Sample records for waste risk reward
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Radioactive waste. Risk, reward, space and time dynamics
International Nuclear Information System (INIS)
Duncan, I.J.
2001-01-01
This study considers, in a geographical context, issues arising from the disposal of radioactive waste with particular emphasis on societal perceptions of Risk, Trust, NIMBYand Time. It establishes that the wider community now accepts the concepts of 'user pays' and offsetting compensation to any community that accepts a risk, such risk to be minimised and interruptible as necessary. The underlying causes of NIMBYism have been misjudged by industry and this work establishes that they are as much due to exclusion from the decision making process as they are to direct concerns about the social impact, health and environment. The principal cause of NIMBYism is discussed and a procedure to assist siting approval is suggested. This study establishes that industry, government authorities or specialists working alone in this field engender less trust by society than composite bodies including government departments, industry, environmentalists, health, science and society. The dimension of an individual's perception of forward time has been quantified and found to be much shorter than the time required for the isolation of radioactive waste. This research highlights the dynamic nature of all waste isolation processes and proposes a procedure that could render the concept of long term geological disposal more acceptable to the public. It evolved that the disposal of all waste is a dynamic process, the management of which must provide the time necessary for physical and chemical change and to ensure isolation from the biosphere while it remains hazardous. The outcome of this research is applicable to the disposal of all solid hazardous waste. (author)
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Reward Processing and Risk for Depression Across Development.
Luking, Katherine R; Pagliaccio, David; Luby, Joan L; Barch, Deanna M
2016-06-01
Striatal response to reward has been of great interest in the typical development and psychopathology literatures. These parallel lines of inquiry demonstrate that although typically developing adolescents show robust striatal response to reward, adolescents with major depressive disorder (MDD) and those at high risk for MDD show a blunted response to reward. Understanding how these findings intersect is crucial for the development and application of early preventative interventions in at-risk children, ideally before the sharp increase in the rate of MDD onset that occurs in adolescence. Robust findings relating blunted striatal response to reward and MDD risk are reviewed and situated within a normative developmental context. We highlight the need for future studies investigating longitudinal development, specificity to MDD, and roles of potential moderators and mediators. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Balancing risk and reward: a rat model of risky decision making.
Simon, Nicholas W; Gilbert, Ryan J; Mayse, Jeffrey D; Bizon, Jennifer L; Setlow, Barry
2009-09-01
We developed a behavioral task in rats to assess the influence of risk of punishment on decision making. Male Long-Evans rats were given choices between pressing a lever to obtain a small, 'safe' food reward and a large food reward associated with risk of punishment (footshock). Each test session consisted of 5 blocks of 10 choice trials, with punishment risk increasing with each consecutive block (0, 25, 50, 75, 100%). Preference for the large, 'risky' reward declined with both increased probability and increased magnitude of punishment, and reward choice was not affected by the level of satiation or the order of risk presentation. Performance in this risky decision-making task was correlated with the degree to which the rats discounted the value of probabilistic rewards, but not delayed rewards. Finally, the acute effects of different doses of amphetamine and cocaine on risky decision making were assessed. Systemic amphetamine administration caused a dose-dependent decrease in choice of the large risky reward (ie, it made rats more risk averse). Cocaine did not cause a shift in reward choice, but instead impaired the rats' sensitivity to changes in punishment risk. These results should prove useful for investigating neuropsychiatric disorders in which risk taking is a prominent feature, such as attention deficit/hyperactivity disorder and addiction.
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The Risks and Rewards of Sexual Debut
Golden, Rachel Lynn; Furman, Wyndol; Collibee, Charlene
2016-01-01
The sex-positive framework of sexual development hypothesizes that healthy sexual experiences can be developmentally appropriate and rewarding for adolescents despite the risks involved. Research has not examined whether risky behaviors and rewarding cognitions actually change with sexual debut at a normative or late age. This study measured the longitudinal impact of sexual debut using 7 waves of data from 88 male and 86 female adolescents from a Western U.S. city who were in the 10th grade at the study’s onset. We used piecewise growth curve analyses to compare behavior and cognitions before and after first sexual intercourse for those whose debut was at a normative or late age. These analyses revealed that sexual debut was related to rewards including increases in romantic appeal, and sexual satisfaction. In addition, internalizing symptoms declined over time after sexual debut, and substance use grew at a slower rate after sexual debut. We also examined whether differences existed among those whose debut was at an early, normative, or late age. Linear growth curve analyses revealed early sexual debut was related to risks, such as greater substance use, more internalizing and externalizing symptoms and lower global self-worth. Rewards associated with an early debut included greater romantic appeal, dating satisfaction (males only), and sexual satisfaction (males only). Although there are some inherent risks with sexual activity, the results suggest that sexual debut at a normative or late age is also associated with a decrease in some risks and increase in rewards. PMID:27709996
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Exploiting risk-reward structures in decision making under uncertainty.
Leuker, Christina; Pachur, Thorsten; Hertwig, Ralph; Pleskac, Timothy J
2018-06-01
People often have to make decisions under uncertainty-that is, in situations where the probabilities of obtaining a payoff are unknown or at least difficult to ascertain. One solution to this problem is to infer the probability from the magnitude of the potential payoff and thus exploit the inverse relationship between payoffs and probabilities that occurs in many domains in the environment. Here, we investigated how the mind may implement such a solution: (1) Do people learn about risk-reward relationships from the environment-and if so, how? (2) How do learned risk-reward relationships impact preferences in decision-making under uncertainty? Across three experiments (N = 352), we found that participants can learn risk-reward relationships from being exposed to choice environments with a negative, positive, or uncorrelated risk-reward relationship. They were able to learn the associations both from gambles with explicitly stated payoffs and probabilities (Experiments 1 & 2) and from gambles about epistemic events (Experiment 3). In subsequent decisions under uncertainty, participants often exploited the learned association by inferring probabilities from the magnitudes of the payoffs. This inference systematically influenced their preferences under uncertainty: Participants who had been exposed to a negative risk-reward relationship tended to prefer the uncertain option over a smaller sure option for low payoffs, but not for high payoffs. This pattern reversed in the positive condition and disappeared in the uncorrelated condition. This adaptive change in preferences is consistent with the use of the risk-reward heuristic. Copyright © 2018 Elsevier B.V. All rights reserved.
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Li, Chia-Wei; Chen, Jyh-Horng; Tsai, Chen-Gia
2015-12-10
Artificial rewards, such as visual arts and music, produce pleasurable feelings. Popular songs in the verse-chorus form provide a useful model for understanding the neural mechanisms underlying the processing of artificial rewards, because the chorus is usually the most rewarding element of a song. In this functional magnetic resonance imaging (fMRI) study, the stimuli were excerpts of 10 popular songs with a tensioned verse-to-chorus transition. We examined the neural correlates of three phases of reward processing: (1) reward-anticipation during the verse-to-chorus transition, (2) reward-gain during the first phrase of the chorus, and (3) reward-loss during the unexpected noise followed by the verse-to-chorus transition. Participants listened to these excerpts in a risk-reward context because the verse was followed by either the chorus or noise with equal probability. The results showed that reward-gain and reward-loss were associated with left- and right-biased temporoparietal junction activation, respectively. The bilateral temporoparietal junctions were active during reward-anticipation. Moreover, we observed left-biased lateral orbitofrontal activation during reward-anticipation, whereas the medial orbitofrontal cortex was activated during reward-gain. The findings are discussed in relation to the cognitive and emotional aspects of reward processing. Copyright © 2015 Elsevier B.V. All rights reserved.
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Offshore wind energy : balancing risk and reward
International Nuclear Information System (INIS)
Nerland, C.
2010-01-01
Offshore wind energy developments are expected to increase as the demand for renewable energy sources grows. This poster presentation described a method of balancing risk and reward in offshore wind energy projects. The method was based on risk assessment strategies used by the oil and gas industry. The dedicated framework considered schedules; budgets; performance; and operating and maintenance costs. A value chain assessment method was used to optimize the balance between risk and reward by evaluating uncertainties and risk related to each project element and its relationship to other elements within an integrated dynamic model designed to determine the net present value of a project. The decision-making criteria included the RISKEX risk expenditure strategy designed to consider the balance between risk exposure, capital expenditures, and operational expenditures in relation to the statistical cost of unplanned repairs, and lost production capacity. A case study of a large offshore wind farm was used to demonstrate the method. tabs., figs.
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Reward salience and risk aversion underlie differential ACC activity in substance dependence.
Alexander, William H; Fukunaga, Rena; Finn, Peter; Brown, Joshua W
2015-01-01
The medial prefrontal cortex, especially the dorsal anterior cingulate cortex (ACC), has long been implicated in cognitive control and error processing. Although the association between ACC and behavior has been established, it is less clear how ACC contributes to dysfunctional behavior such as substance dependence. Evidence from neuroimaging studies investigating ACC function in substance users is mixed, with some studies showing disengagement of ACC in substance dependent individuals (SDs), while others show increased ACC activity related to substance use. In this study, we investigate ACC function in SDs and healthy individuals performing a change signal task for monetary rewards. Using a priori predictions derived from a recent computational model of ACC, we find that ACC activity differs between SDs and controls in factors related to reward salience and risk aversion between SDs and healthy individuals. Quantitative fits of a computational model to fMRI data reveal significant differences in best fit parameters for reward salience and risk preferences. Specifically, the ACC in SDs shows greater risk aversion, defined as concavity in the utility function, and greater attention to rewards relative to reward omission. Furthermore, across participants risk aversion and reward salience are positively correlated. The results clarify the role that ACC plays in both the reduced sensitivity to omitted rewards and greater reward valuation in SDs. Clinical implications of applying computational modeling in psychiatry are also discussed.
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Telzer, Eva H; Fuligni, Andrew J; Lieberman, Matthew D; Galván, Adriana
2013-01-01
Adolescence is a period of intensified emotions and an increase in motivated behaviors and passions. Evidence from developmental neuroscience suggests that this heightened emotionality occurs, in part, due to a peak in functional reactivity to rewarding stimuli, which renders adolescents more oriented toward reward-seeking behaviors. Most prior work has focused on how reward sensitivity may create vulnerabilities, leading to increases in risk taking. Here, we test whether heightened reward sensitivity may potentially be an asset for adolescents when engaged in prosocial activities. Thirty-two adolescents were followed over a one-year period to examine whether ventral striatum activation to prosocial rewards predicts decreases in risk taking over a year. Results show that heightened ventral striatum activation to prosocial stimuli relates to longitudinal declines in risk taking. Therefore, the very same neural region that has conferred vulnerability for adolescent risk taking may also be protective against risk taking. Copyright © 2012 Elsevier Ltd. All rights reserved.
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Risk-taking in disorders of natural and drug rewards
DEFF Research Database (Denmark)
Voon, Valerie; Morris, Laurel S; Irvine, Michael A
2015-01-01
greater risk-taking, similar to substance-use disorders. Methamphetamine-dependent subjects had greater nonlinearity of probability weighting along with impaired subjective discrimination of probability and reward magnitude. Ex-smokers also had lower risk-taking to rewards compared with non......-smokers. In the anticipation of losses, obesity without binge eating had a similar pattern to other substance-use disorders. Obese subjects with binge eating also have impaired discrimination of subjective value similar to that of the methamphetamine-dependent subjects. Nonlinearity of probability weighting was associated...
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Larkin, Joshua D; Jenni, Nicole L; Floresco, Stan B
2016-01-01
Dopamine (DA) transmission within cortico-limbic-striatal circuitry is integral in modulating decisions involving reward uncertainty. The basolateral amygdala (BLA) also plays a role in these processes, yet how DA transmission within this nucleus regulates cost/benefit decision making is unknown. We investigated the contribution of DA transmission within the BLA to risk/reward decision making assessed with a probabilistic discounting task. Rats were well-trained to choose between a small/certain reward and a large/risky reward, with the probability of obtaining the larger reward decreasing (100-12.5 %) or increasing (12.5-100 %) over a session. We examined the effects of antagonizing BLA D1 (SCH 23390, 0.1-1 μg) or D2 (eticlopride, 0.1-1 μg) receptors, as well as intra-BLA infusions of agonists for D1 (SKF 81297, 0.1-1 μg) and D2 (quinpirole, 1-10 μg) receptors. We also assessed how DA receptor stimulation may induce differential effects related to baseline levels of risky choice. BLA D1 receptor antagonism reduced risky choice by decreasing reward sensitivity, whereas D2 antagonism did not affect overall choice patterns. Stimulation of BLA D1 receptors optimized decision making in a baseline-dependent manner: in risk-averse rats, infusions of a lower dose of SKF81297 increased risky choice when reward probabilities were high (50 %), whereas in risk-prone rats, this drug reduced risky choice when probabilities were low (12.5 %). Quinpirole reduced risky choice in risk-prone rats, enhancing lose-shift behavior. These data highlight previously uncharacterized roles for BLA DA D1 and D2 receptors in biasing choice during risk/reward decision making through mediation of reward/negative feedback sensitivity.
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Peeters, Margot; Oldehinkel, Tineke; Vollebergh, Wilma
2017-01-01
Neurodevelopmental theories of risk behavior hypothesize that low behavioral control in combination with high reward sensitivity explains adolescents' risk behavior. However, empirical studies examining this hypothesis while including actual risk taking behavior in adolescence are lacking. In this study we tested whether the imbalance between behavioral control and reward sensitivity underlies risk taking behavior in adolescence, using a nationally representative longitudinal sample of 715 adolescents, of which 66% revealed an increased risk for mental health problems. To assess behavioral control at age 11 we used both self-report (effortful control) as well as behavioral measures of cognitive control (i.e., working memory and response inhibition). Reward sensitivity was assessed with the Bangor Gambling Task. The main finding of this study was that effortful control at age 11 was the best predictor of risk taking behavior (alcohol and cannabis use) at age 16, particularly among adolescents who were more reward sensitive. Risk taking behavior in adolescents might be explained by relatively weak behavioral control functioning combined with high sensitivity for reward.
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International Nuclear Information System (INIS)
Kellas, G.K.; Hodgshon, S.G.
1992-01-01
This paper looks at the problems facing the international oil explorationist and host Governments in 1992, under a cloud of low oil prices and falling company profits, yet with more quality acreage available worldwide than for many years, especially with the emergence of the CIS states as prospective hunting grounds for the western oil company. Given the extent of the spread of opportunities available to companies and recognition of the increasing need to justify, on economic grounds, progress with any licence application this paper suggests two approaches that companies can adopt to rank the opportunities available, and maximize the value, on an after risk basis, of their (limited) international exploration budget : subjective rating by factor or the Risk/Reward balance. Both of these approaches include measures of prospectivity and measures of local cost and fiscal effects in providing an overall exploration rating which can be used by companies to rank the available opportunities
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Reduced reward anticipation in youth at high-risk for unipolar depression: A preliminary study
Directory of Open Access Journals (Sweden)
Thomas M. Olino
2014-04-01
Full Text Available Offspring of depressed parents are at risk for depression and recent evidence suggests that reduced positive affect (PA may be a marker of risk. We investigated whether self-reports of PA and fMRI-measured striatal response to reward, a neural correlate of PA, are reduced in adolescent youth at high familial risk for depression (HR relative to youth at low familial risk for depression (LR. Functional magnetic resonance imaging assessments were conducted with 14 HR and 12 LR youth. All youth completed an ecological momentary assessment protocol to measure PA in natural settings and a self-report measure of depression symptomatology. Analyses found that HR youth demonstrated lower striatal response than LR youth during both reward anticipation and outcome. However, after controlling for youth self-reports of depression, HR youth demonstrated lower striatal response than LR youth only during reward anticipation. No significant differences were found between HR and LR youth on subjective ratings of PA or depressive symptoms. Results are consistent with previous findings that reduced reward response is a marker of risk for depression, particularly during reward anticipation, even in the absence of (or accounting for disrupted subjective mood. Further examinations of prospective associations between reward response and depression onset are needed.
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The neural dynamics of reward value and risk coding in the human orbitofrontal cortex.
Li, Yansong; Vanni-Mercier, Giovanna; Isnard, Jean; Mauguière, François; Dreher, Jean-Claude
2016-04-01
The orbitofrontal cortex is known to carry information regarding expected reward, risk and experienced outcome. Yet, due to inherent limitations in lesion and neuroimaging methods, the neural dynamics of these computations has remained elusive in humans. Here, taking advantage of the high temporal definition of intracranial recordings, we characterize the neurophysiological signatures of the intact orbitofrontal cortex in processing information relevant for risky decisions. Local field potentials were recorded from the intact orbitofrontal cortex of patients suffering from drug-refractory partial epilepsy with implanted depth electrodes as they performed a probabilistic reward learning task that required them to associate visual cues with distinct reward probabilities. We observed three successive signals: (i) around 400 ms after cue presentation, the amplitudes of the local field potentials increased with reward probability; (ii) a risk signal emerged during the late phase of reward anticipation and during the outcome phase; and (iii) an experienced value signal appeared at the time of reward delivery. Both the medial and lateral orbitofrontal cortex encoded risk and reward probability while the lateral orbitofrontal cortex played a dominant role in coding experienced value. The present study provides the first evidence from intracranial recordings that the human orbitofrontal cortex codes reward risk both during late reward anticipation and during the outcome phase at a time scale of milliseconds. Our findings offer insights into the rapid mechanisms underlying the ability to learn structural relationships from the environment. © The Author (2016). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
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Reduced reward anticipation in youth at high-risk for unipolar depression: a preliminary study.
Olino, Thomas M; McMakin, Dana L; Morgan, Judith K; Silk, Jennifer S; Birmaher, Boris; Axelson, David A; Williamson, Douglas E; Dahl, Ronald E; Ryan, Neal D; Forbes, Erika E
2014-04-01
Offspring of depressed parents are at risk for depression and recent evidence suggests that reduced positive affect (PA) may be a marker of risk. We investigated whether self-reports of PA and fMRI-measured striatal response to reward, a neural correlate of PA, are reduced in adolescent youth at high familial risk for depression (HR) relative to youth at low familial risk for depression (LR). Functional magnetic resonance imaging assessments were conducted with 14 HR and 12 LR youth. All youth completed an ecological momentary assessment protocol to measure PA in natural settings and a self-report measure of depression symptomatology. Analyses found that HR youth demonstrated lower striatal response than LR youth during both reward anticipation and outcome. However, after controlling for youth self-reports of depression, HR youth demonstrated lower striatal response than LR youth only during reward anticipation. No significant differences were found between HR and LR youth on subjective ratings of PA or depressive symptoms. Results are consistent with previous findings that reduced reward response is a marker of risk for depression, particularly during reward anticipation, even in the absence of (or accounting for) disrupted subjective mood. Further examinations of prospective associations between reward response and depression onset are needed. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.
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Neural activation to monetary reward is associated with amphetamine reward sensitivity.
Crane, Natania A; Gorka, Stephanie M; Weafer, Jessica; Langenecker, Scott A; de Wit, Harriet; Phan, K Luan
2018-03-14
One known risk factor for drug use and abuse is sensitivity to rewarding effects of drugs. It is not known whether this risk factor extends to sensitivity to non-drug rewards. In this study with healthy young adults, we examined the association between sensitivity to the subjective rewarding effects of amphetamine and a neural indicator of anticipation of monetary reward. We hypothesized that greater euphorigenic response to amphetamine would be associated with greater neural activation to anticipation of monetary reward (Win > Loss). Healthy participants (N = 61) completed four laboratory sessions in which they received d-amphetamine (20 mg) and placebo in alternating order, providing self-report measures of euphoria and stimulation at regular intervals. At a separate visit 1-3 weeks later, participants completed the guessing reward task (GRT) during fMRI in a drug-free state. Participants reporting greater euphoria after amphetamine also exhibited greater neural activation during monetary reward anticipation in mesolimbic reward regions, including the bilateral caudate and putamen. This is the first study to show a relationship between neural correlates of monetary reward and sensitivity to the subjective rewarding effects of amphetamine in humans. These findings support growing evidence that sensitivity to reward in general is a risk factor for drug use and abuse, and suggest that sensitivity of drug-induced euphoria may reflect a general sensitivity to rewards. This may be an index of vulnerability for drug use or abuse.
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Inherent Reward and Risk (Part I): Towards a Universal Paradigm for Investment Analysis
Liang Zou
2000-01-01
In this paper, a new paradigm is developed for analyzinginvestment strategies and pricing financial assets. This paradigmassumes that any investment strategy has its own “inherent reward”and “inherent risk” that can be judged with common sense. Ijustify axiomatically the existence and uniqueness (ratio scale)of inherent reward (U) and inherent risk (D) that could beregarded as universal measures of reward and risk for any giveninvestment strategy. Incorporating the notion of “inherentefficien...
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Nelson, Brady D; McGowan, Sarah Kate; Sarapas, Casey; Robison-Andrew, E Jenna; Altman, Sarah E; Campbell, Miranda L; Gorka, Stephanie M; Katz, Andrea C; Shankman, Stewart A
2013-08-01
Two emotional/motivational constructs that have been posited to underlie anxiety and depressive disorders are heightened sensitivity to threat and reduced sensitivity to reward, respectively. It is unclear, though, whether these constructs are only epiphenomena or also connote risk for these disorders (and relatedly, whether they connote risk for separate disorders). Using family history of psychopathology as an indicator of risk, the present study examined whether biomarkers of sensitivity to threat (startle potentiation) and reward (frontal EEG asymmetry) were associated with similar or different familial liabilities. In addition, the present study examined whether these biomarkers were associated with risk independent of proband DSM-IV diagnosis. One-hundred and seventy-three individuals diagnosed with panic disorder (PD), early onset major depressive disorder (MDD), both (comorbids), or controls completed two laboratory paradigms assessing sensitivity to predictable/unpredictable threat (measured via startle response) and reward (measured via frontal EEG asymmetry during a gambling task). Results indicated that across all participants: (a) startle potentiation to unpredictable threat was associated with family history of PD (but not MDD); and (b) frontal EEG asymmetry while anticipating reward was associated with family history of MDD (but not PD). Additionally, both measures continued to be associated with family history of psychopathology after controlling for proband DSM-IV diagnosis. Results suggest that the proposed biomarkers of sensitivity to unpredictable threat and reward exhibit discriminant validity and may add to the predictive validity of the DSM-IV defined constructs of PD and MDD, respectively. PsycINFO Database Record (c) 2013 APA, all rights reserved.
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Heinrich, Angela; Lourdusamy, Anbarasu; Tzschoppe, Jelka; Vollstädt-Klein, Sabine; Bühler, Mira; Steiner, Sabina; Bach, Christiane; Poustka, Luise; Banaschewski, Tobias; Barker, Gareth; Büchel, Christian; Conrod, Patricia; Garavan, Hugh; Gallinat, Jürgen; Heinz, Andreas; Ittermann, Bernd; Loth, Eva; Mann, Karl; Martinot, Jean-Luc; Paus, Tomáš; Pausova, Zdenka; Smolka, Michael; Ströhle, Andreas; Struve, Maren; Witt, Stephanie; Flor, Herta; Schumann, Gunter; Rietschel, Marcella; Nees, Frauke
2013-06-01
Bipolar disorder is a severe mood disorder, which normally begins during adolescence or early adulthood and has a heritability of up to 80%. The largest genome-wide association analysis of bipolar disorder recently identified a new genome-wide associated variant in OZD4 (rs12576775). The aim of the present study was to further elucidate the role of this risk variant in the disease process using an imaging genetics approach. As increased amygdala and striatal responses during the processing of reward and emotion are characteristic for bipolar disorder patients, it was tested whether the risk variant has an influence on this endophenotype in healthy adolescents. We examined the impact of the risk variant rs12576775 on functional magnetic resonance imaging data in an adolescent sample (N = 485). Differential activation between carriers of the risk allele (G-allele) and homozygous A-allele carriers in the amygdala and the striatum during a modification of the monetary incentive delay task (examining reward) and a face task (examining emotion) was analyzed. Carriers of the risk allele showed an increased blood oxygen level-dependent response in the amygdala during reward sensitivity (p = 0.05) and reward expectation (p < 0.05) but not during the face task. No significant group differences were found in the striatum during both reward and emotion processing. Our results indicate that the ODZ4 risk variant influences reward processing in the amygdala. Alterations in the processing of emotion may have different underlying mechanisms and need to be further examined. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
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Risk, Reward, and Regulations: Reshaping the Financial Services Industry.
Saul, Ralph S.
1984-01-01
Deregulation has had much to do with the competitive drive and vitality of financial services within the United States. The risks and rewards of deregulation for financial institutions are discussed, and principles which should serve as a guide in building any new regulatory structure are examined. (RM)
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International ROR: risk, opportunity, reward
International Nuclear Information System (INIS)
Krentz, D.; Gair, J.
1996-01-01
Norcen Energy Resources Limited's pursuit of international oil and gas opportunities since the late 1980s were outlined. By 1994 Norcen had exploration and production concessions in 12 countries stretching from Algeria, Russia, Argentina, Indonesia to offshore Australia. The company had seen its share of risks, opportunities and rewards. Since 1994 international efforts of the Company have been focused on lower risk opportunities with exploration upside in defined core areas of South America, particularly in Venezuela, a country with conventional, heavy and ultra-heavy oil resources exceeding that of Saudi Arabia. These, and other similar foreign investments in the formerly closed national oil industries of South America have been greatly facilitated by the political liberalization, economic reforms and stabilization that have taken place there over the past ten years. The story of Norcen's successful bidding on the Oritupano-Leona production block in 1993 and Delta Centro exploration block in 1996 was the subject of this presentation
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Risk:reward sharing contracts in the oil industry: the effects of bonus:penalty schemes
International Nuclear Information System (INIS)
Kemp, A.G.; Stephen, L.
1999-01-01
Partnering and alliancing among oil companies and their contractors have become common in the oil industry in recent years. The risk:reward mechanisms established very often incorporate bonus/penalty schemes in relation to agreed base values. This paper examines the efficiency requirements of such schemes. The effects of project cost and completion risks on the risk: reward positions of field investors and contractors with and without bonus/penalty schemes are examined with the aid of Monte Carlo simulation analysis. The schemes increase the total risk for contractors and have consequence for their cost of capital and optimal risk-bearing arrangements within the industry. (author)
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Olino, Thomas M; Silk, Jennifer S; Osterritter, Catherine; Forbes, Erika E
2015-11-01
Offspring of depressed parents are at risk for developing depression at rates higher than the general population. One potential mechanism linking parent and offspring depression involves attenuated reward function. Despite the importance of social incentives for adolescents, no previous studies have relied on active social incentive reward paradigms in youth at risk for depression. The present study examined differences in youth self- and parent-report measures of and neural response to social reward between youth of mothers with and those of mothers without a history of depression. Imaging data were collected on 10 youth with a depressed parent and 23 youth without depressed parent, which included a task examining neural response to social rewards. Youth and parents also completed self-report measures of social reward. Offspring of depressed parents had lower levels of parent-reported affiliation and reduced neural response to social reward in the ventral striatum and anterior cingulate cortex than offspring of parents without a history of depression. Higher parent-reported affiliation was associated with greater ventral striatal response to social reward. Data suggest that risk status differences in ventral striatal response to social acceptance may be accounted for by affiliation. No differences were found in youth self-reports of behavior. The results suggest that attenuated response to social reward, assessed through neurobiology and behavior, may be mechanistically linked to the etiology and pathophysiology of depression. Targeting social interest and engagement may be a new direction in preventing the onset of depressive disorders in youth.
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Pain without gain? Reviewing the risks and rewards of investing in Russian coal-fired electricity
International Nuclear Information System (INIS)
Gorbacheva, Natalya V.; Sovacool, Benjamin K.
2015-01-01
Highlights: • This study explores the risks and rewards facing coal in Russia. • Rewards include low costs, investment, rural modernization, exports, and innovation. • Risks include development challenges, air pollution and climate change, and policy support. - Abstract: Coal use—and thus investment—is expected to grow considerably in the Russian Federation over the next few decades. Projections suggest that at least $200 billion of investment will be needed to modernize existing coal-fired power plants by 2030, but the bulk of this financing is to come from the private sector or foreign enterprises. This study asks: what are the possible investment risks and rewards of pursuing this expansion of coal in the Russian power sector? To provide an answer, the study uses a mixed methods approach consisting of elite semi-structured interviews and a review of English and Russian peer-reviewed literature. The study provides a brief overview of the Russian electricity sector before discussing five distinct rewards to investing in coal such as low production costs, competitive returns on investment, rural modernization, expansion of exports, and the acceleration of innovation. These benefits however are offset by five risks: inferior performance to investments in oil and gas, development challenges, air pollution and climate change, social degradation from mining, and a tradeoff with existing policies incentivizing renewable energy and energy efficiency. The study concludes by analyzing what these disparate risks and rewards mean for policymakers and energy analysts
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Directory of Open Access Journals (Sweden)
Madeleine E Sharp
Full Text Available BACKGROUND: There are few clinical tools that assess decision-making under risk. Tests that characterize sensitivity and bias in decisions between prospects varying in magnitude and probability of gain may provide insights in conditions with anomalous reward-related behaviour. OBJECTIVE: We designed a simple test of how subjects integrate information about the magnitude and the probability of reward, which can determine discriminative thresholds and choice bias in decisions under risk. DESIGN/METHODS: Twenty subjects were required to choose between two explicitly described prospects, one with higher probability but lower magnitude of reward than the other, with the difference in expected value between the two prospects varying from 3 to 23%. RESULTS: Subjects showed a mean threshold sensitivity of 43% difference in expected value. Regarding choice bias, there was a 'risk premium' of 38%, indicating a tendency to choose higher probability over higher reward. An analysis using prospect theory showed that this risk premium is the predicted outcome of hypothesized non-linearities in the subjective perception of reward value and probability. CONCLUSIONS: This simple test provides a robust measure of discriminative value thresholds and biases in decisions under risk. Prospect theory can also make predictions about decisions when subjective perception of reward or probability is anomalous, as may occur in populations with dopaminergic or striatal dysfunction, such as Parkinson's disease and schizophrenia.
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Sharp, Madeleine E.; Viswanathan, Jayalakshmi; Lanyon, Linda J.; Barton, Jason J. S.
2012-01-01
Background There are few clinical tools that assess decision-making under risk. Tests that characterize sensitivity and bias in decisions between prospects varying in magnitude and probability of gain may provide insights in conditions with anomalous reward-related behaviour. Objective We designed a simple test of how subjects integrate information about the magnitude and the probability of reward, which can determine discriminative thresholds and choice bias in decisions under risk. Design/Methods Twenty subjects were required to choose between two explicitly described prospects, one with higher probability but lower magnitude of reward than the other, with the difference in expected value between the two prospects varying from 3 to 23%. Results Subjects showed a mean threshold sensitivity of 43% difference in expected value. Regarding choice bias, there was a ‘risk premium’ of 38%, indicating a tendency to choose higher probability over higher reward. An analysis using prospect theory showed that this risk premium is the predicted outcome of hypothesized non-linearities in the subjective perception of reward value and probability. Conclusions This simple test provides a robust measure of discriminative value thresholds and biases in decisions under risk. Prospect theory can also make predictions about decisions when subjective perception of reward or probability is anomalous, as may occur in populations with dopaminergic or striatal dysfunction, such as Parkinson's disease and schizophrenia. PMID:22493669
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Voon, Valerie; Morris, Laurel S; Irvine, Michael A; Ruck, Christian; Worbe, Yulia; Derbyshire, Katherine; Rankov, Vladan; Schreiber, Liana Rn; Odlaug, Brian L; Harrison, Neil A; Wood, Jonathan; Robbins, Trevor W; Bullmore, Edward T; Grant, Jon E
2015-03-01
Pathological behaviors toward drugs and food rewards have underlying commonalities. Risk-taking has a fourfold pattern varying as a function of probability and valence leading to the nonlinearity of probability weighting with overweighting of small probabilities and underweighting of large probabilities. Here we assess these influences on risk-taking in patients with pathological behaviors toward drug and food rewards and examine structural neural correlates of nonlinearity of probability weighting in healthy volunteers. In the anticipation of rewards, subjects with binge eating disorder show greater risk-taking, similar to substance-use disorders. Methamphetamine-dependent subjects had greater nonlinearity of probability weighting along with impaired subjective discrimination of probability and reward magnitude. Ex-smokers also had lower risk-taking to rewards compared with non-smokers. In the anticipation of losses, obesity without binge eating had a similar pattern to other substance-use disorders. Obese subjects with binge eating also have impaired discrimination of subjective value similar to that of the methamphetamine-dependent subjects. Nonlinearity of probability weighting was associated with lower gray matter volume in dorsolateral and ventromedial prefrontal cortex and orbitofrontal cortex in healthy volunteers. Our findings support a distinct subtype of binge eating disorder in obesity with similarities in risk-taking in the reward domain to substance use disorders. The results dovetail with the current approach of defining mechanistically based dimensional approaches rather than categorical approaches to psychiatric disorders. The relationship to risk probability and valence may underlie the propensity toward pathological behaviors toward different types of rewards.
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Hofenk, D.J.B.; Pennings, J.M.E.; Trujillo Barrera, A.A.
2014-01-01
This paper examines producers’ motives underlying the adoption of sustainable practices. In particular, we focus on expected economic, social, and personal rewards, and examine the role of producers’ risk perception and risk tolerance. Results from personal computer-guided interviews with164 hog
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Legacy Risk Measure for Environmental Waste
International Nuclear Information System (INIS)
Eide, S. A.; Nitschke, R. L.
2002-01-01
The Idaho National Engineering and Environmental Laboratory (INEEL) is investigating the development of a comprehensive and quantitative risk model framework for environmental management activities at the site. Included are waste management programs (high-level waste, transuranic waste, low-level waste, mixed low-level waste, spent nuclear fuel, and special nuclear materials), major environmental restoration efforts, major decontamination and decommissioning projects, and planned long-term stewardship activities. Two basic types of risk estimates are included: risks from environmental management activities, and long-term legacy risks from wastes/materials. Both types of risks are estimated using the Environment, Safety, and Health Risk Assessment Program (ESHRAP) developed at the INEEL. Given these two types of risk calculations, the following evaluations can be performed: risk evaluation of an entire program (covering waste/material as it now exists through disposal or other e nd states); risk comparisons of alternative programs or activities; comparisons of risk benefit versus risk cost for activities or entire programs; ranking of programs or activities by risk; ranking of wastes/materials by risk; evaluation of site risk changes with time as activities progress; and integrated performance measurement using indicators such as injury/death and exposure rates. This paper discusses the definition and calculation of legacy risk measures and associated issues. The legacy risk measure is needed to support three of the seven types of evaluations listed above: comparisons of risk benefit versus risk cost, ranking of wastes/materials by risk, and evaluation of site risk changes with time
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Neural Correlates of Rewarded Response Inhibition in Youth at Risk for Problematic Alcohol Use
Directory of Open Access Journals (Sweden)
Brenden Tervo-Clemmens
2017-11-01
Full Text Available Risk for substance use disorder (SUD is associated with poor response inhibition and heightened reward sensitivity. During adolescence, incentives improve performance on response inhibition tasks and increase recruitment of cortical control areas (Geier et al., 2010 associated with SUD (Chung et al., 2011. However, it is unknown whether incentives moderate the relationship between response inhibition and trait-level psychopathology and personality features of substance use risk. We examined these associations in the current project using a rewarded antisaccade (AS task (Geier et al., 2010 in youth at risk for substance use. Participants were 116 adolescents and young adults (ages 12–21 from the University of Pittsburgh site of the National Consortium on Adolescent Neurodevelopment and Alcohol [NCANDA] study, with neuroimaging data collected at baseline and 1 year follow up visits. Building upon previous work using this task in normative developmental samples (Geier et al., 2010 and adolescents with SUD (Chung et al., 2011, we examined both trial-wise BOLD responses and those associated with individual task-epochs (cue presentation, response preparation, and response and associated them with multiple substance use risk factors (externalizing and internalizing psychopathology, family history of substance use, and trait impulsivity. Results showed that externalizing psychopathology and high levels of trait impulsivity (positive urgency, SUPPS-P were associated with general decreases in antisaccade performance. Accompanying this main effect of poor performance, positive urgency was associated with reduced recruitment of the frontal eye fields (FEF and inferior frontal gyrus (IFG in both a priori regions of interest and at the voxelwise level. Consistent with previous work, monetary incentive improved antisaccade behavioral performance and was associated with increased activation in the striatum and cortical control areas. However, incentives did
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Hofenk, D.J.B.; Pennings, J.M.E.; Trujillo Barrera, A.A.
2014-01-01
Abstract The purpose of this study is to examine producers’ motives underlying the adoption of sustainable practices. In particular, we focus on expected economic, social, and personal rewards, and examine the roles of producers’ risk perception and risk tolerance. Preliminary results from a survey
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Park, Junchol
2017-01-01
Actions motivated by rewards are often associated with risk of punishment. Little is known about the neural representation of punishment risk during reward-seeking behavior. We modeled this circumstance in rats by designing a task where actions were consistently rewarded but probabilistically punished. Spike activity and local field potentials were recorded during task performance simultaneously from VTA and mPFC, two reciprocally connected regions implicated in reward-seeking and aversive behaviors. At the single unit level, we found that ensembles of putative dopamine and non-dopamine VTA neurons and mPFC neurons encode the relationship between action and punishment. At the network level, we found that coherent theta oscillations synchronize VTA and mPFC in a bottom-up direction, effectively phase-modulating the neuronal spike activity in the two regions during punishment-free actions. This synchrony declined as a function of punishment probability, suggesting that during reward-seeking actions, risk of punishment diminishes VTA-driven neural synchrony between the two regions. PMID:29058673
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Peeters, M.; Oldehinkel, Tineke; Vollebergh, W.A.M.
2017-01-01
Neurodevelopmental theories of risk behavior hypothesize that low behavioral control in combination with high reward sensitivity explains adolescents' risk behavior. However, empirical studies examining this hypothesis while including actual risk taking behavior in adolescence are lacking. In this
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Peeters, Margot; Oldehinkel, Tineke; Vollebergh, Wilma
2017-01-01
Neurodevelopmental theories of risk behavior hypothesize that low behavioral control in combination with high reward sensitivity explains adolescents' risk behavior. However, empirical studies examining this hypothesis while including actual risk taking behavior in adolescence are lacking. In this
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Directory of Open Access Journals (Sweden)
Haley L Yarosh
Full Text Available Individuals with a positive family history for alcoholism (FHP have shown differences from family-history-negative (FHN individuals in the neural correlates of reward processing. FHP, compared to FHN individuals, demonstrate relatively diminished ventral striatal activation during anticipation of monetary rewards, and the degree of ventral striatal activation shows an inverse correlation with specific impulsivity measures in alcohol-dependent individuals. Rewards in socially interactive contexts relate importantly to addictive propensities, yet have not been examined with respect to how their neural underpinnings relate to impulsivity-related measures. Here we describe impulsivity measures in FHN and FHP individuals as they relate to a socially interactive functional magnetic resonance imaging (fMRI task.Forty FHP and 29 FHN subjects without histories of Axis-I disorders completed a socially interactive Domino task during functional magnetic resonance imaging and completed self-report and behavioral impulsivity-related assessments.FHP compared to FHN individuals showed higher scores (p = .004 on one impulsivity-related factor relating to both compulsivity (Padua Inventory and reward/punishment sensitivity (Sensitivity to Punishment/Sensitivity to Reward Questionnaire. Multiple regression analysis within a reward-related network revealed a correlation between risk-taking (involving another impulsivity-related factor, the Balloon Analog Risk Task (BART and right ventral striatum activation under reward >punishment contrast (p<0.05 FWE corrected in the social task.Behavioral risk-taking scores may be more closely associated with neural correlates of reward responsiveness in socially interactive contexts than are FH status or impulsivity-related self-report measures. These findings suggest that risk-taking assessments be examined further in socially interactive settings relevant to addictive behaviors.
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Dopamine agonist increases risk taking but blunts reward-related brain activity.
Directory of Open Access Journals (Sweden)
Jordi Riba
Full Text Available The use of D2/D3 dopaminergic agonists in Parkinson's disease (PD may lead to pathological gambling. In a placebo-controlled double-blind study in healthy volunteers, we observed riskier choices in a lottery task after administration of the D3 receptor-preferring agonist pramipexole thus mimicking risk-taking behavior in PD. Moreover, we demonstrate decreased activation in the rostral basal ganglia and midbrain, key structures of the reward system, following unexpected high gains and therefore propose that pathological gambling in PD results from the need to seek higher rewards to overcome the blunted response in this system.
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Dopaminergic circuitry and risk/reward decision making: implications for schizophrenia.
Stopper, Colin M; Floresco, Stan B
2015-01-01
Abnormal reinforcement learning and representations of reward value are present in schizophrenia, and these impairments can manifest as deficits in risk/reward decision making. These abnormalities may be due in part to dopaminergic dysfunction within cortico-limbic-striatal circuitry. Evidence from studies with laboratory animal have revealed that normal DA activity within different nodes of these circuits is critical for mediating dissociable processes that can refine decision biases. Moreover, both phasic and tonic dopamine transmission appear to play separate yet complementary roles in these processes. Tonic dopamine release within the prefrontal cortex and nucleus accumbens, serves as a "running rate-meter" of reward and reflects contextual information such as reward uncertainty and overt choice behavior. On the other hand, manipulations of outcome-related phasic dopamine bursts and dips suggest these signals provide rapid feedback to allow for quick adjustments in choice as reward contingencies change. The lateral habenula is a key input to the DA system that phasic signals is necessary for expressing subjective decision biases; as suppression of activity within this nucleus leads to catastrophic impairments in decision making and random patterns of choice behavior. As schizophrenia is characterized by impairments in using positive and negative feedback to appropriately guide decision making, these findings suggest that these deficits in these processes may be mediated, at least in part, by abnormalities in both tonic and phasic dopamine transmission. © The Author 2014. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.
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Concave utility, transaction costs, and risk in measuring discounting of delayed rewards.
Kirby, Kris N; Santiesteban, Mariana
2003-01-01
Research has consistently found that the decline in the present values of delayed rewards as delay increases is better fit by hyperbolic than by exponential delay-discounting functions. However, concave utility, transaction costs, and risk each could produce hyperbolic-looking data, even when the underlying discounting function is exponential. In Experiments 1 (N = 45) and 2 (N = 103), participants placed bids indicating their present values of real future monetary rewards in computer-based 2nd-price auctions. Both experiments suggest that utility is not sufficiently concave to account for the superior fit of hyperbolic functions. Experiment 2 provided no evidence that the effects of transaction costs and risk are large enough to account for the superior fit of hyperbolic functions.
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Waste-acceptance criteria and risk-based thinking for radioactive-waste classification
International Nuclear Information System (INIS)
Lowenthal, M.D.
1998-01-01
The US system of radioactive-waste classification and its development provide a reference point for the discussion of risk-based thinking in waste classification. The official US system is described and waste-acceptance criteria for disposal sites are introduced because they constitute a form of de facto waste classification. Risk-based classification is explored and it is found that a truly risk-based system is context-dependent: risk depends not only on the waste-management activity but, for some activities such as disposal, it depends on the specific physical context. Some of the elements of the official US system incorporate risk-based thinking, but like many proposed alternative schemes, the physical context of disposal is ignored. The waste-acceptance criteria for disposal sites do account for this context dependence and could be used as a risk-based classification scheme for disposal. While different classes would be necessary for different management activities, the waste-acceptance criteria would obviate the need for the current system and could better match wastes to disposal environments saving money or improving safety or both
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Risk management for noncombustion wastes
International Nuclear Information System (INIS)
Connor, K.K.; Rice, J.S.
1991-01-01
The Noncombustion Waste Risk Management Project is designed to incorporate the insights and information developed in these projects into tools that will help utilities make better noncombustion waste management decisions. Specific project goals are to synthesize information useful to utilities on noncombustion wastes, emphasize waste reduction as a priority over end-of-pipe management, develop methods to manage the costs and risks associated with noncombustion wastes (e.g., direct costs, permitting costs, liability costs, public relations costs), develop software and documentation to deliver the information and analysis methods to the industry. This project was initiated EPRI's Environment Division in late 1988. The early phases of the project involved gathering information on current noncombustion waste management practices, specific utility problems and concerns with respect to these wastes, current and potential future regulations, and current and emerging management options. Recent efforts have focused on characterizing the direct and indirect (e.g., lawsuits, remedial action) costs of managing these wastes and on developing and implementing risk management methods for a subset of wastes. The remainder of this paper describes the specific issues addressed by and the results and insights from the three completed waste-specific studies
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Hanford waste vitrification systems risk assessment
International Nuclear Information System (INIS)
Miller, W.C.; Hamilton, D.W.; Holton, L.K.; Bailey, J.W.
1991-09-01
A systematic Risk Assessment was performed to identify the technical, regulatory, and programmatic uncertainties and to quantify the risks to the Hanford Site double-shell tank waste vitrification program baseline (as defined in December 1990). Mitigating strategies to reduce the overall program risk were proposed. All major program elements were evaluated, including double-shell tank waste characterization, Tank Farms, retrieval, pretreatment, vitrification, and grouting. Computer-based techniques were used to quantify risks to proceeding with construction of the Hanford Waste Vitrification Plant on the present baseline schedule. Risks to the potential vitrification of single-shell tank wastes and cesium and strontium capsules were also assessed. 62 refs., 38 figs., 26 tabs
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Inherent reward & risk (Part I): Towards a universal paradigm for investment analysis
Zou, L.
2000-01-01
In this paper, a new paradigm is developed for analyzinginvestment strategies and pricing financial assets. This paradigmassumes that any investment strategy has its own "inherent reward"and "inherent risk" that can be judged with common sense. Ijustify axiomatically the existence and uniqueness
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Trost, Sarah; Diekhof, Esther K; Mohr, Holger; Vieker, Henning; Krämer, Bernd; Wolf, Claudia; Keil, Maria; Dechent, Peter; Binder, Elisabeth B; Gruber, Oliver
2016-10-01
Recent genome-wide association studies have identified MAD1L1 (mitotic arrest deficient-like 1) as a susceptibility gene for bipolar disorder and schizophrenia. The minor allele of the single-nucleotide polymorphism (SNP) rs11764590 in MAD1L1 was associated with bipolar disorder. Both diseases, bipolar disorder and schizophrenia, are linked to functional alterations in the reward system. We aimed at investigating possible effects of the MAD1L1 rs11764590 risk allele on reward systems functioning in healthy adults. A large homogenous sample of 224 young (aged 18-31 years) participants was genotyped and underwent functional magnetic resonance imaging (fMRI). All participants performed the 'Desire-Reason Dilemma' paradigm investigating the neural correlates that underlie reward processing and active reward dismissal in favor of a long-term goal. We found significant hypoactivations of the ventral tegmental area (VTA), the bilateral striatum and bilateral frontal and parietal cortices in response to conditioned reward stimuli in the risk allele carriers compared with major allele carriers. In the dilemma situation, functional connectivity between prefrontal brain regions and the ventral striatum was significantly diminished in the risk allele carriers. Healthy risk allele carriers showed a significant deficit of their bottom-up response to conditioned reward stimuli in the bilateral VTA and striatum. Furthermore, functional connectivity between the ventral striatum and prefrontal areas exerting top-down control on the mesolimbic reward system was reduced in this group. Similar alterations in reward processing and disturbances of prefrontal control mechanisms on mesolimbic brain circuits have also been reported in bipolar disorder and schizophrenia. Together, these findings suggest the existence of an intermediate phenotype associated with MAD1L1.
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Floresco, Stan B; Montes, David R; Tse, Maric M T; van Holstein, Mieke
2018-02-21
The nucleus accumbens (NAc) is a key node within corticolimbic circuitry for guiding action selection and cost/benefit decision making in situations involving reward uncertainty. Preclinical studies have typically assessed risk/reward decision making using assays where decisions are guided by internally generated representations of choice-outcome contingencies. Yet, real-life decisions are often influenced by external stimuli that inform about likelihoods of obtaining rewards. How different subregions of the NAc mediate decision making in such situations is unclear. Here, we used a novel assay colloquially termed the "Blackjack" task that models these types of situations. Male Long-Evans rats were trained to choose between one lever that always delivered a one-pellet reward and another that delivered four pellets with different probabilities [either 50% (good-odds) or 12.5% (poor-odds)], which were signaled by one of two auditory cues. Under control conditions, rats selected the large/risky option more often on good-odds versus poor-odds trials. Inactivation of the NAc core caused indiscriminate choice patterns. In contrast, NAc shell inactivation increased risky choice, more prominently on poor-odds trials. Additional experiments revealed that both subregions contribute to auditory conditional discrimination. NAc core or shell inactivation reduced Pavlovian approach elicited by an auditory CS+, yet shell inactivation also increased responding during presentation of a CS-. These data highlight distinct contributions for NAc subregions in decision making and reward seeking guided by discriminative stimuli. The core is crucial for implementation of conditional rules, whereas the shell refines reward seeking by mitigating the allure of larger, unlikely rewards and reducing expression of inappropriate or non-rewarded actions. SIGNIFICANCE STATEMENT Using external cues to guide decision making is crucial for adaptive behavior. Deficits in cue-guided behavior have been
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Attentional Bias Predicts Increased Reward Salience and Risk Taking in Bipolar Disorder.
Mason, Liam; Trujillo-Barreto, Nelson J; Bentall, Richard P; El-Deredy, Wael
2016-02-15
There is amassing evidence that risky decision-making in bipolar disorder is related to reward-based differences in frontostriatal regions. However, the roles of early attentional and later cognitive processes remain unclear, limiting theoretical understanding and development of targeted interventions. Twenty euthymic bipolar disorder and 19 matched control participants played a Roulette task in which they won and lost money. Event-related potentials and source analysis were used to quantify predominantly sensory-attentional (N1), motivational salience (feedback-related negativities [FRN]), and cognitive appraisal (P300) stages of processing. We predicted that the bipolar disorder group would show increased N1, consistent with increased attentional orienting, and reduced FRN, consistent with a bias to perceive outcomes more favorably. As predicted, the bipolar disorder group showed increased N1 and reduced FRN but no differences in P300. N1 amplitude was additionally associated with real-life risk taking, and N1 source activity was reduced in visual cortex but increased activity in precuneus, frontopolar, and premotor cortex, compared to those of controls. These findings demonstrate an early attentional bias to reward that potentially drives risk taking by priming approach behavior and elevating reward salience in the frontostriatal pathway. Although later cognitive appraisals of these inputs may be relatively intact in remission, interventions targeting attention orienting may also be effective in long-term reduction of relapse. Copyright © 2016 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.
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International Nuclear Information System (INIS)
Liljenzin, J.O.; Rydberg, J.
1996-11-01
The first part of this review discusses the importance of risk. If there is any relation between the emotional and rational risk perceptions (for example, it is believed that increased knowledge will decrease emotions), it will be a desirable goal for society, and the nuclear industry in particular, to improve the understanding by the laymen of the rational risks from nuclear energy. This review surveys various paths to a more common comprehension - perhaps a consensus - of the nuclear waste risks. The second part discusses radioactivity as a risk factor and concludes that it has no relation in itself to risk, but must be connected to exposure leading to a dose risk, i.e. a health detriment, which is commonly expressed in terms of cancer induction rate. Dose-effect relations are discussed in light of recent scientific debate. The third part of the report describes a number of hazard indexes for nuclear waste found in the literature and distinguishes between absolute and relative risk scales. The absolute risks as well as the relative risks have changed over time due to changes in radiological and metabolic data and by changes in the mode of calculation. To judge from the literature, the risk discussion is huge, even when it is limited to nuclear waste. It would be very difficult to make a comprehensive review and extract the essentials from that. Therefore, we have chosen to select some publications, out of the over 100, which we summarize rather comprehensively; in some cases we also include our remarks. 110 refs, 22 figs
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Energy Technology Data Exchange (ETDEWEB)
Liljenzin, J.O.; Rydberg, J. [Radiochemistry Consultant Group, Vaestra Froelunda (Sweden)
1996-11-01
The first part of this review discusses the importance of risk. If there is any relation between the emotional and rational risk perceptions (for example, it is believed that increased knowledge will decrease emotions), it will be a desirable goal for society, and the nuclear industry in particular, to improve the understanding by the laymen of the rational risks from nuclear energy. This review surveys various paths to a more common comprehension - perhaps a consensus - of the nuclear waste risks. The second part discusses radioactivity as a risk factor and concludes that it has no relation in itself to risk, but must be connected to exposure leading to a dose risk, i.e. a health detriment, which is commonly expressed in terms of cancer induction rate. Dose-effect relations are discussed in light of recent scientific debate. The third part of the report describes a number of hazard indexes for nuclear waste found in the literature and distinguishes between absolute and relative risk scales. The absolute risks as well as the relative risks have changed over time due to changes in radiological and metabolic data and by changes in the mode of calculation. To judge from the literature, the risk discussion is huge, even when it is limited to nuclear waste. It would be very difficult to make a comprehensive review and extract the essentials from that. Therefore, we have chosen to select some publications, out of the over 100, which we summarize rather comprehensively; in some cases we also include our remarks. 110 refs, 22 figs.
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Alloy, Lauren B; Boland, Elaine M; Ng, Tommy H; Whitehouse, Wayne G; Abramson, Lyn Y
2015-11-01
The social zeitgeber model (Ehlers, Frank, & Kupfer, 1988) suggests that irregular daily schedules or social rhythms provide vulnerability to bipolar spectrum disorders. This study tested whether social rhythm regularity prospectively predicted first lifetime onset of bipolar spectrum disorders in adolescents already at risk for bipolar disorder based on exhibiting reward hypersensitivity. Adolescents (ages 14-19 years) previously screened to have high (n = 138) or moderate (n = 95) reward sensitivity, but no lifetime history of bipolar spectrum disorder, completed measures of depressive and manic symptoms, family history of bipolar disorder, and the Social Rhythm Metric. They were followed prospectively with semistructured diagnostic interviews every 6 months for an average of 31.7 (SD = 20.1) months. Hierarchical logistic regression indicated that low social rhythm regularity at baseline predicted greater likelihood of first onset of bipolar spectrum disorder over follow-up among high-reward-sensitivity adolescents but not moderate-reward-sensitivity adolescents, controlling for follow-up time, gender, age, family history of bipolar disorder, and initial manic and depressive symptoms (β = -.150, Wald = 4.365, p = .037, odds ratio = .861, 95% confidence interval [.748, .991]). Consistent with the social zeitgeber theory, low social rhythm regularity provides vulnerability to first onset of bipolar spectrum disorder among at-risk adolescents. It may be possible to identify adolescents at risk for developing a bipolar spectrum disorder based on exhibiting both reward hypersensitivity and social rhythm irregularity before onset occurs. (c) 2015 APA, all rights reserved).
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Dopamine reward prediction error responses reflect marginal utility.
Stauffer, William R; Lak, Armin; Schultz, Wolfram
2014-11-03
Optimal choices require an accurate neuronal representation of economic value. In economics, utility functions are mathematical representations of subjective value that can be constructed from choices under risk. Utility usually exhibits a nonlinear relationship to physical reward value that corresponds to risk attitudes and reflects the increasing or decreasing marginal utility obtained with each additional unit of reward. Accordingly, neuronal reward responses coding utility should robustly reflect this nonlinearity. In two monkeys, we measured utility as a function of physical reward value from meaningful choices under risk (that adhered to first- and second-order stochastic dominance). The resulting nonlinear utility functions predicted the certainty equivalents for new gambles, indicating that the functions' shapes were meaningful. The monkeys were risk seeking (convex utility function) for low reward and risk avoiding (concave utility function) with higher amounts. Critically, the dopamine prediction error responses at the time of reward itself reflected the nonlinear utility functions measured at the time of choices. In particular, the reward response magnitude depended on the first derivative of the utility function and thus reflected the marginal utility. Furthermore, dopamine responses recorded outside of the task reflected the marginal utility of unpredicted reward. Accordingly, these responses were sufficient to train reinforcement learning models to predict the behaviorally defined expected utility of gambles. These data suggest a neuronal manifestation of marginal utility in dopamine neurons and indicate a common neuronal basis for fundamental explanatory constructs in animal learning theory (prediction error) and economic decision theory (marginal utility). Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.
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Chemical risks from nuclear waste repositories
International Nuclear Information System (INIS)
Persson, L.
1988-01-01
Studies concerning the chemical risks of nuclear waste are reviewed. The radiological toxicity of the material is of primary concern but the potential nonradiological toxicity should not be overlooked as the chemotoxic substances may reach the biosphere from a nuclear waste repository. In the report is concluded that the possible chemotoxic effects of a repository for nuclear waste should be studied as a part of the formal risk assessment of the disposal concept. (author)
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Effort–reward imbalance at work and risk of depressive disorders
DEFF Research Database (Denmark)
Rugulies, Reiner; Aust, Birgit; H. Madsen, Ida E.
2017-01-01
Objective: The aim of this review was to determine whether employees exposed to effort–reward imbalance (ERI) at work have a higher risk of depressive disorders than non-exposed employees. Methods: We conducted a systematic review and meta-analysis of published prospective cohort studies examining...... the association of ERI at baseline with onset of depressive disorders at follow-up. The work was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement and a detailed study protocol was registered before literature search commenced (Registration...
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Commercial viability of CNS drugs: balancing the risk/reward profile.
Johnson, Ginger S
2014-01-01
CNS has historically been a formidable therapeutic area in which to innovate owing to biological (e.g., complex neurobiology, difficulty reaching the target), as well as clinical (e.g., subjective clinical endpoints, high placebo response, lack of biomarkers) challenges. In the current market where many of the larger diseases are dominated by a generic standard of care, commercial challenges now make the triple threat of scientific-clinical-commercial risk too much for many players to tackle. However, opportunities do exist for smaller biotech companies to concentrate on narrowly focused patient populations associated with high unmet need for which risk can be tightly defined. In CNS, there are two major areas to balance the risk/reward profile and create commercially viable opportunities: To realize value, all companies (start-ups and big players) must define, measure and quantify clear and meaningful value to all stakeholders: physicians, patients, caregivers and payers. © 2013.
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Pavlovian conditioning to food reward as a function of eating disorder risk.
Astur, Robert S; Palmisano, Alexandra N; Hudd, Ellie C; Carew, Andrew W; Deaton, Bonnie E; Kuhney, Franchesca S; Niezrecki, Rachel N; Santos, Melissa
2015-09-15
The aim of this experiment was to examine the extent to which eating disorder risk affects the strength of food-reward conditioning. Eighty food-restricted undergraduates were placed into a VR environment consisting of two visually distinct rooms. Participants underwent multiple pairing sessions in which they were confined into one of the two rooms and explored a VR environment. Room A was paired with real-life M&Ms for three sessions, and Room B was paired with no food for three sessions. After a short delay, a test session was administered, and participants were given free access to the entire VR environment for 5 min. Participants also completed the Eating Attitudes Test (EAT-26; [11]), which is a standard screening tool of eating disorder risk. Participants displayed a significant conditioned place preference for the VR room previously paired with food, and they displayed a significant explicit preference for the M&M-paired room in a forced-choice test. There was a significant positive correlation between place preference strength and scores on the dieting subscale of the EAT-26. Additionally, ratings of the no-food room were significantly lower as dieting scores increased. This suggests that components of eating disorder risk can influence basic conditioning strength to places associated with food reward. For both males and females, additional correlations between eating disorder risk subscales and conditioning variables are discussed, and implications for future research are proposed in hopes of understanding how conditioning paradigms can provide insight into treating and preventing eating disorders. Copyright © 2015 Elsevier B.V. All rights reserved.
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St Gelais, Adam T; Costa-Pierce, Barry A
2016-01-15
Mercury (Hg) contamination testing was conducted on winter-caught male spiny dogfish (Squalus acanthias) in southern New England and results compared to available data on Hg concentrations for this species. A limited risk-reward assessment for EPA (eicosapentanoic acid) and DHA (docosahexanoic acid) lipid concentrations of spiny dogfish was completed in comparison with other commonly consumed marine fish. Mean Hg concentrations were 0.19 ppm (±0.30) wet weight. In comparison, mean Hg concentrations in S. acanthias varied geographically ranging from 0.05 ppm (Celtic Sea) to 2.07 ppm (Crete, Mediterranean Sea). A risk-reward assessment for Hg and DHA+EPA placed S. acanthias in both "low-risk, high-reward" and "high-risk, high-reward" categories for consumption dependent on locations of the catch. Our results are limited and are not intended as consumption advisories but serve to illustrate the need for making more nuanced, geo-specific, consumption guidance for spiny dogfish that is inclusive of seafood traceability and nutritional benefits. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
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Risk, reward, and decision-making in a rodent model of cognitive aging.
Gilbert, Ryan J; Mitchell, Marci R; Simon, Nicholas W; Bañuelos, Cristina; Setlow, Barry; Bizon, Jennifer L
2011-01-01
Impaired decision-making in aging can directly impact factors (financial security, health care) that are critical to maintaining quality of life and independence at advanced ages. Naturalistic rodent models mimic human aging in other cognitive domains, and afford the opportunity to parse the effects of age on discrete aspects of decision-making in a manner relatively uncontaminated by experiential factors. Young adult (5-7 months) and aged (23-25 months) male F344 rats were trained on a probability discounting task in which they made discrete-trial choices between a small certain reward (one food pellet) and a large but uncertain reward (two food pellets with varying probabilities of delivery ranging from 100 to 0%). Young rats chose the large reward when it was associated with a high probability of delivery and shifted to the small but certain reward as probability of the large reward decreased. As a group, aged rats performed comparably to young, but there was significantly greater variance among aged rats. One subgroup of aged rats showed strong preference for the small certain reward. This preference was maintained under conditions in which large reward delivery was also certain, suggesting decreased sensitivity to reward magnitude. In contrast, another subgroup of aged rats showed strong preference for the large reward at low probabilities of delivery. Interestingly, this subgroup also showed elevated preference for probabilistic rewards when reward magnitudes were equalized. Previous findings using this same aged study population described strongly attenuated discounting of delayed rewards with age, together suggesting that a subgroup of aged rats may have deficits associated with accounting for reward costs (i.e., delay or probability). These deficits in cost-accounting were dissociable from the age-related differences in sensitivity to reward magnitude, suggesting that aging influences multiple, distinct mechanisms that can impact cost-benefit decision-making.
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Risk, reward, and decision-making in a rodent model of cognitive aging
Directory of Open Access Journals (Sweden)
Ryan J Gilbert
2012-01-01
Full Text Available Impaired decision-making in aging can directly impact factors (financial security, quality of healthcare that are critical to maintaining quality of life and independence at advanced ages. Naturalistic rodent models mimic human aging in other cognitive domains, and afford the opportunity to parse the effects of age on discrete aspects of decision-making in a manner relatively uncontaminated by experiential factors. Young adult (5-7 mo. and aged (23-25 mo. male F344 rats were trained on a probability discounting task in which they made discrete-trial choices between a small certain reward (1 food pellet and a large but uncertain reward (2 food pellets with varying probabilities of delivery ranging from 100% to 0%. Young rats chose the large reward when it was associated with a high probability of delivery and shifted to the smaller but certain reward as probability of the large reward decreased. As a group, aged rats performed comparably to young, but there was significantly greater variance among aged rats. One subgroup of aged rats showed strong preference for the small certain reward. This preference was maintained under conditions in which large reward delivery was certain, suggesting decreased sensitivity to reward magnitude. In contrast, another subgroup of aged rats showed strong preference for the large reward at low probabilities of delivery. Interestingly, this subgroup also showed elevated preference for probabilistic rewards when reward magnitudes were equalized. Previous findings using this same aged study population described strongly attenuated discounting of delayed rewards with age, together suggesting that a subgroup of aged rats may have deficits associated with accounting for costs (i.e., delay, probability. These deficits in cost-accounting were dissociable from the age-related differences in sensitivity to reward magnitude, suggesting that aging influences multiple, distinct neural mechanisms that can impact cost
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Risk assessment and radioactive waste management
International Nuclear Information System (INIS)
Cohen, J.J.
1979-01-01
Problems of radioactive waste management, both real and apparent, have provided a serious constraint in the development of nuclear power. Several studies have been conducted in an attempt to evaluate the actual (quantifiable) risks of radioactive waste management and place them in a reasonable perspective. These studies are reviewed and discussed. Generally, the studies indicate the risks to be of a level of seriousness which might normally be considered acceptable in current society. However, it is apparent that this acceptability has not been attained and public apprehension prevails. To understand the reasons for this apprehension requires an assessment of those factors of ''perceived'' risks which play a major role in determining public attitudes toward radioactive waste management programs and nuclear power, in general. Such factors might include the spector of legacies of harm to future generations, genetic effects, nuclear garbage dumps, proliferation of plutonium inventories, nuclear terrorism, etc. A major problem in development of acceptable waste management policies and programs requires not only the recognition of the importance of perceived risk factors but development of a methodology for their incorporation in planning and conduct of such activities. Some approaches to the development of this methodology are discussed
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Kouvonen, Anne; Kivimäki, Mika; Virtanen, Marianna; Heponiemi, Tarja; Elovainio, Marko; Pentti, Jaana; Linna, Anne; Vahtera, Jussi
2006-02-07
In occupational life, a mismatch between high expenditure of effort and receiving few rewards may promote the co-occurrence of lifestyle risk factors, however, there is insufficient evidence to support or refute this hypothesis. The aim of this study is to examine the extent to which the dimensions of the Effort-Reward Imbalance (ERI) model--effort, rewards and ERI--are associated with the co-occurrence of lifestyle risk factors. Based on data from the Finnish Public Sector Study, cross-sectional analyses were performed for 28,894 women and 7233 men. ERI was conceptualized as a ratio of effort and rewards. To control for individual differences in response styles, such as a personal disposition to answer negatively to questionnaires, occupational and organizational-level ecological ERI scores were constructed in addition to individual-level ERI scores. Risk factors included current smoking, heavy drinking, body mass index > or =25 kg/m2, and physical inactivity. Multinomial logistic regression models were used to estimate the likelihood of having one risk factor, two risk factors, and three or four risk factors. The associations between ERI and single risk factors were explored using binary logistic regression models. After adjustment for age, socioeconomic position, marital status, and type of job contract, women and men with high ecological ERI were 40% more likely to have simultaneously > or =3 lifestyle risk factors (vs. 0 risk factors) compared with their counterparts with low ERI. When examined separately, both low ecological effort and low ecological rewards were also associated with an elevated prevalence of risk factor co-occurrence. The results obtained with the individual-level scores were in the same direction. The associations of ecological ERI with single risk factors were generally less marked than the associations with the co-occurrence of risk factors. This study suggests that a high ratio of occupational efforts relative to rewards may be
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Kouvonen, Anne; Kivimäki, Mika; Virtanen, Marianna; Heponiemi, Tarja; Elovainio, Marko; Pentti, Jaana; Linna, Anne; Vahtera, Jussi
2006-01-01
Abstract Background In occupational life, a mismatch between high expenditure of effort and receiving few rewards may promote the co-occurrence of lifestyle risk factors, however, there is insufficient evidence to support or refute this hypothesis. The aim of this study is to examine the extent to which the dimensions of the Effort-Reward Imbalance (ERI) model – effort, rewards and ERI – are associated with the co-occurrence of lifestyle risk factors. Methods Based on data from the Finnish Pu...
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Tank waste remediation system tank waste retrieval risk management plan
International Nuclear Information System (INIS)
Klimper, S.C.
