing effect is discussed within the framework of the scalar expectancy model of timing. In such paradigm the parallel processing itself may interfere with time perception and lead to unexpected deviations. In order to avoid such interference, the timing interruption paradigm would be a better

  6. Instrumental learning and cognitive flexibility processes are impaired in children exposed to early life stress.

    Science.gov (United States)

    Harms, Madeline B; Shannon Bowen, Katherine E; Hanson, Jamie L; Pollak, Seth D

    2017-10-19

    Children who experience severe early life stress show persistent deficits in many aspects of cognitive and social adaptation. Early stress might be associated with these broad changes in functioning because it impairs general learning mechanisms. To explore this possibility, we examined whether individuals who experienced abusive caregiving in childhood had difficulties with instrumental learning and/or cognitive flexibility as adolescents. Fifty-three 14-17-year-old adolescents (31 exposed to high levels of childhood stress, 22 control) completed an fMRI task that required them to first learn associations in the environment and then update those pairings. Adolescents with histories of early life stress eventually learned to pair stimuli with both positive and negative outcomes, but did so more slowly than their peers. Furthermore, these stress-exposed adolescents showed markedly impaired cognitive flexibility; they were less able than their peers to update those pairings when the contingencies changed. These learning problems were reflected in abnormal activity in learning- and attention-related brain circuitry. Both altered patterns of learning and neural activation were associated with the severity of lifetime stress that the adolescents had experienced. Taken together, the results of this experiment suggest that basic learning processes are impaired in adolescents exposed to early life stress. These general learning mechanisms may help explain the emergence of social problems observed in these individuals. © 2017 The Authors. Developmental Science Published by John Wiley & Sons Ltd.

  7. A novel design for storage of inner stress by colloidal processing on rock-like materials

    Science.gov (United States)

    Chen, Weichang; Wang, Sijing; Lekan Olatayo, Afolagboye; Fu, Huanran

    2018-06-01

    Inner stress exists in rocks, affecting rock engineering, yet has received very little attention and quantitative investigation because of uncertainty about its characteristics. Previous studies have suggested that the inner stresses of rock materials are closely related to their physical state variation. In this work, a novel mold was designed to simulate the storage process of inner stress in specimens composed of quartz sands and epoxy. Then, thermal tests were carried out to change the physical state of the specimens, and expansion of the specimens was monitored. The results indicated that inner stress could be partly locked by the mold and it could also be released by heating. It can be inferred from the analysis that one necessary condition of storage and release of inner stress is physical state variation. Additionally, by using an XRD method, the variations in the interplanar spacing of the quartz sands were detected, and the results reflect that inner stress could be locked-in aggregates (quartz sands) by a cement constraint (solid epoxy). The inner stress stored in quartz sands was calculated using height and interplanar spacing variations.

  8. Average thermal stress in the Al+SiC composite due to its manufacturing process

    International Nuclear Information System (INIS)

    Miranda, Carlos A.J.; Libardi, Rosani M.P.; Marcelino, Sergio; Boari, Zoroastro M.

    2013-01-01

    The numerical analyses framework to obtain the average thermal stress in the Al+SiC Composite due to its manufacturing process is presented along with the obtained results. The mixing of Aluminum and SiC powders is done at elevated temperature and the usage is at room temperature. A thermal stress state arises in the composite due to the different thermal expansion coefficients of the materials. Due to the particles size and randomness in the SiC distribution, some sets of models were analyzed and a statistical procedure used to evaluate the average stress state in the composite. In each model the particles position, form and size are randomly generated considering a volumetric ratio (VR) between 20% and 25%, close to an actual composite. The obtained stress field is represented by a certain number of iso stress curves, each one weighted by the area it represents. Systematically it was investigated the influence of: (a) the material behavior: linear x non-linear; (b) the carbide particles form: circular x quadrilateral; (c) the number of iso stress curves considered in each analysis; and (e) the model size (the number of particles). Each of above analyzed condition produced conclusions to guide the next step. Considering a confidence level of 95%, the average thermal stress value in the studied composite (20% ≤ VR ≤ 25%) is 175 MPa with a standard deviation of 10 MPa. Depending on its usage, this value should be taken into account when evaluating the material strength. (author)

  9. Radiative processes for Rindler and accelerating observers and the stress-tensor detector

    International Nuclear Information System (INIS)

    Paola, R. De; Svaiter, N.F.

    1996-04-01

    It is considered a monopole detector interacting with a massive scalar field. Using the rotating wave approximation the radiative processes is discussed from the accelerated frame point of view. After this, it is obtained the Minkowski vacuum stress tensor measured by the accelerated observer using a non-gravitational stress sensor detector. Finally we analyse radiative processes of the monopole detector travelling in a world line that is inertial in the infinite past and has a constant proper acceleration in the infinite future. (author). 30 refs

  10. Stress Induced Charge-Ordering Process in LiMn_2O_4

    International Nuclear Information System (INIS)

    Chen, Yan; Yu, Dunji; An, Ke

    2016-01-01

    In this letter we report the stress-induced Mn charge-ordering process in the LiMn_2O_4 spinel, evidenced by the lattice strain evolutions due to the Jahn–Teller effects. In situ neutron diffraction reveals the initial stage of this process at low stress, indicating the eg electron localization at the preferential Mn sites during the early phase transition as an underlying charge-ordering mechanism in the charge-frustrated LiMn_2O_4. The initial stage of this transition exhibits as a progressive lattice and charge evolution, without showing a first-order behavior.

  11. The influences of fluorine and process variations on polysilicon film stress and MOSFET hot carrier effects

    Science.gov (United States)

    Lowry, Lynn E.; Macwilliams, Kenneth P.; Isaac, Mary

    1991-01-01

    The use of fluorinated gate oxides may provide an improvement in nMOSFET reliability by enhancing hot carrier resistance. In order to clarify the mechanisms by which polysilicon processing and fluorination influence the oxide behavior, a matrix of nMOSFET structures was prepared using various processing, doping, and implantation strategies. These structures were evaluated for crystalline morphology and chemical element distribution. Mechanical stress measurements were taken on the polysilicon films from room temperature to cryogenic temperature. These examinations showed that fluorination of a structure with randomly oriented polysilicon can reduce residual mechanical stress and improve hot carrier resistance at room temperature.

  12. A novel bread making process using salt-stressed Baker's yeast.

    Science.gov (United States)

    Yeh, Lien-Te; Charles, Albert Linton; Ho, Chi-Tang; Huang, Tzou-Chi

    2009-01-01

    By adjusting the mixing order of ingredients in traditional formula, an innovative bread making process was developed. The effect of salt-stressed Baker's yeast on bread dough of different sugar levels was investigated. Baker's yeast was stressed in 7% salt solution then mixed into dough, which was then evaluated for fermentation time, dough fermentation producing gas, dough expansion, bread specific volumes, and sensory and physical properties. The results of this study indicated that salt-stressed Baker's yeast shortened fermentation time in 16% and 24% sugar dough. Forty minutes of salt stress produced significant amount of gas and increased bread specific volumes. The bread was softer and significantly improved sensory properties for aroma, taste, and overall acceptability were obtained.

  13. Reduction of tensile residual stresses during the drawing process of tungsten wires

    International Nuclear Information System (INIS)

    Rodriguez Ripoll, Manel; Weygand, Sabine M.; Riedel, Hermann

    2010-01-01

    Tungsten wires are commonly used in the lighting industry as filaments for lamps. During the drawing process, the inhomogeneous deformation imparted by the drawing die causes tensile residual stresses at the wire surface in circumferential direction. These stresses have a detrimental effect for the wire because they are responsible for driving longitudinal cracks, known as splits. This work proposes two methods for reducing the residual stresses during wire drawing, namely applying an advanced die geometry and performing an inexpensive post-drawing treatment based on targeted bending operations. These two methods are analyzed with finite element simulations using material parameters obtained by mechanical tests on tungsten wires at different temperatures as input data. The computed results predict a substantial reduction of the circumferential residual stresses, thus reducing the risk of splitting.

  14. Effects on residual stresses of aluminum alloy LC4 by laser shock processing

    Science.gov (United States)

    Zhang, Yong-kang; Lu, Jin-zhong; Kong, De-jun; Yao, Hui-xue; Yang, Chao-jun

    2007-12-01

    The influences of processing parameters on laser-induced shock waves in metal components are discussed and analyzed. The effects of different parameters of laser shock processing (LSP) on residual stress of aerospace aluminum alloy LC4 were investigated. LSP was performed by using an Nd: glass phosphate laser with 23 ns pulse width and up to ~45 J pulse energy at power densities above GW/mm -2. Special attention is paid to the residual stresses from laser shock processing. Modification of microstructure, surface morphology by laser shock processing is also discussed. Results to date indicate that laser shock processing has great potential as a means of improving the mechanical performance of components.

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

    Science.gov (United States)

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

    2016-08-01

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

  16. Forgiveness, Stress, and Health: a 5-Week Dynamic Parallel Process Study.

    Science.gov (United States)

    Toussaint, Loren L; Shields, Grant S; Slavich, George M

    2016-10-01

    Psychological stress is a well-known risk factor for poor health, and recent research has suggested that the emotion-focused coping process of forgiveness may help mitigate these effects. To date, however, no studies have examined how levels of forgiveness, stress, and health fluctuate and interrelate over time. We addressed this issue by examining how forgiveness, stress, and mental and physical health symptoms change and relate to one another over 5 weeks. We hypothesized that increases in state levels of forgiveness would be associated with decreases in perceptions of stress, which would in turn be related to decreases in mental and physical health symptoms. A reverse effects model was also tested. We recruited a large, community-based sample of 332 young, middle-aged, and older adults (16-79 years old; M age  = 27.9). Each week for 5 weeks, participants reported on their levels of state forgiveness, perceived stress, and mental and physical health symptoms. Levels of forgiveness, stress, and mental and physical health symptoms each showed significant change and individual variability in change over time. As hypothesized, increases in forgiveness were associated with decreases in stress, which were in turn related to decreases in mental (but not physical) health symptoms (i.e., forgiveness → stress → health). The reverse effects model (i.e., health → stress → forgiveness) provided a relatively poorer fit. This study is the first to provide prospective, longitudinal evidence showing that greater forgiveness is associated with less stress and, in turn, better mental health. Strategies for cultivating forgiveness may thus have beneficial effects on stress and health.

  17. Winnicott's paradigm outlined

    Directory of Open Access Journals (Sweden)

    Zeljko Loparic

    Full Text Available The main objective of this paper is to present a unified view of Winnicott’s contribution to psychoanalysis. Part I (Sections 1-4 starts off by recalling that, according to some important commentators, Winnicott introduced a change in paradigms in psychoanalysis. In order to show that this change can be viewed as an overall “switch in paradigms”, in the sense given by T. S. Kuhn, this paper presents an account of the Kuhn’s view of science and offers a reconstruction of Freud’s Oedipal, Triangular or “Toddler-in-the-Mother’s-Bed” Paradigm. Part II (Sections 5-13 shows that as early as the 1920’s Winnicott encountered insurmountable anomalies in the Oedipal paradigm and, for that reason, started what can be called revolutionary research for a new framework of psychoanalysis. This research led Winnicott, especially during the last period of his life, to produce an alternative dual or “Baby-on-the-Mother’s-Lap” Paradigm. This new paradigm is described in some detail, especially the paradigmatic dual mother-baby relation and Winnicott’s dominant theory of maturation. Final remarks are made regarding Winnicott’s heritage and the future of psychoanalysis.

  18. OXIDATIVE STRESS AND VASCULAR DAMAGE IN HYPOXIA PROCESSES. MALONDIALDEHYDE (MDA AS BIOMARKER FOR OXIDATIVE DAMAGE

    Directory of Open Access Journals (Sweden)

    Muñiz P

    2014-05-01

    Full Text Available Changes in the levels oxidative stress biomarkers are related with different diseases such as ischemia/reperfusion, cardiovascular, renal, aging, etc. One of these biomarkers is the malondialdehyde (MDA generated as resulted of the process of lipid peroxidation. This biomarker is increased under conditions of the oxidative stress. Their levels, have been frequently used to measure plasma oxidative damage to lipids by their atherogenic potential. Its half-life high and their reactivity allows it to act both inside and outside of cells and interaction with proteins and DNA involve their role in different pathophysiological processes. This paper presents an analysis of the use of MDA as a biomarker of oxidative stress and its implications associated pathologies such as cardiovascular diseases ago.

  19. Optimisation of process parameters in friction stir welding based on residual stress analysis: a feasibility study

    DEFF Research Database (Denmark)

    Tutum, Cem Celal; Hattel, Jesper Henri

    2010-01-01

    The present paper considers the optimisation of process parameters in friction stir welding (FSW). More specifically, the choices of rotational speed and traverse welding speed have been investigated using genetic algorithms. The welding process is simulated in a transient, two......-dimensional sequentially coupled thermomechanical model in ANSYS. This model is then used in an optimisation case where the two objectives are the minimisation of the peak residual stresses and the maximisation of the welding speed. The results indicate that the objectives for the considered case are conflicting......, and this is presented as a Pareto optimal front. Moreover, a higher welding speed for a fixed rotational speed results, in general, in slightly higher stress levels in the tension zone, whereas a higher rotational speed for a fixed welding speed yields somewhat lower peak residual stress, however, a wider tension zone...

  20. Linking aims, paradigm and method in nursing research.

    Science.gov (United States)

    Houghton, Catherine; Hunter, Andrew; Meskell, Pauline

    2012-01-01

    To explore the use of paradigms as ontological and philosophical guides for conducting PhD research. A paradigm can help to bridge the aims of a study and the methods to achieve them. However, choosing a paradigm can be challenging for doctoral researchers: there can be ambiguity about which paradigm is suitable for a particular research question and there is a lack of guidance on how to shape the research process for a chosen paradigm. The authors discuss three paradigms used in PhD nursing research: post-positivism, interpretivism and pragmatism. They compare each paradigm in relation to its ontology, epistemology and methodology, and present three examples of PhD nursing research studies to illustrate how research can be conducted using these paradigms in the context of the research aims and methods. The commonalities and differences between the paradigms and their uses are highlighted. Creativity and flexibility are important when deciding on a paradigm. However, consistency and transparency are also needed to ensure the quality and rigour necessary for conducting nursing research. When choosing a suitable paradigm, the researcher should ensure that the ontology, epistemology and methodology of the paradigm are manifest in the methods and research strategies employed.

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

    DEFF Research Database (Denmark)

    Nielsen, Michael Wenani

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

  2. Family-Level Coparenting Processes and Child Gender as Moderators of Family Stress and Toddler Adjustment

    Science.gov (United States)

    Kolak, Amy M.; Vernon-Feagans, Lynne

    2008-01-01

    The goal of this multi-method study was to examine how child gender and coparenting processes influence associations between family stress and toddlers' social adjustment. The participants, 104 dual-earner couples and their 2-year-old children, were videotaped in their home during a freeplay activity. Mothers and fathers completed questionnaires…

  3. Process variables in organizational stress management intervention evaluation research: a systematic review

    NARCIS (Netherlands)

    Havermans, B.M.; Schelvis, R.M.C.; Boot, C.R.L.; Brouwers, E.P.M.; Anema, J.R.; Beek, A.J. van der

    2016-01-01

    Objectives This systematic review aimed to explore which process variables are used in stress management intervention (SMI) evaluation research. Methods A systematic review was conducted using seven electronic databases. Studies were included if they reported on an SMI aimed at primary or secondary

  4. Stress Process of Illicit Drug Use among U.S. Immigrants' Adolescent Children: A Longitudinal Study

    Science.gov (United States)

    Choo, Hyekyung

    2012-01-01

    This study examined a full path model of stress process for predicting illicit drug use among Asian and Latino immigrants' adolescent children. Using 2-year longitudinal data (National Longitudinal Study of Adolescent Health) from a sample of adolescents with Asian or Latino immigrant parents (N = 2,353), the study explored structural…

  5. Process variables in organizational stress management intervention evaluation research : A systematic review

    NARCIS (Netherlands)

    Havermans, B.M.; Schlevis, Roosmarijn Mc; Boot, Cécile Rl; Brouwers, E.P.M.; Anema, Johannes R; van der Beek, Allard J

    2016-01-01

    OBJECTIVES: This systematic review aimed to explore which process variables are used in stress management intervention (SMI) evaluation research. METHODS: A systematic review was conducted using seven electronic databases. Studies were included if they reported on an SMI aimed at primary or

  6. Effects of advanced laser processing on the microstructure and residual stresses of H13 tool steel

    NARCIS (Netherlands)

    Trojan, Karel; Ocelík, Václav; Ganev, Nikolaj; Němeček, Stanislav; Čapek, Jiří

    2017-01-01

    The aim of this paper is to describe the effects of laser processing on the microstructure and residual stresses of laser cladded H13 tool steel on the classical construct steel S355 substrate. This research paper concludes that in this case of laser cladding, phase transformation and not shrinkage

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

    NARCIS (Netherlands)

    Vente, W. de; Kamphuis, J.H.; Blonk, R.W.; Emmelkamp, P.M.

    2015-01-01

    Purpose The process of recovery from work-related stress, consisting of complaint reduction and work-resumption, is not yet fully understood. The aim of this study was to investigate predictors of complaint reduction and work-resumption, as well as testing complaint reduction as a mediator in the

  8. Recovery of work-related stress: Complaint reduction and work-resumption are relatively independent processes

    NARCIS (Netherlands)

    de Vente, W.; Kamphuis, J.H.; Blonk, R.W.B.; Emmelkamp, P.M.G.

    2015-01-01

    Purpose: The process of recovery from work-related stress, consisting of complaint reduction and work-resumption, is not yet fully understood. The aim of this study was to investigate predictors of complaint reduction and work-resumption, as well as testing complaint reduction as a mediator in the

  9. Thermomechanical processing of 5083 aluminum to increase strength without increasing susceptibility to stress corrosion cracking

    International Nuclear Information System (INIS)

    Edstrom, C.M.; Blakeslee, J.J.

    1980-01-01

    5083 aluminium with 25% cold work must be processed above 215 0 C or below 70 0 C to avoid forming continuous precipitate in the grain boundaries which makes the material susceptible to stress corrosion cracking. Time at temperature above 215 0 C should be held to minimum (less than 30 min) to retain some strength from the 25% cold work

  10. Three paradigms of horror

    Directory of Open Access Journals (Sweden)

    Dejan Ognjanović

    2016-07-01

    Full Text Available Starting with the definition of horror as a literary genre the core story of which is based on a meeting with threatening Otherness whose influx into consensual reality and it’s tacit normality creates unrest and awakens fear in the protagonists and the audience, this paper defines the three key paradigms of the horror genre, based on the causes of fear, or rather the “monstrous” Otherness in them. Paradigm 1 concerns the “fear of one’s own self”: the root of the fear is inside, in the individual psyche, in the split, deceived, or in some other way unreliable self which is, consciously or unconsciously, harmful to others, and ultimately to itself. Paradigm 2 deals with the “Fear of others”: the root of fear is outside and is concerned with other people and other creatures which have an urge to occupy a certain human microcosm. Paradigm 3 is concerned with the “Fear of the numinous”: the root of the fear is mostly situated on the outside; however its shape is amorphous, ambivalent and unknowable. The “monster” is faceless; it touches on primary forces of the divine/demonic, and as such is situated on the very border between inside/outside. All three paradigms, with their main approaches and constitutive elements, are modulated through two basic possible treatments: the conservative and the progressive (liberal, which affords a total of six basic variations of horror. Starting from definitions given by John Carpenter, Robin Wood and his own, the author analyzes representative examples from horror literature and film for each paradigm and its variation, with a special accent on the image of Otherness and its connection to the norm, its intrusion into the status quo, anthropocentrism and the presence or absence of a happy ending. The paper demonstrates the richness of connotative potential within the horror genre and provides a basis for its taxonomy.

  11. The safety implications of emerging software paradigms

    International Nuclear Information System (INIS)

    Suski, G.J.; Persons, W.L.; Johnson, G.L.

    1994-10-01

    This paper addresses some of the emerging software paradigms that may be used in developing safety-critical software applications. Paradigms considered in this paper include knowledge-based systems, neural networks, genetic algorithms, and fuzzy systems. It presents one view of the software verification and validation activities that should be associated with each paradigm. The paper begins with a discussion of the historical evolution of software verification and validation. Next, a comparison is made between the verification and validation processes used for conventional and emerging software systems. Several verification and validation issues for the emerging paradigms are discussed and some specific research topics are identified. This work is relevant for monitoring and control at nuclear power plants

  12. Study on residual stress across the pipes' thickness using outer surface rapid heating. Development of pipe outer surface irradiated laser stress improvement process (L-SIP)

    International Nuclear Information System (INIS)

    Ohta, Takahiro; Terasaki, Toshio

    2009-01-01

    The new process called L-SIP (outer surface irradiated Laser Stress Improvement Process) is developed to improve the tensile residual stress of the inner surface near the butt welded joints of pipes in the compression stress. The temperature gradient occurs in the thickness of pipes in heating the outer surface rapidly by laser beam. By the thermal expansion difference between the inner surface and the outer surface, the compression plastic strain generates near the outer surface and the tensile plastic strain generates near the inner surface of pipes. The compression stress occurs near the inner surface of pipes by the plastic deformation. In this paper, the theoretical equation which calculates residual stress distribution from the inherent strain distribution in the thickness of pipes is derived. And, the relation between the distribution of temperature and the residual stress in the thickness is examined for various pipes size. (1) By rapidly heating from the outer surface, the residual stress near the inner surface of the pipe is improved to the compression stress. (2) Pipes size hardly affects the distribution of the residual stress in the stainless steel pipes for piping (JISG3459). (3) The temperature rising area from the outside is smaller, the area of the compression residual stress near the inner surface becomes wider. (author)

  13. Three paradigms of horror

    OpenAIRE

    Dejan Ognjanović

    2016-01-01

    Starting with the definition of horror as a literary genre the core story of which is based on a meeting with threatening Otherness whose influx into consensual reality and it’s tacit normality creates unrest and awakens fear in the protagonists and the audience, this paper defines the three key paradigms of the horror genre, based on the causes of fear, or rather the “monstrous” Otherness in them. Paradigm 1 concerns the “fear of one’s own self”: the root of the fear is inside, in the indivi...

  14. A framework for modelling the behaviour of a process control operator under stress

    International Nuclear Information System (INIS)

    Kan, C-C.F.; Roberts, P.D.; Smith, I.C.

    1990-01-01

    This paper proposes the basis for a framework for modelling effects of stress on the behaviour of a process control plant operator. The qualitative effects of stress on the cognitive processing ability of the operator are discussed. Stress is thought to mainly decrease the reasoning ability of the operator. The operator will experience increased rigidity in problem solving and the narrowing of his attention and perceptual field. At the same time, the operator will be increasingly reluctant in admitting that wrong decisions have been committed. Furthermore, he will revert to skill-based behaviours. The direct consequence of stress on the decision making mechanism of the operator is the selection of inappropriate choice of action. A formal representation of decision errors is proposed and various techniques are suggested for representing various mechanisms for decision error making. The degree of experience possessed by the operator is also an important factor to the operator's tolerance of stress. The framework also allows the experience of the operator to be integrated into the model. Such an operator model can be linked to a plant simulator and the complete behaviour of the plant then be simulated

  15. Modeling the Influence of Process Parameters and Additional Heat Sources on Residual Stresses in Laser Cladding

    Science.gov (United States)

    Brückner, F.; Lepski, D.; Beyer, E.

    2007-09-01

    In laser cladding thermal contraction of the initially liquid coating during cooling causes residual stresses and possibly cracks. Preweld or postweld heating using inductors can reduce the thermal strain difference between coating and substrate and thus reduce the resulting stress. The aim of this work is to better understand the influence of various thermometallurgical and mechanical phenomena on stress evolution and to optimize the induction-assisted laser cladding process to get crack-free coatings of hard materials at high feed rates. First, an analytical one-dimensional model is used to visualize the most important features of stress evolution for a Stellite coating on a steel substrate. For more accurate studies, laser cladding is simulated including the powder-beam interaction, the powder catchment by the melt pool, and the self-consistent calculation of temperature field and bead shape. A three-dimensional finite element model and the required equivalent heat sources are derived from the results and used for the transient thermomechanical analysis, taking into account phase transformations and the elastic-plastic material behavior with strain hardening. Results are presented for the influence of process parameters such as feed rate, heat input, and inductor size on the residual stresses at a single bead of Stellite coatings on steel.

  16. Prefrontal cortex executive processes affected by stress in health and disease.

    Science.gov (United States)

    Girotti, Milena; Adler, Samantha M; Bulin, Sarah E; Fucich, Elizabeth A; Paredes, Denisse; Morilak, David A

    2017-07-06

    Prefrontal cortical executive functions comprise a number of cognitive capabilities necessary for goal directed behavior and adaptation to a changing environment. Executive dysfunction that leads to maladaptive behavior and is a symptom of psychiatric pathology can be instigated or exacerbated by stress. In this review we survey research addressing the impact of stress on executive function, with specific focus on working memory, attention, response inhibition, and cognitive flexibility. We then consider the neurochemical pathways underlying these cognitive capabilities and, where known, how stress alters them. Finally, we review work exploring potential pharmacological and non-pharmacological approaches that can ameliorate deficits in executive function. Both preclinical and clinical literature indicates that chronic stress negatively affects executive function. Although some of the circuitry and neurochemical processes underlying executive function have been characterized, a great deal is still unknown regarding how stress affects these processes. Additional work focusing on this question is needed in order to make progress on developing interventions that ameliorate executive dysfunction. Published by Elsevier Inc.

  17. Stress strain modelling of casting processes in the framework of the control volume method

    DEFF Research Database (Denmark)

    Hattel, Jesper; Andersen, Søren; Thorborg, Jesper

    1998-01-01

    Realistic computer simulations of casting processes call for the solution of both thermal, fluid-flow and stress/strain related problems. The multitude of the influencing parameters, and their non-linear, transient and temperature dependent nature, make the calculations complex. Therefore the nee......, the present model is based on the mainly decoupled representation of the thermal, mechanical and microstructural processes. Examples of industrial applications, such as predicting residual deformations in castings and stress levels in die casting dies, are presented...... for fast, flexible, multidimensional numerical methods is obvious. The basis of the deformation and stress/strain calculation is a transient heat transfer analysis including solidification. This paper presents an approach where the stress/strain and the heat transfer analysis uses the same computational...... domain, which is highly convenient. The basis of the method is the control volume finite difference approach on structured meshes. The basic assumptions of the method are shortly reviewed and discussed. As for other methods which aim at application oriented analysis of casting deformations and stresses...

  18. Process variables in organizational stress management intervention evaluation research: a systematic review.

    Science.gov (United States)

    Havermans, Bo M; Schlevis, Roosmarijn Mc; Boot, Cécile Rl; Brouwers, Evelien Pm; Anema, Johannes; van der Beek, Allard J

    2016-09-01

    This systematic review aimed to explore which process variables are used in stress management intervention (SMI) evaluation research. A systematic review was conducted using seven electronic databases. Studies were included if they reported on an SMI aimed at primary or secondary stress prevention, were directed at paid employees, and reported process data. Two independent researchers checked all records and selected the articles for inclusion. Nielsen and Randall's model for process evaluation was used to cluster the process variables. The three main clusters were context, intervention, and mental models. In the 44 articles included, 47 process variables were found, clustered into three main categories: context (two variables), intervention (31 variables), and mental models (14 variables). Half of the articles contained no reference to process evaluation literature. The collection of process evaluation data mostly took place after the intervention and at the level of the employee. The findings suggest that there is great heterogeneity in methods and process variables used in process evaluations of SMI. This, together with the lack of use of a standardized framework for evaluation, hinders the advancement of process evaluation theory development.

  19. ER stress affects processing of MHC class I-associated peptides

    Directory of Open Access Journals (Sweden)

    Meloche Sylvain

    2009-02-01

    Full Text Available Abstract Background Viral infection and neoplastic transformation trigger endoplasmic reticulum (ER stress. Thus, a large proportion of the cells that must be recognized by the immune system are stressed cells. Cells respond to ER stress by launching the unfolded protein response (UPR. The UPR regulates the two key processes that control major histocompatibility complex class I (MHC I-peptide presentation: protein synthesis and degradation. We therefore asked whether and how the UPR impinges on MHC I-peptide presentation. Results We evaluated the impact of the UPR on global MHC I expression and on presentation of the H2Kb-associated SIINFEKL peptide. EL4 cells stably transfected with vectors coding hen egg lysozyme (HEL-SIINFEKL protein variants were stressed with palmitate or exposed to glucose deprivation. UPR decreased surface expression of MHC I but did not affect MHC I mRNA level nor the total amount of intracellular MHC I proteins. Impaired MHC I-peptide presentation was due mainly to reduced supply of peptides owing to an inhibition of overall protein synthesis. Consequently, generation of H2Kb-SIINFEKL complexes was curtailed during ER stress, illustrating how generation of MHC I peptide ligands is tightly coupled to ongoing protein synthesis. Notably, the UPR-induced decline of MHC I-peptide presentation was more severe when the protein source of peptides was localized in the cytosol than in the ER. This difference was not due to changes in the translation rates of the precursor proteins but to increased stability of the cytosolic protein during ER stress. Conclusion Our results demonstrate that ER stress impairs MHC I-peptide presentation, and that it differentially regulates expression of ER- vs. cytosol-derived peptides. Furthermore, this work illustrates how ER stress, a typical feature of infected and malignant cells, can impinge on cues for adaptive immune recognition.

  20. Effect of processing conditions on residual stress distributions by bead-on-plate welding after surface machining

    International Nuclear Information System (INIS)

    Ihara, Ryohei; Mochizuki, Masahito

    2014-01-01

    Residual stress is important factor for stress corrosion cracking (SCC) that has been observed near the welded zone in nuclear power plants. Especially, surface residual stress is significant for SCC initiation. In the joining processes of pipes, butt welding is conducted after surface machining. Residual stress is generated by both processes, and residual stress distribution due to surface machining is varied by the subsequent butt welding. In previous paper, authors reported that residual stress distribution generated by bead on plate welding after surface machining has a local maximum residual stress near the weld metal. The local maximum residual stress shows approximately 900 MPa that exceeds the stress threshold for SCC initiation. Therefore, for the safety improvement of nuclear power plants, a study on the local maximum residual stress is important. In this study, the effect of surface machining and welding conditions on residual stress distribution generated by welding after surface machining was investigated. Surface machining using lathe machine and bead on plate welding with tungsten inert gas (TIG) arc under various conditions were conducted for plate specimens made of SUS316L. Then, residual stress distributions were measured by X-ray diffraction method (XRD). As a result, residual stress distributions have the local maximum residual stress near the weld metal in all specimens. The values of the local maximum residual stresses are almost the same. The location of the local maximum residual stress is varied by welding condition. It could be consider that the local maximum residual stress is generated by same generation mechanism as welding residual stress in surface machined layer that has high yield stress. (author)

  1. [Perception, processing of visual information and resistance to emotional stresses in athletes of different ages].

    Science.gov (United States)

    Korobeĭnikova, L H; Makarchuk, M Iu

    2013-01-01

    Among the numerous studies devoted to the study of perception and information processing, no data available on the effects of age on these processes. In this paper we studied the influence of psycho-emotional stress and different levels of stress on the mental processes of perception and information processing in highly skilled athletes divided into two groups. The first group included the athletes aged 19-24 years (12 athletes, members of the Ukrainian team in Greco-Roman wrestling), the second group included the athletes aged 27-31 years (7 highly skilled athletes, members of the Ukrainian team in Greco-Roman wrestling). We revealed that the athletes of the first group had higher productivity and better visual perception and visual information processing efficiency, compared with athletes from the second group. This observation suggests a dependency of cognitive component of perception and information processing on the age of the athletes. Sportsmen from the second group had higher stress resistance compared to the older age group.

  2. Process Modelling of Curing Process-Induced Internal Stress and Deformation of Composite Laminate Structure with Elastic and Viscoelastic Models

    Science.gov (United States)

    Li, Dongna; Li, Xudong; Dai, Jianfeng

    2018-06-01

    In this paper, two kinds of transient models, the viscoelastic model and the linear elastic model, are established to analyze the curing deformation of the thermosetting resin composites, and are calculated by COMSOL Multiphysics software. The two models consider the complicated coupling between physical and chemical changes during curing process of the composites and the time-variant characteristic of material performance parameters. Subsequently, the two proposed models are implemented respectively in a three-dimensional composite laminate structure, and a simple and convenient method of local coordinate system is used to calculate the development of residual stresses, curing shrinkage and curing deformation for the composite laminate. Researches show that the temperature, degree of curing (DOC) and residual stresses during curing process are consistent with the study in literature, so the curing shrinkage and curing deformation obtained on these basis have a certain referential value. Compared the differences between the two numerical results, it indicates that the residual stress and deformation calculated by the viscoelastic model are more close to the reference value than the linear elastic model.

