Quantitative risk in radiation protection standards

International Nuclear Information System (INIS)

Bond, V.P.

1979-01-01

Although the overall aim of radiobiology is to understand the biological effects of radiation, it also has the implied practical purpose of developing rational measures for the control of radiation exposure in man. The emphasis in this presentation is to show that the enormous effort expended over the years to develop quantitative dose-effect relationships in biochemical and cellular systems, animals, and human beings now seems to be paying off. The pieces appear to be falling into place, and a framework is evolving to utilize these data. Specifically, quantitative risk assessments will be discussed in terms of the cellular, animal, and human data on which they are based; their use in the development of radiation protection standards; and their present and potential impact and meaning in relation to the quantity dose equivalent and its special unit, the rem

Comprehensive, Quantitative Risk Assessment of CO{sub 2} Geologic Sequestration

Energy Technology Data Exchange (ETDEWEB)

Lepinski, James

2013-09-30

A Quantitative Failure Modes and Effects Analysis (QFMEA) was developed to conduct comprehensive, quantitative risk assessments on CO{sub 2} capture, transportation, and sequestration or use in deep saline aquifers, enhanced oil recovery operations, or enhanced coal bed methane operations. The model identifies and characterizes potential risks; identifies the likely failure modes, causes, effects and methods of detection; lists possible risk prevention and risk mitigation steps; estimates potential damage recovery costs, mitigation costs and costs savings resulting from mitigation; and ranks (prioritizes) risks according to the probability of failure, the severity of failure, the difficulty of early failure detection and the potential for fatalities. The QFMEA model generates the necessary information needed for effective project risk management. Diverse project information can be integrated into a concise, common format that allows comprehensive, quantitative analysis, by a cross-functional team of experts, to determine: What can possibly go wrong? How much will damage recovery cost? How can it be prevented or mitigated? What is the cost savings or benefit of prevention or mitigation? Which risks should be given highest priority for resolution? The QFMEA model can be tailored to specific projects and is applicable to new projects as well as mature projects. The model can be revised and updated as new information comes available. It accepts input from multiple sources, such as literature searches, site characterization, field data, computer simulations, analogues, process influence diagrams, probability density functions, financial analysis models, cost factors, and heuristic best practices manuals, and converts the information into a standardized format in an Excel spreadsheet. Process influence diagrams, geologic models, financial models, cost factors and an insurance schedule were developed to support the QFMEA model. Comprehensive, quantitative risk assessments

Quantitative evaluation of risks for individuals in diagnostic radiology

Energy Technology Data Exchange (ETDEWEB)

Iinuma, T A; Tateno, Y; Hashizume, T [National Inst. of Radiological Sciences, Chiba (Japan)

1980-05-01

A method to estimate quantitatively risks of individual patients due to exposure to diagnostic radiation (carcinogenetic and genetic effects of radiation) was proposed on the basis of ICRP-26. Carcinogenetic effect of radiation was calculated by multiplying mean dose equivalent for each organ per each radiological examination by shortening of average life-expectancy which was calculated from incidence of fetal carcinoma of each organ, latent period of carcinoma, and incidence period of carcinoma. Genetic effect of radiation was calculated by multiplying mean dose equivalent for gonad per each radiological examination by incidence of genetically severe radiation damages due to parent's exposure and child expectancy rate. Three examples were shown on calculations of risks in the photofluorographic examinations of the stomach and chest, and mammography. The same method of calculation could be applied to the in-vivo nuclear medicine examinations. Further investigation was required to calculate the risks quantitatively for various types of diagnostic procedures using radiation.

Quantitative evaluation of risks for individuals in diagnostic radiology

International Nuclear Information System (INIS)

Iinuma, T.A.; Tateno, Yukio; Hashizume, Tadashi

1980-01-01

A method to estimate quantitatively risks of individual patients due to exposure to diagnostic radiation (carcinogenetic and genetic effects of radiation) was proposed on the basis of ICRP-26. Carcinogenetic effect of radiation was calculated by multiplying mean dose equivalent for each organ per each radiological examination by shortening of average life-expectancy which was calculated from incidence of fetal carcinoma of each organ, latent period of carcinoma, and incidence period of carcinoma. Genetic effect of radiation was calculated by multiplying mean dose equivalent for gonad per each radiological examination by incidence of genetically severe radiation damages due to parent's exposure and child expectancy rate. Three examples were shown on calculations of risks in the photofluorographic examinations of the stomach and chest, and mammography. The same method of calculation could be applied to the in-vivo nuclear medicine examinations. Further investigation was required to calculate the risks quantitatively for various types of diagnostic procedures using radiation. (Tsunoda, M.)

Breach Risk Magnitude: A Quantitative Measure of Database Security.

Science.gov (United States)

Yasnoff, William A

2016-01-01

A quantitative methodology is described that provides objective evaluation of the potential for health record system breaches. It assumes that breach risk increases with the number of potential records that could be exposed, while it decreases when more authentication steps are required for access. The breach risk magnitude (BRM) is the maximum value for any system user of the common logarithm of the number of accessible database records divided by the number of authentication steps needed to achieve such access. For a one million record relational database, the BRM varies from 5.52 to 6 depending on authentication protocols. For an alternative data architecture designed specifically to increase security by separately storing and encrypting each patient record, the BRM ranges from 1.3 to 2.6. While the BRM only provides a limited quantitative assessment of breach risk, it may be useful to objectively evaluate the security implications of alternative database organization approaches.

Modeling Logistic Performance in Quantitative Microbial Risk Assessment

NARCIS (Netherlands)

Rijgersberg, H.; Tromp, S.O.; Jacxsens, L.; Uyttendaele, M.

2010-01-01

In quantitative microbial risk assessment (QMRA), food safety in the food chain is modeled and simulated. In general, prevalences, concentrations, and numbers of microorganisms in media are investigated in the different steps from farm to fork. The underlying rates and conditions (such as storage

Simplified quantitative treatment of uncertainty and interindividual variability in health risk assessment

International Nuclear Information System (INIS)

Bogen, K.T.

1993-01-01

A distinction between uncertainty (or the extent of lack of knowledge) and interindividual variability (or the extent of person-to-person heterogeneity) regarding the values of input variates must be maintained if a quantitative characterization of uncertainty in population risk or in individual risk is sought. Here, some practical methods are presented that should facilitate implementation of the analytic framework for uncertainty and variability proposed by Bogen and Spear. (1,2) Two types of methodology are discussed: one that facilitates the distinction between uncertainty and variability per se, and another that may be used to simplify quantitative analysis of distributed inputs representing either uncertainty or variability. A simple and a complex form for modeled increased risk are presented and then used to illustrate methods facilitating the distinction between uncertainty and variability in reference to characterization of both population and individual risk. Finally, a simple form of discrete probability calculus is proposed as an easily implemented, practical altemative to Monte-Carlo based procedures to quantitative integration of uncertainty and variability in risk assessment

Quantitative risk stratification in Markov chains with limiting conditional distributions.

Science.gov (United States)

Chan, David C; Pollett, Philip K; Weinstein, Milton C

2009-01-01

Many clinical decisions require patient risk stratification. The authors introduce the concept of limiting conditional distributions, which describe the equilibrium proportion of surviving patients occupying each disease state in a Markov chain with death. Such distributions can quantitatively describe risk stratification. The authors first establish conditions for the existence of a positive limiting conditional distribution in a general Markov chain and describe a framework for risk stratification using the limiting conditional distribution. They then apply their framework to a clinical example of a treatment indicated for high-risk patients, first to infer the risk of patients selected for treatment in clinical trials and then to predict the outcomes of expanding treatment to other populations of risk. For the general chain, a positive limiting conditional distribution exists only if patients in the earliest state have the lowest combined risk of progression or death. The authors show that in their general framework, outcomes and population risk are interchangeable. For the clinical example, they estimate that previous clinical trials have selected the upper quintile of patient risk for this treatment, but they also show that expanded treatment would weakly dominate this degree of targeted treatment, and universal treatment may be cost-effective. Limiting conditional distributions exist in most Markov models of progressive diseases and are well suited to represent risk stratification quantitatively. This framework can characterize patient risk in clinical trials and predict outcomes for other populations of risk.

Quantitative risk analysis as a basis for emergency planning

Energy Technology Data Exchange (ETDEWEB)

Yogui, Regiane Tiemi Teruya [Bureau Veritas do Brasil, Rio de Janeiro, RJ (Brazil); Macedo, Eduardo Soares de [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil)

2009-07-01

Several environmental accidents happened in Brazil and in the world during the 70's and 80's. This strongly motivated the preparation for emergencies in the chemical and petrochemical industries. Environmental accidents affect the environment and the communities that are neighbor to the industrial facilities. The present study aims at subsidizing and providing orientation to develop Emergency Planning from the data obtained on Quantitative Risk Analysis, elaborated according to the Technical Standard P4.261/03 from CETESB (Sao Paulo Environmental Agency). It was observed, during the development of the research, that the data generated on these studies need a complementation and a deeper analysis, so that it is possible to use them on the Emergency Plans. The main issues that were analyzed and discussed on this study were the reevaluation of hazard identification for the emergency plans, the consequences and vulnerability analysis for the response planning, the risk communication, and the preparation to respond to the emergencies of the communities exposed to manageable risks. As a result, the study intends to improve the interpretation and use of the data deriving from the Quantitative Risk Analysis to develop the emergency plans. (author)

Quantitative Risk Assessment of Contact Sensitization

DEFF Research Database (Denmark)

Api, Anne Marie; Belsito, Donald; Bickers, David

2010-01-01

Background: Contact hypersensitivity quantitative risk assessment (QRA) for fragrance ingredients is being used to establish new international standards for all fragrance ingredients that are potential skin sensitizers. Objective: The objective was to evaluate the retrospective clinical data...... as potential sensitizers. Methods: This article reviews clinical data for three fragrance ingredients cinnamic aldehyde, citral, and isoeugenol to assess the utility of the QRA approach for fragrance ingredients. Results: This assessment suggests that had the QRA approach been available at the time standards...

Expert judgement models in quantitative risk assessment

Energy Technology Data Exchange (ETDEWEB)

Rosqvist, T. [VTT Automation, Helsinki (Finland); Tuominen, R. [VTT Automation, Tampere (Finland)

1999-12-01

Expert judgement is a valuable source of information in risk management. Especially, risk-based decision making relies significantly on quantitative risk assessment, which requires numerical data describing the initiator event frequencies and conditional probabilities in the risk model. This data is seldom found in databases and has to be elicited from qualified experts. In this report, we discuss some modelling approaches to expert judgement in risk modelling. A classical and a Bayesian expert model is presented and applied to real case expert judgement data. The cornerstone in the models is the log-normal distribution, which is argued to be a satisfactory choice for modelling degree-of-belief type probability distributions with respect to the unknown parameters in a risk model. Expert judgements are qualified according to bias, dispersion, and dependency, which are treated differently in the classical and Bayesian approaches. The differences are pointed out and related to the application task. Differences in the results obtained from the different approaches, as applied to real case expert judgement data, are discussed. Also, the role of a degree-of-belief type probability in risk decision making is discussed.

Expert judgement models in quantitative risk assessment

International Nuclear Information System (INIS)

Rosqvist, T.; Tuominen, R.

1999-01-01

Expert judgement is a valuable source of information in risk management. Especially, risk-based decision making relies significantly on quantitative risk assessment, which requires numerical data describing the initiator event frequencies and conditional probabilities in the risk model. This data is seldom found in databases and has to be elicited from qualified experts. In this report, we discuss some modelling approaches to expert judgement in risk modelling. A classical and a Bayesian expert model is presented and applied to real case expert judgement data. The cornerstone in the models is the log-normal distribution, which is argued to be a satisfactory choice for modelling degree-of-belief type probability distributions with respect to the unknown parameters in a risk model. Expert judgements are qualified according to bias, dispersion, and dependency, which are treated differently in the classical and Bayesian approaches. The differences are pointed out and related to the application task. Differences in the results obtained from the different approaches, as applied to real case expert judgement data, are discussed. Also, the role of a degree-of-belief type probability in risk decision making is discussed

Quantitative prediction of oral cancer risk in patients with oral leukoplakia.

Science.gov (United States)

Liu, Yao; Li, Yicheng; Fu, Yue; Liu, Tong; Liu, Xiaoyong; Zhang, Xinyan; Fu, Jie; Guan, Xiaobing; Chen, Tong; Chen, Xiaoxin; Sun, Zheng

2017-07-11

Exfoliative cytology has been widely used for early diagnosis of oral squamous cell carcinoma. We have developed an oral cancer risk index using DNA index value to quantitatively assess cancer risk in patients with oral leukoplakia, but with limited success. In order to improve the performance of the risk index, we collected exfoliative cytology, histopathology, and clinical follow-up data from two independent cohorts of normal, leukoplakia and cancer subjects (training set and validation set). Peaks were defined on the basis of first derivatives with positives, and modern machine learning techniques were utilized to build statistical prediction models on the reconstructed data. Random forest was found to be the best model with high sensitivity (100%) and specificity (99.2%). Using the Peaks-Random Forest model, we constructed an index (OCRI2) as a quantitative measurement of cancer risk. Among 11 leukoplakia patients with an OCRI2 over 0.5, 4 (36.4%) developed cancer during follow-up (23 ± 20 months), whereas 3 (5.3%) of 57 leukoplakia patients with an OCRI2 less than 0.5 developed cancer (32 ± 31 months). OCRI2 is better than other methods in predicting oral squamous cell carcinoma during follow-up. In conclusion, we have developed an exfoliative cytology-based method for quantitative prediction of cancer risk in patients with oral leukoplakia.

Risk prediction, safety analysis and quantitative probability methods - a caveat

International Nuclear Information System (INIS)

Critchley, O.H.

1976-01-01

Views are expressed on the use of quantitative techniques for the determination of value judgements in nuclear safety assessments, hazard evaluation, and risk prediction. Caution is urged when attempts are made to quantify value judgements in the field of nuclear safety. Criteria are given the meaningful application of reliability methods but doubts are expressed about their application to safety analysis, risk prediction and design guidances for experimental or prototype plant. Doubts are also expressed about some concomitant methods of population dose evaluation. The complexities of new designs of nuclear power plants make the problem of safety assessment more difficult but some possible approaches are suggested as alternatives to the quantitative techniques criticized. (U.K.)

EFFICIENT QUANTITATIVE RISK ASSESSMENT OF JUMP PROCESSES: IMPLICATIONS FOR FOOD SAFETY

OpenAIRE

Nganje, William E.

1999-01-01

This paper develops a dynamic framework for efficient quantitative risk assessment from the simplest general risk, combining three parameters (contamination, exposure, and dose response) in a Kataoka safety-first model and a Poisson probability representing the uncertainty effect or jump processes associated with food safety. Analysis indicates that incorporating jump processes in food safety risk assessment provides more efficient cost/risk tradeoffs. Nevertheless, increased margin of safety...

New developments in quantitative risk assessment of campylobacteriosis

DEFF Research Database (Denmark)

Havelaar, Arie; Nauta, Maarten

meat to ready-to-eat foods is the main pathway of consumer exposure. Undercooking appears to be of minor importance. However, this conclusion may need to be reconsidered in the light of increasing consumption of minced meat preparations. Five QMRA models have been compared in detail, and detailed......Quantitative microbiological risk assessment (QMRA) is now broadly accepted as an important decision support tool in food safety risk management. It has been used to support decision making at the global level (Codex Alimentarius, FAO and WHO), at the European level (European Food Safety Authority...

Urban flooding and health risk analysis by use of quantitative microbial risk assessment

DEFF Research Database (Denmark)

Andersen, Signe Tanja

D thesis is to identify the limitations and possibilities for optimising microbial risk assessments of urban flooding through more evidence-based solutions, including quantitative microbial data and hydrodynamic water quality models. The focus falls especially on the problem of data needs and the causes......, but also when wading through a flooded area. The results in this thesis have brought microbial risk assessments one step closer to more uniform and repeatable risk analysis by using actual and relevant measured data and hydrodynamic water quality models to estimate the risk from flooding caused...... are expected to increase in the future. To ensure public health during extreme rainfall, solutions are needed, but limited knowledge on microbial water quality, and related health risks, makes it difficult to implement microbial risk analysis as a part of the basis for decision making. The main aim of this Ph...

Quantitative Security Risk Assessment of Android Permissions and Applications

OpenAIRE

Wang , Yang; Zheng , Jun; Sun , Chen; Mukkamala , Srinivas

2013-01-01

Part 6: Mobile Computing; International audience; The booming of the Android platform in recent years has attracted the attention of malware developers. However, the permissions-based model used in Android system to prevent the spread of malware, has shown to be ineffective. In this paper, we propose DroidRisk, a framework for quantitative security risk assessment of both Android permissions and applications (apps) based on permission request patterns from benign apps and malware, which aims ...

Comparison study on qualitative and quantitative risk assessment methods for urban natural gas pipeline network.

Science.gov (United States)

Han, Z Y; Weng, W G

2011-05-15

In this paper, a qualitative and a quantitative risk assessment methods for urban natural gas pipeline network are proposed. The qualitative method is comprised of an index system, which includes a causation index, an inherent risk index, a consequence index and their corresponding weights. The quantitative method consists of a probability assessment, a consequences analysis and a risk evaluation. The outcome of the qualitative method is a qualitative risk value, and for quantitative method the outcomes are individual risk and social risk. In comparison with previous research, the qualitative method proposed in this paper is particularly suitable for urban natural gas pipeline network, and the quantitative method takes different consequences of accidents into consideration, such as toxic gas diffusion, jet flame, fire ball combustion and UVCE. Two sample urban natural gas pipeline networks are used to demonstrate these two methods. It is indicated that both of the two methods can be applied to practical application, and the choice of the methods depends on the actual basic data of the gas pipelines and the precision requirements of risk assessment. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

A method of quantitative risk assessment for transmission pipeline carrying natural gas

International Nuclear Information System (INIS)

Jo, Young-Do; Ahn, Bum Jong

2005-01-01

Regulatory authorities in many countries are moving away from prescriptive approaches for keeping natural gas pipelines safe. As an alternative, risk management based on a quantitative assessment is being considered to improve the level of safety. This paper focuses on the development of a simplified method for the quantitative risk assessment for natural gas pipelines and introduces parameters of fatal length and cumulative fatal length. The fatal length is defined as the integrated fatality along the pipeline associated with hypothetical accidents. The cumulative fatal length is defined as the section of pipeline in which an accident leads to N or more fatalities. These parameters can be estimated easily by using the information of pipeline geometry and population density of a Geographic Information Systems (GIS). To demonstrate the proposed method, individual and societal risks for a sample pipeline have been estimated from the historical data of European Gas Pipeline Incident Data Group and BG Transco. With currently acceptable criteria taken into account for individual risk, the minimum proximity of the pipeline to occupied buildings is approximately proportional to the square root of the operating pressure of the pipeline. The proposed method of quantitative risk assessment may be useful for risk management during the planning and building stages of a new pipeline, and modification of a buried pipeline

Information Risk Management: Qualitative or Quantitative? Cross industry lessons from medical and financial fields

Directory of Open Access Journals (Sweden)

Upasna Saluja

2012-06-01

Full Text Available Enterprises across the world are taking a hard look at their risk management practices. A number of qualitative and quantitative models and approaches are employed by risk practitioners to keep risk under check. As a norm most organizations end up choosing the more flexible, easier to deploy and customize qualitative models of risk assessment. In practice one sees that such models often call upon the practitioners to make qualitative judgments on a relative rating scale which brings in considerable room for errors, biases and subjectivity. On the other hand under the quantitative risk analysis approach, estimation of risk is connected with application of numerical measures of some kind. Medical risk management models lend themselves as ideal candidates for deriving lessons for Information Security Risk Management. We can use this considerably developed understanding of risk management from the medical field especially Survival Analysis towards handling risks that information infrastructures face. Similarly, financial risk management discipline prides itself on perhaps the most quantifiable of models in risk management. Market Risk and Credit Risk Information Security Risk Management can make risk measurement more objective and quantitative by referring to the approach of Credit Risk. During the recent financial crisis many investors and financial institutions lost money or went bankrupt respectively, because they did not apply the basic principles of risk management. Learning from the financial crisis provides some valuable lessons for information risk management.

77 FR 41985 - Use of Influenza Disease Models To Quantitatively Evaluate the Benefits and Risks of Vaccines: A...

Science.gov (United States)

2012-07-17

... models to generate quantitative estimates of the benefits and risks of influenza vaccination. The public...] Use of Influenza Disease Models To Quantitatively Evaluate the Benefits and Risks of Vaccines: A... Influenza Disease Models to Quantitatively Evaluate the Benefits and Risks of Vaccines: A Technical Workshop...

N reactor individual risk comparison to quantitative nuclear safety goals

International Nuclear Information System (INIS)

Wang, O.S.; Rainey, T.E.; Zentner, M.D.

1990-01-01

A full-scope level III probabilistic risk assessment (PRA) has been completed for N reactor, a US Department of Energy (DOE) production reactor located on the Hanford Reservation in the state of Washington. Sandia National Laboratories (SNL) provided the technical leadership for this work, using the state-of-the-art NUREG-1150 methodology developed for the US Nuclear Regulatory Commission (NRC). The main objectives of this effort were to assess the risks to the public and to the on-site workers posed by the operation of N reactor, to identify changes to the plant that could reduce the overall risk, and to compare those risks to the proposed NRC and DOE quantitative safety goals. This paper presents the methodology adopted by Westinghouse Hanford Company (WHC) and SNL for individual health risk evaluation, its results, and a comparison to the NRC safety objectives and the DOE nuclear safety guidelines. The N reactor results, are also compared with the five NUREG-1150 nuclear plants. Only internal events are compared here because external events are not yet reported in the current draft NUREG-1150. This is the first full-scope level III PRA study with a detailed quantitative safety goal comparison performed for DOE production reactors

Quantitative, Qualitative and Geospatial Methods to Characterize HIV Risk Environments.

Directory of Open Access Journals (Sweden)

Erin E Conners

Full Text Available Increasingly, 'place', including physical and geographical characteristics as well as social meanings, is recognized as an important factor driving individual and community health risks. This is especially true among marginalized populations in low and middle income countries (LMIC, whose environments may also be more difficult to study using traditional methods. In the NIH-funded longitudinal study Mapa de Salud, we employed a novel approach to exploring the risk environment of female sex workers (FSWs in two Mexico/U.S. border cities, Tijuana and Ciudad Juárez. In this paper we describe the development, implementation, and feasibility of a mix of quantitative and qualitative tools used to capture the HIV risk environments of FSWs in an LMIC setting. The methods were: 1 Participatory mapping; 2 Quantitative interviews; 3 Sex work venue field observation; 4 Time-location-activity diaries; 5 In-depth interviews about daily activity spaces. We found that the mixed-methodology outlined was both feasible to implement and acceptable to participants. These methods can generate geospatial data to assess the role of the environment on drug and sexual risk behaviors among high risk populations. Additionally, the adaptation of existing methods for marginalized populations in resource constrained contexts provides new opportunities for informing public health interventions.

Quantitative Risk Analysis: Method And Process

Directory of Open Access Journals (Sweden)

Anass BAYAGA

2010-03-01

Full Text Available Recent and past studies (King III report, 2009: 73-75; Stoney 2007;Committee of Sponsoring Organisation-COSO, 2004, Bartell, 2003; Liebenberg and Hoyt, 2003; Reason, 2000; Markowitz 1957 lament that although, the introduction of quantifying risk to enhance degree of objectivity in finance for instance was quite parallel to its development in the manufacturing industry, it is not the same in Higher Education Institution (HEI. In this regard, the objective of the paper was to demonstrate the methods and process of Quantitative Risk Analysis (QRA through likelihood of occurrence of risk (phase I. This paper serves as first of a two-phased study, which sampled hundred (100 risk analysts in a University in the greater Eastern Cape Province of South Africa.The analysis of likelihood of occurrence of risk by logistic regression and percentages were conducted to investigate whether there were a significant difference or not between groups (analyst in respect of QRA.The Hosmer and Lemeshow test was non-significant with a chi-square(X2 =8.181; p = 0.300, which indicated that there was a good model fit, since the data did not significantly deviate from the model. The study concluded that to derive an overall likelihood rating that indicated the probability that a potential risk may be exercised within the construct of an associated threat environment, the following governing factors must be considered: (1 threat source motivation and capability (2 nature of the vulnerability (3 existence and effectiveness of current controls (methods and process.

Characterizing health risks associated with recreational swimming at Taiwanese beaches by using quantitative microbial risk assessment.

Science.gov (United States)

Jang, Cheng-Shin; Liang, Ching-Ping

2018-01-01

Taiwan is surrounded by oceans, and therefore numerous pleasure beaches attract millions of tourists annually to participate in recreational swimming activities. However, impaired water quality because of fecal pollution poses a potential threat to the tourists' health. This study probabilistically characterized the health risks associated with recreational swimming engendered by waterborne enterococci at 13 Taiwanese beaches by using quantitative microbial risk assessment. First, data on enterococci concentrations at coastal beaches monitored by the Taiwan Environmental Protection Administration were reproduced using nonparametric Monte Carlo simulation (MCS). The ingestion volumes of recreational swimming based on uniform and gamma distributions were subsequently determined using MCS. Finally, after the distribution combination of the two parameters, the beta-Poisson dose-response function was employed to quantitatively estimate health risks to recreational swimmers. Moreover, various levels of risk to recreational swimmers were classified and spatially mapped to explore feasible recreational and environmental management strategies at the beaches. The study results revealed that although the health risks associated with recreational swimming did not exceed an acceptable benchmark of 0.019 illnesses daily at all beaches, they approached to this benchmark at certain beaches. Beaches with relatively high risks are located in Northwestern Taiwan owing to the current movements.

Use of mechanistic simulations as a quantitative risk-ranking tool within the quality by design framework.

Science.gov (United States)

Stocker, Elena; Toschkoff, Gregor; Sacher, Stephan; Khinast, Johannes G

2014-11-20

The purpose of this study is to evaluate the use of computer simulations for generating quantitative knowledge as a basis for risk ranking and mechanistic process understanding, as required by ICH Q9 on quality risk management systems. In this specific publication, the main focus is the demonstration of a risk assessment workflow, including a computer simulation for the generation of mechanistic understanding of active tablet coating in a pan coater. Process parameter screening studies are statistically planned under consideration of impacts on a potentially critical quality attribute, i.e., coating mass uniformity. Based on computer simulation data the process failure mode and effects analysis of the risk factors is performed. This results in a quantitative criticality assessment of process parameters and the risk priority evaluation of failure modes. The factor for a quantitative reassessment of the criticality and risk priority is the coefficient of variation, which represents the coating mass uniformity. The major conclusion drawn from this work is a successful demonstration of the integration of computer simulation in the risk management workflow leading to an objective and quantitative risk assessment. Copyright © 2014. Published by Elsevier B.V.

The Pesticide Risk Beliefs Inventory: A Quantitative Instrument for the Assessment of Beliefs about Pesticide Risks

OpenAIRE

LePrevost, Catherine E.; Blanchard, Margaret R.; Cope, W. Gregory

2011-01-01

Recent media attention has focused on the risks that agricultural pesticides pose to the environment and human health; thus, these topics provide focal areas for scientists and science educators to enhance public understanding of basic toxicology concepts. This study details the development of a quantitative inventory to gauge pesticide risk beliefs. The goal of the inventory was to characterize misconceptions and knowledge gaps, as well as expert-like beliefs, concerning pesticide risk. This...

Quantitative risk assessment of drinking water contaminants

International Nuclear Information System (INIS)

Cothern, C.R.; Coniglio, W.A.; Marcus, W.L.

1986-01-01

The development of criteria and standards for the regulation of drinking water contaminants involves a variety of processes, one of which is risk estimation. This estimation process, called quantitative risk assessment, involves combining data on the occurrence of the contaminant in drinking water and its toxicity. The human exposure to a contaminant can be estimated from occurrence data. Usually the toxicity or number of health effects per concentration level is estimated from animal bioassay studies using the multistage model. For comparison, other models will be used including the Weibull, probit, logit and quadratic ones. Because exposure and toxicity data are generally incomplete, assumptions need to be made and this generally results in a wide range of certainty in the estimates. This range can be as wide as four to six orders of magnitude in the case of the volatile organic compounds in drinking water and a factor of four to five for estimation of risk due to radionuclides in drinking water. As examples of the differences encountered in risk assessment of drinking water contaminants, discussions are presented on benzene, lead, radon and alachlor. The lifetime population risk estimates for these contaminants are, respectively, in the ranges of: <1 - 3000, <1 - 8000, 2000-40,000 and <1 - 80. 11 references, 1 figure, 1 table

Quantitative risk analysis preoperational of gas pipeline

Energy Technology Data Exchange (ETDEWEB)

Manfredi, Carlos; Bispo, Gustavo G.; Esteves, Alvaro [Gie S.A., Buenos Aires (Argentina)

2009-07-01

The purpose of this analysis is to predict how it can be affected the individual risk and the public's general security due to the operation of a gas pipeline. In case that the single or social risks are considered intolerable, compared with the international standards, to be recommended measures of mitigation of the risk associated to the operation until levels that can be considered compatible with the best practices in the industry. The quantitative risk analysis calculates the probability of occurrence of an event based on the frequency of occurrence of the same one and it requires a complex mathematical treatment. The present work has as objective to develop a calculation methodology based on the previously mentioned publication. This calculation methodology is centered in defining the frequencies of occurrence of events, according to representative database of each case in study. Besides, it settles down the consequences particularly according to the considerations of each area and the different possibilities of interferences with the gas pipeline in study. For each one of the interferences a typical curve of ignition probabilities is developed in function from the distance to the pipe. (author)

Is there a place for quantitative risk assessment?

Energy Technology Data Exchange (ETDEWEB)

Hall, Eric J [Columbia University Medical Center, New York, NY (United States)

2009-06-01

The use of ionising radiations is so well established, especially in the practice of medicine, that it is impossible to imagine contemporary life without them. At the same time, ionising radiations are a known and proven human carcinogen. Exposure to radiation in some contexts elicits fear and alarm (nuclear power for example) while in other situations, until recently at least, it was accepted with alacrity (diagnostic x-rays for example). This non-uniform reaction to the potential hazards of radiation highlights the importance of quantitative risk estimates, which are necessary to help put things into perspective. Three areas will be discussed where quantitative risk estimates are needed and where uncertainties and limitations are a problem. First, the question of diagnostic x-rays. CT usage over the past quarter of a century has increased about 12 fold in the UK and more than 20 fold in the US. In both countries, more than 90% of the collective population dose from diagnostic x-rays comes from the few high dose procedures, such as interventional radiology, CT scans, lumbar spine x-rays and barium enemas. These all involve doses close to the lower limit at which there are credible epidemiological data for an excess cancer incidence. This is a critical question; what is the lowest dose at which there is good evidence of an elevated cancer incidence? Without low dose risk estimates the risk-benefit ratio of diagnostic procedures cannot be assessed. Second, the use of new techniques in radiation oncology. IMRT is widely used to obtain a more conformal dose distribution, particularly in children. It results in a larger total body dose, due to an increased number of monitor units and to the application of more radiation fields. The Linacs used today were not designed for IMRT and are based on leakage standards that were decided decades ago. It will be difficult and costly to reduce leakage from treatment machines, and a necessary first step is to refine the available

Is there a place for quantitative risk assessment?

International Nuclear Information System (INIS)

Hall, Eric J

2009-01-01

The use of ionising radiations is so well established, especially in the practice of medicine, that it is impossible to imagine contemporary life without them. At the same time, ionising radiations are a known and proven human carcinogen. Exposure to radiation in some contexts elicits fear and alarm (nuclear power for example) while in other situations, until recently at least, it was accepted with alacrity (diagnostic x-rays for example). This non-uniform reaction to the potential hazards of radiation highlights the importance of quantitative risk estimates, which are necessary to help put things into perspective. Three areas will be discussed where quantitative risk estimates are needed and where uncertainties and limitations are a problem. First, the question of diagnostic x-rays. CT usage over the past quarter of a century has increased about 12 fold in the UK and more than 20 fold in the US. In both countries, more than 90% of the collective population dose from diagnostic x-rays comes from the few high dose procedures, such as interventional radiology, CT scans, lumbar spine x-rays and barium enemas. These all involve doses close to the lower limit at which there are credible epidemiological data for an excess cancer incidence. This is a critical question; what is the lowest dose at which there is good evidence of an elevated cancer incidence? Without low dose risk estimates the risk-benefit ratio of diagnostic procedures cannot be assessed. Second, the use of new techniques in radiation oncology. IMRT is widely used to obtain a more conformal dose distribution, particularly in children. It results in a larger total body dose, due to an increased number of monitor units and to the application of more radiation fields. The Linacs used today were not designed for IMRT and are based on leakage standards that were decided decades ago. It will be difficult and costly to reduce leakage from treatment machines, and a necessary first step is to refine the available

[A quantitative risk assessment model of salmonella on carcass in poultry slaughterhouse].

Science.gov (United States)

Zhang, Yu; Chen, Yuzhen; Hu, Chunguang; Zhang, Huaning; Bi, Zhenwang; Bi, Zhenqiang

2015-05-01

To construct a quantitative risk assessment model of salmonella on carcass in poultry slaughterhouse and to find out effective interventions to reduce salmonella contamination. We constructed a modular process risk model (MPRM) from evisceration to chilling in Excel Sheet using the data of the process parameters in poultry and the Salmomella concentration surveillance of Jinan in 2012. The MPRM was simulated by @ risk software. The concentration of salmonella on carcass after chilling was 1.96MPN/g which was calculated by model. The sensitive analysis indicated that the correlation coefficient of the concentration of salmonella after defeathering and in chilling pool were 0.84 and 0.34,which were the primary factors to the concentration of salmonella on carcass after chilling. The study provided a quantitative assessment model structure for salmonella on carcass in poultry slaughterhouse. The risk manager could control the contamination of salmonella on carcass after chilling by reducing the concentration of salmonella after defeathering and in chilling pool.

A quantitative risk-based model for reasoning over critical system properties

Science.gov (United States)

Feather, M. S.

2002-01-01

This position paper suggests the use of a quantitative risk-based model to help support reeasoning and decision making that spans many of the critical properties such as security, safety, survivability, fault tolerance, and real-time.

Quantitative background parenchymal uptake on molecular breast imaging and breast cancer risk: a case-control study.

Science.gov (United States)

Hruska, Carrie B; Geske, Jennifer R; Swanson, Tiffinee N; Mammel, Alyssa N; Lake, David S; Manduca, Armando; Conners, Amy Lynn; Whaley, Dana H; Scott, Christopher G; Carter, Rickey E; Rhodes, Deborah J; O'Connor, Michael K; Vachon, Celine M

2018-06-05

Background parenchymal uptake (BPU), which refers to the level of Tc-99m sestamibi uptake within normal fibroglandular tissue on molecular breast imaging (MBI), has been identified as a breast cancer risk factor, independent of mammographic density. Prior analyses have used subjective categories to describe BPU. We evaluate a new quantitative method for assessing BPU by testing its reproducibility, comparing quantitative results with previously established subjective BPU categories, and determining the association of quantitative BPU with breast cancer risk. Two nonradiologist operators independently performed region-of-interest analysis on MBI images viewed in conjunction with corresponding digital mammograms. Quantitative BPU was defined as a unitless ratio of the average pixel intensity (counts/pixel) within the fibroglandular tissue versus the average pixel intensity in fat. Operator agreement and the correlation of quantitative BPU measures with subjective BPU categories assessed by expert radiologists were determined. Percent density on mammograms was estimated using Cumulus. The association of quantitative BPU with breast cancer (per one unit BPU) was examined within an established case-control study of 62 incident breast cancer cases and 177 matched controls. Quantitative BPU ranged from 0.4 to 3.2 across all subjects and was on average higher in cases compared to controls (1.4 versus 1.2, p Quantitative BPU was strongly correlated with subjective BPU categories (Spearman's r = 0.59 to 0.69, p quantitative BPU measure, assessed by intraclass correlation, was 0.92 and 0.98, respectively. Quantitative BPU measures showed either no correlation or weak negative correlation with mammographic percent density. In a model adjusted for body mass index and percent density, higher quantitative BPU was associated with increased risk of breast cancer for both operators (OR = 4.0, 95% confidence interval (CI) 1.6-10.1, and 2.4, 95% CI 1.2-4.7). Quantitative

Quantitative coronary plaque analysis predicts high-risk plaque morphology on coronary computed tomography angiography: results from the ROMICAT II trial.

Science.gov (United States)

Liu, Ting; Maurovich-Horvat, Pál; Mayrhofer, Thomas; Puchner, Stefan B; Lu, Michael T; Ghemigian, Khristine; Kitslaar, Pieter H; Broersen, Alexander; Pursnani, Amit; Hoffmann, Udo; Ferencik, Maros

2018-02-01

Semi-automated software can provide quantitative assessment of atherosclerotic plaques on coronary CT angiography (CTA). The relationship between established qualitative high-risk plaque features and quantitative plaque measurements has not been studied. We analyzed the association between quantitative plaque measurements and qualitative high-risk plaque features on coronary CTA. We included 260 patients with plaque who underwent coronary CTA in the Rule Out Myocardial Infarction/Ischemia Using Computer Assisted Tomography (ROMICAT) II trial. Quantitative plaque assessment and qualitative plaque characterization were performed on a per coronary segment basis. Quantitative coronary plaque measurements included plaque volume, plaque burden, remodeling index, and diameter stenosis. In qualitative analysis, high-risk plaque was present if positive remodeling, low CT attenuation plaque, napkin-ring sign or spotty calcium were detected. Univariable and multivariable logistic regression analyses were performed to assess the association between quantitative and qualitative high-risk plaque assessment. Among 888 segments with coronary plaque, high-risk plaque was present in 391 (44.0%) segments by qualitative analysis. In quantitative analysis, segments with high-risk plaque had higher total plaque volume, low CT attenuation plaque volume, plaque burden and remodeling index. Quantitatively assessed low CT attenuation plaque volume (odds ratio 1.12 per 1 mm 3 , 95% CI 1.04-1.21), positive remodeling (odds ratio 1.25 per 0.1, 95% CI 1.10-1.41) and plaque burden (odds ratio 1.53 per 0.1, 95% CI 1.08-2.16) were associated with high-risk plaque. Quantitative coronary plaque characteristics (low CT attenuation plaque volume, positive remodeling and plaque burden) measured by semi-automated software correlated with qualitative assessment of high-risk plaque features.

Applying quantitative benefit-risk analysis to aid regulatory decision making in diagnostic imaging: methods, challenges, and opportunities.

Science.gov (United States)

Agapova, Maria; Devine, Emily Beth; Bresnahan, Brian W; Higashi, Mitchell K; Garrison, Louis P

2014-09-01

Health agencies making regulatory marketing-authorization decisions use qualitative and quantitative approaches to assess expected benefits and expected risks associated with medical interventions. There is, however, no universal standard approach that regulatory agencies consistently use to conduct benefit-risk assessment (BRA) for pharmaceuticals or medical devices, including for imaging technologies. Economics, health services research, and health outcomes research use quantitative approaches to elicit preferences of stakeholders, identify priorities, and model health conditions and health intervention effects. Challenges to BRA in medical devices are outlined, highlighting additional barriers in radiology. Three quantitative methods--multi-criteria decision analysis, health outcomes modeling and stated-choice survey--are assessed using criteria that are important in balancing benefits and risks of medical devices and imaging technologies. To be useful in regulatory BRA, quantitative methods need to: aggregate multiple benefits and risks, incorporate qualitative considerations, account for uncertainty, and make clear whose preferences/priorities are being used. Each quantitative method performs differently across these criteria and little is known about how BRA estimates and conclusions vary by approach. While no specific quantitative method is likely to be the strongest in all of the important areas, quantitative methods may have a place in BRA of medical devices and radiology. Quantitative BRA approaches have been more widely applied in medicines, with fewer BRAs in devices. Despite substantial differences in characteristics of pharmaceuticals and devices, BRA methods may be as applicable to medical devices and imaging technologies as they are to pharmaceuticals. Further research to guide the development and selection of quantitative BRA methods for medical devices and imaging technologies is needed. Copyright © 2014 AUR. Published by Elsevier Inc. All rights

Quantitative risk analysis of the pipeline GASDUC III - solutions

Energy Technology Data Exchange (ETDEWEB)

Silva, Edmilson P.; Bettoni, Izabel Cristina [PETROBRAS, Rio de Janeiro, RJ (Brazil)

2009-07-01

In this work the quantitative risks analysis to the external public of the Pipeline Cabiunas - REDUC (GASDUC III), with 180 km, linking the municipalities of Macae and Duque de Caxias - RJ was performed by the Companies PETROBRAS and ITSEMAP do Brasil. In addition to the large diameter of the pipeline 38 inches and high operation pressure 100 kgf/cm{sup 2} operating with natural gas through several densely populated areas. Initially, the individual risk contours were calculated without considering mitigating measures, obtaining as result the individual risk contour with frequencies of 1x10{sup -06} per year involving sensitive occupations and therefore considered unacceptable when compared with the INEA criterion. The societal risk was calculated for eight densely populated areas and their respective FN-curves situated below the advised limit established by INEA, except for two areas that required the proposal of additional mitigating measures to the reduction of societal risk. Regarding to societal risk, the FN-curve should be below the advised limit presented in the Technical Instruction of INEA. The individual and societal risk were reassessed incorporating some mitigating measures and the results situated below the advised limits established by INEA and PETROBRAS has obtained the license for installation of the pipeline. (author)

Supply chain risk management of newspaper industry: A quantitative study

Science.gov (United States)

Sartika, Viny; Hisjam, Muh.; Sutopo, Wahyudi

2018-02-01

The newspaper industry has several distinctive features that make it stands out from other industries. The strict delivery deadline and zero inventory led to a very short time frame for production and distribution. On the other hand, there is pressure from the newsroom to encourage the start of production as slowly as possible in order to enter the news, while there is pressure from production and distribution to start production as early as possible. Supply chain risk management is needed in determining the best strategy for dealing with possible risks in the newspaper industry. In a case study of a newspaper in Surakarta, quantitative approaches are made to the newspaper supply chain risk management by calculating the expected cost of risk based on the magnitude of the impact and the probability of a risk event. From the calculation results obtained that the five risks with the highest value are newspaper delays to the end customer, broken plate, miss print, down machine, and delayed delivery of newspaper content. Then analyzed appropriate mitigation strategies to cope with such risk events.

Web Applications Vulnerability Management using a Quantitative Stochastic Risk Modeling Method

Directory of Open Access Journals (Sweden)

Sergiu SECHEL

2017-01-01

Full Text Available The aim of this research is to propose a quantitative risk modeling method that reduces the guess work and uncertainty from the vulnerability and risk assessment activities of web based applications while providing users the flexibility to assess risk according to their risk appetite and tolerance with a high degree of assurance. The research method is based on the research done by the OWASP Foundation on this subject but their risk rating methodology needed de-bugging and updates in different in key areas that are presented in this paper. The modified risk modeling method uses Monte Carlo simulations to model risk characteristics that can’t be determined without guess work and it was tested in vulnerability assessment activities on real production systems and in theory by assigning discrete uniform assumptions to all risk charac-teristics (risk attributes and evaluate the results after 1.5 million rounds of Monte Carlo simu-lations.

Genetic toxicology at the crossroads-from qualitative hazard evaluation to quantitative risk assessment.

Science.gov (United States)

White, Paul A; Johnson, George E

2016-05-01

Applied genetic toxicology is undergoing a transition from qualitative hazard identification to quantitative dose-response analysis and risk assessment. To facilitate this change, the Health and Environmental Sciences Institute (HESI) Genetic Toxicology Technical Committee (GTTC) sponsored a workshop held in Lancaster, UK on July 10-11, 2014. The event included invited speakers from several institutions and the contents was divided into three themes-1: Point-of-departure Metrics for Quantitative Dose-Response Analysis in Genetic Toxicology; 2: Measurement and Estimation of Exposures for Better Extrapolation to Humans and 3: The Use of Quantitative Approaches in Genetic Toxicology for human health risk assessment (HHRA). A host of pertinent issues were discussed relating to the use of in vitro and in vivo dose-response data, the development of methods for in vitro to in vivo extrapolation and approaches to use in vivo dose-response data to determine human exposure limits for regulatory evaluations and decision-making. This Special Issue, which was inspired by the workshop, contains a series of papers that collectively address topics related to the aforementioned themes. The Issue includes contributions that collectively evaluate, describe and discuss in silico, in vitro, in vivo and statistical approaches that are facilitating the shift from qualitative hazard evaluation to quantitative risk assessment. The use and application of the benchmark dose approach was a central theme in many of the workshop presentations and discussions, and the Special Issue includes several contributions that outline novel applications for the analysis and interpretation of genetic toxicity data. Although the contents of the Special Issue constitutes an important step towards the adoption of quantitative methods for regulatory assessment of genetic toxicity, formal acceptance of quantitative methods for HHRA and regulatory decision-making will require consensus regarding the

Risk analysis of heat recovery steam generator with semi quantitative risk based inspection API 581

Science.gov (United States)

Prayogo, Galang Sandy; Haryadi, Gunawan Dwi; Ismail, Rifky; Kim, Seon Jin

2016-04-01

Corrosion is a major problem that most often occurs in the power plant. Heat recovery steam generator (HRSG) is an equipment that has a high risk to the power plant. The impact of corrosion damage causing HRSG power plant stops operating. Furthermore, it could be threaten the safety of employees. The Risk Based Inspection (RBI) guidelines by the American Petroleum Institute (API) 58 has been used to risk analysis in the HRSG 1. By using this methodology, the risk that caused by unexpected failure as a function of the probability and consequence of failure can be estimated. This paper presented a case study relating to the risk analysis in the HRSG, starting with a summary of the basic principles and procedures of risk assessment and applying corrosion RBI for process industries. The risk level of each HRSG equipment were analyzed: HP superheater has a medium high risk (4C), HP evaporator has a medium-high risk (4C), and the HP economizer has a medium risk (3C). The results of the risk assessment using semi-quantitative method of standard API 581 based on the existing equipment at medium risk. In the fact, there is no critical problem in the equipment components. Damage mechanisms were prominent throughout the equipment is thinning mechanism. The evaluation of the risk approach was done with the aim of reducing risk by optimizing the risk assessment activities.

Risk analysis of heat recovery steam generator with semi quantitative risk based inspection API 581

International Nuclear Information System (INIS)

Prayogo, Galang Sandy; Haryadi, Gunawan Dwi; Ismail, Rifky; Kim, Seon Jin

2016-01-01

Corrosion is a major problem that most often occurs in the power plant. Heat recovery steam generator (HRSG) is an equipment that has a high risk to the power plant. The impact of corrosion damage causing HRSG power plant stops operating. Furthermore, it could be threaten the safety of employees. The Risk Based Inspection (RBI) guidelines by the American Petroleum Institute (API) 58 has been used to risk analysis in the HRSG 1. By using this methodology, the risk that caused by unexpected failure as a function of the probability and consequence of failure can be estimated. This paper presented a case study relating to the risk analysis in the HRSG, starting with a summary of the basic principles and procedures of risk assessment and applying corrosion RBI for process industries. The risk level of each HRSG equipment were analyzed: HP superheater has a medium high risk (4C), HP evaporator has a medium-high risk (4C), and the HP economizer has a medium risk (3C). The results of the risk assessment using semi-quantitative method of standard API 581 based on the existing equipment at medium risk. In the fact, there is no critical problem in the equipment components. Damage mechanisms were prominent throughout the equipment is thinning mechanism. The evaluation of the risk approach was done with the aim of reducing risk by optimizing the risk assessment activities.

Risk analysis of heat recovery steam generator with semi quantitative risk based inspection API 581

Energy Technology Data Exchange (ETDEWEB)

Prayogo, Galang Sandy, E-mail: gasandylang@live.com; Haryadi, Gunawan Dwi; Ismail, Rifky [Department of Mechanical Engineering, Diponegoro University, Semarang (Indonesia); Kim, Seon Jin [Department of Mechanical & Automotive Engineering of Pukyong National University (Korea, Republic of)

2016-04-19

Corrosion is a major problem that most often occurs in the power plant. Heat recovery steam generator (HRSG) is an equipment that has a high risk to the power plant. The impact of corrosion damage causing HRSG power plant stops operating. Furthermore, it could be threaten the safety of employees. The Risk Based Inspection (RBI) guidelines by the American Petroleum Institute (API) 58 has been used to risk analysis in the HRSG 1. By using this methodology, the risk that caused by unexpected failure as a function of the probability and consequence of failure can be estimated. This paper presented a case study relating to the risk analysis in the HRSG, starting with a summary of the basic principles and procedures of risk assessment and applying corrosion RBI for process industries. The risk level of each HRSG equipment were analyzed: HP superheater has a medium high risk (4C), HP evaporator has a medium-high risk (4C), and the HP economizer has a medium risk (3C). The results of the risk assessment using semi-quantitative method of standard API 581 based on the existing equipment at medium risk. In the fact, there is no critical problem in the equipment components. Damage mechanisms were prominent throughout the equipment is thinning mechanism. The evaluation of the risk approach was done with the aim of reducing risk by optimizing the risk assessment activities.

A quantitative method for risk assessment of agriculture due to climate change

Science.gov (United States)

Dong, Zhiqiang; Pan, Zhihua; An, Pingli; Zhang, Jingting; Zhang, Jun; Pan, Yuying; Huang, Lei; Zhao, Hui; Han, Guolin; Wu, Dong; Wang, Jialin; Fan, Dongliang; Gao, Lin; Pan, Xuebiao

2018-01-01

Climate change has greatly affected agriculture. Agriculture is facing increasing risks as its sensitivity and vulnerability to climate change. Scientific assessment of climate change-induced agricultural risks could help to actively deal with climate change and ensure food security. However, quantitative assessment of risk is a difficult issue. Here, based on the IPCC assessment reports, a quantitative method for risk assessment of agriculture due to climate change is proposed. Risk is described as the product of the degree of loss and its probability of occurrence. The degree of loss can be expressed by the yield change amplitude. The probability of occurrence can be calculated by the new concept of climate change effect-accumulated frequency (CCEAF). Specific steps of this assessment method are suggested. This method is determined feasible and practical by using the spring wheat in Wuchuan County of Inner Mongolia as a test example. The results show that the fluctuation of spring wheat yield increased with the warming and drying climatic trend in Wuchuan County. The maximum yield decrease and its probability were 3.5 and 64.6%, respectively, for the temperature maximum increase 88.3%, and its risk was 2.2%. The maximum yield decrease and its probability were 14.1 and 56.1%, respectively, for the precipitation maximum decrease 35.2%, and its risk was 7.9%. For the comprehensive impacts of temperature and precipitation, the maximum yield decrease and its probability were 17.6 and 53.4%, respectively, and its risk increased to 9.4%. If we do not adopt appropriate adaptation strategies, the degree of loss from the negative impacts of multiclimatic factors and its probability of occurrence will both increase accordingly, and the risk will also grow obviously.

Quantitative risk assessment for environmental and occupational health. The practical solution

International Nuclear Information System (INIS)

Hallenbeck, W.H.; Cunningham, K.M.

1986-01-01

These following topics are covered in this book: concepts, methods, and limitations; exposure characterization; qualitative evaluation of human and animal studies; quantitative evaluation of human and animal studies; risk analysis; acceptable concentrations; environmental and occupational exposure to a hypothetical toxicant; and environmental exposure to a natural toxicant radon-222 and its daughters

A quantitative flood risk analysis methodology for urban areas with integration of social research data

Science.gov (United States)

Escuder-Bueno, I.; Castillo-Rodríguez, J. T.; Zechner, S.; Jöbstl, C.; Perales-Momparler, S.; Petaccia, G.

2012-09-01

Risk analysis has become a top priority for authorities and stakeholders in many European countries, with the aim of reducing flooding risk, considering the population's needs and improving risk awareness. Within this context, two methodological pieces have been developed in the period 2009-2011 within the SUFRI project (Sustainable Strategies of Urban Flood Risk Management with non-structural measures to cope with the residual risk, 2nd ERA-Net CRUE Funding Initiative). First, the "SUFRI Methodology for pluvial and river flooding risk assessment in urban areas to inform decision-making" provides a comprehensive and quantitative tool for flood risk analysis. Second, the "Methodology for investigation of risk awareness of the population concerned" presents the basis to estimate current risk from a social perspective and identify tendencies in the way floods are understood by citizens. Outcomes of both methods are integrated in this paper with the aim of informing decision making on non-structural protection measures. The results of two case studies are shown to illustrate practical applications of this developed approach. The main advantage of applying the methodology herein presented consists in providing a quantitative estimation of flooding risk before and after investing in non-structural risk mitigation measures. It can be of great interest for decision makers as it provides rational and solid information.

Dating Violence among High-Risk Young Women: A Systematic Review Using Quantitative and Qualitative Methods

Science.gov (United States)

Joly, Lauren E.; Connolly, Jennifer

2016-01-01

Our systematic review identified 21 quantitative articles and eight qualitative articles addressing dating violence among high risk young women. The groups of high-risk young women in this review include street-involved, justice-involved, pregnant or parenting, involved with Child Protective Services, and youth diagnosed with a mental health issue. Our meta-analysis of the quantitative articles indicated that 34% (CI = 0.24–0.45) of high-risk young women report that they have been victims of physical dating violence and 45% (CI = 0.31–0.61) of these young women report perpetrating physical dating violence. Significant moderator variables included questionnaire and timeframe. Meta-synthesis of the qualitative studies revealed that high-risk young women report perpetrating dating violence to gain power and respect, whereas women report becoming victims of dating violence due to increased vulnerability. PMID:26840336

Dating Violence among High-Risk Young Women: A Systematic Review Using Quantitative and Qualitative Methods

Directory of Open Access Journals (Sweden)

Lauren E. Joly

2016-01-01

Full Text Available Our systematic review identified 21 quantitative articles and eight qualitative articles addressing dating violence among high risk young women. The groups of high-risk young women in this review include street-involved, justice-involved, pregnant or parenting, involved with Child Protective Services, and youth diagnosed with a mental health issue. Our meta-analysis of the quantitative articles indicated that 34% (CI = 0.24–0.45 of high-risk young women report that they have been victims of physical dating violence and 45% (CI = 0.31–0.61 of these young women report perpetrating physical dating violence. Significant moderator variables included questionnaire and timeframe. Meta-synthesis of the qualitative studies revealed that high-risk young women report perpetrating dating violence to gain power and respect, whereas women report becoming victims of dating violence due to increased vulnerability.