1997-01-01
This Risk Management Plan defines the approach to be taken to manage programmatic risks in the TWRS Tank Waste Retrieval program. It provides specific instructions applicable to TWR, and is used to supplement the guidance given by the TWRS Risk Management procedure
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Directory of Open Access Journals (Sweden)
Ulla K Seidel
Full Text Available Besides motor function, the basal ganglia have been implicated in feedback learning. In patients with chronic basal ganglia infarcts, deficits in reward-based reversal learning have previously been described.We re-examined the acquisition and reversal of stimulus-stimulus-reward associations and acquired equivalence in eleven patients with acute basal ganglia stroke (8 men, 3 women; 57.8±13.3 years, whose performance was compared eleven healthy subjects of comparable age, sex distribution and education, who were recruited outside the hospital. Eleven hospitalized patients with a similar vascular risk profile as the stroke patients but without stroke history served as clinical control group.In a neuropsychological assessment 7±3 days post-stroke, verbal and spatial short-term and working memory and inhibition control did not differ between groups. Compared with healthy subjects, control patients with vascular risk factors exhibited significantly reduced performance in the reversal phase (F[2,30] = 3.47; p = 0.044; post-hoc comparison between risk factor controls and healthy controls: p = 0.030, but not the acquisition phase (F[2,30] = 1.01; p = 0.376 and the acquired equivalence (F[2,30] = 1.04; p = 0.367 tasks. In all tasks, the performance of vascular risk factor patients closely resembled that of basal ganglia stroke patients. Correlation studies revealed a significant association of the number of vascular risk factors with reversal learning (r = -0.33, p = 0.012, but not acquisition learning (r = -0.20, p = 0.121 or acquired equivalence (r = -0.22, p = 0.096.The previously reported impairment of reward-based learning may be attributed to vascular risk factors and associated diseases, which are enriched in stroke patients. This study emphasizes the necessity of appropriate control subjects in cognition studies.
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Weiland, Barbara J; Zucker, Robert A; Zubieta, Jon-Kar; Heitzeg, Mary M
2017-03-01
Dopamine receptor concentrations, primarily in the striatum, are hypothesized to contribute to a developmental imbalance between subcortical and prefrontal control systems in emerging adulthood potentially biasing motivation and increasing risky behaviors. Positron emission tomography studies have found significant reductions in striatal dopamine D2 receptors, and blunted amphetamine-induced dopamine release, in substance users compared with healthy controls. Extant literature is limited and inconsistent concerning vulnerability associated with having a family history of substance abuse (FH+). Some studies have reported familial liability associated with higher dopamine receptor levels, reduced dopamine response to stimulant challenges and decreased response to oral alcohol. However, other reports have failed to find group differences based on family history. We explored the interaction of familial liability and behavioral risk with multi-modal molecular and neural imaging of the dopaminergic system. Forty-four young adult male subjects performed monetary incentive delay tasks during both [ 11 C]raclopride positron emission tomography and functional magnetic resonance imaging scans. FH+ subjects were identified as low (n = 24) or high risk (n = 9) based on early initiation of drunkenness. FH+ high-risk subjects exhibited heightened striatal dopamine response to monetary reward but did not differ in neural activations compared with FH+ low risk subjects and controls with no familial loading (n = 11). Across all subjects, a negative relationship was found between dopamine release and age of first drunkenness and a positive relationship with neural response to reward receipt. These results suggest that in at-risk individuals, higher dopamine transmission associated with monetary reward may represent a particularly useful neurobiological phenotype. © 2016 Society for the Study of Addiction.
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International Nuclear Information System (INIS)
Earle, T.C.; Lindell, M.K.; Rankin, W.L.
1981-07-01
Public acceptance of radioactive waste management alternatives depends in part on public perception of the associated risks. Three aspects of those perceived risks were explored in this study: (1) synthetic measures of risk perception based on judgments of probability and consequences; (2) acceptability of hypothetical radioactive waste policies, and (3) effects of human values on risk perception. Both the work on synthetic measures of risk perception and on the acceptability of hypothetical policies included investigations of three categories of risk: (1) Short-term public risk (affecting persons living when the wastes are created), (2) Long-term public risk (affecting persons living after the time the wastes were created), and (3) Occupational risk (affecting persons working with the radioactive wastes). The human values work related to public risk perception in general, across categories of persons affected
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Effort reward imbalance, and salivary cortisol in the morning
DEFF Research Database (Denmark)
Eller, Nanna Hurwitz; Nielsen, Søren Feodor; Blønd, Morten
2012-01-01
Effort reward imbalance (ERI) is suggested to increase risk for stress and is hypothesized to increase cortisol levels, especially the awakening cortisol response, ACR.......Effort reward imbalance (ERI) is suggested to increase risk for stress and is hypothesized to increase cortisol levels, especially the awakening cortisol response, ACR....
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Directory of Open Access Journals (Sweden)
Söderberg Mia
2012-12-01
Full Text Available Abstract Background This cross-sectional study explored relationships between psychosocial work environment, captured by job demand-control (JDC and effort-reward imbalance (ERI, and seven cardiovascular heart disease (CHD risk factors in a general population. Method The sampled consists of randomly-selected men and women from Gothenburg, Sweden and the city’s surrounding metropolitan areas. Associations between psychosocial variables and biomarkers were analysed with multiple linear regression adjusted for age, smoking, education and occupational status. Results The study included 638 men and 668 women aged 24–71. Analysis between JDC and CHD risk factors illustrated that, for men, JDC was associated with impaired scores in several biomarkers, especially among those in high strain jobs. For women, there were no relationships between JDC and biomarkers. In the analysis of links between ERI and CHD risk factors, most associations tested null. The only findings were raised triglycerides and BMI among men in the fourth quartile of the ERI-ratio distribution, and lowered LDL-cholesterol for women. An complementary ERI analysis, combining high/low effort and reward into categories, illustrated lowered triglycerides and elevated HDL-cholesterol values among women reporting high efforts and high rewards, compared to women experiencing low effort and high reward. Conclusions There were some associations between psychosocial stressors and CHD risk factors. The cross-sectional design did not allow conclusions about causality but some results indicated gender differences regarding sensitivity to work stressors and also how the models might capture different psychosocial dimensions.
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Kouvonen, Anne; Kivimäki, Mika; Virtanen, Marianna; Heponiemi, Tarja; Elovainio, Marko; Pentti, Jaana; Linna, Anne; Vahtera, Jussi
2006-01-01
Background In occupational life, a mismatch between high expenditure of effort and receiving few rewards may promote the co-occurrence of lifestyle risk factors, however, there is insufficient evidence to support or refute this hypothesis. The aim of this study is to examine the extent to which the dimensions of the Effort-Reward Imbalance (ERI) model – effort, rewards and ERI – are associated with the co-occurrence of lifestyle risk factors. Methods Based on data from the Finnish Public Sector Study, cross-sectional analyses were performed for 28,894 women and 7233 men. ERI was conceptualized as a ratio of effort and rewards. To control for individual differences in response styles, such as a personal disposition to answer negatively to questionnaires, occupational and organizational -level ecological ERI scores were constructed in addition to individual-level ERI scores. Risk factors included current smoking, heavy drinking, body mass index ≥25 kg/m2, and physical inactivity. Multinomial logistic regression models were used to estimate the likelihood of having one risk factor, two risk factors, and three or four risk factors. The associations between ERI and single risk factors were explored using binary logistic regression models. Results After adjustment for age, socioeconomic position, marital status, and type of job contract, women and men with high ecological ERI were 40% more likely to have simultaneously ≥3 lifestyle risk factors (vs. 0 risk factors) compared with their counterparts with low ERI. When examined separately, both low ecological effort and low ecological rewards were also associated with an elevated prevalence of risk factor co-occurrence. The results obtained with the individual-level scores were in the same direction. The associations of ecological ERI with single risk factors were generally less marked than the associations with the co-occurrence of risk factors. Conclusion This study suggests that a high ratio of occupational
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Directory of Open Access Journals (Sweden)
Elovainio Marko
2006-02-01
Full Text Available Abstract Background In occupational life, a mismatch between high expenditure of effort and receiving few rewards may promote the co-occurrence of lifestyle risk factors, however, there is insufficient evidence to support or refute this hypothesis. The aim of this study is to examine the extent to which the dimensions of the Effort-Reward Imbalance (ERI model – effort, rewards and ERI – are associated with the co-occurrence of lifestyle risk factors. Methods Based on data from the Finnish Public Sector Study, cross-sectional analyses were performed for 28,894 women and 7233 men. ERI was conceptualized as a ratio of effort and rewards. To control for individual differences in response styles, such as a personal disposition to answer negatively to questionnaires, occupational and organizational -level ecological ERI scores were constructed in addition to individual-level ERI scores. Risk factors included current smoking, heavy drinking, body mass index ≥25 kg/m2, and physical inactivity. Multinomial logistic regression models were used to estimate the likelihood of having one risk factor, two risk factors, and three or four risk factors. The associations between ERI and single risk factors were explored using binary logistic regression models. Results After adjustment for age, socioeconomic position, marital status, and type of job contract, women and men with high ecological ERI were 40% more likely to have simultaneously ≥3 lifestyle risk factors (vs. 0 risk factors compared with their counterparts with low ERI. When examined separately, both low ecological effort and low ecological rewards were also associated with an elevated prevalence of risk factor co-occurrence. The results obtained with the individual-level scores were in the same direction. The associations of ecological ERI with single risk factors were generally less marked than the associations with the co-occurrence of risk factors. Conclusion This study suggests that a high
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Energy Technology Data Exchange (ETDEWEB)
Earle, T.C.; Lindell, M.K.; Rankin, W.L.
1981-07-01
Public acceptance of radioactive waste management alternatives depends in part on public perception of the associated risks. Three aspects of those perceived risks were explored in this study: (1) synthetic measures of risk perception based on judgments of probability and consequences; (2) acceptability of hypothetical radioactive waste policies, and (3) effects of human values on risk perception. Both the work on synthetic measures of risk perception and on the acceptability of hypothetical policies included investigations of three categories of risk: (1) Short-term public risk (affecting persons living when the wastes are created), (2) Long-term public risk (affecting persons living after the time the wastes were created), and (3) Occupational risk (affecting persons working with the radioactive wastes). The human values work related to public risk perception in general, across categories of persons affected. Respondents were selected according to a purposive sampling strategy.
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Sensitivity to reward: implications for overeating and overweight.
Davis, Caroline; Strachan, Shaelyn; Berkson, Marni
2004-04-01
Sensitivity to reward (STR)-a personality trait firmly rooted in the neurobiology of the mesolimbic dopamine system-has been strongly implicated in the risk for addiction. This construct describes the ability to derive pleasure or reward from natural reinforcers like food, and from pharmacologic rewards like addictive drugs. Recently experts in the field of addiction research have acknowledged that psychomotor stimulant drugs are no longer at the heart of all addictions, and that brain circuits can also be deranged with natural rewards like food. The present study tested a model in which STR was expected to relate positively to overeating, which in turn would be associated with higher body weight in woman aged 25-45 years. As predicted, STR was correlated positively with measures of emotional overeating. Also, overweight woman were significantly more sensitive to reward than those of normal weight. Interestingly, however, the obese woman (Body Mass Index>30) were more anhedonic than the overweight woman (Body Mass Index>25reward circuits. Results also indicate that STR may serve as a risk factor for overeating and overweight, especially in cultures such as ours where palatable, calorically-dense food is plentiful.
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Directory of Open Access Journals (Sweden)
Badri Munir Sukoco
2015-06-01
Full Text Available Managers could elicit customers’ repeat purchase behavior through a well-designed reward program. This study examines two extrinsic cues - business longevity and timing effects of reward – to determine the consumers’ perceived risk and intention to participate in this kind of program. Moreover, this study discusses how different levels of involvement might interact with these two cues. An experiment with a 2 (business longevity: long vs. short x 2 (timing of reward: delayed vs. immediate x 2 (involvement: high vs. low between-subject factorial design is conducted to validate the proposed research hypotheses. The results show that an immediate reward offered by an older, more established, firm for a highly-involved product, make loyalty programs less risky and consequently attract consumers to participate. Interestingly, immediate rewards that are offered by older firms for a product that customers are less involved in has the opposite effects. Managerial and academic implications are further presented in this study.
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Heightened Activity in Social Reward Networks is Associated with Adolescents’ Risky Sexual Behaviors
Eckstrand, Kristen L.; Choukas-Bradley, Sophia; Mohanty, Arpita; Cross, Marissa; Allen, Nicholas B.; Silk, Jennifer S.; Jones, Neil P.; Forbes, Erika E.
2018-01-01
Adolescent sexual risk behavior can lead to serious health consequences, yet few investigations have addressed its neurodevelopmental mechanisms. Social neurocircuitry is postulated to underlie the development of risky sexual behavior, and response to social reward may be especially relevant. Typically developing adolescents (N=47; 18M, 29F; 16.3±1.4 years; 42.5% sexual intercourse experience) completed a social reward fMRI task and reported their sexual risk behaviors (e.g., lifetime sexual partners) on the Youth Risk Behavior Survey (YRBS). Neural response and functional connectivity to social reward were compared for adolescents with higher- and lower-risk sexual behavior. Adolescents with higher-risk sexual behaviors demonstrated increased activation in the right precuneus and the right temporoparietal junction during receipt of social reward. Adolescents with higher-risk sexual behaviors also demonstrated greater functional connectivity between the precuneus and the temporoparietal junction bilaterally, dorsal medial prefrontal cortex, and left anterior insula/ventrolateral prefrontal cortex. The greater activation and functional connectivity in self-referential, social reward, and affective processing regions among higher sexual risk adolescents underscores the importance of social influence underlying sexual risk behaviors. Furthermore, results suggest an orientation towards and sensitivity to social rewards among youth engaging in higher-risk sexual behavior, perhaps as a consequence of or vulnerability to such behavior. PMID:28755632
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Heightened activity in social reward networks is associated with adolescents’ risky sexual behaviors
Directory of Open Access Journals (Sweden)
Kristen L. Eckstrand
2017-10-01
Full Text Available Adolescent sexual risk behavior can lead to serious health consequences, yet few investigations have addressed its neurodevelopmental mechanisms. Social neurocircuitry is postulated to underlie the development of risky sexual behavior, and response to social reward may be especially relevant. Typically developing adolescents (N = 47; 18M, 29F; 16.3 ± 1.4 years; 42.5% sexual intercourse experience completed a social reward fMRI task and reported their sexual risk behaviors (e.g., lifetime sexual partners on the Youth Risk Behavior Survey (YRBS. Neural response and functional connectivity to social reward were compared for adolescents with higher- and lower-risk sexual behavior. Adolescents with higher-risk sexual behaviors demonstrated increased activation in the right precuneus and the right temporoparietal junction during receipt of social reward. Adolescents with higher-risk sexual behaviors also demonstrated greater functional connectivity between the precuneus and the temporoparietal junction bilaterally, dorsal medial prefrontal cortex, and left anterior insula/ventrolateral prefrontal cortex. The greater activation and functional connectivity in self-referential, social reward, and affective processing regions among higher sexual risk adolescents underscores the importance of social influence underlying sexual risk behaviors. Furthermore, results suggest an orientation towards and sensitivity to social rewards among youth engaging in higher-risk sexual behavior, perhaps as a consequence of or vulnerability to such behavior.
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Eckstrand, Kristen L; Choukas-Bradley, Sophia; Mohanty, Arpita; Cross, Marissa; Allen, Nicholas B; Silk, Jennifer S; Jones, Neil P; Forbes, Erika E
2017-10-01
Adolescent sexual risk behavior can lead to serious health consequences, yet few investigations have addressed its neurodevelopmental mechanisms. Social neurocircuitry is postulated to underlie the development of risky sexual behavior, and response to social reward may be especially relevant. Typically developing adolescents (N=47; 18M, 29F; 16.3±1.4years; 42.5% sexual intercourse experience) completed a social reward fMRI task and reported their sexual risk behaviors (e.g., lifetime sexual partners) on the Youth Risk Behavior Survey (YRBS). Neural response and functional connectivity to social reward were compared for adolescents with higher- and lower-risk sexual behavior. Adolescents with higher-risk sexual behaviors demonstrated increased activation in the right precuneus and the right temporoparietal junction during receipt of social reward. Adolescents with higher-risk sexual behaviors also demonstrated greater functional connectivity between the precuneus and the temporoparietal junction bilaterally, dorsal medial prefrontal cortex, and left anterior insula/ventrolateral prefrontal cortex. The greater activation and functional connectivity in self-referential, social reward, and affective processing regions among higher sexual risk adolescents underscores the importance of social influence underlying sexual risk behaviors. Furthermore, results suggest an orientation towards and sensitivity to social rewards among youth engaging in higher-risk sexual behavior, perhaps as a consequence of or vulnerability to such behavior. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
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Risk Assessment of Healthcare Waste by Preliminary Hazard Analysis Method
Directory of Open Access Journals (Sweden)
Pouran Morovati
2017-09-01
Full Text Available Introduction and purpose: Improper management of healthcare waste (HCW can pose considerable risks to human health and the environment and cause serious problems in developing countries such as Iran. In this study, we sought to determine the hazards of HCW in the public hospitals affiliated to Abadan School of Medicine using the preliminary hazard analysis (PHA method. Methods: In this descriptive and analytic study, health risk assessment of HCW in government hospitals affiliated to Abadan School of Medicine (4 public hospitals was carried out by using PHA in the summer of 2016. Results: We noted the high risk of sharps and infectious wastes. Considering the dual risk of injury and disease transmission, sharps were classified in the very high-risk group, and pharmaceutical and chemical and radioactive wastes were classified in the medium-risk group. Sharps posed the highest risk, while pharmaceutical and chemical wastes had the lowest risk. Among the various stages of waste management, the waste treatment stage was the most hazardous in all the studied hospitals. Conclusion: To diminish the risks associated with healthcare waste management in the studied hospitals, adequate training of healthcare workers and care providers, provision of suitable personal protective and transportation equipment, and supervision of the environmental health manager of hospitals should be considered by the authorities.
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Learning Reward Uncertainty in the Basal Ganglia.
Directory of Open Access Journals (Sweden)
John G Mikhael
2016-09-01
Full Text Available Learning the reliability of different sources of rewards is critical for making optimal choices. However, despite the existence of detailed theory describing how the expected reward is learned in the basal ganglia, it is not known how reward uncertainty is estimated in these circuits. This paper presents a class of models that encode both the mean reward and the spread of the rewards, the former in the difference between the synaptic weights of D1 and D2 neurons, and the latter in their sum. In the models, the tendency to seek (or avoid options with variable reward can be controlled by increasing (or decreasing the tonic level of dopamine. The models are consistent with the physiology of and synaptic plasticity in the basal ganglia, they explain the effects of dopaminergic manipulations on choices involving risks, and they make multiple experimental predictions.
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Ecological Risk Assessment of Jarosite Waste Disposal
Directory of Open Access Journals (Sweden)
Mihone Kerolli-Mustafa
2015-07-01
Full Text Available Jarosite waste, originating from zinc extraction industry, is considered hazardous due to the presence and the mobility of toxic metals that it contains. Its worldwide disposal in many tailing damps has become a major ecological concern. Three different methods, namely modified Synthetic Precipitation Leaching Procedure (SPLP, three-stage BCR sequential extraction procedure and Potential Ecological Risk Index (PERI Method were used to access the ecological risk of jarosite waste disposal in Mitrovica Industrial Park, Kosovo. The combination of these methods can effectively identify the comprehensive and single pollution levels of heavy metals such as Zn, Pb, Cd, Cu, Ni and As present in jarosite waste. Moreover, the great positive relevance between leaching behavior of heavy metals and F1 fraction was supported by principal component analysis (PCA. PERI results indicate that Cd showed a very high risk class to the environment. The ecological risk of heavy metals declines in the following order: Cd>Zn>Cu>Pb>Ni>As.
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Risk vs. Reward: A Methodology to Assess Investment in Marine Energy
Directory of Open Access Journals (Sweden)
John Hutcheson
2016-08-01
Full Text Available The majority of WEC (wave energy converter projects are expensive and pose a large risk to a developer. Currently no developers have been successful in commercialising a WEC. So far, many wave energy feasibility studies have only considered the LCOE (levelised cost of electricity, assessing investment in marine energy technologies from a purely financial point of view. No previous studies have, however, explicitly accounted for development risk as well as the LCOE to determine the feasibility of a project. This paper proposes a new methodology that can be used to account for both risk and the LCOE to give a clearer picture of the feasibility of a WEC development. By combining the LCOE and risk score for a particular development, the “value for risk” can be calculated, presented here as the “RR ratio” (“Risk/Reward ratio”. A number of case studies were chosen to test the model, investigating the RR ratio for a number of different WEC technologies and ranking them to suggest an optimal development path for the industry. Results showed that projects that combine many innovative technologies provide the best “value for risk”. These devices overall had the highest risk, suggesting that multiple developers are likely required to collaborate in order to reduce the risk down to acceptable levels for each.
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Neural processing of reward in adolescent rodents
Directory of Open Access Journals (Sweden)
Nicholas W. Simon
2015-02-01
Full Text Available Immaturities in adolescent reward processing are thought to contribute to poor decision making and increased susceptibility to develop addictive and psychiatric disorders. Very little is known; however, about how the adolescent brain processes reward. The current mechanistic theories of reward processing are derived from adult models. Here we review recent research focused on understanding of how the adolescent brain responds to rewards and reward-associated events. A critical aspect of this work is that age-related differences are evident in neuronal processing of reward-related events across multiple brain regions even when adolescent rats demonstrate behavior similar to adults. These include differences in reward processing between adolescent and adult rats in orbitofrontal cortex and dorsal striatum. Surprisingly, minimal age related differences are observed in ventral striatum, which has been a focal point of developmental studies. We go on to discuss the implications of these differences for behavioral traits affected in adolescence, such as impulsivity, risk-taking, and behavioral flexibility. Collectively, this work suggests that reward-evoked neural activity differs as a function of age and that regions such as the dorsal striatum that are not traditionally associated with affective processing in adults may be critical for reward processing and psychiatric vulnerability in adolescents.
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Baskin-Sommers, Arielle R; Foti, Dan
2015-11-01
A common criticism of the Diagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 2013) is that its criteria are based more on behavioral descriptions than on underlying biological mechanisms. Increasingly, calls have intensified for a more biologically-based approach to conceptualizing, studying, and treating psychological disorders, as exemplified by the Research Domain Criteria Project (RDoC). Among the most well-studied neurobiological mechanisms is reward processing. Moreover, individual differences in reward sensitivity are related to risk for substance abuse and depression. The current review synthesizes the available preclinical, electrophysiological, and neuroimaging literature on reward processing from a transdiagnostic, multidimensional perspective. Findings are organized with respect to key reward constructs within the Positive Valence Systems domain of the RDoC matrix, including initial responsiveness to reward (physiological 'liking'), approach motivation (physiological 'wanting'), and reward learning/habit formation. In the current review, we (a) describe the neural basis of reward, (b) elucidate differences in reward activity in substance abuse and depression, and (c) suggest a framework for integrating these disparate literatures and discuss the utility of shifting focus from diagnosis to process for understanding liability and co-morbidity. Ultimately, we believe that an integrative focus on abnormal reward functioning across the full continuum of clinically heterogeneous samples, rather than within circumscribed diagnostic categories, might actually help to refine the phenotypes and improve the prediction of onset and recovery of these disorders. Copyright © 2015 Elsevier B.V. All rights reserved.
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Risk management at hazardous waste sites
International Nuclear Information System (INIS)
Travis, C.C.; Doty, C.B.
1990-01-01
The Superfund Amendments and Reauthorization Act of 1986 (SARA) provided the Environmental Protection Agency (EPA) with additional resources and direction for the identification, evaluation, and remediation of hazardous waste sites in the United States. SARA established more stringent requirements for the Superfund program, both in terms of the pace of the program and the types of remedial alternatives selected. The central requirement is that remedial alternatives be ''protective of public health and the environment'' and ''significantly and permanently'' reduce the toxicity, mobility, or volume of contaminants. The mandate also requires that potential risk be considered in the decision-making process. This document discusses risk management at hazardous waste sites. Topics include selection of sites for placement on the National Priority List, risk assessment and the decision process, risk reduction and remedial alternative selection, and aquifer restoration. 10 refs., 2 figs
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Model Checking Markov Reward Models with Impulse Rewards
Cloth, Lucia; Katoen, Joost-Pieter; Khattri, Maneesh; Pulungan, Reza; Bondavalli, Andrea; Haverkort, Boudewijn; Tang, Dong
This paper considers model checking of Markov reward models (MRMs), continuous-time Markov chains with state rewards as well as impulse rewards. The reward extension of the logic CSL (Continuous Stochastic Logic) is interpreted over such MRMs, and two numerical algorithms are provided to check the
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Duell, Natasha; Steinberg, Laurence; Chein, Jason; Al-Hassan, Suha M; Bacchini, Dario; Lei, Chang; Chaudhary, Nandita; Di Giunta, Laura; Dodge, Kenneth A; Fanti, Kostas A; Lansford, Jennifer E; Malone, Patrick S; Oburu, Paul; Pastorelli, Concetta; Skinner, Ann T; Sorbring, Emma; Tapanya, Sombat; Uribe Tirado, Liliana Maria; Alampay, Liane Peña
2016-10-01
In the present analysis, we test the dual systems model of adolescent risk taking in a cross-national sample of over 5,200 individuals aged 10 through 30 (M = 17.05 years, SD = 5.91) from 11 countries. We examine whether reward seeking and self-regulation make independent, additive, or interactive contributions to risk taking, and ask whether these relations differ as a function of age and culture. To compare across cultures, we conduct 2 sets of analyses: 1 comparing individuals from Asian and Western countries, and 1 comparing individuals from low- and high-GDP countries. Results indicate that reward seeking and self-regulation have largely independent associations with risk taking and that the influences of each variable on risk taking are not unique to adolescence, but that their link to risk taking varies across cultures. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
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Tank waste remediation system risk management plan
International Nuclear Information System (INIS)
Zimmerman, B.D.
1998-01-01
The purpose of the Tank Waste Remediation System (TWRS) Risk Management Plan is to describe a consistent approach to risk management such that TWRS Project risks are identified and managed to achieve TWRS Project success. The Risk Management Plan implements the requirements of the Tank Waste Remediation System Systems Engineering Management Plan in the area of risk management. Figure ES-1 shows the relationship of the TWRS Risk Management Plan to other major TWRS Project documents. As the figure indicates, the Risk Management Plan is a tool used to develop and control TWRS Project work. It provides guidance on how TWRS Project risks will be assessed, analyzed, and handled, and it specifies format and content for the risk management lists, which are a primary product of the risk management process. In many instances, the Risk Management Plan references the TWRS Risk Management Procedure, which provides more detailed discussion of many risk management activities. The TWRS Risk Management Plan describes an ongoing program within the TWRS Project. The Risk Management Plan also provides guidance in support of the TWRS Readiness To-Proceed (RTP) assessment package
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The Risks and Rewards of Value-Based Reimbursement.
Henkel, Robert J; Maryland, Patricia A
2015-01-01
As healthcare systems across the country shift to value-based care, they face an enormous challenge. Not only must they reimagine how they identify, engage, and manage the care of patients, they also need to determine new ways of engaging and aligning physicians and other caregivers in creating better-coordinated care across the continuum. This article explores how healthcare systems making the transition from volume to value can maximize their reward while managing their risk. As the largest not-for-profit healthcare system in the United States and the largest Catholic healthcare system in the world, Ascension is committed to making its own transition, marked by broad-based innovation. We call this goal the Quadruple Aim: improving health outcomes, patient experiences, and provider experiences while lowering the overall cost of care. Healthcare systems and providers have many value-based models to choose from, including pay for performance (P4P), shared savings, bundled payments, shared risk, global capitation, and provider-sponsored health plans. Analysis of these options should include an evaluation of market readiness (i.e., the ability of a health system to align with the needs of employers or commercial insurers in a given market). Healthcare systems also must be prepared to invest in resources that facilitate effective transitions and continuity of care--for example, care management. In addition, they need to recognize that as they focus on wellness, inpatient volumes will decline, requiring cost-structure adjustments and added ancillary services to compensate for this decline. Some healthcare systems are even exploring the possibility of becoming their own payer, taking on more risk and responsibility for the health of patients and populations.
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A reliability-risk modelling of nuclear rad-waste facilities
International Nuclear Information System (INIS)
Lehmann, P.H.; El-Bassioni, A.A.
1975-01-01
Rad-waste disposal systems of nuclear power sites are designed and operated to collect, delay, contain, and concentrate radioactive wastes from reactor plant processes such that on-site and off-site exposures to radiation are well below permissible limits. To assist the designer in achieving minimum release/exposure goals, a computerized reliability-risk model has been developed to simulate the rad-waste system. The objectives of the model are to furnish a practical tool for quantifying the effects of changes in system configuration, operation, and equipment, and for the identification of weak segments in the system design. Primarily, the model comprises a marriage of system analysis, reliability analysis, and release-risk assessment. Provisions have been included in the model to permit the optimization of the system design subject to constraints on cost and rad-releases. The system analysis phase involves the preparation of a physical and functional description of the rad-waste facility accompanied by the formation of a system tree diagram. The reliability analysis phase embodies the formulation of appropriate reliability models and the collection of model parameters. Release-risk assessment constitutes the analytical basis whereupon further system and reliability analyses may be warranted. Release-risk represents the potential for release of radioactivity and is defined as the product of an element's unreliability at time, t, and the radioactivity available for release in time interval, Δt. A computer code (RARISK) has been written to simulate the tree diagram of the rad-waste system. Reliability and release-risk results have been generated for cases which examined the process flow paths of typical rad-waste systems, the effects of repair and standby, the variations of equipment failure and repair rates, and changes in system configurations. The essential feature of this model is that a complex system like the rad-waste facility can be easily decomposed into its
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Comparative Risk Analysis for Metropolitan Solid Waste Management Systems
Chang, Ni-Bin; Wang, S. F.
1996-01-01
Conventional solid waste management planning usually focuses on economic optimization, in which the related environmental impacts or risks are rarely considered. The purpose of this paper is to illustrate the methodology of how optimization concepts and techniques can be applied to structure and solve risk management problems such that the impacts of air pollution, leachate, traffic congestion, and noise increments can be regulated in the iong-term planning of metropolitan solid waste management systems. Management alternatives are sequentially evaluated by adding several environmental risk control constraints stepwise in an attempt to improve the management strategies and reduce the risk impacts in the long run. Statistics associated with those risk control mechanisms are presented as well. Siting, routing, and financial decision making in such solid waste management systems can also be achieved with respect to various resource limitations and disposal requirements.
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Relative radiological risks derived from different TENORM wastes in Malaysia.
Ismail, B; Teng, I L; Muhammad Samudi, Y
2011-11-01
In Malaysia technologically enhanced naturally occurring radioactive materials (TENORM) wastes are mainly the product of the oil and gas industry and mineral processing. Among these TENORM wastes are tin tailing, tin slag, gypsum and oil sludge. Mineral processing and oil and gas industries produce large volume of TENORM wastes that has become a radiological concern to the authorities. A study was carried out to assess the radiological risk related to workers working at these disposal sites and landfills as well as to the members of the public should these areas be developed for future land use. Radiological risk was assessed based on the magnitude of radiation hazard, effective dose rates and excess cancer risks. Effective dose rates and excess cancer risks were estimated using RESRAD 6.4 computer code. All data on the activity concentrations of NORM in wastes and sludges used in this study were obtained from the Atomic Energy Licensing Board, Malaysia, and they were collected over a period of between 5 and 10 y. Results obtained showed that there was a wide range in the total activity concentrations (TAC) of nuclides in the TENORM wastes. With the exception of tin slag and tin tailing-based TENORM wastes, all other TENORM wastes have TAC values comparable to that of Malaysia's soil. Occupational Effective Dose Rates estimated in all landfill areas were lower than the 20 mSv y(-1) permissible dose limit. The average Excess Cancer Risk Coefficient was estimated to be 2.77×10(-3) risk per mSv. The effective dose rates for residents living on gypsum and oil sludge-based TENORM wastes landfills were estimated to be lower than the permissible dose limit for members of the public, and was also comparable to that of the average Malaysia's ordinary soils. The average excess cancer risk coefficient was estimated to be 3.19×10(-3) risk per mSv. Results obtained suggest that gypsum and oil sludge-based TENORM wastes should be exempted from any radiological regulatory
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Relative radiological risks derived from different TENORM wastes in Malaysia
International Nuclear Information System (INIS)
Ismail, B.; Teng, I. L.; Muhammad samudi, Y.
2011-01-01
In Malaysia technologically enhanced naturally occurring radioactive materials (TENORM) wastes are mainly the product of the oil and gas industry and mineral processing. Among these TENORM wastes are tin tailing, tin slag, gypsum and oil sludge. Mineral processing and oil and gas industries produce large volume of TENORM wastes that has become a radiological concern to the authorities. A study was carried out to assess the radiological risk related to workers working at these disposal sites and landfills as well as to the members of the public should these areas be developed for future land use. Radiological risk was assessed based on the magnitude of radiation hazard, effective dose rates and excess cancer risks. Effective dose rates and excess cancer risks were estimated using RESRAD 6.4 computer code. All data on the activity concentrations of NORM in wastes and sludges used in this study were obtained from the Atomic Energy Licensing Board (Malaysia), and they were collected over a period of between 5 and 10 y. Results obtained showed that there was a wide range in the total activity concentrations (TAC) of nuclides in the TENORM wastes. With the exception of tin slag and tin tailing-based TENORM wastes, all other TENORM wastes have TAC values comparable to that of Malaysia's soil. Occupational Effective Dose Rates estimated in all landfill areas were lower than the 20 mSv y -1 permissible dose limit. The average Excess Cancer Risk Coefficient was estimated to be 2.77 x 10 -3 risk per mSv. The effective dose rates for residents living on gypsum and oil sludge-based TENORM wastes landfills were estimated to be lower than the permissible dose limit for members of the public, and was also comparable to that of the average Malaysia's ordinary soils. The average excess cancer risk coefficient was estimated to be 3.19 x 10 -3 risk per mSv. Results obtained suggest that gypsum and oil sludge-based TENORM wastes should be exempted from any radiological regulatory
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A risk-based decision-aiding tool for waste disposal
International Nuclear Information System (INIS)
Weiner, R.F.; Reiser, A.S.; Elcock, C.G.; Nevins, S.
1997-01-01
N-CART (the National Spent Nuclear Fuel Program Cost Analysis and Risk Tool) is being developed to aid in low-risk, cost-effective, timely management of radioactive waste and spent nuclear fuel, and can therefore be used in management of mixed waste. N-CART provides evaluation of multiple alternatives and presents the consequences of proposed waste management activities in a clear and concise format. N-CART's decision-aiding analyses include comparisons and sensitivity analyses of multiple alternatives and allows the user to perform quick turn-around open-quotes what ifclose quotes studies to investigate various scenarios. Uncertainties in data (such as cost and schedule of various activities) are represented as distributions. N-CART centralizes documentation of the bases of program alternatives and program decisions, thereby supporting responses to stakeholders concerns. The initial N-CART design considers regulatory requirements, costs, and schedules for alternative courses of action. The final design will include risks (public health, occupational, economic, scheduling), economic benefits, and the impacts of secondary waste generation. An optimization tool is being incorporated that allows the user to specify the relative importance of cost, time risks, and other bases for decisions. The N-CART prototype can be used to compare the costs and schedules of disposal alternatives for mixed low-level radioactive waste (MLLW) and greater-than-Class-C (GTCC) waste, as well as spent nuclear fuel (SNF) and related scrap material
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Lockie, Sarah H; McAuley, Clare V; Rawlinson, Sasha; Guiney, Natalie; Andrews, Zane B
2017-01-01
Most studies that measure food intake in mice do so in the home cage environment. This necessarily means that mice do not engage in food seeking before consumption, a behavior that is ubiquitous in free-living animals. We modified and validated several commonly used anxiety tests to include a palatable food reward within the anxiogenic zone. This allowed us to assess risk-taking behavior in food seeking in mice in response to different metabolic stimuli. We modified the open field test and the light/dark box by placing palatable peanut butter chips within a designated food zone inside the anxiogenic zone of each apparatus. We then assessed parameters of the interaction with the food reward. Fasted mice or mice treated with ghrelin showed increased consumption and increased time spent in the food zone immediately around the food reward compared to ad libitum fed mice or mice treated with saline. However, fasted mice treated with IP glucose before exposure to the behavioral arena showed reduced time in the food zone compared to fasted controls, indicating that acute metabolic signals can modify the assessment of safety in food seeking in a risky environment. The tests described in this study will be useful in assessing risk processing and incentive salience of food reward, which are intrinsic components of food acquisition outside of the laboratory environment, in a range of genetic and pharmacological models.
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On risk assessment of high level radioactive waste disposal
International Nuclear Information System (INIS)
Smith, C.F.; Kastenberg, W.E.
1976-01-01
One of the major concerns with the continued growth of the nuclear power industry is the production of the high level radioactive wastes. The risks associated with the disposal of these wastes derives from the potential for release of radioactive materials into the environment. The development of a methodology for risk analysis is carried out. The methodology suggested involves the probabilistic analysis of a general accident consequence distribution. In this analysis, the frequency aspect of the distribution is treated separately from the normalized probability function. In the final stage of the analysis, the frequency and probability characteristics of the distribution are recombined to provide an estimate of the risk. The characterization of the radioactive source term is accomplished using the ORIGEN computer code. Calculations are carried out for various reactor types and fuel cycles, and the overall waste hazard for a projected 35 year nuclear power program is determined. An index of relative nuclide hazard appropriate to problems involving the management of high level radioactive wastes is developed. As an illustration of the methodology, risk analyses are made for two proposed methods for waste management: extraterrestrial disposal and interim surface storage. The results of these analyses indicate that, within the assumptions used, the risks of these management schemes are small compared with natural background radiation doses. (Auth.)
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Benefits and risks of P & T of nuclear waste
Energy Technology Data Exchange (ETDEWEB)
Abrahams, K. [Netherlands Energy Research Foundation, Petten (Netherlands)
1995-10-01
Efforts on waste transmutation are coordinated in a research programme called RAS. One of the aims of this RAS program is to inform the public and advise the authorities on methods for transmutation/conditioning of nuclear waste, and on techniques which are being developed. Such new procedures for the treatment of waste should of course not lead to significant risks for the present population. Small risks might be accepted, but these should sufficiently be compensated for by favours to future generations.
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Leaching characteristics, ecotoxicity, and risk assessment based management of mine wastes
Kim, J.; Ju, W. J.; Jho, E. H.; Nam, K.; Hong, J. K.
2016-12-01
Mine wastes generated during mining activities in metal mines generally contain high concentrations of metals that may impose toxic effects to surrounding environment. Thus, it is necessary to properly assess the mining-impacted landscapes for management. The study investigated leaching characteristics, potential environmental effects, and human health risk of mine wastes from three different metal mines in South Korea (molybdenum mine, lead-zinc mine, and magnetite mine). The heavy metal concentrations in the leachates obtained by using the Korean Standard Test Method for Solid Wastes (STM), Toxicity Characteristics Leaching Procedure (TCLP), and Synthetic Precipitation Leaching Procedure (SPLP) met the Korea Waste Control Act and the USEPA region 3 regulatory levels accordingly, even though the mine wastes contained high concentrations of metals. Assuming that the leachates may get into nearby water sources, the leachate toxicity was tested using Daphnia Magna. The toxic unit (TU) values after 24 h and 48 h exposure of all the mine wastes tested met the Korea Allowable Effluent Water Quality Standards (TUwaste may have long-term toxic effects (TU>1 for the eluent at L/S of 30) implying that the long-term effect of mine wastes left in mining areas need to be assessed. Considering reuse of mine wastes as a way of managing mine wastes, the human health risk assessment of reusing the lead-zinc mine waste in industrial areas was carried out using the bioavailable fraction of the heavy metals contained in the mine wastes, which was determined by using the Solubility/Bioavailability Research Consortium method. There may be potential carcinogenic risk (9.7E-05) and non-carcinogenic risk (HI, Hazard Index of 1.0E+00) as CR≧1.0E-05 has carcinogenic risk and HI≧1.0E+00 has non-carcinogenic risk. Overall, this study shows that not only the concentration-based assessment but ecological toxic effect and human health risk based assessments can be utilized for mining
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BOLD responses in reward regions to hypothetical and imaginary monetary rewards.
Miyapuram, Krishna P; Tobler, Philippe N; Gregorios-Pippas, Lucy; Schultz, Wolfram
2012-01-16
Monetary rewards are uniquely human. Because money is easy to quantify and present visually, it is the reward of choice for most fMRI studies, even though it cannot be handed over to participants inside the scanner. A typical fMRI study requires hundreds of trials and thus small amounts of monetary rewards per trial (e.g. 5p) if all trials are to be treated equally. However, small payoffs can have detrimental effects on performance due to their limited buying power. Hypothetical monetary rewards can overcome the limitations of smaller monetary rewards but it is less well known whether predictors of hypothetical rewards activate reward regions. In two experiments, visual stimuli were associated with hypothetical monetary rewards. In Experiment 1, we used stimuli predicting either visually presented or imagined hypothetical monetary rewards, together with non-rewarding control pictures. Activations to reward predictive stimuli occurred in reward regions, namely the medial orbitofrontal cortex and midbrain. In Experiment 2, we parametrically varied the amount of visually presented hypothetical monetary reward keeping constant the amount of actually received reward. Graded activation in midbrain was observed to stimuli predicting increasing hypothetical rewards. The results demonstrate the efficacy of using hypothetical monetary rewards in fMRI studies. Copyright © 2011 Elsevier Inc. All rights reserved.
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Comparative estimates of risks arising from storage of intermediate level radioactive wastes
International Nuclear Information System (INIS)
Moore, D.
1986-04-01
Estimates are presented of risks arising from accidents occuring during storage of nine types of conditioned intermediate level waste. Additional data are introduced relating to the risks from accidents affecting raw waste, and to risks associated with the occupational doses received during normal operation of a waste store. Risks in all three categories are shown to be extremely small. (author)
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Reward deficiency and anti-reward in pain chronification
Borsook, D.; Linnman, C.; Faria, Vanda; Strassman, A. M.; Becerra, L.; Elman, I.
2016-01-01
Converging lines of evidence suggest that the pathophysiology of pain is mediated to a substantial degree via allostatic neuroadaptations in reward- and stress-related brain circuits. Thus, reward deficiency (RD) represents a within-system neuroadaptation to pain-induced protracted activation of the reward circuits that leads to depletion-like hypodopaminergia, clinically manifested anhedonia, and diminished motivation for natural reinforcers. Anti-reward (AR) conversely pertains to a between...
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Development of a low-level waste risk methodology
International Nuclear Information System (INIS)
Fisher, J.E.; Falconer, K.L.
1984-01-01
A probabilistic risk assessment method is presented for performance evaluation of low-level waste disposal facilities. The associated program package calculates the risk associated with postulated radionuclide release and transport scenarios. Risk is computed as the mathematical product of two statistical variables: the dose consequence of a given release scenario, and its occurrence probability. A sample risk calculation is included which demonstrates the method. This PRA method will facilitate evaluation of facility performance, including identification of high risk scenarios and their mitigation via optimization of site parameters. The method is intended to be used in facility licensing as a demonstration of compliance with the performance objectives set forth in 10 CFR Part 61, or in corresponding state regulations. The Low-Level Waste Risk Methodology is being developed under sponsorship of the Nuclear Regulatory Commission
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Risk management of onsite transportation of nuclear waste
International Nuclear Information System (INIS)
Field, J.G.; Wang, O.S.; Mercado, J.E.
1993-01-01
The United States Department of Energy (DOE) Hanford Site recently has undergone a significant change in mission. The focus of operations has shifted from plutonium production to environmental restoration. This transition has caused a substantial increase in quantities of nuclear waste and other hazardous materials packaged and transported onsite. In response to the escalating transportation activity, Westinghouse Hanford Company (Westinghouse Hanford), the Hanford Site operations and engineering contractor, is proposing an integrated risk assessment methodology and risk management strategy to enhance the safety of onsite packaging and transportation operations involving nuclear waste. The proposed methodology consists of three integral parts: risk assessment, risk acceptance criteria, and risk minimization. The purpose of the methodology is to ensure that the risk for each ongoing transportation activity is acceptable and to minimize the overall risk for current and future onsite operations. (authors). 2 figs., 6 refs
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Risk management of onsite transportation of nuclear waste
International Nuclear Information System (INIS)
Field, J.G.; Wang, O.S.; Mercado, J.E.
1993-03-01
The United States Department of Energy (DOE) Hanford Site recently has undergone a significant change in mission. The focus of operations has shifted from plutonium production to environmental restoration. This transition has caused a substantial increase in quantities of nuclear waste and other hazardous materials packaged and transported onsite. In response to the escalating transportation activity, Westinghouse Hanford Company (Westinghouse Hanford), the Hanford Site operations and engineering contractor, is proposing an integrated risk assessment methodology and risk management strategy to enhance the safety of onsite packaging and transportation operations involving nuclear waste. The proposed methodology consists of three integral parts: risk assessment, risk acceptance criteria, and risk minimization. The purpose of the methodology is to ensure that the risk for each ongoing transportation activity is acceptable and to minimize the overall risk for current and future onsite operations
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Reward positivity: Reward prediction error or salience prediction error?
Heydari, Sepideh; Holroyd, Clay B
2016-08-01
The reward positivity is a component of the human ERP elicited by feedback stimuli in trial-and-error learning and guessing tasks. A prominent theory holds that the reward positivity reflects a reward prediction error signal that is sensitive to outcome valence, being larger for unexpected positive events relative to unexpected negative events (Holroyd & Coles, 2002). Although the theory has found substantial empirical support, most of these studies have utilized either monetary or performance feedback to test the hypothesis. However, in apparent contradiction to the theory, a recent study found that unexpected physical punishments also elicit the reward positivity (Talmi, Atkinson, & El-Deredy, 2013). The authors of this report argued that the reward positivity reflects a salience prediction error rather than a reward prediction error. To investigate this finding further, in the present study participants navigated a virtual T maze and received feedback on each trial under two conditions. In a reward condition, the feedback indicated that they would either receive a monetary reward or not and in a punishment condition the feedback indicated that they would receive a small shock or not. We found that the feedback stimuli elicited a typical reward positivity in the reward condition and an apparently delayed reward positivity in the punishment condition. Importantly, this signal was more positive to the stimuli that predicted the omission of a possible punishment relative to stimuli that predicted a forthcoming punishment, which is inconsistent with the salience hypothesis. © 2016 Society for Psychophysiological Research.
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Gunderman, Richard B; Kamer, Aaron P
2011-05-01
For much of the 20th century, psychologists and economists operated on the assumption that work is devoid of intrinsic rewards, and the only way to get people to work harder is through the use of rewards and punishments. This so-called carrot-and-stick model of workplace motivation, when applied to medical practice, emphasizes the use of financial incentives and disincentives to manipulate behavior. More recently, however, it has become apparent that, particularly when applied to certain kinds of work, such approaches can be ineffective or even frankly counterproductive. Instead of focusing on extrinsic rewards such as compensation, organizations and their leaders need to devote more attention to the intrinsic rewards of work itself. This article reviews this new understanding of rewards and traces out its practical implications for radiology today. Copyright © 2011. Published by Elsevier Inc.
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The role of cognitive effort in subjective reward devaluation and risky decision-making.
Apps, Matthew A J; Grima, Laura L; Manohar, Sanjay; Husain, Masud
2015-11-20
Motivation is underpinned by cost-benefit valuations where costs-such as physical effort or outcome risk-are subjectively weighed against available rewards. However, in many environments risks pertain not to the variance of outcomes, but to variance in the possible levels of effort required to obtain rewards (effort risks). Moreover, motivation is often guided by the extent to which cognitive-not physical-effort devalues rewards (effort discounting). Yet, very little is known about the mechanisms that underpin the influence of cognitive effort risks or discounting on motivation. We used two cost-benefit decision-making tasks to probe subjective sensitivity to cognitive effort (number of shifts of spatial attention) and to effort risks. Our results show that shifts of spatial attention when monitoring rapidly presented visual stimuli are perceived as effortful and devalue rewards. Additionally, most people are risk-averse, preferring safe, known amounts of effort over risky offers. However, there was no correlation between their effort and risk sensitivity. We show for the first time that people are averse to variance in the possible amount of cognitive effort to be exerted. These results suggest that cognitive effort sensitivity and risk sensitivity are underpinned by distinct psychological and neurobiological mechanisms.
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The role of reward and reward uncertainty in episodic memory
Mason, Alice; Farrell, Simon; Howard-Jones, Paul; Ludwig, Casimir
2017-01-01
Declarative memory has been found to be sensitive to reward-related changes in the environment. The reward signal can be broken down into information regarding the expected value of the reward, reward uncertainty and the prediction error. Research has established that high as opposed to low reward values enhance declarative memory. Research in neuroscience suggests that high uncertainty activates the reward system, which could lead to enhanced learning and memory. Here we present the results ...
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Reward guides vision when it's your thing: trait reward-seeking in reward-mediated visual priming.
Directory of Open Access Journals (Sweden)
Clayton Hickey
Full Text Available Reward-related mesolimbic dopamine is thought to play an important role in guiding animal behaviour, biasing approach towards potentially beneficial environmental stimuli and away from objects unlikely to garner positive outcome. This is considered to result in part from an impact on perceptual and attentional processes: dopamine initiates a series of cognitive events that result in the priming of reward-associated perceptual features. We have provided behavioural and electrophysiological evidence that this mechanism guides human vision in search, an effect we refer to as reward priming. We have also demonstrated that there is substantial individual variability in this effect. Here we show that behavioural differences in reward priming are predicted remarkably well by a personality index that captures the degree to which a person's behaviour is driven by reward outcome. Participants with reward-seeking personalities are found to be those who allocate visual resources to objects characterized by reward-associated visual features. These results add to a rapidly developing literature demonstrating the crucial role reward plays in attentional control. They additionally illustrate the striking impact personality traits can have on low-level cognitive processes like perception and selective attention.
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Risk analysis of radioactive waste management systems in Germany
International Nuclear Information System (INIS)
Wingender, H.J.
1978-01-01
Within the scope of a system study, ''Radioactive wastes in the Federal Republic of Germany,'' performed from 1974 through 1976, the questions of risk assessment were investigated. A risk analysis of a high-level waste (HLW) management system was performed. The results of the HLW tank storage are that the risk expectation value is 700 nJ/kg x RBE (7 x 10 -5 rem) per year for atmospheric release. The discussion of the main contributing accidents shows the possibility of reducing the risk by a technical means. A qualitative comparison on the release basis with the results of the WASH-1400 report shows significant differences that can be explained by the different methodologies applied. The risk analysis activities have led to a comprehensive risk assessment project, which was recently started. The projected includes research and development tasks concerning nuclide migration and transport to the ecosphere, nuclide mobilization by various mechanisms, methodology problems, data collection, computer code development, as well as risk analyses of waste management facilities. It is intended to round off the project with risk analyses of spent fuel element transport, storage, and reprocessing
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Quantifying risks in nuclear waste isolation
International Nuclear Information System (INIS)
Mortenson, S.
1982-01-01
A top-level application of an RSS risk assessment procedure is selected as a unifying framework within which the long-time (about 1000 years) performance of a waste repository may be considered. Two major themes are developed: First, the fractional contribution of the engineered features to the ''system'' risk is determined. This contribution effectively segregates those features over which conservative design and quality control may be used to control risk. Second, the development of event tree logic to support such analysis is shown to represent a meaningful, systematic means of factoring-in the total system dynamics; in particular, the generality provided by such an approach lends itself well to consideration of a broad spectrum of accident sequences which includes varying responses of the waste repository system to time-dependent ''accident'' initiators and system failure synergism. Modification to traditional logic development methods to span the longtime system performance are described in some detail, and the attendant data requirements are developed
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Risk perception: expert opinion versus public understanding. [Of radioactive waste repositories
Energy Technology Data Exchange (ETDEWEB)
Brown, J
1987-02-01
A research project looking at the public's attitudes towards the siting of radioactive waste depositories is reported. The risk perception studies seek to compare expert and lay understanding of risk. Adverse public reactions to risk can only be understood if it is known how people relate to risks in their everyday or working lives. Social trends and experiences are important, for example, the adverse public opinion on the siting of nuclear waste facilities. A number of elements have been identified as common to different risk areas such as chemicals, drugs, food or radioactive waste. These are the clashing of values, polarization of beliefs or clashes of interest.
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Reward deficiency and anti-reward in pain chronification.
Borsook, D; Linnman, C; Faria, V; Strassman, A M; Becerra, L; Elman, I
2016-09-01
Converging lines of evidence suggest that the pathophysiology of pain is mediated to a substantial degree via allostatic neuroadaptations in reward- and stress-related brain circuits. Thus, reward deficiency (RD) represents a within-system neuroadaptation to pain-induced protracted activation of the reward circuits that leads to depletion-like hypodopaminergia, clinically manifested anhedonia, and diminished motivation for natural reinforcers. Anti-reward (AR) conversely pertains to a between-systems neuroadaptation involving over-recruitment of key limbic structures (e.g., the central and basolateral amygdala nuclei, the bed nucleus of the stria terminalis, the lateral tegmental noradrenergic nuclei of the brain stem, the hippocampus and the habenula) responsible for massive outpouring of stressogenic neurochemicals (e.g., norepinephrine, corticotropin releasing factor, vasopressin, hypocretin, and substance P) giving rise to such negative affective states as anxiety, fear and depression. We propose here the Combined Reward deficiency and Anti-reward Model (CReAM), in which biopsychosocial variables modulating brain reward, motivation and stress functions can interact in a 'downward spiral' fashion to exacerbate the intensity, chronicity and comorbidities of chronic pain syndromes (i.e., pain chronification). Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.
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International Nuclear Information System (INIS)
Channell, J.K.; Walker, B.A.
2000-01-01
Specifically this report: 1. Compares requirements of the WAP that are pertinent from a technical viewpoint with the WIPP pre-Permit waste characterization program, 2. Presents the results of a risk analysis of the currently emplaced wastes. Expected and bounding risks from routine operations and possible accidents are evaluated; and 3. Provides conclusions and recommendations
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Effort-reward imbalance in the school setting: associations with somatic pain and self-rated health.
Låftman, Sara Brolin; Modin, Bitte; Östberg, Viveca; Hoven, Hanno; Plenty, Stephanie
2015-03-01
According to the workplace theory of effort-reward imbalance (ERI), individuals who perceive a lack of reciprocity between their effort spent at work and the rewards received in turn are at an increased risk of stress-related ill-health. It is also assumed that being overcommitted to work is linked to an increased risk of stress-related ill-health. This study applies the effort-reward imbalance model to the school setting. It aims to analyse the associations that effort-reward imbalance and overcommitment share with somatic pain and self-rated health among adolescents. Data are from the School Stress and Support Study (TriSSS), involving students in grades 8 and 9 (ages 14-16 years) in two schools in Stockholm, Sweden, during 2010 (n=403). Information on effort-reward imbalance and health outcomes was gathered from self-report questionnaires. An adjusted short version of ERI was used. Factor analysis showed that extrinsic effort, reward and overcommitment constitute three distinct dimensions. The designed measures demonstrated sound psychometric properties both for the full sample and for subgroups. Ordered logistic regressions were conducted. The analyses showed that low reward and higher overcommitment were associated with greater somatic pain and poorer self-rated health. Furthermore, effort-reward imbalance was linked with an elevated risk of somatic pain and poorer self-rated health. Students are more likely to experience stress-related ill-health when they perceive an imbalance between their effort and rewards. In addition, high overcommitment is associated with an increased risk of ill-health among students. © 2014 the Nordic Societies of Public Health.
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Reward sensitivity, attentional bias, and executive control in early adolescent alcohol use.
van Hemel-Ruiter, Madelon E; de Jong, Peter J; Ostafin, Brian D; Wiers, Reinout W
2015-01-01
This study examined whether attentional bias for alcohol stimuli was associated with alcohol use in young adolescents, and whether the frequently demonstrated relationship between reward sensitivity and adolescent alcohol use would be partly mediated by attentional bias for alcohol cues. In addition, this study investigated the potential moderating role of executive control (EC), and tested whether the relationship between alcohol-related attentional bias and alcohol use was especially present in young adolescents with weak EC. Participants were 86 adolescents (mean age=14.86), who completed a Visual Probe Task (VPT) as an index of attentional bias, a flanker-task based Attention Network Task (ANT) as an index of EC, the sensitivity of punishment and sensitivity of reward questionnaire (SPSRQ) as an index of reward sensitivity, and an alcohol use questionnaire. High reward sensitivity, high alcohol-related attentional bias, and weak EC were all related to alcohol use. The relationship between reward sensitivity and alcohol use was not mediated by alcohol-related attentional bias. As hypothesized, attentional bias was only associated with alcohol use in participants with weak EC. Together, the present findings are consistent with the view that high reward sensitivity and low EC may be considered as risk factors for adolescent alcohol use. The independent contribution of reward sensitivity and attentional bias might suggest that adolescents who are highly reward sensitive and display an attentional bias for alcohol cues are at even higher risk for excessive alcohol use and developing alcohol abuse problems. Future research using a longitudinal approach would allow an examination of these risk factors on subsequent alcohol use. Treatment implications are discussed, including the importance of strengthening EC and reducing the rewarding value of alcohol use. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Preliminary risk analysis applied to the handling of health-care waste
Directory of Open Access Journals (Sweden)
Carvalho S.M.L.
2002-01-01
Full Text Available Between 75% and 90% of the waste produced by health-care providers no risk or is "general" health-care waste, comparable to domestic waste. The remaining 10-25% of health-care waste is regarded as hazardous due to one or more of the following characteristics: it may contain infectious agents, sharps, toxic or hazardous chemicals or it may be radioactive. Infectious health-care waste, particularly sharps, has been responsible for most of the accidents reported in the literature. In this work the preliminary risks analysis (PRA technique was used to evaluate practices in the handling of infectious health-care waste. Currently the PRA technique is being used to identify and to evaluate the potential for hazard of the activities, products, and services from facilities and industries. The system studied was a health-care establishment which has handling practices for infectious waste. Thirty-six procedures related to segregation, containment, internal collection, and storage operation were analyzed. The severity of the consequences of the failure (risk that can occur from careless management of infectious health-care waste was classified into four categories: negligible, marginal, critical, and catastrophic. The results obtained in this study showed that events with critics consequences, about 80%, may occur during the implementation of the containment operation, suggesting the need to prioritize this operation. As a result of the methodology applied in this work, a flowchart the risk series was also obtained. In the flowchart the events that can occur as a consequence of a improper handling of infectious health-care waste, which can cause critical risks such as injuries from sharps and contamination (infection from pathogenic microorganisms, are shown.
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Impact of hazardous waste risks and liabilities on the contracting process
International Nuclear Information System (INIS)
Gleason, G.L.
1991-01-01
Hazardous waste risks include the following: (1) An emerging environmental cleanup industry that differs significantly from traditional engineering; (2) The inability to predict and control the subsurface environment; (3) The implementation of new and often untested technologies; (4) The statutory imposition of strict, joint and several, as well as retroactive, liability; (5) The lack of insurance and other risk-transfer mechanisms to protect against losses; (6) Costly and time consuming litigation to determine liability; and (7) Others. The liabilities associated with the risks inherent in hazardous waste cleanup directly impact hazardous waste contracting. Contract negotiations become onerous during discussions of liability, indemnification, and issues surrounding scope of work and other clauses. Other impacts include (1) Defensive engineering; (2) Lack of incentive to implement innovative technologies; (3) Increased costs to cover risks. Required client indemnification is a necessary and responsible risks management practice, regardless of whether the client is a federal or private client. Federal government indemnification authorities, as well as private contract indemnification mechanisms, will be explained and analyzed. Conflict of interest concerns are also of critical importance in the hazardous waste market, particularly due to concerns over the complexity of the litigation surrounding hazardous waste sites and the need to ensure unbiased results. Other examples of hazardous waste risk management impacts on contracting in the following market sectors will also be provided: (1) U.S. Environmental Protection Agency; (2) Department of Defense; (3) Department of Energy; and (4) Private sector contracts
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Risk communication on the siting of radioactive waste management facility
International Nuclear Information System (INIS)
Okoshi, Minoru; Torii, Hiroyuki; Fujii, Yasuhiko
2007-01-01
Siting of radioactive waste management facilities frequently raise arguments among stakeholders such as a municipal government and the residents. Risk communication is one of the useful methods of promoting mutual understanding on related risks among stakeholders. In Finland and Sweden, siting selection procedures of repositories for spent nuclear fuels have been carried out successfully with risk communication. The success reasons are analyzed based on the interviews with those who belong to the regulatory authorities and nuclear industries in both countries. Also, in this paper, risk communication among the Japan Radioisotope Association (JRIA), a local government and the general public, which was carried out during the establishment process of additional radioactive waste treatment facilities in Takizawa Village, Iwate Prefecture, is analyzed based on articles in newspapers and interviews with persons concerned. The analysis results showed that good risk communication was not carried out because of the lack of confidence on the JRIA, decision making rules, enough communication chances and economic benefits. In order to make good use of these experiences for the future establishment of radioactive waste management facilities, the lessons learned from these cases are summarized and proposals for good risk communication (establishment of exploratory committee and technical support system for decision making, and measurements to increase familiarity of radioactive waste) are discussed. (author)
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Risk decisions and nuclear waste
International Nuclear Information System (INIS)
Hansson, S.O.
1987-11-01
The risk concept is multidimensional, and much of its contents is lost in the conventional reduction to a unidimensional and quantifiable term. Eight major dimensions of the risk concept are discussed, among them the time factor and the lack-of-knowledge factor. The requirements of a rational discourse are discussed, in general and in relation to risk issues. It is concluded that no single method for the comparison and assessment of risks can be seen as the only rational method. Different methods can all be rational, although based on different values. Risk evaluations cannot be performed as expert assessments, divorced from the political decision process. Instead, risk evaluation must be seen as an essentially political process. Public participation is necessary in democratic decision-making on risks as well as on other issues. Important conclusions can be drawn for the management of nuclear waste, concerning specifications for the technical solution, the need for research on risk concepts, and the decision-making process. (orig.)
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Rewards and Performance Incentives.
Zigon, Jack
1994-01-01
Discusses rewards and performance incentives for employees, including types of rewards; how rewards help in managing; dysfunctional awards; selecting the right reward; how to find rewards that fit; and delivering rewards effectively. Examples are included. (three references) (LRW)
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Evaluating the operational risks of biomedical waste using failure mode and effects analysis.
Chen, Ying-Chu; Tsai, Pei-Yi
2017-06-01
The potential problems and risks of biomedical waste generation have become increasingly apparent in recent years. This study applied a failure mode and effects analysis to evaluate the operational problems and risks of biomedical waste. The microbiological contamination of biomedical waste seldom receives the attention of researchers. In this study, the biomedical waste lifecycle was divided into seven processes: Production, classification, packaging, sterilisation, weighing, storage, and transportation. Twenty main failure modes were identified in these phases and risks were assessed based on their risk priority numbers. The failure modes in the production phase accounted for the highest proportion of the risk priority number score (27.7%). In the packaging phase, the failure mode 'sharp articles not placed in solid containers' had the highest risk priority number score, mainly owing to its high severity rating. The sterilisation process is the main difference in the treatment of infectious and non-infectious biomedical waste. The failure modes in the sterilisation phase were mainly owing to human factors (mostly related to operators). This study increases the understanding of the potential problems and risks associated with biomedical waste, thereby increasing awareness of how to improve the management of biomedical waste to better protect workers, the public, and the environment.
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Directory of Open Access Journals (Sweden)
Pragathi Priyadharsini Balasubramani
2014-04-01
Full Text Available Although empirical and neural studies show that serotonin (5HT plays many functional roles in the brain, prior computational models mostly focus on its role in behavioral inhibition. In this study, we present a model of risk based decision making in a modified Reinforcement Learning (RL-framework. The model depicts the roles of dopamine (DA and serotonin (5HT in Basal Ganglia (BG. In this model, the DA signal is represented by the temporal difference error (δ, while the 5HT signal is represented by a parameter (α that controls risk prediction error. This formulation that accommodates both 5HT and DA reconciles some of the diverse roles of 5HT particularly in connection with the BG system. We apply the model to different experimental paradigms used to study the role of 5HT: 1 Risk-sensitive decision making, where 5HT controls risk assessment, 2 Temporal reward prediction, where 5HT controls time-scale of reward prediction, and 3 Reward/Punishment sensitivity, in which the punishment prediction error depends on 5HT levels. Thus the proposed integrated RL model reconciles several existing theories of 5HT and DA in the BG.
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Chemical and radiological risk factors associated with waste from energy production
DEFF Research Database (Denmark)
Christensen, T.; Fuglestvedt, J.; Benestad, C.
1992-01-01
We have tried to estimate the toxic potential of waste from nuclear power plants and from power plants burning fossil fuels. The potential risks have been expressed as 'risk potentials' or 'person equivalents'. These are purely theoretical units and represent only an attempt to quantify...... and one has to accept a certain small risk by accepting the concentration limit. This is in line with the establishment of limits for radiation. Waste products from coal combustion have the highest potential risk among the fossil fuel alternatives. The highest risk is caused by metals, and the fly ash...... represents the effluent stream giving the largest contribution to the potential risk. The waste from nuclear power production has a lower potential risk than coal if today's limit values are used. If one adjusts the limits for radiation dose and the concentration limit values so that a similar risk...
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Reward loss and the basolateral amygdala: A function in reward comparisons.
Kawasaki, Katsuyoshi; Annicchiarico, Iván; Glueck, Amanda C; Morón, Ignacio; Papini, Mauricio R
2017-07-28
The neural circuitry underlying behavior in reward loss situations is poorly understood. We considered two such situations: reward devaluation (from large to small rewards) and reward omission (from large rewards to no rewards). There is evidence that the central nucleus of the amygdala (CeA) plays a role in the negative emotion accompanying reward loss. However, little is known about the function of the basolateral nucleus (BLA) in reward loss. Two hypotheses of BLA function in reward loss, negative emotion and reward comparisons, were tested in an experiment involving pretraining excitotoxic BLA lesions followed by training in four tasks: consummatory successive negative contrast (cSNC), autoshaping (AS) acquisition and extinction, anticipatory negative contrast (ANC), and open field testing (OF). Cell counts in the BLA (but not in the CeA) were significantly lower in animals with lesions vs. shams. BLA lesions eliminated cSNC and ANC, and accelerated extinction of lever pressing in AS. BLA lesions had no effect on OF testing: higher activity in the periphery than in the central area. This pattern of results provides support for the hypothesis that BLA neurons are important for reward comparison. The three affected tasks (cSNC, ANC, and AS extinction) involve reward comparisons. However, ANC does not seem to involve negative emotions and it was affected, whereas OF activity is known to involve negative emotion, but it was not affected. It is hypothesized that a circuit involving the thalamus, insular cortex, and BLA is critically involved in the mechanism comparing current and expected rewards. Copyright © 2017 Elsevier B.V. All rights reserved.
