bluuebunny/crossref_metadata_2025 huggingface dataset:
Communicating about the Risks and Benefits of Genetically Modified Foods: The Mediating Role of Trust
Authors: Frewer Lynn J. , Scholderer Joachim , Bredahl Lone
Published: December 2003

Recent research suggests that public attitudes toward emerging technologies are mainly driven by trust in the institutions promoting and regulating these technologies. Alternative views maintain that trust should be seen as a consequence rather than a cause of such attitudes. To test its actual role, direct as well as mediating effects of trust were tested in an attitude change experiment involving 1,405 consumers from Denmark, Germany, Italy, and the United Kingdom. After prior attitudes to genetic modification in food production had been assessed, participants received different information materials (either product‐specific information or balanced/general information about genetic modification in food production) and were asked to evaluate different types of genetically modified foods (either beer or yoghurt). The information materials were attributed to different information sources (either an industry association, a consumer organization, or a government source). After completion, perceived risk and perceived benefit were assessed, and participants indicated their trust in the information sources to which the materials had been attributed. Direct and trust‐mediated attitude change effects were estimated in a multi‐sample structural equation model. The results showed that information provision had little effect on people's attitudes toward genetically modified foods, and that perceptions of information source characteristics contributed very little to attitude change. Furthermore, the type of information strategy adopted had almost no impact on postexperimental attitudes. The extent to which people trusted the information sources appeared to be driven by people's attitudes to genetically modified foods, rather than trust influencing the way that people reacted to the information. Trust was not driving risk perception—rather, attitudes were informing perceptions of the motivation of the source providing the information.
Correlations Between Parameters in Risk Models: Estimation and Propagation of Uncertainty by Markov Chain Monte Carlo
Authors: Ades A. E. , Lu G.
Published: December 2003

Monte Carlo simulation has become the accepted method for propagating parameter uncertainty through risk models. It is widely appreciated, however, that correlations between input variables must be taken into account if models are to deliver correct assessments of uncertainty in risk. Various two‐stage methods have been proposed that first estimate a correlation structure and then generate Monte Carlo simulations, which incorporate this structure while leaving marginal distributions of parameters unchanged. Here we propose a one‐stage alternative, in which the correlation structure is estimated from the data directly by Bayesian Markov Chain Monte Carlo methods. Samples from the posterior distribution of the outputs then correctly reflect the correlation between parameters, given the data and the model. Besides its computational simplicity, this approach utilizes the available evidence from a wide variety of structures, including incomplete data and correlated and uncorrelated repeat observations. The major advantage of a Bayesian approach is that, rather than assuming the correlation structure is fixed and known, it captures the joint uncertainty induced by the data in all parameters, including variances and covariances, and correctly propagates this through the decision or risk model. These features are illustrated with examples on emissions of dioxin congeners from solid waste incinerators.
Simulation Modeling of Anthrax Spore Dispersion in a Bioterrorism Incident
Authors: Reshetin Vladimir P. , Regens James L.
Published: December 2003

Recent events have increased awareness of the risk posed by terrorist attacks. Bacillus anthracis has resurfaced in the 21st century as a deadly agent of bioterrorism because of its potential for causing massive civilian casualties. This analysis presents the results of a computer simulation of the dispersion of anthrax spores in a typical 50‐story, high‐rise building after an intentional release during a bioterrorist incident. The model simulates aerosol dispersion in the case of intensive, small‐scale convection, which equalizes the concentration of anthrax spores over the building volume. The model can be used to predict the time interval required for spore dispersion throughout a building after a terrorist attack in a high‐rise building. The analysis reveals that an aerosol release of even a relatively small volume of anthrax spores during a terrorist incident has the potential to quickly distribute concentrations that are infectious throughout the building.
Dose‐Response and Risk Assessment of Airborne Hexavalent Chromium and Lung Cancer Mortality
Authors: Crump Casey , Crump Kenny , Hack Eric , Luippold Rose , Mundt Kenneth , Liebig Elizabeth , Panko Julie , Paustenbach Dennis , Proctor Deborah
Published: December 2003

This study evaluates the dose‐response relationship for inhalation exposure to hexavalent chromium [Cr(VI)] and lung cancer mortality for workers of a chromate production facility, and provides estimates of the carcinogenic potency. The data were analyzed using relative risk and additive risk dose‐response models implemented with both Poisson and Cox regression. Potential confounding by birth cohort and smoking prevalence were also assessed. Lifetime cumulative exposure and highest monthly exposure were the dose metrics evaluated. The estimated lifetime additional risk of lung cancer mortality associated with 45 years of occupational exposure to 1 μg/m3 Cr(VI) (occupational exposure unit risk) was 0.00205 (90%CI: 0.00134, 0.00291) for the relative risk model and 0.00216 (90%CI: 0.00143, 0.00302) for the additive risk model assuming a linear dose response for cumulative exposure with a five‐year lag. Extrapolating these findings to a continuous (e.g., environmental) exposure scenario yielded an environmental unit risk of 0.00978 (90%CI: 0.00640, 0.0138) for the relative risk model [e.g., a cancer slope factor of 34 (mg/kg‐day)−1] and 0.0125 (90%CI: 0.00833, 0.0175) for the additive risk model. The relative risk model is preferred because it is more consistent with the expected trend for lung cancer risk with age. Based on statistical tests for exposure‐related trend, there was no statistically significant increased lung cancer risk below lifetime cumulative occupational exposures of 1.0 mg‐yr/m3, and no excess risk for workers whose highest average monthly exposure did not exceed the current Permissible Exposure Limit (52 μg/m3). It is acknowledged that this study had limited power to detect increases at these low exposure levels. These cancer potency estimates are comparable to those developed by U.S. regulatory agencies and should be useful for assessing the potential cancer hazard associated with inhaled Cr(VI).
Prediction of Human Blood: Air Partition Coefficient: A Comparison of Structure‐Based and Property‐Based Methods
Authors: Basak Subhash C. , Mills Denise , Hawkins Douglas M. , El‐Masri Hisham A.
Published: December 2003

