bluuebunny/crossref_metadata_2025 huggingface dataset:
5‐HT Transporter Sites and 5‐HT1A and 5‐HT3 Receptors in Fawn‐Hooded Rats: A Quantitative Autoradiography Study
Authors: Chen Feng , Lawrence Andrew J.
Published: May 2006

Background: The neuroanatomical profiles of 5‐HT1A receptors, 5‐HT3 receptors, and 5‐HT transporters (5‐HTT) in the brain of the Fawn‐Hooded (FH) rat, particularly mesocorticolimbic regions, are not fully elucidated.

Methods: By means of in vitro quantitative autoradiography, we used [3H]citalopram, [3H]8‐OH‐DPAT, and [H]GR65630 to label 5‐HTT, 5‐HT1A receptors, and 5‐HT3 receptors in the brain of alcohol‐naïve FH rats, Wistar‐Kyoto (WKY) rats, and FH rats given free access to 5% ethanol and/or after 24 to 48 hr withdrawal.

Results and Conclusions: In alcohol‐naïve rats, FH rats displayed significantly higher (p < 0.05) densities of [3H]citalopram binding in the nucleus accumbens (+30%), lateral septum (+37%), ventral pallidum (+21%), and ventral tegmental area (+24%), as well as an increased binding of [3H]8‐OH‐DPAT to 5‐HT1A receptors in the frontal and parietal cortex (+33%), occipital and temporal cortex (+25%), and hippocampal CA3 region (+31%), compared with WKY rats, whereas both strains exhibited comparable [3H]GR65630 binding to 5‐HT, receptors. Compared with control FH (naïve) rats, chronic ethanol consumption significantly decreased (p < 0.05) [3H]8‐OH‐DPAT binding in the frontal and parietal cortex (‐15%) but significantly increased binding (p < 0.05) in the entorhinal cortex (+25%), retrosplenial granular cortex (+20%), and hippocampal CA1 (+14%) and CA3 regions (+18%). Moreover, ethanol withdrawal induced the same extent of increased [3H]8‐OH‐DPAT binding in the entorhinal and retrosplenial cortex as seen in FH (chronic) rats. In contrast, [3H]8‐OH‐DPAT binding in the hippocampal CA1 and CA3 regions was decreased by ‐9% and ‐20% from the level of chronic ethanol‐treated FH rat (p < 0.05) and returned to the control level seen in FH (naïve) rats.

Significance:

The elevated 5‐HT transporters and 5‐HT1A receptors in the mesocorticolimbic areas in FH rats may reflect a potential innate altered transmission at serotonergic synapses, which possibly may affect the high intake of alcohol in FH rats. The region‐specific alterations of 5‐HT1A receptors in FH rat brain after ethanol challenges suggest that 5‐HT1A receptors are sensitive to ethanol challenges, whereas 5‐HTT are apparently insensitive.
Short‐Term Acetaldehyde Exposure Depresses Ventricular Myocyte Contraction: Role of Cytochrome P450 Oxidase, Xanthine Oxidase, and Lipid Peroxidation
Authors: Aberle Nicholas S. , Ren Jun
Published: May 2006

Background: Chronic alcoholism leads to the development of alcoholic cardiomyopathy, manifested as ventricular dilation and impaired ventricular contractility. However, the specific toxic mechanism responsible for alcoholic cardiomyopathy remains unclear. One major candidate toxin is the first metabolic product of ethanol, acetaldehyde (ACA). This study was designed to examine the role of cytochrome P450 oxidase 2E1 (CYP 2E1), xanthine oxidase, and lipid peroxidation in the short‐term ACA exposure‐induced mechanical defects in adult rat ventricular myocytes.

Methods: Mechanical and intracellular Ca2+ properties were evaluated by an IonOptix SoftEdge® system. Lipid peroxidation was assessed with malondialdehyde levels by using high‐performance liquid chromatography.

Results: Short‐term (4‐ to 6‐hr) culture of myocytes with ACA (1–100 μM) in sealed containers with silicone septum depressed cell‐shortening amplitude, maximal velocity of shortening/relengthening, and prolonged duration of relengthening, as well as intracellular Ca2+ clearing without any effect on the duration of shortening and electrically stimulated an intracellular Ca2+ increase. It is interesting to note that the ACA‐induced effects on myocyte mechanical properties were abolished with co‐treatment of the lipid peroxidation inhibitor butylated hydroxytoluene (20 μM), the CYP 2E1 inhibitor diallyl sulfide (100 μM), and the xanthine oxidase inhibitor allopurinol (100 μM). Short‐term incubation of ACA with the myocytes also produced a significant increase of the lipid peroxidation end product malondialdehyde, which may be prevented by butylated hydroxytoluene.

Conclusions: Collectively, these data provided evidence that ACA depressed cardiomyocyte mechanical function at micromolar levels, possibly through mechanisms related to CYP oxidase, xanthine oxidase, and lipid peroxidation.
Cross‐Sensitization Between the Locomotor Stimulant Effects of Ethanol and Those of Morphine and Cocaine in Mice
Authors: Lessov Christina N. , Phillips Tamara J.
Published: May 2006

Background: Drugs of abuse may share some common mechanisms of action. We examined this idea by determining whether cross‐sensitization would occur between the locomotor stimulant effects of ethanol (EtOH) and those of morphine and cocaine.