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2-Phase NSGA II: An Optimized Reward and Risk Measurements Algorithm in Portfolio Optimization
Directory of Open Access Journals (Sweden)
Seyedeh Elham Eftekharian
2017-11-01
Full Text Available Portfolio optimization is a serious challenge for financial engineering and has pulled down special attention among investors. It has two objectives: to maximize the reward that is calculated by expected return and to minimize the risk. Variance has been considered as a risk measure. There are many constraints in the world that ultimately lead to a non–convex search space such as cardinality constraint. In conclusion, parametric quadratic programming could not be applied and it seems essential to apply multi-objective evolutionary algorithm (MOEA. In this paper, a new efficient multi-objective portfolio optimization algorithm called 2-phase NSGA II algorithm is developed and the results of this algorithm are compared with the NSGA II algorithm. It was found that 2-phase NSGA II significantly outperformed NSGA II algorithm.
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International Nuclear Information System (INIS)
Lazaro, M.A.; Policastro, A.J.; Hartmann, H.M.; Chang, Y.S.
1996-12-01
This report, a supplement to Appendix E (Transportation Risk) of the U.S. Department of Energy Waste Management Programmatic Environmental Impact Statement (WM PEIS), provides additional information supporting the accident data for chemical risk assessment and health risk methodology described in that appendix (Part II) and presents the uncertainty analysis and on-site risk calculations. This report focuses on hazardous material truck accident rates, release probabilities, and release quantities; provides the toxicological values derived for each hazardous chemical assessed in the WM PEIS and further details on the derivation of health criteria; describes the method used in the transportation risk assessments to address potential additivity of health effects from simultaneous exposure to several chemicals and the method used to address transportation risks for maximally exposed individuals; presents an expanded discussion of the uncertainty associated with transportation risk calculations; and includes the results of the on-site transportation risk analysis. In addition, two addenda are provided to detail the risk assessments conducted for the hazardous components of low-level mixed waste (Addendum I) and transuranic waste (Addendum II)
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Preliminary risk benefit assessment for nuclear waste disposal in space
Rice, E. E.; Denning, R. S.; Friedlander, A. L.; Priest, C. C.
1982-01-01
This paper describes the recent work of the authors on the evaluation of health risk benefits of space disposal of nuclear waste. The paper describes a risk model approach that has been developed to estimate the non-recoverable, cumulative, expected radionuclide release to the earth's biosphere for different options of nuclear waste disposal in space. Risk estimates for the disposal of nuclear waste in a mined geologic repository and the short- and long-term risk estimates for space disposal were developed. The results showed that the preliminary estimates of space disposal risks are low, even with the estimated uncertainty bounds. If calculated release risks for mined geologic repositories remain as low as given by the U.S. DOE, and U.S. EPA requirements continue to be met, then no additional space disposal study effort in the U.S. is warranted at this time. If risks perceived by the public are significant in the acceptance of mined geologic repositories, then consideration of space disposal as a complement to the mined geologic repository is warranted.
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Effort-reward imbalance at work and the risk of antidepressant treatment in the Danish workforce
DEFF Research Database (Denmark)
Nielsen, Maj Britt D.; Madsen, Ida E. H.; Aust, Birgit
2016-01-01
Background: Previous studies have shown that high effort-reward imbalance (ERI) at work is a risk factor for the onset of self-reported depressive symptoms. In this study, we examined whether ERI predicts risk of treatment with antidepressant medication in a representative sample of the Danish...... workforce. Methods: We linked survey data on ERI and covariates of 4541 participants from the Danish Work Environment Cohort Study 2000 with the Danish National Prescription Registry that includes all legally purchased prescription drugs at pharmacies in Denmark since 1995. Participants with a history....... Results: A total of 309 (6.8%) participants started antidepressant treatment during follow-up. Exposure to ERI at baseline was not related to risk of antidepressant treatment (hazard ratio: 0.91, 95% CI=0.81–1.03 after adjustment for potential confounders). Limitations: The use of antidepressant treatment...
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Security risks in nuclear waste management: Exceptionalism, opaqueness and vulnerability.
Vander Beken, Tom; Dorn, Nicholas; Van Daele, Stijn
2010-01-01
This paper analyses some potential security risks, concerning terrorism or more mundane forms of crime, such as fraud, in management of nuclear waste using a PEST scan (of political, economic, social and technical issues) and some insights of criminologists on crime prevention. Nuclear waste arises as spent fuel from ongoing energy generation or other nuclear operations, operational contamination or emissions, and decommissioning of obsolescent facilities. In international and EU political contexts, nuclear waste management is a sensitive issue, regulated specifically as part of the nuclear industry as well as in terms of hazardous waste policies. The industry involves state, commercial and mixed public-private bodies. The social and cultural dimensions--risk, uncertainty, and future generations--resonate more deeply here than in any other aspect of waste management. The paper argues that certain tendencies in regulation of the industry, claimed to be justified on security grounds, are decreasing transparency and veracity of reporting, opening up invisible spaces for management frauds, and in doing allowing a culture of impunity in which more serious criminal or terrorist risks could arise. What is needed is analysis of this 'exceptional' industry in terms of the normal cannons of risk assessment - a task that this paper begins. Copyright 2009 Elsevier Ltd. All rights reserved.
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A literature-based preliminary characterization of risks in the nuclear waste management system
International Nuclear Information System (INIS)
Daling, P.M.; Rhoads, R.E.; Van Luik, A.E.
1990-04-01
The objectives of this study were to (1) review the literature containing information on risks in the nuclear waste management system and (2) use this information to develop preliminary estimates of the potential magnitudes of these risks. Information was collected on a broad range of risk categories to assist the US Department of Energy (DOE) in communicating information about the risks in the waste management system. The study, which was completed prior to passage of the Nuclear Waste Policy Amendments Act of 1987, examined all of the portions of the nuclear waste management system envisioned by the DOE in the 1985 ''Mission Plant for the Civilian Radioactive Waste Management Program.'' As such, there may be statements in this paper that are not consistent with current DOE positions. The scope of this paper includes the repository, the integral Monitored Retrievable Storage (MRS) facility, and the transportation system that supports the repository and the MRS facility. Based on the results of this analysis, it is concluded that the radiological risks in the waste management system are small relative to nonradiological risks and relative to the risks of exposure to natural background radiation. 6 refs., 2 figs., 2 tabs
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Risks associated with nuclear material recovery and waste preparation
Energy Technology Data Exchange (ETDEWEB)
Fullwood, R R; Erdmann, R C
1983-01-01
An analysis of the risk associated with nuclear material recovery and waste preparation is presented. The steps involve: reprocessing of spent fuel to recycle fissionable material, refabrication of the recovered material for use as reactor fuel, and the transportation links connecting these plants with the power plants and waste repositories. The risks considered are radiological and non-radiological, accident and routine effects on the public and workers during plant construction, operation and decommissioning.
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Radioactive and mixed waste - risk as a basis for waste classification. Symposium proceedings No. 2
International Nuclear Information System (INIS)
1995-01-01
The management of risks from radioactive and chemical materials has been a major environmental concern in the United states for the past two or three decades. Risk management of these materials encompasses the remediation of past disposal practices as well as development of appropriate strategies and controls for current and future operations. This symposium is concerned primarily with low-level radioactive wastes and mixed wastes. Individual reports were processed separately for the Department of Energy databases
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Radioactive and mixed waste - risk as a basis for waste classification. Symposium proceedings No. 2
Energy Technology Data Exchange (ETDEWEB)
NONE
1995-06-21
The management of risks from radioactive and chemical materials has been a major environmental concern in the United states for the past two or three decades. Risk management of these materials encompasses the remediation of past disposal practices as well as development of appropriate strategies and controls for current and future operations. This symposium is concerned primarily with low-level radioactive wastes and mixed wastes. Individual reports were processed separately for the Department of Energy databases.
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Hall, Philip S.
2009-01-01
Using rewards to impact students' behavior has long been common practice. However, using reward systems to enhance student learning conveniently masks the larger and admittedly more difficult task of finding and implementing the structure and techniques that children with special needs require to learn. More important, rewarding the child for good…
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Pain and suicidality: insights from reward and addiction neuroscience.
Elman, Igor; Borsook, David; Volkow, Nora D
2013-10-01
Suicidality is exceedingly prevalent in pain patients. Although the pathophysiology of this link remains unclear, it may be potentially related to the partial congruence of physical and emotional pain systems. The latter system's role in suicide is also conspicuous during setbacks and losses sustained in the context of social attachments. Here we propose a model based on the neural pathways mediating reward and anti-reward (i.e., allostatic adjustment to recurrent activation of the reward circuitry); both are relevant etiologic factors in pain, suicide and social attachments. A comprehensive literature search on neurobiology of pain and suicidality was performed. The collected articles were critically reviewed and relevant data were extracted and summarized within four key areas: (1) physical and emotional pain, (2) emotional pain and social attachments, (3) pain- and suicide-related alterations of the reward and anti-reward circuits as compared to addiction, which is the premier probe for dysfunction of these circuits and (4) mechanistically informed treatments of co-occurring pain and suicidality. Pain-, stress- and analgesic drugs-induced opponent and proponent states of the mesolimbic dopaminergic pathways may render reward and anti-reward systems vulnerable to sensitization, cross-sensitization and aberrant learning of contents and contexts associated with suicidal acts and behaviors. These findings suggest that pain patients exhibit alterations in the brain circuits mediating reward (depressed function) and anti-reward (sensitized function) that may affect their proclivity for suicide and support pain and suicidality classification among other "reward deficiency syndromes" and a new proposal for "enhanced anti-reward syndromes". We suggest that interventions aimed at restoring the balance between the reward and anti-reward networks in patients with chronic pain may help decreasing their suicide risk. Published by Elsevier Ltd.
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International Nuclear Information System (INIS)
Fang Dong
1997-01-01
The risk of different treatment and disposal strategies of high level liquid radioactive waste from spent fuel reprocessing is estimated and compared. The conclusions obtained are that risk difference from these strategies is very small and high level liquid waste can be reduced to middle and low level waste, if the decontamination factor for 99 Tc is large enough, which is the largest risk contributor in the high level radioactive waste from spent fuel reprocessing. It is also shown that the risk of high level radioactive waste could be reduced by the technical strategy of combining partitioning and transmutation
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Duell, Natasha; Steinberg, Laurence; Chein, Jason; Al-Hassan, Suha M.; Bacchini, Dario; Lei, Chang; Chaudhary, Nandita; Di Giunta, Laura; Dodge, Kenneth A.; Fanti, Kostas A.; Lansford, Jennifer E.; Malone, Patrick S.; Oburu, Paul; Pastorelli, Concetta; Skinner, Ann T.; Sorbring, Emma; Tapanya, Sombat; Uribe Tirado, Liliana Maria; Alampay, Liane Peña
2016-01-01
In the present analysis, we test the dual systems model of adolescent risk taking in a cross-national sample of over 5,200 individuals aged 10 through 30 (M = 17.05 years, SD = 5.91) from 11 countries. We examine whether reward seeking and self-regulation make independent, additive, or interactive contributions to risk taking, and ask whether…
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40 CFR 266.109 - Low risk waste exemption.
2010-07-01
... MANAGEMENT FACILITIES Hazardous Waste Burned in Boilers and Industrial Furnaces § 266.109 Low risk waste exemption. (a) Waiver of DRE standard. The DRE standard of § 266.104(a) does not apply if the boiler or... 99.9 percent destruction and removal efficiency. That is, assume that 0.1 percent of the mass weight...
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International Nuclear Information System (INIS)
Lazaro, M.A.; Policastro, A.J.; Hartmann, H.M.
1995-04-01
This report, a supplement to Appendix E (Transportation Risk) of the U.S. Department of Energy Waste Management Programmatic Environmental Impact Statement (WM PEIS), provides additional information supporting the accident data for chemical risk assessment and health risk methodology described in that appendix (Part II), as well as providing the uncertainty analysis and on-site risk calculations. This report focuses on hazardous material truck accident rates, release probabilities, and release quantities; provides the toxicological values derived for each hazardous chemical assessed in the WM PEIS and further details on the derivation of health criteria; describes the method used in the transportation risk assessments to address potential additivity of health effects from simultaneous exposure to several chemicals and the method used to address transportation risks for maximally exposed individuals; presents an expanded discussion of the uncertainty associated with transportation risk calculations; and includes the results of the on-site transportation risk analysis. In addition, two addenda are provided to detail the risk assessments conducted for the hazardous components of low-level mixed waste (Addendum I) and transuranic waste (Addendum II)
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Development of risk assessment methodology applicable to radioactive waste isolation
International Nuclear Information System (INIS)
Campbell, J.E.; McGrath, P.E.; Cullingford, M.C.
1978-01-01
The risk from radioactive waste disposal in a deep geologic formation has not yet been completely assessed. A complete assessment should include credible estimates of the likelihood that radioactive materials would escape the repository and enter the human environment, and the magnitude of the resultant consequences in terms of human health effects. In addition, such an assessment should identify the dominant contributors to risk and, to the extent possible, quantify the uncertainties in risk estimates. A complete risk assessment may not be possible because of our limited knowledge of various aspects of geology and hydrogeology important to the long-term safety of a radioactive waste repository. The results of past analyses are not entirely consistent, perhaps as a direct result of the limited knowledge of the phenomena involved. It may, therefore, seem premature to attempt a rigorous risk analysis of radioactive waste disposal in deep, geologic media at the present time. However, the value of such analyses lies more in the insight and information they provide than in their prediction of absolute levels of risk
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Risk assessments for the disposal of high level radioactive wastes
International Nuclear Information System (INIS)
Smith, C.F.
1975-01-01
The risks associated with the disposal of high level wastes derive from the potential for release of radioactive materials into the environment. The assessment of these risks requires a methodology for risk analysis, an identification of the radioactive sources, and a method by which to express the relative hazard of the various radionuclides that comprise the high level waste. The development of a methodology for risk analysis is carried out after a review of previous work in the area of probabilistic risk assessment. The methodology suggested involves the probabilistic analysis of a general accident consequence distribution. In this analysis, the frequency aspect of the distribution is treated separately from the normalized probability function. At the final stage of the analysis, the frequency and probability characteristics of the distribution are recombined to provide an estimate of the risk. The characterization of the radioactive source term is accomplished using the ORIGEN computer code. Calculations are carried out for various reactor types and fuel cycles, and the overall waste hazard for a projected thirty-five year nuclear power program is determined
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International Nuclear Information System (INIS)
Biwer, B.M.; Monette, F.A.; Chen, S.Y.
1996-12-01
This report documents the risk assessment performed for the on-site transportation of radioactive wastes in the US Department of Energy (DOE) Waste Management Programmatic Environmental Impact Statement (WM PEIS). Risks for the routine shipment of wastes and the impacts from potential accidental releases are analyzed for operations at the Hanford Site (Hanford) near Richland, Washington. Like other large DOE sites, hanford conducts waste management operations for all wastes types; consequently, the impacts calculated for Hanford are expected to be greater than those for smaller sites. The risk assessment conducted for on-site transportation is intended to provide an estimate of the magnitude of the potential risk for comparison with off-site transportation risks assessed for the WM PEIS
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Liao, Ching-Jong; Ho, Chao Chung
2014-07-01
Using the failure mode and effects analysis, this study examined biomedical waste companies through risk assessment. Moreover, it evaluated the supervisors of biomedical waste units in hospitals, and factors relating to the outsourcing risk assessment of biomedical waste in hospitals by referring to waste disposal acts. An expert questionnaire survey was conducted on the personnel involved in waste disposal units in hospitals, in order to identify important factors relating to the outsourcing risk of biomedical waste in hospitals. This study calculated the risk priority number (RPN) and selected items with an RPN value higher than 80 for improvement. These items included "availability of freezing devices", "availability of containers for sharp items", "disposal frequency", "disposal volume", "disposal method", "vehicles meeting the regulations", and "declaration of three lists". This study also aimed to identify important selection factors of biomedical waste disposal companies by hospitals in terms of risk. These findings can serve as references for hospitals in the selection of outsourcing companies for biomedical waste disposal. Copyright © 2014 Elsevier Ltd. All rights reserved.
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Blum, K; Oscar-Berman, M; Giordano, J; Downs, BW; Simpatico, T; Han, D; Femino, John
2012-01-01
Work from our laboratory in both in-patient and outpatient facilities utilizing the Comprehensive Analysis of Reported Drugs (CARD)™ found a significant lack of compliance to prescribed treatment medications and a lack of abstinence from drugs of abuse during active recovery. This unpublished, ongoing research provides an impetus to develop accurate genetic diagnosis and holistic approaches that will safely activate brain reward circuitry in the mesolimbic dopamine system. This editorial focuses on the neurogenetics of brain reward systems with particular reference to genes related to dopaminergic function. The terminology “Reward Deficiency Syndrome” (RDS), used to describe behaviors found to have an association with gene-based hypodopaminergic function, is a useful concept to help expand our understanding of Substance Use Disorder (SUD), process addictions, and other obsessive, compulsive and impulsive behaviors. This editorial covers the neurological basis of pleasure and the role of natural and unnatural reward in motivating and reinforcing behaviors. Additionally, it briefly describes the concept of natural dopamine D2 receptor agonist therapy coupled with genetic testing of a panel of reward genes, the Genetic Addiction Risk Score (GARS). It serves as a spring-board for this combination of novel approaches to the prevention and treatment of RDS that was developed from fundamental genomic research. We encourage further required studies. PMID:23264886
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Postclosure risks of alternative SRP nuclear waste forms in geologic repositories
International Nuclear Information System (INIS)
Cheung, H.; Edwards, L.; Harvey, T.; Revelli, M.
1982-05-01
The postclosure risk of REFERENCE and ALTERNATIVE waste forms for the defense high-level waste at the Savannah River Plant (SRP) were compared by analyses with a computer code, MISER, written to study the effects of repository features in a probabilistic framework. MISER traces radionuclide flows through a network of stream tubes from the repository to risk-sensitive points. Uncertainties in waste form, package properties, and geotechnical data are accounted for with Monte Carlo techniques. Our results show: (1) for generic layered-salt and basalt repositories, the difference in performance between the two waste forms is insignificant; (2) where the doses are sensitive to uncertainties in leaching rates, the doses are orders of magnitude below background; (3) disruptive events contribute only slightly to the risk of a layered-salt repository; (4) simple design alterations have strong effects on near field doses; (5) great care should be exercised in selecting the location at which repository risks are to be measured, calculated, or regulated
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Reward deficiency syndrome: genetic aspects of behavioral disorders.
Comings, D E; Blum, K
2000-01-01
The dopaminergic and opioidergic reward pathways of the brain are critical for survival since they provide the pleasure drives for eating, love and reproduction; these are called 'natural rewards' and involve the release of dopamine in the nucleus accumbens and frontal lobes. However, the same release of dopamine and production of sensations of pleasure can be produced by 'unnatural rewards' such as alcohol, cocaine, methamphetamine, heroin, nicotine, marijuana, and other drugs, and by compulsive activities such as gambling, eating, and sex, and by risk taking behaviors. Since only a minority of individuals become addicted to these compounds or behaviors, it is reasonable to ask what factors distinguish those who do become addicted from those who do not. It has usually been assumed that these behaviors are entirely voluntary and that environmental factors play the major role; however, since all of these behaviors have a significant genetic component, the presence of one or more variant genes presumably act as risk factors for these behaviors. Since the primary neurotransmitter of the reward pathway is dopamine, genes for dopamine synthesis, degradation, receptors, and transporters are reasonable candidates. However, serotonin, norepinephrine, GABA, opioid, and cannabinoid neurons all modify dopamine metabolism and dopamine neurons. We have proposed that defects in various combinations of the genes for these neurotransmitters result in a Reward Deficiency Syndrome (RDS) and that such individuals are at risk for abuse of the unnatural rewards. Because of its importance, the gene for the [figure: see text] dopamine D2 receptor was a major candidate gene. Studies in the past decade have shown that in various subject groups the Taq I A1 allele of the DRD2 gene is associated with alcoholism, drug abuse, smoking, obesity, compulsive gambling, and several personality traits. A range of other dopamine, opioid, cannabinoid, norepinephrine, and related genes have since been
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Using food as a reward: An examination of parental reward practices.
Roberts, Lindsey; Marx, Jenna M; Musher-Eizenman, Dara R
2018-01-01
Eating patterns and taste preferences are often established early in life. Many studies have examined how parental feeding practices may affect children's outcomes, including food intake and preference. The current study focused on a common food parenting practice, using food as a reward, and used Latent Profile Analysis (LPA) to examine whether mothers (n = 376) and fathers (n = 117) of children ages 2.8 to 7.5 (M = 4.7; SD = 1.1) grouped into profiles (i.e., subgroups) based on how they use of food as a reward. The 4-class model was the best-fitting LPA model, with resulting classes based on both the frequency and type of reward used. Classes were: infrequent reward (33%), tangible reward (21%), food reward (27%), and frequent reward (19%). The current study also explored whether children's eating styles (emotional overeating, rood fussiness, food responsiveness, and satiety responsiveness) and parenting style (Authoritative, Authoritarian, and Permissive) varied by reward profile. Analyses of Variance (ANOVA) revealed that the four profiles differed significantly for all outcome variables except satiety responsiveness. It appears that the use of tangible and food-based rewards have important implications in food parenting. More research is needed to better understand how the different rewarding practices affect additional child outcomes. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Levelized cost-risk reduction prioritization of waste disposal options
International Nuclear Information System (INIS)
Wilkinson, V.K.; Young, J.M.
1992-01-01
The prioritization of solid waste disposal options in terms of reduced risk to workers, the public, and the environment has recently generated considerable governmental and public interest. In this paper we address the development of a methodology to establish priorities for waste disposal options, such as incineration, landfills, long-term storage, waste minimization, etc. The study is one result of an overall project to develop methodologies for Probabilistic Risk Assessments (PRAs) of non-reactor nuclear facilities for the US Department of Energy. Option preferences are based on a levelized cost-risk reduction analysis. Option rankings are developed as functions of disposal option cost and timing, relative long- and short-term risks, and possible accident scenarios. We examine the annual costs and risks for each option over a large number of years. Risk, in this paper, is defined in terms of annual fatalities (both prompt and long-term) and environmental restoration costs that might result from either an accidental release or long-term exposure to both plant workers and the public near the site or facility. We use event timing to weigh both costs and risks; near-term costs and risks are discounted less than future expenditures and fatalities. This technique levels the timing of cash flows and benefits by converting future costs and benefits to present value costs and benefits. We give an example Levelized Cost-Benefit Analysis of incinerator location options to demonstrate the methodology and required data
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International Nuclear Information System (INIS)
Biwer, B.M.; Monette, F.A.; Chen, S.Y.
1995-04-01
This report documents the risk assessment performed for the on-site transportation of radioactive wastes in the U.S. Department of Energy (DOE) Waste Management (WM) Programmatic Environmental Impact Statement (PEIS). Risks for the routine shipment of wastes and the impacts from potential accidental releases are analyzed for operations at the Hanford Site (Hanford) near Richland, Washington. Like other large DOE sites, Hanford conducts waste management operations for all wastes types; consequently, the impacts calculated for Hanford are expected to be greater than those for smaller sites. The risk assessment conducted for on-site transportation is intended to provide an estimate of the magnitude of the potential risk for comparison with off-site transportation risks assessed for the WM PEIS
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Risk evaluations of transuranic waste at the Idaho National Engineering Laboratory
International Nuclear Information System (INIS)
Smith, T.H.; Keneshea, F.J.
1980-01-01
Approximately 75% of the defense low-level transuranic (TRU) waste stored in the United States and 25% of the buried TRU waste is located at the Idaho National Engineering Laboratory (INEL). Studies have been performed to identify and evaluate technical alternatives for the long-term management of this waste. (The alternatives range from leaving the waste in place as is to reviewing, processing, and shipping it to an offsite geological repository.) Among the evalations that have been performed were preliminary risk evaluations. The dose commitment and risk of hypothetical, near-term, accidental or uncontrolled releases of radionuclides have been evaluated for each alternative. The following potential causes of radionuclide release have been studied: process and handling accidents, shipping accidents, natural events (e.g., earthquakes), man-caused events (e.g., airplane crashes), and future intrusion by individuals or small populations after loss of societal control over the waste. The hypothetical releases have been evaluated, in terms of dose commitment and (if pertinent) probability and risk, for all operational steps making up each concept. The dominant scanerios in terms of near-term risk are (1) lava flow up through or over the waste, leading to airbone releases; (2) an explosion or a criticality accident in the waste-processing facility; and (3) a tornado strike or a fire during waste retrieval. The dominant long-term releases are (1) volcanic action; and (2) intrusion of people on the waste site.Although substantial dose commitments to individual members of the public were calculated for the lava flow and intrusion scenarios, no prompt health effects would be expected from the exposures. The effects would be in the form of a slightly increased likelihood of latent cancer induction
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The risks and rewards for exploration and production ventures in Russia
International Nuclear Information System (INIS)
Lavers, B.A.
1996-01-01
At the 1995 APS conference, the author reviewed the difficult investment climate then prevailing in the Russian oil and gas industry. Today the focus is on the progress that has been made during the past twelve months. Will investor confidence be restored and maintained, or is ''plus ca change, plus c'est la meme chose ? Early western investors in joint ventures have had a very difficult time and few of them expect to recover more than a part of their original investment. Most Russian oil companies have virtually stopped investing and only survive by running up large debts with the tax authorities and other creditors. During the past year there have been a number of developments which impact on the risks and rewards of investing in Russia: re-distribution of gross revenue taxation; tax rebates; profit based taxes; production sharing legislation; pipeline access; and transportation tariffs are considered. (author)
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International Nuclear Information System (INIS)
Huang, J.C.; Wright, W.V.
1982-04-01
The Defense Waste Processing Facility (DWPF) for immobilizing nuclear high level waste (HLW) is scheduled to be built at the Savannah River Plant (SRP). High level waste is produced when SRP reactor components are subjected to chemical separation operations. Two candidates for immobilizing this HLW are borosilicate glass and crystalline ceramic, either being contained in weld-sealed stainless steel canisters. A number of technical analyses are being conducted to support a selection between these two waste forms. The present document compares the risks associated with the manufacture and interim storage of these two forms in the DWPF. Process information used in the risk analysis was taken primarily from a DWPF processibility analysis. The DWPF environmental analysis provided much of the necessary environmental information. To perform the comparative risk assessments, consequences of the postulated accidents are calculated in terms of: (1) the maximum dose to an off-site individual; and (2) the dose to off-site population within 80 kilometers of the DWPF, both taken in terms of the 50-year inhalation dose commitment. The consequences are then multiplied by the estimated accident probabilities to obtain the risks. The analyses indicate that the maximum exposure risk to an individual resulting from the accidents postulated for both the production and interim storage of either waste form represents only an insignificant fraction of the natural background radiation of about 90 mrem per year per person in the local area. They also show that there is no disaster potential to the off-site population. Therefore, the risks from abnormal events in the production and the interim storage of the DWPF waste forms should not be considered as a dominant factor in the selection of the final waste form
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Health and environmental risk-related impacts of actinide burning on high-level waste disposal
International Nuclear Information System (INIS)
Forsberg, C.W.
1992-05-01
The potential health and environmental risk-related impacts of actinide burning for high-level waste disposal were evaluated. Actinide burning, also called waste partitioning-transmutation, is an advanced method for radioactive waste management based on the idea of destroying the most toxic components in the waste. It consists of two steps: (1) selective removal of the most toxic radionuclides from high-level/spent fuel waste and (2) conversion of those radionuclides into less toxic radioactive materials and/or stable elements. Risk, as used in this report, is defined as the probability of a failure times its consequence. Actinide burning has two potential health and environmental impacts on waste management. Risks and the magnitude of high-consequence repository failure scenarios are decreased by inventory reduction of the long-term radioactivity in the repository. (What does not exist cannot create risk or uncertainty.) Risk may also be reduced by the changes in the waste characteristics, resulting from selection of waste forms after processing, that are superior to spent fuel and which lower the potential of transport of radionuclides from waste form to accessible environment. There are no negative health or environmental impacts to the repository from actinide burning; however, there may be such impacts elsewhere in the fuel cycle
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Risk methodology for geologic disposal of radioactive waste: interim report
International Nuclear Information System (INIS)
Campbell, J.E.; Dillon, R.T.; Tierney, M.S.; Davis, H.T.; McGrath, P.E.; Pearson, F.J. Jr.; Shaw, H.R.; Helton, J.C.; Donath, F.A.
1978-10-01
The Fuel Cycle Risk Analysis Division of Sandia Laboratories is funded by the Nuclear Regulatory Commission (NRC) to develop a methodology for assessment of the long-term risks from radioactive waste disposal in deep, geologic media. The first phase of this work, which is documented in this report, involves the following: (1) development of analytical models to represent the processes by which radioactive waste might leave the waste repository, enter the surface environment and eventually reach humans and (2) definition of a hypothetical ''reference system'' to provide a realistic setting for exercise of the models in a risk or safety assessment. The second phase of this work, which will be documented in a later report, will involve use of the analytical models in a demonstration risk or safety assessment of the reference system. The analytical methods and data developed in this study are expected to form the basis for a portion of the NRC repository licensing methodology
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Leon, M I; Gallistel, C R
1998-07-01
For rats that bar pressed for intracranial electrical stimulation in a 2-lever matching paradigm with concurrent variable interval schedules of reward, the authors found that the time allocation ratio is based on a multiplicative combination of the ratio of subjective reward magnitudes and the ratio of the rates of reward. Multiplicative combining was observed in a range covering approximately 2 orders of magnitude in the ratio of the rates of reward from about 1:10 to 10:1) and an order of magnitude change in the size of rewards. After determining the relation between the pulse frequency of stimulation and subjective reward magnitude, the authors were able to predict from knowledge of the subjective magnitudes of the rewards and the obtained relative rates of reward the subject's time allocation ratio over a range in which it varied by more than 3 orders of magnitude.
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Tank waste remediation system risk management list
International Nuclear Information System (INIS)
Collard, L.B.
1995-01-01
The Tank Waste Remedation System (TWRS) Risk Management List and it's subset of critical risks, the Critical Risk Management List, provide a tool to senior RL and WHC management (Level-1 and -2) to manage programmatic risks that may significantly impact the TWRS program. The programmatic risks include cost, schedule, and performance risks. Performance risk includes technical risk, supportability risk (such as maintainability and availability), and external risk (i.e., beyond program control, for example, changes in regulations). The risk information includes a description, its impacts, as evaluation of the likelihood, consequences and risk value, possible mitigating actions, and responsible RL and WHC managers. The issues that typically form the basis for the risks are presented in a separate table and the affected functions are provided on the management lists
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Commercial low-level radioactive waste transportation liability and radiological risk
Energy Technology Data Exchange (ETDEWEB)
Quinn, G.J.; Brown, O.F. II; Garcia, R.S.
1992-08-01
This report was prepared for States, compact regions, and other interested parties to address two subjects related to transporting low-level radioactive waste to disposal facilities. One is the potential liabilities associated with low-level radioactive waste transportation from the perspective of States as hosts to low-level radioactive waste disposal facilities. The other is the radiological risks of low-level radioactive waste transportation for drivers, the public, and disposal facility workers.
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Commercial low-level radioactive waste transportation liability and radiological risk
International Nuclear Information System (INIS)
Quinn, G.J.; Brown, O.F. II; Garcia, R.S.
1992-08-01
This report was prepared for States, compact regions, and other interested parties to address two subjects related to transporting low-level radioactive waste to disposal facilities. One is the potential liabilities associated with low-level radioactive waste transportation from the perspective of States as hosts to low-level radioactive waste disposal facilities. The other is the radiological risks of low-level radioactive waste transportation for drivers, the public, and disposal facility workers
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International Nuclear Information System (INIS)
Bergenback, B.; Blaylock, B.P.; Legg, J.L.
1995-05-01
The US Department of Energy (DOE) has produced large quantities of radioactive and hazardous waste during years of nuclear weapons production. As a result, a large number of sites across the DOE Complex have become chemically and/or radiologically contaminated. In 1990, the Secretary of Energy charged the DOE Office of Environmental Restoration and Waste management (EM) with the task of preparing a Programmatic Environmental Impact Statement (PEIS). The PEIS should identify and assess the potential environmental impacts of implementing several integrated Environmental Restoration (ER) and Waste Management (WM) alternatives. The determination and integration of appropriate remediation activities and sound waste management practices is vital for ensuring the diminution of adverse human health impacts during site cleanup and waste management programs. This report documents the PEIS risk assessment methodology used to evaluate human health risks posed by WM activities. The methodology presents a programmatic cradle to grave risk assessment for EM program activities. A unit dose approach is used to estimate risks posed by WM activities and is the subject of this document
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"Small Steps, Big Rewards": You Can Prevent Type 2 Diabetes
... Steps, Big Rewards": You Can Prevent Type 2 Diabetes Past Issues / Winter 2008 Table of Contents For ... million Americans are at risk for type 2 diabetes." "Fifty four million Americans are at risk for ...
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The reward-based eating drive scale: a self-report index of reward-based eating.
Directory of Open Access Journals (Sweden)
Elissa S Epel
Full Text Available Why are some individuals more vulnerable to persistent weight gain and obesity than are others? Some obese individuals report factors that drive overeating, including lack of control, lack of satiation, and preoccupation with food, which may stem from reward-related neural circuitry. These are normative and common symptoms and not the sole focus of any existing measures. Many eating scales capture these common behaviors, but are confounded with aspects of dysregulated eating such as binge eating or emotional overeating. Across five studies, we developed items that capture this reward-based eating drive (RED. Study 1 developed the items in lean to obese individuals (n = 327 and examined changes in weight over eight years. In Study 2, the scale was further developed and expert raters evaluated the set of items. Study 3 tested psychometric properties of the final 9 items in 400 participants. Study 4 examined psychometric properties and race invariance (n = 80 women. Study 5 examined psychometric properties and age/gender invariance (n = 381. Results showed that RED scores correlated with BMI and predicted earlier onset of obesity, greater weight fluctuations, and greater overall weight gain over eight years. Expert ratings of RED scale items indicated that the items reflected characteristics of reward-based eating. The RED scale evidenced high internal consistency and invariance across demographic factors. The RED scale, designed to tap vulnerability to reward-based eating behavior, appears to be a useful brief tool for identifying those at higher risk of weight gain over time. Given the heterogeneity of obesity, unique brief profiling of the reward-based aspect of obesity using a self-report instrument such as the RED scale may be critical for customizing effective treatments in the general population.
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The Hidden Risk Decisions in Waste Repository Regulation
International Nuclear Information System (INIS)
Frishman, Steve
2001-01-01
The move toward risk-informed, performance-based regulation of activities involving radioactive materials is becoming wide spread and broadly applied. While this approach may have some merit in specific applications in which there is a considerable body of experience, its strict application in regulation of geologic repositories for highly radioactive wastes may not be appropriate for this unproven and socially controversial technology. The U.S. Nuclear Regulatory Commission describes risk-informed, performance-based regulation as 'an approach in which risk insights, engineering analysis and judgement (eg. defense in depth), and performance history are used to (1) focus attention on the most important activities, (2) establish objective criteria based upon risk insights for evaluating performance, (3) develop measurable or calculable parameters for monitoring system and licensee performance, and (4) focus on the results as the primary basis for regulatory decision-making.' Both the risk-informed and performance-based elements of the approach are problematic when considering regulation of geologic repositories for highly radioactive wastes - an activity yet to be accomplished by any nation. In investigating potential sites for geologic repositories there will always be residual uncertainty in understanding the natural system and the events and processes that affect it. The more complex the natural system, the greater will be the uncertainty in both the data and the models used to describe the characteristics of the site's natural barriers, and the events and processes that could affect repository waste isolation. The engineered barriers also are subject to uncertainties that are important to the repository system. These uncertainties translate themselves into a range of probabilities that certain events or processes, detrimental to waste isolation, will occur. The uncertainties also translate to a range of consequences and magnitudes of consequences, should the
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Ferreira, Vera; Teixeira, Margarida Ribau
2010-12-01
The management of healthcare wastes is receiving greater attention because of the risks to both human health and the environment caused by inadequate waste management practices. In that context, the objective of this study was to analyse the healthcare waste management practices in hospitals of the Algarve region, Portugal, and in particular to assess the risk perceptions of, and actual risk to, healthcare staff. The study included three of the six hospitals in the region, covering 41% of the bed capacity. Data were collected via surveys, interviews, and on-site observations. The results indicate that waste separation is the main deficiency in healthcare waste practice, with correct separation being positively related to the degree of daily contact with the waste. Risk perceptions of healthcare staff show the highest levels for the environment (4.24) and waste workers (4.08), and the lowest for patients (3.29) and visitors (2.80), again being positively associated with the degree of daily contact. Risk perceptions of healthcare staff are related to the difficulties of the correct separation of wastes and the lack of knowledge concerning the importance of that separation. The risk of infection with needlesticks/sharps is higher during patient care than during waste handling, and the frequency of these injuries is related to the daily tasks of each healthcare group (doctors, nurses, and housekeepers). Furthermore, legislative definitions and classifications of healthcare wastes appear to have conditioned the management practices associated with, and the perceptions of risk concerning, healthcare wastes. Copyright © 2010 Elsevier Ltd. All rights reserved.
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Perceived risks of radioactive waste transport through Oregon: Results of a statewide survey
International Nuclear Information System (INIS)
MacGregor, D.; Slovic, P.; Mason, R.G.; Detweiler, J.; Binney, S.E.; Dodd, B.
1994-01-01
Transportation of hazardous materials, and particularly radioactive wastes, on public highways has become an important risk management issue. The unfavorability of public attitudes regarding hazardous and nuclear waste signals the potential for strong public opposition to programs for transporting these materials. This paper presents the results of a survey conducted to assess public reactions to a long-term nuclear waste transport program planned to follow a route through a portion of rural Oregon. The survey assessed a number of key risk perception issues, including perceived health and safety risks of nuclear waste transport, relative risks of transport vs. storage at an existing site, trust in state officials, and satisfaction with life in communities along the transport route. The survey identified a number of attitudes and concerns that need to be understood and considered by those in charge of designing and implementing the waste-transportation program. 22 refs., 1 fig., 5 tabs
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International Nuclear Information System (INIS)
Liao, Ching-Jong; Ho, Chao Chung
2014-01-01
Highlights: • This study is based on a real case in hospital in Taiwan. • We use Failure Mode and Effects Analysis (FMEA) as the evaluation method. • We successfully identify the evaluation factors of bio-medical waste disposal risk. - Abstract: Using the failure mode and effects analysis, this study examined biomedical waste companies through risk assessment. Moreover, it evaluated the supervisors of biomedical waste units in hospitals, and factors relating to the outsourcing risk assessment of biomedical waste in hospitals by referring to waste disposal acts. An expert questionnaire survey was conducted on the personnel involved in waste disposal units in hospitals, in order to identify important factors relating to the outsourcing risk of biomedical waste in hospitals. This study calculated the risk priority number (RPN) and selected items with an RPN value higher than 80 for improvement. These items included “availability of freezing devices”, “availability of containers for sharp items”, “disposal frequency”, “disposal volume”, “disposal method”, “vehicles meeting the regulations”, and “declaration of three lists”. This study also aimed to identify important selection factors of biomedical waste disposal companies by hospitals in terms of risk. These findings can serve as references for hospitals in the selection of outsourcing companies for biomedical waste disposal
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Energy Technology Data Exchange (ETDEWEB)
Liao, Ching-Jong; Ho, Chao Chung, E-mail: ho919@pchome.com.tw
2014-07-15
Highlights: • This study is based on a real case in hospital in Taiwan. • We use Failure Mode and Effects Analysis (FMEA) as the evaluation method. • We successfully identify the evaluation factors of bio-medical waste disposal risk. - Abstract: Using the failure mode and effects analysis, this study examined biomedical waste companies through risk assessment. Moreover, it evaluated the supervisors of biomedical waste units in hospitals, and factors relating to the outsourcing risk assessment of biomedical waste in hospitals by referring to waste disposal acts. An expert questionnaire survey was conducted on the personnel involved in waste disposal units in hospitals, in order to identify important factors relating to the outsourcing risk of biomedical waste in hospitals. This study calculated the risk priority number (RPN) and selected items with an RPN value higher than 80 for improvement. These items included “availability of freezing devices”, “availability of containers for sharp items”, “disposal frequency”, “disposal volume”, “disposal method”, “vehicles meeting the regulations”, and “declaration of three lists”. This study also aimed to identify important selection factors of biomedical waste disposal companies by hospitals in terms of risk. These findings can serve as references for hospitals in the selection of outsourcing companies for biomedical waste disposal.
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Effort–Reward Imbalance at Work and Incident Coronary Heart Disease
Siegrist, Johannes; Nyberg, Solja T.; Lunau, Thorsten; Fransson, Eleonor I.; Alfredsson, Lars; Bjorner, Jakob B.; Borritz, Marianne; Burr, Hermann; Erbel, Raimund; Fahlén, Göran; Goldberg, Marcel; Hamer, Mark; Heikkilä, Katriina; Jöckel, Karl-Heinz; Knutsson, Anders; Madsen, Ida E. H.; Nielsen, Martin L.; Nordin, Maria; Oksanen, Tuula; Pejtersen, Jan H.; Pentti, Jaana; Rugulies, Reiner; Salo, Paula; Schupp, Jürgen; Singh-Manoux, Archana; Steptoe, Andrew; Theorell, Töres; Vahtera, Jussi; Westerholm, Peter J. M.; Westerlund, Hugo; Virtanen, Marianna; Zins, Marie; Batty, G. David; Kivimäki, Mika
2017-01-01
Background: Epidemiologic evidence for work stress as a risk factor for coronary heart disease is mostly based on a single measure of stressful work known as job strain, a combination of high demands and low job control. We examined whether a complementary stress measure that assesses an imbalance between efforts spent at work and rewards received predicted coronary heart disease. Methods: This multicohort study (the “IPD-Work” consortium) was based on harmonized individual-level data from 11 European prospective cohort studies. Stressful work in 90,164 men and women without coronary heart disease at baseline was assessed by validated effort–reward imbalance and job strain questionnaires. We defined incident coronary heart disease as the first nonfatal myocardial infarction or coronary death. Study-specific estimates were pooled by random effects meta-analysis. Results: At baseline, 31.7% of study members reported effort–reward imbalance at work and 15.9% reported job strain. During a mean follow-up of 9.8 years, 1,078 coronary events were recorded. After adjustment for potential confounders, a hazard ratio of 1.16 (95% confidence interval, 1.00–1.35) was observed for effort–reward imbalance compared with no imbalance. The hazard ratio was 1.16 (1.01–1.34) for having either effort–reward imbalance or job strain and 1.41 (1.12–1.76) for having both these stressors compared to having neither effort–reward imbalance nor job strain. Conclusions: Individuals with effort–reward imbalance at work have an increased risk of coronary heart disease, and this appears to be independent of job strain experienced. These findings support expanding focus beyond just job strain in future research on work stress. PMID:28570388
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Risk assessment of nonhazardous oil-field waste disposal in salt caverns.
Energy Technology Data Exchange (ETDEWEB)
Elcock, D.
1998-03-10
that if caverns are sited and designed well, operated carefully, closed properly, and monitored routinely, they could, from technical and legal perspectives, be suitable for disposing of oil-field wastes. On the basis of these findings, ANL subsequently conducted a preliminary risk assessment on the possibility that adverse human health effects (carcinogenic and noncarcinogenic) could result from exposure to contaminants released from the NOW disposed of in salt caverns. The methodology for the risk assessment included the following steps: identifying potential contaminants of concern; determining how humans could be exposed to these contaminants; assessing contaminant toxicities; estimating contaminant intakes; and estimating human cancer and noncancer risks. To estimate exposure routes and pathways, four postclosure cavern release scenarios were assessed. These were inadvertent cavern intrusion, failure of the cavern seal, failure of the cavern through cracks, failure of the cavern through leaky interbeds, and partial collapse of the cavern roof. Assuming a single, generic, salt cavern and generic oil-field wastes, potential human health effects associated with constituent hazardous substances (arsenic, benzene, cadmium, and chromium) were assessed under each of these scenarios. Preliminary results provided excess cancer risk and hazard index (for noncancer health effects) estimates that were well within the EPA target range for acceptable exposure risk levels. These results lead to the preliminary conclusion that from a human health perspective, salt caverns can provide an acceptable disposal method for nonhazardous oil-field wastes.
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Risk assessment of nonhazardous oil-field waste disposal in salt caverns
International Nuclear Information System (INIS)
Elcock, D.
1998-01-01
that if caverns are sited and designed well, operated carefully, closed properly, and monitored routinely, they could, from technical and legal perspectives, be suitable for disposing of oil-field wastes. On the basis of these findings, ANL subsequently conducted a preliminary risk assessment on the possibility that adverse human health effects (carcinogenic and noncarcinogenic) could result from exposure to contaminants released from the NOW disposed of in salt caverns. The methodology for the risk assessment included the following steps: identifying potential contaminants of concern; determining how humans could be exposed to these contaminants; assessing contaminant toxicities; estimating contaminant intakes; and estimating human cancer and noncancer risks. To estimate exposure routes and pathways, four postclosure cavern release scenarios were assessed. These were inadvertent cavern intrusion, failure of the cavern seal, failure of the cavern through cracks, failure of the cavern through leaky interbeds, and partial collapse of the cavern roof. Assuming a single, generic, salt cavern and generic oil-field wastes, potential human health effects associated with constituent hazardous substances (arsenic, benzene, cadmium, and chromium) were assessed under each of these scenarios. Preliminary results provided excess cancer risk and hazard index (for noncancer health effects) estimates that were well within the EPA target range for acceptable exposure risk levels. These results lead to the preliminary conclusion that from a human health perspective, salt caverns can provide an acceptable disposal method for nonhazardous oil-field wastes
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Abnormal Striatal BOLD Responses to Reward Anticipation and Reward Delivery in ADHD
Furukawa, Emi; Bado, Patricia; Tripp, Gail; Mattos, Paulo; Wickens, Jeff R.; Bramati, Ivanei E.; Alsop, Brent; Ferreira, Fernanda Meireles; Lima, Debora; Tovar-Moll, Fernanda; Sergeant, Joseph A.; Moll, Jorge
2014-01-01
Altered reward processing has been proposed to contribute to the symptoms of attention deficit hyperactivity disorder (ADHD). The neurobiological mechanism underlying this alteration remains unclear. We hypothesize that the transfer of dopamine release from reward to reward-predicting cues, as normally observed in animal studies, may be deficient in ADHD. Functional magnetic resonance imaging (fMRI) was used to investigate striatal responses to reward-predicting cues and reward delivery in a classical conditioning paradigm. Data from 14 high-functioning and stimulant-naïve young adults with elevated lifetime symptoms of ADHD (8 males, 6 females) and 15 well-matched controls (8 males, 7 females) were included in the analyses. During reward anticipation, increased blood-oxygen-level-dependent (BOLD) responses in the right ventral and left dorsal striatum were observed in controls, but not in the ADHD group. The opposite pattern was observed in response to reward delivery; the ADHD group demonstrated significantly greater BOLD responses in the ventral striatum bilaterally and the left dorsal striatum relative to controls. In the ADHD group, the number of current hyperactivity/impulsivity symptoms was inversely related to ventral striatal responses during reward anticipation and positively associated with responses to reward. The BOLD response patterns observed in the striatum are consistent with impaired predictive dopamine signaling in ADHD, which may explain altered reward-contingent behaviors and symptoms of ADHD. PMID:24586543
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Klein-Flügge, Miriam Cornelia; Barron, Helen Catharine; Brodersen, Kay Henning; Dolan, Raymond J; Behrens, Timothy Edward John
2013-02-13
A dominant focus in studies of learning and decision-making is the neural coding of scalar reward value. This emphasis ignores the fact that choices are strongly shaped by a rich representation of potential rewards. Here, using fMRI adaptation, we demonstrate that responses in the human orbitofrontal cortex (OFC) encode a representation of the specific type of food reward predicted by a visual cue. By controlling for value across rewards and by linking each reward with two distinct stimuli, we could test for representations of reward-identity that were independent of associative information. Our results show reward-identity representations in a medial-caudal region of OFC, independent of the associated predictive stimulus. This contrasts with a more rostro-lateral OFC region encoding reward-identity representations tied to the predicate stimulus. This demonstration of adaptation in OFC to reward specific representations opens an avenue for investigation of more complex decision mechanisms that are not immediately accessible in standard analyses, which focus on correlates of average activity.
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Dopamine reward prediction error coding.
Schultz, Wolfram
2016-03-01
Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards-an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less reward than predicted (negative prediction error). The dopamine signal increases nonlinearly with reward value and codes formal economic utility. Drugs of addiction generate, hijack, and amplify the dopamine reward signal and induce exaggerated, uncontrolled dopamine effects on neuronal plasticity. The striatum, amygdala, and frontal cortex also show reward prediction error coding, but only in subpopulations of neurons. Thus, the important concept of reward prediction errors is implemented in neuronal hardware.
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Risk assessments of innovative technologies for treatment of mixed waste
International Nuclear Information System (INIS)
Ragaini, R.C.; Aycock, M.T.; Russell, J.E.
1993-01-01
The mission of the US Department of Energy's (DOE'S) Mixed Waste Integrated Program (MWIP) is to develop complete and appropriate technologies for the treatment of DOE mixed low-level waste and transuranic wastes in order to ensure that all affected DOE installations and projects can come into compliance with environmental law and meet DOE's 30-yr cleanup and operational goals. The MWIP will achieve its goal by developing technologies that are in compliance with regulatory requirements, are socially and politically viable, and are cost beneficial and effective in disposed waste source term and volume reduction. The project management plan for MWIP requires that technologies be evaluated in accordance with criteria that rank technologies with regard to performance, risk, and cost-effectiveness. This paper addresses the methodology used to rank alternative mixed-water treatment technologies with regard to relative risk
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Brain reward region responsivity of adolescents with and without parental substance use disorders.
Stice, Eric; Yokum, Sonja
2014-09-01
The present study tested the competing hypotheses that adolescents at risk for future substance abuse and dependence by virtue of parental substance use disorders show either weaker or stronger responsivity of brain regions implicated in reward relative to youth without parental history of substance use disorders. Adolescents (n = 52) matched on demographics with and without parental substance use disorders, as determined by diagnostic interviews, who denied substance use in the past year were compared on functional MRI (fMRI) paradigms assessing neural response to receipt and anticipated receipt of monetary and food reward. Parental-history-positive versus -negative adolescents showed greater activation in the left dorsolateral prefrontal cortex and bilateral putamen, and less activation in the fusiform gyrus and inferior temporal gyrus in response to anticipating winning money, as well as greater activation in the left midbrain and right paracentral lobule, and less activation in the right middle frontal gyrus in response to milkshake receipt. Results indicate that adolescents at risk for future onset of substance use disorders show elevated responsivity of brain regions implicated in reward, extending results from 2 smaller prior studies that found that individuals with versus without parental alcohol use disorders showed greater reward region response to anticipated monetary reward and pictures of alcohol. Collectively, results provide support for the reward surfeit model of substance use disorders, rather than the reward deficit model.
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Integrated Waste Treatment Unit GFSI Risk Management Plan
International Nuclear Information System (INIS)
W. A. Owca
2007-01-01
This GFSI Risk Management Plan (RMP) describes the strategy for assessing and managing project risks for the Integrated Waste Treatment Unit (IWTU) that are specifically within the control and purview of the U.S. Department of Energy (DOE), and identifies the risks that formed the basis for the DOE contingency included in the performance baseline. DOE-held contingency is required to cover cost and schedule impacts of DOE activities. Prior to approval of the performance baseline (Critical Decision-2) project cost contingency was evaluated during a joint meeting of the Contractor Management Team and the Integrated Project Team for both contractor and DOE risks to schedule and cost. At that time, the contractor cost and schedule risk value was $41.3M and the DOE cost and schedule risk contingency value is $39.0M. The contractor cost and schedule risk value of $41.3M was retained in the performance baseline as the contractor's management reserve for risk contingency. The DOE cost and schedule risk value of $39.0M has been retained in the performance baseline as the DOE Contingency. The performance baseline for the project was approved in December 2006 (Garman 2006). The project will continue to manage to the performance baseline and change control thresholds identified in PLN-1963, ''Idaho Cleanup Project Sodium-Bearing Waste Treatment Project Execution Plan'' (PEP)
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A new "loyalty rewards" program in health care customer relationships.
Macstravic, Scott
2006-01-01
"Loyalty rewards" in sponsored DM and HRM programs can apply to both providers and consumers. Physicians and hospitals can be paid to "loyally" adhere to payers' guidelines for managing diseases and risks. Many payer and their outsourced vendor programs include significant efforts to create collaborations between payer and provider, rather than relying on unilateral efforts. And growing numbers are rewarding providers for their efforts and results achieved.
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Cost benefit and risk assessment for selected tank waste process testing alternatives
International Nuclear Information System (INIS)
Gasper, K.A.
1995-01-01
The US Department of Energy has established the Tank Waste Remediation System (TWRS) program to safely manage wastes currently stored in underground tank at the Hanford Site. A TWRS testing and development strategy was recently developed to define long-range TWRS testing plans. The testing and development strategy considered four alternatives. The primary variable in the alternatives is the level of pilot-scale testing involving actual waste. This study evaluates the cost benefit and risks associated with the four alternatives. Four types of risk were evaluated: programmatic schedule risk, process mishap risk, worker risk, and public health risk. The structure of this report is as follows: Section 1 introduces the report subject; Section 2 describes the test strategy alternative evaluation; Section 3 describes the approach used in this study to assess risk and cost benefit; Section 4 describes the assessment methodologies for costs and risks; Section 5 describes the bases and assumptions used to estimate the costs and risks; Section 6 presents the detailed costs and risks; and Section 7 describes the results of the cost benefit analysis and presents conclusions
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Effect of social influence on effort-allocation for monetary rewards.
Gilman, Jodi M; Treadway, Michael T; Curran, Max T; Calderon, Vanessa; Evins, A Eden
2015-01-01
Though decades of research have shown that people are highly influenced by peers, few studies have directly assessed how the value of social conformity is weighed against other types of costs and benefits. Using an effort-based decision-making paradigm with a novel social influence manipulation, we measured how social influence affected individuals' decisions to allocate effort for monetary rewards during trials with either high or low probability of receiving a reward. We found that information about the effort-allocation of peers modulated participant choices, specifically during conditions of low probability of obtaining a reward. This suggests that peer influence affects effort-based choices to obtain rewards especially under conditions of risk. This study provides evidence that people value social conformity in addition to other costs and benefits when allocating effort, and suggests that neuroeconomic studies that assess trade-offs between effort and reward should consider social environment as a factor that can influence decision-making.
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Effect of social influence on effort-allocation for monetary rewards.
Directory of Open Access Journals (Sweden)
Jodi M Gilman
Full Text Available Though decades of research have shown that people are highly influenced by peers, few studies have directly assessed how the value of social conformity is weighed against other types of costs and benefits. Using an effort-based decision-making paradigm with a novel social influence manipulation, we measured how social influence affected individuals' decisions to allocate effort for monetary rewards during trials with either high or low probability of receiving a reward. We found that information about the effort-allocation of peers modulated participant choices, specifically during conditions of low probability of obtaining a reward. This suggests that peer influence affects effort-based choices to obtain rewards especially under conditions of risk. This study provides evidence that people value social conformity in addition to other costs and benefits when allocating effort, and suggests that neuroeconomic studies that assess trade-offs between effort and reward should consider social environment as a factor that can influence decision-making.
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The effectiveness of loyalty rewards to promote the use of an Internet-based heart health program.
Liu, Sam; Hodgson, Corinne; Zbib, Ahmad M; Payne, Ada Y M; Nolan, Robert P
2014-07-02
Internet-based health programs have been shown to be effective in reducing risk for cardiovascular disease. However, their rates of enrollment and engagement remain low. It is currently unclear whether rewards from established loyalty programs can serve as a conditioned stimulus to improve the use of a freely available Internet-based program. The objectives of the study were to (1) examine enrollment rates and levels of engagement with the My Health eSupport program between a Conditioned Reward group and a Control group, and (2) investigate the influence of loyalty rewards and participant characteristics on levels of enrollment and program engagement. The study sample (n=142,726) consisted of individuals who were offered enrollment in an Internet-based health intervention (My Health eSupport) after completing the Heart&Stroke Risk Assessment on the Heart and Stroke Foundation website. My Health eSupport programs provided encouragement and tips for lifestyle change. This is a free, self-guided, fully automated program that proactively delivers tailored email messages at 2-week intervals based on the participant's stage of motivational "readiness" and priority for lifestyle change. Participants in the Conditioned Reward group were offered a single exposure of 20 loyalty reward points from the Air Miles loyalty program for completing the Heart&Stroke Risk Assessment (10 reward points) and enrolling in the Internet-based program (10 reward points). Meanwhile, no rewards were given to the Control group participants. All data were collected between February 1, 2011 and February 10, 2012. In total, 51.38% (73,327/142,726) of individuals in the Conditioned Reward group and 48.62% (69,399/142,726) of individuals in the Control group completed the Heart&Stroke Risk Assessment. Subsequently, significantly more individuals from the Conditioned Reward group (52.96%, 38,835/73,327) enrolled in the My Health eSupport program than Controls (4.07%, 2826/69,399). Regression analyses
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Reward/Punishment reversal learning in older suicide attempters.
Dombrovski, Alexandre Y; Clark, Luke; Siegle, Greg J; Butters, Meryl A; Ichikawa, Naho; Sahakian, Barbara J; Szanto, Katalin
2010-06-01
Suicide rates are high in old age, and the contribution of cognitive risk factors remains poorly understood. Suicide may be viewed as an outcome of an altered decision process. The authors hypothesized that impairment in reward/punishment-based learning, a component of affective decision making, is associated with attempted suicide in late-life depression. They expected that suicide attempters would discount past reward/punishment history, focusing excessively on the most recent rewards and punishments. The authors further hypothesized that this impairment could be dissociated from executive abilities, such as forward planning. The authors assessed reward/punishment-based learning using the probabilistic reversal learning task in 65 individuals age 60 and older: suicide attempters, suicide ideators, nonsuicidal depressed elderly, and nondepressed comparison subjects. The authors used a reinforcement learning computational model to decompose reward/punishment processing over time. The Stockings of Cambridge test served as a control measure of executive function. Suicide attempters but not suicide ideators showed impaired probabilistic reversal learning compared to both nonsuicidal depressed elderly and nondepressed comparison subjects, after controlling for effects of education, global cognitive function, and substance use. Model-based analyses revealed that suicide attempters discounted previous history to a higher degree relative to comparison subjects, basing their choice largely on reward/punishment received on the last trial. Groups did not differ in their performance on the Stockings of Cambridge test. Older suicide attempters display impaired reward/punishment-based learning. The authors propose a hypothesis that older suicide attempters make overly present-focused decisions, ignoring past experiences. Modification of this "myopia for the past" may have therapeutic potential.
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Employee perceptions of risks and rewards in terms of corporate entrepreneurship participation
Directory of Open Access Journals (Sweden)
Kristo Nikolov
2013-06-01
Research purpose: With the scope of CE widening, organisations that lack prior entrepreneurial recognition are adopting CE in order to survive and succeed in increasingly competitive and financially constrained environments. Motivation for the study: By using conjoint analysis, the study is able to determine empirically which criteria organisations use, when they decide to participate in CE activities, are significant. Research design, approach and method: The authors used conjoint analysis. It simulates real life situations where it presents and tests various scenarios in terms of combinations of attributes and levels of intensity that influence decisions to participate in CE. Main findings: The results show that the most important attribute that influences the decision to participate in CE is the probability of venture success. Financial reward follows closely. As expected, job risk, pay risk and exerted effort are deterrents to CE participation. Practical/managerial implications: The study provides guidance to managers and leaders interested in motivating their employees to undertake CE activities. The results give direction to employees by offering them different scenarios of incentives and commensurate risks when they participate in CE. Contribution/value-add: This is one of the first studies to test empirically the likelihood of CE participation in terms of conjoint analysis. It provides managers with a dashboard of possible attributes, according to which they can devise optimal incentive strategies.
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International Nuclear Information System (INIS)
Assmuth, T.W.
1991-01-01
The environmental impacts and risks of hazardous wastes disposed in Finnish landfills were assessed in a 5-yr field study. By systematic analysis of the acquired information, the toxicological impacts and risks of landfills seem as a whole small when compared with those caused by other kinds of environmental toxicants. Locally more significant risks arise, and may be difficult to manage. Scientific information on risk factors and their development is as yet insufficient, and additional research and monitoring are needed. Since uncertainties will remain, the prevention and control of risks, e.g. by improved hazardous waste management and disposal, are advocated by safety principles, but are made difficult by many technical and societal factors. Control strategies and remedial actions should thus be based on more comprehensive, comparative risk assessments and improved decision methods. Ethical, political and methodological issues in the management of hazardous waste disposal are discussed, with special reference to the interaction of science with regulatory decision-making related to the risks of old chemical waste sites. (44 refs.) (au)
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International Nuclear Information System (INIS)
Lindell, M.K.; Earle, T.C.; Nealey, S.M.
1981-06-01
Three fundamental questions concerning public perception of the measurement of radioactive wastes were addressed in this report. The first question centered on the perceived importance of nuclear waste management as a public issue: how important is nuclear waste management relative to other technological and scientific issues; do different segments of the public disagree on its importance; the second question concerned public attitudes toward a nuclear waste disposal facility: how great a risk to health and safety is a nuclear waste disposal facility relative to other industrial facilities; is there disagreement on its riskiness among various public groups; the third question pertained to the aspects of risks that affect overall risk perception: what are the qualitative aspects of a nuclear waste disposal facility that contribute to overall perceptions of risk; do different segments of the population associate different risk characteristics with hazardous facilities. The questions follow from one another: is the issue important; given the importance of the issue, is the facility designed to deal with it considered risky; given the riskiness of the facility, why is it considered risky. Also addressed in this report, and a main focus of its findings, were the patterns of differences among respondent groups on each of these questions
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Reward, Context, and Human Behaviour
Directory of Open Access Journals (Sweden)
Clare L. Blaukopf
2007-01-01
Full Text Available Animal models of reward processing have revealed an extensive network of brain areas that process different aspects of reward, from expectation and prediction to calculation of relative value. These results have been confirmed and extended in human neuroimaging to encompass secondary rewards more unique to humans, such as money. The majority of the extant literature covers the brain areas associated with rewards whilst neglecting analysis of the actual behaviours that these rewards generate. This review strives to redress this imbalance by illustrating the importance of looking at the behavioural outcome of rewards and the context in which they are produced. Following a brief review of the literature of reward-related activity in the brain, we examine the effect of reward context on actions. These studies reveal how the presence of reward vs. reward and punishment, or being conscious vs. unconscious of reward-related actions, differentially influence behaviour. The latter finding is of particular importance given the extent to which animal models are used in understanding the reward systems of the human mind. It is clear that further studies are needed to learn about the human reaction to reward in its entirety, including any distinctions between conscious and unconscious behaviours. We propose that studies of reward entail a measure of the animal's (human or nonhuman knowledge of the reward and knowledge of its own behavioural outcome to achieve that reward.
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Heterogeneity of reward mechanisms.
Lajtha, A; Sershen, H
2010-06-01
The finding that many drugs that have abuse potential and other natural stimuli such as food or sexual activity cause similar chemical changes in the brain, an increase in extracellular dopamine (DA) in the shell of the nucleus accumbens (NAccS), indicated some time ago that the reward mechanism is at least very similar for all stimuli and that the mechanism is relatively simple. The presently available information shows that the mechanisms involved are more complex and have multiple elements. Multiple brain regions, multiple receptors, multiple distinct neurons, multiple transmitters, multiple transporters, circuits, peptides, proteins, metabolism of transmitters, and phosphorylation, all participate in reward mechanisms. The system is variable, is changed during development, is sex-dependent, and is influenced by genetic differences. Not all of the elements participate in the reward of all stimuli. Different set of mechanisms are involved in the reward of different drugs of abuse, yet different mechanisms in the reward of natural stimuli such as food or sexual activity; thus there are different systems that distinguish different stimuli. Separate functions of the reward system such as anticipation, evaluation, consummation and identification; all contain function-specific elements. The level of the stimulus also influences the participation of the elements of the reward system, there are possible reactions to even below threshold stimuli, and excessive stimuli can change reward to aversion involving parts of the system. Learning and memory of past reward is an important integral element of reward and addictive behavior. Many of the reward elements are altered by repeated or chronic stimuli, and chronic exposure to one drug is likely to alter the response to another stimulus. To evaluate and identify the reward stimulus thus requires heterogeneity of the reward components in the brain.
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U.S. Nuclear Regulatory Commission Process for Risk-Informing the Nuclear Waste Arena
International Nuclear Information System (INIS)
Leslie, B. W.
2003-01-01
The U.S. Nuclear Regulatory Commission (NRC) is increasing the use of risk insights and information in its regulation of nuclear materials and waste. The objective of this risk-informed regulatory effort is to improve the effectiveness and efficiency of the agency, while maintaining or increasing its focus on safety. The agency's Office of Nuclear Material Safety and Safeguards (NMSS) proposed a five-step process to carry out a framework for increasing the use of risk information and insights in its regulation of nuclear materials and waste. The office is carrying out the five-step process to risk-inform the nuclear materials and waste arenas. NMSS's actions included forming a Risk Task Group and the use of case studies to test and complete screening criteria for identifying candidate regulatory applications amenable for risk-informing. Other actions included involving stakeholders through enhanced public participation, developing safety goals for materials and waste regulatory applications, and establishing a risk training program for staff. Through the case studies, NRC staff found the draft screening criteria to be effective in deciding regulatory areas that may be amenable to an increased use of risk insights. NRC staff also found that risk information may have the potential to reduce regulatory burden and improve staff's efficiency in making decisions, while maintaining safety. Finally, staff found that it would be possible to develop safety goals for the nuclear materials and waste arenas
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Effort-Reward Imbalance, Work-Privacy Conflict, and Burnout Among Hospital Employees.
Häusler, Nadine; Bopp, Matthias; Hämmig, Oliver
2018-04-01
Studies investigating the relative importance of effort-reward imbalance and work-privacy conflict for burnout risk between professional groups in the health care sector are rare and analyses by educational attainment within professional groups are lacking. The study population consists of 1422 hospital employees in Switzerland. Multivariate linear regression analyses with standardized coefficients were performed for the overall study population and stratified for professional groups refined for educational attainment. Work-privacy conflict is a strong predictor for burnout and more strongly associated with burnout than effort-reward imbalance in the overall study population and across all professional groups. Effort-reward imbalance only had a minor effect on burnout in tertiary-educated medical professionals. Interventions aiming at increasing the compatibility of work and private life may substantially help to decrease burnout risk of professionals working in a health care setting.
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Occupational Risks Associated with Solid Waste Management in the Informal Sector of Gweru, Zimbabwe.
Jerie, Steven
2016-01-01
This study identifies and analyses the occupational risks associated with solid waste management practices in the informal enterprises of Gweru. Many concerns have been raised about the potential harm from waste to the environment and the general public, but the risks and consequent costs of occupational hazards in waste management have received little attention in the rush to adopt or adapt technologies such as composting. A multimethods research design that triangulates qualitative and quantitative research paradigms is employed in this study. The quantitative design involves physical characterisation of solid waste through material component separation and measurements as well as a questionnaire survey that investigates the risks associated with waste management. The qualitative component includes interviews, open-ended questionnaires, and field observations. Occupational risks occur at every stage in the waste management process, from the point where workers handle waste in the enterprises for collection or recycling to the point of ultimate disposal. Key findings from the study revealed that solid waste management practices are dominated by manual handling tasks hence the higher incidents of muscular-skeletal disorders. Other safety and health hazards associated with waste management in the informal enterprises of Gweru include incidents of diarrhoea, viral hepatitis, and higher incidents of obstructive and restrictive disorders.