  3. Residual stress evaluation and curvature behavior of aluminum 7050 peen forming processed

    International Nuclear Information System (INIS)

    Oliveira, Rene Ramos de

    2011-01-01

    Shot peening is a superficial cold work process used to increase the fatigue life evaluated by residual stress measurements. The peen forming process is a variant of the shot peening process, where a curvature in the plate is obtained by the compression of the grains near to the surface. In this paper, the influence of the parameters such as: pressure of shot, ball shot size and thickness of aluminum 7050 samples with respect to residual stress profile and resulting arc height was studied. The evaluation of the residual stress profile was obtained by sin 2 ψ method. The results show that the formation of the curvature arc height is proportional to the shot peening pressure, of spheres size and inversely proportional to the thickness of the sample, and that stress concentration factor is larger for samples shot peened with small balls. On final of this paper presents an additional study on micro strain and average crystallite size, which can evaluate the profile of the samples after blasting. (author)

  4. Effects of a process-based cognitive training intervention for patients with stress-related exhaustion.

    Science.gov (United States)

    Gavelin, Hanna Malmberg; Boraxbekk, Carl-Johan; Stenlund, Therese; Järvholm, Lisbeth Slunga; Neely, Anna Stigsdotter

    2015-01-01

    Stress-related exhaustion has been linked to a pattern of selective cognitive impairments, mainly affecting executive functioning, attention and episodic memory. Little is known about potential treatments of these cognitive deficits. The purpose of this study was to evaluate the effects of a process-based cognitive training intervention, designed to target the specific cognitive impairments associated with stress-related exhaustion. To this end, patients diagnosed with exhaustion disorder (ED) were randomized to either a multimodal stress rehabilitation program with the addition of a process-based cognitive training intervention (training group, n = 27) or a treatment-as-usual control condition, consisting of multimodal stress rehabilitation with no additional training (control group, n = 32). Treatment effects were evaluated through an extensive cognitive test battery, assessing both near and far transfer effects, as well as self-report forms regarding subjective cognitive complaints and burnout levels. Results showed pronounced training-related improvements on the criterion updating task (p effects to updating (p = 0.01) and episodic memory (p = 0.04). Also, the trained group reported less subjective memory complaints (p = 0.02) and levels of burnout decreased for both groups, but more so for the trained group (p = 0.04), following the intervention. These findings suggest that process-based cognitive training may be a viable method to address the cognitive impairments associated with ED.

  5. Challenging paradigms in estuarine ecology and management

    Science.gov (United States)

    Elliott, M.; Whitfield, A. K.

    2011-10-01

    For many years, estuarine science has been the 'poor relation' in aquatic research - freshwater scientists ignored estuaries as they tended to get confused by salt and tides, and marine scientists were more preoccupied by large open systems. Estuaries were merely regarded by each group as either river mouths or sea inlets respectively. For the past four decades, however, estuaries (and other transitional waters) have been regarded as being ecosystems in their own right. Although often not termed as such, this has led to paradigms being generated to summarise estuarine structure and functioning and which relate to both the natural science and management of these systems. This paper defines, details and affirms these paradigms that can be grouped into those covering firstly the science (definitions, scales, linkages, productivity, tolerances and variability) and secondly the management (pressures, valuation, health and services) of estuaries. The more 'science' orientated paradigms incorporate the development and types of ecotones, the nature of stressed and variable systems (with specific reference to resilience and redundancy), the relationship between generalists and specialists produced by environmental tolerance, the relevance of scale in relation to functioning and connectivity, the sources of production and degree of productivity, the biodiversity-ecosystem functioning and the stress-subsidy debates. The more 'management' targeted paradigms include the development and effects of exogenic unmanaged pressures and endogenic managed pressures, the perception of health and the ability to manage estuaries (related to internal and external influences), and the influence of all of these on the production of ecosystem services and societal benefits.

  6. Paradigms in object recognition

    International Nuclear Information System (INIS)

    Mutihac, R.; Mutihac, R.C.

    1999-09-01

    A broad range of approaches has been proposed and applied for the complex and rather difficult task of object recognition that involves the determination of object characteristics and object classification into one of many a priori object types. Our paper revises briefly the three main different paradigms in pattern recognition, namely Bayesian statistics, neural networks, and expert systems. (author)

  7. Programming Language Paradigms

    Directory of Open Access Journals (Sweden)

    Bartoníček Jan

    2014-01-01

    Full Text Available This paper's goal is to briefly explain the basic theory behind programming languages and their history while taking a close look at different programming paradigms that are used today as well as describing their differences, benefits, and drawbacks

  8. Shifting the paradigm

    DEFF Research Database (Denmark)

    Kiss, Katalin; Brozik, Anna; Kucsma, Nora

    2012-01-01

    ABCB6, a member of the adenosine triphosphate-binding cassette (ABC) transporter family, has been proposed to be responsible for the mitochondrial uptake of porphyrins. Here we show that ABCB6 is a glycoprotein present in the membrane of mature erythrocytes and in exosomes released from reticuloc...... paradigm linking the expression and function of ABCB6 to mitochondria....

  9. Deconstructing Research: Paradigms Lost

    Science.gov (United States)

    Trifonas, Peter Pericles

    2009-01-01

    In recent decades, proponents of naturalistic and/or critical modes of inquiry advocating the use of ethnographic techniques for the narrative-based study of phenomena within pedagogical contexts have challenged the central methodological paradigm of educational research: that is, the tendency among its practitioners to adhere to quantitative…

  10. Effect of acute heat stress and slaughter processing on poultry meat quality and postmortem carbohydrate metabolism.

    Science.gov (United States)

    Wang, R H; Liang, R R; Lin, H; Zhu, L X; Zhang, Y M; Mao, Y W; Dong, P C; Niu, L B; Zhang, M H; Luo, X

    2017-03-01

    This study investigated the effects of acute heat stress and slaughter processing on poultry meat quality and carbohydrate metabolism. Broilers (200) were randomly divided into 2 groups receiving heat stress (HS; 36°C for one h), compared to a non-stressed control (C). At slaughter, each group was further divided into 2 groups for slaughter processing (L = laboratory; F = commercial factory). L group breasts were removed immediately after bleeding without carcass scalding or defeathering, and stored at 4°C. F group broilers were scalded (60°C, 45 s) after bleeding and defeathering. Then the breasts were removed and cooled in ice water until the core temperature was ≤4°C. Rates of Pectoralis core temperature and pH decline were changed by slaughter processing, but only HS affected ultimate pH in group L. HS muscles had higher L* values (P  0.05). Sarcoplasmic protein solubility was higher in F processed birds (P < 0.05). HS decreased the solubility of myofibrillar and total protein in the L-slaughtered birds. Thus, HS caused a higher frequency of accelerated muscle glycolysis than controls. Factory processing (chilling) could not completely eliminate the effects of accelerated glycolysis caused by pre-slaughter HS. © 2016 Poultry Science Association Inc.

  11. The relationship between processing style, trauma memory processes, and the development of posttraumatic stress symptoms in children and adolescents.

    Science.gov (United States)

    McKinnon, Anna; Brewer, Neil; Cameron, Kate; Nixon, Reginald D V

    2017-12-01

    Data-driven processing, peri-event fear, and trauma memory characteristics are hypothesised to play a core role in the development of Posttraumatic Stress Disorder. We assessed the relationships between these characteristics and Posttraumatic Stress (PTS) symptoms in a sample of youth. Study 1 (N = 36, 7-16 years), involved a sample of children who had undergone a stressful orthopaedic procedure. One week later they answered a series of probed recall questions about the trauma (assessed for accuracy by comparison to a video) and reported on their PTS symptoms. They also rated confidence in their probed recall answers to assess meta-cognitive monitoring of their memory for the trauma. In Study 2, a sample of injured children (N = 57, 7-16 years) were assessed within 1-month of a visit to an Emergency Department, and then at 3-month follow-up. They answered probed recall questions, made confidence ratings, and completed measures of data-driven processing, peri-event fear, PTS and associated psychopathology. Memories were verified using witness accounts. Studies 1 and 2 did not find an association between PTS symptoms and trauma memory accuracy or confidence. In Studies 1 and 2 data-driven processing predicted PTS symptoms. The studies had modest samples sizes and there were ceiling effects for some accuracy and confidence items. Data-driven processing at the time of a trauma was associated with PTS symptoms after accounting for fear at the time of the trauma. Accuracy of recall for trauma memories was not significantly related to PTS symptoms. No decisive conclusion could be drawn regarding the relation between confidence in trauma memories and PTS symptoms. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Mechanical Characterization of Thermomechanical Matrix Residual Stresses Incurred During MMC Processing

    Science.gov (United States)

    Castelli, Michael G.

    1998-01-01

    In recent years, much effort has been spent examining the residual stress-strain states of advanced composites. Such examinations are motivated by a number of significant concerns that affect composite development, processing, and analysis. The room-temperature residual stress states incurred in many advanced composite systems are often quite large and can introduce damage even prior to the first external mechanical loading of the material. These stresses, which are induced during the cooldown following high-temperature consolidation, result from the coefficient of thermal expansion mismatch between the fiber and matrix. Experimental techniques commonly used to evaluate composite internal residual stress states are non-mechanical in nature and generally include forms of x-ray and neutron diffraction. Such approaches are usually complex, involving a number of assumptions and limitations associated with a wide range of issues, including the depth of penetration, the volume of material being assessed, and erroneous effects associated with oriented grains. Furthermore, and more important to the present research, these techniques can assess only "single time" stress in the composite. That is, little, if any, information is obtained that addresses the time-dependent point at which internal stresses begin to accumulate, the manner in which the accumulation occurs, and the presiding relationships between thermoelastic, thermoplastic, and thermoviscous behaviors. To address these critical issues, researchers at the NASA Lewis Research Center developed and implemented an innovative mechanical test technique to examine in real time, the time-dependent thermomechanical stress behavior of a matrix alloy as it went through a consolidation cycle.

  13. Respiratory capacity of the Kluyveromyces marxianus yeast isolated from the mezcal process during oxidative stress.

    Science.gov (United States)

    Arellano-Plaza, Melchor; Gschaedler-Mathis, Anne; Noriega-Cisneros, Ruth; Clemente-Guerrero, Mónica; Manzo-Ávalos, Salvador; González-Hernández, Juan Carlos; Saavedra-Molina, Alfredo

    2013-07-01

    During the mezcal fermentation process, yeasts are affected by several stresses that can affect their fermentation capability. These stresses, such as thermal shock, ethanol, osmotic and growth inhibitors are common during fermentation. Cells have improved metabolic systems and they express stress response genes in order to decrease the damage caused during the stress, but to the best of our knowledge, there are no published works exploring the effect of oxidants and prooxidants, such as H2O2 and menadione, during growth. In this article, we describe the behavior of Kluyveromyces marxianus isolated from spontaneous mezcal fermentation during oxidative stress, and compared it with that of Saccharomyces cerevisiae strains that were also obtained from mezcal, using the W303-1A strain as a reference. S. cerevisiae strains showed greater viability after oxidative stress compared with K. marxianus strains. However, when the yeast strains were grown in the presence of oxidants in the media, K. marxianus exhibited a greater ability to grow in menadione than it did in H2O2. Moreover, when K. marxianus SLP1 was grown in a minibioreactor, its behavior when exposed to menadione was different from its behavior with H2O2. The yeast maintained the ability to consume dissolved oxygen during the 4 h subsequent to the addition of menadione, and then stopped respiration. When exposed to H2O2, the yeast stopped consuming oxygen for the following 8 h, but began to consume oxygen when stressors were no longer applied. In conclusion, yeast isolated from spontaneous mezcal fermentation was able to resist oxidative stress for a long period of time.

  14. How Accumulated Real Life Stress Experience and Cognitive Speed Interact on Decision-Making Processes

    Directory of Open Access Journals (Sweden)

    Eva Friedel

    2017-06-01

    stress exposure and slower information processing capacities, however, might favor model-free strategies. Thus, the valence and preference of either system strongly depends on stressful experiences and individual cognitive capacities.

  15. Stress development in heterogenetic lithosphere: Insights into earthquake processes in the New Madrid Seismic Zone

    Science.gov (United States)

    Zhan, Yan; Hou, Guiting; Kusky, Timothy; Gregg, Patricia M.

    2016-03-01

    The New Madrid Seismic Zone (NMSZ) in the Midwestern United States was the site of several major M 6.8-8 earthquakes in 1811-1812, and remains seismically active. Although this region has been investigated extensively, the ultimate controls on earthquake initiation and the duration of the seismicity remain unclear. In this study, we develop a finite element model for the Central United States to conduct a series of numerical experiments with the goal of determining the impact of heterogeneity in the upper crust, the lower crust, and the mantle on earthquake nucleation and rupture processes. Regional seismic tomography data (CITE) are utilized to infer the viscosity structure of the lithosphere which provide an important input to the numerical models. Results indicate that when differential stresses build in the Central United States, the stresses accumulating beneath the Reelfoot Rift in the NMSZ are highly concentrated, whereas the stresses below the geologically similar Midcontinent Rift System are comparatively low. The numerical observations coincide with the observed distribution of seismicity throughout the region. By comparing the numerical results with three reference models, we argue that an extensive mantle low velocity zone beneath the NMSZ produces differential stress localization in the layers above. Furthermore, the relatively strong crust in this region, exhibited by high seismic velocities, enables the elevated stress to extend to the base of the ancient rift system, reactivating fossil rifting faults and therefore triggering earthquakes. These results show that, if boundary displacements are significant, the NMSZ is able to localize tectonic stresses, which may be released when faults close to failure are triggered by external processes such as melting of the Laurentide ice sheet or rapid river incision.

  16. Optimization of the Process Parameters for Controlling Residual Stress and Distortion in Friction Stir Welding

    DEFF Research Database (Denmark)

    Tutum, Cem Celal; Schmidt, Henrik Nikolaj Blicher; Hattel, Jesper Henri

    2008-01-01

    In the present paper, numerical optimization of the process parameters, i.e. tool rotation speed and traverse speed, aiming minimization of the two conflicting objectives, i.e. the residual stresses and welding time, subjected to process-specific thermal constraints in friction stir welding......, is investigated. The welding process is simulated in 2-dimensions with a sequentially coupled transient thermo-mechanical model using ANSYS. The numerical optimization problem is implemented in modeFRONTIER and solved using the Multi-Objective Genetic Algorithm (MOGA-II). An engineering-wise evaluation or ranking...

  17. Compensation processes of Aleppo pine (Pinus halepensis Mill.) to ozone exposure and drought stress

    International Nuclear Information System (INIS)

    Inclan, R.; Gimeno, B.S.; Dizengremel, P.; Sanchez, M.

    2005-01-01

    A long-term experiment was performed to study the effects of O 3 and drought-stress (DS) on Aleppo pine seedlings (Pinus halepensis Mill.) exposed in open-top chambers. Ozone reduced gas exchange rates, ribulose-1,5-biphosphate carboxylase/oxygenase activity (Rubisco), aboveground C and needle N concentrations and C/N ratio and Ca concentrations of the twigs under 3 mm (twigs Pd ), C/N ratio, twigs<3 Ca, plant growth, aerial biomass and increased N, twigs with a diameter above 3 mm P and Mg concentrations. The combined exposure to both stresses increased N concentrations of twigs<3 and roots and aboveground biomass K content and decreased root C, maximum daily assimilation rate and instantaneous water use efficiency. The sensitivity of Aleppo pine to both stresses is determined by plant internal resource allocation and compensation mechanisms to cope with stress. - Ozone and drought stress induce the activation of similar processes related to C and N metabolism

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

    Science.gov (United States)

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

    2018-02-01

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

  19. 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....

  20. 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.

  1. The Underlying Social Dynamics of Paradigm Shifts.

    Science.gov (United States)

    Rodriguez-Sickert, Carlos; Cosmelli, Diego; Claro, Francisco; Fuentes, Miguel Angel

    2015-01-01

    We develop here a multi-agent model of the creation of knowledge (scientific progress or technological evolution) within a community of researchers devoted to such endeavors. In the proposed model, agents learn in a physical-technological landscape, and weight is attached to both individual search and social influence. We find that the combination of these two forces together with random experimentation can account for both i) marginal change, that is, periods of normal science or refinements on the performance of a given technology (and in which the community stays in the neighborhood of the current paradigm); and ii) radical change, which takes the form of scientific paradigm shifts (or discontinuities in the structure of performance of a technology) that is observed as a swift migration of the knowledge community towards the new and superior paradigm. The efficiency of the search process is heavily dependent on the weight that agents posit on social influence. The occurrence of a paradigm shift becomes more likely when each member of the community attaches a small but positive weight to the experience of his/her peers. For this parameter region, nevertheless, a conservative force is exerted by the representatives of the current paradigm. However, social influence is not strong enough to seriously hamper individual discovery, and can act so as to empower successful individual pioneers who have conquered the new and superior paradigm.

  2. The Underlying Social Dynamics of Paradigm Shifts.

    Directory of Open Access Journals (Sweden)

    Carlos Rodriguez-Sickert

    Full Text Available We develop here a multi-agent model of the creation of knowledge (scientific progress or technological evolution within a community of researchers devoted to such endeavors. In the proposed model, agents learn in a physical-technological landscape, and weight is attached to both individual search and social influence. We find that the combination of these two forces together with random experimentation can account for both i marginal change, that is, periods of normal science or refinements on the performance of a given technology (and in which the community stays in the neighborhood of the current paradigm; and ii radical change, which takes the form of scientific paradigm shifts (or discontinuities in the structure of performance of a technology that is observed as a swift migration of the knowledge community towards the new and superior paradigm. The efficiency of the search process is heavily dependent on the weight that agents posit on social influence. The occurrence of a paradigm shift becomes more likely when each member of the community attaches a small but positive weight to the experience of his/her peers. For this parameter region, nevertheless, a conservative force is exerted by the representatives of the current paradigm. However, social influence is not strong enough to seriously hamper individual discovery, and can act so as to empower successful individual pioneers who have conquered the new and superior paradigm.

  3. Defense Profiles in Adaptation Process to Sport Competition and Their Relationships with Coping, Stress and Control

    Directory of Open Access Journals (Sweden)

    Michel Nicolas

    2017-12-01

    Full Text Available The purpose of this study was to identify the potentially distinct defense profiles of athletes in order to provide insight into the complex associations that can exist between defenses and other important variables tied to performance in sports (e.g., coping, perceived stress and control and to further our understanding of the complexity of the adaptation process in sports. Two hundred and ninety-six (N = 296 athletes participated in a naturalistic study that involved a highly stressful situation: a sports competition. Participants were assessed before and after the competition. Hierarchical cluster analysis and a series of MANOVAs with post hoc comparisons indicated two stable defense profiles (high and low defense profiles of athletes both before and during sport competition. These profiles differed with regards to coping, stress and control. Athletes with high defense profiles reported higher levels of coping strategies, perceived stress and control than athletes with low defense profiles. This study confirmed that defenses are involved in the psychological adaptation process and that research and intervention should not be based only on coping, but rather must include defense mechanisms in order to improve our understanding of psychological adaptation in competitive sports.

  4. Defense Profiles in Adaptation Process to Sport Competition and Their Relationships with Coping, Stress and Control.

    Science.gov (United States)

    Nicolas, Michel; Martinent, Guillaume; Drapeau, Martin; Chahraoui, Khadija; Vacher, Philippe; de Roten, Yves

    2017-01-01

    The purpose of this study was to identify the potentially distinct defense profiles of athletes in order to provide insight into the complex associations that can exist between defenses and other important variables tied to performance in sports (e.g., coping, perceived stress and control) and to further our understanding of the complexity of the adaptation process in sports. Two hundred and ninety-six ( N = 296) athletes participated in a naturalistic study that involved a highly stressful situation: a sports competition. Participants were assessed before and after the competition. Hierarchical cluster analysis and a series of MANOVAs with post hoc comparisons indicated two stable defense profiles (high and low defense profiles) of athletes both before and during sport competition. These profiles differed with regards to coping, stress and control. Athletes with high defense profiles reported higher levels of coping strategies, perceived stress and control than athletes with low defense profiles. This study confirmed that defenses are involved in the psychological adaptation process and that research and intervention should not be based only on coping, but rather must include defense mechanisms in order to improve our understanding of psychological adaptation in competitive sports.

  5. Processamento visual da forma: análise de sistema linear e alguns paradigmas psicofísicos Visual processing of form: linear system analysis and some psychophysical paradigms

    Directory of Open Access Journals (Sweden)

    Natanael Antonio dos Santos

    2002-01-01

    Full Text Available O objetivo deste trabalho é discutir alguns aspectos conceituais básicos da análise de Fourier enquanto ferramenta que fundamenta a perspectiva de filtros ou canais múltiplos de freqüências espaciais no estudo do processamento visual da forma. Serão também discutidos alguns dos principais paradigmas psicofísicos utilizados para caracterizar a resposta do sistema visual humano para filtros de freqüências espaciais de banda estreita. A análise de sistema linear e alguns paradigmas psicofísicos têm contribuído para o desenvolvimento teórico da percepção e do processamento visual da forma.The goal of this work is to discuss some basic aspects of Fourier analysis as a tool to be used in the approach of multiple channels of spatial frequencies on the study of visual processing of form. Some of the psychophysical paradigms more frequently used to characterize response of the human visual system to spatial frequency filter of narrow-band. The linear system analysis and some psychophysical paradigms have contributed to theoretical development of perception and of the visual processing of form.

  6. Characterisation of random Gaussian and non-Gaussian stress processes in terms of extreme responses

    Directory of Open Access Journals (Sweden)

    Colin Bruno

    2015-01-01

    Full Text Available In the field of military land vehicles, random vibration processes generated by all-terrain wheeled vehicles in motion are not classical stochastic processes with a stationary and Gaussian nature. Non-stationarity of processes induced by the variability of the vehicle speed does not form a major difficulty because the designer can have good control over the vehicle speed by characterising the histogram of instantaneous speed of the vehicle during an operational situation. Beyond this non-stationarity problem, the hard point clearly lies in the fact that the random processes are not Gaussian and are generated mainly by the non-linear behaviour of the undercarriage and the strong occurrence of shocks generated by roughness of the terrain. This non-Gaussian nature is expressed particularly by very high flattening levels that can affect the design of structures under extreme stresses conventionally acquired by spectral approaches, inherent to Gaussian processes and based essentially on spectral moments of stress processes. Due to these technical considerations, techniques for characterisation of random excitation processes generated by this type of carrier need to be changed, by proposing innovative characterisation methods based on time domain approaches as described in the body of the text rather than spectral domain approaches.

  7. ENVIRONMENTALISM AND CLASSIC PARADIGMS OF INTERNATIONAL RELATIONS

    Directory of Open Access Journals (Sweden)

    D. D. Miniaeva

    2014-06-01

    Full Text Available This article examines an environmentalism integration process into Three classical paradigms of international relations theory (Liberalism, Realism and Marxism into Three classical paradigms of international relations theory (Liberalism, Realism and Marxism. The main purpose of this study is to reveal the result of this integration. Methods used in this article include analysis and comparison of "ecological" paradigms on selected parameters (the nature of international relations, actors, targets, tools, processes. Results of research show that the beginning of the XXI century is distinguished by the development of new types of political concepts that explain interaction of elements in modern international relations in the area of environmental protection. The reason of these changes lies in the phenomena of environmentalism integration into Three paradigms of international relations. However, we cannot say that any of the examined paradigms accumulated all features of environmentalism without their modification. Better to say, it's rather similar to adaptation of environmental ideas. Therefore, to understand modern international relations processes, it is necessary to take into account their environmental element. Purchase on Elibrary.ru > Buy nowDOI: http://dx.doi.org/10.12731/2070-7568-2014-3-4

  8. Effect of processing conditions and methods on residual stress in CeO2 buffer layers and YBCO superconducting films

    International Nuclear Information System (INIS)

    Xiong Jie; Qin Wenfeng; Cui Xumei; Tao Bowan; Tang Jinlong; Li Yanrong

    2006-01-01

    CeO 2 layers have been fabricated by pulsed laser deposition (PLD) technique on (1 1 0 2) sapphire substrate. Microstructure of CeO 2 layers is characterized by X-ray diffraction as functions of substrate temperature. The effects of the substrate temperature on the residual stress have been studied. The results show that residual stress in CeO 2 film decreased with increasing substrate temperature, not the same development tendency as that of thermal stress. This means that the thermal stress is only a fraction of the residual stress. Moreover, YBCO superconducting films were prepared by direct current (DC) sputtering and pulsed laser deposition (PLD) technique. The residual stress and thermal stress of both YBCO films were measured. PLD processing apparently generated higher intrinsic compressive stresses in comparison to DC sputtering

  9. Journaling about stressful events: effects of cognitive processing and emotional expression.

    Science.gov (United States)

    Ullrich, Philip M; Lutgendorf, Susan K

    2002-01-01

    The effects of two journaling interventions, one focusing on emotional expression and the other on both cognitive processing and emotional expression, were compared during 1 month of journaling about a stressful or traumatic event. One hundred twenty-two students were randomly assigned to one of three writing conditions: (a) focusing on emotions related to a trauma or stressor, (b) focusing on cognitions and emotions related to a trauma or stressor, or (c) writing factually about media events. Writers focusing on cognitions and emotions developed greater awareness of the positive benefits of the stressful event than the other two groups. This effect was apparently mediated by greater cognitive processing during writing. Writers focusing on emotions alone reported more severe illness symptoms during the study than those in other conditions. This effect appeared to be mediated by a greater focus on negative emotional expression during writing.

  10. New process for the relief of mechanically induced stresses in steam generator tubes

    International Nuclear Information System (INIS)

    Joyeux, J.P.

    1980-01-01

    Heat exchangers include very generally a set of tubes assembled in 'U-type' exchangers or in 'pass-through' exchangers. The tubes are introduced in holes drilled in the tube sheet plate, welded at their extremity and expanded to insure the necessary tightness. The steam generators built by FRAMATOME belong to the U-type and include, depending upon the nominal power of the plant, about three or five thousand inconel tubes. This material has been selected for its resistance to corrosion action at high temperatures. But one drawback of inconel is that residual stress lowers considerably this resistance to corrosion; so it is very important to apply manufacturing processes involving a residual stress level as low as possible. A new process, which involves 'kiss' rolling, is described. (author)

  11. Finite element modelling of creep process - steady state stresses and strains

    Directory of Open Access Journals (Sweden)

    Sedmak Aleksandar S.

    2014-01-01

    Full Text Available Finite element modelling of steady state creep process has been described. Using an analogy of visco-plastic problem with a described procedure, the finite element method has been used to calculate steady state stresses and strains in 2D problems. An example of application of such a procedure have been presented, using real life problem - cylindrical pipe with longitudinal crack at high temperature, under internal pressure, and estimating its residual life, based on the C*integral evaluation.

  12. Altered Olfactory Processing of Stress Related Body Odors and Artificial Odors in Patients with Panic Disorder

    OpenAIRE

    Wintermann, Gloria-Beatrice; Donix, Markus; Joraschky, Peter; Gerber, Johannes; Petrowski, Katja

    2014-01-01

    Background: Patients with Panic Disorder (PD) direct their attention towards potential threat, followed by panic attacks, and increased sweat production. Onés own anxiety sweat odor influences the attentional focus, and discrimination of threat or non-threat. Since olfactory projection areas overlap with neuronal areas of a panic-specific fear network, the present study investigated the neuronal processing of odors in general and of stress-related sweat odors in particular in patients with PD...

  13. Mechanisms of food processing and storage-related stress tolerance in Clostridium botulinum.

    Science.gov (United States)

    Dahlsten, Elias; Lindström, Miia; Korkeala, Hannu

    2015-05-01

    Vegetative cultures of Clostridium botulinum produce the extremely potent botulinum neurotoxin, and may jeopardize the safety of foods unless sufficient measures to prevent growth are applied. Minimal food processing relies on combinations of mild treatments, primarily to avoid deterioration of the sensory qualities of the food. Tolerance of C. botulinum to minimal food processing is well characterized. However, data on effects of successive treatments on robustness towards further processing is lacking. Developments in genetic manipulation tools and the availability of annotated genomes have allowed identification of genetic mechanisms involved in stress tolerance of C. botulinum. Most studies focused on low temperature, and the importance of various regulatory mechanisms in cold tolerance of C. botulinum has been demonstrated. Furthermore, novel roles in cold tolerance were shown for metabolic pathways under the control of these regulators. A role for secondary oxidative stress in tolerance to extreme temperatures has been proposed. Additionally, genetic mechanisms related to tolerance to heat, low pH, and high salinity have been characterized. Data on genetic stress-related mechanisms of psychrotrophic Group II C. botulinum strains are scarce; these mechanisms are of interest for food safety research and should thus be investigated. This minireview encompasses the importance of C. botulinum as a food safety hazard and its central physiological characteristics related to food-processing and storage-related stress. Special attention is given to recent findings considering genetic mechanisms C. botulinum utilizes in detecting and countering these adverse conditions. Copyright © 2014 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  14. Workplace Flexibility and Daily Stress Processes in Hotel Employees and their Children

    OpenAIRE

    Almeida, David M.; Davis, Kelly D.

    2011-01-01

    Our research aims to understand the consequences of inadequate workplace flexibility through the lens of daily stress processes. Using a sample of hourly hotel employees with children aged 10 to 18 who participated in a daily diary study, we compared workers with low and high flexibility on stressor exposure, reactivity, and transmission. Our findings showed a consistent pattern of hourly workers with low flexibility having greater exposure to work stressors in general and to work place argum...

  15. The resilience of paradigm mixes

    DEFF Research Database (Denmark)

    Daugbjerg, Carsten; Farsund, Arild Aurvåg; Langhelle, Oluf

    2017-01-01

    This paper argues that a policy regime based on a paradigm mix may be resilient when challenged by changing power balances and new agendas. Controversies between the actors can be contained within the paradigm mix as it enables them to legitimize different ideational positions. Rather than engaging...... context changed. The paradigm mix proved sufficiently flexible to accommodate food security concerns and at the same time continue to take steps toward further liberalization. Indeed, the main players have not challenged the paradigm mix....

  16. CHANGE OF ENERGY PARADIGM

    Directory of Open Access Journals (Sweden)

    Ionut PURICA

    2013-05-01

    Full Text Available We are at the beginning of a change of paradigm in the energy systems of the whole World. Both new resources being found and exploited and the new technologies for energy conversion, transport and distribution, along with the associated artificial intelligence systems, are starting to create new futures, with different living values, for the greatest machine created by men: the energy system. Some relevant elements are presented in the paper along with the position and the perspectives of Romania.

  17. Financial stress, parent functioning and adolescent problem behavior: an actor-partner interdependence approach to family stress processes in low-, middle-, and high-income families.

    Science.gov (United States)

    Ponnet, Koen

    2014-10-01

    The family stress model proposes that financial stress experienced by parents is associated with problem behavior in adolescents. The present study applied an actor-partner interdependence approach to the family stress model and focused on low-, middle-, and high-income families to broaden our understanding of the pathways by which the financial stress of mothers and fathers are related to adolescent outcomes. The study uses dyadic data (N = 798 heterosexual couples) from the Relationship between Mothers, Fathers and Children study in which two-parent families with an adolescent between 11 and 17 years of age participated. Path-analytic results indicated that in each of the families the association between parents' financial stress and problem behavior in adolescents is mediated through parents' depressive symptoms, interparental conflict, and positive parenting. Family stress processes also appear to operate in different ways for low-, middle-, and high-income families. In addition to a higher absolute level of financial stress in low-income families, financial stress experienced by mothers and fathers in these families had significant direct and indirect effects on problem behavior in adolescents, while in middle- and high-income families only significant indirect effects were found. The financial stress of a low-income mother also had a more detrimental impact on her level of depressive feelings than it had on mothers in middle-income families. Furthermore, the study revealed gender differences in the pathways of mothers and fathers. Implications for research, clinical practice, and policy are also discussed.

  18. Marital Processes, Neuroticism, and Stress as Risk Factors for Internalizing Symptoms.

    Science.gov (United States)

    Brock, Rebecca L; Lawrence, Erika

    2014-03-01

    Marital discord has a robust association with depression, yet it is rarely considered within broader etiological frameworks of psychopathology. Further, little is known about the particular aspects of relationships that have the greatest impact on psychopathology. The purpose of the present study was to test a novel conceptual framework including neuroticism, specific relationship processes (conflict management, partner support, emotional intimacy, and distribution of power and control), and stress as predictors of internalizing symptoms (depression and anxiety). Questionnaire and interview data were collected from 103 husbands and wives 5 times over the first 7 years of marriage. Results suggest that neuroticism (an expression of the underlying vulnerability for internalizing disorders) contributes to symptoms primarily through high levels of non-marital stress, an imbalance of power/control in one's marriage, and poor partner support for husbands, and through greater emotional disengagement for wives. Marital processes, neuroticism, and stress work together to significantly predict internalizing symptoms, demonstrating the need to routinely consider dyadic processes in etiological models of individual psychopathology. Specific recommendations for adapting and implementing couple interventions to prevent and treat individual psychopathology are discussed.