Methods: Genetically heterogeneous adult female mice were repeatedly treated with 2.5 g/kg EtOH, then challenged 24 hr later with one of four doses of morphine or cocaine (0, 5, 10, or 20 mg/kg for both drugs). Under the reciprocal conditions, mice were repeatedly injected with cocaine or morphine (10 or 20 mg/kg), then challenged 24 hr later with 2.0 g/kg EtOH. In all cases, locomotor responses were compared to those of repeatedly saline‐treated control groups.

Results: Behavioral sensitization was seen to the stimulant effects of EtOH, and to the effects of the higher, 20 mg/kg dose of both morphine and cocaine. EtOH‐sensitized mice did not show cross‐sensitization to morphine or cocaine. However, both single and multiple morphine pre‐exposures induced enhanced activation to an EtOH challenge. Mice repeatedly injected with 10 or 20 mg/kg cocaine also exhibited increased sensitivity to the stimulant effects of EtOH.

Conclusions: There is some overlap in the neural mechanisms underlying behavioral sensitization to the locomotor stimulant effects of EtOH and those mediating sensitization to the locomotor stimulant effects of morphine and cocaine. Differences seen under reciprocal treatments may be associated with conditioning factors, or reflect differences in the neurobiological specificity of the effects of these drugs.
Fragmentary Blackouts: Their Etiology and Effect on Alcohol Expectancies
Authors: Hartzler Bryan , Fromme Kim
Published: May 2006

Background: Fragmentary blackouts, or memory loss for intoxicated events that may be later recalled with the provision of cues, are common sequelae of heavy drinking, yet understanding of their characteristics, correlates, and consequences is limited. Consequently, this alcohol‐administration study addressed questions regarding the etiology of fragmentary blackouts and their effect on alcohol outcome expectancies.

Methods: A placebo‐controlled design addressed the etiology of fragmentary blackouts through assessment of memory formation before and after alcohol consumption. The effect of fragmentary blackouts on prospective beliefs about alcohol was assessed by way of a self‐report outcome expectancy questionnaire and a measure of response latency for alcohol concepts presented after beverage consumption.

Results: Although participants performed similarly on memory indices before consuming beverages, those who reported past fragmentary blackouts and consumed alcohol displayed marked difficulty with recall of a narrative when this was attempted both during intoxication and after detoxification, as well as with a source memory task presented during intoxication. Those reporting fragmentary blackouts also endorsed stronger outcome expectancies for a range of alcohol effects and exhibited greater accessibility for positive alcohol concepts presented after beverage administration. Further, source recall contributed significantly to the episodic recall both during intoxication and after detoxification, as well as to positive outcome expectancies of those receiving alcohol.

Conclusions: Findings suggest that fragmentary blackouts result from poor retrieval and that individual differences in retrieval emerge after alcohol is consumed. Further, one's recall of source aspects of material—its time and social context—is an important determinant of recall of stimuli and events encountered during intoxication, as well as of prospective expectations for positive alcohol effects. The collective findings expand our understanding of this complex yet common neuropsychological consequence of heavy drinking.
Effects of Neuropeptide Y on Sucrose and Ethanol Intake and on Anxiety‐Like Behavior in High Alcohol Drinking (HAD) and Low Alcohol Drinking (LAD) Rats
Authors: Badia‐Elder N. E. , Stewart R. B. , Powrozek Teresa A. , Murphy J. M. , Li T.‐K.
Published: May 2006

Background: In a previous study, neuropeptide Y (NPY) administered into the lateral ventricles decreased ethanol intake in alcohol‐preferring (P) rats but not in alcohol‐nonpreferring (NP) or unselected Wistar rats. The purpose of the present investigation is to extend these findings in selectively‐bred high‐alcohol‐drinking (HAD)1 and low‐alcohol‐drinking (LAD)1 rats by examining the effects of intracerebroventricularly administered NPY on the elevated plus maze test of anxiety and on ethanol and sucrose intake.

Methods: Female HAD1 and LAD1 rats were surgically implanted with cannula into the lateral ventricle. Following recovery, a test of anxiety was conducted in which the rats (n= 12–13/group) received either artificial cerebrospinal fluid (aCSF) or NPY (10 μg) 10 min prior to a 5‐min test on an elevated plus maze. Following anxiety testing, 11 HAD and 11 LAD rats were trained to self‐administer ethanol (8% w/v), and 5 HAD and 8 LAD rats were trained to self‐administer sucrose (2.5%) during daily 2‐hr sessions. A within‐subject design was used in which the rats were pretreated once a week with aCSF, 5 μg NPY, or 10 μg NPY prior to the drinking sessions.

Results: HAD and LAD rats treated with aCSF did not differ in time spent in open arms of the plus maze. NPY increased time spent on the open arms to similar degrees in both rat lines. HAD rats consumed more ethanol and sucrose than LAD rats. NPY increased sucrose intake in both rat lines. However, the same doses of NPY reduced ethanol intake in HAD but not in LAD rats.

