WorldWideScience

Sample records for relative risk estimation

  1. Risk Estimates and Risk Factors Related to Psychiatric Inpatient Suicide

    DEFF Research Database (Denmark)

    Madsen, Trine; Erlangsen, Annette; Nordentoft, Merete

    2017-01-01

    trends, and socio-demographic and clinical risk factors of suicide in psychiatric inpatients. Psychiatric inpatients have a very high risk of suicide relative to the background population, but it remains challenging for clinicians to identify those patients that are most likely to die from suicide during......People with mental illness have an increased risk of suicide. The aim of this paper is to provide an overview of suicide risk estimates among psychiatric inpatients based on the body of evidence found in scientific peer-reviewed literature; primarily focusing on the relative risks, rates, time...... admission. Most studies are based on low power, thus compromising quality and generalisability. The few studies with sufficient statistical power mainly identified non-modifiable risk predictors such as male gender, diagnosis, or recent deliberate self-harm. Also, the predictive value of these predictors...

  2. Risk Estimates and Risk Factors Related to Psychiatric Inpatient Suicide

    DEFF Research Database (Denmark)

    Madsen, Trine; Erlangsen, Annette; Nordentoft, Merete

    2017-01-01

    People with mental illness have an increased risk of suicide. The aim of this paper is to provide an overview of suicide risk estimates among psychiatric inpatients based on the body of evidence found in scientific peer-reviewed literature; primarily focusing on the relative risks, rates, time...... trends, and socio-demographic and clinical risk factors of suicide in psychiatric inpatients. Psychiatric inpatients have a very high risk of suicide relative to the background population, but it remains challenging for clinicians to identify those patients that are most likely to die from suicide during...... is low. It would be of great benefit if future studies would be based on large samples while focusing on modifiable predictors over the course of an admission, such as hopelessness, depressive symptoms, and family/social situations. This would improve our chances of developing better risk assessment...

  3. Adequacy of relative and absolute risk models for lifetime risk estimate of radiation-induced cancer

    International Nuclear Information System (INIS)

    McBride, M.; Coldman, A.J.

    1988-03-01

    This report examines the applicability of the relative (multiplicative) and absolute (additive) models in predicting lifetime risk of radiation-induced cancer. A review of the epidemiologic literature, and a discussion of the mathematical models of carcinogenesis and their relationship to these models of lifetime risk, are included. Based on the available data, the relative risk model for the estimation of lifetime risk is preferred for non-sex-specific epithelial tumours. However, because of lack of knowledge concerning other determinants of radiation risk and of background incidence rates, considerable uncertainty in modelling lifetime risk still exists. Therefore, it is essential that follow-up of exposed cohorts be continued so that population-based estimates of lifetime risk are available

  4. Estimating internal exposure risks by the relative risk and the National Institute of Health risk models

    International Nuclear Information System (INIS)

    Mehta, S.K.; Sarangapani, R.

    1995-01-01

    This paper presents tabulations of risk (R) and person-years of life lost (PYLL) for acute exposures of individual organs at ages 20 and 40 yrs for the Indian and Japanese populations to illustrate the effect of age at exposure in the two models. Results are also presented for the organ wise nominal probability coefficients (NPC) and PYLL for individual organs for the age distributed Indian population by the two models. The results presented show that for all organs the estimates of PYLL and NPC for the Indian population are lower than those for the Japanese population by both models except for oesophagus, breast and ovary by the relative risk (RR) model, where the opposite trend is observed. The results also show that the Indian all-cancer values of NPC averaged over the two models is 2.9 x 10 -2 Sv -1 , significantly lower than the world average value of 5x10 -2 Sv -1 estimated by the ICRP. (author). 9 refs., 2 figs., 2 tabs

  5. Risk Estimates and Risk Factors Related to Psychiatric Inpatient Suicide—An Overview

    Directory of Open Access Journals (Sweden)

    Trine Madsen

    2017-03-01

    Full Text Available People with mental illness have an increased risk of suicide. The aim of this paper is to provide an overview of suicide risk estimates among psychiatric inpatients based on the body of evidence found in scientific peer-reviewed literature; primarily focusing on the relative risks, rates, time trends, and socio-demographic and clinical risk factors of suicide in psychiatric inpatients. Psychiatric inpatients have a very high risk of suicide relative to the background population, but it remains challenging for clinicians to identify those patients that are most likely to die from suicide during admission. Most studies are based on low power, thus compromising quality and generalisability. The few studies with sufficient statistical power mainly identified non-modifiable risk predictors such as male gender, diagnosis, or recent deliberate self-harm. Also, the predictive value of these predictors is low. It would be of great benefit if future studies would be based on large samples while focusing on modifiable predictors over the course of an admission, such as hopelessness, depressive symptoms, and family/social situations. This would improve our chances of developing better risk assessment tools.

  6. Disentangling the risk assessment and intimate partner violence relation: Estimating mediating and moderating effects.

    Science.gov (United States)

    Williams, Kirk R; Stansfield, Richard

    2017-08-01

    To manage intimate partner violence (IPV), the criminal justice system has turned to risk assessment instruments to predict if a perpetrator will reoffend. Empirically determining whether offenders assessed as high risk are those who recidivate is critical for establishing the predictive validity of IPV risk assessment instruments and for guiding the supervision of perpetrators. But by focusing solely on the relation between calculated risk scores and subsequent IPV recidivism, previous studies of the predictive validity of risk assessment instruments omitted mediating factors intended to mitigate the risk of this behavioral recidivism. The purpose of this study was to examine the mediating effects of such factors and the moderating effects of risk assessment on the relation between assessed risk (using the Domestic Violence Screening Instrument-Revised [DVSI-R]) and recidivistic IPV. Using a sample of 2,520 perpetrators of IPV, results revealed that time sentenced to jail and time sentenced to probation each significantly mediated the relation between DVSI-R risk level and frequency of reoffending. The results also revealed that assessed risk moderated the relation between these mediating factors and IPV recidivism, with reduced recidivism (negative estimated effects) for high-risk perpetrators but increased recidivism (positive estimate effects) for low-risk perpetrators. The implication is to assign interventions to the level of risk so that no harm is done. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  7. Estimation of baseline lifetime risk of developed cancer related to radiation exposure in China

    International Nuclear Information System (INIS)

    Li Xiaoliang; Niu Haowei; Sun Quanfu; Ma Weidong

    2011-01-01

    Objective: To introduce the general international method for estimation of lifetime risk of developed cancer, and to estimate the lifetime risk baseline values of several kinds of cancers related to radiation exposures in China. Methods: The risk estimation was based on the data from Chinese Cancer Registry Annual Report (2010) and China Population and Employment Statistics Yearbook (2009), and made according to the method previously published by National Cancer Institute (NCI) in USA. Results: The lifetime risk of all cancer in China in 2007 was estimated to be 27.77%, that of lung cancer 5.96%, that of breast cancer for female 3.34%, that of all leukemia 0.14%, that of thyroid cancer 0.37%. The lifetime risks of all cancer were estimated to be 32.74% for males and 24.73% for females, and that was 36.47% for urban residents and 26.79% for rural people. Conclusions: The lifetime risk of all cancer for males in 2007 was about 1.25 times as much as that for females. The value of all cancer for urban residents was about 1.35 times as much as that for rural residents. The lifetime risk of developed cancers in 2007 in China is lower than that in the developed countries,such as Japan. (authors)

  8. Some statistical considerations related to the estimation of cancer risk following exposure to ionizing radiation

    International Nuclear Information System (INIS)

    Land, C.E.; Pierce, D.A.

    1983-01-01

    Statistical theory and methodology provide the logical structure for scientific inference about the cancer risk associated with exposure to ionizing radiation. Although much is known about radiation carcinogenesis, the risk associated with low-level exposures is difficult to assess because it is too small to measure directly. Estimation must therefore depend upon mathematical models which relate observed risks at high exposure levels to risks at lower exposure levels. Extrapolated risk estimates obtained using such models are heavily dependent upon assumptions about the shape of the dose-response relationship, the temporal distribution of risk following exposure, and variation of risk according to variables such as age at exposure, sex, and underlying population cancer rates. Expanded statistical models, which make explicit certain assumed relationships between different data sets, can be used to strengthen inferences by incorporating relevant information from diverse sources. They also allow the uncertainties inherent in information from related data sets to be expressed in estimates which partially depend upon that information. To the extent that informed opinion is based upon a valid assessment of scientific data, the larger context of decision theory, which includes statistical theory, provides a logical framework for the incorporation into public policy decisions of the informational content of expert opinion

  9. Performance of the modified Poisson regression approach for estimating relative risks from clustered prospective data.

    Science.gov (United States)

    Yelland, Lisa N; Salter, Amy B; Ryan, Philip

    2011-10-15

    Modified Poisson regression, which combines a log Poisson regression model with robust variance estimation, is a useful alternative to log binomial regression for estimating relative risks. Previous studies have shown both analytically and by simulation that modified Poisson regression is appropriate for independent prospective data. This method is often applied to clustered prospective data, despite a lack of evidence to support its use in this setting. The purpose of this article is to evaluate the performance of the modified Poisson regression approach for estimating relative risks from clustered prospective data, by using generalized estimating equations to account for clustering. A simulation study is conducted to compare log binomial regression and modified Poisson regression for analyzing clustered data from intervention and observational studies. Both methods generally perform well in terms of bias, type I error, and coverage. Unlike log binomial regression, modified Poisson regression is not prone to convergence problems. The methods are contrasted by using example data sets from 2 large studies. The results presented in this article support the use of modified Poisson regression as an alternative to log binomial regression for analyzing clustered prospective data when clustering is taken into account by using generalized estimating equations.

  10. Relative risk estimation of Chikungunya disease in Malaysia: An analysis based on Poisson-gamma model

    Science.gov (United States)

    Samat, N. A.; Ma'arof, S. H. Mohd Imam

    2015-05-01

    Disease mapping is a method to display the geographical distribution of disease occurrence, which generally involves the usage and interpretation of a map to show the incidence of certain diseases. Relative risk (RR) estimation is one of the most important issues in disease mapping. This paper begins by providing a brief overview of Chikungunya disease. This is followed by a review of the classical model used in disease mapping, based on the standardized morbidity ratio (SMR), which we then apply to our Chikungunya data. We then fit an extension of the classical model, which we refer to as a Poisson-Gamma model, when prior distributions for the relative risks are assumed known. Both results are displayed and compared using maps and we reveal a smoother map with fewer extremes values of estimated relative risk. The extensions of this paper will consider other methods that are relevant to overcome the drawbacks of the existing methods, in order to inform and direct government strategy for monitoring and controlling Chikungunya disease.

  11. R2 TRI facilities with 1999-2011 risk related estimates throughout the census blockgroup

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset delineates the distribution of estimate risk from the TRI facilities for 1999 - 2011 throughout the census blockgroup of the region using Office of...

  12. Lifetime risk of pregnancy-related death among Zambian women: district-level estimates from the 2010 census

    NARCIS (Netherlands)

    Banda, R.; Fossgard Sandøy, I.; Fylkesnes, K.; Janssen, F.

    The aim of this study was to examine district differentials in the lifetime risk of pregnancy-related death among females aged 15–49 in Zambia. We used data on household deaths collected in the 2010 census to estimate the lifetime risk of pregnancy-related death among females in Zambia. Using

  13. A framework for estimating radiation-related cancer risks in Japan from the 2011 Fukushima nuclear accident.

    Science.gov (United States)

    Walsh, L; Zhang, W; Shore, R E; Auvinen, A; Laurier, D; Wakeford, R; Jacob, P; Gent, N; Anspaugh, L R; Schüz, J; Kesminiene, A; van Deventer, E; Tritscher, A; del Rosarion Pérez, M

    2014-11-01

    We present here a methodology for health risk assessment adopted by the World Health Organization that provides a framework for estimating risks from the Fukushima nuclear accident after the March 11, 2011 Japanese major earthquake and tsunami. Substantial attention has been given to the possible health risks associated with human exposure to radiation from damaged reactors at the Fukushima Daiichi nuclear power station. Cumulative doses were estimated and applied for each post-accident year of life, based on a reference level of exposure during the first year after the earthquake. A lifetime cumulative dose of twice the first year dose was estimated for the primary radionuclide contaminants ((134)Cs and (137)Cs) and are based on Chernobyl data, relative abundances of cesium isotopes, and cleanup efforts. Risks for particularly radiosensitive cancer sites (leukemia, thyroid and breast cancer), as well as the combined risk for all solid cancers were considered. The male and female cumulative risks of cancer incidence attributed to radiation doses from the accident, for those exposed at various ages, were estimated in terms of the lifetime attributable risk (LAR). Calculations of LAR were based on recent Japanese population statistics for cancer incidence and current radiation risk models from the Life Span Study of Japanese A-bomb survivors. Cancer risks over an initial period of 15 years after first exposure were also considered. LAR results were also given as a percentage of the lifetime baseline risk (i.e., the cancer risk in the absence of radiation exposure from the accident). The LAR results were based on either a reference first year dose (10 mGy) or a reference lifetime dose (20 mGy) so that risk assessment may be applied for relocated and non-relocated members of the public, as well as for adult male emergency workers. The results show that the major contribution to LAR from the reference lifetime dose comes from the first year dose. For a dose of 10 mGy in

  14. 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)

  15. Using speeding detections and numbers of fatalities to estimate relative risk of a fatality for motorcyclists and car drivers.

    Science.gov (United States)

    Huggins, Richard

    2013-10-01

    Precise estimation of the relative risk of motorcyclists being involved in a fatal accident compared to car drivers is difficult. Simple estimates based on the proportions of licenced drivers or riders that are killed in a fatal accident are biased as they do not take into account the exposure to risk. However, exposure is difficult to quantify. Here we adapt the ideas behind the well known induced exposure methods and use available summary data on speeding detections and fatalities for motorcycle riders and car drivers to estimate the relative risk of a fatality for motorcyclists compared to car drivers under mild assumptions. The method is applied to data on motorcycle riders and car drivers in Victoria, Australia in 2010 and a small simulation study is conducted. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Estimating the mediating effect of different biomarkers on the relation of alcohol consumption with the risk of type 2 diabetes

    NARCIS (Netherlands)

    Beulens, J.W.J.; Schouw, van der Y.T.; Moons, K.G.M.; Boshuizen, H.C.; A, van der D.L.; Groenwold, R.H.H.

    2013-01-01

    Purpose Moderate alcohol consumption is associated with a reduced type 2 diabetes risk, but the biomarkers that explain this relation are unknown. The most commonly used method to estimate the proportion explained by a biomarker is the difference method. However, influence of alcohol–biomarker

  17. Quantifying IT estimation risks

    NARCIS (Netherlands)

    Kulk, G.P.; Peters, R.J.; Verhoef, C.

    2009-01-01

    A statistical method is proposed for quantifying the impact of factors that influence the quality of the estimation of costs for IT-enabled business projects. We call these factors risk drivers as they influence the risk of the misestimation of project costs. The method can effortlessly be

  18. Comparison of additive (absolute) risk projection models and multiplicative (relative) risk projection models in estimating radiation-induced lifetime cancer risk

    International Nuclear Information System (INIS)

    Kai, Michiaki; Kusama, Tomoko

    1990-01-01

    Lifetime cancer risk estimates depend on risk projection models. While the increasing lengths of follow-up observation periods of atomic bomb survivors in Hiroshima and Nagasaki bring about changes in cancer risk estimates, the validity of the two risk projection models, the additive risk projection model (AR) and multiplicative risk projection model (MR), comes into question. This paper compares the lifetime risk or loss of life-expectancy between the two projection models on the basis of BEIR-III report or recently published RERF report. With Japanese cancer statistics the estimates of MR were greater than those of AR, but a reversal of these results was seen when the cancer hazard function for India was used. When we investigated the validity of the two projection models using epidemiological human data and animal data, the results suggested that MR was superior to AR with respect to temporal change, but there was little evidence to support its validity. (author)

  19. Risk estimation and evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Ferguson, R A.D.

    1982-10-01

    Risk assessment involves subjectivity, which makes objective decision making difficult in the nuclear power debate. The author reviews the process and uncertainties of estimating risks as well as the potential for misinterpretation and misuse. Risk data from a variety of aspects cannot be summed because the significance of different risks is not comparable. A method for including political, social, moral, psychological, and economic factors, environmental impacts, catastrophes, and benefits in the evaluation process could involve a broad base of lay and technical consultants, who would explain and argue their evaluation positions. 15 references. (DCK)

  20. [Estimation of relation between homocysteine concentration and selected lipid parameters and adhesion molecules concentration in children with atherosclerosis risk factors].

    Science.gov (United States)

    Sierakowska-Fijałek, Anna; Baj, Zbigniew; Kaczmarek, Piotr; Stepień, Mariusz; Rysz, Jacek

    2008-10-01

    Atherosclerosis begins in childhood. At present among numerous risk factors of atherosclerosis the role of hiperhomocysteinemia in development of cardiovascular heart disease is taken under consideration. Atherogenic effect of homocystein is related to its cytotoxin action, conducting to endothelial dysfunction and damage. It is correlated with increase of the lipid levels in the blood serum and change of expression of the soluble forms of adhesion molecules. The aim of this study was to estimate relations between the homocystein serum concentration, expression of the selected adhesion molecules and the lipid levels in the blood serum in children with atherosclerosis risk factors. The group consisted of 670 children, 76 of them had atherosclerosis risk factors. In further examination 48 children have taken a part, whose parents were agreed for theirs participation in the program. The comparative group composed of 25 children without the risk factors. We determined total cholesterol (TC), triglycerides (TG), LDL cholesterol fraction (LDL-C), HDL cholesterol fraction (HDL-C), serum homocysteine concentration (Hcy), the expression of the soluble forms of adhesion molecules (sCAM): sP-selectin and sVCAM-1 (vascular cell adhesion molecule-1). Obesity, hypertension and lipid disorders in the shape of higher concentration of TC, LDL-C, TG and lower HDL-C were the most frequent risk factors in the investigated children. No significant differences in serum homocysteine concentration were observed between the investigated groups. However, its concentration was significantly higher in children with two atherosclerosis risk factors. No significant differences in expression of s-VCAM-1 were observed in the investigated groups, concentration of sP-selectin was significantly higher in children with atherosclerosis risk factors (phomocysteine and chosen adhesion molecules in children with atherosclerosis risk factors might potentially constitute the marker of early

  1. Prevalence Estimates for Pharmacological Neuroenhancement in Austrian University Students: Its Relation to Health-Related Risk Attitude and the Framing Effect of Caffeine Tablets

    Directory of Open Access Journals (Sweden)

    Pavel Dietz

    2018-06-01

    Full Text Available Background: Pharmacological neuroenhancement (PN is defined as the use of illicit or prescription drugs by healthy individuals for cognitive-enhancing purposes. The present study aimed (i to investigate whether including caffeine tablets in the definition of PN within a questionnaire increases the PN prevalence estimate (framing effect, (ii to investigate whether the health-related risk attitude is increased in students who use PN.Materials and methods: Two versions of a paper-and-pencil questionnaire (first version included caffeine tablets in the definition of PN, the second excluded caffeine tablets were distributed among university students at the University of Graz, Austria. The unrelated question model (UQM was used to estimate the 12-month PN prevalence and the German version of the 30-item Domain-Specific Risk-Taking (DOSPERT scale to assess the health-related risk attitude. Moreover, large-sample z-tests (α = 0.05 were performed for comparing the PN prevalence estimates of two groups.Results: Two thousand four hundred and eighty-nine questionnaires were distributed and 2,284 (91.8% questionnaires were included in analysis. The overall PN prevalence estimate for all students was 11.9%. One-tailed large-sample z-tests revealed that the PN estimate for students with higher health-related risk attitude was significantly higher compared to students with lower health-related risk attitude (15.6 vs. 8.5%; z = 2.65, p = 0.004. Furthermore, when caffeine tablets were included into the example of PN, the prevalence estimate of PN was significantly higher compared to the version without caffeine tablets (14.9 vs. 9.0%; z = 2.20, p = 0.014.Discussion: This study revealed that the PN prevalence estimate increases when caffeine tablets are included in the definition of PN. Therefore, future studies investigating the prevalence of, and predictors for, PN should be performed and interpreted with respect to potential framing effects. This study further

  2. Estimating Risk Parameters

    OpenAIRE

    Aswath Damodaran

    1999-01-01

    Over the last three decades, the capital asset pricing model has occupied a central and often controversial place in most corporate finance analysts’ tool chests. The model requires three inputs to compute expected returns – a riskfree rate, a beta for an asset and an expected risk premium for the market portfolio (over and above the riskfree rate). Betas are estimated, by most practitioners, by regressing returns on an asset against a stock index, with the slope of the regression being the b...

  3. Risk factors for chronic undernutrition among children in India: Estimating relative importance, population attributable risk and fractions.

    Science.gov (United States)

    Corsi, Daniel J; Mejía-Guevara, Iván; Subramanian, S V

    2016-05-01

    Nearly 40% of the world's stunted children live in India and the prevalence of undernutrition has been persistently high in recent decades. Given numerous available interventions for reducing undernutrition in children, it is not clear of the relative importance of each within a multifactorial framework. We assess the simultaneous contribution of 15 known risk factors for child chronic undernutrition in India. Data are from the 3rd Indian National Family Health Survey (NFHS-3), a nationally representative cross-sectional survey undertaken in 2005-2006. The study population consisted of children aged 6-59 months [n = 26,842 (stunting/low height-for-age), n = 27,483 (underweight/low weight-for-age)]. Risk factors examined for their association with undernutrition were: vitamin A supplementation, vaccination, use of iodized salt, household air quality, improved sanitary facilities, safe disposal of stools, improved drinking water, prevalence of infectious disease, initiation of breastfeeding, dietary diversity, age at marriage, maternal BMI, height, education, and household wealth. Age/sex-adjusted and multivariable adjusted effect sizes (odds ratios) were calculated for risk factors along with Population Attributable Risks (PAR) and Fractions (PAF) using logistic regression. In the mutually adjusted models, the five most important predictors of childhood stunting/underweight were short maternal stature, mother having no education, households in lowest wealth quintile, poor dietary diversity, and maternal underweight. These five factors had a combined PAR of 67.2% (95% CI: 63.3-70.7) and 69.7% (95% CI: 66.3-72.8) for stunting and underweight, respectively. The remaining factors were associated with a combined PAR of 11.7% (95% CI: 6.0-17.4) and 15.1% (95% CI: 8.9-21.3) for stunting and underweight, respectively. Implementing strategies focused on broader progress on social circumstances and infrastructural domains as well as investments in nutrition specific

  4. Russia-specific relative risks and their effects on the estimated alcohol-attributable burden of disease.

    Science.gov (United States)

    Shield, Kevin D; Rehm, Jürgen

    2015-05-10

    Alcohol consumption is a major risk factor for the burden of disease globally. This burden is estimated using Relative Risk (RR) functions for alcohol from meta-analyses that use data from all countries; however, for Russia and surrounding countries, country-specific risk data may need to be used. The objective of this paper is to compare the estimated burden of alcohol consumption calculated using Russia-specific alcohol RRs with the estimated burden of alcohol consumption calculated using alcohol RRs from meta-analyses. Data for 2012 on drinking indicators were calculated based on the Global Information System on Alcohol and Health. Data for 2012 on mortality, Years of Life Lost, Years Lived with Disability, and Disability-Adjusted Life Years (DALYs) lost by cause were obtained by country from the World Health Organization. Alcohol Population-Attributable Fractions (PAFs) were calculated based on a risk modelling methodology from Russia. These PAFs were compared to PAFs calculated using methods applied for all other countries. The 95% Uncertainty Intervals (UIs) for the alcohol PAFs were calculated using a Monte Carlo-like method. Using Russia-specific alcohol RR functions, in Russia in 2012 alcohol caused an estimated 231,900 deaths (95% UI: 185,600 to 278,200) (70,800 deaths among women and 161,100 deaths among men) and 13,295,000 DALYs lost (95% UI: 11,242,000 to 15,348,000) (3,670,000 DALYs lost among women and 9,625,000 DALYs lost among men) among people 0 to 64 years of age. This compares to an estimated 165,600 deaths (95% UI: 97,200 to 228,100) (29,700 deaths among women and 135,900 deaths among men) and 10,623,000 DALYs lost (95% UI: 7,265,000 to 13,754,000) (1,783,000 DALYs lost among women and 8,840,000 DALYs lost among men) among people 0 to 64 years of age caused by alcohol when non-Russia-specific alcohol RRs were used. Results indicate that if the Russia-specific RRs are used when estimating the health burden attributable to alcohol consumption in

  5. Smoking-attributable medical expenditures by age, sex, and smoking status estimated using a relative risk approach☆

    Science.gov (United States)

    Maciosek, Michael V.; Xu, Xin; Butani, Amy L.; Pechacek, Terry F.

    2015-01-01

    Objective To accurately assess the benefits of tobacco control interventions and to better inform decision makers, knowledge of medical expenditures by age, gender, and smoking status is essential. Method We propose an approach to distribute smoking-attributable expenditures by age, gender, and cigarette smoking status to reflect the known risks of smoking. We distribute hospitalization days for smoking-attributable diseases according to relative risks of smoking-attributable mortality, and use the method to determine national estimates of smoking-attributable expenditures by age, sex, and cigarette smoking status. Sensitivity analyses explored assumptions of the method. Results Both current and former smokers ages 75 and over have about 12 times the smoking-attributable expenditures of their current and former smoker counterparts 35–54 years of age. Within each age group, the expenditures of formers smokers are about 70% lower than current smokers. In sensitivity analysis, these results were not robust to large changes to the relative risks of smoking-attributable mortality which were used in the calculations. Conclusion Sex- and age-group-specific smoking expenditures reflect observed disease risk differences between current and former cigarette smokers and indicate that about 70% of current smokers’ excess medical care costs is preventable by quitting. PMID:26051203

  6. Estimating cancer risk in relation to tritium exposure from routine operation of a nuclear-generating station in Pickering, Ontario.

    Science.gov (United States)

    Wanigaratne, S; Holowaty, E; Jiang, H; Norwood, T A; Pietrusiak, M A; Brown, P

    2013-09-01

    Evidence suggests that current levels of tritium emissions from CANDU reactors in Canada are not related to adverse health effects. However, these studies lack tritium-specific dose data and have small numbers of cases. The purpose of our study was to determine whether tritium emitted from a nuclear-generating station during routine operation is associated with risk of cancer in Pickering, Ontario. A retrospective cohort was formed through linkage of Pickering and north Oshawa residents (1985) to incident cancer cases (1985-2005). We examined all sites combined, leukemia, lung, thyroid and childhood cancers (6-19 years) for males and females as well as female breast cancer. Tritium estimates were based on an atmospheric dispersion model, incorporating characteristics of annual tritium emissions and meteorology. Tritium concentration estimates were assigned to each cohort member based on exact location of residence. Person-years analysis was used to determine whether observed cancer cases were higher than expected. Cox proportional hazards regression was used to determine whether tritium was associated with radiation-sensitive cancers in Pickering. Person-years analysis showed female childhood cancer cases to be significantly higher than expected (standardized incidence ratio [SIR] = 1.99, 95% confidence interval [CI]: 1.08-3.38). The issue of multiple comparisons is the most likely explanation for this finding. Cox models revealed that female lung cancer was significantly higher in Pickering versus north Oshawa (HR = 2.34, 95% CI: 1.23-4.46) and that tritium was not associated with increased risk. The improved methodology used in this study adds to our understanding of cancer risks associated with low-dose tritium exposure. Tritium estimates were not associated with increased risk of radiationsensitive cancers in Pickering.

  7. The need to estimate risks

    International Nuclear Information System (INIS)

    Pochin, E.E.

    1980-01-01

    In an increasing number of situations, it is becoming possible to obtain and compare numerical estimates of the biological risks involved in different alternative sources of action. In some cases these risks are similar in kind, as for example when the risk of including fatal cancer of the breast or stomach by x-ray screening of a population at risk, is compared with the risk of such cancers proving fatal if not detected by a screening programme. In other cases in which it is important to attempt a comparison, the risks are dissimilar in type, as when the safety of occupations involving exposure to radiation or chemical carcinogens is compared with that of occupations in which the major risks are from lung disease or from accidental injury and death. Similar problems of assessing the relative severity of unlike effects occur in any attempt to compare the total biological harm associated with a given output of electricity derived from different primary fuel sources, with its contributions both of occupation and of public harm. In none of these instances is the numerical frequency of harmful effects alone an adequate measure of total biological detriment, nor is such detriment the only factor which should influence decisions. Estimations of risk appear important however, since otherwise public health decisions are likely to be made on more arbitrary grounds, and public opinion will continue to be affected predominantly by the type rather than also by the size of risk. (author)

  8. Estimation of Dog-Bite Risk and Related Morbidity Among Personnel Working With Military Dogs.

    Science.gov (United States)

    Schermann, H; Eiges, N; Sabag, A; Kazum, E; Albagli, A; Salai, M; Shlaifer, A

    Soldiers serving in the Israel Defense Force Military Working Dogs (MWD) Unit spend many hours taming dogs' special skills, taking them on combat missions, and performing various dogkeeping activities. During this intensive work with the aggressive military dogs, bites are common, and some of them result in permanent disability. However, this phenomenon has not been quantified or reported as an occupational hazard. This was a retrospective cohort study based on self-administered questionnaires. Information was collected about soldiers' baseline demographics, duration of the experience of working with dogs, total number of bites they had, circumstances of bite events, and complications and medical treatment of each bite. Bite risk was quantified by incidence, mean time to first bite, and a Cox proportional hazards model. Rates of complications and the medical burden of bites were compared between combat soldiers and noncombat dogkeepers. Bite locations were presented graphically. Seventy-eight soldiers participated and reported on 139 bites. Mean time of working with dogs was 16 months (standard deviation, ±9.4 months). Overall bite incidence was 11 bites per 100 person-months; the mean time to first bite event was 6.3 months. The Cox proportional hazards model showed that none of baseline characteristics significantly increased bite hazard. About 90% of bites occurred during routine activities, and 3.3% occurred on combat missions. Only in 9% of bite events did soldiers observed the safety precautions code. Bite complications included fractures, need for intravenous antibiotic treatment and surgical repair, prominent scarring, diminished sensation, and stiffness of proximal joints. Bite complications were similar between combat soldiers and dogkeepers. Most bites (57%) were located on hands and arms. MWD bites are an occupational hazard resulting in significant medical burden. Hands and arms were most common bite locations. Observance of safety precautions may be

  9. Radiation in space: risk estimates

    International Nuclear Information System (INIS)

    Fry, R.J.M.

    2002-01-01

    The complexity of radiation environments in space makes estimation of risks more difficult than for the protection of terrestrial population. In deep space the duration of the mission, position of the solar cycle, number and size of solar particle events (SPE) and the spacecraft shielding are the major determinants of risk. In low-earth orbit missions there are the added factors of altitude and orbital inclination. Different radiation qualities such as protons and heavy ions and secondary radiations inside the spacecraft such as neutrons of various energies, have to be considered. Radiation dose rates in space are low except for short periods during very large SPEs. Risk estimation for space activities is based on the human experience of exposure to gamma rays and to a lesser extent X rays. The doses of protons, heavy ions and neutrons are adjusted to take into account the relative biological effectiveness (RBE) of the different radiation types and thus derive equivalent doses. RBE values and factors to adjust for the effect of dose rate have to be obtained from experimental data. The influence of age and gender on the cancer risk is estimated from the data from atomic bomb survivors. Because of the large number of variables the uncertainties in the probability of the effects are large. Information needed to improve the risk estimates includes: (1) risk of cancer induction by protons, heavy ions and neutrons; (2) influence of dose rate and protraction, particularly on potential tissue effects such as reduced fertility and cataracts; and (3) possible effects of heavy ions on the central nervous system. Risk cannot be eliminated and thus there must be a consensus on what level of risk is acceptable. (author)

  10. Toxoplasma gondii infection in Kyrgyzstan: seroprevalence, risk factor analysis, and estimate of congenital and AIDS-related toxoplasmosis.

    Directory of Open Access Journals (Sweden)

    Gulnara Minbaeva

    Full Text Available BACKGROUND: HIV-prevalence, as well as incidence of zoonotic parasitic diseases like cystic echinococcosis, has increased in the Kyrgyz Republic due to fundamental socio-economic changes after the breakdown of the Soviet Union. The possible impact on morbidity and mortality caused by Toxoplasma gondii infection in congenital toxoplasmosis or as an opportunistic infection in the emerging AIDS pandemic has not been reported from Kyrgyzstan. METHODOLOGY/PRINCIPAL FINDINGS: We screened 1,061 rural and 899 urban people to determine the seroprevalence of T. gondii infection in 2 representative but epidemiologically distinct populations in Kyrgyzstan. The rural population was from a typical agricultural district where sheep husbandry is a major occupation. The urban population was selected in collaboration with several diagnostic laboratories in Bishkek, the largest city in Kyrgyzstan. We designed a questionnaire that was used on all rural subjects so a risk-factor analysis could be undertaken. The samples from the urban population were anonymous and only data with regard to age and gender was available. Estimates of putative cases of congenital and AIDS-related toxoplasmosis in the whole country were made from the results of the serology. Specific antibodies (IgG against Triton X-100 extracted antigens of T. gondii tachyzoites from in vitro cultures were determined by ELISA. Overall seroprevalence of infection with T. gondii in people living in rural vs. urban areas was 6.2% (95%CI: 4.8-7.8 (adjusted seroprevalence based on census figures 5.1%, 95% CI 3.9-6.5, and 19.0% (95%CI: 16.5-21.7 (adjusted 16.4%, 95% CI 14.1-19.3, respectively, without significant gender-specific differences. The seroprevalence increased with age. Independently low social status increased the risk of Toxoplasma seropositivity while increasing numbers of sheep owned decreased the risk of seropositivity. Water supply, consumption of unpasteurized milk products or undercooked

  11. Methods for risk estimation in nuclear energy

    Energy Technology Data Exchange (ETDEWEB)

    Gauvenet, A [CEA, 75 - Paris (France)

    1979-01-01

    The author presents methods for estimating the different risks related to nuclear energy: immediate or delayed risks, individual or collective risks, risks of accidents and long-term risks. These methods have attained a highly valid level of elaboration and their application to other industrial or human problems is currently under way, especially in English-speaking countries.

  12. Estimating risks and relative risks in case-base studies under the assumptions of gene-environment independence and Hardy-Weinberg equilibrium.

    Directory of Open Access Journals (Sweden)

    Tina Tsz-Ting Chui

    Full Text Available Many diseases result from the interactions between genes and the environment. An efficient method has been proposed for a case-control study to estimate the genetic and environmental main effects and their interactions, which exploits the assumptions of gene-environment independence and Hardy-Weinberg equilibrium. To estimate the absolute and relative risks, one needs to resort to an alternative design: the case-base study. In this paper, the authors show how to analyze a case-base study under the above dual assumptions. This approach is based on a conditional logistic regression of case-counterfactual controls matched data. It can be easily fitted with readily available statistical packages. When the dual assumptions are met, the method is approximately unbiased and has adequate coverage probabilities for confidence intervals. It also results in smaller variances and shorter confidence intervals as compared with a previous method for a case-base study which imposes neither assumption.

  13. Estimating Risks and Relative Risks in Case-Base Studies under the Assumptions of Gene-Environment Independence and Hardy-Weinberg Equilibrium

    Science.gov (United States)

    Chui, Tina Tsz-Ting; Lee, Wen-Chung

    2014-01-01

    Many diseases result from the interactions between genes and the environment. An efficient method has been proposed for a case-control study to estimate the genetic and environmental main effects and their interactions, which exploits the assumptions of gene-environment independence and Hardy-Weinberg equilibrium. To estimate the absolute and relative risks, one needs to resort to an alternative design: the case-base study. In this paper, the authors show how to analyze a case-base study under the above dual assumptions. This approach is based on a conditional logistic regression of case-counterfactual controls matched data. It can be easily fitted with readily available statistical packages. When the dual assumptions are met, the method is approximately unbiased and has adequate coverage probabilities for confidence intervals. It also results in smaller variances and shorter confidence intervals as compared with a previous method for a case-base study which imposes neither assumption. PMID:25137392

  14. Estimation of the prevalence and distribution of HPV genotypes and identification of related risk factors among Turkish women

    Directory of Open Access Journals (Sweden)

    Mehmet Kulhan

    2017-09-01

    Full Text Available Aim of the study : The present study aims to estimate the prevalence and distribution of HPV genotypes and identify related risk factors among Turkish women. Material and methods : 11 624 Turkish women attending our gynaecological clinic and expressing a desire for access to cervical cancer screening were assessed during the years 2014–2016. Cervical specimens were collected and transported using the HC2 HPV DNA Collection Device (consisting of a cervical brush and digene Specimen Transport Medium. Results : Among these 11 624 individuals, positive HPV test results were obtained for 325 (2.79%, and negative results were observed for 11 299 (97.2%. The vast majority of patients were between the 3rd and 5th decades and the mean age of the patients was 44 ±9.12 (range 27–66. Among the HPV-positive women, 205 were positive for a single HPV type (205/325 = 63.1% of HPV infections; 205/11624 = 1.76% of all samples and 120 were positive for multiple types (120/325 = 36.9% of HPV infections; 120/11624 = 1.03% of all samples. The four most prevalent high-risk types were HPV 16, 31, 51 and 52, with frequencies of 11.25%, 7.83%, 6.06% and 3.16%, respectively. Conclusions : There appears to be geographic variation in the distribution of HPV genotypes. In this study, the four most prevalent high-risk types were HPV 16, 31, 51 and 52, with frequencies of 11.25%, 7.83%, 6.06% and 3.16%, respectively.