  19. Effects of heat stress on dynamic absorption process, tissue distribution and utilization efficiency of vitamin C in broilers

    International Nuclear Information System (INIS)

    Liu Guohua; Chen Guosheng; Cai Huiyi

    1998-01-01

    The experiment was conducted to determine the effects of heat stress on ascorbic acid nutritional physiology of broilers with radioisotope technology. 3 H-Vc was fed to broilers and then the blood, liver, kidney, breast muscle, and excreta were sampled to determine the dynamic absorption process, the tissue distribution and the utilization efficiency of vitamin C. The results indicated that the absorption, metabolism and mobilization of supplemented vitamin C in broilers with heat stress was faster than that in broilers without heat stress. However, the utilization efficiency of supplemented vitamin C in broilers with heat stress was not higher than that of broilers without heat stress

  20. Processing of word stress related acoustic information: A multi-feature MMN study.

    Science.gov (United States)

    Honbolygó, Ferenc; Kolozsvári, Orsolya; Csépe, Valéria

    2017-08-01

    In the present study, we investigated the processing of word stress related acoustic features in a word context. In a passive oddball multi-feature MMN experiment, we presented a disyllabic pseudo-word with two acoustically similar syllables as standard stimulus, and five contrasting deviants that differed from the standard in that they were either stressed on the first syllable or contained a vowel change. Stress was realized by an increase of f0, intensity, vowel duration or consonant duration. The vowel change was used to investigate if phonemic and prosodic changes elicit different MMN components. As a control condition, we presented non-speech counterparts of the speech stimuli. Results showed all but one feature (non-speech intensity deviant) eliciting the MMN component, which was larger for speech compared to non-speech stimuli. Two other components showed stimulus related effects: the N350 and the LDN (Late Discriminative Negativity). The N350 appeared to the vowel duration and consonant duration deviants, specifically to features related to the temporal characteristics of stimuli, while the LDN was present for all features, and it was larger for speech than for non-speech stimuli. We also found that the f0 and consonant duration features elicited a larger MMN than other features. These results suggest that stress as a phonological feature is processed based on long-term representations, and listeners show a specific sensitivity to segmental and suprasegmental cues signaling the prosodic boundaries of words. These findings support a two-stage model in the perception of stress and phoneme related acoustical information. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Phasic deactivation of the medial temporal lobe enables working memory processing under stress

    NARCIS (Netherlands)

    Cousijn, Helena; Rijpkema, Mark; Qin, Shaozheng; van Wingen, Guido A.; Fernández, Guillén

    2012-01-01

    Demanding cognitive tasks are sometimes carried out under stressful conditions. Several studies indicate that whereas severe stress impairs performance, moderate stress can enhance cognitive performance. In this study, we investigated how moderate stress influences the neural systems supporting

  2. Optimal Constant-Stress Accelerated Degradation Test Plans Using Nonlinear Generalized Wiener Process

    Directory of Open Access Journals (Sweden)

    Zhen Chen

    2016-01-01

    Full Text Available Accelerated degradation test (ADT has been widely used to assess highly reliable products’ lifetime. To conduct an ADT, an appropriate degradation model and test plan should be determined in advance. Although many historical studies have proposed quite a few models, there is still room for improvement. Hence we propose a Nonlinear Generalized Wiener Process (NGWP model with consideration of the effects of stress level, product-to-product variability, and measurement errors for a higher estimation accuracy and a wider range of use. Then under the constraints of sample size, test duration, and test cost, the plans of constant-stress ADT (CSADT with multiple stress levels based on the NGWP are designed by minimizing the asymptotic variance of the reliability estimation of the products under normal operation conditions. An optimization algorithm is developed to determine the optimal stress levels, the number of units allocated to each level, inspection frequency, and measurement times simultaneously. In addition, a comparison based on degradation data of LEDs is made to show better goodness-of-fit of the NGWP than that of other models. Finally, optimal two-level and three-level CSADT plans under various constraints and a detailed sensitivity analysis are demonstrated through examples in this paper.

  3. Beyond Diabetes: Does Obesity-Induced Oxidative Stress Drive the Aging Process?

    Directory of Open Access Journals (Sweden)

    Adam B. Salmon

    2016-07-01

    Full Text Available Despite numerous correlative data, a causative role for oxidative stress in mammalian longevity has remained elusive. However, there is strong evidence that increased oxidative stress is associated with exacerbation of many diseases and pathologies that are also strongly related to advanced age. Obesity, or increased fat accumulation, is one of the most common chronic conditions worldwide and is associated with not only metabolic dysfunction but also increased levels of oxidative stress in vivo. Moreover, obesity is also associated with significantly increased risks of cardiovascular disease, neurological decline and cancer among many other diseases as well as a significantly increased risk of mortality. In this review, we investigate the possible interpretation that the increased incidence of these diseases in obesity may be due to chronic oxidative stress mediating segmental acceleration of the aging process. Understanding how obesity can alter cellular physiology beyond that directly related to metabolic function could open new therapeutic areas of approach to extend the period of healthy aging among people of all body composition.

  4. 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.

  5. Elucidating the iodine stress corrosion cracking (SCC) process for zircaloy tubing

    International Nuclear Information System (INIS)

    Nagai, M.; Shimada, S.; Nishimura, S.; Amano, K.

    1984-01-01

    Several experimental investigations were made to enhance understanding of the iodine stress corrosion cracking (SCC) process for Zircaloy: (1) oxide penetration process, (2) crack initiation process, and (3) crack propagation process. Concerning the effect of the oxide layer produced by conventional steam-autoclaving, no significant difference was found between results for autoclaved and as-pickled samples. Tests with 15 species of metal iodides revealed that only those metal iodides which react thermodynamically with zirconium to produce zirconium tetraiodide (ZrI 4 ) caused SCC of Zircaloy. Detailed SEM examinations were made on the SCC fracture surface of irradiated specimens. The crack propagation rate was expressed with a da/dt=C Ksup(n) type equation by combining results of tests and calculations with a finite element method. (author)

  6. No effect of stress on false recognition.

    Science.gov (United States)

    Beato, María Soledad; Cadavid, Sara; Pulido, Ramón F; Pinho, María Salomé

    2013-02-01

    The present study aimed to analyze the effect of acute stress on false recognition in the Deese/Roediger-McDermott (DRM) paradigm. In this paradigm, lists of words associated with a non-presented critical lure are studied and, in a subsequent memory test, critical lures are often falsely remembered. In two experiments, participants were randomly assigned to either the stress group (Trier Social Stress Test) or the no-stress control group. Because we sought to control the level-of-processing at encoding, in Experiment 1, participants created a visual mental image for each presented word (deep encoding). In Experiment 2, participants performed a shallow encoding (to respond whether each word contained the letter "o"). The results indicated that, in both experiments, as predicted, heart rate and STAI-S scores increased only in the stress group. However, false recognition did not differ across stress and no-stress groups. Results suggest that, although psychosocial stress was successfully induced, it does not enhance the vulnerability of individuals with acute stress to DRM false recognition, regardless of the level of processing.

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

    Science.gov (United States)

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

    2015-09-01

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

  8. The residual stress evaluation for expansion process of steam generator tubes

    International Nuclear Information System (INIS)

    King, C.-S.; Lee, S.-C.; Shim, D.-N.

    2004-01-01

    The reliability of a nuclear power plant is affected by the reliability of steam generator tube and the reliability of steam generator tube is affected by stress corrosion cracking(SCC). Many steam generator tubes were experiencing stress corrosion cracking and stress corrosion cracking is affected material characteristics, corrosive environments and added stresses. The added stresses have the manufacturing stresses and operating stresses, the manufacturing stresses include the residual stresses generating in the tube manufacture and tube expanding procedure. We will investigate for influence which affected to residual stresses with tube plastic deformation method and measurement region. (author)

  9. Cognitive processing therapy versus supportive counseling for acute stress disorder following assault: a randomized pilot trial.

    Science.gov (United States)

    Nixon, Reginald D V

    2012-12-01

    The study tested the efficacy and tolerability of cognitive processing therapy (CPT) for survivors of assault with acute stress disorder. Participants (N=30) were randomly allocated to CPT or supportive counseling. Therapy comprised six individual weekly sessions of 90-min duration. Independent diagnostic assessment for PTSD was conducted at posttreatment. Participants completed self-report measures of posttraumatic stress, depression, and negative trauma-related beliefs at pre-, posttreatment, and 6-month follow-up. Results indicated that both interventions were successful in reducing symptoms at posttreatment with no statistical difference between the two; within and between-group effect sizes and the proportion of participants not meeting PTSD criteria was greater in CPT. Treatment gains were maintained for both groups at 6-month follow-up. Copyright © 2012. Published by Elsevier Ltd.

  10. Modeling of the flow stress for AISI H13 Tool Steel during Hard Machining Processes

    Science.gov (United States)

    Umbrello, Domenico; Rizzuti, Stefania; Outeiro, José C.; Shivpuri, Rajiv

    2007-04-01

    In general, the flow stress models used in computer simulation of machining processes are a function of effective strain, effective strain rate and temperature developed during the cutting process. However, these models do not adequately describe the material behavior in hard machining, where a range of material hardness between 45 and 60 HRC are used. Thus, depending on the specific material hardness different material models must be used in modeling the cutting process. This paper describes the development of a hardness-based flow stress and fracture models for the AISI H13 tool steel, which can be applied for range of material hardness mentioned above. These models were implemented in a non-isothermal viscoplastic numerical model to simulate the machining process for AISI H13 with various hardness values and applying different cutting regime parameters. Predicted results are validated by comparing them with experimental results found in the literature. They are found to predict reasonably well the cutting forces as well as the change in chip morphology from continuous to segmented chip as the material hardness change.

  11. Modeling of the flow stress for AISI H13 Tool Steel during Hard Machining Processes

    International Nuclear Information System (INIS)

    Umbrello, Domenico; Rizzuti, Stefania; Outeiro, Jose C.; Shivpuri, Rajiv

    2007-01-01

    In general, the flow stress models used in computer simulation of machining processes are a function of effective strain, effective strain rate and temperature developed during the cutting process. However, these models do not adequately describe the material behavior in hard machining, where a range of material hardness between 45 and 60 HRC are used. Thus, depending on the specific material hardness different material models must be used in modeling the cutting process. This paper describes the development of a hardness-based flow stress and fracture models for the AISI H13 tool steel, which can be applied for range of material hardness mentioned above. These models were implemented in a non-isothermal viscoplastic numerical model to simulate the machining process for AISI H13 with various hardness values and applying different cutting regime parameters. Predicted results are validated by comparing them with experimental results found in the literature. They are found to predict reasonably well the cutting forces as well as the change in chip morphology from continuous to segmented chip as the material hardness change

  12. A postfoundationalist research paradigm of practical theology

    Directory of Open Access Journals (Sweden)

    Sung Kyu Park

    2010-10-01

    This article examines and argues for postfoundationalism – transversal reason, interdisciplinarity and interpreted experience – as a viable theological option against rigid foundationalism and relativistic nonfoundationalism. Also discussed are the process and the interdisciplinary nature of practical theology. It is suggested that narrative research and social constructionism should be part of the research paradigm of postfoundational practical theology.

  13. Evolving conservation paradigms for the Anthropocene

    Science.gov (United States)

    Ariel E. Lugo

    2014-01-01

    The Anthropocene will have fundamental effects on the species composition, function, and structure of the ecosystems of the world. Land management agencies such as the USDA Forest Service will need to adapt their policies and conservation activities to avoid engaging in continuous conflict with natural processes and unfamiliar biotic assemblages. Conservation paradigms...

  14. The peopleware paradigm.

    Science.gov (United States)

    Andrew, C G

    1996-08-01

    Manufacturing managements and practitioners alike are at long last realizing that the heartbeat of competitive advantage springs from peopleware, not hardware and software. But despite this heightened awareness the problem persists even among manufacturing professionals--they may talk a good game about priortizing people and quality, but all too many have precious little idea of how to go about it with constancy of purpose. This article bridges the gap and addresses the key issues in adopting the powerful new peopleware paradigm that provides the positive motivational climate for the improvement-change journey toward world-class performance through teamwork, innovation, and continuous improvement.

  15. Competitiveness: new economic paradigm?

    Directory of Open Access Journals (Sweden)

    Marlene Peñaloza

    2005-10-01

    Full Text Available Nowadays competitiveness is made up of “the new” paradigm that allows to prevail in the global World. Thus, it is inevitable to ask, was it required to be competitive to be successful in the international trade arena? Recognizing the discussion about it and its theoretical-conceptual density, the present paper studies this old notion whose meaning, in essence, is always the same one. This applies even though new realities in the present world-wide atmosphere confer to it a distinguishing character and new and old players are forced to organize actions and bring efforts together to obtain the competitive supremacy.

  16. Effect of power history on the shape and the thermal stress of a large sapphire crystal during the Kyropoulos process

    Science.gov (United States)

    Nguyen, Tran Phu; Chuang, Hsiao-Tsun; Chen, Jyh-Chen; Hu, Chieh

    2018-02-01

    In this study, the effect of the power history on the shape of a sapphire crystal and the thermal stress during the Kyropoulos process are numerically investigated. The simulation results show that the thermal stress is strongly dependent on the power history. The thermal stress distributions in the crystal for all growth stages produced with different power histories are also studied. The results show that high von Mises stress regions are found close to the seed of the crystal, the highly curved crystal surface and the crystal-melt interface. The maximum thermal stress, which occurs at the crystal-melt interface, increases significantly in value as the crystal expands at the crown. After this, there is reduction in the maximum thermal stress as the crystal lengthens. There is a remarkable enhancement in the maximum von Mises stress when the crystal-melt interface is close to the bottom of the crucible. There are two obvious peaks in the maximum Von Mises stress, at the end of the crown stage and in the final stage, when cracking defects can form. To alleviate this problem, different power histories are considered in order to optimize the process to produce the lowest thermal stress in the crystal. The optimal power history is found to produce a significant reduction in the thermal stress in the crown stage.

  17. A New Paradigm for Chemical Engineering?

    DEFF Research Database (Denmark)

    Gani, Rafiqul

    evidence of this change comes from the jobs taken by graduating chemical engineering professionals in North America, Europe, and some of the Asian countries. In terms of where the graduating chemical engineers are going to work, a clear shift from the commodity chemical industry to the product oriented...... businesses has been observed. There is an increasing trend within the chemical industry to focus on products and the sustainable processes that can make them. Do these changes point to a paradigm shift in chemical engineering as a discipline? Historically, two previous paradigm shifts in chemical engineering...... corresponded to major shifts in chemical engineering as a discipline, which affected not only the education of chemical engineers, but also the development of chemical engineering as a discipline. Has the time come for a new paradigm shift that will prepare the current and future chemical engineering graduates...

  18. Relationships among Career and Life Stress, Negative Career thoughts, and Career Decision State: A Cognitive Information Processing Perspective

    Science.gov (United States)

    Bullock-Yowell, Emily; Peterson, Gary W.; Reardon, Robert C.; Leierer, Stephen J.; Reed, Corey A.

    2011-01-01

    According to cognitive information processing theory, career thoughts mediate the relationship between career and life stress and the ensuing career decision state. Using a sample of 232 college students and structural equation modeling, this study found that an increase in career and life stress was associated with an increase in negative career…

  19. Critical evaluation of paradigms for modelling integrated supply chains

    NARCIS (Netherlands)

    Van Dam, K.H.; Adhitya, A.; Srinivasan, R.; Lukszo, Z.

    2009-01-01

    Contemporary problems in process systems engineering often require model-based decision support tool. Among the various modelling paradigms, equation-based models and agent-based models are widely used to develop dynamic models of systems. Which is the most appropriate modelling paradigm for a

  20. The Use of Dual Task Paradigms in Memory Research: A Methodological Assessment and an Evaluation of Effort as a Measure of Levels of Processing.

    Science.gov (United States)

    1982-03-01

    sustained monitoring tasks. Human Factors, 1979, 21, 647-653. Craik , F. I. M., & Lockhart , R. Levels of processing : A framework for memory research...original levels approach to human memory ( Craik & Lockhart , 1972) contended that verbal stimuli could be classified along a continuum ranging from...AND AN EVALUATION OF EFFORT AS A MEASURr OF LEVELS OF PROCESSING Arthur D. Fisk, William L. Derrick, and Walter Schneider REPORT HARL-ONR-8105 E. C

  1. Inspection indications, stress corrosion cracks and repair of process piping in nuclear materials production reactors

    International Nuclear Information System (INIS)

    Louthan, M.R. Jr.; West, S.L.; Nelson, D.Z.

    1991-01-01

    Ultrasonic inspection of Schedule 40 Type 304 stainless steel piping in the process water system of the Savannah River Site reactors has provided indications of discontinuities in less than 10% of the weld heat affected zones. Pipe sections containing significant indications are replaced with Type 304L components. Post removal metallurgical evaluation showed that the indications resulted from stress corrosion cracking in weld heat-affected zones and that the overall weld quality was excellent. The evaluation also revealed weld fusion zone discontinuities such as incomplete penetration, incomplete fusion, inclusions, underfill at weld roots and hot cracks. Service induced extension of these discontinuities was generally not significant although stress corrosion cracking in one weld fusion zone was noted. One set of UT indications was caused by metallurgical discontinuities at the fusion boundary of an extra weld. This extra weld, not apparent on the outer pipe surface, was slightly overlapping and approximately parallel to the weld being inspected. This extra weld was made during a pipe repair, probably associated with initial construction processes. The two nearly parallel welds made accurate assessment of the UT signal difficult. The implications of these observations to the inspection and repair of process water systems of nuclear reactors is discussed

  2. The functional role of dorso-lateral premotor cortex during mental rotation: an event-related fMRI study separating cognitive processing steps using a novel task paradigm.

    Science.gov (United States)

    Lamm, Claus; Windischberger, Christian; Moser, Ewald; Bauer, Herbert

    2007-07-15

    Subjects deciding whether two objects presented at angular disparity are identical or mirror versions of each other usually show response times that linearly increase with the angle between objects. This phenomenon has been termed mental rotation. While there is widespread agreement that parietal cortex plays a dominant role in mental rotation, reports concerning the involvement of motor areas are less consistent. From a theoretical point of view, activation in motor areas suggests that mental rotation relies upon visuo-motor rather than visuo-spatial processing alone. However, the type of information that is processed by motor areas during mental rotation remains unclear. In this study we used event-related fMRI to assess whether activation in parietal and dorsolateral premotor areas (dPM) during mental rotation is distinctively related to processing spatial orientation information. Using a newly developed task paradigm we explicitly separated the processing steps (encoding, mental rotation proper and object matching) required by mental rotation tasks and additionally modulated the amount of spatial orientation information that had to be processed. Our results show that activation in dPM during mental rotation is not strongly modulated by the processing of spatial orientation information, and that activation in dPM areas is strongest during mental rotation proper. The latter finding suggests that dPM is involved in more generalized processes such as visuo-spatial attention and movement anticipation. We propose that solving mental rotation tasks is heavily dependent upon visuo-motor processes and evokes neural processing that may be considered as an implicit simulation of actual object rotation.

  3. 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.

  4. The influence of punching process on residual stress and magnetic domain structure of non-oriented silicon steel

    International Nuclear Information System (INIS)

    Cao, Hongzhi; Hao, Linpo; Yi, Jingwen; Zhang, Xianglin; Luo, Zhonghan; Chen, Shenglin; Li, Rongfeng

    2016-01-01

    The main purpose of this paper is to investigate the influence of punching process on residual stress and magnetic domain structure. The residual stress in non-oriented silicon steel after punching process was measured by nanoindentation. The maximum depth was kept constant as 300 nm during nanoindentation. The material around indentation region exhibited no significant pile-up deformation. The calculation of residual stress was based on the Suresh theoretical model. Our experimental results show that residual compressive stress was generated around the sheared edge after punching. The width of residual stress affected zone by punching was around 0.4–0.5 mm. After annealing treatment, the residual stress was significantly decreased. Magnetic domain structure was observed according to the Bitter method. The un-annealed sample exhibited complicated domain patterns, and the widths of the magnetic domains varied between 3 µm and 8 µm. Most of the domain patterns of the annealed sample were 180°-domains and 90°-domains, and the widths of the domains decreased to 1–3 µm. - Highlights: • The residual stress distribution on sheared edge was measured. • The residual compressive stress was generated around the sheared edge. • The width of residual stress affected zone was about 0.4–0.5 mm. • The shape and width of the domain structure would be changed by annealing.

  5. Hepatic processing determines dual activity of alpha-tocopheryl succinate: a novel paradigm for a shift in biological activity due to provitamin-to-vitamin conversion

    Czech Academy of Sciences Publication Activity Database

    Neužil, Jiří; Massa, H.

    2005-01-01

    Roč. 327, č. 4 (2005), s. 1024-1027 ISSN 0006-291X Institutional research plan: CEZ:AV0Z5052915; CEZ:AV0Z50520514 Keywords : vitamin E * alpha-tocopheryl succinate * hepatic processing Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.000, year: 2005

  6. Reading Impairments in Schizophrenia Relate to Individual Differences in Phonological Processing and Oculomotor Control: Evidence from a Gaze-Contingent Moving Window Paradigm

    Science.gov (United States)

    Whitford, Veronica; O'Driscoll, Gillian A.; Pack, Christopher C.; Joober, Ridha; Malla, Ashok; Titone, Debra

    2013-01-01

    Language and oculomotor disturbances are 2 of the best replicated findings in schizophrenia. However, few studies have examined skilled reading in schizophrenia (e.g., Arnott, Sali, Copland, 2011; Hayes & O'Grady, 2003; Revheim et al., 2006; E. O. Roberts et al., 2012), and none have examined the contribution of cognitive and motor processes that…

  7. The WIMP Paradigm: Current Status

    International Nuclear Information System (INIS)

    Feng, Jonathan

    2011-01-01

    The WIMP paradigm is the glue that joins together much of the high energy and cosmic frontiers. It postulates that most of the matter in the Universe is made of weakly-interacting massive particles, with implications for a broad range of experiments and observations. I will review the WIMP paradigm's underlying motivations, its current status in view of rapid experimental progress on several fronts, and recent theoretical variations on the WIMP paradigm theme.

  8. PARADIGM OF ACCOUNTING CHANGE

    Directory of Open Access Journals (Sweden)

    Constanta Iacob

    2016-12-01

    Full Text Available The words and phrases swop with each other and the apparent stability of a word’s meaning sometimes change in time. This explains why the generic term of accounting is used when referring to the qualities attributed to accounting,but also when it comes to organizing financial accounting function within the entity, and when referring concretely to keeping a double record with its specific means, methods and tools specific, respectively seen as a technical accounting.Speaking about the qualities of accounting, but also about the organizational form it takes, we note that there is a manifold meaning of the word accounting, which is why the purpose of this article is to demonstrate that the paradigm shift aimed at a new set of rules and if the rules changes, then we can change the very purpose of accounting.

  9. Modulation of Inhibitory Processing by Posttraumatic Stress Symptoms and Anxiety in a Subclinical Sample of Children.

    Science.gov (United States)

    Gindt, Morgane; Chanquoy, Lucile; Garcia, René

    2016-12-01

    In adults, pathologies of anxiety such as posttraumatic stress symptoms (PTSS) involve deficits in information processing that may reflect hypervigilance and deficient inhibitory control, specifically for negative information. However, little is known about inhibitory processing in children, particularly regarding the inhibition of emotional information. This study investigated whether children with PTSS or anxiety show impairments in executive control in an inhibition task. A total of 45 children (M age = 9.2 year, SD = 0.7, range: 8-11) completed an inhibition task involving emotional-happy, angry, and fearful-and neutral stimuli and clinical scales for PTSS and anxiety. The results indicated that the percentage of correct answers was modulated by PTSS status, particularly in the happiness task. PTSS and anxiety altered the inhibition of fearful information in children. These data suggest different types of inhibitory deficits depending on clinical symptoms, and implications are discussed. © The Author(s) 2016.

  10. Chemical and sensory quality of processed carrot puree as influenced by stress-induced phenolic compounds.

    Science.gov (United States)

    Talcott, S T; Howard, L R

    1999-04-01

    Physicochemical analysis of processed strained product was performed on 10 carrot genotypes grown in Texas (TX) and Georgia (GA). Carrots from GA experienced hail damage during growth, resulting in damage to their tops. Measurements included pH, moisture, soluble phenolics, total carotenoids, sugars, organic acids, and isocoumarin (6-MM). Sensory analysis was conducted using a trained panel to evaluate relationships between chemical and sensory attributes of the genotypes and in carrots spiked with increasing levels of 6-MM. Preharvest stress conditions in GA carrots seemed to elicit a phytoalexic response, producing compounds that impacted the perception of bitter and sour flavors. Spiking 6-MM into strained carrots demonstrated the role bitter compounds have in lowering sweetness scores while increasing the perception of sour flavor. Screening fresh carrots for the phytoalexin 6-MM has the potential to significantly improve the sensory quality of processed products.

  11. Paradigms for parasite conservation.

    Science.gov (United States)

    Dougherty, Eric R; Carlson, Colin J; Bueno, Veronica M; Burgio, Kevin R; Cizauskas, Carrie A; Clements, Christopher F; Seidel, Dana P; Harris, Nyeema C

    2016-08-01

    Parasitic species, which depend directly on host species for their survival, represent a major regulatory force in ecosystems and a significant component of Earth's biodiversity. Yet the negative impacts of parasites observed at the host level have motivated a conservation paradigm of eradication, moving us farther from attainment of taxonomically unbiased conservation goals. Despite a growing body of literature highlighting the importance of parasite-inclusive conservation, most parasite species remain understudied, underfunded, and underappreciated. We argue the protection of parasitic biodiversity requires a paradigm shift in the perception and valuation of their role as consumer species, similar to that of apex predators in the mid-20th century. Beyond recognizing parasites as vital trophic regulators, existing tools available to conservation practitioners should explicitly account for the unique threats facing dependent species. We built upon concepts from epidemiology and economics (e.g., host-density threshold and cost-benefit analysis) to devise novel metrics of margin of error and minimum investment for parasite conservation. We define margin of error as the risk of accidental host extinction from misestimating equilibrium population sizes and predicted oscillations, while minimum investment represents the cost associated with conserving the additional hosts required to maintain viable parasite populations. This framework will aid in the identification of readily conserved parasites that present minimal health risks. To establish parasite conservation, we propose an extension of population viability analysis for host-parasite assemblages to assess extinction risk. In the direst cases, ex situ breeding programs for parasites should be evaluated to maximize success without undermining host protection. Though parasitic species pose a considerable conservation challenge, adaptations to conservation tools will help protect parasite biodiversity in the face of

  12. Plants in water-controlled ecosystems: active role in hydrologic processes and response to water stress. III. Vegetation water stress

    Science.gov (United States)

    Porporato, A.; Laio, F.; Ridolfi, L.; Rodriguez-Iturbe, I.

    The reduction of soil moisture content during droughts lowers the plant water potential and decreases transpiration; this in turn causes a reduction of cell turgor and relative water content which brings about a sequence of damages of increasing seriousness. A review of the literature on plant physiology and water stress shows that vegetation water stress can be assumed to start at the soil moisture level corresponding to incipient stomatal closure and reach a maximum intensity at the wilting point. The mean crossing properties of these soil moisture levels crucial for water stress are derived analytically for the stochastic model of soil moisture dynamics described in Part II (F. Laio, A. Porporato, L. Ridolfi, I. Rodriguez-Iturbe. Adv. Water Res. 24 (7) (2001) 707-723). These properties are then used to propose a measure of vegetation water stress which combines the mean intensity, duration, and frequency of periods of soil water deficit. The characteristics of vegetation water stress are then studied under different climatic conditions, showing how the interplay between plant, soil, and environment can lead to optimal conditions for vegetation.

  13. Applications of Recombinant DNA Technology in Gastrointestinal Medicine and Hepatology: Basic Paradigms of Molecular Cell Biology. Part C: Protein Synthesis and Post-Translational Processing in Eukaryotic Cells

    Directory of Open Access Journals (Sweden)

    Gary E Wild

    2000-01-01

    Full Text Available The translation of mRNA constitutes the first step in the synthesis of a functional protein. The polypeptide chain is subsequently folded into the appropriate three-dimensional configuration and undergoes a variety of processing steps before being converted into its active form. These processing steps are intimately related to the cellular events that occur in the endoplasmic reticulum and Golgi compartments, and determine the sorting and transport of different proteins to their appropriate destinations within the cell. While the regulation of gene expression occurs primarily at the level of transcription, the expression of many genes can also be controlled at the level of translation. Most proteins can be regulated in response to extracellular signals. In addition, intracellular protein levels can be controlled by differential rates of protein degradation. Thus, the regulation of both the amounts and activities of intracellular proteins ultimately determines all aspects of cell behaviour.

  14. Deficits in Letter-Speech Sound Associations but Intact Visual Conflict Processing in Dyslexia: Results from a Novel ERP-Paradigm

    OpenAIRE

    Bakos, Sarolta; Landerl, Karin; Bartling, Jürgen; Schulte-Körne, Gerd; Moll, Kristina

    2017-01-01

    The reading and spelling deficits characteristic of developmental dyslexia (dyslexia) have been related to problems in phonological processing and in learning associations between letters and speech-sounds. Even when children with dyslexia have learned the letters and their corresponding speech sounds, letter-speech sound associations might still be less automatized compared to children with age-adequate literacy skills. In order to examine automaticity in letter-speech sound associations and...

  15. SIGNIFICANCE OF THE ACCOUNTING PARADIGM IN THE DECISION-MAKING PROCESS IN COMPANY MANAGEMENT (BASED ONIAS ACCOUNTING PRACTICES IN POLAND AND OTHER COUNTRIES)

    OpenAIRE

    Leszek Michalczyk

    2014-01-01

    In this article, we analyze the relations between modern trends in accounting and the decisionmaking process based on the classic profit-opportunity-cost-risk construction. In this aspect, four main types of accounting practices may be distinguished: bookkeeping (classic accounting), accounting engineering, creative accounting, and praxeological accounting. This study complements the author's series of publications on accounting engineering (which is herein defined as a concept), the structur...

  16. Embodiment and second-language: automatic activation of motor responses during processing spatially associated L2 words and emotion L2 words in a vertical Stroop paradigm.

    Science.gov (United States)

    Dudschig, Carolin; de la Vega, Irmgard; Kaup, Barbara

    2014-05-01

    Converging evidence suggests that understanding our first-language (L1) results in reactivation of experiential sensorimotor traces in the brain. Surprisingly, little is known regarding the involvement of these processes during second-language (L2) processing. Participants saw L1 or L2 words referring to entities with a typical location (e.g., star, mole) (Experiment 1 & 2) or to an emotion (e.g., happy, sad) (Experiment 3). Participants responded to the words' ink color with an upward or downward arm movement. Despite word meaning being fully task-irrelevant, L2 automatically activated motor responses similar to L1 even when L2 was acquired rather late in life (age >11). Specifically, words such as star facilitated upward, and words such as root facilitated downward responses. Additionally, words referring to positive emotions facilitated upward, and words referring to negative emotions facilitated downward responses. In summary our study suggests that reactivation of experiential traces is not limited to L1 processing. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Daily Stress, Hearing-Specific Stress and Coping: Self-Reports from Deaf or Hard of Hearing Children and Children with Auditory Processing Disorder

    Science.gov (United States)

    Eschenbeck, Heike; Gillé, Vera; Heim-Dreger, Uwe; Schock, Alexandra; Schott, Andrea

    2017-01-01

    This study evaluated stressors and coping strategies in 70 children who are deaf or hard of hearing (D/HH) or with auditory processing disorder (APD) attending Grades 5 and 6 of a school for deaf and hard-of-hearing children. Everyday general stressors and more hearing-specific stressors were examined in a hearing-specific modified stress and…

  18. The good and bad of stress : implications for memory and adaptive processes

    NARCIS (Netherlands)

    Wichmann, Romy

    2012-01-01

    Stress spedt een steeds grotere rol in onze moderne samenleving. Iedereen is er ooit mee geconfronteerd en moet ermee omgaan. Echter hoeft stress niet noodzakelijk slecht te zi.in. Op de korte termiin kan stress, of de lichamelijke reactie op stress, ons helpen om in tijden van druk beter te

  19. Stress-induced resistance to the fear memory labilization/reconsolidation process. Involvement of the basolateral amygdala complex.