Conclusion: The plus maze results indicated that selective breeding for high and low alcohol preference in the HAD1 and LAD1 rats, respectively, did not yield differences in anxiety‐like behavior and in response to the anxiolytic effects of NPY. The increases in sucrose intake were consistent with the known orexigenic effects of NPY. The decreased ethanol intake following NPY administration in HAD rats was similar to previous observations with P rats and is consistent with the hypothesis that ethanol intake and NPY activity may be inversely related.
Effect of Baclofen on Alcohol and Sucrose Self‐Administration in Rats
Authors: Anstrom Kristin K. , Cromwell Howard C. , Markowski Tania , Woodward Donald J.
Published: May 2006

Background:Baclofen, a γ‐aminobutyric acid type B agonist, has been proposed as a pharmacotherapeutic agent in the treatment of addictive disorders such as alcoholism. Preclinical studies documenting the effect of baclofen on alcohol intake have provided conflicting results. The goal of this study was to determine the effect of baclofen pretreatment on ethanol‐ and sucrose‐reinforced responding.

Methods:Animals were trained to self‐administer a 10% ethanol in water solution on a fixed ratio 1 schedule of reinforcement by using the sucrose‐fade method. With a within‐subject design, the effect of three doses of baclofen (1.8, 3.2, and 5.6 mg/kg intraperitoneally) was examined on 10% ethanol‐ and 2% sucrose‐reinforced responding. Dose‐dependent effects on responding and on drinking‐pattern microstructure were examined.

Results:Under a fixed ratio 1 schedule, baclofen reduced responding for alcohol and sucrose reinforcement in a similar, dose‐dependent manner. A dose‐dependent response attenuation was seen during the initial segment of an operant session when highly repetitive response patterns were generated. Further analysis of drinking ultrastructure revealed that baclofen altered the patterns of these repetitive responses by lengthening the self‐initiated intertrial intervals.

Conclusions:Systemic baclofen administration attenuates responding for alcohol and sucrose reinforcement in a dose‐dependent manner. If the reinforcing efficacy and response requirement for sucrose and alcohol are matched, then baclofen has similar effects on responding and patterns of drinking microstructure. We conclude that the neural mechanisms that support both ethanol and sucrose self‐administration behavior are sensitive to γ‐aminobutyric acid type B modulation.
Salty and Sour Taste Characteristics and Risk of Alcoholism
Authors: Sandstrom Kristen A. , Rajan Tara M. , Feinn Richard , Kranzler Henry R.
Published: May 2006

Background: This study examined gustatory measures (intensity and hedonic values of salt and citric acid solutions) that have been reported to differentiate nonalcoholics who are at risk of alcoholism by virtue of having an alcoholic father (PHP) from those with no such paternal history (PHN). The study tested the hypothesis that PHPs perceive salty and sour solutions to be more intense and less pleasurable than do PHNs.

Methods: A total of 112 nonalcoholic subjects (44.7% male and 40.2% PHP) provided intensity and pleasantness ratings for a series of salty and sour solutions in varying concentrations.

Results: PHP subjects rated salty solutions as more unpleasant than PHN subjects. PHP subjects also showed higher mean sour intensity ratings and less preference for sour solutions than PHN subjects.

Conclusions: This study replicates and extends prior findings of salty and sour taste differences as a function of paternal history of alcoholism. Further research is needed to replicate these findings in other populations and to examine their implications for the transmission of alcoholism risk.
Effects of Alcohol on Subjective Ratings of Prospective and Everyday Memory Deficits
Authors: Ling J. , Heffernan T. M. , Buchanan T. , Rodgers J. , Scholey A. B. , Parrott A. C.
Published: May 2006

Background: Research has shown that heavy alcohol use has a detrimental effect on retrospective memory. Less is known about the effect of alcohol on everyday memory.

Methods: This study examined self‐ratings of two aspects of memory performance: prospective memory (for example, forgetting to pass on a message) and everyday memory (measured by cognitive failures, such as telling someone a joke that you have told them before). To ensure anonymity and expand on the numbers of participants used in previous studies, data were collected by using the Internet. Data from 763 participants remained after data screening.

Results: After controlling for other drug and strategy use, there was clear evidence that differential use of alcohol was associated with impairments in the long‐term aspect of prospective memory and with an increased number of cognitive failures.

Conclusions: These results support and extend the findings of previous research: our findings are consistent with the idea that heavy use of alcohol does have a significant and negative effect on everyday cognitive performance. Possible causes of these impairments are discussed.
Estimated Cancer Risk Associated with Occupational Asbestos Exposure
Authors: Hogan Michael D. , Hoel David G.
Published: May 2006

This paper estimates the number of workers in the United States who were occupationally exposed to asbestos during and after World War II and assesses the impact of this exposure on overall cancer mortality. The results suggest that over half of the estimated 7–8 million potentially exposed workers employed between 1940 and 1970 may still be alive and at risk of dying from some form of asbestos‐related cancer. While the maximum number of excess cancer deaths associated with this occupational exposure is likely to occur sometime in this decade, such deaths will continue to be seen for many years thereafter. At their peak, these deaths may account for an estimated 3% of the annual cancer death toll, with an associated range of 1.4–4.4%.
Assessment and Management of Risk in the Transport of Dangerous Materials: The Case of Chlorine Transport in France
Authors: Meslin Thierry B.
Published: May 2006