  15. Estimating the temporal and spatial risk of bluetongue related to the incursion of infected vectors into Switzerland

    Directory of Open Access Journals (Sweden)

    Griot C

    2008-10-01

    Full Text Available Abstract Background The design of veterinary and public health surveillance systems has been improved by the ability to combine Geographical Information Systems (GIS, mathematical models and up to date epidemiological knowledge. In Switzerland, an early warning system was developed for detecting the incursion of the bluetongue disease virus (BT and to monitor the frequency of its vectors. Based on data generated by this surveillance system, GIS and transmission models were used in order to determine suitable seasonal vector habitat locations and risk periods for a larger and more targeted surveillance program. Results Combined thematic maps of temperature, humidity and altitude were created to visualize the association with Culicoides vector habitat locations. Additional monthly maps of estimated basic reproduction number transmission rates (R0 were created in order to highlight areas of Switzerland prone to higher BT outbreaks in relation to both vector activity and transmission levels. The maps revealed several foci of higher risk areas, especially in northern parts of Switzerland, suitable for both vector presence and vector activity for 2006. Results showed a variation of R0 values comparing 2005 and 2006 yet suggested that Switzerland was at risk of an outbreak of BT, especially if the incursion arrived in a suitable vector activity period. Since the time of conducting these analyses, this suitability has proved to be the case with the recent outbreaks of BT in northern Switzerland. Conclusion Our results stress the importance of environmental factors and their effect on the dynamics of a vector-borne disease. In this case, results of this model were used as input parameters for creating a national targeted surveillance program tailored to both the spatial and the temporal aspect of the disease and its vectors. In this manner, financial and logistic resources can be used in an optimal way through seasonally and geographically adjusted

  16. Risk estimates for bone

    International Nuclear Information System (INIS)

    Schlenker, R.A.

    1982-01-01

    Bone sarcoma data for 226 228 Ra and 224 Ra are analyzed within the dosage ranges where the observed risk is zero. The uncertainty in the risk may be effectively illustrated by using pairs of functions based on a statistically-based measure of confidence. For radiation protection, the appropriate measure of risk is cumulative incidence in the presence of competing risks, as this takes into account the reduction of radiation effects brought about by natural mortality

  17. Radiation risk estimation

    International Nuclear Information System (INIS)

    Roberts, P.B.

    1981-11-01

    This report outlines the major publications between 1976 and 1981 that have contributed to the evolution of the way in which radiation risks (cancer and hereditary birth defects) are assessed. The publications include the latest findings of the UNSCEAR, BEIR and ICRP committees, epidemiological studies at low doses and new assessments of the doses received by the Japanese A-bomb survivors. This report is not a detailed critique of those publications, but it highlights the impact of their findings on risk assessment

  18. Ecological risk estimation

    International Nuclear Information System (INIS)

    Bartell, S.M.; Gardner, R.H.; O'Neill, R.V.

    1992-01-01

    Ecological risk assessment, the process that evaluates the likelihood that adverse ecological effects may occur or are occurring as a result of exposure to one or more stressors, is being developed by the US EPA as a tool for decision making. This book presents one approach to risk assessment-that of applying laboratory toxicity data within an ecosystem model to predict the potential ecological consequences of toxic chemicals. Both Standard Water Column Model (SWACOM), using zooplankton and fish, and Monte Carlo simulations are discussed in detail, along with quantitative explanations for many responses. Simplifying assumptions are explicitly presented. The final chapter discusses strengths, weaknesses, and future directions of the approach. The book is appropriate for anyone who does or uses ecological risk assessment methodologies

  19. Comparison of robustness to outliers between robust poisson models and log-binomial models when estimating relative risks for common binary outcomes: a simulation study.

    Science.gov (United States)

    Chen, Wansu; Shi, Jiaxiao; Qian, Lei; Azen, Stanley P

    2014-06-26

    To estimate relative risks or risk ratios for common binary outcomes, the most popular model-based methods are the robust (also known as modified) Poisson and the log-binomial regression. Of the two methods, it is believed that the log-binomial regression yields more efficient estimators because it is maximum likelihood based, while the robust Poisson model may be less affected by outliers. Evidence to support the robustness of robust Poisson models in comparison with log-binomial models is very limited. In this study a simulation was conducted to evaluate the performance of the two methods in several scenarios where outliers existed. The findings indicate that for data coming from a population where the relationship between the outcome and the covariate was in a simple form (e.g. log-linear), the two models yielded comparable biases and mean square errors. However, if the true relationship contained a higher order term, the robust Poisson models consistently outperformed the log-binomial models even when the level of contamination is low. The robust Poisson models are more robust (or less sensitive) to outliers compared to the log-binomial models when estimating relative risks or risk ratios for common binary outcomes. Users should be aware of the limitations when choosing appropriate models to estimate relative risks or risk ratios.

  20. Estimation of the radiological risk related to the presence of radon 222 in a hydrotherapy centre in Tunisia

    International Nuclear Information System (INIS)

    Labidi, S; Essafi, F; Mahjoubi, H

    2006-01-01

    The 222 Rn concentration in air was measured in a thermal water spa used as a hydrotherapy centre in Tunisia. The associated health risk for employees and patients due to the inhalation of 222 Rn and its progeny was estimated. A protection scheme for the employees of the spas has been designed. Results show that the 222 Rn concentration varies in the range 33-589 Bq m -3 . The 222 Rn concentrations measured in the present study show lower values in comparison to those reported for thermal spas in other countries. The 222 Rn concentration in different rooms of the spa depends mainly on the ventilation rate. A model based on a dosimetric approach was adopted to estimate the radon risk considering the 222 Rn concentration, the time spent in the spa, and the radioactive equilibrium factor F. The annual effective dose was found to vary between 0.2 and 1.7 mSv for workers while the range for patients was from 2.8 x 10 -4 to 1.1 x 10 -4 mSv. These values are within the ICRP recommended values. (note)

  1. Estimation of the radiological risk related to the presence of radon 222 in a hydrotherapy centre in Tunisia

    Energy Technology Data Exchange (ETDEWEB)

    Labidi, S [Institut Superieur des Technologies Medicales de Tunis (Tunisia); Essafi, F [Faculte de Medecine de Tunis, Section de Biophysique, Tunis (Tunisia); Mahjoubi, H [Institut Superieur des Technologies Medicales de Tunis (Tunisia)

    2006-09-15

    The {sup 222}Rn concentration in air was measured in a thermal water spa used as a hydrotherapy centre in Tunisia. The associated health risk for employees and patients due to the inhalation of {sup 222}Rn and its progeny was estimated. A protection scheme for the employees of the spas has been designed. Results show that the {sup 222}Rn concentration varies in the range 33-589 Bq m{sup -3}. The {sup 222}Rn concentrations measured in the present study show lower values in comparison to those reported for thermal spas in other countries. The {sup 222}Rn concentration in different rooms of the spa depends mainly on the ventilation rate. A model based on a dosimetric approach was adopted to estimate the radon risk considering the {sup 222}Rn concentration, the time spent in the spa, and the radioactive equilibrium factor F. The annual effective dose was found to vary between 0.2 and 1.7 mSv for workers while the range for patients was from 2.8 x 10{sup -4} to 1.1 x 10{sup -4} mSv. These values are within the ICRP recommended values. (note)

  2. A Bayesian model averaging approach for estimating the relative risk of mortality associated with heat waves in 105 U.S. cities.

    Science.gov (United States)

    Bobb, Jennifer F; Dominici, Francesca; Peng, Roger D

    2011-12-01

    Estimating the risks heat waves pose to human health is a critical part of assessing the future impact of climate change. In this article, we propose a flexible class of time series models to estimate the relative risk of mortality associated with heat waves and conduct Bayesian model averaging (BMA) to account for the multiplicity of potential models. Applying these methods to data from 105 U.S. cities for the period 1987-2005, we identify those cities having a high posterior probability of increased mortality risk during heat waves, examine the heterogeneity of the posterior distributions of mortality risk across cities, assess sensitivity of the results to the selection of prior distributions, and compare our BMA results to a model selection approach. Our results show that no single model best predicts risk across the majority of cities, and that for some cities heat-wave risk estimation is sensitive to model choice. Although model averaging leads to posterior distributions with increased variance as compared to statistical inference conditional on a model obtained through model selection, we find that the posterior mean of heat wave mortality risk is robust to accounting for model uncertainty over a broad class of models. © 2011, The International Biometric Society.

  3. The Omega-3 Index and relative risk for coronary heart disease mortality: Estimation from 10 cohort studies.

    Science.gov (United States)

    Harris, William S; Del Gobbo, Liana; Tintle, Nathan L

    2017-07-01

    A recent 19-cohort meta-analysis examined the relationships between biomarkers of omega-3 fatty acids and risk for coronary heart disease (CHD). That study did not, however, report hazard ratios (HRs) specifically as a function of erythrocyte eicosapentaenoic (EPA) plus docosahexaenoic (DHA) levels, a metric called the Omega-3 Index in which EPA + DHA content is expressed as a percent of total fatty acids. The Omega-3 Index has been used in several recent studies and is a validated biomarker of omega-3 fatty acid tissue levels, but additional data are needed to confirm (or refute) the originally-proposed clinical cut-points of Omega-3 Index and median quintile values for this metric across 10 of the cohorts for which the needed data were available. The overall mean (SD) for the Omega-3 Index in these 10 cohort studies was 6.1% (2.1%), and the HR for a 1-SD increase was 0.85 (95% confidence interval, 0.80-0.91). Median quintile 1 and 5 levels were 4.2% vs. 8.3%, respectively. Based on these values, we estimate that risk for fatal CHD would have been reduced by about 30% moving from an Omega-3 Index of 4%-8%. These findings support the use of 8% as reasonable therapeutic targets for the Omega-3 Index. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Model linear absolute and relative risk estimates for cancer induced by ionizing radiation in Mexican cohort of occupationally exposed

    International Nuclear Information System (INIS)

    Alvarez, R.J.T.; Trovar, M.V.M; González, J.F.

    2015-01-01

    From the rate of natural mortality m s cancer (t) for every 100 thousand habitants, modeled by a fourth-degree polynomial function of the age data of the Mexican population (2008), and assuming: a) a relationship 1: 5 of cancer induced radiation respect to presented spontaneously, b) a size of initial cohort No = 100 k SOPs, c) a speed of H E = (2 ± 1) mSv / received by the SOPs from 18 to 65 years, d) a latency of 8 years for cancer induction after irradiation, e) a time tracking cohort to 75 years, f) and taking the coefficients absolute and relative risk BEIRs induction of cancer models II and VII (excluding leukemia); It determined: BEIR II for a total of 125 and 400 deaths from cancer for absolute and relative linear models respectively. For BEIR VII has a number of fatal cases of 345 and 927 deaths respectively for absolute and relative linear model cancer. [es

  5. Decreasing Relative Risk Premium

    DEFF Research Database (Denmark)

    Hansen, Frank

    relative risk premium in the small implies decreasing relative risk premium in the large, and decreasing relative risk premium everywhere implies risk aversion. We finally show that preferences with decreasing relative risk premium may be equivalently expressed in terms of certain preferences on risky......We consider the risk premium demanded by a decision maker with wealth x in order to be indifferent between obtaining a new level of wealth y1 with certainty, or to participate in a lottery which either results in unchanged present wealth or a level of wealth y2 > y1. We define the relative risk...... premium as the quotient between the risk premium and the increase in wealth y1–x which the decision maker puts on the line by choosing the lottery in place of receiving y1 with certainty. We study preferences such that the relative risk premium is a decreasing function of present wealth, and we determine...

  6. Risk estimation using probability machines

    Science.gov (United States)

    2014-01-01

    Background Logistic regression has been the de facto, and often the only, model used in the description and analysis of relationships between a binary outcome and observed features. It is widely used to obtain the conditional probabilities of the outcome given predictors, as well as predictor effect size estimates using conditional odds ratios. Results We show how statistical learning machines for binary outcomes, provably consistent for the nonparametric regression problem, can be used to provide both consistent conditional probability estimation and conditional effect size estimates. Effect size estimates from learning machines leverage our understanding of counterfactual arguments central to the interpretation of such estimates. We show that, if the data generating model is logistic, we can recover accurate probability predictions and effect size estimates with nearly the same efficiency as a correct logistic model, both for main effects and interactions. We also propose a method using learning machines to scan for possible interaction effects quickly and efficiently. Simulations using random forest probability machines are presented. Conclusions The models we propose make no assumptions about the data structure, and capture the patterns in the data by just specifying the predictors involved and not any particular model structure. So they do not run the same risks of model mis-specification and the resultant estimation biases as a logistic model. This methodology, which we call a “risk machine”, will share properties from the statistical machine that it is derived from. PMID:24581306

  7. Comments on mutagenesis risk estimation

    International Nuclear Information System (INIS)

    Russell, W.L.

    1976-01-01

    Several hypotheses and concepts have tended to oversimplify the problem of mutagenesis and can be misleading when used for genetic risk estimation. These include: the hypothesis that radiation-induced mutation frequency depends primarily on the DNA content per haploid genome, the extension of this concept to chemical mutagenesis, the view that, since DNA is DNA, mutational effects can be expected to be qualitatively similar in all organisms, the REC unit, and the view that mutation rates from chronic irradiation can be theoretically and accurately predicted from acute irradiation data. Therefore, direct determination of frequencies of transmitted mutations in mammals continues to be important for risk estimation, and the specific-locus method in mice is shown to be not as expensive as is commonly supposed for many of the chemical testing requirements

  8. Decreasing relative risk premium

    DEFF Research Database (Denmark)

    Hansen, Frank

    2007-01-01

    such that the corresponding relative risk premium is a decreasing function of present wealth, and we determine the set of associated utility functions. We find a new characterization of risk vulnerability and determine a large set of utility functions, closed under summation and composition, which are both risk vulnerable...

  9. Estimation of soil erosion risk within an important agricultural sub-watershed in Bursa, Turkey, in relation to rapid urbanization.

    Science.gov (United States)

    Ozsoy, Gokhan; Aksoy, Ertugrul

    2015-07-01

    This paper integrates the Revised Universal Soil Loss Equation (RUSLE) with a GIS model to investigate the spatial distribution of annual soil loss and identify areas of soil erosion risk in the Uluabat sub-watershed, an important agricultural site in Bursa Province, Turkey. The total soil loss from water erosion was 473,274 Mg year(-1). Accordingly, 60.3% of the surveyed area was classified into a very low erosion risk class while 25.7% was found to be in high and severe erosion risk classes. Soil loss had a close relationship with land use and topography. The most severe erosion risk typically occurs on ridges and steep slopes where agriculture, degraded forest, and shrubs are the main land uses and cover types. Another goal of this study was to use GIS to reveal the multi-year urbanization status caused by rapid urbanization that constitutes another soil erosion risk in this area. Urbanization has increased by 57.7% and the most areal change was determined in class I lands at a rate of 80% over 25 years. Urbanization was identified as one of the causes of excessive soil loss in the study area.

  10. Residual risk over-estimated

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    The way nuclear power plants are built practically excludes accidents with serious consequences. This is attended to by careful selection of material, control of fabrication and regular retesting as well as by several safety systems working independently. But the remaining risk, a 'hypothetic' uncontrollable incident with catastrophic effects is the main subject of the discussion on the peaceful utilization of nuclear power. The this year's 'Annual Meeting on Nuclear Engineering' in Mannheim and the meeting 'Reactor Safety Research' in Cologne showed, that risk studies so far were too pessimistic. 'Best estimate' calculations suggest that core melt-down accidents only occur if almost all safety systems fail, that accidents take place much more slowly, and that the release of radioactive fission products is by several magnitudes lower than it was assumed until now. (orig.) [de

  11. Fuel related risks; Braenslerisker

    Energy Technology Data Exchange (ETDEWEB)

    Englund, Jessica; Sernhed, Kerstin; Nystroem, Olle; Graveus, Frank (Grontmij AB, (Sweden))

    2012-02-15

    The project, within which this work report was prepared, aimed to complement the Vaermeforsk publication 'Handbook of fuels' on fuel related risks and measures to reduce the risks. The fuels examined in this project where the fuels included in the first version of the handbook from 2005 plus four additional fuels that will be included in the second and next edition of the handbook. Following fuels were included: woodfuels (sawdust, wood chips, powder, briquettes), slash, recycled wood, salix, bark, hardwood, stumps, straw, reed canary grass, hemp, cereal, cereal waste, olive waste, cocoa beans, citrus waste, shea, sludge, forest industrial sludge, manure, Paper Wood Plastic, tyre, leather waste, cardboard rejects, meat and bone meal, liquid animal and vegetable wastes, tall oil pitch, peat, residues from food industry, biomal (including slaughterhouse waste) and lignin. The report includes two main chapters; a general risk chapter and a chapter of fuel specific risks. The first one deals with the general concept of risk, it highlights laws and rules relevant for risk management and it discuss general risks that are related to the different steps of fuel handling, i.e. unloading, storing, processing the fuel, transportation within the facility, combustion and handling of ashes. The information that was used to produce this chapter was gathered through a literature review, site visits, and the project group's experience from risk management. The other main chapter deals with fuel-specific risks and the measures to reduce the risks for the steps of unloading, storing, processing the fuel, internal transportation, combustion and handling of the ashes. Risks and measures were considered for all the biofuels included in the second version in the handbook of fuels. Information about the risks and risk management was gathered through interviews with people working with different kinds of fuels in electricity and heat plants in Sweden. The information from

  12. Estimate of the uncertainties in the relative risk of secondary malignant neoplasms following proton therapy and intensity-modulated photon therapy

    International Nuclear Information System (INIS)

    Fontenot, Jonas D; Bloch, Charles; Followill, David; Titt, Uwe; Newhauser, Wayne D

    2010-01-01

    Theoretical calculations have shown that proton therapy can reduce the incidence of radiation-induced secondary malignant neoplasms (SMN) compared with photon therapy for patients with prostate cancer. However, the uncertainties associated with calculations of SMN risk had not been assessed. The objective of this study was to quantify the uncertainties in projected risks of secondary cancer following contemporary proton and photon radiotherapies for prostate cancer. We performed a rigorous propagation of errors and several sensitivity tests to estimate the uncertainty in the ratio of relative risk (RRR) due to the largest contributors to the uncertainty: the radiation weighting factor for neutrons, the dose-response model for radiation carcinogenesis and interpatient variations in absorbed dose. The interval of values for the radiation weighting factor for neutrons and the dose-response model were derived from the literature, while interpatient variations in absorbed dose were taken from actual patient data. The influence of each parameter on a baseline RRR value was quantified. Our analysis revealed that the calculated RRR was insensitive to the largest contributors to the uncertainty. Uncertainties in the radiation weighting factor for neutrons, the shape of the dose-risk model and interpatient variations in therapeutic and stray doses introduced a total uncertainty of 33% to the baseline RRR calculation.

  13. Psychological methods of subjective risk estimates

    International Nuclear Information System (INIS)

    Zimolong, B.

    1980-01-01

    Reactions to situations involving risks can be divided into the following parts/ perception of danger, subjective estimates of the risk and risk taking with respect to action. Several investigations have compared subjective estimates of the risk with an objective measure of that risk. In general there was a mis-match between subjective and objective measures of risk, especially, objective risk involved in routine activities is most commonly underestimated. This implies, for accident prevention, that attempts must be made to induce accurate subjective risk estimates by technical and behavioural measures. (orig.) [de

  14. Estimating risks of radiotherapy complications as part of informed consent: the high degree of variability between radiation oncologists may be related to experience

    International Nuclear Information System (INIS)

    Shakespeare, Thomas Philip; Dwyer, Mary; Mukherjee, Rahul; Yeghiaian-Alvandi, Roland; Gebski, Val

    2002-01-01

    Purpose: Estimating the risks of radiotherapy (RT) toxicity is important for informed consent; however, the consistency in estimates has not been studied. This study aimed to explore the variability and factors affecting risk estimates (REs). Methods and Materials: A survey was mailed to Australian radiation oncologists, who were asked to estimate risks of RT complications given 49 clinical scenarios. The REs were assessed for association with oncologist experience, subspecialization, and private practice. Results: The REs were extremely variable, with a 50-fold median variability. The least variability (sevenfold) was for estimates of late, small intestinal perforation/obstruction after a one-third volume received 50 Gy with concurrent 5-fluorouracil (RE range 5-35%). The variation between the smallest and largest REs in 17 scenarios was ≥100-fold. The years of experience was significantly associated with REs of soft/connective-tissue toxicity (p=0.01) but inversely associated with estimates of neurologic/central nervous system toxicity (p=0.08). Ninety-six percent of respondents believed REs were important to RT practice; only 24% rated evidence to support their estimates as good. Sixty-seven percent believed national/international groups should pursue the issue further. Conclusion: Enormous variability exists in REs for normal tissue complications due to RT that is influenced by the years of experience. Risk estimation is perceived as an important issue without a good evidence base. Additional studies are strongly recommended

  15. [The concept of risk and its estimation].

    Science.gov (United States)

    Zocchetti, C; Della Foglia, M; Colombi, A

    1996-01-01

    The concept of risk, in relation to human health, is a topic of primary interest for occupational health professionals. A new legislation recently established in Italy (626/94) according to European Community directives in the field of Preventive Medicine, called attention to this topic, and in particular to risk assessment and evaluation. Motivated by this context and by the impression that the concept of risk is frequently misunderstood, the present paper has two aims: the identification of the different meanings of the term "risk" in the new Italian legislation and the critical discussion of some commonly used definitions; and the proposal of a general definition, with the specification of a mathematical expression for quantitative risk estimation. The term risk (and risk estimation, assessment, or evaluation) has mainly referred to three different contexts: hazard identification, exposure assessment, and adverse health effects occurrence. Unfortunately, there are contexts in the legislation in which it is difficult to identify the true meaning of the term. This might cause equivocal interpretations and erroneous applications of the law because hazard evaluation, exposure assessment, and adverse health effects identification are completely different topics that require integrated but distinct approaches to risk management. As far as a quantitative definition of risk is of concern, we suggest an algorithm which connects the three basic risk elements (hazard, exposure, adverse health effects) by means of their probabilities of occurrence: the probability of being exposed (to a definite dose) given that a specific hazard is present (Pr(e[symbol: see text]p)), and the probability of occurrence of an adverse health effect as a consequence of that exposure (Pr(d[symbol: see text]e)). Using these quantitative components, risk can be defined as a sequence of measurable events that starts with hazard identification and terminates with disease occurrence; therefore, the

  16. Contemporary risk estimates of three HbA1c variables in relation to heart failure following diagnosis of type 2 diabetes.

    Science.gov (United States)

    Skrtic, Stanko; Cabrera, Claudia; Olsson, Marita; Schnecke, Volker; Lind, Marcus

    2017-03-01

    We evaluated the association between glycaemic control and the risk of heart failure (HF) in a contemporary cohort of persons followed after diagnosis of type 2 diabetes (T2D). Persons with T2D diagnosed between 1998 and 2012 were retrieved from the Clinical Practice Research Data Link in the UK and followed from diagnosis until the event of HF, mortality, drop out from the database due to any other reason, or the end of the study on 1 July 2015. The association between each of three different haemoglobin A 1C (HbA 1c ) metrics and HF was estimated using adjusted proportional hazard models. In the overall cohort (n=94 332), the increased risk for HF per 1% (10 mmol/mol) increase in HbA 1c was 1.15 (95% CI 1.13 to 1.18) for updated mean HbA 1c , and 1.06 (1.04 to 1.07) and 1.06 (1.04 to 1.08) for baseline HbA 1c and updated latest HbA 1c , respectively. When categorised, the hazard risk (HR) for the updated mean HbA 1c in relation to HF became higher than for baseline and updated latest HbA 1c above HbA 1c levels of 9%, but did not differ at lower HbA 1c levels. The updated latest variable showed an increased risk for HbA 1c <6% (42 mmol/mol) of 1.16 (1.07 to 1.25), relative category 6-7%, while the HRs for updated mean and baseline HbA 1c showed no such J-shaped pattern. Hyperglycaemia is still a risk factor for HF in persons with T2D of similar magnitude as in earlier cohorts. Such a relationship exists for current glycaemic levels, at diagnosis and the overall level but the pattern differs for these variables. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  17. Impact of risk factors on cardiovascular risk: a perspective on risk estimation in a Swiss population.

    Science.gov (United States)

    Chrubasik, Sigrun A; Chrubasik, Cosima A; Piper, Jörg; Schulte-Moenting, Juergen; Erne, Paul

    2015-01-01

    In models and scores for estimating cardiovascular risk (CVR), the relative weightings given to blood pressure measurements (BPMs), and biometric and laboratory variables are such that even large differences in blood pressure lead to rather low differences in the resulting total risk when compared with other concurrent risk factors. We evaluated this phenomenon based on the PROCAM score, using BPMs made by volunteer subjects at home (HBPMs) and automated ambulatory BPMs (ABPMs) carried out in the same subjects. A total of 153 volunteers provided the data needed to estimate their CVR by means of the PROCAM formula. Differences (deltaCVR) between the risk estimated by entering the ABPM and that estimated with the HBPM were compared with the differences (deltaBPM) between the ABPM and the corresponding HBPM. In addition to the median values (= second quartile), the first and third quartiles of blood pressure profiles were also considered. PROCAM risk values were converted to European Society of Cardiology (ESC) risk values and all participants were assigned to the risk groups low, medium and high. Based on the PROCAM score, 132 participants had a low risk for suffering myocardial infarction, 16 a medium risk and 5 a high risk. The calculated ESC scores classified 125 participants into the low-risk group, 26 into the medium- and 2 into the high-risk group for death from a cardiovascular event. Mean ABPM tended to be higher than mean HBPM. Use of mean systolic ABPM or HBPM in the PROCAM formula had no major impact on the risk level. Our observations are in agreement with the rather low weighting of blood pressure as risk determinant in the PROCAM score. BPMs assessed with different methods had relatively little impact on estimation of cardiovascular risk in the given context of other important determinants. The risk calculations in our unselected population reflect the given classification of Switzerland as a so-called cardiovascular "low risk country".

  18. Methods to estimate the genetic risk

    International Nuclear Information System (INIS)

    Ehling, U.H.

    1989-01-01

    The estimation of the radiation-induced genetic risk to human populations is based on the extrapolation of results from animal experiments. Radiation-induced mutations are stochastic events. The probability of the event depends on the dose; the degree of the damage dose not. There are two main approaches in making genetic risk estimates. One of these, termed the direct method, expresses risk in terms of expected frequencies of genetic changes induced per unit dose. The other, referred to as the doubling dose method or the indirect method, expresses risk in relation to the observed incidence of genetic disorders now present in man. The advantage of the indirect method is that not only can Mendelian mutations be quantified, but also other types of genetic disorders. The disadvantages of the method are the uncertainties in determining the current incidence of genetic disorders in human and, in addition, the estimasion of the genetic component of congenital anomalies, anomalies expressed later and constitutional and degenerative diseases. Using the direct method we estimated that 20-50 dominant radiation-induced mutations would be expected in 19 000 offspring born to parents exposed in Hiroshima and Nagasaki, but only a small proportion of these mutants would have been detected with the techniques used for the population study. These methods were used to predict the genetic damage from the fallout of the reactor accident at Chernobyl in the vicinity of Southern Germany. The lack of knowledge for the interaction of chemicals with ionizing radiation and the discrepancy between the high safety standards for radiation protection and the low level of knowledge for the toxicological evaluation of chemical mutagens will be emphasized. (author)

  19. Catastrophic healthcare expenditure and poverty related to out-of-pocket payments for healthcare in Bangladesh-an estimation of financial risk protection of universal health coverage.

    Science.gov (United States)

    Khan, Jahangir A M; Ahmed, Sayem; Evans, Timothy G

    2017-10-01

    The Sustainable Development Goals target to achieve Universal Health Coverage (UHC), including financial risk protection (FRP) among other dimensions. There are four indicators of FRP, namely incidence of catastrophic health expenditure (CHE), mean positive catastrophic overshoot, incidence of impoverishment and increase in the depth of poverty occur for high out-of-pocket (OOP) healthcare spending. OOP spending is the major payment strategy for healthcare in most low-and-middle-income countries, such as Bangladesh. Large and unpredictable health payments can expose households to substantial financial risk and, at their most extreme, can result in poverty. The aim of this study was to estimate the impact of OOP spending on CHE and poverty, i.e. status of FRP for UHC in Bangladesh. A nationally representative Household Income and Expenditure Survey 2010 was used to determine household consumption expenditure and health-related spending in the last 30 days. Mean CHE headcount and its concentration indices (CI) were calculated. The propensity of facing CHE for households was predicted by demographic and socioeconomic characteristics. The poverty headcount was estimated using 'total household consumption expenditure' and such expenditure without OOP payments for health in comparison with the poverty-line measured by cost of basic need. In absolute values, a pro-rich distribution of OOP payment for healthcare was found in urban and rural Bangladesh. At the 10%-threshold level, in total 14.2% of households faced CHE with 1.9% overshoot. 16.5% of the poorest and 9.2% of the richest households faced CHE. An overall pro-poor distribution was found for CHE (CI = -0.064) in both urban and rural households, while the former had higher CHE incidences. The poverty headcount increased by 3.5% (5.1 million individuals) due to OOP payments. Reliance on OOP payments for healthcare in Bangladesh should be reduced for poverty alleviation in urban and rural Bangladesh in order to

  20. Development of cancer risk estimates from epidemiologic studies

    International Nuclear Information System (INIS)

    Webster, E.W.

    1983-01-01

    Radiation risk estimates may be made for an increase in mortality from, or for an increase in incidence of, particular types of disease. For both endpoints, two numerical systems of risk expression are used: the absolute risk system (usually the excess deaths or cases per million persons per year per rad), and the relative risk system (usually excess deaths or cases per year per rad expressed as a percentage of those normally expected). Risks may be calculated for specific age groups or for a general population. An alternative in both risk systems is the estimation of cumulative of lifetime risk rather than annual risk (e.g. in excess deaths per million per rad over a specified long period including the remainder of lifespan). The derivation of both absolute and relative risks is illustrated by examples. The effects on risk estimates of latent period, follow-up time, age at exposure and age standardization within dose groups are illustrated. The dependence of the projected cumulative (lifetime) risk on the adoption of a constant absolute risk or constant relative risk is noted. The use of life-table data in the adjustment of cumulative risk for normal mortality following single or annual doses is briefly discussed

  1. Risk estimates for exposure to alpha emitters

    International Nuclear Information System (INIS)

    1982-07-01

    The primary scope of this report is to evaluate the risk of lung cancer from occupational exposure to short-lived daughters of radon and thoron. The Subcommittee on Risk Estimates considers that inhalation of radon and thoron daughters is the major radiation hazard from alpha radiation in uranium mining. The secondary scope of this report is the consideration of the applicability of the risk estimates derived from miners to the general public. The risk to members of the public from radium-226 in drinking water is also considered. Some research requirments are suggested

  2. Risk Probability Estimating Based on Clustering

    DEFF Research Database (Denmark)

    Chen, Yong; Jensen, Christian D.; Gray, Elizabeth

    2003-01-01

    of prior experiences, recommendations from a trusted entity or the reputation of the other entity. In this paper we propose a dynamic mechanism for estimating the risk probability of a certain interaction in a given environment using hybrid neural networks. We argue that traditional risk assessment models...... from the insurance industry do not directly apply to ubiquitous computing environments. Instead, we propose a dynamic mechanism for risk assessment, which is based on pattern matching, classification and prediction procedures. This mechanism uses an estimator of risk probability, which is based...

  3. Risk Aversion Relates to Cognitive Ability

    DEFF Research Database (Denmark)

    Andersson, Ola; Holm, Håkan J.; Tyran, Jean-Robert Karl

    2016-01-01

    Recent experimental studies suggest that risk aversion is negatively related to cognitive ability. In this paper we report evidence that this relation might be spurious. We recruit a large subject pool drawn from the general Danish population for our experiment. By presenting subjects with choice...... tasks that vary the bias induced by random choices, we are able to generate both negative and positive correlations between risk aversion and cognitive ability. Structural estimation allowing for heterogeneity of noise yields no significant relation between risk aversion and cognitive ability. Our...... results suggest that cognitive ability is related to random decision making, rather than to risk preferences....

  4. Risk aversion relates to cognitive ability

    DEFF Research Database (Denmark)

    Andersson, Ola; Holm, Håkan J.; Tyran, Jean-Robert Karl

    Recent experimental studies suggest that risk aversion is negatively related to cognitive ability. In this paper we report evidence that this relation might be spurious. We recruit a large subject pool drawn from the general Danish population for our experiment. By presenting subjects with choice...... tasks that vary the bias induced by random choices, we are able to generate both negative and positive correlations between risk aversion and cognitive ability. Structural estimation allowing for heterogeneity of noise yields no significant relation between risk aversion and cognitive ability. Our...... results suggest that cognitive ability is related to random decision making rather than to risk preferences....

  5. Uranium mill tailings and risk estimation

    International Nuclear Information System (INIS)

    Marks, S.

    1984-04-01

    Work done in estimating projected health effects for persons exposed to mill tailings at vicinity properties is described. The effect of the reassessment of exposures at Hiroshima and Nagasaki on the risk estimates for gamma radiation is discussed. A presentation of current results in the epidemiological study of Hanford workers is included. 2 references

  6. Graphs to estimate an individualized risk of breast cancer.

    Science.gov (United States)

    Benichou, J; Gail, M H; Mulvihill, J J

    1996-01-01

    Clinicians who counsel women about their risk for developing breast cancer need a rapid method to estimate individualized risk (absolute risk), as well as the confidence limits around that point. The Breast Cancer Detection Demonstration Project (BCDDP) model (sometimes called the Gail model) assumes no genetic model and simultaneously incorporates five risk factors, but involves cumbersome calculations and interpolations. This report provides graphs to estimate the absolute risk of breast cancer from the BCDDP model. The BCDDP recruited 280,000 women from 1973 to 1980 who were monitored for 5 years. From this cohort, 2,852 white women developed breast cancer and 3,146 controls were selected, all with complete risk-factor information. The BCDDP model, previously developed from these data, was used to prepare graphs that relate a specific summary relative-risk estimate to the absolute risk of developing breast cancer over intervals of 10, 20, and 30 years. Once a summary relative risk is calculated, the appropriate graph is chosen that shows the 10-, 20-, or 30-year absolute risk of developing breast cancer. A separate graph gives the 95% confidence limits around the point estimate of absolute risk. Once a clinician rules out a single gene trait that predisposes to breast cancer and elicits information on age and four risk factors, the tables and figures permit an estimation of a women's absolute risk of developing breast cancer in the next three decades. These results are intended to be applied to women who undergo regular screening. They should be used only in a formal counseling program to maximize a woman's understanding of the estimates and the proper use of them.

  7. Modeling and E-M estimation of haplotype-specific relative risks from genotype data for a case-control study of unrelated individuals.

    Science.gov (United States)

    Stram, Daniel O; Leigh Pearce, Celeste; Bretsky, Phillip; Freedman, Matthew; Hirschhorn, Joel N; Altshuler, David; Kolonel, Laurence N; Henderson, Brian E; Thomas, Duncan C

    2003-01-01

    The US National Cancer Institute has recently sponsored the formation of a Cohort Consortium (http://2002.cancer.gov/scpgenes.htm) to facilitate the pooling of data on very large numbers of people, concerning the effects of genes and environment on cancer incidence. One likely goal of these efforts will be generate a large population-based case-control series for which a number of candidate genes will be investigated using SNP haplotype as well as genotype analysis. The goal of this paper is to outline the issues involved in choosing a method of estimating haplotype-specific risk estimates for such data that is technically appropriate and yet attractive to epidemiologists who are already comfortable with odds ratios and logistic regression. Our interest is to develop and evaluate extensions of methods, based on haplotype imputation, that have been recently described (Schaid et al., Am J Hum Genet, 2002, and Zaykin et al., Hum Hered, 2002) as providing score tests of the null hypothesis of no effect of SNP haplotypes upon risk, which may be used for more complex tasks, such as providing confidence intervals, and tests of equivalence of haplotype-specific risks in two or more separate populations. In order to do so we (1) develop a cohort approach towards odds ratio analysis by expanding the E-M algorithm to provide maximum likelihood estimates of haplotype-specific odds ratios as well as genotype frequencies; (2) show how to correct the cohort approach, to give essentially unbiased estimates for population-based or nested case-control studies by incorporating the probability of selection as a case or control into the likelihood, based on a simplified model of case and control selection, and (3) finally, in an example data set (CYP17 and breast cancer, from the Multiethnic Cohort Study) we compare likelihood-based confidence interval estimates from the two methods with each other, and with the use of the single-imputation approach of Zaykin et al. applied under both

  8. Estimation of risks from medical irradiation

    International Nuclear Information System (INIS)

    Persson, B.R.R.

    1983-01-01

    This paper discuss various concepts of quantifying risks from medical irradiation. The expected individual risk from specific medical examination can be derived by estimation the dose-equivalent in different organs and tissues and apply the risk factors recommended for these tissues. A more practical way is to estimate or measure the energy imparted which has been found to correlate quite well with the total risk derived by summing up the risks for the involved tissues. The effective dose-equivalent concept can be used to derive the collective effective dose-equivalent in a population in order to compare the contribution from medical exposure with the contribution from other sources of irradiation in the society. In many countries it is thus shown that medical exposures gives the largest man-made contribution to the population dose

  9. The relativity of risk

    International Nuclear Information System (INIS)

    Fisk, R.H.

    1987-01-01

    The transport of radioactive material has long been a subject of emotive controversy. For a realistic assessment of the risks involved, however, they must be seen in the context of the transport of any hazardous cargoes, especially those which are energy-producing products

  10. Cardiovascular risk estimation in older persons

    DEFF Research Database (Denmark)

    Cooney, Marie Therese; Selmer, Randi; Lindman, Anja

    2016-01-01

    .73 to 0.75). Calibration was also reasonable, Hosmer-Lemeshow goodness of fit test: 17.16 (men), 22.70 (women). Compared with the original SCORE function extrapolated to the ≥65 years age group discrimination improved, p = 0.05 (men), p women). Simple risk charts were constructed. On simulated...... risk estimation systems, that risk factors function similarly in all age groups. We aimed to derive and validate a risk estimation function, SCORE O.P., solely from data from individuals aged 65 years and older. METHODS AND RESULTS: 20,704 men and 20,121 women, aged 65 and over and without pre...... model and were included in the SCORE O.P. model were: age, total cholesterol, high-density lipoprotein cholesterol, systolic blood pressure, smoking status and diabetes. SCORE O.P. showed good discrimination; area under receiver operator characteristic curve (AUROC) 0.74 (95% confidence interval: 0...

  11. Panel data nonparametric estimation of production risk and risk preferences

    DEFF Research Database (Denmark)

    Czekaj, Tomasz Gerard; Henningsen, Arne

    approaches for obtaining firm-specific measures of risk attitudes. We found that Polish dairy farmers are risk averse regarding production risk and price uncertainty. According to our results, Polish dairy farmers perceive the production risk as being more significant than the risk related to output price......We apply nonparametric panel data kernel regression to investigate production risk, out-put price uncertainty, and risk attitudes of Polish dairy farms based on a firm-level unbalanced panel data set that covers the period 2004–2010. We compare different model specifications and different...