    Science.gov (United States)

    Espejo, Pablo Javier; Ortiz, Vanesa; Martijena, Irene Delia; Molina, Victor Alejandro

    2016-10-01

    Consolidated memories can enter into a labile state after reactivation followed by a restabilization process defined as reconsolidation. This process can be interfered with Midazolam (MDZ), a positive allosteric modulator of the GABA-A receptor. The present study has evaluated the influence of prior stress on MDZ's interfering effect. We also assessed the influence of both systemic and intra-basolateral amygdala (BLA) infusion of d-cycloserine (DCS), a partial agonist of the NMDA receptors, on the MDZ effect in previously stressed rats. Furthermore, we analyzed the effect of stress on the expression of Zif-268 and the GluN2B sites, two molecular markers of the labilization/reconsolidation process, following reactivation. The results revealed that prior stress resulted into a memory trace that was insensitive to the MDZ impairing effect. Both systemic and intra-BLA DCS administration previous to reactivation restored MDZ's disruptive effect on memory reconsolidation in stressed animals. Further, reactivation enhanced Zif-268 expression in the BLA in control unstressed rats, whereas no elevation was observed in stressed animals. In agreement with the behavioral findings, DCS restored the increased level of Zif-268 expression in the BLA in stressed animals. Moreover, memory reactivation in unstressed animals elevated GluN2B expression in the BLA, thus suggesting that this effect is involved in memory destabilization, whereas stressed animals did not reveal any changes. These findings are consistent with resistance to the MDZ effect in these rats, indicating that stress exposure prevents the onset of destabilization following reactivation. In summary, prior stress limited both the occurrence of the reactivation-induced destabilization and restabilization. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Causal hydrodynamics and the membrane paradigm

    International Nuclear Information System (INIS)

    Natsuume, Makoto

    2008-01-01

    We obtain the relaxation time for the shear viscous stress for various geometries using the 'membrane paradigm' formula proposed recently. We consider the generic Schwarzschild-anti-de Sitter black holes (SAdS), the generic Dp-brane, the Klebanov-Tseytlin (KT) geometry, and the N=2* theory. The formula is the 'shear mode' result and is not fully trustable, but it may be helpful to learn some generic behaviors about the relaxation time. For example, a simple formula summarizes all known results for SAdS, and a single expression summarizes the results for the Dp-brane and the KT geometry.

  1. SIGNIFICANCE OF THE ACCOUNTING PARADIGM IN THE DECISION-MAKING PROCESS IN COMPANY MANAGEMENT (BASED ONIAS ACCOUNTING PRACTICES IN POLAND AND OTHER COUNTRIES

    Directory of Open Access Journals (Sweden)

    Leszek Michalczyk

    2014-06-01

    Full Text Available In this article, we analyze the relations between modern trends in accounting and the decisionmaking process based on the classic profit-opportunity-cost-risk construction. In this aspect, four main types of accounting practices may be distinguished: bookkeeping (classic accounting, accounting engineering, creative accounting, and praxeological accounting. This study complements the author’s series of publications on accounting engineering (which is herein defined as a concept, the structure of economic auxiliary sciences, and causal relations in management practice and theory based on Bertalanffy’s general systems theory. The article covers accounting systems which emerged as a result of combining IAS solutions with domestic accounting standards and balance laws, and relates primarily to accounting theory and practice in Poland. Nevertheless, the Polish system is rooted in accounting solutions previously used in other countries, and as such may be perceived as more utilitarian, also on an international scale.

  2. High level compressive residual stresses produced in aluminum alloys by laser shock processing

    International Nuclear Information System (INIS)

    Gomez-Rosas, G.; Rubio-Gonzalez, C.; Ocana, J.L; Molpeceres, C.; Porro, J.A.; Chi-Moreno, W.; Morales, M.

    2005-01-01

    Laser shock processing (LSP) has been proposed as a competitive alternative technology to classical treatments for improving fatigue and wear resistance of metals. We present a configuration and results for metal surface treatments in underwater laser irradiation at 1064 nm. A convergent lens is used to deliver 1.2 J/cm 2 in a 8 ns laser FWHM pulse produced by 10 Hz Q-switched Nd:YAG, two laser spot diameters were used: 0.8 and 1.5 mm. Results using pulse densities of 2500 pulses/cm 2 in 6061-T6 aluminum samples and 5000 pulses/cm 2 in 2024 aluminum samples are presented. High level of compressive residual stresses are produced -1600 MPa for 6061-T6 Al alloy, and -1400 MPa for 2024 Al alloy. It has been shown that surface residual stress level is higher than that achieved by conventional shot peening and with greater depths. This method can be applied to surface treatment of final metal products

  3. Workplace Flexibility and Daily Stress Processes in Hotel Employees and their Children.

    Science.gov (United States)

    Almeida, David M; Davis, Kelly D

    2011-11-01

    Our research aims to understand the consequences of inadequate workplace flexibility through the lens of daily stress processes. Using a sample of hourly hotel employees with children aged 10 to 18 who participated in a daily diary study, we compared workers with low and high flexibility on stressor exposure, reactivity, and transmission. Our findings showed a consistent pattern of hourly workers with low flexibility having greater exposure to work stressors in general and to work place arguments in particular. Workers with low flexibility were also more emotional and physically reactive to work stressors. There was some evidence of stressor transmission to children when parents had low flexibility. Increasing workplace flexibility could serve as a protective factor in exposure and reactivity to stressors that are experienced in daily life.

  4. Disability, Health Insurance and Psychological Distress among US Adults: An Application of the Stress Process.

    Science.gov (United States)

    Alang, Sirry M; McAlpine, Donna D; Henning-Smith, Carrie E

    2014-11-01

    Structural resources, including access to health insurance, are understudied in relation to the stress process. Disability increases the likelihood of mental health problems, but health insurance may moderate this relationship. We explore health insurance coverage as a moderator of the relationship between disability and psychological distress. A pooled sample from 2008-2010 (N=57,958) was obtained from the Integrated Health Interview Series. Chow tests were performed to assess insurance group differences in the association between disability and distress. Results indicated higher levels of distress associated with disability among uninsured adults compared to their peers with public or private insurance. The strength of the relationship between disability and distress was weaker for persons with public compared to private insurance. As the Affordable Care Act is implemented, decision-makers should be aware of the potential for insurance coverage, especially public, to ameliorate secondary conditions such as psychological distress among persons who report a physical disability.

  5. Mitigation of stress corrosion cracking in pressurized water reactor (PWR) piping systems using the mechanical stress improvement process (MSIPR) or underwater laser beam welding

    International Nuclear Information System (INIS)

    Rick, Grendys; Marc, Piccolino; Cunthia, Pezze; Badlani, Manu

    2009-01-01

    A current issue facing pressurized water reactors (PWRs) is primary water stress corrosion cracking (PWSCC) of bi metallic welds. PWSCC in a PWR requires the presence of a susceptible material, an aggressive environment and a tensile stress of significant magnitude. Reducing the potential for SCC can be accomplished by eliminating any of these three elements. In the U.S., mitigation of susceptible material in the pressurizer nozzle locations has largely been completed via the structural weld overlay (SWOL) process or NuVision Engineering's Mechanical Stress Improvement Process (MSIP R) , depending on inspectability. The next most susceptible locations in Westinghouse designed power plants are the Reactor Vessel (RV) hot leg nozzle welds. However, a full SWOL Process for RV nozzles is time consuming and has a high likelihood of in process weld repairs. Therefore, Westinghouse provides two distinctive methods to mitigate susceptible material for the RV nozzle locations depending on nozzle access and utility preference. These methods are the MSIP and the Underwater Laser Beam Welding (ULBW) process. MSIP applies a load to the outside diameter of the pipe adjacent to the weld, imposing plastic strains during compression that are not reversed after unloading, thus eliminating the tensile stress component of SCC. Recently, Westinghouse and NuVision successfully applied MSIP on all eight RV nozzles at the Salem Unit 1 power plant. Another option to mitigate SCC in RV nozzles is to place a barrier between the susceptible material and the aggressive environment. The ULBW process applies a weld inlay onto the inside pipe diameter. The deposited weld metal (Alloy 52M) is resistant to PWSCC and acts as a barrier to prevent primary water from contacting the susceptible material. This paper provides information on the approval and acceptance bases for MSIP, its recent application on RV nozzles and an update on ULBW development

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

    Science.gov (United States)

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

    2017-12-01

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

  7. The role of saliva in the process of oxidative stress – review of literature

    Directory of Open Access Journals (Sweden)

    Anna Krysińska

    2016-12-01

    Full Text Available Background: Saliva constitutes a first line of defence against free radical-mediated oxidative stress, since the process of mastication and digestion promotes lipid peroxidation. During gingival inflammation, gingival crevicular fluid flow increases the change of saliva composition with products from the inflammatory response, modulating oxidative damages in the oral cavity. Authors review the current literature concerning the reactive oxygen species, oxidants, pro-oxidants and antioxidants in saliva, and methods for assessing the antioxidant capacity of saliva. Comparison of salivary antioxidant status in male and female subjects reveales a significant gender-related difference in saliva composition. The current data demonstrate a significant enhancement of the salivary antioxidant system in juvenile idiopathic arthritis patients. Also patients with chronic renal failure, diabetes and on hemodialysis show increase oxidative stress burden in both serum and saliva. The finding of reduced oral peroxidase levels in smoking subjects may represent a contributory mechanism for initiation and progression of cigarette smoke-related oral diseases such as oral cancer. The results of recent studies indicate that the total antioxidant capacity of saliva decreased in children with HIV infection. Conclusion: Whole saliva may contain simply measured indicators of oxidative processes. This may provide a tool for the development and monitoring of new treatment strategies. A non-invasive determination of the salivary concentrations of antioxidants such as superoxide dismutase (SOD and uric acid (UR allows the evaluation of the defensive capacity of the oral mucosa. Still, there is a need for standardization of methods for saliva sampling and testing protocol.

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

    Science.gov (United States)

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

    2018-05-01

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

  9. Investigation of Performance and Residual Stress Generation of AlSi10Mg Processed by Selective Laser Melting

    Directory of Open Access Journals (Sweden)

    Lianfeng Wang

    2018-01-01

    Full Text Available During the selective laser melting (SLM process, the scanned layers are subjected to rapid thermal cycles. By working on the mechanical properties, residual stress, and microstructure, the high-temperature gradients can have significant effect on the proper functioning and the structural integrity of built parts. This work presents a comprehensive study on the scanning path type and preheating temperature for AlSi10Mg alloy during SLM. According to the results, SLM AlSi10Mg parts fabricated in chessboard scanning strategy have higher mechanical properties or at least comparable to the parts fabricated in uniformity scanning strategy. In the SLM processing, the residual stress in different parts of the specimen varies with temperature gradient, and the residual stress at the edge of the specimen is obviously larger than that at the center. Under the chessboard scanning and preheating temperature 160°C, the residual stress in each direction of the specimens reaches the minimum. Under different forming processes, the morphology of the microstructure is obviously different. With the increase of preheating temperature, the molten pool in the side surface is obviously elongated and highly unevenly distributed. From the coupling relationship between the residual stress and microstructure, it can be found that the microstructure of top surface is affected by residual stresses σx and σy. But the side surface is mainly governed by residual stress σy; moreover, the greater the residual stress, the more obvious the grain tilt. In the XY and XZ surfaces, the scanning strategy has little influence on the tilt angle of the grain. But, the tilt angle and morphology of the microstructure are obviously affected by the preheating temperature. The results show that the residual stresses can effectively change the properties of the materials under the combined influence of scanning strategy and preheating temperature.

  10. Analysis of Filling and Stresses in the Hot Forging Process Depending on Flange Die Shapes

    International Nuclear Information System (INIS)

    Kim, Jun Hyoung; Kim, Cheol

    2010-01-01

    Hot closed-forging process and the die used for forming an automotive flange were analyzed from the viewpoints of heat transfer, grain-flow lines, and stresses to obtain a forged product without defects such as surface cracks, laps, cold shots, and partial filling. The forging process including up-set, pre-forging, final forging and pressing forces was investigated using finite element analysis. The influence of the preform die and the ratio of the heights of the upper die to lower die on the forging process and die were investigated and a die shape (10 .deg. for the preform die, and 1.5:1 ratio for the final die) suitable to achieve successful forging was determined on the basis of a parametric study. All parametric design requirements such as strength, full filling, and a load limit of 13,000 KN were satisfied for this newly developed flange die. New dies and flanges were fabricated and investigated. Defects such as partial filling and surface cracks were not observed

  11. Cracking of GaN on sapphire from etch-process-induced nonuniformity in residual thermal stress

    International Nuclear Information System (INIS)

    Lacroix, Yves; Chung, Sung-Hoon; Sakai, Shiro

    2001-01-01

    An experiment was performed to explain the appearance of cracks along mesa structures during the processing of GaN device layers grown on sapphire substrates. Micro-Raman spectroscopy was used to measure the position-dependent stress in the GaN layer. We show evidence that the stress at the interface with the substrate may be larger along the mesa structures than that of the as-grown layer, and that this increase in stress can be enough to induce cracks along mesa structures during processing. We report on the formation of cracks that propagate guided by the nonuniformity of the stress induced by the formation of mesa structures in the GaN layer, independent of crystal direction. The understanding of cracking mechanisms has implications in GaN-based device structures that require heteroepitaxial growth of layers with different lattice size and thermal expansion coefficients. [copyright] 2001 American Institute of Physics

  12. Influences of Processing and Fatigue Cycling on Residual Stresses in a NiCrY-Coated Powder Metallurgy Disk Superalloy

    Science.gov (United States)

    Gabb, T. P.; Rogers, R. B.; Nesbitt, J. A.; Miller, R. A.; Puleo, B. J.; Johnson, D.; Telesman, J.; Draper, S. L.; Locci, I. E.

    2017-11-01

    Oxidation and corrosion can attack superalloy disk surfaces exposed to increasing operating temperatures in some turbine engine environments. Any potential protective coatings must also be resistant to harmful fatigue cracking during service. The objective of this study was to investigate how residual stresses evolve in one such coating. Fatigue specimens of a powder metallurgy-processed disk superalloy were coated with a NiCrY coating, shot peened, and then subjected to fatigue in air at room and high temperatures. The effects of this processing and fatigue cycling on axial residual stresses and other aspects of the coating were assessed. While shot peening did induce beneficial compressive residual stresses in the coating and substrate, these stresses relaxed in the coating with subsequent heating. Several cast alloys having compositions near the coating were subjected to thermal expansion and tensile stress relaxation tests to help explain this response of residual stresses in the coating. For the coated fatigue specimens, this response contributed to earlier cracking of the coating than for the uncoated surface during long intervals of cycling at 760 °C. Yet, substantial compressive residual stresses still remained in the substrate adjacent to the coating, which were sufficient to suppress fatigue cracking there. The coating continued to protect the substrate from hot corrosion pitting, even after fatigue cracks initiated in the coating.

  13. Experimental and numerical investigation on cold flat rolling processes of DC04 sheets with special focus on residual stresses

    International Nuclear Information System (INIS)

    Bauer, A; Binotsch, C; Awiszus, B; Mehner, T; Sieber, M; Lampke, T

    2016-01-01

    The process of cold flat rolling is a widespread industrial technique to manufacture semi-finished products, e.g., for the automotive or homewares industry. Basic knowledge of the process regarding dimensioning and adjustment of defined characteristics is already state of the art. However, a detailed consideration and analysis with respect to local inhomogeneous residual stresses in several process steps mostly remains disregarded. A broad understanding of the process due to the distribution of residual stresses in the workpiece and the direction of the stress tensors allows for a definition of the characteristics of the workpiece even before the actual manufacturing process. For that purpose, it is necessary to perform numerical investigations by means of the finite element analysis (FEA) of cold flat rolling processes. Within this contribution, several approaches for the calibration of the FEA with the real flat rolling process will be addressed and discussed. To ensure that the numerical consideration provides realistic results, this calibration is indispensable. General parameters such as geometry, height reduction, rolling temperature, process time, and the rolling speed are considered as well as a photogrammetric survey, and calculated residual stresses with results of X-ray diffraction (XRD) will be compared. In the course of the experiments, a good agreement between the stress results of the FEA and the XRD was found in the center of the specimen. In combination with the allocation of the stress orientations, the agreement close to the edges is also fine. Some issues that cause differences between the FEA and the experiment are dis-cussed. (paper)

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

    Data.gov (United States)

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

  15. PROCESS FEATURES OF FLUCTUATIONS PROPAGATION AT STRESS-STRAIN WORK OF THE RAILWAY TRACK

    Directory of Open Access Journals (Sweden)

    I. O. Bondarenko

    2015-12-01

    reliability of trains as part of security checkpoints in the area of rolling stock gauge because of its technical state. Therefore, for examining issues of reliable performance elements of the permanent way and substructures of the railway track are proposed its stress-strain work. It gives the possibility to consider a dynamic process, localized both in time and space.

  16. The stress analyze and damage evaluation in continual process of steel constructions assessment

    International Nuclear Information System (INIS)

    Vincour, D.; Urbanec, L.

    1999-01-01

    The stress determination on the base of continually measured values by diagnostic and monitoring systems will be shown. The neural network, prepared stress databases and analytical equation can be used for stress determination for next assessment on mechanisms of degradation. (orig.)

  17. Relationships between atypical sensory processing patterns, maladaptive behaviour and maternal stress in Spanish children with autism spectrum disorder.

    Science.gov (United States)

    Nieto, C; López, B; Gandía, H

    2017-12-01

    This study investigated sensory processing in a sample of Spanish children with autism spectrum disorder (ASD). Specifically, the study aimed to explore (1) the prevalence and distribution of atypical sensory processing patterns, (2) the relationship between adaptive and maladaptive behaviour with atypical sensory processing and (3) the possible relationship between sensory subtype and maternal stress. The short sensory profile 2 (Dunn 2014) and the vineland adaptive behavior scale (Sparrow et al. 1984) were administered to examine the sensory processing difficulties and maladaptive behaviours of 45 children with ASD aged 3 to 14; their mothers also completed the parenting stress index-short form (Abidin 1995). Atypical sensory features were found in 86.7% of the children; avoider and sensor being the two most common patterns. No significant relationship was found between atypical sensory processing and adaptive behaviour. However, the analysis showed a strong relationship between sensory processing and maladaptive behaviour. Both maladaptive behaviour and sensory processing difficulties correlated significantly with maternal stress although maternal stress was predicted only by the sensory variable, and in particular by the avoider pattern. The findings suggest that sensory features in ASD may be driving the high prevalence of parental stress in carers. They also suggest that the effect on parental stress that has been attributed traditionally to maladaptive behaviours may be driven by sensory difficulties. The implications of these findings are discussed in relation to the development of interventions and the need to explore contextual and cultural variables as possible sources of variability. © 2017 MENCAP and International Association of the Scientific Study of Intellectual and Developmental Disabilities and John Wiley & Sons Ltd.

  18. Cryptic species as a window into the paradigm shift of the species concept.

    Science.gov (United States)

    Fišer, Cene; Robinson, Christopher T; Malard, Florian

    2018-02-01

    The species concept is the cornerstone of biodiversity science, and any paradigm shift in the delimitation of species affects many research fields. Many biologists now are embracing a new "species" paradigm as separately evolving populations using different delimitation criteria. Individual criteria can emerge during different periods of speciation; some may never evolve. As such, a paradigm shift in the species concept relates to this inherent heterogeneity in the speciation process and species category-which is fundamentally overlooked in biodiversity research. Cryptic species fall within this paradigm shift: they are continuously being reported from diverse animal phyla but are poorly considered in current tests of ecological and evolutionary theory. The aim of this review is to integrate cryptic species in biodiversity science. In the first section, we address that the absence of morphological diversification is an evolutionary phenomenon, a "process" counterpart to the long-studied mechanisms of morphological diversification. In the next section regarding taxonomy, we show that molecular delimitation of cryptic species is heavily biased towards distance-based methods. We also stress the importance of formally naming of cryptic species for better integration into research fields that use species as units of analysis. Finally, we show that incorporating cryptic species leads to novel insights regarding biodiversity patterns and processes, including large-scale biodiversity assessments, geographic variation in species distribution and species coexistence. It is time for incorporating multicriteria species approaches aiming to understand speciation across space and taxa, thus allowing integration into biodiversity conservation while accommodating for species uncertainty. © 2018 John Wiley & Sons Ltd.

  19. Neurogenetics of depression: a focus on reward processing and stress sensitivity.

    Science.gov (United States)

    Bogdan, Ryan; Nikolova, Yuliya S; Pizzagalli, Diego A

    2013-04-01

    Major depressive disorder (MDD) is etiologically complex and has a heterogeneous presentation. This heterogeneity hinders the ability of molecular genetic research to reliably detect the small effects conferred by common genetic variation. As a result, significant research efforts have been directed at investigating more homogenous intermediate phenotypes believed to be more proximal to gene function and lie between genes and/or environmental effects and disease processes. In the current review we survey and integrate research on two promising intermediate phenotypes linked to depression: reward processing and stress sensitivity. A synthesis of this burgeoning literature indicates that a molecular genetic approach focused on intermediate phenotypes holds significant promise to fundamentally improve our understanding of the pathophysiology and etiology of depression, which will be required for improved diagnostic definitions and the development of novel and more efficacious treatment and prevention strategies. We conclude by highlighting challenges facing intermediate phenotype research and future development that will be required to propel this pivotal research into new directions. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Do Italian Companies Manage Work-Related Stress Effectively? A Process Evaluation in Implementing the INAIL Methodology.

    Science.gov (United States)

    Di Tecco, Cristina; Ronchetti, Matteo; Ghelli, Monica; Russo, Simone; Persechino, Benedetta; Iavicoli, Sergio

    2015-01-01

    Studies on Intervention Process Evaluation are attracting growing attention in the literature on interventions linked to stress and the wellbeing of workers. There is evidence that some elements relating to the process and content of an intervention may have a decisive role in implementing it by facilitating or hindering the effectiveness of the results. This study aimed to provide a process evaluation on interventions to assess and manage risks related to work-related stress using a methodological path offered by INAIL. The final sample is composed of 124 companies participating to an interview on aspects relating to each phase of the INAIL methodological path put in place to implement the intervention. INAIL methodology has been defined as useful in the process of assessing and managing the risks related to work-related stress. Some factors related to the process (e.g., implementation of a preliminary phase, workers' involvement, and use of external consultants) showed a role in significant differences that emerged in the levels of risk, particularly in relation to findings from the preliminary assessment. Main findings provide information on the key aspects of process and content that are useful in implementing an intervention for assessing and managing risks related to work-related stress.

  1. Do Italian Companies Manage Work-Related Stress Effectively? A Process Evaluation in Implementing the INAIL Methodology

    Science.gov (United States)

    Di Tecco, Cristina; Ronchetti, Matteo; Ghelli, Monica; Russo, Simone; Persechino, Benedetta

    2015-01-01

    Studies on Intervention Process Evaluation are attracting growing attention in the literature on interventions linked to stress and the wellbeing of workers. There is evidence that some elements relating to the process and content of an intervention may have a decisive role in implementing it by facilitating or hindering the effectiveness of the results. This study aimed to provide a process evaluation on interventions to assess and manage risks related to work-related stress using a methodological path offered by INAIL. The final sample is composed of 124 companies participating to an interview on aspects relating to each phase of the INAIL methodological path put in place to implement the intervention. INAIL methodology has been defined as useful in the process of assessing and managing the risks related to work-related stress. Some factors related to the process (e.g., implementation of a preliminary phase, workers' involvement, and use of external consultants) showed a role in significant differences that emerged in the levels of risk, particularly in relation to findings from the preliminary assessment. Main findings provide information on the key aspects of process and content that are useful in implementing an intervention for assessing and managing risks related to work-related stress. PMID:26504788

  2. The concept of the average stress in the fracture process zone for the search of the crack path

    Directory of Open Access Journals (Sweden)

    Yu.G. Matvienko

    2015-10-01

    Full Text Available The concept of the average stress has been employed to propose the maximum average tangential stress (MATS criterion for predicting the direction of fracture angle. This criterion states that a crack grows when the maximum average tangential stress in the fracture process zone ahead of the crack tip reaches its critical value and the crack growth direction coincides with the direction of the maximum average tangential stress along a constant radius around the crack tip. The tangential stress is described by the singular and nonsingular (T-stress terms in the Williams series solution. To demonstrate the validity of the proposed MATS criterion, this criterion is directly applied to experiments reported in the literature for the mixed mode I/II crack growth behavior of Guiting limestone. The predicted directions of fracture angle are consistent with the experimental data. The concept of the average stress has been also employed to predict the surface crack path under rolling-sliding contact loading. The proposed model considers the size and orientation of the initial crack, normal and tangential loading due to rolling–sliding contact as well as the influence of fluid trapped inside the crack by a hydraulic pressure mechanism. The MATS criterion is directly applied to equivalent contact model for surface crack growth on a gear tooth flank.

  3. The Consumption Paradigm in Marketing

    Directory of Open Access Journals (Sweden)

    Eka Ardianto

    2003-08-01

    Full Text Available This article elaborates consumption paradigm in marketing. In background, this paper reviews different perspectives of consumption: economic perspective and marketing perspective. In ontology, this work describes various issues regarding consumption view. In epistemology, this article demonstrates how marketers especially researches explore the consumption phenomena. In methodology, the article describes experiential marketing –one of applied consumption paradigm in marketing, which could be an alternative choice of marketing practices.

  4. Fiber Bragg Grating Sensor to Monitor Stress Kinetics in Drying Process of Commercial Latex Paints

    Directory of Open Access Journals (Sweden)

    Ivo de Lourenço

    2010-05-01

    Full Text Available In this paper, we report a study about the application of packaged fiber Bragg gratings used as strain sensors to monitor the stress kinetics during the drying process of commercial latex paints. Three stages of drying with distinct mechanical deformation and temporal behaviors were identified for the samples, with mechanical deformation from 15 μm to 21 μm in the longitudinal film dimension on time intervals from 370 to 600 minutes. Drying time tests based on human sense technique described by the Brazilian Technical Standards NBR 9558 were also done. The results obtained shows that human sense technique has a limited perception of the drying process and that the optical measurement system proposed can be used to characterize correctly the dry-through stage of paint. The influence of solvent (water addition in the drying process was also investigated. The paint was diluted with four parts paint and one part water (80% paint, and one part paint and one part water (50% paint. It was observed that the increase of the water ratio mixed into the paint decreases both the mechanical deformation magnitude and the paint dry-through time. Contraction of 5.2 μm and 10.4 μm were measured for concentrations of 50% and 80% of paint in the mixture, respectively. For both diluted paints the dry-through time was approximately 170 minutes less than undiluted paint. The optical technique proposed in this work can contribute to the development of new standards to specify the drying time of paint coatings.

  5. Marketing communications: Qualitative and quantitative paradigm

    Directory of Open Access Journals (Sweden)

    Uzelac Nikola

    2005-01-01

    Full Text Available This paper focuses on key issues in relation to the choice of basic language of communication of marketing as a practical and academic field. Principally, marketing managers prefer descriptive way of expression, but they should use the advantages of language of numbers much more. By doing so, they will advance decision-making process - and the communication with finance and top management. In this regard, models offered by academic community could be helpful. This especially pertains to those positive or normative verbal approaches and models in which mathematics and statistical solutions have been embedded, as well as to those which emphasize financial criteria in decision-making. Concerning the process of creation and verification of scientific knowledge, the choice between languages of words and numbers is the part of much wider dimension, because it is inseparable from the decision on basic research orientation. Quantitative paradigm is more appropriate for hypotheses testing, while qualitative paradigm gives greater contribution in their generation. Competition factor could become the key driver of changes by which existing "parallel worlds" of main paradigms would be integrating, for the sake of disciplinary knowledge advancement.

  6. The membrane paradigm for black holes

    International Nuclear Information System (INIS)

    Price, R.H.; Thorne, K.S.

    1988-01-01

    It is now widely accepted that black holes exist and have an astrophysical role, in particular as the likely power source of quasars. To understand this role with ease, the authors and their colleagues have developed a new paradigm for black holes - a new way to picture, think about and describe them. As far as possible it treats black holes as ordinary astrophysical objects, made of real material. A black hole in this description is a spherical or oblate surface made of a thin, electrically conducting membrane. It was the author's quest to understand the Blandford-Znajek process intuitively that led them to create the membrane paradigm. Their strategy was to translate the general-relativistic mathematics of black holes into the same language of three-dimensional space that is used for magnetized plasmas and to create a new set of black-hole diagrams and pictures to go along with the language. 9 figs

  7. Radiation a new paradigm... Societal impacts

    International Nuclear Information System (INIS)

    Sutcliffe, Jill

    2010-01-01

    Latency is associated with the time lag it takes for the health effects resulting from exposure to ionising radiation to show up. However, the term latency can also be applied to the time it takes for a policy to be implemented. This length of time has been suggested as broadly 40-year process. Given that radioactivity was identified and named in 1896, three paradigms are identified and examined from 1896 to 2016 and the criteria for a 4th paradigm suggested for the period 2017-2056. The review examines the changes that have taken place in scientific understanding and in public trust, a few key developments and the associated establishment of the related organisational infrastructure designed to collate and assess the evidence.

  8. [Relationship between occupational stress and working ability of workers in a petroleum processing enterprise in high altitude area].

    Science.gov (United States)

    Ma, X M; Kang, H L; Shi, C B; Li, Y; Wu, Y F; Liu, Z H; Wang, G; Lei, H Y

    2017-12-20

    Objective: To investigate the relationship between occupational stress and working ability of workers in a petroleum processing enterprise in a high altitude area. Methods: A total of 728 workers in a petroleum processing enterprise at an altitude of 2850 m were subjected to a survey using Occupational Stress Inventory (OSI) , Work Ability Index (WAI) Scale, Occupational Role Questionnaire (ORQ) , Personal Strain Questionnaire (PSQ) , and Personal Resource Questionnaire (PRQ) from May 2014 to August 2016. Results: Of the 728 workers, 55 (7.6%) had a poor working ability, moderate in 262 (35.9%) , and good in 411 (56.5%). There were significant differences in WAI between the workers with different types of work, sexes, ages, and working years ( P occupational stress groups ( P Occupational stress is an influencing factor for the working ability of workers in the petroleum processing enterprise in the high altitude area. Hypoxia in high altitude area may further reduce the working ability. In order to reduce occupational stress and improve work ability, it should be considered to strengthen skills training, improve the working environment, and pay attention to mental health.

  9. TAMU: A New Space Mission Operations Paradigm

    Science.gov (United States)

    Meshkat, Leila; Ruszkowski, James; Haensly, Jean; Pennington, Granvil A.; Hogle, Charles

    2011-01-01

    The Transferable, Adaptable, Modular and Upgradeable (TAMU) Flight Production Process (FPP) is a model-centric System of System (SoS) framework which cuts across multiple organizations and their associated facilities, that are, in the most general case, in geographically diverse locations, to develop the architecture and associated workflow processes for a broad range of mission operations. Further, TAMU FPP envisions the simulation, automatic execution and re-planning of orchestrated workflow processes as they become operational. This paper provides the vision for the TAMU FPP paradigm. This includes a complete, coherent technique, process and tool set that result in an infrastructure that can be used for full lifecycle design and decision making during any flight production process. A flight production process is the process of developing all products that are necessary for flight.

  10. Effect of process parameters on the residual stresses in AA5083-H321 friction stir welds

    Energy Technology Data Exchange (ETDEWEB)

    Lombard, H. [NMMU, Gardham Avenue, PO Box 77000, 6031 Port Elizabeth (South Africa); University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Hattingh, D.G. [NMMU, Gardham Avenue, PO Box 77000, 6031 Port Elizabeth (South Africa); Steuwer, A. [NMMU, Gardham Avenue, PO Box 77000, 6031 Port Elizabeth (South Africa); FaME38 at the ILL-ESRF, 6 rue J Horowitz, 38042 Grenoble (France); University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)], E-mail: steuwer@ill.fr; James, M.N. [NMMU, Gardham Avenue, PO Box 77000, 6031 Port Elizabeth (South Africa); University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom)

    2009-02-15

    This paper investigates the effect of varying welding parameters on the residual stress profiles in friction stir welds of aluminium alloy AA5083-H321, which were created on a fully instrumented friction welding machine. The residual stresses were determined non-destructively using synchrotron X-ray diffraction. The width and maximum of the residual stress profile show clear correlation with the heat input, and in particular feed rate, which was found to be the dominant parameter.

  11. Intersection of Stress, Social Disadvantage, and Life Course Processes: Reframing Trauma and Mental Health

    OpenAIRE

    Nurius, Paula S.; Uehara, Edwina; Zatzick, Douglas F.

    2013-01-01

    This paper describes the intersection of converging lines of research on the social structural, psychosocial, and physiological factors involved in the production of stress and implications for the field of mental health. Of particular interest are the stress sensitization consequences stemming from exposure to adversity over the life course. Contemporary stress sensitization theory provides important clinical utility in articulating mechanisms through which these multiple levels exert influe...

  12. Lactic acid bacteria stress response to preservation processes in the beverage and juice industry.

    Science.gov (United States)

    Bucka-Kolendo, Joanna; Sokołowska, Barbara

    2017-01-01

    In this review we summarize stress factors that affect the lactic acid bacteria (LAB) and cause different molecular stress responses. LAB belong to a group of bacteria that is very widespread in food and beverages. They are present, and desired, in fermented products like yogurts, cheese, vegetables, meat or wine. In most of them, LAB are providing positive sensory and nutritive features. However, as harmless and desired microbes in one product, LAB can cause spoilage and a bad taste of others, especially in juices and beverages. LAB are resistant to many stress factors which allows them to survive in harsh environments. The most common stress factors they have to deal with are: heat, cold, acidity, NaCl and high hydrostatic pressure (HHP). Their ability to survive depends on their skills to cope with stress factors. Under stress conditions, LAB activate mechanisms that allow them to adjust to the new conditions, which can influence their viability and technological properties. This ability to adapt to different stress conditions may come from the cross-protection systems they have, as resistance to one factor may help them to deal with the other stress effectors. LAB are highly valuable for the food industry and that is why it is important to understand their stress response mechanisms.