The purpose of this paper is to provide the main results of a study concerning the risk of chlorine transport by train in France. The specific problem of chlorine transport is presented in the framework of a general model for assessing the risk in the transport of dangerous materials. The probability of accidents followed with a chlorine release involving fatalities are put in perspective with other risks having potential health effects on the public. Two types of application of the model are envisaged in relation to the management of risk: the selection of protective measures through a cost‐effectiveness approach and the use of the model for a better planning of decisions in an accident situation.
Siting Hazardous Facilities: Lessons from LNG
Authors: Kunreuther Howard , Lathrop John W.
Published: May 2006

This paper develops a descriptive framework for siting large scale technological facilities such as liquefied natural gas (LNG) terminals, and suggests ways of using analyses to improve the process. A key feature of these problems is that they involve relatively new technologies where there has not been a long history with which to construct a statistical data base. Hence the interested parties will each have different estimates of the probabilities and losses associated with events that affect the environment or safety of the population. The decision‐making process can be characterized as a sequence of decisions, subject to change over time, which are influenced by exogenous factors and new legislation. Each of the separate decisions involves an input phase and an interaction phase. The input phase specifies the relevant alternatives and attributes associated with a particular decision. The interaction phase focuses on the nature of the conflicts between the different parties in evaluating the alternatives. Conflicts are often difficult to resolve because each stakeholder in the process has his own objectives, a limited information base shaped by these objectives and scarce computational resources. We illustrate the above descriptive framework through a case study of the LNG siting process in California. The paper then explores possible ways of improving the input and interaction phases through more structured analyses. Specific attention is given to the role of decision analysis, the analytic hierarchy process, examining assumptions, and the use of interactive computer models for scenario generation. The paper concludes by suggesting future research needs on designing policy instruments for helping to reconcile conflicts between the vying interest parties. Promising areas for more problem‐focused research include the role of insurance and compensation schemes.
On the Development of Threshold Criteria for Action for Light Water Reactors
Authors: Okrent David , Baldewicz William L.
Published: May 2006

A survey of recently proposed threshold criteria for regulatory action on light water reactors (LWRs) is presented together with some commentary. This is followed by a new proposal for threshold action criteria which includes some different risk attributes than are found in previous criteria. Some preliminary risk values are suggested for the criteria and then evaluated in terms of a few hypothetical accident scenarios. Finally, several licensing issues are examined in terms of various threshold action criteria.
Risk‐Based Zoning for Toxic‐Gas Pipelines
Authors: Whittaker John D. , Angle Randolph P. , Wilson David J. , Choukalos Mitchell G.
Published: May 2006

Implicit in the operation of a toxic‐gas pipeline is the possibility of an accidental release, which could have serious consequences if upwind of a nearby populated area. Concern for public safety leads to the establishment of isolation corridors or buffer zones to reduce and control the hazard to human settlements. Although “worst case” or “average case” are often used in the determination of safe distances, a probabilistic approach (risk analysis) is superior because it identifies important factors, it makes maximum use of available data, it allows comparison of alternatives, and it quantifies intuitive risk considerations. To illustrate the method, a risk model developed for sour gas pipelines in the Province of Alberta, Canada is outlined and an actual risk‐distance curve is presented. The current zoning regulations in Alberta are summarized.
An Analysis of Changes in the Risk of Mortality from Chronic Obstructive Lung Disease, 1968‐1977
Authors: Patrick Clifford H. , Manton Kenneth G.
Published: May 2006

Nonlinear hazard models are used to examine temporal trends in the age‐specific mortality risks of chronic obstructive lung diseases for the U.S. population. These hazard functions are fit to age‐specific mortality rates for 1968 and 1977 for four race/sex groups. Changes in the parameters of these models are used to assess two types of differences in the age pattern of the rates between 1968 and 1977. The first measure of trend in the age‐specific mortality rates is the temporal change in the proportionality constant in the function used to model their age variation. By allowing only this proportionality parameter to vary between 1968 and 1977, it is possible to determine an age‐constant percentage increase or decrease. The second measure reflects the absolute displacement in terms of years of life of the fitted mortality curves for the two time points. This second index can be interpreted as the acceleration or deceleration of mortality risks over the life span, i.e., the number of years that is needed for mortality rates to achieve the same level as in the comparison group. The analysis showed that the age changes in chronic obstructive lung disease mortality rates differed by race/sex group and for both measures of change over the period. Adjustment of the fitted curves for the effects of individual variability in risk was significant for three of four groups.
Probabilistic Models for Risk Assessment
Authors: Fiksel Joseph , Rosenfield Donald B.
Published: May 2006

Recent concern with the potential for stray carbon fibers to damage electronic equipment and cause economic losses has led to the development of advanced risk‐assessment methods. Risk assessment often requires the synthesis of risk profiles which represent the probability distribution of total annual losses due to a certain set of events or activities. A number of alternative probabilistic models are presented which the authors have used to develop such profiles. Examples are given of applications of these methods to assessment of risk due to conductive fibers released from aircraft or automobile fires. These assessments usually involve a two‐stage approach: estimation of losses for several subclassifications of the overall process, and synthesis of the results into an aggregate risk profile. The methodology presented is capable of treating a wide variety of situations involving sequences of random physical events.
Characterising the Perceived Risks and Benefits of Some Health Issues
Authors: Harding Christina M. , Eiser J. Richard
Published: May 2006