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Occupational Risks Associated with Solid Waste Management in the Informal Sector of Gweru, Zimbabwe
Jerie, Steven
2016-01-01
This study identifies and analyses the occupational risks associated with solid waste management practices in the informal enterprises of Gweru. Many concerns have been raised about the potential harm from waste to the environment and the general public, but the risks and consequent costs of occupational hazards in waste management have received little attention in the rush to adopt or adapt technologies such as composting. A multimethods research design that triangulates qualitative and quantitative research paradigms is employed in this study. The quantitative design involves physical characterisation of solid waste through material component separation and measurements as well as a questionnaire survey that investigates the risks associated with waste management. The qualitative component includes interviews, open-ended questionnaires, and field observations. Occupational risks occur at every stage in the waste management process, from the point where workers handle waste in the enterprises for collection or recycling to the point of ultimate disposal. Key findings from the study revealed that solid waste management practices are dominated by manual handling tasks hence the higher incidents of muscular-skeletal disorders. Other safety and health hazards associated with waste management in the informal enterprises of Gweru include incidents of diarrhoea, viral hepatitis, and higher incidents of obstructive and restrictive disorders. PMID:27418935
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Dopamine reward prediction error coding
Schultz, Wolfram
2016-01-01
Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards?an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less...
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A proposed risk acceptance criterion for nuclear fuel waste disposal
International Nuclear Information System (INIS)
Mehta, K.
1985-06-01
The need to establish a radiological protection criterion that applies specifically to disposal of high level nuclear fuel wastes arises from the difficulty of applying the present ICRP recommendations. These recommendations apply to situations in which radiological detriment can be actively controlled, while a permanent waste disposal facility is meant to operate without the need for corrective actions. Also, the risks associated with waste disposal depend on events and processes that have various probabilities of occurrence. In these circumstances, it is not suitable to apply standards that are based on a single dose limit as in the present ICRP recommendations, because it will generally be possible to envisage events, perhaps rare, that would lead to doses above any selected limit. To overcome these difficulties, it is proposed to base a criterion for acceptability on a set of dose values and corresponding limiting values of probabilities; this set of values constitutes a risk-limit line. A risk-limit line suitable for waste disposal is proposed that has characteristics consistent with the basic philosophy of the ICRP and UNSCEAR recommendations, and is based on levels on natural background radiation
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Risk comparisons relevant to sea disposal of low level radioactive waste
International Nuclear Information System (INIS)
1993-11-01
This document contains estimates of, and comparisons among, risks to human health posed by exposures to radionuclides, including those associated with low level radioactive wastes dumping at sea, and organic chemical contaminants resulting from seafood consumption. This study was conducted at the request of the Contracting Parties to the Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter (the London Convention 1972, formerly referred to as the London Dumping Convention) as a component of a review of the wider political, legal, economic and social aspects of sea dumping of radioactive wastes. The highest potential risks associated with seafood consumption are generally those resulting from exposures to naturally occurring radionuclides. In some representations, the potential risks associated with polychlorinated biphenyls (ΣPCB) and dieldrin in seafood are of the same order as those arising from naturally occurring radionuclides. The peak annual risks resulting from low level radioactive waste dumping at sea, assessed on any rational basis, are at least two orders of magnitude lower than those associated with the ingestion of common organic chemical contaminants in seafood. 47 refs, 4 figs, 13 tabs
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DEFF Research Database (Denmark)
Macoveanu, Julian; Fisher, Patrick M; Haahr, Mette E
2014-01-01
the involvement of the normally functioning 5HT-system in decision-making under risk and processing of monetary rewards. The data suggest that prolonged SSRI treatment might reduce emotional engagement by reducing the impact of risk during decision-making or the impact of reward during outcome evaluation....... to placebo, the SSRI intervention did not alter individual risk-choice preferences, but modified neural activity during decision-making and reward processing: During the choice phase, SSRI reduced the neural response to increasing risk in lateral orbitofrontal cortex, a key structure for value-based decision-making...... functional MRI (fMRI) to investigate how a three-week fluoxetine intervention influences neural activity related to risk taking and reward processing. Employing a double-blinded parallel-group design, 29 healthy young males were randomly assigned to receive 3 weeks of a daily dose of 40 mg fluoxetine...
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Hanford Waste Vitrification Project Building limited scope risk assessment
International Nuclear Information System (INIS)
Braun, D.J.; Lindberg, S.E.; Reardon, M.F.; Wilson, G.P.
1992-10-01
A limited scope risk assessment was performed on the preliminary design of a high-level waste interim storage facility. The Canister Storage Building (CSB) facility will be built to support remediation at the US Department of Energy Hanford Site in Washington State. The CSB will be part of the support facilities for a high level Hanford Waste Vitrification Plant (HWVP). The limited scope risk assessment is based on a preliminary design which uses forced air circulation systems to move air through the building vault. The current building design calls for natural circulation to move air through the building vault
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International Nuclear Information System (INIS)
Kirchner, Gerald
1989-01-01
Hazard indices are often used for the determination of risk potentials arising from the geological disposal of toxic wastes. They are based on simplified models for the calculation of potential health effects caused by the wastes. The attractiveness of hazard indices lies in their simplicity which nevertheless results in reliable data on necessary isolation times and the most toxic nuclides of a waste. They also make possible comparisons of the potential risks of different wastes. After a discussion of the processes that control the behavior of toxic wastes in the environment after a failure of the geological barriers, a new hazard index is presented. Originally developed for nuclear wastes, it is the first which involves the joint consideration of the composition of a waste, the probability for transport of waste nuclides to man, their toxicity, and the time-dependent changes of the risk potentials which are caused by radioactive buildup and decay processes after the waste has entered the biosphere. The new hazard index makes possible the calculation of risk potentials at a given time of release and time period of concern thereafter. Sample calculations for different nuclear wastes show the importance of the model improvements on resulting time-dependent risk potentials. Applicability of the new hazard index to non-nuclear wastes is described. Potentials and limitations of comparative risk assessments using hazard indices are discussed. (author)
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Cost risk analysis of radioactive waste management Preliminary study
International Nuclear Information System (INIS)
Forsstroem, J.
2006-12-01
This work begins with exposition of the basics of risk analysis. These basics are then applied to the Finnish radioactive waste disposal environment in which the nuclear power companies are responsible for all costs of radioactive waste management including longterm disposal of spent fuel. Nuclear power companies prepare cost estimates of the waste disposal on a yearly basis to support the decision making on accumulation of resources to the nuclear waste disposal fund. These cost estimates are based on the cost level of the ongoing year. A Monte Carlo simulation model of the costs of the waste disposal system was defined and it was used to produce preliminary results of its cost risk characteristics. Input data was synthesised by modifying the original coefficients of cost uncertainty to define a cost range for each cost item. This is a suitable method for demonstrating results obtainable by the model but it is not accurate enough for supporting decision making. Two key areas of further development were identified: the input data preparation and identifying and handling of (i.e. eliminating or merging) interacting cost elements in the simulation model. Further development in both of the mentioned areas can be carried out by co-operating with the power companies as they are the sources of the original data. (orig.)
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Romens, Sarah E; Casement, Melynda D; McAloon, Rose; Keenan, Kate; Hipwell, Alison E; Guyer, Amanda E; Forbes, Erika E
2015-11-01
Children who experience socioeconomic disadvantage are at heightened risk for developing depression; however, little is known about neurobiological mechanisms underlying this association. Low socioeconomic status (SES) during childhood may confer risk for depression through its stress-related effects on the neural circuitry associated with processing monetary rewards. In a prospective study, we examined the relationships among the number of years of household receipt of public assistance from age 5-16 years, neural activation during monetary reward anticipation and receipt at age 16, and depression symptoms at age 16 in 123 girls. Number of years of household receipt of public assistance was positively associated with heightened response in the medial prefrontal cortex during reward anticipation, and this heightened neural response mediated the relationship between socioeconomic disadvantage and current depression symptoms, controlling for past depression. Chronic exposure to socioeconomic disadvantage in childhood may alter neural circuitry involved in reward anticipation in adolescence, which in turn may confer risk for depression. © 2015 Association for Child and Adolescent Mental Health.
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Risk analysis of geological disposal of radioactive waste
International Nuclear Information System (INIS)
Girardi, F.; de Marsily, G.; Weber, J.
1980-01-01
The problems of risk analysis of geological disposal of radioactive waste are briefly summarized. Several characteristics, such as the very long time span considered, make it rather unique among the problems of modern society. The safety of nuclear waste disposal in geological formations is based on several barriers, natural and man-made, which prevent disposed radionuclides from reaching the biosphere. They include a) the physico-chemical form of conditioned waste, b) the waste container, c) the geological isolation, d) buffering and backfilling materials, radionuclide retention in the geosphere and e) environmental dilution and isolation processes. The knowledge available on each barrier and its modelling is reviewed. Specific disposal strategies in clay, granite and salt formations are considered, outlining the performance of the barriers in each particular strategy, and results obtained in preliminary evaluations
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The approach of risk and safety evaluation in radioactive waste transport
International Nuclear Information System (INIS)
Vieru, G.
1996-01-01
Within Institute for Nuclear Research (INR) Pitesti, qualification tests were performed on packages, designed for transport and storage of low activity radioactive waste. Risk assessment activities aiming the evaluation of risk categories that many arise either during accident free transport or during accident conditions of waste transportation to the disposal center, in Romania, have been approached. The accident rates calculation, the distribution within accident scenarios and overall effective collective dose (man.Sv/year),for routine road transportation and the accidental Risk (man.Sv/Year) were determined
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Risk perception as it applies to nuclear power and nuclear waste disposal
International Nuclear Information System (INIS)
Sprecher, W.M.
1988-01-01
Disparate perceptions of risk have emerged as one of the critical issues confronting the future of commercial nuclear power. This paper explores the origins and possible ramifications of the public's perception of risks associated with commercial nuclear power and related high-level nuclear waste disposal programs. This paper summarizes the results of numerous psychometric studies and public opinion polls that analyze the relationship of risk to nuclear power and waste management
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Cigarette craving is associated with blunted reward processing in nicotine-dependent smokers.
Peechatka, Alyssa L; Whitton, Alexis E; Farmer, Stacey L; Pizzagalli, Diego A; Janes, Amy C
2015-10-01
Dysfunctional reward processing leading to the undervaluation of non-drug rewards is hypothesized to play a crucial role in nicotine dependence. However, it is unclear if blunted reward responsivity and the desire to use nicotine are directly linked after a brief period of abstinence. Such an association would suggest that individuals with reduced reward responsivity may be at increased risk to experience nicotine craving. Reward function was evaluated with a probabilistic reward task (PRT), which measures reward responsivity to monetary incentives. To identify whether smoking status influenced reward function, PRT performance was compared between non-depressed, nicotine-dependent smokers and non-smokers. Within smokers, correlations were conducted to determine if blunted reward responsivity on the PRT was associated with increased nicotine craving. Time since last nicotine exposure was standardized to 4h for all smokers. Smokers and non-smokers did not differ in reward responsivity on the PRT. However, within smokers, a significant negative correlation was found between reward responsivity and intensity of nicotine craving. The current findings show that, among smokers, the intensity of nicotine craving is linked to lower sensitivity to non-drug rewards. This finding is in line with prior theories that suggest reward dysfunction in some clinical populations (e.g., depressive disorders, schizophrenia) may facilitate nicotine use. The current study expands on such theories by indicating that sub-clinical variations in reward function are related to motivation for nicotine use. Identifying smokers who show blunted sensitivity to non-drug rewards may help guide treatments aimed at mitigating the motivation to smoke. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
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Blum, Kenneth; Simpatico, Thomas; Badgaiyan, Rajendra D; Demetrovics, Zsolt; Fratantonio, James; Agan, Gozde; Febo, Marcelo; Gold, Mark S
Earlier work from our laboratory, showing anti-addiction activity of a nutraceutical consisting of amino-acid precursors and enkephalinase inhibition properties and our discovery of the first polymorphic gene (Dopamine D2 Receptor Gene [DRD2]) to associate with severe alcoholism serves as a blue-print for the development of "Personalized Medicine" in addiction. Prior to the later genetic finding, we developed the concept of Brain Reward Cascade, which continues to act as an important component for stratification of addiction risk through neurogenetics. In 1996 our laboratory also coined the term "Reward Deficiency Syndrome (RDS)" to define a common genetic rubric for both substance and non-substance related addictive behaviors. Following many reiterations we utilized polymorphic targets of a number of reward genes (serotonergic, Opioidergic, GABAergic and Dopaminergic) to customize KB220 [Neuroadaptogen- amino-acid therapy (NAAT)] by specific algorithms. Identifying 1,000 obese subjects in the Netherlands a subsequent small subset was administered various KB220Z formulae customized according to respective DNA polymorphisms individualized that translated to significant decreases in both Body Mass Index (BMI) and weight in pounds. Following these experiments, we have been successfully developing a panel of genes known as "Genetic Addiction Risk Score" (GARSp DX )™. Selection of 10 genes with appropriate variants, a statistically significant association between the ASI-Media Version-alcohol and drug severity scores and GARSp Dx was found A variant of KB220Z in abstinent heroin addicts increased resting state functional connectivity in a putative network including: dorsal anterior cingulate, medial frontal gyrus, nucleus accumbens, posterior cingulate, occipital cortical areas, and cerebellum. In addition, we show that KB220Z significantly activates, above placebo, seed regions of interest including the left nucleus accumbens, cingulate gyrus, anterior thalamic
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Koch, Alexander K.; Nafziger, Julia
2009-01-01
Self-administered rewards are ubiquitous. They serve as incentives for personal accomplish¬ments and are widely recommended as tools for overcoming self-control problems. However, it seems puzzling why self-rewards can work: the prospect of a reward has a motivating force only if the threat of self-denial of the reward after low performance is credible. We explain how a rational forward-looking individual may achieve commitment to self-rewards, by applying Köszegi and Rabin's (2006) model of ...
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Kirk, Ulrich; Brown, Kirk Warren; Downar, Jonathan
2015-05-01
Reward seeking is ubiquitous and adaptive in humans. But excessive reward seeking behavior, such as chasing monetary rewards, may lead to diminished subjective well-being. This study examined whether individuals trained in mindfulness meditation show neural evidence of lower susceptibility to monetary rewards. Seventy-eight participants (34 meditators, 44 matched controls) completed the monetary incentive delay task while undergoing functional magnetic resonance imaging. The groups performed equally on the task, but meditators showed lower neural activations in the caudate nucleus during reward anticipation, and elevated bilateral posterior insula activation during reward anticipation. Meditators also evidenced reduced activations in the ventromedial prefrontal cortex during reward receipt compared with controls. Connectivity parameters between the right caudate and bilateral anterior insula were attenuated in meditators during incentive anticipation. In summary, brain regions involved in reward processing-both during reward anticipation and receipt of reward-responded differently in mindfulness meditators than in nonmeditators, indicating that the former are less susceptible to monetary incentives. © The Author (2014). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.
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MANAGEING THE RETRIEVAL RISK OF BURIED TRANSURANIC (TRU) WASTE WITH UNIQUE CHARACTERISTICS
International Nuclear Information System (INIS)
WOJTASEK, R.D.; GREENWELL, R.D.
2005-01-01
United States-Department of Energy (DOE) sites that store transuranic (TRU) waste are almost certain to encounter waste packages with characteristics that are so unique as to warrant special precautions for retrieval. At the Hanford Site, a subgroup of stored TRU waste (12 drums) had special considerations due to the radioactive source content of plutonium oxide (PuO 2 ), and the potential for high heat generation, pressurization, criticality, and high radiation. These characteristics bear on the approach to safely retrieve, overpack, vent, store, and transport the waste package. Because of the potential risk to personnel, contingency planning for unexpected conditions played an effective roll in work planning and in preparing workers for the field inspection activity. As a result, the integrity inspections successfully confirmed waste package configuration and waste confinement without experiencing any perturbations due to unanticipated packaging conditions. This paper discusses the engineering and field approach to managing the risk of retrieving TRU waste with unique characteristics
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[MANAGEMENT OF HEALTHCARE WASTE IN THE HOSPITAL SETTING. UNDERSTANDING RISK MANAGEMENT].
Galimany-Masclans, Jordi; Torres-Egea, Pilar; Sancho-Agredano, Raúl; Girbau-García, Ma Rosa; Fabrellas, Núria; Torrens-Garcia, Ma Llum; Martínez-Estalella, Gemma
2015-05-01
The sanitary waste represents a potential hazard for health workers. Given the high risk of infection in labor accidents, the correct management of sanitary waste minimizes this risk and improves labor and environment conditions. To identify risk perception with health professionals in relation to the advanced sorting and management of healthcare waste (HW). The current study is a descriptive, cross-sectional. The sample size was 177 health workers (nurse assistants, nurses, physicians, lab technicians) from three hospitals in Barcelona (Catalonia). Homemade questionnaire and questions with a free and spontaneous association and incomplete sentences were used to analyze labor variables, perception of risk and personal security through a Likert scale. Using a score from 1 (the lowest perception of risk) to 5 (the high perception of risk) to assess the risk perception, the average value for nurse assistants, nurses, physicians, and lab technicians was 3.71, 3.75, 3.83 and 4.03, respectively. Referring to items with free and spontaneous response association, 44.8% of workers consider HW as a biohazard, 29.6% consider it as waste material, 22.1% state that it must be managed properly and 3.5% described it as unknown residues. The results suggest that all health professionals generally have a perception of high risk. The lab technicians have a higher perception of the real risk of inadequate management of HW A 63.2% report that everyone has to make a proper management to preserve their occupational health; the 59% consider that the HW are a biological risk to the general population and only the 47.8% that are harmful to public health. Although it should be noted that only 44.8% think that HW are toxic and dangerous.
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Risk-based waste clearance concept for the D ampersand D program
International Nuclear Information System (INIS)
Chen, S.Y.; Bhattacharyya, S.K.
1996-01-01
Large amounts of radioactively contaminated wastes are expected to result from decontamination and decommissioning (D ampersand D) activities at nuclear facilities. Many of the waste materials, such as concrete rubble and scrap metals, are only slightly contaminated and can be recycled to minimize waste streams, resulting in substantial savings from reducing conventional waste disposal costs and recovering the values of the raw materials. For instance, a recent projection indicates that recycling an estimated 30 million tonnes of radioactive scrap metal (RSM) worldwide, having a corresponding recoverable value of about $10 billion to $20 billion, would avoid an estimated $5 billion in disposal costs. As an average heuristic, waste disposition constitutes ∼50% of total D ampersand D costs. There is thus a strong incentive to minimize the waste from D ampersand D activities. In the United States, no specific standards have been developed for the unrestricted release of bulk contaminated materials, although standards for the unrestricted release of radioactive surface contamination have existed for ∼20 yr. Materials are not commonly released because of the lack of risk-based justifications. Recent guidance from international bodies has established a basis for deriving risk-based release limits for radioactive materials. It is important, therefore, to evaluate the feasibility of recycling, because if it is feasible, risk-based release limits for the reusable materials will need to be established
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Politics and scientific expertise: Scientists, risk perception, and nuclear waste policy
International Nuclear Information System (INIS)
Barke, R.P.; Jenkins-Smith, H.C.
1993-01-01
To study the homogeneity and influences on scientists' perspectives of environmental risks, the authors have examined similarities and differences in risk perceptions, particularly regarding nuclear wastes, and policy preferences among 1011 scientists and engineers. Significant differences (p<0.05) were found in the patterns of beliefs among scientists from different fields of research. In contrast to physicists, chemists, and engineers, life scientists tend to: (a) perceive the greatest risks from nuclear energy and nuclear waste management; (b) perceive higher levels of overall environmental risk; (c) strongly oppose imposing risks on unconsenting individuals; and (d) prefer stronger requirements for environmental management. On some issues related to priorities among public problems and calls for government action, there are significant variations among life scientists or physical scientists. It was also found that-independently of field of research-perceptions of risk and its correlates are significantly associated with the type of institution in which the scientist is employed. Scientists in universities or state and local governments tend to see the risks of nuclear energy and wastes as greater than scientists who work as business consultants, for federal organizations, or for private research laboratories. Significant differences also are found in priority given to environmental risks, the perceived proximity of environmental disaster, willingness to impose risks on an unconsenting population, and the necessity of accepting risks and sacrifices. 33 refs., 3 figs., 9 tabs
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Richards, Jessica M; Patel, Nilam; Daniele-Zegarelli, Teresa; MacPherson, Laura; Lejuez, C W; Ernst, Monique
2015-01-01
Risk-taking behavior increases during adolescence, leading to potentially disastrous consequences. Social anxiety emerges in adolescence and may compound risk-taking propensity, particularly during stress and when reward potential is high. However, the manner in which social anxiety, stress, and reward parameters interact to impact adolescent risk-taking is unclear. To clarify this question, a community sample of 35 adolescents (15-18yo), characterized as having high or low social anxiety, participated in a study over two separate days, during each of which they were exposed to either a social stress or a control condition, while performing a risky decision-making task. The task manipulated, orthogonally, reward magnitude and probability across trials. Three findings emerged. First, reward magnitude had a greater impact on the rate of risky decisions in high social anxiety (HSA) than low social anxiety (LSA) adolescents. Second, reaction times (RTs) were similar during the social stress and the control conditions for the HSA group, whereas the LSA group's RTs differed between conditions. Third, HSA adolescents showed the longest RTs on the most negative trials. These findings suggest that risk-taking in adolescents is modulated by context and reward parameters differentially as a function of social anxiety. Published by Elsevier Ltd.
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Richards, Jessica M.; Patel, Nilam; Daniele, Teresa; MacPherson, Laura; Lejuez, C.W.; Ernst, Monique
2014-01-01
Risk-taking behavior increases during adolescence, leading to potentially disastrous consequences. Social anxiety emerges in adolescence and may compound risk-taking propensity, particularly during stress and when reward potential is high. However, the manner in which social anxiety, stress, and reward parameters interact to impact adolescent risk-taking is unclear. To clarify this question, a community sample of 35 adolescents (15 to 18 yo), characterized as having high or low social anxiety, participated in a 2-day study, during each of which they were exposed to either a social stress or a control condition, while performing a risky decision-making task. The task manipulated, orthogonally, reward magnitude and probability across trials. Three findings emerged. First, reward magnitude had a greater impact on the rate of risky decisions in high social anxiety (HSA) than low social anxiety (LSA) adolescents. Second, reaction times (RTs) were similar during the social stress and the control conditions for the HSA group, whereas the LSA group’s RTs differed between conditions. Third, HSA adolescents showed the longest RTs on the most negative trials. These findings suggest that risk-taking in adolescents is modulated by context and reward parameters differentially as a function of social anxiety. PMID:25465884
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Orbitofrontal reward sensitivity and impulsivity in adult attention deficit hyperactivity disorder.
Wilbertz, Gregor; van Elst, Ludger Tebartz; Delgado, Mauricio R; Maier, Simon; Feige, Bernd; Philipsen, Alexandra; Blechert, Jens
2012-03-01
Impulsivity symptoms of adult attention deficit hyperactivity disorder (ADHD) such as increased risk taking have been linked with impaired reward processing. Previous studies have focused on reward anticipation or on rewarded executive functioning tasks and have described a striatal hyporesponsiveness and orbitofrontal alterations in adult and adolescent ADHD. Passive reward delivery and its link to behavioral impulsivity are less well understood. To study this crucial aspect of reward processing we used functional magnetic resonance imaging (fMRI) combined with electrodermal assessment in male and female adult ADHD patients (N=28) and matched healthy control participants (N=28) during delivery of monetary and non-monetary rewards. Further, two behavioral tasks assessed risky decision making (game of dice task) and delay discounting. Results indicated that both groups activated ventral and dorsal striatum and the medial orbitofrontal cortex (mOFC) in response to high-incentive (i.e. monetary) rewards. A similar, albeit less strong activation pattern was found for low-incentive (i.e. non-monetary) rewards. Group differences emerged when comparing high and low incentive rewards directly: activation in the mOFC coded for the motivational change in reward delivery in healthy controls, but not ADHD patients. Additionally, this dysfunctional mOFC activity in patients correlated with risky decision making and delay discounting and was paralleled by physiological arousal. Together, these results suggest that the mOFC codes reward value and type in healthy individuals whereas this function is deficient in ADHD. The brain-behavior correlations suggest that this deficit might be related to behavioral impulsivity. Reward value processing difficulties in ADHD should be considered when assessing reward anticipation and emotional learning in research and applied settings. Copyright © 2011 Elsevier Inc. All rights reserved.
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Low-risk alternative waste forms for problematic high-level and long-lived nuclear wastes
International Nuclear Information System (INIS)
Stewart, M.W.A.; Begg, B.D.; Moricca, S.; Day, R.A.
2006-01-01
Full text: The highest cost component the nuclear waste clean up challenge centres on high-level waste (HLW) and consequently the greatest opportunity for cost and schedule savings lies with optimising the approach to HLW cleanup. The waste form is the key component of the immobilisation process. To achieve maximum cost savings and optimum performance the selection of the waste form should be driven by the characteristics of the specific nuclear waste to be immobilised, rather than adopting a single baseline approach. This is particularly true for problematic nuclear wastes that are often not amenable to a single baseline approach. The use of tailored, high-performance, alternative waste forms that include ceramics and glass-ceramics, coupled with mature process technologies offer significant performance improvements and efficiency savings for a nuclear waste cleanup program. It is the waste form that determines how well the waste is locked up (chemical durability), and the number of repository disposal canisters required (waste loading efficiency). The use of alternative waste forms for problematic wastes also lowers the overall risk by providing high performance HLW treatment alternatives. The benefits tailored alternative waste forms bring to the HLW cleanup program will be briefly reviewed with reference to work carried out on the following: The HLW calcines at the Idaho National Laboratory; SYNROC ANSTO has developed a process utilising a glass-ceramic combined with mature hot-isostatic pressing (HIP) technology and has demonstrated this at a waste loading of 80 % and at a 30 kg HIP scale. The use of this technology has recently been estimated to result in a 70 % reduction in waste canisters, compared to the baseline borosilicate glass technology; Actinide-rich waste streams, particularly the work being done by SYNROC ANSTO with Nexia Solutions on the Plutonium-residues wastes at Sellafield in the UK, which if implemented is forecast to result in substantial
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Radiological risks of transports to central waste management facilities
International Nuclear Information System (INIS)
Lange, F.
1997-01-01
Transports of radioactive waste from nuclear facilities have been a matter of frequent public concern in the recent past. News reports, protests and questions concerning the radiological risk tended to concentrate on transports to and from central waste management facilities, e.g. transports of spent fuel elements to reprocessing plants abroad (France, England), transports to intermediate storage sites (Ahaus, Gorleben), transports to operative (Morsleben) and projected (Konrad) final storage sites, and transports of vitrified high-activity waste from reprocessing plants to the intermediate storage site (Gorleben). (orig.) [de
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Health Risks Awareness of Electronic Waste Workers in the Informal Sector in Nigeria.
Ohajinwa, Chimere M; Van Bodegom, Peter M; Vijver, Martina G; Peijnenburg, Willie J G M
2017-08-13
Insight into the health risk awareness levels of e-waste workers is important as it may offer opportunities for better e-waste recycling management strategies to reduce the health effects of informal e-waste recycling. Therefore, this study assessed the knowledge, attitude, and practices associated with occupational health risk awareness of e-waste workers compared with a control group (butchers) in the informal sector in Nigeria. A cross-sectional study was used to assess health risk awareness of 279 e-waste workers (repairers and dismantlers) and 221 butchers from the informal sector in three locations in Nigeria in 2015. A questionnaire was used to obtain information on socio-demographic backgrounds, occupational history, knowledge, attitude, and work practices. The data was analysed using Analysis of Variance. The three job designations had significantly different knowledge, attitude, and practice mean scores ( p = 0.000), with butchers consistently having the highest mean scores. Only 43% of e-waste workers could mention one or more Personal Protective Equipment needed for their job compared with 70% of the butchers. The health risk awareness level of the e-waste workers was significantly lower compared with their counterparts in the same informal sector. A positive correlation existed between the workers' knowledge and their attitude and practice. Therefore, increasing the workers' knowledge may decrease risky practices.
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Siegrist, J; Dragano, N
2008-03-01
Given the far-reaching changes of modern working life, psychosocial stress at work has received increased attention. Its influence on stress-related disease risks is analysed with the help of standardised measurements based on theoretical models. Two such models have gained special prominence in recent years, the demand-control model and the effort-reward imbalance model. The former model places its emphasis on a distinct combination of job characteristics, whereas the latter model's focus is on the imbalance between efforts spent and rewards received in turn. The predictive power of these models with respect to coronary or cardiovascular disease and depression was tested in a number of prospective epidemiological investigations. In summary, twofold elevated disease risks are observed. Effects on cardiovascular disease are particularly pronounced among men, whereas no gender differences are observed for depression. Additional evidence derived from experimental and ambulatory monitoring studies supplements this body of findings. Current scientific evidence justifies an increased awareness and assessment of these newly discovered occupational risks, in particular by occupational health professionals. Moreover, structural and interpersonal measures of stress prevention and health promotion at work are warranted, with special emphasis on gender differences.
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Random reward priming is task-contingent: The robustness of the 1-trial reward priming effect
Directory of Open Access Journals (Sweden)
Árni Gunnar Ásgeirsson
2014-04-01
Full Text Available Consistent financial reward of particular features influences the allocation of visual attention in many ways. More surprising are 1-trial reward priming effects on attention where reward schedules are random and reward on one trial influences attentional allocation on the next. Those findings are thought to reflect that rewarded features become more salient than unrewarded ones on the subsequent trial. Here we attempt to conceptually replicate this effect, testing its generalizability. In three versions of an analogous paradigm to the additional singleton paradigm involving singleton search for a Gabor patch of odd spatial frequency we found no evidence of reward priming, while we only partially replicate the reward priming in the exact original paradigm tested by Hickey and colleagues. The results cast doubt on the proposal that random reward enhances salience, suggested in the original papers, and highlight the need for a more nuanced account. In many other paradigms reward effects have been found to progress gradually, becoming stronger as they build up, and we argue that for robust reward priming, reward schedules need to be more consistent than in the original 1-trial reward priming paradigm.
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A correction term for the covariance of renewal-reward processes with multivariate rewards
Patch, B.; Nazarathy, Y.; Taimre, T.
We consider a renewal-reward process with multivariate rewards. Such a process is constructed from an i.i.d. sequence of time periods, to each of which there is associated a multivariate reward vector. The rewards in each time period may depend on each other and on the period length, but not on the
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Instability risk assessment of construction waste pile slope based on fuzzy entropy
Ma, Yong; Xing, Huige; Yang, Mao; Nie, Tingting
2018-05-01
Considering the nature and characteristics of construction waste piles, this paper analyzed the factors affecting the stability of the slope of construction waste piles, and established the system of the assessment indexes for the slope failure risks of construction waste piles. Based on the basic principles and methods of fuzzy mathematics, the factor set and the remark set were established. The membership grade of continuous factor indexes is determined using the "ridge row distribution" function, while that for the discrete factor indexes was determined by the Delphi Method. For the weight of factors, the subjective weight was determined by the Analytic Hierarchy Process (AHP) and objective weight by the entropy weight method. And the distance function was introduced to determine the combination coefficient. This paper established a fuzzy comprehensive assessment model of slope failure risks of construction waste piles, and assessed pile slopes in the two dimensions of hazard and vulnerability. The root mean square of the hazard assessment result and vulnerability assessment result was the final assessment result. The paper then used a certain construction waste pile slope as the example for analysis, assessed the risks of the four stages of a landfill, verified the assessment model and analyzed the slope's failure risks and preventive measures against a slide.
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Directory of Open Access Journals (Sweden)
Melynda D. Casement
2014-04-01
Full Text Available Developmental models of psychopathology posit that exposure to social stressors may confer risk for depression in adolescent girls by disrupting neural reward circuitry. The current study tested this hypothesis by examining the relationship between early adolescent social stressors and later neural reward processing and depressive symptoms. Participants were 120 girls from an ongoing longitudinal study of precursors to depression across adolescent development. Low parental warmth, peer victimization, and depressive symptoms were assessed when the girls were 11 and 12 years old, and participants completed a monetary reward guessing fMRI task and assessment of depressive symptoms at age 16. Results indicate that low parental warmth was associated with increased response to potential rewards in the medial prefrontal cortex (mPFC, striatum, and amygdala, whereas peer victimization was associated with decreased response to potential rewards in the mPFC. Furthermore, concurrent depressive symptoms were associated with increased reward anticipation response in mPFC and striatal regions that were also associated with early adolescent psychosocial stressors, with mPFC and striatal response mediating the association between social stressors and depressive symptoms. These findings are consistent with developmental models that emphasize the adverse impact of early psychosocial stressors on neural reward processing and risk for depression in adolescence.
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Cognitive Control Over Immediate Reward in Binge Alcohol Drinkers.
Poulton, Antoinette; Mackenzie, Caitlyn; Harrington, Kaitlyn; Borg, Sarah; Hester, Robert
2016-02-01
Cognitive control deficits, as captured by inhibitory control measures, are indicative of increased impulsivity and are considered a marker for substance use disorder vulnerability. While individuals with alcohol use disorder (AUD) typically exhibit inhibitory control dysfunction, evidence of impaired inhibitory control among harmful drinkers, who are at increased risk of developing an AUD, is mixed. This study examined the response inhibition of binge drinkers using a task that employed neutral, as well as both immediate and delayed reward contingencies, to determine whether reward induced heightened impulsivity in this population. Binge alcohol users (n = 42) and controls (n = 42) were administered a Monetary Incentive Control Task that required participants to successfully inhibit a prepotent motor response to both neutral and immediately rewarding stimuli in order to secure a large delayed reward. Binge drinkers had significantly worse response inhibition than controls irrespective of trial condition and even after controlling for differences in weekly intake. Although both binge and control participants exhibited significantly worse inhibitory control in the presence of immediate reward, the control group showed a greater reduction in inhibition accuracy compared to the binge group in reward relative to neutral conditions. Both groups demonstrated significantly enhanced control when forewarned there was an increased chance response inhibition would be required. Control participants secured the delayed reward more often than binge participants. Despite the variability in the literature, this study demonstrated consistent generalized impulse control deficits among binge-drinking individuals that were unrelated to reward manipulations. These findings point to mechanisms that may confer vulnerability for transition from binge drinking to AUD. Copyright © 2016 by the Research Society on Alcoholism.
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Gold, Mark S; Blum, Kenneth; Febo, Marcelo; Baron, David; Modestino, Edward Justin; Elman, Igor; Badgaiyan, Rajendra D
2018-03-01
Anhedonia is a condition that leads to the loss of feelings pleasure in response to natural reinforcers like food, sex, exercise, and social activities. This disorder occurs in addiction, and an array of related neuropsychiatric syndromes, including schizophrenia, depression, and Post Traumatic Stress Disorder (PTSD). Anhedonia may by due to derangements in mesolimbic dopaminergic pathways and their terminal fields (e.g., striatum, amygdala, and prefrontal cortex) that persist long after the traces of the causative drugs are eliminated (pharmacokinetically). Here we postulate that anhedonia is not a distinct entity but is rather an epiphenomenon of hypodopaminergic states and traits arising from the interaction of genetic traits and epigenetic neurobiological alterations in response to environmental influences. Moreover, dopaminergic activity is rather complex, and so it may give rise to differential pathophysiological processes such as incentive sensitization, aberrant learning and stress-like "anti-reward" phenomena. These processes may have additive, synergistic or antagonistic interactions with the concurrent reward deficiency states leading in some instances to more severe and long-lasting symptoms. Operant understanding of the neurogenetic antecedents to reward deficiency syndrome (RDS) and the elucidation of reward gene polymorphisms may provide a map for accessing an individual's genetic risk for developing Anhedonia. Prevention techniques that can restore homeostatic balance via physiological activation of dopaminergic receptors (D2/D3) may be instrumental for targeting not only anhedonia per se but also drug craving and relapse.
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International Nuclear Information System (INIS)
Esh, D.W.; Pinkston, K.E.; Barr, C.S.; Bradford, A.H.; Ridge, A.Ch.
2009-01-01
Nuclear Regulatory Commission (NRC) staff has developed a concentration averaging approach and guidance for the review of Department of Energy (DOE) non-HLW determinations. Although the approach was focused on this specific application, concentration averaging is generally applicable to waste classification and thus has implications for waste management decisions as discussed in more detail in this paper. In the United States, radioactive waste has historically been classified into various categories for the purpose of ensuring that the disposal system selected is commensurate with the hazard of the waste such that public health and safety will be protected. However, the risk from the near-surface disposal of radioactive waste is not solely a function of waste concentration but is also a function of the volume (quantity) of waste and its accessibility. A risk-informed approach to waste classification for near-surface disposal of low-level waste would consider the specific characteristics of the waste, the quantity of material, and the disposal system features that limit accessibility to the waste. NRC staff has developed example analytical approaches to estimate waste concentration, and therefore waste classification, for waste disposed in facilities or with configurations that were not anticipated when the regulation for the disposal of commercial low-level waste (i.e. 10 CFR Part 61) was developed. (authors)
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International Nuclear Information System (INIS)
Frazzoli, Chiara; Orisakwe, Orish Ebere; Dragone, Roberto; Mantovani, Alberto
2010-01-01
E-waste is the generic name for technological waste. Even though aspects related to e-waste environmental pollution and human exposure are known, scientific assessments are missing so far on the actual risks for health sustainability of the general population exposed to e-waste scenarios, such as illicit dumping, crude recycling and improper treatment and disposal. In fact, further to occupational and direct local exposure, e-waste scenarios may impact on the environment-to-food chain, thus eliciting a widespread and repeated exposure of the general population to mixtures of toxicants, mainly toxic chemical elements, polycyclic aromatic hydrocarbons and persistent organic pollutants. In the absence of any clear policy on e-waste flow management, the situation in the e-waste receiver countries may become quite scary; accordingly, here we address a diagnostic risk assessment of health issues potentially elicited by e-waste related mixtures of toxicants. Scientific evidence available so far (mainly from China) is discussed with special attention to the concept of health sustainability, i.e. the poor health burden heritage perpetuated through the mother-to-child dyad. Endocrine disruption and neurotoxicity are specifically considered as examples of main health burden issues relevant to perpetuation through life cycle and across generations; toxicological information are considered along with available data on environmental and food contamination and human internal exposure. The risk from exposure to e-waste related mixtures of toxicants of vulnerable subpopulation like breast-fed infants is given special attention. The diagnostic risk assessment demonstrates how e-waste exposure poses an actual public health emergency, as it may entrain significant health risks also for generations to come. Exposure scenarios as well as specific chemicals of major concern may vary in different contexts; for instance, only limited information is available on e-waste related exposures in
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Risk communication on the construction of radioactive waste treatment facility
International Nuclear Information System (INIS)
Okoshi, Minoru
2005-01-01
In this paper, risk communications among the Japan Radioisotope Association (JRIA), a local government and the general public which were carried out during the development process of a radioactive waste treatment facility in Takizawa Village, Iwate Prefecture are analyzed based on the articles of newspapers and the interviews with the concerned people. The analysis results show good risk communications were not carried out because of the absence of the confidence to the JRIA, decision making rules and the merits. In order to make good use of this experience for the future development of radioactive waste management facilities, the lessons learned from this case are summarized and the check lists for good risk communication are proposed. (author)
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Extending overjustification: the effect of perceived reward-giver intention on response to rewards.
Forehand, M R
2000-12-01
The perceived intention model incorporates a new moderator, beliefs about reward-giver intention, into the overjustification paradigm. In 2 simulated shopping studies featuring products paired with promotional rewards, consumers who believed the marketer was promotion focused (reward used to encourage purchase) reported lower purchase intentions and brand attitudes for promoted products after promotion, whereas consumers who believed the marketer was reward focused (promotion used to distribute the reward) showed no attitude change. Promotion-focus beliefs lowered attitudes by heightening the contingency between the promotion and purchase and thereby increasing the perceived causal role of the reward. This effect was contingent on initial behavior--postpromotion attitude change occurred for consumers who actively engaged in product decisions but not for consumers who passively observed the choice sets.
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Heightened activity in social reward networks is associated with adolescents’ risky sexual behaviors
Kristen L. Eckstrand; Sophia Choukas-Bradley; Arpita Mohanty; Marissa Cross; Nicholas B. Allen; Jennifer S. Silk; Neil P. Jones; Erika E. Forbes
2017-01-01
Adolescent sexual risk behavior can lead to serious health consequences, yet few investigations have addressed its neurodevelopmental mechanisms. Social neurocircuitry is postulated to underlie the development of risky sexual behavior, and response to social reward may be especially relevant. Typically developing adolescents (N = 47; 18M, 29F; 16.3 ± 1.4 years; 42.5% sexual intercourse experience) completed a social reward fMRI task and reported their sexual risk behaviors (e.g., lifetime sex...
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Neural Processing of Calories in Brain Reward Areas Can be Modulated by Reward Sensitivity
van Rijn, Inge; Griffioen-Roose, Sanne; de Graaf, Cees; Smeets, Paul A M
A food's reward value is dependent on its caloric content. Furthermore, a food's acute reward value also depends on hunger state. The drive to obtain rewards (reward sensitivity), however, differs between individuals. Here, we assessed the association between brain responses to calories in the mouth
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Citizen perceptions of risks associated with moving radiological waste
International Nuclear Information System (INIS)
McBeth, M.K.; Oakes, A.S.
1996-01-01
Much has been written about public support or opposition to the siting of hazardous waste facilities and more generally about concern for radioactive contamination. Much less has been written about the perceived risks of citizens' specific concerns about the transportation of radiological waste to temporary or permanent sites. This study reviews the existing literature in the area and presents new data on the subject from an Idaho survey. The new data indicates: (1) age, gender, and knowledge are the key variables predicting opposition to the transportation of such waste, (2) the primary concern among the opposing and unsure public is the planned use of trucks to move the TRU waste, and (3) respondents have high degrees of trust in officials who make decisions based on technical knowledge, are charged with the safety of transporting TRU waste, and who respond to mishaps. These attitudes need to be understood by policy makers and administrators when designing and implementing waste-transportation programs. 19 refs., 4 tabs
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Richards, Jessica M.; Patel, Nilam; Daniele, Teresa; MacPherson, Laura; Lejuez, C.W.; Ernst, Monique
2014-01-01
Risk-taking behavior increases during adolescence, leading to potentially disastrous consequences. Social anxiety emerges in adolescence and may compound risk-taking propensity, particularly during stress and when reward potential is high. However, the manner in which social anxiety, stress, and reward parameters interact to impact adolescent risk-taking is unclear. To clarify this question, a community sample of 35 adolescents (15 to 18 yo), characterized as having high or low social anxiety...
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Radioactive wastes and the social amplification of risk
International Nuclear Information System (INIS)
Kasperson, R.E.; Emel, J.; Goble, R.; Hohenemser, C.; Kasperson, J.X.; Renn, O.
1987-01-01
A significant problem in radioactive waste facility siting is that apparent small risks or minor risks events produce substantial public concern and social impacts. The reasons for this difference in public health and societal impacts is not well understood. This paper explores the issues involved in the social amplification of risk, using the risk associated with site characterization as the example. Noteworthy as sources of amplification are the information flow associated with risks and risk events including the large volume of information, the extent of dispute, and misinformation and rumor. Such information passes through the mass media and interpersonal networks. The major mechanisms involved in risk amplifications are discussed and their likely impacts on society described
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van Eerde, W.; Vodosek, M.; den Hartog, D.N.; McNett, J.M.
2014-01-01
Reward systems are identified as one of the human resource management (HRM) practices that may impact motivation. Reward systems may consist of several components, including financial and nonfinancial rewards, in fixed and variable amounts. Reinforcement, expectancy, and equity principles are
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The aesthetics of hazardous waste - Distinguishing visual impacts from publicly perceived risk
International Nuclear Information System (INIS)
Sheppard, S.
1986-01-01
The need to address the aesthetic impacts of hazardous waste projects on the environment and the public stems from two sources: government regulations which specifically require assessment of aesthetic effects; and rapidly increasing public concern for perceived impacts and risks of existing or proposed hazardous waste facilities. How aesthetic issues are handled on hazardous waste projects can potentially have significant implications on the fate of those projects. These implications range from delays in the permitting process to denial of sites or costly legal judgments in damage suits. This paper discusses strategies for evaluating the aesthetic/perceptual aspects of hazardous waste. In particular, it focuses upon ways to distinguish visual concerns from other influences on public perceptions such as perceived health and safety risks
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Smoski, Moria J; Rittenberg, Alison; Dichter, Gabriel S
2011-12-30
Anhedonia, the loss of interest or pleasure in normally rewarding activities, is a hallmark feature of unipolar Major Depressive Disorder (MDD). A growing body of literature has identified frontostriatal dysfunction during reward anticipation and outcomes in MDD. However, no study to date has directly compared responses to different types of rewards such as pleasant images and monetary rewards in MDD. To investigate the neural responses to monetary and pleasant image rewards in MDD, a modified Monetary Incentive Delay task was used during functional magnetic resonance imaging to assess neural responses during anticipation and receipt of monetary and pleasant image rewards. Participants included nine adults with MDD and 13 affectively healthy controls. The MDD group showed lower activation than controls when anticipating monetary rewards in right orbitofrontal cortex and subcallosal cortex, and when anticipating pleasant image rewards in paracingulate and supplementary motor cortex. The MDD group had relatively greater activation in right putamen when anticipating monetary versus pleasant image rewards, relative to the control group. Results suggest reduced reward network activation in MDD when anticipating rewards, as well as relatively greater hypoactivation to pleasant image than monetary rewards. 2011 Elsevier Ireland Ltd. All rights reserved.
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Hunger does not motivate reward in women remitted from anorexia nervosa.
Wierenga, Christina E; Bischoff-Grethe, Amanda; Melrose, A James; Irvine, Zoe; Torres, Laura; Bailer, Ursula F; Simmons, Alan; Fudge, Julie L; McClure, Samuel M; Ely, Alice; Kaye, Walter H
2015-04-01
Hunger enhances sensitivity to reward, yet individuals with anorexia nervosa (AN) are not motivated to eat when starved. This study investigated brain response to rewards during hunger and satiated states to examine whether diminished response to reward could underlie food restriction in AN. Using a delay discounting monetary decision task known to discriminate brain regions contributing to processing of immediate rewards and cognitive control important for decision making regarding future rewards, we compared 23 women remitted from AN (RAN group; to reduce the confounding effects of starvation) with 17 healthy comparison women (CW group). Monetary rewards were used because the rewarding value of food may be confounded by anxiety in AN. Interactions of Group (RAN, CW) × Visit (hunger, satiety) revealed that, for the CW group, hunger significantly increased activation in reward salience circuitry (ventral striatum, dorsal caudate, anterior cingulate cortex) during processing of immediate reward, whereas satiety increased activation in cognitive control circuitry (ventrolateral prefrontal cortex, insula) during decision making. In contrast, brain response in reward and cognitive neurocircuitry did not differ during hunger and satiety in the RAN group. A main effect of group revealed elevated response in the middle frontal gyrus for the RAN group compared with the CW group. Women remitted from AN failed to increase activation of reward valuation circuitry when hungry and showed elevated response in cognitive control circuitry independent of metabolic state. Decreased sensitivity to the motivational drive of hunger may explain the ability of individuals with AN to restrict food when emaciated. Difficulties in valuating emotional salience may contribute to inabilities to appreciate the risks inherent in this disorder. Copyright © 2015 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.
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De Tommaso, Matteo; Mastropasqua, Tommaso; Turatto, Massimo
2018-01-25
Reward-predicting cues attract attention because of their motivational value. A debated question regards the conditions under which the cue's attentional salience is governed more by reward expectancy rather than by reward uncertainty. To help shedding light on this relevant issue, here, we manipulated expectancy and uncertainty using three levels of reward-cue contingency, so that, for example, a high level of reward expectancy (p = .8) was compared with the highest level of reward uncertainty (p = .5). In Experiment 1, the best reward-cue during conditioning was preferentially attended in a subsequent visual search task. This result was replicated in Experiment 2, in which the cues were matched in terms of response history. In Experiment 3, we implemented a hybrid procedure consisting of two phases: an omission contingency procedure during conditioning, followed by a visual search task as in the previous experiments. Crucially, during both phases, the reward-cues were never task relevant. Results confirmed that, when multiple reward-cue contingencies are explored by a human observer, expectancy is the major factor controlling both the attentional and the oculomotor salience of the reward-cue.
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Testing contamination risk assessment methods for toxic elements from mine waste sites
Abdaal, A.; Jordan, G.; Szilassi, P.; Kiss, J.; Detzky, G.
2012-04-01
Major incidents involving mine waste facilities and poor environmental management practices have left a legacy of thousands of contaminated sites like in the historic mining areas in the Carpathian Basin. Associated environmental risks have triggered the development of new EU environmental legislation to prevent and minimize the effects of such incidents. The Mine Waste Directive requires the risk-based inventory of all mine waste sites in Europe by May 2012. In order to address the mining problems a standard risk-based Pre-selection protocol has been developed by the EU Commission. This paper discusses the heavy metal contamination in acid mine drainage (AMD) for risk assessment (RA) along the Source-Pathway-Receptor chain using decision support methods which are intended to aid national and regional organizations in the inventory and assessment of potentially contaminated mine waste sites. Several recognized methods such as the European Environmental Agency (EEA) standard PRAMS model for soil contamination, US EPA-based AIMSS and Irish HMS-IRC models for RA of abandoned sites are reviewed, compared and tested for the mining waste environment. In total 145 ore mine waste sites have been selected for scientific testing using the EU Pre-selection protocol as a case study from Hungary. The proportion of uncertain to certain responses for a site and for the total number of sites may give an insight of specific and overall uncertainty in the data we use. The Pre-selection questions are efficiently linked to a GIS system as database inquiries using digital spatial data to directly generate answers. Key parameters such as distance to the nearest surface and ground water bodies, to settlements and protected areas are calculated and statistically evaluated using STATGRAPHICS® in order to calibrate the RA models. According to our scientific research results, of the 145 sites 11 sites are the most risky having foundation slope >20o, 57 sites are within distance 66 (class VI
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Risk and safety analyses for disposal of alpha-contaminated waste in INEL
International Nuclear Information System (INIS)
Smith, T.
1982-01-01
The author first discusses the context, objectives, and scope of the risk analysis. Then he gives some background on the waste and how its managed, including the alternatives for long-term management. These are followed by risk evaluation approach, results, and 7 conclusions and problems. One of his conclusions is that a 100 nCi/g limit would provide adequate safety margins. Raising the limit to 100 nCi/g would allow about 20% of the stored waste to be diverted to near-surface disposal. He added that analyzing waste packages at 10 nCi/g is not now practical. 21 figures
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Risk assessment for radioactive waste disposal
International Nuclear Information System (INIS)
Lyon, R.B.; Rosinger, E.L.J.
1979-01-01
The objectives of risk assessment studies for radioactive waste disposal are: to specify the features that prevent the escape of radionuclides from a deep disposal vault, to estimate how effective these features are likely to be, and to determine the potential consequences of the expected situation and conceivable but unlikely situations. The major features to be analysed include the insoluble nature of the waste form itself, the resistance of its container to corrosion or mechanical damage, the effectiveness of the massive rock barrier and the hold-up and dilution of radionuclides in the surface environment. Computer modelling is used in a technique called ''pathway analysis'' to bring together the experimental data, field data and understanding of the relevant phenomena into an assessment of the resultant effect on man and the environment. (author)
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The amygdala, reward and emotion.
Murray, Elisabeth A
2007-11-01
Recent research provides new insights into amygdala contributions to positive emotion and reward. Studies of neuronal activity in the monkey amygdala and of autonomic responses mediated by the monkey amygdala show that, contrary to a widely held view, the amygdala is just as important for processing positive reward and reinforcement as it is for negative. In addition, neuropsychological studies reveal that the amygdala is essential for only a fraction of what might be considered 'stimulus-reward processing', and that the neural substrates for emotion and reward are partially nonoverlapping. Finally, evidence suggests that two systems within the amygdala, operating in parallel, enable reward-predicting cues to influence behavior; one mediates a general, arousing effect of reward and the other links the sensory properties of reward to emotion.
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Cherniawsky, Avital S; Holroyd, Clay B
2013-03-01
Impulsivity is characterized in part by heightened sensitivity to immediate relative to future rewards. Although previous research has suggested that "high discounters" in intertemporal choice tasks tend to prefer immediate over future rewards because they devalue the latter, it remains possible that they instead overvalue immediate rewards. To investigate this question, we recorded the reward positivity, a component of the event-related brain potential (ERP) associated with reward processing, with participants engaged in a task in which they received both immediate and future rewards and nonrewards. The participants also completed a temporal discounting task without ERP recording. We found that immediate but not future rewards elicited the reward positivity. High discounters also produced larger reward positivities to immediate rewards than did low discounters, indicating that high discounters relatively overvalued immediate rewards. These findings suggest that high discounters may be more motivated than low discounters to work for monetary rewards, irrespective of the time of arrival of the incentives.
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Blum, Kenneth; Simpatico, Thomas; Badgaiyan, Rajendra D.; Demetrovics, Zsolt; Fratantonio, James; Agan, Gozde; Febo, Marcelo; Gold, Mark S.
2016-01-01
Earlier work from our laboratory, showing anti-addiction activity of a nutraceutical consisting of amino-acid precursors and enkephalinase inhibition properties and our discovery of the first polymorphic gene (Dopamine D2 Receptor Gene [DRD2]) to associate with severe alcoholism serves as a blue-print for the development of “Personalized Medicine” in addiction. Prior to the later genetic finding, we developed the concept of Brain Reward Cascade, which continues to act as an important component for stratification of addiction risk through neurogenetics. In 1996 our laboratory also coined the term “Reward Deficiency Syndrome (RDS)” to define a common genetic rubric for both substance and non-substance related addictive behaviors. Following many reiterations we utilized polymorphic targets of a number of reward genes (serotonergic, Opioidergic, GABAergic and Dopaminergic) to customize KB220 [Neuroadaptogen- amino-acid therapy (NAAT)] by specific algorithms. Identifying 1,000 obese subjects in the Netherlands a subsequent small subset was administered various KB220Z formulae customized according to respective DNA polymorphisms individualized that translated to significant decreases in both Body Mass Index (BMI) and weight in pounds. Following these experiments, we have been successfully developing a panel of genes known as “Genetic Addiction Risk Score” (GARSpDX)™. Selection of 10 genes with appropriate variants, a statistically significant association between the ASI-Media Version-alcohol and drug severity scores and GARSpDx was found A variant of KB220Z in abstinent heroin addicts increased resting state functional connectivity in a putative network including: dorsal anterior cingulate, medial frontal gyrus, nucleus accumbens, posterior cingulate, occipital cortical areas, and cerebellum. In addition, we show that KB220Z significantly activates, above placebo, seed regions of interest including the left nucleus accumbens, cingulate gyrus, anterior
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Addictive drugs and brain stimulation reward.
Wise, R A
1996-01-01
Direct electrical or chemical stimulation of specific brain regions can establish response habits similar to those established by natural rewards such as food or sexual contact. Cocaine, mu and delta opiates, nicotine, phencyclidine, and cannabis each have actions that summate with rewarding electrical stimulation of the medial forebrain bundle (MFB). The reward-potentiating effects of amphetamine and opiates are associated with central sites of action where these drugs also have their direct rewarding effects, suggesting common mechanisms for drug reward per se and for drug potentiation of brain stimulation reward. The central sites at which these and perhaps other drugs of abuse potentiate brain stimulation reward and are rewarding in their own right are consistent with the hypothesis that the laboratory reward of brain stimulation and the pharmacological rewards of addictive drugs are habit forming because they act in the brain circuits that subserve more natural and biologically significant rewards.
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Screening Level Risk Assessment for the New Waste Calcining Facility
Energy Technology Data Exchange (ETDEWEB)
M. L. Abbott; K. N. Keck; R. E. Schindler; R. L. VanHorn; N. L. Hampton; M. B. Heiser
1999-05-01
This screening level risk assessment evaluates potential adverse human health and ecological impacts resulting from continued operations of the calciner at the New Waste Calcining Facility (NWCF) at the Idaho Nuclear Technology and Engineering Center (INTEC), Idaho National Engineering and Environmental Laboratory (INEEL). The assessment was conducted in accordance with the Environmental Protection Agency (EPA) report, Guidance for Performing Screening Level Risk Analyses at Combustion Facilities Burning Hazardous Waste. This screening guidance is intended to give a conservative estimate of the potential risks to determine whether a more refined assessment is warranted. The NWCF uses a fluidized-bed combustor to solidify (calcine) liquid radioactive mixed waste from the INTEC Tank Farm facility. Calciner off volatilized metal species, trace organic compounds, and low-levels of radionuclides. Conservative stack emission rates were calculated based on maximum waste solution feed samples, conservative assumptions for off gas partitioning of metals and organics, stack gas sampling for mercury, and conservative measurements of contaminant removal (decontamination factors) in the off gas treatment system. Stack emissions were modeled using the ISC3 air dispersion model to predict maximum particulate and vapor air concentrations and ground deposition rates. Results demonstrate that NWCF emissions calculated from best-available process knowledge would result in maximum onsite and offsite health and ecological impacts that are less then EPA-established criteria for operation of a combustion facility.
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High-risk facilities. Emergency management in nuclear, chemical and hazardous waste facilities
International Nuclear Information System (INIS)
Kloepfer, Michael
2012-01-01
The book on emergency management in high-risk facilities covers the following topics: Change in the nuclear policy, risk management of high-risk facilities as a constitutional problem - emergency management in nuclear facilities, operational mechanisms of risk control in nuclear facilities, regulatory surveillance responsibilities for nuclear facilities, operational mechanism of the risk control in chemical plants, regulatory surveillance responsibilities for chemical facilities, operational mechanisms of the risk control in hazardous waste facilities, regulatory surveillance responsibilities for hazardous waste facilities, civil law consequences in case of accidents in high-risk facilities, criminal prosecution in case of accidents in high-risk facilities, safety margins as site risk for emission protection facilities, national emergency management - strategic emergency management structures, warning and self-protection of the public in case of CBRN hazards including aspects of the psych-social emergency management.
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Katoen, Joost P.; Maneesh Khattri, M.; Zapreev, I.S.; Zapreev, I.S.
2005-01-01
This short tool paper introduces MRMC, a model checker for discrete-time and continuous-time Markov reward models. It supports reward extensions of PCTL and CSL, and allows for the automated verification of properties concerning long-run and instantaneous rewards as well as cumulative rewards. In
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Blunted responses to reward in remitted post-traumatic stress disorder.
Kalebasi, Nilufer; Kuelen, Eveline; Schnyder, Ulrich; Schumacher, Sonja; Mueller-Pfeiffer, Christoph; Wilhelm, Frank H; Athilingam, Jegath; Moergeli, Hanspeter; Martin-Soelch, Chantal
2015-08-01
Recent evidence suggests blunted responses to rewarding stimuli in patients with post-traumatic stress disorder (PTSD). However, it is not clear whether these alterations in reward processing normalize in remitted PTSD patients. We tested behavioral and physiological responses to monetary reward in a spatial memory task in 13 accident survivors with remitted PTSD, 14 accident survivors who never had PTSD, and 16 nontrauma-exposed subjects. All accident survivors were recruited from two samples of severely physically injured patients, who had participated in previous prospective studies on the incidence of PTSD after accidental injury approximately 10 years ago. Reaction time, accuracy, skin conductance responses, and self-reported mood were assessed during the task. Accident survivors who never had PTSD and nontrauma exposed controls reported significantly higher positive mood in the reinforced versus nonreinforced condition (P PTSD subjects. Our findings suggest an alteration of the reward system in remitted PTSD. Further research is needed to investigate whether altered reward processing is a residual characteristic in PTSD after remission of symptoms or, alternatively, a preexisting risk factor for the development of PTSD after a traumatic event.
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A new way to ask the experts: Rating radioactive waste risks
International Nuclear Information System (INIS)
Kerr, R.A.
1996-01-01
The possible risks of a proposed nuclear waste repository at Yucca Mountain include the dozen or more young volcanos near by. Now some earth scientists have a new approach to evaluating hazards accounting for uncertainty at every step - 'expert elicitation.' This pulls together a panel of experts, carefully assesses the uncertainties of each of their views then mathematically combines their risk estimates along with the accompanying uncertainties. The article goes on to describe just such a panel which considered seismic hazards to Yucca Mountain, how they came to their conclusions, the arguments about the conclusions, and the future of expert elicitation in evaluating the risks of nuclear waste disposal
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Waste management project’s alternatives: A risk-based multi-criteria assessment (RBMCA) approach
International Nuclear Information System (INIS)
Karmperis, Athanasios C.; Sotirchos, Anastasios; Aravossis, Konstantinos; Tatsiopoulos, Ilias P.
2012-01-01
Highlights: ► We examine the evaluation of a waste management project’s alternatives. ► We present a novel risk-based multi-criteria assessment (RBMCA) approach. ► In the RBMCA the evaluation criteria are based on the quantitative risk analysis of the project’s alternatives. ► Correlation between the criteria weight values and the decision makers’ risk preferences is examined. ► Preference to the multi-criteria against the one-criterion evaluation process is discussed. - Abstract: This paper examines the evaluation of a waste management project’s alternatives through a quantitative risk analysis. Cost benefit analysis is a widely used method, in which the investments are mainly assessed through the calculation of their evaluation indicators, namely benefit/cost (B/C) ratios, as well as the quantification of their financial, technical, environmental and social risks. Herein, a novel approach in the form of risk-based multi-criteria assessment (RBMCA) is introduced, which can be used by decision makers, in order to select the optimum alternative of a waste management project. Specifically, decision makers use multiple criteria, which are based on the cumulative probability distribution functions of the alternatives’ B/C ratios. The RBMCA system is used for the evaluation of a waste incineration project’s alternatives, where the correlation between the criteria weight values and the decision makers’ risk preferences is analyzed and useful conclusions are discussed.
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Risk and cost tradeoffs for remote retrieval of buried waste
International Nuclear Information System (INIS)
Hyde, R.A.; Grienbenow, B.E.; Nickelson, D.F.
1994-01-01
The Buried Waste Integrated Demonstration is supporting the development, demonstration, testing, and evaluation of a suite of technologies that, when integrated with commercially available technologies, form a comprehensive system for the remediation of radioactive and hazardous buried waste. As a part of the program's technology development, remote retrieval equipment is being developed and tested for the remediation of buried waste. During remedial planning, several factors are considered when choosing remote versus manual retrieval systems. Time that workers are exposed to radioactivity, chemicals, air particulate, and industrial hazards is one consideration. The generation of secondary waste is also a consideration because it amounts to more waste to treat and some wastes may require special handling or treatment. Cost is also a big factor in determining whether remote or manual operations will be used. Other considerations include implementability, effectiveness, and the number of required personnel. This paper investigates each of these areas to show the risk and cost benefits and limitations for remote versus manual retrieval of buried waste
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Premotor and Motor Cortices Encode Reward.
Directory of Open Access Journals (Sweden)
Pavan Ramkumar
Full Text Available Rewards associated with actions are critical for motivation and learning about the consequences of one's actions on the world. The motor cortices are involved in planning and executing movements, but it is unclear whether they encode reward over and above limb kinematics and dynamics. Here, we report a categorical reward signal in dorsal premotor (PMd and primary motor (M1 neurons that corresponds to an increase in firing rates when a trial was not rewarded regardless of whether or not a reward was expected. We show that this signal is unrelated to error magnitude, reward prediction error, or other task confounds such as reward consumption, return reach plan, or kinematic differences across rewarded and unrewarded trials. The availability of reward information in motor cortex is crucial for theories of reward-based learning and motivational influences on actions.
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Impaired reward responsiveness in schizophrenia.
Taylor, Nicholas; Hollis, Jeffrey P; Corcoran, Sarah; Gross, Robin; Cuthbert, Bruce; Swails, Lisette W; Duncan, Erica
2018-03-08
Anhedonia is a core negative symptom of schizophrenia. Schizophrenia patients report largely intact pleasure in consuming rewards, but have impairments in generating motivated behavior to pursue rewards, and show reduced fMRI activation of the reward pathway during presentation of rewarded stimuli. A computer based task measuring the development of a response bias in favor of rewarded stimuli permits assessment of reward-induced motivation. We hypothesized that subjects with schizophrenia would be impaired on this task. 58 schizophrenia subjects (SCZ) and 52 healthy controls (CON) were studied with a signal detection task to assess reward responsiveness. In multiple trials over three blocks subjects were asked to correctly identify two stimuli that were paired with unequal chance of monetary reward. The critical outcome variable was response bias, the development of a greater percent correct identification of the stimulus that was rewarded more often. An ANOVA on response bias with Block as a repeated-measures factor and Diagnosis as a between-group factor indicated that SCZ subjects achieved a lower bias to rewarded stimuli than CON subjects (F(1,105)=8.82, p=0.004, η 2 =0.078). Post hoc tests indicated that SCZ subjects had significantly impaired bias in Block 1 (p=0.002) and Block 2 (p=0.05), indicating that SCZ were slower to achieve normal levels of bias during the session. SCZ subjects were slower to develop response bias to rewarded stimuli than CON subjects. This finding is consonant with the hypothesis that people with schizophrenia have a blunted capacity to modify behavior in response to reward. Copyright © 2018. Published by Elsevier B.V.
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Monetary rewards modulate inhibitory control
Directory of Open Access Journals (Sweden)
Paula Marcela Herrera
2014-05-01
Full Text Available The ability to override a dominant response, often referred to as behavioural inhibiton, is considered a key element of executive cognition. Poor behavioural inhibition is a defining characteristic of several neurological and psychiatric populations. Recently, there has been increasing interest in the motivational dimension of behavioural inhibition, with some experiments incorporating emotional contingencies in classical inhibitory paradigms such as the Go/Nogo and Stop Signal Tasks. Several studies have reported a positive modulatory effect of reward on the performance of such tasks in pathological conditions such as substance abuse, pathological gambling, and ADHD. However, experiments that directly investigate the modulatory effects of reward magnitudes on the performance of inhibitory paradigms are rare and consequently, little is known about the finer grained relationship between motivation and self-control. Here, we probed the effect of reward and reward magnitude on behavioural inhibition using two modified version of the widely used Stop Signal Task. The first task compared no reward with reward, whilst the other compared two different reward magnitudes. The reward magnitude effect was confirmed by the second study, whereas it was less compelling in the first study, possibly due to the effect of having no reward in some conditions. In addition, our results showed a kick start effect over global performance measures. More specifically, there was a long lasting improvement in performance throughout the task, when participants received the highest reward magnitudes at the beginning of the protocol. These results demonstrate that individuals’ behavioural inhibition capacities are dynamic not static because they are modulated by the reward magnitude and initial reward history of the task at hand.
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Risks from principal components and their daughter products in alpha-contaminated waste
International Nuclear Information System (INIS)
Rogers, V.