Quantitative risk assessment of continuous liquid spill fires based on spread and burning behaviours

DEFF Research Database (Denmark)

Zhao, Jinlong; Huang, Hong; Li, Yuntao

2017-01-01

Spill fires usually occur during the storage and transportation of hazardous materials, posing a threat to the people and environment in their immediate proximity. In this paper, a classical Quantitative Risk Assessment (QRA) method is used to assess the risk of spill fires. In this method......, the maximum spread area and the steady burning area are introduced as parameters to clearly assess the range of influence of the spill fire. In the calculations, a modified spread model that takes into consideration the burning rate variation is established to calculate the maximum spread area. Furthermore......, large-scale experiments of spill fires on water and a glass sheet were conducted to verify the accuracy and application of the model. The results show that the procedure we developed can be used to quantitatively calculate the risk associated with a continuous spill fire....

Information Risk Management: Qualitative or Quantitative? Cross industry lessons from medical and financial fields

OpenAIRE

Upasna Saluja; Norbik Bashah Idris

2012-01-01

Enterprises across the world are taking a hard look at their risk management practices. A number of qualitative and quantitative models and approaches are employed by risk practitioners to keep risk under check. As a norm most organizations end up choosing the more flexible, easier to deploy and customize qualitative models of risk assessment. In practice one sees that such models often call upon the practitioners to make qualitative judgments on a relative rating scale which brings in consid...

A probabilistic method for computing quantitative risk indexes from medical injuries compensation claims.

Science.gov (United States)

Dalle Carbonare, S; Folli, F; Patrini, E; Giudici, P; Bellazzi, R

2013-01-01

The increasing demand of health care services and the complexity of health care delivery require Health Care Organizations (HCOs) to approach clinical risk management through proper methods and tools. An important aspect of risk management is to exploit the analysis of medical injuries compensation claims in order to reduce adverse events and, at the same time, to optimize the costs of health insurance policies. This work provides a probabilistic method to estimate the risk level of a HCO by computing quantitative risk indexes from medical injury compensation claims. Our method is based on the estimate of a loss probability distribution from compensation claims data through parametric and non-parametric modeling and Monte Carlo simulations. The loss distribution can be estimated both on the whole dataset and, thanks to the application of a Bayesian hierarchical model, on stratified data. The approach allows to quantitatively assessing the risk structure of the HCO by analyzing the loss distribution and deriving its expected value and percentiles. We applied the proposed method to 206 cases of injuries with compensation requests collected from 1999 to the first semester of 2007 by the HCO of Lodi, in the Northern part of Italy. We computed the risk indexes taking into account the different clinical departments and the different hospitals involved. The approach proved to be useful to understand the HCO risk structure in terms of frequency, severity, expected and unexpected loss related to adverse events.

Quantitative microbial risk assessment (QMRA) shows increased public health risk associated with exposure to river water under conditions of riverbed sediment resuspension

CSIR Research Space (South Africa)

Abia

2016-10-01

Full Text Available of The Total Environment, 556-557, pp 1143-1151 Quantitative microbial risk assessment (QMRA) shows increased public health risk associated with exposure to river water under conditions of riverbed sediment resuspension Akebe Luther King Abia a...

Integrating expert opinion with modelling for quantitative multi-hazard risk assessment in the Eastern Italian Alps

Science.gov (United States)

Chen, Lixia; van Westen, Cees J.; Hussin, Haydar; Ciurean, Roxana L.; Turkington, Thea; Chavarro-Rincon, Diana; Shrestha, Dhruba P.

2016-11-01

Extreme rainfall events are the main triggering causes for hydro-meteorological hazards in mountainous areas, where development is often constrained by the limited space suitable for construction. In these areas, hazard and risk assessments are fundamental for risk mitigation, especially for preventive planning, risk communication and emergency preparedness. Multi-hazard risk assessment in mountainous areas at local and regional scales remain a major challenge because of lack of data related to past events and causal factors, and the interactions between different types of hazards. The lack of data leads to a high level of uncertainty in the application of quantitative methods for hazard and risk assessment. Therefore, a systematic approach is required to combine these quantitative methods with expert-based assumptions and decisions. In this study, a quantitative multi-hazard risk assessment was carried out in the Fella River valley, prone to debris flows and flood in the north-eastern Italian Alps. The main steps include data collection and development of inventory maps, definition of hazard scenarios, hazard assessment in terms of temporal and spatial probability calculation and intensity modelling, elements-at-risk mapping, estimation of asset values and the number of people, physical vulnerability assessment, the generation of risk curves and annual risk calculation. To compare the risk for each type of hazard, risk curves were generated for debris flows, river floods and flash floods. Uncertainties were expressed as minimum, average and maximum values of temporal and spatial probability, replacement costs of assets, population numbers, and physical vulnerability. These result in minimum, average and maximum risk curves. To validate this approach, a back analysis was conducted using the extreme hydro-meteorological event that occurred in August 2003 in the Fella River valley. The results show a good performance when compared to the historical damage reports.

Using integrated environmental modeling to automate a process-based Quantitative Microbial Risk Assessment

Science.gov (United States)

Integrated Environmental Modeling (IEM) organizes multidisciplinary knowledge that explains and predicts environmental-system response to stressors. A Quantitative Microbial Risk Assessment (QMRA) is an approach integrating a range of disparate data (fate/transport, exposure, an...

Approaches to quantitative risk assessment with applications to PP

International Nuclear Information System (INIS)

Geiger, G.; Schaefer, A.

2002-01-01

Full text: Experience with accidents such as Goiania in Brazil and indications of a considerable number of orphan sources suggest that improved protection would be desirable for some types of radioactive material of wide-spread use such as radiation sources for civil purposes. Regarding large potential health and economic consequences (in particular, if terrorists attacks cannot be excluded), significant costs of preventive actions, and large uncertainties about both the likelihood of occurrence and the potential consequences of PP safety and security incidents, an optimum relationship between preventive and mitigative efforts is likely to be a key issue for successful risk management in this field. Thus, possible violations of physical protection combined with threats of misuse of nuclear materials, including terrorist attack, pose considerable challenges to global security from various perspectives. In view of these challenges, recent advance in applied risk and decision analysis suggests methodological and procedural improvements in quantitative risk assessment, the demarcation of acceptable risk, and risk management. Advance is based on a recently developed model of optimal risky choice suitable for assessing and comparing the cumulative probability distribution functions attached to safety and security risks. Besides quantification of risk (e. g., in economic terms), the standardization of various risk assessment models frequently used in operations research can be approached on this basis. The paper explores possible applications of these improved methods to the safety and security management of nuclear materials, cost efficiency of risk management measures, and the establishment international safety and security standards of PP. Examples will be presented that are based on selected scenarios of misuse involving typical radioactive sources. (author)

A quantitative flood risk analysis methodology for urban areas with integration of social research data

Directory of Open Access Journals (Sweden)

I. Escuder-Bueno

2012-09-01

Full Text Available Risk analysis has become a top priority for authorities and stakeholders in many European countries, with the aim of reducing flooding risk, considering the population's needs and improving risk awareness. Within this context, two methodological pieces have been developed in the period 2009–2011 within the SUFRI project (Sustainable Strategies of Urban Flood Risk Management with non-structural measures to cope with the residual risk, 2nd ERA-Net CRUE Funding Initiative. First, the "SUFRI Methodology for pluvial and river flooding risk assessment in urban areas to inform decision-making" provides a comprehensive and quantitative tool for flood risk analysis. Second, the "Methodology for investigation of risk awareness of the population concerned" presents the basis to estimate current risk from a social perspective and identify tendencies in the way floods are understood by citizens. Outcomes of both methods are integrated in this paper with the aim of informing decision making on non-structural protection measures. The results of two case studies are shown to illustrate practical applications of this developed approach. The main advantage of applying the methodology herein presented consists in providing a quantitative estimation of flooding risk before and after investing in non-structural risk mitigation measures. It can be of great interest for decision makers as it provides rational and solid information.

A quantitative framework for estimating risk of collision between marine mammals and boats

Science.gov (United States)

Martin, Julien; Sabatier, Quentin; Gowan, Timothy A.; Giraud, Christophe; Gurarie, Eliezer; Calleson, Scott; Ortega-Ortiz, Joel G.; Deutsch, Charles J.; Rycyk, Athena; Koslovsky, Stacie M.

2016-01-01

Speed regulations of watercraft in protected areas are designed to reduce lethal collisions with wildlife but can have economic consequences. We present a quantitative framework for investigating the risk of deadly collisions between boats and wildlife.

Fixing the cracks in the crystal ball: A maturity model for quantitative risk assessment

International Nuclear Information System (INIS)

Rae, Andrew; Alexander, Rob; McDermid, John

2014-01-01

Quantitative risk assessment (QRA) is widely practiced in system safety, but there is insufficient evidence that QRA in general is fit for purpose. Defenders of QRA draw a distinction between poor or misused QRA and correct, appropriately used QRA, but this distinction is only useful if we have robust ways to identify the flaws in an individual QRA. In this paper we present a comprehensive maturity model for QRA which covers all the potential flaws discussed in the risk assessment literature and in a collection of risk assessment peer reviews. We provide initial validation of the completeness and realism of the model. Our risk assessment maturity model provides a way to prioritise both process development within an organisation and empirical research within the QRA community. - Highlights: • Quantitative risk assessment (QRA) is widely practiced, but there is insufficient evidence that it is fit for purpose. • A given QRA may be good, or it may not – we need systematic ways to distinguish this. • We have created a maturity model for QRA which covers all the potential flaws discussed in the risk assessment literature. • We have provided initial validation of the completeness and realism of the model. • The maturity model can also be used to prioritise QRA research discipline-wide

Quantitative risk analysis for landslides ‒ Examples from Bíldudalur, NW-Iceland

Directory of Open Access Journals (Sweden)

R. Bell

2004-01-01

Full Text Available Although various methods to carry out quantitative landslide risk analyses are available, applications are still rare and mostly dependent on the occurrence of disasters. In Iceland, two catastrophic snow avalanches killed 34 people in 1995. As a consequence the Ministry of the Environment issued a new regulation on hazard zoning due to snow avalanches and landslides in 2000, which aims to prevent people living or working within the areas most at risk until 2010. The regulation requires to carry out landslide and snow avalanche risk analyses, however, a method to calculate landslide risk adopted to Icelandic conditions is still missing. Therefore, the ultimate goal of this study is to develop such a method for landslides, focussing on debris flows and rock falls and to test it in Bíldudalur, NW-Iceland. Risk analysis, beside risk evaluation and risk management, is part of the holistic concept of risk assessment. Within this study, risk analysis is considered only, focussing on the risks to life. To calculate landslide risk, the spatial and temporal probability of occurrence of potential damaging events, as well as the distribution of the elements at risk in space and time, considering also changing vulnerabilities, must be determined. Within this study, a new raster-based approach is developed. Thus, all existent vector data are transferred into raster data using a resolution of 1m x 1m. The specific attribute data are attributed to the grid cells, resulting in specific raster data layers for each input parameter. The calculation of the landslide risk follows a function of the input parameters hazard, damage potential of the elements at risk, vulnerability, probability of the spatial impact, probability of the temporal impact and probability of the seasonal occurrence. Finally, results are upscaled to a resolution of 20m x 20m and are presented as individual risk to life and object risk to life for each process. Within the quantitative

Quantitative risk analysis offshore-Human and organizational factors

International Nuclear Information System (INIS)

Espen Skogdalen, Jon; Vinnem, Jan Erik

2011-01-01

Quantitative Risk Analyses (QRAs) are one of the main tools for risk management within the Norwegian and UK oil and gas industry. Much criticism has been given to the limitations related to the QRA-models and that the QRAs do not include human and organizational factors (HOF-factors). Norway and UK offshore legislation and guidelines require that the HOF-factors are included in the QRAs. A study of 15 QRAs shows that the factors are to some extent included, and there are large differences between the QRAs. The QRAs are categorized into four levels according to the findings. Level 1 QRAs do not describe or comment on the HOF-factors at all. Relevant research projects have been conducted to fulfill the requirements of Level 3 analyses. At this level, there is a systematic collection of data related to HOF. The methods are systematic and documented, and the QRAs are adjusted. None of the QRAs fulfill the Level 4 requirements. Level 4 QRAs include the model and describe the HOF-factors as well as explain how the results should be followed up in the overall risk management. Safety audits by regulatory authorities are probably necessary to point out the direction for QRA and speed up the development.

Modeling logistic performance in quantitative microbial risk assessment.

Science.gov (United States)

Rijgersberg, Hajo; Tromp, Seth; Jacxsens, Liesbeth; Uyttendaele, Mieke

2010-01-01

In quantitative microbial risk assessment (QMRA), food safety in the food chain is modeled and simulated. In general, prevalences, concentrations, and numbers of microorganisms in media are investigated in the different steps from farm to fork. The underlying rates and conditions (such as storage times, temperatures, gas conditions, and their distributions) are determined. However, the logistic chain with its queues (storages, shelves) and mechanisms for ordering products is usually not taken into account. As a consequence, storage times-mutually dependent in successive steps in the chain-cannot be described adequately. This may have a great impact on the tails of risk distributions. Because food safety risks are generally very small, it is crucial to model the tails of (underlying) distributions as accurately as possible. Logistic performance can be modeled by describing the underlying planning and scheduling mechanisms in discrete-event modeling. This is common practice in operations research, specifically in supply chain management. In this article, we present the application of discrete-event modeling in the context of a QMRA for Listeria monocytogenes in fresh-cut iceberg lettuce. We show the potential value of discrete-event modeling in QMRA by calculating logistic interventions (modifications in the logistic chain) and determining their significance with respect to food safety.

A suite of models to support the quantitative assessment of spread in pest risk analysis

NARCIS (Netherlands)

Robinet, C.; Kehlenbeck, H.; Werf, van der W.

2012-01-01

In the frame of the EU project PRATIQUE (KBBE-2007-212459 Enhancements of pest risk analysis techniques) a suite of models was developed to support the quantitative assessment of spread in pest risk analysis. This dataset contains the model codes (R language) for the four models in the suite. Three

Linkage of DNA Methylation Quantitative Trait Loci to Human Cancer Risk

Directory of Open Access Journals (Sweden)

Holger Heyn

2014-04-01

Full Text Available Epigenetic regulation and, in particular, DNA methylation have been linked to the underlying genetic sequence. DNA methylation quantitative trait loci (meQTL have been identified through significant associations between the genetic and epigenetic codes in physiological and pathological contexts. We propose that interrogating the interplay between polymorphic alleles and DNA methylation is a powerful method for improving our interpretation of risk alleles identified in genome-wide association studies that otherwise lack mechanistic explanation. We integrated patient cancer risk genotype data and genome-scale DNA methylation profiles of 3,649 primary human tumors, representing 13 solid cancer types. We provide a comprehensive meQTL catalog containing DNA methylation associations for 21% of interrogated cancer risk polymorphisms. Differentially methylated loci harbor previously reported and as-yet-unidentified cancer genes. We suggest that such regulation at the DNA level can provide a considerable amount of new information about the biology of cancer-risk alleles.

Using Integrated Environmental Modeling to Automate a Process-Based Quantitative Microbial Risk Assessment (presentation)

Science.gov (United States)

Integrated Environmental Modeling (IEM) organizes multidisciplinary knowledge that explains and predicts environmental-system response to stressors. A Quantitative Microbial Risk Assessment (QMRA) is an approach integrating a range of disparate data (fate/transport, exposure, and...

Quantitative assessment of changes in landslide risk using a regional scale run-out model

Science.gov (United States)

Hussin, Haydar; Chen, Lixia; Ciurean, Roxana; van Westen, Cees; Reichenbach, Paola; Sterlacchini, Simone

2015-04-01

The risk of landslide hazard continuously changes in time and space and is rarely a static or constant phenomena in an affected area. However one of the main challenges of quantitatively assessing changes in landslide risk is the availability of multi-temporal data for the different components of risk. Furthermore, a truly "quantitative" landslide risk analysis requires the modeling of the landslide intensity (e.g. flow depth, velocities or impact pressures) affecting the elements at risk. Such a quantitative approach is often lacking in medium to regional scale studies in the scientific literature or is left out altogether. In this research we modelled the temporal and spatial changes of debris flow risk in a narrow alpine valley in the North Eastern Italian Alps. The debris flow inventory from 1996 to 2011 and multi-temporal digital elevation models (DEMs) were used to assess the susceptibility of debris flow triggering areas and to simulate debris flow run-out using the Flow-R regional scale model. In order to determine debris flow intensities, we used a linear relationship that was found between back calibrated physically based Flo-2D simulations (local scale models of five debris flows from 2003) and the probability values of the Flow-R software. This gave us the possibility to assign flow depth to a total of 10 separate classes on a regional scale. Debris flow vulnerability curves from the literature and one curve specifically for our case study area were used to determine the damage for different material and building types associated with the elements at risk. The building values were obtained from the Italian Revenue Agency (Agenzia delle Entrate) and were classified per cadastral zone according to the Real Estate Observatory data (Osservatorio del Mercato Immobiliare, Agenzia Entrate - OMI). The minimum and maximum market value for each building was obtained by multiplying the corresponding land-use value (€/msq) with building area and number of floors

Epidemiology and quantitation of environmental risk in humans from radiation and other agents

International Nuclear Information System (INIS)

Castellani, Amleto

1985-01-01

The identification and quantitation of environmental risk in humans is one of the main problems to be solved in order to improve the protection of individuals and of human populations against physical and chemical pollutants. Epidemiology plays a central role in the evaluation of health risk directly in human populations. In this volume are collected 33 lectures presented at the AS! course on ''Epidemiology and quantitation of environmental risk in humans from radiation and other agents: potential and limitations'', sponsored by NATO and Italian Association of Radiobiology and organized by ENEA. The course has been devoted to a number of aspects of environmental risk analysis and evaluation based on epidemiological investigation. Basic epidemiological concepts and methods have been reviewed. Fundamentals of dosimetry and microdosimetry were presented in relation to the contribution of epidemiology in defining the dose effect relationships for radiation carcinogenesis and its relation with age, sex and ethnicity. The mechanisms of carcinogenesis as a multi-stage process were illustrated. One of the main topics was 'cancer epidemiology' and its correlation with: - occupational and non-occupational exposure to radiation - diagnostic and therapeutic irradiation - cancer proneness - hereditary and familiar diseases - abnormal response to carcinogens - environmental pollution in air and water - exposure to radon in mines and in building material - atomic bomb explosion - chemotherapy - dioxin and related compounds

A combined usage of stochastic and quantitative risk assessment methods in the worksites: Application on an electric power provider

International Nuclear Information System (INIS)

Marhavilas, P.K.; Koulouriotis, D.E.

2012-01-01

An individual method cannot build either a realistic forecasting model or a risk assessment process in the worksites, and future perspectives should focus on the combined forecasting/estimation approach. The main purpose of this paper is to gain insight into a risk prediction and estimation methodological framework, using the combination of three different methods, including the proportional quantitative-risk-assessment technique (PRAT), the time-series stochastic process (TSP), and the method of estimating the societal-risk (SRE) by F–N curves. In order to prove the usefulness of the combined usage of stochastic and quantitative risk assessment methods, an application on an electric power provider industry is presented to, using empirical data.

Quantitative assessment of the microbial risk of leafy greens from farm to consumption: preliminary framework, data, and risk estimates.

Science.gov (United States)

Danyluk, Michelle D; Schaffner, Donald W

2011-05-01

This project was undertaken to relate what is known about the behavior of Escherichia coli O157:H7 under laboratory conditions and integrate this information to what is known regarding the 2006 E. coli O157:H7 spinach outbreak in the context of a quantitative microbial risk assessment. The risk model explicitly assumes that all contamination arises from exposure in the field. Extracted data, models, and user inputs were entered into an Excel spreadsheet, and the modeling software @RISK was used to perform Monte Carlo simulations. The model predicts that cut leafy greens that are temperature abused will support the growth of E. coli O157:H7, and populations of the organism may increase by as much a 1 log CFU/day under optimal temperature conditions. When the risk model used a starting level of -1 log CFU/g, with 0.1% of incoming servings contaminated, the predicted numbers of cells per serving were within the range of best available estimates of pathogen levels during the outbreak. The model predicts that levels in the field of -1 log CFU/g and 0.1% prevalence could have resulted in an outbreak approximately the size of the 2006 E. coli O157:H7 outbreak. This quantitative microbial risk assessment model represents a preliminary framework that identifies available data and provides initial risk estimates for pathogenic E. coli in leafy greens. Data gaps include retail storage times, correlations between storage time and temperature, determining the importance of E. coli O157:H7 in leafy greens lag time models, and validation of the importance of cross-contamination during the washing process.

Affordable, automatic quantitative fall risk assessment based on clinical balance scales and Kinect data.

Science.gov (United States)

Colagiorgio, P; Romano, F; Sardi, F; Moraschini, M; Sozzi, A; Bejor, M; Ricevuti, G; Buizza, A; Ramat, S

2014-01-01

The problem of a correct fall risk assessment is becoming more and more critical with the ageing of the population. In spite of the available approaches allowing a quantitative analysis of the human movement control system's performance, the clinical assessment and diagnostic approach to fall risk assessment still relies mostly on non-quantitative exams, such as clinical scales. This work documents our current effort to develop a novel method to assess balance control abilities through a system implementing an automatic evaluation of exercises drawn from balance assessment scales. Our aim is to overcome the classical limits characterizing these scales i.e. limited granularity and inter-/intra-examiner reliability, to obtain objective scores and more detailed information allowing to predict fall risk. We used Microsoft Kinect to record subjects' movements while performing challenging exercises drawn from clinical balance scales. We then computed a set of parameters quantifying the execution of the exercises and fed them to a supervised classifier to perform a classification based on the clinical score. We obtained a good accuracy (~82%) and especially a high sensitivity (~83%).

A simplified method for quantitative assessment of the relative health and safety risk of environmental management activities

International Nuclear Information System (INIS)

Eide, S.A.; Smith, T.H.; Peatross, R.G.; Stepan, I.E.

1996-09-01

This report presents a simplified method to assess the health and safety risk of Environmental Management activities of the US Department of Energy (DOE). The method applies to all types of Environmental Management activities including waste management, environmental restoration, and decontamination and decommissioning. The method is particularly useful for planning or tradeoff studies involving multiple conceptual options because it combines rapid evaluation with a quantitative approach. The method is also potentially applicable to risk assessments of activities other than DOE Environmental Management activities if rapid quantitative results are desired

A Quantitative Measure For Evaluating Project Uncertainty Under Variation And Risk Effects

Directory of Open Access Journals (Sweden)

A. Chenarani

2017-10-01

Full Text Available The effects of uncertainty on a project and the risk event as the consequence of uncertainty are analyzed. The uncertainty index is proposed as a quantitative measure for evaluating the uncertainty of a project. This is done by employing entropy as the indicator of system disorder and lack of information. By employing this index, the uncertainty of each activity and its increase due to risk effects as well as project uncertainty changes as a function of time can be assessed. The results are implemented and analyzed for a small turbojet engine development project as the case study. The results of this study can be useful for project managers and other stakeholders for selecting the most effective risk management and uncertainty controlling method.

Quantitative assessment of exposure and risk for three carcinogenics in long-standing pollution sites

International Nuclear Information System (INIS)

Wichmann, H.E.; Wuppertal Univ.; Ihme, W.; Mekel, O.C.L.; Wuppertal Univ.

1993-01-01

The project attempts a quantitative assessment of risks for three carcinogenics that are common in sites of long-standing pollution. Benzo(a)pyrene stands for the group of polycyclic aromatic hydrocarbons, cadmium for heavy metals, and benzene for volatile aromatic compounds. The report discusses the general fundamentals of exposure and risk assessment. The exposure model is described in detail and applied to the three test substances. (orig./MG) [de

An approach to quantitative assessment of relative proliferation risks from nuclear fuel cycles

International Nuclear Information System (INIS)

Silvennoinen, P.; Vira, J.

1981-01-01

Feasibility of quantitative assessments of the risk of nuclear weapons proliferation is discussed in this paper. The proliferation risk is defined as a combined utility of the different fuel cycle processes or materials for the proscribed acquisition of a nuclear weapon. Based on a set of selected weighted criteria, the process utilities are calculated employing utility functions or fuzzy expectation values. The methods are compared to each other. The scheme appears feasible in relative comparisons while certain leeway must still be retained for political judgement. (author)

Quantitative Deficits of Preschool Children at Risk for Mathematical Learning Disability

Directory of Open Access Journals (Sweden)

Felicia W. Chu

2013-05-01

Full Text Available The study tested the hypothesis that acuity of the potentially inherent approximate number system (ANS contributes to risk of mathematical learning disability (MLD. Sixty-eight (35 boys preschoolers at risk for school failure were assessed on a battery of quantitative tasks, and on intelligence, executive control, preliteracy skills, and parental education. Mathematics achievement scores at the end of one year of preschool indicated that 34 of these children were at high risk for MLD. Relative to the 34 typically achieving children, the at risk children were less accurate on the ANS task, and a one standard deviation deficit on this task resulted in a 2.4 fold increase in the odds of MLD status. The at risk children also had a poor understanding of ordinal relations, and had slower learning of Arabic numerals, number words, and their cardinal values. Poor performance on these tasks resulted in 3.6 to 4.5 fold increases in the odds of MLD status. The results provide some support for the ANS hypothesis but also suggest these deficits are not the primary source of poor mathematics learning.

Challenges in Risk Assessment: Quantitative Risk Assessment

OpenAIRE

Jacxsens, Liesbeth; Uyttendaele, Mieke; De Meulenaer, Bruno

2016-01-01

The process of risk analysis consists out of three components, risk assessment, risk management and risk communication. These components are internationally well spread by Codex Alimentarius Commission as being the basis for setting science based standards, criteria on food safety hazards, e.g. setting maximum limits of mycotoxins in foodstuffs. However, the technical component risk assessment is hard to elaborate and to understand. Key in a risk assessment is the translation of biological or...

Quantitative risk assessment of foods containing peanut advisory labeling.

Science.gov (United States)

Remington, Benjamin C; Baumert, Joseph L; Marx, David B; Taylor, Steve L

2013-12-01

Foods with advisory labeling (i.e. "may contain") continue to be prevalent and the warning may be increasingly ignored by allergic consumers. We sought to determine the residual levels of peanut in various packaged foods bearing advisory labeling, compare similar data from 2005 and 2009, and determine any potential risk for peanut-allergic consumers. Of food products bearing advisory statements regarding peanut or products that had peanut listed as a minor ingredient, 8.6% and 37.5% contained detectable levels of peanut (>2.5 ppm whole peanut), respectively. Peanut-allergic individuals should be advised to avoid such products regardless of the wording of the advisory statement. Peanut was detected at similar rates and levels in products tested in both 2005 and 2009. Advisory labeled nutrition bars contained the highest levels of peanut and an additional market survey of 399 products was conducted. Probabilistic risk assessment showed the risk of a reaction to peanut-allergic consumers from advisory labeled nutrition bars was significant but brand-dependent. Peanut advisory labeling may be overused on some nutrition bars but prudently used on others. The probabilistic approach could provide the food industry with a quantitative method to assist with determining when advisory labeling is most appropriate. Copyright © 2013 Elsevier Ltd. All rights reserved.

Local scale multiple quantitative risk assessment and uncertainty evaluation in a densely urbanised area (Brescia, Italy

Directory of Open Access Journals (Sweden)

S. Lari

2012-11-01

Full Text Available The study of the interactions between natural and anthropogenic risks is necessary for quantitative risk assessment in areas affected by active natural processes, high population density and strong economic activities.

We present a multiple quantitative risk assessment on a 420 km² high risk area (Brescia and surroundings, Lombardy, Northern Italy, for flood, seismic and industrial accident scenarios. Expected economic annual losses are quantified for each scenario and annual exceedance probability-loss curves are calculated. Uncertainty on the input variables is propagated by means of three different methodologies: Monte-Carlo-Simulation, First Order Second Moment, and point estimate.

Expected losses calculated by means of the three approaches show similar values for the whole study area, about 64 000 000 € for earthquakes, about 10 000 000 € for floods, and about 3000 € for industrial accidents. Locally, expected losses assume quite different values if calculated with the three different approaches, with differences up to 19%.

The uncertainties on the expected losses and their propagation, performed with the three methods, are compared and discussed in the paper. In some cases, uncertainty reaches significant values (up to almost 50% of the expected loss. This underlines the necessity of including uncertainty in quantitative risk assessment, especially when it is used as a support for territorial planning and decision making. The method is developed thinking at a possible application at a regional-national scale, on the basis of data available in Italy over the national territory.

A Quantitative Microbiological Risk Assessment for Salmonella in Pigs for the European Union

DEFF Research Database (Denmark)

Snary, Emma L.; Swart, Arno N.; Simons, Robin R. L.

2016-01-01

,000 and 1 in 10 million servings given consumption of one of the three product types considered (pork cuts, minced meat, and fermented ready‐to‐eat sausages). Further analyses of the farm‐to‐consumption QMRA suggest that the vast majority of human risk derives from infected pigs with a high concentration......A farm‐to‐consumption quantitative microbiological risk assessment (QMRA) for Salmonella in pigs in the European Union has been developed for the European Food Safety Authority. The primary aim of the QMRA was to assess the impact of hypothetical reductions of slaughter‐pig prevalence...

Quantitative rock-fall hazard and risk assessment for Yosemite Valley, California

Science.gov (United States)

Stock, G. M.; Luco, N.; Collins, B. D.; Harp, E.; Reichenbach, P.; Frankel, K. L.

2011-12-01

Rock falls are a considerable hazard in Yosemite Valley, California with more than 835 rock falls and other slope movements documented since 1857. Thus, rock falls pose potentially significant risk to the nearly four million annual visitors to Yosemite National Park. Building on earlier hazard assessment work by the U.S. Geological Survey, we performed a quantitative rock-fall hazard and risk assessment for Yosemite Valley. This work was aided by several new data sets, including precise Geographic Information System (GIS) maps of rock-fall deposits, airborne and terrestrial LiDAR-based point cloud data and digital elevation models, and numerical ages of talus deposits. Using Global Position Systems (GPS), we mapped the positions of over 500 boulders on the valley floor and measured their distance relative to the mapped base of talus. Statistical analyses of these data yielded an initial hazard zone that is based on the 90th percentile distance of rock-fall boulders beyond the talus edge. This distance was subsequently scaled (either inward or outward from the 90th percentile line) based on rock-fall frequency information derived from a combination of cosmogenic beryllium-10 exposure dating of boulders beyond the edge of the talus, and computer model simulations of rock-fall runout. The scaled distances provide the basis for a new hazard zone on the floor of Yosemite Valley. Once this zone was delineated, we assembled visitor, employee, and resident use data for each structure within the hazard zone to quantitatively assess risk exposure. Our results identify areas within the new hazard zone that may warrant more detailed study, for example rock-fall susceptibility, which can be assessed through examination of high-resolution photographs, structural measurements on the cliffs, and empirical calculations derived from LiDAR point cloud data. This hazard and risk information is used to inform placement of existing and potential future infrastructure in Yosemite Valley.

Quantitative autistic trait measurements index background genetic risk for ASD in Hispanic families.

Science.gov (United States)

Page, Joshua; Constantino, John Nicholas; Zambrana, Katherine; Martin, Eden; Tunc, Ilker; Zhang, Yi; Abbacchi, Anna; Messinger, Daniel

2016-01-01

Recent studies have indicated that quantitative autistic traits (QATs) of parents reflect inherited liabilities that may index background genetic risk for clinical autism spectrum disorder (ASD) in their offspring. Moreover, preferential mating for QATs has been observed as a potential factor in concentrating autistic liabilities in some families across generations. Heretofore, intergenerational studies of QATs have focused almost exclusively on Caucasian populations-the present study explored these phenomena in a well-characterized Hispanic population. The present study examined QAT scores in siblings and parents of 83 Hispanic probands meeting research diagnostic criteria for ASD, and 64 non-ASD controls, using the Social Responsiveness Scale-2 (SRS-2). Ancestry of the probands was characterized by genotype, using information from 541,929 single nucleotide polymorphic markers. In families of Hispanic children with an ASD diagnosis, the pattern of quantitative trait correlations observed between ASD-affected children and their first-degree relatives (ICCs on the order of 0.20), between unaffected first-degree relatives in ASD-affected families (sibling/mother ICC = 0.36; sibling/father ICC = 0.53), and between spouses (mother/father ICC = 0.48) were in keeping with the influence of transmitted background genetic risk and strong preferential mating for variation in quantitative autistic trait burden. Results from analysis of ancestry-informative genetic markers among probands in this sample were consistent with that from other Hispanic populations. Quantitative autistic traits represent measurable indices of inherited liability to ASD in Hispanic families. The accumulation of autistic traits occurs within generations, between spouses, and across generations, among Hispanic families affected by ASD. The occurrence of preferential mating for QATs-the magnitude of which may vary across cultures-constitutes a mechanism by which background genetic liability

Sugar concentration in nectar: a quantitative metric of crop attractiveness for refined pollinator risk assessments.

Science.gov (United States)

Knopper, Loren D; Dan, Tereza; Reisig, Dominic D; Johnson, Josephine D; Bowers, Lisa M

2016-10-01

Those involved with pollinator risk assessment know that agricultural crops vary in attractiveness to bees. Intuitively, this means that exposure to agricultural pesticides is likely greatest for attractive plants and lowest for unattractive plants. While crop attractiveness in the risk assessment process has been qualitatively remarked on by some authorities, absent is direction on how to refine the process with quantitative metrics of attractiveness. At a high level, attractiveness of crops to bees appears to depend on several key variables, including but not limited to: floral, olfactory, visual and tactile cues; seasonal availability; physical and behavioral characteristics of the bee; plant and nectar rewards. Notwithstanding the complexities and interactions among these variables, sugar content in nectar stands out as a suitable quantitative metric by which to refine pollinator risk assessments for attractiveness. Provided herein is a proposed way to use sugar nectar concentration to adjust the exposure parameter (with what is called a crop attractiveness factor) in the calculation of risk quotients in order to derive crop-specific tier I assessments. This Perspective is meant to invite discussion on incorporating such changes in the risk assessment process. © 2016 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2016 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Quantitative Risk Assessment of Human Trichinellosis Caused by Consumption of Pork Meat Sausages in Argentina.

Science.gov (United States)

Sequeira, G J; Zbrun, M V; Soto, L P; Astesana, D M; Blajman, J E; Rosmini, M R; Frizzo, L S; Signorini, M L

2016-03-01

In Argentina, there are three known species of genus Trichinella; however, Trichinella spiralis is most commonly associated with domestic pigs and it is recognized as the main cause of human trichinellosis by the consumption of products made with raw or insufficiently cooked pork meat. In some areas of Argentina, this disease is endemic and it is thus necessary to develop a more effective programme of prevention and control. Here, we developed a quantitative risk assessment of human trichinellosis following pork meat sausage consumption, which may be used to identify the stages with greater impact on the probability of acquiring the disease. The quantitative model was designed to describe the conditions in which the meat is produced, processed, transported, stored, sold and consumed in Argentina. The model predicted a risk of human trichinellosis of 4.88 × 10(-6) and an estimated annual number of trichinellosis cases of 109. The risk of human trichinellosis was sensitive to the number of Trichinella larvae that effectively survived the storage period (r = 0.89), the average probability of infection (PPinf ) (r = 0.44) and the storage time (Storage) (r = 0.08). This model allowed assessing the impact of different factors influencing the risk of acquiring trichinellosis. The model may thus help to select possible strategies to reduce the risk in the chain of by-products of pork production. © 2015 Blackwell Verlag GmbH.

76 FR 77543 - Quantitative Summary of the Benefits and Risks of Prescription Drugs: A Literature Review

Science.gov (United States)

2011-12-13

... psychology'' (section 3507(b), Pub. L. 111-148, 124 Stat. 530), and to consult manufacturers and consumers... communication of quantitative benefit and risk information. FDA is making available the literature review report...

A methodology for the quantitative risk assessment of major accidents triggered by seismic events

International Nuclear Information System (INIS)

Antonioni, Giacomo; Spadoni, Gigliola; Cozzani, Valerio

2007-01-01

A procedure for the quantitative risk assessment of accidents triggered by seismic events in industrial facilities was developed. The starting point of the procedure was the use of available historical data to assess the expected frequencies and the severity of seismic events. Available equipment-dependant failure probability models (vulnerability or fragility curves) were used to assess the damage probability of equipment items due to a seismic event. An analytic procedure was subsequently developed to identify, evaluate the credibility and finally assess the expected consequences of all the possible scenarios that may follow the seismic events. The procedure was implemented in a GIS-based software tool in order to manage the high number of event sequences that are likely to be generated in large industrial facilities. The developed methodology requires a limited amount of additional data with respect to those used in a conventional QRA, and yields with a limited effort a preliminary quantitative assessment of the contribution of the scenarios triggered by earthquakes to the individual and societal risk indexes. The application of the methodology to several case-studies evidenced that the scenarios initiated by seismic events may have a relevant influence on industrial risk, both raising the overall expected frequency of single scenarios and causing specific severe scenarios simultaneously involving several plant units

Mammographic features and subsequent risk of breast cancer: a comparison of qualitative and quantitative evaluations in the Guernsey prospective studies.

Science.gov (United States)

Torres-Mejía, Gabriela; De Stavola, Bianca; Allen, Diane S; Pérez-Gavilán, Juan J; Ferreira, Jorge M; Fentiman, Ian S; Dos Santos Silva, Isabel

2005-05-01

Mammographic features are known to be associated with breast cancer but the magnitude of the effect differs markedly from study to study. Methods to assess mammographic features range from subjective qualitative classifications to computer-automated quantitative measures. We used data from the UK Guernsey prospective studies to examine the relative value of these methods in predicting breast cancer risk. In all, 3,211 women ages > or =35 years who had a mammogram taken in 1986 to 1989 were followed-up to the end of October 2003, with 111 developing breast cancer during this period. Mammograms were classified using the subjective qualitative Wolfe classification and several quantitative mammographic features measured using computer-based techniques. Breast cancer risk was positively associated with high-grade Wolfe classification, percent breast density and area of dense tissue, and negatively associated with area of lucent tissue, fractal dimension, and lacunarity. Inclusion of the quantitative measures in the same model identified area of dense tissue and lacunarity as the best predictors of breast cancer, with risk increasing by 59% [95% confidence interval (95% CI), 29-94%] per SD increase in total area of dense tissue but declining by 39% (95% CI, 53-22%) per SD increase in lacunarity, after adjusting for each other and for other confounders. Comparison of models that included both the qualitative Wolfe classification and these two quantitative measures to models that included either the qualitative or the two quantitative variables showed that they all made significant contributions to prediction of breast cancer risk. These findings indicate that breast cancer risk is affected not only by the amount of mammographic density but also by the degree of heterogeneity of the parenchymal pattern and, presumably, by other features captured by the Wolfe classification.

Navigational Traffic Conflict Technique: A Proactive Approach to Quantitative Measurement of Collision Risks in Port Waters

Science.gov (United States)

Debnath, Ashim Kumar; Chin, Hoong Chor

Navigational safety analysis relying on collision statistics is often hampered because of the low number of observations. A promising alternative approach that overcomes this problem is proposed in this paper. By analyzing critical vessel interactions this approach proactively measures collision risk in port waters. The proposed method is illustrated for quantitative measurement of collision risks in Singapore port fairways, and validated by examining correlations between the measured risks with those perceived by pilots. This method is an ethically appealing alternative to the collision-based analysis for fast, reliable and effective safety assessment, thus possessing great potential for managing collision risks in port waters.

Applied quantitative finance

CERN Document Server

Chen, Cathy; Overbeck, Ludger

2017-01-01

This volume provides practical solutions and introduces recent theoretical developments in risk management, pricing of credit derivatives, quantification of volatility and copula modeling. This third edition is devoted to modern risk analysis based on quantitative methods and textual analytics to meet the current challenges in banking and finance. It includes 14 new contributions and presents a comprehensive, state-of-the-art treatment of cutting-edge methods and topics, such as collateralized debt obligations, the high-frequency analysis of market liquidity, and realized volatility. The book is divided into three parts: Part 1 revisits important market risk issues, while Part 2 introduces novel concepts in credit risk and its management along with updated quantitative methods. The third part discusses the dynamics of risk management and includes risk analysis of energy markets and for cryptocurrencies. Digital assets, such as blockchain-based currencies, have become popular b ut are theoretically challenging...

Process Review for Development of Quantitative Risk Analyses for Transboundary Animal Disease to Pathogen-Free Territories

Directory of Open Access Journals (Sweden)

Jonathan Miller

2017-10-01

Full Text Available Outbreaks of transboundary animal diseases (TADs have the potential to cause significant detriment to animal, human, and environmental health; severe economic implications; and national security. Challenges concerning data sharing, model development, decision support, and disease emergence science have recently been promoted. These challenges and recommendations have been recognized and advocated in the disciplines intersecting with outbreak prediction and forecast modeling regarding infectious diseases. To advance the effective application of computation and risk communication, analytical products ought to follow a collaboratively agreed common plan for implementation. Research articles should seek to inform and assist prioritization of national and international strategies in developing established criteria to identify and follow best practice standards to assess risk model attributes and performance. A well-defined framework to help eliminate gaps in policy, process, and planning knowledge areas would help alleviate the intense need for the formation of a comprehensive strategy for countering TAD outbreak risks. A quantitative assessment that accurately captures the risk of introduction of a TAD through various pathways can be a powerful tool in guiding where government, academic, and industry resources ought to be allocated, whether implementation of additional risk management solutions is merited, and where research efforts should be directed to minimize risk. This review outlines a part of a process for the development of quantitative risk analysis to collect, analyze, and communicate this knowledge. A more comprehensive and unabridged manual was also developed. The framework used in supporting the application of aligning computational tools for readiness continues our approach to apply a preparedness mindset to challenges concerning threats to global biosecurity, secure food systems, and risk-mitigated agricultural economies.

Revisiting support optimization at the Driskos tunnel using a quantitative risk approach

Directory of Open Access Journals (Sweden)

J. Connor Langford

2016-04-01

Full Text Available With the scale and cost of geotechnical engineering projects increasing rapidly over the past few decades, there is a clear need for the careful consideration of calculated risks in design. While risk is typically dealt with subjectively through the use of conservative design parameters, with the advent of reliability-based methods, this no longer needs to be the case. Instead, a quantitative risk approach can be considered that incorporates uncertainty in ground conditions directly into the design process to determine the variable ground response and support loads. This allows for the optimization of support on the basis of both worker safety and economic risk. This paper presents the application of such an approach to review the design of the initial lining system along a section of the Driskos twin tunnels as part of the Egnatia Odos highway in northern Greece. Along this section of tunnel, weak rock masses were encountered as well as high in situ stress conditions, which led to excessive deformations and failure of the as built temporary support. Monitoring data were used to validate the rock mass parameters selected in this area and a risk approach was used to determine, in hindsight, the most appropriate support category with respect to the cost of installation and expected cost of failure. Different construction sequences were also considered in the context of both convenience and risk cost.

Study on quantitative risk assessment model of the third party damage for natural gas pipelines based on fuzzy comprehensive assessment

International Nuclear Information System (INIS)

Qiu, Zeyang; Liang, Wei; Lin, Yang; Zhang, Meng; Wang, Xue

2017-01-01

As an important part of national energy supply system, transmission pipelines for natural gas are possible to cause serious environmental pollution, life and property loss in case of accident. The third party damage is one of the most significant causes for natural gas pipeline system accidents, and it is very important to establish an effective quantitative risk assessment model of the third party damage for reducing the number of gas pipelines operation accidents. Against the third party damage accident has the characteristics such as diversity, complexity and uncertainty, this paper establishes a quantitative risk assessment model of the third party damage based on Analytic Hierarchy Process (AHP) and Fuzzy Comprehensive Evaluation (FCE). Firstly, risk sources of third party damage should be identified exactly, and the weight of factors could be determined via improved AHP, finally the importance of each factor is calculated by fuzzy comprehensive evaluation model. The results show that the quantitative risk assessment model is suitable for the third party damage of natural gas pipelines and improvement measures could be put forward to avoid accidents based on the importance of each factor. (paper)

Enhancing local action planning through quantitative flood risk analysis: a case study in Spain

Science.gov (United States)

Castillo-Rodríguez, Jesica Tamara; Escuder-Bueno, Ignacio; Perales-Momparler, Sara; Ramón Porta-Sancho, Juan

2016-07-01

This article presents a method to incorporate and promote quantitative risk analysis to support local action planning against flooding. The proposed approach aims to provide a framework for local flood risk analysis, combining hazard mapping with vulnerability data to quantify risk in terms of expected annual affected population, potential injuries, number of fatalities, and economic damages. Flood risk is estimated combining GIS data of loads, system response, and consequences and using event tree modelling for risk calculation. The study area is the city of Oliva, located on the eastern coast of Spain. Results from risk modelling have been used to inform local action planning and to assess the benefits of structural and non-structural risk reduction measures. Results show the potential impact on risk reduction of flood defences and improved warning communication schemes through local action planning: societal flood risk (in terms of annual expected affected population) would be reduced up to 51 % by combining both structural and non-structural measures. In addition, the effect of seasonal population variability is analysed (annual expected affected population ranges from 82 to 107 %, compared with the current situation, depending on occupancy rates in hotels and campsites). Results highlight the need for robust and standardized methods for urban flood risk analysis replicability at regional and national scale.

Using MFM methodology to generate and define major accident scenarios for quantitative risk assessment studies

DEFF Research Database (Denmark)

Hua, Xinsheng; Wu, Zongzhi; Lind, Morten

2017-01-01

to calculate likelihood of each MAS. Combining the likelihood of each scenario with a qualitative risk matrix, each major accident scenario is thereby ranked for consideration for detailed consequence analysis. The methodology is successfully highlighted using part of BMA-process for production of hydrogen......Generating and defining Major Accident Scenarios (MAS) are commonly agreed as the key step for quantitative risk assessment (QRA). The aim of the study is to explore the feasibility of using Multilevel Flow Modeling (MFM) methodology to formulating MAS. Traditionally this is usually done based...

Fatalities in high altitude mountaineering: a review of quantitative risk estimates.

Science.gov (United States)

Weinbruch, Stephan; Nordby, Karl-Christian

2013-12-01

Quantitative estimates for mortality in high altitude mountaineering are reviewed. Special emphasis is placed on the heterogeneity of the risk estimates and on confounding. Crude estimates for mortality are on the order of 1/1000 to 40/1000 persons above base camp, for both expedition members and high altitude porters. High altitude porters have mostly a lower risk than expedition members (risk ratio for all Nepalese peaks requiring an expedition permit: 0.73; 95 % confidence interval 0.59-0.89). The summit bid is generally the most dangerous part of an expedition for members, whereas most high altitude porters die during route preparation. On 8000 m peaks, the mortality during descent from summit varies between 4/1000 and 134/1000 summiteers (members plus porters). The risk estimates are confounded by human and environmental factors. Information on confounding by gender and age is contradictory and requires further work. There are indications for safety segregation of men and women, with women being more risk averse than men. Citizenship appears to be a significant confounder. Prior high altitude mountaineering experience in Nepal has no protective effect. Commercial expeditions in the Nepalese Himalayas have a lower mortality than traditional expeditions, though after controlling for confounding, the difference is not statistically significant. The overall mortality is increasing with increasing peak altitude for expedition members but not for high altitude porters. In the Nepalese Himalayas and in Alaska, a significant decrease of mortality with calendar year was observed. A few suggestions for further work are made at the end of the article.

Databases applicable to quantitative hazard/risk assessment-Towards a predictive systems toxicology

International Nuclear Information System (INIS)

Waters, Michael; Jackson, Marcus

2008-01-01

The Workshop on The Power of Aggregated Toxicity Data addressed the requirement for distributed databases to support quantitative hazard and risk assessment. The authors have conceived and constructed with federal support several databases that have been used in hazard identification and risk assessment. The first of these databases, the EPA Gene-Tox Database was developed for the EPA Office of Toxic Substances by the Oak Ridge National Laboratory, and is currently hosted by the National Library of Medicine. This public resource is based on the collaborative evaluation, by government, academia, and industry, of short-term tests for the detection of mutagens and presumptive carcinogens. The two-phased evaluation process resulted in more than 50 peer-reviewed publications on test system performance and a qualitative database on thousands of chemicals. Subsequently, the graphic and quantitative EPA/IARC Genetic Activity Profile (GAP) Database was developed in collaboration with the International Agency for Research on Cancer (IARC). A chemical database driven by consideration of the lowest effective dose, GAP has served IARC for many years in support of hazard classification of potential human carcinogens. The Toxicological Activity Profile (TAP) prototype database was patterned after GAP and utilized acute, subchronic, and chronic data from the Office of Air Quality Planning and Standards. TAP demonstrated the flexibility of the GAP format for air toxics, water pollutants and other environmental agents. The GAP format was also applied to developmental toxicants and was modified to represent quantitative results from the rodent carcinogen bioassay. More recently, the authors have constructed: 1) the NIEHS Genetic Alterations in Cancer (GAC) Database which quantifies specific mutations found in cancers induced by environmental agents, and 2) the NIEHS Chemical Effects in Biological Systems (CEBS) Knowledgebase that integrates genomic and other biological data including

Quantitative Microbial Risk Assessment Tutorial Installation of Software for Watershed Modeling in Support of QMRA - Updated 2017

Science.gov (United States)

This tutorial provides instructions for accessing, retrieving, and downloading the following software to install on a host computer in support of Quantitative Microbial Risk Assessment (QMRA) modeling: • QMRA Installation • SDMProjectBuilder (which includes the Microbial ...

Quantitative risk trends deriving from PSA-based event analyses. Analysis of results from U.S.NRC's accident sequence precursor program

International Nuclear Information System (INIS)

Watanabe, Norio

2004-01-01

The United States Nuclear Regulatory Commission (U.S.NRC) has been carrying out the Accident Sequence Precursor (ASP) Program to identify and categorize precursors to potential severe core damage accident sequences using the probabilistic safety assessment (PSA) technique. The ASP Program has identified a lot of risk significant events as precursors that occurred at U.S. nuclear power plants. Although the results from the ASP Program include valuable information that could be useful for obtaining and characterizing risk significant insights and for monitoring risk trends in nuclear power industry, there are only a few attempts to determine and develop the trends using the ASP results. The present study examines and discusses quantitative risk trends for the industry level, using two indicators, that is, the occurrence frequency of precursors and the annual core damage probability, deriving from the results of the ASP analysis. It is shown that the core damage risk at U.S. nuclear power plants has been lowered and the likelihood of risk significant events has been remarkably decreasing. As well, the present study demonstrates that two risk indicators used here can provide quantitative information useful for examining and monitoring the risk trends and/or risk characteristics in nuclear power industry. (author)

A probabilistic quantitative risk assessment model for the long-term work zone crashes.

Science.gov (United States)

Meng, Qiang; Weng, Jinxian; Qu, Xiaobo

2010-11-01

Work zones especially long-term work zones increase traffic conflicts and cause safety problems. Proper casualty risk assessment for a work zone is of importance for both traffic safety engineers and travelers. This paper develops a novel probabilistic quantitative risk assessment (QRA) model to evaluate the casualty risk combining frequency and consequence of all accident scenarios triggered by long-term work zone crashes. The casualty risk is measured by the individual risk and societal risk. The individual risk can be interpreted as the frequency of a driver/passenger being killed or injured, and the societal risk describes the relation between frequency and the number of casualties. The proposed probabilistic QRA model consists of the estimation of work zone crash frequency, an event tree and consequence estimation models. There are seven intermediate events--age (A), crash unit (CU), vehicle type (VT), alcohol (AL), light condition (LC), crash type (CT) and severity (S)--in the event tree. Since the estimated value of probability for some intermediate event may have large uncertainty, the uncertainty can thus be characterized by a random variable. The consequence estimation model takes into account the combination effects of speed and emergency medical service response time (ERT) on the consequence of work zone crash. Finally, a numerical example based on the Southeast Michigan work zone crash data is carried out. The numerical results show that there will be a 62% decrease of individual fatality risk and 44% reduction of individual injury risk if the mean travel speed is slowed down by 20%. In addition, there will be a 5% reduction of individual fatality risk and 0.05% reduction of individual injury risk if ERT is reduced by 20%. In other words, slowing down speed is more effective than reducing ERT in the casualty risk mitigation. 2010 Elsevier Ltd. All rights reserved.

Integrating a quantitative risk appraisal in a health impact assessment

DEFF Research Database (Denmark)

Adám, Balázs; Molnár, Agnes; Gulis, Gabriel

2013-01-01

BACKGROUND: Although the quantification of health outcomes in a health impact assessment (HIA) is scarce in practice, it is preferred by policymakers, as it assists various aspects of the decision-making process. This article provides an example of integrating a quantitative risk appraisal...... in an HIA performed for the recently adopted Hungarian anti-smoking policy which introduced a smoking ban in closed public places, workplaces and public transport vehicles, and is one of the most effective measures to decrease smoking-related ill health. METHODS: A comprehensive, prospective HIA...... to decrease the prevalence of active and passive smoking and result in a considerably positive effect on several diseases, among which lung cancer, chronic pulmonary diseases, coronary heart diseases and stroke have the greatest importance. The health gain calculated for the quantifiable health outcomes...