  12. Estimation, assessment and management of risks

    International Nuclear Information System (INIS)

    Reinoehl-Kompa, S.

    2005-01-01

    After the introductory lectures the closed conference divided into sessions on the estimation, assessment and management of risks. This review article summarises some of the central issues which were addressed in the discussions held during the closed conference and which may be of significance for the future work of the ''Radiation Risk'' Committee within the Radiation Protection Commission. Fundamental difficulties still persist in the implementation of risk quantities within the concepts of radiation protection (lectures by Breckow and Kiefer). Some of these difficulties have to do with the definition of dose quantities, in particular with the one most central to radiation protection, the effective dose. In the field of sparsely ionizing radiation attention was focused on two main topics, namely the risk of acquiring thyroid cancer in association with the Chernobyl desaster and analyses of new mortality data on the survivors of the nuclear bomb attacks on Hiroshima and Nagasaki. In the area of lung cancer risk from radon exposure, attention was focused on indoor exposure and the cohort study on bismuth miners. The body of knowledge that has accumulated on the risk of acquiring cancer through UV radiation takes a special position within the wider field of risks associated with nonionizing radiation, since much has already been achieved towards identifying the action mechanisms involved here. Since skin cancer shows the highest increments in incidence of all types of cancer, estimating the risk of acquiring skin cancer through UV radiation will be an important issue in future. One of the tasks of risk management is to translate the results of risk assessment into action. One task of particular importance in this regard is ''risk communication'', the problems surrounding which were illuminated from different perspectives in various contributions

  13. 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...

  14. Minimax estimation of qubit states with Bures risk

    Science.gov (United States)

    Acharya, Anirudh; Guţă, Mădălin

    2018-04-01

    The central problem of quantum statistics is to devise measurement schemes for the estimation of an unknown state, given an ensemble of n independent identically prepared systems. For locally quadratic loss functions, the risk of standard procedures has the usual scaling of 1/n. However, it has been noticed that for fidelity based metrics such as the Bures distance, the risk of conventional (non-adaptive) qubit tomography schemes scales as 1/\\sqrt{n} for states close to the boundary of the Bloch sphere. Several proposed estimators appear to improve this scaling, and our goal is to analyse the problem from the perspective of the maximum risk over all states. We propose qubit estimation strategies based on separate adaptive measurements, and collective measurements, that achieve 1/n scalings for the maximum Bures risk. The estimator involving local measurements uses a fixed fraction of the available resource n to estimate the Bloch vector direction; the length of the Bloch vector is then estimated from the remaining copies by measuring in the estimator eigenbasis. The estimator based on collective measurements uses local asymptotic normality techniques which allows us to derive upper and lower bounds to its maximum Bures risk. We also discuss how to construct a minimax optimal estimator in this setup. Finally, we consider quantum relative entropy and show that the risk of the estimator based on collective measurements achieves a rate O(n-1log n) under this loss function. Furthermore, we show that no estimator can achieve faster rates, in particular the ‘standard’ rate n ‑1.

  15. Estimating the re-identification risk of clinical data sets

    Directory of Open Access Journals (Sweden)

    Dankar Fida

    2012-07-01

    Full Text Available Abstract Background De-identification is a common way to protect patient privacy when disclosing clinical data for secondary purposes, such as research. One type of attack that de-identification protects against is linking the disclosed patient data with public and semi-public registries. Uniqueness is a commonly used measure of re-identification risk under this attack. If uniqueness can be measured accurately then the risk from this kind of attack can be managed. In practice, it is often not possible to measure uniqueness directly, therefore it must be estimated. Methods We evaluated the accuracy of uniqueness estimators on clinically relevant data sets. Four candidate estimators were identified because they were evaluated in the past and found to have good accuracy or because they were new and not evaluated comparatively before: the Zayatz estimator, slide negative binomial estimator, Pitman’s estimator, and mu-argus. A Monte Carlo simulation was performed to evaluate the uniqueness estimators on six clinically relevant data sets. We varied the sampling fraction and the uniqueness in the population (the value being estimated. The median relative error and inter-quartile range of the uniqueness estimates was measured across 1000 runs. Results There was no single estimator that performed well across all of the conditions. We developed a decision rule which selected between the Pitman, slide negative binomial and Zayatz estimators depending on the sampling fraction and the difference between estimates. This decision rule had the best consistent median relative error across multiple conditions and data sets. Conclusion This study identified an accurate decision rule that can be used by health privacy researchers and disclosure control professionals to estimate uniqueness in clinical data sets. The decision rule provides a reliable way to measure re-identification risk.

  16. Bayesian parameter estimation in probabilistic risk assessment

    International Nuclear Information System (INIS)

    Siu, Nathan O.; Kelly, Dana L.

    1998-01-01

    Bayesian statistical methods are widely used in probabilistic risk assessment (PRA) because of their ability to provide useful estimates of model parameters when data are sparse and because the subjective probability framework, from which these methods are derived, is a natural framework to address the decision problems motivating PRA. This paper presents a tutorial on Bayesian parameter estimation especially relevant to PRA. It summarizes the philosophy behind these methods, approaches for constructing likelihood functions and prior distributions, some simple but realistic examples, and a variety of cautions and lessons regarding practical applications. References are also provided for more in-depth coverage of various topics

  17. Absolute risk, absolute risk reduction and relative risk

    Directory of Open Access Journals (Sweden)

    Jose Andres Calvache

    2012-12-01

    Full Text Available This article illustrates the epidemiological concepts of absolute risk, absolute risk reduction and relative risk through a clinical example. In addition, it emphasizes the usefulness of these concepts in clinical practice, clinical research and health decision-making process.

  18. New risk estimates at low doses

    International Nuclear Information System (INIS)

    Fry, R.J.M.

    1992-01-01

    The age of molecular radiation epidemiology may be at hand. The techniques are available to establish with the degree of precision required to determine whether agent-specific mutations can be identified consistently. A concerted effort to examine radiation-induced changes in as many relevant genes as possible appears to be justified. Cancers in those exposed to low doses of ionizing radiation should be chosen for the investigation. Parallel studies of radiation-induced cancers in experimental animals would not only complement the human studies, but perhaps reveal approaches to extrapolation of risk estimates across species. A caveat should be added to this optimistic view of what molecular studies might contribute to the knotty problem of risk estimates at low doses. The suggestions are made by one with no expertise in the field of molecular biology

  19. Risk estimates for the health effects of alpha radiation

    International Nuclear Information System (INIS)

    Thomas, D.C.; McNeill, K.G.

    1981-09-01

    This report provides risk estimates for various health effects of alpha radiation. Human and animal data have been used to characterize the shapes of dose-response relations and the effects of various modifying factors, but quantitative risk estimates are based solely on human data: for lung cancer, on miners in the Colorado plateau, Czechoslovakia, Sweden, Ontario and Newfoundland; for bone and head cancers, on radium dial painters and radium-injected patients. Slopes of dose-response relations for lung cancer show a tendency to decrease with increasing dose. Linear extrapolation is unlikely to underestimate the excess risk at low doses by more than a factor of l.5. Under the linear cell-killing model, our best estimate

  20. Relative Pose Estimation Algorithm with Gyroscope Sensor

    Directory of Open Access Journals (Sweden)

    Shanshan Wei

    2016-01-01

    Full Text Available This paper proposes a novel vision and inertial fusion algorithm S2fM (Simplified Structure from Motion for camera relative pose estimation. Different from current existing algorithms, our algorithm estimates rotation parameter and translation parameter separately. S2fM employs gyroscopes to estimate camera rotation parameter, which is later fused with the image data to estimate camera translation parameter. Our contributions are in two aspects. (1 Under the circumstance that no inertial sensor can estimate accurately enough translation parameter, we propose a translation estimation algorithm by fusing gyroscope sensor and image data. (2 Our S2fM algorithm is efficient and suitable for smart devices. Experimental results validate efficiency of the proposed S2fM algorithm.

  1. MARKET RISK ESTIMATION IN (T+-TRANSACTIONS

    Directory of Open Access Journals (Sweden)

    Radik B. Begov

    2016-01-01

    Full Text Available Market risk analysis and estimation are presentedin T+ transactionsas they are used within the Moscow Exchange. There is a need to do so as a result of the cut-off of a new REPO product with Central Counterpartner (CCP. Here repurchase agreement goes through the National Clearing Center (NCC, the last being a bank and a clearing structure within the Moscow Exchange group.NCC actsas an intermediary (so called “Central Counterpartner” between trading participants.REPOs with CCP raisecontractor claims and commitments to the CCP which takes the risk of default on commitments from unfair contract side. The REPO with CCP cut-off made ready a technological platform to implement T+2 trades at the Moscow Exchange. As a result of it there appeared the possibility to enter security purchase/sell contracts partially collateralized. All these transactions (the REPO with CCP, T+ made it a must determining security market risks. The paper is aimed at presenting VaR-like risk estimates. The methods used are from the computer fi nance. Unusual TS rate of return indicator is proposed and applied to find optimal portfolios under the Markowitz approach and their VaRs (losses forecasts given the real “big” share price data and various horizons. Portfolio extreme rate and loss forecasting is our goal. To this end the forecasts are computed for three horizons (2, 5 and 10 days and for three significance levels.There were developed R-, Excel- and Bloomberg-basedsoftware tools as needed. The whole range of proposed computing steps and the tables with charts may be considered as candidates to be included in the future market risk standards.Paper results permit capital market participants to choose the correct (as to the required risk level common stocks.

  2. Uncertainty relations for approximation and estimation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jaeha, E-mail: jlee@post.kek.jp [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Tsutsui, Izumi, E-mail: izumi.tsutsui@kek.jp [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Theory Center, Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)

    2016-05-27

    We present a versatile inequality of uncertainty relations which are useful when one approximates an observable and/or estimates a physical parameter based on the measurement of another observable. It is shown that the optimal choice for proxy functions used for the approximation is given by Aharonov's weak value, which also determines the classical Fisher information in parameter estimation, turning our inequality into the genuine Cramér–Rao inequality. Since the standard form of the uncertainty relation arises as a special case of our inequality, and since the parameter estimation is available as well, our inequality can treat both the position–momentum and the time–energy relations in one framework albeit handled differently. - Highlights: • Several inequalities interpreted as uncertainty relations for approximation/estimation are derived from a single ‘versatile inequality’. • The ‘versatile inequality’ sets a limit on the approximation of an observable and/or the estimation of a parameter by another observable. • The ‘versatile inequality’ turns into an elaboration of the Robertson–Kennard (Schrödinger) inequality and the Cramér–Rao inequality. • Both the position–momentum and the time–energy relation are treated in one framework. • In every case, Aharonov's weak value arises as a key geometrical ingredient, deciding the optimal choice for the proxy functions.

  3. Uncertainty relations for approximation and estimation

    International Nuclear Information System (INIS)

    Lee, Jaeha; Tsutsui, Izumi

    2016-01-01

    We present a versatile inequality of uncertainty relations which are useful when one approximates an observable and/or estimates a physical parameter based on the measurement of another observable. It is shown that the optimal choice for proxy functions used for the approximation is given by Aharonov's weak value, which also determines the classical Fisher information in parameter estimation, turning our inequality into the genuine Cramér–Rao inequality. Since the standard form of the uncertainty relation arises as a special case of our inequality, and since the parameter estimation is available as well, our inequality can treat both the position–momentum and the time–energy relations in one framework albeit handled differently. - Highlights: • Several inequalities interpreted as uncertainty relations for approximation/estimation are derived from a single ‘versatile inequality’. • The ‘versatile inequality’ sets a limit on the approximation of an observable and/or the estimation of a parameter by another observable. • The ‘versatile inequality’ turns into an elaboration of the Robertson–Kennard (Schrödinger) inequality and the Cramér–Rao inequality. • Both the position–momentum and the time–energy relation are treated in one framework. • In every case, Aharonov's weak value arises as a key geometrical ingredient, deciding the optimal choice for the proxy functions.

  4. A review of radiation risk estimates

    International Nuclear Information System (INIS)

    1991-06-01

    Three authoritative reports (UNSCEAR-1988, BEIR-V-1990, and ICRP-1990 Recommendations) on risk estimates have been reviewed and compared to previous risk estimates published by the same organizations. The ICRP now uses the term 'probability' in place of the term 'risk'. For fatal cancers, the new ICRP probability estimates are 5.0 x 10 -2 Sv -1 for a population of all ages and 4.0 x 10 -2 Sv -1 for a population of working age. For serious hereditary effects summarized over all generations, the ICRP probability coefficients are 1.0 x 10 -2 Sv -1 for a population of all ages and 0.6 x 10 -2 Sv -1 for a population of working age. For prenatal irradiation, at 8 - 15 weeks after conception, there may be a decrease of 30 I.Q. points per Sv and a risk of cancer which may lie in the range of 2 to 10 x 10 -2 Sv -1 . Based mainly on the new probability estimates the ICRP recommends a limit on effective dose of 20 mSv per year, averaged over 5 years (100 mSv in 5 years) with the further provision that the effective dose should not exceed 50 mSv in any single year. For public exposure the ICRP recommends an annual limit on effective dose of 1 mSv. However, in special circumstances, a higher value of effective dose could be allowed in a single year provided that the average over 5 five years does not exceed 1 mSv per year. Once pregnancy has been declared, the conceptus should be protected by applying a supplementary equivalent dose limit to the surface of the woman's abdomen of 2 mSv for the remainder of the pregnancy and by limiting intakes of radionuclides to about 1/20 of the annual limit on intake. A brief survey of epidemiological studies of workers and the risks from radon and thoron progeny is also included. (110 refs, 29 tabs., 10 figs.)

  5. Estimating the commodity market price of risk for energy prices

    International Nuclear Information System (INIS)

    Kolos, Sergey P.; Ronn, Ehud I.

    2008-01-01

    The purpose of this paper is to estimate the ''market price of risk'' (MPR) for energy commodities, the ratio of expected return to standard deviation. The MPR sign determines whether energy forward prices are upward- or downward-biased predictors of expected spot prices. We estimate MPRs using spot and futures prices, while accounting for the Samuelson effect. We find long-term MPRs generally positive and short-term negative, consistent with positive energy betas and hedging, respectively. In spot electricity markets, MPRs in Day-Ahead Prices agree with short-dated futures. Our results relate risk premia to informed hedging decisions, and futures prices to forecast/expected prices. (author)

  6. Life cycle cost and risk estimation of environmental management options

    International Nuclear Information System (INIS)

    Shropshire, D.; Sherick, M.

    1996-01-01

    The evaluation process is demonstrated in this paper through comparative analysis of two alternative scenarios identified for the management of the alpha-contaminated fixed low-level waste currently stored at INEL. These two scenarios, the Base Case and the Delay Case, are realistic and based on actual data, but are not intended to exactly match actual plans currently being developed at INEL. Life cycle cost estimates were developed for both scenarios using the System Cost Model; resulting costs are presented and compared. Life cycle costs are shown as a function of time and also aggregated by pretreatment, treatment, storage, and disposal activities. Although there are some short-term cost savings for the Delay Case, cumulative life cycle costs eventually become much higher than costs for the Base Case over the same period of time, due mainly to the storage and repackaging necessary to accommodate the longer Delay Case schedule. Life cycle risk estimates were prepared using a new risk analysis method adapted to the System Cost Model architecture for automated, systematic cost/risk applications. Relative risk summaries are presented for both scenarios as a function of time and also aggregated by pretreatment, treatment, storage, and disposal activities. Relative risk of the Delay Case is shown to be higher than that of the Base Case. Finally, risk and cost results are combined to show how the collective information can be used to help identify opportunities for risk or cost reduction and highlight areas where risk reduction can be achieved most economically

  7. Estimating the Risks of Breast Cancer Radiotherapy

    DEFF Research Database (Denmark)

    Taylor, Carolyn; Correa, Candace; Duane, Frances K

    2017-01-01

    Purpose Radiotherapy reduces the absolute risk of breast cancer mortality by a few percentage points in suitable women but can cause a second cancer or heart disease decades later. We estimated the absolute long-term risks of modern breast cancer radiotherapy. Methods First, a systematic literature...... review was performed of lung and heart doses in breast cancer regimens published during 2010 to 2015. Second, individual patient data meta-analyses of 40,781 women randomly assigned to breast cancer radiotherapy versus no radiotherapy in 75 trials yielded rate ratios (RRs) for second primary cancers...... and cause-specific mortality and excess RRs (ERRs) per Gy for incident lung cancer and cardiac mortality. Smoking status was unavailable. Third, the lung or heart ERRs per Gy in the trials and the 2010 to 2015 doses were combined and applied to current smoker and nonsmoker lung cancer and cardiac mortality...

  8. Estimating the relative utility of screening mammography.

    Science.gov (United States)

    Abbey, Craig K; Eckstein, Miguel P; Boone, John M

    2013-05-01

    The concept of diagnostic utility is a fundamental component of signal detection theory, going back to some of its earliest works. Attaching utility values to the various possible outcomes of a diagnostic test should, in principle, lead to meaningful approaches to evaluating and comparing such systems. However, in many areas of medical imaging, utility is not used because it is presumed to be unknown. In this work, we estimate relative utility (the utility benefit of a detection relative to that of a correct rejection) for screening mammography using its known relation to the slope of a receiver operating characteristic (ROC) curve at the optimal operating point. The approach assumes that the clinical operating point is optimal for the goal of maximizing expected utility and therefore the slope at this point implies a value of relative utility for the diagnostic task, for known disease prevalence. We examine utility estimation in the context of screening mammography using the Digital Mammographic Imaging Screening Trials (DMIST) data. We show how various conditions can influence the estimated relative utility, including characteristics of the rating scale, verification time, probability model, and scope of the ROC curve fit. Relative utility estimates range from 66 to 227. We argue for one particular set of conditions that results in a relative utility estimate of 162 (±14%). This is broadly consistent with values in screening mammography determined previously by other means. At the disease prevalence found in the DMIST study (0.59% at 365-day verification), optimal ROC slopes are near unity, suggesting that utility-based assessments of screening mammography will be similar to those found using Youden's index.

  9. Population-based absolute risk estimation with survey data

    Science.gov (United States)

    Kovalchik, Stephanie A.; Pfeiffer, Ruth M.

    2013-01-01

    Absolute risk is the probability that a cause-specific event occurs in a given time interval in the presence of competing events. We present methods to estimate population-based absolute risk from a complex survey cohort that can accommodate multiple exposure-specific competing risks. The hazard function for each event type consists of an individualized relative risk multiplied by a baseline hazard function, which is modeled nonparametrically or parametrically with a piecewise exponential model. An influence method is used to derive a Taylor-linearized variance estimate for the absolute risk estimates. We introduce novel measures of the cause-specific influences that can guide modeling choices for the competing event components of the model. To illustrate our methodology, we build and validate cause-specific absolute risk models for cardiovascular and cancer deaths using data from the National Health and Nutrition Examination Survey. Our applications demonstrate the usefulness of survey-based risk prediction models for predicting health outcomes and quantifying the potential impact of disease prevention programs at the population level. PMID:23686614

  10. Employment relations, flexibility and risk

    DEFF Research Database (Denmark)

    Jensen, Carsten Strøby

    Employment relations literature often distinguishes between social democratic/corporatist models of employment relations and liberal models of employment relations as they are seen as opposite or at least different ways of organizing labor markets. They are often characterized as having very...... different risk profiles in terms of relationships between employees, employers, and the state. Low levels of labor market regulation very often characterize the liberal models of employment relations as we know them from, for instance, the USA and the UK. This means that employment conditions are very often...... insecure and that the burden of unemployment risk mostly lies with the employees rather than the employer. Corporatist – or social democratic – employment relations models are, in contrast to the liberal models, often characterized by stricter regulation of the labor market and by high standards...

  11. Closed-Loop Surface Related Multiple Estimation

    NARCIS (Netherlands)

    Lopez Angarita, G.A.

    2016-01-01

    Surface-related multiple elimination (SRME) is one of the most commonly used methods for suppressing surface multiples. However, in order to obtain an accurate surface multiple estimation, dense source and receiver sampling is required. The traditional approach to this problem is performing data

  12. Estimating the risk of Amazonian forest dieback.

    Science.gov (United States)

    Rammig, Anja; Jupp, Tim; Thonicke, Kirsten; Tietjen, Britta; Heinke, Jens; Ostberg, Sebastian; Lucht, Wolfgang; Cramer, Wolfgang; Cox, Peter

    2010-08-01

    *Climate change will very likely affect most forests in Amazonia during the course of the 21st century, but the direction and intensity of the change are uncertain, in part because of differences in rainfall projections. In order to constrain this uncertainty, we estimate the probability for biomass change in Amazonia on the basis of rainfall projections that are weighted by climate model performance for current conditions. *We estimate the risk of forest dieback by using weighted rainfall projections from 24 general circulation models (GCMs) to create probability density functions (PDFs) for future forest biomass changes simulated by a dynamic vegetation model (LPJmL). *Our probabilistic assessment of biomass change suggests a likely shift towards increasing biomass compared with nonweighted results. Biomass estimates range between a gain of 6.2 and a loss of 2.7 kg carbon m(-2) for the Amazon region, depending on the strength of CO(2) fertilization. *The uncertainty associated with the long-term effect of CO(2) is much larger than that associated with precipitation change. This underlines the importance of reducing uncertainties in the direct effects of CO(2) on tropical ecosystems.

  13. Neoplastic potential of gastric irradiation. IV. Risk estimates

    International Nuclear Information System (INIS)

    Griem, M.L.; Justman, J.; Weiss, L.

    1984-01-01

    No significant tumor increase was found in the initial analysis of patients irradiated for peptic ulcer and followed through 1962. A preliminary study was undertaken 22 years later to estimate the risk of cancer due to gastric irradiation for peptic ulcer disease. A population of 2,049 irradiated patients and 763 medically managed patients has been identified. A relative risk of 3.7 was found for stomach cancer and an initial risk estimate of 5.5 x 10(-6) excess stomach cancers per person rad was calculated. A more complete follow-up is in progress to further elucidate this observation and decrease the ascertainment bias; however, preliminary data are in agreement with the Japanese atomic bomb reports

  14. Estimating population health risk from low-level environmental radon

    International Nuclear Information System (INIS)

    Fisher, D.R.

    1980-01-01

    Although incidence of respiratory cancer is directly related to inhalation of radon and radon daughters, the magnitude of the actual risk is uncertain for members of the general population exposed for long periods to low-level concentrations. Currently, any such estimate of the risk must rely on data obtained through previous studies of underground-miner populations. Several methods of risk analysis have resulted from these studies. Since the breathing atmospheres, smoking patterns, and physiology are different between miners and the general public, overestimates of lung cancer risk to the latter may have resulted. Strong evidence exists to support the theory of synergistic action between alpha radiation and other agents, and therefore a modified relative risk model was developed to predict lung cancer risks to the general public. The model considers latent period, observation period, age dependency, and inherent risks from smoking or geographical location. A test of the model showed excellent agreement with results of the study of Czechoslovakian uranium miners, for which the necessary time factors were available. The risk model was also used to predict lung cancer incidence among residents of homes on reclaimed Florida phosphate lands, and results of this analysis indicate that over the space of many years, the increased incidence of lung cancer due to elevated radon levels may be indisgtinguishable from those due to other causes

  15. Simplifying cardiovascular risk estimation using resting heart rate.

    LENUS (Irish Health Repository)

    Cooney, Marie Therese

    2010-09-01

    Elevated resting heart rate (RHR) is a known, independent cardiovascular (CV) risk factor, but is not included in risk estimation systems, including Systematic COronary Risk Evaluation (SCORE). We aimed to derive risk estimation systems including RHR as an extra variable and assess the value of this addition.

  16. Variance computations for functional of absolute risk estimates.

    Science.gov (United States)

    Pfeiffer, R M; Petracci, E

    2011-07-01

    We present a simple influence function based approach to compute the variances of estimates of absolute risk and functions of absolute risk. We apply this approach to criteria that assess the impact of changes in the risk factor distribution on absolute risk for an individual and at the population level. As an illustration we use an absolute risk prediction model for breast cancer that includes modifiable risk factors in addition to standard breast cancer risk factors. Influence function based variance estimates for absolute risk and the criteria are compared to bootstrap variance estimates.

  17. A New Model for the Estimation of Breast Cancer Risk

    National Research Council Canada - National Science Library

    Giger, Maryellen Lissak

    2001-01-01

    ... for use in estimating risk of breast cancer. The specific aims include 1. Creating a database of mammograms, along with tabulated clinical information of women at low risk and high risk for breast cancer; 2...

  18. Relative and absolute risk in epidemiology and health physics

    International Nuclear Information System (INIS)

    Goldsmith, R.; Peterson, H.T. Jr.

    1983-01-01

    The health risk from ionizing radiation commonly is expressed in two forms: (1) the relative risk, which is the percentage increase in natural disease rate and (2) the absolute or attributable risk which represents the difference between the natural rate and the rate associated with the agent in question. Relative risk estimates for ionizing radiation generally are higher than those expressed as the absolute risk. This raises the question of which risk estimator is the most appropriate under different conditions. The absolute risk has generally been used for radiation risk assessment, although mathematical combinations such as the arithmetic or geometric mean of both the absolute and relative risks, have also been used. Combinations of the two risk estimators are not valid because the absolute and relative risk are not independent variables. Both human epidemiologic studies and animal experimental data can be found to illustrate the functional relationship between the natural cancer risk and the risk associated with radiation. This implies that the radiation risk estimate derived from one population may not be appropriate for predictions in another population, unless it is adjusted for the difference in the natural disease incidence between the two populations

  19. Best-Estimates in Bond Markets with Reinvestment Risk

    Directory of Open Access Journals (Sweden)

    Anne MacKay

    2015-07-01

    Full Text Available The concept of best-estimate, prescribed by regulators to value insurance liabilities for accounting and solvency purposes, has recently been discussed extensively in the industry and related academic literature. To differentiate hedgeable and non-hedgeable risks in a general case, recent literature defines best-estimates using orthogonal projections of a claim on the space of replicable payoffs. In this paper, we apply this concept of best-estimate to long-maturity claims in a market with reinvestment risk, since in this case the total liability cannot easily be separated into hedgeable and non-hedgeable parts. We assume that a limited number of short-maturity bonds are traded, and derive the best-estimate price of bonds with longer maturities, thus obtaining a best-estimate yield curve. We therefore use the multifactor Vasiˇcek model and derive within this framework closed-form expressions for the best-estimate prices of long-term bonds.

  20. Epidemiological data and radiation risk estimates

    International Nuclear Information System (INIS)

    Cardis, E.

    2002-01-01

    The results of several major epidemiology studies on populations with particular exposure to ionizing radiation should become available during the first years of the 21. century. These studies are expected to provide answers to a number of questions concerning public health and radiation protection. Most of the populations concerned were accidentally exposed to radiation in ex-USSR or elsewhere or in a nuclear industrial context. The results will complete and test information on risk coming from studies among survivors of the Hiroshima and Nagasaki atomic bombs, particularly studies on the effects of low dose exposure and prolonged low-dose exposure, of different types of radiation, and environmental and host-related factors which could modify the risk of radiation-induced effects. These studies are thus important to assess the currently accepted scientific evidence on radiation protection for workers and the general population. In addition, supplementary information on radiation protection could be provided by formal comparisons and analyses combining data from populations with different types of exposure. Finally, in order to provide pertinent information for public health and radiation protection, future epidemiology studies should be targeted and designed to answer specific questions, concerning, for example, the risk for specific populations (children, patients, people with genetic predisposition). An integrated approach, combining epidemiology and studies on the mechanisms of radiation induction should provide particularly pertinent information. (author)

  1. Estimation of health risks from radiation exposures

    Energy Technology Data Exchange (ETDEWEB)

    Randolph, M.L.

    1983-08-01

    An informal presentation is given of the cancer and genetic risks from exposures to ionizing radiations. The risks from plausible radiation exposures are shown to be comparable to other commonly encountered risks.

  2. Estimation of health risks from radiation exposures

    International Nuclear Information System (INIS)

    Randolph, M.L.

    1983-08-01

    An informal presentation is given of the cancer and genetic risks from exposures to ionizing radiations. The risks from plausible radiation exposures are shown to be comparable to other commonly encountered risks

  3. Review of the current status of radiation risk estimates

    International Nuclear Information System (INIS)

    Charles, M.W.; Little, M.P.

    1988-10-01

    This report reviews the current status of radiation risk estimation for low linear energy transfer radiation. Recent statements by various national and international organisations regarding risk estimates are critically discussed. The recently published revised population risk estimates from the study of Japanese bomb survivors are also reviewed and used with some unpublished data from Japan to calculate risk figures for a general work force. (author)

  4. An application of extreme value theory in estimating liquidity risk

    Directory of Open Access Journals (Sweden)

    Sonia Benito Muela

    2017-09-01

    Full Text Available The last global financial crisis (2007–2008 has highlighted the weaknesses of value at risk (VaR as a measure of market risk, as this metric by itself does not take liquidity risk into account. To address this problem, the academic literature has proposed incorporating liquidity risk into estimations of market risk by adding the VaR of the spread to the risk price. The parametric model is the standard approach used to estimate liquidity risk. As this approach does not generate reliable VaR estimates, we propose estimating liquidity risk using more sophisticated models based on extreme value theory (EVT. We find that the approach based on conditional extreme value theory outperforms the standard approach in terms of accurate VaR estimates and the market risk capital requirements of the Basel Capital Accord.

  5. Backtesting Portfolio Value-at-Risk with Estimated Portfolio Weights

    OpenAIRE

    Pei Pei

    2010-01-01

    This paper theoretically and empirically analyzes backtesting portfolio VaR with estimation risk in an intrinsically multivariate framework. For the first time in the literature, it takes into account the estimation of portfolio weights in forecasting portfolio VaR and its impact on backtesting. It shows that the estimation risk from estimating the portfolio weights as well as that from estimating the multivariate dynamic model of asset returns make the existing methods in a univariate framew...

  6. Radiation risk estimation based on measurement error models

    CERN Document Server

    Masiuk, Sergii; Shklyar, Sergiy; Chepurny, Mykola; Likhtarov, Illya

    2017-01-01

    This monograph discusses statistics and risk estimates applied to radiation damage under the presence of measurement errors. The first part covers nonlinear measurement error models, with a particular emphasis on efficiency of regression parameter estimators. In the second part, risk estimation in models with measurement errors is considered. Efficiency of the methods presented is verified using data from radio-epidemiological studies.

  7. Drought-related vulnerability and risk assessment of groundwater in Belgium: estimation of the groundwater recharge and crop yield vulnerability with the B-CGMS

    Science.gov (United States)

    Jacquemin, Ingrid; Verbeiren, Boud; Vanderhaegen, Sven; Canters, Frank; Vermeiren, Karolien; Engelen, Guy; Huysmans, Marijke; Batelaan, Okke; Tychon, Bernard

    2016-04-01

    Due to common belief that regions under temperate climate are not affected by (meteorological and groundwater) drought, these events and their impacts remain poorly studied: in the GroWaDRISK, we propose to take stock of this question. We aim at providing a better understanding of the influencing factors (land use and land cover changes, water demand and climate) and the drought-related impacts on the environment, water supply and agriculture. The study area is located in the North-East of Belgium, corresponding approximatively to the Dijle and Demer catchments. To establish an overview of the groundwater situation, we assess the system input: the recharge. To achieve this goal, two models, B-CGMS and WetSpass are used to evaluate the recharge, respectively, over agricultural land and over the remaining areas, as a function of climate and for various land uses and land covers. B-CGMS, which is an adapted version for Belgium of the European Crop Growth Monitoring System, is used for assessing water recharge at a daily timestep and under different agricultural lands: arable land (winter wheat, maize...), orchards, horticulture and floriculture and for grassland. B-CGMS is designed to foresee crop yield and obviously it studies the impact of drought on crop yield and raises issues for the potential need of irrigation. For both yields and water requirements, the model proposes a potential mode, driven by temperature and solar radiation, and a water-limited mode for which water availability can limit crop growth. By this way, we can identify where and when water consumption and yield are not optimal, in addition to the Crop Water Stress Index. This index is calculated for a given crop, as the number of days affected by water stress during the growth sensitive period. Both recharge and crop yield are assessed for the current situation (1980 - 2012), taking into account the changing land use/land cover, in terms of areas and localization of the agricultural land and where

  8. Radiation-Induced Second Cancer Risk Estimates From Radionuclide Therapy

    Science.gov (United States)

    Bednarz, Bryan; Besemer, Abigail

    2017-09-01

    The use of radionuclide therapy in the clinical setting is expected to increase significantly over the next decade. There is an important need to understand the radiation-induced second cancer risk associated with these procedures. In this study the radiation-induced cancer risk in five radionuclide therapy patients was investigated. These patients underwent serial SPECT imaging scans following injection as part of a clinical trial testing the efficacy of a 131Iodine-labeled radiopharmaceutical. Using these datasets the committed absorbed doses to multiple sensitive structures were calculated using RAPID, which is a novel Monte Carlo-based 3D dosimetry platform developed for personalized dosimetry. The excess relative risk (ERR) for radiation-induced cancer in these structures was then derived from these dose estimates following the recommendations set forth in the BEIR VII report. The radiation-induced leukemia ERR was highest among all sites considered reaching a maximum value of approximately 4.5. The radiation-induced cancer risk in the kidneys, liver and spleen ranged between 0.3 and 1.3. The lifetime attributable risks (LARs) were also calculated, which ranged from 30 to 1700 cancers per 100,000 persons and were highest for leukemia and the liver for both males and females followed by radiation-induced spleen and kidney cancer. The risks associated with radionuclide therapy are similar to the risk associated with external beam radiation therapy.

  9. Comparative estimates of risks arising from storage of intermediate level radioactive wastes

    International Nuclear Information System (INIS)

    Moore, D.

    1986-04-01

    Estimates are presented of risks arising from accidents occuring during storage of nine types of conditioned intermediate level waste. Additional data are introduced relating to the risks from accidents affecting raw waste, and to risks associated with the occupational doses received during normal operation of a waste store. Risks in all three categories are shown to be extremely small. (author)

  10. Competing risk bias was common in Kaplan-Meier risk estimates published in prominent medical journals.

    Science.gov (United States)

    van Walraven, Carl; McAlister, Finlay A

    2016-01-01

    Risk estimates from Kaplan-Meier curves are well known to medical researchers, reviewers, and editors. In this study, we determined the proportion of Kaplan-Meier analyses published in prominent medical journals that are potentially biased because of competing events ("competing risk bias"). We randomly selected 100 studies that had at least one Kaplan-Meier analysis and were recently published in prominent medical journals. Susceptibility to competing risk bias was determined by examining the outcome and potential competing events. In susceptible studies, bias was quantified using a previously validated prediction model when the number of outcomes and competing events were given. Forty-six studies (46%) contained Kaplan-Meier analyses susceptible to competing risk bias. Sixteen studies (34.8%) susceptible to competing risk cited the number of outcomes and competing events; in six of these studies (6/16, 37.5%), the outcome risk from the Kaplan-Meier estimate (relative to the true risk) was biased upward by 10% or more. Almost half of Kaplan-Meier analyses published in medical journals are susceptible to competing risk bias and may overestimate event risk. This bias was found to be quantitatively important in a third of such studies. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Estimating Worker Risk Levels Using Accident/Incident Data

    Energy Technology Data Exchange (ETDEWEB)

    Kenoyer, Judson L.; Stenner, Robert D.; Andrews, William B.; Scherpelz, Robert I.; Aaberg, Rosanne L.

    2000-09-26

    The purpose of the work described in this report was to identify methods that are currently being used in the Department of Energy (DOE) complex to identify and control hazards/risks in the workplace, evaluate them in terms of their effectiveness in reducing risk to the workers, and to develop a preliminary method that could be used to predict the relative risks to workers performing proposed tasks using some of the current methodology. This report describes some of the performance indicators (i.e., safety metrics) that are currently being used to track relative levels of workplace safety in the DOE complex, how these fit into an Integrated Safety Management (ISM) system, some strengths and weaknesses of using a statistically based set of indicators, and methods to evaluate them. Also discussed are methods used to reduce risk to the workers and some of the techniques that appear to be working in the process of establishing a condition of continuous improvement. The results of these methods will be used in future work involved with the determination of modifying factors for a more complex model. The preliminary method to predict the relative risk level to workers during an extended future time period is based on a currently used performance indicator that uses several factors tracked in the CAIRS. The relative risks for workers in a sample (but real) facility on the Hanford site are estimated for a time period of twenty years and are based on workforce predictions. This is the first step in developing a more complex model that will incorporate other modifying factors related to the workers, work environment and status of the ISM system to adjust the preliminary prediction.

  12. Seismic Risk Assessment and Loss Estimation for Tbilisi City

    Science.gov (United States)

    Tsereteli, Nino; Alania, Victor; Varazanashvili, Otar; Gugeshashvili, Tengiz; Arabidze, Vakhtang; Arevadze, Nika; Tsereteli, Emili; Gaphrindashvili, Giorgi; Gventcadze, Alexander; Goguadze, Nino; Vephkhvadze, Sophio

    2013-04-01

    The proper assessment of seismic risk is of crucial importance for society protection and city sustainable economic development, as it is the essential part to seismic hazard reduction. Estimation of seismic risk and losses is complicated tasks. There is always knowledge deficiency on real seismic hazard, local site effects, inventory on elements at risk, infrastructure vulnerability, especially for developing countries. Lately great efforts was done in the frame of EMME (earthquake Model for Middle East Region) project, where in the work packages WP1, WP2 , WP3 and WP4 where improved gaps related to seismic hazard assessment and vulnerability analysis. Finely in the frame of work package wp5 "City Scenario" additional work to this direction and detail investigation of local site conditions, active fault (3D) beneath Tbilisi were done. For estimation economic losses the algorithm was prepared taking into account obtained inventory. The long term usage of building is very complex. It relates to the reliability and durability of buildings. The long term usage and durability of a building is determined by the concept of depreciation. Depreciation of an entire building is calculated by summing the products of individual construction unit' depreciation rates and the corresponding value of these units within the building. This method of calculation is based on an assumption that depreciation is proportional to the building's (constructions) useful life. We used this methodology to create a matrix, which provides a way to evaluate the depreciation rates of buildings with different type and construction period and to determine their corresponding value. Finally loss was estimated resulting from shaking 10%, 5% and 2% exceedance probability in 50 years. Loss resulting from scenario earthquake (earthquake with possible maximum magnitude) also where estimated.