1982-01-01
This paper presents an overview on risk assessment, particularly as it applies to limits for alpha-contaminated waste. The general conclusions are: (1) no special characteristics of transuranic (TRU) waste justify its being a special category; (2) model calculations are largely subjective and can be influenced by the bias of the modeler; (3) ingrowth and concentration of TRU daughter products could be an important consideration in risk assessment. 13 figures
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DEFF Research Database (Denmark)
Koch, Alexander; Nafziger, Julia
People often overcome self-control problems by promising to reward themselves for accomplishing a task. Such strategies based on self-administered rewards however require the person to believe that she would indeed deny herself the reward if she should fail to achieve the desired outcome. Drawing...... on Koszegi and Rabin's (2006) model of endogenous reference point formation, we show how a rational forward-looking individual can achieve such internal commitment. But our results also demonstrate the limitations of self regulation based on self-rewards....
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Perceived risk impacts from siting hazardous waste facilities
International Nuclear Information System (INIS)
Hemphill, R.C.; Edwards, B.K.; Bassett, G.W. Jr.
1992-01-01
This paper describes methods for evaluating perception-based economic impacts resulting from siting hazardous waste facilities. Socioeconomic impact analysis has devoted increasing attention to the potential implications of changed public perceptions of risk due to an activity or situation. This contrasts with traditional socioecconomic impact analysis, which has been limited to measuring direct and indirect consequences of activities, e.g., the employment effects of placing a military base in a specified location. Approaches to estimating economic impacts due to changes in public perceptions are ex ante or ex post. The former predict impacts prior to the construction and operation of a facility, while the later is based on impacts that become evident only when the facility is up and running. The theoretical foundations and practical requirements for demonstrating impacts, resulting from the siting of a hazardous facility are described. The theoretical rationale supporting the study of perceived risk research is presented along with discussion of problems that arise in demonstrating the existence and measuring the quantitative importance of economic impacts due to changes in perceived risk. The high-level nuclear waste facility being considered in Nevada is presented as an example in which there is potential for impacts, but where the link between perceived risk and economic conditions has not yet been developed
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Perceived risk impacts from siting hazardous waste facilities
International Nuclear Information System (INIS)
Hemphill, R.C.; Edwards, B.K.; Bassett, G.W. Jr.
1992-01-01
This paper describes methods for evaluating perception-based economic impacts resulting from siting hazardous waste facilities. Socioeconomic impact analysis has devoted increasing attention to the potential implications of changed public perceptions of risk due to an activity or situation. This contrasts with traditional socioeconomic impact analysis, which has been limited to measuring direct and indirect consequences of activities, e.g., the employment effects of placing a military base in a specified location. Approaches to estimating economic impacts due to changes in public perceptions are ex ante or ex post. The former predict impacts prior to the construction and operation of a facility, while the later is based on impacts that become evident only when the facility is up and running. The theoretical foundations and practical requirements for demonstrating impacts resulting from the siting of a hazardous facility are described. The theoretical rationale supporting the study of perceived risk research is presented along with discussion of problems that arise in demonstrating the existence and measuring the quantitative importance of economic impacts due to changes in perceived risk. The high-level nuclear waste facility being considered in Nevada is presented as an example in which there is potential for impacts, but where the link between perceived risk and economic conditions has not yet been developed
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Introduction: Addiction and Brain Reward and Anti-Reward Pathways
Gardner, Eliot L.
2013-01-01
Addictive drugs have in common that they are voluntarily self-administered by laboratory animals (usually avidly) and that they enhance the functioning of the reward circuitry of the brain (producing the “high” that the drug-user seeks). The core reward circuitry consists of an “in series” circuit linking the ventral tegmental area, nucleus accumbens, and ventral pallidum - via the medial forebrain bundle. Although originally believed to encode simply the set-point of hedonic tone, these circuits are now believed to be functionally far more complex - also encoding attention, expectancy of reward, disconfirmation of reward expectancy, and incentive motivation. “Hedonic dysregulation” within these circuits may lead to addiction. The “second-stage” dopaminergic component in this reward circuitry is the crucial addictive-drug-sensitive component. All addictive drugs have in common that they enhance (directly or indirectly or even transsynaptically) dopaminergic reward synaptic function in the nucleus accumbens. Drug self-administration is regulated by nucleus accumbens dopamine levels, and is done to keep nucleus accumbens dopamine within a specific elevated range (to maintain a desired hedonic level). For some classes of addictive drugs (e.g., opiates), tolerance to the euphoric effects develops with chronic use. Post-use dysphoria then comes to dominate reward circuit hedonic tone, and addicts no longer use drugs to get “high,” but simply to get back to normal (“get straight”). The brain circuits mediating the pleasurable effects of addictive drugs are anatomically, neurophysiologically, and neurochemically different from those mediating physical dependence, and from those mediating craving and relapse. There are important genetic variations in vulnerability to drug addiction, yet environmental factors such as stress and social defeat also alter brain-reward mechanisms in such a manner as to impart vulnerability to addiction. In short, the
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Health Risks Awareness of Electronic Waste Workers in the Informal Sector in Nigeria.
Ohajinwa, Chimere M; Van Bodegom, Peter M; Vijver, Martina G; Peijnenburg, Willie J G M
2017-01-01
Insight into the health risk awareness levels of e-waste workers is important as it may offer opportunities for better e-waste recycling management strategies to reduce the health effects of informal e-waste recycling. Therefore, this study assessed the knowledge, attitude, and practices associated
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Use of risk to resolve conflicts in assessing hazards at mixed-waste sites
International Nuclear Information System (INIS)
Rechard, R.P.; Chu, M.S.Y.
1991-01-01
Two main issues contribute to the assessment of health hazard from mixed waste: the scientific methods to assess these materials and the legislative and regulatory control of these materials. This paper is primarily concerned with the scientific method of assessing hazards from mixed waste (i.e., carcinogenic chemicals, noncarcinogenic chemicals, and radioactive material). This paper discusses SRS, a Site Ranking System, and its use of risk concepts to avoid introducing new inconsistencies when ranking mixed-waste sites. SRS ranks each site by scoring factors that influence the human health risk. The factors are (1) the potentially exposed population, (2) the average amount of exposure to the waste, and (3) the toxicity of the waste. The relative risk of a release is measured as the product of these three factors. The third factor, toxicity, is indexed with a single score, but because methods of measuring toxicity differ for carcinogenic chemicals, noncarcinogenic chemicals, and radionuclides, comparison can be difficult; hence, this paper also summarizes the logic and assumptions used to make toxicity comparisons in SRS. As may be expected, results from a ranking scheme based on risk are different from results generated by the original Hazard Ranking System (HRS), used by the Environmental Protection Agency. This paper briefly discusses these differences for five Superfund sites (no mixed waste). The legislative and regulatory control of these materials to protect human health is also discussed. 37 refs., 1 tab
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Monetary rewards influence retrieval orientations.
Halsband, Teresa M; Ferdinand, Nicola K; Bridger, Emma K; Mecklinger, Axel
2012-09-01
Reward anticipation during learning is known to support memory formation, but its role in retrieval processes is so far unclear. Retrieval orientations, as a reflection of controlled retrieval processing, are one aspect of retrieval that might be modulated by reward. These processes can be measured using the event-related potentials (ERPs) elicited by retrieval cues from tasks with different retrieval requirements, such as via changes in the class of targeted memory information. To determine whether retrieval orientations of this kind are modulated by reward during learning, we investigated the effects of high and low reward expectancy on the ERP correlates of retrieval orientation in two separate experiments. The reward manipulation at study in Experiment 1 was associated with later memory performance, whereas in Experiment 2, reward was directly linked to accuracy in the study task. In both studies, the participants encoded mixed lists of pictures and words preceded by high- or low-reward cues. After 24 h, they performed a recognition memory exclusion task, with words as the test items. In addition to a previously reported material-specific effect of retrieval orientation, a frontally distributed, reward-associated retrieval orientation effect was found in both experiments. These findings suggest that reward motivation during learning leads to the adoption of a reward-associated retrieval orientation to support the retrieval of highly motivational information. Thus, ERP retrieval orientation effects not only reflect retrieval processes related to the sought-for materials, but also relate to the reward conditions with which items were combined during encoding.
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DEFF Research Database (Denmark)
Rugulies, Reiner; Norborg, Malene; Sørensen, Tilde Sand
2009-01-01
OBJECTIVES: This study aimed to analyze if adverse psychosocial working conditions, defined by the model of effort-reward imbalance (ERI), increase the risk of sleep disturbances in the Danish workforce. METHODS: Analyses were conducted both cross-sectionally and prospectively in a representative...... disturbances in the Danish workforce. Among women, an association between ERI and sleep disturbances was restricted to the cross-sectional sample. Improving psychosocial working conditions might reduce the risk of sleep disturbances and subsequently also help to prevent clinical disorders related to sleep...
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Sigmund, K; Hauert, C; Nowak, M A
2001-09-11
Minigames capturing the essence of Public Goods experiments show that even in the absence of rationality assumptions, both punishment and reward will fail to bring about prosocial behavior. This result holds in particular for the well-known Ultimatum Game, which emerges as a special case. But reputation can induce fairness and cooperation in populations adapting through learning or imitation. Indeed, the inclusion of reputation effects in the corresponding dynamical models leads to the evolution of economically productive behavior, with agents contributing to the public good and either punishing those who do not or rewarding those who do. Reward and punishment correspond to two types of bifurcation with intriguing complementarity. The analysis suggests that reputation is essential for fostering social behavior among selfish agents, and that it is considerably more effective with punishment than with reward.
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Competition between learned reward and error outcome predictions in anterior cingulate cortex.
Alexander, William H; Brown, Joshua W
2010-02-15
The anterior cingulate cortex (ACC) is implicated in performance monitoring and cognitive control. Non-human primate studies of ACC show prominent reward signals, but these are elusive in human studies, which instead show mainly conflict and error effects. Here we demonstrate distinct appetitive and aversive activity in human ACC. The error likelihood hypothesis suggests that ACC activity increases in proportion to the likelihood of an error, and ACC is also sensitive to the consequence magnitude of the predicted error. Previous work further showed that error likelihood effects reach a ceiling as the potential consequences of an error increase, possibly due to reductions in the average reward. We explored this issue by independently manipulating reward magnitude of task responses and error likelihood while controlling for potential error consequences in an Incentive Change Signal Task. The fMRI results ruled out a modulatory effect of expected reward on error likelihood effects in favor of a competition effect between expected reward and error likelihood. Dynamic causal modeling showed that error likelihood and expected reward signals are intrinsic to the ACC rather than received from elsewhere. These findings agree with interpretations of ACC activity as signaling both perceptions of risk and predicted reward. Copyright 2009 Elsevier Inc. All rights reserved.
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Reward Processing in Adolescents with Bipolar I Disorder
Singh, Manpreet K.; Chang, Kiki D.; Kelley, Ryan G.; Cui, Xu; Sherdell, Lindsey; Howe, Meghan E.; Gotlib, Ian H.; Reiss, Allan L.
2013-01-01
Objective: Bipolar disorder (BD) is a debilitating psychiatric condition that commonly begins in adolescence, a developmental period that has been associated with increased reward seeking. Because youth with BD are especially vulnerable to negative risk-taking behaviors, understanding the neural mechanisms by which dysregulated affect interacts…
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International Nuclear Information System (INIS)
GREENWLL, R.D.
2005-01-01
A risk identification and mitigation method applied to the Transuranic (TRU) Waste Retrieval Project performed at the Hanford 200 Area burial grounds is described. Retrieval operations are analyzed using process flow diagramming. and the anticipated project contingencies are included in the Authorization Basis and operational plans. Examples of uncertainties assessed include degraded container integrity, bulged drums, unknown containers, and releases to the environment. Identification and mitigation of project risks contributed to the safe retrieval of over 1700 cubic meters of waste without significant work stoppage and below the targeted cost per cubic meter retrieved. This paper will be of interest to managers, project engineers, regulators, and others who are responsible for successful performance of waste retrieval and other projects with high safety and performance risks
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Rajalingham, Rishi; Stacey, Richard Greg; Tsoulfas, Georgios
2014-01-01
To restore movements to paralyzed patients, neural prosthetic systems must accurately decode patients' intentions from neural signals. Despite significant advancements, current systems are unable to restore complex movements. Decoding reward-related signals from the medial intraparietal area (MIP) could enhance prosthetic performance. However, the dynamics of reward sensitivity in MIP is not known. Furthermore, reward-related modulation in premotor areas has been attributed to behavioral confounds. Here we investigated the stability of reward encoding in MIP by assessing the effect of reward history on reward sensitivity. We recorded from neurons in MIP while monkeys performed a delayed-reach task under two reward schedules. In the variable schedule, an equal number of small- and large-rewards trials were randomly interleaved. In the constant schedule, one reward size was delivered for a block of trials. The memory period firing rate of most neurons in response to identical rewards varied according to schedule. Using systems identification tools, we attributed the schedule sensitivity to the dependence of neural activity on the history of reward. We did not find schedule-dependent behavioral changes, suggesting that reward modulates neural activity in MIP. Neural discrimination between rewards was less in the variable than in the constant schedule, degrading our ability to decode reach target and reward simultaneously. The effect of schedule was mitigated by adding Haar wavelet coefficients to the decoding model. This raises the possibility of multiple encoding schemes at different timescales and reinforces the potential utility of reward information for prosthetic performance. PMID:25008408
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Rajalingham, Rishi; Stacey, Richard Greg; Tsoulfas, Georgios; Musallam, Sam
2014-10-01
To restore movements to paralyzed patients, neural prosthetic systems must accurately decode patients' intentions from neural signals. Despite significant advancements, current systems are unable to restore complex movements. Decoding reward-related signals from the medial intraparietal area (MIP) could enhance prosthetic performance. However, the dynamics of reward sensitivity in MIP is not known. Furthermore, reward-related modulation in premotor areas has been attributed to behavioral confounds. Here we investigated the stability of reward encoding in MIP by assessing the effect of reward history on reward sensitivity. We recorded from neurons in MIP while monkeys performed a delayed-reach task under two reward schedules. In the variable schedule, an equal number of small- and large-rewards trials were randomly interleaved. In the constant schedule, one reward size was delivered for a block of trials. The memory period firing rate of most neurons in response to identical rewards varied according to schedule. Using systems identification tools, we attributed the schedule sensitivity to the dependence of neural activity on the history of reward. We did not find schedule-dependent behavioral changes, suggesting that reward modulates neural activity in MIP. Neural discrimination between rewards was less in the variable than in the constant schedule, degrading our ability to decode reach target and reward simultaneously. The effect of schedule was mitigated by adding Haar wavelet coefficients to the decoding model. This raises the possibility of multiple encoding schemes at different timescales and reinforces the potential utility of reward information for prosthetic performance. Copyright © 2014 the American Physiological Society.
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Byrnes, Nadia K; Hayes, John E
2016-08-01
Based on work a quarter century ago, it is widely accepted personality traits like sensation seeking are related to the enjoyment and intake of spicy foods; however, data supporting this belief is actually quite limited. Recently, we reported strong to moderate correlations between remembered spicy food liking and two personality traits measured with validated questionnaires. Here, participants consumed capsaicin-containing strawberry jelly to generate acute estimates of spicy food liking. Additionally, we used a laboratory-based behavioral measure of risk taking (the mobile Balloon Analogue Risk Task; mBART) to complement a range of validated self-report measures of risk-related personality traits. Present data confirm Sensation Seeking correlates with overall spicy meal liking and liking of the burn of a spicy meal, and extends prior findings by showing novel correlations with the liking of sampled stimuli. Other personality measures, including Sensitivity to Punishment (SP), Sensitivity to Reward (SR), and the Impulsivity and Risk Taking subscales of the DSM5 Personality Inventory (PID-5) did not show significant relationships with liking of spicy foods, either sampled or remembered. Our behavioral risk taking measure, the mBART, also failed to show a relationship with remembered or sampled liking. However, significant relationships were observed between reported intake of spicy foods and Sensitivity to Reward, and the Risk Taking subscale of the PID-5 (PID5-RT). Based on the observed patterns among various personality measures, and spicy food liking and intake, we propose that personality measures may exert their influence on intake of spicy food via different mechanisms. We also speculate that Sensation Seeking may reflect motivations for consuming spicy foods that are more intrinsic, while the motivations for eating spicy foods measured by SR and PID5-RT may be more extrinsic. Copyright © 2016 Elsevier Ltd. All rights reserved.
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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.
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Risks of municipal solid waste incineration: an environmental perspective.
Denison, R A; Silbergeld, E K
1988-09-01
The central focus of the debate over incineration of municipal solid waste (MSW) has shifted from its apparent management advantages to unresolved risk issues. This shift is a result of the lack of comprehensive consideration of risks associated with incineration. We discuss the need to expand incinerator risk assessment beyond the limited view of incinerators as stationary air pollution sources to encompass the following: other products of incineration, ash in particular, and pollutants other than dioxins, metals in particular; routes of exposure in addition to direct inhalation; health effects in addition to cancer; and the cumulative nature of exposure and health effects induced by many incinerator-associated pollutants. Rational MSW management planning requires that the limitations as well as advantages of incineration be recognized. Incineration is a waste-processing--not a waste disposal--technology, and its products pose substantial management and disposal problems of their own. Consideration of the nature of these products suggests that incineration is ill-suited to manage the municipal wastestream in its entirety. In particular, incineration greatly enhances the mobility and bioavailability of toxic metals present in MSW. These factors suggest that incineration must be viewed as only one component in an integrated MSW management system. The potential for source reduction, separation, and recycling to increase the safety and efficiency of incineration should be counted among their many benefits. Risk considerations dictate that alternatives to the use of toxic metals at the production stage also be examined in designing an effective, long-term MSW management strategy.
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Nuclear Waste, Risks and Sustainable Development
International Nuclear Information System (INIS)
Karlsson, Mikael; Swahn, Johan
2006-01-01
to increase trust in so far as gaining public commitment for a repository, but only as long as long-term environmental safety is made the central objective. Trust will also increase along with continued transfer to a sustainable energy system. The problems of dealing with nuclear waste are often seen as a 'show-stopper' for nuclear power. It must, however, be emphasised that nuclear power does not become compatible with sustainable development even if the best environmental solution is found for the already existing waste. Nuclear power is fundamentally based on finite resources. The technology relies on environmentally harmful mining and creates extremely hazardous waste. It also has an intrinsic risk for catastrophic release of harmful radiation and increases the risk of nuclear weapons proliferation
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Nuclear Waste, Risks and Sustainable Development
Energy Technology Data Exchange (ETDEWEB)
Karlsson, Mikael [Swedish Society for Nature Conservation, Stockholm (Sweden); Swahn, Johan [Swedish NGO Office for Nuclear Waste Review (MKG), Goeteborg (Sweden)
2006-09-15
believe it is possible to increase trust in so far as gaining public commitment for a repository, but only as long as long-term environmental safety is made the central objective. Trust will also increase along with continued transfer to a sustainable energy system. The problems of dealing with nuclear waste are often seen as a 'show-stopper' for nuclear power. It must, however, be emphasised that nuclear power does not become compatible with sustainable development even if the best environmental solution is found for the already existing waste. Nuclear power is fundamentally based on finite resources. The technology relies on environmentally harmful mining and creates extremely hazardous waste. It also has an intrinsic risk for catastrophic release of harmful radiation and increases the risk of nuclear weapons proliferation.
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Qualitative risk assessment of subsurface barriers in applications supporting retrieval of SST waste
International Nuclear Information System (INIS)
Treat, R.L.
1994-04-01
This report provides a brief, qualitative assessment of risks associated with the potential use of impermeable surface barriers installed around and beneath Hanford Site single-shell tanks (SSTs) to support the retrieval of wastes from those tanks. These risks are compared to qualitative assessment of costs and risks associated with a case in which barriers are not used. A quantitative assessment of costs and risks associated with these two cases will be prepared and documented in a companion report. The companion report will compare quantitatively the costs and risks of several retrieval options with varying parameters, such as effectiveness of retrieval, effectiveness of subsurface barriers, and the use of surface barriers. For ease of comparison of qualitative risks, a case in which impermeable subsurface barriers are used in conjunction with another technology to remove tank waste is referred, to in this report as the Barrier Case. A case in which waste removal technologies are used without employing a subsurface barrier is referred to as the No Barrier Case. The technologies associated with each case are described in the following sections
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Risk assessment of hazardous waste transport - perspectives of GIS application
International Nuclear Information System (INIS)
Lazar, R.E.; Dumitrescu, M.; Stefanescu, I.
2001-01-01
Due to the increasing public awareness of the potential risks associated with waste transport, the environmental impact assessment of this activity has become an issue of major importance. This paper presents a project proposal, which can establish a national action plan for waste transport evaluation. Such a programme is sustained by the necessity to obtain an adequate method for the rapid and efficient estimation of individual and social risks due to the transport of hazardous substances in Romania. The main objective is to develop regional strategies for risk assessment in comprising: establishing the areas that must be investigated and their particular characteristics; identifying the transport activities in the areas; determining hazards; establishing the analysis criteria and prioritizing the study areas; evaluating continuous emissions; studying major accidents; studying population health; classifying the risks; establishing regional strategies; implementing political and regulatory measures. The project expectation is to provide a decision tool for risk managers and authorities in order to control or limit transportation and the storage of hazardous substances.(author)
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A generic risk assessment from unrestricted releases for RI waste
International Nuclear Information System (INIS)
Won-Jae Park; Sang-hoon Park
1993-01-01
It has long been recognized in the nuclear industries and the regulatory body that exemption from the regulatory control for a given practice or source of radioactive materials, which is very low radiation exposure situation where the level of risk to any of the public would be considered as trivial, may be beneficial and practical. Therefore, it is necessary to establish the exempt levels of radioactive wastes for unconditional disposal, incineration, recycle and reuse of slightly contaminated materials. In Korea, from its announcement of the Enforcement Regulation of Atomic Energy Act, the Article 97 (Exemption from Permanent Disposal) for very low-level waste disposal in January 1990, the KINS (Korea Institute of Nuclear Safety) have made their efforts to establish a de minimis level (a level of radioactivity in waste that is sufficiently low that the waste can be disposed of as ordinary, non-radioactive trash) for short-lived radioisotopes commonly used in medical, research institutes and industrial applications and to study the possibility for unrestricted deregulation of those radioisotopes. As one of preliminary works to predict environmental radiological impacts from uncontrolled and unrestricted release of RI waste, an average effective dose to any ordinary individual and a collective dose for total population in Korea was estimated, based on conservative assumptions and Korean specific environment data, by an equilibrium biosphere models with a generic probabilistic risk approach
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Risk behavior in petroleum exploration
International Nuclear Information System (INIS)
Rose, P.R.
1992-01-01
In this paper, the author uses the term risk aversion, which weighs the magnitude of investment against four factors: size of available budget, potential gain, potential loss, and probabilities of each outcome. Modern petroleum exploration consists of a series of investment decisions on whether to acquire additional technical data (geological, geophysical, engineering, drilling, or economic) and/or additional mineral interests. Each decision should allow a progressively clearer perception of project risk versus reward and should support timely management action concerning the inferred accumulation. Companies searching for oil and natural gas make hundreds of such exploration decisions each year. So the problem in serial exploration decision making is twofold: to be consistent in the way we deal with risk and uncertainty and to perceive risk and uncertainty accurately and reduce them where possible. Risk aversion is not just a hypothetical nuisance. It causes explorationists to make inconsistent investment decisions, and it costs exploration companies millions of dollars annually in lost opportunities, bad choices, and wasted investment dollars
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Proposal for a questionnaire to assess risk perception concerning a radioactive waste repository
International Nuclear Information System (INIS)
Tanimoto, Katia Suemi
2011-01-01
One of the key features for public acceptance of nuclear energy is the belief that radioactive waste can be managed safely, in order to protect human beings from its possible harmful effects in present and future generations. In this sense, it is essential to understand how people perceive the risk associated with radioactive waste and which the main factors driving their attitudes toward its disposal are. One of the ways to achieve this understanding is through opinion polls. In this study, a questionnaire focused on the nuclear energy acceptability issue and its association with radioactive waste management was proposed, covering the following aspects: attitudes towards radioactive waste and nuclear power, credibility on institutions and sectors responsible by the nuclear safety, identification of perceived benefits, risk perception of specific technologies and activities, perception of real risk, emotional reaction comprehension and precautionary principle. Results obtained from a pilot questionnaire application are presented and discussed in this paper. (author)
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Torres, Carmen; Glueck, Amanda C; Conrad, Shannon E; Morón, Ignacio; Papini, Mauricio R
2016-09-22
The dorsomedial striatum (DMS) has been implicated in the acquisition of reward representations, a proposal leading to the hypothesis that it should play a role in situations involving reward loss. We report the results of an experiment in which the effects of DMS excitotoxic lesions were tested in consummatory successive negative contrast (reward devaluation), autoshaping training with partial vs. continuous reinforcement (reward uncertainty), and appetitive extinction (reward omission). Animals with DMS lesions exhibited reduced lever pressing responding, but enhanced goal entries, during partial reinforcement training in autoshaping. However, they showed normal negative contrast, acquisition under continuous reinforcement (CR), appetitive extinction, and response facilitation in early extinction trials. Open-field testing also indicated normal motor behavior. Thus, DMS lesions selectively affected the behavioral adjustment to a situation involving reward uncertainty, producing a behavioral reorganization according to which goal tracking (goal entries) became predominant at the expense of sign tracking (lever pressing). This pattern of results shows that the function of the DMS in situations involving reward loss is not general, but restricted to reward uncertainty. We suggest that a nonassociative, drive-related process induced by reward uncertainty requires normal output from DMS neurons. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.
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Effort-Reward Imbalance at Work and Risk of Long-Term Sickness Absence in the Danish Workforce
Nielsen, Maj Britt D.; Madsen, Ida E. H.; Bultmann, Ute; Aust, Birgit; Burr, Hermann; Rugulies, Reiner
Objective: To examine whether effort-reward imbalance (ERI) at work predicts onset of register-based long-term sickness absence (LTSA) in a representative sample of the Danish workforce. Methods: We measured effort, reward, ERI, and covariates with self-administered questionnaires in a sample of
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Avinun, Reut; Nevo, Adam; Knodt, Annchen R; Elliott, Maxwell L; Radtke, Spenser R; Brigidi, Bartholomew D; Hariri, Ahmad R
2017-10-04
Sleep disturbances represent one risk factor for depression. Reward-related brain function, particularly the activity of the ventral striatum (VS), has been identified as a potential buffer against stress-related depression. We were therefore interested in testing whether reward-related VS activity would moderate the effect of sleep disturbances on depression in a large cohort of young adults. Data were available from 1129 university students (mean age 19.71 ± 1.25 years; 637 women) who completed a reward-related functional MRI task to assay VS activity and provided self-reports of sleep using the Pittsburgh Sleep Quality Index and symptoms of depression using a summation of the General Distress/Depression and Anhedonic Depression subscales of the Mood and Anxiety Symptoms Questionnaire-short form. Analyses revealed that as VS activity increased the association between sleep disturbances and depressive symptoms decreased. The interaction between sleep disturbances and VS activity was robust to the inclusion of sex, age, race/ethnicity, past or present clinical disorder, early and recent life stress, and anxiety symptoms, as well as the interactions between VS activity and early or recent life stress as covariates. We provide initial evidence that high reward-related VS activity may buffer against depressive symptoms associated with poor sleep. Our analyses help advance an emerging literature supporting the importance of individual differences in reward-related brain function as a potential biomarker of relative risk for depression. SIGNIFICANCE STATEMENT Sleep disturbances are a common risk factor for depression. An emerging literature suggests that reward-related activity of the ventral striatum (VS), a brain region critical for motivation and goal-directed behavior, may buffer against the effect of negative experiences on the development of depression. Using data from a large sample of 1129 university students we demonstrate that as reward-related VS activity
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Extinction Can Reduce the Impact of Reward Cues on Reward-Seeking Behavior.
Lovibond, Peter F; Satkunarajah, Michelle; Colagiuri, Ben
2015-07-01
Reward-associated cues are thought to promote relapse after treatment of appetitive disorders such as drug-taking, binge eating, and gambling. This process has been modelled in the laboratory using a Pavlovian-instrumental transfer (PIT) design in which Pavlovian cues facilitate instrumental reward-directed action. Attempts to reduce facilitation by cue exposure (extinction) have produced mixed results. We tested the effect of extinction in a recently developed PIT procedure using a natural reward, chocolate, in human participants. Facilitation of instrumental responding was only observed in participants who were aware of the Pavlovian contingencies. Pavlovian extinction successfully reduced, but did not completely eliminate, expectancy of reward and facilitation of instrumental responding. The results indicate that exposure can reduce the ability of cues to promote reward-directed behavior in the laboratory. However, the residual potency of extinguished cues means that additional active strategies may be needed in clinical practice to train patients to resist the impact of these cues in their environment. Copyright © 2015. Published by Elsevier Ltd.
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Energy Technology Data Exchange (ETDEWEB)
Porter, R.D.; Hamby, D.M.; Martin, J.E.
1997-07-01
This study was done to examine the risks of remediation and the effectiveness of removal methods for thorium and its associated radioactive decay products from various soils and wastes associated with DOE`s Formerly Utilized Sites Remedial Action Program (FUSRAP). Its purpose was to provide information to the Environmental Management Advisory Board`s FUSRAP Committee for use in its deliberation of guiding principles for FUSRAP sites, in particular the degree to which treatment should be considered in the FUSRAP Committee`s recommendations. Treatment of FUSRAP wastes to remove thorium could be beneficial to management of lands that contain thorium if such treatment were effective and cost efficient. It must be recognized, however, that treatment methods invariably require workers to process residues and waste materials usually with bulk handling techniques. These processes expose workers to the radioactivity in the materials, therefore, workers would incur radiological risks in addition to industrial accident risks. An important question is whether the potential reduction of future radiological risks to members of the public justifies the risks that are incurred by remediation workers due to handling materials. This study examines, first, the effectiveness of treatment and then the risks that would be associated with remediation. Both types of information should be useful for decisions on whether and how to apply thorium removal methods to FUSRAP waste materials.
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International Nuclear Information System (INIS)
Porter, R.D.; Hamby, D.M.; Martin, J.E.
1997-07-01
This study was done to examine the risks of remediation and the effectiveness of removal methods for thorium and its associated radioactive decay products from various soils and wastes associated with DOE's Formerly Utilized Sites Remedial Action Program (FUSRAP). Its purpose was to provide information to the Environmental Management Advisory Board's FUSRAP Committee for use in its deliberation of guiding principles for FUSRAP sites, in particular the degree to which treatment should be considered in the FUSRAP Committee's recommendations. Treatment of FUSRAP wastes to remove thorium could be beneficial to management of lands that contain thorium if such treatment were effective and cost efficient. It must be recognized, however, that treatment methods invariably require workers to process residues and waste materials usually with bulk handling techniques. These processes expose workers to the radioactivity in the materials, therefore, workers would incur radiological risks in addition to industrial accident risks. An important question is whether the potential reduction of future radiological risks to members of the public justifies the risks that are incurred by remediation workers due to handling materials. This study examines, first, the effectiveness of treatment and then the risks that would be associated with remediation. Both types of information should be useful for decisions on whether and how to apply thorium removal methods to FUSRAP waste materials
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BOLD responses in reward regions to hypothetical and imaginary monetary rewards.
Miyapuram Krishna P; Tobler Philippe N; Gregorios-Pippas Lucy; Schultz Wolfram
2012-01-01
Monetary rewards are uniquely human. Because money is easy to quantify and present visually, it is the reward of choice for most fMRI studies, even though it cannot be handed over to participants inside the scanner. A typical fMRI study requires hundreds of trials and thus small amounts of monetary rewards per trial (e.g. 5p) if all trials are to be treated equally. However, small payoffs can have detrimental effects on performance due to their limited buying power. Hypothetical monetary rewa...
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Nuclear waste in the Pacific: perceptions of the risks
International Nuclear Information System (INIS)
Childs, I.R.W.
1984-01-01
This dissertation examines the problem of the disposal of high-level nuclear waste in the Pacific region. There is a consensus of scientific opinion that the technical difficulties in waste disposal can be overcome. The most acceptable solution seems to be the multi-barrier approach for deep land-based geologic disposal. A questionnaire survey on the perception of nuclear and other hazards, conducted with student populations in Japan and Australia, and a survey of reporting of nuclear events in Pacific newspapers over the period 1946 to the 1980s, reveal that the image of nuclear weapons dominates public views on the risks associated with waste disposal in Australia, Japan, and the Pacific Islands. The problem of finding a suitable site for a nuclear waste disposal facility is to a large extent political. The capacity of anti-nuclear groups to influence waste disposal policies in Australia, Japan, and the Pacific Islands is examined. Current public attitudes toward nuclear waste disposal will delay the further development of activities connected with the nuclear fuel cycle, but this may change over time if the connection between commercial nuclear power and nuclear weapons can be severed more effectively. The most urgent problem in the region is the waste from the ambitious nuclear power programs of Japan, South Korea, and Taiwan
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Reward eliminates retrieval-induced forgetting.
Imai, Hisato; Kim, Dongho; Sasaki, Yuka; Watanabe, Takeo
2014-12-02
Although it is well known that reward enhances learning and memory, how extensively such enhancement occurs remains unclear. To address this question, we examined how reward influences retrieval-induced forgetting (RIF) in which the retrieval of a nonpracticed item under the same category as a practiced item is worse than the retrieval of a nonpracticed item outside the category. Subjects were asked to try to encode category-exemplar pairs (e.g., FISH-salmon). Then, they were presented with a category name and a two-letter word stem (e.g., FISH-sa) and were asked to complete an encoded word (retrieval practice). For a correct response, apple juice was given as a reward in the reward condition and a beeping sound was presented in the no-reward condition. Finally, subjects were asked to report whether each exemplar had been presented in the first phase. RIF was replicated in the no-reward condition. However, in the reward condition, RIF was eliminated. These results suggest that reward enhances processing of retrieval of unpracticed members by mechanisms such as spreading activation within the same category, irrespective of whether items were practiced or not.
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Tank waste remediation system programmatic risk management plan
International Nuclear Information System (INIS)
Seaver, D.A.
1995-01-01
This risk management plan defines the approach to be taken to managing risks in the Tank Waste Remediation System (TWRS) program. It defines the actions to be taken at the overall program level, and the risk management requirements for lower-level projects and other activities. The primary focus of this plan is on ''programmatic'' risks, i.e., risks with respect to the cost, schedule, and technical performance of the program. The plan defines an approach providing managers with the flexibility to manage risks according to their specific needs, yet creates. The consistency needed for effectiveness across the program. The basic risk management approach uses a risk management list for the program, each project, and additional lower-level activities. The risk management list will be regularly reviewed and updated by appropriate level of management. Each list defines key risks, their likelihood and consequences, risk management actions to be taken, responsible individuals, and other management information
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Ho, Chao-Chung; Chen, Ming-Shu
2018-01-01
The policy of establishing new universities across Taiwan has led to an increase in the number of universities, and many schools have constructed new laboratories to meet students' academic needs. In recent years, there has been an increase in the number of laboratory accidents from the liquid waste in universities. Therefore, how to build a safety system for laboratory liquid waste disposal has become an important issue in the environmental protection, safety, and hygiene of all universities. This study identifies the risk factors of liquid waste disposal and presents an agenda for practices to laboratory managers. An expert questionnaire is adopted to probe into the risk priority procedures of liquid waste disposal; then, the fuzzy theory-based FMEA method and the traditional FMEA method are employed to analyze and improve the procedures for liquid waste disposal. According to the research results, the fuzzy FMEA method is the most effective, and the top 10 potential disabling factors are prioritized for improvement according to the risk priority number (RNP), including "Unclear classification", "Gathering liquid waste without a funnel or a drain pan", "Lack of a clearance and transport contract", "Liquid waste spill during delivery", "Spill over", "Decentralized storage", "Calculating weight in the wrong way", "Compatibility between the container material and the liquid waste", "Lack of dumping and disposal tools", and "Lack of a clear labels for liquid waste containers". After tracking improvements, the overall improvement rate rose to 60.2%. Copyright © 2017 Elsevier Ltd. All rights reserved.
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Risk and cost tradeoffs for remote retrieval of buried waste
Energy Technology Data Exchange (ETDEWEB)
Hyde, R.A.; Grienbenow, B.E.; Nickelson, D.F.
1994-12-31
The Buried Waste Integrated Demonstration is supporting the development, demonstration, testing, and evaluation of a suite of technologies that, when integrated with commercially available technologies, form a comprehensive system for the remediation of radioactive and hazardous buried waste. As a part of the program`s technology development, remote retrieval equipment is being developed and tested for the remediation of buried waste. During remedial planning, several factors are considered when choosing remote versus manual retrieval systems. Time that workers are exposed to radioactivity, chemicals, air particulate, and industrial hazards is one consideration. The generation of secondary waste is also a consideration because it amounts to more waste to treat and some wastes may require special handling or treatment. Cost is also a big factor in determining whether remote or manual operations will be used. Other considerations include implementability, effectiveness, and the number of required personnel. This paper investigates each of these areas to show the risk and cost benefits and limitations for remote versus manual retrieval of buried waste.
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EXAMPLE OF A RISK-BASED DISPOSAL APPROVAL: SOLIDIFICATION OF HANFORD SITE TRANSURANIC (TRU) WASTE
International Nuclear Information System (INIS)
PRIGNANO AL
2007-01-01
The Hanford Site requested, and the U.S. Environmental Protection Agency (EPA) Region 10 approved, a Toxic Substances Control Act of 1976 (TSCA) risk-based disposal approval (RBDA) for solidifying approximately four cubic meters of waste from a specific area of one of the K East Basin: the North Loadout Pit (NLOP). The NLOP waste is a highly radioactive sludge that contained polychlorinated biphenyls (PCBs) regulated under TSCA. The prescribed disposal method for liquid PCB waste under TSCA regulations is either thermal treatment or decontamination. Due to the radioactive nature of the waste, however, neither thermal treatment nor decontamination was a viable option. As a result, the proposed treatment consisted of solidifying the material to comply with waste acceptance criteria at the Waste Isolation Pilot Plant (WPP) in Carlsbad, New Mexico, or possibly the Environmental Restoration Disposal Facility at the Hanford Site, depending on the resulting transuranic (TRU) content of the stabilized waste. The RBDA evaluated environmental risks associated with potential airborne PCBs. In addition, the RBDA made use of waste management controls already in place at the treatment unit. The treatment unit, the T Plant Complex, is a Resource Conservation and Recovery Act of 1976 (RCRA)-permitted facility used for storing and treating radioactive waste. The EPA found that the proposed activities did not pose an unreasonable risk to human health or the environment. Treatment took place from October 26,2005 to June 9,2006, and 332 208-liter (55-gallon) containers of solidified waste were produced. All treated drums assayed to date are TRU and will be disposed at WIPP
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Considering Risk Associated with the Realization of Waste Management Investment Plans in Cracow
Directory of Open Access Journals (Sweden)
Hajduga Gabriela
2017-01-01
Full Text Available To fulfill obligations to the European Union on waste management, the authorities of the city of Cracow, decided to build a waste incineration plant. Such investment involves considerable risks, not only financial but also social. The paper conducted a risk analysis based on the index net present value, identifies factors which are particularly exposed, and proposes solutions for reducing its level.
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Singh, Varsha; Khan, Azizuddin
2012-01-01
Surface-level differences in the reward and punishment variants, specifically greater long-term decision making in the punishment variant of the Iowa Gambling Task (IGT) observed in previous studies led to the present comparison of long-term decision making in the two IGT variants (n = 320, male = 160). It was contended that risk aversion triggered by a positive frame of the reward variant and risk seeking triggered by a negative frame of the punishment variant appears as long-term decision making in the two IGT variants. Apart from the frame of the variant as a within-subjects factor (variant type: reward and punishment), the order in which the frame was triggered (order type: reward-punishment or punishment-reward), and the four types of instructions that delineated motivation toward reward from that of punishment (reward, punishment, reward and punishment, and no-hint) were hypothesized to have an effect on foresighted decision making in the IGT. As expected, long-term decision making differed across the two IGT variants suggesting that the frame of the variant has an effect on long-term decision making in the IGT (p decision making in the two IGT variants (p decision making is sensitive to reward and punishment frame in an asymmetric manner, an observation that is aligned with the behavioral decision making framework. Benefits of integrating findings from behavioral studies in decision neuroscience are discussed, and a need to investigate cultural differences in the IGT studies is pointed out.
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An assessment methodology of environmental risks associated with radioactive waste management
International Nuclear Information System (INIS)
Goldberg, S.M.; Logan, S.E.; Berbano, M.C.
1977-01-01
One major environmental concern associated with the projected increase in nuclear power generation is the treatment and storage or disposal of radioactive wastes. The US Environmental Protection Agency (EPA), in collaboration with the University of New Mexico, has been developing a detailed assessment methodology of short- and long-term quantitative risks to the environment resulting from release of radionuclides during all phases of radioactive waste management operations. The paper describes a comprehensive model developed during 1976 for the public health and environmental impacts from the disposal of high-level and transuranic waste in geological formations. Parametric studies have been performed with this model for various geological disposal media and for waste in different forms. EPA has planned to utilize these parametric risk calculations to translate probabilities and consequences of risk occurrences into a cost-effectiveness perspective for decision-making purposes. This comprehensive model consisted of a release or fault-tree model, an environmental model and an economic model. Fault trees have been constructed to provide the relationships between various geophysical, meteorological and man-caused events which are potential mechanisms for release of radioactive material to the environment from waste repositories. The environmental model includes transport to and accumulations at various receptors in the biosphere, including a determination of pathways from environmental input concentrations to radiation dose to man. Finally, the economic results are used to compare and assess the various disposal concepts as a basis for formulating policy decisions. Implementation of this assessment methodology is possible for a whole range of radioactive and non-radioactive hazardous materials which require perpetual care. Further, the output will be used by EPA in the short term to develop general environmental standards applicable to any radioactive waste management
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An assessment methodology of environmental risks associated with radioactive waste management
International Nuclear Information System (INIS)
Goldberg, S.M.; Logan, S.E.; Brebano, M.C.
1977-01-01
One of the major environmental concerns associated with the projected increase in nuclear power generation is the treatment and storage or disposal of radioactive wastes. The U.S. Environmental Protection Agency (EPA) in collaboration with the University of New Mexico has been developing a detailed assessment methodology of both the short-term as well as long-term quantitative risks on the environment resulting from the release of radionuclides during all phases of radioactive waste management operations. This past year a comprehensive model has been developed for the public health and environmental impacts from the disposal of high-level and transuranic waste in geological formations. Parametric studies have been performed with this model for various geological disposal media and for waste in different forms. EPA has planned to utilize these parametric risk calculations to translate probabilities and consequences of risk occurrences into a cost-effectiveness perspective for decision-making purposes. This comprehensive model has consisted of a release or fault tree model, an environmental model, and an economic model. Fault trees have been constructed to provide the relationships between various geophysical, meteorological, and man-caused events which are potential mechanisms for release of radioactive material to the environment from waste repositories. The environmental model includes the transport to and accumulations at various receptors in the biosphere, including a determination of pathways from environmental input concentrations to radiation dose to man. Finally, the economic results are used to compare and assess the various disposal concepts as a basis for formulating policy decisions. Implementation of this assessment methodology is possible for a whole range of both radioactive as well as non-radioactive hazardous materials which require perpetual care. Further, the output will be used by EPA in the short-term to develop general environmental standards
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ALLOCATING VENDOR RISKS IN THE HANFORD WASTE CLEANUP
International Nuclear Information System (INIS)
Keisler, Jeff M.; Buehring, William A.; McLaughlin, Peter D.; Robershotte, Mark A.; Whitfield, Ronald G.
2004-01-01
Organizations may view outsourcing as a way to eliminate risk. This application uses a decision analytic approach to determine which risks can be shared or shifted to vendors and which ones should be borne by the buyer. In this case, we found that allocating risks incorrectly could increase costs dramatically. This approach was used to develop the Request for Proposals (RFP) for the U.S. Department of Energy's (DOE's) privatization initiative for the Hanford Tank Waste Remediation System (TWRS). We describe this application and/SUMmarize technical and organizational lessons learned in the years following. The model used an assessment protocol to predict how vendors would react to proposed risk allocations in terms of their actions and their pricing
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Risk factors for episodes of enteric disease in cattle wastes handlers in Tanzania
DEFF Research Database (Denmark)
Madoshi, B; Lupindu, A. M.; Mtambo, MMA
2017-01-01
of handlers who were aware of risks of acquiring enteric episodes in animal waste handlers was low (43.6 %. There was limited awareness of government guideline on handling such wastes (3.2%) and washing hands without soap was found to be the most common health measures taken after handling animal wastes (70...
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LeMoult, Joelle; Colich, Natalie L; Sherdell, Lindsey; Hamilton, J Paul; Gotlib, Ian H
2015-09-01
Adolescence is characterized by an increase in risk-taking and reward-seeking behaviors. In other populations, increased risk taking has been associated with tighter coupling between cortisol production and ventral striatum (VS) activation during reward anticipation; this relation has not yet been examined, however, as a function of adolescent development. This study examined the influence of pubertal development on the association between diurnal cortisol production and VS activity during reward anticipation. Pre- and post-menarcheal girls collected diurnal cortisol and completed an functional magnetic resonance imaging-based monetary incentive delay task, from which we extracted estimates of VS activity during the anticipation of reward, anticipation of loss and anticipation of non-incentive neutral trials. Post-menarcheal girls showed greater coupling between the cortisol awakening response and VS activation during anticipation of reward and loss than did their pre-menarcheal counterparts. Post-menarcheal girls did not differ from pre-menarcheal girls in their cortisol-VS coupling during anticipation of neutral trials, suggesting that puberty-related changes in cortisol-VS coupling are specific to affective stimuli. Interestingly, behavioral responses during the task indicate that post-menarcheal girls are faster to engage with affective stimuli than are pre-menarcheal girls. Thus, post-menarcheal girls exhibit neurobiological and behavioral patterns that have been associated with risk taking and that may underlie the dramatic increase in risk-taking behavior documented during adolescence. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.
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Monetary reward speeds up voluntary saccades.
Chen, Lewis L; Chen, Y Mark; Zhou, Wu; Mustain, William D
2014-01-01
Past studies have shown that reward contingency is critical for sensorimotor learning, and reward expectation speeds up saccades in animals. Whether monetary reward speeds up saccades in human remains unknown. Here we addressed this issue by employing a conditional saccade task, in which human subjects performed a series of non-reflexive, visually-guided horizontal saccades. The subjects were (or were not) financially compensated for making a saccade in response to a centrally-displayed visual congruent (or incongruent) stimulus. Reward modulation of saccadic velocities was quantified independently of the amplitude-velocity coupling. We found that reward expectation significantly sped up voluntary saccades up to 30°/s, and the reward modulation was consistent across tests. These findings suggest that monetary reward speeds up saccades in human in a fashion analogous to how juice reward sped up saccades in monkeys. We further noticed that the idiosyncratic nasal-temporal velocity asymmetry was highly consistent regardless of test order, and its magnitude was not correlated with the magnitude of reward modulation. This suggests that reward modulation and the intrinsic velocity asymmetry may be governed by separate mechanisms that regulate saccade generation.
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Association of Marijuana Use With Blunted Nucleus Accumbens Response to Reward Anticipation.
Martz, Meghan E; Trucco, Elisa M; Cope, Lora M; Hardee, Jillian E; Jester, Jennifer M; Zucker, Robert A; Heitzeg, Mary M
2016-08-01
Marijuana use may alter ventral striatal response to reward, which might heighten susceptibility to substance use disorder. Longitudinal research is needed to determine the effects of marijuana use on neural function involved in reward response. To determine whether marijuana use among young adults prospectively affects nucleus accumbens (NAcc) activation during reward anticipation. One hundred eight young adults were recruited from the Michigan Longitudinal Study, an ongoing study of youth at high risk for substance use disorder and a contrast sample of control families. Participants underwent 3 consecutive functional magnetic resonance imaging scans at approximate ages of 20 (time 1), 22 (time 2), and 24 (time 3) years. Self-report data on marijuana and other drug use occasions were collected annually since age 11 years. Cross-lagged models were used to test the association of marijuana use with neural response in the NAcc to reward anticipation during a monetary incentive delay task controlling for sex, age, other substance use, and family history of substance use disorder. Of 108 participants, 39 (36.1%) were female and mean (SD) age at baseline was 20.1 (1.4) years. Greater marijuana use was associated with later blunted activation in the NAcc during reward anticipation (time 1 to time 2: β = -0.26, P = .04; time 2 to time 3: β = -0.25, P = .01). When the cross-lagged model was tested with the inclusion of previous and concurrent cigarette use, the effect of marijuana use from time 2 to time 3 remained significant (β = -0.29; P = .005) and the effect of cigarette use was nonsignificant. The findings of this study indicate that marijuana use is associated with decreased neural response in the NAcc during the anticipation of nondrug rewards. Over time, marijuana use may alter anticipatory reward processing in the NAcc, which may increase the risk for continued drug use and later addiction.
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Energy Technology Data Exchange (ETDEWEB)
Eriksson, Leif G. [GRAM, Inc., Albuquerque, NM (United States)
1999-12-01
The Waste Isolation Pilot Plant (WIPP) deep geological defense-generated transuranic radioactive waste (TRUW) repository in the United States was certified on the 13 of May 1998 and opened on the 26 of March 1999. Two sets of safety/performance assessment calculations supporting the certification of the WIPP TRUW repository show that the maximum annual individual committed effective dose will be 32 times lower than the regulatory limit and that the cumulative amount of radionuclide releases will be at least 10 times, more likely at least 20 times, lower than the regulatory limits. Yet, perceptions remain among the public that the WIPP TRUW repository imposes an unacceptable risk.
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International Nuclear Information System (INIS)
Eriksson, Leif G.
1999-01-01
The Waste Isolation Pilot Plant (WIPP) deep geological defense-generated transuranic radioactive waste (TRUW) repository in the United States was certified on the 13 of May 1998 and opened on the 26 of March 1999. Two sets of safety/performance assessment calculations supporting the certification of the WIPP TRUW repository show that the maximum annual individual committed effective dose will be 32 times lower than the regulatory limit and that the cumulative amount of radionuclide releases will be at least 10 times, more likely at least 20 times, lower than the regulatory limits. Yet, perceptions remain among the public that the WIPP TRUW repository imposes an unacceptable risk
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International Nuclear Information System (INIS)
Daling, P.M.; Rhoads, R.E.; Van Luick, A.E.; Fecht, B.A.; Nilson, S.A.; Sevigny, N.L.; Armstrong, G.R.; Hill, D.H.; Rowe, M.; Stern, E.
1992-01-01
This document presents preliminary information on the radiological and nonradiological risks in the nuclear waste management system. The objective of the study was to (1) review the literature containing information on risks in the nuclear waste management system and (2) use this information to develop preliminary estimates of the potential magnitude of these risks. Information was collected on a broad range of risk categories to assist the US Department of Energy (DOE) in communicating information about the risks in the waste management systems. The study examined all of the portions of the nuclear waste management system currently expected to be developed by the DOE. The scope of this document includes the potential repository, the integral MRS facility, and the transportation system that supports the potential repository and the MRS facility. Relevant literature was reviewed for several potential repository sites and geologic media. A wide range of ''risk categories'' are addressed in this report: (1) public and occupational risks from accidents that could release radiological materials, (2) public and occupational radiation exposure resulting from routine operations, (3) public and occupational risks from accidents involving hazards other than radioactive materials, and (4) public and occupational risks from exposure to nonradioactive hazardous materials during routine operations. The report is intended to provide a broad spectrum of risk-related information about the waste management system. This information is intended to be helpful for planning future studies
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Directory of Open Access Journals (Sweden)
Carmen N. Lukie
2014-07-01
Full Text Available Children and adolescents learn to regulate their behavior by utilizing feedback from the environment but exactly how this ability develops remains unclear. To investigate this question, we recorded the event-related brain potential (ERP from children (8–13 years, adolescents (14–17 years and young adults (18–23 years while they navigated a “virtual maze” in pursuit of monetary rewards. The amplitude of the reward positivity, an ERP component elicited by feedback stimuli, was evaluated for each age group. A current theory suggests the reward positivity is produced by the impact of reinforcement learning signals carried by the midbrain dopamine system on anterior cingulate cortex, which utilizes the signals to learn and execute extended behaviors. We found that the three groups produced a reward positivity of comparable size despite relatively longer ERP component latencies for the children, suggesting that the reward processing system reaches maturity early in development. We propose that early development of the midbrain dopamine system facilitates the development of extended goal-directed behaviors in anterior cingulate cortex.
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Risk perception of various technical options in the field of radioactive waste management
International Nuclear Information System (INIS)
Cameron, F.X.
1996-01-01
The author's group had a wide ranging discussion of risk and, at the very end of the discussion got to the question that was posed to them, which is that of risk perception of various technical options in the field of radioactive waste management. Some of the points that were made in this discussion is a reality that the group, as decision-makers, have to deal with, and it has to be treated as a reality. Secondly, the scientist looks at risk from the classic definition of ''probability times consequences'', but the public only looks at the consequences side of the equation, and too often the probability of something happening is treated as a probability of one that it will actually happen. A third problem that was identified in this area is that often the efforts to make the disposal of waste safer may contribute, in the public mind, to the fact that the risk is even more hazardous. And the last problem is that people do not trust what a decision maker is saying when he talks about the fact that there is little probability of something happening. The group then went on to a discussion of how he should try to treat risk perception. One point that was made is that voluntary acceptance of a risk is important. A second point that was made on how to deal with risk perception problems is that the group could try to put the risk of radioactive waste disposal in the perspective of other risks to society, from the chemical industry for instance. The group also talked about the possibility of putting the benefits in perspective for people. Another point was that the group should have different communications strategies for different audiences. But, the more the public is involved in the decision making process, the more comfortable they are going to be with the risk, and the more consistent the perception of risk may be with the scientific definition thereof. In terms of new technologies, new innovations on the generation and management of waste, although these may actually
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Blum, Kenneth; Gardner, Eliot; Oscar-Berman, Marlene; Gold, Mark
2012-01-01
In an attempt to resolve controversy regarding the causal contributions of mesolimbic dopamine (DA) systems to reward, we evaluate the three main competing explanatory categories: "liking,"learning," and "wanting" [1]. That is, DA may mediate (a) the hedonic impact of reward (liking), (b) learned predictions about rewarding effects (learning), or (c) the pursuit of rewards by attributing incentive salience to reward-related stimuli (wanting). We evaluate these hypotheses, especially as they relate to the Reward Deficiency Syndrome (RDS), and we find that the incentive salience or "wanting" hypothesis of DA function is supported by a majority of the evidence. Neuroimaging studies have shown that drugs of abuse, palatable foods, and anticipated behaviors such as sex and gaming affect brain regions involving reward circuitry, and may not be unidirectional. Drugs of abuse enhance DA signaling and sensitize mesolimbic mechanisms that evolved to attribute incentive salience to rewards. Addictive drugs have in common that they are voluntarily selfadministered, they enhance (directly or indirectly) dopaminergic synaptic function in the nucleus accumbens (NAC), and they stimulate the functioning of brain reward circuitry (producing the "high" that drug users seek). Although originally believed simply to encode the set point of hedonic tone, these circuits now are believed to be functionally more complex, also encoding attention, reward expectancy, disconfirmation of reward expectancy, and incentive motivation. Elevated stress levels, together with polymorphisms of dopaminergic genes and other neurotransmitter genetic variants, may have a cumulative effect on vulnerability to addiction. The RDS model of etiology holds very well for a variety of chemical and behavioral addictions.
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Random reward priming is task-contingent
DEFF Research Database (Denmark)
Ásgeirsson, Árni Gunnar; Kristjánsson, Árni
2014-01-01
Consistent financial reward of particular features influences the allocation of visual attention in many ways. More surprising are 1-trial reward priming effects on attention where reward schedules are random and reward on one trial influences attentional allocation on the next. Those findings...
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International Nuclear Information System (INIS)
Breshears, D.D.; Martens, S.N.; Nyhan, J.W.; Springer, E.P.; Wilcox, B.P.
1994-01-01
Numerous regulations govern the disposal of low-level radioactive and hazardous waste by burial in shallow pits. The overall goal of these regulations is to reduce the risk to humans and components of the ecosystem for 500 to 1 000 years. Erosional loss of the soil profile covering waste and contamination of groundwater by leachate are two pathways that influence human and ecological risks. Screening calculations for a waste site in a pinyon-juniper woodland at Los Alamos National Laboratory predict the entire 2 m cover of a waste site could be lost by erosion in less than 500 years. In contrast, less than 0.001% of the waste would reach groundwater by leachate. Predicted erosion rates depend highly on plant cover. The boundary between ponderosa pine forest and pinyon-juniper woodland has shifted more than 1 km in less than 50 years in the Los Alamos region and additional boundary shifts have been hypothesized in conjunction with global warming. High erosion rates (> 0.2 cm per year) have been measured in these transition zones. In concert, these results suggest that risk associated with erosional loss of the waste site cover may greatly exceed risks associated with groundwater contamination in semiarid ecosystems
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Ross, M; Lanyon, L J; Viswanathan, J; Manoach, D S; Barton, J J S
2011-11-24
Monkey studies report greater activity in the lateral intraparietal area and more efficient saccades when targets coincide with the location of prior reward cues, even when cue location does not indicate which responses will be rewarded. This suggests that reward can modulate spatial attention and visual selection independent of the "action value" of the motor response. Our goal was first to determine whether reward modulated visual selection similarly in humans, and next, to discover whether reward and penalty differed in effect, if cue effects were greater for cognitively demanding antisaccades, and if financial consequences that were contingent on stimulus location had spatially selective effects. We found that motivational cues reduced all latencies, more for reward than penalty. There was an "inhibition-of-return"-like effect at the location of the cue, but unlike the results in monkeys, cue valence did not modify this effect in prosaccades, and the inhibition-of-return effect was slightly increased rather than decreased in antisaccades. When financial consequences were contingent on target location, locations without reward or penalty consequences lost the benefits seen in noncontingent trials, whereas locations with consequences maintained their gains. We conclude that unlike monkeys, humans show reward effects not on visual selection but on the value of actions. The human saccadic system has both the capacity to enhance responses to multiple locations simultaneously, and the flexibility to focus motivational enhancement only on locations with financial consequences. Reward is more effective than penalty, and both interact with the additional attentional demands of the antisaccade task. Copyright © 2011 IBRO. Published by Elsevier Ltd. All rights reserved.
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Preliminary evidence for genetic overlap between body mass index and striatal reward response.
Lancaster, T M; Ihssen, I; Brindley, L M; Linden, D E
2018-01-10
The reward-processing network is implicated in the aetiology of obesity. Several lines of evidence suggest obesity-linked genetic risk loci (such as DRD2 and FTO) may influence individual variation in body mass index (BMI) through neuropsychological processes reflected in alterations in activation of the striatum during reward processing. However, no study has tested the broader hypotheses that (a) the relationship between BMI and reward-related brain activation (measured through the blood oxygenation-dependent (BOLD) signal) may be observed in a large population study and (b) the overall genetic architecture of these phenotypes overlap, an assumption critical for the progression of imaging genetic studies in obesity research. Using data from the Human Connectome Project (N = 1055 healthy, young individuals: average BMI = 26.4), we first establish a phenotypic relationship between BMI and ventral striatal (VS) BOLD during the processing of rewarding (monetary) stimuli (β = 0.44, P = 0.013), accounting for potential confounds. BMI and VS BOLD were both significantly influenced by additive genetic factors (H2r = 0.57; 0.12, respectively). Further decomposition of this variance suggested that the relationship was driven by shared genetic (ρ g = 0.47, P = 0.011), but not environmental (ρ E = -0.07, P = 0.29) factors. To validate the assumption of genetic pleiotropy between BMI and VS BOLD, we further show that polygenic risk for higher BMI is also associated with increased VS BOLD response to appetitive stimuli (calorically high food images), in an independent sample (N = 81; P FWE-ROI < 0.005). Together, these observations suggest that the genetic factors link risk to obesity to alterations within key nodes of the brain's reward circuity. These observations provide a basis for future work exploring the mechanistic role of genetic loci that confer risk for obesity using the imaging genetics approach.
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Adverse health effects of high-effort/low-reward conditions.
Siegrist, J
1996-01-01
In addition to the person-environment fit model (J. R. French, R. D. Caplan, & R. V. Harrison, 1982) and the demand-control model (R. A. Karasek & T. Theorell, 1990), a third theoretical concept is proposed to assess adverse health effects of stressful experience at work: the effort-reward imbalance model. The focus of this model is on reciprocity of exchange in occupational life where high-cost/low-gain conditions are considered particularly stressful. Variables measuring low reward in terms of low status control (e.g., lack of promotion prospects, job insecurity) in association with high extrinsic (e.g., work pressure) or intrinsic (personal coping pattern, e.g., high need for control) effort independently predict new cardiovascular events in a prospective study on blue-collar men. Furthermore, these variables partly explain prevalence of cardiovascular risk factors (hypertension, atherogenic lipids) in 2 independent studies. Studying adverse health effects of high-effort/low-reward conditions seems well justified, especially in view of recent developments of the labor market.
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Incremental effects of reward on creativity.
Eisenberger, R; Rhoades, L
2001-10-01
The authors examined 2 ways reward might increase creativity. First, reward contingent on creativity might increase extrinsic motivation. Studies 1 and 2 found that repeatedly giving preadolescent students reward for creative performance in 1 task increased their creativity in subsequent tasks. Study 3 reported that reward promised for creativity increased college students' creative task performance. Second, expected reward for high performance might increase creativity by enhancing perceived self-determination and, therefore, intrinsic task interest. Study 4 found that employees' intrinsic job interest mediated a positive relationship between expected reward for high performance and creative suggestions offered at work. Study 5 found that employees' perceived self-determination mediated a positive relationship between expected reward for high performance and the creativity of anonymous suggestions for helping the organization.
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Byrne, Jamie E M; Murray, Greg
2017-01-01
A range of evidence suggests that human reward functioning is partly driven by the endogenous circadian system, generating 24-hour rhythms in behavioural measures of reward activation. Reward functioning is multifaceted but literature to date is largely limited to measures of self-reported positive mood states. The aim of this study was to advance the field by testing for hypothesised diurnal variation in previously unexplored components of psychological reward: 'wanting', liking, and learning using subjective and behavioural measures. Risky decision making (automatic Balloon Analogue Risk Task), affective responsivity to positive images (International Affective Pictures System), uncued self-reported discrete emotions, and learning-contingent reward (Iowa Gambling Task) were measured at 10.00 hours, 14.00 hours, and 19.00 hours in a counterbalanced repeated measures design with 50 healthy male participants (aged 18-30). As hypothesised, risky decision making (unconscious 'wanting') and ratings of arousal towards positive images (conscious wanting) exhibited a diurnal waveform with indices highest at 14.00 hours. No diurnal rhythm was observed for liking (pleasure ratings to positive images, discrete uncued positive emotions) or in a learning-contingent reward task. Findings reaffirm that diurnal variation in human reward functioning is most pronounced in the motivational 'wanting' components of reward.
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Expected reward value and reward uncertainty have temporally dissociable effects on memory formation
Adcock, R; Clement, Nathaniel; Chiew, Kimberly; Dickerson, Kathryn; Stanek, Jessica
2018-01-01
Anticipating rewards has been shown to enhance memory formation. While substantial evidence implicates dopamine in this behavioral effect, the precise mechanisms remain ambiguous. Because dopamine nuclei show two distinct physiological signatures of reward prediction, we hypothesized two dissociable effects on memory formation. These two signatures are a phasic dopamine response immediately following a reward cue that encodes its expected value, and a sustained, ramping dopamine response that...
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Morie, K P; De Sanctis, P; Foxe, J J
2014-07-25
Task execution almost always occurs in the context of reward-seeking or punishment-avoiding behavior. As such, ongoing task-monitoring systems are influenced by reward anticipation systems. In turn, when a task has been executed either successfully or unsuccessfully, future iterations of that task will be re-titrated on the basis of the task outcome. Here, we examined the neural underpinnings of the task-monitoring and reward-evaluation systems to better understand how they govern reward-seeking behavior. Twenty-three healthy adult participants performed a task where they accrued points that equated to real world value (gift cards) by responding as rapidly as possible within an allotted timeframe, while success rate was titrated online by changing the duration of the timeframe dependent on participant performance. Informative cues initiated each trial, indicating the probability of potential reward or loss (four levels from very low to very high). We manipulated feedback by first informing participants of task success/failure, after which a second feedback signal indicated actual magnitude of reward/loss. High-density electroencephalography (EEG) recordings allowed for examination of event-related potentials (ERPs) to the informative cues and in turn, to both feedback signals. Distinct ERP components associated with reward cues, task-preparatory and task-monitoring processes, and reward feedback processes were identified. Unsurprisingly, participants displayed increased ERP amplitudes associated with task-preparatory processes following cues that predicted higher chances of reward. They also rapidly updated reward and loss prediction information dependent on task performance after the first feedback signal. Finally, upon reward receipt, initial reward probability was no longer taken into account. Rather, ERP measures suggested that only the magnitude of actual reward or loss was now processed. Reward and task-monitoring processes are clearly dissociable, but
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Hanssen, E.M.E.
2015-01-01
Deficits in motivational behavior and psychotic symptoms often observed in schizophrenia (SZ) may be driven by dysfunctional reward processing (RP). RP can be divided in two different stages; reward anticipation and reward consumption. Aberrant processing during reward anticipation seems to be
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Urošević, Snežana; Collins, Paul; Muetzel, Ryan; Lim, Kelvin; Luciana, Monica
2012-01-01
Adolescence is a period of radical normative changes and increased risk for substance use, mood disorders, and physical injury. Researchers have proposed that increases in reward sensitivity, i.e., sensitivity of the behavioral approach system (BAS), and/or increases in reactivity to all emotional stimuli (i.e., reward and threat sensitivities) lead to these phenomena. The present study is the first longitudinal investigation of changes in reward (i.e., BAS) sensitivity in 9 to 23-year-olds a...
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Social reward shapes attentional biases.
Anderson, Brian A
2016-01-01
Paying attention to stimuli that predict a reward outcome is important for an organism to survive and thrive. When visual stimuli are associated with tangible, extrinsic rewards such as money or food, these stimuli acquire high attentional priority and come to automatically capture attention. In humans and other primates, however, many behaviors are not motivated directly by such extrinsic rewards, but rather by the social feedback that results from performing those behaviors. In the present study, I examine whether positive social feedback can similarly influence attentional bias. The results show that stimuli previously associated with a high probability of positive social feedback elicit value-driven attentional capture, much like stimuli associated with extrinsic rewards. Unlike with extrinsic rewards, however, such stimuli also influence task-specific motivation. My findings offer a potential mechanism by which social reward shapes the information that we prioritize when perceiving the world around us.