In recent years, there has been increased interest in the development and use of quantitative structure‐activity/property relationship (QSAR/QSPR) models. For the most part, this is due to the fact that experimental data is sparse and obtaining such data is costly, while theoretical structural descriptors can be obtained quickly and inexpensively. In this study, three linear regression methods, viz. principal component regression (PCR), partial least squares (PLS), and ridge regression (RR), were used to develop QSPR models for the estimation of human blood:air partition coefficient (logPblood:air) for a group of 31 diverse low‐molecular weight volatile chemicals from their computed molecular descriptors. In general, RR was found to be superior to PCR or PLS. Comparisons were made between models developed using parameters based solely on molecular structure and linear regression (LR) models developed using experimental properties, including saline:air partition coefficient (logPsaline:air) and olive oil:air partition coefficient (logPolive  oil:air), as independent variables, indicating that the structure‐property correlations are comparable to the property‐property correlations. The best models, however, were those that used rat logPblood:air as the independent variable. Haloalkane subgroups were modeled separately for comparative purposes and, although models based on the congeneric compounds were superior, the models developed on the complete set of diverse compounds were of acceptable quality. The structural descriptors were placed into one of three classes based on level of complexity: topostructural (TS), topochemical (TC), or three‐dimensional/geometrical (3D). Modeling was performed using the structural descriptor classes both in a hierarchical fashion and separately. The results indicate that highest quality structure‐based models, in terms of descriptor classes, were those derived using TC descriptors.
Weighing Health Benefit and Health Risk Information when Consuming Sport‐Caught Fish
Authors: Knuth Barbara A. , A. Connelly Nancy , Sheeshka Judy , Patterson Jacqueline
Published: December 2003

Fish consumers may incur benefits and risks from eating fish. Health advisories issued by states, tribes, and other entities typically include advice about how to limit fish consumption or change other behaviors (e.g., fish cleaning or cooking) to reduce health risks from exposure to contaminants. Eating fish, however, may provide health benefits. Risk communicators and fish consumers have suggested the importance of including risk comparison information, as well as health risk‐benefit comparisons in health advisory communications. To improve understanding about how anglers fishing in waters affected by health advisories may respond to such risk‐risk or risk‐benefit information, we surveyed Lake Ontario (NY, USA) anglers. We interviewed by telephone 4,750 anglers, 2,593 of which had fished Lake Ontario in the past 12 months and were sent a detailed mail questionnaire (1,245 responded). We posed questions varying the magnitude of health risks and health benefits to be gained by fish consumption, and varied the population affected by these risks and benefits (anglers, children, women of childbearing age, and unborn children). Respondents were influenced by health benefit and health risk information. When risks were high, most respondents would eat less fish regardless of the benefit level. When risks were low, the magnitude of change in fish consumption was related to level of benefit. Responses differed depending on the question wording order, that is, whether “risks” were posed before “benefits.” For a given risk‐benefit level, respondents would give different advice to women of childbearing age versus children, with more conservative advice (eat less fish) provided to women of childbearing age. Respondents appeared to be influenced more strongly by risk‐risk comparisons (e.g., risks from other foods vs. risks from fish) than by risk‐benefit comparisons (e.g., risks from fish vs. benefits from fish). Risk analysts and risk communicators should improve efforts to include risk‐risk and risk‐benefit comparisons in communication efforts, and to clarify to whom the health risks and benefits from fish consumption may accrue.
Health Risk Assessment After Decontamination of the Beaches Polluted by the Wrecked ERIKA Tanker
Authors: Dor Frédéric , Bonnard Roseline , Gourier‐Fréry Claire , Cicolella André , Dujardin Roland , Zmirou Denis
Published: December 2003

Following the wreck of the oil tanker ERIKA off the north‐west coast of France in December 1999, cleaning up of the beaches involved considerable work, which in any case could not be perfect. This raised the question of the short‐ and long‐term health risks for the future bathers related to the toxicity of the remaining oil polycyclic aromatic hydrocarbons (PAHs). This risk assessment study was conducted to help health authorities plan risk management policies and inform the public. Thirty‐six beaches were selected, representing a sample of the most frequently encountered topographic and beach usage situations; seven “control” beaches, unspoiled by ERIKA, were also investigated. Samples of water and sand were taken from each site, as well as from the surface of rocks. The 16 PAHs selected by the U.S. EPA were quantified in each environment. Several scenarios of exposure were contemplated: (1) a child between 2 and 4 years accidentally ingesting a small ball of fuel, (2) a child daily exposed throughout his holiday‐time stay, (3) an adult (including a pregnant woman) spending his/her holidays on the coast, (4) an adult working on the beach, (5) and an adult practicing water sports. Among the available and significant toxicological values, the most conservative ones were selected for computing risks.