  13. Estimating Risk and Return Combinations for New Derivatives Funds

    Directory of Open Access Journals (Sweden)

    Alexandre Bona

    2004-12-01

    Full Text Available Active funds are typically managed by placing bets against a well defined passive bench-mark. In this context, when examining the launching of a new actively managed fund with a target expected excess rate of return relative to the benchmark equal to µ, asset managers face the problem of estimating the risk σ of excess rates of return. This estimate is critical to examine whether the product is commercially feasible and to define risk limits for the manager, if the product is launched. This paper proceeds to examine the solution to this problem assuming an especial form of the binomial model, in the context of the market timing structure advanced by Merton (1981. The paper shows that two variables are relevant for the solution of the proposed problem. The first, and the most relevant, is the skill level of the manager. A ore skilled manager is able to operate a less risky product with the same target excess rate of return µ. The second relevant variable is the trade-off between risk and return determined by existing investment opportunities in the market. The smaller the increases in risk exposure required to obtain an increase in excess returns, the less risky the product will be After solving the problem under specific assumptions, the paper proceeds to test empirically their validity using a representative sample of hedge funds in the Brazilian market. The empirical results strongly support the validity of the required assumptions.

  14. Cancer risk estimation from the A-bomb survivors

    International Nuclear Information System (INIS)

    Pierce, D.A.; Vaeth, M.

    1989-10-01

    Generalizations regarding radiogenic cancer risks from the A-bomb survivor data of the Radiation Effects Research Foundation involve a large number of well-identified uncertainties and approximations. These include extrapolation to low doses and dose rates, projections in time, sampling variation, the quality of the data, extrapolation to other populations, and the use of simplifying conventions. This paper discusses some of these issues, with emphasis on the first three. Results are given regarding the maximum 'linear-quadratic' curvature consistent with these data, taking into account uncertainties in individual exposure estimates. Discussion is given regarding use of relative risk models and projection of lifetime risks, emphasizing results for those who were old enough at exposure to have been followed up for a major part of their lives by now, and stressing the speculative aspects of conclusions about those exposed as children. Combining these results, and brief discussion of other uncertainties itemized above, comment is made on the evolution of risk estimates over the past 15 years. (author)

  15. A Gaussian IV estimator of cointegrating relations

    DEFF Research Database (Denmark)

    Bårdsen, Gunnar; Haldrup, Niels

    2006-01-01

    In static single equation cointegration regression modelsthe OLS estimator will have a non-standard distribution unless regressors arestrictly exogenous. In the literature a number of estimators have been suggestedto deal with this problem, especially by the use of semi-nonparametricestimators. T......In static single equation cointegration regression modelsthe OLS estimator will have a non-standard distribution unless regressors arestrictly exogenous. In the literature a number of estimators have been suggestedto deal with this problem, especially by the use of semi...... in cointegrating regressions. These instruments are almost idealand simulations show that the IV estimator using such instruments alleviatethe endogeneity problem extremely well in both finite and large samples....

  16. METHODOLOGICAL PROBLEMS OF PRACTICAL RADIOGENIC RISK ESTIMATIONS

    Directory of Open Access Journals (Sweden)

    A. Т. Gubin

    2014-01-01

    Full Text Available Mathematical ratios were established according to the description of the calculation procedure for the values of the nominal risk coefficient given in the ICRP Recommendations 2007. It is shown that the lifetime radiogenic risk is a linear functional from the distribution of the dose in time with a multiplier descending with age. As a consequence, application of the nominal risk coefficient in the risk calculations is justified in the case when prolonged exposure is practically evenly distributed in time, and gives a significant deviation at a single exposure. When using the additive model of radiogenic risk proposed in the UNSCEAR Report 2006 for solid cancers, this factor is almost linearly decreasing with the age, which is convenient for its practical application.

  17. Radiation risk and its estimation for nuclear facilities

    International Nuclear Information System (INIS)

    Krueger, F.W.

    1979-01-01

    The level of knowledge achieved in estimating risks due to the operation of nuclear facilities is discussed. In this connection it is analyzed to what extent risk estimates may be used for establishing requirements for facilities and measures of radiation protection and accident prevention. At present, estimates of risks are subject to great uncertainties. However, the results attainable already permit to discern the causes of possible accidents and to develop effective measures for preventing such accidents. For the time being (and maybe in principle) risk estimation is possible only with more or less arbitrary premises. Within the foreseeable future, cost-benefit comparisons cannot compensate for discretionary decisions in establishing requirements for measures of radiation protection and accident prevention. In preparing such decisions based on experience, expert opinions, political and socio-economic reflections and views, comparison of the risk of novel technologies with existing ones or accepted risks may be a useful means. (author)

  18. Estimation of foetus risk from x-ray pelvimetric examinations

    International Nuclear Information System (INIS)

    Iba, Shozo; Sato, Kazuichi

    1983-01-01

    X-ray pelvimetric examinations are carried out for the purpose of diagnosing the cephalo pelvic disproportion at terminal pregnancy and they are still an excellent method, being performed more often than other examinations. However the invitable fetal exposure is considered to be a significant dose and makes an estimation of stochastic fetal risk related to x-ray exposure and to investigate the methods of dose reduction. As the methods judging the exposure dose actually made in the hospitals, a questionnarie regarding the main technical factors of an x-ray examination was given to 26 hospitals, including 5 university hospitals, in Kantou district, and the answeres were analyzed. The estimated risks involving genetics, leukemia and malignant diseases were dependent on the exposure dose which could be calculated on the basis of the technical factors obtained. Total risks on the foetus ranged widely from 1.27 x 10 rad -1 to 1.19 x 10 rad -1 . So for as we have investigated, if all the hospitals used a grid ratio of 5:1, a tube voltage of 120 kV, intensitying screens with rare earth phosphors and green-sensitive orthomatic medical x-ray films for the x-ray pelvimetric examinations, it would be possible to reduce the present exposure dose by one-fourth. The ratio of the x-ray pelvimetry taken on pregnant patients ranged from 2 % to 33 %, having a mean value of 15 %. (author)

  19. Political risk in fair market value estimates

    International Nuclear Information System (INIS)

    Gruy, H.J.; Hartsock, J.H.

    1996-01-01

    Political risk arises from unstable governments, commercial establishments and infrastructure as well as labor unrest. All these factors vary from country to country and from time to time. Banks and insurance companies quantify these risks, but they are reluctant to divulge their opinions for fear of alienating possible customers that have been assigned a high risk. An investment in a fixed property such as an oil and gas lease, concession or other mineral interest is subject to political risk. No one will deny that money to be received several years in the future has a greater value today in a country with a stable government, stable tax regime, a sound economy and reliable labor force than in a Third World country where a revolution is brewing. Even in stable countries, the risk of tax law changes, exorbitant environmental production regulations and cleanup costs may vary. How do these factors affect fair market value and how are these calculations made? An important consideration discussed in this paper is the treatment of capital investments

  20. The estimation of small probabilities and risk assessment

    International Nuclear Information System (INIS)

    Kalbfleisch, J.D.; Lawless, J.F.; MacKay, R.J.

    1982-01-01

    The primary contribution of statistics to risk assessment is in the estimation of probabilities. Frequently the probabilities in question are small, and their estimation is particularly difficult. The authors consider three examples illustrating some problems inherent in the estimation of small probabilities

  1. Relative Hazard and Risk Measure Calculation Methodology

    International Nuclear Information System (INIS)

    Stenner, Robert D.; Strenge, Dennis L.; Elder, Matthew S.; Andrews, William B.; Walton, Terry L.

    2003-01-01

    The RHRM equations, as represented in methodology and code presented in this report, are primarily a collection of key factors normally used in risk assessment that are relevant to understanding the hazards and risks associated with projected mitigation, cleanup, and risk management activities. The RHRM code has broad application potential. For example, it can be used to compare one mitigation, cleanup, or risk management activity with another, instead of just comparing it to just the fixed baseline. If the appropriate source term data are available, it can be used in its non-ratio form to estimate absolute values of the associated controlling hazards and risks. These estimated values of controlling hazards and risks can then be examined to help understand which mitigation, cleanup, or risk management activities are addressing the higher hazard conditions and risk reduction potential at a site. Graphics can be generated from these absolute controlling hazard and risk values to graphically compare these high hazard and risk reduction potential conditions. If the RHRM code is used in this manner, care must be taken to specifically define and qualify (e.g., identify which factors were considered and which ones tended to drive the hazard and risk estimates) the resultant absolute controlling hazard and risk values

  2. Estimation of extreme risk regions under multivariate regular variation

    NARCIS (Netherlands)

    Cai, J.; Einmahl, J.H.J.; de Haan, L.F.M.

    2011-01-01

    When considering d possibly dependent random variables, one is often interested in extreme risk regions, with very small probability p. We consider risk regions of the form {z ∈ Rd : f (z) ≤ β}, where f is the joint density and β a small number. Estimation of such an extreme risk region is difficult

  3. Probabilistic fuzzy systems in value-at-risk estimation

    NARCIS (Netherlands)

    Almeida, R.J.; Kaymak, U.

    2009-01-01

    Value-at-risk (VaR) is a popular measure for quantifying the market risk that a financial institution faces into a single number. Owing to the complexity of financial markets, the risks associated with a portfolio varies over time. Consequently, advanced methods of VaR estimation use parametric

  4. Cancer Related-Knowledge - Small Area Estimates

    Science.gov (United States)

    These model-based estimates are produced using statistical models that combine data from the Health Information National Trends Survey, and auxiliary variables obtained from relevant sources and borrow strength from other areas with similar characteristics.

  5. Method-related estimates of sperm vitality.

    Science.gov (United States)

    Cooper, Trevor G; Hellenkemper, Barbara

    2009-01-01

    Comparison of methods that estimate viability of human spermatozoa by monitoring head membrane permeability revealed that wet preparations (whether using positive or negative phase-contrast microscopy) generated significantly higher percentages of nonviable cells than did air-dried eosin-nigrosin smears. Only with the latter method did the sum of motile (presumed live) and stained (presumed dead) preparations never exceed 100%, making this the method of choice for sperm viability estimates.

  6. Uncertainty estimation and risk prediction in air quality

    International Nuclear Information System (INIS)

    Garaud, Damien

    2011-01-01

    This work is about uncertainty estimation and risk prediction in air quality. Firstly, we build a multi-model ensemble of air quality simulations which can take into account all uncertainty sources related to air quality modeling. Ensembles of photochemical simulations at continental and regional scales are automatically generated. Then, these ensemble are calibrated with a combinatorial optimization method. It selects a sub-ensemble which is representative of uncertainty or shows good resolution and reliability for probabilistic forecasting. This work shows that it is possible to estimate and forecast uncertainty fields related to ozone and nitrogen dioxide concentrations or to improve the reliability of threshold exceedance predictions. The approach is compared with Monte Carlo simulations, calibrated or not. The Monte Carlo approach appears to be less representative of the uncertainties than the multi-model approach. Finally, we quantify the observational error, the representativeness error and the modeling errors. The work is applied to the impact of thermal power plants, in order to quantify the uncertainty on the impact estimates. (author) [fr

  7. Estimating Fire Risks at Industrial Nuclear Facilities

    International Nuclear Information System (INIS)

    Coutts, D.A.

    1999-01-01

    The Savannah River Site (SRS) has a wide variety of nuclear production facilities that include chemical processing facilities, machine shops, production reactors, and laboratories. Current safety documentation must be maintained for the nuclear facilities at SRS. Fire Risk Analyses (FRAs) are used to support the safety documentation basis. These FRAs present the frequency that specified radiological and chemical consequences will be exceeded. The consequence values are based on mechanistic models assuming specific fire protection features fail to function as designed

  8. Risk estimation for LCF crack initiation

    OpenAIRE

    Schmitz, Sebastian; Rollmann, Georg; Gottschalk, Hanno; Krause, Rolf

    2013-01-01

    An accurate risk assessment for fatigue damage is of vital importance for the design and service of today's turbomachinery components. We present an approach for quantifying the probability of crack initiation due to surface driven low-cycle fatigue (LCF). This approach is based on the theory of failure-time processes and takes inhomogeneous stress fields and size effects into account. The method has been implemented as a finite-element postprocessor which uses quadrature formulae of higher o...

  9. On the relation between S-Estimators and M-Estimators of multivariate location and covariance

    NARCIS (Netherlands)

    Lopuhaa, H.P.

    1987-01-01

    We discuss the relation between S-estimators and M-estimators of multivariate location and covariance. As in the case of the estimation of a multiple regression parameter, S-estimators are shown to satisfy first-order conditions of M-estimators. We show that the influence function IF (x;S F) of

  10. Estimating radiation-induced cancer risk using MVK two-stage model for carcinogenesis

    International Nuclear Information System (INIS)

    Kai, M.; Kusama, T.; Aoki, Y.

    1993-01-01

    Based on the carcinogenesis model as proposed by Moolgavkar et al., time-dependent relative risk models were derived for projecting the time variation in excess relative risk. If it is assumed that each process is described by time-independent linear dose-response relationship, the time variation in excess relative risk is influenced by the parameter related with the promotion process. The risk model based carcinogenesis theory would play a marked role in estimating radiation-induced cancer risk in constructing a projection model or transfer model

  11. Assessment of Methods for Estimating Risk to Birds from ...

    Science.gov (United States)

    The U.S. EPA Ecological Risk Assessment Support Center (ERASC) announced the release of the final report entitled, Assessment of Methods for Estimating Risk to Birds from Ingestion of Contaminated Grit Particles. This report evaluates approaches for estimating the probability of ingestion by birds of contaminated particles such as pesticide granules or lead particles (i.e. shot or bullet fragments). In addition, it presents an approach for using this information to estimate the risk of mortality to birds from ingestion of lead particles. Response to ERASC Request #16

  12. A new relation to estimate nuclear radius

    International Nuclear Information System (INIS)

    Singh, M.; Kumar, Pradeep; Singh, Y.; Gupta, K.K.; Varshney, A.K.; Gupta, D.K.

    2013-01-01

    The uncertainty found in Grodzins semi empirical relation may be due to the non - consideration of asymmetry in the relation. In the present work we propose a new relation connecting B(E2; 2 1 + → 0 1 + ) and E2 1 + with asymmetric parameter γ

  13. Estimating and comparing risks in the future

    International Nuclear Information System (INIS)

    Llewellyn, Gareth

    1998-01-01

    The current position of power generation in UK is balanced. Recently 16 advanced gas cooled reactors are in operation. Privatisation of most power generation plants is done. Some trialing of environmental premia is performed. Environmental management is very strong. Nuclear power status in the UK is as follows: 16 Advanced gas cooled reactors, 1 Pressurised water reactor, Nuclear Electric/Scottish Nuclear in commercial operation; out of 18 Magnox reactors in operation 3 are decommissioned, 8 are due to stop operating before 2000. Non-nuclear fuel used are coal, oil, gas, hydropower. Besides carbon dioxide emissions emerging issue is rad waste disposal. This presentation deals with the strategic risk assessment in power generation sector

  14. An interim UK response to revised risk estimates

    International Nuclear Information System (INIS)

    Beaver, P.F.; Bines, W.P.

    1992-01-01

    This paper describes the legal framework in place when the revised risk estimates were announced by the International Commission for Radiological Protection (ICRP) in 1987 and how an addition to that framework enabled the revised risk estimates to be taken into account when making decisions about radiation protection practice both at plant and individual worker level. It is suggested that this a may be an early example of the use of a constraint applied generically. (author)

  15. ICRP risk estimates - an alternative view

    International Nuclear Information System (INIS)

    Morgan, K.Z.

    1987-01-01

    This criticism of the worth of the ICRP Main Commission spans 60 years, reviewed by a member of the Commission. Beginning in 1960 two serious radiation exposure problems (occupational exposure in uranium mines and population exposure from testing of nuclear weapons) came to their attention. One might have expected ICRP to be the first to try to reduce these exposures but it was conspicuous by its silence. In 1958 ICRP set limits of exposure for radiation workers and member of the public. Nineteen years later (1977) when it was realized that the risk of radiation induced cancer was ten to thirty times what it was perceived to be in 1958, ICRP might have been expected to recommend a major reduction in permissible exposure levels, but to the dismay of some it increased them. It was also a great disappointment when in 1977, levels of MPC of radionuclides in air, water and food were increased for a large fraction of the more dangerous radionuclides. The reactor accident at Chernobyl calls for a number of new ICRP recommendations. When can we expect them? (author)

  16. Explaining behavior change after genetic testing: the problem of collinearity between test results and risk estimates.

    Science.gov (United States)

    Fanshawe, Thomas R; Prevost, A Toby; Roberts, J Scott; Green, Robert C; Armstrong, David; Marteau, Theresa M

    2008-09-01

    This paper explores whether and how the behavioral impact of genotype disclosure can be disentangled from the impact of numerical risk estimates generated by genetic tests. Secondary data analyses are presented from a randomized controlled trial of 162 first-degree relatives of Alzheimer's disease (AD) patients. Each participant received a lifetime risk estimate of AD. Control group estimates were based on age, gender, family history, and assumed epsilon4-negative apolipoprotein E (APOE) genotype; intervention group estimates were based upon the first three variables plus true APOE genotype, which was also disclosed. AD-specific self-reported behavior change (diet, exercise, and medication use) was assessed at 12 months. Behavior change was significantly more likely with increasing risk estimates, and also more likely, but not significantly so, in epsilon4-positive intervention group participants (53% changed behavior) than in control group participants (31%). Intervention group participants receiving epsilon4-negative genotype feedback (24% changed behavior) and control group participants had similar rates of behavior change and risk estimates, the latter allowing assessment of the independent effects of genotype disclosure. However, collinearity between risk estimates and epsilon4-positive genotypes, which engender high-risk estimates, prevented assessment of the independent effect of the disclosure of an epsilon4 genotype. Novel study designs are proposed to determine whether genotype disclosure has an impact upon behavior beyond that of numerical risk estimates.

  17. How are flood risk estimates affected by the choice of return-periods?

    Science.gov (United States)

    Ward, P. J.; de Moel, H.; Aerts, J. C. J. H.

    2011-12-01

    Flood management is more and more adopting a risk based approach, whereby flood risk is the product of the probability and consequences of flooding. One of the most common approaches in flood risk assessment is to estimate the damage that would occur for floods of several exceedance probabilities (or return periods), to plot these on an exceedance probability-loss curve (risk curve) and to estimate risk as the area under the curve. However, there is little insight into how the selection of the return-periods (which ones and how many) used to calculate risk actually affects the final risk calculation. To gain such insights, we developed and validated an inundation model capable of rapidly simulating inundation extent and depth, and dynamically coupled this to an existing damage model. The method was applied to a section of the River Meuse in the southeast of the Netherlands. Firstly, we estimated risk based on a risk curve using yearly return periods from 2 to 10 000 yr (€ 34 million p.a.). We found that the overall risk is greatly affected by the number of return periods used to construct the risk curve, with over-estimations of annual risk between 33% and 100% when only three return periods are used. In addition, binary assumptions on dike failure can have a large effect (a factor two difference) on risk estimates. Also, the minimum and maximum return period considered in the curve affects the risk estimate considerably. The results suggest that more research is needed to develop relatively simple inundation models that can be used to produce large numbers of inundation maps, complementary to more complex 2-D-3-D hydrodynamic models. It also suggests that research into flood risk could benefit by paying more attention to the damage caused by relatively high probability floods.

  18. 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.

  19. Model-based Small Area Estimates of Cancer Risk Factors and Screening Behaviors - Small Area Estimates

    Science.gov (United States)

    These model-based estimates use two surveys, the Behavioral Risk Factor Surveillance System (BRFSS) and the National Health Interview Survey (NHIS). The two surveys are combined using novel statistical methodology.

  20. Heterogenous Intertemporal Elasticity of Substitution and Relative Risk Aversion

    DEFF Research Database (Denmark)

    Khorunzhina, Natalia; Gayle, Wayne-Roy

    This paper investigates the existence and degree of variation across house holds and over time in the intertemporal elasticity of substitution (IES) and the coefficient of relative risk aversion (RRA) that is generated by habit forming preferences. To do so, we develop a new nonlinear GMM estimator...... in food consumption. Using these estimates, we develop bounds for the expectation of the implied heterogenous intertemporal elasticity of substitution and relative risk aversion that account for measurement errors and compute asymptotically valid confidence intervals on these bounds. We find...

  1. Impact of microbial count distributions on human health risk estimates

    DEFF Research Database (Denmark)

    Ribeiro Duarte, Ana Sofia; Nauta, Maarten

    2015-01-01

    Quantitative microbiological risk assessment (QMRA) is influenced by the choice of the probability distribution used to describe pathogen concentrations, as this may eventually have a large effect on the distribution of doses at exposure. When fitting a probability distribution to microbial...... enumeration data, several factors may have an impact on the accuracy of that fit. Analysis of the best statistical fits of different distributions alone does not provide a clear indication of the impact in terms of risk estimates. Thus, in this study we focus on the impact of fitting microbial distributions...... on risk estimates, at two different concentration scenarios and at a range of prevalence levels. By using five different parametric distributions, we investigate whether different characteristics of a good fit are crucial for an accurate risk estimate. Among the factors studied are the importance...

  2. Using the Violence Risk Scale-Sexual Offense version in sexual violence risk assessments: Updated risk categories and recidivism estimates from a multisite sample of treated sexual offenders.

    Science.gov (United States)

    Olver, Mark E; Mundt, James C; Thornton, David; Beggs Christofferson, Sarah M; Kingston, Drew A; Sowden, Justina N; Nicholaichuk, Terry P; Gordon, Audrey; Wong, Stephen C P

    2018-04-30

    The present study sought to develop updated risk categories and recidivism estimates for the Violence Risk Scale-Sexual Offense version (VRS-SO; Wong, Olver, Nicholaichuk, & Gordon, 2003-2017), a sexual offender risk assessment and treatment planning tool. The overarching purpose was to increase the clarity and accuracy of communicating risk assessment information that includes a systematic incorporation of new information (i.e., change) to modify risk estimates. Four treated samples of sexual offenders with VRS-SO pretreatment, posttreatment, and Static-99R ratings were combined with a minimum follow-up period of 10-years postrelease (N = 913). Logistic regression was used to model 5- and 10-year sexual and violent (including sexual) recidivism estimates across 6 different regression models employing specific risk and change score information from the VRS-SO and/or Static-99R. A rationale is presented for clinical applications of select models and the necessity of controlling for baseline risk when utilizing change information across repeated assessments. Information concerning relative risk (percentiles) and absolute risk (recidivism estimates) is integrated with common risk assessment language guidelines to generate new risk categories for the VRS-SO. Guidelines for model selection and forensic clinical application of the risk estimates are discussed. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  3. Multivariate Risk-Return Decision Making Within Dynamic Estimation

    Directory of Open Access Journals (Sweden)

    Josip Arnerić

    2008-10-01

    Full Text Available Risk management in this paper is focused on multivariate risk-return decision making assuming time-varying estimation. Empirical research in risk management showed that the static "mean-variance" methodology in portfolio optimization is very restrictive with unrealistic assumptions. The objective of this paper is estimation of time-varying portfolio stocks weights by constraints on risk measure. Hence, risk measure dynamic estimation is used in risk controlling. By risk control manager makes free supplementary capital for new investments.Univariate modeling approach is not appropriate, even when portfolio returns are treated as one variable. Portfolio weights are time-varying, and therefore it is necessary to reestimate whole model over time. Using assumption of bivariate Student´s t-distribution, in multivariate GARCH(p,q models, it becomes possible to forecast time-varying portfolio risk much more precisely. The complete procedure of analysis is established from Zagreb Stock Exchange using daily observations of Pliva and Podravka stocks.

  4. Estimating cancer risks to adults undergoing body CT examinations

    International Nuclear Information System (INIS)

    Huda, W.; He, W.

    2012-01-01

    The purpose of the study is to estimate cancer risks from the amount of radiation used to perform body computed tomography (CT) examination. The ImPACT CT Patient Dosimetry Calculator was used to compute values of organ doses for adult body CT examinations. The radiation used to perform each examination was quantified by the dose-length product (DLP). Patient organ doses were converted into corresponding age and sex dependent cancer risks using data from BEIR VII. Results are presented for cancer risks per unit DLP and unit effective dose for 11 sensitive organs, as well as estimates of the contribution from 'other organs'. For patients who differ from a standard sized adult, correction factors based on the patient weight and antero-posterior dimension are provided to adjust organ doses and the corresponding risks. At constant incident radiation intensity, for CT examinations that include the chest, risks for females are markedly higher than those for males, whereas for examinations that include the pelvis, risks in males were slightly higher than those in females. In abdominal CT scans, risks for males and female patients are very similar. For abdominal CT scans, increasing the patient age from 20 to 80 resulted in a reduction in patient risks of nearly a factor of 5. The average cancer risk for chest/abdomen/pelvis CT examinations was ∼26 % higher than the cancer risk caused by 'sensitive organs'. Doses and radiation risks in 80 kg adults were ∼10 % lower than those in 70 kg patients. Cancer risks in body CT can be estimated from the examination DLP by accounting for sex, age, as well as patient physical characteristics. (authors)

  5. Estimating and mapping the population at risk of sleeping sickness.

    Directory of Open Access Journals (Sweden)

    Pere P Simarro

    Full Text Available Human African trypanosomiasis (HAT, also known as sleeping sickness, persists as a public health problem in several sub-Saharan countries. Evidence-based, spatially explicit estimates of population at risk are needed to inform planning and implementation of field interventions, monitor disease trends, raise awareness and support advocacy. Comprehensive, geo-referenced epidemiological records from HAT-affected countries were combined with human population layers to map five categories of risk, ranging from "very high" to "very low," and to estimate the corresponding at-risk population.Approximately 70 million people distributed over a surface of 1.55 million km(2 are estimated to be at different levels of risk of contracting HAT. Trypanosoma brucei gambiense accounts for 82.2% of the population at risk, the remaining 17.8% being at risk of infection from T. b. rhodesiense. Twenty-one million people live in areas classified as moderate to very high risk, where more than 1 HAT case per 10,000 inhabitants per annum is reported.Updated estimates of the population at risk of sleeping sickness were made, based on quantitative information on the reported cases and the geographic distribution of human population. Due to substantial methodological differences, it is not possible to make direct comparisons with previous figures for at-risk population. By contrast, it will be possible to explore trends in the future. The presented maps of different HAT risk levels will help to develop site-specific strategies for control and surveillance, and to monitor progress achieved by ongoing efforts aimed at the elimination of sleeping sickness.

  6. Validating diagnoses from hospital discharge registers change risk estimates for acute coronary syndrome

    DEFF Research Database (Denmark)

    Joensen, Albert Marni; Schmidt, E.B.; Dethlefsen, Claus

    2007-01-01

    of acute coronary syndrome (ACS) diagnoses identified in a hospital discharge register changed the relative risk estimates of well-established risk factors for ACS. Methods All first-time ACS diagnoses (n=1138) in the Danish National Patient Registry were identified among male participants in the Danish...

  7. Counselees’ expressed level of understanding of the risk estimate and surveillance recommendation are not associated with breast cancer surveillance adherence.

    NARCIS (Netherlands)

    Albada, A.; Dulmen, S. van; Dijkstra, H.; Wieffer, I.; Witkamp, A.; Ausems, M.G.E.M.

    2016-01-01

    We studied counselees’ expressed understanding of the risk estimate and surveillance recommendation in the final consultation for breast cancer genetic counseling in relation with their risk perception, worry and cancer surveillance adherence 1 year post-counseling. Consecutive counselees were

  8. Calculating excess lifetime risk in relative risk models

    International Nuclear Information System (INIS)

    Vaeth, M.; Pierce, D.A.

    1990-01-01

    When assessing the impact of radiation exposure it is common practice to present the final conclusions in terms of excess lifetime cancer risk in a population exposed to a given dose. The present investigation is mainly a methodological study focusing on some of the major issues and uncertainties involved in calculating such excess lifetime risks and related risk projection methods. The age-constant relative risk model used in the recent analyses of the cancer mortality that was observed in the follow-up of the cohort of A-bomb survivors in Hiroshima and Nagasaki is used to describe the effect of the exposure on the cancer mortality. In this type of model the excess relative risk is constant in age-at-risk, but depends on the age-at-exposure. Calculation of excess lifetime risks usually requires rather complicated life-table computations. In this paper we propose a simple approximation to the excess lifetime risk; the validity of the approximation for low levels of exposure is justified empirically as well as theoretically. This approximation provides important guidance in understanding the influence of the various factors involved in risk projections. Among the further topics considered are the influence of a latent period, the additional problems involved in calculations of site-specific excess lifetime cancer risks, the consequences of a leveling off or a plateau in the excess relative risk, and the uncertainties involved in transferring results from one population to another. The main part of this study relates to the situation with a single, instantaneous exposure, but a brief discussion is also given of the problem with a continuous exposure at a low-dose rate

  9. Estimation of cancer risks from radiotherapy of benign diseases

    International Nuclear Information System (INIS)

    Trott, K.R.; Kamprad, F.

    2006-01-01

    Background: The effective-dose method which was proposed by the ICRP (International Commission of Radiation Protection) for the estimation of risk to the general population from occupational or environmental, low-dose radiation exposure is not adequate for estimating the risk of cancer induction by radiotherapy of malignant or nonmalignant diseases. Methods:The risk of cancer induction by radiotherapy of benign diseases should be based on epidemiologic data directly derived from follow-up studies of patients who had been given radiotherapy for nonmalignant diseases in the past. Results: Risk factors were derived from epidemiologic studies of patients treated with irradiation for nonmalignant diseases to be used for selecting treatment options and optimizing treatment procedures. Conclusion: In most cases, cancer risks estimated by the effective-dose method may overestimate the true risks by one order of magnitude, yet in other cases even may underestimate it. The proposed method using organ-specific risk factors may be more suitable for treatment planning. (orig.)

  10. Managing risk in statistics - "Relative risk" | Durrheim | South African ...

    African Journals Online (AJOL)

    South African Family Practice. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 45, No 8 (2003) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Managing risk in statistics - "Relative risk". DN Durrheim ...

  11. Nonparametric estimation of benchmark doses in environmental risk assessment

    Science.gov (United States)

    Piegorsch, Walter W.; Xiong, Hui; Bhattacharya, Rabi N.; Lin, Lizhen

    2013-01-01

    Summary An important statistical objective in environmental risk analysis is estimation of minimum exposure levels, called benchmark doses (BMDs), that induce a pre-specified benchmark response in a dose-response experiment. In such settings, representations of the risk are traditionally based on a parametric dose-response model. It is a well-known concern, however, that if the chosen parametric form is misspecified, inaccurate and possibly unsafe low-dose inferences can result. We apply a nonparametric approach for calculating benchmark doses, based on an isotonic regression method for dose-response estimation with quantal-response data (Bhattacharya and Kong, 2007). We determine the large-sample properties of the estimator, develop bootstrap-based confidence limits on the BMDs, and explore the confidence limits’ small-sample properties via a short simulation study. An example from cancer risk assessment illustrates the calculations. PMID:23914133

  12. Current estimates of radiation risks and implications for dose limits

    International Nuclear Information System (INIS)

    Clarke, R.H.

    1989-01-01

    The publication of the 1988 report of UNSCEAR represents a major step forward in that there is an international consensus on the estimation of risk from exposure to ionising radiation. The estimates of fatal cancers in the UNSCEAR report are up to 4 times the values in the 1977 review. This paper will describe the reasons for the increase, the remaining uncertainties and the implications for dose limits in occupational and public exposure. (author)

  13. Estimation of risks to humans following intake of plutonium

    International Nuclear Information System (INIS)

    Dolphin, G.W.

    1979-01-01

    The lung cancer in humans induced by plutonium intake usually starts in bronchial epithelium. The main types of lung cancer are epidermoid or squamous cell carcinoma, small cell anaplastic carcinoma, carcinoid types and bronchio-loalveolar cell carcinoma. The data on cancer in the patients given intravascular injections of Thorotrast are the only source of data from which risk estimates can be made for liver cancer. In the beagles injected with plutonium citrate, the only type of liver tumors observed in cholangiosarcoma, and if this were the case for humans, then the appropriate risk estimate is 3 times lower in human patients. Bone sarcoma and the cancer of the epithelial surfaces close to bones have been reported extensively in workers and patients exposed to radium-226 and radium-224. In the case of plutonium, it is assumed for the purpose of risk estimates that the cancer of the epithelial surfaces near bones does not occur. Plutonium passes through guts following ingestion or following the clearance of particles initially deposited in respiratory tracts. In the case of all long-lived radionuclides, lower large intestines are the region which receive the greatest dose from the activity passing through guts. It is assumed that plutonium accumulates in bone marrows through the action of macrophages engulfing the plutonium resorbed from bone surfaces. The main uncertainty in estimating the annual limit of intake probably lies in the metabolic and dosimetric models, and to a lesser extent, in the estimate of risk. (Yamashita, S.)

  14. Stochastic evaluation of tsunami inundation and quantitative estimating tsunami risk

    International Nuclear Information System (INIS)

    Fukutani, Yo; Anawat, Suppasri; Abe, Yoshi; Imamura, Fumihiko

    2014-01-01

    We performed a stochastic evaluation of tsunami inundation by using results of stochastic tsunami hazard assessment at the Soma port in the Tohoku coastal area. Eleven fault zones along the Japan trench were selected as earthquake faults generating tsunamis. The results show that estimated inundation area of return period about 1200 years had good agreement with that in the 2011 Tohoku earthquake. In addition, we evaluated quantitatively tsunami risk for four types of building; a reinforced concrete, a steel, a brick and a wood at the Soma port by combining the results of inundation assessment and tsunami fragility assessment. The results of quantitative estimating risk would reflect properly vulnerability of the buildings, that the wood building has high risk and the reinforced concrete building has low risk. (author)

  15. The complex model of risk and progression of AMD estimation

    Directory of Open Access Journals (Sweden)

    V. S. Akopyan

    2012-01-01

    Full Text Available Purpose: to develop a method and a statistical model to estimate individual risk of AMD and the risk for progression to advanced AMD using clinical and genetic risk factors.Methods: A statistical risk assessment model was developed using stepwise binary logistic regression analysis. to estimate the population differences in the prevalence of allelic variants of genes and for the development of models adapted to the population of Moscow region genotyping and assessment of the influence of other risk factors was performed in two groups: patients with differ- ent stages of AMD (n = 74, and control group (n = 116. Genetic risk factors included in the study: polymorphisms in the complement system genes (C3 and CFH, genes at 10q26 locus (ARMS2 and HtRA1, polymorphism in the mitochondrial gene Mt-ND2. Clinical risk factors included in the study: age, gender, high body mass index, smoking history.Results: A comprehensive analysis of genetic and clinical risk factors for AMD in the study group was performed. Compiled statis- tical model assessment of individual risk of AMD, the sensitivity of the model — 66.7%, specificity — 78.5%, AUC = 0.76. Risk factors of late AMD, compiled a statistical model describing the probability of late AMD, the sensitivity of the model — 66.7%, specificity — 78.3%, AUC = 0.73. the developed system allows determining the most likely version of the current late AMD: dry or wet.Conclusion: the developed test system and the mathematical algorhythm for determining the risk of AMD, risk of progression to advanced AMD have fair diagnostic informative and promising for use in clinical practice.

  16. Summary of the BEIR V committee's estimates of genetic risks

    International Nuclear Information System (INIS)

    Grahn, D.

    1990-01-01

    The Committee on the Biological Effects of Ionizing Radiations (BEIR V) was constituted in late 1986 to conduct a comprehensive review of the biological effects of ionizing radiations focusing on information reported since the conclusion of the 1980 BEIR study, and to provide new estimates of the risks of genetic and somatic effects in humans due to low-level exposures of ionizing radiation. The Committee preferred the doubling-dose method of genetic risk estimation over the direct method. Data from animal (mouse) studies provide a median value of 100 to 114 cGy for long-term low dose rate exposure doubling doses. These values are lower than the median from human studies. The BEIR Committee believed that a doubling dose of 100 cGy would be a prudent value leading to conservative estimates. The estimated risks themselves are not much different from those generated by previous BEIR committees, UNSCEAR, and other published estimates. The Committee estimates that between 100 and 200 added cases per million live births will be observed at genetic equilibrium if the population is exposed each generation to a dose of 0.01 Sv (1 rem). Nearly half ware attributed to clinically mild dominant defects, and the balance to congenital abnormalities. (L.L.) (2 tabs.)

  17. Revision of risk estimates and implications for dose limits

    International Nuclear Information System (INIS)

    Clarke, R.H.

    1989-01-01

    It has been apparent for some time that our estimates of the risks associated with exposure to ionizing radiation must be increased above those values reported by UNSCEAR in 1977 an dused by ICRP to form their present recommendations. NRPB foresaw some of these changes and introduced interim advice within the UK to restrict exposures of wordkers and members of the public to levels below the existing limits. Since that advice was given, UNSCEAR has produced a 1988 report reviewing human data to provide new estimates of risks associated with exposure at high doses and high doserates. These risk figures are up to 4 times higher than when UNSCEAR reported in 1977. In this paper, the reasons for the changes in the estimates of risk will be described and the current NRPB guidelines for risk factors for protection purposes will be presented. The implications of these new risk factors for the setting of dose limits will then be discussed. (Author). 10 refs.; 2 tabs

  18. Aspects of risk analysis application to estimation of nuclear accidents and tests consequences and intervention management

    International Nuclear Information System (INIS)

    Demin, V.F.; Hedemann-Jensen, P.; Rolevich, I.V.; Schneider, T.S.; Sobolev, B.G.

    1996-01-01

    For assessment of accident consequences and a post-accident management a risk analysis methodology and data bank (BARD) with allowance for radiation and non-radiation risk causes should be developed and used. Aspects of these needs and developments are considered. Some illustrative results of health risk estimation made with BARD for the Bryansk region territory with relatively high radioactive contamination from the Chernobyl accident are presented

  19. Evaluation of energy related risk acceptance (APHA energy task force)

    International Nuclear Information System (INIS)

    Hull, A.P.