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Environmental risk assessment of the use of different organic wastes as soil amendments
Alvarenga, Paula; Palma, Patrícia; Mourinha, Clarisse; Farto, Márcia; Cunha-Queda, Ana Cristina; Natal-da-Luz, Tiago; Sousa, José Paulo
2013-04-01
The use of organic wastes in agriculture is considered a way of maintaining or restoring the quality of soils, enlarging the slow cycling soil organic carbon pool. However, a wide variety of undesired substances, such as potentially trace elements and organic contaminants, can have adverse effects on the environment. That fact was highlighted by the Proposal for a Soil Framework Directive, which recognized that "soil degradation or soil improvements have a major impact on other areas, (…) such as surface waters and groundwater, human health, climate change, protection of nature and biodiversity, and food safety". Taking that into account, the research project "ResOrgRisk" aims to assess the environmental risk involved in the use of different organic wastes as soil amendments, evidencing their benefits and constraints, and defining the most suitable tests to reach such assessment. The organic wastes selected for this purpose were: sewage sludge, limed, not limed, and co-composted with agricultural wastes, agro-industrial sludge, mixed municipal solid waste compost, compost produced from organic farming residues, and pig slurry digestate. Whereas threshold values for heavy metals in sludge used for agriculture have been set by the European Commission, actually there is no definitive European legislation for organic contaminants. Guide values for some organic contaminants (e.g. polychlorinated biphenyls - PCBs, and polycyclic aromatic hydrocarbons - PAHs) have been adopted at national level by many European countries, such as Portugal. These values should be taken into account when assessing the risk involved in the use of organic wastes as soil amendments. However, chemical analysis of organic waste often gives scarce information because it does not include possible interactions between chemicals. Furthermore, an exhaustive identification and quantification of all substances is impractical. In this study, ecotoxicological tests (comprising solid and aquatic phases
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Adolescence and Reward: Making Sense of Neural and Behavioral Changes Amid the Chaos.
Walker, Deena M; Bell, Margaret R; Flores, Cecilia; Gulley, Joshua M; Willing, Jari; Paul, Matthew J
2017-11-08
Adolescence is a time of significant neural and behavioral change with remarkable development in social, emotional, and cognitive skills. It is also a time of increased exploration and risk-taking (e.g., drug use). Many of these changes are thought to be the result of increased reward-value coupled with an underdeveloped inhibitory control, and thus a hypersensitivity to reward. Perturbations during adolescence can alter the developmental trajectory of the brain, resulting in long-term alterations in reward-associated behaviors. This review highlights recent developments in our understanding of how neural circuits, pubertal hormones, and environmental factors contribute to adolescent-typical reward-associated behaviors with a particular focus on sex differences, the medial prefrontal cortex, social reward, social isolation, and drug use. We then introduce a new approach that makes use of natural adaptations of seasonally breeding species to investigate the role of pubertal hormones in adolescent development. This research has only begun to parse out contributions of the many neural, endocrine, and environmental changes to the heightened reward sensitivity and increased vulnerability to mental health disorders that characterize this life stage. Copyright © 2017 the authors 0270-6474/17/3710855-12$15.00/0.
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Tank Waste Remediation System Characterization Project Programmatic Risk Management Plan
International Nuclear Information System (INIS)
Baide, D.G.; Webster, T.L.
1995-12-01
The TWRS Characterization Project has developed a process and plan in order to identify, manage and control the risks associated with tank waste characterization activities. The result of implementing this process is a defined list of programmatic risks (i.e. a risk management list) that are used by the Project as management tool. This concept of risk management process is a commonly used systems engineering approach which is being applied to all TWRS program and project elements. The Characterization Project risk management plan and list are subset of the overall TWRS risk management plan and list
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Murayama, Kou; Kitagami, Shinji
2014-02-01
Recent research suggests that extrinsic rewards promote memory consolidation through dopaminergic modulation processes. However, no conclusive behavioral evidence exists given that the influence of extrinsic reward on attention and motivation during encoding and consolidation processes are inherently confounded. The present study provides behavioral evidence that extrinsic rewards (i.e., monetary incentives) enhance human memory consolidation independently of attention and motivation. Participants saw neutral pictures, followed by a reward or control cue in an unrelated context. Our results (and a direct replication study) demonstrated that the reward cue predicted a retrograde enhancement of memory for the preceding neutral pictures. This retrograde effect was observed only after a delay, not immediately upon testing. An additional experiment showed that emotional arousal or unconscious resource mobilization cannot explain the retrograde enhancement effect. These results provide support for the notion that the dopaminergic memory consolidation effect can result from extrinsic reward.
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Human health and ecological risks from environmental restoration and waste management activities
International Nuclear Information System (INIS)
Pehlman, P.A.; Wollert, D.A.; Phillippi, R.H.
1994-01-01
This paper summarizes the methodologies for estimating human health and ecological risks resulting from Environmental Restoration and Waste Management activities across the Department of Energy (DOE) complex. DOE is currently assessing these activities as part of the Environmental Restoration and Waste Management Programmatic Environmental Impact Statement (EM-PEIS)
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Discrete-time rewards model-checked
Larsen, K.G.; Andova, S.; Niebert, Peter; Hermanns, H.; Katoen, Joost P.
2003-01-01
This paper presents a model-checking approach for analyzing discrete-time Markov reward models. For this purpose, the temporal logic probabilistic CTL is extended with reward constraints. This allows to formulate complex measures – involving expected as well as accumulated rewards – in a precise and
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Risks from proposed nuclear waste dump unacceptable
International Nuclear Information System (INIS)
Veevers, John
1999-01-01
The author has a critical look at the proposal by Pangea Resources Australia Pty Ltd (PARPL) to establish in Australia a permanent underground disposal site for radioactive waste from around the world. In his opinion, the inevitable risk in the proposal stems from the magnitudes: 250,000 tonnes of enormously dangerous RADwaste in the northern hemisphere 20,000 km from its destined dump in Australia, where it must remain intact for at least 10,000 years. These magnitudes - of tonnage, lethality, distance of transport, and time - entail great inherent risk. He also argue that the job of the Australian scientists is to apply due diligence to PARPL proposal
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Risks to farm animals from pathogens in composted catering waste containing meat.
Gale, P
2004-07-17
Uncooked meat may contain animal pathogens, including bovine spongiform encephalopathy, foot-and-mouth disease virus, African swine fever virus and classical swine fever virus, and to prevent outbreaks of these diseases in farm animals, the disposal of meat from catering waste is controlled under the Animal By-Products Regulations. This paper estimates the risks to farm animals of grazing land on to which compost, produced by the composting of catering waste containing meat, has been applied. The factors controlling the level of risk are the separation of the meat at source, the efficiency of the composting process, and the decay and dilution of the pathogens in soil. The net pathogen destruction by the composting process is determined largely by the degree of bypass, and to accommodate the possibility of large joints or even whole carcases being discarded uncooked to catering waste, a time/temperature condition of 60 degrees C for two days is recommended. Where data are lacking, worst-case assumptions have been applied. According to the model, classical swine fever virus constitutes the highest risk, but the assessment shows that a two-barrier composting approach, together with a two-month grazing ban, reduces the risk to one infection in pigs every 190 years in England and Wales. This work defined the operational conditions for the composting of catering waste as set out in the Animal By-Products Regulations 2003 (SI 1482).
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Anderson, Brian A
2017-03-01
Through associative reward learning, arbitrary cues acquire the ability to automatically capture visual attention. Previous studies have examined the neural correlates of value-driven attentional orienting, revealing elevated activity within a network of brain regions encompassing the visual corticostriatal loop [caudate tail, lateral occipital complex (LOC) and early visual cortex] and intraparietal sulcus (IPS). Such attentional priority signals raise a broader question concerning how visual signals are combined with reward signals during learning to create a representation that is sensitive to the confluence of the two. This study examines reward signals during the cued reward training phase commonly used to generate value-driven attentional biases. High, compared with low, reward feedback preferentially activated the value-driven attention network, in addition to regions typically implicated in reward processing. Further examination of these reward signals within the visual system revealed information about the identity of the preceding cue in the caudate tail and LOC, and information about the location of the preceding cue in IPS, while early visual cortex represented both location and identity. The results reveal teaching signals within the value-driven attention network during associative reward learning, and further suggest functional specialization within different regions of this network during the acquisition of an integrated representation of stimulus value. © The Author (2016). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.
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2012-01-01
Background Research into neural mechanisms of drug abuse risk has focused on the role of dysfunction in neural circuits for reward. In contrast, few studies have examined the role of dysfunction in neural circuits of threat in mediating drug abuse risk. Although typically regarded as a risk factor for mood and anxiety disorders, threat-related amygdala reactivity may serve as a protective factor against substance use disorders, particularly in individuals with exaggerated responsiveness to reward. Findings We used well-established neuroimaging paradigms to probe threat-related amygdala and reward-related ventral striatum reactivity in a sample of 200 young adult students from the ongoing Duke Neurogenetics Study. Recent life stress and problem drinking were assessed using self-report. We found a significant three-way interaction between threat-related amygdala reactivity, reward-related ventral striatum reactivity, and recent stress, wherein individuals with higher reward-related ventral striatum reactivity exhibit higher levels of problem drinking in the context of stress, but only if they also have lower threat-related amygdala reactivity. This three-way interaction predicted both contemporaneous problem drinking and problem drinking reported three-months later in a subset of participants. Conclusions These findings suggest complex interactions between stress and neural responsiveness to both threat and reward mediate problem drinking. Furthermore, they highlight a novel protective role for threat-related amygdala reactivity against drug use in individuals with high neural reactivity to reward. PMID:23151390
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Reward processing and mood-related symptoms: An RDoC and translational neuroscience perspective.
Nusslock, Robin; Alloy, Lauren B
2017-07-01
Two objectives of the NIMH Research Domain Criteria (RDoC) initiative are to identify (a) mechanisms that are common to multiple psychiatric disorders, and (b) mechanisms that are unique to specific psychiatric symptoms, and that reflect markers of differential risk for these symptoms. With respect to these objectives, a brain-behavior dimension that has received considerable attention and that is directly relevant to the Positive Valence Systems domain of the RDoC initiative involves reward processing. The present review paper first examines the relationship between reward processing and mood-related symptoms from an RDoC perspective. We then place this work in a larger context by examining the relationship between reward processing abnormalities and psychiatric symptoms defined broadly, including mood-related symptoms, schizophrenia, and addiction. Our review suggests that reward hyposensitivity relates to a subtype of anhedonia characterized by motivational deficits in unipolar depression, and reward hypersensitivity relates to a cluster of hypo/manic symptoms characterized by excessive approach motivation in the context of bipolar disorder. Integrating this perspective with research on reward processing abnormalities in schizophrenia and addiction, we further argue that the principles of equifinality and multifinality may be preferable to a transdiagnostic perspective for conceptualizing the relationship between reward processing and psychiatric symptoms defined broadly. We propose that vulnerability to either motivational anhedonia or approach-related hypo/manic symptoms involve extreme and opposite profiles of reward processing. We further propose that an equifinality and multifinality perspective may serve as a useful framework for future research on reward processing abnormalities and psychiatric symptoms. Copyright © 2017. Published by Elsevier B.V.
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Kim, Sang Hee; Yoon, HeungSik; Kim, Hackjin; Hamann, Stephan
2015-09-01
In this functional neuroimaging study, we investigated neural activations during the process of learning to gain monetary rewards and to avoid monetary loss, and how these activations are modulated by individual differences in reward and punishment sensitivity. Healthy young volunteers performed a reinforcement learning task where they chose one of two fractal stimuli associated with monetary gain (reward trials) or avoidance of monetary loss (avoidance trials). Trait sensitivity to reward and punishment was assessed using the behavioral inhibition/activation scales (BIS/BAS). Functional neuroimaging results showed activation of the striatum during the anticipation and reception periods of reward trials. During avoidance trials, activation of the dorsal striatum and prefrontal regions was found. As expected, individual differences in reward sensitivity were positively associated with activation in the left and right ventral striatum during reward reception. Individual differences in sensitivity to punishment were negatively associated with activation in the left dorsal striatum during avoidance anticipation and also with activation in the right lateral orbitofrontal cortex during receiving monetary loss. These results suggest that learning to attain reward and learning to avoid loss are dependent on separable sets of neural regions whose activity is modulated by trait sensitivity to reward or punishment. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.
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International Nuclear Information System (INIS)
1992-09-01
The Lawrence Livermore National Laboratory (LLNL) operates three Hazardous Waste Management Facilities with 24 associated waste management units for the treatment and storage of hazardous and mixed wastes. These wastes are generated by research programs and support operations. The storage and treatment units are presently operated under interim status in accordance with the requirements of the US Envirorunental Protection Agency (US EPA) and the Department of Toxic Substances Control (DTSC), a division of the California Envirorunental Protection Agency (Cal/EPA). As required by the California Hazardous Waste Control Act and the Resource Conservation and Recovery Act (RCRA), LLNL ha s applied for a Part B permit to continue operating the storage and waste treatment facilities. As part of this permitting process, LLNL is required to conduct a health risk assessment (HRA) to examine the potential health impacts to the surrounding community from continued storage and treatment of hazardous and mixed wastes. analysis document presents the results of this risk assessment. An analysis of maximum credible chemical accidents is also included in Section 7.0. This HRA was prepared in accordance with procedures set forth by the California Air Pollution Control Officers Association (CAPCOA) ''Air Toxics Assessment Manual,'' CAPCOA guidelines for preparing risk assessments under the Air Toxic ''Hot Spots'' Act (AB 2588) and requirements of the US EPA. By following these procedures, this risk assessment presents a conservative analysis of a hypothetical Maximally Exposed Individual (MEI) using many worst-case assumptions that will not apply to an actual individual. As such, the risk estimates presented should be regarded as a worst-case estimate of any actual risk that may be present
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Acute subjective response to alcohol as a function of reward and punishment sensitivity.
Morris, David H; Treloar, Hayley; Tsai, Chia-Lin; McCarty, Kayleigh N; McCarthy, Denis M
2016-09-01
Individual differences in subjective response to alcohol play a crucial role in the development of heavy drinking and related problems. In light of this, a growing focus of research has been identifying factors that contribute to differences in response. The aim of the present study was to determine whether individual differences in the subjective experience of rewarding and aversive effects of alcohol are a specific manifestation of general differences in reward and punishment sensitivity. Eighty-nine participants (M age=22.4, SD=1.9; 47.2% women) consumed a moderate dose of alcohol, i.e., peak breath alcohol concentration (BrAC)≈0.080g%, and rated their level of stimulation and sedation at seven timepoints over the BrAC curve. Sensitivity to reward and punishment were assessed by a self-report questionnaire prior to consumption. Multilevel growth models showed that post-consumption changes in stimulation ratings varied as a function of participants' level of reward and punishment sensitivity. Drinkers more sensitive to reward reported feeling more stimulated shortly after drinking and exhibited an attenuated rate of decline in stimulation over the blood alcohol curve, relative to drinkers with less strong reward sensitivity. Reward sensitivity was not related to subjective ratings of sedation, and punishment sensitivity was not related to either stimulation or sedation ratings. Findings suggest that reward sensitivity may increase risk for alcohol misuse among young adult social drinkers by increasing their subjective feelings of stimulation while drinking. Copyright © 2016. Published by Elsevier Ltd.
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International Nuclear Information System (INIS)
Cheung, H.; Jackson, D.D.; Revelli, M.A.
1981-07-01
Waste form dissolution studies and preliminary performance analyses were carried out to contribute a part of the data needed for the selection of a waste form for the disposal of Savannah River Plant defense waste in a deep geologic repository. The first portion of this work provides descriptions of the chemical interactions between the waste form and the geologic environment. We reviewed critically the dissolution/leaching data for borosilicate glass and SYNROC. Both chemical kinetic and thermodynamic models were developed to describe the dissolution process of these candidate waste forms so as to establish a fundamental basis for interpretation of experimental data and to provide directions for future experiments. The complementary second portion of this work is an assessment of the impacts of alternate waste forms upon the consequences of disposal in various proposed geological media. Employing systems analysis methodology, we began to evaluate the performance of a generic waste form for the case of a high risk scenario for a bedded salt repository. Results of sensitivity analysis, uncertainty analyses, and sensitivity to uncertainty analysis are presented
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Waste transmutation with minimal fuel cycle long-term risk
Energy Technology Data Exchange (ETDEWEB)
Slessarev, I.; Salvatores, M.; Uematsu, M. [Direction des Reacteurs Nucleaires, Cadarache (France)
1995-10-01
Hybrid systems (source-driven subcritical reactors), are investigated at CEA, mainly from a conceptual point of view, in order to assess their potential to transmute radioactive wastes (mainly long-lived fission products, LLFP) and their potential to insure a minimal long-term radiological risk related both to the fuel inventory inside the system and to the full fuel cycle (mass flows, reprocessing transport, waste disposal). The physics of these systems has been explored and work is in progress both in the field of basic data and INC code validation, in the frame of international collaborations and in the field of conceptual design studies. The most interesting feature of subcritical source-driven system is related to the possibility to obtain an {open_quotes}excess{close_quotes} of neutrons per fission, which can be used to reduce the long-term radiological risk. A specific example will be discussed here.
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Learned reward association improves visual working memory.
Gong, Mengyuan; Li, Sheng
2014-04-01
Statistical regularities in the natural environment play a central role in adaptive behavior. Among other regularities, reward association is potentially the most prominent factor that influences our daily life. Recent studies have suggested that pre-established reward association yields strong influence on the spatial allocation of attention. Here we show that reward association can also improve visual working memory (VWM) performance when the reward-associated feature is task-irrelevant. We established the reward association during a visual search training session, and investigated the representation of reward-associated features in VWM by the application of a change detection task before and after the training. The results showed that the improvement in VWM was significantly greater for items in the color associated with high reward than for those in low reward-associated or nonrewarded colors. In particular, the results from control experiments demonstrate that the observed reward effect in VWM could not be sufficiently accounted for by attentional capture toward the high reward-associated item. This was further confirmed when the effect of attentional capture was minimized by presenting the items in the sample and test displays of the change detection task with the same color. The results showed significantly larger improvement in VWM performance when the items in a display were in the high reward-associated color than those in the low reward-associated or nonrewarded colors. Our findings suggest that, apart from inducing space-based attentional capture, the learned reward association could also facilitate the perceptual representation of high reward-associated items through feature-based attentional modulation.
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Reward signals, attempted suicide, and impulsivity in late-life depression.
Dombrovski, Alexandre Y; Szanto, Katalin; Clark, Luke; Reynolds, Charles F; Siegle, Greg J
2013-10-01
IMPORTANCE—Suicide can be viewed as an escape from unendurable punishment at the cost of any future rewards. Could faulty estimation of these outcomes predispose to suicidal behavior? In behavioral studies, many of those who have attempted suicide misestimate expected rewards on gambling and probabilistic learning tasks.OBJECTIVES—To describe the neural circuit abnormalities that underlie disadvantageous choices in people at risk for suicide and to relate these abnormalities to impulsivity, which is one of the components of vulnerability to suicide.DESIGN—Case-control functional magnetic resonance imaging study of reward learning using are inforcement learning model.SETTING—University hospital and outpatient clinic.PATIENTS—Fifty-three participants 60 years or older, including 15 depressed patients who had attempted suicide, 18 depressed patients who had never attempted suicide (depressed control subjects), and 20 psychiatrically healthy controls.MAIN OUTCOMES AND MEASURES—Components of the cortical blood oxygenation level–dependent response tracking expected and unpredicted rewards.RESULTS—Depressed elderly participants displayed 2 distinct disruptions of control over reward-guided behavior. First, impulsivity and a history of suicide attempts (particularly poorly planned ones) were associated with a weakened expected reward signal in the paralimbic cortex,which in turn predicted the behavioral insensitivity to contingency change. Second, depression was associated with disrupted corticostriatothalamic encoding of unpredicted rewards, which in turn predicted the behavioral over sensitivity to punishment. These results were robust to the effects of possible brain damage from suicide attempts, depressive severity, co-occurring substance use and anxiety disorders, antidepressant and anticholinergic exposure, lifetime exposure to electroconvulsive therapy, vascular illness, and incipient dementia.CONCLUSIONS AND RELEVANCE—Altered paralimbic reward
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BOLD responses in reward regions to hypothetical and imaginary monetary rewards
Miyapuram, K.P.; Tobler, P.N.; Gregorios-Pippas, L.; Schultz, W.
2012-01-01
Monetary rewards are uniquely human. Because money is easy to quantify and present visually, it is the reward of choice for most fMRI studies, even though it cannot be handed over to participants inside the scanner. A typical fMRI study requires hundreds of trials and thus small amounts of monetary
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Neural processing of calories in brain reward areas can be modulated by reward sensitivity
Directory of Open Access Journals (Sweden)
Inge eVan Rijn
2016-01-01
Full Text Available A food’s reward value is dependent on its caloric content. Furthermore, a food’s acute reward value also depends on hunger state. The drive to obtain rewards (reward sensitivity, however, differs between individuals. Here, we assessed the association between brain responses to calories in the mouth and trait reward sensitivity in different hunger states. Firstly, we assessed this in data from a functional neuroimaging study (van Rijn et al., 2015, in which participants (n=30 tasted simple solutions of a non-caloric sweetener with or without a non-sweet carbohydrate (maltodextrin during hunger and satiety. Secondly, we expanded these analyses to regular drinks by assessing the same relationship in data from a study in which soft drinks sweetened with either sucrose or a non-caloric sweetener were administered during hunger (n=18 (Griffioen-Roose et al., 2013. First, taste activation by the non-caloric solution/soft drink was subtracted from that by the caloric solution/soft drink to eliminate sweetness effects and retain activation induced by calories. Subsequently, this difference in taste activation was correlated with reward sensitivity as measured with the BAS drive subscale of the Behavioral Activation System (BAS questionnaire.When participants were hungry and tasted calories from the simple solution, brain activation in the right ventral striatum (caudate, right amygdala and anterior cingulate cortex (bilaterally correlated negatively with BAS drive scores. In contrast, when participants were satiated, taste responses correlated positively with BAS drive scores in the left caudate. These results were not replicated for soft drinks. Thus, neural responses to oral calories from maltodextrin were modulated by reward sensitivity in reward-related brain areas. This was not the case for sucrose. This may be due to the direct detection of maltodextrin, but not sucrose in the oral cavity. Also, in a familiar beverage, detection of calories per
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Neural Processing of Calories in Brain Reward Areas Can be Modulated by Reward Sensitivity.
van Rijn, Inge; Griffioen-Roose, Sanne; de Graaf, Cees; Smeets, Paul A M
2015-01-01
A food's reward value is dependent on its caloric content. Furthermore, a food's acute reward value also depends on hunger state. The drive to obtain rewards (reward sensitivity), however, differs between individuals. Here, we assessed the association between brain responses to calories in the mouth and trait reward sensitivity in different hunger states. Firstly, we assessed this in data from a functional neuroimaging study (van Rijn et al., 2015), in which participants (n = 30) tasted simple solutions of a non-caloric sweetener with or without a non-sweet carbohydrate (maltodextrin) during hunger and satiety. Secondly, we expanded these analyses to regular drinks by assessing the same relationship in data from a study in which soft drinks sweetened with either sucrose or a non-caloric sweetener were administered during hunger (n = 18) (Griffioen-Roose et al., 2013). First, taste activation by the non-caloric solution/soft drink was subtracted from that by the caloric solution/soft drink to eliminate sweetness effects and retain activation induced by calories. Subsequently, this difference in taste activation was correlated with reward sensitivity as measured with the BAS drive subscale of the Behavioral Activation System (BAS) questionnaire. When participants were hungry and tasted calories from the simple solution, brain activation in the right ventral striatum (caudate), right amygdala and anterior cingulate cortex (bilaterally) correlated negatively with BAS drive scores. In contrast, when participants were satiated, taste responses correlated positively with BAS drive scores in the left caudate. These results were not replicated for soft drinks. Thus, neural responses to oral calories from maltodextrin were modulated by reward sensitivity in reward-related brain areas. This was not the case for sucrose. This may be due to the direct detection of maltodextrin, but not sucrose in the oral cavity. Also, in a familiar beverage, detection of calories per se may be
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Urosevic, Snezana; Collins, Paul; Muetzel, Ryan; Lim, Kelvin; Luciana, Monica
2012-01-01
Adolescence is a period of radical normative changes and increased risk for substance use, mood disorders, and physical injury. Researchers have proposed that increases in reward sensitivity (i.e., sensitivity of the behavioral approach system [BAS]) and/or increases in reactivity to all emotional stimuli (i.e., reward and threat sensitivities)…
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A new hazard index for the determination of risk potentials of disposed radioactive wastes
International Nuclear Information System (INIS)
Kirchner, Gerald
1990-01-01
On the basis of a discussion of advantages and limitations of hazard calculations of nuclear waste, a new hazard index is presented. The model deals with environmental processes that determine radiation exposure to man after failure of a geologic repository and release of radionuclides into the biosphere. Included in the model are isotopic composition of the waste, probability for transport of nuclides to man, cycling in the biosphere, radiotoxicity to man and changes of the risk potential which are due to radioactive build-up and decay processes after the waste nuclides enter the biosphere. Nuclide-specific data necessary for the use of the new index are compiled. Calculations for wastes from different nuclear power reactor types and fuel cycle options indicate that 237 Np and 241 Am are the waste constituents with the most demanding requirements in regard to the long-term isolation potential of a repository. Isolation times required for the wastes analyzed are of the order of 10 7 years. Hazard analyses of nuclear wastes with negligible heat generation from various sources show that secondary wastes from nuclear fuel reprocessing and mixed-oxide fuel fabrication have long-term risk potentials which are about two orders of magnitude higher than those from other wastes. They should be disposed of together with high-level wastes. (author)
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[Effort-reward imbalance at work and depression: current research evidence].
Siegrist, J
2013-01-01
In view of highly prevalent stressful conditions in modern working life, in particular increasing work pressure and job insecurity, it is of interest to know whether specific constellations of an adverse psychosocial work environment increase the risk of depressive disorder among employed people. This contribution gives a short overview of current research evidence based on an internationally established work stress model of effort-reward imbalance. Taken together, results from seven prospective epidemiological investigations demonstrate a two-fold elevated relative risk of incident depressive disorder over a mean observation period of 2.7 years among exposed versus non-exposed employees. Additional findings from experimental and quasi-experimental studies point to robust associations of effort-reward imbalance at work with proinflammatory cytokines and markers of reduced immune competence. These latter markers may indicate potential psychobiological pathways. In conclusion, incorporating this new knowledge into medical treatment and preventive efforts seems well justified.
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Cassidy, Clifford M.; Brodeur, Mathieu B.; Lepage, Martin; Malla, Ashok
2014-01-01
Background Dysfunctional reward processing is present in individuals with schizophrenia-spectrum disorders (SSD) and may confer vulnerability to addiction. Our objective was to identify a deficit in patients with SSD on response to rewarding stimuli and determine whether this deficit predicts cannabis use. Methods We divided a group of patients with SSD and nonpsychotic controls into cannabis users and nonusers. Response to emotional and cannabis-associated visual stimuli was assessed using self-report, event-related potentials (using the late positive potential [LPP]), facial electromyography and skin-conductance response. Results Our sample comprised 35 patients with SSD and 35 nonpsychotic controls. Compared with controls, the patients with SSD showed blunted LPP response to pleasant stimuli (p = 0.003). Across measures, cannabis-using controls showed greater response to pleasant stimuli than to cannabis stimuli whereas cannabis-using patients showed little bias toward pleasant stimuli. Reduced LPP response to pleasant stimuli was predictive of more frequent subsequent cannabis use (β = −0.24, p = 0.034). Limitations It is not clear if the deficit associated with cannabis use is specific to rewarding stimuli or nonspecific to any kind of emotionally salient stimuli. Conclusion The LPP captures a reward-processing deficit in patients with SSD and shows potential as a biomarker for identifying patients at risk of heavy cannabis use. PMID:24913137
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Adolescents, adults and rewards: comparing motivational neurocircuitry recruitment using fMRI.
Directory of Open Access Journals (Sweden)
James M Bjork
Full Text Available BACKGROUND: Adolescent risk-taking, including behaviors resulting in injury or death, has been attributed in part to maturational differences in mesolimbic incentive-motivational neurocircuitry, including ostensible oversensitivity of the nucleus accumbens (NAcc to rewards. METHODOLOGY/PRINCIPAL FINDINGS: To test whether adolescents showed increased NAcc activation by cues for rewards, or by delivery of rewards, we scanned 24 adolescents (age 12-17 and 24 adults age (22-42 with functional magnetic resonance imaging while they performed a monetary incentive delay (MID task. The MID task was configured to temporally disentangle potential reward or potential loss anticipation-related brain signal from reward or loss notification-related signal. Subjects saw cues signaling opportunities to win or avoid losing $0, $.50, or $5 for responding quickly to a subsequent target. Subjects then viewed feedback of their trial success after a variable interval from cue presentation of between 6 to 17 s. Adolescents showed reduced NAcc recruitment by reward-predictive cues compared to adult controls in a linear contrast with non-incentive cues, and in a volume-of-interest analysis of signal change in the NAcc. In contrast, adolescents showed little difference in striatal and frontocortical responsiveness to reward deliveries compared to adults. CONCLUSIONS/SIGNIFICANCE: In light of divergent developmental difference findings between neuroimaging incentive paradigms (as well as at different stages within the same task, these data suggest that maturational differences in incentive-motivational neurocircuitry: 1 may be sensitive to nuances of incentive tasks or stimuli, such as behavioral or learning contingencies, and 2 may be specific to the component of the instrumental behavior (such as anticipation versus notification.
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Food reward from a behavioural and (neuro)physiological perspective
Bruijn, Suzanne E.M.
2017-01-01
Food reward is an important driver of food intake and triggers consumption of foods for pleasure, so-called hedonic eating, even in the absence of any energy deficits. Hedonic eating can trigger overeating and may therefore lead to obesity. Given the rise in obesity rates and the health risks
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Distinct Reward Properties are Encoded via Corticostriatal Interactions.
Smith, David V; Rigney, Anastasia E; Delgado, Mauricio R
2016-02-02
The striatum serves as a critical brain region for reward processing. Yet, understanding the link between striatum and reward presents a challenge because rewards are composed of multiple properties. Notably, affective properties modulate emotion while informative properties help obtain future rewards. We approached this problem by emphasizing affective and informative reward properties within two independent guessing games. We found that both reward properties evoked activation within the nucleus accumbens, a subregion of the striatum. Striatal responses to informative, but not affective, reward properties predicted subsequent utilization of information for obtaining monetary reward. We hypothesized that activation of the striatum may be necessary but not sufficient to encode distinct reward properties. To investigate this possibility, we examined whether affective and informative reward properties were differentially encoded in corticostriatal interactions. Strikingly, we found that the striatum exhibited dissociable connectivity patterns with the ventrolateral prefrontal cortex, with increasing connectivity for affective reward properties and decreasing connectivity for informative reward properties. Our results demonstrate that affective and informative reward properties are encoded via corticostriatal interactions. These findings highlight how corticostriatal systems contribute to reward processing, potentially advancing models linking striatal activation to behavior.
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International Nuclear Information System (INIS)
Till, J.E.; Meyer, K.R.
1990-01-01
Methods for assessing radioactive waste sites that contain chemical constituents are in the formative stages. In evaluating these sites, a key concern will be the hazard to personnel involved in cleanup work and to the general population. This paper focuses on what we have learned from pathway analysis and risk assessment about providing a combined estimate of risk from exposure to both chemicals and radionuclides. Quantitative radiation risk assessment involves a high degree of uncertainty. Chemical risk assessment generally does not provide quantitative results. Thus, it is not currently possible to develop a useful, quantitative combined risk assessment for mixed-waste sites
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DEFF Research Database (Denmark)
Macoveanu, Julian; Fisher, Patrick M; Haahr, Mette E
2014-01-01
the involvement of the normally functioning 5HT-system in decision-making under risk and processing of monetary rewards. The data suggest that prolonged SSRI treatment might reduce emotional engagement by reducing the impact of risk during decision-making or the impact of reward during outcome evaluation.......Selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine are commonly prescribed antidepressant drugs targeting the dysfunctional serotonin (5-HT) system, yet little is known about the functional effects of prolonged serotonin reuptake inhibition in healthy individuals. Here we used...... functional MRI (fMRI) to investigate how a three-week fluoxetine intervention influences neural activity related to risk taking and reward processing. Employing a double-blinded parallel-group design, 29 healthy young males were randomly assigned to receive 3 weeks of a daily dose of 40 mg fluoxetine...
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Risk identification for PPP waste-to-energy incineration projects in China
International Nuclear Information System (INIS)
Song, Jinbo; Song, Danrong; Zhang, Xueqing; Sun, Yan
2013-01-01
Municipal solid waste (MSW) is regarded as a renewable energy source. In China, the sharp increase of MSW has precipitated the rapid growth of waste-to-energy (WTE) incineration plants. Private capital has been getting into the WTE incineration industry through the public–private partnership (PPP) arrangement. Due to the large construction cost and the long concession period commonly associated with this arrangement, a number of failures have emerged in PPP WTE incineration projects. The aim of this paper is to investigate the key risks of PPP WTE incineration projects in China and study the strategies for managing these risks by drawing experience and learning lessons from these projects. First, we analyzed the MSW management practices, relevant legislations and policies, and the development of PPP WTE incineration projects in China. Second, we identified ten key risks through interviews, surveys and visits to some selected projects, and provided detailed analysis of these risks. Lastly, we developed response strategies for these risks from the perspectives of both public and private sectors. - Highlights: • We analyze MSW management practices, relevant legislations and policies in China. • Through case study on PPP WTE incineration projects, ten key risks are identified. • Response strategies for key risks are developed
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The role of economic incentives in nuclear waste facility siting
International Nuclear Information System (INIS)
Davis, E.M.
1986-01-01
There is a need to provide some public benefit and/or reward for accepting a ''locally unwanted land use'' (LULU) facility such as a nuclear waste storage or disposal facility. This paper concludes that DOE, Congress and the states should immediately quantify an economic incentive for consideration ''up front'' by society on siting decisions for nuclear waste storage and disposal facilities
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Minamimoto, Takafumi; La Camera, Giancarlo; Richmond, Barry J
2009-01-01
Motivation is usually inferred from the likelihood or the intensity with which behavior is carried out. It is sensitive to external factors (e.g., the identity, amount, and timing of a rewarding outcome) and internal factors (e.g., hunger or thirst). We trained macaque monkeys to perform a nonchoice instrumental task (a sequential red-green color discrimination) while manipulating two external factors: reward size and delay-to-reward. We also inferred the state of one internal factor, level of satiation, by monitoring the accumulated reward. A visual cue indicated the forthcoming reward size and delay-to-reward in each trial. The fraction of trials completed correctly by the monkeys increased linearly with reward size and was hyperbolically discounted by delay-to-reward duration, relations that are similar to those found in free operant and choice tasks. The fraction of correct trials also decreased progressively as a function of the satiation level. Similar (albeit noiser) relations were obtained for reaction times. The combined effect of reward size, delay-to-reward, and satiation level on the proportion of correct trials is well described as a multiplication of the effects of the single factors when each factor is examined alone. These results provide a quantitative account of the interaction of external and internal factors on instrumental behavior, and allow us to extend the concept of subjective value of a rewarding outcome, usually confined to external factors, to account also for slow changes in the internal drive of the subject.
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Tank Waste Remediation System decisions and risk assessment
International Nuclear Information System (INIS)
Johnson, M.E.
1994-09-01
The Tank Waste Remediation System (TWRS) mission is to store, treat, and immobilize the highly radioactive Hanford Site tank wastes and encapsulated cesium and strontium materials in an environmentally sound, safe, and cost effective manner. Additionally, the TWRS conducts, as part of this mission, resolution of safety issues associated with the wastes within the 177 underground radioactive waste tanks. Systems engineering principles are being applied to determine the functions and establish requirements necessary for accomplishing the TWRS mission (DOE 1994 draft). This systematic evaluation of the TWRS program has identified key decisions that must be executed to establish mission scope, determine requirements, or select a technical solution for accomplishing identified functions and requirements. Key decisions identified through the systematic evaluation of the TWRS mission are presented in this document. Potential alternative solutions to each decision are discussed. After-discussion and evaluation of each decision with effected stakeholder groups, the US Department of Energy (DOE) will select a solution from the identified alternatives for implementation. In order to proceed with the development and execution of the tank waste remediation program, the DOE has adopted a planning basis for several of these decisions, until a formal basis is established. The planning bases adopted by the DOE is continuing to be discussed with stakeholder groups to establish consensus for proceeding with proposed actions. Technical and programmatic risks associated with the planning basis adopted by the DOE are discussed
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Determination of acceptable risk criteria for nuclear waste management
International Nuclear Information System (INIS)
Cohen, J.J.
1977-01-01
The initial phase of the work performed during FY 1977 consisted of performing a ''scoping'' study to define issues, determine an optimal methodology for their resolution, and compile a data base for acceptable risk criteria development. The issues, spanning technical, psychological, and ethical dimensions, were categorized in seven major areas: (1) unplanned or accidental events, (2) present vs future risks, (3) institutional controls and retrievability, (4) dose-response mechanism and uncertainty, (5) spatial distribution of exposed populations, (6) different types of nuclear wastes, and (7) public perception. The optimum methodology for developing ARC was determined to be multi-attribute decision analysis encompassing numerous specific techniques for choosing, from among several alternatives, the optimal course of action when the alternatives are constrained to meet specified attributes. The data base developed during the study comprises existing regulations and guidelines, maximum permissible dose, natural geologic hazards, nonradioactive hazardous waste practices, bioethical perspectives, and data from an opinion survey
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Determination of acceptable risk criteria for nuclear waste management
Energy Technology Data Exchange (ETDEWEB)
Cohen, J.J.
1977-10-21
The initial phase of the work performed during FY 1977 consisted of performing a ''scoping'' study to define issues, determine an optimal methodology for their resolution, and compile a data base for acceptable risk criteria development. The issues, spanning technical, psychological, and ethical dimensions, were categorized in seven major areas: (1) unplanned or accidental events, (2) present vs future risks, (3) institutional controls and retrievability, (4) dose-response mechanism and uncertainty, (5) spatial distribution of exposed populations, (6) different types of nuclear wastes, and (7) public perception. The optimum methodology for developing ARC was determined to be multi-attribute decision analysis encompassing numerous specific techniques for choosing, from among several alternatives, the optimal course of action when the alternatives are constrained to meet specified attributes. The data base developed during the study comprises existing regulations and guidelines, maximum permissible dose, natural geologic hazards, nonradioactive hazardous waste practices, bioethical perspectives, and data from an opinion survey.
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International Nuclear Information System (INIS)
Kirby, P.N.; Iacovino, J.M.
1990-01-01
In order to evaluate the public health risk of potential radioactive releases from operation of the Waste Isolation Pilot Plant (WIPP), a probabilistic risk assessment of waste-handling operations was conducted. One major aspect of this risk assessment involved fault-tree analysis of the plant heating, ventilation, and air-conditioning (HVAC) systems, which constitute the final barrier between waste-handling operations and the environment. The WIPP site is designed to receive and store two types of waste: contact-handled transuranic (CH TRU) wastes to be shipped in 208-ell drums and remote-handled (RH) TRU wastes to be shipped in shielded casks. The identification of accident sequences for CH waste operations revealed no identified accidents that could release significant radioactive particulates to the environment without a failure in the HVAC systems. When the HVAC fault-tree results were combined with other critical system fault trees and the analysis of waste-handling accident sequences, the approximation of the overall WIPP plant risk due to airborne releases was determined to be 2.6 x 10 -7 fatalities per year for the population within a 50-mile radius of the WIPP site. This risk was demonstrated to be well below the risk of fatality from other voluntary and involuntary activities for the population within the vicinity of the WIPP
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International Nuclear Information System (INIS)
Till, J.E.; Meyer, K.R.
1988-01-01
Many radioactive waste sites contain not only radioactive material but also varying amounts of chemical waste. The use of such procedures implies some risk at any exposure level, and thus requires that an exposure level be determined that corresponds to an acceptable risk to an individual or a population. Although the uncertainties and limitations of these methods are of concern, the assumption has been generally adopted that the human dose response for all carcinogens is linear, with no threshold occurring at low levels of exposure. With the move toward decontamination programs and clean-up of various mixed waste sites throughout the US, there is interest in the possibility that risk estimates calculated individually for radionuclides and for chemicals may be combined to reflect the total risk for each site. The purpose of this paper is to examine the feasibility of combining risk estimates during risk/benefit analyses. For a variety of reasons, the state of radiation risk assessment is more advanced than that of chemical risk assessment. The reasons for this disparity are summarized in this paper. Quantitative radiation risk assessment is currently being performed, but involves a high degree of uncertainty. Chemical risk assessment in general does not allow quantitative results bracketed by uncertainty analysis. Therefore, it is concluded that it is currently not possible to develop a useful, quantitative combined risk assessment for a mixed waste site, but that it may be possible to develop such a capability in the future
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Job strain, effort-reward imbalance and employee well-being: a large-scale cross-sectional study.
de Jonge, J; Bosma, H; Peter, R; Siegrist, J
2000-05-01
This study investigated the effects of the Job Demand-Control (JD-C) Model and the Effort-Reward Imbalance (ERI) Model on employee well-being. A cross-sectional survey was conducted comprising a large representative sample of 11,636 employed Dutch men and women. Logistic regression analyses were used. Controlling for job sector, demographic characteristics (including educational level) and managerial position, employees reporting high job demands (i.e. psychological and physical demands) and low job control had elevated risks of emotional exhaustion, psychosomatic and physical health complaints and job dissatisfaction (odds ratios ranged from 2.89 to 10.94). Odds ratios were generally higher in employees reporting both high (psychological and physical) efforts and low rewards (i.e. poor salary, job insecurity and low work support): they ranged from 3.23 to 15.43. Furthermore, overcommitted people had higher risks of poor well-being due to a high effort-low reward mismatch (ORs: 3.57-20.81) than their less committed counterparts (ORs: 3.01-12.71). Finally, high efforts and low occupational rewards were stronger predictors of poor well-being than low job control when both job stress models were simultaneously adjusted. In conclusion, our findings show independent cumulative effects of both the JD-C Model and the ERI Model on employee well-being and are not significantly different in men and women as well as in young and old people. In particular, high (psychological and physical) efforts and low rewards adversely affected employee well-being. Preliminary findings also indicate excess risks of poor well-being in overcommitted persons suffering from high cost--low gain conditions at work.
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Strategic management of health risks posed by buried transuranic wastes
International Nuclear Information System (INIS)
Jump, R.A.
1994-01-01
A strategy is presented for reducing health risks at sites contaminated with buried transuranic (TRU) wastes by first taking measures to immobilize the contaminants until the second step, final action, becomes cost-effective and poses less risk to the remediation workers. The first step of this strategy does not preclude further action if it is warranted and is in harmony with environmental laws and regulations
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Blum, Kenneth; Gardner, Eliot; Oscar-Berman, Marlene; Gold, Mark
2012-01-01
In an attempt to resolve controversy regarding the causal contributions of mesolimbic dopamine (DA) systems to reward, we evaluate the three main competing explanatory categories: “liking,” “learning,” and “wanting” [1]. That is, DA may mediate (a) the hedonic impact of reward (liking), (b) learned predictions about rewarding effects (learning), or (c) the pursuit of rewards by attributing incentive salience to reward-related stimuli (wanting). We evaluate these hypotheses, especially as they...
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Risk assessment of nonhazardous oil-field waste disposal in salt caverns.
Energy Technology Data Exchange (ETDEWEB)
Elcock, D.
1998-03-05
In 1996, Argonne National Laboratory (ANL) conducted a preliminary technical and legal evaluation of disposing of nonhazardous oil-field wastes (NOW) into salt caverns. Argonne determined that if caverns are sited and designed well, operated carefully, closed properly, and monitored routinely, they could be suitable for disposing of oil-field wastes. On the basis of these findings, Argonne subsequently conducted a preliminary evaluation of the possibility that adverse human health effects (carcinogenic and noncarcinogenic) could result from exposure to contaminants released from the NOW disposed of in domal salt caverns. Steps used in this evaluation included the following: identifying potential contaminants of concern, determining how humans could be exposed to these contaminants, assessing contaminant toxicities, estimating contaminant intakes, and calculating human cancer and noncancer risk estimates. Five postclosure cavern release scenarios were assessed. These were inadvertent cavern intrusion, failure of the cavern seal, failure of the cavern through cracks, failure of the cavern through leaky interbeds, and a partial collapse of the cavern roof. Assuming a single, generic, salt cavern and generic oil-field wastes, potential human health effects associated with constituent hazardous substances (arsenic, benzene, cadmium, and chromium) were assessed under each of these scenarios. Preliminary results provided excess cancer risk and hazard index (referring to noncancer health effects) estimates that were well within the US Environmental Protection Agency (EPA) target range for acceptable exposure risk levels. These results led to the preliminary conclusion that from a human health perspective, salt caverns can provide an acceptable disposal method for nonhazardous oil-field wastes.
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Risk assessment of nonhazardous oil-field waste disposal in salt caverns
International Nuclear Information System (INIS)
Elcock, D.
1998-01-01
In 1996, Argonne National Laboratory (ANL) conducted a preliminary technical and legal evaluation of disposing of nonhazardous oil-field wastes (NOW) into salt caverns. Argonne determined that if caverns are sited and designed well, operated carefully, closed properly, and monitored routinely, they could be suitable for disposing of oil-field wastes. On the basis of these findings, Argonne subsequently conducted a preliminary evaluation of the possibility that adverse human health effects (carcinogenic and noncarcinogenic) could result from exposure to contaminants released from the NOW disposed of in domal salt caverns. Steps used in this evaluation included the following: identifying potential contaminants of concern, determining how humans could be exposed to these contaminants, assessing contaminant toxicities, estimating contaminant intakes, and calculating human cancer and noncancer risk estimates. Five postclosure cavern release scenarios were assessed. These were inadvertent cavern intrusion, failure of the cavern seal, failure of the cavern through cracks, failure of the cavern through leaky interbeds, and a partial collapse of the cavern roof. Assuming a single, generic, salt cavern and generic oil-field wastes, potential human health effects associated with constituent hazardous substances (arsenic, benzene, cadmium, and chromium) were assessed under each of these scenarios. Preliminary results provided excess cancer risk and hazard index (referring to noncancer health effects) estimates that were well within the US Environmental Protection Agency (EPA) target range for acceptable exposure risk levels. These results led to the preliminary conclusion that from a human health perspective, salt caverns can provide an acceptable disposal method for nonhazardous oil-field wastes
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Registered nurses' perceptions of rewarding and its significance.
Seitovirta, Jaana; Lehtimäki, Aku-Ville; Vehviläinen-Julkunen, Katri; Mitronen, Lasse; Kvist, Tarja
2017-11-07
To examine reward type preferences and their relationships with the significance of rewarding perceived by registered nurses in Finland. Previous studies have found relationships between nurses' rewarding and their motivation at work, job satisfaction and organisational commitment. Data were collected in a cross-sectional, descriptive, questionnaire survey from 402 registered nurses using the Registered Nurses' Perceptions of Rewarding Scale in 2015, and analysed with descriptive and multivariate statistical methods. Registered nurses assigned slightly higher values to several non-financial than to financial rewards. The non-financial reward types appreciation and feedback from work community, worktime arrangements, work content, and opportunity to develop, influence and participate were highly related to the significance of rewarding. We identified various rewards that registered nurses value, and indications that providing an appropriate array of rewards, particularly non-financial rewards, is a highly beneficial element of nursing management. It is important to understand the value of rewards for nursing management. Nurse managers should offer diverse rewards to their registered nurses to promote excellent performance and to help efforts to secure and maintain high-quality, safe patient care. The use of appropriate rewards is especially crucial to improving registered nurses' reward satisfaction and job satisfaction globally in the nursing profession. © 2017 John Wiley & Sons Ltd.
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International Nuclear Information System (INIS)
Guillaume, B.; Charron, S.
2000-01-01
Understanding public perceptions of risks is increasingly considered to be important in order to make sound policy decisions. For many years, social scientists have been working to understand why the public is so concerned about nuclear energy and radioactive waste. Indeed, risk perception studies have essentially focused on high-level nuclear waste. As a result, there is now a fair understanding of what determines public support or opposition to high-level nuclear waste storage and disposal facilities. However, to date, little research has been conducted into radioactive waste from mining and milling of uranium ores. In France, such waste have a much debated legal status, which illustrates their ambiguous origin (natural versus artificial) and the manner people can perceive them. Therefore, it seems relevant to explore the individual judgements, attitudes and beliefs towards risk associated with uranium mill tailings. The present study provides a structural model based on both the identification and analysis of implicit dimensions underlying risk perception (psychological, cultural, moral...) applied to the case of french uranium mill tailings. One objective of the research has been to develop an interview grid based on this conceptual model in order to elicit social demand beyond public attitudes. Semi-structured interviews have been conducted on site in french uranium bearing areas. The relationships inferred between identified risk characteristics and contextual risk perceptions suggest that five majors thematics (time, space, nature, ethics and trust) build determinants of the public's perceptions of risk related to waste from mining and milling of uranium ores. (author)
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Decision-Making Risks Concerning the Construction of the Goiania Waste Repository
International Nuclear Information System (INIS)
Paschoa, A.S.; Rozental, J.J.; Tranjan Filho, A.
2001-01-01
As it is well known, an accident with a teletherapy source made of 137 CsCl with an initial activity of 59 TBq occurred in Goiania, in September of 1987. This paper will discuss the decision-making process, and the struggle that followed the decision to build the final repository for the remnants of the Goiania accident. The Goiania final repository was built as planned. The two subsurface structures under the grassy artificial hills hold the overall volume of the remnants of the Goiania accident. The near hill holds 5x10 3 m3 of stabilized wastes without radioactivity, or with very low radioactivity. The far hill holds the remaining 6.5x10 3 m 3 of stabilized wastes with low and medium radioactivity. The central part of each subsurface hill has been shielded by wastes with less and less radioactivity. The overall fenced area occupies 1.85x10 5 m 2 . The external radiation levels are similar to the surrounding background, and much lower than those found in the Brazilian areas of high natural radioactivity. The site is permanently monitored by independent institutions, including Brazilian universities, and national and international organizations. As it was mentioned earlier, the final repository was build to last for at least 400 years. Although the initial decision to adopt a too conservative decontamination criterion in the case of the Goiania accident was bound to produce excessive amount of waste; such decision proved, retrospectively, not to be bad because the excess low radioactive waste produced was used as extra shielding material in final repository. The technical decision-maker should not abandon risk estimates, but should be aware that credibility is the main basis to achieve acceptability of a decision by the general public. Risk perception should be regarded as only a first step towards what may be called knowledge, or comprehension of risk estimates, but risk perception by the general public is still an open issue. The problem of a fixed, or near
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The relationship between personality types and reward preferences
Directory of Open Access Journals (Sweden)
R. Nienaber
2011-12-01
Full Text Available Orientation: Research has shown that total rewards models structured according to individual preferences, positively influence efforts to attract, retain and motivate key employees. Yet, this is seldom done. Structuring total rewards models according to the preferences of employee segments is a viable alternative to accommodate individual preferences. Research purpose: The primary aim of the study was to determine the relationship between personality types and reward preferences. The secondary aim was to determine the reward preferences for different demographic groups. Motivation for the study: An enhanced understanding of reward preferences for different employee segments will enable employers to offer more competitive reward options to their employees. This may, in turn, have a positive impact on retention. Research design, approach and method: Two measuring instruments, the MBTI® Form GRV and the Rewards Preferences Questionnaire, were distributed electronically to 5 000 potential respondents. The results from 589 sets of questionnaires were used in the data analyses. Primary and secondary factor analyses were done on the items in the Rewards Preferences Questionnaire. Main findings/results: The study confirmed that individuals with certain personality types and personality preferences, have different preferences for certain reward categories. There was a stronger relationship between reward preferences and personality preferences than for reward preferences and personality types. Preferences for reward categories by different demographic groups were confirmed. The significant difference in reward preferences between Black and White respondents in particular was noteworthy, with Black respondents indicating significantly higher mean scores for all reward categories than White respondents. Finally, a total rewards framework influenced by the most prominent preferences for reward categories, was designed. Practical/Managerial implications
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Chronic wasting disease risk analysis workshop: An integrative approach
Gillette, Shana; Dein, Joshua; Salman, Mo; Richards, Bryan; Duarte, Paulo
2004-01-01
Risk analysis tools have been successfully used to determine the potential hazard associated with disease introductions and have facilitated management decisions designed to limit the potential for disease introduction. Chronic Wasting Disease (CWD) poses significant challenges for resource managers due to an incomplete understanding of disease etiology and epidemiology and the complexity of management and political jurisdictions. Tools designed specifically to assess the risk of CWD introduction would be of great value to policy makers in areas where CWD has not been detected.
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Directory of Open Access Journals (Sweden)
Varsha eSingh
2012-07-01
Full Text Available Surface-level differences in the reward and punishment variants, specifically greater long-term decision making in the punishment variant of the Iowa Gambling Task (IGT observed in previous studies led to the present comparison of long-term decision making in the two IGT variants (n = 320, male = 160. It was contended that risk-aversion triggered by a positive frame of the reward variant and risk seeking triggered by a negative frame of the punishment variant appears as long-term decision making in the two IGT variants. Apart from the frame of the variant as a within-subjects factor (variant type: reward and punishment, the order in which the frame was triggered (order type: reward–punishment or punishment–reward, and the four types of instructions that delineated motivation towards reward from that of punishment (reward, punishment, reward and punishment, and no-hint were hypothesized to have an effect on foresighted decision making in the IGT. As expected, long-term decision making differed across the two IGT variants suggesting that the frame of the variant has an effect on long-term decision making in the IGT (p < 0.001. The order in which a variant was presented, and the type of the instructions that were used both had an effect on long-term decision making in the two IGT variants (p < 0.05. A post hoc test suggested that the instructions that differentiated between reward and punishment resulted in greater foresight than the commonly used IGT instructions that fail to distinguish between reward and punishment. As observed in previous studies, there were more number of participants (60% who showed greater foresight in the punishment variant than in the reward variant (p< 0.001. The results suggest that foresight in IGT decision making is sensitive to reward and punishment frame in an asymmetric manner, an observation that is aligned with the behavioral decision-making framework. Benefits of integrating findings from behavioral studies
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Brain Circuits Encoding Reward from Pain Relief.
Navratilova, Edita; Atcherley, Christopher W; Porreca, Frank
2015-11-01
Relief from pain in humans is rewarding and pleasurable. Primary rewards, or reward-predictive cues, are encoded in brain reward/motivational circuits. While considerable advances have been made in our understanding of reward circuits underlying positive reinforcement, less is known about the circuits underlying the hedonic and reinforcing actions of pain relief. We review findings from electrophysiological, neuroimaging, and behavioral studies supporting the concept that the rewarding effect of pain relief requires opioid signaling in the anterior cingulate cortex (ACC), activation of midbrain dopamine neurons, and the release of dopamine in the nucleus accumbens (NAc). Understanding of circuits that govern the reward of pain relief may allow the discovery of more effective and satisfying therapies for patients with acute or chronic pain.
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The endocannabinoid system in brain reward processes.
Solinas, M; Goldberg, S R; Piomelli, D
2008-05-01
Food, drugs and brain stimulation can serve as strong rewarding stimuli and are all believed to activate common brain circuits that evolved in mammals to favour fitness and survival. For decades, endogenous dopaminergic and opioid systems have been considered the most important systems in mediating brain reward processes. Recent evidence suggests that the endogenous cannabinoid (endocannabinoid) system also has an important role in signalling of rewarding events. First, CB(1) receptors are found in brain areas involved in reward processes, such as the dopaminergic mesolimbic system. Second, activation of CB(1) receptors by plant-derived, synthetic or endogenous CB(1) receptor agonists stimulates dopaminergic neurotransmission, produces rewarding effects and increases rewarding effects of abused drugs and food. Third, pharmacological or genetic blockade of CB(1) receptors prevents activation of dopaminergic neurotransmission by several addictive drugs and reduces rewarding effects of food and these drugs. Fourth, brain levels of the endocannabinoids anandamide and 2-arachidonoylglycerol are altered by activation of reward processes. However, the intrinsic activity of the endocannabinoid system does not appear to play a facilitatory role in brain stimulation reward and some evidence suggests it may even oppose it. The influence of the endocannabinoid system on brain reward processes may depend on the degree of activation of the different brain areas involved and might represent a mechanism for fine-tuning dopaminergic activity. Although involvement of the various components of the endocannabinoid system may differ depending on the type of rewarding event investigated, this system appears to play a major role in modulating reward processes.
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Criteria for waste-related risks to be below regulatory concern
International Nuclear Information System (INIS)
Trubatch, S.L.
1986-01-01
This paper describes and analyzes the criteria recently established by the US Court of Appeals for the District of Columbia Circuit for determining that a risk is de minimis, i.e., below regulatory concern (BRC), for the purpose of the Atomic Energy Act of 1954, as amended, 42 USC 2011 et seq. The court established these BRC criteria incidentally during its review of intervenors' challenge to the US Nuclear Regulatory Commission's (NRC's) issuance of an operating license for the Diablo Canyon Nuclear Power Plant. In the course of that licensing proceeding, the NRC had determined that its regulations did not require it to consider the complicating effects of earthquakes on emergency planning. Although the legal standard and its quantitation arose in the context of emergency planning, these criteria are equally applicable to waste-related risks cognizable under the Atomic Energy Act. These criteria imply that the NRC, when licensing a waste repository, need not consider the risk of a catastrophic accident having a frequency of occurrence of less than one chance in one hundred thousand per year
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Wimmer, G Elliott; Büchel, Christian
2016-03-09
Rewarding experiences exert a strong influence on later decision making. While decades of neuroscience research have shown how reinforcement gradually shapes preferences, decisions are often influenced by single past experiences. Surprisingly, relatively little is known about the influence of single learning episodes. Although recent work has proposed a role for episodes in decision making, it is largely unknown whether and how episodic experiences contribute to value-based decision making and how the values of single episodes are represented in the brain. In multiple behavioral experiments and an fMRI experiment, we tested whether and how rewarding episodes could support later decision making. Participants experienced episodes of high reward or low reward in conjunction with incidental, trial-unique neutral pictures. In a surprise test phase, we found that participants could indeed remember the associated level of reward, as evidenced by accurate source memory for value and preferences to re-engage with rewarded objects. Further, in a separate experiment, we found that high-reward objects shown as primes before a gambling task increased financial risk taking. Neurally, re-exposure to objects in the test phase led to significant reactivation of reward-related patterns. Importantly, individual variability in the strength of reactivation predicted value memory performance. Our results provide a novel demonstration that affect-related neural patterns are reactivated during later experience. Reactivation of value information represents a mechanism by which memory can guide decision making. Copyright © 2016 the authors 0270-6474/16/362868-13$15.00/0.
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Nanometer-sized emissions from municipal waste incinerators: A qualitative risk assessment
Energy Technology Data Exchange (ETDEWEB)
Johnson, David R., E-mail: david.r.johnson@ghd.com
2016-12-15
Municipal waste incinerators (MWI) are beneficial alternatives to landfills for waste management. A recent constituent of concern in emissions from these facilities is incidental nanometer-sized particles (INP{sub MWI}), i.e., particles smaller than 1 micrometer in size that may deposit in the deepest parts of the lungs, cross into the bloodstream, and affect different regions of the body. With limited data, the public may fear INP{sub MWI} due to uncertainty, which may affect public acceptance, regulatory permitting, and the increased lowering of air quality standards. Despite limited data, a qualitative risk assessment paradigm can be applied to determine the relative risk due to INP{sub MWI} emissions. This review compiles existing data on nanometer-sized particle generation by MWIs, emissions control technologies used at MWIs, emission releases into the atmosphere, human population exposure, and adverse health effects of nanometer-sized particles to generate a qualitative risk assessment and identify data gaps. The qualitative risk assessment conservatively concludes that INP{sub MWI} pose a low to moderate risk to individuals, primarily due to the lack of relevant toxicological data on INP{sub MWI} mixtures in ambient particulate matter.
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Reward system dysfunction in autism spectrum disorders
Schulte-Rüther, Martin; Nehrkorn, Barbara; Müller, Kristin; Fink, Gereon R.; Kamp-Becker, Inge; Herpertz-Dahlmann, Beate; Schultz, Robert T.; Konrad, Kerstin
2013-01-01
Although it has been suggested that social deficits of autism spectrum disorders (ASDs) are related to reward circuitry dysfunction, very little is known about the neural reward mechanisms in ASD. In the current functional magnetic resonance imaging study, we investigated brain activations in response to both social and monetary reward in a group of children with ASD, relative to matched controls. Participants with ASD showed the expected hypoactivation in the mesocorticolimbic circuitry in response to both reward types. In particular, diminished activation in the nucleus accumbens was observed when money, but not when social reward, was at stake, whereas the amygdala and anterior cingulate cortex were hypoactivated within the ASD group in response to both rewards. These data indicate that the reward circuitry is compromised in ASD in social as well as in non-social, i.e. monetary conditions, which likely contributes to atypical motivated behaviour. Taken together, with incentives used in this study sample, there is evidence for a general reward dysfunction in ASD. However, more ecologically valid social reward paradigms are needed to fully understand, whether there is any domain specificity to the reward deficit that appears evident in ASD, which would be most consistent with the ASD social phenotype. PMID:22419119
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Model-free and model-based reward prediction errors in EEG.
Sambrook, Thomas D; Hardwick, Ben; Wills, Andy J; Goslin, Jeremy
2018-05-24
Learning theorists posit two reinforcement learning systems: model-free and model-based. Model-based learning incorporates knowledge about structure and contingencies in the world to assign candidate actions with an expected value. Model-free learning is ignorant of the world's structure; instead, actions hold a value based on prior reinforcement, with this value updated by expectancy violation in the form of a reward prediction error. Because they use such different learning mechanisms, it has been previously assumed that model-based and model-free learning are computationally dissociated in the brain. However, recent fMRI evidence suggests that the brain may compute reward prediction errors to both model-free and model-based estimates of value, signalling the possibility that these systems interact. Because of its poor temporal resolution, fMRI risks confounding reward prediction errors with other feedback-related neural activity. In the present study, EEG was used to show the presence of both model-based and model-free reward prediction errors and their place in a temporal sequence of events including state prediction errors and action value updates. This demonstration of model-based prediction errors questions a long-held assumption that model-free and model-based learning are dissociated in the brain. Copyright © 2018 Elsevier Inc. All rights reserved.
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Options for improving hazardous waste cleanups using risk-based criteria
International Nuclear Information System (INIS)
Elcock, D.
1995-01-01
This paper explores how risk- and technology-based criteria are currently used in the RCRA and CERCLA cleanup programs. It identifies ways in which risk could be further incorporated into RCRA and CERCLA cleanup requirements and the implications of risk-based approaches. The more universal use of risk assessment as embodied in the risk communication and risk improvement bills before Congress is not addressed. Incorporating risk into the laws and regulations governing hazardous waste cleanup, will allow the use of the best scientific information available to further the goal of environmental protection in the United States while containing costs. and may help set an example for other countries that may be developing cleanup programs, thereby contributing to enhanced global environmental management
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Andrews, Hans A.
1987-01-01
Describes the efforts of two educational institutions to reward teaching excellence using positive feedback rather than merit pay incentives. An Arizona district, drawing on Herzberg's motivation theories, offers highly individualized rewards ranging from computers to conference money, while an Illinois community college bestows engraved plaques…
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McMurray, Matthew S; Conway, Sineadh M; Roitman, Jamie D
2017-01-01
Animal models of decision-making rely on an animal's motivation to decide and its ability to detect differences among various alternatives. Food reinforcement, although commonly used, is associated with problematic confounds, especially satiety. Here, we examined the use of brain stimulation reward (BSR) as an alternative reinforcer in rodent models of decision-making and compared it with the effectiveness of sugar pellets. The discriminability of various BSR frequencies was compared to differing numbers of sugar pellets in separate free-choice tasks. We found that BSR was more discriminable and motivated greater task engagement and more consistent preference for the larger reward. We then investigated whether rats prefer BSR of varying frequencies over sugar pellets. We found that animals showed either a clear preference for sugar reward or no preference between reward modalities, depending on the frequency of the BSR alternative and the size of the sugar reward. Overall, these results suggest that BSR is an effective reinforcer in rodent decision-making tasks, removing food-related confounds and resulting in more accurate, consistent, and reliable metrics of choice.
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Reduced cerebellar brain activity during reward processing in adolescent binge drinkers.
Cservenka, Anita; Jones, Scott A; Nagel, Bonnie J
2015-12-01
Due to ongoing development, adolescence may be a period of heightened vulnerability to the neurotoxic effects of alcohol. Binge drinking may alter reward-driven behavior and neurocircuitry, thereby increasing risk for escalating alcohol use. Therefore, we compared reward processing in adolescents with and without a history of recent binge drinking. At their baseline study visit, all participants (age=14.86 ± 0.88) were free of heavy alcohol use and completed a modified version of the Wheel of Fortune (WOF) functional magnetic resonance imaging task. Following this visit, 17 youth reported binge drinking on ≥3 occasions within a 90 day period and were matched to 17 youth who remained alcohol and substance-naïve. All participants repeated the WOF task during a second visit (age=16.83 ± 1.22). No significant effects were found in a region of interest analysis of the ventral striatum, but whole-brain analyses showed significant group differences in reward response at the second study visit in the left cerebellum, controlling for baseline visit brain activity (p/αreward processing in a dose-dependent manner. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
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Reward-dependent modulation of movement variability.
Pekny, Sarah E; Izawa, Jun; Shadmehr, Reza
2015-03-04
Movement variability is often considered an unwanted byproduct of a noisy nervous system. However, variability can signal a form of implicit exploration, indicating that the nervous system is intentionally varying the motor commands in search of actions that yield the greatest success. Here, we investigated the role of the human basal ganglia in controlling reward-dependent motor variability as measured by trial-to-trial changes in performance during a reaching task. We designed an experiment in which the only performance feedback was success or failure and quantified how reach variability was modulated as a function of the probability of reward. In healthy controls, reach variability increased as the probability of reward decreased. Control of variability depended on the history of past rewards, with the largest trial-to-trial changes occurring immediately after an unrewarded trial. In contrast, in participants with Parkinson's disease, a known example of basal ganglia dysfunction, reward was a poor modulator of variability; that is, the patients showed an impaired ability to increase variability in response to decreases in the probability of reward. This was despite the fact that, after rewarded trials, reach variability in the patients was comparable to healthy controls. In summary, we found that movement variability is partially a form of exploration driven by the recent history of rewards. When the function of the human basal ganglia is compromised, the reward-dependent control of movement variability is impaired, particularly affecting the ability to increase variability after unsuccessful outcomes. Copyright © 2015 the authors 0270-6474/15/354015-10$15.00/0.
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Risk assessment framework of fate and transport models applied to hazardous waste sites
International Nuclear Information System (INIS)
Hwang, S.T.
1993-06-01
Risk assessment is an increasingly important part of the decision-making process in the cleanup of hazardous waste sites. Despite guidelines from regulatory agencies and considerable research efforts to reduce uncertainties in risk assessments, there are still many issues unanswered. This paper presents new research results pertaining to fate and transport models, which will be useful in estimating exposure concentrations and will help reduce uncertainties in risk assessment. These developments include an approach for (1) estimating the degree of emissions and concentration levels of volatile pollutants during the use of contaminated water, (2) absorption of organic chemicals in the soil matrix through the skin, and (3) steady state, near-field, contaminant concentrations in the aquifer within a waste boundary
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A risk management approach to double-shell tank waste volume versus storage capacity
Energy Technology Data Exchange (ETDEWEB)
Coles, G.A. [Westinghouse Hanford Co., Richland, WA (United States); Thurkow, T.J.; Fritz, R.L.; Nuhlestein, L.O.; Allen, M.R.; Stuart, R.J. [ARES Corp. (United States)
1996-01-01
A risk-based assessment of the overall waste volume versus double-shell tank storage capacity was conducted to develop fallback positions for projections where the waste volume was at a high risk of exceeding capacity. This study was initiated to provide that assessment. A working simulation model was the primary deliverable of this study. The model validates the approach and demonstrates that simulation analysis can provide a method of tracking uncertainties in available data, assessing probabilities, and serves as a tool to be used by management to determine the consequences of various off-normal occurrences.