The sand and water, after decontamination, were slightly polluted (respectively, 7.8 μg/kg and 23.3 ng/l of total 16 PAHs), with values similar to those found in the control beaches. By contrast, the rocky areas in some places were still highly polluted (up to 23 mg/kg on the surface layer).

No lethal risk was found for a young child who had accidentally ingested a small ball of fuel. The life‐long excess risks for skin cancer and for all other cancers were about 10−5 in scenarios including contact with the polluted rocks. In all other cases, excess risks were considerably lower. The hazard quotient for teratogenic effects was very small, except in scenarios where pregnant women would walk among rocks containing high pollution levels.

In conclusion, exposure was mainly associated with polluted water among children, and with spoiled rocks for adults. Despite uncertainties, mainly dealing with the prediction of long‐term risks following a short‐term exposure, this study showed that beaches where pollution was no longer visible after decontamination did not entail any significant health risks and could be opened to the public.
A Model for Optimization of Biomarker Testing Frequency to Minimize Disease and Cost: Example of Beryllium Sensitization Testing
Authors: Judd Nancy L. , Griffith William C. , Takaro Tim , Faustman Elaine M.
Published: December 2003

A common problem with medical surveillance programs using biomarkers is determining the optimal frequency of testing to minimize adverse health effects and cost. In the case of beryllium‐exposed workers, frequency of testing for beryllium sensitization may be especially important. Recent studies indicate a lack of dose response for beryllium sensitization, but do support a dose response for the development of chronic beryllium disease (CBD). Though unproven, this implies that early identification of sensitization and immediate removal from exposure may reduce development of CBD. A model is proposed to project the optimal frequency of sensitization testing using the current beryllium lymphocyte proliferation test (BeLPT) to minimize disease‐related costs, assuming that a positive BeLPT will precede CBD. Conversion rates for cumulative exposure to disease development were adapted from the literature and used with testing costs and cost of disease estimates in the model. The model was run assuming several test frequency regimes. Results support the use of periodic testing in line with the annual schedule proposed in the Final Chronic Beryllium Disease Prevention Program Rule (1999) following initial testing within three months of first beryllium exposure. The financial and health benefits of reducing the time from exposure to detection of early disease was also explored with the model and demonstrated as a highly desirable characteristic for an alternative test or improved BeLPT. Limitations of the approach are discussed as well as options for adapting this biomarker optimization methodology to consider biomarkers of other exposure‐associated diseases.
The Impact of Cytochrome P450 2E1‐Dependent Metabolic Variance on a Risk‐Relevant Pharmacokinetic Outcome in Humans
Authors: Lipscomb John C. , Teuschler Linda K. , Swartout Jeff , Popken Doug , Cox Tony , Kedderis Gregory L.
Published: December 2003

Risk assessments include assumptions about sensitive subpopulations, such as the fraction of the general population that is sensitive and the extent that biochemical or physiological attributes influence sensitivity. Uncertainty factors (UF) account for both pharmacokinetic (PK) and pharmacodynamic (PD) components, allowing the inclusion of risk‐relevant information to replace default assumptions about PK and PD variance (uncertainty). Large numbers of human organ donor samples and recent advances in methods to extrapolate in vitro enzyme expression and activity data to the intact human enable the investigation of the impact of PK variability on human susceptibility. The hepatotoxicity of trichloroethylene (TCE) is mediated by acid metabolites formed by cytochrome P450 2E1 (CYP2E1) oxidation, and differences in the CYP2E1 expression are hypothesized to affect susceptibility to TCE's liver injury. This study was designed specifically to examine the contribution of statistically quantified variance in enzyme content and activity on the risk of hepatotoxic injury among adult humans. We combined data sets describing (1) the microsomal protein content of human liver, (2) the CYP2E1 content of human liver microsomal protein, and (3) the in vitro Vmax for TCE oxidation by humans. The 5th and 95th percentiles of the resulting distribution (TCE oxidized per minute per gram liver) differed by approximately sixfold. These values were converted to mg TCE oxidized/h/kg body mass and incorporated in a human PBPK model. Simulations of 8‐hour inhalation exposure to 50 ppm and oral exposure to 5 µg TCE/L in 2 L drinking water showed that the amount of TCE oxidized in the liver differs by 2% or less under extreme values of CYP2E1 expression and activity (here, selected as the 5th and 95th percentiles of the resulting distribution). This indicates that differences in enzyme expression and TCE oxidation among the central 90% of the adult human population account for approximately 2% of the difference in production of the risk‐relevant PK outcome for TCE‐mediated liver injury. Integration of in vitro metabolism information into physiological models may reduce the uncertainties associated with risk contributions of differences in enzyme expression and the UF that represent PK variability.
Probabilistic Framework for the Estimation of the Adult and Child Toxicokinetic Intraspecies Uncertainty Factors
Authors: Pelekis Michael , Nicolich Mark J. , Gauthier Joseph S.
Published: December 2003

Human health risk assessments use point values to develop risk estimates and thus impart a deterministic character to risk, which, by definition, is a probability phenomenon. The risk estimates are calculated based on individuals and then, using uncertainty factors (UFs), are extrapolated to the population that is characterized by variability. Regulatory agencies have recommended the quantification of the impact of variability in risk assessments through the application of probabilistic methods.