  13. Study on the essential variables for pipe outer surface irradiated laser stress improvement process (L-SIP). Development of pipe outer surface irradiated laser stress improvement process (L-SIP)

    International Nuclear Information System (INIS)

    Ohta, Takahiro; Kamo, Kazuhiko; Muroya, Itaru; Asada, Seiji; Nakamura, Yasuo

    2009-01-01

    The new process called L-SIP (outer surface irradiated Laser Stress Improvement Process) is developed to improve the tensile residual stress of the inner surface near the butt welded joints of pipes in the compression stress. The temperature gradient occurs in the thickness of pipes in heating the outer surface rapidly by laser beam. By the thermal expansion difference between the inner surface and the outer surface, the compression stress occurs near the inner surface of pipes. In this paper, the essential variables for L-SIP is studied by experimental and FEM analysis. The range of the essential variables for L-SIP, which are defined by thermo-elastic FEM analysis, are Tmax=550 - 650degC, L Q /√rh ≥ 3, W Q /√rh ≥ 1.7, and, 0.04 ≤ F 0 ≤ 0.10 where Tmax is maximum temperature on the monitor point of the outer surface, F 0 is k x τ 0 /h 2 , k is thermal diffusivity coefficient, τ 0 is the temperature rise time from 100degC to maximum temperature on the monitor point of the outer surface, W Q is τ 0 x v, υ is moving velocity, L Q is the uniform temperature length in the axial direction, h is thickness of the pipe, and r is average radius of the pipe. It is showed by thermo-elastic-plastic FEM analysis that the residual stresses near the inner surface of pipes are improved in 4 different size pipes under the same essential variables. L-SIP is actually applied to welding joints of 4B x Sch160 and 2B x Sch80 SUS304 type stainless steel pipes within the defined range of the essential variables. The measured welding residual stresses on the inner surface near the welding joints are tensile. The residual stresses on the inner surface change to compression in all joints by L-SIP. (author)

  14. Stress corrosion cracking of stainless steel under deaerated high-temperature water. Influence of cold work and processing orientation

    International Nuclear Information System (INIS)

    Terachi, Takumi; Yamada, Takuyo; Chiba, Goro; Arioka, Koji

    2006-01-01

    The influence of cold work and processing orientation on the propagation of stress corrosion cracking (SCC) of stainless steel under hydrogenated high-temperature water was examined. It was shown that (1) the crack growth rates increased with heaviness of cold work, and (2) processing orientation affected crack growth rate with cracking direction. Crack growth rates showed anisotropy of T-L>>T-S>L-S, with T-S and L-S branches representing high shear stress direction. Geometric deformation of crystal grains due to cold work caused the anisotropy and shear stress also assisted the SCC propagation. (3) The step intervals of slip like patterns observed on intergranular facets increased cold work. (4) Nano-indentation hardness of the crack tip together with EBSD measurement indicated that the change of hardness due to crack propagation was less than 5% cold-work, even though the distance from the crack tip was 10μm. (author)

  15. Altered processing of visual emotional stimuli in posttraumatic stress disorder: an event-related potential study.

    Science.gov (United States)

    Saar-Ashkenazy, Rotem; Shalev, Hadar; Kanthak, Magdalena K; Guez, Jonathan; Friedman, Alon; Cohen, Jonathan E

    2015-08-30

    Patients with posttraumatic stress disorder (PTSD) display abnormal emotional processing and bias towards emotional content. Most neurophysiological studies in PTSD found higher amplitudes of event-related potentials (ERPs) in response to trauma-related visual content. Here we aimed to characterize brain electrical activity in PTSD subjects in response to non-trauma-related emotion-laden pictures (positive, neutral and negative). A combined behavioral-ERP study was conducted in 14 severe PTSD patients and 14 controls. Response time in PTSD patients was slower compared with that in controls, irrespective to emotional valence. In both PTSD and controls, response time to negative pictures was slower compared with that to neutral or positive pictures. Upon ranking, both control and PTSD subjects similarly discriminated between pictures with different emotional valences. ERP analysis revealed three distinctive components (at ~300, ~600 and ~1000 ms post-stimulus onset) for emotional valence in control subjects. In contrast, PTSD patients displayed a similar brain response across all emotional categories, resembling the response of controls to negative stimuli. We interpret these findings as a brain-circuit response tendency towards negative overgeneralization in PTSD. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  16. Instrumental and laboratory assessment of stressful remodelling processes in bone tissue at total hip replacement

    Directory of Open Access Journals (Sweden)

    E.V. Karjakina

    2010-06-01

    Full Text Available Research objective is to estimate stressful remodelling features of bone tissue according to the densitometry data and to the level of biochemical markers of bone resorption and formation in total hip replacement (THR. Bone tissue mineral density (BTMD, condition of calcium-phosphoric metabolism and biochemical markers of bone formation (osteocalcin and bone isoenzyme of alkaline phosphatase and resorption (С-terminal bodypeptide of the I type collagen have been determined in 52 patients with coxarthrosis of ll-lll stages with marked joint dysfunction before and after THR. The control group included 24 donors. The data were considered to be reliable when the probability index was р<0,05. The reliable (р<0,05 change of BTMD was determined only in 3-6 months after the operation, whereas the change of biochemical markers of remodeling had already been done after 1,5-3 months, allowing to define the group of patients with obvious negative bone balance: strong predominance of resorption processes without compensation of the subsequent adequate osteogenesis, that subsequently could lead to significant bone tissue deficiency in the area adjacent to the endoprosthesis. Changes of indices of calcium-phosphoric metabolism were not certain during the investigation term. ln conclusion it is to state that biochemical markers of remodeling in comparison with BTMD allow to estimate objectively features of adaptive bone tissue remodeling after THR in earlier periods and to define group of patients with sharp intensification of metabolism and obvious negative bone balance

  17. Decreased oxidative stress may contribute to the disease process in placenta accreta

    Science.gov (United States)

    Öztaş, Efser; Özler, Sibel; Ergin, Merve; Erel, Özcan; Gümüş Güler, Başak; Çağlar, Ali Turhan; Yücel, Aykan; Uygur, Dilek; Danışman, Nuri

    2017-08-23

    Background/aim: The main aim of this study was to investigate serum total oxidant status (TOS), total antioxidant status (TAS), oxidative stress index (OSI), and arylesterase levels in pregnant women with placenta accreta and to compare those with age-matched healthy pregnant women. Materials and methods: A total of 27 pregnant women who had clinically and pathologically proven placenta accreta and 30 age- and BMI- matched healthy pregnant women were enrolled in this case control study. Maternal serum TOS, TAS, OSI, and arylesterase levels were evaluated using logistic regression analysis to determine if there was an association with abnormal placental invasion or not. Results: Decreased OSI (OR= 0.999, 95%CI: 0.998-1.000, P = 0.035) and increased arylesterase levels (OR= 0.981, 95%CI: 0.970-0.993, P = 0.001) were significantly associated with the presence of placenta accreta. Maternal serum TOS, TAS, OSI, and arylesterase levels were not predictive for adverse perinatal outcomes (P > 0.05). Conclusions: Decreased OSI and increased arylesterase levels are significantly associated with placenta accreta and may contribute to the abnormal invasion process.

  18. Comunication: the Paradigms of symmetry, antisymmetry anda asymmetry

    OpenAIRE

    Winfried Nöth

    2011-01-01

    The paper examines how the process of communication is represented (a) in the etymology of the conceptof communication, (b) in everyday metaphors of communication, and (c) in 20th century theories andmodels of communication. These reflect this paradox in three different scenarios: the paradigms ofsymmetry, antisymmetry and asymmetry. The dead end into which communication theory is led by theproponents of the latter paradigm is contrasted with some solutions offered by Charles S. Peirce’scommu...

  19. Pins and posters: paradigms for content publication on situated displays

    OpenAIRE

    José, Rui; Pinto, Helder; Siva, Bruno; Melro, Ana

    2013-01-01

    Public display systems are still far from being a communication medium that people can appropriate to serve diverse communication goals. Moving towards open displays will require new publication paradigms that can overcome the challenges of meaningful engagement and enable users to fully understand and control the entire publication process. In this paper, we report on the study of two novel and complimentary communication paradigms for public displays inspired by the metaphors of pin badges ...

  20. Optimal temperature profiles for minimum residual stress in the cure process of polymer composites

    CSIR Research Space (South Africa)

    Gopal, AK

    2000-01-01

    Full Text Available include the minimum residual stresses, minimum cure cycle lime and full degree of cure. The development of residual stresses during the cure cycle is one of the most important problems as they affect the strength and the mechanical properties of the final...

  1. Measurement and Interpretation of Flow Stress Data for the Simulation of Metal-Forming Processes

    Science.gov (United States)

    2010-01-01

    fitting constants that differ in each equation): Ludwik Equation: c)εb(aσ += , (29) Voce Equation: )]εcexp([1*a][baσ −−−+= (30) Swift...stress at low strains (ɘ.2) and to overestimate the stress for high strains. For heavily prestrained materials, c ~ 1. The Voce and Swift equations tend

  2. Investigation of Techno-Stress Levels of Teachers Who Were Included in Technology Integration Processes

    Science.gov (United States)

    Çoklar, Ahmet Naci; Efilti, Erkan; Sahin, Yusef Levent; Akçay, Arif

    2016-01-01

    Techno-stress is defined as a modern adaptation disorder resulting from the failure in coping with new technologies in a healthy way. Techno-stress affects many occupational groups, including teachers. FATIH project and many other previous studies conducted in Turkey in recent years have necessitated the use of technology for teachers. The present…

  3. Automated assessment of patients' self-narratives for posttraumatic stress disorder screening using natural language processing and text mining

    NARCIS (Netherlands)

    He, Qiwei; Veldkamp, Bernard P.; Glas, Cornelis A.W.; de Vries, Theo

    2017-01-01

    Patients’ narratives about traumatic experiences and symptoms are useful in clinical screening and diagnostic procedures. In this study, we presented an automated assessment system to screen patients for posttraumatic stress disorder via a natural language processing and text-mining approach. Four

  4. Symptoms of Depression and Anxiety in Adolescents with Sickle Cell Disease: The Role of Intrapersonal Characteristics and Stress Processing Variables

    Science.gov (United States)

    Simon, Katherine; Barakat, Lamia P.; Patterson, Chavis A.; Dampier, Carlton

    2009-01-01

    Sickle cell disease (SCD) complications place patients at risk for poor psychosocial adaptation, including depression and anxiety symptoms. This study aimed to test a mediator model based on the Risk and Resistance model to explore the role of intrapersonal characteristics and stress processing variables in psychosocial functioning. Participants…

  5. Forming the stress state of a vibroisolated building in the process of mounting rubber steel vibration isolator

    Directory of Open Access Journals (Sweden)

    Dashevskiy Mikhail Aronovich

    2015-12-01

    Full Text Available The necessity to specificate the formation process of stress-strain state of buildings in the construction process is a new problem which requires including real production characteristics going beyond calculation models into calculation methods. Today the construction process lacks this specification. When mounting vibroisolators the stress-strein of a structure state is changing. The mounting method of vibroisolators is patented and consists in multistage successive compression loading of each vibroisolator with the constant speed and following fixation of this displacement. The specified engineering method of rubber-steel pads calculation in view of change of their form during deformation, nonlinearity, rheological processes is offered. Resilient pads look like rubber plates rectangular in plane reinforced on the basic surfaces with metal sheets. The influence of a time-variable static load and free vibrations of loaded pads are considered.

  6. Intersection of Stress, Social Disadvantage, and Life Course Processes: Reframing Trauma and Mental Health.

    Science.gov (United States)

    Nurius, Paula S; Uehara, Edwina; Zatzick, Douglas F

    2013-04-01

    This paper describes the intersection of converging lines of research on the social structural, psychosocial, and physiological factors involved in the production of stress and implications for the field of mental health. Of particular interest are the stress sensitization consequences stemming from exposure to adversity over the life course. Contemporary stress sensitization theory provides important clinical utility in articulating mechanisms through which these multiple levels exert influence on mental health. Stress sensitization models (a) extend understanding of neurobiological and functional contexts within which extreme stressors operate and (b) make clear how these can influence psychologically traumatic outcomes. The value of interventions that are sensitive to current contexts as well as life course profiles of cumulative stress are illustrated through recent treatment innovations.

  7. Development of intergranular thermal residual stresses in beryllium during cooling from processing temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.W. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)], E-mail: dbrown@lanl.gov; Sisneros, T.A.; Clausen, B.; Abeln, S.; Bourke, M.A.M.; Smith, B.G.; Steinzig, M.L.; Tome, C.N.; Vogel, S.C. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2009-02-15

    The intergranular thermal residual stresses in texture-free solid polycrystalline beryllium were determined by comparison of crystallographic lattice parameters in solid and powder samples measured by neutron diffraction during cooling from 800 deg. C. The internal stresses are not significantly different from zero >575 deg. C and increase nearly linearly <525 deg. C. At room temperature, the c axis of an average grain is under {approx}200 MPa of compressive internal stress, and the a axis is under 100 MPa of tensile stress. For comparison, the stresses have also been calculated using an Eshelby-type polycrystalline model. The measurements and calculations agree very well when temperature dependence of elastic constants is accounted for, and no plastic relaxation is allowed in the model.

  8. Operations Strategy under Chaos –Lessons to be learned from a new Paradigm

    DEFF Research Database (Denmark)

    Koch, Christian

    2004-01-01

    The purpose of this paper is to introduce a new paradigm being able to conceptualize content and process aspects of Operations Strategy. Based on a critical reading of literature; two opposing paradigms of Operations Strategy are identified and described. The first focuses on content issues...... of Operations Strategy and relies on a normative orientation and the second focuses on process issues of Operations Strategy and relies on a descriptive orientation. To compare and evaluate the two paradigms; the results of a longitudinal case-study of Operations Strategy formulation and implementation...... in practice are shown. These results promote the need for a new or third paradigm to integrate and balance the two former paradigms. The new paradigm is labeled as a moderate constructivist paradigm using the metaphor of chaos and seems suitable for conceptualizing Operations Strategy as it is in practice...

  9. Stress-strain effects in alumina-Cu reinforced Nb3Sn wires fabricated by the tube process

    International Nuclear Information System (INIS)

    Murase, Satoru; Nakayama, Shigeo; Masegi, Tamaki; Koyanagi, Kei; Nomura, Shunji; Shiga, Noriyuki; Kobayashi, Norio; Watanabe, Kazuo.

    1997-01-01

    In order to fabricate a large-bore, high-field magnet which achieves a low coil weight and volume, a high strength compound superconducting wire is required. For those demands we have developed the reinforced Nb 3 Sn wire using alumina dispersion strengthened copper (alumina-Cu) as a reinforcement material and the tube process of the Nb 3 Sn wire fabrication. The ductility study of the composites which consisted of the reinforcement, Nb tube, Cu, and Cu clad Sn brought a 1 km long alumina-Cu reinforced Nb 3 Sn wire successfully. Using fabricated wires measurements and evaluations of critical current density as parameters of magnetic field, tensile stress, tensile strain, and transverse compressive stress, and those of stress-strain curves at 4.2 K were performed. They showed superior performance such as high 0.3% proof stress (240 MPa at 0.3% strain) and high maximum tolerance stress (320 MPa) which were two times as large as those of conventional Cu matrix Nb 3 Sn wire. The strain sensitivity parameters were obtained for the reinforced Nb 3 Sn wire and the Cu matrix one using the scaling law. Residual stress of the component materials caused by cooling down to 4.2 K from heat-treatment temperature was calculated using equivalent Young's modulus, equivalent yield strength, thermal expansion coefficient and other mechanical parameters. Calculated stress-strain curves at 4.2 K for the reinforced Nb 3 Sn wire and the Cu matrix one based on calculation of residual stress, had good agreement with the experimental values. (author)

  10. Acute Stress Modulates Feedback Processing in Men and Women: Differential Effects on the Feedback-Related Negativity and Theta and Beta Power

    Science.gov (United States)

    Banis, Stella; Geerligs, Linda; Lorist, Monicque M.

    2014-01-01

    Sex-specific prevalence rates in mental and physical disorders may be partly explained by sex differences in physiological stress responses. Neural networks that might be involved are those underlying feedback processing. Aim of the present EEG study was to investigate whether acute stress alters feedback processing, and whether stress effects differ between men and women. Male and female participants performed a gambling task, in a control and a stress condition. Stress was induced by exposing participants to a noise stressor. Brain activity was analyzed using both event-related potential and time-frequency analyses, measuring the feedback-related negativity (FRN) and feedback-related changes in theta and beta oscillatory power, respectively. While the FRN and feedback-related theta power were similarly affected by stress induction in both sexes, feedback-related beta power depended on the combination of stress induction condition and sex. FRN amplitude and theta power increases were smaller in the stress relative to the control condition in both sexes, demonstrating that acute noise stress impairs performance monitoring irrespective of sex. However, in the stress but not in the control condition, early lower beta-band power increases were larger for men than women, indicating that stress effects on feedback processing are partly sex-dependent. Our findings suggest that sex-specific effects on feedback processing may comprise a factor underlying sex-specific stress responses. PMID:24755943

  11. Acute stress modulates feedback processing in men and women: differential effects on the feedback-related negativity and theta and beta power.

    Directory of Open Access Journals (Sweden)

    Stella Banis

    Full Text Available Sex-specific prevalence rates in mental and physical disorders may be partly explained by sex differences in physiological stress responses. Neural networks that might be involved are those underlying feedback processing. Aim of the present EEG study was to investigate whether acute stress alters feedback processing, and whether stress effects differ between men and women. Male and female participants performed a gambling task, in a control and a stress condition. Stress was induced by exposing participants to a noise stressor. Brain activity was analyzed using both event-related potential and time-frequency analyses, measuring the feedback-related negativity (FRN and feedback-related changes in theta and beta oscillatory power, respectively. While the FRN and feedback-related theta power were similarly affected by stress induction in both sexes, feedback-related beta power depended on the combination of stress induction condition and sex. FRN amplitude and theta power increases were smaller in the stress relative to the control condition in both sexes, demonstrating that acute noise stress impairs performance monitoring irrespective of sex. However, in the stress but not in the control condition, early lower beta-band power increases were larger for men than women, indicating that stress effects on feedback processing are partly sex-dependent. Our findings suggest that sex-specific effects on feedback processing may comprise a factor underlying sex-specific stress responses.

  12. The Knowledge Society: A Sustainability Paradigm

    Directory of Open Access Journals (Sweden)

    Naim Hamdija Afgan

    2010-10-01

    Full Text Available This paper defines the knowledge society as a human structured organisation based on contemporary developed knowledge and representing new quality of life support systems. It implies the need for a full understanding of distribution of knowledge, access to information and the capability to transfer information into a knowledge. The understanding of knowledge is the central challenge when defining a knowledge society. From our present perception of knowledge society, it is of interest to emphasize the role of the knowledge society in future development of human society. The life support systems are essential pillars of human society development. In this respect knowledge society represents a new paradigm for future development and it is strongly correlated to sustainable development. For this reason the sustainability paradigm of knowledge society is a potential frame for human society development leading to social cohesion, economic competitiveness and stability, use of resources and economic development, safeguarding biodiversity and the ecosystem.In order to verify the mutual relation between knowledge society and sustainability, we have to introduce the difference between these two terms. The knowledge society is based on the agglomeration of eco-knowledge, env-knowledge and soc-knowledge, it may be evaluated as the complex knowledge of quality of life support systems. We have to introduce metrics which will allow us to present knowledge as the paradigm of the number of indicators for verifying progress made.Sustainability metrics are designed to consolidate measures of economic, environmental and social performance of any system. It can be understood as a pattern for evaluation of the available knowledge about systems and their performance. In particular the decision-making process for the selection of the system under consideration must be based on the available knowledge. The link between knowledge and sustainability makes it possible for

  13. Transactional processes in children born preterm: Influences of mother-child interactions and parenting stress.

    Science.gov (United States)

    Gerstein, Emily D; Poehlmann-Tynan, Julie

    2015-10-01

    This prospective, longitudinal study examined the transactional relations among perceived maternal parenting stress, maternal insensitivity, and child behavior across toddlerhood through age 6 within families of a child born preterm. A sample of 173 mother-child dyads were followed from just before the infant was discharged from the neonatal intensive care unit to 6 years of age, with observational measurements of maternal insensitivity and child noncompliance (24 and 36 months), maternal self-reports of perceived parenting stress (24 months, 36 months, 6 years), and maternal reports of child externalizing behavior at 6 years. Results indicated that maternal insensitivity at 36 months significantly mediated the relation between parenting stress at 24 months and externalizing behaviors at 6 years. Parenting stress was also directly associated with child noncompliance at 36 months and with child externalizing behavior at 6 years. Neonatal risk was associated with increased maternal insensitivity at 24 months, but also decreased parenting stress at 24 months. No significant "child effects" from child behavior to either maternal insensitivity or parenting stress were found. Parenting stress appears to play a critical role for children born preterm, and it is associated with children's behavior both directly and through its influence on parenting. The role of neonatal risk needs continued investigation, as families traditionally considered to be at lower risk may still face significant challenges. (c) 2015 APA, all rights reserved).

  14. Health problems and stress in Information Technology and Business Process Outsourcing employees.

    Science.gov (United States)

    Padma, V; Anand, N N; Gurukul, S M G Swaminatha; Javid, S M A Syed Mohammed; Prasad, Arun; Arun, S

    2015-04-01

    Stress is high in software profession because of their nature of work, target, achievements, night shift, over work load. 1. To study the demographic profile of the employees. 2. To access the level of job stress and quality of life of the respondents. 3. To study in detail the health problems of the employees. All employees working in IT and BPO industry for more than two years were included into the study. A detailed questionnaire of around 1000 IT and BPO employees including their personal details, stress score by Holmes and Rahe to assess the level of stress and master health checkup profile were taken and the results were analysed. Around 56% had musculoskeletal symptoms. 22% had newly diagnosed hypertension,10% had diabetes, 36% had dyslipidemia, 54% had depression, anxiety and insomnia, 40% had obesity. The stress score was higher in employees who developed diabetes, hypertension and depression. Early diagnosis of stress induced health problems can be made out by stress scores, intense lifestyle modification, diet advice along with psychological counselling would reduce the incidence of health problems in IT sector and improve the quality of work force.

  15. Plastic deformation, residual stress, and crystalline texture measurements for in-process characterization of FCC metal alloys

    International Nuclear Information System (INIS)

    Ruud, C.O.; Jacobs, M.E.; Weedman, S.D.; Snoha, D.J.

    1989-01-01

    This paper describes the results of several on-going investigations on the measurement of plastic deformation, residual stress, and crystalline texture in nickel, copper, and aluminum base alloys by x-ray diffraction techniques. X-ray diffraction techniques have been shown to be effective in the measurement of plastic deformation, residual stress, and crystalline texture in FCC metals, from the breadth, position, and intensity of the x-ray diffraction peaks. The Ruud-Barrett position-sensitive scintillation detector has been demonstrated to be fast, non-contacting, and tolerant of detector to component distance variation -- necessary requirements for cost-effective in-process inspection of materials

  16. Weld residual stress according to the ways of heat input in the simulation of weld process using finite element analysis

    International Nuclear Information System (INIS)

    Yang, Jun Seog; Lee, Kyoung Soo; Park, Chi Yong

    2008-01-01

    This paper is to discuss distribution of welding residual stresses of a ferritic low alloy steel nozzle with dissimilar metal weld using Alloy 82/182. Two Dimensional (2D) thermo-mechanical finite element analyses are carried out to simulate multi-pass welding process on the basis of the detailed and fabrication data. On performing the welding analysis generally, the characteristics on the heat input and heat transfer of weld are affected on the weld residual stress analyses. Thermal analyses in the welding heat cycle process is very important process in weld residual stress analyses. Therefore, heat is rapidly input to the weld pass material, using internal volumetric heat generation, at a rate which raises the peak weld metal temperature to 2200 .deg. C and the base metal adjacent to the weld to about 1400 .deg. C. These are approximately the temperature that the weld metal and surrounding base materials reach during welding. Also, According to the various ways of applying the weld heat source, the predicted residual stress results are compared with measured axial, hoop and radial through-wall profiles in the heat affected zone of test component. Also, those results are compared with those of full 3-dimensional simulation

  17. Paradigm Shifts in Ophthalmic Diagnostics.

    Science.gov (United States)

    Sebag, J; Sadun, Alfredo A; Pierce, Eric A

    2016-08-01

    Future advances in ophthalmology will see a paradigm shift in diagnostics from a focus on dysfunction and disease to better measures of psychophysical function and health. Practical methods to define genotypes will be increasingly important and non-invasive nanotechnologies are needed to detect molecular changes that predate histopathology. This is not a review nor meant to be comprehensive. Specific topics have been selected to illustrate the principles of important paradigm shifts that will influence the future of ophthalmic diagnostics. It is our impression that future evaluation of vision will go beyond visual acuity to assess ocular health in terms of psychophysical function. The definition of disease will incorporate genotype into what has historically been a phenotype-centric discipline. Non-invasive nanotechnologies will enable a paradigm shift from disease detection on a cellular level to a sub-cellular molecular level. Vision can be evaluated beyond visual acuity by measuring contrast sensitivity, color vision, and macular function, as these provide better insights into the impact of aging and disease. Distortions can be quantified and the psychophysical basis of vision can be better evaluated than in the past by designing tests that assess particular macular cell function(s). Advances in our understanding of the genetic basis of eye diseases will enable better characterization of ocular health and disease. Non-invasive nanotechnologies can assess molecular changes in the lens, vitreous, and macula that predate visible pathology. Oxygen metabolism and circulatory physiology are measurable indices of ocular health that can detect variations of physiology and early disease. This overview of paradigm shifts in ophthalmology suggests that the future will see significant improvements in ophthalmic diagnostics. The selected topics illustrate the principles of these paradigm shifts and should serve as a guide to further research and development. Indeed

  18. Paradigm shift in psychiatry: what may it involve?

    Science.gov (United States)

    Valent, Paul

    2018-02-01

    This study aims to examine the potential nature of an ongoing paradigm shift in psychiatry that has been suggested to be occurring. New findings in traumatology and neuroscience do form a potential platform for a paradigm shift. Prior conflicting paradigms are suggested to be due to biases arising from mental structures themselves. A new wholist perspective is proposed, which makes sense of and incorporates previous paradigms, and coheres recent understanding of right- and left-brain functioning and biopsychosocial traumatic processes and their ramifications. The perspective makes sense of the great variety of post-traumatic manifestations ranging from somatic to meaning-making dysfunctions. The wholist perspective may well be an important step in solidifying a fresh paradigmatic perspective in psychiatry.

  19. The "extended mind" approach for a new paradigm of psychology.

    Science.gov (United States)

    Kono, Tetsuya

    2010-12-01

    In this paper, I would like to propose the idea of "extended mind" for a new paradigm of psychology. Kohler (Integrative Psychology & Behavioral Science 44:39-57, 2010) correctly pointed out the serious problems of the machine paradigm, and proposed the "organic" view as a new paradigm. But the term "organic" signifying the processes inside the body, is inadequate to express the characteristic of human mind. The recent philosophy of mind suggests that the mind is realized neither only in the brain nor only in the body, but in the whole system of brain-body-environment, namely, in the "extended mind". The characteristic of human mind resides in the interaction with the mediating tools, artifacts, and the humanized environment. We should propose an "extended mind approach" or an "ecological approach to humanized environment" as a new paradigm for a psychology.

  20. [New Paradigms? Current Trends within National and International Psychotherapy Research].

    Science.gov (United States)

    Strauß, Bernhard

    2015-09-01

    This article is devoted to the question which paradigms currently determine psychotherapy and psychotherapy research, and if there are indicators of paradigm changes in this field. The question of the efficacy and effectiveness (including the effectiveness of a transfer of psychotherapeutic knowledge to service) is specifically focussed as well as the question of the central therapeutic factors and the significance of the person of the therapist. It is argued that there are really some signals of a paradigm switch, with a turn away from controlled outcome research, representing only a minor part of patients in need of psychotherapy, towards a more specific process oriented research, also considering differential effects of the therapist. The most prominent indicator of a paradigm change is reflected by an increasing influence of patient oriented psychotherapy research which - consequently - should also be supported by the insurances as well as the funding organisations. © Georg Thieme Verlag KG Stuttgart · New York.

  1. The synthesis paradigm in genetics.

    Science.gov (United States)

    Rice, William R

    2014-02-01

    Experimental genetics with model organisms and mathematically explicit genetic theory are generally considered to be the major paradigms by which progress in genetics is achieved. Here I argue that this view is incomplete and that pivotal advances in genetics--and other fields of biology--are also made by synthesizing disparate threads of extant information rather than generating new information from experiments or formal theory. Because of the explosive expansion of information in numerous "-omics" data banks, and the fragmentation of genetics into numerous subdisciplines, the importance of the synthesis paradigm will likely expand with time.

  2. Transmission pricing: paradigms and methodologies

    Energy Technology Data Exchange (ETDEWEB)

    Shirmohammadi, Dariush [Pacific Gas and Electric Co., San Francisco, CA (United States); Vieira Filho, Xisto; Gorenstin, Boris [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil); Pereira, Mario V.P. [Power System Research, Rio de Janeiro, RJ (Brazil)

    1994-12-31

    In this paper we describe the principles of several paradigms and methodologies for pricing transmission services. The paper outlines some of the main characteristics of these paradigms and methodologies such as where they may be used for best results. Due to their popularity, power flow based MW-mile and short run marginal cost pricing methodologies will be covered in some detail. We conclude the paper with examples of the application of these two pricing methodologies for pricing transmission services in Brazil. (author) 25 refs., 2 tabs.

  3. Changing Rural Paradigms

    DEFF Research Database (Denmark)

    Høst, Jeppe Engset

    2016-01-01

    In this article I will review the historical, cultural and social formation of rural development policies in Denmark and situate these in a Scandinavian context. The review is based on a reading of commission reports, law documents and texts produced by the planners and scholars involved...... paradigm” (OECD 2006) and its implications for ethnological scholars and practitioners of today. In the “new rural paradigm”, bottom-up processes, “place-bound” cultural and historical values are highlighted as essential to local development. This of course empowers the ethnologists, but also put us...

  4. New radiobiological, radiation risk and radiation protection paradigms

    International Nuclear Information System (INIS)

    Goodhead, Dudley T.

    2010-01-01

    The long-standing conventional paradigm for radiobiology has formed a logical basis for the standard paradigm for radiation risk of cancer and heritable effects and, from these paradigms, has developed the internationally applied system for radiation protection, but with many simplifications, assumptions and generalizations. A variety of additional radiobiological phenomena that do not conform to the standard paradigm for radiobiology may have potential implications for radiation risk and radiation protection. It is suggested, however, that the current state of knowledge is still insufficient for these phenomena, individually or collectively, to be formulated systematically into a new paradigm for radiobiology. Additionally, there is at present lack of direct evidence of their relevance to risk for human health, despite attractive hypotheses as to how they might be involved. Finally, it remains to be shown how incorporation of such phenomena into the paradigm for radiation protection would provide sufficient added value to offset disruption to the present widely applied system. Further research should aim for better mechanistic understanding of processes such as radiation-induced genomic instability (for all radiation types) and bystander effects (particularly for low-fluence high-LET particles) and also priority should be given to confirmation, or negation, of the relevance of the processes to human health risks from radiation.

  5. Formation of stress students in the process of notions of martial arts in high school

    Directory of Open Access Journals (Sweden)

    S.V. Uskov

    2013-10-01

    Full Text Available Various aspects of the development of resistance to psychophysiological stress among students in the classroom arts. In the experiment involved 40 students (20 - boys, 20 girls. In the experiment, teaching methods and means of special psychological training in the martial arts. Disclosed the specifics of individual psycho-oriented methodology in the modern system of martial arts. The possibility of its use in physical education classes. It is noted that not all stress are barriers health, and only excessive. The most destructive are excessive psychogenic stresses caused by adverse of psychological factors. Psychogenic stress has a great destructive impact on health. It is a major cause of morbidity students. Recommended didactically well-designed prevention techniques.

  6. Longitudinal associations between marital stress and externalizing behavior : Does Parental Sense of Competence Mediate Processes?

    NARCIS (Netherlands)

    van Eldik, W. M.; Prinzie, Peter; Dekovic, M.; de Haan, A.D.