Skin sensitisation quantitative risk assessment (QRA) based on aggregate dermal exposure to methylisothiazolinone in personal care and household cleaning products.

NARCIS (Netherlands)

Ezendam, J; Bokkers, B G H; Bil, W; Delmaar, J E

2017-01-01

Contact allergy to preservatives is an important public health problem. Ideally, new substances should be evaluated for the risk on skin sensitization before market entry, for example by using a quantitative risk assessment (QRA) as developed for fragrances. As a proof-of-concept, this QRA was

Quantitative meta-analytic approaches for the analysis of animal toxicology and epidemiologic data in human health risk assessments

Science.gov (United States)

Often, human health risk assessments have relied on qualitative approaches for hazard identification to integrate evidence across multiple studies to conclude whether particular hazards exist. However, quantitative approaches for evidence integration, including the application o...

New Approaches to Transport Project Assessment: Reference Scenario Forecasting and Quantitative Risk Analysis

DEFF Research Database (Denmark)

Salling, Kim Bang

2010-01-01

however has proved that the point estimates derived from such analyses are embedded with a large degree of uncertainty. Thus, a new scheme was proposed in terms of applying quantitative risk analysis (QRA) and Monte Carlo simulation in order to represent the uncertainties within the cost-benefit analysis....... Additionally, the handling of uncertainties is supplemented by making use of the principle of Optimism Bias, which depicts the historical tendency of overestimating transport related benefits (user demands i.e. travel time savings) and underestimating investment costs....

Combination of qualitative and quantitative sources of knowledge for risk assessment in the framework of possibility theory

NARCIS (Netherlands)

Oussalah, M.; Newby, M.J.

2004-01-01

This paper focuses on a representation of system reliability in the framework of possibility theory. Particularly, given a (probabilistic) quantitative knowledge pertaining to the time to failure of a system (risk function) and some qualitative knowledge about the degree of pessimism and optimism of

78 FR 9701 - Draft Joint Food and Drug Administration/Health Canada Quantitative Assessment of the Risk of...

Science.gov (United States)

2013-02-11

... on the sources of L. monocytogenes contamination, the effects of individual manufacturing and/or... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2012-N-1182] Draft Joint Food and Drug Administration/Health Canada Quantitative Assessment of the Risk of...

Human-Associated Fecal Quantitative Polymerase Chain ReactionMeasurements and Simulated Risk of Gastrointestinal Illness in Recreational Waters Contaminated with Raw Sewage

Science.gov (United States)

We used quantitative microbial risk assessment (QMRA) to estimate the risk of gastrointestinal (GI) illness associated with swimming in recreational waters containing different concentrations of human-associated fecal qPCR markers from raw sewage– HF183 and HumM2. The volume/volu...

Are risks quantitatively determinable

International Nuclear Information System (INIS)

Buetzer, P.

1985-01-01

''Chemical risks'' can only be determined with accurate figures in a few extraordinary cases. The difficulties lie, as has been shown by the example of the Flixborough catastrophe, mostly in the determination of the probabilities of occurrence. With a rough semiquantitative estimate of the potential hazards and the corresponding probabilities we can predict the risks with astonishing accuracy. Statistical data from incidents in the chemical industry are very useful, and they also show that ''chemical catastrophes'' are only to a very small extent initiated by uncontrolled chemical reactions. (orig.) [de

Quantitative microbiological risk assessment as a tool to obtain useful information for risk managers - specific application to Listeria monocytogenes and ready-to-eat meat products

NARCIS (Netherlands)

Mataragas, M.; Zwietering, M.H.; Skandamis, P.N.; Drosinos, E.H.

2010-01-01

The presence of Listeria monocytogenes in a sliced cooked, cured ham-like meat product was quantitatively assessed. Sliced cooked, cured meat products are considered as high risk products. These ready-to-eat, RTE, products (no special preparation, e.g. thermal treatment, before eating is required),

Using a quantitative risk register to promote learning from a patient safety reporting system.

Science.gov (United States)

Mansfield, James G; Caplan, Robert A; Campos, John S; Dreis, David F; Furman, Cathie

2015-02-01

Patient safety reporting systems are now used in most health care delivery organizations. These systems, such as the one in use at Virginia Mason (Seattle) since 2002, can provide valuable reports of risk and harm from the front lines of patient care. In response to the challenge of how to quantify and prioritize safety opportunities, a risk register system was developed and implemented. Basic risk register concepts were refined to provide a systematic way to understand risks reported by staff. The risk register uses a comprehensive taxonomy of patient risk and algorithmically assigns each patient safety report to 1 of 27 risk categories in three major domains (Evaluation, Treatment, and Critical Interactions). For each category, a composite score was calculated on the basis of event rate, harm, and cost. The composite scores were used to identify the "top five" risk categories, and patient safety reports in these categories were analyzed in greater depth to find recurrent patterns of risk and associated opportunities for improvement. The top five categories of risk were easy to identify and had distinctive "profiles" of rate, harm, and cost. The ability to categorize and rank risks across multiple dimensions yielded insights not previously available. These results were shared with leadership and served as input for planning quality and safety initiatives. This approach provided actionable input for the strategic planning process, while at the same time strengthening the Virginia Mason culture of safety. The quantitative patient safety risk register serves as one solution to the challenge of extracting valuable safety lessons from large numbers of incident reports and could profitably be adopted by other organizations.

The Functional Resonance Analysis Method for a systemic risk based environmental auditing in a sinter plant: A semi-quantitative approach

International Nuclear Information System (INIS)

Patriarca, Riccardo; Di Gravio, Giulio; Costantino, Francesco; Tronci, Massimo

2017-01-01

Environmental auditing is a main issue for any production plant and assessing environmental performance is crucial to identify risks factors. The complexity of current plants arises from interactions among technological, human and organizational system components, which are often transient and not easily detectable. The auditing thus requires a systemic perspective, rather than focusing on individual behaviors, as emerged in recent research in the safety domain for socio-technical systems. We explore the significance of modeling the interactions of system components in everyday work, by the application of a recent systemic method, i.e. the Functional Resonance Analysis Method (FRAM), in order to define dynamically the system structure. We present also an innovative evolution of traditional FRAM following a semi-quantitative approach based on Monte Carlo simulation. This paper represents the first contribution related to the application of FRAM in the environmental context, moreover considering a consistent evolution based on Monte Carlo simulation. The case study of an environmental risk auditing in a sinter plant validates the research, showing the benefits in terms of identifying potential critical activities, related mitigating actions and comprehensive environmental monitoring indicators. - Highlights: • We discuss the relevance of a systemic risk based environmental audit. • We present FRAM to represent functional interactions of the system. • We develop a semi-quantitative FRAM framework to assess environmental risks. • We apply the semi-quantitative FRAM framework to build a model for a sinter plant.

The Functional Resonance Analysis Method for a systemic risk based environmental auditing in a sinter plant: A semi-quantitative approach

Energy Technology Data Exchange (ETDEWEB)

Patriarca, Riccardo, E-mail: riccardo.patriarca@uniroma1.it; Di Gravio, Giulio; Costantino, Francesco; Tronci, Massimo

2017-03-15

Environmental auditing is a main issue for any production plant and assessing environmental performance is crucial to identify risks factors. The complexity of current plants arises from interactions among technological, human and organizational system components, which are often transient and not easily detectable. The auditing thus requires a systemic perspective, rather than focusing on individual behaviors, as emerged in recent research in the safety domain for socio-technical systems. We explore the significance of modeling the interactions of system components in everyday work, by the application of a recent systemic method, i.e. the Functional Resonance Analysis Method (FRAM), in order to define dynamically the system structure. We present also an innovative evolution of traditional FRAM following a semi-quantitative approach based on Monte Carlo simulation. This paper represents the first contribution related to the application of FRAM in the environmental context, moreover considering a consistent evolution based on Monte Carlo simulation. The case study of an environmental risk auditing in a sinter plant validates the research, showing the benefits in terms of identifying potential critical activities, related mitigating actions and comprehensive environmental monitoring indicators. - Highlights: • We discuss the relevance of a systemic risk based environmental audit. • We present FRAM to represent functional interactions of the system. • We develop a semi-quantitative FRAM framework to assess environmental risks. • We apply the semi-quantitative FRAM framework to build a model for a sinter plant.

Modeling number of bacteria per food unit in comparison to bacterial concentration in quantitative risk assessment: impact on risk estimates.

Science.gov (United States)

Pouillot, Régis; Chen, Yuhuan; Hoelzer, Karin

2015-02-01

When developing quantitative risk assessment models, a fundamental consideration for risk assessors is to decide whether to evaluate changes in bacterial levels in terms of concentrations or in terms of bacterial numbers. Although modeling bacteria in terms of integer numbers may be regarded as a more intuitive and rigorous choice, modeling bacterial concentrations is more popular as it is generally less mathematically complex. We tested three different modeling approaches in a simulation study. The first approach considered bacterial concentrations; the second considered the number of bacteria in contaminated units, and the third considered the expected number of bacteria in contaminated units. Simulation results indicate that modeling concentrations tends to overestimate risk compared to modeling the number of bacteria. A sensitivity analysis using a regression tree suggests that processes which include drastic scenarios consisting of combinations of large bacterial inactivation followed by large bacterial growth frequently lead to a >10-fold overestimation of the average risk when modeling concentrations as opposed to bacterial numbers. Alternatively, the approach of modeling the expected number of bacteria in positive units generates results similar to the second method and is easier to use, thus potentially representing a promising compromise. Published by Elsevier Ltd.

Quantitative risk-based approach for improving water quality management in mining.

Science.gov (United States)

Liu, Wenying; Moran, Chris J; Vink, Sue

2011-09-01

The potential environmental threats posed by freshwater withdrawal and mine water discharge are some of the main drivers for the mining industry to improve water management. The use of multiple sources of water supply and introducing water reuse into the mine site water system have been part of the operating philosophies employed by the mining industry to realize these improvements. However, a barrier to implementation of such good water management practices is concomitant water quality variation and the resulting impacts on the efficiency of mineral separation processes, and an increased environmental consequence of noncompliant discharge events. There is an increasing appreciation that conservative water management practices, production efficiency, and environmental consequences are intimately linked through the site water system. It is therefore essential to consider water management decisions and their impacts as an integrated system as opposed to dealing with each impact separately. This paper proposes an approach that could assist mine sites to manage water quality issues in a systematic manner at the system level. This approach can quantitatively forecast the risk related with water quality and evaluate the effectiveness of management strategies in mitigating the risk by quantifying implications for production and hence economic viability.

Quantitative Risk Analysis of a Pervaporation Process for Concentrating Hydrogen Peroxide

Energy Technology Data Exchange (ETDEWEB)

Jung, Ho Jin; Yoon, Ik Keun [Korea Gas Corporation, Ansan (Korea, Republic of); Choi, Soo Hyoung [Chonbuk National University, Jeonju (Korea, Republic of)

2014-12-15

Quantitative risk analysis has been performed for a pervaporation process for production of high test peroxide. Potential main accidents are explosion and fire caused by a decomposition reaction. As the target process has a laboratory scale, the consequence is considered to belong to Category 3. An event tree has been developed as a model for occurrence of a decomposition reaction in the target process. The probability functions of the accident causes have been established based on the frequency data of similar events. Using the constructed model, the failure rate has been calculated. The result indicates that additional safety devices are required in order to achieve an acceptable risk level, i.e. an accident frequency less than 10{sup -4}/yr. Therefore, a layer of protection analysis has been applied. As a result, it is suggested to introduce inherently safer design to avoid catalytic reaction, a safety instrumented function to prevent overheating, and a relief system that prevents explosion even if a decomposition reaction occurs. The proposed method is expected to contribute to developing safety management systems for various chemical processes including concentration of hydrogen peroxide.

What is a risk. [Quantitative risk analysis

Energy Technology Data Exchange (ETDEWEB)

Schoen, G [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany, F.R.)

1979-02-01

The following article is a revised version of a lecture given by the author during the VDE meeting 'Technical Expert Activities' in Brunswick. First of all, the concept of 'risk' is discussed which leads to a probability scale which then permits a definition of the 'justifiable risk' as the boundary between 'hazard' and 'safety'. The boundary is quantified indirectly from laws, regulations, instructions, etc. to the 'Technological rules' for special fields of application by minimum requirement data. These viewpoints described in detail are not only of substantial significance for the creation of safety regulations but also for their application and consequently for jurisdiction.

Comparing models for quantitative risk assessment: an application to the European Registry of foreign body injuries in children.

Science.gov (United States)

Berchialla, Paola; Scarinzi, Cecilia; Snidero, Silvia; Gregori, Dario

2016-08-01

Risk Assessment is the systematic study of decisions subject to uncertain consequences. An increasing interest has been focused on modeling techniques like Bayesian Networks since their capability of (1) combining in the probabilistic framework different type of evidence including both expert judgments and objective data; (2) overturning previous beliefs in the light of the new information being received and (3) making predictions even with incomplete data. In this work, we proposed a comparison among Bayesian Networks and other classical Quantitative Risk Assessment techniques such as Neural Networks, Classification Trees, Random Forests and Logistic Regression models. Hybrid approaches, combining both Classification Trees and Bayesian Networks, were also considered. Among Bayesian Networks, a clear distinction between purely data-driven approach and combination of expert knowledge with objective data is made. The aim of this paper consists in evaluating among this models which best can be applied, in the framework of Quantitative Risk Assessment, to assess the safety of children who are exposed to the risk of inhalation/insertion/aspiration of consumer products. The issue of preventing injuries in children is of paramount importance, in particular where product design is involved: quantifying the risk associated to product characteristics can be of great usefulness in addressing the product safety design regulation. Data of the European Registry of Foreign Bodies Injuries formed the starting evidence for risk assessment. Results showed that Bayesian Networks appeared to have both the ease of interpretability and accuracy in making prediction, even if simpler models like logistic regression still performed well. © The Author(s) 2013.

A quantitative risk assessment model to evaluate effective border control measures for rabies prevention

Science.gov (United States)

Weng, Hsin-Yi; Wu, Pei-I; Yang, Ping-Cheng; Tsai, Yi-Lun; Chang, Chao-Chin

2009-01-01

Border control is the primary method to prevent rabies emergence. This study developed a quantitative risk model incorporating stochastic processes to evaluate whether border control measures could efficiently prevent rabies introduction through importation of cats and dogs using Taiwan as an example. Both legal importation and illegal smuggling were investigated. The impacts of reduced quarantine and/or waiting period on the risk of rabies introduction were also evaluated. The results showed that Taiwan’s current animal importation policy could effectively prevent rabies introduction through legal importation of cats and dogs. The median risk of a rabid animal to penetrate current border control measures and enter Taiwan was 5.33 × 10−8 (95th percentile: 3.20 × 10−7). However, illegal smuggling may pose Taiwan to the great risk of rabies emergence. Reduction of quarantine and/or waiting period would affect the risk differently, depending on the applied assumptions, such as increased vaccination coverage, enforced custom checking, and/or change in number of legal importations. Although the changes in the estimated risk under the assumed alternatives were not substantial except for completely abolishing quarantine, the consequences of rabies introduction may yet be considered to be significant in a rabies-free area. Therefore, a comprehensive benefit-cost analysis needs to be conducted before recommending these alternative measures. PMID:19822125

Long-term risk of cervical intraepithelial neoplasia grade 3 or worse according to high-risk human papillomavirus genotype and semi-quantitative viral load among 33,288 women with normal cervical cytology

DEFF Research Database (Denmark)

Thomsen, Louise T; Frederiksen, Kirsten; Munk, Christian

2015-01-01

with single hrHPV infections. The cohort was followed in a nationwide pathology register for up to 11.5 years. In women aged ≥30 years at baseline, the 8-year absolute risk for CIN3+ following baseline detection of HPV16 was 21.8% (95% confidence interval [CI]: 18.0-25.6%). The corresponding risks for HPV18......In this prospective cohort study, we estimated the long-term risk of cervical intraepithelial neoplasia grade 3 or cancer (CIN3+) by high-risk human papillomavirus (hrHPV) genotype and semi-quantitative viral load at baseline among 33,288 women aged 14-90 years with normal baseline cytology. During...... 2002-2005, residual liquid-based cervical cytology samples were collected from women screened for cervical cancer in Copenhagen, Denmark. Samples were HPV-tested with Hybrid Capture 2 (HC2) and genotyped with INNO-LiPA. Semi-quantitative viral load was measured by HC2 relative light units in women...

Communicating quantitative risks and benefits in promotional prescription drug labeling or print advertising.

Science.gov (United States)

West, Suzanne L; Squiers, Linda B; McCormack, Lauren; Southwell, Brian G; Brouwer, Emily S; Ashok, Mahima; Lux, Linda; Boudewyns, Vanessa; O'Donoghue, Amie; Sullivan, Helen W

2013-05-01

Under the Food, Drug, and Cosmetic Act, all promotional materials for prescription drugs must strike a fair balance in presentation of risks and benefits. How to best present this information is not clear. We sought to determine if the presentation of quantitative risk and benefit information in drug advertising and labeling influences consumers', patients', and clinicians' information processing, knowledge, and behavior by assessing available empirical evidence. We used PubMed for a literature search, limiting to articles published in English from 1990 forward. Two reviewers independently reviewed the titles and abstracts for inclusion, after which we reviewed the full texts to determine if they communicated risk/benefit information either: (i) numerically (e.g., percent) versus non-numerically (e.g., using text such as "increased risk") or (ii) numerically using different formats (e.g., "25% of patients", "one in four patients", or use of pictographs). We abstracted information from included articles into standardized evidence tables. The research team identified a total of 674 relevant publications, of which 52 met our inclusion criteria. Of these, 37 focused on drugs. Presenting numeric information appears to improve understanding of risks and benefits relative to non-numeric presentation; presenting both numeric and non-numeric information when possible may be best practice. No single specific format or graphical approach emerged as consistently superior. Numeracy and health literacy also deserve more empirical attention as moderators. Copyright © 2013 John Wiley & Sons, Ltd.

Presentation of a method for consequence modeling and quantitative risk assessment of fire and explosion in process industry (Case study: Hydrogen Production Process

Directory of Open Access Journals (Sweden)

M J Jafari

2013-05-01

 .Conclusion: Since the proposed method is applicable in all phases of process or system design, and estimates the risk of fire and explosion by a quantitative, comprehensive and mathematical-based equations approach. It can be used as an alternative method instead of qualitative and semi quantitative methods.

Quantitative microbial risk assessment to estimate the health risk from exposure to noroviruses in polluted surface water in South Africa.

Science.gov (United States)

Van Abel, Nicole; Mans, Janet; Taylor, Maureen B

2017-10-01

This study assessed the risks posed by noroviruses (NoVs) in surface water used for drinking, domestic, and recreational purposes in South Africa (SA), using a quantitative microbial risk assessment (QMRA) methodology that took a probabilistic approach coupling an exposure assessment with four dose-response models to account for uncertainty. Water samples from three rivers were found to be contaminated with NoV GI (80-1,900 gc/L) and GII (420-9,760 gc/L) leading to risk estimates that were lower for GI than GII. The volume of water consumed and the probabilities of infection were lower for domestic (2.91 × 10 -8 to 5.19 × 10 -1 ) than drinking water exposures (1.04 × 10 -5 to 7.24 × 10 -1 ). The annual probabilities of illness varied depending on the type of recreational water exposure with boating (3.91 × 10 -6 to 5.43 × 10 -1 ) and swimming (6.20 × 10 -6 to 6.42 × 10 -1 ) being slightly greater than playing next to/in the river (5.30 × 10 -7 to 5.48 × 10 -1 ). The QMRA was sensitive to the choice of dose-response model. The risk of NoV infection or illness from contaminated surface water is extremely high in SA, especially for lower socioeconomic individuals, but is similar to reported risks from limited international studies.

Approaches to advancing quantitative human health risk assessment of environmental chemicals in the post-genomic era.

Science.gov (United States)

Chiu, Weihsueh A; Euling, Susan Y; Scott, Cheryl Siegel; Subramaniam, Ravi P

2013-09-15

The contribution of genomics and associated technologies to human health risk assessment for environmental chemicals has focused largely on elucidating mechanisms of toxicity, as discussed in other articles in this issue. However, there is interest in moving beyond hazard characterization to making more direct impacts on quantitative risk assessment (QRA)--i.e., the determination of toxicity values for setting exposure standards and cleanup values. We propose that the evolution of QRA of environmental chemicals in the post-genomic era will involve three, somewhat overlapping phases in which different types of approaches begin to mature. The initial focus (in Phase I) has been and continues to be on "augmentation" of weight of evidence--using genomic and related technologies qualitatively to increase the confidence in and scientific basis of the results of QRA. Efforts aimed towards "integration" of these data with traditional animal-based approaches, in particular quantitative predictors, or surrogates, for the in vivo toxicity data to which they have been anchored are just beginning to be explored now (in Phase II). In parallel, there is a recognized need for "expansion" of the use of established biomarkers of susceptibility or risk of human diseases and disorders for QRA, particularly for addressing the issues of cumulative assessment and population risk. Ultimately (in Phase III), substantial further advances could be realized by the development of novel molecular and pathway-based biomarkers and statistical and in silico models that build on anticipated progress in understanding the pathways of human diseases and disorders. Such efforts would facilitate a gradual "reorientation" of QRA towards approaches that more directly link environmental exposures to human outcomes. Published by Elsevier Inc.

Approaches to advancing quantitative human health risk assessment of environmental chemicals in the post-genomic era

Energy Technology Data Exchange (ETDEWEB)

Chiu, Weihsueh A., E-mail: chiu.weihsueh@epa.gov [National Center for Environmental Assessment, U.S. Environmental Protection Agency, Washington DC, 20460 (United States); Euling, Susan Y.; Scott, Cheryl Siegel; Subramaniam, Ravi P. [National Center for Environmental Assessment, U.S. Environmental Protection Agency, Washington DC, 20460 (United States)

2013-09-15

The contribution of genomics and associated technologies to human health risk assessment for environmental chemicals has focused largely on elucidating mechanisms of toxicity, as discussed in other articles in this issue. However, there is interest in moving beyond hazard characterization to making more direct impacts on quantitative risk assessment (QRA) — i.e., the determination of toxicity values for setting exposure standards and cleanup values. We propose that the evolution of QRA of environmental chemicals in the post-genomic era will involve three, somewhat overlapping phases in which different types of approaches begin to mature. The initial focus (in Phase I) has been and continues to be on “augmentation” of weight of evidence — using genomic and related technologies qualitatively to increase the confidence in and scientific basis of the results of QRA. Efforts aimed towards “integration” of these data with traditional animal-based approaches, in particular quantitative predictors, or surrogates, for the in vivo toxicity data to which they have been anchored are just beginning to be explored now (in Phase II). In parallel, there is a recognized need for “expansion” of the use of established biomarkers of susceptibility or risk of human diseases and disorders for QRA, particularly for addressing the issues of cumulative assessment and population risk. Ultimately (in Phase III), substantial further advances could be realized by the development of novel molecular and pathway-based biomarkers and statistical and in silico models that build on anticipated progress in understanding the pathways of human diseases and disorders. Such efforts would facilitate a gradual “reorientation” of QRA towards approaches that more directly link environmental exposures to human outcomes.

Approaches to advancing quantitative human health risk assessment of environmental chemicals in the post-genomic era

International Nuclear Information System (INIS)

Chiu, Weihsueh A.; Euling, Susan Y.; Scott, Cheryl Siegel; Subramaniam, Ravi P.

2013-01-01

The contribution of genomics and associated technologies to human health risk assessment for environmental chemicals has focused largely on elucidating mechanisms of toxicity, as discussed in other articles in this issue. However, there is interest in moving beyond hazard characterization to making more direct impacts on quantitative risk assessment (QRA) — i.e., the determination of toxicity values for setting exposure standards and cleanup values. We propose that the evolution of QRA of environmental chemicals in the post-genomic era will involve three, somewhat overlapping phases in which different types of approaches begin to mature. The initial focus (in Phase I) has been and continues to be on “augmentation” of weight of evidence — using genomic and related technologies qualitatively to increase the confidence in and scientific basis of the results of QRA. Efforts aimed towards “integration” of these data with traditional animal-based approaches, in particular quantitative predictors, or surrogates, for the in vivo toxicity data to which they have been anchored are just beginning to be explored now (in Phase II). In parallel, there is a recognized need for “expansion” of the use of established biomarkers of susceptibility or risk of human diseases and disorders for QRA, particularly for addressing the issues of cumulative assessment and population risk. Ultimately (in Phase III), substantial further advances could be realized by the development of novel molecular and pathway-based biomarkers and statistical and in silico models that build on anticipated progress in understanding the pathways of human diseases and disorders. Such efforts would facilitate a gradual “reorientation” of QRA towards approaches that more directly link environmental exposures to human outcomes

Risk Assessment and Integration Team (RAIT) Portfolio Risk Analysis Strategy

Science.gov (United States)

Edwards, Michelle

2010-01-01

Impact at management level: Qualitative assessment of risk criticality in conjunction with risk consequence, likelihood, and severity enable development of an "investment policy" towards managing a portfolio of risks. Impact at research level: Quantitative risk assessments enable researchers to develop risk mitigation strategies with meaningful risk reduction results. Quantitative assessment approach provides useful risk mitigation information.

Quantitative microbiological risk assessment in food industry: Theory and practical application.

Science.gov (United States)

Membré, Jeanne-Marie; Boué, Géraldine

2018-04-01

The objective of this article is to bring scientific background as well as practical hints and tips to guide risk assessors and modelers who want to develop a quantitative Microbiological Risk Assessment (MRA) in an industrial context. MRA aims at determining the public health risk associated with biological hazards in a food. Its implementation in industry enables to compare the efficiency of different risk reduction measures, and more precisely different operational settings, by predicting their effect on the final model output. The first stage in MRA is to clearly define the purpose and scope with stakeholders, risk assessors and modelers. Then, a probabilistic model is developed; this includes schematically three important phases. Firstly, the model structure has to be defined, i.e. the connections between different operational processing steps. An important step in food industry is the thermal processing leading to microbial inactivation. Growth of heat-treated surviving microorganisms and/or post-process contamination during storage phase is also important to take into account. Secondly, mathematical equations are determined to estimate the change of microbial load after each processing step. This phase includes the construction of model inputs by collecting data or eliciting experts. Finally, the model outputs are obtained by simulation procedures, they have to be interpreted and communicated to targeted stakeholders. In this latter phase, tools such as what-if scenarios provide an essential added value. These different MRA phases are illustrated through two examples covering important issues in industry. The first one covers process optimization in a food safety context, the second one covers shelf-life determination in a food quality context. Although both contexts required the same methodology, they do not have the same endpoint: up to the human health in the foie gras case-study illustrating here a safety application, up to the food portion in the

Exploring probabilistic tools for the development of a platform for Quantitative Risk Assessment (QRA) of hydro-meteorological hazards in Europe

Science.gov (United States)

Zumpano, V.; Hussin, H. Y.; Breinl, K.

2012-04-01

Mass-movements and floods are hydro-meteorological hazards that can have catastrophic effects on communities living in mountainous areas prone to these disastrous events. Environmental, climate and socio-economic changes are expected to affect the tempo-spatial patterns of hydro-meteorological hazards and associated risks in Europe. These changes and their effects on the occurrence of future hazards need to be analyzed and modeled using probabilistic hazard and risk assessment methods in order to assist stakeholders in disaster management strategies and policy making. Quantitative Risk Assessment (QRA) using probabilistic methods can further calculate damage and losses to multi-hazards and determine the uncertainties related to all the probabilistic components of the hazard and the vulnerability of the elements at risk. Therefore, in order to develop an effective platform that can quantitatively calculate the risk of mass-movements and floods in several European test sites, an extensive inventory and analysis has been carried out of the available tools and software related to the probabilistic risk assessment of single and multi-hazards. The tools have been reviewed based on whether they are open source and freely available, their required input data, the availability and type of hazard and vulnerability modules, transparency of methods used, their validation and calibration techniques, the inclusion of uncertainties and their state of the art. The analysis also specially focused on the applicability of the tools to European study areas. The findings showed that assumptions and simplifications are made when assessing and quantifying the hazards. The interaction between multiple hazards, like cascading effects are not assessed in most tools and some consider the hazard and vulnerability as qualitative components, rather than quantitative ones. This analysis of hazard and risk assessment tools and software will give future developers and experts a better overview of

Quantitative Microbial Risk Assessment in Occupational Settings Applied to the Airborne Human Adenovirus Infection

Directory of Open Access Journals (Sweden)

Annalaura Carducci

2016-07-01

Full Text Available Quantitative Microbial Risk Assessment (QMRA methodology, which has already been applied to drinking water and food safety, may also be applied to risk assessment and management at the workplace. The present study developed a preliminary QMRA model to assess microbial risk that is associated with inhaling bioaerosols that are contaminated with human adenovirus (HAdV. This model has been applied to air contamination data from different occupational settings, including wastewater systems, solid waste landfills, and toilets in healthcare settings and offices, with different exposure times. Virological monitoring showed the presence of HAdVs in all the evaluated settings, thus confirming that HAdV is widespread, but with different average concentrations of the virus. The QMRA results, based on these concentrations, showed that toilets had the highest probability of viral infection, followed by wastewater treatment plants and municipal solid waste landfills. Our QMRA approach in occupational settings is novel, and certain caveats should be considered. Nonetheless, we believe it is worthy of further discussions and investigations.

Quantitative risk assessment of human salmonellosis in the smallholder pig value chains in urban of Vietnam.

Science.gov (United States)

Dang-Xuan, Sinh; Nguyen-Viet, Hung; Unger, Fred; Pham-Duc, Phuc; Grace, Delia; Tran-Thi, Ngan; Barot, Max; Pham-Thi, Ngoc; Makita, Kohei

2017-02-01

To quantify salmonellosis risk in humans through consumption of boiled pork in urban Hung Yen Province, Vietnam, using a quantitative microbial risk assessment. We collected 302 samples along the pork value chain in Hung Yen between April 2014 and February 2015. We developed a model in @Risk, based on microbiological, market, and household surveys on cooking, cross-contamination and consumption, and conducted sensitivity analysis. Salmonella prevalence of pen floor swabs, slaughterhouse carcasses and cut pork were 33.3, 41.7 and 44.4%, respectively. The annual incidence rate of salmonellosis in humans was estimated to be 17.7% (90% CI 0.89-45.96). Parameters with the greatest influence risk were household pork handling practice followed by prevalence in pork sold in the central market. Wide confidence interval in the incidence estimate was mainly due to the variability in the degree of reduction in bacteria concentration by cooking, and pork consumption pattern. The risk of salmonellosis in humans due to boiled pork consumption appears to be high. Control measures may include improving the safety of retailed pork and improving household hygiene.

Physically based dynamic run-out modelling for quantitative debris flow risk assessment: a case study in Tresenda, northern Italy

Czech Academy of Sciences Publication Activity Database

Quan Luna, B.; Blahůt, Jan; Camera, C.; Van Westen, C.; Apuani, T.; Jetten, V.; Sterlacchini, S.

2014-01-01

Roč. 72, č. 3 (2014), s. 645-661 ISSN 1866-6280 Institutional support: RVO:67985891 Keywords : debris flow * FLO-2D * run-out * quantitative hazard and risk assessment * vulnerability * numerical modelling Subject RIV: DB - Geology ; Mineralogy Impact factor: 1.765, year: 2014

Quantitative Experimental Determination of Primer-Dimer Formation Risk by Free-Solution Conjugate Electrophoresis

Science.gov (United States)

Desmarais, Samantha M.; Leitner, Thomas; Barron, Annelise E.

2012-01-01

DNA barcodes are short, unique ssDNA primers that “mark” individual biomolecules. To gain better understanding of biophysical parameters constraining primer-dimer formation between primers that incorporate barcode sequences, we have developed a capillary electrophoresis method that utilizes drag-tag-DNA conjugates to quantify dimerization risk between primer-barcode pairs. Results obtained with this unique free-solution conjugate electrophoresis (FSCE) approach are useful as quantitatively precise input data to parameterize computation models of dimerization risk. A set of fluorescently labeled, model primer-barcode conjugates were designed with complementary regions of differing lengths to quantify heterodimerization as a function of temperature. Primer-dimer cases comprised two 30-mer primers, one of which was covalently conjugated to a lab-made, chemically synthesized poly-N-methoxyethylglycine drag-tag, which reduced electrophoretic mobility of ssDNA to distinguish it from ds primer-dimers. The drag-tags also provided a shift in mobility for the dsDNA species, which allowed us to quantitate primer-dimer formation. In the experimental studies, pairs of oligonucleotide primer-barcodes with fully or partially complementary sequences were annealed, and then separated by free-solution conjugate CE at different temperatures, to assess effects on primer-dimer formation. When less than 30 out of 30 basepairs were bonded, dimerization was inversely correlated to temperature. Dimerization occurred when more than 15 consecutive basepairs formed, yet non-consecutive basepairs did not create stable dimers even when 20 out of 30 possible basepairs bonded. The use of free-solution electrophoresis in combination with a peptoid drag-tag and different fluorophores enabled precise separation of short DNA fragments to establish a new mobility shift assay for detection of primer-dimer formation. PMID:22331820

On the quantitative definition of risk

International Nuclear Information System (INIS)

Kaplan, S.; Garrick, B.J.

1985-01-01

The purpose of this paper is to provide some suggestions and contributions toward a uniform conceptual/linguistic framework for quantifying and making precise the notion of risk. The concepts and definitions the authors present in this connection have shown themselves to be sturdy and serviceable in practical application to a wide variety of risk situations. They have demonstrated in the courtroom and elsewhere the ability to improve communication and greatly diminish the confusion and controversy that often swirls around public decision making involving risk. They hope therefore with this paper to widen the understanding and adoption of this framework, and to that end adopt a leisurely and tutorial place. In particular, they carefully draw a distinction between ''probability'' and ''frequency.'' Then, using this distinction, they return to the idea of risk, and give a ''second-level'' definition (of risk which generalizes the first-level definition) and is large enough and flexible enough to include at least all the aspects and subtleties of risk that have been encountered in the authors' experience

Quantitative Identification of Construction Risk

OpenAIRE

Kasprowicz T.

2017-01-01

Risks pertaining to construction work relate to situations in which various events may randomly change the duration and cost of the project or worsen its quality. Because of possible significant changes of random events, favorable, moderate, and difficult conditions of construction work are considered. It is the first stage of the construction risk analysis. The probabilistic parameters of construction are identified and described by using the design characteristics model of the structure and...

A quantitative risk assessment of multiple factors influencing HIV/AIDS transmission through unprotected sex among HIV-seropositive men.

Science.gov (United States)

Gerbi, Gemechu B; Habtemariam, Tsegaye; Tameru, Berhanu; Nganwa, David; Robnett, Vinaida

2012-01-01

The objective of this study is to conduct a quantitative risk assessment of multiple factors influencing HIV/AIDS transmission through unprotected sexual practices among HIV-seropositive men. A knowledgebase was developed by reviewing different published sources. The data were collected from different sources including Centers for Disease Control and Prevention, selected journals, and reports. The risk pathway scenario tree was developed based on a comprehensive review of published literature. The variables are organized into nine major parameter categories. Monte Carlo simulations for the quantitative risk assessment of HIV/AIDS transmission was executed with the software @Risk 4.0 (Palisade Corporation). Results show that the value for the likelihood of unprotected sex due to having less knowledge about HIV/AIDS and negative attitude toward condom use and safer sex ranged from 1.24 × 10(-5) to 8.47 × 10(-4) with the mean and standard deviation of 1.83 × 10(-4) and 8.63 × 10(-5), respectively. The likelihood of unprotected sex due to having greater anger-hostility, anxiety, less satisfied with aspects of life, and greater depressive symptoms ranged from 2.76 × 10(-9) to 5.34 × 10(-7) with the mean and standard deviation of 5.23 × 10(-8) and 3.58 × 10(-8), respectively. The findings suggest that HIV/AIDS research and intervention programs must be focused on behavior, and the broader setting within which individual risky behaviors occur.

A quantitative approach for integrating multiple lines of evidence for the evaluation of environmental health risks

Directory of Open Access Journals (Sweden)

Jerome J. Schleier III

2015-01-01

Full Text Available Decision analysis often considers multiple lines of evidence during the decision making process. Researchers and government agencies have advocated for quantitative weight-of-evidence approaches in which multiple lines of evidence can be considered when estimating risk. Therefore, we utilized Bayesian Markov Chain Monte Carlo to integrate several human-health risk assessment, biomonitoring, and epidemiology studies that have been conducted for two common insecticides (malathion and permethrin used for adult mosquito management to generate an overall estimate of risk quotient (RQ. The utility of the Bayesian inference for risk management is that the estimated risk represents a probability distribution from which the probability of exceeding a threshold can be estimated. The mean RQs after all studies were incorporated were 0.4386, with a variance of 0.0163 for malathion and 0.3281 with a variance of 0.0083 for permethrin. After taking into account all of the evidence available on the risks of ULV insecticides, the probability that malathion or permethrin would exceed a level of concern was less than 0.0001. Bayesian estimates can substantially improve decisions by allowing decision makers to estimate the probability that a risk will exceed a level of concern by considering seemingly disparate lines of evidence.

Quantitative occupational risk model: Single hazard

International Nuclear Information System (INIS)

Papazoglou, I.A.; Aneziris, O.N.; Bellamy, L.J.; Ale, B.J.M.; Oh, J.

2017-01-01

A model for the quantification of occupational risk of a worker exposed to a single hazard is presented. The model connects the working conditions and worker behaviour to the probability of an accident resulting into one of three types of consequence: recoverable injury, permanent injury and death. Working conditions and safety barriers in place to reduce the likelihood of an accident are included. Logical connections are modelled through an influence diagram. Quantification of the model is based on two sources of information: a) number of accidents observed over a period of time and b) assessment of exposure data of activities and working conditions over the same period of time and the same working population. Effectiveness of risk reducing measures affecting the working conditions, worker behaviour and/or safety barriers can be quantified through the effect of these measures on occupational risk. - Highlights: • Quantification of occupational risk from a single hazard. • Influence diagram connects working conditions, worker behaviour and safety barriers. • Necessary data include the number of accidents and the total exposure of worker • Effectiveness of risk reducing measures is quantified through the impact on the risk • An example illustrates the methodology.

Risk of vertebral insufficiency fractures in relation to compressive strength predicted by quantitative computed tomography

International Nuclear Information System (INIS)

Biggemann, M.; Hilweg, D.; Seidel, S.; Horst, M.; Brinckmann, P.

1991-01-01

Vertebral insufficiency fractures may result from excessive loading of normal and routine loading of osteoporotic spines. Fractures occur when the mechanical load exceeds the vertebral compressive strength, i.e., the maximum load a vertebra can tolerate. Vertebral compressive strength is determined by trabecular bone density and the size of end-plate area. Both parameters can be measured non-invasively by quanti-tative computed tomography (QCT). In 75 patients compressive strength (i.e., trabecular bone density and endplate area) of the vertebra L3 was determined using QCT. In addition, conventional radiographs of the spines were analysed for the prevalence of insufficiency fractures in each case. By relating fracture prevalence to strength, 3 fracture risk groups were found: a high-risk group with strength values of L3 5 kN and a fracture risk near 0 percent. Biomechanical measurements and model calculations indicate that spinal loads of 3 to 4 kN at L3/4 will be common in everyday activities. These data and the results described above suggest that spines with strength values of L3<3 kN are at an extremely high risk of insufficiency fractures in daily life. Advantages of fracture risk assessment by strength determination over risk estimation based on clinically used trabecular bone density measurements are discussed. (author). 18 refs.; 4 figs

Model risk analysis for risk management and option pricing

NARCIS (Netherlands)

Kerkhof, F.L.J.

2003-01-01

Due to the growing complexity of products in financial markets, market participants rely more and more on quantitative models for trading and risk management decisions. This introduces a fairly new type of risk, namely, model risk. In the first part of this thesis we investigate the quantitative

Quantitative risk assessment of the New York State operated West Valley Radioactive Waste Disposal Area.

Science.gov (United States)

Garrick, B John; Stetkar, John W; Bembia, Paul J

2010-08-01

This article is based on a quantitative risk assessment (QRA) that was performed on a radioactive waste disposal area within the Western New York Nuclear Service Center in western New York State. The QRA results were instrumental in the decision by the New York State Energy Research and Development Authority to support a strategy of in-place management of the disposal area for another decade. The QRA methodology adopted for this first of a kind application was a scenario-based approach in the framework of the triplet definition of risk (scenarios, likelihoods, consequences). The measure of risk is the frequency of occurrence of different levels of radiation dose to humans at prescribed locations. The risk from each scenario is determined by (1) the frequency of disruptive events or natural processes that cause a release of radioactive materials from the disposal area; (2) the physical form, quantity, and radionuclide content of the material that is released during each scenario; (3) distribution, dilution, and deposition of the released materials throughout the environment surrounding the disposal area; and (4) public exposure to the distributed material and the accumulated radiation dose from that exposure. The risks of the individual scenarios are assembled into a representation of the risk from the disposal area. In addition to quantifying the total risk to the public, the analysis ranks the importance of each contributing scenario, which facilitates taking corrective actions and implementing effective risk management. Perhaps most importantly, quantification of the uncertainties is an intrinsic part of the risk results. This approach to safety analysis has demonstrated many advantages of applying QRA principles to assessing the risk of facilities involving hazardous materials.

Quantitative flood risk assessment for Polders

International Nuclear Information System (INIS)

Manen, Sipke E. van; Brinkhuis, Martine

2005-01-01

In the Netherlands, the design of dikes and other water retaining structures is based on an acceptable probability (frequency) of overtopping. In 1993 a new safety concept was introduced based on total flood risk. Risk was defined as the product of probability and consequences. In recent years advanced tools have become available to calculate the actual flood risk of a polder. This paper describes the application of these tools to an existing lowland river area. The complete chain of calculations necessary to estimate the risk of flooding of a polder (or dike ring) is presented. The difficulties in applying the present day tools and the largest uncertainties in the calculations are shown

Quantitative flood risk assessment for Polders

Energy Technology Data Exchange (ETDEWEB)

Manen, Sipke E. van [Ministry of Transport, Public Works and Water Management, Bouwdienst Rijkswaterstaat, Griffioenlaan 2, Utrecht 3526 (Netherlands)]. E-mail: s.e.vmanen@bwd.rws.minvenw.nl; Brinkhuis, Martine [Ministry of Transport, Public Works and Water Management, Delft (Netherlands)

2005-12-01

In the Netherlands, the design of dikes and other water retaining structures is based on an acceptable probability (frequency) of overtopping. In 1993 a new safety concept was introduced based on total flood risk. Risk was defined as the product of probability and consequences. In recent years advanced tools have become available to calculate the actual flood risk of a polder. This paper describes the application of these tools to an existing lowland river area. The complete chain of calculations necessary to estimate the risk of flooding of a polder (or dike ring) is presented. The difficulties in applying the present day tools and the largest uncertainties in the calculations are shown.

IWGT report on quantitative approaches to genotoxicity risk assessment II. Use of point-of-departure (PoD) metrics in defining acceptable exposure limits and assessing human risk.

Science.gov (United States)

MacGregor, James T; Frötschl, Roland; White, Paul A; Crump, Kenny S; Eastmond, David A; Fukushima, Shoji; Guérard, Melanie; Hayashi, Makoto; Soeteman-Hernández, Lya G; Johnson, George E; Kasamatsu, Toshio; Levy, Dan D; Morita, Takeshi; Müller, Lutz; Schoeny, Rita; Schuler, Maik J; Thybaud, Véronique

2015-05-01

This is the second of two reports from the International Workshops on Genotoxicity Testing (IWGT) Working Group on Quantitative Approaches to Genetic Toxicology Risk Assessment (the QWG). The first report summarized the discussions and recommendations of the QWG related to the need for quantitative dose-response analysis of genetic toxicology data, the existence and appropriate evaluation of threshold responses, and methods to analyze exposure-response relationships and derive points of departure (PoDs) from which acceptable exposure levels could be determined. This report summarizes the QWG discussions and recommendations regarding appropriate approaches to evaluate exposure-related risks of genotoxic damage, including extrapolation below identified PoDs and across test systems and species. Recommendations include the selection of appropriate genetic endpoints and target tissues, uncertainty factors and extrapolation methods to be considered, the importance and use of information on mode of action, toxicokinetics, metabolism, and exposure biomarkers when using quantitative exposure-response data to determine acceptable exposure levels in human populations or to assess the risk associated with known or anticipated exposures. The empirical relationship between genetic damage (mutation and chromosomal aberration) and cancer in animal models was also examined. It was concluded that there is a general correlation between cancer induction and mutagenic and/or clastogenic damage for agents thought to act via a genotoxic mechanism, but that the correlation is limited due to an inadequate number of cases in which mutation and cancer can be compared at a sufficient number of doses in the same target tissues of the same species and strain exposed under directly comparable routes and experimental protocols. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.

Comparison of recreational health risks associated with surfing and swimming in dry weather and post-storm conditions at Southern California beaches using quantitative microbial risk assessment (QMRA).

Science.gov (United States)

Tseng, Linda Y; Jiang, Sunny C

2012-05-01

Southern California is an increasingly urbanized hotspot for surfing, thus it is of great interest to assess the human illness risks associated with this popular ocean recreational water sport from exposure to fecal bacteria contaminated coastal waters. Quantitative microbial risk assessments were applied to eight popular Southern California beaches using readily available enterococcus and fecal coliform data and dose-response models to compare health risks associated with surfing during dry weather and storm conditions. The results showed that the level of gastrointestinal illness risks from surfing post-storm events was elevated, with the probability of exceeding the US EPA health risk guideline up to 28% of the time. The surfing risk was also elevated in comparison with swimming at the same beach due to ingestion of greater volume of water. The study suggests that refinement of dose-response model, improving monitoring practice and better surfer behavior surveillance will improve the risk estimation. Copyright © 2012 Elsevier Ltd. All rights reserved.

Development of a Model for Quantitative Assessment of Risks and Identification of Threats in Anti-Crisis Management of a Machine-Building Enterprise

Directory of Open Access Journals (Sweden)

Kozyk Vasyl V.

2017-03-01

Full Text Available The aim of the article is to develop a model for quantitative assessment of risks in anti-crisis management of a machine-building enterprise. The quantitative assessment will allow to identify among the risks the threats that can be considered as catastrophic risks. To assess the integral risk of anti-crisis management of the enterprise, there used a process approach distinguishing the process of anti-crisis management activity and the process of implementation of the anti-crisis program. Within the framework of the process the types of activity are singled out, for each of them risks are identified with revealing their reasons. There built a fuzzy hierarchical model comprising the following elements: terminal nodes — indicators (factors of risks; non-terminal nodes — separate risks that are characteristic for the processes and risks of each process as a whole; root of the tree — the integral risk of anti-crisis management. The expediency of building a hierarchical fuzzy model, within which conclusions are formed for intermediate variables, is substantiated. Based on the own research and taking into account the opinion of experts, the parameters of the trapezoidal membership functions for assessing indicators and risks are determined. Fuzzy bases of knowledge about the correlation are formed using the Mamdani algorithm. The adequacy of the model is estimated on the basis of the learning sample. The built fuzzy model makes it possible to obtain risk assessment based on the set values of the indicators, thus providing an analysis of the sensitivity of risks to various factors. It is easily adjusted to other conditions and types of economic activity of the enterprise.

Quantitative microbial risk assessment of Cryptosporidium and Giardia in well water from a native community of Mexico.

Science.gov (United States)

Balderrama-Carmona, Ana Paola; Gortáres-Moroyoqui, Pablo; Álvarez-Valencia, Luis Humberto; Castro-Espinoza, Luciano; Balderas-Cortés, José de Jesús; Mondaca-Fernández, Iram; Chaidez-Quiroz, Cristóbal; Meza-Montenegro, María Mercedes

2015-01-01

Cryptosporidium and Giardia are gastrointestinal disease-causing organisms transmitted by the fecal-oral route, zoonotic and prevalent in all socioeconomic segments with greater emphasis in rural communities. The goal of this study was to assess the risk of cryptosporidiosis and giardiasis of Potam dwellers consuming drinking water from communal well water. To achieve the goal, quantitative microbial risk assessment (QMRA) was carried out as follows: (a) identification of Cryptosporidium oocysts and Giardia cysts in well water samples by information collection rule method, (b) assessment of exposure to healthy Potam residents, (c) dose-response modelling, and (d) risk characterization using an exponential model. All well water samples tested were positive for Cryptosporidium and Giardia. The QMRA results indicate a mean of annual risks of 99:100 (0.99) for cryptosporidiosis and 1:1 (1.0) for giardiasis. The outcome of the present study may drive decision-makers to establish an educational and treatment program to reduce the incidence of parasite-borne intestinal infection in the Potam community, and to conduct risk analysis programs in other similar rural communities in Mexico.

Risk Perception as the Quantitative Parameter of Ethics and Responsibility in Disaster Study

Science.gov (United States)

Kostyuchenko, Yuriy; Movchan, Dmytro

2014-05-01

Intensity of impacts of natural disasters is increasing with climate and ecological changes spread. Frequency of disasters is increasing, and recurrence of catastrophes characterizing by essential spatial heterogeneity. Distribution of losses is fundamentally non-linear and reflects complex interrelation of natural, social and environmental factor in the changing world on multi scale range. We faced with new types of risks, which require a comprehensive security concept. Modern understanding of complex security, and complex risk management require analysis of all natural and social phenomena, involvement of all available data, constructing of advanced analytical tools, and transformation of our perception of risk and security issues. Traditional deterministic models used for risk analysis are difficult applicable for analysis of social issues, as well as for analysis of multi scale multi-physics phenomena quantification. Also parametric methods are not absolutely effective because the system analyzed is essentially non-ergodic. The stochastic models of risk analysis are applicable for quantitative analysis of human behavior and risk perception. In framework of risk analysis models the risk perception issues were described. Risk is presented as the superposition of distribution (f(x,y)) and damage functions (p(x,y)): P →δΣ x,yf(x,y)p(x,y). As it was shown risk perception essentially influents to the damage function. Basing on the prospect theory and decision making under uncertainty on cognitive bias and handling of risk, modification of damage function is proposed: p(x,y|α(t)). Modified damage function includes an awareness function α(t), which is the system of risk perception function (rp) and function of education and log-term experience (c) as: α(t) → (c - rp). Education function c(t) describes the trend of education and experience. Risk perception function rp reflects security concept of human behavior, is the basis for prediction of socio-economic and

EFSA Panel on Biological Hazards; Scientific Opinion on a Quantitative Microbiological Risk Assessment of Salmonella in slaughter and breeder pigs

DEFF Research Database (Denmark)

Hald, Tine

This Quantitative Microbiological Risk Assessment (QMRA) represents a major step forward in terms of modelling Salmonella in pigs from farm to consumption as it takes into account the variability between and within EU Member States (MSs). Around 10-20% of human Salmonella infections in EU may...

A quantitative microbial risk assessment model for Listeria monocytogenes in RTE sandwiches

DEFF Research Database (Denmark)

Tirloni, E.; Stella, S.; de Knegt, Leonardo

2018-01-01

within each serving. Then, two dose-response models were alternatively applied: the first used a fixed r value for each of the three population groups, while the second considered a variable r value (lognormal distribution), taking into account the variability in strain virulence and different host...... subpopulations susceptibility. The stochastic model predicted zero cases for total population for both the substrates by using the fixed r approach, while 3 cases were expected when a higher variability (in virulence and susceptibility) was considered in the model; the number of cases increased to 45......A Quantitative Microbial Risk Assessment (QMRA) was performed to estimate the expected number of listeriosis cases due to the consumption, on the last day of shelf life, of 20 000 servings of multi-ingredient sandwiches produced by a medium scale food producer in Italy, by different population...

Quantitative Metrics and Risk Assessment: The Three Tenets Model of Cybersecurity

Directory of Open Access Journals (Sweden)

Jeff Hughes

2013-08-01

Full Text Available Progress in operational cybersecurity has been difficult to demonstrate. In spite of the considerable research and development investments made for more than 30 years, many government, industrial, financial, and consumer information systems continue to be successfully attacked and exploited on a routine basis. One of the main reasons that progress has been so meagre is that most technical cybersecurity solutions that have been proposed to-date have been point solutions that fail to address operational tradeoffs, implementation costs, and consequent adversary adaptations across the full spectrum of vulnerabilities. Furthermore, sound prescriptive security principles previously established, such as the Orange Book, have been difficult to apply given current system complexity and acquisition approaches. To address these issues, the authors have developed threat-based descriptive methodologies to more completely identify system vulnerabilities, to quantify the effectiveness of possible protections against those vulnerabilities, and to evaluate operational consequences and tradeoffs of possible protections. This article begins with a discussion of the tradeoffs among seemingly different system security properties such as confidentiality, integrity, and availability. We develop a quantitative framework for understanding these tradeoffs and the issues that arise when those security properties are all in play within an organization. Once security goals and candidate protections are identified, risk/benefit assessments can be performed using a novel multidisciplinary approach, called “QuERIES.” The article ends with a threat-driven quantitative methodology, called “The Three Tenets”, for identifying vulnerabilities and countermeasures in networked cyber-physical systems. The goal of this article is to offer operational guidance, based on the techniques presented here, for informed decision making about cyber-physical system security.

Skin sensitization quantitative risk assessment for occupational exposure of hairdressers to hair dye ingredients.