Previous work on perceived risk, particularly a study by Fischhoff et al. (1978), is critically examined with reference to its applicability to specific health related issues. Judgments were obtained from 159 subjects of 15 health‐related items in terms of perceived risk, benefit, and a number of risk characteristics based on the Fischhoff et al. research. In addition, demographic details concerning sex of respondent, seat belt usage, smoking status, and birth order were collected. Using regression analyses it was found that the direction of the risk‐benefit relationship was dependent on the issue being judged. Risk was found to be better explained by ratings of likelihood of mishap and likelihood of death as a consequence of mishap. Benefit was poorly explained by the risk characteristics and demographic data. However, subject group characteristics were shown to be important influences on risk and benefit perception in certain situations. The implications of these results for understanding behavioral decisions involving risk in relation to specific activities are discussed.
Nuclear Plant PRA: How Far Has It Come?
Authors: Levine S. , Rasmussen N. C.
Published: May 2006

Nearly ten years have passed since the publication in August 1974 of the draft Reactor Safety Study (WASH 1400), the first detailed attempt to apply probabilistic risk assessment (PRA) techniques to estimate the public risks posed by commercial nuclear power plants. Now is an opportune time to look back and see how PRA has fared over these ten years. We will not attempt to pass judgement on how the Reactor Safety Study report itself has withstood the test of time, as that task is best left to others less directly involved in preparing the report. Instead, we will examine advances in the understanding, acceptance, and utilization of PRA techniques, as well as technical advances in PRA methods. Some of the significant insights gained from PRAs will be discussed. Finally, some observations on the future of PRA will be offered.
Uncertainties in Nuclear Probabilistic Risk Analyses
Authors: Vesely W. E. , Rasmuson D. M.
Published: May 2006

There are many uncertainties in a probabilistic risk analysis (PRA). We identify the different types of uncertainties and describe their implications. We then summarize the uncertainty analyses which have performed in current PRAs and characterize results which have been obtained. We draw conclusions regarding interpretations of uncertainties, areas having largest uncertainties, and needs which exist in uncertainty analysis. We finally characterize the robustness of various utilizations of PRA results.
External Initiators in Probabilistic Reactor Accident Analysis—Earthquakes, Fires, Floods, Winds
Authors: Budnitz Robert J.
Published: May 2006

This article discusses the methodologies presently available for analyzing the contribution of “external initiators” to overall risks in the context of PRA (probabilistic risk assessment) of large commercial nuclear power reactors. “External initiators” include earthquakes, fires and floods inside the plant, external floods, high winds, aircraft, barge, and ship collisions, noxious or explosive gases offsite, and so on. These are in contrast to “internal initiators” such as active or passive plant equipment failures, human errors, and loss of electrical power. The ability to consider external initiators within PRA has undergone major advances in recent years. In general, uncertainties associated with the calculated risks from external initiators are much larger than those associated with internal initiators. The principal uncertainties lie with development of hazard curves (such as the frequency of occurrence of an event exceeding a given size: for example, the likelihood of a hurricane with winds exceeding 125 knots). For assessment of earthquakes, internal fires and floods, and high winds, the methodology is reasonably mature for qualitative assessment but not for quantitative application. The risks from other external initiators are generally considered to be low, either because of the very long recurrence time associated with the events or because the plants are judged to be well designed to withstand them.
Fire Risks in Oil Refineries: Economic Analysis of Camera Monitoring
Authors: Paté‐Cornell M. Elisabeth
Published: May 2006

A probabilistic method is presented to evaluate the economic value of fire monitoring by closed circuit TV camera in petroleum refineries. The proposed model is restricted to the analysis of risk reduction in an area where fires can be caused either by pump failure or by failure of valves and lines. The benefits come from reducing the time during which the fire grows undetected. Fire growth and expected values of losses are analyzed by a Markov model that includes five phases: (1) active undetected growth, (2) detection, (3) fire growth at the beginning of the firemen's intervention, (4) fire control, and (5) fire extinction. The results (e.g., the expected net present value of the investment) show that the proposed monitoring investment is attractive for an illustrative example.
Entropy Principles in Decision Making Under Risk
Authors: Buckley James J.
Published: May 2006

This paper considers decision problems where: (1) The exact probability distribution over the states of nature is not precisely known, but certain prior information is available about the possibilities of these outcomes; (2) A prior distribution over the states of nature is known, but new constraint information about the probabilities becomes available. The maximum entropy principle asserts that the probability distribution with maximum entropy, satisfying the prior knowledge, should be used in the decision problem. The minimum cross‐entropy principle says that the posterior distribution is the one which minimizes cross‐entropy, subject to the new constraint information. The entropy principles have not gone uncriticized, and this literature, together with that justifying the principles, is surveyed. Both principles are illustrated in a number of situations where the distribution is either discrete or continuous. The discrete distribution case with prior interval estimates based on expert opinions is considered in detail.
Socioeconomic Risk in Development of Energy Systems
Authors: Ursu Ion , Vamanu Dan , Gheorghe Adrian , Purica Ion I.
Published: May 2006