In the present study, a framework that deals with the quantitative analysis of uncertainty (U) and variability (V) in target tissue dose in the population was developed by applying probabilistic analysis to physiologically‐based toxicokinetic models. The mechanistic parameters that determine kinetics were described with probability density functions (PDFs). Since each PDF depicts the frequency of occurrence of all expected values of each parameter in the population, the combined effects of multiple sources of U/V were accounted for in the estimated distribution of tissue dose in the population, and a unified (adult and child) intraspecies toxicokinetic uncertainty factor UFH‐TK was determined.

The results show that the proposed framework accounts effectively for U/V in population toxicokinetics. The ratio of the 95th percentile to the 50th percentile of the annual average concentration of the chemical at the target tissue organ (i.e., the UFH‐TK) varies with age. The ratio is equivalent to a unified intraspecies toxicokinetic UF, and it is one of the UFs by which the NOAEL can be divided to obtain the RfC/RfD. The 10‐fold intraspecies UF is intended to account for uncertainty and variability in toxicokinetics (3.2×) and toxicodynamics (3.2×). This article deals exclusively with toxicokinetic component of UF.

The framework provides an alternative to the default methodology and is advantageous in that the evaluation of toxicokinetic variability is based on the distribution of the effective target tissue dose, rather than applied dose. It allows for the replacement of the default adult and children intraspecies UF with toxicokinetic data‐derived values and provides accurate chemical‐specific estimates for their magnitude. It shows that proper application of probability and toxicokinetic theories can reduce uncertainties when establishing exposure limits for specific compounds and provide better assurance that established limits are adequately protective. It contributes to the development of a probabilistic noncancer risk assessment framework and will ultimately lead to the unification of cancer and noncancer risk assessment methodologies.
Public Meetings and Risk Amplification: A Longitudinal Study
Authors: McComas Katherine A.
Published: December 2003

This article offers longitudinal data tracking people who did and did not attend a series of public meetings in an upstate New York rural community grappling with the expansion of an existing solid waste landfill and remediation of an adjacent inactive hazardous waste site. Before and after the public meetings, mailed questionnaires measured risk perceptions and perceived credibility of risk managers (here, the state government agencies and the responsible industry) conducting the meetings. Respondents at each measurement point included meeting attendees and nonattendees, with some fluctuation over time when attendees at one measurement point were nonattendees at the next and vice versa. The results from the first survey indicate that following the first two public meetings, attendees perceived greater risks from the waste sites than did nonattendees; attendees also perceived the risk managers as less credible. After the third public meeting, the results showed that attendees' risk perceptions remained steady; however, perceptions of government agency credibility significantly decreased. After the fourth public meeting, the survey found that attendees' risk perceptions were again not significantly different, whereas perceptions of government agency credibility increased significantly. The industry's credibility also increased, though only among attendees who had attended the most recent public meeting, not among attendees who had attended both the third and fourth public meetings. For nonattendees, risk perceptions and credibility ratings did not change. The discussion examines how distinctive characteristics of communication at each public meeting may have resulted in different effects and proposes hypotheses for future research.
Risk Perception in a Developing Country: The Case of Chile
Authors: Bronfman Nicolás C. , Cifuentes Luis A.
Published: December 2003

In this work we characterize risk perception in Chile, based on the psychometric paradigm, exploring the difference between perceived social and personal risk. For this purpose, we conducted a survey including 54 hazards, 16 risk attributes, and 3 risk constructs. The survey, divided into four parts, was administered to 508 residents of Santiago, Chile. Using factor analysis, three main factors, which accounted for 80% of the sample's variance, were identified: factor 1, commonly called “Dread Risk” in the literature, explained 37% of variance; factor 2, “Unknown Risk,” explained 28%; and factor 3, which we called “Personal Effect,” explained 15% of the variance. On average, individuals perceived themselves as less exposed to risk and with more control and knowledge about them than the general population. OLS regression models were used to test the association of perceived risk with the three main factors. For social risk, factor 1 had the greatest explanatory power, while factor 2 had a negative sign. For personal risk, only factors 2 and 3 were significant, with factor 3 having the greatest explanatory power. Risk denial (defined as the difference between perceived personal and social risk) was associated with factors 1 and 2 only, with factor 2 having a negative sign. The difference between desired and actual regulation levels proved positive for all hazards, thus indicating that Chileans are dissatisfied with the current regulation level for all the hazards analyzed. The comparison of data at the aggregate and at the individual subject's level suggests that while the aggregate analysis overestimates the magnitude of the correlations it still reflects the tendency of the individual responses.
Risk Communication and Foodborne Illness: Message Sponsorship and Attempts to Stimulate Perceptions of Risk
Authors: Gordon Joye
Published: December 2003