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A risk management approach to double-shell tank waste volume versus storage capacity
International Nuclear Information System (INIS)
Coles, G.A.; Thurkow, T.J.; Fritz, R.L.; Nuhlestein, L.O.; Allen, M.R.; Stuart, R.J.
1996-01-01
A risk-based assessment of the overall waste volume versus double-shell tank storage capacity was conducted to develop fallback positions for projections where the waste volume was at a high risk of exceeding capacity. This study was initiated to provide that assessment. A working simulation model was the primary deliverable of this study. The model validates the approach and demonstrates that simulation analysis can provide a method of tracking uncertainties in available data, assessing probabilities, and serves as a tool to be used by management to determine the consequences of various off-normal occurrences
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A test of the reward-value hypothesis.
Smith, Alexandra E; Dalecki, Stefan J; Crystal, Jonathon D
2017-03-01
Rats retain source memory (memory for the origin of information) over a retention interval of at least 1 week, whereas their spatial working memory (radial maze locations) decays within approximately 1 day. We have argued that different forgetting functions dissociate memory systems. However, the two tasks, in our previous work, used different reward values. The source memory task used multiple pellets of a preferred food flavor (chocolate), whereas the spatial working memory task provided access to a single pellet of standard chow-flavored food at each location. Thus, according to the reward-value hypothesis, enhanced performance in the source memory task stems from enhanced encoding/memory of a preferred reward. We tested the reward-value hypothesis by using a standard 8-arm radial maze task to compare spatial working memory accuracy of rats rewarded with either multiple chocolate or chow pellets at each location using a between-subjects design. The reward-value hypothesis predicts superior accuracy for high-valued rewards. We documented equivalent spatial memory accuracy for high- and low-value rewards. Importantly, a 24-h retention interval produced equivalent spatial working memory accuracy for both flavors. These data are inconsistent with the reward-value hypothesis and suggest that reward value does not explain our earlier findings that source memory survives unusually long retention intervals.
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Reward inference by primate prefrontal and striatal neurons.
Pan, Xiaochuan; Fan, Hongwei; Sawa, Kosuke; Tsuda, Ichiro; Tsukada, Minoru; Sakagami, Masamichi
2014-01-22
The brain contains multiple yet distinct systems involved in reward prediction. To understand the nature of these processes, we recorded single-unit activity from the lateral prefrontal cortex (LPFC) and the striatum in monkeys performing a reward inference task using an asymmetric reward schedule. We found that neurons both in the LPFC and in the striatum predicted reward values for stimuli that had been previously well experienced with set reward quantities in the asymmetric reward task. Importantly, these LPFC neurons could predict the reward value of a stimulus using transitive inference even when the monkeys had not yet learned the stimulus-reward association directly; whereas these striatal neurons did not show such an ability. Nevertheless, because there were two set amounts of reward (large and small), the selected striatal neurons were able to exclusively infer the reward value (e.g., large) of one novel stimulus from a pair after directly experiencing the alternative stimulus with the other reward value (e.g., small). Our results suggest that although neurons that predict reward value for old stimuli in the LPFC could also do so for new stimuli via transitive inference, those in the striatum could only predict reward for new stimuli via exclusive inference. Moreover, the striatum showed more complex functions than was surmised previously for model-free learning.
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Distinct Reward Properties are Encoded via Corticostriatal Interactions
David V. Smith; Anastasia E. Rigney; Mauricio R. Delgado
2016-01-01
The striatum serves as a critical brain region for reward processing. Yet, understanding the link between striatum and reward presents a challenge because rewards are composed of multiple properties. Notably, affective properties modulate emotion while informative properties help obtain future rewards. We approached this problem by emphasizing affective and informative reward properties within two independent guessing games. We found that both reward properties evoked activation within the nu...
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van Hulst, Branko M; de Zeeuw, Patrick; Lupas, Kellina; Bos, Dienke J; Neggers, Sebastiaan F W; Durston, Sarah
2015-01-01
Reward processing has been implicated in developmental disorders. However, the classic task to probe reward anticipation, the monetary incentive delay task, has an abstract coding of reward and no storyline and may therefore be less appropriate for use with developmental populations. We modified the task to create a version appropriate for use with children. We investigated whether this child-friendly version could elicit ventral striatal activation during reward anticipation in typically developing children and young adolescents (aged 9.5-14.5). In addition, we tested whether our performance-based measure of reward sensitivity was associated with anticipatory activity in ventral striatum. Reward anticipation was related to activity in bilateral ventral striatum. Moreover, we found an association between individual reward sensitivity and activity in ventral striatum. We conclude that this task assesses ventral striatal activity in a child-friendly paradigm. The combination with a performance-based measure of reward sensitivity potentially makes the task a powerful tool for developmental imaging studies of reward processing.
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Ecological risk of reprocessing of uranium wastes of the Gafurov's tailing pit
International Nuclear Information System (INIS)
Khakimov, N.; Nazarov, Kh.M.; Kamalov, D.D.; Mirsaidov, U.M.
2010-01-01
Present article is devoted to assessment ecological risk of reprocessing of uranium wastes of the Gafurov's tailing pit. Authors set as their purpose the investigation of ecological risk of reprocessing of uranium wastes of the Gafurov-city's tailing pit. Having carried out their investigations, the authors came to the conclusion that the effect of radon gas during reprocessing to workers and specialists is minimal if they follow all the required safety rules.
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International Nuclear Information System (INIS)
Emel, J.; Cook, B.; Kasperson, R.; Brown, H.; Guble, R.; Himmelberger, J.; Tuller, S.
1988-09-01
The discussion to follow explores the nature of the high-level radioactive waste disposal tasks and their implications for the design and organizational structure of effective risk management systems. We organize this discussion in a set of interrelated tasks that draw upon both relevant theory and accumulated experience. Specifically these tasks are to assess the management implications of the high levels of technical and social uncertainty that characterize the technology and mission; to identify the elements of organizational theory that bear upon risk management system design; to explore these theoretical issues in the context of two hypothetical risk scenarios associated with radioactive waste disposal; to consider the appropriate role of engineered and geological barriers; to examine briefly issues implicit in DOE's past waste management performance, with special attention to the Hanford facility; and to suggest findings and recommendations that require further attention. 74 refs
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Directory of Open Access Journals (Sweden)
Howes Nathan J
2005-05-01
Full Text Available Abstract Background Animals must frequently make choices between alternative courses of action, seeking to maximize the benefit obtained. They must therefore evaluate the magnitude and the likelihood of the available outcomes. Little is known of the neural basis of this process, or what might predispose individuals to be overly conservative or to take risks excessively (avoiding or preferring uncertainty, respectively. The nucleus accumbens core (AcbC is known to contribute to rats' ability to choose large, delayed rewards over small, immediate rewards; AcbC lesions cause impulsive choice and an impairment in learning with delayed reinforcement. However, it is not known how the AcbC contributes to choice involving probabilistic reinforcement, such as between a large, uncertain reward and a small, certain reward. We examined the effects of excitotoxic lesions of the AcbC on probabilistic choice in rats. Results Rats chose between a single food pellet delivered with certainty (p = 1 and four food pellets delivered with varying degrees of uncertainty (p = 1, 0.5, 0.25, 0.125, and 0.0625 in a discrete-trial task, with the large-reinforcer probability decreasing or increasing across the session. Subjects were trained on this task and then received excitotoxic or sham lesions of the AcbC before being retested. After a transient period during which AcbC-lesioned rats exhibited relative indifference between the two alternatives compared to controls, AcbC-lesioned rats came to exhibit risk-averse choice, choosing the large reinforcer less often than controls when it was uncertain, to the extent that they obtained less food as a result. Rats behaved as if indifferent between a single certain pellet and four pellets at p = 0.32 (sham-operated or at p = 0.70 (AcbC-lesioned by the end of testing. When the probabilities did not vary across the session, AcbC-lesioned rats and controls strongly preferred the large reinforcer when it was certain, and strongly
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Alloy, Lauren B; Bender, Rachel E; Whitehouse, Wayne G; Wagner, Clara A; Liu, Richard T; Grant, David A; Jager-Hyman, Shari; Molz, Ashleigh; Choi, James Y; Harmon-Jones, Eddie; Abramson, Lyn Y
2012-05-01
A prospective, behavioral high-risk design provided a theoretically guided examination of vulnerability to first onset of bipolar spectrum disorder based on the Behavioral Approach System (BAS) model. Adolescents (ages 14-19) at an "age of risk" for bipolar disorder onset were screened on BAS sensitivity by interviewers blind to current symptoms, lifetime history, and family history of psychopathology. Participants were selected with high versus moderate levels of BAS sensitivity and administered a lifetime diagnostic interview. Those with a bipolar spectrum disorder, psychosis, or hypomanic episode with onset prior to the BAS sensitivity assessment were excluded. High BAS (n = 171) and moderate BAS (n = 119) sensitivity participants in the final sample completed baseline measures of symptoms, goal-setting, and reward responsiveness and were followed prospectively with semistructured diagnostic interviews every 6 months. Consistent with the vulnerability hypothesis of the BAS model of bipolar disorder, high BAS participants had a greater likelihood, and shorter time to onset, of bipolar spectrum disorder than moderate BAS participants across an average of 12.8 months of follow-up (12.9% vs. 4.2%), controlling for baseline depressive and hypomanic symptoms, and family history of bipolar disorder. High reward responsiveness on a behavioral task and ambitious goal-striving for popular fame and financial success (but not impulsivity) also predicted first onset of bipolar spectrum disorder controlling for the covariates and BAS risk group, and ambitious goal-striving partially mediated the BAS risk group effect. We discuss implications of the findings for the BAS model of bipolar disorder and early intervention efforts.
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Extinction and renewal of cue-elicited reward-seeking.
Bezzina, Louise; Lee, Jessica C; Lovibond, Peter F; Colagiuri, Ben
2016-12-01
Reward cues can contribute to overconsumption of food and drugs and can relapse. The failure of exposure therapies to reduce overconsumption and relapse is generally attributed to the context-specificity of extinction. However, no previous study has examined whether cue-elicited reward-seeking (as opposed to cue-reactivity) is sensitive to context renewal. We tested this possibility in 160 healthy volunteers using a Pavlovian-instrumental transfer (PIT) design involving voluntary responding for a high value natural reward (chocolate). One reward cue underwent Pavlovian extinction in the same (Group AAA) or different context (Group ABA) to all other phases. This cue was compared with a second non-extinguished reward cue and an unpaired control cue. There was a significant overall PIT effect with both reward cues eliciting reward-seeking on test relative to the unpaired cue. Pavlovian extinction substantially reduced this effect, with the extinguished reward cue eliciting less reward-seeking than the non-extinguished reward cue. Most interestingly, extinction of cue-elicited reward-seeking was sensitive to renewal, with extinction less effective for reducing PIT when conducted in a different context. These findings have important implications for extinction-based interventions for reducing maladaptive reward-seeking in practice. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Risks attached to container- and bunker-storage of nuclear waste
International Nuclear Information System (INIS)
Jager, D. de
1987-12-01
The results are presented of a literature study into the risks attached to the two dry-storage options selected by the Dutch Central Organization For Radioactive Waste (COVRA): the container- and the bunker-storage for irradiated nuclear-fuel elements and nuclear waste. Since the COVRA does not make it clear how these concepts should have to be realized, the experiences abroad with dry interim-storage are considered. In particular the Castor-container-storage and the bunker storage proposed in the committee MINSK (Possibilities of Interim-storage in the Netherlands of Irradiated nuclear-fuel elements and Nuclear waste) are studied further in depth. The committee MINSK has performed a study into the technical realizability of various interim-storage facilities, among which a storage in bunkers. (author). 75 refs.; 14 figs.; 16 tabs
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Reward modulates oculomotor competition between differently valued stimuli.
Bucker, Berno; Silvis, Jeroen D; Donk, Mieke; Theeuwes, Jan
2015-03-01
The present work explored the effects of reward in the well-known global effect paradigm in which two objects appear simultaneously in close spatial proximity. The experiment consisted of three phases (i) a pre-training phase that served as a baseline, (ii) a reward-training phase to associate differently colored stimuli with high, low and no reward value, and (iii) a post-training phase in which rewards were no longer delivered, to examine whether objects previously associated with higher reward value attracted the eyes more strongly than those associated with low or no reward value. Unlike previous reward studies, the differently valued objects directly competed with each other on the same trial. The results showed that initially eye movements were not biased towards any particular stimulus, while in the reward-training phase, eye movements started to land progressively closer towards stimuli that were associated with a high reward value. Even though rewards were no longer delivered, this bias remained robustly present in the post-training phase. A time course analysis showed that the effect of reward was present for the fastest saccades (around 170 ms) and increased with increasing latency. Although strategic effects for slower saccades cannot be ruled out, we suggest that fast oculomotor responses became habituated and were no longer under strategic attentional control. Together the results imply that reward affects oculomotor competition in favor of stimuli previously associated high reward, when multiple reward associated objects compete for selection. Copyright © 2015 Elsevier Ltd. All rights reserved.
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Reward, Distraction, and the Overjustification Effect
Smith, Timothy W.; Pittman, Thane S.
1978-01-01
This study tests two differing hypotheses: the competing response hypothesis, which states that both reward and non-reward distractions produce decreases in interest which weaken over repeated trials, and the attribution/overjustification hypothesis, which maintains that rewards produce a decrease in interest that does not weaken over trials.…
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Renewal processes with costs and rewards
Vlasiou, M.; Cochran, J.J.; Cox, L.A.; Keskinocak, P.; Kharoufeh, J.P.; Smith, J.C.
2011-01-01
We review the theory of renewal reward processes, which describes renewal processes that have some cost or reward associated with each cycle. We present a new simplified proof of the renewal reward theorem that mimics the proof of the Elementary Renewal Theorem and avoids the technicalities in the
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Dragano, Nico; Siegrist, Johannes; Nyberg, Solja T; Lunau, Thorsten; Fransson, Eleonor I; Alfredsson, Lars; Bjorner, Jakob B; Borritz, Marianne; Burr, Hermann; Erbel, Raimund; Fahlén, Göran; Goldberg, Marcel; Hamer, Mark; Heikkilä, Katriina; Jöckel, Karl-Heinz; Knutsson, Anders; Madsen, Ida E H; Nielsen, Martin L; Nordin, Maria; Oksanen, Tuula; Pejtersen, Jan H; Pentti, Jaana; Rugulies, Reiner; Salo, Paula; Schupp, Jürgen; Singh-Manoux, Archana; Steptoe, Andrew; Theorell, Töres; Vahtera, Jussi; Westerholm, Peter J M; Westerlund, Hugo; Virtanen, Marianna; Zins, Marie; Batty, G David; Kivimäki, Mika
2017-07-01
Epidemiologic evidence for work stress as a risk factor for coronary heart disease is mostly based on a single measure of stressful work known as job strain, a combination of high demands and low job control. We examined whether a complementary stress measure that assesses an imbalance between efforts spent at work and rewards received predicted coronary heart disease. This multicohort study (the "IPD-Work" consortium) was based on harmonized individual-level data from 11 European prospective cohort studies. Stressful work in 90,164 men and women without coronary heart disease at baseline was assessed by validated effort-reward imbalance and job strain questionnaires. We defined incident coronary heart disease as the first nonfatal myocardial infarction or coronary death. Study-specific estimates were pooled by random effects meta-analysis. At baseline, 31.7% of study members reported effort-reward imbalance at work and 15.9% reported job strain. During a mean follow-up of 9.8 years, 1,078 coronary events were recorded. After adjustment for potential confounders, a hazard ratio of 1.16 (95% confidence interval, 1.00-1.35) was observed for effort-reward imbalance compared with no imbalance. The hazard ratio was 1.16 (1.01-1.34) for having either effort-reward imbalance or job strain and 1.41 (1.12-1.76) for having both these stressors compared to having neither effort-reward imbalance nor job strain. Individuals with effort-reward imbalance at work have an increased risk of coronary heart disease, and this appears to be independent of job strain experienced. These findings support expanding focus beyond just job strain in future research on work stress.
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Nuclear waste and hazardous waste in the public perception
International Nuclear Information System (INIS)
Kruetli, Pius; Seidl, Roman; Stauffacher, Michael
2015-01-01
The disposal of nuclear waste has gained attention of the public for decades. Accordingly, nuclear waste has been a prominent issue in natural, engineer and social science for many years. Although bearing risks for todays and future generations hazardous waste in contrast is much less an issue of public concern. In 2011, we conducted a postal survey among Swiss Germans (N = 3.082) to learn more about, how nuclear waste is perceived against hazardous waste. We created a questionnaire with two versions, nuclear waste and hazardous waste, respectively. Each version included an identical part with well-known explanatory factors for risk perception on each of the waste types separately and additional questions directly comparing the two waste types. Results show that basically both waste types are perceived similarly in terms of risk/benefit, emotion, trust, knowledge and responsibility. However, in the direct comparison of the two waste types a complete different pattern can be observed: Respondents perceive nuclear waste as more long-living, more dangerous, less controllable and it, furthermore, creates more negative emotions. On the other hand, respondents feel more responsible for hazardous waste and indicate to have more knowledge about this waste type. Moreover, nuclear waste is perceived as more carefully managed. We conclude that mechanisms driving risk perception are similar for both waste types but an overarching negative image of nuclear waste prevails. We propose that hazardous waste should be given more attention in the public as well as in science which may have implications on further management strategies of hazardous waste.
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Nuclear waste and hazardous waste in the public perception
Energy Technology Data Exchange (ETDEWEB)
Kruetli, Pius; Seidl, Roman; Stauffacher, Michael [ETH Zurich (Switzerland). Inst. for Environmental Decisions
2015-07-01
The disposal of nuclear waste has gained attention of the public for decades. Accordingly, nuclear waste has been a prominent issue in natural, engineer and social science for many years. Although bearing risks for todays and future generations hazardous waste in contrast is much less an issue of public concern. In 2011, we conducted a postal survey among Swiss Germans (N = 3.082) to learn more about, how nuclear waste is perceived against hazardous waste. We created a questionnaire with two versions, nuclear waste and hazardous waste, respectively. Each version included an identical part with well-known explanatory factors for risk perception on each of the waste types separately and additional questions directly comparing the two waste types. Results show that basically both waste types are perceived similarly in terms of risk/benefit, emotion, trust, knowledge and responsibility. However, in the direct comparison of the two waste types a complete different pattern can be observed: Respondents perceive nuclear waste as more long-living, more dangerous, less controllable and it, furthermore, creates more negative emotions. On the other hand, respondents feel more responsible for hazardous waste and indicate to have more knowledge about this waste type. Moreover, nuclear waste is perceived as more carefully managed. We conclude that mechanisms driving risk perception are similar for both waste types but an overarching negative image of nuclear waste prevails. We propose that hazardous waste should be given more attention in the public as well as in science which may have implications on further management strategies of hazardous waste.
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Reward Inference by Primate Prefrontal and Striatal Neurons
Pan, Xiaochuan; Fan, Hongwei; Sawa, Kosuke; Tsuda, Ichiro; Tsukada, Minoru; Sakagami, Masamichi
2014-01-01
The brain contains multiple yet distinct systems involved in reward prediction. To understand the nature of these processes, we recorded single-unit activity from the lateral prefrontal cortex (LPFC) and the striatum in monkeys performing a reward inference task using an asymmetric reward schedule. We found that neurons both in the LPFC and in the striatum predicted reward values for stimuli that had been previously well experienced with set reward quantities in the asymmetric reward task. Im...
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Ventral pallidum roles in reward and motivation.
Smith, Kyle S; Tindell, Amy J; Aldridge, J Wayne; Berridge, Kent C
2009-01-23
In recent years the ventral pallidum has become a focus of great research interest as a mechanism of reward and incentive motivation. As a major output for limbic signals, the ventral pallidum was once associated primarily with motor functions rather than regarded as a reward structure in its own right. However, ample evidence now suggests that ventral pallidum function is a major mechanism of reward in the brain. We review data indicating that (1) an intact ventral pallidum is necessary for normal reward and motivation, (2) stimulated activation of ventral pallidum is sufficient to cause reward and motivation enhancements, and (3) activation patterns in ventral pallidum neurons specifically encode reward and motivation signals via phasic bursts of excitation to incentive and hedonic stimuli. We conclude that the ventral pallidum may serve as an important 'limbic final common pathway' for mesocorticolimbic processing of many rewards.
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Reward modulates perception in binocular rivalry.
Marx, Svenja; Einhäuser, Wolfgang
2015-01-14
Our perception does not provide us with an exact imprint of the outside world, but is continuously adapted to our internal expectations, task sets, and behavioral goals. Although effects of reward-or value in general-on perception therefore seem likely, how valuation modulates perception and how such modulation relates to attention is largely unknown. We probed effects of reward on perception by using a binocular-rivalry paradigm. Distinct gratings drifting in opposite directions were presented to each observer's eyes. To objectify their subjective perceptual experience, the optokinetic nystagmus was used as measure of current perceptual dominance. In a first experiment, one of the percepts was either rewarded or attended. We found that reward and attention similarly biased perception. In a second experiment, observers performed an attentionally demanding task either on the rewarded stimulus, the other stimulus, or both. We found that-on top of an attentional effect on perception-at each level of attentional load, reward still modulated perception by increasing the dominance of the rewarded percept. Similarly, penalizing one percept increased dominance of the other at each level of attentional load. In turn, rewarding-and similarly nonpunishing-a percept yielded performance benefits that are typically associated with selective attention. In conclusion, our data show that value modulates perception in a similar way as the volitional deployment of attention, even though the relative effect of value is largely unaffected by an attention task. © 2015 ARVO.
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It's about time: Earlier rewards increase intrinsic motivation.
Woolley, Kaitlin; Fishbach, Ayelet
2018-06-01
Can immediate (vs. delayed) rewards increase intrinsic motivation? Prior research compared the presence versus absence of rewards. By contrast, this research compared immediate versus delayed rewards, predicting that more immediate rewards increase intrinsic motivation by creating a perceptual fusion between the activity and its goal (i.e., the reward). In support of the hypothesis, framing a reward from watching a news program as more immediate (vs. delayed) increased intrinsic motivation to watch the program (Study 1), and receiving more immediate bonus (vs. delayed, Study 2; and vs. delayed and no bonus, Study 3) increased intrinsic motivation in an experimental task. The effect of reward timing was mediated by the strength of the association between an activity and a reward, and was specific to intrinsic (vs. extrinsic) motivation-immediacy influenced the positive experience of an activity, but not perceived outcome importance (Study 4). In addition, the effect of the timing of rewards was independent of the effect of the magnitude of the rewards (Study 5). (PsycINFO Database Record (c) 2018 APA, all rights reserved).
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Evolutionary advantages of adaptive rewarding
International Nuclear Information System (INIS)
Szolnoki, Attila; Perc, Matjaž
2012-01-01
Our well-being depends on both our personal success and the success of our society. The realization of this fact makes cooperation an essential trait. Experiments have shown that rewards can elevate our readiness to cooperate, but since giving a reward inevitably entails paying a cost for it, the emergence and stability of such behavior remains elusive. Here we show that allowing for the act of rewarding to self-organize in dependence on the success of cooperation creates several evolutionary advantages that instill new ways through which collaborative efforts are promoted. Ranging from indirect territorial battle to the spontaneous emergence and destruction of coexistence, phase diagrams and the underlying spatial patterns reveal fascinatingly rich social dynamics that explain why this costly behavior has evolved and persevered. Comparisons with adaptive punishment, however, uncover an Achilles heel of adaptive rewarding, coming from over-aggression, which in turn hinders optimal utilization of network reciprocity. This may explain why, despite its success, rewarding is not as firmly embedded into our societal organization as punishment. (paper)
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Decision-Making Risks Concerning the Construction of the Goiania Waste Repository
Energy Technology Data Exchange (ETDEWEB)
Paschoa, A.S. [Pontificia Univ. Catolica, Rio de Janeiro (Brazil); Rozental, J.J. [Ministry of Environment (Israel); Tranjan Filho, A. [Comissao Nacional de Energia Nuclear (CNEN) (Brazil)
2001-07-01
As it is well known, an accident with a teletherapy source made of {sup 137}CsCl with an initial activity of 59 TBq occurred in Goiania, in September of 1987. This paper will discuss the decision-making process, and the struggle that followed the decision to build the final repository for the remnants of the Goiania accident. The Goiania final repository was built as planned. The two subsurface structures under the grassy artificial hills hold the overall volume of the remnants of the Goiania accident. The near hill holds 5x10{sup 3} m3 of stabilized wastes without radioactivity, or with very low radioactivity. The far hill holds the remaining 6.5x10{sup 3} m{sup 3} of stabilized wastes with low and medium radioactivity. The central part of each subsurface hill has been shielded by wastes with less and less radioactivity. The overall fenced area occupies 1.85x10{sup 5} m{sup 2}. The external radiation levels are similar to the surrounding background, and much lower than those found in the Brazilian areas of high natural radioactivity. The site is permanently monitored by independent institutions, including Brazilian universities, and national and international organizations. As it was mentioned earlier, the final repository was build to last for at least 400 years. Although the initial decision to adopt a too conservative decontamination criterion in the case of the Goiania accident was bound to produce excessive amount of waste; such decision proved, retrospectively, not to be bad because the excess low radioactive waste produced was used as extra shielding material in final repository. The technical decision-maker should not abandon risk estimates, but should be aware that credibility is the main basis to achieve acceptability of a decision by the general public. Risk perception should be regarded as only a first step towards what may be called knowledge, or comprehension of risk estimates, but risk perception by the general public is still an open issue. The
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Estimating risk at a Superfund site contaminated with radiological and chemical wastes
International Nuclear Information System (INIS)
Temeshy, A.; Liedle, J.M.; Sims, L.M.; Efird, C.R.
1992-01-01
This paper describes the method and results for estimating carcinogenic and noncarcinogenic effects at a Superfund site that is radiologically and chemically contaminated. Risk to receptors from disposal of waste in soil and resulting contamination of groundwater, air, surface water, and sediment is quantified. Specific risk assessment components which are addressed are the exposure assessment, toxicity assessment, and the resulting risk characterization. In the exposure assessment, potential exposure pathways are identified using waste disposal inventory information for soil and modeled information for other media. Models are used to calculate future radionuclide concentrations in groundwater, soil, surface water and air. Chemical exposure concentrations are quantified using site characterization data. Models are used to determine concentrations of chemicals in surface water and in air. Toxicity parameters used to quantify the dose-response relationship associated with the carcinogenic contaminants are slope factors and with noncarcinogenic contaminants are reference doses. In the risk characterization step, results from the exposure assessment and toxicity assessment are summarized and integrated into quantitative risk estimates for carcinogens and hazard induces for noncarcinogens. Calculated risks for carcinogenic contaminants are compared with EPA's target risk range. At WAG 6, the risk from radionuclides and chemicals for an on-WAG homesteader exceeds EPA's target risk range. Hazard indices are compared to unity for noncarcinogenic contaminants. At WAG 6, the total pathway hazard index for the on-WAG homesteader exceeds unity
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Treatment methods and comparative risks of thorium removal from waste residues
International Nuclear Information System (INIS)
Porter, R.D.; Hamby, D.M.; Martin, J.E.
1997-07-01
This study was done to examine the risks of remediation and the effectiveness of removal methods for thorium and its associated radioactive decay products from various soils and wastes associated with DOE's Formerly Utilized Sites Remedial Action Program (FUSRAP). Removal of 230 Th from uranium process residues would significantly reduce the buildup of 226 Ra (half-life of 1600 years), and since 230 Th concentrations at most of the important sites greatly exceed the 226 Ra concentrations, such removal would reduce the accumulation of additional radiation risks associated with 226 Ra and its products; and, if treatment also removed 226 Ra, these risks could be mitigated even further. Removal of 232 Th from thorium process residues would remove the source material for 228 Ra, and since 228 Ra has a half-life of 5.76 years, its control at FUSRAP sites could be done with land use controls for the 30--50 years required for 228 Ra and the risks associated with its decay products to decay away. It must be recognized, however, that treatment methods invariably require workers to process residues and waste materials usually with bulk handling techniques. These processes expose workers to the radioactivity in the materials, therefore, workers would incur radiological risks in addition to industrial accident risks. An important question is whether the potential reduction of future radiological risks to members of the public justifies the risks that are incurred by remediation workers due to handling materials. This study examines, first, the effectiveness of treatment and then the risks that would be associated with remediation
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Overt and covert attention to location-based reward.
McCoy, Brónagh; Theeuwes, Jan
2018-01-01
Recent research on the impact of location-based reward on attentional orienting has indicated that reward factors play an influential role in spatial priority maps. The current study investigated whether and how reward associations based on spatial location translate from overt eye movements to covert attention. If reward associations can be tied to locations in space, and if overt and covert attention rely on similar overlapping neuronal populations, then both overt and covert attentional measures should display similar spatial-based reward learning. Our results suggest that location- and reward-based changes in one attentional domain do not lead to similar changes in the other. Specifically, although we found similar improvements at differentially rewarded locations during overt attentional learning, this translated to the least improvement at a highly rewarded location during covert attention. We interpret this as the result of an increased motivational link between the high reward location and the trained eye movement response acquired during learning, leading to a relative slowing during covert attention when the eyes remained fixated and the saccade response was suppressed. In a second experiment participants were not required to keep fixated during the covert attention task and we no longer observed relative slowing at the high reward location. Furthermore, the second experiment revealed no covert spatial priority of rewarded locations. We conclude that the transfer of location-based reward associations is intimately linked with the reward-modulated motor response employed during learning, and alternative attentional and task contexts may interfere with learned spatial priorities. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
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Bioethical perspective on acceptable-risk criteria for nuclear-waste management
International Nuclear Information System (INIS)
Maxey, M.N.
1977-01-01
Wisely managing the profound human and environmental risks of nuclear wastes requires complex moral and ethical judgments. Whereas traditional ethics is limited to interpersonal relations, a new system of ethics--bioethics--concerns man's relation with nature. Environmentalists claim that technology has upset the balance of nature, that nature is sacred and has inviolable rights, and that man must therefore regulate his behavior to conform to earth's limited carrying capacity. They also say that Judeo-Christian monotheism and anthropocentrism have sanctioned the exploitation of nature in the West, whereas Eastern religions teach adaptation to nature. Evidence suggests, however, that the balance of nature is neither absolute nor precarious, but is continually changing. Moreover, technology has brought more good than harm to man, and man's needs should supersede nature's. Other evidence indicates that the earth's resources may be neither limited nor nearly exhausted. Persuasive arguments also demonstrate that man's relation with nature is not traceable to religious assumptions. In assessing the risks/benefits of nuclear-waste management, we should avoid risks that jeopardize the rights of future generations without imposing excessive sacrifices on the present generation
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Bioethical perspective on acceptable-risk criteria for nuclear-waste management
Energy Technology Data Exchange (ETDEWEB)
Maxey, M.N.
1977-07-15
Wisely managing the profound human and environmental risks of nuclear wastes requires complex moral and ethical judgments. Whereas traditional ethics is limited to interpersonal relations, a new system of ethics--bioethics--concerns man's relation with nature. Environmentalists claim that technology has upset the balance of nature, that nature is sacred and has inviolable rights, and that man must therefore regulate his behavior to conform to earth's limited carrying capacity. They also say that Judeo-Christian monotheism and anthropocentrism have sanctioned the exploitation of nature in the West, whereas Eastern religions teach adaptation to nature. Evidence suggests, however, that the balance of nature is neither absolute nor precarious, but is continually changing. Moreover, technology has brought more good than harm to man, and man's needs should supersede nature's. Other evidence indicates that the earth's resources may be neither limited nor nearly exhausted. Persuasive arguments also demonstrate that man's relation with nature is not traceable to religious assumptions. In assessing the risks/benefits of nuclear-waste management, we should avoid risks that jeopardize the rights of future generations without imposing excessive sacrifices on the present generation.
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Hunger and Satiety Gauge Reward Sensitivity
Directory of Open Access Journals (Sweden)
Ryan Michael Cassidy
2017-05-01
Full Text Available Many of the neurocircuits and hormones known to underlie the sensations of hunger and satiety also substantially alter the activity of the dopaminergic reward system. Much interest lies in the ways that hunger, satiety, and reward tie together, as the epidemic of obesity seems tied to the recent development and mass availability of highly palatable foods. In this review, we will first discuss the basic neurocircuitry of the midbrain and basal forebrain reward system. We will elaborate how several important mediators of hunger—the agouti-related protein neurons of the arcuate nucleus, the lateral hypothalamic nucleus, and ghrelin—enhance the sensitivity of the dopaminergic reward system. Then, we will elaborate how mediators of satiety—the nucleus tractus solitarius, pro-opiomelanocortin neurons of the arcuate nucleus, and its peripheral hormonal influences such as leptin—reduce the reward system sensitivity. We hope to provide a template by which future research may identify the ways in which highly rewarding foods bypass this balanced system to produce excessive food consumption.
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Identifying nurses' rewards: a qualitative categorization study in Belgium
Directory of Open Access Journals (Sweden)
Du Bois Cindy
2006-07-01
Full Text Available Abstract Background Rewards are important in attracting, motivating and retaining the most qualified employees, and nurses are no exception to this rule. This makes the establishment of an efficient reward system for nurses a true challenge for every hospital manager. A reward does not necessarily have a financial connotation: non-financial rewards may matter too, or may even be more important. Therefore, the present study examines nurses' reward perceptions, in order to identify potential reward options. Methods To answer the research question "What do nurses consider a reward and how can these rewards be categorized?", 20 in-depth semi-structured interviews with nurses were conducted and analysed using discourse and content analyses. In addition, the respondents received a list of 34 rewards (derived from the literature and were asked to indicate the extent to which they perceived each of them to be rewarding. Results Discourse analysis revealed three major reward categories: financial, non-financial and psychological, each containing different subcategories. In general, nurses more often mentioned financial rewards spontaneously in the interview, compared to non-financial and psychological rewards. The questionnaire results did not, however, indicate a significant difference in the rewarding potential of these three categories. Both the qualitative and quantitative data revealed that a number of psychological and non-financial rewards were important for nurses in addition to their monthly pay and other remunerations. In particular, appreciation for their work by others, compliments from others, presents from others and contact with patients were highly valued. Moreover, some demographical variables influenced the reward perceptions. Younger and less experienced nurses considered promotion possibilities as more rewarding than the older and more senior ones. The latter valued job security and working for a hospital with a good reputation higher
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Social and monetary reward processing in autism spectrum disorders.
Delmonte, Sonja; Balsters, Joshua H; McGrath, Jane; Fitzgerald, Jacqueline; Brennan, Sean; Fagan, Andrew J; Gallagher, Louise
2012-09-26
Social motivation theory suggests that deficits in social reward processing underlie social impairments in autism spectrum disorders (ASD). However, the extent to which abnormalities in reward processing generalize to other classes of stimuli remains unresolved. The aim of the current study was to examine if reward processing abnormalities in ASD are specific to social stimuli or can be generalized to other classes of reward. Additionally, we sought to examine the results in the light of behavioral impairments in ASD. Participants performed adapted versions of the social and monetary incentive delay tasks. Data from 21 unmedicated right-handed male participants with ASD and 21 age- and IQ-matched controls were analyzed using a factorial design to examine the blood-oxygen-level-dependent (BOLD) response during the anticipation and receipt of both reward types. Behaviorally, the ASD group showed less of a reduction in reaction time (RT) for rewarded compared to unrewarded trials than the control group. In terms of the fMRI results, there were no significant group differences in reward circuitry during reward anticipation. During the receipt of rewards, there was a significant interaction between group and reward type in the left dorsal striatum (DS). The ASD group showed reduced activity in the DS compared to controls for social rewards but not monetary rewards and decreased activation for social rewards compared to monetary rewards. Controls showed no significant difference between the two reward types. Increased activation in the DS during social reward processing was associated with faster response times for rewarded trials, compared to unrewarded trials, in both groups. This is in line with behavioral results indicating that the ASD group showed less of a reduction in RT for rewarded compared to unrewarded trials. Additionally, de-activation to social rewards was associated with increased repetitive behavior in ASD. In line with social motivation theory, the ASD
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Memory Consolidation and Neural Substrate of Reward
Directory of Open Access Journals (Sweden)
Redolar-Ripoll, Diego
2012-08-01
Full Text Available The aim of this report is to analyze the relationships between reward and learning and memory processes. Different studies have described how information about rewards influences behavior and how the brain uses this reward information to control learning and memory processes. Reward nature seems to be processed in different ways by neurons in different brain structures, ranging from the detection and perception of rewards to the use of information about predicted rewards for the control of goal-directed behavior. The neural substrate underling this processing of reward information is a reliable way of improving learning and memory processes. Evidence from several studies indicates that this neural system can facilitate memory consolidation in a wide variety of learning tasks. From a molecular perspective, certain cardinal features of reward have been described as forms of memory. Studies of human addicts and studies in animal models of addiction show that chronic drug exposure produces stable changes in the brain at the cellular and molecular levels that underlie the long-lasting behavioral plasticity associated with addiction. These molecular and cellular adaptations involved in addiction are also implicated in learning and memory processes. Dopamine seems to be a critical common signal to activate different genetic mechanisms that ultimately remodel synapses and circuits. Despite memory is an active and complex process mediated by different brain areas, the neural substrate of reward is able to improve memory consolidation in a several paradigms. We believe that there are many equivalent traits between reward and learning and memory processes.
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[Effect of occupational stress and effort-reward imbalance on sleep quality of people's policeman].
Wu, Hui; Gu, Guizhen; Yu, Shanfa
2014-04-01
To explore the effect of occupational stress and effort-reward imbalance on sleep quality of people's police. A cluster sampling survey of sleep quality and occupational stress correlated factors was conducted on 287 police from a city public security bureau by questionnaires in May, 2011; the relationship between sleep quality and occupational stress correlated factors was analyzed by one-way ANOVA and multivariate non-conditional logistic regression using effort-reward imbalance model (ERI) and demand-control-support model (DCS). And the subjects were divided into high tension group and low tension group using the 1.0 of ERI and DCS coefficients as the boundary. The sleep quality score of shift work police was higher than day work police (11.95 ± 6.54 vs 9.52 ± 6.43, t = 2.77, P argument, sex (OR = 3.0, 95%CI:1.16-7.73) , age for 30-39 years (OR = 3.48, 95%CI:1.32-9.16) , intrinsic effort (OR = 2.30, 95%CI:1.10-4.81) and daily hassles (OR = 2.15, 95%CI:1.06-4.33) were risk factors of low sleep quality, and reward (OR = 0.26, 95%CI:0.12-0.52) was the protective factor.For the regression analysis of DCS model as an argument , age for 30-39 years (OR = 2.55, 95%CI:1.02-6.37) , depressive symptom (OR = 2.10, 95%CI:1.14-3.89) and daily hassles (OR = 3.25, 95%CI:1.70-6.19) were risk factors of low sleep quality.While the ERI model and the DCS model were analyzed simultaneously, sex (OR = 3.03, 95%CI:1.15-7.98) , age for 30-39 years (OR = 3.71, 95%CI:1.38-9.98) and daily hassles (OR = 2.09, 95%CI:1.01-4.30) were the risk factors of low sleep quality, and reward (OR = 0.22, 95%CI:0.10-0.48) was the protective factor. Occupational stress and effort-reward imbalance affected the sleep quality to people's policeman.
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Energy Technology Data Exchange (ETDEWEB)
Sasser, K.
1994-06-01
In FY 1993, the Los Alamos National Laboratory Waste Management Group [CST-7 (formerly EM-7)] requested the Probabilistic Risk and Hazards Analysis Group [TSA-11 (formerly N-6)] to conduct a study of the hazards associated with several CST-7 facilities. Among these facilities are the Hazardous Waste Treatment Facility (HWTF), the HWTF Drum Storage Building (DSB), and the Mixed Waste Receiving and Storage Facility (MWRSF), which are proposed for construction beginning in 1996. These facilities are needed to upgrade the Laboratory`s storage capability for hazardous and mixed wastes and to provide treatment capabilities for wastes in cases where offsite treatment is not available or desirable. These facilities will assist Los Alamos in complying with federal and state requlations.
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Incentive theory: IV. Magnitude of reward
Killeen, Peter R.
1985-01-01
Incentive theory is successfully applied to data from experiments in which the amount of food reward is varied. This is accomplished by assuming that incentive value is a negatively accelerated function of reward duration. The interaction of the magnitude of a reward with its delay is confirmed, and the causes and implications of this interaction are discussed.
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Directory of Open Access Journals (Sweden)
Rochmoeljati Rr.
2017-06-01
Full Text Available The major problem faced by PT. Varia Usaha Beton Gresik is not the maintenance activity according to Standard Operation Procedure (SOP, but the activities conducted without taking into account the waste. The purpose of this study is to examine the waste in the maintenance activities as to minimize it by the lean maintenance method. This is taken on a conveyor belt weigher machine, a bucket conveyor, a concrete mixer, and a machine host. The variable is the flow of treatment by reducing waste and by giving recommendation of improvement. Data collection includes damage data, production data, product disability data, and maintenance activity data. The conclusion is QT-10 waste motion machine takes 532 minutes for waste repair, 45 minutes for waste process, and 90 minutes for waste waiting. Our recommendations include improvement on the information provided, on training and rewards, and on supervisors of the production line.
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External Criticality Risk of Immobilized Plutonium Waste Form in a Geologic Repository
International Nuclear Information System (INIS)
McClure, J.
2001-01-01
This purpose of this technical report is to provide a comprehensive summary of the waste package (WP) external criticality-related risk of the Plutonium Disposition ceramic waste form, which is being developed and evaluated by the Office of Fissile Materials Disposition of the United States Department of Energy (DOE). Potential accumulation of the fissile materials, 239 Pu and 235 U, in rock formations having a favorable chemical environment for such actions, requires analysis because autocatalytic configurations, while unlikely to form, never-the-less have consequences which are undesirable and require evaluation. Secondly, the WP design has evolved necessitating a re-evaluation of the internal WP degradation scenarios that contribute to the external source terms. The scope of this study includes a summary of the revised WP degradation calculations, a summary of the accumulation mechanisms in fractures and lithophysae in the tuff beneath the WP footprint, and a summary of the criticality risk calculations from any accumulated fissile material. Accumulations of fissile material external to the WP sufficient to pose a potential criticality risk require a deposition mechanism operating over sufficient time to reach required levels. The transporting solution concentrations themselves are well below critical levels (CRWMS 2001e). The ceramic waste form consists of Pu immobilized in ceramic disks, which would be embedded in High-Level Waste (HLW) glass in the standard HLW glass disposal canister. The ceramic disks would occupy approximately 12% of the HLW canister volume, while most of the remaining 88% of the volume would be occupied by HLW glass
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Niedhammer, I; Siegrist, J
1998-11-01
The effect of psychosocial factors at work on health, especially cardiovascular health, has given rise to growing concern in occupational epidemiology over the last few years. Two theoretical models, Karasek's model and the Effort-Reward Imbalance model, have been developed to evaluate psychosocial factors at work within specific conceptual frameworks in an attempt to take into account the serious methodological difficulties inherent in the evaluation of such factors. Karasek's model, the most widely used model, measures three factors: psychological demands, decision latitude and social support at work. Many studies have shown the predictive effects of these factors on cardiovascular diseases independently of well-known cardiovascular risk factors. More recently, the Effort-Reward Imbalance model takes into account the role of individual coping characteristics which was neglected in the Karasek model. The effort-reward imbalance model focuses on the reciprocity of exchange in occupational life where high-cost/low-gain conditions are considered particularly stressful. Three dimensions of rewards are distinguished: money, esteem and gratifications in terms of promotion prospects and job security. Some studies already support that high-effort/low reward-conditions are predictive of cardiovascular diseases.
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Risk analyses for disposing nonhazardous oil field wastes in salt caverns
Energy Technology Data Exchange (ETDEWEB)
Tomasko, D.; Elcock, D.; Veil, J.; Caudle, D.
1997-12-01
Salt caverns have been used for several decades to store various hydrocarbon products. In the past few years, four facilities in the US have been permitted to dispose nonhazardous oil field wastes in salt caverns. Several other disposal caverns have been permitted in Canada and Europe. This report evaluates the possibility that adverse human health effects could result from exposure to contaminants released from the caverns in domal salt formations used for nonhazardous oil field waste disposal. The evaluation assumes normal operations but considers the possibility of leaks in cavern seals and cavern walls during the post-closure phase of operation. In this assessment, several steps were followed to identify possible human health risks. At the broadest level, these steps include identifying a reasonable set of contaminants of possible concern, identifying how humans could be exposed to these contaminants, assessing the toxicities of these contaminants, estimating their intakes, and characterizing their associated human health risks. The contaminants of concern for the assessment are benzene, cadmium, arsenic, and chromium. These were selected as being components of oil field waste and having a likelihood to remain in solution for a long enough time to reach a human receptor.
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The Relationship Between the Effort-Reward Imbalance and Psychosocial Health in Nurses
Directory of Open Access Journals (Sweden)
Fariborz Roshangar
2017-09-01
Full Text Available The health of nurses as providers of health affects the quality of care provided by health care organizations to patients. The effort-reward imbalance is accompanied by repressive responses that can lead to physical and psychological diseases as well as stressful experiences in nurses’ activity. Regarding the existence of some discrimination in the system of health, the present study was conducted to determine the relationship between the effort-reward imbalance and psychosocial health in nurses. In this descriptive cross-sectional study, 270 nurses working in five medical-educational centers in Tabriz participated through random-quota sampling. The research tool included a demographic questionnaire, Siegrist effort- reward imbalance questionnaire and Copenhagen Psychosocial questionnaire. Data were analyzed by SPSS V18 and descriptive and inferential statistics. In the present study, 54.8% of the patients were suffering from effort- reward imbalance model (occupational stress. The relatively high prevalence of this can be attributed to the conditions of the hospital's working environment. The results of this study showed a significant relationship between psychosocial health and balance of reward and effort in nurses and also the findings of the research showed a positive and significant relationship between mental and social health and the score of effort-reward imbalance model (0.95 = R, and P <0.05. There was a significant relationship between effort and work commitment and job burnout. Considering the stressful nature of the profession among many reasons, the mental health of nurses is at a higher risk than that of other groups in the society. Because some factors related to the imbalance in the effort and reward (stress is inevitable, it is necessary in the profession of nursing for managers to review their employees' position and characteristics to find out their staff’s attitudes and behaviors and direct them in the right path.
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Directory of Open Access Journals (Sweden)
Tim eHahn
2014-11-01
Full Text Available Millions of people regularly play so-called Massively Multiplayer Online Role Playing Games (MMORPGs. Recently, it has been argued that MMORPG overuse is becoming a significant health problem worldwide. Symptoms such as tolerance, withdrawal and craving have been described. Based on behavioral, resting state and task-related neuroimaging data, we test whether frequent players of the MMORPG World of Warcraft (WoW – similar to drug addicts and individuals with an increased risk for addictions – show a generally deficient reward system. In frequent players of the MMORPG World of Warcraft (WoW-players and in a control group of non-gamers we assessed 1 trait sensitivity to reward, 2 BOLD responses during monetary reward processing in the ventral striatum and 3 ventral-striatal resting state dynamics. We find a decreased neural activation in the ventral striatum during the anticipation of both small and large monetary rewards. Additionally, we show generally altered neurodynamics in this region independent of any specific task for WoW players (resting state. On the behavioral level, we found differences in trait sensitivity to reward, suggesting that the reward processing deficiencies found in this study are not a consequence of gaming, but predisposed to it. These findings empirically support a direct link between frequent online gaming and the broad field of behavioral and drug addiction research, thus opening new avenues for clinical interventions in addicted gamers and potentially improving the assessment of addiction-risk in the vast population of frequent gamers.
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Radioactive Waste Transport: Managing Risk Perception and Communication
International Nuclear Information System (INIS)
Murray, Ch.
2009-01-01
The implementation of a national transportation system for spent nuclear fuel and high-level waste that merits public trust and confidence will require the delivery of consistent, accurate and timely transportation messages; stakeholder and public understanding of the need for, and safety of, shipments; and effective two-way communication to address stakeholder concerns in its decision-making processes. Building the trust and consent of stakeholders and the public is complex and challenging. In order to accomplish this goal, it is imperative to understand how and why members of society develop various perceptions of risks and assessments of benefits with regard to the nuclear energy cycle. Understanding the basis and reasons for the public's beliefs concerning the nuclear energy cycle will allow OCRWM to more effectively address concerns regarding the national transportation program. This paper will examine how a person's gender, sources of information, world-view, culture, emotion, cognition, and other factors affect their beliefs and perceptions of risk. It will also explore the reasons why nuclear energy and nuclear waste are viewed with such a distinctly different attitude than other hazardous materials that pose a comparable or greater hazard. Drawing on research from prominent experts in risk perception and communication methods, this study will conduct a unique investigation into the perspectives of a diverse set of key stakeholders and experts involved in the transportation process. This paper will present several hypotheses on why there are unique challenges involved in communicating about transportation of spent nuclear fuel and other nuclear fuel cycle activities, and also present recommendations for remediating such challenges. (authors)
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Reward Circuitry in Addiction.
Cooper, Sarah; Robison, A J; Mazei-Robison, Michelle S
2017-07-01
Understanding the brain circuitry that underlies reward is critical to improve treatment for many common health issues, including obesity, depression, and addiction. Here we focus on insights into the organization and function of reward circuitry and its synaptic and structural adaptations in response to cocaine exposure. While the importance of certain circuits, such as the mesocorticolimbic dopamine pathway, are well established in drug reward, recent studies using genetics-based tools have revealed functional changes throughout the reward circuitry that contribute to different facets of addiction, such as relapse and craving. The ability to observe and manipulate neuronal activity within specific cell types and circuits has led to new insight into not only the basic connections between brain regions, but also the molecular changes within these specific microcircuits, such as neurotrophic factor and GTPase signaling or α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor function, that underlie synaptic and structural plasticity evoked by drugs of abuse. Excitingly, these insights from preclinical rodent work are now being translated into the clinic, where transcranial magnetic simulation and deep brain stimulation therapies are being piloted in human cocaine dependence. Thus, this review seeks to summarize current understanding of the major brain regions implicated in drug-related behaviors and the molecular mechanisms that contribute to altered connectivity between these regions, with the postulation that increased knowledge of the plasticity within the drug reward circuit will lead to new and improved treatments for addiction.
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Music-related reward responses predict episodic memory performance.
Ferreri, Laura; Rodriguez-Fornells, Antoni
2017-12-01
Music represents a special type of reward involving the recruitment of the mesolimbic dopaminergic system. According to recent theories on episodic memory formation, as dopamine strengthens the synaptic potentiation produced by learning, stimuli triggering dopamine release could result in long-term memory improvements. Here, we behaviourally test whether music-related reward responses could modulate episodic memory performance. Thirty participants rated (in terms of arousal, familiarity, emotional valence, and reward) and encoded unfamiliar classical music excerpts. Twenty-four hours later, their episodic memory was tested (old/new recognition and remember/know paradigm). Results revealed an influence of music-related reward responses on memory: excerpts rated as more rewarding were significantly better recognized and remembered. Furthermore, inter-individual differences in the ability to experience musical reward, measured through the Barcelona Music Reward Questionnaire, positively predicted memory performance. Taken together, these findings shed new light on the relationship between music, reward and memory, showing for the first time that music-driven reward responses are directly implicated in higher cognitive functions and can account for individual differences in memory performance.
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Hospital waste management in Lebanon
International Nuclear Information System (INIS)
Chaker, Alissar
1999-01-01
Hospital wastes comprises approximately 80% domestic waste components, also known as non-risk waste and 20% hazardous or risk waste. The 20% of the hospital waste stream or the risk waste (also known as infectious, medical, clinical wastes) comprises components which could be potentially contaminated with infections, chemical or radioactive agents. Therefore, it should be handled and disposed of in such a manner as to minimize potential human exposure and cross-contamination. Hospital risk waste and be subdivided into seven general categories as follows: infections, anatomical/pathological, chemical, pharmaceutical, radioactive waste, sharps and pressurised containers. These waste categories are generated by many types of health care establishments, including hospitals, clinics, infirmaries.... The document presents also tables of number of hospitals and estimated bed number in different regions in Lebanon; estimated hospital risk and non-risk waste generation per tonnes per day for the years 1998 until 2010 and finally sensitivity analysis of estimated generation of hospital risk waste in Lebanon per tonnes per day for the years 1998 until 2010. The management, treatment and disposal of hospital risk waste constitute important environmental and public safety issues. It is recognised that there is alack of infrastructure for the safe and environmentally acceptable disposal of hospital waste in Lebanon
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The risk of storing radioactive wastes from nuclear power plants
International Nuclear Information System (INIS)
Gruemm, H.
1976-09-01
Serious bottle-necks exist in the nuclear fuel cycle and will continue for the next decade. A total of 800 nuclear reactors are now in operation. 153 nuclear power plants represent an installed capacity of 70 GVe. Until 1985 five hundred nuclear power plants will be in operation from which up to this date 53.000 t uranium will have been discharged. Part of this will have to be reprocessed. Associated with the above mentioned amount are 500 t plutonium and 1.500 t highly radioactive wastes. Two risks for the population have to be considered: firstly, the effect of small amounts of radioactive substances released during normal operation of nuclear power plants (the annual dose is about 1 mrem per person). Secondly, the possibility of the release of great amounts of radioactivity during heavy accidents (the probability for which is extremely small). A series of feasible possibilities for conditioning are shown. Firstly, the wastes are packed in substances which are insoluble in water. Secondly, for low and medium wastes these can be mixed with concrete or bitumen and filled into stable containers. Thirdly, the wastes could also be solidified. Fourthly, the wastes could be enclosed in small glass spheres which are embedded in a metal matrix. (H.G.)
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Sensitivity to Temporal Reward Structure in Amygdala Neurons
Bermudez, Maria A.; Göbel, Carl; Schultz, Wolfram
2012-01-01
Summary The time of reward and the temporal structure of reward occurrence fundamentally influence behavioral reinforcement and decision processes [1–11]. However, despite knowledge about timing in sensory and motor systems [12–17], we know little about temporal mechanisms of neuronal reward processing. In this experiment, visual stimuli predicted different instantaneous probabilities of reward occurrence that resulted in specific temporal reward structures. Licking behavior demonstrated that...
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International Nuclear Information System (INIS)
Cheung, H.; Edwards, L.L.; Harvey, T.F.
1982-01-01
A network model was developed to simulate the hydrological flow and the transport of radionuclides from a deep geological repository to the biosphere subsequent to closure. By means of very efficient computational methods for solving the fundamental differential equations, a code was developed to treat in great detail the effects of waste form characteristics and of repository designs on the repository risks. It is possible to examine near field effects heretofore not attempted. Without sacrificing the essential details of description, the code can also be applied to perform probabilistic risk analyses to high confidence levels. Analytical results showed: (1) for waste form release rates greater than approximately 5 x 10 -7 /yr, dose to man is insensitive to release rate and release rate uncertainty; (2) significant reduction in dose can be achieved through simple design modifications; (3) a basalt repository generally does not perform as well as a salt repository; and (4) disruptive events are relatively unimportant for repository safety. 82 references
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The role of the media in the coverage of risks associated with nuclear waste
International Nuclear Information System (INIS)
Renn, O.
1998-01-01
Nuclear waste has become the prime target for an increasingly concerned public over the acceptability of technological risks. In recent times the major conflict is about the distribution and the tolerability of risks for different social groups, regions, and future generations. This shift of focus implies new forms of conflict resolution and underlines the importance of communication as a necessary, though not sufficient, step towards a social equilibrium. Interest of public institutions and academia in risk communication has considerably grown during the last five years. Risk communication has become a popular topic in the literature. Risk communication can serve many purposes ranging from enlightenment, to inducing behavioral changes, to conflict resolution. The crucial issue of how the media shape the perception of risk among individuals and social groups is discussed, and how trust and credibility have become major agents in the public communication process. Some advices are given for risk managers, in particular those dealing with nuclear waste, about potential improvement in their risk communication efforts. (R.P.)
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Reward sensitivity and food addiction in women.
Loxton, Natalie J; Tipman, Renée J
2017-08-01
Sensitivity to the rewarding properties of appetitive substances has long been implicated in excessive consumption of palatable foods and drugs of abuse. Previous research focusing on individual differences in reward responsiveness has found heightened trait reward sensitivity to be associated with binge-eating, hazardous drinking, and illicit substance use. Food addiction has been proposed as an extreme form of compulsive-overeating and has been associated with genetic markers of heightened reward responsiveness. However, little research has explicitly examined the association between reward sensitivity and food addiction. Further, the processes by which individual differences in this trait are associated with excessive over-consumption has not been determined. A total of 374 women from the community completed an online questionnaire assessing reward sensitivity, food addiction, emotional, externally-driven, and hedonic eating. High reward sensitivity was significantly associated with greater food addiction symptoms (r = 0.31). Bootstrapped tests of indirect effects found the relationship between reward sensitivity and food addiction symptom count to be uniquely mediated by binge-eating, emotional eating, and hedonic eating (notably, food availability). These indirect effects held even when controlling for BMI, anxiety, depression, and trait impulsivity. This study further supports the argument that high levels of reward sensitivity may offer a trait marker of vulnerability to excessive over-eating, beyond negative affect and impulse-control deficits. That the hedonic properties of food (especially food availability), emotional, and binge-eating behavior act as unique mediators suggest that interventions for reward-sensitive women presenting with food addiction may benefit from targeting food availability in addition to management of negative affect. Copyright © 2016 Elsevier Ltd. All rights reserved.
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Video game training and the reward system.
Lorenz, Robert C; Gleich, Tobias; Gallinat, Jürgen; Kühn, Simone
2015-01-01
Video games contain elaborate reinforcement and reward schedules that have the potential to maximize motivation. Neuroimaging studies suggest that video games might have an influence on the reward system. However, it is not clear whether reward-related properties represent a precondition, which biases an individual toward playing video games, or if these changes are the result of playing video games. Therefore, we conducted a longitudinal study to explore reward-related functional predictors in relation to video gaming experience as well as functional changes in the brain in response to video game training. Fifty healthy participants were randomly assigned to a video game training (TG) or control group (CG). Before and after training/control period, functional magnetic resonance imaging (fMRI) was conducted using a non-video game related reward task. At pretest, both groups showed strongest activation in ventral striatum (VS) during reward anticipation. At posttest, the TG showed very similar VS activity compared to pretest. In the CG, the VS activity was significantly attenuated. This longitudinal study revealed that video game training may preserve reward responsiveness in the VS in a retest situation over time. We suggest that video games are able to keep striatal responses to reward flexible, a mechanism which might be of critical value for applications such as therapeutic cognitive training.
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Reward Systems in the Brain and Nutrition.
Rolls, Edmund T
2016-07-17
The taste cortex in the anterior insula provides separate and combined representations of the taste, temperature, and texture of food in the mouth independently of hunger and thus of reward value and pleasantness. One synapse on, in the orbitofrontal cortex, these sensory inputs are combined by associative learning with olfactory and visual inputs for some neurons, and these neurons encode food reward value in that they respond to food only when hunger is present and in that activations correlate linearly with subjective pleasantness. Cognitive factors, including word-level descriptions and selective attention to affective value, modulate the representation of the reward value of taste, olfactory, and flavor stimuli in the orbitofrontal cortex and a region to which it projects, the anterior cingulate cortex. These food reward representations are important in the control of appetite and food intake. Individual differences in reward representations may contribute to obesity, and there are age-related differences in these reward representations. Implications of how reward systems in the brain operate for understanding, preventing, and treating obesity are described.
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Differentiating neural reward responsiveness in autism versus ADHD
Directory of Open Access Journals (Sweden)
Gregor Kohls
2014-10-01
Full Text Available Although attention deficit hyperactivity disorders (ADHD and autism spectrum disorders (ASD share certain neurocognitive characteristics, it has been hypothesized to differentiate the two disorders based on their brain's reward responsiveness to either social or monetary reward. Thus, the present fMRI study investigated neural activation in response to both reward types in age and IQ-matched boys with ADHD versus ASD relative to typically controls (TDC. A significant group by reward type interaction effect emerged in the ventral striatum with greater activation to monetary versus social reward only in TDC, whereas subjects with ADHD responded equally strong to both reward types, and subjects with ASD showed low striatal reactivity across both reward conditions. Moreover, disorder-specific neural abnormalities were revealed, including medial prefrontal hyperactivation in response to social reward in ADHD versus ventral striatal hypoactivation in response to monetary reward in ASD. Shared dysfunction was characterized by fronto-striato-parietal hypoactivation in both clinical groups when money was at stake. Interestingly, lower neural activation within parietal circuitry was associated with higher autistic traits across the entire study sample. In sum, the present findings concur with the assumption that both ASD and ADHD display distinct and shared neural dysfunction in response to reward.
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Application of Bayesian network to the probabilistic risk assessment of nuclear waste disposal
International Nuclear Information System (INIS)
Lee, Chang-Ju; Lee, Kun Jai
2006-01-01
The scenario in a risk analysis can be defined as the propagating feature of specific initiating event which can go to a wide range of undesirable consequences. If we take various scenarios into consideration, the risk analysis becomes more complex than do without them. A lot of risk analyses have been performed to actually estimate a risk profile under both uncertain future states of hazard sources and undesirable scenarios. Unfortunately, in case of considering specific systems such as a radioactive waste disposal facility, since the behaviour of future scenarios is hardly predicted without special reasoning process, we cannot estimate their risk only with a traditional risk analysis methodology. Moreover, we believe that the sources of uncertainty at future states can be reduced pertinently by setting up dependency relationships interrelating geological, hydrological, and ecological aspects of the site with all the scenarios. It is then required current methodology of uncertainty analysis of the waste disposal facility be revisited under this belief. In order to consider the effects predicting from an evolution of environmental conditions of waste disposal facilities, this paper proposes a quantitative assessment framework integrating the inference process of Bayesian network to the traditional probabilistic risk analysis. We developed and verified an approximate probabilistic inference program for the specific Bayesian network using a bounded-variance likelihood weighting algorithm. Ultimately, specific models, including a model for uncertainty propagation of relevant parameters were developed with a comparison of variable-specific effects due to the occurrence of diverse altered evolution scenarios (AESs). After providing supporting information to get a variety of quantitative expectations about the dependency relationship between domain variables and AESs, we could connect the results of probabilistic inference from the Bayesian network with the consequence
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Risk perspective on final disposal of nuclear waste. Individuals, society and communication
International Nuclear Information System (INIS)
Lindblad, Inga-Britt
2007-01-01
This report tries to evaluate the importance of the risk perspective in connection with final storage of nuclear waste. The concept 'risk' has different importance for experts and general public, within different research directions and among stakeholders in the nuclear waste issue. The report has been published in order to give an interdisciplinary scientific perspective on the risk concept. The authors have their background in different disciplines: radiation physics, psychology, media- and communications-science. The report treats four different themes: The first theme concerns perspectives on the risk concept and describes various principles for how risks can be handled in the society. The next theme is about comparing various risks. This section shows that risk comparisons can to be done within the framework of a scientific attitude and during certain given conditions. The third theme elucidates results from research about subjective risk, and shows that a large number of factors influence how risks are considered by individuals, and can influence his risk behavior and also how the individual means that the society will make decisions in risk-related questions. The fourth and last theme is about risk communication. Since the risk concept contains many different aspects it is clear that risk should not only be informed about, but also communicated. If a purely mathematical definition of risk was the only valid form, such information, from experts to the citizens, would possibly be sufficient. But since there are other relevant factors to take into consideration (t.ex the individual's own values), a communicative process must take place, i.e. the citizens should have influence on how risks are compared and managed. In the final theme, the authors have chosen to reflect around the themes above, i.e. different perspectives on the risk concept, risk comparisons, subjective risk view and risk communication are discussed
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Video game training and the reward system
Lorenz, R.; Gleich, T.; Gallinat, J.; Kühn, S.
2015-01-01
Video games contain elaborate reinforcement and reward schedules that have the potential to maximize motivation. Neuroimaging studies suggest that video games might have an influence on the reward system. However, it is not clear whether reward-related properties represent a precondition, which biases an individual toward playing video games, or if these changes are the result of playing video games. Therefore, we conducted a longitudinal study to explore reward-related functional predictors ...
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Long-term risk assessment of radioactive waste disposal in geological formations
International Nuclear Information System (INIS)
Girardi, F.; Bertozzi, G.; D'Alessandro, M.
1978-01-01
Methods for long-term safety analysis of waste from nuclear power production in the European Community are under study at the Joint Research Centre (JRC) at Ispra, Italy. Aim of the work is to develop a suitable methodology for long-term risk assessment. The methodology under study is based on the assessment of the quantitative value of a system of barriers which may be interposed between waste and man. The barriers considered are: a) quality of the segregation afforded by the geological formation, b) chemical and physical stability of conditioned waste, c) interaction with geological environments (subsoil retention), d) distribution in the biosphere. The methodology is presently being applied to idealized test cases based on the following assumptions: waste are generated during 30 years of operations in a nuclear park (reprocessing + refabrication plant) capable of treating 1000 ton/yr of LWR fuel. High activity waste is conditioned as borosilicate glass (HAW) while low- and medium-level wastes are bituminized (BIP). All waste is disposed off into a salt formation. Transport to the biosphere, following the containment failure occurs by groundwater, with no delay due to retention on adsorbing media. Distribution into the biosphere occurs according to the terrestrial model indicated. Under these assumptions, information was drawn concerning environmental contamination, its levels, contributing elements and pathways to man
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Trait Anticipatory Pleasure Predicts Effort Expenditure for Reward.
Directory of Open Access Journals (Sweden)
Joachim T Geaney
Full Text Available Research in motivation and emotion has been increasingly influenced by the perspective that processes underpinning the motivated approach of rewarding goals are distinct from those underpinning enjoyment during reward consummation. This distinction recently inspired the construction of the Temporal Experience of Pleasure Scale (TEPS, a self-report measure that distinguishes trait anticipatory pleasure (pre-reward feelings of desire from consummatory pleasure (feelings of enjoyment and gratification upon reward attainment. In a university community sample (N = 97, we examined the TEPS subscales as predictors of (1 the willingness to expend effort for monetary rewards, and (2 affective responses to a pleasant mood induction procedure. Results showed that both anticipatory pleasure and a well-known trait measure of reward motivation predicted effort-expenditure for rewards when the probability of being rewarded was relatively low. Against expectations, consummatory pleasure was unrelated to induced pleasant affect. Taken together, our findings provide support for the validity of the TEPS anticipatory pleasure scale, but not the consummatory pleasure scale.
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Treatment methods and comparative risks of thorium removal from waste residues
Energy Technology Data Exchange (ETDEWEB)
Porter, R.D.; Hamby, D.M.; Martin, J.E.