A soft mathematical model, taking stock of the stochastic and cooperative features of the economy of thinking in the decision making, is aggregated to unveil hidden connections between energy policy and the energy technology choices of an establishment. Starting from several assumptions on the nature of the collective decisional behavior, one obtains a probabilistic interpretation of the mechanism of penetration of energy technologies. The probability that the establishment bets on a certain technological profile is given as a solution to a Fokker‐Planck equation accounting for the decision game. It provides a topological variety that accomodates possible states of the system and their trajectories, and indicates ways in which different attractors drive the technology choice in the space of the energy policy.

In this framework, a series of concepts (i.e., logistic evolution, resilience, stability, risks of disruption or crisis, energy security) can find in a natural way strikingly intuitive interpretations. Strategic games are possible on this ground, confirming facts of life and also showing predictive power. The complex and difficult to manage interdependence between energy policy and technology appears as a challenge to the long‐term planning of alternative energy systems. To meet the challenge, preparedness for changes through a large freedom of choice on the technological options appears as a necessary complement to the faithful observance of the market drives, which stresses the importance of having available perceptive, coherent, reliable, and responsible mechanisms of decision making.
Stochastic Dominance: An Approach to Decision Making Under Risk
Authors: Buckley James J.
Published: May 2006

This paper introduces stochastic dominance as a technique to reduce the set of possible actions that a decision maker must consider in a decision problem under risk. The procedure usually does not choose an optimal action, but instead eliminates certain actions as unacceptable. Very little need be known about the decision maker's utility function. Two possible applications are presented: (1) upgrading buildings to better withstand an earthquake; and (2) choosing a site for a LNG facility.
Warning Systems in Risk Management
Authors: Paté‐Cornell M. Elisabeth
Published: May 2006

A method is presented here that allows probabilistic evaluation and optimization of warning systems, and comparison of their performance and cost‐effectiveness with those of other means of risk management. The model includes an assessment (1) of the signals, and (2) of human response, given the memory that people have kept of the quality of previous alerts. The trade‐off between the rate of false alerts and the length of the lead time is studied to account for the long‐term effects of “crying wolf” and the effectiveness of emergency actions. An explicit formulation of the system's benefits, including inputs from a signal model, a response model, and a consequence model, is given to allow optimization of the warning threshold and of the system's sensitivity.
Six Propositions on Public Participation and Their Relevance for Risk Communication
Authors: Kasperson Roger E.
Published: May 2006

New societal obligations for communicating risk information are emerging in a variety of contexts. This article draws upon the lengthy societal experience with citizen participation programs to identify how risk communication efforts may be effectively structured and implemented. Six major propositions address such themes as means/ends differences in expectations, the timing of the program, the role of credibility and trust, the need for technical and analytical resources, differing thresholds of public involvement, and limitations upon current understandings. Key conclusions for the design of risk communication programs are set forth.
Monte Carlo Sampling for Generalized Knowledge Dependence with Application to Human Reliability
Authors: Cooke Roger M. , Waij Rudi
Published: May 2006

A general discussion of knowledge dependence in risk calculations shows that the assumption of independence underlying standard Monte Carlo simulation in uncertainty analysis is frequently violated. A model is presented for performing Monte Carlo simulation when the variabilities of the component failure probabilities are either negatively or positively coupled. The model is applied to examples in human reliability analysis and the results are compared to the results of Sandia Laboratories as published in the Peer Review Study and to recalculations using more recent methods of uncertainty analysis.
Informing and Educating the Public About Risk
Authors: Slovic Paul
Published: May 2006

The objective of informing and educating the public about risk issues seems easy to attain in principle, but, in practice, may be difficult to accomplish. This paper attempts to illustrate why this is so. To be effective, risk communicators must recognize and overcome a number of obstacles that have their roots in the limitations of scientific risk assessment and the idiosyncrasies of the human mind. Doing an adequate job of communicating means finding comprehensible ways of presenting complex technical material that is clouded by uncertainty and inherently difficult to understand. The problems may not be insurmountable, however, if designers of risk information programs are sensitive to the difficulties.
Estimation of Long‐Term Risk from Canadian Uranium Mill Tailings
Authors: Murray M. L. , Chambers D. B. , Knapp R. A. , Kaplan S.
Published: May 2006

A methodology is presented for assessing the risk from Canadian uranium mill tailings piles. The methodology is based on the “set of triplets” concept and uses an event tree to identify various scenarios representing the performance of a pile over its 1,000‐year design life. Compartment‐type mathematical models are used to quantify the movement of hazardous substances through the environment. Numerical examples are given of both “level 1” (straight probabilistic) and “level 2” (probability of frequency) type analyses.
On Analytic Empirical Bayes Estimation of Failure Rates
Authors: Vaurio J. K.
Published: May 2006