Foodborne illness represents a serious health hazard in the United States. Since foodborne illness can often be prevented by an individual's behavior, messages aimed at promoting safe food‐handling behaviors should be a major tool to reduce the incidence of foodborne illness. This article argues that to achieve adoption of safe food‐handling practices in the home, food‐safety messages should both stimulate risk perceptions and promote self‐efficacy, feelings that one can successfully enact recommended behaviors. A content analysis of nationally distributed food‐safety messages questioned if messages incorporated these features. Since food‐safety communicators operate in complex environments with multiple and sometimes competing objectives, this study also questioned if sponsorship of foodborne illness prevention messages was related to the amount of content designed to alter risk perceptions associated with foodborne illness. Results of the quantitative content analysis found that copywriters generally included content designed to stimulate risk perception about foodborne illness but virtually ignored self‐efficacy needs of the audience. A marked difference in tendencies to stimulate risk perceptions was found based on sponsorship. Both in volume and proportion, results show that governmentally sponsored messages more aggressively attempted to heighten risk perceptions associated with foodborne illness than did messages sponsored by privately funded communicators.
Model Uncertainty and Choices Made by Modelers: Lessons Learned from the International Atomic Energy Agency Model Intercomparisons†
Authors: Linkov Igor , Burmistrov Dmitriy
Published: December 2003

The treatment of uncertainties associated with modeling and risk assessment has recently attracted significant attention. The methodology and guidance for dealing with parameter uncertainty have been fairly well developed and quantitative tools such as Monte Carlo modeling are often recommended. However, the issue of model uncertainty is still rarely addressed in practical applications of risk assessment. The use of several alternative models to derive a range of model outputs or risks is one of a few available techniques. This article addresses the often‐overlooked issue of what we call “modeler uncertainty,” i.e., difference in problem formulation, model implementation, and parameter selection originating from subjective interpretation of the problem at hand. This study uses results from the Fruit Working Group, which was created under the International Atomic Energy Agency (IAEA) BIOMASS program (BIOsphere Modeling and ASSessment). Model‐model and model‐data intercomparisons reviewed in this study were conducted by the working group for a total of three different scenarios. The greatest uncertainty was found to result from modelers' interpretation of scenarios and approximations made by modelers. In scenarios that were unclear for modelers, the initial differences in model predictions were as high as seven orders of magnitude. Only after several meetings and discussions about specific assumptions did the differences in predictions by various models merge. Our study shows that parameter uncertainty (as evaluated by a probabilistic Monte Carlo assessment) may have contributed over one order of magnitude to the overall modeling uncertainty. The final model predictions ranged between one and three orders of magnitude, depending on the specific scenario. This study illustrates the importance of problem formulation and implementation of an analytic‐deliberative process in risk characterization.
Distribution of Arsenic and Copper in Sediment Pore Water: An Ecological Risk Assessment Case Study for Offshore Drilling Waste Discharges
Authors: Sadiq Rehan , Husain Tahir , Veitch Brian , Bose Neil
Published: December 2003

Due to the hydrophobic nature of synthetic based fluids (SBFs), drilling cuttings are not very dispersive in the water column and settle down close to the disposal site. Arsenic and copper are two important toxic heavy metals, among others, found in the drilling waste. In this article, the concentrations of heavy metals are determined using a steady state “aquivalence‐based” fate model in a probabilistic mode. Monte Carlo simulations are employed to determine pore water concentrations. A hypothetical case study is used to determine the water quality impacts for two discharge options: 4% and 10% attached SBFs, which correspond to the best available technology option and the current discharge practice in the U.S. offshore. The exposure concentration (CE) is a predicted environmental concentration, which is adjusted for exposure probability and bioavailable fraction of heavy metals. The response of the ecosystem (RE) is defined by developing an empirical distribution function of predicted no‐effect concentration. The pollutants' pore water concentrations within the radius of 750 m are estimated and cumulative distributions of risk quotient (RQ=CE/RE) are developed to determine the probability of RQ greater than 1.
Risk Modeling, Assessment, and Management of Lahar Flow Threat
Authors: Leung M. F. , Santos J. R. , Haimes Y. Y.
Published: December 2003

The 1991 eruption of Mount Pinatubo in the Philippines is considered one of the most violent and destructive volcanic activities in the 20th century. Lahar is the Indonesian term for volcanic ash, and lahar flows resulting from the massive amount of volcanic materials deposited on the mountain's slope posed continued post‐eruption threats to the surrounding areas, destroying lives, homes, agricultural products, and infrastructures. Risks of lahar flows were identified immediately after the eruption, with scientific data provided by the Philippine Institute of Volcanology, the U.S. Geological Survey, and other research institutions. However, competing political, economic, and social agendas subordinated the importance of scientific information to policy making. Using systemic risk analysis and management, this article addresses the issues of multiple objectives and the effective integration of scientific techniques into the decision‐making process. It provides a modeling framework for identifying, prioritizing, and evaluating policies for managing risk. The major considerations are: (1) applying a holistic approach to risk analysis through hierarchical holographic modeling, (2) applying statistical methods to gain insight into the problem of uncertainty in risk assessment, (3) using multiobjective trade‐off analysis to address the issue of multiple decisionmakers and stakeholders in the decision‐making process, (4) using the conditional expected value of extreme events to complement and supplement the expected value in quantifying risk, and (5) assessing the impacts of multistage decisions. Numerical examples based on ex post data are formulated to illustrate applications to various problems. The resulting framework from this study can serve as a general baseline model for assessing and managing risks of natural disasters, which the Philippines' lead agency—the National Disaster Coordinating Council (NDCC)—and other related organizations can use for their decision‐making processes.
Comparative Risk and Policy Analysis in Environmental Health
Authors: Wong E. Y. , Ponce R. A. , Farrow S. , Bartell S. M. , Lee R. C. , Faustman E. M.
Published: December 2003