    1977-01-01

    Living in a technological society with large energy requirements involves a number of related actities with attendant health risks, both to the working and to the general public. Therefore, the formulation of some general principles for risk acceptance is necessary. In addition to maximizing benefits and minimizing risk, relevant considerations must be made about the perception of risk as voluntary or involuntary, the number of persons collectively at risk at any one occasion, and the extent to which a risk is a familiar one. With regard to a given benefit, such as a given amount of energy, comparisons of the risks of alternate modes of production may be utilized. However, cost-benefit consideration is essential to the amelioration of current or prospective risks. This is unusual, since it is based on some estimate of the monetary value per premature death averted. It is proposed that increased longevity would be a more satisfactory measure. On a societal basis, large expenditures for additional energy-related pollution control do not appear justifiable since much larger, nonenergy-related health risks are relatively underaddressed. Knowledgeable health professionals could benefit the public by imparting authoritative information in this area

  20. Risk sharing relations and enforcement mechanisms

    NARCIS (Netherlands)

    Barr, A.; Dekker, M.; Fafchamps, M.

    2008-01-01

    We investigate whether the set of available enforcement mechanisms affects the formation of risk sharing relations by applying dyadic regression analysis to data from a specifically designed behavioural experiment, two surveys and a genealogical mapping exercise. During the experiment participants

  1. Human Immunodeficiency Virus Related Knowledge, Risk ...

    African Journals Online (AJOL)

    There was poor HIV preventive practices; indicating ... Gyawali, et al.: HIV related knowledge, risk perception and practices among married women. Annals of Medical .... of this study correspond to the Indian, Nigerian and Iranian studies cited ...

  2. Roadway related tort liability and risk management.

    Science.gov (United States)

    2010-06-01

    This workbook provide government employees background information related to tort liability and risk management. Past experience with lawsuits against government entities are summarized. The reasons for the lawsuits and results are analyzed. The obje...

  3. Estimation of Radiological Terrorism Risk by Administrative Districts

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Suk Hoon; Kim, Ju Youl [Seoul National Univ., Seoul (Korea, Republic of); Yoo, Ho Sik [Korea Institute of Nuclear Nonproliferation and Control, Daejeon (Korea, Republic of)

    2008-10-15

    Since the 9/11 attack in USA, the threat of terrorism across the world has dramatically increased. Accordingly, estimating terrorism risk has become an essential part of catastrophe risk strategies throughout the world. There are many forms of terrorism. Recently, the prospect of the radiological terrorist attack using the radioactive material is considered as one of the most serious threats. The aim of this paper is to assess the radiological terrorism risk by administrative districts based on the parameters that imply threat, vulnerability, and consequences of terrorist attacks.

  4. Estimation of Radiological Terrorism Risk by Administrative Districts

    International Nuclear Information System (INIS)

    Kim, Suk Hoon; Kim, Ju Youl; Yoo, Ho Sik

    2008-01-01

    Since the 9/11 attack in USA, the threat of terrorism across the world has dramatically increased. Accordingly, estimating terrorism risk has become an essential part of catastrophe risk strategies throughout the world. There are many forms of terrorism. Recently, the prospect of the radiological terrorist attack using the radioactive material is considered as one of the most serious threats. The aim of this paper is to assess the radiological terrorism risk by administrative districts based on the parameters that imply threat, vulnerability, and consequences of terrorist attacks

  5. Estimation of Cardiovascular Risk in Patients with Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Belkis Vicente Sánchez

    2015-09-01

    Full Text Available Background: diabetes mellitus accelerates atherosclerotic changes throughout the vascular tree and consequently increases the risk of developing fatal acute events. Objective: to estimate the global cardiovascular risk in patients with type 2 diabetes mellitus. Method: a cross-sectional study of a series of type 2 diabetic patients from the People's Council of Constancia, Abreus municipality, Cienfuegos province was conducted from July to December 2012. The universe comprised the 180 people with diabetes in the area. Variables studied were: age, sex, body mass index, nutritional assessment, blood pressure, toxic habits, associated chronic diseases, blood levels of glucose, lipids (total cholesterol and triglycerides and microalbuminuria. World Health Organization/International Society of Hypertension prediction charts specific to the region of the Americas, in which Cuba is included, were used to estimate the cardiovascular risk. Results: mean age was 61.63 years and females predominated. Relevant risk factors were hypertension followed by obesity, smoking and dyslipidemia. Mean body mass index was 27.66kg/m2; waist circumference was 94.45 cm in women and 96.86 cm in men. Thirty point six percent had more than two uncontrolled risk factors and 28.3 % of the total presented a high to very high cardiovascular risk. Conclusions: cardiovascular risk prediction charts are helpful tools for making clinical decisions, but their interpretation must be flexible and allow the intervention of clinical reasoning.

  6. Reconstruction of financial networks for robust estimation of systemic risk

    International Nuclear Information System (INIS)

    Mastromatteo, Iacopo; Zarinelli, Elia; Marsili, Matteo

    2012-01-01

    In this paper we estimate the propagation of liquidity shocks through interbank markets when the information about the underlying credit network is incomplete. We show that techniques such as maximum entropy currently used to reconstruct credit networks severely underestimate the risk of contagion by assuming a trivial (fully connected) topology, a type of network structure which can be very different from the one empirically observed. We propose an efficient message-passing algorithm to explore the space of possible network structures and show that a correct estimation of the network degree of connectedness leads to more reliable estimations for systemic risk. Such an algorithm is also able to produce maximally fragile structures, providing a practical upper bound for the risk of contagion when the actual network structure is unknown. We test our algorithm on ensembles of synthetic data encoding some features of real financial networks (sparsity and heterogeneity), finding that more accurate estimations of risk can be achieved. Finally we find that this algorithm can be used to control the amount of information that regulators need to require from banks in order to sufficiently constrain the reconstruction of financial networks

  7. Reconstruction of financial networks for robust estimation of systemic risk

    Science.gov (United States)

    Mastromatteo, Iacopo; Zarinelli, Elia; Marsili, Matteo

    2012-03-01

    In this paper we estimate the propagation of liquidity shocks through interbank markets when the information about the underlying credit network is incomplete. We show that techniques such as maximum entropy currently used to reconstruct credit networks severely underestimate the risk of contagion by assuming a trivial (fully connected) topology, a type of network structure which can be very different from the one empirically observed. We propose an efficient message-passing algorithm to explore the space of possible network structures and show that a correct estimation of the network degree of connectedness leads to more reliable estimations for systemic risk. Such an algorithm is also able to produce maximally fragile structures, providing a practical upper bound for the risk of contagion when the actual network structure is unknown. We test our algorithm on ensembles of synthetic data encoding some features of real financial networks (sparsity and heterogeneity), finding that more accurate estimations of risk can be achieved. Finally we find that this algorithm can be used to control the amount of information that regulators need to require from banks in order to sufficiently constrain the reconstruction of financial networks.

  8. Biomechanical Indices for Rupture Risk Estimation in Abdominal Aortic Aneurysms

    NARCIS (Netherlands)

    Leemans, Eva L.; Willems, Tineke P.; van der Laan, Maarten J.; Slump, Cornelis H.; Zeebregts, Clark J.

    2017-01-01

    Purpose: To review the use of biomechanical indices for the estimation of abdominal aortic aneurysm (AAA) rupture risk, emphasizing their potential use in a clinical setting. Methods: A search of the PubMed, Embase, Scopus, and Compendex databases was made up to June 2015 to identify articles

  9. [Survival analysis with competing risks: estimating failure probability].

    Science.gov (United States)

    Llorca, Javier; Delgado-Rodríguez, Miguel

    2004-01-01

    To show the impact of competing risks of death on survival analysis. We provide an example of survival time without chronic rejection after heart transplantation, where death before rejection acts as a competing risk. Using a computer simulation, we compare the Kaplan-Meier estimator and the multiple decrement model. The Kaplan-Meier method overestimated the probability of rejection. Next, we illustrate the use of the multiple decrement model to analyze secondary end points (in our example: death after rejection). Finally, we discuss Kaplan-Meier assumptions and why they fail in the presence of competing risks. Survival analysis should be adjusted for competing risks of death to avoid overestimation of the risk of rejection produced with the Kaplan-Meier method.

  10. Exposure Estimation and Interpretation of Occupational Risk: Enhanced Information for the Occupational Risk Manager

    Science.gov (United States)

    Waters, Martha; McKernan, Lauralynn; Maier, Andrew; Jayjock, Michael; Schaeffer, Val; Brosseau, Lisa

    2015-01-01

    The fundamental goal of this article is to describe, define, and analyze the components of the risk characterization process for occupational exposures. Current methods are described for the probabilistic characterization of exposure, including newer techniques that have increasing applications for assessing data from occupational exposure scenarios. In addition, since the probability of health effects reflects variability in the exposure estimate as well as the dose-response curve—the integrated considerations of variability surrounding both components of the risk characterization provide greater information to the occupational hygienist. Probabilistic tools provide a more informed view of exposure as compared to use of discrete point estimates for these inputs to the risk characterization process. Active use of such tools for exposure and risk assessment will lead to a scientifically supported worker health protection program. Understanding the bases for an occupational risk assessment, focusing on important sources of variability and uncertainty enables characterizing occupational risk in terms of a probability, rather than a binary decision of acceptable risk or unacceptable risk. A critical review of existing methods highlights several conclusions: (1) exposure estimates and the dose-response are impacted by both variability and uncertainty and a well-developed risk characterization reflects and communicates this consideration; (2) occupational risk is probabilistic in nature and most accurately considered as a distribution, not a point estimate; and (3) occupational hygienists have a variety of tools available to incorporate concepts of risk characterization into occupational health and practice. PMID:26302336

  11. Parametric Bayesian Estimation of Differential Entropy and Relative Entropy

    Directory of Open Access Journals (Sweden)

    Maya Gupta

    2010-04-01

    Full Text Available Given iid samples drawn from a distribution with known parametric form, we propose the minimization of expected Bregman divergence to form Bayesian estimates of differential entropy and relative entropy, and derive such estimators for the uniform, Gaussian, Wishart, and inverse Wishart distributions. Additionally, formulas are given for a log gamma Bregman divergence and the differential entropy and relative entropy for the Wishart and inverse Wishart. The results, as always with Bayesian estimates, depend on the accuracy of the prior parameters, but example simulations show that the performance can be substantially improved compared to maximum likelihood or state-of-the-art nonparametric estimators.

  12. Testing for changes in spatial relative risk.

    Science.gov (United States)

    Hazelton, Martin L

    2017-07-30

    The spatial relative risk function is a useful tool for describing geographical variation in disease incidence. We consider the problem of comparing relative risk functions between two time periods, with the idea of detecting alterations in the spatial pattern of disease risk irrespective of whether there has been a change in the overall incidence rate. Using case-control datasets for each period, we use kernel smoothing methods to derive a test statistic based on the difference between the log-relative risk functions, which we term the log-relative risk ratio. For testing a null hypothesis of an unchanging spatial pattern of risk, we show how p-values can be computed using both randomization methods and an asymptotic normal approximation. The methodology is applied to data on campylobacteriosis from 2006 to 2013 in a region of New Zealand. We find clear evidence of a change in the spatial pattern of risk between those years, which can be explained in differences by response to a public health initiative between urban and rural communities. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  13. The estimation of risk-premium implicit in oil prices

    International Nuclear Information System (INIS)

    Luis, J.B.

    2001-01-01

    The futures price can be seen as the sum of the expected value of the underlying asset price and a risk-premium. In order to disentangle these two components of the futures price, one can try to model the relationship between spot and futures prices, in order to obtain a closed expression for the risk-premium, or to use information from spot and option prices to estimate risk-aversion functions. Given the high volatility of the ratios between futures and spot prices, we opted for the latter, estimating risk-neutral and subjective probability density functions, respectively, from observed option and spot prices. looking at the prices of Brent and West Texas Intermediate light/sweet crude oil options, the obtained evidence suggests that risk-aversion is typically very low for levels near the futures prices. However, due to price volatility and, consequently, to the tails of distribution, the risk-aversion functions are badly behaved in extreme prices and futures prices do not anticipate sharp movements in oil spot prices. Therefore, futures oil prices seem to be useful in forecasting spot prices only when moderate price changes occur. (author)

  14. Model dependencies of risk aversion and working interest estimates

    International Nuclear Information System (INIS)

    Lerche, I.

    1996-01-01

    Working interest, W, and risk adjusted value, RAV, are evaluated using both Cozzolino's formula for exponential dependence of risk aversion and also for a hyperbolic tangent dependence. In addition, the general method is given of constructing an RAV formula for any functional choice of risk aversion dependence. Two examples are given to illustrate how the model dependencies influence choices of working interest and risk adjusted value depending on whether the expected value of the project is positive or negative. In general the Cozzolino formula provides a more conservative position for risk than does the hyperbolic tangent formula, reflecting the difference in corporate attitudes to risk aversion. The commonly used Cozzolino formula is shown to have simple exact arithmetic expressions for maximum working interest and maximum RAV; the hyperbolic tangent formula has approximate analytic expressions. Both formulae also yield approximate analytical expressions for the working interest yielding a risk neutral RAV of zero. These arithmetic results are useful for making quick estimates of working interest ranges and risk adjusted values. (Author)

  15. 41 CFR 102-80.50 - Are Federal agencies responsible for identifying/estimating risks and for appropriate risk...

    Science.gov (United States)

    2010-07-01

    ... Environmental Management Risks and Risk Reduction Strategies § 102-80.50 Are Federal agencies responsible for... identify and estimate safety and environmental management risks and appropriate risk reduction strategies... responsible for identifying/estimating risks and for appropriate risk reduction strategies? 102-80.50 Section...

  16. Estimation of lung cancer risk from environmental exposure to airborne plutonium from the Rocky Flats Plant

    International Nuclear Information System (INIS)

    Sutherland, J.V.

    1983-01-01

    A three-phase study was undertaken to (1) determine the nature of disagreement among scientists concerning risk of environmental release of plutonium, (2) develop an analytic procedure for determining risk based on clearly stated principles defensible by reference to the literature, and (3) develop estimates of radiation dose to the lung from exposure to plutonium in ambient air for the purpose of evaluating risk to an individual with a specified age and smoking history. Eleven epidemiologists, biostatisticians and radiation scientists participated in Phase I of the study. It was shown that no clearly stated analytical principles for risk estimation were in common use, resulting in widely divergent risk estimates. Five of these disagreeing scientists in Phase I (including all cancer epidemiologists in the Denver metropolitan area) were chosen for Phase II of the study. A single analytic procedure was developed which was unanimously agreed upon. This procedure was dependent on the estimate of dose to the lung from ambient air levels of Rocky Flats plutonium. In Phase III of the study, a panel of four radiation scientists developed a procedure for estimation of dose to the lung from chronic exposure to plutonium ambient air levels. Results from all phases of the study were used to develop a method for estimation of relative risk of lung cancer for an individual, given plutonium dose to the lung, age, smoking history and other radiation exposure

  17. Methods for estimating risks to nuclear power plants from shipping

    International Nuclear Information System (INIS)

    Walker, D.H.; Hartman, M.G.; Robbins, T.R.

    1975-01-01

    Nuclear power plants sited on land near shipping lanes or offshore can be exposed to potential risks if there is nearby ship or barge traffic which involves the transport of hazardous cargo. Methods that have been developed for estimating the degree of risk are summarized. Of concern are any accidents which could lead to a release or spill of the hazardous cargo, or to an explosion. A probability of occurrence of the order of 10 -7 per year is a general guideline which has been used to judge whether or not the risk from hazards created by accidents is acceptable. This guideline has been followed in the risk assessment discussed in this paper. 19 references

  18. Parametric Bayesian Estimation of Differential Entropy and Relative Entropy

    OpenAIRE

    Gupta; Srivastava

    2010-01-01

    Given iid samples drawn from a distribution with known parametric form, we propose the minimization of expected Bregman divergence to form Bayesian estimates of differential entropy and relative entropy, and derive such estimators for the uniform, Gaussian, Wishart, and inverse Wishart distributions. Additionally, formulas are given for a log gamma Bregman divergence and the differential entropy and relative entropy for the Wishart and inverse Wishart. The results, as always with Bayesian est...

  19. Estimating radiation risk induced by CT screening for Korean population

    Science.gov (United States)

    Yang, Won Seok; Yang, Hye Jeong; Min, Byung In

    2017-02-01

    The purposes of this study are to estimate the radiation risks induced by chest/abdomen computed tomography (CT) screening for healthcare and to determine the cancer risk level of the Korean population compared to other populations. We used an ImPACT CT Patient Dosimetry Calculator to compute the organ effective dose induced by CT screening (chest, low-dose chest, abdomen/pelvis, and chest/abdomen/pelvis CT). A risk model was applied using principles based on the BEIR VII Report in order to estimate the lifetime attributable risk (LAR) using the Korean Life Table 2010. In addition, several countries including Hong Kong, the United States (U.S.), and the United Kingdom, were selected for comparison. Herein, each population exposed radiation dose of 100 mSv was classified according to country, gender and age. For each CT screening the total organ effective dose calculated by ImPACT was 6.2, 1.5, 5.2 and 11.4 mSv, respectively. In the case of Korean female LAR, it was similar to Hong Kong female but lower than those of U.S. and U.K. females, except for those in their twenties. The LAR of Korean males was the highest for all types of CT screening. However, the difference of the risk level was negligible because of the quite low value.

  20. Estimation of lifetime cumulative incidence and mortality risk of gastric cancer.

    Science.gov (United States)

    Taniyama, Yukari; Katanoda, Kota; Charvat, Hadrien; Hori, Megumi; Ohno, Yuko; Sasazuki, Shizuka; Tsugane, Shoichiro

    2017-11-01

    To estimate cumulative incidence and mortality risk for gastric cancer by risk category. Risk was classified into four types according to the presence/absence of Helicobacter pylori infection and chronic atrophic gastritis: in order of lowest to highest risk, Group A: H. pylori(-) and atrophic gastritis(-); Group B: H. pylori(+) and atrophic gastritis(-); Group C:H. pylori(+) and atrophic gastritis(+); and, Group D: H. pylori(-) and atrophic gastritis(+). We used vital statistics for the crude all-cause and crude gastric cancer mortality rates in 2011 and data from population-based cancer registries (the Monitoring of Cancer Incidence in Japan) for gastric cancer incidence in 2011. For relative risk and prevalence, we used the results of a meta-analysis integrating previous studies and data from the Japan Public Health Center-based Prospective Study for the Next Generation, respectively (baseline survey 2011-16). We calculated the crude incidence and mortality rates and estimated the cumulative risk using a life-table method. The estimated lifetime cumulative incidence risk was 11.4% for men and 5.7% for women. The estimated risk for Groups A, B, C and D was 2.4%, 10.8%, 26.7% and 35.5% for men, and 1.2%, 5.5%, 13.5% and 18.0% for women, respectively. Similarly, the estimated lifetime cumulative mortality risk was 3.9% for men and 1.8% for women. The estimated risk of mortality for Groups A, B, C and D was 0.8%, 3.6%, 9.0% and 12.0% for men, and 0.4%, 1.7%, 4.2% and 5.7% for women, respectively. Our results may be useful for designing individually tailored prevention programs. © The Author 2017. Published by Oxford University Press.

  1. Stochastic risk estimation from medical x-ray diagnostic examinations, 2. Risk estimates of individuals from x-ray diagnosis

    Energy Technology Data Exchange (ETDEWEB)

    Hashizume, T; Maruyama, T; Noda, Y; Iwai, K; Tateno, Y [National Inst. of Radiological Sciences, Chiba (Japan); Nishizawa, K

    1981-01-01

    The risks of genetic, leukemia and malignant diseases from medical X-ray diagnostic examinations were estimated using the frequency of radiographic and fluoroscopic exposures per diagnostic examination, child expectancy, leukemia and malignancy significant factors, and using a weighting factor determined on the basis of data concerning the cancer mortality among atomic bomb survivors in Nagasaki and of a recommendation of International Commission of Radiological Protection. The organ or tissue doses with respect to the stochastic risks were determined with ionization chambers and thermoluminescent dosimeters placed at the positions of the organs or tissues in a RANDO woman phantom which was exposed to diagnostic X-rays according to technical factors of typical radiographic and fluoroscopic examinations obtained from a nationwide survey. The resultant risks by age-group and type of radiographic and fluoroscopic examination are tabulated in terms of risk level of 10/sup -6/. In general, the total risk defined as the sum of genetic, leukemia and malignant risks was a high value for the X-ray diagnosis of digestive organs involving barium meal and barium enema. For example, the total risk for young age-group was 100 to 200 x 10/sup -6/ for the X-ray diagnosis of digestive organs. The total risk from the chest radiography was lower value as compared with the risk from the X-ray diagnosis of other organs or tissues. On the contrary, the risk from the chest tomography was comparable to the risk from the diagnosis of digestive organs. The total risk decreased with increasing of age for every X-ray diagnostic examination.

  2. Blind estimation of a ship's relative wave heading

    DEFF Research Database (Denmark)

    Nielsen, Ulrik Dam; Iseki, Toshio

    2012-01-01

    This article proposes a method to estimate a ship’s relative heading against the waves. The procedure relies purely on ship- board measurements of global responses such as motion components, accelerations and the bending moment amidships. There is no particular (mathematical) model connected to t...... to the estimate, and therefore it is called a ’blind estimate’. The approach is in this introductory study tested by analysing simulated data. The analysis reveals that it is possible to estimate a ship’s relative heading on the basis of shipboard measurements only....

  3. Effects of exposure estimation errors on estimated exposure-response relations for PM2.5.

    Science.gov (United States)

    Cox, Louis Anthony Tony

    2018-07-01

    Associations between fine particulate matter (PM2.5) exposure concentrations and a wide variety of undesirable outcomes, from autism and auto theft to elderly mortality, suicide, and violent crime, have been widely reported. Influential articles have argued that reducing National Ambient Air Quality Standards for PM2.5 is desirable to reduce these outcomes. Yet, other studies have found that reducing black smoke and other particulate matter by as much as 70% and dozens of micrograms per cubic meter has not detectably affected all-cause mortality rates even after decades, despite strong, statistically significant positive exposure concentration-response (C-R) associations between them. This paper examines whether this disconnect between association and causation might be explained in part by ignored estimation errors in estimated exposure concentrations. We use EPA air quality monitor data from the Los Angeles area of California to examine the shapes of estimated C-R functions for PM2.5 when the true C-R functions are assumed to be step functions with well-defined response thresholds. The estimated C-R functions mistakenly show risk as smoothly increasing with concentrations even well below the response thresholds, thus incorrectly predicting substantial risk reductions from reductions in concentrations that do not affect health risks. We conclude that ignored estimation errors obscure the shapes of true C-R functions, including possible thresholds, possibly leading to unrealistic predictions of the changes in risk caused by changing exposures. Instead of estimating improvements in public health per unit reduction (e.g., per 10 µg/m 3 decrease) in average PM2.5 concentrations, it may be essential to consider how interventions change the distributions of exposure concentrations. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. Uncertainties in fatal cancer risk estimates used in radiation protection

    International Nuclear Information System (INIS)

    Kai, Michiaki

    1999-01-01

    Although ICRP and NCRP had not described the details of uncertainties in cancer risk estimates in radiation protection, NCRP, in 1997, firstly reported the results of uncertainty analysis (NCRP No.126) and which is summarized in this paper. The NCRP report pointed out that there are following five factors which uncertainty possessing: uncertainty in epidemiological studies, in dose assessment, in transforming the estimates to risk assessment, in risk prediction and in extrapolation to the low dose/dose rate. These individual factors were analyzed statistically to obtain the relationship between the probability of cancer death in the US population and life time risk coefficient (% per Sv), which showed that, for the latter, the mean value was 3.99 x 10 -2 /Sv, median, 3.38 x 10 -2 /Sv, GSD (geometrical standard deviation), 1.83 x 10 -2 /Sv and 95% confidential limit, 1.2-8.84 x 10 -2 /Sv. The mean value was smaller than that of ICRP recommendation (5 x 10 -2 /Sv), indicating that the value has the uncertainty factor of 2.5-3. Moreover, the most important factor was shown to be the uncertainty in DDREF (dose/dose rate reduction factor). (K.H.)

  5. Method of risk estimates for genetic, leukemogenic and carcinogenic effects from medical and occupational exposures

    Energy Technology Data Exchange (ETDEWEB)

    Hashizume, T; Maruyama, T [National Inst. of Radiological Sciences, Chiba (Japan)

    1980-12-01

    For the risk estimate of fatal malignancies, an effective dose was proposed on the basis of the assumption that the risk should be equal whether the whole body irradiated uniformly or whether there is non-uniform irradiation. The effective dose was defined by the product of organ or tissue doses and a weighting factor representing the proportion of risk factor for a fatal malignancy resulting from organ or tissue irradiation to the total malignant factor. The risk of malignancies can be derived by multiplying the malignant significant factor by the product of the risk factor and the effective dose. For the genetic risk, a significant factor was a relative child expectancy and organ or tissue doses were gonad doses. And, for the leukemogenic risk, a significant factor was the leukemia significant factor and organ or tissue dose was mean bone marrow dose. The present method makes it easy to estimate the risk for individuals and population from medical and occupational exposures. The variation with age and sex of risk rates for stochastic effects was discussed, and the present data on risk rates were compared with the variation of risk rates recommended by the International Commission on Radiological Protection.

  6. Estimating pediatric general anesthesia exposure: Quantifying duration and risk.

    Science.gov (United States)

    Bartels, Devan Darby; McCann, Mary Ellen; Davidson, Andrew J; Polaner, David M; Whitlock, Elizabeth L; Bateman, Brian T

    2018-05-02

    Understanding the duration of pediatric general anesthesia exposure in contemporary practice is important for identifying groups at risk for long general anesthesia exposures and designing trials examining associations between general anesthesia exposure and neurodevelopmental outcomes. We performed a retrospective cohort analysis to estimate pediatric general anesthesia exposure duration during 2010-2015 using the National Anesthesia Clinical Outcomes Registry. A total of 1 548 021 pediatric general anesthetics were included. Median general anesthesia duration was 57 minutes (IQR: 28-86) with 90th percentile 145 minutes. Children aged 3 hours. High ASA physical status and care at a university hospital were associated with longer exposure times. While the vast majority (94%) of children undergoing general anesthesia are exposed for risk for longer exposures. These findings may help guide the design of future trials aimed at understanding neurodevelopmental impact of prolonged exposure in these high-risk groups. © 2018 John Wiley & Sons Ltd.

  7. Estimating the risk of cardio vascular diseases among pakistani diabetics using uk pds risk engine

    International Nuclear Information System (INIS)

    Moazzam, A.; Amer, J.

    2015-01-01

    The concept of risk estimation of Coronary Heart Disease (CHD) is helpful for clinician to identifying high risk populations for their effective treatment. Latest studies recommended only initiating cardio-protective treatment in diabetic patients based on personalized CHD risk estimates so as to reduce undue harm from overly aggressive risk factor modification. The United Kingdom Prospective Diabetes Study (UK PDS) Risk Engine is a widely used tool to assess the risk of Cardio Vascular diseases (CVD) in diabetics. The literature search so far did not reveal any study of risk assessment among Pakistani Diabetics. Methods: This descriptive study is based on the data of 470 type-2 diabetics seen in Department of Endocrinology and Metabolism, Services Institute of Medical Sciences, Lahore during 2011. The data of these 470 patients was analyzed through UKPDS Risk Engine. CHD risk was calculated. Results: The 10 years risk of CHD, fatal CHD, stroke and fatal stroke was 9.4%, 4.4%, 1.7% and 0.2% respectively. Conclusions: The present study show a lower risk of CVD occurring among Pakistani diabetics as compared to studies from western countries. (author)

  8. Economic estimation of risk and compensation of damage from accidents in power engineering objects

    International Nuclear Information System (INIS)

    Lesnykh, V.V.

    1996-01-01

    Place and basic peculiarities of the task relative to compensation of damage due to accidents in the problem on technical-economical studies of the power engineering objects, including NPPs, are analyzed. Certain approaches in the task of the risk economical estimates and basic provisions of the economical damage compensation system are presented. Description of imitated and analytical approach in the task of estimating financial state is given and certain study results are presented. 11 refs., 8 figs

  9. Future flood risk estimates along the river Rhine

    Directory of Open Access Journals (Sweden)

    A. H. te Linde

    2011-02-01

    Full Text Available In Europe, water management is moving from flood defence to a risk management approach, which takes both the probability and the potential consequences of flooding into account. It is expected that climate change and socio-economic development will lead to an increase in flood risk in the Rhine basin. To optimize spatial planning and flood management measures, studies are needed that quantify future flood risks and estimate their uncertainties. In this paper, we estimated the current and future fluvial flood risk in 2030 for the entire Rhine basin in a scenario study. The change in value at risk is based on two land-use projections derived from a land-use model representing two different socio-economic scenarios. Potential damage was calculated by a damage model, and changes in flood probabilities were derived from two climate scenarios and hydrological modeling. We aggregated the results into seven sections along the Rhine. It was found that the annual expected damage in the Rhine basin may increase by between 54% and 230%, of which the major part (~ three-quarters can be accounted for by climate change. The highest current potential damage can be found in the Netherlands (110 billion €, compared with the second (80 billion € and third (62 billion € highest values in two areas in Germany. Results further show that the area with the highest fluvial flood risk is located in the Lower Rhine in Nordrhein-Westfalen in Germany, and not in the Netherlands, as is often perceived. This is mainly due to the higher flood protection standards in the Netherlands as compared to Germany.

  10. METHODOLOGY RELATED TO ESTIMATION OF INVESTMENT APPEAL OF RURAL SETTLEMENTS

    Directory of Open Access Journals (Sweden)

    A. S. Voshev

    2010-03-01

    Full Text Available Conditions for production activity vary considerably from region to region, from area to area, from settlement to settlement. In this connection, investors are challenged to choose an optimum site for a new enterprise. To make the decision, investors follow such references as: investment potential and risk level; their interrelation determines investment appeal of a country, region, area, city or rural settlement. At present Russia faces a problem of «black boxes» represented by a lot of rural settlements. No effective and suitable techniques of quantitative estimation of investment potential, rural settlement risks and systems to make the given information accessible for potential investors exist until now.

  11. Estimating maneuvers for precise relative orbit determination using GPS

    Science.gov (United States)

    Allende-Alba, Gerardo; Montenbruck, Oliver; Ardaens, Jean-Sébastien; Wermuth, Martin; Hugentobler, Urs

    2017-01-01

    Precise relative orbit determination is an essential element for the generation of science products from distributed instrumentation of formation flying satellites in low Earth orbit. According to the mission profile, the required formation is typically maintained and/or controlled by executing maneuvers. In order to generate consistent and precise orbit products, a strategy for maneuver handling is mandatory in order to avoid discontinuities or precision degradation before, after and during maneuver execution. Precise orbit determination offers the possibility of maneuver estimation in an adjustment of single-satellite trajectories using GPS measurements. However, a consistent formulation of a precise relative orbit determination scheme requires the implementation of a maneuver estimation strategy which can be used, in addition, to improve the precision of maneuver estimates by drawing upon the use of differential GPS measurements. The present study introduces a method for precise relative orbit determination based on a reduced-dynamic batch processing of differential GPS pseudorange and carrier phase measurements, which includes maneuver estimation as part of the relative orbit adjustment. The proposed method has been validated using flight data from space missions with different rates of maneuvering activity, including the GRACE, TanDEM-X and PRISMA missions. The results show the feasibility of obtaining precise relative orbits without degradation in the vicinity of maneuvers as well as improved maneuver estimates that can be used for better maneuver planning in flight dynamics operations.

  12. Measurement of total risk of spontaneous abortion: the virtue of conditional risk estimation

    DEFF Research Database (Denmark)

    Modvig, J; Schmidt, L; Damsgaard, M T

    1990-01-01

    The concepts, methods, and problems of measuring spontaneous abortion risk are reviewed. The problems touched on include the process of pregnancy verification, the changes in risk by gestational age and maternal age, and the presence of induced abortions. Methods used in studies of spontaneous...... abortion risk include biochemical assays as well as life table technique, although the latter appears in two different forms. The consequences of using either of these are discussed. It is concluded that no study design so far is appropriate for measuring the total risk of spontaneous abortion from early...... conception to the end of the 27th week. It is proposed that pregnancy may be considered to consist of two or three specific periods and that different study designs should concentrate on measuring the conditional risk within each period. A careful estimate using this principle leads to an estimate of total...

  13. A simultaneous approach to the estimation of risk aversion and the subjective time discount rate

    NARCIS (Netherlands)

    Booij, A.S.; van Praag, B.M.S.

    2009-01-01

    In this paper we analyze a sample of 1832 individuals who responded to six randomly generated lottery questions that differ with respect to chance, prize and the timing of the draw. Using a model that explicitly allows for consumption smoothing, we obtain an estimate of relative risk aversion of 82.

  14. Estimating adolescent risk for hearing loss based on data from a large school-based survey

    NARCIS (Netherlands)

    Vogel, L.; Verschuure, H.; Ploeg, C.P.B. van der; Brug, J.; Raat, H.

    2010-01-01

    Objectives. We estimated whether and to what extent a group of adolescents were at risk of developing permanent hearing loss as a result of voluntary exposure to high-volume music, and we assessed whether such exposure was associated with hearing-related symptoms. Methods. In 2007, 1512 adolescents

  15. Estimating adolescent risk for hearing loss based on data from a large school-based survey

    NARCIS (Netherlands)

    I. Vogel (Ineke); H. Verschuure (Hans); C.P.B. van der Ploeg (Catharina); J. Brug (Hans); H. Raat (Hein)

    2010-01-01

    textabstractObjectives. We estimated whether and to what extent a group of adolescents were at risk of developing permanent hearing loss as a result of voluntary exposure to high-volume music, and we assessed whether such exposure was associated with hearing-related symptoms. Methods. In 2007, 1512

  16. Estimating twin concordance for bivariate competing risks twin data

    DEFF Research Database (Denmark)

    Scheike, Thomas; Holst, Klaus K.; Hjelmborg, Jacob B.

    2014-01-01

    For twin time-to-event data, we consider different concordance probabilities, such as the casewise concordance that are routinely computed as a measure of the lifetime dependence/correlation for specific diseases. The concordance probability here is the probability that both twins have experience...... events with the competing risk death. We thus aim to quantify the degree of dependence through the casewise concordance function and show a significant genetic component...... the event of interest. Under the assumption that both twins are censored at the same time, we show how to estimate this probability in the presence of right censoring, and as a consequence, we can then estimate the casewise twin concordance. In addition, we can model the magnitude of within pair dependence...... over time, and covariates may be further influential on the marginal risk and dependence structure. We establish the estimators large sample properties and suggest various tests, for example, for inferring familial influence. The method is demonstrated and motivated by specific twin data on cancer...

  17. Estimation of unit risk for coke oven emissions

    International Nuclear Information System (INIS)

    Moolgavkar, S.H.; Luebeck, E.G.; Anderson, E.L.

    1998-01-01

    In 1984, based on epidemiological data on cohorts of coke oven workers, USEPA estimated a unit risk for lung cancer associated with continuous exposure from birth to 1 microg/m 3 of coke oven emissions, of 6.2 x 10 -4 . This risk assessment was based on information on the cohorts available through 1966. Follow-up of these cohorts has now been extended to 1982 and, moreover, individual job histories, which were not available in 1984, have been constructed. In this study, lung cancer mortality in these cohorts of coke oven workers with extended follow-up was analyzed using standard techniques of survival analysis and a new approach based on the two stage clonal expansion model of carcinogenesis. The latter approach allows the explicit consideration of detailed patterns of exposure of each individual in the cohort. The analyses used the extended follow-up data through 1982 and the detailed job histories now available. Based on these analyses, the best estimate of unit risk is 1.5 x 10 -4 with 95% confidence interval = 1.2 x 10 -4 --1.8 x 10 -4

  18. Estimating relative demand for wildlife: Conservation activity indicators

    Science.gov (United States)

    Gray, Gary G.; Larson, Joseph S.

    1982-09-01

    An alternative method of estimating relative demand among nonconsumptive uses of wildlife and among wildlife species is proposed. A demand intensity score (DIS), derived from the relative extent of an individual's involvement in outdoor recreation and conservation activities, is used as a weighting device to adjust the importance of preference rankings for wildlife uses and wildlife species relative to other members of a survey population. These adjusted preference rankings were considered to reflect relative demand levels (RDLs) for wildlife uses and for species by the survey population. This technique may be useful where it is not possible or desirable to estimate demand using traditional economic means. In one of the findings from a survey of municipal conservation commission members in Massachusetts, presented as an illustration of this methodology, poisonous snakes were ranked third in preference among five groups of reptiles. The relative demand level for poisonous snakes, however, was last among the five groups.

  19. Schistosomiasis and water resources development: systematic review, meta-analysis, and estimates of people at risk.

    Science.gov (United States)

    Steinmann, Peter; Keiser, Jennifer; Bos, Robert; Tanner, Marcel; Utzinger, Jürg

    2006-07-01

    An estimated 779 million people are at risk of schistosomiasis, of whom 106 million (13.6%) live in irrigation schemes or in close proximity to large dam reservoirs. We identified 58 studies that examined the relation between water resources development projects and schistosomiasis, primarily in African settings. We present a systematic literature review and meta-analysis with the following objectives: (1) to update at-risk populations of schistosomiasis and number of people infected in endemic countries, and (2) to quantify the risk of water resources development and management on schistosomiasis. Using 35 datasets from 24 African studies, our meta-analysis showed pooled random risk ratios of 2.4 and 2.6 for urinary and intestinal schistosomiasis, respectively, among people living adjacent to dam reservoirs. The risk ratio estimate for studies evaluating the effect of irrigation on urinary schistosomiasis was in the range 0.02-7.3 (summary estimate 1.1) and that on intestinal schistosomiasis in the range 0.49-23.0 (summary estimate 4.7). Geographic stratification showed important spatial differences, idiosyncratic to the type of water resources development. We conclude that the development and management of water resources is an important risk factor for schistosomiasis, and hence strategies to mitigate negative effects should become integral parts in the planning, implementation, and operation of future water projects.

  20. Global building inventory for earthquake loss estimation and risk management

    Science.gov (United States)

    Jaiswal, Kishor; Wald, David; Porter, Keith

    2010-01-01

    We develop a global database of building inventories using taxonomy of global building types for use in near-real-time post-earthquake loss estimation and pre-earthquake risk analysis, for the U.S. Geological Survey’s Prompt Assessment of Global Earthquakes for Response (PAGER) program. The database is available for public use, subject to peer review, scrutiny, and open enhancement. On a country-by-country level, it contains estimates of the distribution of building types categorized by material, lateral force resisting system, and occupancy type (residential or nonresidential, urban or rural). The database draws on and harmonizes numerous sources: (1) UN statistics, (2) UN Habitat’s demographic and health survey (DHS) database, (3) national housing censuses, (4) the World Housing Encyclopedia and (5) other literature.