Science.gov (United States)

Goebel, Carsten; Diepgen, Thomas L; Blömeke, Brunhilde; Gaspari, Anthony A; Schnuch, Axel; Fuchs, Anne; Schlotmann, Kordula; Krasteva, Maya; Kimber, Ian

2018-06-01

Occupational exposure of hairdressers to hair dyes has been associated with the development of allergic contact dermatitis (ACD) involving the hands. p-Phenylenediamine (PPD) and toluene-2,5-diamine (PTD) have been implicated as important occupational contact allergens. To conduct a quantitative risk assessment for the induction of contact sensitization to hair dyes in hairdressers, available data from hand rinsing studies following typical occupational exposure conditions to PPD, PTD and resorcinol were assessed. By accounting for wet work, uneven exposure and inter-individual variability for professionals, daily hand exposure concentrations were derived. Secondly, daily hand exposure was compared with the sensitization induction potency of the individual hair dye defined as the No Expected Sensitization Induction Levels (NESIL). For PPD and PTD hairdresser hand exposure levels were 2.7 and 5.9 fold below the individual NESIL. In contrast, hand exposure to resorcinol was 50 fold below the NESIL. Correspondingly, the risk assessment for PPD and PTD indicates that contact sensitization may occur, when skin protection and skin care are not rigorously applied. We conclude that awareness of health risks associated with occupational exposure to hair dyes, and of the importance of adequate protective measures, should be emphasized more fully during hairdresser education and training. Copyright © 2018 Elsevier Inc. All rights reserved.

Quantitative Measures of Mineral Supply Risk

Science.gov (United States)

Long, K. R.

2009-12-01

Almost all metals and many non-metallic minerals are traded internationally. An advantage of global mineral markets is that minerals can be obtained from the globally lowest-cost source. For example, one rare-earth element (REE) mine in China, Bayan Obo, is able to supply most of world demand for rare earth elements at a cost significantly less than its main competitors. Concentration of global supplies at a single mine raises significant political risks, illustrated by China’s recent decision to prohibit the export of some REEs and severely limit the export of others. The expected loss of REE supplies will have a significant impact on the cost and production of important national defense technologies and on alternative energy programs. Hybrid vehicles and wind-turbine generators, for example, require REEs for magnets and batteries. Compact fluorescent light bulbs use REE-based phosphors. These recent events raise the general issue of how to measure the degree of supply risk for internationally sourced minerals. Two factors, concentration of supply and political risk, must first be addressed. Concentration of supply can be measured with standard economic tools for measuring industry concentration, using countries rather than firms as the unit of analysis. There are many measures of political risk available. That of the OECD is a measure of a country’s commitment to rule-of-law and enforcement of contracts, as well as political stability. Combining these measures provides a comparative view of mineral supply risk across commodities and identifies several minerals other than REEs that could suddenly become less available. Combined with an assessment of the impact of a reduction in supply, decision makers can use these measures to prioritize risk reduction efforts.

Contract farming risks: A quantitative assessment

Directory of Open Access Journals (Sweden)

Arkins M Kabungo

2016-03-01

Full Text Available The objective of this study is to identify the key risks facing each of the stakeholders in the export-focused paprika value chain in Zambia. Although a deterministic cost-benefit analysis indicated that this outgrower scheme would have a very satisfactory net present value (NPV, a Monte Carlo analysis using an integrated financial–economic–stakeholder model identifies a number of risk variables that could make this system unsustainable. The major risks include the variability of the real exchange rate in Zambia; the international price of paprika; and the farm yield rates. This analysis points out that irrigation systems are very important for both stabilising and increasing yields. The analysis also shows the limitations of loan financing for such outgrower arrangements when at the sector level it is difficult or even impossible to mitigate the risks from real exchange rate movements and changes in international commodity prices. This micro-level analysis shows how critical real exchange rate management policies are in achieving sustainability of such export-oriented value chains.

Quantitative Ultrasound Measurements at the Heel

DEFF Research Database (Denmark)

Daugschies, M.; Brixen, K.; Hermann, P.

2015-01-01

Calcaneal quantitative ultrasound can be used to predict osteoporotic fracture risk, but its ability to monitor therapy is unclear possibly because of its limited precision. We developed a quantitative ultrasound device (foot ultrasound scanner) that measures the speed of sound at the heel...... with the foot ultrasound scanner reduced precision errors by half (p quantitative ultrasound measurements is feasible. (E-mail: m.daugschies@rad.uni-kiel.de) (C) 2015 World Federation for Ultrasound in Medicine & Biology....

Quantitative Microbial Risk Assessment for Escherichia coli O157:H7 in Fresh-Cut Lettuce.

Science.gov (United States)

Pang, Hao; Lambertini, Elisabetta; Buchanan, Robert L; Schaffner, Donald W; Pradhan, Abani K

2017-02-01

Leafy green vegetables, including lettuce, are recognized as potential vehicles for foodborne pathogens such as Escherichia coli O157:H7. Fresh-cut lettuce is potentially at high risk of causing foodborne illnesses, as it is generally consumed without cooking. Quantitative microbial risk assessments (QMRAs) are gaining more attention as an effective tool to assess and control potential risks associated with foodborne pathogens. This study developed a QMRA model for E. coli O157:H7 in fresh-cut lettuce and evaluated the effects of different potential intervention strategies on the reduction of public health risks. The fresh-cut lettuce production and supply chain was modeled from field production, with both irrigation water and soil as initial contamination sources, to consumption at home. The baseline model (with no interventions) predicted a mean probability of 1 illness per 10 million servings and a mean of 2,160 illness cases per year in the United States. All intervention strategies evaluated (chlorine, ultrasound and organic acid, irradiation, bacteriophage, and consumer washing) significantly reduced the estimated mean number of illness cases when compared with the baseline model prediction (from 11.4- to 17.9-fold reduction). Sensitivity analyses indicated that retail and home storage temperature were the most important factors affecting the predicted number of illness cases. The developed QMRA model provided a framework for estimating risk associated with consumption of E. coli O157:H7-contaminated fresh-cut lettuce and can guide the evaluation and development of intervention strategies aimed at reducing such risk.

Use of static Quantitative Microbial Risk Assessment to determine pathogen risks in an unconfined carbonate aquifer used for Managed Aquifer Recharge.

Science.gov (United States)

Toze, Simon; Bekele, Elise; Page, Declan; Sidhu, Jatinder; Shackleton, Mark

2010-02-01

Managed Aquifer Recharge (MAR) is becoming a mechanism used for recycling treated wastewater and captured urban stormwater and is being used as a treatment barrier to remove contaminants such as pathogens from the recharged water. There is still a need, however, to demonstrate the effectiveness of MAR to reduce any residual risk of pathogens in the recovered water. A MAR research site recharging secondary treated wastewater in an unconfined carbonate aquifer was used in conjunction with a static Quantitative Microbial Risk Assessment (QMRA) to assess the microbial pathogen risk in the recovered water following infiltration and aquifer passage. The research involved undertaking a detailed hydrogeological assessment of the aquifer at the MAR site and determining the decay rates of reference pathogens from an in-situ decay study. These variables along with literature data were then used in the static QMRA which demonstrated that the recovered water at this site did not meet the Australian Guidelines for recycled water when used for differing private green space irrigation scenarios. The results also confirmed the importance of obtaining local hydrogeological data as local heterogeneity can influence of residence time in the aquifer which, in turn, influences the outcomes. The research demonstrated that a static QMRA can be used to determine the residual risk from pathogens in recovered water and showed that it can be a valuable tool in the preliminary design and operation of MAR systems and the incorporation of complementary engineered treatment processes to ensure that there is acceptable health risk from the recovered water. Crown Copyright 2009. Published by Elsevier Ltd. All rights reserved.

Asset backed securities : risks, ratings and quantitative modelling

NARCIS (Netherlands)

Jönsson, B.H.B.; Schoutens, W.

2009-01-01

Asset backed securities (ABSs) are structured finance products backed by pools of assets and are created through a securitisation process. The risks in asset backed securities, such as, credit risk, prepayment risk, market risks, operational risk, and legal risks, are directly connected with the

Quantitative evaluation of the impact of human reliability in risk assessment for nuclear power plants

International Nuclear Information System (INIS)

Samanta, P.K.

1981-01-01

The role of human beings in the safe operation of a nuclear power plant has been a matter of concern. This study describes methods for the quantitative description of that role and its impact on the risk from nuclear power plants. The impact of human errors was calculated by observing the changes in risk parameters, such as core melt probability, release category probabilities, accident sequence probabilities and system unavailabilities due to changes in the contribution to unavailablity of human errors, within the framework of risk assessment methodology. It was found that for operational pressurized water reactors the opportunity for reduction in core melt probability by reducing the human error rates without simultaneous reduction of hardware failures is limited, but that core melt probability would significantly increase as human error rates increased. More importantly, most of the dominant accident sequences showed a significant increase in their probabilities with an increase in human error rates. Release categories resulting in high consequences showed a much larger sensitivity to human errors than categories resulting in low consequences. A combination of structural importance and reliability importance measure was used to describe the importance of individual errors

Quantitative rockfall hazard and risk analysis in selected municipalities of the České Švýcarsko National Park, northwestern Czechia

Czech Academy of Sciences Publication Activity Database

Blahůt, Jan; Klimeš, Jan; Vařilová, Z.

2013-01-01

Roč. 118, č. 3 (2013), s. 205-220 ISSN 1212-0014 R&D Projects: GA ČR GP205/09/P383 Institutional support: RVO:67985891 Keywords : rockfall hazard and risk * quantitative risk * Cretaceous sandstones * CONEFALL Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 0.400, year: 2013 http://geography.cz/sbornik/wp-content/uploads/downloads/2013/10/g13-3-s205-220-blahút.pdf

Credit Institutions Management Evaluation using Quantitative Methods

Directory of Open Access Journals (Sweden)

Nicolae Dardac

2006-02-01

Full Text Available Credit institutions supervising mission by state authorities is mostly assimilated with systemic risk prevention. In present, the mission is orientated on analyzing the risk profile of the credit institutions, the mechanism and existing systems as management tools providing to bank rules the proper instruments to avoid and control specific bank risks. Rating systems are sophisticated measurement instruments which are capable to assure the above objectives, such as success in banking risk management. The management quality is one of the most important elements from the set of variables used in the quoting process in credit operations. Evaluation of this quality is – generally speaking – fundamented on quantitative appreciations which can induce subjectivism and heterogeneity in quotation. The problem can be solved by using, complementary, quantitative technics such us DEA (Data Envelopment Analysis.

A Quantitative Approach to Credit Risk Management in the Underwriting Process for the Retail Portfolio

Directory of Open Access Journals (Sweden)

Andreea Costea

2017-03-01

Full Text Available The core of this paper encloses a mathematical approach of credit risk management, based on a scorecard model used in the bank’s underwriting process. The main purpose of this paper is to present how to develop, validate and apply a rating model in practice. Using 21568 loan applications provided by one of the largest banks from Romania, a scorecard is built for the underwriting purposes. The customer data used in the modeling is based on socio-demographic characteristics. The model is developed according to a set of statistical methods for parameter estimation. A real-life example of how to use such a model in the strategic decisions of a bank is presented. The cut-off score for the acceptance of the applications is calibrated to a potential risk appetite of the main four banks in Romania. From an evaluative perspective, this paper is compatible with an exploratory approach to quantitative research methodology.

Quantitative and qualitative analysis of the expert and non-expert opinion in fire risk in buildings

International Nuclear Information System (INIS)

Hanea, D.M.; Jagtman, H.M.; Alphen, L.L.M.M. van; Ale, B.J.M.

2010-01-01

Expert judgment procedure is a method very often used in the area of risk assessments of complex systems or processes to fill in quantitative data. Although it has been proved to be a very reliable source of information when no other data are available, the choice of experts is always questioned. When the available data are limited, the seed questions cover only partially the domains of expertise, which may cause problems. Expertise is assessed not covering the full object of study but only those topics for which seed questions can be formulated. The commonly used quantitative analysis of an expert judgment exercise is combined with a qualitative analysis. The latter adds more insights to the relation between the assessor's field and statistical knowledge and their performance in an expert judgment. In addition the qualitative analysis identifies different types of seed questions. Three groups of assessors with different levels of statistical and domain knowledge are studied. The quantitative analysis shows no differences between field experts and non-experts and no differences between having advanced statistical knowledge or not. The qualitative analysis supports these findings. In addition it is found that especially technical questions are answered with larger intervals. Precaution is required when using seed questions for which the real value can be calculated, which was the case for one of the seed questions.

Risk Control of Offshore Installations. A Framework for the Establishment of Risk Indicators

Energy Technology Data Exchange (ETDEWEB)

Oeien, Knut

2001-07-01

Currently quantitative risk assessments are carried out to analyze the risk level of offshore installations and to evaluate whether or not the risk level is acceptable. By way of the quantitative risk analysis the risk status of a given installation is obtained. However, the risk status is obtained so infrequently that it is inadequate for risk control. It can be compared to economic control having the economic status presented about each fifth year, which is obviously inadequate. It is important to know the risk status because this may provide an early warning about the need for remedial actions. Without frequent information about the risk status, control of risk cannot be claimed. The main objective of this thesis has been the development of a framework for the establishment of risk indicators. These risk indicators provide a status of the risk level through measuring of changes in technical, operational and organizational factors important to risk, and is thus a means to control risk during operation of offshore petroleum installations. The framework consists of a technical methodology using the quantitative risk assessment as a basis, an organizational model, and an organizational quantification methodology. Technical risk indicators are established from the technical methodology covering the risk factors explicitly included in the quantitative risk assessment. Organizational risk indicators measure changes in the organizational risk factors included in the organizational model, but not included in the quantitative risk assessment. The organizational model is an extension to the risk model in the quantitative risk assessment. The organizational quantification methodology calculates the effect of the changes measured by the organizational risk indicators. The organizational model may also be applied as a qualitative tool for root cause analysis of incidents (process leaks). Other results are an intermediate-level expert judgment procedure applicable for

Quantitative tools for addressing hospital readmissions

Directory of Open Access Journals (Sweden)

Lagoe Ronald J

2012-11-01

Full Text Available Abstract Background Increased interest in health care cost containment is focusing attention on reduction of hospital readmissions. Major payors have already developed financial penalties for providers that generate excess readmissions. This subject has benefitted from the development of resources such as the Potentially Preventable Readmissions software. This process has encouraged hospitals to renew efforts to improve these outcomes. The aim of this study was to describe quantitative tools such as definitions, risk estimation, and tracking of patients for reducing hospital readmissions. Findings This study employed the Potentially Preventable Readmissions software to develop quantitative tools for addressing hospital readmissions. These tools included two definitions of readmissions that support identification and management of patients. They also included analytical approaches for estimation of the risk of readmission for individual patients by age, discharge status of the initial admission, and severity of illness. They also included patient specific spreadsheets for tracking of target populations and for evaluation of the impact of interventions. Conclusions The study demonstrated that quantitative tools including the development of definitions of readmissions, estimation of the risk of readmission, and patient specific spreadsheets could contribute to the improvement of patient outcomes in hospitals.

Quantitative evaluation of the risk induced by dominant geomorphological processes on different land uses, based on GIS spatial analysis models

Science.gov (United States)

Ştefan, Bilaşco; Sanda, Roşca; Ioan, Fodorean; Iuliu, Vescan; Sorin, Filip; Dănuţ, Petrea

2017-12-01

Maramureş Land is mostly characterized by agricultural and forestry land use due to its specific configuration of topography and its specific pedoclimatic conditions. Taking into consideration the trend of the last century from the perspective of land management, a decrease in the surface of agricultural lands to the advantage of built-up and grass lands, as well as an accelerated decrease in the forest cover due to uncontrolled and irrational forest exploitation, has become obvious. The field analysis performed on the territory of Maramureş Land has highlighted a high frequency of two geomorphologic processes — landslides and soil erosion — which have a major negative impact on land use due to their rate of occurrence. The main aim of the present study is the GIS modeling of the two geomorphologic processes, determining a state of vulnerability (the USLE model for soil erosion and a quantitative model based on the morphometric characteristics of the territory, derived from the HG. 447/2003) and their integration in a complex model of cumulated vulnerability identification. The modeling of the risk exposure was performed using a quantitative approach based on models and equations of spatial analysis, which were developed with modeled raster data structures and primary vector data, through a matrix highlighting the correspondence between vulnerability and land use classes. The quantitative analysis of the risk was performed by taking into consideration the exposure classes as modeled databases and the land price as a primary alphanumeric database using spatial analysis techniques for each class by means of the attribute table. The spatial results highlight the territories with a high risk to present geomorphologic processes that have a high degree of occurrence and represent a useful tool in the process of spatial planning.

Quantitative evaluation of the risk induced by dominant geomorphological processes on different land uses, based on GIS spatial analysis models

Science.gov (United States)

Ştefan, Bilaşco; Sanda, Roşca; Ioan, Fodorean; Iuliu, Vescan; Sorin, Filip; Dănuţ, Petrea

2018-06-01

Maramureş Land is mostly characterized by agricultural and forestry land use due to its specific configuration of topography and its specific pedoclimatic conditions. Taking into consideration the trend of the last century from the perspective of land management, a decrease in the surface of agricultural lands to the advantage of built-up and grass lands, as well as an accelerated decrease in the forest cover due to uncontrolled and irrational forest exploitation, has become obvious. The field analysis performed on the territory of Maramureş Land has highlighted a high frequency of two geomorphologic processes — landslides and soil erosion — which have a major negative impact on land use due to their rate of occurrence. The main aim of the present study is the GIS modeling of the two geomorphologic processes, determining a state of vulnerability (the USLE model for soil erosion and a quantitative model based on the morphometric characteristics of the territory, derived from the HG. 447/2003) and their integration in a complex model of cumulated vulnerability identification. The modeling of the risk exposure was performed using a quantitative approach based on models and equations of spatial analysis, which were developed with modeled raster data structures and primary vector data, through a matrix highlighting the correspondence between vulnerability and land use classes. The quantitative analysis of the risk was performed by taking into consideration the exposure classes as modeled databases and the land price as a primary alphanumeric database using spatial analysis techniques for each class by means of the attribute table. The spatial results highlight the territories with a high risk to present geomorphologic processes that have a high degree of occurrence and represent a useful tool in the process of spatial planning.

Novel Threat-risk Index Using Probabilistic Risk Assessment and Human Reliability Analysis - Final Report

Energy Technology Data Exchange (ETDEWEB)

George A. Beitel

2004-02-01

In support of a national need to improve the current state-of-the-art in alerting decision makers to the risk of terrorist attack, a quantitative approach employing scientific and engineering concepts to develop a threat-risk index was undertaken at the Idaho National Engineering and Environmental Laboratory (INEEL). As a result of this effort, a set of models has been successfully integrated into a single comprehensive model known as Quantitative Threat-Risk Index Model (QTRIM), with the capability of computing a quantitative threat-risk index on a system level, as well as for the major components of the system. Such a threat-risk index could provide a quantitative variant or basis for either prioritizing security upgrades or updating the current qualitative national color-coded terrorist threat alert.

Risk Factors for Chronic Subdural Hematoma Recurrence Identified Using Quantitative Computed Tomography Analysis of Hematoma Volume and Density.

Science.gov (United States)

Stavrinou, Pantelis; Katsigiannis, Sotirios; Lee, Jong Hun; Hamisch, Christina; Krischek, Boris; Mpotsaris, Anastasios; Timmer, Marco; Goldbrunner, Roland

2017-03-01

Chronic subdural hematoma (CSDH), a common condition in elderly patients, presents a therapeutic challenge with recurrence rates of 33%. We aimed to identify specific prognostic factors for recurrence using quantitative analysis of hematoma volume and density. We retrospectively reviewed radiographic and clinical data of 227 CSDHs in 195 consecutive patients who underwent evacuation of the hematoma through a single burr hole, 2 burr holes, or a mini-craniotomy. To examine the relationship between hematoma recurrence and various clinical, radiologic, and surgical factors, we used quantitative image-based analysis to measure the hematoma and trapped air volumes and the hematoma densities. Recurrence of CSDH occurred in 35 patients (17.9%). Multivariate logistic regression analysis revealed that the percentage of hematoma drained and postoperative CSDH density were independent risk factors for recurrence. All 3 evacuation methods were equally effective in draining the hematoma (71.7% vs. 73.7% vs. 71.9%) without observable differences in postoperative air volume captured in the subdural space. Quantitative image analysis provided evidence that percentage of hematoma drained and postoperative CSDH density are independent prognostic factors for subdural hematoma recurrence. Copyright © 2016 Elsevier Inc. All rights reserved.

Quantitative risk assessment of E. coli in street-vended cassava-based delicacies in the Philippines

Science.gov (United States)

Mesias, I. C. P.

2018-01-01

In the Philippines, rootcrop-based food products are gaining popularity in street food trade. However, a number of street-vended food products in the country are reported to be contaminated with E. coli posing possible risk among consumers. In this study, information on quantitative risk assessment of E. coli in street-vended cassava-based delicacies was generated. The assessment started with the prevalence and concentration of E. coli at post production in packages of the cassava-based delicacies. Combase growth predictor was used to trace the microbial population of E. coli in each step of the food chain. The @Risk software package, version 6 (Palisade USA) was used to run the simulations. Scenarios in the post-production to consumption pathway were simulated. The effect was then assessed in relation to exposure to the defined infective dose. In the worst case scenario, a minimum and most likely concentration of 6.3 and 7.8 log CFU of E. coli per serving respectively were observed. The simulation revealed that lowering the temperature in the chain considerably decreased the E. coli concentration prior to consumption and subsequently decreased the percentage of exposure to the infective dose. Exposure to infective dose however was increased with longer lag time from postproduction to consumption.

Synthesis strategy: building a culturally sensitive mid-range theory of risk perception using literary, quantitative, and qualitative methods.

Science.gov (United States)

Siaki, Leilani A; Loescher, Lois J; Trego, Lori L

2013-03-01

This article presents a discussion of development of a mid-range theory of risk perception. Unhealthy behaviours contribute to the development of health inequalities worldwide. The link between perceived risk and successful health behaviour change is inconclusive, particularly in vulnerable populations. This may be attributed to inattention to culture. The synthesis strategy of theory building guided the process using three methods: (1) a systematic review of literature published between 2000-2011 targeting perceived risk in vulnerable populations; (2) qualitative and (3) quantitative data from a study of Samoan Pacific Islanders at high risk of cardiovascular disease and diabetes. Main concepts of this theory include risk attention, appraisal processes, cognition, and affect. Overarching these concepts is health-world view: cultural ways of knowing, beliefs, values, images, and ideas. This theory proposes the following: (1) risk attention varies based on knowledge of the health risk in the context of health-world views; (2) risk appraisals are influenced by affect, health-world views, cultural customs, and protocols that intersect with the health risk; (3) strength of cultural beliefs, values, and images (cultural identity) mediate risk attention and risk appraisal influencing the likelihood that persons will engage in health-promoting behaviours that may contradict cultural customs/protocols. Interventions guided by a culturally sensitive mid-range theory may improve behaviour-related health inequalities in vulnerable populations. The synthesis strategy is an intensive process for developing a culturally sensitive mid-range theory. Testing of the theory will ascertain its usefulness for reducing health inequalities in vulnerable groups. © 2012 Blackwell Publishing Ltd.

Quantitative analysis and health risk assessment of polycyclic aromatic hydrocarbons in edible vegetable oils marketed in Shandong of China.

Science.gov (United States)

Jiang, Dafeng; Xin, Chenglong; Li, Wei; Chen, Jindong; Li, Fenghua; Chu, Zunhua; Xiao, Peirui; Shao, Lijun

2015-09-01

This work studies on the quantitative analysis and health risk assessment of polycyclic aromatic hydrocarbons (PAHs) in edible vegetable oils in Shandong, China. The concentrations of 15 PAHs in 242 samples were determined by high performance liquid chromatography coupled with fluorescence detection. The results indicated that the mean concentration of 15 PAHs in oil samples was 54.37 μg kg(-1). Low molecular weight PAH compounds were the predominant contamination. Especially, the carcinogenic benzo(a)pyrene (BaP) was detected at a mean concentration of 1.28 μg kg(-1), which was lower than the limit of European Union and China. A preliminary evaluation of human health risk assessment for PAHs was accomplished using BaP toxic equivalency factors and the incremental lifetime cancer risk (ILCR). The ILCR values for children, adolescents, adults, and seniors were all larger than 1 × 10(-6), indicating a high potential carcinogenic risk on the dietary exposed populations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Quantitative assessments of indoor air pollution and the risk of childhood acute leukemia in Shanghai

International Nuclear Information System (INIS)

Gao, Yu; Zhang, Yan; Kamijima, Michihiro; Sakai, Kiyoshi; Khalequzzaman, Md; Nakajima, Tamie; Shi, Rong; Wang, Xiaojin; Chen, Didi; Ji, Xiaofan; Han, Kaiyi; Tian, Ying

2014-01-01

We investigated the association between indoor air pollutants and childhood acute leukemia (AL). A total of 105 newly diagnosed cases and 105 1:1 gender-, age-, and hospital-matched controls were included. Measurements of indoor pollutants (including nitrogen dioxide (NO 2 ) and 17 types of volatile organic compounds (VOCs)) were taken with diffusive samplers for 64 pairs of cases and controls. Higher concentrations of NO 2 and almost half of VOCs were observed in the cases than in the controls and were associated with the increased risk of childhood AL. The use of synthetic materials for wall decoration and furniture in bedroom was related to the risk of childhood AL. Renovating the house in the last 5 years, changing furniture in the last 5 years, closing the doors and windows overnight in the winter and/or summer, paternal smoking history and outdoor pollutants affected VOC concentrations. Our results support the association between childhood AL and indoor air pollution. - Highlights: • We firstly assessed the effects of indoor air pollution on childhood AL in China. • Indoor air pollutants were assessed by questionnaire and quantitative measurements. • NO 2 and 17 types of VOCs were measured in bedrooms of both cases and controls. • Higher concentrations of indoor air pollutants increased the risk of childhood AL. • Indoor behavioral factors and outdoor pollution might affect indoor air pollution. - Higher concentrations of indoor air pollutants were related to an elevated risk of childhood AL

Probabilistic quantitative microbial risk assessment model of norovirus from wastewater irrigated vegetables in Ghana using genome copies and fecal indicator ratio conversion for estimating exposure dose

DEFF Research Database (Denmark)

Owusu-Ansah, Emmanuel de-Graft Johnson; Sampson, Angelina; Amponsah, Samuel K.

2017-01-01

physical and environmental factors that might influence the reliability of using indicator organisms in microbial risk assessment. The challenges facing analytical studies on virus enumeration (genome copies or particles) have contributed to the already existing lack of data in QMRA modelling. This study......The need to replace the commonly applied fecal indicator conversions ratio (an assumption of 1:10− 5 virus to fecal indicator organism) in Quantitative Microbial Risk Assessment (QMRA) with models based on quantitative data on the virus of interest has gained prominence due to the different...... attempts to fit a QMRA model to genome copies of norovirus data. The model estimates the risk of norovirus infection from the intake of vegetables irrigated with wastewater from different sources. The results were compared to the results of a corresponding model using the fecal indicator conversion ratio...

Rapid Quantification of Viable Campylobacter Bacteria on Chicken Carcasses, Using Real-Time PCR and Propidium Monoazide Treatment, as a Tool for Quantitative Risk Assessment

DEFF Research Database (Denmark)

Josefsen, Mathilde Hartmann; Löfström, Charlotta; Hansen, Tina Beck

2010-01-01

A number of intervention strategies against Campylobacter contaminated poultry focus on post-slaughter reduction of the number of cells, emphasizing the need for rapid and reliable quantitative detection of only viable Campylobacter. We present a new and rapid quantitative approach for enumeration...... method does not detect DNA from dead Campylobacter, but recognises the infectious potential of the VBNC state, and is thereby able to assess the effect of control strategies, and provide trustworthy data for risk assessment....

Exploration Health Risks: Probabilistic Risk Assessment

Science.gov (United States)

Rhatigan, Jennifer; Charles, John; Hayes, Judith; Wren, Kiley

2006-01-01

Maintenance of human health on long-duration exploration missions is a primary challenge to mission designers. Indeed, human health risks are currently the largest risk contributors to the risks of evacuation or loss of the crew on long-duration International Space Station missions. We describe a quantitative assessment of the relative probabilities of occurrence of the individual risks to human safety and efficiency during space flight to augment qualitative assessments used in this field to date. Quantitative probabilistic risk assessments will allow program managers to focus resources on those human health risks most likely to occur with undesirable consequences. Truly quantitative assessments are common, even expected, in the engineering and actuarial spheres, but that capability is just emerging in some arenas of life sciences research, such as identifying and minimize the hazards to astronauts during future space exploration missions. Our expectation is that these results can be used to inform NASA mission design trade studies in the near future with the objective of preventing the higher among the human health risks. We identify and discuss statistical techniques to provide this risk quantification based on relevant sets of astronaut biomedical data from short and long duration space flights as well as relevant analog populations. We outline critical assumptions made in the calculations and discuss the rationale for these. Our efforts to date have focussed on quantifying the probabilities of medical risks that are qualitatively perceived as relatively high risks of radiation sickness, cardiac dysrhythmias, medically significant renal stone formation due to increased calcium mobilization, decompression sickness as a result of EVA (extravehicular activity), and bone fracture due to loss of bone mineral density. We present these quantitative probabilities in order-of-magnitude comparison format so that relative risk can be gauged. We address the effects of

Quantitative falls risk estimation through multi-sensor assessment of standing balance.

Science.gov (United States)

Greene, Barry R; McGrath, Denise; Walsh, Lorcan; Doheny, Emer P; McKeown, David; Garattini, Chiara; Cunningham, Clodagh; Crosby, Lisa; Caulfield, Brian; Kenny, Rose A

2012-12-01

Falls are the most common cause of injury and hospitalization and one of the principal causes of death and disability in older adults worldwide. Measures of postural stability have been associated with the incidence of falls in older adults. The aim of this study was to develop a model that accurately classifies fallers and non-fallers using novel multi-sensor quantitative balance metrics that can be easily deployed into a home or clinic setting. We compared the classification accuracy of our model with an established method for falls risk assessment, the Berg balance scale. Data were acquired using two sensor modalities--a pressure sensitive platform sensor and a body-worn inertial sensor, mounted on the lower back--from 120 community dwelling older adults (65 with a history of falls, 55 without, mean age 73.7 ± 5.8 years, 63 female) while performing a number of standing balance tasks in a geriatric research clinic. Results obtained using a support vector machine yielded a mean classification accuracy of 71.52% (95% CI: 68.82-74.28) in classifying falls history, obtained using one model classifying all data points. Considering male and female participant data separately yielded classification accuracies of 72.80% (95% CI: 68.85-77.17) and 73.33% (95% CI: 69.88-76.81) respectively, leading to a mean classification accuracy of 73.07% in identifying participants with a history of falls. Results compare favourably to those obtained using the Berg balance scale (mean classification accuracy: 59.42% (95% CI: 56.96-61.88)). Results from the present study could lead to a robust method for assessing falls risk in both supervised and unsupervised environments.

Effects of a 20 year rain event: a quantitative microbial risk assessment of a case of contaminated bathing water in Copenhagen, Denmark

DEFF Research Database (Denmark)

Andersen, Signe Tanja; Erichsen, A. C.; Mark, O.

2013-01-01

Quantitative microbial risk assessments (QMRAs) often lack data on water quality leading to great uncertainty in the QMRA because of the many assumptions. The quantity of waste water contamination was estimated and included in a QMRA on an extreme rain event leading to combined sewer overflow (CS...

A risk assessment-driven quantitative comparison of gene expression profiles in PBMCs and white adipose tissue of humans and rats after isoflavone supplementation

NARCIS (Netherlands)

Velpen, van der V.; Veer, van 't P.; Islam, M.A.; Braak, ter C.J.F.; Leeuwen, F.X.R.; Afman, L.A.; Hollman, P.C.H.; Schouten, A.; Geelen, M.M.E.E.

2016-01-01

Quantitative insight into species differences in risk assessment is expected to reduce uncertainty and variability related to extrapolation from animals to humans. This paper explores quantification and comparison of gene expression data between tissues and species from intervention studies with

Quantitative relationships between aging failure data and risk

International Nuclear Information System (INIS)

Vesely, W.E.; Vora, J.P.

1988-01-01

As part of the United States Nuclear Regulatory Commission's Nuclear Plant Aging Research program, a project is being carried out to quantify the risk effects of aging. The project is called the Risk Evaluation of Aging Phenomena (REAP) Project. With the REAP Project, a procedure has been developed to quantify nuclear power plant risks from aging failure data. The procedure utilizes the linear aging model and its extensions in order to relate component aging failure rates to aging mechanism parameters which are estimable from failure and maintenance data. The aging failure rates can then be used to quantify the age dependent plant risks, such as system unavailabilities, core melt frequency and public health risks. The REAP procedure is different from standard time dependent approaches in that the failure rates are phenomenologically based, allowing engineering information to be utilized. Furthermore, gross data and incomplete data can be utilized. A software package has been developed which systematically analyzes data for aging effects and interfaces with a time dependent risk analysis module to determine the risk implications of the aging effects. (author). 10 refs, 10 figs

Quantitative comparison of genotoxic (mutagenic and carcinogenic) risks and the choice of energy sources

International Nuclear Information System (INIS)

Latarjet, R.

1983-01-01

For 25 years, pollution for radiation has been governed by restrictive rules enacted and periodically revised by an international commission, and adopted by all countries. Nothing similar exists for mutagenic and carcinogenic chemicals. Since these substances affect the genetic material in the cells with reactions often similar to those caused by radiation, quantitative comparisons are possible, in particular for some of those compounds produced by the combustion of coal, oil and gaz. This paper describes the main results obtained at the Institut Curie, since 1975, with ethylene, ethylene oxide and vinyl chloride monomer. The consequences are discussed for: a) the establishement of control rules for the main genotoxic chemical pollutions; b) the assessment of long term risks in the cases of nuclear energy and of the energies obtained by combustion [fr

A quantitative assessment of risks of heavy metal residues in laundered shop towels and their use by workers.

Science.gov (United States)

Connor, Kevin; Magee, Brian

2014-10-01

This paper presents a risk assessment of exposure to metal residues in laundered shop towels by workers. The concentrations of 27 metals measured in a synthetic sweat leachate were used to estimate the releasable quantity of metals which could be transferred to workers' skin. Worker exposure was evaluated quantitatively with an exposure model that focused on towel-to-hand transfer and subsequent hand-to-food or -mouth transfers. The exposure model was based on conservative, but reasonable assumptions regarding towel use and default exposure factor values from the published literature or regulatory guidance. Transfer coefficients were derived from studies representative of the exposures to towel users. Contact frequencies were based on assumed high-end use of shop towels, but constrained by a theoretical maximum dermal loading. The risk estimates for workers developed for all metals were below applicable regulatory risk benchmarks. The risk assessment for lead utilized the Adult Lead Model and concluded that predicted lead intakes do not constitute a significant health hazard based on potential worker exposures. Uncertainties are discussed in relation to the overall confidence in the exposure estimates developed for each exposure pathway and the likelihood that the exposure model is under- or overestimating worker exposures and risk. Copyright © 2014 Elsevier Inc. All rights reserved.

Quantitative Microbial Risk Assessment for Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes in Leafy Green Vegetables Consumed at Salad Bars, Based on Modeling Supply Chain Logistics

NARCIS (Netherlands)

Tromp, S.O.; Rijgersberg, H.; Franz, E.

2010-01-01

Quantitative microbial risk assessments do not usually account for the planning and ordering mechanisms (logistics) of a food supply chain. These mechanisms and consumer demand determine the storage and delay times of products. The aim of this study was to quantitatively assess the difference

Quantitative falls risk estimation through multi-sensor assessment of standing balance

International Nuclear Information System (INIS)

Greene, Barry R; McGrath, Denise; Walsh, Lorcan; Doheny, Emer P; McKeown, David; Garattini, Chiara; Cunningham, Clodagh; Crosby, Lisa; Caulfield, Brian; Kenny, Rose A

2012-01-01

Falls are the most common cause of injury and hospitalization and one of the principal causes of death and disability in older adults worldwide. Measures of postural stability have been associated with the incidence of falls in older adults. The aim of this study was to develop a model that accurately classifies fallers and non-fallers using novel multi-sensor quantitative balance metrics that can be easily deployed into a home or clinic setting. We compared the classification accuracy of our model with an established method for falls risk assessment, the Berg balance scale. Data were acquired using two sensor modalities—a pressure sensitive platform sensor and a body-worn inertial sensor, mounted on the lower back—from 120 community dwelling older adults (65 with a history of falls, 55 without, mean age 73.7 ± 5.8 years, 63 female) while performing a number of standing balance tasks in a geriatric research clinic. Results obtained using a support vector machine yielded a mean classification accuracy of 71.52% (95% CI: 68.82–74.28) in classifying falls history, obtained using one model classifying all data points. Considering male and female participant data separately yielded classification accuracies of 72.80% (95% CI: 68.85–77.17) and 73.33% (95% CI: 69.88–76.81) respectively, leading to a mean classification accuracy of 73.07% in identifying participants with a history of falls. Results compare favourably to those obtained using the Berg balance scale (mean classification accuracy: 59.42% (95% CI: 56.96–61.88)). Results from the present study could lead to a robust method for assessing falls risk in both supervised and unsupervised environments. (paper)

An educationally inspired illustration of two-dimensional Quantitative Microbiological Risk Assessment (QMRA) and sensitivity analysis.

Science.gov (United States)

Vásquez, G A; Busschaert, P; Haberbeck, L U; Uyttendaele, M; Geeraerd, A H

2014-11-03

Quantitative Microbiological Risk Assessment (QMRA) is a structured methodology used to assess the risk involved by ingestion of a pathogen. It applies mathematical models combined with an accurate exploitation of data sets, represented by distributions and - in the case of two-dimensional Monte Carlo simulations - their hyperparameters. This research aims to highlight background information, assumptions and truncations of a two-dimensional QMRA and advanced sensitivity analysis. We believe that such a detailed listing is not always clearly presented in actual risk assessment studies, while it is essential to ensure reliable and realistic simulations and interpretations. As a case-study, we are considering the occurrence of listeriosis in smoked fish products in Belgium during the period 2008-2009, using two-dimensional Monte Carlo and two sensitivity analysis methods (Spearman correlation and Sobol sensitivity indices) to estimate the most relevant factors of the final risk estimate. A risk estimate of 0.018% per consumption of contaminated smoked fish by an immunocompromised person was obtained. The final estimate of listeriosis cases (23) is within the actual reported result obtained for the same period and for the same population. Variability on the final risk estimate is determined by the variability regarding (i) consumer refrigerator temperatures, (ii) the reference growth rate of L. monocytogenes, (iii) the minimum growth temperature of L. monocytogenes and (iv) consumer portion size. Variability regarding the initial contamination level of L. monocytogenes tends to appear as a determinant of risk variability only when the minimum growth temperature is not included in the sensitivity analysis; when it is included the impact regarding the variability on the initial contamination level of L. monocytogenes is disappearing. Uncertainty determinants of the final risk indicated the need of gathering more information on the reference growth rate and the minimum

Risk Quantitative Determination of Fire and Explosion in a Process Unit By Dow’s Fire and Explosion Index

Directory of Open Access Journals (Sweden)

S. Varmazyar

2008-04-01

Full Text Available Background and aims   Fire and explosion hazards are the first and second of major hazards in process industries, respectively. This study has been done to determine fire and explosion risk severity,radius of exposure and estimating of most probable loss.   Methods   In this quantitative study process unit has been selected with affecting parameters on  fire and explosion risk. Then, it was analyzed by DOW's fire and explosion index (F&EI. Technical data were obtained from process documents and reports, fire and explosion guideline.After calculating of DOW's index, radius of exposure determined and finally most  probable loss was estimated.   Results   The results showed an F&EI value of 226 for this process unit.The F&EI was extremely  high and unacceptable.Risk severity was categorized in sever class.Radius of exposure and damage factor were calculated 57 meters and 83%,respectively. As well as most probable loss was  estimated about 6.7 million dollars.   Conclusion   F&EI is a proper technique for risk assessment and loss estimation of fire and  explosion in process industries.Also,It is an important index for detecting high risk and low risk   areas in an industry. At this technique, all of factors affecting on fire and explosion risk was  showed as index that is a base for judgement risk class. Finally, estimated losses could be used as  a base of fire and explosion insurance.

Approaches to acceptable risk

International Nuclear Information System (INIS)

Whipple, C.

1997-01-01

Several alternative approaches to address the question open-quotes How safe is safe enough?close quotes are reviewed and an attempt is made to apply the reasoning behind these approaches to the issue of acceptability of radiation exposures received in space. The approaches to the issue of the acceptability of technological risk described here are primarily analytical, and are drawn from examples in the management of environmental health risks. These include risk-based approaches, in which specific quantitative risk targets determine the acceptability of an activity, and cost-benefit and decision analysis, which generally focus on the estimation and evaluation of risks, benefits and costs, in a framework that balances these factors against each other. These analytical methods tend by their quantitative nature to emphasize the magnitude of risks, costs and alternatives, and to downplay other factors, especially those that are not easily expressed in quantitative terms, that affect acceptance or rejection of risk. Such other factors include the issues of risk perceptions and how and by whom risk decisions are made

Quantitative Microbial Risk Assessment for Escherichia coli O157 : H7, Salmonella, and Listeria monocytogenes in Leafy Green Vegetables Consumed at Salad Bars

NARCIS (Netherlands)

Franz, E.; Tromp, S.O.; Rijgersberg, H.; Fels-Klerx, van der H.J.

2010-01-01

Fresh vegetables are increasingly recognized as a source of foodborne outbreaks in many parts of the world. The purpose of this study was to conduct a quantitative microbial risk assessment for Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes infection from consumption of leafy green

Quantitative risk assessment via uncertainty analysis in combination with error propagation for the determination of the dynamic Design Space of the primary drying step during freeze-drying

DEFF Research Database (Denmark)

Van Bockstal, Pieter Jan; Mortier, Séverine Thérèse F.C.; Corver, Jos

2017-01-01

of a freeze-drying process, allowing to quantitatively estimate and control the risk of cake collapse (i.e., the Risk of Failure (RoF)). The propagation of the error on the estimation of the thickness of the dried layer Ldried as function of primary drying time was included in the uncertainty analysis...

Industrial risks

International Nuclear Information System (INIS)

Okrent, D.

1981-01-01

A brief look is taken at the status of progress, or the lack of it, towards a quantitative approach to the estimation and assessment of risk for several technologies in the United States. The increase of interest in the consideration of comparative risks in decision-making is also discussed. Finally, a recently proposed trial approach to quantitative safety goals for light-water nuclear power reactors is summarized. The approach is divided into two major tasks: the predominantly social and political task of setting safety criteria, and the technical task of estimating the risks and deciding whether the safety criteria have been met. The safety criteria include the following: limits on hazard states within the reactor; limits on risk to the individual; limits on societal risk; a cost-effectiveness criterion as low as reasonably achievable; a small element of risk aversion. (author)

Quantitative microbial risk assessment for spray irrigation of dairy manure based on an empirical fate and transport model

Science.gov (United States)

Burch, Tucker R; Spencer, Susan K.; Stokdyk, Joel; Kieke, Burney A; Larson, Rebecca A; Firnstahl, Aaron; Rule, Ana M; Borchardt, Mark A.

2017-01-01

BACKGROUND: Spray irrigation for land-applying livestock manure is increasing in the United States as farms become larger and economies of scale make manure irrigation affordable. Human health risks from exposure to zoonotic pathogens aerosolized during manure irrigation are not well understood. OBJECTIVES: We aimed to a) estimate human health risks due to aerosolized zoonotic pathogens downwind of spray-irrigated dairy manure; and b) determine which factors (e.g., distance, weather conditions) have the greatest influence on risk estimates. METHODS: We sampled downwind air concentrations of manure-borne fecal indicators and zoonotic pathogens during 21 full-scale dairy manure irri- gation events at three farms. We fit these data to hierarchical empirical models and used model outputs in a quantitative microbial risk assessment (QMRA) to estimate risk [probability of acute gastrointestinal illness (AGI)] for individuals exposed to spray-irrigated dairy manure containing Campylobacter jejuni, enterohemorrhagic Escherichia coli (EHEC), or Salmonella spp. RESULTS: Median risk estimates from Monte Carlo simulations ranged from 10−5 to 10−2 and decreased with distance from the source. Risk estimates for Salmonella or EHEC-related AGI were most sensitive to the assumed level of pathogen prevalence in dairy manure, while risk estimates for C. jejuni were not sensitive to any single variable. Airborne microbe concentrations were negatively associated with distance and positively associated with wind speed, both of which were retained in models as a significant predictor more often than relative humidity, solar irradiation, or temperature. CONCLUSIONS: Our model-based estimates suggest that reducing pathogen prevalence and concentration in source manure would reduce the risk of AGI from exposure to manure irrigation, and that increasing the distance from irrigated manure (i.e., setbacks) and limiting irrigation to times of low wind speed may also reduce risk.

Assessment of the health impact of an environmental pollution and quantitative assessment of health risks; Estimation de l'impact sanitaire d'une pollution environnementale et evaluation quantitative des risques sanitaires

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-09-15

The report made by a working group is written for experts in health risk assessment or for professionals involved in risk management. It proposes a methodological and conceptual framework which could build a unified approach to a quantitative assessment of health risks. In the first part, under the form of questions and answers, it defines the health impact, describes how to assess the excess of individual risk and the related hypothesis, how to pass from the excess of individual risk to the health impact, how to express the results of an health impact calculation, how to take the lack of knowledge into account at the different steps of this calculation, what is the significance of the result of such a calculation, and how useful an health impact assessment can be. The second part proposes a more detailed presentation of the scientific background for the health impact calculation with its indicators, its uncertainties, its practice in other countries, its relevance, and its fields of application. Then, after a comment of the dose-response relationship, it reports the scientific validity of the assessment of a number of cases.

Predictive value of quantitative dipyridamole-thallium scintigraphy in assessing cardiovascular risk after vascular surgery in diabetes mellitus

International Nuclear Information System (INIS)

Lane, S.E.; Lewis, S.M.; Pippin, J.J.; Kosinski, E.J.; Campbell, D.; Nesto, R.W.; Hill, T.

1989-01-01

Cardiac complications represent a major risk to patients undergoing vascular surgery. Diabetic patients may be particularly prone to such complications due to the high incidence of concomitant coronary artery disease, the severity of which may be clinically unrecognized. Attempts to stratify groups by clinical criteria have been useful but lack the predictive value of currently used noninvasive techniques such as dipyridamole-thallium scintigraphy. One hundred one diabetic patients were evaluated with dipyridamole-thallium scintigraphy before undergoing vascular surgery. The incidence of thallium abnormalities was high (80%) and did not correlate with clinical markers of coronary disease. Even in a subgroup of patients with no overt clinical evidence of underlying heart disease, thallium abnormalities were present in 59%. Cardiovascular complications, however, occurred in only 11% of all patients. Statistically significant prediction of risk was not achieved with simple assessment of thallium results as normal or abnormal. Quantification of total number of reversible defects, as well as assessment of ischemia in the distribution of the left anterior descending coronary artery was required for optimum predictive accuracy. The prevalence of dipyridamole-thallium abnormalities in a diabetic population is much higher than that reported in nondiabetic patients and cannot be predicted by usual clinical indicators of heart disease. In addition, cardiovascular risk of vascular surgery can be optimally assessed by quantitative analysis of dipyridamole-thallium scintigraphy and identification of high- and low-risk subgroups

Quantitative imaging methods in osteoporosis.

Science.gov (United States)

Oei, Ling; Koromani, Fjorda; Rivadeneira, Fernando; Zillikens, M Carola; Oei, Edwin H G

2016-12-01

Osteoporosis is characterized by a decreased bone mass and quality resulting in an increased fracture risk. Quantitative imaging methods are critical in the diagnosis and follow-up of treatment effects in osteoporosis. Prior radiographic vertebral fractures and bone mineral density (BMD) as a quantitative parameter derived from dual-energy X-ray absorptiometry (DXA) are among the strongest known predictors of future osteoporotic fractures. Therefore, current clinical decision making relies heavily on accurate assessment of these imaging features. Further, novel quantitative techniques are being developed to appraise additional characteristics of osteoporosis including three-dimensional bone architecture with quantitative computed tomography (QCT). Dedicated high-resolution (HR) CT equipment is available to enhance image quality. At the other end of the spectrum, by utilizing post-processing techniques such as the trabecular bone score (TBS) information on three-dimensional architecture can be derived from DXA images. Further developments in magnetic resonance imaging (MRI) seem promising to not only capture bone micro-architecture but also characterize processes at the molecular level. This review provides an overview of various quantitative imaging techniques based on different radiological modalities utilized in clinical osteoporosis care and research.

Quantitative risk assessment using the capacity-demand analysis

International Nuclear Information System (INIS)

Morgenroth, M.; Donnelly, C.R.; Westermann, G.D.; Huang, J.H.S.; Lam, T.M.

1999-01-01

The hydroelectric industry's recognition of the importance of avoiding unexpected failure, or forced outages, led to the development of probabilistic, or risk-based, methods in order to attempt to quantify exposures. Traditionally, such analysis has been carried out by qualitative assessments, relying on experience and sound engineering judgment to determine the optimum time to maintain, repair or replace a part or system. Depending on the nature of the problem, however, and the level of experience of those included in the decision making process, it is difficult to find a balance between acting proactively and accepting some amount of risk. The development of a practical means for establishing the probability of failure of any part or system, based on the determination of the statistical distribution of engineering properties such as acting stresses, is discussed. The capacity-demand analysis methodology, coupled with probablistic, risk-based analysis, permits all the factors associated with a decision to rehabilitate or replace a part, including the risks associated with the timing of the decision, to be assessed in a transparent and defendable manner. The methodology does not eliminate judgment altogether, but does move it from the level of estimating the risk of failure to the lower level of estimating variability in material properties, uncertainty in loading, and the uncertainties inherent in any engineering analysis. The method was successfully used in 1998 to carry out a comprehensive, economic risk analysis for the entire water conveyance system of a 90 year old hydropower station. The analysis included a number of diverse parts ranging from rock slopes and aging steel and concrete conduits, and the method allowed a rational assessment of the risks associated with reach of these varied parts to be determined, permitting the essential remedial works to be prioritized. 14 refs., 4 figs

Distinguishing nanomaterial particles from background airborne particulate matter for quantitative exposure assessment

Science.gov (United States)

Ono-Ogasawara, Mariko; Serita, Fumio; Takaya, Mitsutoshi

2009-10-01

As the production of engineered nanomaterials quantitatively expands, the chance that workers involved in the manufacturing process will be exposed to nanoparticles also increases. A risk management system is needed for workplaces in the nanomaterial industry based on the precautionary principle. One of the problems in the risk management system is difficulty of exposure assessment. In this article, examples of exposure assessment in nanomaterial industries are reviewed with a focus on distinguishing engineered nanomaterial particles from background nanoparticles in workplace atmosphere. An approach by JNIOSH (Japan National Institute of Occupational Safety and Health) to quantitatively measure exposure to carbonaceous nanomaterials is also introduced. In addition to real-time measurements and qualitative analysis by electron microscopy, quantitative chemical analysis is necessary for quantitatively assessing exposure to nanomaterials. Chemical analysis is suitable for quantitative exposure measurement especially at facilities with high levels of background NPs.

Potential impacts of radon, terrestrial gamma and cosmic rays on childhood leukemia in France: a quantitative risk assessment

Energy Technology Data Exchange (ETDEWEB)

Laurent, Olivier [French Institute for Radiological Protection and Nuclear Safety, Radiobiology and Epidemiology Department, IRSN, PRP-HOM, SRBE, LEPID, Fontenay aux Roses (France); University of California, Irvine, Department of Population Health and Disease Prevention, Irvine, CA (United States); Ancelet, Sophie; Laurier, Dominique [French Institute for Radiological Protection and Nuclear Safety, Radiobiology and Epidemiology Department, IRSN, PRP-HOM, SRBE, LEPID, Fontenay aux Roses (France); Richardson, David B. [University of North Carolina at Chapel Hill, Department of Epidemiology, School of Public Health, Chapel Hill, NC (United States); Hemon, Denis; Demoury, Claire; Clavel, Jacqueline [Inserm, CESP Center for Research in Epidemiology and Population Health, U1018, Environmental Epidemiology of Cancer Team, Villejuif (France); Paris-Sud University, UMRS 1018, Villejuif (France); Ielsch, Geraldine [French Institute for Radiological Protection and Nuclear Safety, Assessment Unit for Risks Related to Natural Radioactivity, IRSN, PRP-DGE, SEDRAN, BRN, Fontenay aux Roses (France)

2013-05-15

Previous epidemiological studies and quantitative risk assessments (QRA) have suggested that natural background radiation may be a cause of childhood leukemia. The present work uses a QRA approach to predict the excess risk of childhood leukemia in France related to three components of natural radiation: radon, cosmic rays and terrestrial gamma rays, using excess relative and absolute risk models proposed by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Both models were developed from the Life Span Study (LSS) of Japanese A-bomb survivors. Previous risk assessments were extended by considering uncertainties in radiation-related leukemia risk model parameters as part of this process, within a Bayesian framework. Estimated red bone marrow doses cumulated during childhood by the average French child due to radon, terrestrial gamma and cosmic rays are 4.4, 7.5 and 4.3 mSv, respectively. The excess fractions of cases (expressed as percentages) associated with these sources of natural radiation are 20 % [95 % credible interval (CI) 0-68 %] and 4 % (95 % CI 0-11 %) under the excess relative and excess absolute risk models, respectively. The large CIs, as well as the different point estimates obtained under these two models, highlight the uncertainties in predictions of radiation-related childhood leukemia risks. These results are only valid provided that models developed from the LSS can be transferred to the population of French children and to chronic natural radiation exposures, and must be considered in view of the currently limited knowledge concerning other potential risk factors for childhood leukemia. Last, they emphasize the need for further epidemiological investigations of the effects of natural radiation on childhood leukemia to reduce uncertainties and help refine radiation protection standards. (orig.)