There is increasing interest in the integration of quantitative risk analysis with benefit‐cost and cost‐effectiveness methods to evaluate environmental health policy making and perform comparative analyses. However, the combined use of these methods has revealed deficiencies in the available methods, and the lack of useful analytical frameworks currently constrains the utility of comparative risk and policy analyses. A principal issue in integrating risk and economic analysis is the lack of common performance metrics, particularly when conducting comparative analyses of regulations with disparate health endpoints (e.g., cancer and noncancer effects or risk‐benefit analysis) and quantitative estimation of cumulative risk, whether from exposure to single agents with multiple health impacts or from exposure to mixtures. We propose a general quantitative framework and examine assumptions required for performing analyses of health risks and policies. We review existing and proposed risk and health‐impact metrics for evaluating policies designed to protect public health from environmental exposures, and identify their strengths and weaknesses with respect to their use in a general comparative risk and policy analysis framework. Case studies are presented to demonstrate applications of this framework with risk‐benefit and air pollution risk analyses. Through this analysis, we hope to generate discussions regarding the data requirements, analytical approaches, and assumptions required for general models to be used in comparative risk and policy analysis.
Review of Methods for Texture Analysis of Myocardium From Echocardiographic Images: A Means of Tissue Characterization
Authors: Kerut Edmund Kenneth , Given Michael , Giles Thomas D.
Published: December 2003

This review discusses the definition of texture and identifies its utility in echocardiography for characterization of tissue. Methods used for quantification of texture in echocardiography and other disciplines are discussed. Several methodologies, particularly the wavelet method of texture quantification, seem to be promising. Image texture analysis appears to be a fertile area for research in echocardiography. (ECHOCARDIOGRAPHY, Volume 20, November 2003)
Echocardiographic Study of an Intravenous Leiomyoma: Case Report and Review of the Literature
Authors: Baca López Francisco Martínez , Martínez‐Enriquez Agustín , Castrejón‐Aivar Francisco José , Ruanova‐León David , Yánez‐Gutiérrez Lucelli
Published: December 2003

Intravenous leiomyoma is a rare tumor of smooth muscle with invasion to veined channels that affects women at reproductive age. The case of a 45‐year‐old woman is described, with history of oophorectomy and hysterectomy, in addition to abdominal surgery due to mesenteric tumor. Several months later, the patient developed syncope and dyspnea secondary to pulmonary embolism. Echocardiographic study reported a mass in right side of heart proceding from inferior vena cava. The patient underwent tumor surgical resection from left iliac vein and histologic study concluded intravascular leiomyomatosis. (ECHOCARDIOGRAPHY, Volume 20, November 2003)
Prediction of Heart Failure Post Myocardial Infarction: Comparison of Ejection Fraction, Transmitral Filling Parameters, and the Index of Myocardial Performance
Authors: Lavine Steven J.
Published: December 2003

Following an acute myocardial infarction (MI), the development of congestive heart failure (CHF) has been associated with a reduced ejection fraction (EF), pseudonormal or restrictive diastolic filling, and an increased index of myocardial performance (IMP). Study Objectives: To determine the comparative predictive value of EF, transmitral filling parameters, and IMP for the development of CHF following a first MI. Design and Setting: A retrospective analysis of consecutive echocardiographic and Doppler studies in patients admitted for their first acute MI from the years 1988 through 1992. We studied 109 patients following their first MI with two‐dimensional and Doppler within 24 hours of MI. We divided patients into those who developed CHF within 15 days (43 patients) and without CHF (66 patients). Results: Patients who developed CHF had greater LV dilatation, lower EF (27.7%± 10.2% vs 45.6%± 13.2%, P < 0.001), higher E/A, shorter deceleration times (DCT; 157 ± 69 msec vs 248 ± 105 msec, P < 0.001), and increased IMP. Utilizing multiple logistic regression, EF (strongest predictor), DCT, and IMP were predictive of CHF. Nineteen patients in the no CHF group developed late CHF and had lower EFs (30.5%± 13.1% vs 50.5%± 9.8%, P < 0.001), higher E/A and shorter DCTs (161 ± 39 msec vs 283 ± 103 msec, P < 0.001). EF, DCT, and E/A were predictive of late CHF in patients without initial CHF. For patients admitted with a first MI, the EF, DCT, and to a lesser extent IMP predicted who would ultimately develop CHF. An EF < 40% or a DCT < 200 msec correctly predicted CHF in 60 of 62 patients. Conclusion: We conclude that the early and ultimate development of CHF following a first MI were associated with an moderately reduced EF < 40%, pseudonormal diastolic filling indices, and an increased IMP. (ECHOCARDIOGRAPHY, Volume 20, November 2003)
Effect of Atrial Septal Mobility on Transcatheter Closure of Interatrial Communications
Authors: Scott Nandita S. , King Mary Etta , McQuillan Brendan , Shariff Salima , Hung Judy W. , Januzzi James L. , Palacios Igor F. , Picard Michael H.
Published: December 2003