  1. Risk considerations related to lung modeling

    International Nuclear Information System (INIS)

    Masse, R.; Cross, F.T.

    1989-01-01

    Improved lung models provide a more accurate assessment of dose from inhalation exposures and, therefore, more accurate dose-response relationships for risk evaluation and exposure limitation. Epidemiological data for externally irradiated persons indicate that the numbers of excess respiratory tract carcinomas differ in the upper airways, bronchi, and distal lung. Neither their histogenesis and anatomical location nor their progenitor cells are known with sufficient accuracy for accurate assessment of the microdosimetry. The nuclei of sensitive cells generally can be assumed to be distributed at random in the epithelium, beneath the mucus and tips of the beating cilia and cells. In stratified epithelia, basal cells may be considered the only cells at risk. Upper-airway tumors have been observed in both therapeutically irradiated patients and in Hiroshima-Nagasaki survivors. The current International Commission on Radiological Protection Lung-Model Task Group proposes that the upper airways and lung have a similar relative risk coefficient for cancer induction. The partition of the risk weighting factor, therefore, will be proportional to the spontaneous death rate from tumors, and 80% of the weighting factor for the respiratory tract should be attributed to the lung. For Weibel lung-model branching generations 0 to 16 and 17 to 23, the Task Group proposes an 80/20 partition of the risk, i.e., 64% and 16%, respectively, of the total risk. Regarding risk in animals, recent data in rats indicate a significantly lower effectiveness for lung-cancer induction at low doses from insoluble long-lived alpha-emitters than from Rn daughters. These findings are due, in part, to the fact that different regions of the lung are irradiated. Tumors in the lymph nodes are rare in people and animals exposed to radiation.44 references

  2. Risk factors for age-related maculopathy.

    Science.gov (United States)

    Connell, Paul P; Keane, Pearse A; O'Neill, Evelyn C; Altaie, Rasha W; Loane, Edward; Neelam, Kumari; Nolan, John M; Beatty, Stephen

    2009-01-01

    Age-related maculopathy (ARM) is the leading cause of blindness in the elderly. Although beneficial therapeutic strategies have recently begun to emerge, much remains unclear regarding the etiopathogenesis of this disorder. Epidemiologic studies have enhanced our understanding of ARM, but the data, often conflicting, has led to difficulties with drawing firm conclusions with respect to risk for this condition. As a consequence, we saw a need to assimilate the published findings with respect to risk factors for ARM, through a review of the literature appraising results from published cross-sectional studies, prospective cohort studies, case series, and case control studies investigating risk for this condition. Our review shows that, to date, and across a spectrum of epidemiologic study designs, only age, cigarette smoking, and family history of ARM have been consistently demonstrated to represent risk for this condition. In addition, genetic studies have recently implicated many genes in the pathogenesis of age-related maculopathy, including Complement Factor H, PLEKHA 1, and LOC387715/HTRA1, demonstrating that environmental and genetic factors are important for the development of ARM suggesting that gene-environment interaction plays an important role in the pathogenesis of this condition.

  3. Risk Factors for Age-Related Maculopathy

    Directory of Open Access Journals (Sweden)

    Paul P. Connell

    2009-01-01

    Full Text Available Age-related maculopathy (ARM is the leading cause of blindness in the elderly. Although beneficial therapeutic strategies have recently begun to emerge, much remains unclear regarding the etiopathogenesis of this disorder. Epidemiologic studies have enhanced our understanding of ARM, but the data, often conflicting, has led to difficulties with drawing firm conclusions with respect to risk for this condition. As a consequence, we saw a need to assimilate the published findings with respect to risk factors for ARM, through a review of the literature appraising results from published cross-sectional studies, prospective cohort studies, case series, and case control studies investigating risk for this condition. Our review shows that, to date, and across a spectrum of epidemiologic study designs, only age, cigarette smoking, and family history of ARM have been consistently demonstrated to represent risk for this condition. In addition, genetic studies have recently implicated many genes in the pathogenesis of age-related maculopathy, including Complement Factor H, PLEKHA 1, and LOC387715/HTRA1, demonstrating that environmental and genetic factors are important for the development of ARM suggesting that gene-environment interaction plays an important role in the pathogenesis of this condition.

  4. Risk factors for age-related maculopathy.

    LENUS (Irish Health Repository)

    Connell, Paul P

    2012-02-01

    Age-related maculopathy (ARM) is the leading cause of blindness in the elderly. Although beneficial therapeutic strategies have recently begun to emerge, much remains unclear regarding the etiopathogenesis of this disorder. Epidemiologic studies have enhanced our understanding of ARM, but the data, often conflicting, has led to difficulties with drawing firm conclusions with respect to risk for this condition. As a consequence, we saw a need to assimilate the published findings with respect to risk factors for ARM, through a review of the literature appraising results from published cross-sectional studies, prospective cohort studies, case series, and case control studies investigating risk for this condition. Our review shows that, to date, and across a spectrum of epidemiologic study designs, only age, cigarette smoking, and family history of ARM have been consistently demonstrated to represent risk for this condition. In addition, genetic studies have recently implicated many genes in the pathogenesis of age-related maculopathy, including Complement Factor H, PLEKHA 1, and LOC387715\\/HTRA1, demonstrating that environmental and genetic factors are important for the development of ARM suggesting that gene-environment interaction plays an important role in the pathogenesis of this condition.

  5. Data Sources for the Model-based Small Area Estimates of Cancer Risk Factors and Screening Behaviors - Small Area Estimates

    Science.gov (United States)

    The model-based estimates of important cancer risk factors and screening behaviors are obtained by combining the responses to the Behavioral Risk Factor Surveillance System (BRFSS) and the National Health Interview Survey (NHIS).

  6. Improved Radiation Dosimetry/Risk Estimates to Facilitate Environmental Management of Plutonium Contaminated Sites

    International Nuclear Information System (INIS)

    Scott, Bobby R.

    1999-01-01

    The objective of this research is to evaluate distributions of possible alpha radiation doses to the lung, bone, and liver, and associated health-risk distributions for plutonium (Pu) inhalation exposure scenarios relevant to environmental management of PuO2-contaminated sites. Currently available dosimetry/risk models do not apply to exposure scenarios where relatively small numbers of highly radioactive PuO2 particles are presented for inhalation (stochastic exposure [SE] paradigm). For the SE paradigm, distributions of possible risks are more relevant than point estimates of risk. The main goal of the project is to deliver a computer program that will allow evaluation of the indicated risk distributions for the SE paradigm. However, some of our work also relates to the deterministic exposure [DE] paradigm where large numbers of airborne particles (resuspended dust containing PuO2) are presented for inhalation to members of the public residing or working at a remediated Department of Energy (DOE) site

  7. [Ionizing and non-ionizing radiation (comparative risk estimations)].

    Science.gov (United States)

    Grigor'ev, Iu G

    2012-01-01

    The population has widely used mobile communication for already more than 15 years. It is important to note that the use of mobile communication has sharply changed the conditions of daily exposure of the population to EME We expose our brain daily for the first time in the entire civilization. The mobile phone is an open and uncontrollable source of electromagnetic radiation. The comparative risk estimation for the population of ionizing and non-ionizing radiation was carried out taking into account the real conditions of influence. Comparison of risks for the population of ionizing and non-ionizing radiation leads us to a conclusion that EMF RF exposure in conditions of wide use of mobile communication is potentially more harmful than ionizing radiation influence.

  8. Relative azimuth inversion by way of damped maximum correlation estimates

    Science.gov (United States)

    Ringler, A.T.; Edwards, J.D.; Hutt, C.R.; Shelly, F.

    2012-01-01

    Horizontal seismic data are utilized in a large number of Earth studies. Such work depends on the published orientations of the sensitive axes of seismic sensors relative to true North. These orientations can be estimated using a number of different techniques: SensOrLoc (Sensitivity, Orientation and Location), comparison to synthetics (Ekstrom and Busby, 2008), or by way of magnetic compass. Current methods for finding relative station azimuths are unable to do so with arbitrary precision quickly because of limitations in the algorithms (e.g. grid search methods). Furthermore, in order to determine instrument orientations during station visits, it is critical that any analysis software be easily run on a large number of different computer platforms and the results be obtained quickly while on site. We developed a new technique for estimating relative sensor azimuths by inverting for the orientation with the maximum correlation to a reference instrument, using a non-linear parameter estimation routine. By making use of overlapping windows, we are able to make multiple azimuth estimates, which helps to identify the confidence of our azimuth estimate, even when the signal-to-noise ratio (SNR) is low. Finally, our algorithm has been written as a stand-alone, platform independent, Java software package with a graphical user interface for reading and selecting data segments to be analyzed.

  9. Estimation of radiation cancer risk in CT-KUB

    Science.gov (United States)

    Karim, M. K. A.; Hashim, S.; Bakar, K. A.; Bradley, D. A.; Ang, W. C.; Bahrudin, N. A.; Mhareb, M. H. A.

    2017-08-01

    The increased demand for computed tomography (CT) in radiological scanning examinations raises the question of a potential health impact from the associated radiation exposures. Focusing on CT kidney-ureter-bladder (CT-KUB) procedures, this work was aimed at determining organ equivalent dose using a commercial CT dose calculator and providing an estimate of cancer risks. The study, which included 64 patients (32 males and 32 females, mean age 55.5 years and age range 30-80 years), involved use of a calibrated CT scanner (Siemens-Somatom Emotion 16-slice). The CT exposures parameter including tube potential, pitch factor, tube current, volume CT dose index (CTDIvol) and dose-length product (DLP) were recorded and analyzed using CT-EXPO (Version 2.3.1, Germany). Patient organ doses, including for stomach, liver, colon, bladder, red bone marrow, prostate and ovaries were calculated and converted into cancer risks using age- and sex-specific data published in the Biological Effects of Ionizing Radiation (BEIR) VII report. With a median value scan range of 36.1 cm, the CTDIvol, DLP, and effective dose were found to be 10.7 mGy, 390.3 mGy cm and 6.2 mSv, respectively. The mean cancer risks for males and females were estimated to be respectively 25 and 46 out of 100,000 procedures with effective doses between 4.2 mSv and 10.1 mSv. Given the increased cancer risks from current CT-KUB procedures compared to conventional examinations, we propose that the low dose protocols for unenhanced CT procedures be taken into consideration before establishing imaging protocols for CT-KUB.

  10. Research on the method of information system risk state estimation based on clustering particle filter

    Science.gov (United States)

    Cui, Jia; Hong, Bei; Jiang, Xuepeng; Chen, Qinghua

    2017-05-01

    With the purpose of reinforcing correlation analysis of risk assessment threat factors, a dynamic assessment method of safety risks based on particle filtering is proposed, which takes threat analysis as the core. Based on the risk assessment standards, the method selects threat indicates, applies a particle filtering algorithm to calculate influencing weight of threat indications, and confirms information system risk levels by combining with state estimation theory. In order to improve the calculating efficiency of the particle filtering algorithm, the k-means cluster algorithm is introduced to the particle filtering algorithm. By clustering all particles, the author regards centroid as the representative to operate, so as to reduce calculated amount. The empirical experience indicates that the method can embody the relation of mutual dependence and influence in risk elements reasonably. Under the circumstance of limited information, it provides the scientific basis on fabricating a risk management control strategy.

  11. Research on the method of information system risk state estimation based on clustering particle filter

    Directory of Open Access Journals (Sweden)

    Cui Jia

    2017-05-01

    Full Text Available With the purpose of reinforcing correlation analysis of risk assessment threat factors, a dynamic assessment method of safety risks based on particle filtering is proposed, which takes threat analysis as the core. Based on the risk assessment standards, the method selects threat indicates, applies a particle filtering algorithm to calculate influencing weight of threat indications, and confirms information system risk levels by combining with state estimation theory. In order to improve the calculating efficiency of the particle filtering algorithm, the k-means cluster algorithm is introduced to the particle filtering algorithm. By clustering all particles, the author regards centroid as the representative to operate, so as to reduce calculated amount. The empirical experience indicates that the method can embody the relation of mutual dependence and influence in risk elements reasonably. Under the circumstance of limited information, it provides the scientific basis on fabricating a risk management control strategy.

  12. Estimated risks and optimistic self-perception of breast cancer risk in Korean women.

    Science.gov (United States)

    Chung, ChaeWeon; Lee, Suk Jeong

    2013-11-01

    To determine women's perceived personal and comparative risks of breast cancer, and to examine the relationships with risk factors. Despite the increasing incidence of breast cancer in younger women and the availability of screening, women's health behaviors have not advanced accordingly. A cross-sectional survey design utilized a convenience sample of 222 women in their 30s and 40s recruited from community settings in Seoul. Self-administered questionnaire data were analyzed by descriptive statistics, the chi-squared test, and ANOVA. Risk perception levels differed significantly by breast cancer risk factors. Half of the women were optimistic about their breast cancer risk, while perceived personal risk did not reflect women's own risk factors and comparative risk differed only by the practice of clinical breast exam. Women's knowledge and awareness of their breast cancer risk factors need to be improved for appropriate risk perception and health behaviors, and accurate risk estimation could be utilized to educate them in clinical settings. © 2013.

  13. The Hurst Phenomenon in Error Estimates Related to Atmospheric Turbulence

    Science.gov (United States)

    Dias, Nelson Luís; Crivellaro, Bianca Luhm; Chamecki, Marcelo

    2018-05-01

    The Hurst phenomenon is a well-known feature of long-range persistence first observed in hydrological and geophysical time series by E. Hurst in the 1950s. It has also been found in several cases in turbulence time series measured in the wind tunnel, the atmosphere, and in rivers. Here, we conduct a systematic investigation of the value of the Hurst coefficient H in atmospheric surface-layer data, and its impact on the estimation of random errors. We show that usually H > 0.5 , which implies the non-existence (in the statistical sense) of the integral time scale. Since the integral time scale is present in the Lumley-Panofsky equation for the estimation of random errors, this has important practical consequences. We estimated H in two principal ways: (1) with an extension of the recently proposed filtering method to estimate the random error (H_p ), and (2) with the classical rescaled range introduced by Hurst (H_R ). Other estimators were tried but were found less able to capture the statistical behaviour of the large scales of turbulence. Using data from three micrometeorological campaigns we found that both first- and second-order turbulence statistics display the Hurst phenomenon. Usually, H_R is larger than H_p for the same dataset, raising the question that one, or even both, of these estimators, may be biased. For the relative error, we found that the errors estimated with the approach adopted by us, that we call the relaxed filtering method, and that takes into account the occurrence of the Hurst phenomenon, are larger than both the filtering method and the classical Lumley-Panofsky estimates. Finally, we found that there is no apparent relationship between H and the Obukhov stability parameter. The relative errors, however, do show stability dependence, particularly in the case of the error of the kinematic momentum flux in unstable conditions, and that of the kinematic sensible heat flux in stable conditions.

  14. Estimating Body Related Soft Biometric Traits in Video Frames

    Directory of Open Access Journals (Sweden)

    Olasimbo Ayodeji Arigbabu

    2014-01-01

    Full Text Available Soft biometrics can be used as a prescreening filter, either by using single trait or by combining several traits to aid the performance of recognition systems in an unobtrusive way. In many practical visual surveillance scenarios, facial information becomes difficult to be effectively constructed due to several varying challenges. However, from distance the visual appearance of an object can be efficiently inferred, thereby providing the possibility of estimating body related information. This paper presents an approach for estimating body related soft biometrics; specifically we propose a new approach based on body measurement and artificial neural network for predicting body weight of subjects and incorporate the existing technique on single view metrology for height estimation in videos with low frame rate. Our evaluation on 1120 frame sets of 80 subjects from a newly compiled dataset shows that the mentioned soft biometric information of human subjects can be adequately predicted from set of frames.

  15. Estimation of value at risk and conditional value at risk using normal mixture distributions model

    Science.gov (United States)

    Kamaruzzaman, Zetty Ain; Isa, Zaidi

    2013-04-01

    Normal mixture distributions model has been successfully applied in financial time series analysis. In this paper, we estimate the return distribution, value at risk (VaR) and conditional value at risk (CVaR) for monthly and weekly rates of returns for FTSE Bursa Malaysia Kuala Lumpur Composite Index (FBMKLCI) from July 1990 until July 2010 using the two component univariate normal mixture distributions model. First, we present the application of normal mixture distributions model in empirical finance where we fit our real data. Second, we present the application of normal mixture distributions model in risk analysis where we apply the normal mixture distributions model to evaluate the value at risk (VaR) and conditional value at risk (CVaR) with model validation for both risk measures. The empirical results provide evidence that using the two components normal mixture distributions model can fit the data well and can perform better in estimating value at risk (VaR) and conditional value at risk (CVaR) where it can capture the stylized facts of non-normality and leptokurtosis in returns distribution.

  16. Magnitudes and frequencies of earthquakes in relation to seismic risk

    International Nuclear Information System (INIS)

    Sharma, R.D.

    1989-01-01

    Estimating the frequencies of occurrence of earthquakes of different magnitudes on a regional basis is an important task in estimating seismic risk at a construction site. Analysis of global earthquake data provides an insight into the magnitudes frequency relationship in a statistical manner. It turns out that, whereas a linear relationship between the logarithm of earthquake occurrence rates and the corresponding earthquake magnitudes fits well in the magnitude range between 5 and 7, a second degree polynomial in M, the earthquake magnitude provides a better description of the frequencies of earthquakes in a much wider range of magnitudes. It may be possible to adopt magnitude frequency relation for regions, for which adequate earthquake data are not available, to carry out seismic risk calculations. (author). 32 refs., 8 tabs., 7 figs

  17. FN-curves: preliminary estimation of severe accident risks after Fukushima

    Energy Technology Data Exchange (ETDEWEB)

    Vasconcelos, Vanderley de; Soares, Wellington Antonio; Costa, Antonio Carlos Lopes da, E-mail: vasconv@cdtn.br, E-mail: soaresw@cdtn.br, E-mail: aclc@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2015-07-01

    Doubts of whether the risks related to severe accidents in nuclear reactors are indeed very low were raised after the nuclear accident at Fukushima Daiichi in 2011. Risk estimations of severe accidents in nuclear power plants involve both probability and consequence assessment of such events. Among the ways to display risks, risk curves are tools that express the frequency of exceeding a certain magnitude of consequence. Societal risk is often represented graphically in a FN-curve, a type of risk curve, which displays the probability of having N or more fatalities per year, as a function of N, on a double logarithmic scale. The FN-curve, originally introduced for the assessment of the risks in the nuclear industry through the U.S.NRC Reactor Safety Study WASH-1400 (1975), is used in various countries to express and limit risks of hazardous activities. This first study estimated an expected rate of core damage equal to 5x10{sup -5} by reactor-year and suggested an upper bound of 3x10{sup -4} by reactor-year. A more recent report issued by Electric Power Research Institute - EPRI (2008) estimates a figure of the order of 2x10{sup -5} by reactor-year. The Fukushima nuclear accident apparently implies that the observed core damage frequency is higher than that predicted by these probabilistic safety assessments. Therefore, this paper presents a preliminary analyses of the FN-curves related to severe nuclear reactor accidents, taking into account a combination of available data of past accidents, probability modelling to estimate frequencies, and expert judgments. (author)

  18. FN-curves: preliminary estimation of severe accident risks after Fukushima

    International Nuclear Information System (INIS)

    Vasconcelos, Vanderley de; Soares, Wellington Antonio; Costa, Antonio Carlos Lopes da

    2015-01-01

    Doubts of whether the risks related to severe accidents in nuclear reactors are indeed very low were raised after the nuclear accident at Fukushima Daiichi in 2011. Risk estimations of severe accidents in nuclear power plants involve both probability and consequence assessment of such events. Among the ways to display risks, risk curves are tools that express the frequency of exceeding a certain magnitude of consequence. Societal risk is often represented graphically in a FN-curve, a type of risk curve, which displays the probability of having N or more fatalities per year, as a function of N, on a double logarithmic scale. The FN-curve, originally introduced for the assessment of the risks in the nuclear industry through the U.S.NRC Reactor Safety Study WASH-1400 (1975), is used in various countries to express and limit risks of hazardous activities. This first study estimated an expected rate of core damage equal to 5x10 -5 by reactor-year and suggested an upper bound of 3x10 -4 by reactor-year. A more recent report issued by Electric Power Research Institute - EPRI (2008) estimates a figure of the order of 2x10 -5 by reactor-year. The Fukushima nuclear accident apparently implies that the observed core damage frequency is higher than that predicted by these probabilistic safety assessments. Therefore, this paper presents a preliminary analyses of the FN-curves related to severe nuclear reactor accidents, taking into account a combination of available data of past accidents, probability modelling to estimate frequencies, and expert judgments. (author)

  19. Relative radiological risks derived from different TENORM wastes in Malaysia.

    Science.gov (United States)

    Ismail, B; Teng, I L; Muhammad Samudi, Y

    2011-11-01

    In Malaysia technologically enhanced naturally occurring radioactive materials (TENORM) wastes are mainly the product of the oil and gas industry and mineral processing. Among these TENORM wastes are tin tailing, tin slag, gypsum and oil sludge. Mineral processing and oil and gas industries produce large volume of TENORM wastes that has become a radiological concern to the authorities. A study was carried out to assess the radiological risk related to workers working at these disposal sites and landfills as well as to the members of the public should these areas be developed for future land use. Radiological risk was assessed based on the magnitude of radiation hazard, effective dose rates and excess cancer risks. Effective dose rates and excess cancer risks were estimated using RESRAD 6.4 computer code. All data on the activity concentrations of NORM in wastes and sludges used in this study were obtained from the Atomic Energy Licensing Board, Malaysia, and they were collected over a period of between 5 and 10 y. Results obtained showed that there was a wide range in the total activity concentrations (TAC) of nuclides in the TENORM wastes. With the exception of tin slag and tin tailing-based TENORM wastes, all other TENORM wastes have TAC values comparable to that of Malaysia's soil. Occupational Effective Dose Rates estimated in all landfill areas were lower than the 20 mSv y(-1) permissible dose limit. The average Excess Cancer Risk Coefficient was estimated to be 2.77×10(-3) risk per mSv. The effective dose rates for residents living on gypsum and oil sludge-based TENORM wastes landfills were estimated to be lower than the permissible dose limit for members of the public, and was also comparable to that of the average Malaysia's ordinary soils. The average excess cancer risk coefficient was estimated to be 3.19×10(-3) risk per mSv. Results obtained suggest that gypsum and oil sludge-based TENORM wastes should be exempted from any radiological regulatory

  20. Relative radiological risks derived from different TENORM wastes in Malaysia

    International Nuclear Information System (INIS)

    Ismail, B.; Teng, I. L.; Muhammad samudi, Y.

    2011-01-01

    In Malaysia technologically enhanced naturally occurring radioactive materials (TENORM) wastes are mainly the product of the oil and gas industry and mineral processing. Among these TENORM wastes are tin tailing, tin slag, gypsum and oil sludge. Mineral processing and oil and gas industries produce large volume of TENORM wastes that has become a radiological concern to the authorities. A study was carried out to assess the radiological risk related to workers working at these disposal sites and landfills as well as to the members of the public should these areas be developed for future land use. Radiological risk was assessed based on the magnitude of radiation hazard, effective dose rates and excess cancer risks. Effective dose rates and excess cancer risks were estimated using RESRAD 6.4 computer code. All data on the activity concentrations of NORM in wastes and sludges used in this study were obtained from the Atomic Energy Licensing Board (Malaysia), and they were collected over a period of between 5 and 10 y. Results obtained showed that there was a wide range in the total activity concentrations (TAC) of nuclides in the TENORM wastes. With the exception of tin slag and tin tailing-based TENORM wastes, all other TENORM wastes have TAC values comparable to that of Malaysia's soil. Occupational Effective Dose Rates estimated in all landfill areas were lower than the 20 mSv y -1 permissible dose limit. The average Excess Cancer Risk Coefficient was estimated to be 2.77 x 10 -3 risk per mSv. The effective dose rates for residents living on gypsum and oil sludge-based TENORM wastes landfills were estimated to be lower than the permissible dose limit for members of the public, and was also comparable to that of the average Malaysia's ordinary soils. The average excess cancer risk coefficient was estimated to be 3.19 x 10 -3 risk per mSv. Results obtained suggest that gypsum and oil sludge-based TENORM wastes should be exempted from any radiological regulatory

  1. Estimates of health risk from exposure to radioactive pollutants

    International Nuclear Information System (INIS)

    Sullivan, R.E.; Nelson, N.S.; Ellett, W.H.; Dunning, D.E. Jr.; Leggett, R.W.; Yalcintas, M.G.; Eckerman, K.F.

    1981-11-01

    A dosimetric and health effects analysis has been performed for the Office of Radiation Programs of the Environmental Protection Agency (EPA) to assess potential hazards from radioactive pollutants. Contemporary dosimetric methods were used to obtain estimates of dose rates to reference organs from internal exposures due to either inhalation of contaminated air or ingestion of contaminated food, or from external exposures due to either immersion in contaminated air or proximity to contaminated ground surfaces. These dose rates were then used to estimate the number of premature cancer deaths arising from such exposures and the corresponding number of years of life lost in a cohort of 100,000 persons, all simultaneously liveborn and all going through life with the same risks of dying from competing causes. The risk of dying from a competing cause for a given year was taken to be the probability of dying from all causes as given in a recent actuarial life table for the total US popula six times larger than the first reservoir.onunding. Analytical work cthe Department of Energy

  2. Data Sources for the Model-based Small Area Estimates of Cancer-Related Knowledge - Small Area Estimates

    Science.gov (United States)

    The model-based estimates of important cancer risk factors and screening behaviors are obtained by combining the responses to the Behavioral Risk Factor Surveillance System (BRFSS) and the National Health Interview Survey (NHIS).

  3. Studies on risk estimation to public from medical radiation (III)

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hai Yong; Kim, Jong Hyung; Kim, Hyeog Ju; Kim, Ji Soon; Oh, Hyeon Joo; Kim, Cheol Hyeon; Yang, Hyun Kyu [Korea Food and Drug Administraion, Seoul (Korea, Republic of); Park, Chan Il [Seoul National Univ., Seoul (Korea, Republic of)

    1998-06-01

    A nationwide survey was conducted to give representative levels of effective doses to patient for 17 types of CT examination and also representative level of MGD (mean glandular dose) to standard breast for mammography X-ray equipment. The effective doses to patient from 16 CT scanners were estimated from measurement of CTDI (Computed Tomography Dose Index) in air by multiplying conversion coefficients which are specified by National Radiological Protection Board in United Kingdom. The lowest and hightest mean values of effective dose measured to patient from CT scanner were 0.05 mSv for IAM examination and 17.75 mSv for routine abdomen examination, respectively. The average values of 17 effective doses were lower than other results of foreign countrys' surveys. The mean glandular doses to a standard breast for 26 mammography units were estimated from measurement of the air kerma at the surface of a 40 mm plain Perspex phantom by applying conversion factors described in Report 59 of the Institute of Physical Sciences in Medicine of United Kingdom. The exposure factors for this measurement were those used clinically at each hospital. The average MGD to standard breast was 1.06 mGy in units with grid and 0.49 mGy in units without grid. These results are lower than guidance levels by IPSM and AAPM. These results will be used for risk estimation to the Korean public from the medical radiation.

  4. How to Estimate Epidemic Risk from Incomplete Contact Diaries Data?

    Science.gov (United States)

    Mastrandrea, Rossana; Barrat, Alain

    2016-06-01

    Social interactions shape the patterns of spreading processes in a population. Techniques such as diaries or proximity sensors allow to collect data about encounters and to build networks of contacts between individuals. The contact networks obtained from these different techniques are however quantitatively different. Here, we first show how these discrepancies affect the prediction of the epidemic risk when these data are fed to numerical models of epidemic spread: low participation rate, under-reporting of contacts and overestimation of contact durations in contact diaries with respect to sensor data determine indeed important differences in the outcomes of the corresponding simulations with for instance an enhanced sensitivity to initial conditions. Most importantly, we investigate if and how information gathered from contact diaries can be used in such simulations in order to yield an accurate description of the epidemic risk, assuming that data from sensors represent the ground truth. The contact networks built from contact sensors and diaries present indeed several structural similarities: this suggests the possibility to construct, using only the contact diary network information, a surrogate contact network such that simulations using this surrogate network give the same estimation of the epidemic risk as simulations using the contact sensor network. We present and compare several methods to build such surrogate data, and show that it is indeed possible to obtain a good agreement between the outcomes of simulations using surrogate and sensor data, as long as the contact diary information is complemented by publicly available data describing the heterogeneity of the durations of human contacts.

  5. Estimating risk using bounding calculations and limited data

    International Nuclear Information System (INIS)

    COWLEY, W.L.

    1999-01-01

    This paper describes a methodology for estimating the potential risk to workers and the public from igniting organic solvents in any of the 177 underground waste storage tanks at the Hanford Site in southeastern Washington state. The Hanford Site is one of the U.S. Department of Energy's former production facilities for nuclear materials. The tanks contain mixed radioactive wastes. Risk is measured by calculating toxicological and radiological accident consequences and frequencies and comparing the results to established regulatory guidelines. Available sample data is insufficient to adequately characterize the waste and solvent, so a model that maximizes releases from the tanks (bounding case) is used. Maximizing releases (and thus consequences) is a standard technique used in safety analysis to compensate for lack of information. The model predicts bounding values of fire duration, the time at which the fire extinguishes because of lack of oxygen, and a pressure history of a fire in a tank. The model output is used to calculate mass and volume release rates of material from the tanks. The mass and volume release rates permit calculation of radiological and toxicological consequences. The resulting consequence calculations demonstrate that risk from an organic solvent fire in the tanks is within regulatory guidelines

  6. Stochastic risk estimation from medical x-ray diagnostic examinations, 3

    International Nuclear Information System (INIS)

    Hashizume, Tadashi; Maruyama, Takashi; Noda, Yutaka; Iwai, Kazuo; Fukuhisa, Kenjiro

    1981-01-01

    The genetically significant dose (GSD), per Caput mean bone marrow dose (CMD), leukemia significant dose (LSD) and malignancy significant dose (MSD) from medical diagnostic X-ray examinations in Japan were estimated based on a 1979 nationwide survey of randomly sampled hospitals and clinics. The population risk estimates were carried out using the resultant values of GSD, LSD and MSD. In the risk estimates, the significant factors, namely, the relative child expectancy, the leukemia significant factor and the malignancy significant factor, for patients were assumed to be same as those of general population. The risk factors used were 185 x 10 -6 rad -1 for genetic risk of all generations, 20 x 10 -6 rad -1 for fatal leukemia and 165 x 10 -6 rad -1 for fatal malignant diseases, respectively. The resultant annual population doses per person were 15 mrad (0.15 mGy) for GSD, 107 mrad (1.07 mGy) for CMD, 86 mrad (0.86 mGy) for LSD and 43 mrad (0.43 mGy) for MSD, respectively. The present data other than the MSD were compared with the data in 1960, 1969 and 1974. For example, the GSD of 1979 was approximately same as that of 1974, although the annual number of examinations in 1979 increased by about 30 percent as compared with those of 1974. The population risks from X-ray diagnosis were estimated to be 260 persons per year for genetic risk of all generations, 192 person per year for fatal leukemic risk and 825 person per year for malignant risk, respectively, for the whole population in Japan, assuming that the X-ray diagnosis in 1979 will be performed continuously in the future. The average risks per one exposure for X-ray radiography were estimated using the weighted average of the significant factor and the organ or tissue dose with the number of radiographic exposures by age and by type of examination. The average risks per radiographic exposure were 176 x 10 -9 for genetic risk, 285 x 10 -9 for leukemic risk and 1.75 x 10 -6 for malignant risk respectively. (author)

  7. MicroRNA Related Polymorphisms and Breast Cancer Risk

    DEFF Research Database (Denmark)

    Khan, Sofia; Greco, Dario; Michailidou, Kyriaki

    2014-01-01

    Genetic variations, such as single nucleotide polymorphisms (SNPs) in microRNAs (miRNA) or in the miRNA binding sites may affect the miRNA dependent gene expression regulation, which has been implicated in various cancers, including breast cancer, and may alter individual susceptibility to cancer....... We investigated associations between miRNA related SNPs and breast cancer risk. First we evaluated 2,196 SNPs in a case-control study combining nine genome wide association studies (GWAS). Second, we further investigated 42 SNPs with suggestive evidence for association using 41,785 cases and 41......,880 controls from 41 studies included in the Breast Cancer Association Consortium (BCAC). Combining the GWAS and BCAC data within a meta-analysis, we estimated main effects on breast cancer risk as well as risks for estrogen receptor (ER) and age defined subgroups. Five miRNA binding site SNPs associated...

  8. Estimation of nuclear power-related expenditures in fiscal 1982

    International Nuclear Information System (INIS)

    1981-01-01

    In fiscal 1982 (April to March, 1983), the research and development on nuclear power should be promoted actively and extensively by taking the appropriate measures. In view of the importance, the budgetary expenditures are to be estimated duly for the purpose, considering also the stringent financial situation. The budgetary expenditures for nuclear power estimated for the fiscal year 1982 are about 292,800 Million in total and the obligation act limit is about 139,900 Million. The following matters are described: nuclear power-related measures for securing nuclear power safety, promotion of nuclear power generation, establishment of the nuclear fuel cycle, development of power reactors, research on nuclear fusion, strengthening of the foundation in nuclear power research, development and utilization, promotion of international cooperation, etc.; estimated budgetary expenditures; tables of budgetary demands in various categories. (J.P.N.)

  9. Estimated risk of radiation-induced cancer from paediatric chest CT: two-year cohort study

    Energy Technology Data Exchange (ETDEWEB)

    Niemann, Tilo [Cantonal Hospital Baden, Department of Radiology, Baden (Switzerland); University Lille Nord de France, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Colas, Lucie; Santangelo, Teresa; Faivre, Jean Baptiste; Remy, Jacques; Remy-Jardin, Martine [University Lille Nord de France, Department of Thoracic Imaging, Hospital Calmette, Lille (France); Roser, Hans W.; Bremerich, Jens [University of Basel Hospital, Clinic of Radiology and Nuclear Medicine, Medical Physics, Basel (Switzerland)

    2015-03-01

    The increasing absolute number of paediatric CT scans raises concern about the safety and efficacy and the effects of consecutive diagnostic ionising radiation. To demonstrate a method to evaluate the lifetime attributable risk of cancer incidence/mortality due to a single low-dose helical chest CT in a two-year patient cohort. A two-year cohort of 522 paediatric helical chest CT scans acquired using a dedicated low-dose protocol were analysed retrospectively. Patient-specific estimations of radiation doses were modelled using three different mathematical phantoms. Per-organ attributable cancer risk was then estimated using epidemiological models. Additional comparison was provided for naturally occurring risks. Total lifetime attributable risk of cancer incidence remains low for all age and sex categories, being highest in female neonates (0.34%). Summation of all cancer sites analysed raised the relative lifetime attributable risk of organ cancer incidence up to 3.6% in female neonates and 2.1% in male neonates. Using dedicated scan protocols, total lifetime attributable risk of cancer incidence and mortality for chest CT is estimated low for paediatric chest CT, being highest for female neonates. (orig.)

  10. Estimation of enhanced cancer risk with 18FDG PET/CT investigations

    International Nuclear Information System (INIS)

    Kaushik, Aruna; Mishra, Anil K.; Sharma, Rajnish; Mondal, Anupam; Dwarakanath, B.S.

    2014-01-01

    18 F-Fluorodeoxyglucose ( 18 FDG) Positron Emission Tomography/Computed Tomography (PET/CT) investigation involves internal administration of 18 FDG and use of CT X-rays for the purpose of obtaining functional and anatomical information of a patient. However, the radiation exposure from undergoing PET/CT investigation may enhance the risk of cancer incidence as per the Linear-No-Threshold (LNT) model. The objective of the present study was to quantify the risk of cancer incidence associated with radiation exposure from 18 FDG PET/CT investigations. The organ doses from internally administered 18 FDG were estimated using OLINDA/EXM Code by performing dynamic PET scans in different regions of the body in a total of forty-nine patients. Organ doses from the CT component were calculated using the software CT-Expo. The associated cancer risk was calculated in terms of life time risk of cancer incidence resulting from a specified dose of ionizing radiation and was expressed in terms of Lifetime Attributable Risk (LAR). LAR values and the organ doses estimated for males and females were used to estimate the lifetime risk of cancer incidence from whole body 18 FDG PET/CT scan. Since from 18 FDG whole body PET/CT investigations, various tissues of the body receive substantially different doses, the site specific risk of cancer incidence was estimated and summed to obtain the total risk. This was compared with the baseline lifetime risk of cancer incidence in Indian population. LAR of cancer incidence was observed to be relatively higher in females as compared to males. The risk estimates ranged from 0.36% to 0.49% for a 20 year old male and 0.58% to 0.79% for a 20 year old female and were observed to be higher in younger ages and decreased with age. 18 FDG whole body PET/CT investigation was observed to be associated with non-negligible radiation risk as compared to the risks associated with other diagnostic modalities. (author)

  11. Bayesian estimation of covariance matrices: Application to market risk management at EDF

    International Nuclear Information System (INIS)

    Jandrzejewski-Bouriga, M.