Potential impacts of radon, terrestrial gamma and cosmic rays on childhood leukemia in France: a quantitative risk assessment

International Nuclear Information System (INIS)

Laurent, Olivier; Ancelet, Sophie; Laurier, Dominique; Richardson, David B.; Hemon, Denis; Demoury, Claire; Clavel, Jacqueline; Ielsch, Geraldine

2013-01-01

Previous epidemiological studies and quantitative risk assessments (QRA) have suggested that natural background radiation may be a cause of childhood leukemia. The present work uses a QRA approach to predict the excess risk of childhood leukemia in France related to three components of natural radiation: radon, cosmic rays and terrestrial gamma rays, using excess relative and absolute risk models proposed by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). Both models were developed from the Life Span Study (LSS) of Japanese A-bomb survivors. Previous risk assessments were extended by considering uncertainties in radiation-related leukemia risk model parameters as part of this process, within a Bayesian framework. Estimated red bone marrow doses cumulated during childhood by the average French child due to radon, terrestrial gamma and cosmic rays are 4.4, 7.5 and 4.3 mSv, respectively. The excess fractions of cases (expressed as percentages) associated with these sources of natural radiation are 20 % [95 % credible interval (CI) 0-68 %] and 4 % (95 % CI 0-11 %) under the excess relative and excess absolute risk models, respectively. The large CIs, as well as the different point estimates obtained under these two models, highlight the uncertainties in predictions of radiation-related childhood leukemia risks. These results are only valid provided that models developed from the LSS can be transferred to the population of French children and to chronic natural radiation exposures, and must be considered in view of the currently limited knowledge concerning other potential risk factors for childhood leukemia. Last, they emphasize the need for further epidemiological investigations of the effects of natural radiation on childhood leukemia to reduce uncertainties and help refine radiation protection standards. (orig.)

Review of interspecies risk comparisons

International Nuclear Information System (INIS)

Brown, S.L.; Brett, S.M.; Gough, M.; Rodricks, J.V.; Tardiff, R.G.; Turnbull, D.

1988-01-01

Use of laboratory animal data to make quantitative predictions of the risks of toxic effects in humans assumes that a relationship exists between the potencies in animals and humans and that its parameters can be estimated adequately. Such ''scaling rules'' have been used to predict the risks of carcinogenicity or other effects. A survey of the literature yielded only a modest number of papers devoted to the validity of these interspecies risk extrapolations, of which approximately 25 attempt quantitative comparisons for either radiation or chemical hazards. Some authors have investigated relatively large data sets in an attempt to identify the scaling rule that provides the best correlation of risks in two or more species. Others have selected a scaling rule and investigated whether its predictions from data in laboratory species match the risks found in humans. Opinion is divided on the validity of specific extrapolation rules and the utility of animal experiments for quantitative risk assessment. Correlations exist among risk levels in various species, but many factors appear to influence toxicity that are not captured in a simple scaling rule such as dose per unit weight or per unit surface area. Although scaling rules are useful, better projections will be made if case-specific factors such as pharmacokinetics can be considered. Further careful comparisons of quantitative risk estimates are needed. 38 references

Evaluations and utilizations of risk importances

International Nuclear Information System (INIS)

Vesely, W.E.; Davis, T.C.

1985-08-01

This report presents approaches for utilizing Probabilistic Risk Analyses (PRA's) to determine risk importances. Risk importances are determined for design features, plant operations, and other factors that can affect risk. PRA's can be used to identify the importances of risk contributors or proposed changes to designs or operations. The objective of this report is to serve as a handbook and guide in evaluating and applying risk importances. The utilization of both qualitative risk importances and quantitative risk importances is described in this report. Qualitative risk importances are based on the logic models in the PRA, while quantitative risk importances are based on the quantitative results of the PRA. Both types of importances are among the most robust and meaningful information a PRA can provide. A wide variety of risk importance evaluations are described including evaluations of the importances of design changes, testing, maintenance, degrading environments, and aging. Specific utilizations are described in inspection and in reliability assurance programs, however the general approaches have widespread applicability. The role of personal computers and decision support programs in applying risk importance evaluations is also described

HERMES docking/berthing system pilot study. Quantitative assessment

International Nuclear Information System (INIS)

Munoz Blasco, J.; Goicoechea Sanchez, F.J.

1993-01-01

This study falls within the framework of the incorporation of quantitative risk assessment to the activities planned for the ESA-HERMES project (ESA/ CNES). The main objective behind the study was the analysis and evaluation of the potential contribution of so-called probabilistic or quantitative safety analysis to the optimization of the safety development process for the systems carrying out the safety functions required by the new and complex HERMES Space Vehicle. For this purpose, a pilot study was considered a good start in quantitative safety assessments (QSA), as this approach has been frequently used in the past to establish a solid base in large-scale QSA application programs while avoiding considerable economic risks. It was finally decided to select the HERMES docking/berthing system with Man Tender Free Flyer as the case-study. This report describes the different steps followed in the study, along with the main insights obtained and the general conclusions drawn from the study results. (author)

Evaluating the Spatial Distribution of Quantitative Risk and Hazard Level of Arsenic Exposure in Groundwater, case Study of Qorveh County, Kurdistan Iran

Directory of Open Access Journals (Sweden)

Touraj Nasrabadi

2013-04-01

Full Text Available Regional distribution of quantitative risk and hazard levels due to arsenic poisoning in some parts of Iran’s Kurdistan province is considered. To investigate the potential risk and hazard level regarding arsenic-contaminated drinking water and further carcinogenic and non-carcinogenic effects on villagers, thirteen wells in rural areas of Qorveh County were considered for evaluation of arsenic concentration in water. Sampling campaign was performed in August 2010 and arsenic concentration was measured via the Silver Diethyldithiocarbamate method. The highest and lowest arsenic concentration are reported in Guilaklu and Qezeljakand villages with 420 and 67 μg/L, respectively. None of thirteen water samples met the maximum contaminant level issued by USEPA and Institute of Standards and Industrial Research of Iran (10 ppb. The highest arsenic concentration and consequently risk and hazard levels belong to villages situated alongside the eastern frontiers of the county. Existence of volcanic activities within the upper Miocene and Pleistocene in this part of the study area may be addressed as the main geopogenic source of arsenic pollution. Quantitative risk values are varying from 1.49E-03 in Qezeljakand to 8.92E-03 in Guilaklu and may be interpreted as very high when compared by similar studies in Iran. Regarding non-carcinogenic effects, all thirteen water samples are considered hazardous while all calculated chronic daily intakes are greater than arsenic reference dose. Such drinking water source has the potential to impose adverse carcinogenic and non-carcinogenic effects on villagers. Accordingly, an urgent decision must be made to substitute the current drinking water source with a safer one.

Improved cancer risk stratification and diagnosis via quantitative phase microscopy (Conference Presentation)

Science.gov (United States)

Liu, Yang; Uttam, Shikhar; Pham, Hoa V.; Hartman, Douglas J.

2017-02-01

Pathology remains the gold standard for cancer diagnosis and in some cases prognosis, in which trained pathologists examine abnormality in tissue architecture and cell morphology characteristic of cancer cells with a bright-field microscope. The limited resolution of conventional microscope can result in intra-observer variation, missed early-stage cancers, and indeterminate cases that often result in unnecessary invasive procedures in the absence of cancer. Assessment of nanoscale structural characteristics via quantitative phase represents a promising strategy for identifying pre-cancerous or cancerous cells, due to its nanoscale sensitivity to optical path length, simple sample preparation (i.e., label-free) and low cost. I will present the development of quantitative phase microscopy system in transmission and reflection configuration to detect the structural changes in nuclear architecture, not be easily identifiable by conventional pathology. Specifically, we will present the use of transmission-mode quantitative phase imaging to improve diagnostic accuracy of urine cytology and the nuclear dry mass is progressively correlate with negative, atypical, suspicious and positive cytological diagnosis. In a second application, we will present the use of reflection-mode quantitative phase microscopy for depth-resolved nanoscale nuclear architecture mapping (nanoNAM) of clinically prepared formalin-fixed, paraffin-embedded tissue sections. We demonstrated that the quantitative phase microscopy system detects a gradual increase in the density alteration of nuclear architecture during malignant transformation in animal models of colon carcinogenesis and in human patients with ulcerative colitis, even in tissue that appears histologically normal according to pathologists. We evaluated the ability of nanoNAM to predict "future" cancer progression in patients with ulcerative colitis.

Development of a semi-quantitative risk assessment model for evaluating environmental threat posed by the three first EU watch-list pharmaceuticals to urban wastewater treatment plants: An Irish case study.

Science.gov (United States)

Tahar, Alexandre; Tiedeken, Erin Jo; Clifford, Eoghan; Cummins, Enda; Rowan, Neil

2017-12-15

Contamination of receiving waters with pharmaceutical compounds is of pressing concern. This constitutes the first study to report on the development of a semi-quantitative risk assessment (RA) model for evaluating the environmental threat posed by three EU watch list pharmaceutical compounds namely, diclofenac, 17-beta-estradiol and 17-alpha-ethinylestradiol, to aquatic ecosystems using Irish data as a case study. This RA model adopts the Irish Environmental Protection Agency Source-Pathway-Receptor concept to define relevant parameters for calculating low, medium or high risk score for each agglomeration of wastewater treatment plant (WWTP), which include catchment, treatments, operational and management factors. This RA model may potentially be used on a national scale to (i) identify WWTPs that pose a particular risk as regards releasing disproportionally high levels of these pharmaceutical compounds, and (ii) help identify priority locations for introducing or upgrading control measures (e.g. tertiary treatment, source reduction). To assess risks for these substances of emerging concern, the model was applied to 16 urban WWTPs located in different regions in Ireland that were scored for the three different compounds and ranked as low, medium or high risk. As a validation proxy, this case study used limited monitoring data recorded at some these plants receiving waters. It is envisaged that this semi-quantitative RA approach may aid other EU countries investigate and screen for potential risks where limited measured or predicted environmental pollutant concentrations and/or hydrological data are available. This model is semi-quantitative, as other factors such as influence of climate change and drug usage or prescription data will need to be considered in a future point for estimating and predicting risks. Copyright © 2017 Elsevier B.V. All rights reserved.

SNP rs16906252C>T is an expression and methylation quantitative trait locus associated with an increased risk of developing MGMT-methylated colorectal cancer

Science.gov (United States)

Kuroiwa-Trzmielina, Joice; Wang, Fan; Rapkins, Robert W.; Ward, Robyn L.; Buchanan, Daniel D.; Win, Aung Ko; Clendenning, Mark; Rosty, Christophe; Southey, Melissa C.; Winship, Ingrid M.; Hopper, John L.; Jenkins, Mark A.; Olivier, Jake; Hawkins, Nicholas J.; Hitchins, Megan P.

2016-01-01

Purpose Methylation of the MGMT promoter is the major cause of O6-methylguanine methyltransferase deficiency in cancer and has been associated with the T variant of the promoter-enhancer SNP rs16906252C>T. We sought evidence for an association between the rs16906252C>T genotype and increased risk of developing a subtype of colorectal cancer (CRC) featuring MGMT methylation, mediated by genotype-dependent epigenetic silencing within normal tissues. Experimental design By applying a molecular pathological epidemiology case-control study design, associations between rs16906252C>T and risk for CRC overall, and CRC stratified by MGMT methylation status, were estimated using multinomial logistic regression in two independent retrospective series of CRC cases and controls. The test sample comprised 1054 CRC cases and 451 controls from Sydney, Australia. The validation sample comprised 612 CRC cases and 245 controls from the Australasian Colon Cancer Family Registry (ACCFR). To determine if rs16906252C>T was linked to a constitutively altered epigenetic state, quantitative allelic expression and methylation analyses were performed in normal tissues. Results An association between rs16906252C>T and increased risk of developing MGMT-methylated CRC in the Sydney sample was observed (OR 3.3; 95%CI=2.0–5.3; PT represents an expression and methylation quantitative trait locus. Conclusions We provide evidence that rs16906252C>T is associated with elevated risk for MGMT-methylated CRC, likely mediated by constitutive epigenetic repression of the T allele. PMID:27267851

Application of Quantitative Microbial Risk Assessment to analyze the public health risk from poor drinking water quality in a low income area in Accra, Ghana.

Science.gov (United States)

Machdar, E; van der Steen, N P; Raschid-Sally, L; Lens, P N L

2013-04-01

In Accra, Ghana, a majority of inhabitants lives in over-crowded areas with limited access to piped water supply, which is often also intermittent. This study assessed in a densely populated area the risk from microbial contamination of various sources of drinking water, by conducting a Quantitative Microbiological Risk Assessment (QMRA) to estimate the risk to human health from microorganism exposure and dose-response relationships. Furthermore the cost-effectiveness in reducing the disease burden through targeted interventions was evaluated. Five risk pathways for drinking water were identified through a survey (110 families), namely household storage, private yard taps, communal taps, communal wells and water sachets. Samples from each source were analyzed for Escherichia coli and Ascaris contamination. Published ratios between E. coli and other pathogens were used for the QMRA and disease burden calculations. The major part of the burden of disease originated from E. coli O157:H7 (78%) and the least important contributor was Cryptosporidium (0.01%). Other pathogens contributed 16% (Campylobacter), 5% (Rotavirus) and 0.3% (Ascaris). The sum of the disease burden of these pathogens was 0.5 DALYs per person per year, which is much higher than the WHO reference level. The major contamination pathway was found to be household storage. Disinfection of water at household level was the most cost-effective intervention (Water supply network improvements were significantly less cost-effective. Copyright © 2013 Elsevier B.V. All rights reserved.

Credit Risk Modeling

DEFF Research Database (Denmark)

Lando, David

Credit risk is today one of the most intensely studied topics in quantitative finance. This book provides an introduction and overview for readers who seek an up-to-date reference to the central problems of the field and to the tools currently used to analyze them. The book is aimed at researchers...... and students in finance, at quantitative analysts in banks and other financial institutions, and at regulators interested in the modeling aspects of credit risk. David Lando considers the two broad approaches to credit risk analysis: that based on classical option pricing models on the one hand...

Quantitative Risk Assessment (QRA) for an Underground Blowout Scenario in the Gulf of Mexico (GoM) Well

Science.gov (United States)

Tyagi, M.; Zulqarnain, M.

2017-12-01

Offshore oil and gas exploration and production operations, involve the use of some of the cutting edge and challenging technologies of the modern time. These technological complex operations involves the risk of major accidents as well, which have been demonstrated by disasters such as the explosion and fire on the UK production platform piper alpha, the Canadian semi-submersible drilling rig Ocean Ranger and the explosion and capsizing of Deepwater horizon rig in the Gulf of Mexico. By conducting Quantitative Risk Assessment (QRA), safety of various operations as well as their associated risks and significance during the entire life phase of an offshore project can be quantitatively estimated. In an underground blowout, the uncontrolled formation fluids from higher pressure formation may charge up shallower overlying low pressure formations or may migrate to sea floor. Consequences of such underground blowouts range from no visible damage at the surface to the complete loss of well, loss of drilling rig, seafloor subsidence or hydrocarbons discharged to the environment. These blowouts might go unnoticed until the over pressured sands, which are the result of charging from higher pressure reservoir due to an underground blowout. Further, engineering formulas used to estimate the fault permeability and thickness are very simple in nature and may add to uncertainty in the estimated parameters. In this study the potential of a deepwater underground blowout are assessed during drilling life phase of a well in Popeye-Genesis field reservoir in the Gulf of Mexico to estimate the time taken to charge a shallower zone to its leak-off test (LOT) value. Parametric simulation results for selected field case show that for relatively high permeability (k = 40mD) fault connecting a deep over-pressured zone to a shallower low-pressure zone of similar reservoir volumes, the time to recharge the shallower zone up to its threshold LOT value is about 135 years. If the ratio of the

Skin sensitisation quantitative risk assessment (QRA) based on aggregate dermal exposure to methylisothiazolinone in personal care and household cleaning products.

Science.gov (United States)

Ezendam, J; Bokkers, B G H; Bil, W; Delmaar, J E

2018-02-01

Contact allergy to preservatives is an important public health problem. Ideally, new substances should be evaluated for the risk on skin sensitisation before market entry, for example by using a quantitative risk assessment (QRA) as developed for fragrances. As a proof-of-concept, this QRA was applied to the preservative methylisothiazolinone (MI), a common cause of contact allergy. MI is used in different consumer products, including personal care products (PCPs) and household cleaning products (HCPs). Aggregate exposure to MI in PCPs and HCPs was therefore assessed with the Probabilistic Aggregated Consumer Exposure Model (PACEM). Two exposure scenarios were evaluated: scenario 1 calculated aggregate exposure on actual MI product concentrations before the restricted use in PCPs and scenario 2 calculated aggregate exposure using the restrictions for MI in PCPs. The QRA for MI showed that in scenarios 1 and 2, the proportion of the population at risk for skin sensitisation is 0.7% and 0.5%, respectively. The restricted use of MI in PCPs does not seem very effective in lowering the risk on skin sensitization. To conclude, it is important to consider aggregate exposure from the most important consumer products into consideration in the risk assessment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Use of quantitative uncertainty analysis for human health risk assessment

International Nuclear Information System (INIS)

Duncan, F.L.W.; Gordon, J.W.; Kelly, M.

1994-01-01

Current human health risk assessment method for environmental risks typically use point estimates of risk accompanied by qualitative discussions of uncertainty. Alternatively, Monte Carlo simulations may be used with distributions for input parameters to estimate the resulting risk distribution and descriptive risk percentiles. These two techniques are applied for the ingestion of 1,1=dichloroethene in ground water. The results indicate that Monte Carlo simulations provide significantly more information for risk assessment and risk management than do point estimates

Current developments in the assessment of petroleum hydrocarbon contaminated sites: Analysis, interpretation, and use of the TPH parameter for quantitative risk assessment

International Nuclear Information System (INIS)

Garcia-Surette, M.; Maynard, P.; Lamie, P.O.; Kaslick, C.

1995-01-01

In 1994, the Massachusetts Department of Environmental Protection (MDEP) estimated that petroleum-only cases comprised approximately one-half of the state's hazardous waste sites currently under investigation and/or remediation. Because of this significant percentage, it became clear that assessing petroleum sites more efficiently in terms of risk and cleanup alternatives was necessary. One of these key MDEP policies describes an alternative risk assessment approach enabling the quantitative characterization of total petroleum hydrocarbon (TPH)-related health risks. The approach relies on the use of an analytical technique by which the mass of petroleum hydrocarbons within specified carbon ranges is quantified. MDEP's TPH risk assessment approach was successfully employed at a residential site contaminated with No. 2 fuel oil. The combined use of MDEP's suggested analytical methods, alternative reference compounds and toxicity values, as well as chromatograms, standard dose equations, and an EPA-approved box model, facilitated the performance of a more realistic and cost-effective assessment of risk. Such assessment provided key management information to regulatory agencies, and project managers, as well as property owners concerned with potential property value loss

Rational quantitative safety goals: a summary

International Nuclear Information System (INIS)

Unwin, S.D.; Hayns, M.R.

1984-08-01

We introduce the notion of a Rational Quantitative Safety Goal. Such a goal reflects the imprecision and vagueness inherent in any reasonable notion of adequate safety and permits such vagueness to be incorporated into the formal regulatory decision-making process. A quantitative goal of the form, the parameter x, characterizing the safety level of the nuclear plant, shall not exceed the value x 0 , for example, is of a non-rational nature in that it invokes a strict binary logic in which the parameter space underlying x is cut sharply into two portions: that containing those values of x that comply with the goal and that containing those that do not. Here, we utilize an alternative form of logic which, in accordance with any intuitively reasonable notion of safety, permits a smooth transition of a safety determining parameter between the adequately safe and inadequately safe domains. Fuzzy set theory provides a suitable mathematical basis for the formulation of rational quantitative safety goals. The decision-making process proposed here is compatible with current risk assessment techniques and produces results in a transparent and useful format. Our methodology is illustrated with reference to the NUS Corporation risk assessment of the Limerick Generating Station

Risks, risk assessment and risk competence in toxicology.

Science.gov (United States)

Stahlmann, Ralf; Horvath, Aniko

2015-01-01

Understanding the toxic effects of xenobiotics requires sound knowledge of physiology and biochemistry. The often described lack of understanding pharmacology/toxicology is therefore primarily caused by the general absence of the necessary fundamental knowledge. Since toxic effects depend on exposure (or dosage) assessing the risks arising from toxic substances also requires quantitative reasoning. Typically public discussions nearly always neglect quantitative aspects and laypersons tend to disregard dose-effect-relationships. One of the main reasons for such disregard is the fact that exposures often occur at extremely low concentrations that can only be perceived intellectually but not by the human senses. However, thresholds in the low exposure range are often scientifically disputed. At the same time, ignorance towards known dangers is wide-spread. Thus, enhancing the risk competence of laypersons will have to be initially restricted to increasing the awareness of existing problems.

A two-stage method of quantitative flood risk analysis for reservoir real-time operation using ensemble-based hydrologic forecasts

Science.gov (United States)

Liu, P.

2013-12-01

Quantitative analysis of the risk for reservoir real-time operation is a hard task owing to the difficulty of accurate description of inflow uncertainties. The ensemble-based hydrologic forecasts directly depict the inflows not only the marginal distributions but also their persistence via scenarios. This motivates us to analyze the reservoir real-time operating risk with ensemble-based hydrologic forecasts as inputs. A method is developed by using the forecast horizon point to divide the future time into two stages, the forecast lead-time and the unpredicted time. The risk within the forecast lead-time is computed based on counting the failure number of forecast scenarios, and the risk in the unpredicted time is estimated using reservoir routing with the design floods and the reservoir water levels of forecast horizon point. As a result, a two-stage risk analysis method is set up to quantify the entire flood risks by defining the ratio of the number of scenarios that excessive the critical value to the total number of scenarios. The China's Three Gorges Reservoir (TGR) is selected as a case study, where the parameter and precipitation uncertainties are implemented to produce ensemble-based hydrologic forecasts. The Bayesian inference, Markov Chain Monte Carlo, is used to account for the parameter uncertainty. Two reservoir operation schemes, the real operated and scenario optimization, are evaluated for the flood risks and hydropower profits analysis. With the 2010 flood, it is found that the improvement of the hydrologic forecast accuracy is unnecessary to decrease the reservoir real-time operation risk, and most risks are from the forecast lead-time. It is therefore valuable to decrease the avarice of ensemble-based hydrologic forecasts with less bias for a reservoir operational purpose.

Probabilistic risk assessment as an aid to risk management

International Nuclear Information System (INIS)

Garrick, B.J.

1982-01-01

Probabilistic risk assessments are providing important insights into nuclear power plant safety. Their value is two-fold: first as a means of quantifying nuclear plant risk including contributors to risk, and second as an aid to risk management. A risk assessment provides an analytical plant model that can be the basis for performing meaningful decision analyses for controlling safety. It is the aspect of quantitative risk management that makes probabilistic risk assessment an important technical discipline of the future

Characterizing trabecular bone structure for assessing vertebral fracture risk on volumetric quantitative computed tomography

Science.gov (United States)

Nagarajan, Mahesh B.; Checefsky, Walter A.; Abidin, Anas Z.; Tsai, Halley; Wang, Xixi; Hobbs, Susan K.; Bauer, Jan S.; Baum, Thomas; Wismüller, Axel

2015-03-01

While the proximal femur is preferred for measuring bone mineral density (BMD) in fracture risk estimation, the introduction of volumetric quantitative computed tomography has revealed stronger associations between BMD and spinal fracture status. In this study, we propose to capture properties of trabecular bone structure in spinal vertebrae with advanced second-order statistical features for purposes of fracture risk assessment. For this purpose, axial multi-detector CT (MDCT) images were acquired from 28 spinal vertebrae specimens using a whole-body 256-row CT scanner with a dedicated calibration phantom. A semi-automated method was used to annotate the trabecular compartment in the central vertebral slice with a circular region of interest (ROI) to exclude cortical bone; pixels within were converted to values indicative of BMD. Six second-order statistical features derived from gray-level co-occurrence matrices (GLCM) and the mean BMD within the ROI were then extracted and used in conjunction with a generalized radial basis functions (GRBF) neural network to predict the failure load of the specimens; true failure load was measured through biomechanical testing. Prediction performance was evaluated with a root-mean-square error (RMSE) metric. The best prediction performance was observed with GLCM feature `correlation' (RMSE = 1.02 ± 0.18), which significantly outperformed all other GLCM features (p biomechanical strength prediction in spinal vertebrae can be significantly improved through characterization of trabecular bone structure with GLCM-derived texture features.

Meta-analysis for quantitative microbiological risk assessments and benchmarking data

NARCIS (Netherlands)

Besten, den H.M.W.; Zwietering, M.H.

2012-01-01

Meta-analysis studies are increasingly being conducted in the food microbiology area to quantitatively integrate the findings of many individual studies on specific questions or kinetic parameters of interest. Meta-analyses provide global estimates of parameters and quantify their variabilities, and

A risk-based microbiological criterion that uses the relative risk as the critical limit

DEFF Research Database (Denmark)

Andersen, Jens Kirk; Nørrung, Birgit; da Costa Alves Machado, Simone

2015-01-01

A risk-based microbiological criterion is described, that is based on the relative risk associated to the analytical result of a number of samples taken from a food lot. The acceptable limit is a specific level of risk and not a specific number of microorganisms, as in other microbiological...... criteria. The approach requires the availability of a quantitative microbiological risk assessment model to get risk estimates for food products from sampled food lots. By relating these food lot risk estimates to the mean risk estimate associated to a representative baseline data set, a relative risk...... estimate can be obtained. This relative risk estimate then can be compared with a critical value, defined by the criterion. This microbiological criterion based on a relative risk limit is particularly useful when quantitative enumeration data are available and when the prevalence of the microorganism...

Quantitative risk analysis in two pipelines operated by TRANSPETRO

Energy Technology Data Exchange (ETDEWEB)

Garcia, Claudio B. [PETROBRAS Transporte S/A (TRANSPETRO), Rio de Janeiro, RJ (Brazil); Pinho, Edson [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil); Bittencourt, Euclides [Centro Universitario FIB, Salvador , BA (Brazil)

2009-07-01

Transportation risk analysis techniques were used to study two pipelines operated by TRANSPETRO. The Pipeline A is for the simultaneous transportation of diesel, gasoline and LPG and comprises three parts, all of them crossing rural areas. The Pipeline B is for oil transportation and one of its ends is located in an area of a high density population. Both pipelines had their risk studied using the PHAST RISK{sup R} software and the individual risk measures, the only considered measures for license purposes for this type of studies, presented level far below the maximum tolerable levels considered. (author)

Risk assessment and risk management in managed aquifer recharge

CSIR Research Space (South Africa)

Page, D

2012-06-01

Full Text Available This chapter presents the methodologies used for risk assessment and risk management in MAR in Australia and the European Union, qualitative and quantitative approaches adopted within the RECLAIM Water project and case studies where the outcomes...

Proposed quantitative approach to safety for nuclear power plants in Canada

International Nuclear Information System (INIS)

1995-07-01

A set of quantitative risk and frequency limits plus required processes is proposed to help ensure that a nuclear power plant in Canada meets the qualitative safety objectives defined in ACNS-2 and in IAEA 75-INSAG-3. As emphasized in this report, risks and hence doses are to be reduced below the limits using ALARA (As Low as Reasonably Achievable, economic and social factors being taken into account) or VIA (value-impact analysis) processes unless, in general, calculated risks and hence doses are below recommended de minimis levels. An updated version of ACNS-4, which will be issued as ACNS-21, will incorporate a statement of these limits and objectives as well as assessment criteria and procedures that will facilitate their application. The quantitative approach proposed here is consistent with a growing consensus on the need for, and the elements of, a quantitative approach to risk management of all major activities in an advanced industrial society. The ACNS recommends that the Atomic Energy Control Board adopt the proposed approach as a rational and coherent basis for nuclear power plant safety policy and requirements in Canada. (author). 68 refs., 4 tabs., 1 fig

Proposed quantitative approach to safety for nuclear power plants in Canada

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-01

A set of quantitative risk and frequency limits plus required processes is proposed to help ensure that a nuclear power plant in Canada meets the qualitative safety objectives defined in ACNS-2 and in IAEA 75-INSAG-3. As emphasized in this report, risks and hence doses are to be reduced below the limits using ALARA (As Low as Reasonably Achievable, economic and social factors being taken into account) or VIA (value-impact analysis) processes unless, in general, calculated risks and hence doses are below recommended de minimis levels. An updated version of ACNS-4, which will be issued as ACNS-21, will incorporate a statement of these limits and objectives as well as assessment criteria and procedures that will facilitate their application. The quantitative approach proposed here is consistent with a growing consensus on the need for, and the elements of, a quantitative approach to risk management of all major activities in an advanced industrial society. The ACNS recommends that the Atomic Energy Control Board adopt the proposed approach as a rational and coherent basis for nuclear power plant safety policy and requirements in Canada. (author). 68 refs., 4 tabs., 1 fig.

Risks, risk assessment and risk competence in toxicology

Science.gov (United States)

Stahlmann, Ralf; Horvath, Aniko

2015-01-01

Understanding the toxic effects of xenobiotics requires sound knowledge of physiology and biochemistry. The often described lack of understanding pharmacology/toxicology is therefore primarily caused by the general absence of the necessary fundamental knowledge. Since toxic effects depend on exposure (or dosage) assessing the risks arising from toxic substances also requires quantitative reasoning. Typically public discussions nearly always neglect quantitative aspects and laypersons tend to disregard dose-effect-relationships. One of the main reasons for such disregard is the fact that exposures often occur at extremely low concentrations that can only be perceived intellectually but not by the human senses. However, thresholds in the low exposure range are often scientifically disputed. At the same time, ignorance towards known dangers is wide-spread. Thus, enhancing the risk competence of laypersons will have to be initially restricted to increasing the awareness of existing problems. PMID:26195922

Risks, risk assessment and risk competence in toxicology

Directory of Open Access Journals (Sweden)

Stahlmann, Ralf

2015-07-01

Full Text Available Understanding the toxic effects of xenobiotics requires sound knowledge of physiology and biochemistry. The often described lack of understanding pharmacology/toxicology is therefore primarily caused by the general absence of the necessary fundamental knowledge. Since toxic effects depend on exposure (or dosage assessing the risks arising from toxic substances also requires quantitative reasoning. Typically public discussions nearly always neglect quantitative aspects and laypersons tend to disregard dose-effect-relationships. One of the main reasons for such disregard is the fact that exposures often occur at extremely low concentrations that can only be perceived intellectually but not by the human senses. However, thresholds in the low exposure range are often scientifically disputed. At the same time, ignorance towards known dangers is wide-spread. Thus, enhancing the risk competence of laypersons will have to be initially restricted to increasing the awareness of existing problems.

Quantitative microbial risk assessment (QMRA) shows increased public health risk associated with exposure to river water under conditions of riverbed sediment resuspension.

Science.gov (United States)

Abia, Akebe Luther King; Ubomba-Jaswa, Eunice; Genthe, Bettina; Momba, Maggy Ndombo Benteke

2016-10-01

Although higher microbial concentrations have been reported in sediments than in the overlying water column, most quantitative microbial risk assessment (QMRA) studies have not clearly indicated the contribution of sediment-borne pathogens to estimated risks. Thus, the present study aimed at determining the public health risk associated with exposure to pathogenic bacteria in polluted river water under undisturbed conditions and conditions of sediment resuspension in the Apies River, Gauteng, South Africa. Microbial pathogens were isolated and identified using culture and molecular methods. The beta-Poisson dose-response model was used to estimate the probability of infection (Pi) with the various pathogens, following accidental/intentional ingestion of 1mL or 100mL (or 50mL) of untreated river water. Mean wet season Escherichia coli counts ranged between 5.8E+01 and 8.8E+04MPN/100mL (water column) and between 2.40E+03 and 1.28E+05MPN/100mL (sediments). Mean dry season E. coli counts ranged between 5.11E+00 and 3.40E+03MPN/100mL (water column) and between 5.09E+00 and 6.30E+03MPN/100mL (sediments). Overall (water and sediments) Vibrio cholerae was the most detected pathogen (58.8%) followed by Salmonella spp. (23.9%) and Shigella (10.1%). Ingestion of 1mL of river water could lead to 0%-4% and 1%-74% Pi with E. coli during the dry and wet season, respectively. During the dry season, the Pi with V. cholerae, Salmonella spp. and Shigella spp. were 0%-1.39%, 0%-4.11% and 0%-0.16% respectively, depending on volume of water ingested. The risks of infections with all microorganisms increased during the wet season. A 2-log increase in water E. coli count following sediments disturbance led to approximately 10 times higher Pi with E. coli than when sediments were undisturbed. Therefore, the use of the untreated water from the Apies River for drinking, household purposes or recreational activities poses a potential health risk to the users of the river. Copyright © 2016

Quantitative penetration testing with item response theory

NARCIS (Netherlands)

Pieters, W.; Arnold, F.; Stoelinga, M.I.A.

2013-01-01

Existing penetration testing approaches assess the vulnerability of a system by determining whether certain attack paths are possible in practice. Therefore, penetration testing has thus far been used as a qualitative research method. To enable quantitative approaches to security risk management,

Coupling mode-destination accessibility with seismic risk assessment to identify at-risk communities

International Nuclear Information System (INIS)

Miller, Mahalia; Baker, Jack W.

2016-01-01

In this paper, we develop a framework for coupling mode-destination accessibility with quantitative seismic risk assessment to identify communities at high risk for travel disruptions after an earthquake. Mode-destination accessibility measures the ability of people to reach destinations they desire. We use a probabilistic seismic risk assessment procedure, including a stochastic set of earthquake events, ground-motion intensity maps, damage maps, and realizations of traffic and accessibility impacts. For a case study of the San Francisco Bay Area, we couple our seismic risk framework with a practical activity-based traffic model. As a result, we quantify accessibility risk probabilistically by community and household type. We find that accessibility varies more strongly as a function of travelers' geographic location than as a function of their income class, and we identify particularly at-risk communities. We also observe that communities more conducive to local trips by foot or bike are predicted to be less impacted by losses in accessibility. This work shows the potential to link quantitative risk assessment methodologies with high-resolution travel models used by transportation planners. Quantitative risk metrics of this type should have great utility for planners working to reduce risk to a region's infrastructure systems. - Highlights: • We couple mode-destination accessibility with probabilistic seismic risk assessment. • Results identify communities at high risk for post-earthquake travel disruptions. • Accessibility varies more as a function of home location than by income. • Our model predicts reduced accessibility risk for more walking-friendly communities.

Farm to Fork Quantitative Risk Assessment of Listeria monocytogenes Contamination in Raw and Pasteurized Milk Cheese in Ireland.

Science.gov (United States)

Tiwari, Uma; Cummins, Enda; Valero, Antonio; Walsh, Des; Dalmasso, Marion; Jordan, Kieran; Duffy, Geraldine

2015-06-01

The objective of this study was to model and quantify the level of Listeria monocytogenes in raw milk cheese (RMc) and pasteurized milk cheese (PMc) from farm to fork using a Bayesian inference approach combined with a quantitative risk assessment. The modeling approach included a prediction of contamination arising from the farm environment as well from cross-contamination within the cheese-processing facility through storage and subsequent human exposure. The model predicted a high concentration of L. monocytogenes in contaminated RMc (mean 2.19 log10 CFU/g) compared to PMc (mean -1.73 log10 CFU/g). The mean probability of illness (P1 for low-risk population, LR) and (P2 for high-risk population, HR, e.g., immunocompromised) adult Irish consumers following exposure to contaminated cheese was 7 × 10(-8) (P1 ) and 9 × 10(-4) (P2 ) for RMc and 7 × 10(-10) (P1 ) and 8 × 10(-6) (P2 ) for PMc, respectively. In addition, the model was used to evaluate performance objectives at various stages, namely, the cheese making and ripening stages, and to set a food safety objective at the time of consumption. A scenario analysis predicted various probabilities of L. monocytogenes contamination along the cheese-processing chain for both RMc and PMc. The sensitivity analysis showed the critical factors for both cheeses were the serving size of the cheese, storage time, and temperature at the distribution stage. The developed model will allow food processors and policymakers to identify the possible routes of contamination along the cheese-processing chain and to reduce the risk posed to human health. © 2015 Society for Risk Analysis.

Critical Race Quantitative Intersections: A "testimonio" Analysis

Science.gov (United States)

Covarrubias, Alejandro; Nava, Pedro E.; Lara, Argelia; Burciaga, Rebeca; Vélez, Verónica N.; Solorzano, Daniel G.

2018-01-01

The educational pipeline has become a commonly referenced depiction of educational outcomes for racialized groups across the country. While visually impactful, an overreliance on decontextualized quantitative data often leads to majoritarian interpretations. Without sociohistorical contexts, these interpretations run the risk of perpetuating…

Quantitative Penetration Testing with Item Response Theory

NARCIS (Netherlands)

Arnold, Florian; Pieters, Wolter; Stoelinga, Mariëlle Ida Antoinette

2014-01-01

Existing penetration testing approaches assess the vulnerability of a system by determining whether certain attack paths are possible in practice. Thus, penetration testing has so far been used as a qualitative research method. To enable quantitative approaches to security risk management, including

Quantitative penetration testing with item response theory

NARCIS (Netherlands)

Arnold, Florian; Pieters, Wolter; Stoelinga, Mariëlle

2013-01-01

Existing penetration testing approaches assess the vulnerability of a system by determining whether certain attack paths are possible in practice. Thus, penetration testing has so far been used as a qualitative research method. To enable quantitative approaches to security risk management, including

Qualitative versus quantitative assessment of cerebrovascular reserve capacity

International Nuclear Information System (INIS)

Okuguchi, Taku

2000-01-01

Quantitative studies of cerebral blood flow (CBF) combined with a acetazolamide (ACZ) challenge have defined a subgroup of patients with symptomatic carotid or middle cerebral artery (MCA) occlusive diseases who are at an increased risk for stroke. Recent reports suggest that qualitative CBF techniques could also define the same high-risk subgroup. To evaluate the accuracy of the qualitative method, we compared qualitative ratios with quantitative CBF data, obtained using iodine-123-N-isopropyl-p-iodoamphetamine (IMP) single-photon emission computed tomography (SPECT). We analyzed qualitative and quantitative IMP SPECT images for 50 patients with symptomatic carotid or middle cerebral artery occlusive diseases. Quantitative CBF data were measured by the autoradiographic technique. One region-of-interest within each hemisphere was within the MCA territory. Relative cerebrovascular reserve capacity (CVRC) obtained using qualitative images before and after the intravenous administration of 1 g of ACZ was defined as follows: ( ACZ C occl / ACZ C non )/( baseline C occl / baseline C non ). The threshold for abnormal relative CVRC was defined as less than 1.0. Quantitative CBF was considered abnormal when the response to ACZ (percent change) on the symptomatic side (absolute CVRC) was a decrease of more than 10%. Of 39 patients whose relative CVRC were considered abnormal, 29 (74%) were normal in absolute CVRC (i.e., false positive). Two of 12 (17%) who were not considered compromised by qualitative criteria had abnormal absolute CVRC (i.e., false negative). This study demonstrates that this important subgroup cannot be accurately defined with qualitative methodology. (author)

Qualitative versus quantitative assessment of cerebrovascular reserve capacity

Energy Technology Data Exchange (ETDEWEB)

Okuguchi, Taku [Iwate Medical Univ., Morioka (Japan). School of Medicine

2000-06-01

Quantitative studies of cerebral blood flow (CBF) combined with a acetazolamide (ACZ) challenge have defined a subgroup of patients with symptomatic carotid or middle cerebral artery (MCA) occlusive diseases who are at an increased risk for stroke. Recent reports suggest that qualitative CBF techniques could also define the same high-risk subgroup. To evaluate the accuracy of the qualitative method, we compared qualitative ratios with quantitative CBF data, obtained using iodine-123-N-isopropyl-p-iodoamphetamine (IMP) single-photon emission computed tomography (SPECT). We analyzed qualitative and quantitative IMP SPECT images for 50 patients with symptomatic carotid or middle cerebral artery occlusive diseases. Quantitative CBF data were measured by the autoradiographic technique. One region-of-interest within each hemisphere was within the MCA territory. Relative cerebrovascular reserve capacity (CVRC) obtained using qualitative images before and after the intravenous administration of 1 g of ACZ was defined as follows: ({sub ACZ}C{sub occl}/{sub ACZ}C{sub non})/({sub baseline}C{sub occl}/{sub baseline}C{sub n}= {sub on}). The threshold for abnormal relative CVRC was defined as less than 1.0. Quantitative CBF was considered abnormal when the response to ACZ (percent change) on the symptomatic side (absolute CVRC) was a decrease of more than 10%. Of 39 patients whose relative CVRC were considered abnormal, 29 (74%) were normal in absolute CVRC (i.e., false positive). Two of 12 (17%) who were not considered compromised by qualitative criteria had abnormal absolute CVRC (i.e., false negative). This study demonstrates that this important subgroup cannot be accurately defined with qualitative methodology. (author)

Systems approach to project risk management

Energy Technology Data Exchange (ETDEWEB)

Kindinger, J. P. (John P.)

2002-01-01

This paper describes the need for better performance in the planning and execution of projects and examines the capabilities of two different project risk analysis methods for improving project performance. A quantitative approach based on concepts and tools adopted from the disciplines of systems analysis, probabilistic risk analysis, and other fields is advocated for managing risk in large and complex research & development projects. This paper also provides an overview of how this system analysis approach for project risk management is being used at Los Alamos National Laboratory along with examples of quantitative risk analysis results and their application to improve project performance.

An innovative expression model of human health risk based on the quantitative analysis of soil metals sources contribution in different spatial scales.

Science.gov (United States)

Zhang, Yimei; Li, Shuai; Wang, Fei; Chen, Zhuang; Chen, Jie; Wang, Liqun

2018-09-01

Toxicity of heavy metals from industrialization poses critical concern, and analysis of sources associated with potential human health risks is of unique significance. Assessing human health risk of pollution sources (factored health risk) concurrently in the whole and the sub region can provide more instructive information to protect specific potential victims. In this research, we establish a new expression model of human health risk based on quantitative analysis of sources contribution in different spatial scales. The larger scale grids and their spatial codes are used to initially identify the level of pollution risk, the type of pollution source and the sensitive population at high risk. The smaller scale grids and their spatial codes are used to identify the contribution of various sources of pollution to each sub region (larger grid) and to assess the health risks posed by each source for each sub region. The results of case study show that, for children (sensitive populations, taking school and residential area as major region of activity), the major pollution source is from the abandoned lead-acid battery plant (ALP), traffic emission and agricultural activity. The new models and results of this research present effective spatial information and useful model for quantifying the hazards of source categories and human health a t complex industrial system in the future. Copyright © 2018 Elsevier Ltd. All rights reserved.

Quantitative risk assessment of digitalized safety systems

Energy Technology Data Exchange (ETDEWEB)

Shin, Sung Min; Lee, Sang Hun; Kang, Hym Gook [KAIST, Daejeon (Korea, Republic of); Lee, Seung Jun [UNIST, Ulasn (Korea, Republic of)

2016-05-15

A report published by the U.S. National Research Council indicates that appropriate methods for assessing reliability are key to establishing the acceptability of digital instrumentation and control (I and C) systems in safety-critical plants such as NPPs. Since the release of this issue, the methodology for the probabilistic safety assessment (PSA) of digital I and C systems has been studied. However, there is still no widely accepted method. Kang and Sung found three critical factors for safety assessment of digital systems: detection coverage of fault-tolerant techniques, software reliability quantification, and network communication risk. In reality the various factors composing digitalized I and C systems are not independent of each other but rather closely connected. Thus, from a macro point of view, a method that can integrate risk factors with different characteristics needs to be considered together with the micro approaches to address the challenges facing each factor.

Health risks in perspective: Judging health risks of energy technologies. Revision 5/94

Energy Technology Data Exchange (ETDEWEB)

Rowe, M.D.

1992-09-01

The purpose of this report is to provide perspective on the various risks to which man is routinely exposed. It serves as a basis for understanding the meaning of quantitative risk estimates and for comparing new or newly-discovered risks with other, better-understood risks. Specific emphasis is placed on health risks of energy technologies. This report is not a risk assessment; nor does it contain instructions on how to do a risk assessment. Rather, it provides background information on how most of us think about risks and why it is difficult to do it rationally, it provides a philosophy and data with which to do a better job of judging risks more rationally, and it provides an overview of where risks of energy technologies fit within the spectrum of all risks. Much of the quantitative information provided here is on relative risk of dying of various causes. This is not because risk of dying is seen as the most important kind of risk, but because the statistics on mortality rates by cause are the highest quality data available on health risks in the general population.

Specialist antenatal clinics for women at high risk of preterm birth: a systematic review of qualitative and quantitative research.

Science.gov (United States)

Malouf, Reem; Redshaw, Maggie

2017-02-02

Preterm birth (PTB) is the leading cause of perinatal morbidity and mortality. Women with previous prenatal loss are at higher risk of preterm birth. A specialist antenatal clinic is considered as one approach to improve maternity and pregnancy outcomes. A systematic review of quantitative, qualitative and mixed method studies conducted on women at high risk of preterm birth (PTB). The review primary outcomes were to report on the specialist antenatal clinics effect in preventing or reducing preterm birth, perinatal mortality and morbidity and women's perceptions and experiences of a specialist clinic whether compared or not compared with standard antenatal care. Other secondary maternal, infant and economic outcomes were also determined. A comprehensive search strategy was carried out in English within electronic databases as far back as 1980. The reviewers selected studies, assessed the quality, and extracted data independently. Results were summarized and tabulated. Eleven studies fully met the review inclusion criteria, ten were quantitative design studies and only one was a qualitative design study. No mixed method design study was included in the review. All were published after 1989, seven were conducted in the USA and four in the UK. Results from five good to low quality randomised controlled trials (RCTs), all conducted before 1990, did not illustrate the efficacy of the clinic in reducing preterm birth. Whereas results from more recent low quality cohort studies showed some positive neonatal outcomes. Themes from one good quality qualitative study reflected on the emotional and psychological need to reduce anxiety and stress of women referred to such a clinic. Women expressed their negative emotional responses at being labelled as high risk and positive responses to being assessed and treated in the clinic. Women also reported that their partners were struggling to cope emotionally. Findings from this review were mixed. Evidence from cohort studies

QUANTITATIVE INDICATORS OF THE SECURITIZATION OF ASSETS

Directory of Open Access Journals (Sweden)

Denis VOSTRICOV

2018-02-01

Full Text Available Securitization is instrumental in return on capital increment through the withdrawal from the balance oflending activities being accompanied by off-balance incomes flow from fees, which are less capital-intensive. Thepurpose of this paper is to analyze the quantitative indicators characterizing the securitization of assets. For draftingthis article, the method of analysis, synthesis method, logic and dialectic method, normative method, the study ofstatistical sampling and time series of expert evaluations (Standard and Poor’s, personal observations, andmonographic studies have been used. The main difference between the securitization of assets from traditional waysof financing is related to the achievement of a plenty of secondary goals in attracting financial resources, whichcan play a significant role in choosing to favour the securitization of assets or other types of financing. Inparticular, it gives a possibility to write off the assets from the balance sheet along with the relevant obligationsunder the securities, to expand the range of potential investors accompanied by the reducing of credit risk, interestrate and liquidity risk, as well as to improve the management quality of assets, liabilities and risks. All of thesesecondary effects are achieved by the isolation of selected assets from the total credit risk of the enterprise, raisingits funds, which forms the pivotal actuality and significance of asset securitization. The article containsdemonstrations of quantitative and qualitative indicators characterizing the securitization of assets.

Multiple-Strain Approach and Probabilistic Modeling of Consumer Habits in Quantitative Microbial Risk Assessment: A Quantitative Assessment of Exposure to Staphylococcal Enterotoxin A in Raw Milk.

Science.gov (United States)

Crotta, Matteo; Rizzi, Rita; Varisco, Giorgio; Daminelli, Paolo; Cunico, Elena Cosciani; Luini, Mario; Graber, Hans Ulrich; Paterlini, Franco; Guitian, Javier

2016-03-01

Quantitative microbial risk assessment (QMRA) models are extensively applied to inform management of a broad range of food safety risks. Inevitably, QMRA modeling involves an element of simplification of the biological process of interest. Two features that are frequently simplified or disregarded are the pathogenicity of multiple strains of a single pathogen and consumer behavior at the household level. In this study, we developed a QMRA model with a multiple-strain approach and a consumer phase module (CPM) based on uncertainty distributions fitted from field data. We modeled exposure to staphylococcal enterotoxin A in raw milk in Lombardy; a specific enterotoxin production module was thus included. The model is adaptable and could be used to assess the risk related to other pathogens in raw milk as well as other staphylococcal enterotoxins. The multiplestrain approach, implemented as a multinomial process, allowed the inclusion of variability and uncertainty with regard to pathogenicity at the bacterial level. Data from 301 questionnaires submitted to raw milk consumers were used to obtain uncertainty distributions for the CPM. The distributions were modeled to be easily updatable with further data or evidence. The sources of uncertainty due to the multiple-strain approach and the CPM were identified, and their impact on the output was assessed by comparing specific scenarios to the baseline. When the distributions reflecting the uncertainty in consumer behavior were fixed to the 95th percentile, the risk of exposure increased up to 160 times. This reflects the importance of taking into consideration the diversity of consumers' habits at the household level and the impact that the lack of knowledge about variables in the CPM can have on the final QMRA estimates. The multiple-strain approach lends itself to use in other food matrices besides raw milk and allows the model to better capture the complexity of the real world and to be capable of geographical

Quantitative approach for the risk assessment of African swine fever and Classical swine fever introduction into the United States through legal imports of pigs and swine products.

Directory of Open Access Journals (Sweden)

Diana María Herrera-Ibatá

Full Text Available The US livestock safety strongly depends on its capacity to prevent the introduction of Transboundary Animal Diseases (TADs. Therefore, accurate and updated information on the location and origin of those potential TADs risks is essential, so preventive measures as market restrictions can be put on place. The objective of the present study was to evaluate the current risk of African swine fever (ASF and Classical swine fever (CSF introduction into the US through the legal importations of live pigs and swine products using a quantitative approach that could be later applied to other risks. Four quantitative stochastic risk assessment models were developed to estimate the monthly probabilities of ASF and CSF release into the US, and the exposure of susceptible populations (domestic and feral swine to these introductions at state level. The results suggest a low annual probability of either ASF or CSF introduction into the US, by any of the analyzed pathways (5.5*10-3. Being the probability of introduction through legal imports of live pigs (1.8*10-3 for ASF, and 2.5*10-3 for CSF higher than the risk of legally imported swine products (8.90*10-4 for ASF, and 1.56*10-3 for CSF. This could be caused due to the low probability of exposure associated with this type of commodity (products. The risk of feral pigs accessing to swine products discarded in landfills was slightly higher than the potential exposure of domestic pigs through swill feeding. The identification of the months at highest risk, the origin of the higher risk imports, and the location of the US states most vulnerable to those introductions (Iowa, Minnesota and Wisconsin for live swine and California, Florida and Texas for swine products, is valuable information that would help to design prevention, risk-mitigation and early-detection strategies that would help to minimize the catastrophic consequences of potential ASF/CSF introductions into the US.

Issues regarding Risk Effect Analysis of Digitalized Safety Systems and Main Risk Contributors

International Nuclear Information System (INIS)

Kang, Hyun Gook; Jang, Seung-Cheol

2008-01-01

Risk factors of safety-critical digital systems affect overall plant risk. In order to assess this risk effect, a risk model of a digitalized safety system is required. This article aims to provide an overview of the issues when developing a risk model and demonstrate their effect on plant risk quantitatively. Research activities in Korea for addressing these various issues, such as the software failure probability and the fault coverage of self monitoring mechanism are also described. The main risk contributors related to the digitalized safety system were determined in a quantitative manner. Reactor protection system and engineered safety feature component control system designed as part of the Korean Nuclear I and C System project are used as example systems. Fault-tree models were developed to assess the failure probability of a system function which is designed to generate an automated signal for actuating both of the reactor trip and the complicated accident-mitigation actions. The developed fault trees were combined with a plant risk model to evaluate the effect of a digitalized system's failure on the plant risk. (authors)

Probabilistic quantitative microbial risk assessment model of norovirus from wastewater irrigated vegetables in Ghana using genome copies and fecal indicator ratio conversion for estimating exposure dose.

Science.gov (United States)

Owusu-Ansah, Emmanuel de-Graft Johnson; Sampson, Angelina; Amponsah, Samuel K; Abaidoo, Robert C; Dalsgaard, Anders; Hald, Tine

2017-12-01

The need to replace the commonly applied fecal indicator conversions ratio (an assumption of 1:10 -5 virus to fecal indicator organism) in Quantitative Microbial Risk Assessment (QMRA) with models based on quantitative data on the virus of interest has gained prominence due to the different physical and environmental factors that might influence the reliability of using indicator organisms in microbial risk assessment. The challenges facing analytical studies on virus enumeration (genome copies or particles) have contributed to the already existing lack of data in QMRA modelling. This study attempts to fit a QMRA model to genome copies of norovirus data. The model estimates the risk of norovirus infection from the intake of vegetables irrigated with wastewater from different sources. The results were compared to the results of a corresponding model using the fecal indicator conversion ratio to estimate the norovirus count. In all scenarios of using different water sources, the application of the fecal indicator conversion ratio underestimated the norovirus disease burden, measured by the Disability Adjusted Life Years (DALYs), when compared to results using the genome copies norovirus data. In some cases the difference was >2 orders of magnitude. All scenarios using genome copies met the 10 -4 DALY per person per year for consumption of vegetables irrigated with wastewater, although these results are considered to be highly conservative risk estimates. The fecal indicator conversion ratio model of stream-water and drain-water sources of wastewater achieved the 10 -6 DALY per person per year threshold, which tends to indicate an underestimation of health risk when compared to using genome copies for estimating the dose. Copyright © 2017 Elsevier B.V. All rights reserved.