    2017-01-01

    Ecological theories emphasize associations between children and elements within their family system, such as the marital relationship. Within a developmental perspective, we longitudinally examined (a) dynamic associations between marital stress and children’s externalizing behavior, (b) mediation

  7. Longitudinal associations between marital stress and externalizing behavior: Does parental sense of competence mediate processes?

    NARCIS (Netherlands)

    Eldik, W.M. van; Prinzie, P.; Dekoviç, M.; Haan, A.D. de

    2017-01-01

    Ecological theories emphasize associations between children and elements within their family system, such as the marital relationship. Within a developmental perspective, we longitudinally examined (a) dynamic associations between marital stress and children's externalizing behavior, (b) mediation

  8. Trauma, stress, and preconscious threat processing in patients with psychogenic nonepileptic seizures

    NARCIS (Netherlands)

    Bakvis, P.; Roelofs, K.; Kuyk, J.; Edelbroek, P.M.; Swinkels, W.A.M.; Spinhoven, P.

    2009-01-01

    Psychogenic nonepileptic seizures (PNES) have long been considered as paroxysmal dissociative symptoms characterized by an alteration of attentional functions caused by severe stress or trauma. Although interpersonal trauma is common in PNES, the proposed relation between trauma and attentional

  9. Silicon Regulates Potential Genes Involved in Major Physiological Processes in Plants to Combat Stress

    Directory of Open Access Journals (Sweden)

    Abinaya Manivannan

    2017-08-01

    Full Text Available Silicon (Si, the quasi-essential element occurs as the second most abundant element in the earth's crust. Biological importance of Si in plant kingdom has become inevitable particularly under stressed environment. In general, plants are classified as high, medium, and low silicon accumulators based on the ability of roots to absorb Si. The uptake of Si directly influence the positive effects attributed to the plant but Si supplementation proves to mitigate stress and recover plant growth even in low accumulating plants like tomato. The application of Si in soil as well as soil-less cultivation systems have resulted in the enhancement of quantitative and qualitative traits of plants even under stressed environment. Silicon possesses several mechanisms to regulate the physiological, biochemical, and antioxidant metabolism in plants to combat abiotic and biotic stresses. Nevertheless, very few reports are available on the aspect of Si-mediated molecular regulation of genes with potential role in stress tolerance. The recent advancements in the era of genomics and transcriptomics have opened an avenue for the determination of molecular rationale associated with the Si amendment to the stress alleviation in plants. Therefore, the present endeavor has attempted to describe the recent discoveries related to the regulation of vital genes involved in photosynthesis, transcription regulation, defense, water transport, polyamine synthesis, and housekeeping genes during abiotic and biotic stress alleviation by Si. Furthermore, an overview of Si-mediated modulation of multiple genes involved in stress response pathways such as phenylpropanoid pathway, jasmonic acid pathway, ABA-dependent or independent regulatory pathway have been discussed in this review.

  10. Dynamic Failure Processes Under Confining Stress in AlON, a Transparent Polycrystalline Ceramic

    Science.gov (United States)

    2009-09-01

    homogeneous compressive stress state in the specimen, a 500 µm thick, soft-annealed AISI 4140 steel ‘cushion’ is sandwiched between the specimen and the...1. The AlON prismatic specimen (shown in green in the figure) is placed between two very hard steel “T-blocks” made from ~ HRC 55 hardened AISI ... 4140 steel alloy. The blocks were polished to obtain precise dimensions and a mirror surface finish. Compressive stress was generated by tightening

  11. Longitudinal associations between marital stress and externalizing behavior: Does parental sense of competence mediate processes?

    Science.gov (United States)

    van Eldik, Willemijn M; Prinzie, Peter; Deković, Maja; de Haan, Amaranta D

    2017-06-01

    Ecological theories emphasize associations between children and elements within their family system, such as the marital relationship. Within a developmental perspective, we longitudinally examined (a) dynamic associations between marital stress and children's externalizing behavior, (b) mediation of these associations by parental sense of competence, and (c) the extent to which associations are similar for mothers and fathers. The sample consisted of 369 two-parent families (46.1% boys; Mage at Time 1 = 7.70 years; 368 mothers, 355 fathers). Marital stress related to having a child, children's externalizing behavior, and perceived parental competence were assessed three times across 8 years. Multigroup analyses were used to examine models for both parents simultaneously and test for similarity in associations across spouses. A bivariate latent growth model indicated positive associated change between marital stress and externalizing behavior, supporting the idea of codevelopment. The cross-lagged panel model revealed a reciprocal relation between marital stress and perceived parental competence across a time interval of 6 years. Additionally, two elicitation effects appeared during adolescence, showing that parents who reported higher externalizing problems in early adolescence reported more marital stress and a lower sense of competence two years later. Similar associations were found for mothers and fathers. Overall, this study indicates that marital stress and externalizing behavior codevelop over time and supports literature on developmental differences regarding interrelations between subsystems and individuals within the family system. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  12. Using X-ray microbeam diffraction to study the long-range internal stresses in aluminum processed by ECAP

    International Nuclear Information System (INIS)

    Lee, I-Fang; Phan, Thien Q.; Levine, Lyle E.; Tischler, Jonathan Z.; Geantil, Peter T.; Huang, Yi; Langdon, Terence G.; Kassner, Michael E.

    2013-01-01

    Aluminum alloy 1050 was processed by equal-channel angular pressing (ECAP) using a single pass (equivalent uniaxial strain of about 0.88). Long-range internal stresses (LRISs) were assessed in the grain/subgrain interiors using X-ray microbeam diffraction to measure the spacing of {5 3 1} planes, with normals oriented approximately +27.3°, +4.9° and −17.5° off the pressing (axial) direction. The results are consistent with mechanical analysis that suggests the maximum tensile plastic-strain after one pass is expected for +22.5°, roughly zero along the pressing axis, and maximum compressive strain for the −67.5° direction. The magnitude of the measured maximum compressive long-range internal stress is about 0.13σ a (applied stress) in low-dislocation regions within the grain/subgrain interiors. This work is placed in the context of earlier work where convergent beam electron diffraction was used to analyze LRISs in close proximity to the deformation-induced boundaries. The results are complementary and the measured stresses are consistent with a composite model for long-range internal stresses

  13. Programming Language: Concepts and Paradigms

    OpenAIRE

    Ruiz Lizama, Edgar

    2014-01-01

    The article presents the concepts that govern around the programming languages and the paradigms of the programming and the influence in the development of the software. El artículo presenta los conceptos que rigen a los lenguajes de programación y los paradigmas de la programación y como estos influyen en el desarrollo del software.

  14. Understanding the land management paradigm

    DEFF Research Database (Denmark)

    Enemark, Stig

    2006-01-01

    There is a worldwide need to build understanding of the land management paradigm and for institutional development to establish sustainable national concepts. This includes creation and adoption of a policy on land development, and an approach that combines the land administration...

  15. Artificial life, the new paradigm

    International Nuclear Information System (INIS)

    Martinez Paez, Jose Jesus

    1998-01-01

    A chronological synthesis of the most important facts is presented in the theoretical development and computational simulation that they have taken to the formation of a new paradigm that is known as artificial life; their characteristics and their main investigation lines are analyzed. Finally, a description of its work is made in the National University of Colombia

  16. Novel processing of Barkhausen noise signal for assessment of residual stress in surface ground components exhibiting poor magnetic response

    International Nuclear Information System (INIS)

    Vashista, M.; Paul, S.

    2011-01-01

    The Barkhausen Noise Analysis (BNA) technique has been utilised to assess surface integrity of steels. But the BNA technique is not very successful in evaluating surface integrity of ground steels that exhibit poor micro-magnetic response. A new approach has been proposed for the processing of BN signal and two newly proposed parameters, namely 'count' and 'event', have been shown to correlate linearly with the residual stress upon grinding, with judicious choice of user defined 'threshold', even when the micro-magnetic response of the work material is poor. In the present study, residual stress induced upon conventional plunge surface grinding of hardened bearing steel has been investigated along with unhardened bearing steel for benchmarking. Moreover, similar correlation has been established, when primarily compressive stress is induced upon high speed grinding using cBN wheel with moderately deep cut suppressing the micro-magnetic response from the ground medium carbon steel as the work material. - Highlights: → The problem of work materials exhibiting poor BN response and poor Barkhausen Noise response is identified. → A novel signal processing strategy is introduced to address the issue of poor micro-magnetic response of some ferromagnetic material. → Potential of newly introduced BN parameters has been studied. → These two BN parameters exhibited linear correlation with residual stress for work material with poor micro-magnetic response.

  17. Effect of an absorbent overlay on the residual stress field induced by laser shock processing on aluminum samples

    International Nuclear Information System (INIS)

    Rubio-Gonzalez, C.; Gomez-Rosas, G.; Ocana, J.L.; Molpeceres, C.; Banderas, A.; Porro, J.; Morales, M.

    2006-01-01

    Laser shock processing (LSP) or laser shock peening is a new technique for strengthening metals. This process induces a compressive residual stress field, which increases fatigue crack initiation life and reduces fatigue crack growth rate. Specimens of 6061-T6 aluminum alloy are used in this investigation. A convergent lens is used to deliver 2.5 J, 8 ns laser pulses by a Q-switch Nd:YAG laser, operating at 10 Hz. The pulses are focused to a diameter of 1.5 mm onto aluminum samples. Density of 2500 pulses/cm 2 with infrared (1064 nm) radiation was used. The effect of an absorbent overlay on the residual stress field using this LSP setup and this energy level is evaluated. Residual stress distribution as a function of depth is assessed by the hole drilling method. It is observed that the overlay makes the compressive residual stress profile move to the surface. This effect is explained on the basis of the vaporization of the coat layer suppressing thermal effects on the metallic substrate. The effect of coating the specimen surface before LSP treatment may have advantages on improving wear and contact fatigue properties of this aluminum alloy

  18. Effect of Tip Shape of Frictional Stir Burnishing Tool on Processed Layer’s Hardness, Residual Stress and Surface Roughness

    Directory of Open Access Journals (Sweden)

    Yoshimasa Takada

    2018-01-01

    Full Text Available Friction stir burnishing (FSB is a surface-enhancement method used after machining, without the need for an additional device. The FSB process is applied on a machine that uses rotation tools (e.g., machining center or multi-tasking machine. Therefore, the FSB process can be applied immediately after the cutting process using the same machine tool. Here, we apply the FSB to the shaft materials of 0.45% C steel using a multi-tasking machine. In the FSB process, the burnishing tool rotates at a high-revolution speed. The thin surface layer is rubbed and stirred as the temperature is increased and decreased. With the FSB process, high hardness or compressive residual stress can be obtained on the surface layer. However, when we applied the FSB process using a 3 mm diameter sphere tip shape tool, the surface roughness increased substantially (Ra = 20 µm. We therefore used four types of tip shape tools to examine the effect of burnishing tool tip radius on surface roughness, hardness, residual stress in the FSB process. Results indicated that the surface roughness was lowest (Ra = 10 µm when the tip radius tool diameter was large (30 mm.

  19. Stress management skills, neuroimmune processes and fatigue levels in persons with chronic fatigue syndrome.

    Science.gov (United States)

    Lattie, Emily G; Antoni, Michael H; Fletcher, Mary Ann; Penedo, Frank; Czaja, Sara; Lopez, Corina; Perdomo, Dolores; Sala, Andreina; Nair, Sankaran; Fu, Shih Hua; Klimas, Nancy

    2012-08-01

    Stressors and emotional distress responses impact chronic fatigue syndrome (CFS) symptoms, including fatigue. Having better stress management skills might mitigate fatigue by decreasing emotional distress. Because CFS patients comprise a heterogeneous population, we hypothesized that the role of stress management skills in decreasing fatigue may be most pronounced in the subgroup manifesting the greatest neuroimmune dysfunction. In total, 117 individuals with CFS provided blood and saliva samples, and self-report measures of emotional distress, perceived stress management skills (PSMS), and fatigue. Plasma interleukin-1-beta (IL-1β, IL-2, IL-6, IL-10, and tumor necrosis factor-alpha (TNF-α), and diurnal salivary cortisol were analyzed. We examined relations among PSMS, emotional distress, and fatigue in CFS patients who did and did not evidence neuroimmune abnormalities. Having greater PSMS related to less fatigue (p=.019) and emotional distress (pfatigue levels most strongly in CFS patients in the top tercile of IL-6, and emotional distress mediated the relationship between PSMS and fatigue most strongly in patients with the greatest circulating levels of IL-6 and a greater inflammatory (IL-6):anti-inflammatory (IL-10) cytokine ratio. CFS patients having greater PSMS show less emotional distress and fatigue, and the influence of stress management skills on distress and fatigue appear greatest among patients who have elevated IL-6 levels. These findings support the need for research examining the impact of stress management interventions in subgroups of CFS patients showing neuroimmune dysfunction. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. [Process and mechanism of plants in overcoming acid soil aluminum stress].

    Science.gov (United States)

    Zhao, Tian-Long; Xie, Guang-Ning; Zhang, Xiao-Xia; Qiu, Lin-Quan; Wang, Na; Zhang, Su-Zhi

    2013-10-01

    Aluminum (Al) stress is one of the most important factors affecting the plant growth on acid soil. Currently, global soil acidification further intensifies the Al stress. Plants can detoxify Al via the chelation of ionic Al and organic acids to store the ionic Al in vacuoles and extrude it from roots. The Al extrusion is mainly performed by the membrane-localized anion channel proteins Al(3+)-activated malate transporter (ALMT) and multi-drug and toxin extrusion (MATE). The genes encoding ABC transporter and zinc-finger protein conferred plant Al tolerance have also been found. The identification of these Al-resistant genes makes it possible to increase the Al resistance of crop plants and enhance their production by the biological methods such as gene transformation and mark-associated breeding. The key problems needed to be solved and the possible directions in the researches of plant Al stress resistance were proposed.

  1. Finite element modelling of shot peening process: Prediction of the compressive residual stresses, the plastic deformations and the surface integrity

    International Nuclear Information System (INIS)

    Frija, M.; Hassine, T.; Fathallah, R.; Bouraoui, C.; Dogui, A.

    2006-01-01

    This paper presents a numerical simulation of the shot peening process using finite element method. The majority of the controlling parameters of the process have been taken into account. The shot peening loading has been characterised by using energy equivalence between the dynamic impact and a static indentation of a peening shot in the treated surface. The behaviour of the subjected material is supposed to be elastic plastic with damage. An integrated law of the damage proposed by Lemaitre and Chaboche has been used. The proposed model leads to obtain the residual stress, the plastic deformation profiles and the surface damage. An application on a shot peened Ni-based super alloy Waspaloy has been carried out. The comparison of the residual stresses, obtained by X-ray diffraction method and by finite element calculation, shows a good correlation. The in-depth profile of the plastic deformations and the superficial damage values are in good agreement with the experimental observations

  2. Language-learning disabilities: Paradigms for the nineties.

    Science.gov (United States)

    Wiig, E H

    1991-01-01

    We are beginning a decade, during which many traditional paradigms in education, special education, and speech-language pathology will undergo change. Among paradigms considered promising for speech-language pathology in the schools are collaborative language intervention and strategy training for language and communication. This presentation introduces management models for developing a collaborative language intervention process, among them the Deming Management Method for Total Quality (TQ) (Deming 1986). Implementation models for language assessment and IEP planning and multicultural issues are also introduced (Damico and Nye 1990; Secord and Wiig in press). While attention to processes involved in developing and implementing collaborative language intervention is paramount, content should not be neglected. To this end, strategy training for language and communication is introduced as a viable paradigm. Macro- and micro-level process models for strategy training are featured and general issues are discussed (Ellis, Deshler, and Schumaker 1989; Swanson 1989; Wiig 1989).

  3. Trends in global development paradigms and the ramifications in ...

    African Journals Online (AJOL)

    Since the 1950s, Ghana has rolled out a number of development paradigms in a bid to ... the general systems theory and spatial processes of rural–urban migration in ..... The processes embody nodes (countries, regional blocs, and cardinal ... interconnectedness (as in networking including relationships among the nodes).

  4. Long-term reliability of the visual EEG Poffenberger paradigm.

    Science.gov (United States)

    Friedrich, Patrick; Ocklenburg, Sebastian; Mochalski, Lisa; Schlüter, Caroline; Güntürkün, Onur; Genc, Erhan

    2017-07-14

    The Poffenberger paradigm is a simple perception task that is used to estimate the speed of information transfer between the two hemispheres, the so-called interhemispheric transfer time (IHTT). Although the original paradigm is a behavioral task, it can be combined with electroencephalography (EEG) to assess the underlying neurophysiological processes during task execution. While older studies have supported the validity of both paradigms for investigating interhemispheric interactions, their long-term reliability has not been assessed systematically before. The present study aims to fill this gap by determining both internal consistency and long-term test-retest reliability of IHTTs produced by using the two different versions of the Poffenberger paradigm in a sample of 26 healthy subjects. The results show high reliability for the EEG Poffenberger paradigm. In contrast, reliability measures for the behavioral Poffenberger paradigm were low. Hence, our results indicate that electrophysiological measures of interhemispheric transfer are more reliable than behavioral measures; the later should be used with caution in research investigating inter-individual differences of neurocognitive measures. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Multi-parameter crack tip stress state description for estimation of fracture process zone extent in silicate composite WST specimens

    Czech Academy of Sciences Publication Activity Database

    Veselý, V.; Sobek, J.; Šestáková, L.; Frantík, P.; Seitl, Stanislav

    2013-01-01

    Roč. 7, č. 25 (2013), s. 69-78 ISSN 1971-8993 R&D Projects: GA ČR(CZ) GAP104/11/0833; GA ČR(CZ) GAP105/11/1551 Institutional support: RVO:68081723 Keywords : Near-crack tip fields * Williams series * higher-order terms * stress field approximation * wedge splitting test * fracture process zone Subject RIV: JL - Materials Fatigue, Friction Mechanics

  6. Particularities of infectious process in children under the circumstances of prolonged acid stress after the radiation influence

    International Nuclear Information System (INIS)

    Buchneva, N.N.; Baleva, L.S.; Sipyagina, A.E.; Klembovskij, A.I.; Karakhan, N.M.; Safronova, O.N.; Shcherbo, S.N.; Viduta, O.D.; Makarov, V.B.

    1999-01-01

    Problems of origin and course of chlamydia and herpes-virus infection in the children with chronic somatic pathology and different degree of radiation-oxidation stress under conditions of constant residence at the contaminated territory due to the Chernobyl accident (Bryansk Oblast', contamination level was 137 Cs = 9.37-19.73 Ci/km 2 ). Criteria for assessing the infection process and possibilities of identifying it's active form are stated [ru

  7. Optimal brain network synchrony visualization: application in an alcoholism paradigm.

    Science.gov (United States)

    Sakkalis, Vangelis; Tsiaras, Vassilis; Zervakis, Michalis; Tollis, Ioannis

    2007-01-01

    Although Electroencephalographic (EEG) signal synchronization studies have been a topic of increasing interest lately, there is no similar effort in the visualization of such measures. In this direction a graph-theoretic approach devised to study and stress the coupling dynamics of task-performing dynamical networks is proposed. Both linear and nonlinear interdependence measures are investigated in an alcoholism paradigm during mental rehearsal of pictures, which is known to reflect synchronization impairment. More specifically, the widely used magnitude squared coherence; phase synchronization and a robust nonlinear state-space generalized synchronization assessment method are investigated. This paper mostly focuses on a signal-based technique of selecting the optimal visualization threshold using surrogate datasets to correctly identify the most significant correlation patterns. Furthermore, a graph statistical parameter attempts to capture and quantify collective motifs present in the functional brain network. The results are in accordance with previous psychophysiology studies suggesting that an alcoholic subject has impaired synchronization of brain activity and loss of lateralization during the rehearsal process, most prominently in alpha (8-12 Hz) band, as compared to a control subject. Lower beta (13-30 Hz) synchronization was also evident in the alcoholic subject.

  8. Molecular Mechanisms and New Treatment Paradigm for Atrial Fibrillation.

    Science.gov (United States)

    Sirish, Padmini; Li, Ning; Timofeyev, Valeriy; Zhang, Xiao-Dong; Wang, Lianguo; Yang, Jun; Lee, Kin Sing Stephen; Bettaieb, Ahmed; Ma, Sin Mei; Lee, Jeong Han; Su, Demetria; Lau, Victor C; Myers, Richard E; Lieu, Deborah K; López, Javier E; Young, J Nilas; Yamoah, Ebenezer N; Haj, Fawaz; Ripplinger, Crystal M; Hammock, Bruce D; Chiamvimonvat, Nipavan

    2016-05-01

    Atrial fibrillation represents the most common arrhythmia leading to increased morbidity and mortality, yet, current treatment strategies have proven inadequate. Conventional treatment with antiarrhythmic drugs carries a high risk for proarrhythmias. The soluble epoxide hydrolase enzyme catalyzes the hydrolysis of anti-inflammatory epoxy fatty acids, including epoxyeicosatrienoic acids from arachidonic acid to the corresponding proinflammatory diols. Therefore, the goal of the study is to directly test the hypotheses that inhibition of the soluble epoxide hydrolase enzyme can result in an increase in the levels of epoxyeicosatrienoic acids, leading to the attenuation of atrial structural and electric remodeling and the prevention of atrial fibrillation. For the first time, we report findings that inhibition of soluble epoxide hydrolase reduces inflammation, oxidative stress, atrial structural, and electric remodeling. Treatment with soluble epoxide hydrolase inhibitor significantly reduces the activation of key inflammatory signaling molecules, including the transcription factor nuclear factor κ-light-chain-enhancer, mitogen-activated protein kinase, and transforming growth factor-β. This study provides insights into the underlying molecular mechanisms leading to atrial fibrillation by inflammation and represents a paradigm shift from conventional antiarrhythmic drugs, which block downstream events to a novel upstream therapeutic target by counteracting the inflammatory processes in atrial fibrillation. © 2016 American Heart Association, Inc.

  9. A comparative evaluation of acute stress and corticosterone on the process of learning and emotional memory in rat

    Directory of Open Access Journals (Sweden)

    Vafaei AA

    2009-07-01

    Full Text Available "nBackground: Previous studies suggested that stressful events that release Glucocorticoid from adrenal cortex and also injection of agonists of glucocorticoids receptors probably affect emotional learning and memory process and modulate them. The aim of this study was to determine the effects of acute stress and systemic injection of Corticosterone (as agonist of glucocorticoid receptors on acquisition (ACQ, consolidation (CONS and retrieval (RET of emotional memory in rat. "nMethods: In this experimental study we used 180 male Wistar rats (220-250. At the first rats was training in one trial inhibitory avoidance task. On the retention test given 48 h after training, the latency to re-enter the dark compartment of the apparatus (Step-through latency, STL and the time spent in light chamber (TLC were recorded during 10 min test. Intraperitoneal corticosterone in doses of 0.5, 1 and 3mg/kg injected 30min before, immediately after instruction and 30min before retrieval test. Also some groups received 10min stressful stimulation by restrainer at the same time. At the end locomotor's activity was measured for all animals. "nResults: The data indicated that administration of corticosterone 30min before ACQ (1mg/kg, and immediately after CONS (1, 3mg/kg enhance and 30min before RET (1, 3mg/kg impair emotional memory (p<0.05. Acute stress impaired emotional memory in all phases (p<0.05. Also acute stress and injection of Corticosterone have not significantly affect motor activity.  "nConclusions: These findings show that Glucocorticoid receptors in activation dependently plays an important role in modulation of emotional spatial memory processes (ACQ, CONS and RET in new information for emotional events and these effects varies in different phases.

  10. [Occupational stress and assessment of human resources in health: from assessment to the changing process].

    Science.gov (United States)

    Ragazzoni, P; Tangolo, D; Zotti, A M

    2004-01-01

    Health professionals are at risk for occupational stress, as confirmed by diverse sources including the Italian legislative decree, D.L. 626/94, the Health Promoting Hospital of the World Health Organization, and the Ottawa Charter. The aim of this study was to analyze quantitatively and qualitatively the principal sources of stress in the work environment and the resources, both individual and organizational, that health professionals feel they possess to cope with it. The instruments utilized for the first quantitative phase were: the Maslach Burn out Inventory, the Job Content Questionnaire, Coping Inventory for Stressful Situation and Team Climate Inventory. The study population consisted of 224 subjects belonging to the nursing profession (nurses-in-charge of ward, specialized and general nurses), working in the community and in hospital. The results show medium levels of burn out, and coping strategies that are primarily oriented towards a direct solution of the stressful situation. Vision is a critical aspect, ie. a clear perception of institutional choices and goals is lacking. The administration and analysis of the questionnaires was followed by a second phase in which, by means of the focus group methodology, the results were qualitatively analyzed and the health professionals stimulated to an active and pro-positive approach in the search for solutions to the critical situations.

  11. Fueling a Third Paradigm of Education: The Pedagogical Implications of Digital, Social and Mobile Media

    Science.gov (United States)

    Pavlik, John V.

    2015-01-01

    Emerging technologies are fueling a third paradigm of education. Digital, networked and mobile media are enabling a disruptive transformation of the teaching and learning process. This paradigm challenges traditional assumptions that have long characterized educational institutions and processes, including basic notions of space, time, content,…

  12. Pavlovian-to-instrumental transfer: A new paradigm to assess pathological mechanisms with regard to the use of Internet applications.

    Science.gov (United States)

    Vogel, Verena; Kollei, Ines; Duka, Theodora; Snagowski, Jan; Brand, Matthias; Müller, Astrid; Loeber, Sabine

    2018-07-16

    At present, there is a considerable lack of human studies that investigated the impact of conditioned cues on instrumental responding although these processes are considered as core mechanisms contributing to the development and maintenance of addictive behaviours. No studies are available that assessed these processes with regard to Internet gaming or Internet shopping applications. We thus developed a Pavlovian-to-instrumental transfer (PIT)-Paradigm implementing appetitive stimuli related to Internet gaming and Internet shopping applications and investigated whether an outcome-specific PIT-Effect is observed. In addition, we assessed whether the problematic use of gaming or shopping applications, personality traits and stress would affect the acquisition of knowledge of the experimental contingencies during Pavlovian training and the impact of conditioned stimuli on instrumental responding. A PIT-Paradigm, screenings for Internet gaming disorder and Internet shopping disorder (s-IAT), and questionnaires on personality traits (NEO-FFI, BIS-15) and perceived stress (PSQ20) were administered to sixty-six participants. The PIT-Paradigm demonstrated the effects of stimuli conditioned to rewards related to Internet gaming and Internet shopping applications on instrumental responding to obtain such rewards. Findings also indicated that severity of problematic Internet gaming, but not Internet shopping, contributed to the acquisition of knowledge of the experimental contingencies. Stress, extraversion, neuroticism and gender emerged as further predictors. The strength of expectancy of the different reinforcers affected the 'gaming PIT'-Effect; however, none of the variables assessed in the present study showed any effect on the 'shopping PIT'-Effect. Future studies including participants with pathological use patterns that can be classified as internet use disorder are warranted to extend these findings. Copyright © 2018 Elsevier B.V. All rights reserved.

  13. Policy paradigms, transnationalism, and domestic politics

    National Research Council Canada - National Science Library

    Skogstad, Grace Darlene

    2011-01-01

    Policy Paradigms, Transnationalism, and Domestic Politics offers a variety of perspectives on the development of policy paradigms -- the ideas that structure thinking about what can and should be done in a policy domain...

  14. Bias-stress characterization of solution-processed organic field-effect transistor based on highly ordered liquid crystals

    Science.gov (United States)

    Kunii, M.; Iino, H.; Hanna, J.

    2017-06-01

    Bias-stress effects in solution-processed, 2-decyl-7-phenyl-[1]benzothieno[3,2-b][1]benzothiophene (Ph-BTBT-10) field effect transistors (FETs) are studied under negative and positive direct current bias. The bottom gate, bottom contact polycrystalline Ph-BTBT-10 FET with a hybrid gate dielectric of polystyrene and SiO2 shows high field effect mobility as well as a steep subthreshold slope when fabricated with a highly ordered smectic E liquid crystalline (SmE) film as a precursor. Negative gate bias-stress causes negative threshold voltage shift (ΔVth) for Ph-BTBT-10 FET in ambient air, but ΔVth rapidly decreases as the gate bias decreases and approaches to near zero when the gate bias goes down to 9 V in amplitude. In contrast, positive gate bias-stress causes negligible ΔVth even with a relatively high bias voltage. These results conclude that Ph-BTBT-10 FET has excellent bias-stress stability in ambient air in the range of low to moderate operating voltages.

  15. SCHOOL ECONOMY IN THE INVENTING EDUCATION PARADIGM

    Directory of Open Access Journals (Sweden)

    Anatoliy Alexandrovich Lepeshev

    2018-01-01

    Full Text Available Requirements applied to specialists for working in the sixth wave of innovation, i.e. Industry 4.0, determines the necessity of education system improvement concerning training solution and, as a result, creation of inventive ideas. Today in our country this process is stimulated by various competitions, including financing for the implementation of results. In training programs knowledge approach still prevails. The corresponding methods, along with stimulation, are included into educational programs in leading foreign educational institutions, mostly at universities. If in previous decades mostly divergent methods were studied (morphological analysis, the focal objects method, synectics, etc., then now the leading place is taken by theory of inventive problem solving – TRIZ created in the former USSR by G.S. Altshuller in connection with the increasing leading corporations requirement for specialists in TRIZ. This fact gives Russia essential competitive advantages in the innovative way of development. For effective use of this advantage it is important to form the TRIZ-based innovative thinking beginning from school days. For this purpose authors developed new methods in TRIZ-pedagogics, uniting metasubject results (in higher education institutions – competences into the system of innovative thinking. As a result, both educational and economic effects are achieved: the intellectual property created in educational process. For schools it is the possibility of significant improvement of financing causing importance of new mechanisms of intellectual property fixation, protection and implementation. Recommendations about creation of such system are provided in the article. Purpose Defining the opportunities and ways of improving economic effectiveness of educational activities in the paradigm of inventive education. Tasks: – analysis of school education institutions experience in implementation of approaches preceding the inventing education

  16. Three Paradigms of Social Assistance

    Directory of Open Access Journals (Sweden)

    Pierre-Marc Daigneault

    2014-11-01

    Full Text Available “Ideas,” which are defined as the normative and cognitive beliefs of actors, are fundamental to a full understanding of the welfare state and, in particular, of social assistance. However, policy ideas have been neglected in most typologies of social assistance regimes. Based on a selective review of the literature, this article proposes a brief but systematic analysis of policy paradigms in the field of social assistance. Three ideal types that emphasize the ideational dimension of social assistance are analyzed, namely, the entitlement, workfare, and activation paradigms. The value of the typology lies in its utility for characterizing the ideational orientation of social assistance regimes. Specifically, the typology provides a yardstick for measuring the ideas of policy actors with respect to social assistance and can facilitate the conduct of case studies, comparative research, and causal analyses on this policy sector.

  17. Exploring Paradigms of Crime Reduction

    DEFF Research Database (Denmark)

    Soothill, Keith; Christoffersen, Mogens N.; Hussain, Azhar

    2010-01-01

    Using Danish registers for a 1980 birth cohort of 29,944 males with parental information and following up these cases for 25 years, the study considers four paradigms of crime reduction (parental child rearing, structural factors around adolescence, locality and individual resources). Focusing on...... have more widespread benefits, but the assumed causal links need to be further explored. The use of population registers, under controlled conditions, provides an important window on criminal careers....

  18. Storytelling, advertising and paradigm fusion

    OpenAIRE

    Anderson, David

    2012-01-01

    'The art of storytelling in the modern age is fundamentally important. So, how we create stories for a screen-based culture is vitally important to master' (Hegarty, 2011, p.96-97). This paper explores the potential benefit of fusing aspects of creative writing with the curriculum of the BA Creative Advertising programme (BACAP) at Leeds College of Art (LCA) in order to address Sir John Hegarty's assertion. In particular it will focus on the characteristics of the 'classical paradigms' us...

  19. Mandarin functional MRI Language paradigms

    OpenAIRE

    Ci, He; van Graan, Andre; Gonz?lvez, Gloria; Thompson, Pamela; Hill, Andrea; Duncan, John S.

    2016-01-01

    Abstract Objective The objective of this study was to implement convenient, fast, and accurate Mandarin task paradigms for functional MRI, and to locate the Chinese language functional areas in frontal and temporal lobes. Materials and Methods Nineteen healthy Chinese volunteers participated in this study, which utilized a block design with four language tasks: auditory naming (AN), picture naming (PN), verbal fluency?character (VFC), and verbal fluency?letter (VFL). All functional images wer...

  20. Convergent paradigms for visual neuroscience and dissociative identity disorder.

    Science.gov (United States)

    Manning, Mark L; Manning, Rana L

    2009-01-01

    Although dissociative identity disorder, a condition in which multiple individuals appear to inhabit a single body, is a recognized psychiatric disorder, patients may yet encounter health professionals who declare that they simply "do not believe in multiple personalities." This article explores the proposal that resistance to the disorder represents a failure to apply an appropriate paradigm from which the disorder should be interpreted. Trauma and sociocognitive explanations of dissociative identity disorder are contrasted. The trauma hypothesis is further differentiated into paradigms in which trauma affects a defense mechanism, and one in which trauma serves to inhibit the normal integration sequence of parallel processes of the self in childhood. This latter paradigm is shown to be broadly consistent with current models of cortical processing in another system, the cortical visual system.