1997-07-01
This study was done to examine the risks of remediation and the effectiveness of removal methods for thorium and its associated radioactive decay products from various soils and wastes associated with DOE`s Formerly Utilized Sites Remedial Action Program (FUSRAP). Removal of {sup 230}Th from uranium process residues would significantly reduce the buildup of {sup 226}Ra (half-life of 1600 years), and since {sup 230}Th concentrations at most of the important sites greatly exceed the {sup 226}Ra concentrations, such removal would reduce the accumulation of additional radiation risks associated with {sup 226}Ra and its products; and, if treatment also removed {sup 226}Ra, these risks could be mitigated even further. Removal of {sup 232}Th from thorium process residues would remove the source material for {sup 228}Ra, and since {sup 228}Ra has a half-life of 5.76 years, its control at FUSRAP sites could be done with land use controls for the 30--50 years required for {sup 228}Ra and the risks associated with its decay products to decay away. It must be recognized, however, that treatment methods invariably require workers to process residues and waste materials usually with bulk handling techniques. These processes expose workers to the radioactivity in the materials, therefore, workers would incur radiological risks in addition to industrial accident risks. An important question is whether the potential reduction of future radiological risks to members of the public justifies the risks that are incurred by remediation workers due to handling materials. This study examines, first, the effectiveness of treatment and then the risks that would be associated with remediation.
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International Nuclear Information System (INIS)
Hawley, K.A.; Napier, B.A.
1986-01-01
Pacific Northwest Laboratory continued to provide technical assistance to the Department of Energy (DOE) Office of Operational Safety (OOS) in the area of risk assessment for hazardous and radioactive-mixed waste management. The overall objective is to provide technical assistance to OOS in developing cost-effective risk assessment tools and strategies for bringing DOE facilities into compliance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA or Superfund) and the Resource Conservation and Recovery Act (RCRA). Major efforts during FY 1985 included (1) completing the modification of the Environmental Protection Agency (EPA) Hazard Ranking System (HRS) and developing training manuals and courses to assist in field office implementation of the modified Hazard Ranking System (mHRS); (2) initiating the development of a system for reviewing field office HRS/mHRS evaluations for appropriate use of data and appropriate application of the methodology; (3) initiating the development of a data base management system to maintain all field office HRS/mHRS scoring sheets and to support the master OOS environmental data base system; (4) developing implementation guidance for Phase I of the DOE CERCLA Program, Installation Assessment; (5) continuing to develop an objective, scientifically based methodology for DOE management to use in establishing priorities for conducting site assessments under Phase II of the DOE CERCLA Program, Confirmation; and (6) participating in developing the DOE response to EPA on the proposed listing of three sites on the National Priorities List
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Risk assessment of particle dispersion and trace element contamination from mine-waste dumps.
Romero, Antonio; González, Isabel; Martín, José María; Vázquez, María Auxiliadora; Ortiz, Pilar
2015-04-01
In this study, a model to delimit risk zones influenced by atmospheric particle dispersion from mine-waste dumps is developed to assess their influence on the soil and the population according to the concentration of trace elements in the waste. The model is applied to the Riotinto Mine (in SW Spain), which has a long history of mining and heavy land contamination. The waste materials are separated into three clusters according to the mapping, mineralogy, and geochemical classification using cluster analysis. Two of the clusters are composed of slag, fresh pyrite, and roasted pyrite ashes, which may contain high concentrations of trace elements (e.g., >1 % As or >4 % Pb). The average pollution load index (PLI) calculated for As, Cd, Co, Cu, Pb, Tl, and Zn versus the baseline of the regional soil is 19. The other cluster is primarily composed of sterile rocks and ochreous tailings, and the average PLI is 3. The combination of particle dispersion calculated by a Gaussian model, the PLI, the surface area of each waste and the wind direction is used to develop a risk-assessment model with Geographic Information System GIS software. The zone of high risk can affect the agricultural soil and the population in the study area, particularly if mining activity is restarted in the near future. This model can be applied to spatial planning and environmental protection if the information is complemented with atmospheric particulate matter studies.
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Facilitation of voluntary goal-directed action by reward cues.
Lovibond, Peter F; Colagiuri, Ben
2013-10-01
Reward-associated cues are known to influence motivation to approach both natural and man-made rewards, such as food and drugs. However, the mechanisms underlying these effects are not well understood. To model these processes in the laboratory with humans, we developed an appetitive Pavlovian-instrumental transfer procedure with a chocolate reward. We used a single unconstrained response that led to an actual rather than symbolic reward to assess the strength of reward motivation. Presentation of a chocolate-paired cue, but not an unpaired cue, markedly enhanced instrumental responding over a 30-s period. The same pattern was observed with 10-s and 30-s cues, showing that close cue-reward contiguity is not necessary for facilitation of reward-directed action. The results confirm that reward-related cues can instigate voluntary action to obtain that reward. The effectiveness of long-duration cues suggests that in clinical settings, attention should be directed to both proximal and distal cues for reward.
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Rewards and advancements for clinical pharmacists.
Goodwin, S Diane; Kane-Gill, Sandra L; Ng, Tien M H; Melroy, Joel T; Hess, Mary M; Tallian, Kimberly; Trujillo, Toby C; Vermeulen, Lee C
2010-01-01
The American College of Clinical Pharmacy charged the Clinical Practice Affairs Committee to review and update the College's 1995 White Paper, "Rewards and Advancements for Clinical Pharmacy Practitioners." Because of the limited data on the present state of rewards and advancements for clinical pharmacists, an online survey of "front-line" clinical pharmacists and pharmacy managers was conducted (1126 total respondents, 14% response rate). The resulting White Paper discusses motivators and existing systems of rewards and advancements for clinical pharmacists, as well as perceived barriers to implementation of these systems. Clinical pharmacists reported work-life balance, a challenging position, and opportunities for professional advancement as the most important factors for career success. At the time of the survey, financial rewards appeared not to be a major motivator for clinical pharmacists. Managers underestimated the importance that clinical pharmacists place on work-life balance and favorable work schedules. Although almost two thirds of the clinical pharmacists surveyed had not developed a professional development plan, 84% indicated an interest in career planning. Both clinical pharmacists and managers rated the lack of a clear reward and advancement structure as the most important barrier to effective systems of rewards and advancements. Pharmacy managers and administrators are encouraged to develop effective systems of rewards and advancements for clinical pharmacists that positively impact patient care and the institution's mission; these systems will benefit the clinical pharmacist, the health care institution, and the patient.
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Model Checking Multivariate State Rewards
DEFF Research Database (Denmark)
Nielsen, Bo Friis; Nielson, Flemming; Nielson, Hanne Riis
2010-01-01
We consider continuous stochastic logics with state rewards that are interpreted over continuous time Markov chains. We show how results from multivariate phase type distributions can be used to obtain higher-order moments for multivariate state rewards (including covariance). We also generalise...
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Self-rewards and personal motivation
DEFF Research Database (Denmark)
Koch, Alexander Karl; Nafziger, Julia; Suvorov, Anton
2014-01-01
Self-administered rewards are ubiquitous. They serve as incentives for personal accomplishments and are widely recommended to increase personal motivation. We show that in a model with time-inconsistent and reference-dependent preferences, self-rewards can be a credible and effective tool...
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Self-Rewards and Personal Motivation
DEFF Research Database (Denmark)
Koch, Alexander Karl; Nafziger, Julia; Suvorov, Anton
Self-administered rewards are ubiquitous. They serve as incentives for personal accomplishments and are widely recommended to increase personal motivation. We show that in a model with time-inconsistent and reference-dependent preferences, self-rewards can be a credible and effective tool...
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Self-rewards and personal motivation
Koch, A.K.; Nafziger, J.; Suvorov, A.; van de Ven, J.
2014-01-01
Self-administered rewards are ubiquitous. They serve as incentives for personal accomplishments and are widely recommended to increase personal motivation. We show that in a model with time-inconsistent and reference-dependent preferences, self-rewards can be a credible and effective tool to
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Acuff, Samuel F; Luciano, Matthew T; Soltis, Kathryn E; Joyner, Keanan J; McDevitt-Murphy, Meghan; Murphy, James G
2018-04-01
Symptoms of posttraumatic stress (PTS) show significant comorbidity with alcohol use, but little is known about the mechanisms that might account for this comorbidity. Deficits in reward functioning have long been implicated in alcohol misuse and more recently in PTS reactions, but no study has examined whether reward deprivation may serve as a transdiagnostic risk factor for comorbid PTS-alcohol misuse. The current cross-sectional study sought to test the behavioral economic hypothesis that reward deprivation would be related to both PTS symptoms and alcohol problems, and would mediate the relation between PTS symptoms and alcohol problems in college students. We recruited a diverse sample of urban college students (N = 203, M age = 21.5 years, SD = 5.5; 79.5% female; 56.8% White, 28.1% Black, .9% Asian, 9.8% Multiracial) who endorsed both alcohol use and PTS symptoms. Reward deprivation (lack of access to, and ability to, experience reward) was related to alcohol problems, and a lack of access to reward was related to PTS symptoms. Furthermore, reward access mediated the relation between PTS symptoms and alcohol problems and craving, after controlling for alcohol use, age, gender, and race. These data provide preliminary support for behavioral economic models of alcohol comorbidity and suggest that treatments for combined PTS and alcohol misuse should attempt to reduce barriers to accessing natural rewards. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
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Video Game Training and the Reward System
Directory of Open Access Journals (Sweden)
Robert C. Lorenz
2015-02-01
Full Text Available Video games contain elaborate reinforcement and reward schedules that have the potential to maximize motivation. Neuroimaging studies suggest that video games might have an influence on the reward system. However, it is not clear whether reward-related properties represent a precondition, which biases an individual towards playing video games, or if these changes are the result of playing video games. Therefore, we conducted a longitudinal study to explore reward-related functional predictors in relation to video gaming experience as well as functional changes in the brain in response to video game training.Fifty healthy participants were randomly assigned to a video game training (TG or control group (CG. Before and after training/control period, functional magnetic resonance imaging (fMRI was conducted using a non-video game related reward task.At pretest, both groups showed strongest activation in ventral striatum (VS during reward anticipation. At posttest, the TG showed very similar VS activity compared to pretest. In the CG, the VS activity was significantly attenuated.This longitudinal study revealed that video game training may preserve reward responsiveness in the ventral striatum in a retest situation over time. We suggest that video games are able to keep striatal responses to reward flexible, a mechanism which might be of critical value for applications such as therapeutic cognitive training.
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Video game training and the reward system
Lorenz, Robert C.; Gleich, Tobias; Gallinat, Jürgen; Kühn, Simone
2015-01-01
Video games contain elaborate reinforcement and reward schedules that have the potential to maximize motivation. Neuroimaging studies suggest that video games might have an influence on the reward system. However, it is not clear whether reward-related properties represent a precondition, which biases an individual toward playing video games, or if these changes are the result of playing video games. Therefore, we conducted a longitudinal study to explore reward-related functional predictors in relation to video gaming experience as well as functional changes in the brain in response to video game training. Fifty healthy participants were randomly assigned to a video game training (TG) or control group (CG). Before and after training/control period, functional magnetic resonance imaging (fMRI) was conducted using a non-video game related reward task. At pretest, both groups showed strongest activation in ventral striatum (VS) during reward anticipation. At posttest, the TG showed very similar VS activity compared to pretest. In the CG, the VS activity was significantly attenuated. This longitudinal study revealed that video game training may preserve reward responsiveness in the VS in a retest situation over time. We suggest that video games are able to keep striatal responses to reward flexible, a mechanism which might be of critical value for applications such as therapeutic cognitive training. PMID:25698962
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Reward disrupts reactivated human skill memory.
Dayan, Eran; Laor-Maayany, Rony; Censor, Nitzan
2016-06-16
Accumulating evidence across species and memory domains shows that when an existing memory is reactivated, it becomes susceptible to modifications. However, the potential role of reward signals in these mechanisms underlying human memory dynamics is unknown. Leaning on a wealth of findings on the role of reward in reinforcing memory, we tested the impact of reinforcing a skill memory trace with monetary reward following memory reactivation, on strengthening of the memory trace. Reinforcing reactivated memories did not strengthen the memory, but rather led to disruption of the memory trace, breaking down the link between memory reactivation and subsequent memory strength. Statistical modeling further revealed a strong mediating role for memory reactivation in linking between memory encoding and subsequent memory strength only when the memory was replayed without reinforcement. We suggest that, rather than reinforcing the existing memory trace, reward creates a competing memory trace, impairing expression of the original reward-free memory. This mechanism sheds light on the processes underlying skill acquisition, having wide translational implications.
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Community-based faculty: motivation and rewards.
Fulkerson, P K; Wang-Cheng, R
1997-02-01
The reasons why practicing physicians precept students in their offices, and the rewards they wish to receive for this work, have not been clearly elucidated. This study determined the reasons for precepting and the rewards expected among a network of preceptors in Milwaukee. A questionnaire was mailed to 120 community-based physician preceptors in a required, third-year ambulatory care clerkship. Respondents were asked to identify why they volunteered and what they considered appropriate recognition or reward. The personal satisfaction derived from the student-teacher interaction was, by far, the most important motivator for preceptors (84%). The most preferred rewards for teaching included clinical faculty appointment, CME and bookstore discounts, computer networking, and workshops for improving skills in clinical teaching. Community-based private physicians who participate in medical student education programs are primarily motivated by the personal satisfaction that they derive from the teaching encounter. An effective preceptor recognition/reward program can be developed using input from the preceptors themselves.
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Risk analysis for new nuclear waste sites: Will it generate public acceptance?
International Nuclear Information System (INIS)
Inhaber, H.
1993-01-01
This report discusses public acceptance of radioactive waste facilities and what seems to be increasingly militant stances against such facilities. The role of risk assessment in possibly enhancing public acceptance is investigated
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Intersection of reward and memory in monkey rhinal cortex.
Clark, Andrew M; Bouret, Sebastien; Young, Adrienne M; Richmond, Barry J
2012-05-16
In humans and other animals, the vigor with which a reward is pursued depends on its desirability, that is, on the reward's predicted value. Predicted value is generally context-dependent, varying according to the value of rewards obtained in the recent and distant past. Signals related to reward prediction and valuation are believed to be encoded in a circuit centered around midbrain dopamine neurons and their targets in the prefrontal cortex and basal ganglia. Notably absent from this hypothesized reward pathway are dopaminergic targets in the medial temporal lobe. Here we show that a key part of the medial temporal lobe memory system previously reported to be important for sensory mnemonic and perceptual processing, the rhinal cortex (Rh), is required for using memories of previous reward values to predict the value of forthcoming rewards. We tested monkeys with bilateral Rh lesions on a task in which reward size varied across blocks of uncued trials. In this experiment, the only cues for predicting current reward value are the sizes of rewards delivered in previous blocks. Unexpectedly, monkeys with Rh ablations, but not intact controls, were insensitive to differences in predicted reward, responding as if they expected all rewards to be of equal magnitude. Thus, it appears that Rh is critical for using memory of previous rewards to predict the value of forthcoming rewards. These results are in agreement with accumulating evidence that Rh is critical for establishing the relationships between temporally interleaved events, which is a key element of episodic memory.
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Singh, Varsha; Khan, Azizuddin
2012-01-01
Surface-level differences in the reward and punishment variants, specifically greater long-term decision making in the punishment variant of the Iowa Gambling Task (IGT) observed in previous studies led to the present comparison of long-term decision making in the two IGT variants (n = 320, male = 160). It was contended that risk aversion triggered by a positive frame of the reward variant and risk seeking triggered by a negative frame of the punishment variant appears as long-term decision m...
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International Nuclear Information System (INIS)
Li Ying; Li Jinhui; Chen Shusheng; Diao Weihua
2012-01-01
Groundwater contamination by leachate is the most damaging environmental impact over the entire life of a hazardous waste landfill (HWL). With the number of HWL facilities in China rapidly increasing, and considering the poor status of environmental risk management, it is imperative that effective environmental risk management methods be implemented. A risk assessment indices system for HWL groundwater contamination is here proposed, which can simplify the risk assessment procedure and make it more user-friendly. The assessment framework and indices were drawn from five aspects: source term, underground media, leachate properties, risk receptors and landfill management quality, and a risk assessment indices system consisting of 38 cardinal indicators was established. Comparison with multimedia models revealed that the proposed indices system was integrated and quantitative, that input data for it could be easily collected, and that it could be widely used for environmental risk assessment (ERA) in China. - Highlights: ► No comprehensive environmental risk assessment method for hazardous waste management is proposed in China. ► An assessment indices system is established for groundwater contamination in the vicinity of hazardous waste landfill. ► All indicators are quantitative and applicable in China. - Capsule: This research identified critical indices and established a system for environmental risk assessment for groundwater contamination in the vicinity of HWLs in China.
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Lighting up the brain's reward circuitry.
Lobo, Mary Kay
2012-07-01
The brain's reward circuit is critical for mediating natural reward behaviors including food, sex, and social interaction. Drugs of abuse take over this circuit and produce persistent molecular and cellular alterations in the brain regions and their neural circuitry that make up the reward pathway. Recent use of optogenetic technologies has provided novel insights into the functional and molecular role of the circuitry and cell subtypes within these circuits that constitute this pathway. This perspective will address the current and future use of light-activated proteins, including those involved in modulating neuronal activity, cellular signaling, and molecular properties in the neural circuitry mediating rewarding stimuli and maladaptive responses to drugs of abuse. © 2012 New York Academy of Sciences.
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Ziaei, Mansour; Choobineh, Alireza; Abdoli-Eramaki, Mohammad; Ghaem, Haleh
2018-03-03
In Iran-Shiraz, municipal solid waste is collected manually requiring strenuous physical activities. This study was conducted to determine the prevalence rate of musculoskeletal disorders (MSDs) and its associated risk factors. Two hundred male waste collectors participated in this cross-sectional study, in which task analysis followed by motion and timeline analysis were performed. The data were collected using demographic, occupation-specific physical and organizational demands, and Nordic musculoskeletal questionnaires. Logistic regression analysis was used for identifying independent risk factors for MSDs. Ten motions observed during waste collection, and the most physical and organizational demands were related to the running along with bag carriage, and the time pressure, respectively. About 39% and 36.5% of the workers reported very high physical and psychological workloads, respectively. Totally, 92.5% of waste collectors reported MSDs symptom at least in one body region during the last 12 months. Lower back and knee injuries were more prevalent and more severe. Some individual factors (age, body weight, and waste collecting duration), physical demands (lifting bag/bucket, pulling/pushing waste container, walking along with bag/bucket carriage, and jumping up/down on the garbage truck), and organizational demands (low vacation and high decision) were the most important risk factors for developing MSDs.
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Watanabe, Noriya; Sakagami, Masamichi; Haruno, Masahiko
2013-03-06
Learning does not only depend on rationality, because real-life learning cannot be isolated from emotion or social factors. Therefore, it is intriguing to determine how emotion changes learning, and to identify which neural substrates underlie this interaction. Here, we show that the task-independent presentation of an emotional face before a reward-predicting cue increases the speed of cue-reward association learning in human subjects compared with trials in which a neutral face is presented. This phenomenon was attributable to an increase in the learning rate, which regulates reward prediction errors. Parallel to these behavioral findings, functional magnetic resonance imaging demonstrated that presentation of an emotional face enhanced reward prediction error (RPE) signal in the ventral striatum. In addition, we also found a functional link between this enhanced RPE signal and increased activity in the amygdala following presentation of an emotional face. Thus, this study revealed an acceleration of cue-reward association learning by emotion, and underscored a role of striatum-amygdala interactions in the modulation of the reward prediction errors by emotion.
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Distinct Motivational Effects of Contingent and Noncontingent Rewards.
Manohar, Sanjay G; Finzi, Rebecca Dawn; Drew, Daniel; Husain, Masud
2017-07-01
When rewards are available, people expend more energy, increasing their motivational vigor. In theory, incentives might drive behavior for two distinct reasons: First, they increase expected reward; second, they increase the difference in subjective value between successful and unsuccessful performance, which increases contingency-the degree to which action determines outcome. Previous studies of motivational vigor have never compared these directly. Here, we indexed motivational vigor by measuring the speed of eye movements toward a target after participants heard a cue indicating how outcomes would be determined. Eye movements were faster when the cue indicated that monetary rewards would be contingent on performance than when the cue indicated that rewards would be random. But even when the cue indicated that a reward was guaranteed regardless of speed, movement was still faster than when no reward was available. Motivation by contingent and certain rewards was uncorrelated across individuals, which suggests that there are two separable, independent components of motivation. Contingent motivation generated autonomic arousal, and unlike noncontingent motivation, was effective with penalties as well as rewards.
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Mechanisms of impulsive choice: III. The role of reward processes
Marshall, Andrew T.
2015-01-01
Two experiments examined the relationship between reward processing and impulsive choice. In Experiment 1, rats chose between a smaller-sooner (SS) reward (1 pellet, 10 s) and a larger-later (LL) reward (1, 2, and 4 pellets, 30 s). The rats then experienced concurrent variable-interval 30-s schedules with variations in reward magnitude to evaluate reward magnitude discrimination. LL choice behavior positively correlated with reward magnitude discrimination. In Experiment 2, rats chose between an SS reward (1 pellet, 10 s) and an LL reward (2 and 4 pellets, 30 s). The rats then received either a reward intervention which consisted of concurrent fixed-ratio schedules associated with different magnitudes to improve their reward magnitude discrimination, or a control task. All rats then experienced a post-intervention impulsive choice task followed by a reward magnitude discrimination task to assess intervention efficacy. The rats that received the intervention exhibited increases in post-intervention LL choice behavior, and made more responses for larger-reward magnitudes in the reward magnitude discrimination task, suggesting that the intervention heightened sensitivities to reward magnitude. The results suggest that reward magnitude discrimination plays a key role in individual differences in impulsive choice, and could be a potential target for further intervention developments. PMID:26506254
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International Nuclear Information System (INIS)
Sasser, K.
1994-06-01
In FY 1993, the Los Alamos National Laboratory Waste Management Group [CST-7 (formerly EM-7)] requested the Probabilistic Risk and Hazards Analysis Group [TSA-11 (formerly N-6)] to conduct a study of the hazards associated with several CST-7 facilities. Among these facilities are the Hazardous Waste Treatment Facility (HWTF), the HWTF Drum Storage Building (DSB), and the Mixed Waste Receiving and Storage Facility (MWRSF), which are proposed for construction beginning in 1996. These facilities are needed to upgrade the Laboratory's storage capability for hazardous and mixed wastes and to provide treatment capabilities for wastes in cases where offsite treatment is not available or desirable. These facilities will assist Los Alamos in complying with federal and state requlations
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Validation and extension of the reward-mountain model.
Breton, Yannick-André; Mullett, Ada; Conover, Kent; Shizgal, Peter
2013-01-01
The reward-mountain model relates the vigor of reward seeking to the strength and cost of reward. Application of this model provides information about the stage of processing at which manipulations such as drug administration, lesions, deprivation states, and optogenetic interventions act to alter reward seeking. The model has been updated by incorporation of new information about frequency following in the directly stimulated neurons responsible for brain stimulation reward and about the function that maps objective opportunity costs into subjective ones. The behavioral methods for applying the model have been updated and improved as well. To assess the impact of these changes, two related predictions of the model that were supported by earlier work have been retested: (1) altering the duration of rewarding brain stimulation should change the pulse frequency required to produce a reward of half-maximal intensity, and (2) this manipulation should not change the opportunity cost at which half-maximal performance is directed at earning a maximally intense reward. Prediction 1 was supported in all six subjects, but prediction 2 was supported in only three. The latter finding is interpreted to reflect recruitment, at some stimulation sites, of a heterogeneous reward substrate comprising dual, parallel circuits that integrate the stimulation-induced neural signals.
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Informationally administered reward enhances intrinsic motivation in schizophrenia.
Lee, Hyeon-Seung; Jang, Seon-Kyeong; Lee, Ga-Young; Park, Seon-Cheol; Medalia, Alice; Choi, Kee-Hong
2017-10-01
Even when individuals with schizophrenia have an intact ability to enjoy rewarding moments, the means to assist them to translate rewarding experiences into goal-directed behaviors is unclear. The present study sought to determine whether informationally administered rewards enhance intrinsic motivation to foster goal-directed behaviors in individuals with schizophrenia (SZ) and healthy controls (HCs). Eighty-four participants (SZ=43, HCs=41) were randomly assigned to conditions involving either a performance-contingent reward with an informationally administered reward or a task-contingent reward with no feedback. Participants were asked to play two cognitive games of equalized difficulty. Accuracy, self-reported intrinsic motivation, free-choice intrinsic motivation (i.e., game play during a free-choice observation period), and perceived competency were measured. Intrinsic motivation and perceived competency in the cognitive games were similar between the two participant groups. The informationally administered reward significantly enhanced self-reported intrinsic motivation and perceived competency in both the groups. The likelihood that individuals with schizophrenia would play the game during the free-choice observation period was four times greater in the informationally administered reward condition than that in the no-feedback condition. Our findings suggest that, in the context of cognitive remediation, individuals with schizophrenia would benefit from informationally administered rewards. Copyright © 2017 Elsevier B.V. All rights reserved.
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Basolateral amygdala lesions abolish mutual reward preferences in rats.
Hernandez-Lallement, Julen; van Wingerden, Marijn; Schäble, Sandra; Kalenscher, Tobias
2016-01-01
In a recent study, we demonstrated that rats prefer mutual rewards in a Prosocial Choice Task. Here, employing the same task, we show that the integrity of basolateral amygdala was necessary for the expression of mutual reward preferences. Actor rats received bilateral excitotoxic (n=12) or sham lesions (n=10) targeting the basolateral amygdala and were subsequently tested in a Prosocial Choice Task where they could decide between rewarding ("Both Reward") or not rewarding a partner rat ("Own Reward"), either choice yielding identical reward to the actors themselves. To manipulate the social context and control for secondary reinforcement sources, actor rats were paired with either a partner rat (partner condition) or with an inanimate rat toy (toy condition). Sham-operated animals revealed a significant preference for the Both-Reward-option in the partner condition, but not in the toy condition. Amygdala-lesioned animals exhibited significantly lower Both-Reward preferences than the sham group in the partner but not in the toy condition, suggesting that basolateral amygdala was required for the expression of mutual reward preferences. Critically, in a reward magnitude discrimination task in the same experimental setup, both sham-operated and amygdala-lesioned animals preferred large over small rewards, suggesting that amygdala lesion effects were restricted to decision making in social contexts, leaving self-oriented behavior unaffected. Copyright © 2015 Elsevier Inc. All rights reserved.
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Reward disrupts reactivated human skill memory
Dayan, Eran; Laor-Maayany, Rony; Censor, Nitzan
2016-01-01
Accumulating evidence across species and memory domains shows that when an existing memory is reactivated, it becomes susceptible to modifications. However, the potential role of reward signals in these mechanisms underlying human memory dynamics is unknown. Leaning on a wealth of findings on the role of reward in reinforcing memory, we tested the impact of reinforcing a skill memory trace with monetary reward following memory reactivation, on strengthening of the memory trace. Reinforcing re...
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Reward and Attentional Control in Visual Search
Anderson, Brian A.; Wampler, Emma K.; Laurent, Patryk A.
2015-01-01
It has long been known that the control of attention in visual search depends both on voluntary, top-down deployment according to context-specific goals, and on involuntary, stimulus-driven capture based on the physical conspicuity of perceptual objects. Recent evidence suggests that pairing target stimuli with reward can modulate the voluntary deployment of attention, but there is little evidence that reward modulates the involuntary deployment of attention to task-irrelevant distractors. We report several experiments that investigate the role of reward learning on attentional control. Each experiment involved a training phase and a test phase. In the training phase, different colors were associated with different amounts of monetary reward. In the test phase, color was not task-relevant and participants searched for a shape singleton; in most experiments no reward was delivered in the test phase. We first show that attentional capture by physically salient distractors is magnified by a previous association with reward. In subsequent experiments we demonstrate that physically inconspicuous stimuli previously associated with reward capture attention persistently during extinction—even several days after training. Furthermore, vulnerability to attentional capture by high-value stimuli is negatively correlated across individuals with working memory capacity and positively correlated with trait impulsivity. An analysis of intertrial effects reveals that value-driven attentional capture is spatially specific. Finally, when reward is delivered at test contingent on the task-relevant shape feature, recent reward history modulates value-driven attentional capture by the irrelevant color feature. The influence of learned value on attention may provide a useful model of clinical syndromes characterized by similar failures of cognitive control, including addiction, attention-deficit/hyperactivity disorder, and obesity. PMID:23437631
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Hahn, Tim; Notebaert, Karolien Hilde; Dresler, Thomas; Kowarsch, Linda; Reif, Andreas; Fallgatter, Andreas J
2014-01-01
Millions of people regularly play so-called massively multiplayer online role playing games (MMORPGs). Recently, it has been argued that MMORPG overuse is becoming a significant health problem worldwide. Symptoms such as tolerance, withdrawal, and craving have been described. Based on behavioral, resting state, and task-related neuroimaging data, we test whether frequent players of the MMORPG "World of Warcraft" (WoW) - similar to drug addicts and individuals with an increased risk for addictions - show a generally deficient reward system. In frequent players of the MMORPG "World of Warcraft" (WoW-players) and in a control group of non-gamers we assessed (1) trait sensitivity to reward (SR), (2) BOLD responses during monetary reward processing in the ventral striatum, and (3) ventral-striatal resting-state dynamics. We found a decreased neural activation in the ventral striatum during the anticipation of both small and large monetary rewards. Additionally, we show generally altered neurodynamics in this region independent of any specific task for WoW players (resting state). On the behavioral level, we found differences in trait SR, suggesting that the reward processing deficiencies found in this study are not a consequence of gaming, but predisposed to it. These findings empirically support a direct link between frequent online gaming and the broad field of behavioral and drug addiction research, thus opening new avenues for clinical interventions in addicted gamers and potentially improving the assessment of addiction-risk in the vast population of frequent gamers.
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Reward-enhanced memory in younger and older adults.
Spaniol, Julia; Schain, Cécile; Bowen, Holly J
2014-09-01
We investigated how the anticipation of remote monetary reward modulates intentional episodic memory formation in younger and older adults. On the basis of prior findings of preserved reward-cognition interactions in aging, we predicted that reward anticipation would be associated with enhanced memory in both younger and older adults. On the basis of previous demonstrations of a time-dependent effect of reward anticipation on memory, we expected the memory enhancement to increase with study-test delay. In Experiment 1, younger and older participants encoded a series of picture stimuli associated with high- or low-reward values. At test (24-hr postencoding), recognition hits resulted in either high or low monetary rewards, whereas false alarms were penalized to discourage guessing. Experiment 2 was similar to Experiment 1, but the study-test delay was manipulated within subjects (immediate vs 24hr). In Experiment 1, younger and older adults showed enhanced recognition for high-reward pictures compared with low-reward pictures. Experiment 2 replicated this finding and additionally showed that the effect did not extend to immediate recognition. The current findings provide support for a time-dependent mechanism of reward-based memory enhancement. They also suggest that aging leaves intact the positive influence of reward anticipation on intentional long-term memory formation. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
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Within-subject neural reactivity to reward and threat is inverted in young adolescents.
Thomason, M E; Marusak, H A
2017-07-01
As children mature, they become increasingly independent and less reliant on caregiver support. Changes in brain systems are likely to stimulate and guide this process. One mechanistic hypothesis suggests that changes in neural systems that process reward and threat support the increase in exploratory behavior observed in the transition to adolescence. This study examines the basic tenets of this hypothesis by performing functional magnetic resonance imaging (fMRI) during well-established reward and threat processing tasks in 40 children and adolescents, aged 9-15 years. fMRI responses in the striatum and amygdala are fit to a model predicting that striatal reward and amygdala threat-responses will be unrelated in younger participants (aged 9-12 years), while older participants (aged 13-15 years) will differentially engage these structures. Our data are consistent with this model. Activity in the striatum and amygdala are comparable in younger children, but in older children, they are inversely related; those more responsive to reward show a reduced threat-response. Analyses testing age as a continuous variable yield consistent results. In addition, the proportion of threat to reward-response relates to self-reported approach behavior in older but not younger youth, exposing behavioral relevance in the relative level of activity in these structures. Results are consistent with the notion that both individual and developmental differences drive reward-seeking behavior in adolescence. While these response patterns may serve adaptive functions in the shift to independence, skew in these systems may relate to increased rates of emotional psychopathology and risk-taking observed in adolescence.
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Benefit-cost-risk analysis of alternatives for greater-confinement disposal of radioactive waste
International Nuclear Information System (INIS)
Gilbert, T.L.; Luner, C.; Peterson, J.M.
1983-01-01
Seven alternatives are included in the analysis: near-surface disposal; improved waste form; below-ground engineered structure; augered shaft; shale fracturing; shallow geologic repository; and high-level waste repository. These alternatives are representative generic facilities that span the range from low-level waste disposal practice to high-level waste disposal practice, tentatively ordered according to an expected increasing cost and/or effectiveness of confinement. They have been chosen to enable an assessment of the degree of confinement that represents an appropriate balance between public health and safety requirements and costs rather than identification of a specific preferred facility design. The objective of the analysis is to provide a comparative ranking of the alternatives on the basis of benefit-cost-risk considerations
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O'Hora, Denis; Carey, Rachel; Kervick, Aoife; Crowley, David; Dabrowski, Maciej
2016-02-01
People tend to discount rewards or losses that occur in the future. Such delay discounting has been linked to many behavioral and health problems, since people choose smaller short-term gains over greater long-term gains. We investigated whether the effect of delays on the subjective value of rewards is expressed in how people move when they make choices. Over 600 patrons of the RISK LAB exhibition hosted by the Science Gallery DublinTM played a short computer game in which they used a computer mouse to choose between amounts of money at various delays. Typical discounting effects were observed and decision dynamics indicated that choosing smaller short-term rewards became easier (i.e., shorter response times, tighter trajectories, less vacillation) as the delays until later rewards increased. Based on a sequence of choices, subjective values of delayed outcomes were estimated and decision dynamics during initial choices predicted these values. Decision dynamics are affected by subjective values of available options and thus provide a means to estimate such values.
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Effect of Gun Carrying on Perceptions of Risk Among Adolescent Offenders.
Loughran, Thomas A; Reid, Joan A; Collins, Megan Eileen; Mulvey, Edward P
2016-02-01
We observed how perceptions of risks, costs, crime rewards, and violence exposure change as individual gun-carrying behavior changes among high-risk adolescents. We analyzed a longitudinal study (2000-2010) of serious juvenile offenders in Maricopa County, Arizona, or Philadelphia County, Pennsylvania, assessing within-person changes in risk and reward perceptions, and violence exposure as individuals initiated or ceased gun carrying. Despite being associated with heightened exposure to violence, gun carrying was linked to lower perceptions of risks and costs and higher perceived rewards of offending. Gun carrying was not time-stable, as certain individuals both started and stopped carrying during the study. Within-person changes in carrying guns were associated with shifting perceptions of risks, costs, and rewards of crime, and changes in exposure to violence in expected directions. Gun carrying reduces perceptions of risks associated with offending while increasing actual risk of violence exposure. This suggests that there is an important disconnect between perceptions and objective levels of safety among high-risk youths. Gun-carrying decisions may not only be influenced by factors of protection and self-defense, but also by perceptions of risks and reward associated with engaging in crime more generally.
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Spatial and temporal distribution of risks associated with low-level radioactive waste disposal
International Nuclear Information System (INIS)
Thompson, P.B.
1988-01-01
The major purposes of this dissertation are to examine the economic tradeoffs which arise in the process of LLW disposal and to derive a framework within which the impact of these tradeoffs on LLW disposal policy can be analyzed. There are two distinct stages in the disposal of LLW - the transportation of the waste from sources to disposal sites and the disposal of the waste. The levels of costs and risks associated with these two stages depend on the number and location of disposal sites. Having more disposal sites results in lower transportation costs and risks but also in greater disposal costs and risks. The tradeoff between transportation costs and risks can also be viewed as a tradeoff between present and future risks. Therefore, an alteration in the spatial distribution of LLW disposal sites necessarily implies a change in the temporal distribution of risks. These tradeoffs are examined in this work through the use of a transportation model to which probabilistic radiation exposure constraints are added. Future (disposal) risks are discounted. The number and capacities of LLW disposal sites are varied in order to derive a series of system costs and corresponding expected cancers. This provides policy makers with a cost vs. cancers possibility function
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Information search with situation-specific reward functions
Directory of Open Access Journals (Sweden)
Bjorn Meder
2012-03-01
Full Text Available can strongly conflict with the goal of obtaining information for improving payoffs. Two environments with such a conflict were identified through computer optimization. Three subsequent experiments investigated people's search behavior in these environments. Experiments 1 and 2 used a multiple-cue probabilistic category-learning task to convey environmental probabilities. In a subsequent search task subjects could query only a single feature before making a classification decision. The crucial manipulation concerned the search-task reward structure. The payoffs corresponded either to accuracy, with equal rewards associated with the two categories, or to an asymmetric payoff function, with different rewards associated with each category. In Experiment 1, in which learning-task feedback corresponded to the true category, people later preferentially searched the accuracy-maximizing feature, whether or not this would improve monetary rewards. In Experiment 2, an asymmetric reward structure was used during learning. Subjects searched the reward-maximizing feature when asymmetric payoffs were preserved in the search task. However, if search-task payoffs corresponded to accuracy, subjects preferentially searched a feature that was suboptimal for reward and accuracy alike. Importantly, this feature would have been most useful, under the learning-task payoff structure. Experiment 3 found that, if words and numbers are used to convey environmental probabilities, neither reward nor accuracy consistently predicts search. These findings emphasize the necessity of taking into account people's goals and search-and-decision processes during learning, thereby challenging current models of information search.
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Effect of effort-reward imbalance and burnout on infection control among Ecuadorian nurses.
Colindres, C V; Bryce, E; Coral-Rosero, P; Ramos-Soto, R M; Bonilla, F; Yassi, A
2018-06-01
Nurses are frequently exposed to transmissible infections, yet adherence to infection control measures is suboptimal. There has been inadequate research into how the psychosocial work environment affects compliance with infection control measures, especially in low- and middle-income countries. To examine the association between effort-reward imbalance, burnout and adherence to infection control measures among nurses in Ecuador. A cross-sectional study linking psychosocial work environment indicators to infection control adherence. The study was conducted among 333 nurses in four Ecuadorian hospitals. Self-administered questionnaires assessed demographic variables, perceived infection risk, effort-reward imbalance, burnout and infection control adherence. Increased effort-reward imbalance was found to be a unique incremental predictor of exposure to burnout, and burnout was a negative unique incremental predictor of nurses' self-reported adherence with infection control measures. Results suggest an effort-reward imbalance-burnout continuum, which, at higher levels, contributes to reduce adherence to infection control. The Ecuadorean government has made large efforts to improve universal access to health care, yet this study suggests that workplace demands on nurses remain problematic. This study highlights the contribution of effort-reward-imbalance-burnout continuum to the chain of infection by decreased adherence to infection control of nurses. Health authorities should closely monitor the effect of new policies on psychosocial work environment, especially when expanding services and increasing public accessibility with limited resources. Additionally, organizational and psychosocial interventions targeting effort-reward imbalance and burnout in nurses should be considered part of a complete infection prevention and control strategy. Further study is warranted to identify interventions that best ameliorate effort-reward imbalance and burnout in low- and middle
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Risk assessment and management in IOR projects
International Nuclear Information System (INIS)
Goodyear, S.G.; Gregory, A.T.
1994-01-01
The application of IOR techniques is one of the investment opportunities open to Exploration and Production companies. A project will only go forward if the perceived balance between the rewards and the risks is acceptable. IOR projects may be ruled out because they are considered to involve significantly higher risks than conventional developments. Therefore, some means of evaluating the actual level of risk may be required if the full economic benefits from IOR techniques are to be realized. Risk assessment is a key element in safety cases, where a well-established methodology for quantifying risk exists. This paper discusses the extension of these methods to IOR project risk assessment. Combining reservoir and IOR technique uncertainties with their impact on project performance allows project risk to be better quantified. The results of the risk assessment are presented in terms of a risk-reward diagram that plots the probability surface for possible project outcomes as a function of NPV (reward) and exposure (risk)
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Reduced cerebellar brain activity during reward processing in adolescent binge drinkers
Directory of Open Access Journals (Sweden)
Anita Cservenka
2015-12-01
Full Text Available Due to ongoing development, adolescence may be a period of heightened vulnerability to the neurotoxic effects of alcohol. Binge drinking may alter reward-driven behavior and neurocircuitry, thereby increasing risk for escalating alcohol use. Therefore, we compared reward processing in adolescents with and without a history of recent binge drinking. At their baseline study visit, all participants (age = 14.86 ± 0.88 were free of heavy alcohol use and completed a modified version of the Wheel of Fortune (WOF functional magnetic resonance imaging task. Following this visit, 17 youth reported binge drinking on ≥3 occasions within a 90 day period and were matched to 17 youth who remained alcohol and substance-naïve. All participants repeated the WOF task during a second visit (age = 16.83 ± 1.22. No significant effects were found in a region of interest analysis of the ventral striatum, but whole-brain analyses showed significant group differences in reward response at the second study visit in the left cerebellum, controlling for baseline visit brain activity (p/α < 0.05, which was negatively correlated with mean number of drinks consumed/drinking day in the last 90 days. These findings suggest that binge drinking during adolescence may alter brain activity during reward processing in a dose-dependent manner.
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Risk analysis of radioactive waste repository based on the time dependent hazard rate
International Nuclear Information System (INIS)
Chang, S.H.; Cho, W.J.
1984-01-01
For the probabilistic risk analysis of the radioactive high level waste repository, the simplified method based on the time dependent hazard rate is proposed. The obtained results are compared with those from the time independent hazard rate. The estimation of the failure probability of the waste repository through this method gives more conservative results, especially when the half-life of nuclide is larger and retardation factors of nuclide is smaller. (Auth.)
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Farji-Brener, Alejandro G; Elizalde, Luciana; Fernández-Marín, Hermógenes; Amador-Vargas, Sabrina
2016-05-25
Adequate waste management is vital for the success of social life, because waste accumulation increases sanitary risks in dense societies. We explored why different leaf-cutting ants (LCA) species locate their waste in internal nest chambers or external piles, including ecological context and accounting for phylogenetic relations. We propose that waste location depends on whether the environmental conditions enhance or reduce the risk of infection. We obtained the geographical range, habitat and refuse location of LCA from published literature, and experimentally determined whether pathogens on ant waste survived to the high soil temperatures typical of xeric habitats. The habitat of the LCA determined waste location after phylogenetic correction: species with external waste piles mainly occur in xeric environments, whereas those with internal waste chambers mainly inhabit more humid habitats. The ancestral reconstruction suggests that dumping waste externally is less derived than digging waste nest chambers. Empirical results showed that high soil surface temperatures reduce pathogen prevalence from LCA waste. We proposed that LCA living in environments unfavourable for pathogens (i.e. xeric habitats) avoid digging costs by dumping the refuse above ground. Conversely, in environments suitable for pathogens, LCA species prevent the spread of diseases by storing waste underground, presumably, a behaviour that contributed to the colonization of humid habitats. These results highlight the adaptation of organisms to the hygienic challenges of social living, and illustrate how sanitary behaviours can result from a combination of evolutionary history and current environmental conditions. © 2016 The Author(s).
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The Two Faces of Social Interaction Reward in Animal Models of Drug Dependence.
El Rawas, Rana; Saria, Alois
2016-03-01
Drug dependence is a serious health and social problem. Social factors can modify vulnerability to developing drug dependence, acting as risk factors or protective factors. Whereas stress and peer environment that encourage substance use may increase drug taking, strong attachments between family members and peer environment that do not experience drug use may protect against drug taking and, ultimately, drug dependence. The rewarding effects of drug abuse and social interaction can be evaluated using animal models. In this review we focus on evaluating social interaction reward in the conditioned place preference paradigm. We give an overview of how social interaction, if made available within the drug context, may facilitate, promote and interact with the drug's effects. However, social interaction, if offered alternatively outside the drug context, may have pronounced protective effects against drug abuse and relapse. We also address the importance of the weight difference parameter between the social partners in determining the positive or "agonistic" versus the hostile or "antagonistic" social interaction. We conclude that understanding social interaction reward and its subsequent effects on drug reward is sorely needed for therapeutic interventions against drug dependence.
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International Nuclear Information System (INIS)
Wilmot, R.D.; Galson, D.A.; Pollard, S.J.T.; Smith, R.E.; Yearsley, R.A.
1999-01-01
The Environment Agency of England and Wales (the 'Agency') has an extremely broad regulatory remit covering aspects of flood defence, integrated pollution control, water quality, waste management, abstraction control, navigation, fisheries, conservation and recreation. Risk assessment, as a regulatory and management tool plays an essential role in the targeting and prioritisation of this activity, as well as in aiding site-specific decisions on authorisations for abstraction, discharge and/or disposal. From a regulatory perspective, the majority of the Agency's risk assessment activity is focused on critically reviewing risk assessments submitted to the Agency in support of requests for authorisation. With increasing calls for openness in all areas of regulatory decision-making, new demands are being placed on risk assessments with a view to allowing far more transparency and traceability of 'process' and 'content' than has historically been the case. The Agency is responsible for the licensing of radioactive waste disposal facilities in England and Wales. It has issued guidance on what is expected of an application for an authorisation to dispose of low and intermediate level radioactive waste to land - the 'Guidance on Requirements for Authorisation' (the 'GRA'). The GRA includes a risk target and places a strong emphasis on confidence-building during the preparation and assessment of post-closure safety cases for such facilities. In this paper we discuss a recent study commissioned by the Agency which has examined the use of expectation value of risk in assessments and considered ways of improving transparency. The study has concluded that the expectation value is an appropriate measure of risk for comparison with a single-value criterion, provided that the scope of the assessment does not involve undue speculation regarding the FEPs (Features, Events and Processes) to be included. Low probability or speculative events and processes for which no data can be
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The risk evaluation of a model of a high-level waste solidification plant
International Nuclear Information System (INIS)
Bruecher, H.
1977-02-01
In this report the risk associated with the operation of a plant for vitrification of high-level liquid waste is evaluated. Considerung risk assessment it turns out that the important accidents occur during off-gas cleaning. On the other hand effects of explosions in the process equipment don't contribute very much to the overall risk. These data are compared with the risk resulting from routine discharge of the plant. It is of the same magnitude as or greater than the most important accident risks. (orig.) [de
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Appelhans, Bradley M; Woolf, Kathleen; Pagoto, Sherry L; Schneider, Kristin L; Whited, Matthew C; Liebman, Rebecca
2011-11-01
Overeating is believed to result when the appetitive motivation to consume palatable food exceeds an individual's capacity for inhibitory control of eating. This hypothesis was supported in recent studies involving predominantly normal weight women, but has not been tested in obese populations. The current study tested the interaction between food reward sensitivity and inhibitory control in predicting palatable food intake among energy-replete overweight and obese women (N = 62). Sensitivity to palatable food reward was measured with the Power of Food Scale. Inhibitory control was assessed with a computerized choice task that captures the tendency to discount large delayed rewards relative to smaller immediate rewards. Participants completed an eating in the absence of hunger protocol in which homeostatic energy needs were eliminated with a bland preload of plain oatmeal, followed by a bogus laboratory taste test of palatable and bland snacks. The interaction between food reward sensitivity and inhibitory control was a significant predictor of palatable food intake in regression analyses controlling for BMI and the amount of preload consumed. Probing this interaction indicated that higher food reward sensitivity predicted greater palatable food intake at low levels of inhibitory control, but was not associated with intake at high levels of inhibitory control. As expected, no associations were found in a similar regression analysis predicting intake of bland foods. Findings support a neurobehavioral model of eating behavior in which sensitivity to palatable food reward drives overeating only when accompanied by insufficient inhibitory control. Strengthening inhibitory control could enhance weight management programs.
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International Nuclear Information System (INIS)
Vieru, G.
2000-01-01
Problems related to the handling, treatment, packaging, storage, transportation, and disposal of radioactive wastes (radwastes) are very important and the responsibility for the safe management of radioactive wastes for the protection of human health and the environment has long been recognized. Safety and public welfare are to be considered within the radioactive waste management, particularly in the field of transportation because of the potential risk that it could pose to the public and to the environment. The IAEA regulations ensure safety in the transport of Radioactive Materials (RAM) by laying down detailed requirements, appropriate to the degree of hazard represented by the respective material, taking into account its form and quantity. Risk assessment provides a basis for routing radwastes and developing mitigation plans, prioritizing initiatives and enacting legislation to protect human beings and the environment. Factors such as shipment cost, distance, population exposed, environmental impacts or sensitivity, time in transit and infrastructure related issues, could be included in the terms of safety and risk. The paper presents risk assessment activities aimed to evaluate risk categories and the radiological consequences that may arise during normal (accident free) transport and those resulting from transport accidents involving waste shipments in Romania. (author)
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International Nuclear Information System (INIS)
Smith, K.P.; Arnish, J.J.; Williams, G.P.; Blunt, D.L.
2003-01-01
Certain petroleum production activities cause naturally occurring radioactive materials (NORM) to accumulate in concentrations above natural background levels, making safe and cost-effective management of such technologically enhanced NORM (TENORM) a key issue for the petroleum industry. As a result, both industry and regulators are interested in identifying cost-effective disposal alternatives that provide adequate protection of human health and the environment. One such alternative, currently allowed in Michigan with restrictions, is the disposal of TENORM wastes in nonhazardous waste landfills. The disposal of petroleum industry wastes containing radium-226 (Ra-226) in nonhazardous landfills was modeled to evaluate the potential radiological doses and health risks to workers and the public. Multiple scenarios were considered in evaluating the potential risks associated with landfill operations and the future use of the property. The scenarios were defined, in part, to evaluate the Michigan policy; sensitivity analyses were conducted to evaluate the impact of key parameters on potential risks. The results indicate that the disposal of petroleum industry TENORM wastes in nonhazardous landfills in accordance with the Michigan policy and existing landfill regulations presents a negligible risk to most of the potential receptors considered in this study.
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International Nuclear Information System (INIS)
Wilmot, E.L.; Madsen, M.M.; Cashwell, J.W.; Joy, D.S.
1983-06-01
This report documents preliminary cost and risk analyses that were performed in support of the Nuclear Waste Terminal Storage (NWTS) program. The analyses compare the costs and hazards of transporting wastes to each of five regions that contain potential candidate nuclear waste repository sites being considered by the NWTS program. These regions are: the Gulf Interior Region, the Permian Basin, the Paradox Basin, Yucca Mountain, and Hanford. Two fuel-cycle scenarios were analyzed: once-through and reprocessing. Transportation was assumed to be either entirely by truck or entirely by rail for each of the scenarios. The results from the risk analyses include those attributable to nonradiological causes and those attributable to the radioactive character of the wastes being transported. 17 references
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Ikemoto, Satoshi; Bonci, Antonello
2013-01-01
In recent years, neuroscientists have produced profound conceptual and mechanistic advances on the neurocircuitry of reward and substance use disorders. Here, we will provide a brief review of intracranial drug self-administration and optogenetic self-stimulation studies that identified brain regions and neurotransmitter systems involved in drug- and reward-related behaviors. Also discussed is a theoretical framework that helps to understand the functional properties of the circuitry involved in these behaviors. The circuitry appears to be homeostatically regulated and mediate anticipatory processes that regulate behavioral interaction with the environment in response to salient stimuli. That is, abused drugs or, at least, some may act on basic motivation and mood processes, regulating behavior-environment interaction. Optogenetics and related technologies have begun to uncover detailed circuit mechanisms linking key brain regions in which abused drugs act for rewarding effects. PMID:23664810
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Neural reward and punishment sensitivity in cigarette smokers.
Potts, Geoffrey F; Bloom, Erika L; Evans, David E; Drobes, David J
2014-11-01
Nicotine addiction remains a major public health problem but the neural substrates of addictive behavior remain unknown. One characteristic of smoking behavior is impulsive choice, selecting the immediate reward of smoking despite the potential long-term negative consequences. This suggests that drug users, including cigarette smokers, may be more sensitive to rewards and less sensitive to punishment. We used event-related potentials (ERPs) to test the hypothesis that smokers are more responsive to reward signals and less responsive to punishment, potentially predisposing them to risky behavior. We conducted two experiments, one using a reward prediction design to elicit a Medial Frontal Negativity (MFN) and one using a reward- and punishment-motivated flanker task to elicit an Error Related Negativity (ERN), ERP components thought to index activity in the cortical projection of the dopaminergic reward system. The smokers had a greater MFN response to unpredicted rewards, and non-smokers, but not smokers, had a larger ERN on punishment motivated trials indicating that smokers are more reward sensitive and less punishment sensitive than nonsmokers, overestimating the appetitive value and underestimating aversive outcomes of stimuli and actions. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
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Employee Reward Systems in Organizations
Directory of Open Access Journals (Sweden)
Došenović Dragana
2016-06-01
Full Text Available Employee rewarding is one of the activities of human resource management concerning the management of money, goods and services that employees receive from their employer in exchange for their work. Given that a properly designed reward system is one of the conditions for a stable business, successful performance of work activities and the achievement of set objectives in each organization, the basic theme of this paper is the employee reward system, with a special focus on different elements of it. The purpose of this paper is to describe the role and significance of the observed system and to draw attention to its role in employee’s motivation.
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Fire simulation in radioactive waste disposal and the radiation risk associated
International Nuclear Information System (INIS)
Domingos, Érica Nascimento
2018-01-01
An atmospheric dispersion of radioactive material is one of the possible consequences of an accident scenario in nuclear installations, radiative and radioactive waste deposit. Taking into account a possibility of this release of radioactive material into the atmosphere this work proposes a modeling of the atmospheric dispersion from a fire scenario in a deposit of radioactive waste of low and middle level of radiation varying the amount of inventory released in the fire. For this simulation was adopted the software of physical codes of medical health, the HotSpot Health Physics Codes which uses the Gaussian model to calculate an atmospheric dispersion based on the Pasquill atmospheric stability classes. This software calculates a total effective dose in relation to distance, such as a compromised dose in a list of specific organs, among them the lung, object of work study for calculating the risk of cancer associated with a low dose of radiation. The radiological risk calculation is held by the BEIR V model, Biological Effects of Ionizing Radiations, one of the models to estimate the relative risk of cancer induced by ionizing radiation. (author)
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International Nuclear Information System (INIS)
Lange, F.; Fett, H.J.; Gruendler, D.; Schwarz, G.
1993-01-01
Radiation exposures of members of critical groups of the general population and of transport personnel resulting from normal transport of radioactive wastes to the planned final waste repository Konrad have been evaluated in detail. By applying probabilistic safety assessment techniques radiological risks from transport accidents have been analysed by quantifying potential radiation exposures and contaminations of the biosphere in connection with their expected frequencies of occurrence. The Konrad transport study concentrates on the local region of the waste repository, where all transports converge. (orig.) [de
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Black, I; Seaton, R; Chackiath, S; Wagland, S T; Pollard, S J T; Longhurst, P J
2011-12-01
The identification of risk and its appropriate allocation to partners in project consortia is essential for minimizing overall project risks, ensuring timely delivery and maximizing benefit for money invested. Risk management guidance available from government bodies, especially in the UK, does not specify methodologies for quantitative risk assessment, nor does it offer a procedure for allocating risk among project partners. Here, a methodology to quantify project risk and potential approaches to allocating risk and their implications are discussed. Construction and operation of a waste management facility through a public-private finance contract are discussed. Public-private partnership contracts are special purpose vehicle (SPV) financing methods promoted by the UK government to boost private sector investment in facilities for public service enhancement. Our findings question the appropriateness of using standard deviation as a measure for project risk and confirm the concept of portfolio theory, suggesting the pooling of risk can reduce total risk and its impact.
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Role of delay-based reward in the spatial cooperation
Wang, Xu-Wen; Nie, Sen; Jiang, Luo-Luo; Wang, Bing-Hong; Chen, Shi-Ming
2017-01-01
Strategy selection in games, a typical decision making, usually brings noticeable reward for players which have discounted value if the delay appears. The discounted value is measure: earning sooner with a small reward or later with a delayed larger reward. Here, we investigate effects of delayed rewards on the cooperation in structured population. It is found that delayed reward supports the spreading of cooperation in square lattice, small-world and random networks. In particular, intermediate reward differences between delays impel the highest cooperation level. Interestingly, cooperative individuals with the same delay time steps form clusters to resist the invasion of defects, and cooperative individuals with lowest delay reward survive because they form the largest clusters in the lattice.
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Motivational orientation modulates the neural response to reward.
Linke, Julia; Kirsch, Peter; King, Andrea V; Gass, Achim; Hennerici, Michael G; Bongers, André; Wessa, Michèle
2010-02-01
Motivational orientation defines the source of motivation for an individual to perform a particular action and can either originate from internal desires (e.g., interest) or external compensation (e.g., money). To this end, motivational orientation should influence the way positive or negative feedback is processed during learning situations and this might in turn have an impact on the learning process. In the present study, we thus investigated whether motivational orientation, i.e., extrinsic and intrinsic motivation modulates the neural response to reward and punishment as well as learning from reward and punishment in 33 healthy individuals. To assess neural responses to reward, punishment and learning of reward contingencies we employed a probabilistic reversal learning task during functional magnetic resonance imaging. Extrinsic and intrinsic motivation were assessed with a self-report questionnaire. Rewarding trials fostered activation in the medial orbitofrontal cortex and anterior cingulate gyrus (ACC) as well as the amygdala and nucleus accumbens, whereas for punishment an increased neural response was observed in the medial and inferior prefrontal cortex, the superior parietal cortex and the insula. High extrinsic motivation was positively correlated to increased neural responses to reward in the ACC, amygdala and putamen, whereas a negative relationship between intrinsic motivation and brain activation in these brain regions was observed. These findings show that motivational orientation indeed modulates the responsiveness to reward delivery in major components of the human reward system and therefore extends previous results showing a significant influence of individual differences in reward-related personality traits on the neural processing of reward. Copyright (c) 2009 Elsevier Inc. All rights reserved.
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Nicotine Withdrawal Induces Neural Deficits in Reward Processing.
Oliver, Jason A; Evans, David E; Addicott, Merideth A; Potts, Geoffrey F; Brandon, Thomas H; Drobes, David J
2017-06-01
Nicotine withdrawal reduces neurobiological responses to nonsmoking rewards. Insight into these reward deficits could inform the development of targeted interventions. This study examined the effect of withdrawal on neural and behavioral responses during a reward prediction task. Smokers (N = 48) attended two laboratory sessions following overnight abstinence. Withdrawal was manipulated by having participants smoke three regular nicotine (0.6 mg yield; satiation) or very low nicotine (0.05 mg yield; withdrawal) cigarettes. Electrophysiological recordings of neural activity were obtained while participants completed a reward prediction task that involved viewing four combinations of predictive and reward-determining stimuli: (1) Unexpected Reward; (2) Predicted Reward; (3) Predicted Punishment; (4) Unexpected Punishment. The task evokes a medial frontal negativity that mimics the phasic pattern of dopaminergic firing in ventral tegmental regions associated with reward prediction errors. Nicotine withdrawal decreased the amplitude of the medial frontal negativity equally across all trial types (p nicotine dependence (p Nicotine withdrawal had equivocal impact across trial types, suggesting reward processing deficits are unlikely to stem from changes in phasic dopaminergic activity during prediction errors. Effects on tonic activity may be more pronounced. Pharmacological interventions directly targeting the dopamine system and behavioral interventions designed to increase reward motivation and responsiveness (eg, behavioral activation) may aid in mitigating withdrawal symptoms and potentially improving smoking cessation outcomes. Findings from this study indicate nicotine withdrawal impacts reward processing signals that are observable in smokers' neural activity. This may play a role in the subjective aversive experience of nicotine withdrawal and potentially contribute to smoking relapse. Interventions that address abnormal responding to both pleasant and
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A Fly's Eye View of Natural and Drug Reward.
Lowenstein, Eve G; Velazquez-Ulloa, Norma A
2018-01-01
Animals encounter multiple stimuli each day. Some of these stimuli are innately appetitive or aversive, while others are assigned valence based on experience. Drugs like ethanol can elicit aversion in the short term and attraction in the long term. The reward system encodes the predictive value for different stimuli, mediating anticipation for attractive or punishing stimuli and driving animal behavior to approach or avoid conditioned stimuli. The neurochemistry and neurocircuitry of the reward system is partly evolutionarily conserved. In both vertebrates and invertebrates, including Drosophila melanogaster , dopamine is at the center of a network of neurotransmitters and neuromodulators acting in concert to encode rewards. Behavioral assays in D. melanogaster have become increasingly sophisticated, allowing more direct comparison with mammalian research. Moreover, recent evidence has established the functional modularity of the reward neural circuits in Drosophila . This functional modularity resembles the organization of reward circuits in mammals. The powerful genetic and molecular tools for D. melanogaster allow characterization and manipulation at the single-cell level. These tools are being used to construct a detailed map of the neural circuits mediating specific rewarding stimuli and have allowed for the identification of multiple genes and molecular pathways that mediate the effects of reinforcing stimuli, including their rewarding effects. This report provides an overview of the research on natural and drug reward in D. melanogaster , including natural rewards such as sugar and other food nutrients, and drug rewards including ethanol, cocaine, amphetamine, methamphetamine, and nicotine. We focused mainly on the known genetic and neural mechanisms underlying appetitive reward for sugar and reward for ethanol. We also include genes, molecular pathways, and neural circuits that have been identified using assays that test the palatability of the rewarding
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Musculoskeletal pain and effort-reward imbalance--a systematic review.
Koch, Peter; Schablon, Anja; Latza, Ute; Nienhaus, Albert
2014-01-15
Musculoskeletal pain may be triggered by physical strains and psychosocial risk factors. The effort-reward imbalance model (ERI model) is a stress model which measures psychosocial factors in the working world. The question is whether workers with an effort-reward imbalance report musculoskeletal pain more frequently than those with no effort-reward imbalance. A systematic review using a best evidence synthesis approach was conducted to answer this question. A literature search was conducted for the period from 1996 to 2012, using three databases (Pubmed, Embase and PsycINFO). The research criteria related to psychosocial, work-related stress as per the ERI model and to musculoskeletal pain. A quality score was developed using various quality criteria to assess the standard of the studies. The level of evidence was graded as in (Am J Ind Med 39:180-193, 2001). After applying the inclusion criteria, a total of 19 studies were included in the review: 15 cross-sectional studies, three prospective studies and one case-control study. 74% of all studies exhibited good methodological quality, 53% collected data using the original ERI questionnaire, and in 42% of the studies, there was adequate control for physical working conditions. Furthermore, different cut-off points were used to classify exposed and non-exposed individuals. On the basis of 13 studies with a positive, statistically significant association, a moderate level of evidence was inferred for the association between effort-reward imbalance and musculoskeletal pain. The evidence for a role of over-commitment and for its interaction with effort-reward imbalance was rated as inconclusive - on the basis of eight and five studies, respectively. On the basis of the available evidence, no reliable conclusion may be drawn about any association between the psychosocial factors ascertained using the ERI model and musculoskeletal pain. Before a reliable statement can be made on the association between ERI and
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Aberg, Kristoffer C; Müller, Julia; Schwartz, Sophie
2017-01-01
Anticipation and delivery of rewards improves memory formation, but little effort has been made to disentangle their respective contributions to memory enhancement. Moreover, it has been suggested that the effects of reward on memory are mediated by dopaminergic influences on hippocampal plasticity. Yet, evidence linking memory improvements to actual reward computations reflected in the activity of the dopaminergic system, i.e., prediction errors and expected values, is scarce and inconclusive. For example, different previous studies reported that the magnitude of prediction errors during a reinforcement learning task was a positive, negative, or non-significant predictor of successfully encoding simultaneously presented images. Individual sensitivities to reward and punishment have been found to influence the activation of the dopaminergic reward system and could therefore help explain these seemingly discrepant results. Here, we used a novel associative memory task combined with computational modeling and showed independent effects of reward-delivery and reward-anticipation on memory. Strikingly, the computational approach revealed positive influences from both reward delivery, as mediated by prediction error magnitude, and reward anticipation, as mediated by magnitude of expected value, even in the absence of behavioral effects when analyzed using standard methods, i.e., by collapsing memory performance across trials within conditions. We additionally measured trait estimates of reward and punishment sensitivity and found that individuals with increased reward (vs. punishment) sensitivity had better memory for associations encoded during positive (vs. negative) prediction errors when tested after 20 min, but a negative trend when tested after 24 h. In conclusion, modeling trial-by-trial fluctuations in the magnitude of reward, as we did here for prediction errors and expected value computations, provides a comprehensive and biologically plausible description of
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International Nuclear Information System (INIS)
Blaylock, B.P.; Legg, J.; Travis, C.C.; Scofield, P.A.
1995-06-01
This document describes a worker health risk evaluation methodology for assessing risks associated with Environmental Restoration (ER) and Waste Management (WM). The methodology is appropriate for estimating worker risks across the Department of Energy (DOE) Complex at both programmatic and site-specific levels. This document supports the worker health risk methodology used to perform the human health risk assessment portion of the DOE Programmatic Environmental Impact Statement (PEIS) although it has applications beyond the PEIS, such as installation-wide worker risk assessments, screening-level assessments, and site-specific assessments
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Energy Technology Data Exchange (ETDEWEB)
Blaylock, B.P.; Legg, J.; Travis, C.C. [Oak Ridge National Lab., TN (United States). Center for Risk Management; Simek, M.A.; Sutherland, J. [Univ. of Tennessee, Knoxville, TN (United States); Scofield, P.A. [Office of Environmental Compliance and Documentation (United States)
1995-06-01
This document describes a worker health risk evaluation methodology for assessing risks associated with Environmental Restoration (ER) and Waste Management (WM). The methodology is appropriate for estimating worker risks across the Department of Energy (DOE) Complex at both programmatic and site-specific levels. This document supports the worker health risk methodology used to perform the human health risk assessment portion of the DOE Programmatic Environmental Impact Statement (PEIS) although it has applications beyond the PEIS, such as installation-wide worker risk assessments, screening-level assessments, and site-specific assessments.
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International Nuclear Information System (INIS)
Wilmot, R.D.
2002-10-01
The Swedish regulators have been active in the field of performance assessment of radioactive waste disposal facilities for many years and have developed sophisticated approaches to the development of scenarios and other aspects of assessments. These assessments have generally used dose as the assessment end-point. Regulations recently established in Sweden (SSI FS 1998:1) have introduced a risk criterion for radioactive waste disposal: the annual risk of harmful effects after closure of a disposal facility should not exceed 10 -6 for a representative individual in the group exposed to the greatest risk. This report evaluates different approaches to the definition and use of probabilities in the context of risk assessments, and examines the presentation of the results of risk assessments in safety cases to meet risk targets. The report illustrates the strengths and weaknesses of different possible approaches to risk assessment by reference to assessments in other countries, and provides suggestions for future activity and development in this area by the Swedish regulators. The review of experience in other countries has led to a number of key observations relevant to the conduct of regulatory work on risk assessments and preparations for review. These highlight the importance of developing a protocol for conducting calculations, and linking such a protocol to the requirements of risk assessment calculations and to existing code and model capabilities. There are a number of decisions and assumptions required in developing a risk assessment methodology that could potentially affect the calculated results. These assumptions are independent of the analysis of performance, and relate to issues such as the expectation value of risk, risk dilution, the definition of probability density functions and achieving convergence. A review of a proponent's risk assessment should address these issues in determining the appropriateness and validity of the results presented