Security Events and Vulnerability Data for Cybersecurity Risk Estimation.

Science.gov (United States)

Allodi, Luca; Massacci, Fabio

2017-08-01

Current industry standards for estimating cybersecurity risk are based on qualitative risk matrices as opposed to quantitative risk estimates. In contrast, risk assessment in most other industry sectors aims at deriving quantitative risk estimations (e.g., Basel II in Finance). This article presents a model and methodology to leverage on the large amount of data available from the IT infrastructure of an organization's security operation center to quantitatively estimate the probability of attack. Our methodology specifically addresses untargeted attacks delivered by automatic tools that make up the vast majority of attacks in the wild against users and organizations. We consider two-stage attacks whereby the attacker first breaches an Internet-facing system, and then escalates the attack to internal systems by exploiting local vulnerabilities in the target. Our methodology factors in the power of the attacker as the number of "weaponized" vulnerabilities he/she can exploit, and can be adjusted to match the risk appetite of the organization. We illustrate our methodology by using data from a large financial institution, and discuss the significant mismatch between traditional qualitative risk assessments and our quantitative approach. © 2017 Society for Risk Analysis.

Regulatory cost-risk study

International Nuclear Information System (INIS)

1983-04-01

This study is intended to provide some quantitative perspective by selecting certain examples of criteria for which estimates of risks and costs can be obtained, and the balance of the various risks, (i.e., internal versus external risks), can be put into perspective. 35 refs., 39 tabs

Quantitative Risk Assessment of Patient Manual Handling in Wards of One of the Hospitals of Tehran using MAPO Method, Iran

Directory of Open Access Journals (Sweden)

Sajad Ataei

2017-05-01

Full Text Available Background and Objectives: Manual handling of disabled patients is one of the important and effective factors in acute low back pain among exposed nurses. The present study was conducted with the objective of quantitative risk assessment of patient manual handling among nurses in wards of one of the hospitals in Tehran using MAPO method. Methods: The present study was conducted as an analytical-cross-sectional study in 26 wards of one of the hospitals in Tehran city. Samples were selected by census method from nurses and paramedics of different wards of hospital. Data collection was performed using demographic information and MAPO checklist. Results: The highest score of MAPO were, respectively, related to wards of DI clinic (score, 14.7, men orthopedic (score, 6.3, and general operating room (score, 57. 53.8% of hospital wards were at the level 2 corrective action, which indicated that the risk of musculoskeletal disorder is 2.4 times higher than level 1 corrective action. Conclusion: Given that the proportion of disabled patient in cooperation and/or partial cooperation, lifting tools, auxiliary, wheelchair, and training have the most role among risk factors for above-mentioned wards, increasing the number of human resources and wheelchair, use of lifting and auxiliary tools and training reduce MAPO score and consequently the risk of musculoskeletal disorders.

A Quantitative Risk Assessment Model Involving Frequency and Threat Degree under Line-of-Business Services for Infrastructure of Emerging Sensor Networks.

Science.gov (United States)

Jing, Xu; Hu, Hanwen; Yang, Huijun; Au, Man Ho; Li, Shuqin; Xiong, Naixue; Imran, Muhammad; Vasilakos, Athanasios V

2017-03-21

The prospect of Line-of-Business Services (LoBSs) for infrastructure of Emerging Sensor Networks (ESNs) is exciting. Access control remains a top challenge in this scenario as the service provider's server contains a lot of valuable resources. LoBSs' users are very diverse as they may come from a wide range of locations with vastly different characteristics. Cost of joining could be low and in many cases, intruders are eligible users conducting malicious actions. As a result, user access should be adjusted dynamically. Assessing LoBSs' risk dynamically based on both frequency and threat degree of malicious operations is therefore necessary. In this paper, we proposed a Quantitative Risk Assessment Model (QRAM) involving frequency and threat degree based on value at risk. To quantify the threat degree as an elementary intrusion effort, we amend the influence coefficient of risk indexes in the network security situation assessment model. To quantify threat frequency as intrusion trace effort, we make use of multiple behavior information fusion. Under the influence of intrusion trace, we adapt the historical simulation method of value at risk to dynamically access LoBSs' risk. Simulation based on existing data is used to select appropriate parameters for QRAM. Our simulation results show that the duration influence on elementary intrusion effort is reasonable when the normalized parameter is 1000. Likewise, the time window of intrusion trace and the weight between objective risk and subjective risk can be set to 10 s and 0.5, respectively. While our focus is to develop QRAM for assessing the risk of LoBSs for infrastructure of ESNs dynamically involving frequency and threat degree, we believe it is also appropriate for other scenarios in cloud computing.

A Quantitative Risk Assessment Model Involving Frequency and Threat Degree under Line-of-Business Services for Infrastructure of Emerging Sensor Networks

Science.gov (United States)

Jing, Xu; Hu, Hanwen; Yang, Huijun; Au, Man Ho; Li, Shuqin; Xiong, Naixue; Imran, Muhammad; Vasilakos, Athanasios V.

2017-01-01

The prospect of Line-of-Business Services (LoBSs) for infrastructure of Emerging Sensor Networks (ESNs) is exciting. Access control remains a top challenge in this scenario as the service provider’s server contains a lot of valuable resources. LoBSs’ users are very diverse as they may come from a wide range of locations with vastly different characteristics. Cost of joining could be low and in many cases, intruders are eligible users conducting malicious actions. As a result, user access should be adjusted dynamically. Assessing LoBSs’ risk dynamically based on both frequency and threat degree of malicious operations is therefore necessary. In this paper, we proposed a Quantitative Risk Assessment Model (QRAM) involving frequency and threat degree based on value at risk. To quantify the threat degree as an elementary intrusion effort, we amend the influence coefficient of risk indexes in the network security situation assessment model. To quantify threat frequency as intrusion trace effort, we make use of multiple behavior information fusion. Under the influence of intrusion trace, we adapt the historical simulation method of value at risk to dynamically access LoBSs’ risk. Simulation based on existing data is used to select appropriate parameters for QRAM. Our simulation results show that the duration influence on elementary intrusion effort is reasonable when the normalized parameter is 1000. Likewise, the time window of intrusion trace and the weight between objective risk and subjective risk can be set to 10 s and 0.5, respectively. While our focus is to develop QRAM for assessing the risk of LoBSs for infrastructure of ESNs dynamically involving frequency and threat degree, we believe it is also appropriate for other scenarios in cloud computing. PMID:28335569

Risk and medical ethics

International Nuclear Information System (INIS)

Pochin, E.

1982-01-01

Quantitative estimates of risk, and their comparison with quantitative estimates of benefit, contribute usefully to decision-making in many fields. In medicine, assessments of the probability of harm, and of the likelihood of benefit, resulting from many procedures are at present very limited. Moreover, the comparison of risk and of benefit is difficult to make in any quantitative way, whether for a procedure in general or, even more so, for its application in any particular patient. Yet it must be ethically insecure to propose or to use a procedure without some assessment, however approximate, of the hazards involved, and without some indication of whether those hazards will be clearly offset by the likelihood of benefit that should result from use of the procedure. (author)

Safety analysis, risk assessment, and risk acceptance criteria

International Nuclear Information System (INIS)

Jamali, K.

1997-01-01

This paper discusses a number of topics that relate safety analysis as documented in the Department of Energy (DOE) safety analysis reports (SARs), probabilistic risk assessments (PRA) as characterized primarily in the context of the techniques that have assumed some level of formality in commercial nuclear power plant applications, and risk acceptance criteria as an outgrowth of PRA applications. DOE SARs of interest are those that are prepared for DOE facilities under DOE Order 5480.23 and the implementing guidance in DOE STD-3009-94. It must be noted that the primary area of application for DOE STD-3009 is existing DOE facilities and that certain modifications of the STD-3009 approach are necessary in SARs for new facilities. Moreover, it is the hazard analysis (HA) and accident analysis (AA) portions of these SARs that are relevant to the present discussions. Although PRAs can be qualitative in nature, PRA as used in this paper refers more generally to all quantitative risk assessments and their underlying methods. HA as used in this paper refers more generally to all qualitative risk assessments and their underlying methods that have been in use in hazardous facilities other than nuclear power plants. This discussion includes both quantitative and qualitative risk assessment methods. PRA has been used, improved, developed, and refined since the Reactor Safety Study (WASH-1400) was published in 1975 by the Nuclear Regulatory Commission (NRC). Much debate has ensued since WASH-1400 on exactly what the role of PRA should be in plant design, reactor licensing, 'ensuring' plant and process safety, and a large number of other decisions that must be made for potentially hazardous activities. Of particular interest in this area is whether the risks quantified using PRA should be compared with numerical risk acceptance criteria (RACs) to determine whether a facility is 'safe.' Use of RACs requires quantitative estimates of consequence frequency and magnitude

Regulatory cost-risk study

Energy Technology Data Exchange (ETDEWEB)

1983-04-01

This study is intended to provide some quantitative perspective by selecting certain examples of criteria for which estimates of risks and costs can be obtained, and the balance of the various risks, (i.e., internal versus external risks), can be put into perspective. 35 refs., 39 tabs. (JDB)

Semi-Quantitative Assessment of the Health Risk of Occupational Exposure to Chemicals and Evaluation of Spirometry Indices on the Staff of Petrochemical Industry

Directory of Open Access Journals (Sweden)

Hajar Dazi

2017-01-01

Full Text Available Background & Aims of the Study: Petrochemical industry is an important industry in the economic development of the country that causes employees have exposure with several kinds of contamination. The aim of this study was Semi-quantitative assessment of the health risk of occupational exposure to chemical materials and investigation of spirometry indices between employees of petrochemical industry. Material & Methods: This cross-sectional study was conducted in one of the petrochemical industry complex in a special area of Assaluyeh in Iran in 2016. Health risk assessment of exposure to harmful chemical agents was performed in all of units and during three stages (identification of harmful material, determination of hazard rate of the chemical material, exposure rate and estimate of risk rate. Spirometry indices were measured using spirometry. Results: The results of chemical materials risk assessment showed that Raffinate in Butadiene unit has identified the highest amount of risk rank among 27 chemical materials in investigated units. In comparison with spirometry indices in Olefine unit between age with FVC parameter and history work with FVC and FEV1 parameters has observed a significant and negative correlation (P<0.05. Conclusion: The results of risk assessment in all of the petrochemical units showed that 48.14% of materials were at low risk level, 29.62% medium risk, 18.51% high risk and 3.7% had very high risk level. The variables affecting on spirometry employees such as age and work experience play an important role in reducing the pulmonary function tests in exposed subjects.

A systematic review of quantitative burn wound microbiology in the management of burns patients.

Science.gov (United States)

Halstead, Fenella D; Lee, Kwang Chear; Kwei, Johnny; Dretzke, Janine; Oppenheim, Beryl A; Moiemen, Naiem S

2018-02-01

The early diagnosis of infection or sepsis in burns are important for patient care. Globally, a large number of burn centres advocate quantitative cultures of wound biopsies for patient management, since there is assumed to be a direct link between the bioburden of a burn wound and the risk of microbial invasion. Given the conflicting study findings in this area, a systematic review was warranted. Bibliographic databases were searched with no language restrictions to August 2015. Study selection, data extraction and risk of bias assessment were performed in duplicate using pre-defined criteria. Substantial heterogeneity precluded quantitative synthesis, and findings were described narratively, sub-grouped by clinical question. Twenty six laboratory and/or clinical studies were included. Substantial heterogeneity hampered comparisons across studies and interpretation of findings. Limited evidence suggests that (i) more than one quantitative microbiology sample is required to obtain reliable estimates of bacterial load; (ii) biopsies are more sensitive than swabs in diagnosing or predicting sepsis; (iii) high bacterial loads may predict worse clinical outcomes, and (iv) both quantitative and semi-quantitative culture reports need to be interpreted with caution and in the context of other clinical risk factors. The evidence base for the utility and reliability of quantitative microbiology for diagnosing or predicting clinical outcomes in burns patients is limited and often poorly reported. Consequently future research is warranted. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Quantitative safety goals for the regulatory process

International Nuclear Information System (INIS)

Joksimovic, V.; O'Donnell, L.F.

1981-01-01

The paper offers a brief summary of the current regulatory background in the USA, emphasizing nuclear, related to the establishment of quantitative safety goals as a way to respond to the key issue of 'how safe is safe enough'. General Atomic has taken a leading role in advocating the use of probabilistic risk assessment techniques in the regulatory process. This has led to understanding of the importance of quantitative safety goals. The approach developed by GA is discussed in the paper. It is centred around definition of quantitative safety regions. The regions were termed: design basis, safety margin or design capability and safety research. The design basis region is bounded by the frequency of 10 -4 /reactor-year and consequences of no identifiable public injury. 10 -4 /reactor-year is associated with the total projected lifetime of a commercial US nuclear power programme. Events which have a 50% chance of happening are included in the design basis region. In the safety margin region, which extends below the design basis region, protection is provided against some events whose probability of not happening during the expected course of the US nuclear power programme is within the range of 50 to 90%. Setting the lower mean frequency to this region of 10 -5 /reactor-year is equivalent to offering 90% assurance that an accident of given severity will not happen. Rare events with a mean frequency below 10 -5 can be predicted to occur. However, accidents predicted to have a probability of less than 10 -6 are 99% certain not to happen at all, and are thus not anticipated to affect public health and safety. The area between 10 -5 and 10 -6 defines the frequency portion of the safety research region. Safety goals associated with individual risk to a maximum-exposed member of public, general societal risk and property risk are proposed in the paper

Prevalence of low bone health using quantitative ultrasound in Indian women aged 41-60 years: Its association with nutrition and other related risk factors.

Science.gov (United States)

Shenoy, Shweta; Chawla, Jasmine Kaur; Gupta, Swati; Sandhu, Jaspal Singh

2017-01-01

The purpose of this study was to find the prevalence of low bone health conditions and assess associated nutritional and other risk factors in Indian women aged 41-60 years. A total of 1,911 women participated in this cross-sectional study. Bone health was assessed using an Omnisense multisite quantitative ultrasound bone densitometer on two sites (radius and tibia). Crude prevalence of osteopenia and osteoporosis was found to be 30.09% and 19.89%, respectively. The Indian women were deficient in a majority of nutrients. Postmenopause, hysterectomy, hyperthyroid, hypothyroid, hypertension, low physical activity, low sun exposure, high stress levels, and low calcium levels were found to be independent risk factors of low bone health.

Methodology for development of risk indicators for offshore platforms

International Nuclear Information System (INIS)

Oeien, K.; Sklet, S.

1999-01-01

This paper presents a generic methodology for development of risk indicators for petroleum installations and a specific set of risk indicators established for one offshore platform. The risk indicators should be used to control the risk during operation of platforms. The methodology is purely risk-based and the basis for development of risk indicators is the platform specific quantitative risk analysis (QRA). In order to identify high risk contributing factors, platform personnel are asked to assess whether and how much the risk influencing factors will change. A brief comparison of probabilistic safety assessment (PSA) for nuclear power plants and quantitative risk analysis (QRA) for petroleum platforms is also given. (au)

Quantitative risk assessment: an emerging tool for emerging foodborne pathogens.

OpenAIRE

Lammerding, A. M.; Paoli, G. M.

1997-01-01

New challenges to the safety of the food supply require new strategies for evaluating and managing food safety risks. Changes in pathogens, food preparation, distribution, and consumption, and population immunity have the potential to adversely affect human health. Risk assessment offers a framework for predicting the impact of changes and trends on the provision of safe food. Risk assessment models facilitate the evaluation of active or passive changes in how foods are produced, processed, d...

Risk indicators as a tool for risk control

International Nuclear Information System (INIS)

Oien, K.

2001-01-01

This paper presents a general methodology for the establishment of risk indicators that can be used as a tool for risk control during operation of offshore petroleum installations. The risk indicators established are based on the platform specific quantitative risk analysis (QRA). The general methodology is evaluated against comparable approaches both in offshore and nuclear industry. There are two distinct features of this methodology. The first is that it is truly risk-based with the intention of covering the total risk picture. The second is that the identification of the risk factors contributing most to the total risk is based on realistic changes of each factor assessed by the platform personnel, not a theoretically assumed change. The set of risk indicators for one specific installation is presented along with test results

A quantitative benefit-risk assessment approach to improve decision making in drug development: Application of a multicriteria decision analysis model in the development of combination therapy for overactive bladder.

Science.gov (United States)

de Greef-van der Sandt, I; Newgreen, D; Schaddelee, M; Dorrepaal, C; Martina, R; Ridder, A; van Maanen, R

2016-04-01

A multicriteria decision analysis (MCDA) approach was developed and used to estimate the benefit-risk of solifenacin and mirabegron and their combination in the treatment of overactive bladder (OAB). The objectives were 1) to develop an MCDA tool to compare drug effects in OAB quantitatively, 2) to establish transparency in the evaluation of the benefit-risk profile of various dose combinations, and 3) to quantify the added value of combination use compared to monotherapies. The MCDA model was developed using efficacy, safety, and tolerability attributes and the results of a phase II factorial design combination study were evaluated. Combinations of solifenacin 5 mg and mirabegron 25 mg and mirabegron 50 (5+25 and 5+50) scored the highest clinical utility and supported combination therapy development of solifenacin and mirabegron for phase III clinical development at these dose regimens. This case study underlines the benefit of using a quantitative approach in clinical drug development programs. © 2015 The American Society for Clinical Pharmacology and Therapeutics.

Predicted cancer risks induced by computed tomography examinations during childhood, by a quantitative risk assessment approach.

Science.gov (United States)

Journy, Neige; Ancelet, Sophie; Rehel, Jean-Luc; Mezzarobba, Myriam; Aubert, Bernard; Laurier, Dominique; Bernier, Marie-Odile

2014-03-01

The potential adverse effects associated with exposure to ionizing radiation from computed tomography (CT) in pediatrics must be characterized in relation to their expected clinical benefits. Additional epidemiological data are, however, still awaited for providing a lifelong overview of potential cancer risks. This paper gives predictions of potential lifetime risks of cancer incidence that would be induced by CT examinations during childhood in French routine practices in pediatrics. Organ doses were estimated from standard radiological protocols in 15 hospitals. Excess risks of leukemia, brain/central nervous system, breast and thyroid cancers were predicted from dose-response models estimated in the Japanese atomic bomb survivors' dataset and studies of medical exposures. Uncertainty in predictions was quantified using Monte Carlo simulations. This approach predicts that 100,000 skull/brain scans in 5-year-old children would result in eight (90 % uncertainty interval (UI) 1-55) brain/CNS cancers and four (90 % UI 1-14) cases of leukemia and that 100,000 chest scans would lead to 31 (90 % UI 9-101) thyroid cancers, 55 (90 % UI 20-158) breast cancers, and one (90 % UI risks without exposure). Compared to background risks, radiation-induced risks would be low for individuals throughout life, but relative risks would be highest in the first decades of life. Heterogeneity in the radiological protocols across the hospitals implies that 5-10 % of CT examinations would be related to risks 1.4-3.6 times higher than those for the median doses. Overall excess relative risks in exposed populations would be 1-10 % depending on the site of cancer and the duration of follow-up. The results emphasize the potential risks of cancer specifically from standard CT examinations in pediatrics and underline the necessity of optimization of radiological protocols.

[Risk assessment and risk control for occupational exposure to chemical toxicants from an isophorone nitrile device].

Science.gov (United States)

Wang, Dejun; Fu, Xiaokuan; Kong, Fanling; Sui, Shaofeng; Jiang, Yuanyuan; Du, Yinglin; Zhou, Jingyang

2014-06-01

Risk assessment and risk control for occupational exposure to chemical toxicants were performed on an isophorone nitrile device with an annual production of 5,000 tons, based on improved Singaporean semi-quantitative risk assessment method, with consideration of actual situation in China and in the present project. With the use of engineering analysis and identification of occupational hazards in the improved Singaporean semi-quantitative risk assessment method, hazard rating (HR) and risk assessment were performed on chemical toxicants from an isophorone nitrile device with an annual production of 5,000 tons. The chemical toxicants in the isophorone nitrile device were mainly isophorone, hydrocyanic acid, methanol, phosphoric acid, sodium hydroxide, and sodium cyanide; the HR values were mild hazard (2), extreme hazard (5), mild hazard (2), mild hazard (2), moderate hazard (3), and extreme hazard (5), respectively, and the corresponding exposure rating (ER) values were 2.09, 2.72, 2.76, 1.68, 2.0, and 1.59, respectively. The risk of chemical toxicants in this project was assessed according to the formula Risk = [HR×ER](1/2). Hydrocyanic acid was determined as high risk, sodium hydroxide and sodium cyanide as medium risk, and isophorone, methanol, and phosphoric acid as low risk. Priority in handling of risks was determined by risk rating. The table of risk control measure was established for pre-assessment of occupational hazards. With risk assessment in this study, we concluded that the isophorone nitrile device with 5,000 ton annual production was a high-occupational hazard device. This device is a project of extreme occupational hazard. The improved Singaporean semi-quantitative risk assessment method is a scientific and applicable method, and is especially suitable for pre-evaluation of on-site project with no analogy.

Human fecal source identification with real-time quantitative PCR

Science.gov (United States)

Waterborne diseases represent a significant public health risk worldwide, and can originate from contact with water contaminated with human fecal material. We describe a real-time quantitative PCR (qPCR) method that targets a Bacteroides dori human-associated genetic marker for...

Quantitative penetration testing with item response theory (extended version)

NARCIS (Netherlands)

Arnold, Florian; Pieters, Wolter; Stoelinga, Mariëlle Ida Antoinette

2013-01-01

Existing penetration testing approaches assess the vulnerability of a system by determining whether certain attack paths are possible in practice. Therefore, penetration testing has thus far been used as a qualitative research method. To enable quantitative approaches to security risk management,

Exploring the uncertainties in cancer risk assessment using the integrated probabilistic risk assessment (IPRA) approach.

Science.gov (United States)

Slob, Wout; Bakker, Martine I; Biesebeek, Jan Dirk Te; Bokkers, Bas G H

2014-08-01

Current methods for cancer risk assessment result in single values, without any quantitative information on the uncertainties in these values. Therefore, single risk values could easily be overinterpreted. In this study, we discuss a full probabilistic cancer risk assessment approach in which all the generally recognized uncertainties in both exposure and hazard assessment are quantitatively characterized and probabilistically evaluated, resulting in a confidence interval for the final risk estimate. The methodology is applied to three example chemicals (aflatoxin, N-nitrosodimethylamine, and methyleugenol). These examples illustrate that the uncertainty in a cancer risk estimate may be huge, making single value estimates of cancer risk meaningless. Further, a risk based on linear extrapolation tends to be lower than the upper 95% confidence limit of a probabilistic risk estimate, and in that sense it is not conservative. Our conceptual analysis showed that there are two possible basic approaches for cancer risk assessment, depending on the interpretation of the dose-incidence data measured in animals. However, it remains unclear which of the two interpretations is the more adequate one, adding an additional uncertainty to the already huge confidence intervals for cancer risk estimates. © 2014 Society for Risk Analysis.

Risk Management Practices: The Ghanaian Firms' Perspective ...

African Journals Online (AJOL)

Using a quantitative approach the findings of the study are that Ghanaian firms understand risk and risk management. Additionally, operational, liquidity and credit risk are the most dominant risks experienced while risk identification and selection jointly determine risk management practices in Ghana. Based on the findings ...

The watchdog role of risk analysis

International Nuclear Information System (INIS)

Reijen, G. van; Vinck, W.

1983-01-01

The reason why the risks of large-scale technology attract more attention lies in the fact that accidents would have more disastrous results and in the fact that it is probably more attractive to study the risks of some large projects than to do the same for a greater number of smaller projects. Within this presentation there will be some opening remarks on the Role of the Commission of the European Community with regard to accident prevention. The development of the concept of quantitative risks is dealt with. This development leads to a combinded of deterministic and probabilistic methods. The presentation concludes with some critical remarks on quantitative risk analysis and its use. (orig./HP) [de

MATHEMATICAL RISK ANALYSIS: VIA NICHOLAS RISK MODEL AND BAYESIAN ANALYSIS

Directory of Open Access Journals (Sweden)

Anass BAYAGA

2010-07-01

Full Text Available The objective of this second part of a two-phased study was to explorethe predictive power of quantitative risk analysis (QRA method andprocess within Higher Education Institution (HEI. The method and process investigated the use impact analysis via Nicholas risk model and Bayesian analysis, with a sample of hundred (100 risk analysts in a historically black South African University in the greater Eastern Cape Province.The first findings supported and confirmed previous literature (KingIII report, 2009: Nicholas and Steyn, 2008: Stoney, 2007: COSA, 2004 that there was a direct relationship between risk factor, its likelihood and impact, certiris paribus. The second finding in relation to either controlling the likelihood or the impact of occurrence of risk (Nicholas risk model was that to have a brighter risk reward, it was important to control the likelihood ofoccurrence of risks as compared with its impact so to have a direct effect on entire University. On the Bayesian analysis, thus third finding, the impact of risk should be predicted along three aspects. These aspects included the human impact (decisions made, the property impact (students and infrastructural based and the business impact. Lastly, the study revealed that although in most business cases, where as business cycles considerably vary dependingon the industry and or the institution, this study revealed that, most impacts in HEI (University was within the period of one academic.The recommendation was that application of quantitative risk analysisshould be related to current legislative framework that affects HEI.

Extracting additional risk managers information from a risk assessment of Listeria monocytogenes in deli meats

NARCIS (Netherlands)

Pérez-Rodríguez, F.; Asselt, van E.D.; García-Gimeno, R.M.; Zurera, G.; Zwietering, M.H.

2007-01-01

The risk assessment study of Listeria monocytogenes in ready-to-eat foods conducted by the U.S. Food and Drug Administration is an example of an extensive quantitative microbiological risk assessment that could be used by risk analysts and other scientists to obtain information and by managers and

Adding an alcohol-related risk score to an existing categorical risk classification for older adults: sensitivity to group differences.

Science.gov (United States)

Wilson, Sandra R; Fink, Arlene; Verghese, Shinu; Beck, John C; Nguyen, Khue; Lavori, Philip

2007-03-01

To evaluate a new alcohol-related risk score for research use. Using data from a previously reported trial of a screening and education system for older adults (Computerized Alcohol-Related Problems Survey), secondary analyses were conducted comparing the ability of two different measures of risk to detect post-intervention group differences: the original categorical outcome measure and a new, finely grained quantitative risk score based on the same research-based risk factors. Three primary care group practices in southern California. Six hundred sixty-five patients aged 65 and older. A previously calculated, three-level categorical classification of alcohol-related risk and a newly developed quantitative risk score. Mean post-intervention risk scores differed between the three experimental conditions: usual care, patient report, and combined report (Ptrinary risk classification. The additional clinical value of the risk score relative to the categorical measure needs to be determined.

QMRA (quantitative microbial risk assessment) and HACCP (hazard analysis and critical control points) for management of pathogens in wastewater and sewage sludge treatment and reuse.

Science.gov (United States)

Westrell, T; Schönning, C; Stenström, T A; Ashbolt, N J

2004-01-01

Hazard Analysis and Critical Control Points (HACCP) was applied for identifying and controlling exposure to pathogenic microorganisms encountered during normal sludge and wastewater handling at a 12,500 m3/d treatment plant utilising tertiary wastewater treatment and mesophilic sludge digestion. The hazardous scenarios considered were human exposure during treatment, handling, soil application and crop consumption, and exposure via water at the wetland-area and recreational swimming. A quantitative microbial risk assessment (QMRA), including rotavirus, adenovirus, haemorrhagic E. coli, Salmonella, Giardia and Cryptosporidium, was performed in order to prioritise pathogen hazards for control purposes. Human exposures were treated as individual risks but also related to the endemic situation in the general population. The highest individual health risk from a single exposure was via aerosols for workers at the belt press for sludge dewatering (virus infection risk = 1). The largest impact on the community would arise if children ingested sludge at the unprotected storage site, although in the worst-case situation the largest number of infections would arise through vegetables fertilised with sludge and eaten raw (not allowed in Sweden). Acceptable risk for various hazardous scenarios, treatment and/or reuse strategies could be tested in the model.

New quantitative safety standards: different techniques, different results?

International Nuclear Information System (INIS)

Rouvroye, J.L.; Brombacher, A.C.

1999-01-01

Safety Instrumented Systems (SIS) are used in the process industry to perform safety functions. Many factors can influence the safety of a SIS like system layout, diagnostics, testing and repair. In standards like the German DIN no quantitative analysis is demanded (DIN V 19250 Grundlegende Sicherheitsbetrachtungen fuer MSR-Schutzeinrichtungen, Berlin, 1994; DIN/VDE 0801 Grundsaetze fuer Rechner in Systemen mit Sicherheitsaufgaben, Berlin, 1990). The analysis according to these standards is based on expert opinion and qualitative analysis techniques. New standards like the IEC 61508 (IEC 61508 Functional safety of electrical/electronic/programmable electronic safety-related systems, IEC, Geneve, 1997) and the ISA-S84.01 (ISA-S84.01.1996 Application of Safety Instrumented Systems for the Process Industries, Instrument Society of America, Research Triangle Park, 1996) require quantitative risk analysis but do not prescribe how to perform the analysis. Earlier publications of the authors (Rouvroye et al., Uncertainty in safety, new techniques for the assessment and optimisation of safety in process industry, D W. Pyatt (ed), SERA-Vol. 4, Safety engineering and risk analysis, ASME, New York 1995; Rouvroye et al., A comparison study of qualitative and quantitative analysis techniques for the assessment of safety in industry, P.C. Cacciabue, I.A. Papazoglou (eds), Proceedings PSAM III conference, Crete, Greece, June 1996) have shown that different analysis techniques cover different aspects of system behaviour. This paper shows by means of a case study, that different (quantitative) analysis techniques may lead to different results. The consequence is that the application of the standards to practical systems will not always lead to unambiguous results. The authors therefore propose a technique to overcome this major disadvantage

Health risk assessment of exposure to ionizing radiation

International Nuclear Information System (INIS)

Ogata, Hiromitsu

2011-01-01

Risk assessment is an essential process for evaluating the human health effects of exposure to ionizing radiation and for determining acceptable levels of exposure. There are two major components of radiation risk assessment: a measure of exposure level and a measure of disease occurrence. For quantitative estimation of health risks, it is important to evaluate the association between exposure and disease occurrence using epidemiological or experimental data. In these approaches, statistical risk models are used particularly for estimating cancer risks related to exposure to low levels of radiation. This paper presents a summary of basic models and methods of risk assessment for studying exposure-risk relationships. Moreover, quantitative risk estimates are subject to several sources of uncertainty due to inherent limitations in risk assessment studies. This paper also discusses the limitations of radiation risk assessment. (author)

Correlation between quantitative HER-2 protein expression and risk for brain metastases in HER-2+ advanced breast cancer patients receiving trastuzumab-containing therapy.

Science.gov (United States)

Duchnowska, Renata; Biernat, Wojciech; Szostakiewicz, Barbara; Sperinde, Jeff; Piette, Fanny; Haddad, Mojgan; Paquet, Agnes; Lie, Yolanda; Czartoryska-Arłukowicz, Bogumiła; Wysocki, Piotr; Jankowski, Tomasz; Radecka, Barbara; Foszczynska-Kłoda, Małgorzata; Litwiniuk, Maria; Debska, Sylwia; Weidler, Jodi; Huang, Weidong; Buyse, Marc; Bates, Michael; Jassem, Jacek

2012-01-01

Patients with human epidermal growth factor receptor (HER)-2+ breast cancer are at particularly high risk for brain metastases; however, the biological basis is not fully understood. Using a novel HER-2 assay, we investigated the correlation between quantitative HER-2 expression in primary breast cancers and the time to brain metastasis (TTBM) in HER-2+ advanced breast cancer patients treated with trastuzumab. The study group included 142 consecutive patients who were administered trastuzumab-based therapy for HER-2+ metastatic breast cancer. HER-2/neu gene copy number was quantified as the HER-2/centromeric probe for chromosome 17 (CEP17) ratio by central laboratory fluorescence in situ hybridization (FISH). HER-2 protein was quantified as total HER-2 protein expression (H2T) by the HERmark® assay (Monogram Biosciences, Inc., South San Francisco, CA) in formalin-fixed, paraffin-embedded tumor samples. HER-2 variables were correlated with clinical features and TTBM was measured from the initiation of trastuzumab-containing therapy. A higher H2T level (continuous variable) was correlated with shorter TTBM, whereas HER-2 amplification by FISH and a continuous HER-2/CEP17 ratio were not predictive (p = .013, .28, and .25, respectively). In the subset of patients that was centrally determined by FISH to be HER-2+, an above-the-median H2T level was significantly associated with a shorter TTBM (hazard ratio, [HR], 2.4; p = .005), whereas this was not true for the median HER-2/CEP17 ratio by FISH (p = .4). Correlation between a continuous H2T level and TTBM was confirmed on multivariate analysis (HR, 3.3; p = .024). These data reveal a strong relationship between the quantitative HER-2 protein expression level and the risk for brain relapse in HER-2+ advanced breast cancer patients. Consequently, quantitative assessment of HER-2 protein expression may inform and facilitate refinements in therapeutic treatment strategies for selected subpopulations of patients in this

A clustering approach to segmenting users of internet-based risk calculators.

Science.gov (United States)

Harle, C A; Downs, J S; Padman, R

2011-01-01

Risk calculators are widely available Internet applications that deliver quantitative health risk estimates to consumers. Although these tools are known to have varying effects on risk perceptions, little is known about who will be more likely to accept objective risk estimates. To identify clusters of online health consumers that help explain variation in individual improvement in risk perceptions from web-based quantitative disease risk information. A secondary analysis was performed on data collected in a field experiment that measured people's pre-diabetes risk perceptions before and after visiting a realistic health promotion website that provided quantitative risk information. K-means clustering was performed on numerous candidate variable sets, and the different segmentations were evaluated based on between-cluster variation in risk perception improvement. Variation in responses to risk information was best explained by clustering on pre-intervention absolute pre-diabetes risk perceptions and an objective estimate of personal risk. Members of a high-risk overestimater cluster showed large improvements in their risk perceptions, but clusters of both moderate-risk and high-risk underestimaters were much more muted in improving their optimistically biased perceptions. Cluster analysis provided a unique approach for segmenting health consumers and predicting their acceptance of quantitative disease risk information. These clusters suggest that health consumers were very responsive to good news, but tended not to incorporate bad news into their self-perceptions much. These findings help to quantify variation among online health consumers and may inform the targeted marketing of and improvements to risk communication tools on the Internet.

Pulmonary nodule characterization, including computer analysis and quantitative features.

Science.gov (United States)

Bartholmai, Brian J; Koo, Chi Wan; Johnson, Geoffrey B; White, Darin B; Raghunath, Sushravya M; Rajagopalan, Srinivasan; Moynagh, Michael R; Lindell, Rebecca M; Hartman, Thomas E

2015-03-01

Pulmonary nodules are commonly detected in computed tomography (CT) chest screening of a high-risk population. The specific visual or quantitative features on CT or other modalities can be used to characterize the likelihood that a nodule is benign or malignant. Visual features on CT such as size, attenuation, location, morphology, edge characteristics, and other distinctive "signs" can be highly suggestive of a specific diagnosis and, in general, be used to determine the probability that a specific nodule is benign or malignant. Change in size, attenuation, and morphology on serial follow-up CT, or features on other modalities such as nuclear medicine studies or MRI, can also contribute to the characterization of lung nodules. Imaging analytics can objectively and reproducibly quantify nodule features on CT, nuclear medicine, and magnetic resonance imaging. Some quantitative techniques show great promise in helping to differentiate benign from malignant lesions or to stratify the risk of aggressive versus indolent neoplasm. In this article, we (1) summarize the visual characteristics, descriptors, and signs that may be helpful in management of nodules identified on screening CT, (2) discuss current quantitative and multimodality techniques that aid in the differentiation of nodules, and (3) highlight the power, pitfalls, and limitations of these various techniques.

Packaging and transportation risk management and evaluation plan

International Nuclear Information System (INIS)

Rhyne, W.R.

1993-09-01

Shipments of radioactive materials and hazardous chemicals at the Los Alamos National Laboratory (LANL) are governed by a variety of Federal and state regulations, industrial standards, and LANL processes and procedures. Good judgement is exercised in situations that are not covered by regulations. As a result, the safety record for transporting hazardous materials at LANL has been excellent. However, future decisions should be made such that the decision-making process produces a defensible record of the safety of onsite shipments. This report proposes the development of a risk management tool to meet this need. First, the application of quantitative risk analysis methodology to transportation is presented to provide a framework of understanding. Risk analysis definitions, the basic quantitative risk analysis procedure, quantitative methodologies, transportation data bases, and risk presentation techniques are described. Quantitative risk analysis is frequently complex; but simplified approaches can be used as a management tool to make good decisions. Second, a plan to apply the use of risk management principles to the selection of routes, special administrative controls, and containers for hazardous material transportation at LANL is provided. A risk management tool is proposed that can be used by MAT-2 without substantial support from specialized safety and risk analysis personnel, e.g., HS-3. A workbook approach is proposed that can be automated at a later date. The safety of some types of onsite shipments at LANL is not well documented. Documenting that shipments are safe, i.e., present acceptable risks, will likely require elaborate analyses that should be thoroughly reviewed by safety and risk professionals. These detailed analyses are used as benchmarks and as examples for the use of the proposed tool by MAT-2. Once the benchmarks are established, the workbook can be used by MAT-2 to quantify that safety goals are met by similar shipments

Risk assessment for federal regulatory decisions on organisms produced through biotechnology

International Nuclear Information System (INIS)

Payne, John H.; Medley, Terry L.

1992-01-01

This article discusses: 1. Purposes and history of risk assessment: application to biotechnology; 2. Framework in the United States for decisions on organisms produced through biotechnology; 3. Choosing from among potential approaches to assessment: a). exposure assessment does not equate to risk assessment: what are the hazards?; b). Setting risk assessment priorities; c). 'Quantitative' environmental and 'quantitative' ecological risk assessments; d). Ecological risk assessments based on biological and ecological principles. 4. The bases for good regulatory decisions

Risk assessment for federal regulatory decisions on organisms produced through biotechnology

Energy Technology Data Exchange (ETDEWEB)

Payne, John H; Medley, Terry L [Biotechnology, Biologics and Environmental Protection Animal and Plant Health Inspection Service, U.S. Department of Agriculture, Hyattsville, MD (United States)

1992-07-01

This article discusses: 1. Purposes and history of risk assessment: application to biotechnology; 2. Framework in the United States for decisions on organisms produced through biotechnology; 3. Choosing from among potential approaches to assessment: a). exposure assessment does not equate to risk assessment: what are the hazards?; b). Setting risk assessment priorities; c). 'Quantitative' environmental and 'quantitative' ecological risk assessments; d). Ecological risk assessments based on biological and ecological principles. 4. The bases for good regulatory decisions.

Quantitative assessment of breast density from mammograms

International Nuclear Information System (INIS)

Jamal, N.; Ng, K.H.

2004-01-01

Full text: It is known that breast density is increasingly used as a risk factor for breast cancer. This study was undertaken to develop and validate a semi-automated computer technique for the quantitative assessment of breast density from digitised mammograms. A computer technique had been developed using MATLAB (Version 6.1) based GUI applications. This semi-automated image analysis tool consists of gradient correction, segmentation of breast region from background, segmentation of fibroglandular and adipose region within the breast area and calculation of breast density. The density is defined as the percentage of fibroglandular tissue area divided by the total breast area in the mammogram. This technique was clinically validated with 122 normal mammograms; these were subjectively evaluated and classified according to the five parenchyma patterns of the Tabar's scheme (Class I- V) by a consultant radiologist. There was a statistical significant correlation between the computer technique and subjective classification (r 2 = 0.84, p<0.05). 71.3% of subjective classification was correctly classified using the computer technique. We had developed a computer technique for the quantitative assessment of breast density and validated its accuracy for computerized classification based on Tabar's scheme. This quantitative tool is useful for the evaluation of a large dataset of mammograms to predict breast cancer risk based on density. Furthermore it has the potential to provide an early marker for success or failure in chemoprevention studies such as hormonal replacement therapy. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

Dose response models and a quantitative microbial risk assessment framework for the Mycobacterium avium complex that account for recent developments in molecular biology, taxonomy, and epidemiology.

Science.gov (United States)

Hamilton, Kerry A; Weir, Mark H; Haas, Charles N

2017-02-01

Mycobacterium avium complex (MAC) is a group of environmentally-transmitted pathogens of great public health importance. This group is known to be harbored, amplified, and selected for more human-virulent characteristics by amoeba species in aquatic biofilms. However, a quantitative microbial risk assessment (QMRA) has not been performed due to the lack of dose response models resulting from significant heterogeneity within even a single species or subspecies of MAC, as well as the range of human susceptibilities to mycobacterial disease. The primary human-relevant species and subspecies responsible for the majority of the human disease burden and present in drinking water, biofilms, and soil are M. avium subsp. hominissuis, M. intracellulare, and M. chimaera. A critical review of the published literature identified important health endpoints, exposure routes, and susceptible populations for MAC risk assessment. In addition, data sets for quantitative dose-response functions were extracted from published in vivo animal dosing experiments. As a result, seven new exponential dose response models for human-relevant species of MAC with endpoints of lung lesions, death, disseminated infection, liver infection, and lymph node lesions are proposed. Although current physical and biochemical tests used in clinical settings do not differentiate between M. avium and M. intracellulare, differentiating between environmental species and subspecies of the MAC can aid in the assessment of health risks and control of MAC sources. A framework is proposed for incorporating the proposed dose response models into susceptible population- and exposure route-specific QMRA models. Copyright © 2016 Elsevier Ltd. All rights reserved.

Risk assessment - a research program aimed at health risks from air pollution in the general environment

International Nuclear Information System (INIS)

Lindahl-Kiessling, K.; Ahlborg, U.; Bylin, G.; Ehrenberg, L.; Hemminki, K.; Lindell, B.; Nilsson, Robert; Bostroem, C.E.; Swarn, U.

1991-01-01

The paper presents a new research program for assessment of health risks caused by air pollutants. It is important to develop general methods for quantitative risk assessments and to improve the scientific base materials. (KAE)

Quantitative structure-activity relationships for predicting potential ecological hazard of organic chemicals for use in regulatory risk assessments.

Science.gov (United States)

Comber, Mike H I; Walker, John D; Watts, Chris; Hermens, Joop

2003-08-01

The use of quantitative structure-activity relationships (QSARs) for deriving the predicted no-effect concentration of discrete organic chemicals for the purposes of conducting a regulatory risk assessment in Europe and the United States is described. In the United States, under the Toxic Substances Control Act (TSCA), the TSCA Interagency Testing Committee and the U.S. Environmental Protection Agency (U.S. EPA) use SARs to estimate the hazards of existing and new chemicals. Within the Existing Substances Regulation in Europe, QSARs may be used for data evaluation, test strategy indications, and the identification and filling of data gaps. To illustrate where and when QSARs may be useful and when their use is more problematic, an example, methyl tertiary-butyl ether (MTBE), is given and the predicted and experimental data are compared. Improvements needed for new QSARs and tools for developing and using QSARs are discussed.

Multi-factor models and signal processing techniques application to quantitative finance

CERN Document Server

Darolles, Serges; Jay, Emmanuelle

2013-01-01

With recent outbreaks of multiple large-scale financial crises, amplified by interconnected risk sources, a new paradigm of fund management has emerged. This new paradigm leverages "embedded" quantitative processes and methods to provide more transparent, adaptive, reliable and easily implemented "risk assessment-based" practices.This book surveys the most widely used factor models employed within the field of financial asset pricing. Through the concrete application of evaluating risks in the hedge fund industry, the authors demonstrate that signal processing techniques are an intere

Generalized indices for radiation risk analysis

International Nuclear Information System (INIS)

Bykov, A.A.; Demin, V.F.

1989-01-01

A new approach to ensuring nuclear safety has begun forming since the early eighties. The approach based on the probabilistic safety analysis, the principles of acceptable risk, the optimization of safety measures, etc. has forced a complex of adequate quantitative methods of assessment, safety analysis and risk management to be developed. The method of radiation risk assessment and analysis hold a prominent place in the complex. National and international research and regulatory organizations ICRP, IAEA, WHO, UNSCEAR, OECD/NEA have given much attention to the development of the conceptual and methodological basis of those methods. Some resolutions of the National Commission of Radiological Protection (NCRP) and the Problem Commission on Radiation Hygiene of the USSR Ministry of Health should be also noted. Both CBA (cost benefit analysis) and other methods of radiation risk analysis and safety management use a system of natural and socio-economic indices characterizing the radiation risk or damage. There exist a number of problems associated with the introduction, justification and use of these indices. For example, the price, a, of radiation damage, or collective dose unit, is a noteworthy index. The difficulties in its qualitative and quantitative determination are still an obstacle for a wide application of CBA to the radiation risk analysis and management. During recent 10-15 years these problems have been a subject of consideration for many authors. The present paper also considers the issues of the qualitative and quantitative justification of the indices of radiation risk analysis

Prediction of Maintenance Period of Equipment Through Risk Assessment of Thermal Power Plants

Energy Technology Data Exchange (ETDEWEB)

Song, Gee Wook; Kim, Bum Shin; Choi, Woo Song; Park, Myung Soo [KEPCO Research Institute, Daejeon (Korea, Republic of)

2013-10-15

Risk-based inspection (RBI) is a well-known method that is used to optimize inspection activities based on risk analysis in order to identify the high-risk components of major facilities such as power plants. RBI, when implemented and maintained properly, improves plant reliability and safety while reducing unplanned outages and repair costs. Risk is given by the product of the probability of failure (Pof) and the consequence of failure (COF). A semi-quantitative method is generally used for risk assessment. Semi-quantitative risk assessment complements the low accuracy of qualitative risk assessment and the high expense and long calculation time of quantitative risk assessment. The first step of RB I is to identify important failure modes and causes in the equipment. Once these are defined, the Pof and COF can be assessed for each failure. During Pof and COF assessment, an effective inspection method and range can be easily found. In this paper, the calculation of the Pof is improved for accurate risk assessment. A modified semi-quantitative risk assessment was carried out for boiler facilities of thermal power plants, and the next maintenance schedules for the equipment were decided.

Prediction of Maintenance Period of Equipment Through Risk Assessment of Thermal Power Plants

International Nuclear Information System (INIS)

Song, Gee Wook; Kim, Bum Shin; Choi, Woo Song; Park, Myung Soo

2013-01-01

Risk-based inspection (RBI) is a well-known method that is used to optimize inspection activities based on risk analysis in order to identify the high-risk components of major facilities such as power plants. RBI, when implemented and maintained properly, improves plant reliability and safety while reducing unplanned outages and repair costs. Risk is given by the product of the probability of failure (Pof) and the consequence of failure (COF). A semi-quantitative method is generally used for risk assessment. Semi-quantitative risk assessment complements the low accuracy of qualitative risk assessment and the high expense and long calculation time of quantitative risk assessment. The first step of RB I is to identify important failure modes and causes in the equipment. Once these are defined, the Pof and COF can be assessed for each failure. During Pof and COF assessment, an effective inspection method and range can be easily found. In this paper, the calculation of the Pof is improved for accurate risk assessment. A modified semi-quantitative risk assessment was carried out for boiler facilities of thermal power plants, and the next maintenance schedules for the equipment were decided

A quantitative and comparative evaluation of the risks from nuclear power plants

International Nuclear Information System (INIS)

Vignes, S.; Bertin, M.; Nenot, J.C.

1980-01-01

All the significant data for the assessment of risks from the operation of nuclear power plants was collected and these risks were compared with all the risks of modern life. The scientific bases for the evaluation of individual risks and detriment were defined by UNSCEAR (1977) and by ICRP 26 (1978). In different industries, the risk of death from long term occupational illness is about 130 to 14,000 per million workers. For accidental deaths, the risk is estimated at about 16 to 1,600. The risk for the nuclear industry is lower than 100 per million workers. Comparisons are made with different causes of lethality: deaths from atmospheric pollution (sulfur compounds and dusts) related to fossile fuel combustion; iatrogenic accidents attributed to some drugs used in medicine or to other kind of treatment; calculated mortality for workers exposed to asestosis. The nuclear industr of the safest. The only risk to be considered is the major accident, the probability of which is very low. (H.K.)

Quantitative Structure activity relationship and risk analysis of some pesticides in the cattle milk

Directory of Open Access Journals (Sweden)

Faqir Muhammad*, Ijaz Javed, Masood Akhtar1, Zia-ur-Rahman, Mian Muhammad Awais1, Muhammad Kashif Saleemi2 and Muhammad Irfan Anwar3

2012-10-01

Full Text Available Milk of cattle was collected from various localities of Faisalabad, Pakistan. Pesticides concentration was determined by HPLC using solid phase microextraction. The residue analysis revealed that about 40% milk samples were contaminated with pesticides. The mean±SE levels (ppm of cyhalothrin, endosulfan, chlorpyrifos and cypermethrin were 0.38±0.02, 0.26±0.02, 0.072±0.01 and 0.085±0.02, respectively. Quantitative structure activity relationship (QSAR models were used to predict the residues of unknown pesticides in the milk of cattle using their known physicochemical properties such as molecular weight (MW, melting point (MP, and log octanol to water partition coefficient (Ko/w as well as the milk characteristics such as pH, % fat, and specific gravity (SG in this species. The analysis revealed good correlation coefficients (R2 = 0.91 for cattle QSAR model. The coefficient for Ko/w for the studied pesticides was higher in cattle milk. Risk analysis was conducted based upon the determined pesticide residues and their provisional tolerable daily intakes. The daily intake levels of pesticide residues including cyhalothrin, chlorpyrifos and cypermethrin in present study were 3, 11, 2.5 times higher, respectively in cattle milk. This intake of pesticide contaminated milk might pose health hazards to humans in this locality.

Quantitative microbial risk assessment for Escherichia coli O157 on lettuce, based on survival data from controlled studies in a climate chamber.

Science.gov (United States)

Ottoson, Jakob R; Nyberg, Karin; Lindqvist, Roland; Albihn, Ann

2011-12-01

The aims of the study were to determine the survival of Escherichia coli O157 on lettuce as a function of temperature and light intensity, and to use that information in a screening-level quantitative microbial risk assessment (QMRA) in order to evaluate risk-reducing strategies including irrigation water quality guidelines, rinsing, and holding time between last irrigation and harvest. Iceberg lettuce was grown in a climate chamber and inoculated with E. coli O157. Bacterial numbers were determined with the standard plate count method after inoculation and 1, 2, 4, and 7 day(s) postinoculation. The experiments were carried out at 11, 18, and 25°C in light intensities of 0, 400, and 600 mmol (m(2))(-1) s(-1). There was a significant effect of temperature and light intensity on survival, with less bacteria isolated from lettuce incubated at 25 and 18°C compared with 11°C (P < 0.0001), and in light intensities of 400 and 600 mmol (m(2))(-1) s(-1) compared with 0 mmol (m(2))(-1) s(-1) (P < 0.001). The average log reductions after 1, 2, 4, and 7 day(s) were 1.14, 1.71, 2.04, and 3.0, respectively. The QMRA compared the relative risk with lettuce consumption from 20 scenarios. A stricter water quality guideline gave a mean fivefold risk reduction. Holding times of 1, 2, 4, and 7 day(s) reduced the risk 3, 8, 8, and 18 times, respectively, compared with harvest the same day as the last irrigation. Finally, rinsing lettuce for 15 s in cold tap water prior to consumption gave a sixfold risk reduction compared with eating unrinsed lettuce. Sensitivity analyses indicated that variation in bacterial inactivation had the most significant effect on the risk outcome. A QMRA determining the relative risks between scenarios reduces uncertainty and can provide risk managers with decision support.

Quantitative risk assessment of WSSV transmission through partial harvesting and transport practices for shrimp aquaculture in Mexico.