Background: Transcatheter techniques have evolved as alternatives to surgical closure of interatrial communications due to its less invasive nature and low morbidity. The technique may be limited by the inability to deploy the device and, thus, may be complicated by significant residual shunting. Mobile or redundant septal tissue has been implicated as a possible cause of unsuccessful closure. Methods: To determine if atrial septal hypermobility precludes successful transcatheter device closure of interatrial communications, 69 patients (mean age 46.4 ± 17.5 years [male:female ratio 34:35]) with periprocedural transesophageal echocardiograms were reviewed. Septal excursion was defined as the maximal transit of the interatrial septum between either side of the plane connecting the superior and inferior attachment points. Unsuccessful closure was defined as subsequent cardiac surgery to close the defect, inability to deploy the device, recurrent attempts at closure, device malalignment, residual shunting greater than mild in degree on follow‐up transthoracic study, and procedural complications. Results: Reasons for closure were the following: embolic events (n = 48); platypnea/orthodeoxia (n = 15); atrial septal defect with right ventricular dilatation and paroxysmal atrial tachycardia (n = 2); atrial septal defect (n = 3); and prophylactic patent foramen ovale closure in a scuba diver (n = 1). Successful closure occurred in 76% of patients (n = 53). Compared with those patients with successful transcatheter closure, the mean septal excursion in patients with failed closure was 0.66 ± 0.56 cm versus 0.76 ± 0.47 cm (P = not significant [NS]). Conclusion: Our results do not support the concern that exaggerated septal mobility compromises successful device closure of interatrial communications. (ECHOCARDIOGRAPHY, Volume 20, November 2003)
Increased Volume Reduction of Late Left‐Atrial Emptying for Patients with Pseudonormal Mitral Inflow: An Analysis for Differentiation Between Normal and Pseudonormal Mitral Inflow
Authors: Hung Ming‐Jui , Cherng Wen‐Jin , Cheng Chi‐Wen
Published: December 2003

This study was designed to define the role of left atrial (LA) wall motion during left ventricular (LV) diastolic phase for patients with pseudonormal mitral inflow. We perform the M‐mode of posterior aortic, indicating LA, wall motion, and Doppler echocardiography following cardiac catheterization among 71 patients with a ratio of early (E) to late mitral flow (A) >1. The amplitude of total LA wall motion (TM), early LA rapid emptying (EM), and late LA emptying (AM) during the LV diastolic phase were all derived from M‐mode analysis. Study patients were classified into two distinct groups according to the LV end‐diastolic pressure (EDP): patients with a LVEDP value < 15 mmHg (n = 36, normal group), and patients with a LVEDP value ≥ 15 mmHg (n = 35, pseudonormal group). Values of AM (4.7 ± 1.2 vs 5.5 ± 1.2 mm) and AM/TM (0.43 ± 0.07 vs 0.55 ± 0.08) for the normal and pseudonormal groups, respectively, were significantly higher for the pseudonormal group, whereas EM (6.6 ± 1.8 vs 4.8 ± 1.4 mm), TM (11 ± 3 vs 10 ± 2 mm), EM/AM (1.41 ± 0.46 vs 0.91 ± 0.28), EM/TM (0.58 ± 0.10 vs 0.48 ± 0.07) were significantly higher for the normal group. Among these parameters, AM/TM correlated best with the time constant of LV isovolumic relaxation (r = 0.77, P < 0.001). Using an AM/TM ratio value of >0.5 as an indicator of LV diastolic function abnormality, the sensitivity, specificity, positive predictive values, and negative predictive values for the detection of pseudonormalization were 85%, 94%, 94%, and 87%, respectively. These findings suggest that the increased volume reduction of late LA emptying (AM/TM) during LV diastolic phase assessed by M‐mode echocardiography is useful for evaluating pseudonormal mitral inflow. (ECHOCARDIOGRAPHY, Volume 20, November 2003)
Innovations in Transesophageal Echocardiographic Imaging
Authors: Ward R. Parker , Lang Roberto M.
Published: December 2003

Over the last three decades, the continuing development of transesophageal echocardiography (TEE) has represented a major advance in our ability to visualize cardiovascular structures with ultrasound. TEE serves as a valuable complement to transthoracic echocardiography (TTE) by allowing: images to be obtained with less attenuation from structures such as the lung, muscle, bone, and soft tissue; high resolution visualization of structures not well seen by TTE, such as left atrial appendage, descending thoracic aorta, and prosthetic heart valves; and assessment of hemodynamics and flow disorders in greater detail. This article provides a brief overview of current as well as emerging clinical applications of transesophageal echocardiography. (ECHOCARDIOGRAPHY, Volume 20, November 2003)
Esophageal Doppler: Noninvasive Cardiac Output Monitor
Authors: Cholley Bernard P. , Singer Mervyn
Published: December 2003