The estimation of plant accident rates and component failure rates is addressed within the framework of a parametric empirical Bayes approach. The observables, the numbers of failures recorded in various similar systems, obey the Poisson probability law. The parameters of a common gamma prior distribution are determined by a special moment matching method such that the results are consistent with classical (fiducial) confidence limits. Relations between Bayesian, classical, and Stein's estimation are discussed. The theory of the method is fully developed, although the suggested procedure itself is relatively simple. Solutions exist and they are in allowed ranges for all practical cases, including small samples and clustered data. They are also unbiased for large samples. Numerical examples are analyzed to illustrate the method and to allow comparisons with other methods.
Estimated Soil Ingestion Rates for Use in Risk Assessment
Authors: LaGoy Peter K.
Published: May 2006

Assessing the risks to human health posed by contaminants present in soil requires an estimate of likely soil ingestion rates. In the past, direct measurements of soil ingestion were not available and risk assessors were forced to estimate soil ingestion rates based on observations of mouthing behavior and measurements of soil on hands. Recently, empirical data on soil ingestion rates have become available from two sources (Binder et al., 1986(1) and van Wijnen et al., 1986(2). Although preliminary, these data can be used to derive better estimates of soil ingestion rates for use in risk assessments. Estimates of average soil ingestion rates derived in this paper range from 25 to 100 mg/day, depending on the age of the individual at risk. Maximum soil ingestion rates that are unlikely to underestimate exposure range from 100 to 500 mg. A value of 5,000 mg/day is considered a reasonable estimate of a maximum single‐day exposure for a child with habitual pica.
Integrating Uncertainty and Interindividual Variability in Environmental Risk Assessment
Authors: Bogen Kenneth T. , Spear Robert C.
Published: May 2006

An integrated, quantitative approach to incorporating both uncertainty and interindividual variability into risk prediction models is described. Individual risk R is treated as a variable distributed in both an uncertainty dimension and a variability dimension, whereas population risk I (the number of additional cases caused by R) is purely uncertain. I is shown to follow a compound Poisson‐binomial distribution, which in low‐level risk contexts can often be approximated well by a corresponding compound Poisson distribution. The proposed analytic framework is illustrated with an application’to cancer risk assessment for a California population exposed to 1,2‐dibromo‐3‐chloropropane from ground water.
How Fair Is Safe Enough? The Cultural Approach to Societal Technology Choice1
Authors: Rayner Steve , Cantor Robin
Published: May 2006

This paper consists of an argument and a pilot study. First is a general, perhaps philosophical, argument against the National Academy's viewpoint(1) that dealing with risk is a two‐stage process consisting of (a) assessment of facts, and (b) evaluation of facts in sociopolitical context. We argue that societal risk intrinsically revolves around social relations as much as around evaluations of probability. Second, we outline one particular approach to analyzing societal risk management styles. We call this the fairness hypothesis. Rather than focusing on probabilities and magnitudes of undesired events, this approach emphasizes societal preferences for principles of achieving consent to a technology, distributing liabilities, and investing trust in institutions. Conflict rather than probability is the chief focus of this approach to societal risk management. This view is illustrated by a recent empirical pilot study that explored the fairness hypothesis in the context of new nuclear technologies.
An Improved Condensation Procedure in Discrete Probability Distribution Calculations
Authors: Kaplan Stan , Lin James C.
Published: May 2006

A “vertical” condensation scheme for discrete probability distribution (DPD) calculations is presented as an alternative to the earlier “horizontal” scheme, an example of which was presented recently by Kurth and Cox. When applied to DPDs over a space of curves, the vertical condensation results in a “regularization” of the “spaghetti” of curves that results from combination operations on such DPDs.
Statistical Issues in the Estimation of Assigned Shares for Carcinogenesis Liability
Authors: Cox Louis Anthony
Published: May 2006

Congress is currently considering adopting a mathematical formula to assign shares in cancer causation to specific doses of radiation, for use in establishing liability and compensation awards. The proposed formula, if it were sound, would allow difficult problems in tort law and public policy to be resolved by reference to tabulated “probabilities of causation.” This article examines the statistical and conceptual bases for the proposed methodology. We find that the proposed formula is incorrect as an expression for “probability and causation,” that it implies hidden, debatable policy judgments in its treatment of factor interactions and uncertainties, and that it can not in general be quantified with sufficient precision to be useful. Three generic sources of statistical uncertainty are identified—sampling variability, population heterogeneity, and error propagation—that prevent accurate quantification of “assigned shares.” These uncertainties arise whenever aggregate epidemiological or risk data are used to draw causal inferences about individual cases.
A Method for Estimating Lifetime Cancer Risks from Limited Epidemiologic Data
Authors: Enterline Phillip E.
Published: May 2006

Partly because of the poor quality of exposure information on humans, most lifetime carcinogenic risk assessments have been based on animal data. There are, however, surrogate measures for exposure that have not been fully utilized. One of these is duration of exposure where data on mean exposure levels are available. A method is presented for the use of such data, and the method is illustrated by developing a risk assessment from the available epidemiologic literature on gasoline and kidney cancer. This risk assessment is fairly consistent across studies and close to a risk assessment based upon an experiment with rats. While there needs to be much improvement in the quality of environmental data available to epidemiologists, it is possible that a number of risk assessments can be made from existing epidemiologic data and efforts directed away from extrapolation from animal data.
Biologically Motivated Cancer Risk Models
Authors: Thorslund Todd W. , Brown Charles C. , Charnley Gail
Published: May 2006