Science.gov (United States)

Sanchez-Zazueta, Edgar; Martínez-Cordero, Francisco Javier; Chávez-Sánchez, María Cristina; Montoya-Rodríguez, Leobardo

2017-10-01

This quantitative risk assessment provided an analytical framework to estimate white spot syndrome virus (WSSV) transmission risks in the following different scenarios: (1) partial harvest from rearing ponds and (2) post-harvest transportation, assuming that the introduction of contaminated water with viral particles into shrimp culture ponds is the main source of viral transmission risk. Probabilities of infecting shrimp with waterborne WSSV were obtained by approaching the functional form that best fits (likelihood ratio test) published data on the dose-response relationship for WSSV orally inoculated through water into shrimp. Expert opinion defined the ranges for the following uncertain factors: (1) the concentrations of WSSV in the water spilled from the vehicles transporting the infected shrimp, (2) the total volume of these spills, and (3) the dilution into culture ponds. Multiple scenarios were analysed, starting with a viral load (VL) of 1×10 2 mL -1 in the contaminated water spilled that reached the culture pond, whose probability of infection of an individual shrimp (P i ) was negligible (1.7×10 -7 ). Increasing the VL to 1×10 4.5 mL -1 and 1×10 7 mL -1 yielded results into very low (P i =5.3×10 -5 ) and high risk (P i =1.6×10 -2 ) categories, respectively. Furthermore, different pond stocking density (SD) scenarios (20 and 30 post-larvae [PL]/m 2 ) were evaluated, and the probability of infection of at least one out of the total number of shrimp exposed (P N ) was derived; for the scenarios with a low VL (1×10 2 mL -1 ), the P N remained at a negligible risk level (P N , 2.4×10 -7 to 1.8×10 -6 ). For most of the scenarios with the moderate VL (1×10 4.5 mL -1 ), the P N scaled up to a low risk category (P N , 1.1×10 -4 to 5.6×10 -4 ), whereas for the scenarios with a high VL (1×10 7 mL -1 ), the risk levels were high (P N , 2.3×10 -2 to 3.5×10 -2 ) or very high (P N , 1.1×10 -1 to 1.6×10 -1 ) depending on the volume of contaminated water

A Quantitative Risk Analysis of Deficient Contractor Business System

Science.gov (United States)

2012-04-30

Mathematically , Jorion’s concept of VaR looks like this: ( > ) ≤ 1 − (2) where, = ^Åèìáëáíáçå=oÉëÉ~êÅÜ=éêçÖê~ãW= `êÉ~íáåÖ=póåÉêÖó=Ñçê=fåÑçêãÉÇ=ÅÜ...presents three models for calculating VaR. The local-valuation method determines the value of a portfolio once and uses mathematical derivatives...management. In the insurance industry, actuarial data is applied to model risk and risk capital reserves are “held” to cover the expected values for

The influence of graphic format on breast cancer risk communication.

Science.gov (United States)

Schapira, Marilyn M; Nattinger, Ann B; McAuliffe, Timothy L

2006-09-01

Graphic displays can enhance quantitative risk communication. However, empiric data regarding the effect of graphic format on risk perception is lacking. We evaluate the effect of graphic format elements on perceptions of risk magnitude and perceived truth of data. Preferences for format also were assessed. Participants (254 female primary care patients) viewed a series of hypothetical risk communications regarding the lifetime risk of breast cancer. Identical numeric risk information was presented using different graphic formats. Risk was perceived to be of lower magnitude when communicated with a bar graph as compared with a pictorial display (p graphic format used to convey quantitative risk information effects key domains of risk perception. One must be cognizant of these effects when designing risk communication strategies.

Genetic and environmental determinants of violence risk in psychotic disorders: a multivariate quantitative genetic study of 1.8 million Swedish twins and siblings.

Science.gov (United States)

Sariaslan, A; Larsson, H; Fazel, S

2016-09-01

Patients diagnosed with psychotic disorders (for example, schizophrenia and bipolar disorder) have elevated risks of committing violent acts, particularly if they are comorbid with substance misuse. Despite recent insights from quantitative and molecular genetic studies demonstrating considerable pleiotropy in the genetic architecture of these phenotypes, there is currently a lack of large-scale studies that have specifically examined the aetiological links between psychotic disorders and violence. Using a sample of all Swedish individuals born between 1958 and 1989 (n=3 332 101), we identified a total of 923 259 twin-sibling pairs. Patients were identified using the National Patient Register using validated algorithms based on International Classification of Diseases (ICD) 8-10. Univariate quantitative genetic models revealed that all phenotypes (schizophrenia, bipolar disorder, substance misuse, and violent crime) were highly heritable (h(2)=53-71%). Multivariate models further revealed that schizophrenia was a stronger predictor of violence (r=0.32; 95% confidence interval: 0.30-0.33) than bipolar disorder (r=0.23; 0.21-0.25), and large proportions (51-67%) of these phenotypic correlations were explained by genetic factors shared between each disorder, substance misuse, and violence. Importantly, we found that genetic influences that were unrelated to substance misuse explained approximately a fifth (21%; 20-22%) of the correlation with violent criminality in bipolar disorder but none of the same correlation in schizophrenia (Pbipolar disordergenetically similar phenotypes as the latter sources may include aetiologically important clues. Clinically, these findings underline the importance of assessing risk of different phenotypes together and integrating interventions for psychiatric disorders, substance misuse, and violence.

Genetic toxicology and cancer risk assessment

National Research Council Canada - National Science Library

Choy, Wai Nang

2001-01-01

... their risks to humans are obvious goals for the protection of public health. When exposure is unavoidable, an accurate estimation of human risk as a result of exposure is essential for making regulatory decisions. Quantitative cancer risk assessment is an intricate process that utilizes knowledge from many different scien...

Potential application of quantitative microbiological risk assessment techniques to an aseptic-UHT process in the food industry.

Science.gov (United States)

Pujol, Laure; Albert, Isabelle; Johnson, Nicholas Brian; Membré, Jeanne-Marie

2013-04-01

Aseptic ultra-high-temperature (UHT)-type processed food products (e.g., milk or soup) are ready to eat products which are consumed extensively globally due to a combination of their comparative high quality and long shelf life, with no cold chain or other preservation requirements. Due to the inherent microbial vulnerability of aseptic-UHT product formulations, the safety and stability-related performance objectives (POs) required at the end of the manufacturing process are the most demanding found in the food industry. The key determinants to achieving sterility, and which also differentiates aseptic-UHT from in-pack sterilised products, are the challenges associated with the processes of aseptic filling and sealing. This is a complex process that has traditionally been run using deterministic or empirical process settings. Quantifying the risk of microbial contamination and recontamination along the aseptic-UHT process, using the scientifically based process quantitative microbial risk assessment (QMRA), offers the possibility to improve on the currently tolerable sterility failure rate (i.e., 1 defect per 10,000 units). In addition, benefits of applying QMRA are (i) to implement process settings in a transparent and scientific manner; (ii) to develop a uniform common structure whatever the production line, leading to a harmonisation of these process settings, and; (iii) to bring elements of a cost-benefit analysis of the management measures. The objective of this article is to explore how QMRA techniques and risk management metrics may be applied to aseptic-UHT-type processed food products. In particular, the aseptic-UHT process should benefit from a number of novel mathematical and statistical concepts that have been developed in the field of QMRA. Probabilistic techniques such as Monte Carlo simulation, Bayesian inference and sensitivity analysis, should help in assessing the compliance with safety and stability-related POs set at the end of the manufacturing

Comparative measurement and quantitative risk assessment of alcohol consumption through wastewater-based epidemiology: An international study in 20 cities

DEFF Research Database (Denmark)

Ryu, Yeonsuk; Barceló, Damià; Barron, Leon P.

2016-01-01

Quantitative measurement of drug consumption biomarkers in wastewater can provide objective information on community drug use patterns and trends. This study presents the measurement of alcohol consumption in 20 cities across 11 countries through the use of wastewater-based epidemiology (WBE...... consumption biomarker, ethyl sulfate (EtS) was determined by liquid chromatography coupled to tandem mass spectrometry. The EtS concentrations were used for estimation of per capita alcohol consumption in each city, which was further compared with international reports and applied for risk assessment by MOE....... The average per capita consumption in 20 cities ranged between 6.4 and 44.3. L/day/1000 inhabitants. An increase in alcohol consumption during the weekend occurred in all cities, however the level of this increase was found to differ. In contrast to conventional data (sales statistics and interviews), WBE...

Quantitative Portfolio Optimization Techniques Applied to the Brazilian Stock Market

Directory of Open Access Journals (Sweden)

André Alves Portela Santos

2012-09-01

Full Text Available In this paper we assess the out-of-sample performance of two alternative quantitative portfolio optimization techniques - mean-variance and minimum variance optimization – and compare their performance with respect to a naive 1/N (or equally-weighted portfolio and also to the market portfolio given by the Ibovespa. We focus on short selling-constrained portfolios and consider alternative estimators for the covariance matrices: sample covariance matrix, RiskMetrics, and three covariance estimators proposed by Ledoit and Wolf (2003, Ledoit and Wolf (2004a and Ledoit and Wolf (2004b. Taking into account alternative portfolio re-balancing frequencies, we compute out-of-sample performance statistics which indicate that the quantitative approaches delivered improved results in terms of lower portfolio volatility and better risk-adjusted returns. Moreover, the use of more sophisticated estimators for the covariance matrix generated optimal portfolios with lower turnover over time.

Quantitative modeling of operational risk in finance and banking using possibility theory

CERN Document Server

Chaudhuri, Arindam

2016-01-01

This book offers a comprehensive guide to the modelling of operational risk using possibility theory. It provides a set of methods for measuring operational risks under a certain degree of vagueness and impreciseness, as encountered in real-life data. It shows how possibility theory and indeterminate uncertainty-encompassing degrees of belief can be applied in analysing the risk function, and describes the parametric g-and-h distribution associated with extreme value theory as an interesting candidate in this regard. The book offers a complete assessment of fuzzy methods for determining both value at risk (VaR) and subjective value at risk (SVaR), together with a stability estimation of VaR and SVaR. Based on the simulation studies and case studies reported on here, the possibilistic quantification of risk performs consistently better than the probabilistic model. Risk is evaluated by integrating two fuzzy techniques: the fuzzy analytic hierarchy process and the fuzzy extension of techniques for order prefere...

Quantitative microbial risk assessment for Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes in leafy green vegetables consumed at salad bars, based on modeling supply chain logistics.

Science.gov (United States)

Tromp, S O; Rijgersberg, H; Franz, E

2010-10-01

Quantitative microbial risk assessments do not usually account for the planning and ordering mechanisms (logistics) of a food supply chain. These mechanisms and consumer demand determine the storage and delay times of products. The aim of this study was to quantitatively assess the difference between simulating supply chain logistics (MOD) and assuming fixed storage times (FIX) in microbial risk estimation for the supply chain of fresh-cut leafy green vegetables destined for working-canteen salad bars. The results of the FIX model were previously published (E. Franz, S. O. Tromp, H. Rijgersberg, and H. J. van der Fels-Klerx, J. Food Prot. 73:274-285, 2010). Pathogen growth was modeled using stochastic discrete-event simulation of the applied logistics concept. The public health effects were assessed by conducting an exposure assessment and risk characterization. The relative growths of Escherichia coli O157 (17%) and Salmonella enterica (15%) were identical in the MOD and FIX models. In contrast, the relative growth of Listeria monocytogenes was considerably higher in the MOD model (1,156%) than in the FIX model (194%). The probability of L. monocytogenes infection in The Netherlands was higher in the MOD model (5.18×10(-8)) than in the FIX model (1.23×10(-8)). The risk of listeriosis-induced fetal mortality in the perinatal population increased from 1.24×10(-4) (FIX) to 1.66×10(-4) (MOD). Modeling the probabilistic nature of supply chain logistics is of additional value for microbial risk assessments regarding psychrotrophic pathogens in food products for which time and temperature are the postharvest preventive measures in guaranteeing food safety.

Development of a Quantitative Framework for Regulatory Risk Assessments: Probabilistic Approaches

International Nuclear Information System (INIS)

Wilmot, R.D.

2003-11-01

The Swedish regulators have been active in the field of performance assessment for many years and have developed sophisticated approaches to the development of scenarios and other aspects of assessments. These assessments have generally used dose as the assessment end-point and have been based on deterministic calculations. Recently introduced Swedish regulations have introduced a risk criterion for radioactive waste disposal: the annual risk of harmful effects after closure of a disposal facility should not exceed 10 -6 for a representative individual in the group exposed to the greatest risk. A recent review of the overall structure of risk assessments in safety cases concluded that there are a number of decisions and assumptions in the development of a risk assessment methodology that could potentially affect the calculated results. Regulatory understanding of these issues, potentially supported by independent calculations, is important in preparing for review of a proponent's risk assessment. One approach to evaluating risk in performance assessments is to use the concept of probability to express uncertainties, and to propagate these probabilities through the analysis. This report describes the various approaches available for undertaking such probabilistic analyses, both as a means of accounting for uncertainty in the determination of risk and more generally as a means of sensitivity and uncertainty analysis. The report discusses the overall nature of probabilistic analyses and how they are applied to both the calculation of risk and sensitivity analyses. Several approaches are available, including differential analysis, response surface methods and simulation. Simulation is the approach most commonly used, both in assessments for radioactive waste disposal and in other subject areas, and the report describes the key stages of this approach in detail. Decisions relating to the development of input PDFs, sampling methods (including approaches to the treatment

Combining quantitative and qualitative breast density measures to assess breast cancer risk.

Science.gov (United States)

Kerlikowske, Karla; Ma, Lin; Scott, Christopher G; Mahmoudzadeh, Amir P; Jensen, Matthew R; Sprague, Brian L; Henderson, Louise M; Pankratz, V Shane; Cummings, Steven R; Miglioretti, Diana L; Vachon, Celine M; Shepherd, John A

2017-08-22

Accurately identifying women with dense breasts (Breast Imaging Reporting and Data System [BI-RADS] heterogeneously or extremely dense) who are at high breast cancer risk will facilitate discussions of supplemental imaging and primary prevention. We examined the independent contribution of dense breast volume and BI-RADS breast density to predict invasive breast cancer and whether dense breast volume combined with Breast Cancer Surveillance Consortium (BCSC) risk model factors (age, race/ethnicity, family history of breast cancer, history of breast biopsy, and BI-RADS breast density) improves identifying women with dense breasts at high breast cancer risk. We conducted a case-control study of 1720 women with invasive cancer and 3686 control subjects. We calculated ORs and 95% CIs for the effect of BI-RADS breast density and Volpara™ automated dense breast volume on invasive cancer risk, adjusting for other BCSC risk model factors plus body mass index (BMI), and we compared C-statistics between models. We calculated BCSC 5-year breast cancer risk, incorporating the adjusted ORs associated with dense breast volume. Compared with women with BI-RADS scattered fibroglandular densities and second-quartile dense breast volume, women with BI-RADS extremely dense breasts and third- or fourth-quartile dense breast volume (75% of women with extremely dense breasts) had high breast cancer risk (OR 2.87, 95% CI 1.84-4.47, and OR 2.56, 95% CI 1.87-3.52, respectively), whereas women with extremely dense breasts and first- or second-quartile dense breast volume were not at significantly increased breast cancer risk (OR 1.53, 95% CI 0.75-3.09, and OR 1.50, 95% CI 0.82-2.73, respectively). Adding continuous dense breast volume to a model with BCSC risk model factors and BMI increased discriminatory accuracy compared with a model with only BCSC risk model factors (C-statistic 0.639, 95% CI 0.623-0.654, vs. C-statistic 0.614, 95% CI 0.598-0.630, respectively; P breasts and fourth

Quantitative Microbial Risk Assessment for in Natural and Processed Cheeses

Directory of Open Access Journals (Sweden)

Heeyoung Lee

2016-08-01

Full Text Available This study evaluated the risk of Clostridium perfringens (C. perfringens foodborne illness from natural and processed cheeses. Microbial risk assessment in this study was conducted according to four steps: hazard identification, hazard characterization, exposure assessment, and risk characterization. The hazard identification of C. perfringens on cheese was identified through literature, and dose response models were utilized for hazard characterization of the pathogen. For exposure assessment, the prevalence of C. perfringens, storage temperatures, storage time, and annual amounts of cheese consumption were surveyed. Eventually, a simulation model was developed using the collected data and the simulation result was used to estimate the probability of C. perfringens foodborne illness by cheese consumption with @RISK. C. perfringens was determined to be low risk on cheese based on hazard identification, and the exponential model (r = 1.82×10−11 was deemed appropriate for hazard characterization. Annual amounts of natural and processed cheese consumption were 12.40±19.43 g and 19.46±14.39 g, respectively. Since the contamination levels of C. perfringens on natural (0.30 Log CFU/g and processed cheeses (0.45 Log CFU/g were below the detection limit, the initial contamination levels of natural and processed cheeses were estimated by beta distribution (α1 = 1, α2 = 91; α1 = 1, α2 = 309×uniform distribution (a = 0, b = 2; a = 0, b = 2.8 to be −2.35 and −2.73 Log CFU/g, respectively. Moreover, no growth of C. perfringens was observed for exposure assessment to simulated conditions of distribution and storage. These data were used for risk characterization by a simulation model, and the mean values of the probability of C. perfringens foodborne illness by cheese consumption per person per day for natural and processed cheeses were 9.57×10−14 and 3.58×10−14, respectively. These results indicate that probability of C. perfringens

A quantitative analysis of a risk impact due to a starting time extension of the emergency diesel generator in optimized power reactor-1000

International Nuclear Information System (INIS)

Lim, Ho-Gon; Yang, Joon-Eon; Hwang, Mee-Jeong

2007-01-01

An emergency diesel generator (EDG) is the ultimate electric power supply source for the operation of emergency engineered safety features when a nuclear power plant experiences a loss of off-site power (LOOP). If a loss of coolant accident (LOCA) with a simultaneous LOOP occurs, the EDG should be in the state of a full power within 10 s, which is a prescribed regulatory requirement in the technical specifications (TS) of the Optimized Power Reactor-1000 (OPR-1000). Recently, the US nuclear regulatory commission (NRC) has been preparing a new risk-informed emergency core cooling system (ECCS) rule called 10 CFR 50.46. The new rule redefines the size for the design basis LOCA and it relaxes some of the requirements such as the single failure criteria, simultaneous LOOP, and the methods of analysis. The revision of the ECCS rule will provide flexibility for plant changes if the plant risks are checked and balanced with the specified criteria. The present study performed a quantitative analysis of the plant risk impact due to the EDG starting time extension given that the new rule will be applied to OPR-1000. The thermal-hydraulic analysis and OPR-1000 probabilistic safety assessment (PSA) model were combined to estimate the whole plant risk impact. Also, sensitivity analyses were implemented for the important uncertainty parameters

Uncertainty in ecological risk assessment: A statistician's view

International Nuclear Information System (INIS)

Smith, E.P.

1995-01-01

Uncertainty is a topic that has different meanings to researchers, modelers, managers and policy makers. The perspective of this presentation will be on the modeling view of uncertainty and its quantitative assessment. The goal is to provide some insight into how a statistician visualizes and addresses the issue of uncertainty in ecological risk assessment problems. In ecological risk assessment, uncertainty arises from many sources and is of different type depending on what is studies, where it is studied and how it is studied. Some major sources and their impact are described. A variety of quantitative approaches to modeling uncertainty are characterized and a general taxonomy given. Examples of risk assessments of lake acidification, power plant impact assessment and the setting of standards for chemicals will be used discuss approaches to quantitative assessment of uncertainty and some of the potential difficulties

The additivity of radionuclide and chemical risk estimates in performance evaluation of mixed-waste sites

International Nuclear Information System (INIS)

Till, J.E.; Meyer, K.R.

1990-01-01

Methods for assessing radioactive waste sites that contain chemical constituents are in the formative stages. In evaluating these sites, a key concern will be the hazard to personnel involved in cleanup work and to the general population. This paper focuses on what we have learned from pathway analysis and risk assessment about providing a combined estimate of risk from exposure to both chemicals and radionuclides. Quantitative radiation risk assessment involves a high degree of uncertainty. Chemical risk assessment generally does not provide quantitative results. Thus, it is not currently possible to develop a useful, quantitative combined risk assessment for mixed-waste sites

Predictors of pneumothorax after CT-guided transthoracic needle lung biopsy: the role of quantitative CT

International Nuclear Information System (INIS)

Chami, H.A.; Faraj, W.; Yehia, Z.A.; Badour, S.A.; Sawan, P.; Rebeiz, K.; Safa, R.; Saade, C.; Ghandour, B.; Shamseddine, A.; Mukherji, D.; Haydar, A.A.

2015-01-01

Aim: To evaluate the association of quantitative computed tomography (CT) measures of emphysema with the occurrence of pneumothorax after CT-guided needle lung biopsy (NLB) accounting for other risk factors. Materials and methods: One hundred and sixty-three CT-guided NLBs performed between 2008 and 2013 with available complete chest CT within 30 days were reviewed for the occurrence of post-procedure pneumothorax. Percent emphysema was determined quantitatively as the percentage of lung voxels below −950 HU on chest CT images using automated software. Multivariable regression was used to assess the association of percent emphysema volume with the occurrence of post-procedure pneumothorax. The association of percent emphysema volume with the pneumothorax size and need for chest tube placement after NLB was also explored. Results: Percent emphysema was significantly associated with the incidence of post-NLB pneumothorax (OR=1.10 95% confidence interval: 1.01–1.15; p=0.03) adjusting for lower-lobe lesion location, needle path length, lesion size, number of passes, and pleural needle trajectory angle. Percent emphysema was not associated with the size of the pneumothorax, nor the need for chest tube placement after NLB. Conclusion: Percent emphysema determined quantitatively from chest CT is a significant predictor of post-NLB pneumothorax. - Highlights: • Examine the association between quantitative emphysema measures & post NLB pneumothorax. • The risk of post-NLB pneumothorax increases with every unit increase in percent emphysema. • Percent emphysema is a significant predictor of pneumothorax post transthoracic NLB. • Quantitative analysis of chest CT offers clinicians' objective measures to assess pneumothorax risk.

Risk communication. Risk studies in social science; Risk communication. Risk kenkyu eno shakai kagakuteki approach

Energy Technology Data Exchange (ETDEWEB)

Asami, M. [Keio Univ., Tokyo (Japan)

1995-11-05

It is recently, that is, in and after the 1980s that socio-scientific approaches began to be made to studies on `risk`. It started to be made clear that the progress of the scientific technology does not necessarily bring about good news to man, and obvious estrangement has begun to appear between scientific evaluation and social evaluation of risk. The subject of risk communication (RC) study is to tackle a proposition whether the estrangement will continue to exist as estrangement or the estrangement can be made smaller by any means. This paper explains the recent trend of the study. For example, as for how each individual thinks about risk, that is, the risk perception, a new framework is trially being constructed by introduction of the quantitative method using psychometrics. A duty of RC is to serve to bridge the gap between scientific technology and society which are controlled by values which are incompatible with each other. Therefore, RC will be more and more important. 15 refs., 1 fig., 2 tabs.

Failure data specialization in quantitative risk assessments of process plants; Especializacao de dados de falha em analise quantitativa de riscos de plantas de processo

Energy Technology Data Exchange (ETDEWEB)

Ribeiro, Antonio C.O. [Bayer S.A., Sao Paulo, SP (Brazil); Melo, P.F. Frutuoso e [Universidade Federal, Rio de Janeiro, RJ (Brazil). Coordenacao dos Programas de Pos-graduacao de Engenharia

2005-07-01

The aim of this paper is to show the Bayesian inference in reliability studies, which are used to failures rates updating in safety analyses. It is developed the impact of its using in quantitative risks assessments for industrial process plants. With this approach we find a structured and auditable way of showing the difference between an industrial installation with a good project and maintenance structure from another one that shows a low level of quality in these areas. In general the evidence from failures rates and as follow the frequency of occurrence from scenarios, which the risks taken in account in ERA, are taken from generics data banks, instead of, the installation in analysis. When using the plant data we need special effort to develop a data bank, that is, a maintenance managing system, which allows the data insertion as for example the SAP{sup R} and its PM module. (author)

Risk Implications of Energy Policy Instruments

DEFF Research Database (Denmark)

Kitzing, Lena

papers and a working paper), based on a combination of micro-economic and policy analysis. Financial theory is used for the quantitative analysis of investment problems under uncertainty, including mean-variance portfolio theory, real option analysis, Monte Carlo simulations and time series analysis...... show, both qualitatively and quantitatively, that policy makers cannot neglect risk implications when designing RES support instruments without compromising either on effectiveness or cost-efficiency of energy policy. The central research questions are: how can risk implications of RES policy...... instruments be integrated into policy design, so that the policies provide adequate investment incentives? And can the consideration of such risk implications in policy design make overall energy policy more successful? These questions are answered in seven research papers (four journal papers, two conference...

Information security risk assessment, aggregation, and mitigation

NARCIS (Netherlands)

Lenstra, A.K.; Voss, T.; Wang, H.; Pieprzyk, J.; Varadharajan, V.

2004-01-01

As part of their compliance process with the Basel 2 operational risk management requirements, banks must define how they deal with information security risk management. In this paper we describe work in progress on a new quantitative model to assess and aggregate information security risks that is

Logic and Risk as Qualitative and Quantitative Dimensions of Decision-Making Process

Directory of Open Access Journals (Sweden)

Tadeusz Galanc

2016-01-01

Full Text Available Key problems in the field of decision-making have been considered. The authors' aim was to indicate the extremely important for management role of logic and risk in relation to decisions taken under conditions of uncertainty. In the course of the research, the following hypothesis was tested: the complexity of risk is determined by the diversity of reality. The result of this is that in science there is no current study developing a uniform methodology for the assessment of risk. It might even be doubtful whether it can be created. In a certain sense, this is indicated in the article by the discussion about the dimensions of logic and risk apparent in any decisions taken by a man. The paper presents the complexity and diversity of risk assessment on the basis of selected, but essential to the discussed issue, fields of knowledge. This is valid when the numerical or qualitative level of risk is substantial in the context of the analyzed problem. (original abstract

Validation study of a quantitative multigene reverse transcriptase-polymerase chain reaction assay for assessment of recurrence risk in patients with stage II colon cancer.

Science.gov (United States)

Gray, Richard G; Quirke, Philip; Handley, Kelly; Lopatin, Margarita; Magill, Laura; Baehner, Frederick L; Beaumont, Claire; Clark-Langone, Kim M; Yoshizawa, Carl N; Lee, Mark; Watson, Drew; Shak, Steven; Kerr, David J

2011-12-10

We developed quantitative gene expression assays to assess recurrence risk and benefits from chemotherapy in patients with stage II colon cancer. We sought validation by using RNA extracted from fixed paraffin-embedded primary colon tumor blocks from 1,436 patients with stage II colon cancer in the QUASAR (Quick and Simple and Reliable) study of adjuvant fluoropyrimidine chemotherapy versus surgery alone. A recurrence score (RS) and a treatment score (TS) were calculated from gene expression levels of 13 cancer-related genes (n = 7 recurrence genes and n = 6 treatment benefit genes) and from five reference genes with prespecified algorithms. Cox proportional hazards regression models and log-rank methods were used to analyze the relationship between the RS and risk of recurrence in patients treated with surgery alone and between TS and benefits of chemotherapy. Risk of recurrence was significantly associated with RS (hazard ratio [HR] per interquartile range, 1.38; 95% CI, 1.11 to 1.74; P = .004). Recurrence risks at 3 years were 12%, 18%, and 22% for predefined low, intermediate, and high recurrence risk groups, respectively. T stage (HR, 1.94; P < .001) and mismatch repair (MMR) status (HR, 0.31; P < .001) were the strongest histopathologic prognostic factors. The continuous RS was associated with risk of recurrence (P = .006) beyond these and other covariates. There was no trend for increased benefit from chemotherapy at higher TS (P = .95). The continuous 12-gene RS has been validated in a prospective study for assessment of recurrence risk in patients with stage II colon cancer after surgery and provides prognostic value that complements T stage and MMR. The TS was not predictive of chemotherapy benefit.

A study on framework for assessing limiting condition for operation(LCOs) quantitatively in a CANDU reactor

International Nuclear Information System (INIS)

Kang, Kyung Min

2003-02-01

Limiting conditions for operations define the allowed outage times and the actions to be taken if the repair cannot be completed within the AOT. Typically the actions required are plant shutdown. In situations where the risk associated with the action, i.e., the risk of plant shutdown given a failure in the safety system, may be substantial, a strategy is needed to control the risk implications. In this study the strategy is evaluated quantitatively using a tool of system dynamics. The strategic actions associated with LCO needs to be assessed dynamically. System dynamics technique is easy enough to be applied for quantitative assessment of LCO, where the system dynamics is an important factor in evaluating operational modes of nuclear power plants. The review on the improvements of overly conservative technical specification has been performed in this study. The VENSIM tool has been applied to evaluate quantitatively the LCO of the auxiliary feed water systems in the Wol-Sung nuclear power plant. A value of core damage frequency in PSA is used as risk measure. The analysis of both full power operation and shutdown operation has been compared for the value of the CDF. This study shows a plot of LCO full power operating and shutdown risks in term of core damage probability for failure of AFWS (auxiliary feedwater system). Obtaining a lower risk level in a stable mode, compared to the LCO operation alternative, is the principal motivation of going to full power operational mode or shutdown operational mode. A time dependent framework developed in this study has been applied to assess the LCO of the example problem and it is shown that it is very flexible in that it can be applied to assess LCO quantitatively under any operational context of the technical specifications. This study contributes risk informed regulation to enhance and optimize the LCO of previous technical specifications for CANDU through developing framework in application proposed in this methodology

Risk analysis: assessing uncertainties beyond expected values and probabilities

National Research Council Canada - National Science Library

Aven, T. (Terje)

2008-01-01

... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 How to describe risk quantitatively . . . . . . . . . . . . . . . . . 2.2.1 Description of risk in a financial context . . . . . . . . . 2.2.2 Description...

A Quantitative ADME-base Tool for Exploring Human ...

Science.gov (United States)

Exposure to a wide range of chemicals through our daily habits and routines is ubiquitous and largely unavoidable within modern society. The potential for human exposure, however, has not been quantified for the vast majority of chemicals with wide commercial use. Creative advances in exposure science are needed to support efficient and effective evaluation and management of chemical risks, particularly for chemicals in consumer products. The U.S. Environmental Protection Agency Office of Research and Development is developing, or collaborating in the development of, scientifically-defensible methods for making quantitative or semi-quantitative exposure predictions. The Exposure Prioritization (Ex Priori) model is a simplified, quantitative visual dashboard that provides a rank-ordered internalized dose metric to simultaneously explore exposures across chemical space (not chemical by chemical). Diverse data streams are integrated within the interface such that different exposure scenarios for “individual,” “population,” or “professional” time-use profiles can be interchanged to tailor exposure and quantitatively explore multi-chemical signatures of exposure, internalized dose (uptake), body burden, and elimination. Ex Priori has been designed as an adaptable systems framework that synthesizes knowledge from various domains and is amenable to new knowledge/information. As such, it algorithmically captures the totality of exposure across pathways. It

Quantitative Model for Economic Analyses of Information Security Investment in an Enterprise Information System

Directory of Open Access Journals (Sweden)

Bojanc Rok

2012-11-01

Full Text Available The paper presents a mathematical model for the optimal security-technology investment evaluation and decision-making processes based on the quantitative analysis of security risks and digital asset assessments in an enterprise. The model makes use of the quantitative analysis of different security measures that counteract individual risks by identifying the information system processes in an enterprise and the potential threats. The model comprises the target security levels for all identified business processes and the probability of a security accident together with the possible loss the enterprise may suffer. The selection of security technology is based on the efficiency of selected security measures. Economic metrics are applied for the efficiency assessment and comparative analysis of different protection technologies. Unlike the existing models for evaluation of the security investment, the proposed model allows direct comparison and quantitative assessment of different security measures. The model allows deep analyses and computations providing quantitative assessments of different options for investments, which translate into recommendations facilitating the selection of the best solution and the decision-making thereof. The model was tested using empirical examples with data from real business environment.

RISKS MANAGEMENT. A PROPENSITY SCORE APPLICATION

Directory of Open Access Journals (Sweden)

Constangioara Alexandru

2008-05-01

Full Text Available Risk management is relatively unexplored in Romania. Although Romanian specialists dwell on theoretical aspects such as the risks classification and the important distinction between risks and uncertainty the practical relevance of the matter is outside existing studies. Present paper uses a dataset of consumer data to build a propensity scorecard based on relevant quantitative modeling.

HTGR accident and risk assessment

International Nuclear Information System (INIS)

Silady, F.A.; Everline, C.J.; Houghton, W.J.

1982-01-01

This paper is a synopsis of the high-temperature gas-cooled reactor probabilistic risk assessments (PRAs) performed by General Atomic Company. Principal topics presented include: HTGR safety assessments, peer interfaces, safety research, process gas explosions, quantitative safety goals, licensing applications of PRA, enhanced safety, investment risk assessments, and PRA design integration

Using Quantitative Data Analysis Techniques for Bankruptcy Risk Estimation for Corporations

Directory of Open Access Journals (Sweden)

Ştefan Daniel ARMEANU

2012-01-01

Full Text Available Diversification of methods and techniques for quantification and management of risk has led to the development of many mathematical models, a large part of which focused on measuring bankruptcy risk for businesses. In financial analysis there are many indicators which can be used to assess the risk of bankruptcy of enterprises but to make an assessment it is needed to reduce the number of indicators and this can be achieved through principal component, cluster and discriminant analyses techniques. In this context, the article aims to build a scoring function used to identify bankrupt companies, using a sample of companies listed on Bucharest Stock Exchange.

Quantitative prediction of drug side effects based on drug-related features.

Science.gov (United States)

Niu, Yanqing; Zhang, Wen

2017-09-01

Unexpected side effects of drugs are great concern in the drug development, and the identification of side effects is an important task. Recently, machine learning methods are proposed to predict the presence or absence of interested side effects for drugs, but it is difficult to make the accurate prediction for all of them. In this paper, we transform side effect profiles of drugs as their quantitative scores, by summing up their side effects with weights. The quantitative scores may measure the dangers of drugs, and thus help to compare the risk of different drugs. Here, we attempt to predict quantitative scores of drugs, namely the quantitative prediction. Specifically, we explore a variety of drug-related features and evaluate their discriminative powers for the quantitative prediction. Then, we consider several feature combination strategies (direct combination, average scoring ensemble combination) to integrate three informative features: chemical substructures, targets, and treatment indications. Finally, the average scoring ensemble model which produces the better performances is used as the final quantitative prediction model. Since weights for side effects are empirical values, we randomly generate different weights in the simulation experiments. The experimental results show that the quantitative method is robust to different weights, and produces satisfying results. Although other state-of-the-art methods cannot make the quantitative prediction directly, the prediction results can be transformed as the quantitative scores. By indirect comparison, the proposed method produces much better results than benchmark methods in the quantitative prediction. In conclusion, the proposed method is promising for the quantitative prediction of side effects, which may work cooperatively with existing state-of-the-art methods to reveal dangers of drugs.

Quantitative Risk Modeling of Fire on the International Space Station

Science.gov (United States)

Castillo, Theresa; Haught, Megan

2014-01-01

The International Space Station (ISS) Program has worked to prevent fire events and to mitigate their impacts should they occur. Hardware is designed to reduce sources of ignition, oxygen systems are designed to control leaking, flammable materials are prevented from flying to ISS whenever possible, the crew is trained in fire response, and fire response equipment improvements are sought out and funded. Fire prevention and mitigation are a top ISS Program priority - however, programmatic resources are limited; thus, risk trades are made to ensure an adequate level of safety is maintained onboard the ISS. In support of these risk trades, the ISS Probabilistic Risk Assessment (PRA) team has modeled the likelihood of fire occurring in the ISS pressurized cabin, a phenomenological event that has never before been probabilistically modeled in a microgravity environment. This paper will discuss the genesis of the ISS PRA fire model, its enhancement in collaboration with fire experts, and the results which have informed ISS programmatic decisions and will continue to be used throughout the life of the program.

Risk-based regulation: A regulatory perspective

International Nuclear Information System (INIS)

Scarborough, J.C.

1993-01-01

In the early development of regulations for nuclear power plants, risk was implicitly considered through qualitative assessments and engineering reliability principles and practices. Examples included worst case analysis, defense in depth, and the single failure criterion. However, the contributions of various systems, structures, components and operator actions to plant safety were not explicitly assessed since a methodology for this purpose had not been developed. As a consequence of the TMI accident, the use of more quantitative risk methodology and information in regulation such as probabilistic risk analysis (PRA) increased. The use of both qualitative and quantitative consideration of risk in regulation has been a set of regulations and regulatory guides and practices that ensure adequate protection of public health and safety. Presently, the development of PRA techniques has developed to the point that safety goals, expressed in terms of risk, have been established to help guide further regulatory decision making. This paper presents the personal opinions of the author as regards the use of risk today in nuclear power plant regulation, areas of further information needs, and necessary plans for moving toward a more systematic use of risk-based information in regulatory initiatives in the future

Radiation risk estimation

International Nuclear Information System (INIS)

Schull, W.J.; Texas Univ., Houston, TX

1992-01-01

Estimation of the risk of cancer following exposure to ionizing radiation remains largely empirical, and models used to adduce risk incorporate few, if any, of the advances in molecular biology of a past decade or so. These facts compromise the estimation risk where the epidemiological data are weakest, namely, at low doses and dose rates. Without a better understanding of the molecular and cellular events ionizing radiation initiates or promotes, it seems unlikely that this situation will improve. Nor will the situation improve without further attention to the identification and quantitative estimation of the effects of those host and environmental factors that enhance or attenuate risk. (author)

Designing SQCRA as a Software to Semi-quantitative Chemical Risk Assessment in Workplace

Directory of Open Access Journals (Sweden)

Ali Karimi

2014-06-01

Full Text Available Background & Objectives : The aim of chemical risk assessment is to identify and evaluate risks originated from chemicals usages. This study aims to design a practical tool for facilitating chemical risk assessment. Methods: The proposed software was derived from chemical risk assessment method which was recommended by Ministry of Human Resources of Malaysia. All of the processes in question are designed in operating system software. Based on some revisions, this software was developed using Visual Basic (VB titled as SQCRA. The developed software was used for chemical risk assessment in Narges Vegetale Oil Company in Shiraz (center of Iran. Result: The output of software showed that the level of risk derived from sulfuric acid, phosphoric acid, aluminum sulphate, nickel catalyst, acetic acid used as a raw material were 2.4, 2.84, 2.3, 3.5 and 2.66, respectively. Moreover, risk rank and proposed control methods for each of these materials were determined. Conclusions : The developed software calculates the health risk level based on the degree of hazard and exposure in shorttime and without using risk matrix and chemical formula. After determining the risk rank, the software proposes the control procedures to reduce occupational exposure.

Fire Risk Assessment in Germany

International Nuclear Information System (INIS)

Berg, H. P.

2000-01-01

Quantitative fire risk assessment can serve as an additional tool to assess the safety level of a nuclear power plant (NPP) and to set priorities for fire protection improvement measures. The recommended approach to be applied within periodic safety reviews of NPPs in Germany starts with a screening process providing critical fire zones in which a fully developed fire has the potential to both cause an initiating event and impair the function of at least one component or system critical to safety. The second step is to perform a quantitative analysis using a standard event tree has been developed with elements for fire initiation, ventilation of the room, fire detection, fire suppression, and fire propagation. In a final step, the fire induced frequency of initiating events, the main contributors and the calculated hazard state frequency for the fire event are determined. Results of the first quantitative fire risk studies performed in Germany are reported. (author)

Use of risk information in regulatory reviews

International Nuclear Information System (INIS)

Sagar, B.; Benke, R.; Mohanty, S.

2004-01-01

The regulatory framework for licensing any high-level waste repository at Yucca Mountain in the United States, calls for appropriate use of risk information to ensure operational safety during the pre-closure period and long-term safety during the post-closure period. This paper focuses on the post-closure period. Regulations in the Code of Federal Regulations (CFR), Title 10, Part 63, apply to any repository at Yucca Mountain and envision use of probabilistic methods to develop quantitative risk information. Accumulated engineering and scientific experience at Yucca Mountain and analog sites and quantitative risk information from studies conducted by the implementer, regulator, and others are combined to formulate 'risk insights,' which are then used to plan and execute regulatory reviews. The U.S. Nuclear Regulatory Commission (NRC) and the Center for Nuclear Waste Regulatory Analyses (CNWRA) recently consolidated the knowledge gained during several g ears and developed such risk insights for the potential repository at Yucca Mountain. This paper discusses the types of risk information used to generate risk insights and how the risk insights will be used in regulatory reviews. A companion paper presents more details on sensitivity analysis methods used to generate risk information. (authors)

A quantitative microbial risk assessment for meatborne Toxoplasma gondii infection in The Netherlands

NARCIS (Netherlands)

Opsteegh, M.; Prickaerts, S.; Frankena, K.; Evers, E.G.

2011-01-01

Toxoplasma gondii is an important foodborne pathogen, and the cause of a high disease burden due to congenital toxoplasmosis in The Netherlands. The aim of this study was to quantify the relative contribution of sheep, beef and pork products to human T. gondii infections by Quantitative Microbial

Testing decision rules for categorizing species' extinction risk to help develop quantitative listing criteria for the U.S. Endangered Species Act.

Science.gov (United States)

Regan, Tracey J; Taylor, Barbara L; Thompson, Grant G; Cochrane, Jean Fitts; Ralls, Katherine; Runge, Michael C; Merrick, Richard

2013-08-01

Lack of guidance for interpreting the definitions of endangered and threatened in the U.S. Endangered Species Act (ESA) has resulted in case-by-case decision making leaving the process vulnerable to being considered arbitrary or capricious. Adopting quantitative decision rules would remedy this but requires the agency to specify the relative urgency concerning extinction events over time, cutoff risk values corresponding to different levels of protection, and the importance given to different types of listing errors. We tested the performance of 3 sets of decision rules that use alternative functions for weighting the relative urgency of future extinction events: a threshold rule set, which uses a decision rule of x% probability of extinction over y years; a concave rule set, where the relative importance of future extinction events declines exponentially over time; and a shoulder rule set that uses a sigmoid shape function, where relative importance declines slowly at first and then more rapidly. We obtained decision cutoffs by interviewing several biologists and then emulated the listing process with simulations that covered a range of extinction risks typical of ESA listing decisions. We evaluated performance of the decision rules under different data quantities and qualities on the basis of the relative importance of misclassification errors. Although there was little difference between the performance of alternative decision rules for correct listings, the distribution of misclassifications differed depending on the function used. Misclassifications for the threshold and concave listing criteria resulted in more overprotection errors, particularly as uncertainty increased, whereas errors for the shoulder listing criteria were more symmetrical. We developed and tested the framework for quantitative decision rules for listing species under the U.S. ESA. If policy values can be agreed on, use of this framework would improve the implementation of the ESA by

Quantitative genetic tools for insecticide resistance risk assessment: estimating the heritability of resistance

Science.gov (United States)

Michael J. Firko; Jane Leslie Hayes

1990-01-01

Quantitative genetic studies of resistance can provide estimates of genetic parameters not available with other types of genetic analyses. Three methods are discussed for estimating the amount of additive genetic variation in resistance to individual insecticides and subsequent estimation of heritability (h2) of resistance. Sibling analysis and...

Decisions on the tolerability of risk: The use of quantitative risk assessment and the relevance of other factors

Energy Technology Data Exchange (ETDEWEB)

Cohen, A V [Health and Safety Executive, Baynards House, London (United Kingdom)

1989-07-01

A recent Discussion Document of the UK Health and Safety Executive proposes guidelines on the tolerable levels of individual and societal risks from nuclear power stations. At the various proposed levels a risk would be just tolerable and must be reduced further 'as low as reasonably practicable' (i.e. taking account of costs and benefits). These levels are induced from contemporary experience. No uniform upper level is proposed for tolerability for all societal risks. A stricter level is explicitly suggested for nuclear plant. A further study currently under way shows that FN curves suggest that (predictions for the very low probability of very high consequences apart) nuclear reactors rank favourably compared to many important non nuclear installations; in contrast to views held by some. Other factors are evidently involved in these views; there are some aspects of risk which cannot readily be presented on an FN curve, and there are 'dread' associations for some of the nuclear risks. The study is therefore also examining some decisions that have been taken in the UK about nuclear and non nuclear risks, based in part on estimates of societal risk. Comparison suggests that different levels of tolerability seem to be applied, according to the specific circumstances. Factors other than those shown in an FN curve evidently apply to these actual decisions as well. A preliminary identification of some of these factors is made. (author)

The Dutch risk management policy and its impact for radiation protection

International Nuclear Information System (INIS)

Brinkman, Rob; Bosnjakovic, Branko; Jongh, Paul de

1989-01-01

Since 1985 the environmental policy in the Netherlands is based on a quantitative risk management policy. This policy was developed for reasons of external safety and for the management of chemical substances in the environment. The experiences with this quantitative risk management policy are positive. An extension of the risk policy is currently in preparation: the risks of other aspects than the death of human beings will be included. For example, the risk of damage to the environmental production function of soils and water will be taken into account. Meanwhile, a policy whitebook on radiation protection standards is in preparation. In this whitebook the occupational and environmental aspects of radiation protection will be dealt with. The whitebook will be sent to Parliament in 1989. in the radiation protection policy to be developed there will be a strong relation between the quantitative risk management of the environmental policy and the system of radiation protection standards to be developed. In the paper some basic presumptions as well as the international context of changes in standard setting will be discussed. (author)

Quantitative and Qualitative Assessment of Pulmonary Emphysema with T2-Weighted PROPELLER MRI in a High-Risk Population Compared to Low-Dose CT.

Science.gov (United States)

Meier-Schroers, Michael; Sprinkart, Alois Martin; Becker, Manuel; Homsi, Rami; Thomas, Daniel

2018-03-07

 To determine the suitability of T2-weighted PROPELLER MRI for the assessment of pulmonary emphysema.  60 participants in a lung cancer screening program (30 subjects with pulmonary emphysema, and 30 control subjects without emphysema) were included for this retrospective study. All subjects were examined with low-dose CT (LDCT) and MRI within the screening program. The use of a T2-weighted PROPELLER sequence for the assessment of emphysema was analyzed and correlated with the results of LDCT. The presence and the extent of pulmonary emphysema were first assessed qualitatively using a three-point score, and then quantitatively with a semi-automated software program to obtain emphysema indices.  All 30 cases with pulmonary emphysema were accurately detected by MRI. There were 3 cases with emphysema according to MRI without emphysematous changes on LDCT (false-positive results). The qualitative scores as well as the emphysema indices were significantly higher in the emphysema group compared to the control group for MRI and LDCT (p emphysema group and r = 0.668/p emphysema index: r = 0.960/p emphysema group and r = 0.746/p pulmonary emphysema may be assessed qualitatively and quantitatively by T2-weighted PROPELLER MRI with very good correlation to LDCT.   · T2-weighted PROPELLER MRI may be suitable for the assessment of pulmonary emphysema.. · There was significant correlation between MRI and LDCT regarding qualitative scores and quantitative emphysema indices in our study with correlation coefficients for different subgroups ranging from r = 0.668 to r = 0.960.. · T2-weighted PROPELLER MRI may have the potential to be used for follow-up examinations in patients with severe emphysema to avoid radiation exposure of repeated CTs.. · Meier-Schroers M, Sprinkart AM, Becker M et al. Quantitative and Qualitative Assessment of Pulmonary Emphysema with T2-Weighted PROPELLER MRI in a High-Risk Population Compared to Low-Dose CT

1st International Congress on Actuarial Science and Quantitative Finance

CERN Document Server

Garrido, José; Hernández-Hernández, Daniel; ICASQF

2015-01-01

Featuring contributions from industry and academia, this volume includes chapters covering a diverse range of theoretical and empirical aspects of actuarial science and quantitative finance, including portfolio management, derivative valuation, risk theory and the economics of insurance. Developed from the First International Congress on Actuarial Science and Quantitative Finance, held at the Universidad Nacional de Colombia in Bogotá in June 2014, this volume highlights different approaches to issues arising from industries in the Andean and Carribean regions. Contributions address topics such as Reverse mortgage schemes and urban dynamics, modeling spot price dynamics in the electricity market, and optimizing calibration and pricing with SABR models.

2nd International Congress on Actuarial Science and Quantitative Finance

CERN Document Server

Garrido, José; Jeanblanc, Monique

2017-01-01

Developed from the Second International Congress on Actuarial Science and Quantitative Finance, this volume showcases the latest progress in all theoretical and empirical aspects of actuarial science and quantitative finance. Held at the Universidad de Cartagena in Cartegena, Colombia in June 2016, the conference emphasized relations between industry and academia and provided a platform for practitioners to discuss problems arising from the financial and insurance industries in the Andean and Caribbean regions. Based on invited lectures as well as carefully selected papers, these proceedings address topics such as statistical techniques in finance and actuarial science, portfolio management, risk theory, derivative valuation and economics of insurance.

EIF onshore discharges : a quantitative environmental risk assessment tool for onshore facilities

Energy Technology Data Exchange (ETDEWEB)

Hagemann, R.; Smit, M.G.D.; Frost, T.K. [Statoil ASA, Stavenger (Norway); Firth, S.K. [Firth Consultants, Bristol (United Kingdom); Stone, K. [WorleyParsons, Victoria, BC (Canada)

2009-07-01

The proper management of environmental risk is a key requirement of StatoilHydro's governing documents and is a key consideration in all phases of StatoilHydro's activities. In order to help manage risks in an effective and sustainable manner, StatoilHydro has led the development of the environmental impact factor (EIF) risk assessment tool. The EIF is utilized by all operators on the Norwegian Continental Shelf for reporting continuous improvements in produced water management to the authorities. The EIF concept has also been applied to evaluate environmental risk from air emissions, offshore oil spills and drilling discharges, discharges from onshore facilities to sea and discharges and spills from onshore installations. In order to identify the remaining hypothetical risk from a new facility, optimized with respect to environmental protection, this paper presented a case study, where the tool was applied to an oil sands steam assisted gravity drainage facility in Alberta. The paper discussed the EIF model and results of the case study. It was concluded that as a result of the use of generic principles for environmental risk assessment, combined with databases with parameter information for common soil and aquifer types, the EIF tool could be applied to any site ranging from wetlands to deserts. 5 refs., 2 tabs., 3 figs.

Prognostic Value of Quantitative Stress Perfusion Cardiac Magnetic Resonance.

Science.gov (United States)

Sammut, Eva C; Villa, Adriana D M; Di Giovine, Gabriella; Dancy, Luke; Bosio, Filippo; Gibbs, Thomas; Jeyabraba, Swarna; Schwenke, Susanne; Williams, Steven E; Marber, Michael; Alfakih, Khaled; Ismail, Tevfik F; Razavi, Reza; Chiribiri, Amedeo

2018-05-01

established risk factors, potentially representing an important step forward in the translation of quantitative CMR perfusion analysis to the clinical setting. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

Quantitative structure activity relationship and risk analysis of some pesticides in the goat milk.

Science.gov (United States)

Muhammad, Faqir; Awais, Mian Muhammad; Akhtar, Masood; Anwar, Muhammad Irfan

2013-01-04

The detection and quantification of different pesticides in the goat milk samples collected from different localities of Faisalabad, Pakistan was performed by HPLC using solid phase microextraction. The analysis showed that about 50% milk samples were contaminated with pesticides. The mean±SEM levels (ppm) of cyhalothrin, endosulfan, chlorpyrifos and cypermethrin were 0.34±0.007, 0.063±0.002, 0.034±0.002 and 0.092±0.002, respectively; whereas, methyl parathion was not detected in any of the analyzed samples. Quantitative structure activity relationship (QSAR) models were suggested to predict the residues of unknown pesticides in the goat milk using their known physicochemical characteristics including molecular weight (MW), melting point (MP), and log octanol to water partition coefficient (Ko/w) in relation to the characteristics such as pH, % fat, specific gravity and refractive index of goat milk. The analysis revealed good correlation coefficient (R2 = 0.985) for goat QSAR model. The coefficients for Ko/w and refractive index for the studied pesticides were higher in goat milk. This suggests that these are better determinants for pesticide residue prediction in the milk of these animals. Based upon the determined pesticide residues and their provisional tolerable daily intakes, risk analysis was also conducted which showed that daily intake levels of pesticide residues including cyhalothrin, chlorpyrifos and cypermethrin in present study are 2.68, 5.19 and 2.71 times higher, respectively in the goat milk. This intake of pesticide contaminated milk might pose health hazards to humans in this locality.

Quantitative Structure Activity Relationship and Risk Analysis of Some Pesticides in the Goat milk

Directory of Open Access Journals (Sweden)

Faqir Muhammad

2013-01-01

Full Text Available The detection and quantification of different pesticides in the goat milk samples collected from different localities of Faisalabad, Pakistan was performed by HPLC using solid phase microextraction. The analysis showed that about 50% milk samples were contaminated with pesticides. The mean+/-SEM levels (ppm of cyhalothrin, endosulfan, chlorpyrifos and cypermethrin were 0.34+/-0.007, 0.063+/-0.002, 0.034+/-0.002 and 0.092+/-0.002, respectively; whereas, methyl parathion was not detected in any of the analyzed samples. Quantitative structure activity relationship (QSAR models were suggested to predict the residues of unknown pesticides in the goat milk using their known physicochemical characteristics including molecular weight (MW, melting point (MP, and log octanol to water partition coefficient (Ko/w in relation to the characteristics such as pH, % fat, specific gravity and refractive index of goat milk. The analysis revealed good correlation coefficient (R2 = 0.985 for goat QSAR model. The coefficients for Ko/w and refractive index for the studied pesticides were higher in goat milk. This suggests that these are better determinants for pesticide residue prediction in the milk of these animals. Based upon the determined pesticide residues and their provisional tolerable daily intakes, risk analysis was also conducted which showed that daily intake levels of pesticide residues including cyhalothrin, chlorpyrifos and cypermethrin in present study are 2.68, 5.19 and 2.71 times higher, respectively in the goat milk. This intake of pesticide contaminated milk might pose health hazards to humans in this locality.

Appetite For Risk Of The Bank (Ii)

OpenAIRE

Manolescu, Gheorghe

2011-01-01

Representing the "amount" of risk that a bank is able and willing to accept in pursuit of its objectives, so as to balance the needs of all interested parties the risk appetite (propensity) is expressed in terms of both quantitative and qualitative, and covers all risks and not just financial risk, as understood in recent years. Risk appetite problems include issues such as the context and relationship of the risk appetite to the appetite risk aversion, fair and transparent declaration and co...

Providing Quantitative Information and a Nudge to Undergo Stool Testing in a Colorectal Cancer Screening Decision Aid: A Randomized Clinical Trial.