  1. Embracing the new paradigm of assessment in residency training

    DEFF Research Database (Denmark)

    Ringsted, C; Østergaard, D; Scherpbier, A

    2003-01-01

    Assessment of clinical competence is facing a paradigm shift in more than one sense. The shift relates to test content, which increasingly covers a broader spectrum of competences than mere medical expertise, and to test methods, with an increasing focus on testing performance in realistic settings....... Also there is a shift in the concept of assessment in that instruction and assessment are no longer seen as being separate in time and purpose, but as integral parts of the learning process. The nature of the new paradigm for assessment is well described but the challenge to programme directors...... is to specify the evaluation situations and develop appropriate methods. This paper describes the intrinsic rational validation process in outlining an assessment programme for first-year anaesthesiology residency training according to the new paradigm. The applicability to other residency programmes and higher...

  2. Atmospheric plasma processes for microbial inactivation: food applications and stress response in Listeria monocytogenes

    OpenAIRE

    Gozzi, Giorgia

    2015-01-01

    This PhD thesis is focused on cold atmospheric plasma treatments (GP) for microbial inactivation in food applications. In fact GP represents a promising emerging technology alternative to the traditional methods for the decontamination of foods. The objectives of this work were to evaluate: - the effects of GP treatments on microbial inactivation in model systems and in real foods; - the stress response in L. monocytogenes following exposure to different GP treatments. As far as t...

  3. Supportability of a High-Yield-Stress Slurry in a New Stereolithography-Based Ceramic Fabrication Process

    Science.gov (United States)

    He, Li; Song, Xuan

    2018-03-01

    In recent years, ceramic fabrication using stereolithography (SLA) has gained in popularity because of its high accuracy and density that can be achieved in the final part of production. One of the key challenges in ceramic SLA is that support structures are required for building overhanging features, whereas removing these support structures without damaging the components is difficult. In this research, a suspension-enclosing projection-stereolithography process is developed to overcome this challenge. This process uses a high-yield-stress ceramic slurry as the feedstock material and exploits the elastic force of the material to support overhanging features without the need for building additional support structures. Ceramic slurries with different solid loadings are studied to identify the rheological properties most suitable for supporting overhanging features. An analytical model of a double doctor-blade module is established to obtain uniform and thin recoating layers from a high-yield-stress slurry. Several test cases highlight the feasibility of using a high-yield-stress slurry to support overhanging features in SLA.

  4. Molecular Chaperones of Leishmania: Central Players in Many Stress-Related and -Unrelated Physiological Processes

    Directory of Open Access Journals (Sweden)

    Jose M. Requena

    2015-01-01

    Full Text Available Molecular chaperones are key components in the maintenance of cellular homeostasis and survival, not only during stress but also under optimal growth conditions. Folding of nascent polypeptides is supported by molecular chaperones, which avoid the formation of aggregates by preventing nonspecific interactions and aid, when necessary, the translocation of proteins to their correct intracellular localization. Furthermore, when proteins are damaged, molecular chaperones may also facilitate their refolding or, in the case of irreparable proteins, their removal by the protein degradation machinery of the cell. During their digenetic lifestyle, Leishmania parasites encounter and adapt to harsh environmental conditions, such as nutrient deficiency, hypoxia, oxidative stress, changing pH, and shifts in temperature; all these factors are potential triggers of cellular stress. We summarize here our current knowledge on the main types of molecular chaperones in Leishmania and their functions. Among them, heat shock proteins play important roles in adaptation and survival of this parasite against temperature changes associated with its passage from the poikilothermic insect vector to the warm-blooded vertebrate host. The study of structural features and the function of chaperones in Leishmania biology is providing opportunities (and challenges for drug discovery and improving of current treatments against leishmaniasis.

  5. Molecular Chaperones of Leishmania: Central Players in Many Stress-Related and -Unrelated Physiological Processes

    Science.gov (United States)

    Requena, Jose M.; Montalvo, Ana M.; Fraga, Jorge

    2015-01-01

    Molecular chaperones are key components in the maintenance of cellular homeostasis and survival, not only during stress but also under optimal growth conditions. Folding of nascent polypeptides is supported by molecular chaperones, which avoid the formation of aggregates by preventing nonspecific interactions and aid, when necessary, the translocation of proteins to their correct intracellular localization. Furthermore, when proteins are damaged, molecular chaperones may also facilitate their refolding or, in the case of irreparable proteins, their removal by the protein degradation machinery of the cell. During their digenetic lifestyle, Leishmania parasites encounter and adapt to harsh environmental conditions, such as nutrient deficiency, hypoxia, oxidative stress, changing pH, and shifts in temperature; all these factors are potential triggers of cellular stress. We summarize here our current knowledge on the main types of molecular chaperones in Leishmania and their functions. Among them, heat shock proteins play important roles in adaptation and survival of this parasite against temperature changes associated with its passage from the poikilothermic insect vector to the warm-blooded vertebrate host. The study of structural features and the function of chaperones in Leishmania biology is providing opportunities (and challenges) for drug discovery and improving of current treatments against leishmaniasis. PMID:26167482

  6. Modeling and Parameter Optimization for Surface Roughness and Residual Stress in Dry Turning Process

    Directory of Open Access Journals (Sweden)

    M. H. El-Axir

    2017-10-01

    Full Text Available The influence of some turning variables and tool overhang on surface roughness parameters and residual stress induced due to machining 6061-T6 aluminum alloy is investigated in this paper. Four input parameters (cutting speed, feed rate, depth of cut and tool overhang are considered. Tests are carried out by precision turning operation on a lathe. Design of experiment techniques, i.e. response surface methodology (RSM and Taguchi's technique have been used to accomplish the objective of the experimental study. Surface roughness parameters are measured using a portable surface roughness device while residual stresses are measured employing deflection-etching technique using electrochemical analysis. The results obtained reveal that feed and rotational speed play significant role in determining the average surface roughness. Furthermore, the depth of cut and tool overhang are less significant parameters, whereas tool overhang interacts with feed rate. The best result of surface roughness was obtained using low or medium values of overhang with low speed and /or feed rate. Minimum maximum tensile residual stress can be obtained with a combination of tool overhang of 37 mm with very low depth of cut, low rotational speed and feed rate of 0.188 mm/rev.

  7. Group Reality Therapy in Addicts Rehabilitation Process to Reduce Depression, Anxiety and Stress

    Directory of Open Access Journals (Sweden)

    Omid Massah

    2015-03-01

    Full Text Available Objectives: Substance abuse is one of the most outstanding socio-psychological hazards that can easily wreck one’s personal, family and social life. Reality Therapy is a type of Cognitive rehabilitation (known as psychosocial rehabilitation, and the application of this method in the treatment of different disorders has recently been the topic of research. The objective of this study was to examine the effectiveness of group reality therapy on the reduction of stress, anxiety and depression in addicts. Methods: A quasi-experimental study of pretest-posttest design, with a control group was conducted. The study population consisted of all addicts attending Tehran’s ‘Neda’ Rehab Clinic. First, the DASS-21 questionnaire was administered and then 40 people were selected from those who had scored average and higher. They were then randomly assigned to two test and control groups of 20 each. Analysis of co-variance was used to analyze the data, with which pretest scores were controlled, and the effect of the independent variable on posttest scores was evaluated. Results: Following the intervention, there were significant decreases in the mean scores of all three variables, i.e. stress, anxiety and depression in the test group (P<0.05. Discussion: Psychosocial rehabilitation based on reality therapy can be considered as an effective method for reducing stress, anxiety and depression in addicts and also as an adjunctive therapy in treating other ailments.

  8. Conventionality of the quality of studies : context of the expression of educational paradigm

    OpenAIRE

    Jucevičienė, Palmira; Valuckienė, Jūratė

    2008-01-01

    The article addresses the following research questions: what influences the conception of the quality of studies as well as assessment in the context of educational paradigm? What are the main quality assessment criteria for studies, based on different educational paradigm? How is the educational paradigm, substantiating the study programme, envisaged in the expression of attitude of students when assessing the quality of process of studies? The aim of the article is to reveal the conventiona...

  9. Diffusion-bonded 16MND5-Inconel 690-316LN junction: elaboration and process residual stresses modeling

    International Nuclear Information System (INIS)

    Martinez, Michael

    1999-01-01

    The objective of this research thesis is, on the one hand, to elaborate and to characterise a bonded junction of 16MND5 and 316LN steels, and, on the other hand, to develop a simulation tool for the prediction of microstructures after bonding, as well as residual stresses related to this process. The author first reports the study of the use of diffusion bonding by hot isostatic pressing (HIP diffusion bonding) for the bonding of 16MND5 (steel used in French PWR vessel) and 316LN (austenitic stainless steel used in piping), in order to obtain junctions adapted to a use within PWRs. In this case, the use of an Inconel insert material appeared to be necessary to avoid stainless steel carburization. Thus, inserts in Inconel 600 and 690 have been tested. The objective has then been to develop a realistic calculation of residual stresses in this assembly. These stresses are stimulated by quenching. The author notably studied the simulation of temperature dependent phase transformations, and stress induced phase transformations. An existing model is validated and applied to HIP and quenching cycles. The last part reports the calculation of residual stresses by simulation of the mechanical response of the three-component material cooled from 900 C to room temperature and thus submitted to a loading of thermal origin (dilatation) and metallurgical origin (phase transformations in the 16MND5). The effect of carbon diffusion on mechanical properties has also been taken into account. The author discusses problems faced by existing models, and explains the choice of conventional macro-mechanical models. The three materials are supposed to have a plastic-viscoplastic behaviour with isotropic and kinematic strain hardening, and this behaviour is identified between 20 and 900 C [fr

  10. On the diffusion process of irradiation-induced point defects in the stress field of a moving dislocation

    International Nuclear Information System (INIS)

    Steinbach, E.

    1987-01-01

    The cellular model of a dislocation is used for an investigation of the time-dependent diffusion process of irradiation-induced point defects interacting with the stress field of a moving dislocation. An analytic solution is given taking into account the elastic interaction due to the first-order size effect and the stress-induced interaction, the kinematic interaction due to the dislocation motion as well as the presence of secondary neutral sinks. The results for the space and time-dependent point defect concentration, represented in terms of Mathieu-Bessel and Mathieu-Hankel functions, emphasize the influence of the parameters which have been taken into consideration. Proceeding from these solutions, formulae for the diffusion flux reaching unit length of the dislocation, which plays an important role with regard to void swelling and irradiation-induced creep, are derived

  11. About hypotheses and paradigms: exploring the Discreetness-Chance Paradigm.

    Science.gov (United States)

    Kaellis, Eugene

    2006-01-01

    Hypotheses generally conform to paradigms which, over time, change, usually tardily, after they have become increasingly difficult to sustain under the impact of non-conforming evidence and alternative hypotheses, but more important, when they no longer are comfortably ensconced in the surrounding social-economic-political-cultural milieu. It is asserted that this milieu is the most important factor in shaping scientific theorizing. Some examples are cited: the rejection of the evidence that the world orbits around the sun (suspected by Pythagoras) in favor of centuries-long firm adherence to the Ptolemaic geocentric system; the early acceptance of Natural Selection in spite of its tautological essence and only conjectural supporting evidence, because it justified contemporaneous social-political ideologies as typified by, e.g., Spencer and Malthus. Economic, social, and cultural factors are cited as providing the ground, i.e., ideational substrate, for what is cited as the Discreetness-Chance Paradigm (DCP), that has increasingly dominated physics, biology, and medicine for over a century and which invokes small, discrete packets of energy/matter (quanta, genes, microorganisms, aberrant cells) functioning within an environment of statistical, not determined, causality. There is speculation on a possible paradigmatic shift from the DCP, which has fostered the proliferation, parallel with ("splitting") taxonomy, of alleged individual disease entities, their diagnoses, and, when available, their specific remedies, something particularly prominent in, e.g., psychiatry's Diagnostic and Statistical Manual, a codified compendium of alleged mental and behavioral disorders, but evident in any textbook of diagnosis and treatment of physical ailments. This presumed paradigm shift may be reflected in Western medicine, presently increasingly empirical and atomized, towards a growing acceptance of a more generalized, subject-oriented, approach to health and disease, a non

  12. Thermal stress during RTP processes and its possible effect on the light induced degradation in Cz-Si wafers

    Science.gov (United States)

    Kouhlane, Yacine; Bouhafs, Djoudi; Khelifati, Nabil; Guenda, Abdelkader; Demagh, Nacer-Eddine; Demagh, Assia; Pfeiffer, Pierre; Mezghiche, Salah; Hetatache, Warda; Derkaoui, Fahima; Nasraoui, Chahinez; Nwadiaru, Ogechi Vivian

    2018-04-01

    In this study, the carrier lifetime variation of p-type boron-doped Czochralski silicon (Cz-Si) wafers was investigated after a direct rapid thermal processing (RTP). Two wafers were passivated by silicon nitride (SiNx:H) layers, deposited by a PECVD system on both surfaces. Then the wafers were subjected to an RTP cycle at a peak temperature of 620 °C. The first wafer was protected (PW) from the direct radiative heating of the RTP furnace by placing the wafer between two as-cut Cz-Si shield wafers during the heat processing. The second wafer was not protected (NPW) and followed the same RTP cycle procedure. The carrier lifetime τ eff was measured using the QSSPC technique before and after illumination for 5 h duration at 0.5 suns. The immediate results of the measured lifetime (τ RTP ) after the RTP process have shown a regeneration in the lifetime of the two wafers with the PW wafer exhibiting an important enhancement in τ RTP as compared to the NPW wafer. The QSSPC measurements have indicated a good stable lifetime (τ d ) and a weak degradation effect was observed in the case of the PW wafer as compared to their initial lifetime value. Interferometry technique analyses have shown an enhancement in the surface roughness for the NPW wafer as compared to the protected one. Additionally, to improve the correlation between the RTP heat radiation stress and the carrier lifetime behavior, a simulation of the thermal stress and temperature profile using the finite element method on the wafers surface at RTP peak temperature of 620 °C was performed. The results confirm the reduction of the thermal stress with less heat losses for the PW wafer. Finally, the proposed method can lead to improving the lifetime of wafers by an RTP process at minimum energy costs.

  13. X-ray microbeam measurements of long-range internal stresses in commercial-purity aluminum processed by multiple passes of equal-channel angular pressing

    International Nuclear Information System (INIS)

    Phan, Thien Q.; Lee, I-Fang; Levine, Lyle E.; Tischler, Jonathan Z.; Huang, Yi; Fox, Alan G.; Langdon, Terence G.; Kassner, Michael E.

    2014-01-01

    X-ray microbeam diffraction was used to measure long-range internal stresses (LRISs) in the grain/subgrain interiors of commercial-purity aluminum processed by equal-channel angular pressing for up to eight passes. The LRIS values at +4.9° off the axial (pressing) direction show only a slight increase with increasing numbers of passes. The normalized stress remains approximately constant at ∼0.10 of the flow stress

  14. Wind power, policy learning and paradigm change

    International Nuclear Information System (INIS)

    Szarka, Joseph

    2006-01-01

    The aim of this article is to study how policy learning has led to new understandings of ways to support renewable energies, based on experience in the wind power sector. Drawing on analysis of the literature and informed by field-work in the wind power sector in Denmark, France and the UK, it explores the extent to which policy learning over the medium term has brought us closer to models that integrate economic, environmental and societal desiderata into renewables policy in a manner congruent with the sustainable development aspirations espoused by the European Union and its constituent states. It contributes to policy theory development by arguing in favour of a new policy paradigm that reaches beyond measures to increase production capacity per se to embrace both the institutional dynamics of innovation processes and the fostering of societal engagement in implementation processes

  15. Three paradigms for the analysis of corruption

    Directory of Open Access Journals (Sweden)

    Alberto Vannucci

    2015-10-01

    Full Text Available In the last decades a growing awareness emerged of the relevance of corruption as an hidden factor which may negatively affect political and economic decision-making processes. In spite of a lively scientific debate there is no general consensus on a commonly accepted definition of what corruption is.The A. distinguishes three main paradigms, focusing on different (though not irreconcilable variables.The first is the economic paradigm, which usually takes the principal-agent model of corruption as its founding pillar. In this paradigm corruption is considered the outcome of rational individual choices, and its spread within a certain organization is influenced by the factors defining the structure of expected costs and rewards.A second approach – the cultural paradigm – looks at the differences in cultural traditions, social norms and interiorized values which shape individuals’ moral preferences and consideration of his social and institutional role. These are a leading forces that can push a corrupt public or private agent (not to violate legal norms.A third neo-institutional approach considers also mechanisms which allow the internal regulation of social interactions within corrupt networks, and their effects on individuals’ beliefs and preferences. Though the corrupt agreements cannot be enforced with legal sanctions, several informal, non-written rules, contractual provisos and conventions may regulate the corrupt exchange between agent and corruptor.The A. underlines that corruption is the outcome of a multitude of individual and collective choices which change public opinion towards corruption and its diffusion throughout the state, markets and civil society. There is no univocal recipe to deal with anti-bribery measures, since corruption is a complex and multifaceted phenomenon.Reforms aimed at dismantling systemic corruption have to be finely tuned against its hidden governance structures, i.e. its internal regulation of

  16. The maturing of the quality improvement paradigm in the SEL

    Science.gov (United States)

    Basili, Victor R.

    1993-01-01

    The Software Engineering Laboratory uses a paradigm for improving the software process and product, called the quality improvement paradigm. This paradigm has evolved over the past 18 years, along with our software development processes and product. Since 1976, when we first began the SEL, we have learned a great deal about improving the software process and product, making a great many mistakes along the way. Quality improvement paradigm, as it is currently defined, can be broken up into six steps: characterize the current project and its environment with respect to the appropriate models and metrics; set the quantifiable goals for successful project performance and improvement; choose the appropriate process model and supporting methods and tools for this project; execute the processes, construct the products, and collect, validate, and analyze the data to provide real-time feedback for corrective action; analyze the data to evaluate the current practices, determine problems, record findings, and make recommendations for future project improvements; and package the experience gained in the form of updated and refined models and other forms of structured knowledge gained from this and prior projects and save it in an experience base to be reused on future projects.

  17. [Psychological processes of stress management and neuroendocrine regulation in incarcerated adolescent offenders: A pilot study].

    Science.gov (United States)

    Guillod, L; Habersaat, S; Suter, M; Jeanneret, T; Bertoni, C; Stéphan, P; Urben, S

    2018-04-01

    Adolescence is a stressful period where important biological, psychological and social changes occur. Adolescents are particularly vulnerable during this developmental period and can use various strategies to deal with daily stress, such as substance use or externalizing behaviors. In previous studies, stress in adolescents with externalizing behaviors was often linked to ineffective cognitive coping strategies (i.e., constructive thinking) and overlooking the biological aspects involved in stress management such as neuroendocrine regulation. Indeed, repeated activation of the hypothalamic-pituitary-adrenal (HPA) axis in chronic stress situations may have long-term effects on subsequent cortisol regulation and lead to psychological difficulties. It was also shown that basal cortisol levels are lower in adolescents with externalizing behaviors. This study aims to assess the links between constructive thinking and neuroendocrine regulation in adolescent offenders and their association with externalizing symptoms (e.g., aggression, delinquency, psychopathic traits, substance use). Identifying particular biopsychological patterns can help to better understand stress management in youth with externalizing behaviors and to improve clinical treatments. Sixteen adolescent males aged from 12 to 18 years were recruited in an institution for juvenile offenders. Exclusion criteria were insufficient reasoning abilities assessed using the Raven Matrices Test. Regarding psychological dimensions, constructive thinking was assessed through the Constructive thinking inventory (CTI), psychopathic traits through the Youth psychopathic traits inventory (YPI), externalizing behaviors through 30 items (out of 113) and 2 subscales (aggressive behavior and delinquency problems) from the Child behavior checklist-youth self-report (CBCL), and substance use through the Dep-ado. Regarding biological dimensions, cortisol daily secretion and regulation were assessed through saliva samples

  18. Using normalisation process theory to understand barriers and facilitators to implementing mindfulness-based stress reduction for people with multiple sclerosis.

    Science.gov (United States)

    Simpson, Robert; Simpson, Sharon; Wood, Karen; Mercer, Stewart W; Mair, Frances S

    2018-01-01

    Objectives To study barriers and facilitators to implementation of mindfulness-based stress reduction for people with multiple sclerosis. Methods Qualitative interviews were used to explore barriers and facilitators to implementation of mindfulness-based stress reduction, including 33 people with multiple sclerosis, 6 multiple sclerosis clinicians and 2 course instructors. Normalisation process theory provided the underpinning conceptual framework. Data were analysed deductively using normalisation process theory constructs (coherence, cognitive participation, collective action and reflexive monitoring). Results Key barriers included mismatched stakeholder expectations, lack of knowledge about mindfulness-based stress reduction, high levels of comorbidity and disability and skepticism about embedding mindfulness-based stress reduction in routine multiple sclerosis care. Facilitators to implementation included introducing a pre-course orientation session; adaptations to mindfulness-based stress reduction to accommodate comorbidity and disability and participants suggested smaller, shorter classes, shortened practices, exclusion of mindful-walking and more time with peers. Post-mindfulness-based stress reduction booster sessions may be required, and objective and subjective reports of benefit would increase clinician confidence in mindfulness-based stress reduction. Discussion Multiple sclerosis patients and clinicians know little about mindfulness-based stress reduction. Mismatched expectations are a barrier to participation, as is rigid application of mindfulness-based stress reduction in the context of disability. Course adaptations in response to patient needs would facilitate uptake and utilisation. Rendering access to mindfulness-based stress reduction rapid and flexible could facilitate implementation. Embedded outcome assessment is desirable.

  19. Residual stress evaluation and curvature behavior of aluminium 7050 peen forming processed; Avaliacao da tensao residual em aluminio 7050 conformado pelo processo peen forming

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, R.R. de; Lima, N.B., E-mail: rolivier@ipen.b, E-mail: nblima@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Braga, A.P.V.; Goncalves, M., E-mail: anapaola@ipt.b, E-mail: mgoncalves@ipt.b [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil)

    2010-07-01

    Shot peening is a superficial cold work process used to increase the fatigue life evaluated by residual stress measurements. The peen forming process is a variant of the shot peening process, where a curvature in the plate is obtained by the compression of the grains near to the surface. In this paper, the influence of the parameters such as: pressure of shot, ball shot size and thickness of aluminum 7050 samples with respect to residual stress profile and resulting arc height was studied. The evaluation of the residual stress profile was obtained by sin{sup 2} {Psi} method. (author)

  20. Imaging deductive reasoning and the new paradigm

    Science.gov (United States)

    Oaksford, Mike

    2015-01-01

    There has been a great expansion of research into human reasoning at all of Marr’s explanatory levels. There is a tendency for this work to progress within a level largely ignoring the others which can lead to slippage between levels (Chater et al., 2003). It is argued that recent brain imaging research on deductive reasoning—implementational level—has largely ignored the new paradigm in reasoning—computational level (Over, 2009). Consequently, recent imaging results are reviewed with the focus on how they relate to the new paradigm. The imaging results are drawn primarily from a recent meta-analysis by Prado et al. (2011) but further imaging results are also reviewed where relevant. Three main observations are made. First, the main function of the core brain region identified is most likely elaborative, defeasible reasoning not deductive reasoning. Second, the subtraction methodology and the meta-analytic approach may remove all traces of content specific System 1 processes thought to underpin much human reasoning. Third, interpreting the function of the brain regions activated by a task depends on theories of the function that a task engages. When there are multiple interpretations of that function, interpreting what an active brain region is doing is not clear cut. It is concluded that there is a need to more tightly connect brain activation to function, which could be achieved using formalized computational level models and a parametric variation approach. PMID:25774130

  1. A novel attention training paradigm based on operant conditioning of eye gaze: Preliminary findings.

    Science.gov (United States)

    Price, Rebecca B; Greven, Inez M; Siegle, Greg J; Koster, Ernst H W; De Raedt, Rudi

    2016-02-01

    Inability to engage with positive stimuli is a widespread problem associated with negative mood states across many conditions, from low self-esteem to anhedonic depression. Though attention retraining procedures have shown promise as interventions in some clinical populations, novel procedures may be necessary to reliably attenuate chronic negative mood in refractory clinical populations (e.g., clinical depression) through, for example, more active, adaptive learning processes. In addition, a focus on individual difference variables predicting intervention outcome may improve the ability to provide such targeted interventions efficiently. To provide preliminary proof-of-principle, we tested a novel paradigm using operant conditioning to train eye gaze patterns toward happy faces. Thirty-two healthy undergraduates were randomized to receive operant conditioning of eye gaze toward happy faces (train-happy) or neutral faces (train-neutral). At the group level, the train-happy condition attenuated sad mood increases following a stressful task, in comparison to train-neutral. In individual differences analysis, greater physiological reactivity (pupil dilation) in response to happy faces (during an emotional face-search task at baseline) predicted decreased mood reactivity after stress. These Preliminary results suggest that operant conditioning of eye gaze toward happy faces buffers against stress-induced effects on mood, particularly in individuals who show sufficient baseline neural engagement with happy faces. Eye gaze patterns to emotional face arrays may have a causal relationship with mood reactivity. Personalized medicine research in depression may benefit from novel cognitive training paradigms that shape eye gaze patterns through feedback. Baseline neural function (pupil dilation) may be a key mechanism, aiding in iterative refinement of this approach. (c) 2016 APA, all rights reserved).

  2. Alleviating exercise-induced muscular stress using neat and processed bee pollen: oxidative markers, mitochondrial enzymes, and myostatin expression in rats

    Directory of Open Access Journals (Sweden)

    Sameer Ketkar

    2015-09-01

    Conclusion: The study establishes the antioxidant, mitochondrial upregulatory, and myostatin inhibitory effects of both MIMBP and PMIMBP in exercise-induced oxidative stress conditions, suggesting their usefulness in effective management of exercise-induced muscular stress. Further, processing of MIMBP with an edible lipid-surfactant mixture was found to improve the therapeutic efficiency of pollen.

  3. Acute Stress Modulates Feedback Processing in Men and Women : Differential Effects on the Feedback-Related Negativity and Theta and Beta Power

    NARCIS (Netherlands)

    Banis, Stella; Geerligs, Linda; Lorist, Monicque M.; Banis, Hendrika

    2014-01-01

    Sex-specific prevalence rates in mental and physical disorders may be partly explained by sex differences in physiological stress responses. Neural networks that might be involved are those underlying feedback processing. Aim of the present EEG study was to investigate whether acute stress alters

  4. Paradigm for new scientific technology; Shinkagaku gijutsu paradigm

    Energy Technology Data Exchange (ETDEWEB)

    Shindo, Y [National Chemical Lab. for Industry, Tokyo (Japan)

    1995-01-05

    This paper reviews the current status from the standpoint of chemical engineers facing the coming of the 21st century, and surveys the paradigm for new scientific technologies. The criticism is mixed with unique opinions everywhere, such as `departure of students from scientific and engineering faculties is none other than the result of a market principle`, `national burden of trillions of yens should not be spent only under a justice of advancement of the science`, and `the global civilization itself has no other way but to change from the conventional expansive development type of the western country style to the internal development type of the oriental country style`. Values that define the paradigm for new scientific technologies may include such keywords as saturation in technology, baseless expansion of research projects, criticism on science, market principle, and centering human being. It should be looked at seriously that profit from research and development should exceed the cast invested therein in the future, and scientific technologies that serve truly the society should be aimed at. These efforts will result in one of the large pillars that support the future in which creation of new functions is aimed at as a result of structuring the new systems. Trying to overcome the environmental problems is one of them.

  5. Inhibition of nitrate stress corrosion cracking of mild steel in nuclear process wastes

    International Nuclear Information System (INIS)

    Donovan, J.A.

    1975-01-01

    The concentration of hydroxide and nitrite ions necessary to prevent crack growth in A-285-B steel exposed to waste solutions was determined by the systematic testing of solutions within the ranges of hydroxide, nitrate, and nitrite concentrations found in waste tanks. The relative susceptibility to SCC was assumed to be dependent on the concentrations of nitrate, nitrite, and hydroxyl ions; the other components were assumed to have little effect on cracking. All of the tests were done at 97 0 C, with specimens loaded initially to an effective stress intensity of 45 ksi √in. Both the temperature of exposure and the initial stress intensity create conditions more severe than would normally be found in the waste tanks. All specimens were exposed for a minimum of 1000 hours. Results showed that the aggressiveness of the solutions increased with increasing nitrate ion concentration. For example, cracks grew in 5M NO 3 - + 0.3M NO 2 - , but not in 1.5M NO 3 - + 0.3M NO 2 - . Also, the solutions causing crack growth within the range of compositions found in the waste tank were concentrated in the high nitrate--low nitrite, hydroxyl ion region. Most of the results were obtained with solutions containing 5M NO 3 - and various amounts of nitrite and hydroxyl ion concentrations. (U.S.)

  6. Potential of plant polyphenols to combat oxidative stress and inflammatory processes in farm animals.

    Science.gov (United States)

    Gessner, D K; Ringseis, R; Eder, K

    2017-08-01

    Polyphenols are secondary plant metabolites which have been shown to exert antioxidative and antiinflamma tory effects in cell culture, rodent and human studies. Based on the fact that conditions of oxidative stress and inflammation are highly relevant in farm animals, polyphenols are considered as promising feed additives in the nutrition of farm animals. However, in contrast to many studies existing with model animals and humans, potential antioxidative and antiinflammatory effects of polyphenols have been less investigated in farm animals so far. This review aims to give an overview about potential antioxidative and antiinflammatory effects in farm animals. The first part of the review highlights the occurrence and the consequences of oxidative stress and inflammation on animal health and performance. The second part of the review deals with bioavailability and metabolism of polyphenols in farm animals. The third and main part of the review presents an overview of the findings from studies which investigated the effects of polyphenols of various plant sources in pigs, poultry and cattle, with particular consideration of effects on the antioxidant system and inflammation. Journal of Animal Physiology and Animal Nutrition © 2016 Blackwell Verlag GmbH.

  7. HPA-axis stress reactivity in youth depression: evidence of impaired regulatory processes in depressed boys.

    Science.gov (United States)

    Lopez-Duran, Nestor L; McGinnis, Ellen; Kuhlman, Kate; Geiss, Elisa; Vargas, Ivan; Mayer, Stefanie

    2015-01-01

    Given the link between youth depression and stress exposure, efforts to identify related biomarkers have involved examinations of stress regulation systems, including the hypothalamic-pituitary-adrenal (HPA) axis. Despite these vast efforts, the underlying mechanisms at play, as well as factors that may explain heterogeneity of past findings, are not well understood. In this study, we simultaneously examined separate components of the HPA-axis response (e.g. activation intensity, peak levels, recovery) to the Socially Evaluated Cold-Pressor Test in a targeted sample of 115 youth (age 9-16), recruited to overrepresent youth with elevated symptoms of depression. Among youth who displayed a cortisol response to the task, depression symptoms were associated with higher peak responses but not greater rate of activation or recovery in boys only. Among those who did not respond to the task, depression symptoms were associated with greater cortisol levels throughout the visit in boys and girls. Results suggest that depression symptoms are associated with a more prolonged activation of the axis and impaired recovery to psychosocial stressors primarily in boys. We discussed two potential mechanistic explanations of the link between depression symptoms and the duration of activation: (1) inhibitory shift (i.e. point at which the ratio of inhibitory and excitatory input into the axis shifts from greater excitatory to greater inhibitory input) or (2) inhibitory threshold (i.e. level of cortisol exposure required to activate the axis' feedback inhibition system).

  8. The grapevine kinome: annotation, classification and expression patterns in developmental processes and stress responses.

    Science.gov (United States)

    Zhu, Kaikai; Wang, Xiaolong; Liu, Jinyi; Tang, Jun; Cheng, Qunkang; Chen, Jin-Gui; Cheng, Zong-Ming Max

    2018-01-01

    Protein kinases (PKs) have evolved as the largest family of molecular switches that regulate protein activities associated with almost all essential cellular functions. Only a fraction of plant PKs, however, have been functionally characterized even in model plant species. In the present study, the entire grapevine kinome was identified and annotated using the most recent version of the grapevine genome. A total of 1168 PK-encoding genes were identified and classified into 20 groups and 121 families, with the RLK-Pelle group being the largest, with 872 members. The 1168 kinase genes were unevenly distributed over all 19 chromosomes, and both tandem and segmental duplications contributed to the expansion of the grapevine kinome, especially of the RLK-Pelle group. Ka/Ks values indicated that most of the tandem and segmental duplication events were under purifying selection. The grapevine kinome families exhibited different expression patterns during plant development and in response to various stress treatments, with many being coexpressed. The comprehensive annotation of grapevine kinase genes, their patterns of expression and coexpression, and the related information facilitate a more complete understanding of the roles of various grapevine kinases in growth and development, responses to abiotic stress, and evolutionary history.