    2012-01-01

    In this thesis, we develop new methods of regularized covariance matrix estimation, under the Bayesian setting. The regularization methodology employed is first related to shrinkage. We investigate a new Bayesian modeling of covariance matrix, based on hierarchical inverse-Wishart distribution, and then derive different estimators under standard loss functions. Comparisons between shrunk and empirical estimators are performed in terms of frequentist performance under different losses. It allows us to highlight the critical importance of the definition of cost function and show the persistent effect of the shrinkage-type prior on inference. In a second time, we consider the problem of covariance matrix estimation in Gaussian graphical models. If the issue is well treated for the decomposable case, it is not the case if you also consider non-decomposable graphs. We then describe a Bayesian and operational methodology to carry out the estimation of covariance matrix of Gaussian graphical models, decomposable or not. This procedure is based on a new and objective method of graphical-model selection, combined with a constrained and regularized estimation of the covariance matrix of the model chosen. The procedures studied effectively manage missing data. These estimation techniques were applied to calculate the covariance matrices involved in the market risk management for portfolios of EDF (Electricity of France), in particular for problems of calculating Value-at-Risk or in Asset Liability Management. (author)

  12. A novel tool for user-friendly estimation of natural, diagnostic and professional radiation risk: Radio-Risk software

    International Nuclear Information System (INIS)

    Carpeggiani, Clara; Paterni, Marco; Caramella, Davide; Vano, Eliseo; Semelka, Richard C.; Picano, Eugenio

    2012-01-01

    Background: Awareness of radiological risk is low among doctors and patients. An educational/decision tool that considers each patient’ s cumulative lifetime radiation exposure would facilitate provider–patient communication. Aim: The purpose of this work was to develop user-friendly software for simple estimation and communication of radiological risk to patients and doctors as a part of the SUIT-Heart (Stop Useless Imaging Testing in Heart disease) Project of the Tuscany Region. Methods: We developed a novel software program (PC-platform, Windows OS fully downloadable at (http://suit-heart.ifc.cnr.it)) considering reference dose estimates from American Heart Association Radiological Imaging 2009 guidelines and UK Royal College of Radiology 2007 guidelines. Cancer age and gender-weighted risk were derived from Biological Effects of Ionising Radiation VII Committee, 2006. Results: With simple input functions (demographics, age, gender) the user selects from a predetermined menu variables relating to natural (e.g., airplane flights and geo-tracked background exposure), professional (e.g., cath lab workers) and medical (e.g., CT, cardiac scintigraphy, coronary stenting) sources. The program provides a simple numeric (cumulative effective dose in milliSievert, mSv, and equivalent number of chest X-rays) and graphic (cumulative temporal trends of exposure, cancer cases out of 100 exposed persons) display. Conclusions: A simple software program allows straightforward estimation of cumulative dose (in multiples of chest X-rays) and risk (in extra % lifetime cancer risk), with simple numbers quantifying lifetime extra cancer risk. Pictorial display of radiation risk may be valuable for increasing radiological awareness in cardiologists.

  13. A novel tool for user-friendly estimation of natural, diagnostic and professional radiation risk: Radio-Risk software

    Energy Technology Data Exchange (ETDEWEB)

    Carpeggiani, Clara; Paterni, Marco [CNR, Institute of Clinical Physiology (Italy); Caramella, Davide [Radiology Department, Pisa University, Pisa (Italy); Vano, Eliseo [San Carlos Hospital, Radiology Department, Complutense University, Madrid (Spain); Semelka, Richard C. [University of North Carolina, Chapel Hill, NC (United States); Picano, Eugenio, E-mail: picano@ifc.cnr.it [CNR, Institute of Clinical Physiology (Italy)

    2012-11-15

    Background: Awareness of radiological risk is low among doctors and patients. An educational/decision tool that considers each patient' s cumulative lifetime radiation exposure would facilitate provider-patient communication. Aim: The purpose of this work was to develop user-friendly software for simple estimation and communication of radiological risk to patients and doctors as a part of the SUIT-Heart (Stop Useless Imaging Testing in Heart disease) Project of the Tuscany Region. Methods: We developed a novel software program (PC-platform, Windows OS fully downloadable at (http://suit-heart.ifc.cnr.it)) considering reference dose estimates from American Heart Association Radiological Imaging 2009 guidelines and UK Royal College of Radiology 2007 guidelines. Cancer age and gender-weighted risk were derived from Biological Effects of Ionising Radiation VII Committee, 2006. Results: With simple input functions (demographics, age, gender) the user selects from a predetermined menu variables relating to natural (e.g., airplane flights and geo-tracked background exposure), professional (e.g., cath lab workers) and medical (e.g., CT, cardiac scintigraphy, coronary stenting) sources. The program provides a simple numeric (cumulative effective dose in milliSievert, mSv, and equivalent number of chest X-rays) and graphic (cumulative temporal trends of exposure, cancer cases out of 100 exposed persons) display. Conclusions: A simple software program allows straightforward estimation of cumulative dose (in multiples of chest X-rays) and risk (in extra % lifetime cancer risk), with simple numbers quantifying lifetime extra cancer risk. Pictorial display of radiation risk may be valuable for increasing radiological awareness in cardiologists.

  14. Identifying patient preferences for communicating risk estimates: A descriptive pilot study

    Directory of Open Access Journals (Sweden)

    O'Connor Annette M

    2001-08-01

    Full Text Available Abstract Background Patients increasingly seek more active involvement in health care decisions, but little is known about how to communicate complex risk information to patients. The objective of this study was to elicit patient preferences for the presentation and framing of complex risk information. Method To accomplish this, eight focus group discussions and 15 one-on-one interviews were conducted, where women were presented with risk data in a variety of different graphical formats, metrics, and time horizons. Risk data were based on a hypothetical woman's risk for coronary heart disease, hip fracture, and breast cancer, with and without hormone replacement therapy. Participants' preferences were assessed using likert scales, ranking, and abstractions of focus group discussions. Results Forty peri- and postmenopausal women were recruited through hospital fliers (n = 25 and a community health fair (n = 15. Mean age was 51 years, 50% were non-Caucasian, and all had completed high school. Bar graphs were preferred by 83% of participants over line graphs, thermometer graphs, 100 representative faces, and survival curves. Lifetime risk estimates were preferred over 10 or 20-year horizons, and absolute risks were preferred over relative risks and number needed to treat. Conclusion Although there are many different formats for presenting and framing risk information, simple bar charts depicting absolute lifetime risk were rated and ranked highest overall for patient preferences for format.

  15. Comparing cancer screening estimates: Behavioral Risk Factor Surveillance System and National Health Interview Survey.

    Science.gov (United States)

    Sauer, Ann Goding; Liu, Benmei; Siegel, Rebecca L; Jemal, Ahmedin; Fedewa, Stacey A

    2018-01-01

    Cancer screening prevalence from the Behavioral Risk Factor Surveillance System (BRFSS), designed to provide state-level estimates, and the National Health Interview Survey (NHIS), designed to provide national estimates, are used to measure progress in cancer control. A detailed description of the extent to which recent cancer screening estimates vary by key demographic characteristics has not been previously described. We examined national prevalence estimates for recommended breast, cervical, and colorectal cancer screening using data from the 2012 and 2014 BRFSS and the 2010 and 2013 NHIS. Treating the NHIS estimates as the reference, direct differences (DD) were calculated by subtracting NHIS estimates from BRFSS estimates. Relative differences were computed by dividing the DD by the NHIS estimates. Two-sample t-tests (2-tails), were performed to test for statistically significant differences. BRFSS screening estimates were higher than those from NHIS for breast (78.4% versus 72.5%; DD=5.9%, pNHIS, each survey has a unique and important role in providing information to track cancer screening utilization among various populations. Awareness of these differences and their potential causes is important when comparing the surveys and determining the best application for each data source. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Value at risk estimation with entropy-based wavelet analysis in exchange markets

    Science.gov (United States)

    He, Kaijian; Wang, Lijun; Zou, Yingchao; Lai, Kin Keung

    2014-08-01

    In recent years, exchange markets are increasingly integrated together. Fluctuations and risks across different exchange markets exhibit co-moving and complex dynamics. In this paper we propose the entropy-based multivariate wavelet based approaches to analyze the multiscale characteristic in the multidimensional domain and improve further the Value at Risk estimation reliability. Wavelet analysis has been introduced to construct the entropy-based Multiscale Portfolio Value at Risk estimation algorithm to account for the multiscale dynamic correlation. The entropy measure has been proposed as the more effective measure with the error minimization principle to select the best basis when determining the wavelet families and the decomposition level to use. The empirical studies conducted in this paper have provided positive evidence as to the superior performance of the proposed approach, using the closely related Chinese Renminbi and European Euro exchange market.

  17. Combining ungrouped and grouped wildfire data to estimate fire risk

    KAUST Repository

    Hernandez-Magallanes, I.

    2013-10-11

    © 2013 John Wiley & Sons, Ltd. Frequently, models are required to combine information obtained from different data sources and on different scales. In this work, we are interested in estimating the risk of wildfire ignition in the USA for a particular time and location by merging two levels of data, namely, individual points and aggregate count of points into areas. The data for federal lands consist of the point location and time of each fire. Nonfederal fires are aggregated by county for a particular year. The probability model is based on the wildfire point process. Assuming a smooth intensity function, a locally weighted likelihood fit is used, which incorporates the group effect. A logit model is used under the assumption of the existence of a latent process, and fuel conditions are included as a covariate. The model assessment is based on a residual analysis, while the False Discovery Rate detects spatial patterns. A benefit of the proposed model is that there is no need of arbitrary aggregation of individual fires into counts. A map of predicted probability of ignition for the Midwest US in 1990 is included. The predicted ignition probabilities and the estimated total number of expected fires are required for the allocation of resources.

  18. Gambling disorder: estimated prevalence rates and risk factors in Macao.

    Science.gov (United States)

    Wu, Anise M S; Lai, Mark H C; Tong, Kwok-Kit

    2014-12-01

    An excessive, problematic gambling pattern has been regarded as a mental disorder in the Diagnostic and Statistical Manual for Mental Disorders (DSM) for more than 3 decades (American Psychiatric Association [APA], 1980). In this study, its latest prevalence in Macao (one of very few cities with legalized gambling in China and the Far East) was estimated with 2 major changes in the diagnostic criteria, suggested by the 5th edition of DSM (APA, 2013): (a) removing the "Illegal Act" criterion, and (b) lowering the threshold for diagnosis. A random, representative sample of 1,018 Macao residents was surveyed with a phone poll design in January 2013. After the 2 changes were adopted, the present study showed that the estimated prevalence rate of gambling disorder was 2.1% of the Macao adult population. Moreover, the present findings also provided empirical support to the application of these 2 recommended changes when assessing symptoms of gambling disorder among Chinese community adults. Personal risk factors of gambling disorder, namely being male, having low education, a preference for casino gambling, as well as high materialism, were identified.

  19. Estimation of Employee Turnover with Competing Risks Models

    Directory of Open Access Journals (Sweden)

    Grzenda Wioletta

    2015-12-01

    Full Text Available Employee turnover accompanies every business organization, regardless of the industry and size. Nowadays, many companies struggle with problems related to the lack of sufficient information about the nature of employee turnover processes. Therefore, comprehensive analysis of these processes is necessary. This article aims to examine the turnover of employees from a big manufacturing company using competing risks models with covariates and without covariates. This technique allows to incorporate the information about the type of employment contract termination. Moreover, Cox proportional hazard model enables the researcher to analyse simultaneously multiple factors that affect employment duration. One of the major observations is that employee remuneration level differentiates most strongly the risk of job resignation.

  20. Dose dependence on stochastic radiobiological effect in radiation risk estimation

    International Nuclear Information System (INIS)

    Komochkov, M.M.

    1999-01-01

    The analysis of the results in dose -- effect relationship observation has been carried out on the cell and organism levels, with the aim to obtain more precise data on the risk coefficients at low doses. The results are represented by two contrasting groups of dose dependence on effect: a downwards concave and a J-shaped curve. Both types of dependence are described by the equation solutions of an assumed unified protective mechanism, which comprises two components: constitutive and adaptive or inducible ones. The latest data analysis of the downwards concave dependence curves shows a considerable underestimation of radiation risk in all types of cancer, except leukemia, for a number of critical groups in a population, at low doses comparing to the ICRP recommendations. With the dose increase, the decrease of the effect value per dose unit is observed. It may be possibly related to the switching of the activity of the adaptive protective mechanism, with some threshold dose values being exceeded

  1. A case-control study estimating accident risk for alcohol, medicines and illegal drugs.

    Directory of Open Access Journals (Sweden)

    Kim Paula Colette Kuypers

    Full Text Available The aim of the present study was to assess the risk of having a traffic accident after using alcohol, single drugs, or a combination, and to determine the concentrations at which this risk is significantly increased.A population-based case-control study was carried out, collecting whole blood samples of both cases and controls, in which a number of drugs were detected. The risk of having an accident when under the influence of drugs was estimated using logistic regression adjusting for gender, age and time period of accident (cases/sampling (controls. The main outcome measures were odds ratio (OR for accident risk associated with single and multiple drug use. In total, 337 cases (negative: 176; positive: 161 and 2726 controls (negative: 2425; positive: 301 were included in the study.Main findings were that 1 alcohol in general (all the concentrations together caused an elevated crash risk; 2 cannabis in general also caused an increase in accident risk; at a cut-off of 2 ng/mL THC the risk of having an accident was four times the risk associated with the lowest THC concentrations; 3 when ranking the adjusted OR from lowest to highest risk, alcohol alone or in combination with other drugs was related to a very elevated crash risk, with the highest risk for stimulants combined with sedatives.The study demonstrated a concentration-dependent crash risk for THC positive drivers. Alcohol and alcohol-drug combinations are by far the most prevalent substances in drivers and subsequently pose the largest risk in traffic, both in terms of risk and scope.

  2. Distribution of Estimated 10-Year Risk of Recurrent Vascular Events and Residual Risk in a Secondary Prevention Population

    NARCIS (Netherlands)

    Kaasenbrood, Lotte; Boekholdt, S. Matthijs; van der Graaf, Yolanda; Ray, Kausik K.; Peters, Ron J. G.; Kastelein, John J. P.; Amarenco, Pierre; LaRosa, John C.; Cramer, Maarten J. M.; Westerink, Jan; Kappelle, L. Jaap; de Borst, Gert J.; Visseren, Frank L. J.

    2016-01-01

    Among patients with clinically manifest vascular disease, the risk of recurrent vascular events is likely to vary. We assessed the distribution of estimated 10-year risk of recurrent vascular events in a secondary prevention population. We also estimated the potential risk reduction and residual

  3. Distribution of Estimated 10-Year Risk of Recurrent Vascular Events and Residual Risk in a Secondary Prevention Population

    NARCIS (Netherlands)

    Kaasenbrood, Lotte; Boekholdt, S. Matthijs; Van Der Graaf, Yolanda; Ray, Kausik K.; Peters, Ron J G; Kastelein, John J P; Amarenco, Pierre; Larosa, John C.; Cramer, Maarten J M; Westerink, Jan; Kappelle, L. Jaap; De Borst, Gert J.; Visseren, Frank L J

    2016-01-01

    Background: Among patients with clinically manifest vascular disease, the risk of recurrent vascular events is likely to vary. We assessed the distribution of estimated 10-year risk of recurrent vascular events in a secondary prevention population. We also estimated the potential risk reduction and

  4. Risk estimation and decision making: the health effects on populations of exposure to low levels of ionizing radiation

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1982-01-01

    Presented is a background for an understanding of the potential health effects in populations exposed to low-level radiation. Discussed is the knowledge about the health effects of low-level radiation. Comments on how the risks of radiation-induced cancer and genetically-related ill-health in man may be estimated, the sources of the scientific and epidemiological data, the dose-response models used, and the uncertainties which limit precise estimates of excess risks from radiation. Also discussed are the implications of numerical risk estimation for radiation protection and decision-making for public health policy

  5. People at High Risk of Developing Flu-Related Complications

    Science.gov (United States)

    ... Influenza Types Seasonal Avian Swine Variant Pandemic Other People at High Risk of Developing Flu–Related Complications ... related complications if they get sick with influenza. People at High Risk for Developing Flu-Related Complications ...

  6. Relative Pose Estimation and Accuracy Verification of Spherical Panoramic Image

    Directory of Open Access Journals (Sweden)

    XIE Donghai

    2017-11-01

    Full Text Available This paper improves the method of the traditional 5-point relative pose estimation algorithm, and proposes a relative pose estimation algorithm which is suitable for spherical panoramic images. The algorithm firstly computes the essential matrix, then decomposes the essential matrix to obtain the rotation matrix and the translation vector using SVD, and finally the reconstructed three-dimensional points are used to eliminate the error solution. The innovation of the algorithm lies the derivation of panorama epipolar formula and the use of the spherical distance from the point to the epipolar plane as the error term for the spherical panorama co-planarity function. The simulation experiment shows that when the random noise of the image feature points is within the range of pixel, the error of the three Euler angles is about 0.1°, and the error between the relative translational displacement and the simulated value is about 1.5°. The result of the experiment using the data obtained by the vehicle panorama camera and the POS shows that:the error of the roll angle and pitch angle can be within 0.2°, the error of the heading angle can be within 0.4°, and the error between the relative translational displacement and the POS can be within 2°. The result of our relative pose estimation algorithm is used to generate the spherical panoramic epipolar images, then we extract the key points between the spherical panoramic images and calculate the errors in the column direction. The result shows that the errors is less than 1 pixel.

  7. Cancer risk estimation for mixtures of coal tars and benzo(a)pyrene

    International Nuclear Information System (INIS)

    Gaylor, D.W.; Culp, S.J.; Goldstein, L.S.; Beland, F.A.

    2000-01-01

    Two-year chronic bioassays were conducted by using B6C3F1 female mice fed several concentrations of two different mixtures of coal tars from manufactured gas waste sites or benzo(a)pyrene (BaP). The purpose of the study was to obtain estimates of cancer potency of coal tar mixtures, by using conventional regulatory methods, for use in manufactured gas waste site remediation. A secondary purpose was to investigate the validity of using the concentration of a single potent carcinogen, in this case benzo(a)pyrene, to estimate the relative risk for a coal tar mixture. The study has shown that BaP dominates the cancer risk when its concentration is greater than 6,300 ppm in the coal tar mixture. In this case the most sensitive tissue site is the forestomach. Using low-dose linear extrapolation, the lifetime cancer risk for humans is estimated to be: Risk -4 (ppm coal tar in total diet) + 240 x 10 -4 (ppm BaP in total diet), based on forestomach tumors. If the BaP concentration in the coal tar mixture is less than 6,300 ppm, the more likely case, then lung tumors provide the largest estimated upper limit of risk, Risk -4 (ppm coal tar in total diet), with no contribution of BaP to lung tumors. The upper limit of the cancer potency (slope factor) for lifetime oral exposure to benzo(a)pyrene is 1.2 x 10 -3 per microg per kg body weight per day from this Good Laboratory Practice (GLP) study compared with the current value of 7.3 x 10 -3 per microg per kg body weight per day listed in the US EPA Integrated Risk Information System

  8. The influence of nuclear risk sense to atomic industry's public relation

    International Nuclear Information System (INIS)

    Biryukova, P.; Kazakevich, Yu.

    2001-01-01

    The goal of this report is estimation of the influence of sensing of nuclear risk to atomic industry's public relation. In this report the reasons of the negative relation to nuclear energetic owing to inadequate sensing of the risk dealing with this fields have been represented. (authors)

  9. Multi-hazard risk analysis related to hurricanes

    Science.gov (United States)

    Lin, Ning

    Hurricanes present major hazards to the United States. Associated with extreme winds, heavy rainfall, and storm surge, landfalling hurricanes often cause enormous structural damage to coastal regions. Hurricane damage risk assessment provides the basis for loss mitigation and related policy-making. Current hurricane risk models, however, often oversimplify the complex processes of hurricane damage. This dissertation aims to improve existing hurricane risk assessment methodology by coherently modeling the spatial-temporal processes of storm landfall, hazards, and damage. Numerical modeling technologies are used to investigate the multiplicity of hazards associated with landfalling hurricanes. The application and effectiveness of current weather forecasting technologies to predict hurricane hazards is investigated. In particular, the Weather Research and Forecasting model (WRF), with Geophysical Fluid Dynamics Laboratory (GFDL)'s hurricane initialization scheme, is applied to the simulation of the wind and rainfall environment during hurricane landfall. The WRF model is further coupled with the Advanced Circulation (AD-CIRC) model to simulate storm surge in coastal regions. A case study examines the multiple hazards associated with Hurricane Isabel (2003). Also, a risk assessment methodology is developed to estimate the probability distribution of hurricane storm surge heights along the coast, particularly for data-scarce regions, such as New York City. This methodology makes use of relatively simple models, specifically a statistical/deterministic hurricane model and the Sea, Lake and Overland Surges from Hurricanes (SLOSH) model, to simulate large numbers of synthetic surge events, and conducts statistical analysis. The estimation of hurricane landfall probability and hazards are combined with structural vulnerability models to estimate hurricane damage risk. Wind-induced damage mechanisms are extensively studied. An innovative windborne debris risk model is

  10. Peripheral intravenous catheter-related phlebitis and related risk factors.

    Science.gov (United States)

    Nassaji-Zavareh, M; Ghorbani, R

    2007-08-01

    Peripheral intravenous catheter-related phlebitis is a common and significant problem in clinical practice. This study aims to investigate the incidence of phlebitis and to evaluate some important related factors. 300 patients admitted to medical and surgical wards of hospitals in Semnan, Iran from April 2003 to February 2004 were prospectively studied. Variables evaluated were age, gender, site and size of catheter, type of insertion and underlying conditions (diabetes mellitus, trauma, infectious disease and burns). Phlebitis was defined when at least four criteria were fulfilled (erythema, pain, tenderness, warmth, induration, palpable cord and swelling). Any patient who was discharged or their catheter removed before three days were excluded. Phlebitis occurred in 26 percent (95 percent confidence interval [CI] 21- 31 percent) of patients. There was no significant relationship between age, catheter bore size, trauma and phlebitis. Related risk factors were gender (odds-ratio [OR] 1.50, 95 percent CI 1.01-2.22), site (OR 3.25, 95 percent CI 2.26-4.67) and type of insertion (OR 2.04, 95 percent CI 1.36-3.05) of catheter, diabetes mellitus (OR 7.78, 95 percent CI 4.59-13.21), infectious disease (OR 6.21, 95 percent CI 4.27-9.03) and burns (OR 3.96, 95 percent CI 3.26-4.82). Phlebitis is still an important and ongoing problem in medical practice. In patients with diabetes mellitus and infectious diseases, more attention is needed.

  11. [Identification of risk factors in relatives of type-2 diabetics].

    Science.gov (United States)

    Cuevas-Alvarez, Norma Angélica; Vela-Otero, Yolanda; Carrada-Brav, Teodoro

    2006-01-01

    To identify risk factors and warning signs in a sample of first-degree relatives of type-2 diabetics at the Family Medicine Unit 2 of the General Hospital in Irapuato, Guanajuato, Mexico. In a non-probabilistic sample of 360 relatives, a 14-item questionnaire was applied to measure abdominal perimeter and body mass index (obesity and overweight), eating habits, addictions and sedentarism. The questionnaire was made by general consent of experts, by applying Cronbach's alpha reliability coefficient. Specific rates of prevalence by sex and age groups were estimated. 233 (65%) relatives were females. As part of their family history background, arterial hypertension was recorded in 263 (73%) and acute myocardial infarction in 97 (27%). Among the dangerous food for health consumed by the relatives of diabetics are cola drinks in 94.7%, red meat in 83%, candies in 74.7% and chips in 65.8%; only half of them consumed fresh fruits and vegetables; a quarter of them ate prickly pears or whole wheat bread. There were 163 (45.3%) persons with high-risk abdominal perimeter, and sedentarism was present in 267 (74.2%). However, obesity was 3 times more frequent in females, but excessive drinking or smoking habits were 7 times more prevailing in males. A high-risk behavior was demonstrated among relativies of diabetic patients. Therefore, a public-health educational program is required to modify risky habits. A change towards prevention rather than cure is much needed in health staff.

  12. Climate Change and Food-Related Risks

    Directory of Open Access Journals (Sweden)

    Isidro Juan Mirón Pérez

    2017-06-01

    Full Text Available There are two principal concepts to take into account relating food and climate change: food security and food safety. Most papers linking climate change to food risks deal with the first one: the security of the food supply.The increase of the concentration of carbon dioxide in the atmosphere, together with the rise of the temperatures on a global level would theorically lead to greater yields of crops grown for human and animal consumption. Howevwe, most of these studies have shown that, in general, crop yields are decreasing as this global change also brings about an increase in the frequency of extreme weather events. In adition, these weather anomalies would be unevenly spread and affect developing countries, which are less capable of tackling this change, more severely. All these factors would result in greater uncertainty in the supply of food, which consequently would be less predictable and leave it more exposed to market speculation.A rise in average temperatures would be expected to increase the risk of proliferation of foodborne disease-causing microorganisms such as Salmonella or Campylobacter. Nevertheless, a trend of this sort has not been detected yet in developed countries, where information systems allow the temporal evolution of the occurrence of those diseases to be tracked, since means for food preservation and food controls are wide spread.

  13. Soil-ecological risks for soil degradation estimation

    Science.gov (United States)

    Trifonova, Tatiana; Shirkin, Leonid; Kust, German; Andreeva, Olga

    2016-04-01

    Soil degradation includes the processes of soil properties and quality worsening, primarily from the point of view of their productivity and decrease of ecosystem services quality. Complete soil cover destruction and/or functioning termination of soil forms of organic life are considered as extreme stages of soil degradation, and for the fragile ecosystems they are normally considered in the network of their desertification, land degradation and droughts /DLDD/ concept. Block-model of ecotoxic effects, generating soil and ecosystem degradation, has been developed as a result of the long-term field and laboratory research of sod-podzol soils, contaminated with waste, containing heavy metals. The model highlights soil degradation mechanisms, caused by direct and indirect impact of ecotoxicants on "phytocenosis- soil" system and their combination, frequently causing synergistic effect. The sequence of occurring changes here can be formalized as a theory of change (succession of interrelated events). Several stages are distinguished here - from heavy metals leaching (releasing) in waste and their migration downward the soil profile to phytoproductivity decrease and certain phytocenosis composition changes. Phytoproductivity decrease leads to the reduction of cellulose content introduced into the soil. The described feedback mechanism acts as a factor of sod-podzolic soil self-purification and stability. It has been shown, that using phytomass productivity index, integrally reflecting the worsening of soil properties complex, it is possible to solve the problems dealing with the dose-reflecting reactions creation and determination of critical levels of load for phytocenosis and corresponding soil-ecological risks. Soil-ecological risk in "phytocenosis- soil" system means probable negative changes and the loss of some ecosystem functions during the transformation process of dead organic substance energy for the new biomass composition. Soil-ecological risks estimation is

  14. Regional scale ecological risk assessment: using the relative risk model

    National Research Council Canada - National Science Library

    Landis, Wayne G

    2005-01-01

    ...) in the performance of regional-scale ecological risk assessments. The initial chapters present the methodology and the critical nature of the interaction between risk assessors and decision makers...

  15. Identification and risk estimation of movement strategies during cutting maneuvers.

    Science.gov (United States)

    David, Sina; Komnik, Igor; Peters, Markus; Funken, Johannes; Potthast, Wolfgang

    2017-12-01

    Approximately 70% of anterior cruciate ligament (ACL) injuries occur in non-contact situations during cutting and landing maneuvers. Parameters such as footstrike patterns and trunk orientation were found to influence ACL relevant knee loading, however, the relationship between the whole body movement and injury risk is debated. This study identifies whole body movement strategies that increase injury risk, and provides training recommendations to reduce this risk or enable a save return to sports after injury. Experimental cross-sectional study design. Three dimensional movement analysis was carried out to investigate 50 participants performing anticipated 90° cutting maneuvers. To identify and characterize movement strategies, footstrike pattern, knee valgus moment, knee internal rotation moment, angle of attack, shoulder and pelvis axis were analyzed using statistical parametric mapping. Three different movement strategies were identified. One strategy included rearfoot striking in combination with a relatively upright body position which generated higher knee joint loads than the second strategy, forefoot striking in combination with more backwards leaning and pre-rotation of the trunk towards the new movement direction. A third strategy combined forefoot striking with less preorientation which increased the ACL relevant knee joint load compared to the second strategy. The identified movement strategies clearly pre-determine the injury risk during non-contact situations with the third strategy as the most unfavorable one. Compared to the study of isolated parameters, the analysis of the whole body movement allowed for detailed separation of more risky from less risky cutting strategies. These results give practical recommendations for the prevention of ACL injury. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  16. [Estimation of the excess of lung cancer mortality risk associated to environmental tobacco smoke exposure of hospitality workers].

    Science.gov (United States)

    López, M José; Nebot, Manel; Juárez, Olga; Ariza, Carles; Salles, Joan; Serrahima, Eulàlia

    2006-01-14

    To estimate the excess lung cancer mortality risk associated with environmental tobacco (ETS) smoke exposure among hospitality workers. The estimation was done using objective measures in several hospitality settings in Barcelona. Vapour phase nicotine was measured in several hospitality settings. These measurements were used to estimate the excess lung cancer mortality risk associated with ETS exposure for a 40 year working life, using the formula developed by Repace and Lowrey. Excess lung cancer mortality risk associated with ETS exposure was higher than 145 deaths per 100,000 workers in all places studied, except for cafeterias in hospitals, where excess lung cancer mortality risk was 22 per 100,000. In discoteques, for comparison, excess lung cancer mortality risk is 1,733 deaths per 100,000 workers. Hospitality workers are exposed to ETS levels related to a very high excess lung cancer mortality risk. These data confirm that ETS control measures are needed to protect hospital workers.

  17. Longtime napping is associated with cardiovascular risk estimation according to Framingham risk score in postmenopausal women.

    Science.gov (United States)

    Li, Feng; Sun, Kan; Lin, Diaozhu; Qi, Yiqin; Li, Yan; Yan, Li; Ren, Meng

    2016-09-01

    Menopause can affect the physiological timing system, which could result in circadian rhythm changes and development of napping habits. Whether longtime napping in postmenopausal women is associated with cardiovascular disease is, however, still debated. The present study aims to investigate this association. We conducted a population-based study in 4,616 postmenopausal Chinese women. Information on sleep duration was self-reported. The Framingham General Cardiovascular Risk Score was calculated and used to identify participants at high risk of coronary heart disease (CHD). Increased daytime napping hours were positively associated with cardiovascular disease risk factors in postmenopausal women, such as age, waist circumference, systolic blood pressure, triglycerides, fasting glucose, postload glucose, and hemoglobin A1C (all P for trend napping hours, and was 3.7%, 4.3%, and 6.9% in the no daytime napping group, the 0.1 to 1 hour group, and the more than 1 hour group, respectively (P for trend = 0.005). Compared with the no daytime napping group, postmenopausal women with daytime napping more than 1 hour had higher risk of CHD in both univariate (odds ratio 1.94, 95% CI, 1.29-2.95) and multivariate (odds ratio 1.61, 95% CI, 1.03-2.52) logistic regression analyses. No statistically significant association was detected between night sleeping hours and high risk of CHD in postmenopausal participants. Daytime napping is positively associated with estimated 10-year CHD risk in postmenopausal Chinese women.

  18. How much does HDL cholesterol add to risk estimation? A report from the SCORE Investigators.

    LENUS (Irish Health Repository)

    Cooney, Marie Therese

    2009-06-01

    Systematic COronary Risk Evaluation (SCORE), the risk estimation system recommended by the European guidelines on cardiovascular disease prevention, estimates 10-year risk of cardiovascular disease mortality based on age, sex, country of origin, systolic blood pressure, smoking status and either total cholesterol (TC) or TC\\/high-density lipoprotein cholesterol (HDL-C) ratio. As, counterintuitively, these two systems perform very similarly, we have investigated whether incorporating HDL-C and TC as separate variables improves risk estimation.

  19. Maximum Correntropy Unscented Kalman Filter for Spacecraft Relative State Estimation

    Directory of Open Access Journals (Sweden)

    Xi Liu

    2016-09-01

    Full Text Available A new algorithm called maximum correntropy unscented Kalman filter (MCUKF is proposed and applied to relative state estimation in space communication networks. As is well known, the unscented Kalman filter (UKF provides an efficient tool to solve the non-linear state estimate problem. However, the UKF usually plays well in Gaussian noises. Its performance may deteriorate substantially in the presence of non-Gaussian noises, especially when the measurements are disturbed by some heavy-tailed impulsive noises. By making use of the maximum correntropy criterion (MCC, the proposed algorithm can enhance the robustness of UKF against impulsive noises. In the MCUKF, the unscented transformation (UT is applied to obtain a predicted state estimation and covariance matrix, and a nonlinear regression method with the MCC cost is then used to reformulate the measurement information. Finally, the UT is adopted to the measurement equation to obtain the filter state and covariance matrix. Illustrative examples demonstrate the superior performance of the new algorithm.

  20. Estimates o the risks associated with dam failure

    Energy Technology Data Exchange (ETDEWEB)

    Ayyaswamy, P.; Hauss, B.; Hseih, T.; Moscati, A.; Hicks, T.E.; Okrent, D.

    1974-03-01

    The probabilities and potential consequences of dam failure in California, primarily due to large earthquakes, was estimated, taking as examples eleven dams having a relatively large population downstream. Mortalities in the event of dam failure range from 11,000 to 260,000, while damage to property may be as high as $720 million. It was assumed that an intensity IX or X earthquake (on the Modified Mercalli Scale) would be sufficient to completely fail earthen dams. Predictions of dam failure were based on the recurrence times of such earthquakes. For the dams studied, the recurrence intervals for an intensity IX earthquake varied between 20 and 800 years; for an intensity X between 50 and 30,000 years. For the Lake Chabot and San Pablo dams (respectively 20, 30 years recurrent earthquake times for a intensity X) the associated consequences are: 34,000 (Lake Chabot) and 30,000 (San Pablo) people killed; damage $140 million and $77 million. Evaculation was found to ameliorate the consequences slightly in most cases because of the short time available. Calculations are based on demography, and assume 10 foot floodwaters will drown all in their path and destroy all one-unit homes in the flood area. Damage estimates reflect losses incurred by structural damage to buildings and do not include loss of income. Hence the economic impact is probably understated.

  1. Risk estimation of radiation exposure in early pregnancy

    International Nuclear Information System (INIS)

    Neumeister, K.; Waesser, S.

    1977-01-01

    The biomedical effects of radiation exposure (occupational, by X-ray diagnosis or examinations in nuclear medicine) to low doses on early pregnancy have been subject of a research work dealing with the dose level which, in case of exceeding, may lead to somatic damage (1.5 to 10 rem), and with the type of radiation injuries (malformations, functional disorder, cancer induction, increase in morbidity rate, genetic damage). A pilot study was the basis for the programme which will record such cases from all over the GDR. Within the scope of the health centre at the National Board of Nuclear Safety and Radiation Protection of the GDR, medical opinion on the interruption or preservation of pregnancy at its early stage, after exposure, was delivered in more than 50 cases. Exposure of the foetus was exactly determined. These children were re-investigated at the age of 1 to 3 years by applying pediatric and genetic examinations. The latter were based on clinical and biochemical methods as well as chromosome analyses. From these results, the risk of exposure in early pregnancy is estimated and adequate dose limits are suggested. In case these limits are exceeded, an interruption should be advised

  2. Estimates of radiological risk from depleted uranium weapons in war scenarios.

    Science.gov (United States)

    Durante, Marco; Pugliese, Mariagabriella

    2002-01-01

    Several weapons used during the recent conflict in Yugoslavia contain depleted uranium, including missiles and armor-piercing incendiary rounds. Health concern is related to the use of these weapons, because of the heavy-metal toxicity and radioactivity of uranium. Although chemical toxicity is considered the more important source of health risk related to uranium, radiation exposure has been allegedly related to cancers among veterans of the Balkan conflict, and uranium munitions are a possible source of contamination in the environment. Actual measurements of radioactive contamination are needed to assess the risk. In this paper, a computer simulation is proposed to estimate radiological risk related to different exposure scenarios. Dose caused by inhalation of radioactive aerosols and ground contamination induced by Tomahawk missile impact are simulated using a Gaussian plume model (HOTSPOT code). Environmental contamination and committed dose to the population resident in contaminated areas are predicted by a food-web model (RESRAD code). Small values of committed effective dose equivalent appear to be associated with missile impacts (50-y CEDE radiological risk. These computer simulations suggest that little radiological risk is associated to the use of depleted uranium weapons.

  3. Affect and Acceptability: Exploring Teachers' Technology-Related Risk Perceptions

    Science.gov (United States)

    Howard, Sarah K.

    2011-01-01

    Educational change, such as technology integration, involves risk. Teachers are encouraged to "take risks", but what risks they are asked to take and how do they perceive these risks? Developing an understanding of teachers' technology-related risk perceptions can help explain their choices and behaviours. This paper presents a way to…

  4. Uncertainty related to Environmental Data and Estimated Extreme Events

    DEFF Research Database (Denmark)

    Burcharth, H. F.

    The design loads on rubble mound breakwaters are almost entirely determined by the environmental conditions, i.e. sea state, water levels, sea bed characteristics, etc. It is the objective of sub-group B to identify the most important environmental parameters and evaluate the related uncertainties...... including those corresponding to extreme estimates typically used for design purposes. Basically a design condition is made up of a set of parameter values stemming from several environmental parameters. To be able to evaluate the uncertainty related to design states one must know the corresponding joint....... Consequently this report deals mainly with each parameter separately. Multi parameter problems are briefly discussed in section 9. It is important to notice that the quantified uncertainties reported in section 7.7 represent what might be regarded as typical figures to be used only when no more qualified...

  5. Work related injuries: estimating the incidence among illegally employed immigrants

    Directory of Open Access Journals (Sweden)

    Fadda Emanuela

    2010-12-01

    Full Text Available Abstract Background Statistics on occupational accidents are based on data from registered employees. With the increasing number of immigrants employed illegally and/or without regular working visas in many developed countries, it is of interest to estimate the injury rate among such unregistered workers. Findings The current study was conducted in an area of North-Eastern Italy. The sources of information employed in the present study were the Accidents and Emergencies records of a hospital; the population data on foreign-born residents in the hospital catchment area (Health Care District 4, Primary Care Trust 20, Province of Verona, Veneto Region, North-Eastern Italy; and the estimated proportion of illegally employed workers in representative samples from the Province of Verona and the Veneto Region. Of the 419 A&E records collected between January and December 2004 among non European Union (non-EU immigrants, 146 aroused suspicion by reporting the home, rather than the workplace, as the site of the accident. These cases were the numerator of the rate. The number of illegally employed non-EU workers, denominator of the rate, was estimated according to different assumptions and ranged from between 537 to 1,338 individuals. The corresponding rates varied from 109.1 to 271.8 per 1,000 non-EU illegal employees, against 65 per 1,000 reported in Italy in 2004. Conclusions The results of this study suggest that there is an unrecorded burden of illegally employed immigrants suffering from work related injuries. Additional efforts for prevention of injuries in the workplace are required to decrease this number. It can be concluded that the Italian National Institute for the Insurance of Work Related Injuries (INAIL probably underestimates the incidence of these accidents in Italy.