In this article we describe the esophageal Doppler, a noninvasive, instantaneous cardiac output monitor. Its reliability has been demonstrated to be comparable to that of other current techniques used in the clinical arena to measure cardiac output. It helps guiding intravascular fluid resuscitation by quantifying the increase in flow in response to fluid challenges and by indicating the plateau of the patient's cardiac function curve. When the plateau has been reached, further fluid loading may result in congestion without improvement in systemic flow. Thus, measuring cardiac output is the only way to determine the upper limit for fluid intake. In addition, a strategy based on cardiac output optimization has proven beneficial in high‐risk surgical patients. (ECHOCARDIOGRAPHY, Volume 20, November 2003)
Current State of Intraoperative Echocardiography
Authors: Katsnelson Yan , Raman Jai , Katsnelson Flora , Mor‐Avi Victor , Heller Lorri B. , Jayakar David , Bacha Emile , Jeevanandam Valluvan
Published: December 2003

Intraoperative use of echocardiography is becoming more prevalent and is now considered an essential part of modern cardiac surgery. Echocardiography can be performed intraoperatively using transesophageal, epicardial or epiaortic, and substernal approaches. These techniques have a variety of applications in evaluating myocardial and valvular function, assessing aortic atheroma, and determining adequacy of various kinds of repair and reconstruction. Future applications will most likely involve more compact equipment, the implementation of epicardial and transesophageal real‐time three‐dimensional echocardiography, and better use of provocative methods of intraoperative testing. (ECHOCARDIOGRAPHY, Volume 20, November 2003)
Use of Intracardiac Echocardiography to Guide Catheter Closure of Atrial Communications
Authors: Koenig Peter R. , Abdulla Ra‐id , Cao Qi‐Ling , Hijazi Ziyad M.
Published: December 2003

Intracardiac echocardiography (ICE) is slowly replacing transesophageal echocardiography as the preferred imaging tool to guide device closure of atrial septal defects and patent foramen ovale. This article is a brief review of the literature related to ICE, the technical aspects ICE imaging, techniques for obtaining the standard views, and the future directions of this methodology. (ECHOCARDIOGRAPHY, Volume 20, November 2003)
Live Three‐Dimensional Transthoracic Echocardiographic Assessment of Coronary Arteries
Authors: Vengala Srinivas , Nanda Navin C. , Agrawal Gopal , Singh Vikramjit , Dod Harvinder S. , Khanna Deepak , Chapman Gregory , Upendram Sailendra
Published: December 2003

In the present study, we are illustrating some of the adult patients in whom live three‐dimensional transthoracic echocardiography was found useful in assessing proximal and mid‐coronary arteries. (ECHOCARDIOGRAPHY, Volume 20, November 2003)
Live Three‐Dimensional Echocardiographic Assessment of Mitral Stenosis
Authors: Singh Vikramjit , Nanda Navin C. , Agrawal Gopal , Vengala Srinivas , Dod Harvinder S. , Misra Vijay , Narayan Virenjan
Published: December 2003

In the present study, we describe our experience in using live three‐dimensional transthoracic echocardiography in the assessment of mitral stenosis. (ECHOCARDIOGRAPHY, Volume 20, November 2003)
Live Three‐Dimensional Echocardiography of the Human Fetus
Authors: Maulik Dev , Nanda Navin C. , Singh Vikramjit , Dod Harvinder , Vengala Srinivas , Sinha Ashish , Sidhu Maninder S. , Khanna Deepak , Lysikiewicz Andrzej , Sicuranza Genevieve , Modh Nayana
Published: December 2003

The purpose of this study was to investigate the feasibility of using a new three‐dimensional ultrasound system to perform fetal echocardiographic examination in real time. The device consisted of a Philips Sonos 7500 (Andover, MA) ultrasound system and a 4 MHz, 4X matrix transducer. The study was approved by the Institutional Review Board and was performed with the informed consent of the mother. The study population consisted of 12 singleton fetuses with gestational ages of 16–37 weeks. Of these, ten fetuses had normal cardiac anatomy, one had complete atrioventricular septal defect, and the other a thickened tricuspid valve. The system allowed comprehensive visualization of fetal cardiac anatomy and color Doppler flow unattainable by two‐dimensional approaches. This preliminary investigation suggests that live three‐dimensional fetal echocardiography could be a significant tool for prenatal diagnosis and assessment of congenital heart disease in the human fetus. (ECHOCARDIOGRAPHY, Volume 20, November 2003)
Scottish Higher Education and the FE‐HE Nexus
Authors: Morgan‐Klein Brenda
Published: December 2003

Over half of Scottish higher education entrants in 2000/01 began their studies in further education. This reflects the growing diversity of higher education in Scotland as a result of institutional change and trends in policy and practice. While these changes have been constructed positively as contributing to the accessibility of Scottish higher education, clear differences between HE provision in the two sectors and sectoral differentiation in patterns of participation have given rise to two relatively disconnected systems of higher education. The emergence of parallel systems may conceal new patterns of inequality, giving rise to a new learning divide.