  9. Understanding the Intersections of Paradigm, Meta-Theory, and ...

    African Journals Online (AJOL)

    Researchers rely on theories to guide the research process. Theories provide directions in formulating research questions and in the interpretation of findings. The choice of theory to guide inquiry must relate to research paradigm and corresponding meta-theory. However, many beginning scholars experience difficulty in ...

  10. The National Terminology Services: a new paradigm | Jordaan ...

    African Journals Online (AJOL)

    The new dispensation in South Africa necessitated a paradigm shift at the National Terminology Services (NTS). Being part of the Central Government, the NTS has to implement policy as laid down by the government of the day. Former policy, processes and products are described as well as the vision and objectives for the ...

  11. The Paradigm of Distributed Creativity

    DEFF Research Database (Denmark)

    Glaveanu, Vlad Petre

    This presentation aims to focus on and develop the notion of distributed creativity from a cultural psychological perspective. It will start by outlining the need for a cultural psychological paradigm of creative expression and argue that this perspective is primarily concerned with what can...... be called ‘distributed creativity’. Drawing on related literature on distributed cognition (Hutchins, 2000), I will consider here the three inter-related ways in which creative action is distributed: across people, across people and objects, and across time. This particular understanding of creativity...

  12. Psychiatry beyond the current paradigm.

    LENUS (Irish Health Repository)

    Bracken, Pat

    2012-12-01

    A series of editorials in this Journal have argued that psychiatry is in the midst of a crisis. The various solutions proposed would all involve a strengthening of psychiatry\\'s identity as essentially \\'applied neuroscience\\'. Although not discounting the importance of the brain sciences and psychopharmacology, we argue that psychiatry needs to move beyond the dominance of the current, technological paradigm. This would be more in keeping with the evidence about how positive outcomes are achieved and could also serve to foster more meaningful collaboration with the growing service user movement.

  13. Stress analysis and optimization of Nd:YAG pulsed laser processing of notches for fracture splitting of a C70S6 connecting rod

    International Nuclear Information System (INIS)

    Kou, Shuqing; Gao, Yan; Zhao, Yong; Lin, Baojun

    2017-01-01

    The pulsed laser pre-processing of a notch as the fracture initiation source for the splitting process is the key mechanism of an advanced fracture splitting technology for C70S6 connecting rods. This study investigated the stress field of Nd:YAG pulsed laser grooving, which affects the rapid fracture initiation at the notch root and the controlled crack extension in the critical fracture splitting quality, to improve manufacturing quality. Thermal elastic-plastic incremental theory was applied to build the finite element analysis model of the stress field of pulsed laser grooving for fracture splitting based on the Rotary-Gauss body heat source. The corresponding numerical simulation of the stress field was conducted. The changes and distributions of the stress during pulsed laser grooving were examined, the influence rule of the primary technological parameters on the residual stress was analyzed, and the analysis results were validated by the corresponding cutting experiment. Results showed that the residual stress distribution was concentrated in the Heat-affected zone (HAZ) near the fracture splitting notch, which would cause micro-cracks in the HAZ. The stress state of the notch root in the fracture initiation direction was tensile stress, which was beneficial to the fracture initiation and the crack rapid extension in the subsequent fracture splitting process. However, the uneven distribution of the stress could lead to fracture splitting defects, and thus the residual stress should be lowered to a reasonable range. Decreasing the laser pulse power, increasing the processing speed, and lowering the pulse width can lower the residual stress. Along with the actual production, the reasonable main technological parameters were obtained.

  14. Stress analysis and optimization of Nd:YAG pulsed laser processing of notches for fracture splitting of a C70S6 connecting rod

    Energy Technology Data Exchange (ETDEWEB)

    Kou, Shuqing; Gao, Yan; Zhao, Yong; Lin, Baojun [Jilin University, Changchun (China)

    2017-05-15

    The pulsed laser pre-processing of a notch as the fracture initiation source for the splitting process is the key mechanism of an advanced fracture splitting technology for C70S6 connecting rods. This study investigated the stress field of Nd:YAG pulsed laser grooving, which affects the rapid fracture initiation at the notch root and the controlled crack extension in the critical fracture splitting quality, to improve manufacturing quality. Thermal elastic-plastic incremental theory was applied to build the finite element analysis model of the stress field of pulsed laser grooving for fracture splitting based on the Rotary-Gauss body heat source. The corresponding numerical simulation of the stress field was conducted. The changes and distributions of the stress during pulsed laser grooving were examined, the influence rule of the primary technological parameters on the residual stress was analyzed, and the analysis results were validated by the corresponding cutting experiment. Results showed that the residual stress distribution was concentrated in the Heat-affected zone (HAZ) near the fracture splitting notch, which would cause micro-cracks in the HAZ. The stress state of the notch root in the fracture initiation direction was tensile stress, which was beneficial to the fracture initiation and the crack rapid extension in the subsequent fracture splitting process. However, the uneven distribution of the stress could lead to fracture splitting defects, and thus the residual stress should be lowered to a reasonable range. Decreasing the laser pulse power, increasing the processing speed, and lowering the pulse width can lower the residual stress. Along with the actual production, the reasonable main technological parameters were obtained.

  15. Life course pathways of adverse childhood experiences toward adult psychological well-being: A stress process analysis.

    Science.gov (United States)

    Nurius, Paula S; Green, Sara; Logan-Greene, Patricia; Borja, Sharon

    2015-07-01

    Growing evidence suggests that toxic stressors early in life not only convey developmental impacts but also augment risk of proliferating chains of additional stressors that can overwhelm individual coping and undermine recovery and health. Examining trauma within a life course stress process perspective, we posit that early childhood adversity carries a unique capacity to impair adult psychological well-being both independent of and cumulative with other contributors, including social disadvantage and stressful adult experiences. This study uses data from a representative population-based health survey (N=13,593) to provide one of the first multivariate assessments of unique, cumulative, and moderated effects of adverse childhood experiences (ACEs) toward explaining 3 related yet distinct measures of adult mental health: perceived well-being, psychological distress, and impaired daily activities. Results demonstrate support for each set of hypothesized associations, including exacerbation and amelioration of ACEs effects by adult stress and resilience resources, respectively. Implications for services and future research are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Evaluation between residual stresses obtained by neutron diffraction and simulation for dual phase steel welded by laser process

    Science.gov (United States)

    Kouadri-Henni, Afia; Malard, Benoit

    2018-05-01

    This study aimed at characterizing the residual stresses (RS) distribution of a Dual Phase Steel (DP600) undergoing a Laser Beam Welding (LBW) with two different laser parameters. The RS in the ferritic phase have been experimentally determined by the use of the neutrons diffraction technique. The results confirmed a gradient of RS among different zones both on the top and below surfaces but also through the thickness of the fusion zone. Low compressive stresses were observed in the Base Metal (BM) close to the Heat Affected Zone (HAZ) whereas high tensile stresses were observed in the Fusion Zone (FZ). Numerical results showed a difference in the RS distribution depending on the model used. In the end, it appears that the high temperature gradient, specific to the laser beam, is the main factor governing the RS. Our results suggest as well that the approach regarding the RS should consider not only the temperature but also process parameters. When comparing simulation results with experimental data, the values converge well in some zones, in particular the FZ and the others less.

  17. The bereavement process of tissue donors' family members: responses of grief, posttraumatic stress, personal growth, and ongoing attachment.

    Science.gov (United States)

    Hogan, Nancy; Schmidt, Lee; Coolican, Maggie

    2014-09-01

    Donated tissues can save lives of critically burned patients and those needing a heart valve replacement. Tissues enhance the lives of a million recipients annually through transplants of corneas, bones, tendons, and vein grafts. Unfortunately, the need for some tissues exceeds their availability. The goal of the quantitative component of this mixed methods study was to identify the grief, posttraumatic stress, personal growth, and ongoing attachment response of tissue donors' family members during a 2-year period. Simultaneous mixed methods design. The sample for this study consisted of 52 tissue donors' family members, mostly widows (83%). Data were collected for 2 years to test changes in grief, posttraumatic stress, panic behavior, personal growth, and ongoing attachment. The bereaved participants experienced significantly fewer grief reactions, less posttraumatic stress, and greater personal growth. There was no significant difference in the ongoing attachment to their deceased loved ones. The results of this study may reinforce the positive meaning that tissue donors' family members can find in tissue donation. Findings also demonstrate that the bereavement process corroborates contemporary bereavement and attachment theories. Health professionals are encouraged to seek donations with less worry that tissue donors' family members will experience adverse outcomes during bereavement.

  18. A novel kerf-free wafering process combining stress-induced spalling and low energy hydrogen implantation

    Energy Technology Data Exchange (ETDEWEB)

    Pingault, Timothee; Pokam-Kuisseu, Pauline Sylvia; Ntsoenzok, Esidor [CEMTHI - CNRS, Site Cyclotron, 3 A rue de la Ferollerie, 45071 Orleans (France); Blondeau, Jean-Philippe [CEMTHI - CNRS, Site Cyclotron, 3 A rue de la Ferollerie, 45071 Orleans (France); Universite d' Orleans, Chateau de la Source, 45100 Orleans (France); Ulyashin, Alexander [SINTEF, Forskningsveien 1, 0314 Oslo (Norway); Labrim, Hicham; Belhorma, Bouchra [CNESTEN, B.P. 1382 R.P., 10001 Rabat (Morocco)

    2016-12-15

    In this work, we studied the potential use of low-energy hydrogen implantation as a guide for the stress-induced cleavage. Low-energy, high fluence hydrogen implantation in silicon leads, in the right stiffening conditions, to the detachment of a thin layer, around a few hundreds nm thick, of monocrystalline silicon. We implanted monocrystalline silicon wafers with low-energy hydrogen, and then glued them on a cheap metal layer. Upon cooling down, the stress induced by the stressor layers (hardened glue and metal) leads to the detachment of a thin silicon layer, which thickness is determined by the implantation energy. We were then able to clearly demonstrate that, as expected, hydrogen oversaturation layer is very efficient to guide the stress. Using such process, thin silicon layers of around 710 nm-thick were successfully detached from low-energy implanted silicon wafers. Such layers can be used for the growth of very good quality monocrystalline silicon of around 50 μm-thick or less. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Critical examination of RHIC paradigms - mostly high pT

    International Nuclear Information System (INIS)

    Tannenbaum, M.I.

    2009-01-01

    A critical examination of RHIC paradigms is presented. Topics include: search for a critical point with a low energy scan; the lack of understanding of radiative processes in a medium in QCD compared in detail to examples from QED; the reason why some physicists started to measure particles at large p T in the 1960's; a review of the discovery of hard-scattering in p-p collisions in the 1970's via single-inclusive and two-particle correlations and application of these techniques at RHIC. Several paradigms in both soft and hard physics which are popular at RHIC are discussed and challenged.

  20. Dynamics of systems and change in the accounting paradigm

    Directory of Open Access Journals (Sweden)

    Jorge Luis Juliao Rossi

    2006-07-01

    Full Text Available The objective of this document is to demonstrate the potential of the dynamics of systems as a thinking trend which may help in the understanding process and the construction of an accounting paradigm change. This objective is framed inside a wider purpose: to propase interdisciplinary encounters that contribute to the necessary paradigm change. The described problem is studied from the «System Thinking», which is an approach with theoretical framework and representation and simulation tools related to the tapie.

  1. The Influence of Perceived Stress on Cortical Reactivity: A Proof-Of-Principle Study.

    Directory of Open Access Journals (Sweden)

    Rosan Luijcks

    Full Text Available The aim of this study was to investigate how perceived stress may affect electroencephalographical (EEG activity in a stress paradigm in a sample of 76 healthy participants. EEG activity was analyzed using multilevel modeling, allowing estimation of nested effects (EEG time segments within subjects. The stress paradigm consisted of a 3-minute pre-stimulus stress period and a 2-minute post-stimulus phase. At t=3 minutes, a single electrical stimulus was delivered. Participants were unaware of the precise moment of stimulus delivery and its intensity level. In the EEG time course of alpha activity, a stronger increase was observed during the post-stimulus period as compared to the pre-stimulus period. An opposite time course effect was apparent for gamma activity. Both effects were in line with a priori expectations and support the validity of this experimental EEG-stress paradigm. Secondly, we investigated whether interaction effects of stress and coping, as measured with the Perceived Stress Scale-10 questionnaire (PSS-10, could be demonstrated. A higher perceived stress score was accompanied by a greater increase in delta- and theta-activity during the post-stimulus phase, compared to low scores. In contrast, low coping capacity was associated with a stronger decrease in slow beta, fast beta and gamma activity during the post-stimulus phase. The results of the present article may be interpreted as proof-of-principle that EEG stress-related activity depends on the level of subjectively reported perceived stress. The inclusion of psychosocial variables measuring coping styles as well as stress-related personality aspects permits further examination of the interconnection between mind and body and may inform on the process of transformation from acute to chronic stress.

  2. Reexamining unconscious response priming: A liminal-prime paradigm.

    Science.gov (United States)

    Avneon, Maayan; Lamy, Dominique

    2018-03-01

    Research on the limits of unconscious processing typically relies on the subliminal-prime paradigm. However, this paradigm is limited in the issues it can address. Here, we examined the implications of using the liminal-prime paradigm, which allows comparing unconscious and conscious priming with constant stimulation. We adapted an iconic demonstration of unconscious response priming to the liminal-prime paradigm. On the one hand, temporal attention allocated to the prime and its relevance to the task increased the magnitude of response priming. On the other hand, the longer RTs associated with the dual task inherent to the paradigm resulted in response priming being underestimated, because unconscious priming effects were shorter-lived than conscious-priming effects. Nevertheless, when the impact of long RTs was alleviated by considering the fastest trials or by imposing a response deadline, conscious response priming remained considerably larger than unconscious response priming. These findings suggest that conscious perception strongly modulates response priming. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Pins and posters: Paradigms for content publication on situated displays.

    Science.gov (United States)

    José, Rui; Pinto, Hélder; Silva, Bruno; Melro, Ana

    2013-01-01

    Public-display systems are still far from being a medium for meeting people's diverse communication goals. Moving toward open displays will require publication paradigms that can overcome the challenges of meaningful engagement and enable users to fully understand and control the publication process. The metaphors of pins and posters have inspired two complementary paradigms for public displays. Researchers implemented these paradigms in the Instant Places system, which they deployed on 10 displays in diverse urban locations for six months. They collected user and system data regarding the users' practices. The findings improve the understanding of what might drive user-generated content in networks of urban displays. Such knowledge can inform the design of tools and procedures for situated publication in public displays.

  4. Stress/strain characteristics of Cu alloy sheath in situ processed MgB2 superconducting wires

    International Nuclear Information System (INIS)

    Katagiri, Kazumune; Kasaba, Koichi; Shoji, Yoshitaka

    2005-01-01

    The mechanical properties of copper and copper alloy (Cu-Zr, Cu-Be and Cu-Cr) sheath in situ PIT-processed MgB 2 superconducting wires were studied at room temperature (RT) and 4.2 K. The effects of stress-strain on the critical current (I c ) of the wires have also been studied at 4.2 K and in magnetic fields up to 5 T. It has been clarified that alloying the Cu sheath significantly increases the yield and flow stresses of the wires at both RT and 4.2 K. The 0.5% flow stresses of the Cu alloy sheath wire were 147-237 MPa, whereas that of Cu was 55 MPa. At RT, serration corresponding to multiple cracking was observed around a strain of 0.4% and the stress-strain curves saturated beyond that point. The strain dependence of I c prior to the critical strain (ε irr ) was different depending on the magnetic field; being almost constant at 2 T and increasing with strain at 5 T. The I c decreased beyond ε irr , which is much larger for Cu alloy sheath wires as compared to Cu sheath wire. This is due to the difference in the residual compressive strain in the MgB 2 core during cooling from the heat-treatment temperature to 4.2 K, which is determined through relaxation by yielding in the sheath materials. The transverse compression tests revealed that the I c of the Cu alloy sheath wire did not degrade up to 314 MPa, which is also higher than that of Cu sheath wire. (author)

  5. Stress analysis of the O-element pipe during the process of flue gases purification

    Directory of Open Access Journals (Sweden)

    Nekvasil R.

    2008-11-01

    Full Text Available Equipment for flue gases purification from undesired substances is used throughout power and other types of industry. This paper deals with damaging of the O-element pipe designed to remove sulphur from the flue gases, i.e. damaging of the pipe during flue gases purification. This purification is conducted by spraying the water into the O-shaped pipe where the flue gases flow. Thus the sulphur binds itself onto the water and gets removed from the flue gas. Injection of cold water into hot flue gases, however, causes high stress on the inside of the pipe, which can gradually damage the O-element pipe. In this paper initial injection of water into hot pipe all the way to stabilization of temperature fields will be analyzed and the most dangerous places which shall be considered for fatigue will be determined.

  6. Bonds or Bargains: Relationship Paradigms and Their Significance for Marital Therapy.

    Science.gov (United States)

    Johnson, Sue

    1986-01-01

    Discusses contrasting conceptual paradigms describing the nature of intimate relationships. Relationships may be viewed in terms of a rational bargain or as an emotional bond. The implications of each paradigm for the process of marital therapy and the role of bonding and attachment in adult intimacy are prescribed. Implications for marital…

  7. Chronic stress does not impair liver regeneration in rats

    DEFF Research Database (Denmark)

    Andersen, Kasper J; Knudsen, Anders Riegels; Wiborg, Ove

    2015-01-01

    a 70 % partial hepatectomy (PHx). The animals were evaluated on postoperative day 2 or 4. Blood samples were collected to examine circulating markers of inflammation and liver cell damage. Additionally, liver tissues were sampled to evaluate liver weight and regeneration rate. RESULTS: None......BACKGROUND: Although wound healing is a simple regenerative process that is critical after surgery, it has been shown to be impaired under psychological stress. The liver has a unique capacity to regenerate through highly complex mechanisms. The aim of this study was to investigate the effects...... of chronic stress, which may induce a depression-like state, on the complex process of liver regeneration in rats. METHODS: Twenty rats were included in this study. The animals received either a standard housing protocol or were subjected to a Chronic Mild Stress (CMS) stress paradigm. All rats underwent...

  8. Behavioral and molecular processing of visceral pain in the brain of mice: impact of colitis and psychological stress

    Directory of Open Access Journals (Sweden)

    Piyush eJain

    2015-07-01

    Full Text Available Gastrointestinal disorders with abdominal pain are associated with central sensitization and psychopathologies that are often exacerbated by stress. Here we investigated the impact of colitis induced by dextran sulfate sodium (DSS and repeated water avoidance stress (WAS on spontaneous and nociception-related behavior and molecular signaling in the mouse brain. DSS increased the mechanical pain sensitivity of the abdominal skin while both WAS and DSS enhanced the mechanical and thermal pain sensitivity of the plantar skin. These manifestations of central sensitization were associated with augmented c-Fos expression in spinal cord, thalamus, hypothalamus, amygdala and prefrontal cortex. While WAS stimulated phosphorylation of mitogen-activated protein kinase (MAPK p42/44, DSS activated another signaling pathway, both of which converged on c-Fos. The DSS- and WAS-induced hyperalgesia in the abdominal and plantar skin and c-Fos expression in the brain disappeared when the mice were subjected to WAS+DSS treatment. Intrarectal allyl isothiocyanate (AITC evoked aversive behavior (freezing, reduction of locomotion and exploration in association with p42/44 MAPK and c-Fos activation in spinal cord and brain. These effects were inhibited by morphine, which attests to their relationship with nociception. DSS and WAS exerted opposite effects on AITC-evoked p42/44 MAPK and c-Fos activation, which indicates that these transduction pathways subserve different aspects of visceral pain processing in the brain. In summary, behavioral perturbations caused by colitis and psychological stress are associated with distinct alterations in cerebral signaling. These findings provide novel perspectives on central sensitization and the sensory and emotional processing of visceral pain stimuli in the brain.

  9. Constitutive Modeling of the Flow Stress of GCr15 Continuous Casting Bloom in the Heavy Reduction Process

    Science.gov (United States)

    Ji, Cheng; Wang, Zilin; Wu, Chenhui; Zhu, Miaoyong

    2018-04-01

    According to the calculation results of a 3D thermomechanical-coupled finite-element (FE) model of GCr15 bearing steel bloom during a heavy reduction (HR) process, the variation ranges in the strain rate and strain under HR were described. In addition, the hot deformation behavior of the GCr15 bearing steel was studied over the temperature range from 1023 K to 1573 K (750 °C to 1300 °C) with strain rates of 0.001, 0.01, and 0.1 s-1 in single-pass thermosimulation compression experiments. To ensure the accuracy of the constitutive model, the temperature range was divided into two temperature intervals according to the fully austenitic temperature of GCr15 steel [1173 K (900 °C)]. Two sets of material parameters for the constitutive model were derived based on the true stress-strain curves of the two temperature intervals. A flow stress constitutive model was established using a revised Arrhenius-type constitutive equation, which considers the relationships among the material parameters and true strain. This equation describes dynamic softening during hot compression processes. Considering the effect of glide and climb on the deformation mechanism, the Arrhenius-type constitutive equation was modified by a physically based approach. This model is the most accurate over the temperatures ranging from 1173 K to 1573 K (900 °C to 1300 °C) under HR deformation conditions (ignoring the range from 1273 K to 1573 K (1000 °C to 1300 °C) with a strain rate of 0.1 s-1). To ensure the convergence of the FE calculation, an approximated method was used to estimate the flow stress at temperatures greater than 1573 K (1300 °C).

  10. Altered olfactory processing of stress-related body odors and artificial odors in patients with panic disorder.

    Science.gov (United States)

    Wintermann, Gloria-Beatrice; Donix, Markus; Joraschky, Peter; Gerber, Johannes; Petrowski, Katja

    2013-01-01

    Patients with Panic Disorder (PD) direct their attention towards potential threat, followed by panic attacks, and increased sweat production. Onés own anxiety sweat odor influences the attentional focus, and discrimination of threat or non-threat. Since olfactory projection areas overlap with neuronal areas of a panic-specific fear network, the present study investigated the neuronal processing of odors in general and of stress-related sweat odors in particular in patients with PD. A sample of 13 patients with PD with/ without agoraphobia and 13 age- and gender-matched healthy controls underwent an fMRI investigation during olfactory stimulation with their stress-related sweat odors (TSST, ergometry) as well as artificial odors (peach, artificial sweat) as non-fearful non-body odors. The two groups did not differ with respect to their olfactory identification ability. Independent of the kind of odor, the patients with PD showed activations in fronto-cortical areas in contrast to the healthy controls who showed activations in olfaction-related areas such as the amygdalae and the hippocampus. For artificial odors, the patients with PD showed a decreased neuronal activation of the thalamus, the posterior cingulate cortex and the anterior cingulate cortex. Under the presentation of sweat odor caused by ergometric exercise, the patients with PD showed an increased activation in the superior temporal gyrus, the supramarginal gyrus, and the cingulate cortex which was positively correlated with the severity of the psychopathology. For the sweat odor from the anxiety condition, the patients with PD showed an increased activation in the gyrus frontalis inferior, which was positively correlated with the severity of the psychopathology. The results suggest altered neuronal processing of olfactory stimuli in PD. Both artificial odors and stress-related body odors activate specific parts of a fear-network which is associated with an increased severity of the psychopathology.

  11. Altered olfactory processing of stress-related body odors and artificial odors in patients with panic disorder.

    Directory of Open Access Journals (Sweden)

    Gloria-Beatrice Wintermann

    Full Text Available Patients with Panic Disorder (PD direct their attention towards potential threat, followed by panic attacks, and increased sweat production. Onés own anxiety sweat odor influences the attentional focus, and discrimination of threat or non-threat. Since olfactory projection areas overlap with neuronal areas of a panic-specific fear network, the present study investigated the neuronal processing of odors in general and of stress-related sweat odors in particular in patients with PD.A sample of 13 patients with PD with/ without agoraphobia and 13 age- and gender-matched healthy controls underwent an fMRI investigation during olfactory stimulation with their stress-related sweat odors (TSST, ergometry as well as artificial odors (peach, artificial sweat as non-fearful non-body odors.The two groups did not differ with respect to their olfactory identification ability. Independent of the kind of odor, the patients with PD showed activations in fronto-cortical areas in contrast to the healthy controls who showed activations in olfaction-related areas such as the amygdalae and the hippocampus. For artificial odors, the patients with PD showed a decreased neuronal activation of the thalamus, the posterior cingulate cortex and the anterior cingulate cortex. Under the presentation of sweat odor caused by ergometric exercise, the patients with PD showed an increased activation in the superior temporal gyrus, the supramarginal gyrus, and the cingulate cortex which was positively correlated with the severity of the psychopathology. For the sweat odor from the anxiety condition, the patients with PD showed an increased activation in the gyrus frontalis inferior, which was positively correlated with the severity of the psychopathology.The results suggest altered neuronal processing of olfactory stimuli in PD. Both artificial odors and stress-related body odors activate specific parts of a fear-network which is associated with an increased severity of the

  12. The Rational Relevance of the Diffuse Paradigms

    Directory of Open Access Journals (Sweden)

    Marin Dinu

    2006-01-01

    Full Text Available Processes like the globalization consistency and learning about society are screened by diffuse concepts such as those taking the last steps of the industrial civilization and hierarchically ordered world through hegemony. This is why the meaning of globalization is given by deviant trends, like globalism, and the knowledge society is taken for the tools promoted by itself, such as the internet. This does not imply only approximations of meaning but rather the vanity of change, preserving the status quo represented by the pre-global world or the adversity principle. Historicism of paradigm cannot be avoided. Evolvement towards something else, announced by globalization is implacable, and the new ordinating principle, the one of competition, opens the opportunity horizon to global world.

  13. The Rational Relevance of the Diffuse Paradigms

    Directory of Open Access Journals (Sweden)

    Marin Dinu

    2006-03-01

    Full Text Available Processes like the globalization consistency and learning about society are screened by diffuse concepts such as those taking the last steps of the industrial civilization and hierarchically ordered world through hegemony. This is why the meaning of globalization is given by deviant trends, like globalism, and the knowledge society is taken for the tools promoted by itself, such as the internet. This does not imply only approximations of meaning but rather the vanity of change, preserving the status quo represented by the pre-global world or the adversity principle. Historicism of paradigm cannot be avoided. Evolvement towards something else, announced by globalization is implacable, and the new ordinating principle, the one of competition, opens the opportunity horizon to global world

  14. Rationale for Spiritually Oriented Cognitive Processing Therapy for Moral Injury in Active Duty Military and Veterans With Posttraumatic Stress Disorder.

    Science.gov (United States)

    Koenig, Harold G; Boucher, Nathan A; Oliver, Rev John P; Youssef, Nagy; Mooney, Scott R; Currier, Joseph M; Pearce, Michelle

    2017-02-01

    Wartime experiences have long been known to cause ethical conflict, guilt, self-condemnation, difficulty forgiving, loss of trust, lack of meaning and purpose, and spiritual struggles. "Moral injury" (MI) (also sometimes called "inner conflict") is the term used to capture this emotional, cognitive, and behavioral state. In this article, we provide rationale for developing and testing Spiritually Oriented Cognitive Processing Therapy, a version of standard cognitive processing therapy for the treatment of MI in active duty and veteran service members (SMs) with posttraumatic stress disorder symptoms who are spiritual or religious (S/R). Many SMs have S/R beliefs that could increase vulnerability to MI. Because the injury is to deeply held moral standards and ethical values and often adversely affects spiritual beliefs and worldview, we believe that those who are S/R will respond more favorably to a therapy that directly targets this injury from a spiritually oriented perspective. An evidence-based treatment for MI in posttraumatic stress disorder that not only respects but also utilizes SMs' spiritual beliefs/behaviors may open the door to treatment for many S/R military personnel.

  15. Effects of face/head and whole body cooling during passive heat stress on human somatosensory processing.

    Science.gov (United States)

    Nakata, Hiroki; Namba, Mari; Kakigi, Ryusuke; Shibasaki, Manabu

    2017-06-01

    We herein investigated the effects of face/head and whole body cooling during passive heat stress on human somatosensory processing recorded by somatosensory-evoked potentials (SEPs) at C4' and Fz electrodes. Fourteen healthy subjects received a median nerve stimulation at the left wrist. SEPs were recorded at normothermic baseline (Rest), when esophageal temperature had increased by ~1.2°C (heat stress: HS) during passive heating, face/head cooling during passive heating (face/head cooling: FHC), and after HS (whole body cooling: WBC). The latencies and amplitudes of P14, N20, P25, N35, P45, and N60 at C4' and P14, N18, P22, and N30 at Fz were evaluated. Latency indicated speed of the subcortical and cortical somatosensory processing, while amplitude reflected the strength of neural activity. Blood flow in the internal and common carotid arteries (ICA and CCA, respectively) and psychological comfort were recorded in each session. Increases in esophageal temperature due to HS significantly decreased the amplitude of N60, psychological comfort, and ICA blood flow in the HS session, and also shortened the latencies of SEPs (all, P body temperature. Copyright © 2017 the American Physiological Society.

  16. Family Complexity and the Stress Process in Prison: How Sibling Living Arrangements of Minor Children Influence Maternal Role Strains

    Directory of Open Access Journals (Sweden)

    Holly Foster

    2017-07-01

    Full Text Available This paper offers a life-course stress process perspective on maternal role strain as a ‘pain of imprisonment’ by engaging the concept of ‘family complexity’ in the context of mass incarceration I consider how the living arrangements of minor siblings (i.e., those living apart or together during maternal incarceration functions as a form of family complexity. When minor children live apart from their siblings, they may experience more isolation which may further serve as a stressor for incarcerated mothers. A positive association between siblings living apart and maternal role strain would support a process of ‘stress proliferation’ across the prison-family interface. I investigate these connections using survey-based data on mothers with multiple minor children (n = 80 collected in 2011 from a voluntary sample of respondents housed in a federal minimum security prison in the United States. Multivariate logistic regression results indicate that minor siblings living apart during periods of maternal confinement elevates role strain among mothers (odds ratio = 3.66, p < 0.05. This connection is indicative of an ‘inter-institutional strain.’ Finally, children’s age also increases maternal role strain, but this finding is explained by sibling living arrangements during the mother’s incarceration.

  17. Metallic materials for heat exchanger components and highly stressed internal of HTR reactors for nuclear process heat generation

    International Nuclear Information System (INIS)

    1982-01-01

    The programme was aimed at the development and improvement of materials for the high-temperature heat exchanger components of a process steam HTR. The materials must have high resistance to corrosion, i.e. carburisation and internal oxidation, and high long-term toughness over a wide range of temperatures. They must also meet the requirements set in the nuclear licensing procedure, i.e. resistance to cyclic stress and irradiation, non-destructive testing, etc. Initially, it was only intended to improve and qualify commercial alloys. Later on an alloy development programme was initiated in which new, non-commercial alloys were produced and modified for use in a nuclear process heat facility. Separate abstracts were prepared for 19 pays of this volume. (orig./IHOE) [de

  18. An application of computer image-processing and filmy replica technique to the copper electroplating method of stress analysis

    Science.gov (United States)

    Sugiura, M.; Seika, M.

    1994-02-01

    In this study, a new technique to measure the density of slip-bands automatically is developed, namely, a TV image of the slip-bands observed through a microscope is directly processed by an image-processing system using a personal computer and an accurate value of the density of slip-bands is measured quickly. In the case of measuring the local stresses in machine parts of large size with the copper plating foil, the direct observation of slip-bands through an optical microscope is difficult. In this study, to facilitate a technique close to the direct microscopic observation of slip-bands in the foil attached to a large-sized specimen, the replica method using a platic film of acetyl cellulose is applied to replicate the slip-bands in the attached foil.

  19. Theoretical reflections on the paradigmatic construction of Information Science: considerations about the (s paradigm (s cognitive (s and social

    Directory of Open Access Journals (Sweden)

    Jonathas Luiz Carvalho Silva

    2013-07-01

    Full Text Available It presents a research about the theoretical and epistemological processes that influence the formation of the cognitive paradigm of Information Science (IS, noting the emergence of social paradigm within the domain analysis and hermeneutics of information. For this, we adopted the reflections of classical and contemporary authors, like Thomas Kuhn, Boaventura Santos, Capurro, Hjørland and Albrechtsen. We conclude that the perception paradigm in IS is a consolidated issue, however the social paradigm is still under construction, which will allow the creation of perceptions, interpretations and contributions in order to fill gaps left by other paradigms.

  20. The Relevance of Theories of the Policy Process to Educational Decision-Making.

    Science.gov (United States)

    Ryan, R. J.

    1985-01-01

    Two case studies of educational decision making are used to test the utility of some current theories of the policy-formation process; a framework for the application of these theories is proposed; and the merits of applying existing theories before seeking new paradigms are stressed. (MSE)