Science.gov (United States)

Schwartz, Peter H; Perkins, Susan M; Schmidt, Karen K; Muriello, Paul F; Althouse, Sandra; Rawl, Susan M

2017-08-01

Guidelines recommend that patient decision aids should provide quantitative information about probabilities of potential outcomes, but the impact of this information is unknown. Behavioral economics suggests that patients confused by quantitative information could benefit from a "nudge" towards one option. We conducted a pilot randomized trial to estimate the effect sizes of presenting quantitative information and a nudge. Primary care patients (n = 213) eligible for colorectal cancer screening viewed basic screening information and were randomized to view (a) quantitative information (quantitative module), (b) a nudge towards stool testing with the fecal immunochemical test (FIT) (nudge module), (c) neither a nor b, or (d) both a and b. Outcome measures were perceived colorectal cancer risk, screening intent, preferred test, and decision conflict, measured before and after viewing the decision aid, and screening behavior at 6 months. Patients viewing the quantitative module were more likely to be screened than those who did not ( P = 0.012). Patients viewing the nudge module had a greater increase in perceived colorectal cancer risk than those who did not ( P = 0.041). Those viewing the quantitative module had a smaller increase in perceived risk than those who did not ( P = 0.046), and the effect was moderated by numeracy. Among patients with high numeracy who did not view the nudge module, those who viewed the quantitative module had a greater increase in intent to undergo FIT ( P = 0.028) than did those who did not. The limitations of this study were the limited sample size and single healthcare system. Adding quantitative information to a decision aid increased uptake of colorectal cancer screening, while adding a nudge to undergo FIT did not increase uptake. Further research on quantitative information in decision aids is warranted.

The effects of infographics and several quantitative versus qualitative formats for cardiovascular disease risk, including heart age, on people's risk understanding.

Science.gov (United States)

Damman, Olga C; Vonk, Suzanne I; van den Haak, Maaike J; van Hooijdonk, Charlotte M J; Timmermans, Danielle R M

2018-03-11

To study how comprehension of cardiovascular disease (CVD) risk is influenced by: (1) infographics about qualitative risk information, with/without risk numbers; (2) which qualitative risk dimension is emphasized; (3) heart age vs. traditional risk format. For aim 1, a 2 (infographics versus text) x 2 (risk number versus no risk number) between-subjects design was used. For aim 2, three pieces of information were tested within-subjects. Aim 3 used a simple comparison group. Participants (45-65 yrs old) were recruited through an online access panel; low educated people were oversampled. They received hypothetical risk information (20%/61yrs). Primary outcomes: recall, risk appraisals, subjective/objective risk comprehension. behavioral intentions, information evaluations. Infographics of qualitative risk dimensions negatively affected recall, subjective risk comprehension and information evaluations. No effect of type of risk dimension was found on risk perception. Heart age influenced recall, comprehension, evaluations and affective risk appraisals. Infographics of hypothetical CVD risk information had detrimental effects on measures related to risk perception/comprehension, but effects were mainly seen in undereducated participants. Heart age influenced perceptions/comprehension of hypothetical risk in a way that seemed to support understanding. Heart age seems a fruitful risk communication approach in disease risk calculators. Copyright © 2018 Elsevier B.V. All rights reserved.

CEA: risk management assessment 2011

International Nuclear Information System (INIS)

Bigot, Bernard; Bonnevie, Edwige; Maillot, Bernard

2012-01-01

This report proposes a qualitative and quantitative overview of CEA activities in the field of risk management during 2011. These activities concerned the impact on the environment, the safety of installations, the management of professional risks (safety and health at work), the radiological protection of workers, the transports of hazardous materials, waste management, protection of sites, installations and heritage, the management of emergency situations, the management of law risks, controls and audits

Quantitative weight of evidence assessment of risk to honeybee colonies from use of imidacloprid, clothianidin, and thiamethoxam as seed treatments: a postscript.

Science.gov (United States)

Solomon, Keith R; Stephenson, Gladys L

2017-01-01

This paper is a postscript to the four companion papers in this issue of the Journal (Solomon and Stephenson 2017a , 2017b ; Stephenson and Solomon 2017a , 2017b ). The first paper in the series described the conceptual model and the methods of the QWoE process. The other three papers described the application of the QWoE process to studies on imidacloprid (IMI), clothianidin (CTD), and thiamethoxam (TMX). This postscript was written to summarize the utility of the methods used in the quantitative weight of evidence (QWoE), the overall relevance of the results, and the environmental implications of the findings. Hopefully, this will be helpful to others who wish to conduct QWoEs and use these methods in assessment of risks.

Making the business case for process safety using value-at-risk concepts

International Nuclear Information System (INIS)

Fang, Jayming S.; Ford, David M.; Mannan, M. Sam

2004-01-01

An increasing emphasis on chemical process safety over the last two decades has led to the development and application of powerful risk assessment tools. Hazard analysis and risk evaluation techniques have developed to the point where quantitatively meaningful risks can be calculated for processes and plants. However, the results are typically presented in semi-quantitative 'ranked list' or 'categorical matrix' formats, which are certainly useful but not optimal for making business decisions. A relatively new technique for performing valuation under uncertainty, value at risk (VaR), has been developed in the financial world. VaR is a method of evaluating the probability of a gain or loss by a complex venture, by examining the stochastic behavior of its components. We believe that combining quantitative risk assessment techniques with VaR concepts will bridge the gap between engineers and scientists who determine process risk and business leaders and policy makers who evaluate, manage, or regulate risk. We present a few basic examples of the application of VaR to hazard analysis in the chemical process industry

NASA's Risk Management System

Science.gov (United States)

Perera, Jeevan S.

2011-01-01

Leadership is key to success. Phased-approach for implementation of risk management is necessary. Risk management system will be simple, accessible and promote communication of information to all relevant stakeholders for optimal resource allocation and risk mitigation. Risk management should be used by all team members to manage risks -- risk office personnel. Each group is assigned Risk Integrators who are facilitators for effective risk management. Risks will be managed at the lowest-level feasible, elevate only those risks that require coordination or management from above. Risk reporting and communication is an essential element of risk management and will combine both qualitative and quantitative elements. Risk informed decision making should be introduced to all levels of management. Provide necessary checks and balances to insure that risks are caught/identified and dealt with in a timely manner. Many supporting tools, processes & training must be deployed for effective risk management implementation. Process improvement must be included in the risk processes.

Genetic risks of ionizing radiation

International Nuclear Information System (INIS)

Sankaranarayanan, K.

1990-01-01

Quantitative genetic risk estimation is made using two methods: the direct method, and the doubling dose (DD) method. The doubling dose currently used is 1 Gy for low LET, low dose, low dose rate irradiation, and is based on mouse data. Tables present the 1988 UNSCEAR estimates of genetic risk using both methods. (L.L.) (Tab.)

Quantitative Prediction of Systemic Toxicity Points of Departure (OpenTox USA 2017)

Science.gov (United States)

Human health risk assessment associated with environmental chemical exposure is limited by the tens of thousands of chemicals little or no experimental in vivo toxicity data. Data gap filling techniques, such as quantitative models based on chemical structure information, are c...

Baseline risk and marginal willingness to pay for health risk reduction.

Science.gov (United States)

Gerking, Shelby; Adamowicz, Wiktor; Dickie, Mark; Veronesi, Marcella

2017-01-01

Empirical results presented in this paper suggest that parents' marginal willingness to pay (MWTP) for a reduction in morbidity risk from heart disease is inversely related to baseline risk (i.e., the amount of risk initially faced) both for themselves and for their children. For instance, a 40% reduction from the mean of baseline risk results in an increase in MWTP by 70% or more. Thus, estimates of monetary benefits of public programs to reduce heart disease risk would be understated if the standard practice is followed of evaluating MWTP at initial risk levels and then multiplying this value by the number of cases avoided. Estimates are supported by: (1) unique quantitative information on perceptions of the risk of getting heart disease that allow baseline risk to be defined at an individual level and (2) improved econometric procedures to control for well-known difficulties associated with stated preference data.

Advances in Imaging Approaches to Fracture Risk Evaluation

Science.gov (United States)

Manhard, Mary Kate; Nyman, Jeffry S.; Does, Mark D.

2016-01-01

Fragility fractures are a growing problem worldwide, and current methods for diagnosing osteoporosis do not always identify individuals who require treatment to prevent a fracture and may misidentify those not a risk. Traditionally, fracture risk is assessed using dual-energy X-ray absorptiometry, which provides measurements of areal bone mineral density (BMD) at sites prone to fracture. Recent advances in imaging show promise in adding new information that could improve the prediction of fracture risk in the clinic. As reviewed herein, advances in quantitative computed tomography (QCT) predict hip and vertebral body strength; high resolution HR-peripheral QCT (HR-pQCT) and micro-magnetic resonance imaging (μMRI) assess the micro-architecture of trabecular bone; quantitative ultrasound (QUS) measures the modulus or tissue stiffness of cortical bone; and quantitative ultra-short echo time MRI methods quantify the concentrations of bound water and pore water in cortical bone, which reflect a variety of mechanical properties of bone. Each of these technologies provides unique characteristics of bone and may improve fracture risk diagnoses and reduce prevalence of fractures by helping to guide treatment decisions. PMID:27816505

Current features on risk perception and risk communication of radiation

International Nuclear Information System (INIS)

Kusama, Tomoko

1997-01-01

Health effects and risks of radiation and radionuclides are being misunderstood by many members of general public. Many peoples have fear and anxieties for radiation. So far, the health effects from radiation at low dose and low dose rate have not been cleared on biological aspects. Then, we have quantitatively estimated health risks of low-dose radiation on the basis of linear dose response relationship without threshold from the viewpoints of radiation protection by using both epidemiological data, such as atomic bomb survivors, and some models and assumptions. It is important for researchers and relevant persons in radiation protection to understand the process of risk estimation of radiation and to communicate an exact knowledge of radiation risks of the public members. (author)

Quantitative risk assessment for Escherichia coli O157:H7 in frozen ground beef patties consumed by young children in French households.

Science.gov (United States)

Delignette-Muller, M L; Cornu, M

2008-11-30

A quantitative risk assessment for Escherichia coli O157:H7 in frozen ground beef patties consumed by children under 10 years of age in French households was conducted by a national study group describing an outbreak which occurred in France in 2005. Our exposure assessment model incorporates results from French surveys on consumption frequency of ground beef patties, serving size and consumption preference, microbial destruction experiments and microbial counts on patties sampled from the industrial batch which were responsible for the outbreak. Two different exposure models were proposed, respectively for children under the age of 5 and for children between 5 and 10 years. For each of these two age groups, a single-hit dose-response model was proposed to describe the probability of hemolytic and uremic syndrome (HUS) as a function of the ingested dose. For each group, the single parameter of this model was estimated by Bayesian inference, using the results of the exposure assessment and the epidemiological data collected during the outbreak. Results show that children under 5 years of age are roughly 5 times more susceptible to the pathogen than children over 5 years. Exposure and dose-response models were used in a scenario analysis in order to validate the use of the model and to propose appropriate guidelines in order to prevent new outbreaks. The impact of the cooking preference was evaluated, showing that only a well-done cooking notably reduces the HUS risk, without annulling it. For each age group, a relation between the mean individual HUS risk per serving and the contamination level in a ground beef batch was proposed, as a tool to help French risk managers.

Qualitative to quantitative: linked trajectory of method triangulation in a study on HIV/AIDS in Goa, India.

Science.gov (United States)

Bailey, Ajay; Hutter, Inge

2008-10-01

With 3.1 million people estimated to be living with HIV/AIDS in India and 39.5 million people globally, the epidemic has posed academics the challenge of identifying behaviours and their underlying beliefs in the effort to reduce the risk of HIV transmission. The Health Belief Model (HBM) is frequently used to identify risk behaviours and adherence behaviour in the field of HIV/AIDS. Risk behaviour studies that apply HBM have been largely quantitative and use of qualitative methodology is rare. The marriage of qualitative and quantitative methods has never been easy. The challenge is in triangulating the methods. Method triangulation has been largely used to combine insights from the qualitative and quantitative methods but not to link both the methods. In this paper we suggest a linked trajectory of method triangulation (LTMT). The linked trajectory aims to first gather individual level information through in-depth interviews and then to present the information as vignettes in focus group discussions. We thus validate information obtained from in-depth interviews and gather emic concepts that arise from the interaction. We thus capture both the interpretation and the interaction angles of the qualitative method. Further, using the qualitative information gained, a survey is designed. In doing so, the survey questions are grounded and contextualized. We employed this linked trajectory of method triangulation in a study on the risk assessment of HIV/AIDS among migrant and mobile men. Fieldwork was carried out in Goa, India. Data come from two waves of studies, first an explorative qualitative study (2003), second a larger study (2004-2005), including in-depth interviews (25), focus group discussions (21) and a survey (n=1259). By employing the qualitative to quantitative LTMT we can not only contextualize the existing concepts of the HBM, but also validate new concepts and identify new risk groups.

Qualitative and Quantitative Analysis of Off-Shore Wind Energy Project’s Risks

Directory of Open Access Journals (Sweden)

Sayed Amir Hamzeh Mirkheshti

2017-01-01

Full Text Available The benefits of wind power can solve the issue of growing power consumption with insufficient distribution facilities. Based on an extensive research on more than 20 studies, this study explores the risks associated with off-shore wind energy in Persian Gulf in Iran. This paper tries to identify the risks in related off-shore wind energy project, in order to specify which variables have the most impact on project by qualitative analysis through application of the impact and the possibility of every risk. A survey was conducted in order to determine the relative importance of variables and risks. Certain key components in completion of the project should be taken into account such as technology, research team, expert teams (personnel that have a good knowledge of this industry, and choosing the right spot where the wind farms will be located. The objective of this paper is to present the variables encountered in wind power project and to highlight the risks that must be controlled by the project developers, project team, supply chain actors, manufacturers, and all the stockholders involved in successful completion of a project.

An approach to societal risk acceptance criteria and risk management

International Nuclear Information System (INIS)

Okrent, D.; Whipple, C.

1977-06-01

A quantitative approach to risk acceptance criteria and risk management is proposed for activities involving risk to individuals not receiving direct benefits, such as employment, from the activity. Societal activities are divided into major facilities or technologies, all or part of which are categorized as essential, beneficial, or peripheral, and a decreasing level of acceptable risk to the most exposed individual is proposed (say, 0.0002/year for essential, 0.00001/year for beneficial, and 0.000002/year for peripheral activity). The risk would be assessed at a high confidence level (say, 90%), thereby providing an incentive to the gaining of better knowledge. Each risk-producing facility, technology, etc., would have to undergo assessment both of risk to the individual and to society. The cost of the latter would have to be internalized, probably via a tax paid to the Federal Government, which in turn would redistribute the benefit as national health insurance or reduced taxes to the individual. Risk aversion to large events would be built into the internalization of the cost of risk

ANALYSIS OF ECONOMIC RISK IN EUROPEAN INVESTMENT PROJECTS

Directory of Open Access Journals (Sweden)

Margareta Stela FLORESCU

2012-06-01

Full Text Available Risk is a reality of the economic environment, with consequences which cannot always be foreseen or anticipated. Risk management becomes more stringent as potential exo/endogenous vulnerability factors are rapidly increasing. Identifying risk areas, structuring risk factors and defining their probability, optimal management of resources in order to reduce risk factors, creating alternatives for each high-probability risk factor are part of project risk management. Risk is quantified through probability and incidence and is assessed using quantitative and qualitative methods.

Model-based approach for quantitative estimates of skin, heart, and lung toxicity risk for left-side photon and proton irradiation after breast-conserving surgery.

Science.gov (United States)

Tommasino, Francesco; Durante, Marco; D'Avino, Vittoria; Liuzzi, Raffaele; Conson, Manuel; Farace, Paolo; Palma, Giuseppe; Schwarz, Marco; Cella, Laura; Pacelli, Roberto

2017-05-01

Proton beam therapy represents a promising modality for left-side breast cancer (BC) treatment, but concerns have been raised about skin toxicity and poor cosmesis. The aim of this study is to apply skin normal tissue complication probability (NTCP) model for intensity modulated proton therapy (IMPT) optimization in left-side BC. Ten left-side BC patients undergoing photon irradiation after breast-conserving surgery were randomly selected from our clinical database. Intensity modulated photon (IMRT) and IMPT plans were calculated with iso-tumor-coverage criteria and according to RTOG 1005 guidelines. Proton plans were computed with and without skin optimization. Published NTCP models were employed to estimate the risk of different toxicity endpoints for skin, lung, heart and its substructures. Acute skin NTCP evaluation suggests a lower toxicity level with IMPT compared to IMRT when the skin is included in proton optimization strategy (0.1% versus 1.7%, p < 0.001). Dosimetric results show that, with the same level of tumor coverage, IMPT attains significant heart and lung dose sparing compared with IMRT. By NTCP model-based analysis, an overall reduction in the cardiopulmonary toxicity risk prediction can be observed for all IMPT compared to IMRT plans: the relative risk reduction from protons varies between 0.1 and 0.7 depending on the considered toxicity endpoint. Our analysis suggests that IMPT might be safely applied without increasing the risk of severe acute radiation induced skin toxicity. The quantitative risk estimates also support the potential clinical benefits of IMPT for left-side BC irradiation due to lower risk of cardiac and pulmonary morbidity. The applied approach might be relevant on the long term for the setup of cost-effectiveness evaluation strategies based on NTCP predictions.

Multi-attribute risk assessment for risk ranking of natural gas pipelines

International Nuclear Information System (INIS)

Brito, A.J.; Almeida, A.T. de

2009-01-01

The paper presents a decision model for risk assessment and for risk ranking of sections of natural gas pipelines based on multi-attribute utility theory. Pipeline hazard scenarios are surveyed and the reasons for a risk assessment model based on a multi-attribute approach are presented. Three dimensions of impact and the need to translate decision-makers' preferences into risk management decisions are highlighted. The model approaches these factors by using a multi-attribute utility function, in order to produce multi-dimensional risk measurements. By using decision analysis concepts, this model quantitatively incorporates the decision-maker's preferences and behavior regarding risk within clear and consistent risk measurements. In order to support the prioritizing of critical sections of pipeline in natural gas companies, this multi-attribute model also allows sections of pipeline to be ranked into a risk hierarchy. A numerical application based on a real case study was undertaken so that the effectiveness of the decision model could be verified

A risk microbiological profile of the Australian red meat industry: risk ratings of hazard-product pairings.

Science.gov (United States)

Sumner, John; Ross, Tom; Jenson, Ian; Pointon, Andrew

2005-11-25

A risk profile of microbial hazards across the supply continuum for the beef, sheep and goat meat industries was developed using both a qualitative tool and a semi-quantitative, spreadsheet tool, Risk Ranger. The latter is useful for highlighting factors contributing to food safety risk and for ranking the risk of various product/pathogen combinations. In the present profile the qualitative tool was used as a preliminary screen for a wide range of hazard-product pairings while Risk Ranger was used to rank in order of population health risk pairings for which quantitative data were available and for assessing the effect of hypothetical scenarios. 'High' risk hazard-product pairings identified were meals contaminated with Clostridium perfringens provided by caterers which have not implemented HACCP; kebabs cross-contaminated by Salmonella present in drip trays or served undercooked; meals served in the home cross-contaminated with Salmonella. 'Medium' risk hazard-product pairings identified were ready-to-eat meats contaminated with Listeria monocytogenes and which have extended shelf life; Uncooked Comminuted Fermented Meat (UCFM)/Salami contaminated with Enterohaemorrhagic E. coli (EHEC) and Salmonella; undercooked hamburgers contaminated with EHEC; kebabs contaminated by Salmonella under normal production or following final "flash" heating. Identified 'low' risk hazard-product pairings included cooked, ready-to-eat sausages contaminated with Salmonella; UCFM/Salami contaminated with L. monocytogenes; well-cooked hamburgers contaminated with EHEC. The risk profile provides information of value to Australia's risk managers in the regulatory, processing and R&D sectors of the meat and meat processing industry for the purposes of identifying food safety risks in the industry and for prioritising risk management actions.

Risks in our society

International Nuclear Information System (INIS)

Cohen, B.L.

1985-01-01

This chapter summarizes quantitative information on risks from a wide variety of sources and analyzes it in terms of life expectancy reduction (LER). The data indicate that the greatest common risk in terms of LER, next to remaining unmarried, is cigarette smoking. When all of the effects of energy production and use (e.g., burning coal, reactor accidents) are totalled, the resulting LER is only about 25 days. It is pointed out that the risks to the residents of the Harrisburg area from radiation caused by the Three Mile Island accident is hundreds of thousands of times smaller than their risk from being overweight

Quantitative Relationship Between Cumulative Risk Alleles Based on Genome-Wide Association Studies and Type 2 Diabetes Mellitus: A Systematic Review and Meta-analysis

Directory of Open Access Journals (Sweden)

Satoru Kodama

2018-01-01

Full Text Available Many epidemiological studies have assessed the genetic risk of having undiagnosed or of developing type 2 diabetes mellitus (T2DM using several single nucleotide polymorphisms (SNPs based on findings of genome-wide association studies (GWAS. However, the quantitative association of cumulative risk alleles (RAs of such SNPs with T2DM risk has been unclear. The aim of this meta-analysis is to review the strength of the association between cumulative RAs and T2DM risk. Systematic literature searches were conducted for cross-sectional or longitudinal studies that examined odds ratios (ORs for T2DM in relation to genetic profiles. Logarithm of the estimated OR (log OR of T2DM for 1 increment in RAs carried (1-ΔRA in each study was pooled using a random-effects model. There were 46 eligible studies that included 74,880 cases among 249,365 participants. In 32 studies with a cross-sectional design, the pooled OR for T2DM morbidity for 1-ΔRA was 1.16 (95% confidence interval [CI], 1.13–1.19. In 15 studies that had a longitudinal design, the OR for incident T2DM was 1.10 (95% CI, 1.08–1.13. There was large heterogeneity in the magnitude of log OR (P < 0.001 for both cross-sectional studies and longitudinal studies. The top 10 commonly used genes significantly explained the variance in the log OR (P = 0.04 for cross-sectional studies; P = 0.006 for longitudinal studies. The current meta-analysis indicated that carrying 1-ΔRA in T2DM-associated SNPs was associated with a modest risk of prevalent or incident T2DM, although the heterogeneity in the used genes among studies requires us to interpret the results with caution.

Peer effects in risk aversion.

Science.gov (United States)

Balsa, Ana I; Gandelman, Néstor; González, Nicolás

2015-01-01

We estimate peer effects in risk attitudes in a sample of high school students. Relative risk aversion is elicited from surveys administered at school. Identification of peer effects is based on parents not being able to choose the class within the school of their choice, and on the use of instrumental variables conditional on school-grade fixed effects. We find a significant and quantitatively large impact of peers' risk attitudes on a male individual's coefficient of risk aversion. Specifically, a one standard deviation increase in the group's coefficient of risk aversion increases an individual's risk aversion by 43%. Our findings shed light on the origin and stability of risk attitudes and, more generally, on the determinants of economic preferences. © 2014 Society for Risk Analysis.

The effects of infographics and several quantitative versus qualitative formats for cardiovascular disease risk, including heart age, on people's risk understanding.

NARCIS (Netherlands)

Damman, Olga C; Vonk, Suzanne I; Van den Haak, Maaike J; van Hooijdonk, Charlotte M J; Timmermans, Danielle R M

2018-01-01

To study how comprehension of cardiovascular disease (CVD) risk is influenced by: (1) infographics about qualitative risk information, with/without risk numbers; (2) which qualitative risk dimension is emphasized; (3) heart age vs. traditional risk format.

[Quantitative classification in catering trade and countermeasures of supervision and management in Hunan Province].

Science.gov (United States)

Liu, Xiulan; Chen, Lizhang; He, Xiang

2012-02-01

To analyze the status quo of quantitative classification in Hunan Province catering industry, and to discuss the countermeasures in-depth. According to relevant laws and regulations, and after referring to Daily supervision and quantitative scoring sheet and consulting experts, a checklist of key supervision indicators was made. The implementation of quantitative classification in 10 cities in Hunan Province was studied, and the status quo was analyzed. All the 390 catering units implemented quantitative classified management. The larger the catering enterprise, the higher level of quantitative classification. In addition to cafeterias, the smaller the catering units, the higher point of deduction, and snack bars and beverage stores were the highest. For those quantified and classified as C and D, the point of deduction was higher in the procurement and storage of raw materials, operation processing and other aspects. The quantitative classification of Hunan Province has relatively wide coverage. There are hidden risks in food security in small catering units, snack bars, and beverage stores. The food hygienic condition of Hunan Province needs to be improved.

Assessing vertebral fracture risk on volumetric quantitative computed tomography by geometric characterization of trabecular bone structure

Science.gov (United States)

Checefsky, Walter A.; Abidin, Anas Z.; Nagarajan, Mahesh B.; Bauer, Jan S.; Baum, Thomas; Wismüller, Axel

2016-03-01

The current clinical standard for measuring Bone Mineral Density (BMD) is dual X-ray absorptiometry, however more recently BMD derived from volumetric quantitative computed tomography has been shown to demonstrate a high association with spinal fracture susceptibility. In this study, we propose a method of fracture risk assessment using structural properties of trabecular bone in spinal vertebrae. Experimental data was acquired via axial multi-detector CT (MDCT) from 12 spinal vertebrae specimens using a whole-body 256-row CT scanner with a dedicated calibration phantom. Common image processing methods were used to annotate the trabecular compartment in the vertebral slices creating a circular region of interest (ROI) that excluded cortical bone for each slice. The pixels inside the ROI were converted to values indicative of BMD. High dimensional geometrical features were derived using the scaling index method (SIM) at different radii and scaling factors (SF). The mean BMD values within the ROI were then extracted and used in conjunction with a support vector machine to predict the failure load of the specimens. Prediction performance was measured using the root-mean-square error (RMSE) metric and determined that SIM combined with mean BMD features (RMSE = 0.82 +/- 0.37) outperformed MDCT-measured mean BMD (RMSE = 1.11 +/- 0.33) (p biomechanical strength prediction in vertebrae can be significantly improved through the use of SIM-derived texture features from trabecular bone.

Quantitation: clinical applications

International Nuclear Information System (INIS)

Britton, K.E.

1982-01-01

Single photon emission tomography may be used quantitatively if its limitations are recognized and quantitation is made in relation to some reference area on the image. Relative quantitation is discussed in outline in relation to the liver, brain and pituitary, thyroid, adrenals, and heart. (U.K.)

Quantitative Risks

Science.gov (United States)

2015-02-24

design failure modes and effects analysis (DFMEA), (b) Fault Tree Analysis ( FTA ) for all essential functions listed in the Failure Definition and...subsystem reliability date from Accomplishment 3, completed (a) updated DFMEA, (b) updated FTA , (c) updated reliability and maintainability estimates, (d...www.gao.gov/assets/660/658615.pdf [4] Karen Richey. Update to GAO’s Cost Estimating Assessment Guide and Scheduling Guide (draft). GAO. Mar 2013

Risk management guide

International Nuclear Information System (INIS)

Briscoe, G.J.

1977-06-01

Risk management requires an assessment or a knowledge of risk. This, in turn, requires identification of hazards (sources of risk) and a determination of risk (evaluation of the hazard degree). The hazard identification and risk analysis techniques presented in this Guide are, in general, based on the MORT concept that accidents result from unwanted energy flow in the absence of adequate controls and/or barriers. This Guide presents an analytical tree designed to prevent oversight of specific energy sources in risk identification. Hazard identification by field personnel is also discussed. Quantitative risk analysis is discussed in the following section. A method for summary of the risks for each energy classification is given. This method uses a graphical log-normal projection so that low probability events, which are not adequately represented in the experience data, are included in the risk assessment. This permits a more acceptable risk assessment since catastrophes are not ignored, even though the actual risk is only approximated. In addition, a few examples of risk analysis of specific hazards are given. Rudimentary probability and fault tree theory are used in these examples. Total risk assessment and resource allocation and safety performance trend analysis are discussed

The quantitative Morse theorem

OpenAIRE

Loi, Ta Le; Phien, Phan

2013-01-01

In this paper, we give a proof of the quantitative Morse theorem stated by {Y. Yomdin} in \\cite{Y1}. The proof is based on the quantitative Sard theorem, the quantitative inverse function theorem and the quantitative Morse lemma.

Campylobacter Risk Analysis

DEFF Research Database (Denmark)

Nauta, Maarten

In several countries quantitative microbiological risk assessments (QMRAs) have been performed for Campylobacter in chicken meat. The models constructed for this purpose provide a good example of the development of QMRA in general and illustrate the diversity of available methods. Despite...... the differences between the models, the most prominent conclusions of the QMRAs are similar. These conclusions for example relate to the large risk of highly contaminated meat products and the insignificance of contamination from Campylobacter positive flocks to negative flocks during slaughter and processing...

Quantitative fetal fibronectin and cervical length in symptomatic women: results from a prospective blinded cohort study.

Science.gov (United States)

Levine, Lisa D; Downes, Katheryne L; Romero, Julie A; Pappas, Hope; Elovitz, Michal A

2018-05-15

Our objectives were to determine whether quantitative fetal fibronectin (fFN) and cervical length (CL) screening can be used alone or in combination as prognostic tests to identify symptomatic women at the highest or lowest risk for spontaneous preterm birth (sPTB). A prospective, blinded cohort study of women presenting with a singleton gestation to our triage unit between 22-33w6d with preterm labor symptoms was performed. Women with ruptured membranes, moderate/severe bleeding, and dilation >2 cm were excluded. The primary outcome was sPTB quantitative fFN and CL assessment, both separately and in combination, considering traditionally reported cut-points (fFN ≥50 and CL 50 and CL quantitative level chosen. For all women, a shorter CL was associated with an increased sPTB risk. Among nulliparas and multiparas without a prior sPTB, a CL quantitative fFN or cervical length assessment can be utilized, depending on resources available, but a lower cut-point of 20 ng/mL should be used for quantitative fFN. For multiparous women, fFN is not useful and cervical length assessment should be the main screening tool utilized when there is clinical uncertainty. Regardless of parity, the PPV of fFN and CL is low and therefore the greatest clinical utility remains in its NPV.

A spatially explicit and quantitative vulnerability assessment of ecosystem service change in Europe

NARCIS (Netherlands)

Metzger, M.J.; Schröter, D.; Leemans, R.; Cramer, W.

2008-01-01

Environmental change alters ecosystem functioning and may put the provision of services to human at risk. This paper presents a spatially explicit and quantitative assessment of the corresponding vulnerability for Europe, using a new framework designed to answer multidisciplinary policy relevant

Quantitative weight of evidence assessment of higher tier studies on the toxicity and risks of neonicotinoids in honeybees. 3. Clothianidin.

Science.gov (United States)

Solomon, Keith R; Stephenson, Gladys L

2017-01-01

A quantitative weight of evidence (QWoE) methodology was used to assess higher tier studies on the effects of clothianidin (CTD) on honeybees. Assessment endpoints were population size and viability of commercially managed bees and quantity of hive products. A colony-level no-observed-adverse effect concentration (NOAEC) of 25 µg CTD/kg syrup, equivalent to an oral no-observed-adverse effect-dose (NOAED) of 7.3 ng/bee/d for all responses measured. Based on a NOAEC of 19.7 µg/kg pollen, the NOAED for honeybee larvae was 2.4 ng/bee larva/d. For exposures via dust, a no-observed-adverse effect rate of 4 g CTD/ha was used to assess relevance of exposures via deposition of dust. The overall weight of evidence suggested that there is minimal risk to honeybees from exposure to CTD from its use as a seed treatment. For exposures via dust, dust/seed and dust/foliar applications, there were no exposures greater than the NOAED for CTD in nectar and pollen, indicating a de minimis risk to honeybees when the route of exposure was via uptake in plants. Analysis of effect studies in the field indicated a consistent lack of relevant effects, regardless of the way CTD was applied. For exposures via dust, there were no adverse effects because of these applications and there were no exposures greater than the NOAED for CTD in nectar and pollen. The overall weight of evidence based on many studies indicated no adverse effects on colony viability or survival of the colony. Thus, the overall conclusion is that clothianidin, as currently used in good agricultural practices, does not present a significant risk to honeybees at the level of the colony.

Microbial risk assessment and its implications for risk management in urban water systems

OpenAIRE

Westrell, Therese

2004-01-01

Infectious disease can be transmitted via various environmental pathways, many of which are incorporated into our water and wastewater systems. Quantitative microbial risk assessment (QMRA) can be a valuable tool in identifying hazard exposure pathways and estimating their associated health impacts. QMRA can be applied to establish standards and guidelines and has been adopted by the World Health Organisation for the management of risks from water-related infectious diseases. This thesis aims...

Health risks in perspective: Judging health risks of energy technologies

Energy Technology Data Exchange (ETDEWEB)

Rowe, M.D.

1992-09-18

Almost daily, Americans receive reports from the mass news media about some new and frightening risk to health and welfare. Most such reports emphasize the newsworthiness of the risks -- the possibility of a crisis, disagreements among experts, how things happened, who is responsible for fixing them, how much will it cost, conflict among parties involved, etc. As a rule, the magnitudes of the risks, or the difficulty of estimating those magnitudes, have limited newsworthiness, and so they are not mentioned. Because of this emphasis in the news media, most people outside the risk assessment community must judge the relative significance of the various risks to which we all are exposed with only that information deemed newsworthy by reporters. This information is biased and shows risks in isolation. There is no basis for understanding and comparing the relative importance of risks among themselves, or for comparing one risk, perhaps a new or newly-discovered one, in the field of all risks. The purpose of this report is to provide perspective on the various risks to which we are routinely exposed. It serves as a basis for understanding the meaning of quantitative risk estimates and for comparing new or newly-discovered risks with other, better-understood risks. Specific emphasis is placed on health risks of energy technologies.

The total theory about risk management

International Nuclear Information System (INIS)

Furuya, Shunsuke

2003-01-01

A general working procedure of risk management, some example of other countries, topics and problems in the future are described. A definition of risk, risk assessment, risk management process, setting of aim and definite policy are explained. As a fundamental way of thinking, risk is controlled by ALARP (As Low As Reasonably Practicable). The upper and lower limit of risk level is called as Quantitative Safety Goal and Target Level of Safety, respectively. These limits in the atomic power and airplane are decided. Evaluation of risk, countermeasure and practice are explained. For example, a permissible range of risk and practical use in England, U.S.A, Holland and Japan are stated. Recently, accountability risk, missing demand risk and control risk are important. (S.Y.)

Qualitative techniques for managing operational risk

OpenAIRE

Delfiner, Miguel; Pailhé, Cristina

2009-01-01

Qualitative techniques are essential tools for identifying and assessing operational risk (OR). Their relevance in assessing OR can be understood due to the lack of a quantitative static model capable of capturing the dynamic operational risk profile which is shaped by managerial decisions. An operational risk profile obtained solely from historical loss data could further change due to corrective actions implemented by the bank after the occurrence of those events. This document introduces s...

Central sensitization phenomena after third molar surgery: A quantitative sensory testing study

DEFF Research Database (Denmark)

Jensen, T.S.; Norholt, S.E.; Svensson, P.

2008-01-01

Background: Surgical removal of third molars may carry a risk of developing persistent orofacial pain, and central sensitization appears to play an important role in the transition from acute to chronic pain. Aim: The aim of this study was to investigate sensitization (primarily central sensitiza......Background: Surgical removal of third molars may carry a risk of developing persistent orofacial pain, and central sensitization appears to play an important role in the transition from acute to chronic pain. Aim: The aim of this study was to investigate sensitization (primarily central...... sensitization) after orofacial trauma using quantitative sensory testing (QST). Methods: A total of 32 healthy men (16 patients and 16 age-matched control subjects) underwent a battery of quantitative tests adapted to the trigeminal area at baseline and 2, 7, and 30 days following surgical removal of a lower...... impacted third molar. Results: Central sensitization for at least one week was indicated by significantly increased pain intensity evoked by intraoral repetitive pinprick and electrical stimulation (p

Distribution of bacterial contamination in non-sterile pharmaceutical materials and assessment of its risk to the health of the final consumers quantitatively

Directory of Open Access Journals (Sweden)

Mostafa Essam Eissa

2016-09-01

Full Text Available Bacterial contamination control in pharmaceutical products is a critical aspect in the field of drug manufacturing industry due to the encountered risk to the patients' health and possibly their life. The application of commercial bacterial identification system is crucial to identify the type of contamination and its source to anticipate the impact of bioburden on the products and setting corrective and preventive actions. During the period of one year, random samples from raw materials and final products were tested according to United States Pharmacopeia, and those that showed suspect results for specified microorganisms and/or out-of-specification limits or showed out-of-trend results were subjected to further identification by using miniaturized biochemical identification system after performing Gram stain. From the total bacterial isolates of the investigated products, more than 60% were primarily belonging to Micrococcaceae 16.98% (empty hard gelatin capsules, Enterobacteriaceae 18.86% (vaginal cream applicator, plastic caps for bottles, Sorbitol solution, finished hard gelatin capsule product, topical cream and oral suspension and Bacillaceae 24.53% (Talc powder, liquid oral preparation and finished hard gelatin capsule product. Gram Positive and Negative samples were 56.60% and 41.51% respectively from the total investigated sample products and materials. Finished pharmaceutical products constituted 53.33% and 68.18% from Gram-positive and Gram-negative microorganisms respectively. An approach to quantitative risk assessment for pharmaceutical products was conducted on selected medicinal items and showed that Enterobacteriaceae followed by Burkholderiaceae contributed by more than 80% to the major hazard that could be delivered to patients through drugs. The applied risk can be used as a milestone for setting goals by pharmaceutical companies to improve the safety of medicinal products microbiologically and to identify the major sources

Project risk management in the construction of high-rise buildings

Science.gov (United States)

Titarenko, Boris; Hasnaoui, Amir; Titarenko, Roman; Buzuk, Liliya

2018-03-01

This paper shows the project risk management methods, which allow to better identify risks in the construction of high-rise buildings and to manage them throughout the life cycle of the project. One of the project risk management processes is a quantitative analysis of risks. The quantitative analysis usually includes the assessment of the potential impact of project risks and their probabilities. This paper shows the most popular methods of risk probability assessment and tries to indicate the advantages of the robust approach over the traditional methods. Within the framework of the project risk management model a robust approach of P. Huber is applied and expanded for the tasks of regression analysis of project data. The suggested algorithms used to assess the parameters in statistical models allow to obtain reliable estimates. A review of the theoretical problems of the development of robust models built on the methodology of the minimax estimates was done and the algorithm for the situation of asymmetric "contamination" was developed.

Quantitative Decision Support Requires Quantitative User Guidance

Science.gov (United States)

Smith, L. A.

2009-12-01

for a given problem is presented. Based on climate science, meteorology, and the details of the question in hand, this approach identifies necessary (never sufficient) conditions required for the rational use of climate model output in quantitative decision support tools. Inasmuch as climate forecasting is a problem of extrapolation, there will always be harsh limits on our ability to establish where a model is fit for purpose, this does not, however, limit us from identifying model noise as such, and thereby avoiding some cases of the misapplication and over interpretation of model output. It is suggested that failure to clearly communicate the limits of today’s climate model in providing quantitative decision relevant climate information to today’s users of climate information, would risk the credibility of tomorrow’s climate science and science based policy more generally.

Development and Evaluation of a PCR and Mass Spectroscopy-based (PCR-MS) Method for Quantitative, Type-specific Detection of Human Papillomavirus

Science.gov (United States)

Patel, Divya A.; Shih, Yang-Jen; Newton, Duane W.; Michael, Claire W.; Oeth, Paul A.; Kane, Michael D.; Opipari, Anthony W.; Ruffin, Mack T.; Kalikin, Linda M.; Kurnit, David M.

2010-01-01

Knowledge of the central role of high-risk human papillomavirus (HPV) in cervical carcinogenesis, coupled with an emerging need to monitor the efficacy of newly introduced HPV vaccines, warrant development and evaluation of type-specific, quantitative HPV detection methods. In the present study, a prototype PCR and mass spectroscopy (PCR-MS)-based method to detect and quantitate 13 high-risk HPV types is compared to the Hybrid Capture 2 High Risk HPV DNA test (HC2; Digene Corp., Gaithersburg, MD) in 199 cervical scraping samples and to DNA sequencing in 77 cervical tumor samples. High-risk HPV types were detected in 76/77 (98.7%) cervical tumor samples by PCR-MS. Degenerate and type-specific sequencing confirmed the types detected by PCR-MS. In 199 cervical scraping samples, all 13 HPV types were detected by PCR-MS. Eighteen (14.5%) of 124 cervical scraping samples that were positive for high-risk HPV by HC2 were negative by PCR-MS. In all these cases, degenerate DNA sequencing failed to detect any of the 13 high-risk HPV types. Nearly half (46.7%) of the 75 cervical scraping samples that were negative for high-risk HPV by the HC2 assay were positive by PCR-MS. Type-specific sequencing in a subset of these samples confirmed the HPV type detected by PCR-MS. Quantitative PCR-MS results demonstrated that 11/75 (14.7%) samples contained as much HPV copies/cell as HC2-positive samples. These findings suggest that this prototype PCR-MS assay performs at least as well as HC2 for HPV detection, while offering the additional, unique advantages of type-specific identification and quantitation. Further validation work is underway to define clinically meaningful HPV detection thresholds and to evaluate the potential clinical application of future generations of the PCR-MS assay. PMID:19410602

Development and evaluation of a PCR and mass spectroscopy (PCR-MS)-based method for quantitative, type-specific detection of human papillomavirus.

Science.gov (United States)

Patel, Divya A; Shih, Yang-Jen; Newton, Duane W; Michael, Claire W; Oeth, Paul A; Kane, Michael D; Opipari, Anthony W; Ruffin, Mack T; Kalikin, Linda M; Kurnit, David M

2009-09-01

Knowledge of the central role of high-risk human papillomavirus (HPV) in cervical carcinogenesis, coupled with an emerging need to monitor the efficacy of newly introduced HPV vaccines, warrant development and evaluation of type-specific, quantitative HPV detection methods. In the present study, a prototype PCR and mass spectroscopy (PCR-MS)-based method to detect and quantitate 13 high-risk HPV types is compared to the Hybrid Capture 2 High-Risk HPV DNA test (HC2; Digene Corp., Gaithersburg, MD) in 199 cervical scraping samples and to DNA sequencing in 77 cervical tumor samples. High-risk HPV types were detected in 76/77 (98.7%) cervical tumor samples by PCR-MS. Degenerate and type-specific sequencing confirmed the types detected by PCR-MS. In 199 cervical scraping samples, all 13 HPV types were detected by PCR-MS. Eighteen (14.5%) of 124 cervical scraping samples that were positive for high-risk HPV by HC2 were negative by PCR-MS. In all these cases, degenerate DNA sequencing failed to detect any of the 13 high-risk HPV types. Nearly half (46.7%) of the 75 cervical scraping samples that were negative for high-risk HPV by the HC2 assay were positive by PCR-MS. Type-specific sequencing in a subset of these samples confirmed the HPV type detected by PCR-MS. Quantitative PCR-MS results demonstrated that 11/75 (14.7%) samples contained as much HPV copies/cell as HC2-positive samples. These findings suggest that this prototype PCR-MS assay performs at least as well as HC2 for HPV detection, while offering the additional, unique advantages of type-specific identification and quantitation. Further validation work is underway to define clinically meaningful HPV detection thresholds and to evaluate the potential clinical application of future generations of the PCR-MS assay.

Quantitative microbial risk assessment for Escherichia coli O157:H7, salmonella, and Listeria monocytogenes in leafy green vegetables consumed at salad bars.

Science.gov (United States)

Franz, E; Tromp, S O; Rijgersberg, H; van der Fels-Klerx, H J

2010-02-01

Fresh vegetables are increasingly recognized as a source of foodborne outbreaks in many parts of the world. The purpose of this study was to conduct a quantitative microbial risk assessment for Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes infection from consumption of leafy green vegetables in salad from salad bars in The Netherlands. Pathogen growth was modeled in Aladin (Agro Logistics Analysis and Design Instrument) using time-temperature profiles in the chilled supply chain and one particular restaurant with a salad bar. A second-order Monte Carlo risk assessment model was constructed (using @Risk) to estimate the public health effects. The temperature in the studied cold chain was well controlled below 5 degrees C. Growth of E. coli O157:H7 and Salmonella was minimal (17 and 15%, respectively). Growth of L. monocytogenes was considerably greater (194%). Based on first-order Monte Carlo simulations, the average number of cases per year in The Netherlands associated the consumption leafy greens in salads from salad bars was 166, 187, and 0.3 for E. coli O157:H7, Salmonella, and L. monocytogenes, respectively. The ranges of the average number of annual cases as estimated by second-order Monte Carlo simulation (with prevalence and number of visitors as uncertain variables) were 42 to 551 for E. coli O157:H7, 81 to 281 for Salmonella, and 0.1 to 0.9 for L. monocytogenes. This study included an integration of modeling pathogen growth in the supply chain of fresh leafy vegetables destined for restaurant salad bars using software designed to model and design logistics and modeling the public health effects using probabilistic risk assessment software.

A quantitative approach for risk-informed safety significance categorization in option-2

International Nuclear Information System (INIS)

Ha, Jun Su; Seong, Poong Hyun

2004-01-01

OPTION-2 recommends that Structures, Systems, or Components (SSCs) of Nuclear Power Plants (NPPs) should be categorized into four groups according to their safety significance as well as whether they are safety-related or not. With changes to the scope of SSCs covered by 10 CFR 50, safety-related components which categorized into low safety significant SSC (RISC-3 SSC) can be exempted from the existing conservative burden (or requirements). As OPTION-2 paradigm is applied, a lot of SSCs may be categorized into RISC-3 SSCs. Changes in treatment of the RISC-3 SSCs will be recommended and then finally the recommended changes shall be evaluated. Consequently, before recommending the changes in treatment, probable candidate SSCs for the changes in treatment need to be identified for efficient risk-informed regulation and application (RIRA). Hence, in this work, a validation focused on the RISC-3 SSCs is proposed to identify probable candidate SSCs. Burden to Importance Ratio (BIR) is utilized as a quantitative measure for the validation. BIR is a measure representing the extent of resources or requirements imposed on a SSC with respect to the value of the importance measure of the SSC. Therefore SSCs having high BIR can be considered as probable candidate SSCs for the changes in treatment. In addition, the final decision whether RISC-3 SSCs can be considered as probable candidate SSCs or not should be made by an expert panel. For the effective decision making, a structured mathematical decision-making process is constructed based on Belief Networks (BBN) to overcome demerits of conventional group meeting based on unstructured discussion for decision-making. To demonstrate the usefulness of the proposed approach, the approach is applied to 22 components selected from 512 In-Service Test (IST) components of Ulchin unit 3. The results of the application show that the proposed approach can identify probable candidate SSCs for changes in treatment. The identification of the

Quantitative Algebraic Reasoning

DEFF Research Database (Denmark)

Mardare, Radu Iulian; Panangaden, Prakash; Plotkin, Gordon

2016-01-01

We develop a quantitative analogue of equational reasoning which we call quantitative algebra. We define an equality relation indexed by rationals: a =ε b which we think of as saying that “a is approximately equal to b up to an error of ε”. We have 4 interesting examples where we have a quantitative...... equational theory whose free algebras correspond to well known structures. In each case we have finitary and continuous versions. The four cases are: Hausdorff metrics from quantitive semilattices; pWasserstein metrics (hence also the Kantorovich metric) from barycentric algebras and also from pointed...

An evaluation of risk methods for prioritizing fire protection features: a procedure for fire barrier penetration seals

International Nuclear Information System (INIS)

Dey, M.K.

2004-01-01

This paper generally evaluates risk methods available for prioritizing fire protection features. Risk methods involving both the use of qualitative insights, and quantitative results from a fire probabilistic risk analysis are reviewed. The applicability of these methods to develop a prioritized list of fire barrier penetration seals in a plant based on risk significance is presented as a procedure to illustrate the benefits of the methods. The paper concludes that current fire risk assessment methods can be confidently used to prioritize plant fire protection features, specifically fire barrier penetration seals. Simple prioritization schemes, using qualitative assessments and insights from fire PRA methodology may be implemented without the need for quantitative results. More elaborate prioritization schemes that allow further refinements to the categorization process may be implemented using the quantitative results of the screening processes in good fire PRAs. The use of the quantitative results from good fire PRAs provide several benefits for risk prioritization of fire protection features at plants, mainly from the plant systems analyses conducted for a fire PRA

Modelling IT risk in banking industry : A study on how to calculate the aggregate loss distribution of IT risk

OpenAIRE

Isaksson, Didrik

2017-01-01

Background: Lack of internal data makes some operational risks hard to calculate with quantitative models. This is true for the IT risk or the risk that a bank will experience losses caused by IT System and Infrastructure failure. IT systems and infrastructure are getting more predominant and important in the banking industry which makes the IT risk even more important to quantify.  Purpose: The aim of this thesis is to find an appropriate way of modelling IT risk for the banking industry. Th...

Connecting qualitative observation and quantitative measurement for enhancing quantitative literacy in plant anatomy course

Science.gov (United States)

Nuraeni, E.; Rahmat, A.

2018-05-01

Forming of cognitive schemes of plant anatomy concepts is performed by processing of qualitative and quantitative data obtained from microscopic observations. To enhancing student’s quantitative literacy, strategy of plant anatomy course was modified by adding the task to analyze quantitative data produced by quantitative measurement of plant anatomy guided by material course. Participant in this study was 24 biology students and 35 biology education students. Quantitative Literacy test, complex thinking in plant anatomy test and questioner used to evaluate the course. Quantitative literacy capability data was collected by quantitative literacy test with the rubric from the Association of American Colleges and Universities, Complex thinking in plant anatomy by test according to Marzano and questioner. Quantitative literacy data are categorized according to modified Rhodes and Finley categories. The results showed that quantitative literacy of biology education students is better than biology students.

Probabilistic risk analysis in chemical engineering

International Nuclear Information System (INIS)

Schmalz, F.

1991-01-01

In risk analysis in the chemical industry, recognising potential risks is considered more important than assessing their quantitative extent. Even in assessing risks, emphasis is not on the probability involved but on the possible extent. Qualitative assessment has proved valuable here. Probabilistic methods are used in individual cases where the wide implications make it essential to be able to assess the reliability of safety precautions. In this case, assessment therefore centres on the reliability of technical systems and not on the extent of a chemical risk. 7 figs

A quantitative approach to the risk perception associated with nuclear safety

International Nuclear Information System (INIS)

Black, S.

2015-01-01

Subjective risk perception associated with nuclear safety is hard-wired into the general public psyche; but as real as this 'feels', and as much as it requires to be respected in a democracy, misguided risk perception on nuclear safety can create its own perils for humans. The objective of this paper is to create a better understanding of the phenomena of risk perception associated with nuclear safety presented by journalistic media. It will attempt to quantify the manifestation of risk perception associated with nuclear safety by providing comparison between the media coverage of nuclear and industrial accidents of similar magnitude. It will utilise the Fog Index, a mathematical formula that defines the readability of an article, allowing for an unbiased numerical comparison on 'readability' to be derived. Fog Index is expressed as: Fog Index = 0.4(N/S + 100*L/N), where N is the number of words in the article, S is the number of sentences and L is the number of words with 3 syllables or more. To provide consistency, the medium chosen to compare industrial accidents are reports extracted from 'The Times' newspaper, written at the time of the accidents and concerning Chernobyl and Bhopal disasters. 'The Times' is respected newspaper, written for a knowledgeable audience who have an in-depth interest in the news from the UK and abroad; subsequently this causes it to have a relatively high Fog index, compared to its tabloid counterparts. The higher the Fog Index, the more education the reader requires to fully understand the article, a Fog Index of 12 is the limit for the majority of the general public. Research found that reporting of nuclear safety accidents has a Fog Index of approximately 14 while it was only of 10 for Bhopal accident. These values go someway in demonstrating that the complexity of media information on nuclear safety transferred via journalistic media is beyond what can reasonably be expected to be

Does Corporate Governance Impact Risk Management System?

Directory of Open Access Journals (Sweden)

Petre BREZEANU

2011-04-01

Full Text Available This paper brings forth the contribution of corporate governance to risk management system at the enterprise level. The research is a complex one, integrating both quantitative and qualitative information. The quantitative information consists of balance sheet and profit and loss account data while the qualitative one includes dummy variables reflecting the agency and monitoring costs which govern the relationship between managers and shareholders.

Risk assessment of carcinogens in food

International Nuclear Information System (INIS)

Barlow, Susan; Schlatter, Josef

2010-01-01

Approaches for the risk assessment of carcinogens in food have evolved as scientific knowledge has advanced. Early methods allowed little more than hazard identification and an indication of carcinogenic potency. Evaluation of the modes of action of carcinogens and their broad division into genotoxic and epigenetic (non-genotoxic, non-DNA reactive) carcinogens have played an increasing role in determining the approach followed and provide possibilities for more detailed risk characterisation, including provision of quantitative estimates of risk. Reliance on experimental animal data for the majority of risk assessments and the fact that human exposures to dietary carcinogens are often orders of magnitude below doses used in experimental studies has provided a fertile ground for discussion and diverging views on the most appropriate way to offer risk assessment advice. Approaches used by national and international bodies differ, with some offering numerical estimates of potential risks to human health, while others express considerable reservations about the validity of quantitative approaches requiring extrapolation of dose-response data below the observed range and instead offer qualitative advice. Recognising that qualitative advice alone does not provide risk managers with information on which to prioritise the need for risk management actions, a 'margin of exposure' approach for substances that are both genotoxic and carcinogenic has been developed, which is now being used by the World Health Organization and the European Food Safety Authority. This review describes the evolution of risk assessment advice on carcinogens and discusses examples of ways in which carcinogens in food have been assessed in Europe.

Risk assessment of carcinogens in food.

Science.gov (United States)

Barlow, Susan; Schlatter, Josef