A two‐stage dose response model is proposed for use in cancer risk assessment. The model assumes that transformation probabilities and cellular dynamics are exposure‐ and time‐dependent.
Dioxin in the Agricultural Food Chain
Authors: Stevens Jeffrey B. , Gerbec Elizabeth N.
Published: May 2006

Polychlorinated dibenzo‐p‐dioxin's (PCDD) behavior in the agricultural food chain was modeled in this study. The source of PCDD was a municipal solid waste (MSW) incinerator. Of the farm livestock investigated only the beef cow and the milk cow were shown to contribute significant amounts of PCDD to humans. Milk was the single highest dietary source of PCDD. Comparison of the calculated human dose of PCDD from the agricultural food chain with an estimate human PCDD dose from inhalation of contaminated air revealed that the agricultural food chain could be responsible for a vast majority of the dose to an individual impacted by these facilities. Thus, these data suggest that operating MSW facilities in agricultural areas may result in enhanced PCDD exposure to individuals via the agricultural food chain. The data also suggest that milk and beef may be good sentinels to evaluate environmental impacts of these facilities.
Early Indicators of Male Reproductive Toxicity
Authors: Overstreet James W. , Samuels Steven J. , Day Patricia , Hendrickx Andrew G. , Prahalada Srinivasa , Mast Terry , Katz David F. , Sakai Carol
Published: May 2006

Longitudinal data were analyzed for seminal characteristics of rhesus monkeys and beagles. The monkeys were exposed to DBCP; the beagles were exposed to acute or chronic whole body gamma irradiation. The semen was analyzed for volume and sperm concentration. Sperm were measured for percent motility, swimming speed, and head dimensions. Abnormalities of the sperm tail were also noted. All treatments resulted in measurable effects on the semen parameters. Sperm production, as evaluated by seminal sperm concentration or total sperm numbers in the ejaculate, was as informative of testicular toxicity as any other parameter or combination of parameters. A consistent finding was that changes in sperm output occurred concomitantly with changes in sperm motility.
Chemical Scoring by a Rapid Screening of Hazard (RASH) Method
Authors: Jones Troyce D. , Walsh Phillip J. , Watson Annette P. , Owen Bruce A. , Barnthouse Larry W. , Sanders Dee A.
Published: May 2006

A rapid screening of hazard method (RASH) is presented for deriving relative potency estimates for hazardous substances. The method utilizes data from any available toxicological database such as the Registry of Toxic Effects of Chemical Substances (RTECS) or EPA's GENE‐TOX database on genetic activity profiles. The method has been applied to derive relative potency values and permissible environmental concentrations for 278 chemicals. The derived values have been compared with recommendations of expert committees where possible, and substantial agreement is found.
The Distribution of Risks: Vehicle Occupant Fatalities and Time of the Week
Authors: Schwing Richard C. , Kamerud Dana B.
Published: May 2006

Automobile accident risks vary significantly across populations, places, and times. This study describes the time‐varying pattern of societal risk. The relative risks of occupant fatality per person‐mile of travel are estimated here for each hour of the week, using 1983 data. The results exhibit a strong time‐of‐day effect and have a highly skewed frequency distribution, implying wide variations in risk‐taking behavior. Indeed, the 168 hourly estimates ranged from a low of 0.32 times the average around Sunday noon to a high of 43 times the average at 3:00 a.m. on Sunday, i.e., by a factor of 134 from bottom to top. Quantile‐quantile plots or “Lorenz curves,” introduced to display the unequal distribution of risks, show that approximately 34% of the vehicle occupant fatalities occur in hours representing only 5% of the travel. These findings have serious implications for risk analysis. First, when attempting to reconcile objective and subjective risk estimates, risk communicators should carefully control for when and to whom the risk in question is applicable. Second, comparisons of hazards on the basis of average risk are necessarily misleading for risks distributed so unevenly. Third, resource allocation decisions can benefit by knowing how incidence, exposure, and risk vary across time, place, and other relevant variables. Finally, certain cost‐benefit analyses that use average values to estimate risk exposure can be misleading.
How Do Cancer Risks Predicted From Animal Bioassays Compare with the Epidemiologic Evidence? The Case of Ethylene Dibromide
Authors: Hertz‐Picciotto Irva , Gravitz Norman , Neutra Raymond
Published: May 2006

Cancer risks for ethylene dibromide (EDB) were estimated by fitting several linear non‐threshold additive models to data from a gavage bioassay. Risks predicted by these models were compared to the observed cancer mortality among a cohort of workers occupationally exposed to the same chemical. Models that accounted for the shortened latency period in the gavaged rats predicted upper bound risks that were within a factor of 3 of the observed cancer deaths. Data from an animal inhalation study of EDB also were compatible with the epidemiologic data. These findings contradict those of Ramsey et al. (1978), who reported that extrapolation from animal data produced highly exaggerated risk estimates for EDB‐exposed workers. This paper explores the reasons for these discrepant findings.