  6. Work related injuries: estimating the incidence among illegally employed immigrants.

    Science.gov (United States)

    Mastrangelo, Giuseppe; Rylander, Ragnar; Buja, Alessandra; Marangi, Gianluca; Fadda, Emanuela; Fedeli, Ugo; Cegolon, Luca

    2010-12-08

    Statistics on occupational accidents are based on data from registered employees. With the increasing number of immigrants employed illegally and/or without regular working visas in many developed countries, it is of interest to estimate the injury rate among such unregistered workers. The current study was conducted in an area of North-Eastern Italy. The sources of information employed in the present study were the Accidents and Emergencies records of a hospital; the population data on foreign-born residents in the hospital catchment area (Health Care District 4, Primary Care Trust 20, Province of Verona, Veneto Region, North-Eastern Italy); and the estimated proportion of illegally employed workers in representative samples from the Province of Verona and the Veneto Region. Of the 419 A&E records collected between January and December 2004 among non European Union (non-EU) immigrants, 146 aroused suspicion by reporting the home, rather than the workplace, as the site of the accident. These cases were the numerator of the rate. The number of illegally employed non-EU workers, denominator of the rate, was estimated according to different assumptions and ranged from between 537 to 1,338 individuals. The corresponding rates varied from 109.1 to 271.8 per 1,000 non-EU illegal employees, against 65 per 1,000 reported in Italy in 2004. The results of this study suggest that there is an unrecorded burden of illegally employed immigrants suffering from work related injuries. Additional efforts for prevention of injuries in the workplace are required to decrease this number. It can be concluded that the Italian National Institute for the Insurance of Work Related Injuries (INAIL) probably underestimates the incidence of these accidents in Italy.

  7. Risk estimation by exposure to PM10 particles in the Toluca Valley

    International Nuclear Information System (INIS)

    Flores R, J.H.; Pena G, P.; Balcazar, M.; Lopez M, A.; Morelos M, J.

    2007-01-01

    Full text: Risk estimation to PM10 in the Toluca valley and surrounding areas was estimated, for several return periods, evaluating the occurrence probability to several interval times (1, 5, 10, 12.5, 15, 17.5 and 20 years) using the extreme values of the Gumbel-1 distribution; those intervals were employed to predict and analyze the behaviour of maximum contaminant concentrations in the study region. A high degree of risk to health due to the mean concentration of these particles is obtained from statistical considerations. The evaluation took into consideration the eight monitoring years from the Automatic Atmospheric Monitoring Network (RAMAT) and its output predicts, if present conditions maintain, this statistical relation remain invariant between the next 20 years. Such particles affect the human respiratory system, besides, present a carcinogenic potential due to the volume of hydrocarbons combustion to the atmosphere. (Author)

  8. Pregnancy-related venous thromboembolism and risk of occult cancer

    DEFF Research Database (Denmark)

    Hansen, Anette Tarp; Veres, Katalin; Horváth-Puhó, Erzsébet

    2017-01-01

    The cancer risk during the first year after a pregnancy-related venous thromboembolism episode is higher than expected. An aggressive search for cancer in women with pregnancy-related venous thromboembolism is probably not warranted, due to low absolute risk.......The cancer risk during the first year after a pregnancy-related venous thromboembolism episode is higher than expected. An aggressive search for cancer in women with pregnancy-related venous thromboembolism is probably not warranted, due to low absolute risk....

  9. Accounting for individualized competing mortality risks in estimating postmenopausal breast cancer risk

    Science.gov (United States)

    Schonberg, Mara A.; Li, Vicky W.; Eliassen, A. Heather; Davis, Roger B.; LaCroix, Andrea Z.; McCarthy, Ellen P.; Rosner, Bernard A.; Chlebowski, Rowan T.; Hankinson, Susan E.; Marcantonio, Edward R.; Ngo, Long H.

    2016-01-01

    Purpose Accurate risk assessment is necessary for decision-making around breast cancer prevention. We aimed to develop a breast cancer prediction model for postmenopausal women that would take into account their individualized competing risk of non-breast cancer death. Methods We included 73,066 women who completed the 2004 Nurses’ Health Study (NHS) questionnaire (all ≥57 years) and followed participants until May 2014. We considered 17 breast cancer risk factors (health behaviors, demographics, family history, reproductive factors), 7 risk factors for non-breast cancer death (comorbidities, functional dependency), and mammography use. We used competing risk regression to identify factors independently associated with breast cancer. We validated the final model by examining calibration (expected-to-observed ratio of breast cancer incidence, E/O) and discrimination (c-statistic) using 74,887 subjects from the Women’s Health Initiative Extension Study (WHI-ES; all were ≥55 years and followed for 5 years). Results Within 5 years, 1.8% of NHS participants were diagnosed with breast cancer (vs. 2.0% in WHI-ES, p=0.02) and 6.6% experienced non-breast cancer death (vs. 5.2% in WHI-ES, prisk factors, 5 comorbidities, functional dependency, and mammography use. The model’s c-statistic was 0.61 (95% CI [0.60–0.63]) in NHS and 0.57 (0.55–0.58) in WHI-ES. On average our model under predicted breast cancer in WHI-ES (E/O 0.92 [0.88–0.97]). Conclusions We developed a novel prediction model that factors in postmenopausal women’s individualized competing risks of non-breast cancer death when estimating breast cancer risk. PMID:27770283

  10. 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.

  11. The relative pose estimation of aircraft based on contour model

    Science.gov (United States)

    Fu, Tai; Sun, Xiangyi

    2017-02-01

    This paper proposes a relative pose estimation approach based on object contour model. The first step is to obtain a two-dimensional (2D) projection of three-dimensional (3D)-model-based target, which will be divided into 40 forms by clustering and LDA analysis. Then we proceed by extracting the target contour in each image and computing their Pseudo-Zernike Moments (PZM), thus a model library is constructed in an offline mode. Next, we spot a projection contour that resembles the target silhouette most in the present image from the model library with reference of PZM; then similarity transformation parameters are generated as the shape context is applied to match the silhouette sampling location, from which the identification parameters of target can be further derived. Identification parameters are converted to relative pose parameters, in the premise that these values are the initial result calculated via iterative refinement algorithm, as the relative pose parameter is in the neighborhood of actual ones. At last, Distance Image Iterative Least Squares (DI-ILS) is employed to acquire the ultimate relative pose parameters.

  12. Estimating the temporal distribution of exposure-related cancers

    International Nuclear Information System (INIS)

    Carter, R.L.; Sposto, R.; Preston, D.L.

    1993-09-01

    The temporal distribution of exposure-related cancers is relevant to the study of carcinogenic mechanisms. Statistical methods for extracting pertinent information from time-to-tumor data, however, are not well developed. Separation of incidence from 'latency' and the contamination of background cases are two problems. In this paper, we present methods for estimating both the conditional distribution given exposure-related cancers observed during the study period and the unconditional distribution. The methods adjust for confounding influences of background cases and the relationship between time to tumor and incidence. Two alternative methods are proposed. The first is based on a structured, theoretically derived model and produces direct inferences concerning the distribution of interest but often requires more-specialized software. The second relies on conventional modeling of incidence and is implemented through readily available, easily used computer software. Inferences concerning the effects of radiation dose and other covariates, however, are not always obtainable directly. We present three examples to illustrate the use of these two methods and suggest criteria for choosing between them. The first approach was used, with a log-logistic specification of the distribution of interest, to analyze times to bone sarcoma among a group of German patients injected with 224 Ra. Similarly, a log-logistic specification was used in the analysis of time to chronic myelogenous leukemias among male atomic-bomb survivors. We used the alternative approach, involving conventional modeling, to estimate the conditional distribution of exposure-related acute myelogenous leukemias among male atomic-bomb survivors, given occurrence between 1 October 1950 and 31 December 1985. All analyses were performed using Poisson regression methods for analyzing grouped survival data. (J.P.N.)

  13. Methodology for the Model-based Small Area Estimates of Cancer Risk Factors and Screening Behaviors - Small Area Estimates

    Science.gov (United States)

    This model-based approach uses data from both the Behavioral Risk Factor Surveillance System (BRFSS) and the National Health Interview Survey (NHIS) to produce estimates of the prevalence rates of cancer risk factors and screening behaviors at the state, health service area, and county levels.

  14. Robust estimation of event-related potentials via particle filter.

    Science.gov (United States)

    Fukami, Tadanori; Watanabe, Jun; Ishikawa, Fumito

    2016-03-01

    In clinical examinations and brain-computer interface (BCI) research, a short electroencephalogram (EEG) measurement time is ideal. The use of event-related potentials (ERPs) relies on both estimation accuracy and processing time. We tested a particle filter that uses a large number of particles to construct a probability distribution. We constructed a simple model for recording EEG comprising three components: ERPs approximated via a trend model, background waves constructed via an autoregressive model, and noise. We evaluated the performance of the particle filter based on mean squared error (MSE), P300 peak amplitude, and latency. We then compared our filter with the Kalman filter and a conventional simple averaging method. To confirm the efficacy of the filter, we used it to estimate ERP elicited by a P300 BCI speller. A 400-particle filter produced the best MSE. We found that the merit of the filter increased when the original waveform already had a low signal-to-noise ratio (SNR) (i.e., the power ratio between ERP and background EEG). We calculated the amount of averaging necessary after applying a particle filter that produced a result equivalent to that associated with conventional averaging, and determined that the particle filter yielded a maximum 42.8% reduction in measurement time. The particle filter performed better than both the Kalman filter and conventional averaging for a low SNR in terms of both MSE and P300 peak amplitude and latency. For EEG data produced by the P300 speller, we were able to use our filter to obtain ERP waveforms that were stable compared with averages produced by a conventional averaging method, irrespective of the amount of averaging. We confirmed that particle filters are efficacious in reducing the measurement time required during simulations with a low SNR. Additionally, particle filters can perform robust ERP estimation for EEG data produced via a P300 speller. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. Events per variable for risk differences and relative risks using pseudo-observations

    DEFF Research Database (Denmark)

    Hansen, Stefan Nygaard; Andersen, Per Kragh; Parner, Erik Thorlund

    2014-01-01

    A method based on pseudo-observations has been proposed for direct regression modeling of functionals of interest with right-censored data, including the survival function, the restricted mean and the cumulative incidence function in competing risks. The models, once the pseudo-observations have...... been computed, can be fitted using standard generalized estimating equation software. Regression models can however yield problematic results if the number of covariates is large in relation to the number of events observed. Guidelines of events per variable are often used in practice. These rules...

  16. Managing IT-related operational risks

    Directory of Open Access Journals (Sweden)

    Savić Ana

    2008-01-01

    Full Text Available Not so long ago, information technology (IT risk occupied a small corner of operational risk - the opportunity loss from a missed IT development deadline. Today, the success of an entire financial institution may lay on managing a broad landscape of IT risks. IT risk is a potential damage to an organization's value, resulting from inadequate managing of processes and technologies. IT risk includes the failure to respond to security and privacy requirements, as well as many other issues such as: human error, internal fraud through software manipulation, external fraud by intruders, obsolesce in applications and machines, reliability issues or mismanagement. The World Economic Forum provides best information about this problem. They rank a breakdown of critical information infrastructure among the most likely core global risks, with 10-20 % likelihood over the next 10 years and potential worldwide impact of $250 billion. Sustained investment in IT - almost $1.2 trillion or 29% of 2006 private-sector capital investment in the U.S. alone fuels growing exposure to IT risk. Greg Hughes, chief strategy officer in Symantec Corp. recently claimed "IT risk management is more than using technology to solve security problems. With proper planning and broad support, it can give an organization the confidence to innovate, using IT to outdistance competitors".

  17. Value-at-risk estimation with fuzzy histograms

    NARCIS (Netherlands)

    Almeida, R.J.; Kaymak, U.

    2008-01-01

    Value at risk (VaR) is a measure for senior management that summarises the financial risk a company faces into one single number. In this paper, we consider the use of fuzzy histograms for quantifying the value-at-risk of a portfolio. It is shown that the use of fuzzy histograms provides a good

  18. Estimates of Leaf Relative Water Content from Optical Polarization Measurements

    Science.gov (United States)

    Dahlgren, R. P.; Vanderbilt, V. C.; Daughtry, C. S. T.

    2017-12-01

    Remotely sensing the water status of plant canopies remains a long term goal of remote sensing research. Existing approaches to remotely sensing canopy water status, such as the Crop Water Stress Index (CWSI) and the Equivalent Water Thickness (EWT), have limitations. The CWSI, based upon remotely sensing canopy radiant temperature in the thermal infrared spectral region, does not work well in humid regions, requires estimates of the vapor pressure deficit near the canopy during the remote sensing over-flight and, once stomata close, provides little information regarding the canopy water status. The EWT is based upon the physics of water-light interaction in the 900-2000nm spectral region, not plant physiology. Our goal, development of a remote sensing technique for estimating plant water status based upon measurements in the VIS/NIR spectral region, would potentially provide remote sensing access to plant dehydration physiology - to the cellular photochemistry and structural changes associated with water deficits in leaves. In this research, we used optical, crossed polarization filters to measure the VIS/NIR light reflected from the leaf interior, R, as well as the leaf transmittance, T, for 78 corn (Zea mays) and soybean (Glycine max) leaves having relative water contents (RWC) between 0.60 and 0.98. Our results show that as RWC decreases R increases while T decreases. Our results tie R and T changes in the VIS/NIR to leaf physiological changes - linking the light scattered out of the drying leaf interior to its relative water content and to changes in leaf cellular structure and pigments. Our results suggest remotely sensing the physiological water status of a single leaf - and perhaps of a plant canopy - might be possible in the future.

  19. Risk and size estimation of debris flow caused by storm rainfall in mountain regions

    Institute of Scientific and Technical Information of China (English)

    CHENG; Genwei

    2003-01-01

    Debris flow is a common disaster in mountain regions. The valley slope, storm rainfall and amassed sand-rock materials in a watershed may influence the types of debris flow. The bursting of debris flow is not a pure random event. Field investigations show the periodicity of its burst, but no directive evidence has been found yet. A risk definition of debris flow is proposed here based upon the accumulation and the starting conditions of loose material in channel. According to this definition, the risk of debris flow is of quasi-periodicity. A formula of risk estimation is derived. Analysis of relative factors reveals the relationship between frequency and size of debris flow. For a debris flow creek, the longer the time interval between two occurrences of debris flows is, the bigger the bursting event will be.

  20. Mental health of a police force: estimating prevalence of work-related depression in Australia without a direct national measure.

    Science.gov (United States)

    Lawson, Katrina J; Rodwell, John J; Noblet, Andrew J

    2012-06-01

    The risk of work-related depression in Australia was estimated based on a survey of 631 police officers. Psychological wellbeing and psychological distress items were mapped onto a measure of depression to identify optimal cutoff points. Based on a sample of police officers, Australian workers, in general, are at risk of depression when general psychological wellbeing is considerably compromised. Large-scale estimation of work-related depression in the broader population of employed persons in Australia is reasonable. The relatively high prevalence of depression among police officers emphasizes the need to examine prevalence rates of depression among Australian employees.

  1. Estimation of sport fish harvest for risk and hazard assessment of environmental contaminants

    International Nuclear Information System (INIS)

    Poston, T.M.; Strenge, D.L.

    1989-01-01

    Consumption of contaminated fish flesh can be a significant route of human exposure to hazardous chemicals. Estimation of exposure resulting from the consumption of fish requires knowledge of fish consumption and contaminant levels in the edible portion of fish. Realistic figures of sport fish harvest are needed to estimate consumption. Estimates of freshwater sport fish harvest were developed from a review of 72 articles and reports. Descriptive statistics based on fishing pressure were derived from harvest data for four distinct groups of freshwater sport fish in three water types: streams, lakes, and reservoirs. Regression equations were developed to relate harvest to surface area fished where data bases were sufficiently large. Other aspects of estimating human exposure to contaminants in fish flesh that are discussed include use of bioaccumulation factors for trace metals and organic compounds. Using the bioaccumulation factor and the concentration of contaminants in water as variables in the exposure equation may also lead to less precise estimates of tissue concentration. For instance, muscle levels of contaminants may not increase proportionately with increases in water concentrations, leading to overestimation of risk. In addition, estimates of water concentration may be variable or expressed in a manner that does not truly represent biological availability of the contaminant. These factors are discussed. 45 refs., 1 fig., 7 tabs

  2. Estimate of lifetime excess lung cancer risk due to indoor exposure to natural radon-222 daughters in Korea

    International Nuclear Information System (INIS)

    Si-Young Chang; Jeong-Ho Lee; Chung-Woo Ha

    1993-01-01

    Lifetime excess lung cancer risk due to indoor 222 Rn daughters exposure in Korea was quantitatively estimated by a modified relative risk projection model proposed by the U.S. National Academy of Science and the recent Korean life table data. The lifetime excess risk of lung cancer death attributable to annual constant exposure to Korean indoor radon daughters was estimated to be about 230/10 6 per WLM, which seemed to be nearly in the median of the range of 150-450/10 6 per WLM reported by the UNSCEAR in 1988. (1 fig., 2 tabs.)

  3. Obesity phenotype and coronary heart disease risk as estimated by the Framingham risk score.

    Science.gov (United States)

    Park, Yong Soon; Kim, Jun-Su

    2012-03-01

    There are conflicting data as to whether general or abdominal obesity is a better predictor of cardiovascular risk. This cross-sectional study involved 4,573 subjects aged 30 to 74 yr who participated in the Fourth Korea National Health and Nutrition Examination Survey conducted in 2008. Obesity phenotype was classified by means of body mass index (BMI) and waist circumference (WC), and participants were categorized into 4 groups. Individuals' 10-yr risk of coronary heart diseases (CHD) was determined from the Framingham risk score. Subjects with obese WC had a higher proportion of high risk for CHD compared to the normal WC group, irrespective of BMI level. Relative to subjects with normal BMI/normal WC, the adjusted odds ratios (ORs) of normal BMI/obese WC group (OR 2.93 [1.70, 5.04] and OR 3.10 [1.49, 6.46]) for CHD risk in male were higher than obese BMI/obese WC group (OR 1.91 [1.40, 2.61] and OR 1.70 [1.16, 2.47]), whereas the adjusted ORs of obese BMI/obese WC group (OR 1.94 [1.24, 3.04] and OR 3.92 [1.75, 8.78]) were higher than the others in female. Subjects with obese BMI/normal WC were not significantly associated with 10-yr CHD risk in men (P = 0.449 and P = 0.067) and women (P = 0.702 and P = 0.658). WC is associated with increased CHD risk regardless of the level of BMI. Men with normal BMI and obese WC tend to be associated with CHD risk than those with obese BMI and obese WC.

  4. A Risk Metric Assessment of Scenario-Based Market Risk Measures for Volatility and Risk Estimation: Evidence from Emerging Markets

    Directory of Open Access Journals (Sweden)

    Sitima Innocent

    2015-03-01

    Full Text Available The study evaluated the sensitivity of the Value- at- Risk (VaR and Expected Shortfalls (ES with respect to portfolio allocation in emerging markets with an index portfolio of a developed market. This study utilised different models for VaR and ES techniques using various scenario-based models such as Covariance Methods, Historical Simulation and the GARCH (1, 1 for the predictive ability of these models in both relatively stable market conditions and extreme market conditions. The results showed that Expected Shortfall has less risk tolerance than VaR based on the same scenario-based market risk measures

  5. Association between firearm ownership, firearm-related risk and risk reduction behaviours and alcohol-related risk behaviours.

    Science.gov (United States)

    Wintemute, Garen J

    2011-12-01

    Alcohol use and firearm ownership are risk factors for violent injury and death. To determine whether firearm ownership and specific firearm-related behaviours are associated with alcohol-related risk behaviours, the author conducted a cross-sectional study using Behavioral Risk Factor Surveillance System data for eight states in the USA from 1996 to 1997 (the most recent data available). Altogether, 15 474 respondents provided information on firearm exposure. After adjustment for demographics and state of residence, firearm owners were more likely than those with no firearms at home to have ≥5 drinks on one occasion (OR 1.32; 95% CI 1.16 to 1.50), to drink and drive (OR 1.79; 95% CI 1.34 to 2.39) and to have ≥60 drinks per month (OR 1.45; 95% CI 1.14 to 1.83). Heavy alcohol use was most common among firearm owners who also engaged in behaviours such as carrying a firearm for protection against other people and keeping a firearm at home that was both loaded and not locked away. The author concludes that firearm ownership and specific firearm-related behaviours are associated with alcohol-related risk behaviours.

  6. Report on estimated nuclear energy related cost for fiscal 1991

    International Nuclear Information System (INIS)

    1991-01-01

    The report first describes major actions planned to be taken in Japan in fiscal 1991 in the field of nuclear energy utilization. Major activities to be made for comprehensive strengthening of safety assurance measures are described, focusing on improvement of nuclear energy related safety regulations, promotion of research for safety assurance, improvement and strengthening of disaster prevention measures, environmental radioactivity surveys, control of exposure of workers engaged in radioactivity related jobs, etc. The report then describes actions required for the establishment of a nuclear fuel cycle, focusing on the procurement of uranium resources, establishment of a uranium enrichment process, reprocessing of spent fuel, application of recovered uranium, etc. Other activities are required for the development of new type reactors, effective application of plutonium, development of basic techniques, international contributions, cooperation with the public. Then, the report summarizes estimated costs required for the activities to be performed by the Japan Atomic Energy Research Institute, Power Reactor and Nuclear Fuel Development Corporation, National Institute of Radiological Sciences, Institute of Physical and Chemical Research. (N.K.)

  7. [Estimation of the risk of upper digestive tract bleeding in patients with portal cavernomatosis].

    Science.gov (United States)

    Couselo, M; Ibáñez, V; Mangas, L; Gómez-Chacón, J; Vila Carbó, J J

    2011-01-01

    The aim of this study is to find out the risk of upper gastrointestinal bleeding (UGB) after the diagnosis of portal cavernoma in children, and to investigate several potential risk factors. We analyzed retrospectively 13 cases of portal cavernoma and estimated the risk of UGB with the Kaplan-Meier survival analysis. We calculated the incidence rate of the sample and the number of haemorrhages per year for each patient individually. From the moment of the diagnosis various parameters were recorded: age, platelets, leukocytes, hemoblobin, hematocrit, prothrombin time and number of bleedings. The relation between these parameters and the risk of bleeding was assessed with the Cox analysis. The patients were followed for a median period of 7.1 years. 10 patients (77%) presented at least 1 episode of UGB after the diagnosis. The median survival time until the first haemorrhage was 314 days. After the diagnosis the incidence rate of the sample was 0.43 episodes of upper gastrointestinal bleeding per person-year. The number of individual bleedings per person had a range of 0-2.2 episodes per year. There is very few data about the risk of bleeding in children with portal cavernoma. In our sample, we found out an incidence rate of 0.43 and a median survival time of 314 days until the first episode of bleeding after the diagnosis, but we were not able to find a statistically significant association between the studied variables and the risk of bleeding.

  8. MicroRNA Related Polymorphisms and Breast Cancer Risk

    Science.gov (United States)

    Khan, Sofia; Greco, Dario; Michailidou, Kyriaki; Milne, Roger L.; Muranen, Taru A.; Heikkinen, Tuomas; Aaltonen, Kirsimari; Dennis, Joe; Bolla, Manjeet K.; Liu, Jianjun; Hall, Per; Irwanto, Astrid; Humphreys, Keith; Li, Jingmei; Czene, Kamila; Chang-Claude, Jenny; Hein, Rebecca; Rudolph, Anja; Seibold, Petra; Flesch-Janys, Dieter; Fletcher, Olivia; Peto, Julian; dos Santos Silva, Isabel; Johnson, Nichola; Gibson, Lorna; Aitken, Zoe; Hopper, John L.; Tsimiklis, Helen; Bui, Minh; Makalic, Enes; Schmidt, Daniel F.; Southey, Melissa C.; Apicella, Carmel; Stone, Jennifer; Waisfisz, Quinten; Meijers-Heijboer, Hanne; Adank, Muriel A.; van der Luijt, Rob B.; Meindl, Alfons; Schmutzler, Rita K.; Müller-Myhsok, Bertram; Lichtner, Peter; Turnbull, Clare; Rahman, Nazneen; Chanock, Stephen J.; Hunter, David J.; Cox, Angela; Cross, Simon S.; Reed, Malcolm W. R.; Schmidt, Marjanka K.; Broeks, Annegien; Veer, Laura J. V. a. n't.; Hogervorst, Frans B.; Fasching, Peter A.; Schrauder, Michael G.; Ekici, Arif B.; Beckmann, Matthias W.; Bojesen, Stig E.; Nordestgaard, Børge G.; Nielsen, Sune F.; Flyger, Henrik; Benitez, Javier; Zamora, Pilar M.; Perez, Jose I. A.; Haiman, Christopher A.; Henderson, Brian E.; Schumacher, Fredrick; Le Marchand, Loic; Pharoah, Paul D. P.; Dunning, Alison M.; Shah, Mitul; Luben, Robert; Brown, Judith; Couch, Fergus J.; Wang, Xianshu; Vachon, Celine; Olson, Janet E.; Lambrechts, Diether; Moisse, Matthieu; Paridaens, Robert; Christiaens, Marie-Rose; Guénel, Pascal; Truong, Thérèse; Laurent-Puig, Pierre; Mulot, Claire; Marme, Frederick; Burwinkel, Barbara; Schneeweiss, Andreas; Sohn, Christof; Sawyer, Elinor J.; Tomlinson, Ian; Kerin, Michael J.; Miller, Nicola; Andrulis, Irene L.; Knight, Julia A.; Tchatchou, Sandrine; Mulligan, Anna Marie; Dörk, Thilo; Bogdanova, Natalia V.; Antonenkova, Natalia N.; Anton-Culver, Hoda; Darabi, Hatef; Eriksson, Mikael; Garcia-Closas, Montserrat; Figueroa, Jonine; Lissowska, Jolanta; Brinton, Louise; Devilee, Peter; Tollenaar, Robert A. E. M.; Seynaeve, Caroline; van Asperen, Christi J.; Kristensen, Vessela N.; Slager, Susan; Toland, Amanda E.; Ambrosone, Christine B.; Yannoukakos, Drakoulis; Lindblom, Annika; Margolin, Sara; Radice, Paolo; Peterlongo, Paolo; Barile, Monica; Mariani, Paolo; Hooning, Maartje J.; Martens, John W. M.; Collée, J. Margriet; Jager, Agnes; Jakubowska, Anna; Lubinski, Jan; Jaworska-Bieniek, Katarzyna; Durda, Katarzyna; Giles, Graham G.; McLean, Catriona; Brauch, Hiltrud; Brüning, Thomas; Ko, Yon-Dschun; Brenner, Hermann; Dieffenbach, Aida Karina; Arndt, Volker; Stegmaier, Christa; Swerdlow, Anthony; Ashworth, Alan; Orr, Nick; Jones, Michael; Simard, Jacques; Goldberg, Mark S.; Labrèche, France; Dumont, Martine; Winqvist, Robert; Pylkäs, Katri; Jukkola-Vuorinen, Arja; Grip, Mervi; Kataja, Vesa; Kosma, Veli-Matti; Hartikainen, Jaana M.; Mannermaa, Arto; Hamann, Ute; Chenevix-Trench, Georgia; Blomqvist, Carl; Aittomäki, Kristiina; Easton, Douglas F.; Nevanlinna, Heli

    2014-01-01

    Genetic variations, such as single nucleotide polymorphisms (SNPs) in microRNAs (miRNA) or in the miRNA binding sites may affect the miRNA dependent gene expression regulation, which has been implicated in various cancers, including breast cancer, and may alter individual susceptibility to cancer. We investigated associations between miRNA related SNPs and breast cancer risk. First we evaluated 2,196 SNPs in a case-control study combining nine genome wide association studies (GWAS). Second, we further investigated 42 SNPs with suggestive evidence for association using 41,785 cases and 41,880 controls from 41 studies included in the Breast Cancer Association Consortium (BCAC). Combining the GWAS and BCAC data within a meta-analysis, we estimated main effects on breast cancer risk as well as risks for estrogen receptor (ER) and age defined subgroups. Five miRNA binding site SNPs associated significantly with breast cancer risk: rs1045494 (odds ratio (OR) 0.92; 95% confidence interval (CI): 0.88–0.96), rs1052532 (OR 0.97; 95% CI: 0.95–0.99), rs10719 (OR 0.97; 95% CI: 0.94–0.99), rs4687554 (OR 0.97; 95% CI: 0.95–0.99, and rs3134615 (OR 1.03; 95% CI: 1.01–1.05) located in the 3′ UTR of CASP8, HDDC3, DROSHA, MUSTN1, and MYCL1, respectively. DROSHA belongs to miRNA machinery genes and has a central role in initial miRNA processing. The remaining genes are involved in different molecular functions, including apoptosis and gene expression regulation. Further studies are warranted to elucidate whether the miRNA binding site SNPs are the causative variants for the observed risk effects. PMID:25390939

  9. MicroRNA related polymorphisms and breast cancer risk.

    Science.gov (United States)

    Khan, Sofia; Greco, Dario; Michailidou, Kyriaki; Milne, Roger L; Muranen, Taru A; Heikkinen, Tuomas; Aaltonen, Kirsimari; Dennis, Joe; Bolla, Manjeet K; Liu, Jianjun; Hall, Per; Irwanto, Astrid; Humphreys, Keith; Li, Jingmei; Czene, Kamila; Chang-Claude, Jenny; Hein, Rebecca; Rudolph, Anja; Seibold, Petra; Flesch-Janys, Dieter; Fletcher, Olivia; Peto, Julian; dos Santos Silva, Isabel; Johnson, Nichola; Gibson, Lorna; Aitken, Zoe; Hopper, John L; Tsimiklis, Helen; Bui, Minh; Makalic, Enes; Schmidt, Daniel F; Southey, Melissa C; Apicella, Carmel; Stone, Jennifer; Waisfisz, Quinten; Meijers-Heijboer, Hanne; Adank, Muriel A; van der Luijt, Rob B; Meindl, Alfons; Schmutzler, Rita K; Müller-Myhsok, Bertram; Lichtner, Peter; Turnbull, Clare; Rahman, Nazneen; Chanock, Stephen J; Hunter, David J; Cox, Angela; Cross, Simon S; Reed, Malcolm W R; Schmidt, Marjanka K; Broeks, Annegien; Van't Veer, Laura J; Hogervorst, Frans B; Fasching, Peter A; Schrauder, Michael G; Ekici, Arif B; Beckmann, Matthias W; Bojesen, Stig E; Nordestgaard, Børge G; Nielsen, Sune F; Flyger, Henrik; Benitez, Javier; Zamora, Pilar M; Perez, Jose I A; Haiman, Christopher A; Henderson, Brian E; Schumacher, Fredrick; Le Marchand, Loic; Pharoah, Paul D P; Dunning, Alison M; Shah, Mitul; Luben, Robert; Brown, Judith; Couch, Fergus J; Wang, Xianshu; Vachon, Celine; Olson, Janet E; Lambrechts, Diether; Moisse, Matthieu; Paridaens, Robert; Christiaens, Marie-Rose; Guénel, Pascal; Truong, Thérèse; Laurent-Puig, Pierre; Mulot, Claire; Marme, Frederick; Burwinkel, Barbara; Schneeweiss, Andreas; Sohn, Christof; Sawyer, Elinor J; Tomlinson, Ian; Kerin, Michael J; Miller, Nicola; Andrulis, Irene L; Knight, Julia A; Tchatchou, Sandrine; Mulligan, Anna Marie; Dörk, Thilo; Bogdanova, Natalia V; Antonenkova, Natalia N; Anton-Culver, Hoda; Darabi, Hatef; Eriksson, Mikael; Garcia-Closas, Montserrat; Figueroa, Jonine; Lissowska, Jolanta; Brinton, Louise; Devilee, Peter; Tollenaar, Robert A E M; Seynaeve, Caroline; van Asperen, Christi J; Kristensen, Vessela N; Slager, Susan; Toland, Amanda E; Ambrosone, Christine B; Yannoukakos, Drakoulis; Lindblom, Annika; Margolin, Sara; Radice, Paolo; Peterlongo, Paolo; Barile, Monica; Mariani, Paolo; Hooning, Maartje J; Martens, John W M; Collée, J Margriet; Jager, Agnes; Jakubowska, Anna; Lubinski, Jan; Jaworska-Bieniek, Katarzyna; Durda, Katarzyna; Giles, Graham G; McLean, Catriona; Brauch, Hiltrud; Brüning, Thomas; Ko, Yon-Dschun; Brenner, Hermann; Dieffenbach, Aida Karina; Arndt, Volker; Stegmaier, Christa; Swerdlow, Anthony; Ashworth, Alan; Orr, Nick; Jones, Michael; Simard, Jacques; Goldberg, Mark S; Labrèche, France; Dumont, Martine; Winqvist, Robert; Pylkäs, Katri; Jukkola-Vuorinen, Arja; Grip, Mervi; Kataja, Vesa; Kosma, Veli-Matti; Hartikainen, Jaana M; Mannermaa, Arto; Hamann, Ute; Chenevix-Trench, Georgia; Blomqvist, Carl; Aittomäki, Kristiina; Easton, Douglas F; Nevanlinna, Heli

    2014-01-01

    Genetic variations, such as single nucleotide polymorphisms (SNPs) in microRNAs (miRNA) or in the miRNA binding sites may affect the miRNA dependent gene expression regulation, which has been implicated in various cancers, including breast cancer, and may alter individual susceptibility to cancer. We investigated associations between miRNA related SNPs and breast cancer risk. First we evaluated 2,196 SNPs in a case-control study combining nine genome wide association studies (GWAS). Second, we further investigated 42 SNPs with suggestive evidence for association using 41,785 cases and 41,880 controls from 41 studies included in the Breast Cancer Association Consortium (BCAC). Combining the GWAS and BCAC data within a meta-analysis, we estimated main effects on breast cancer risk as well as risks for estrogen receptor (ER) and age defined subgroups. Five miRNA binding site SNPs associated significantly with breast cancer risk: rs1045494 (odds ratio (OR) 0.92; 95% confidence interval (CI): 0.88-0.96), rs1052532 (OR 0.97; 95% CI: 0.95-0.99), rs10719 (OR 0.97; 95% CI: 0.94-0.99), rs4687554 (OR 0.97; 95% CI: 0.95-0.99, and rs3134615 (OR 1.03; 95% CI: 1.01-1.05) located in the 3' UTR of CASP8, HDDC3, DROSHA, MUSTN1, and MYCL1, respectively. DROSHA belongs to miRNA machinery genes and has a central role in initial miRNA processing. The remaining genes are involved in different molecular functions, including apoptosis and gene expression regulation. Further studies are warranted to elucidate whether the miRNA binding site SNPs are the causative variants for the observed risk effects.

  10. MicroRNA related polymorphisms and breast cancer risk.

    Directory of Open Access Journals (Sweden)

    Sofia Khan

    Full Text Available Genetic variations, such as single nucleotide polymorphisms (SNPs in microRNAs (miRNA or in the miRNA binding sites may affect the miRNA dependent gene expression regulation, which has been implicated in various cancers, including breast cancer, and may alter individual susceptibility to cancer. We investigated associations between miRNA related SNPs and breast cancer risk. First we evaluated 2,196 SNPs in a case-control study combining nine genome wide association studies (GWAS. Second, we further investigated 42 SNPs with suggestive evidence for association using 41,785 cases and 41,880 controls from 41 studies included in the Breast Cancer Association Consortium (BCAC. Combining the GWAS and BCAC data within a meta-analysis, we estimated main effects on breast cancer risk as well as risks for estrogen receptor (ER and age defined subgroups. Five miRNA binding site SNPs associated significantly with breast cancer risk: rs1045494 (odds ratio (OR 0.92; 95% confidence interval (CI: 0.88-0.96, rs1052532 (OR 0.97; 95% CI: 0.95-0.99, rs10719 (OR 0.97; 95% CI: 0.94-0.99, rs4687554 (OR 0.97; 95% CI: 0.95-0.99, and rs3134615 (OR 1.03; 95% CI: 1.01-1.05 located in the 3' UTR of CASP8, HDDC3, DROSHA, MUSTN1, and MYCL1, respectively. DROSHA belongs to miRNA machinery genes and has a central role in initial miRNA processing. The remaining genes are involved in different molecular functions, including apoptosis and gene expression regulation. Further studies are warranted to elucidate whether the miRNA binding site SNPs are the causative variants for the observed risk effects.

  11. Aid decision algorithms to estimate the risk in congenital heart surgery.

    Science.gov (United States)

    Ruiz-Fernández, Daniel; Monsalve Torra, Ana; Soriano-Payá, Antonio; Marín-Alonso, Oscar; Triana Palencia, Eddy

    2016-04-01

    In this paper, we have tested the suitability of using different artificial intelligence-based algorithms for decision support when classifying the risk of congenital heart surgery. In this sense, classification of those surgical risks provides enormous benefits as the a priori estimation of surgical outcomes depending on either the type of disease or the type of repair, and other elements that influence the final result. This preventive estimation may help to avoid future complications, or even death. We have evaluated four machine learning algorithms to achieve our objective: multilayer perceptron, self-organizing map, radial basis function networks and decision trees. The architectures implemented have the aim of classifying among three types of surgical risk: low complexity, medium complexity and high complexity. Accuracy outcomes achieved range between 80% and 99%, being the multilayer perceptron method the one that offered a higher hit ratio. According to the results, it is feasible to develop a clinical decision support system using the evaluated algorithms. Such system would help cardiology specialists, paediatricians and surgeons to forecast the level of risk related to a congenital heart disease surgery. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  12. Latent-failure risk estimates for computer control

    Science.gov (United States)

    Dunn, William R.; Folsom, Rolfe A.; Green, Owen R.

    1991-01-01

    It is shown that critical computer controls employing unmonitored safety circuits are unsafe. Analysis supporting this result leads to two additional, important conclusions: (1) annual maintenance checks of safety circuit function do not, as widely believed, eliminate latent failure risk; (2) safety risk remains even if multiple, series-connected protection circuits are employed. Finally, it is shown analytically that latent failure risk is eliminated when continuous monitoring is employed.

  13. Job related mortality risks of Hanford workers and their relation to cancer effects of measured doses of external radiation

    International Nuclear Information System (INIS)

    Kneale, G.W.; Mancuso, T.F.; Stewart, A.M.

    1984-01-01

    A continuation of the series by Mancuso, Stewart, and Kneale (MSK) on studies of cancer risks for radiation workers at Hanford is presented. It concentrates on the statistical problems posed by the need to estimate and control for job related mortality risks when there are several changes of occupation and no certainty about how different occupations are related to two socioeconomic factors which have strong health associations-namely, education and income. The final conclusion is that for tissues which are sensitive to cancer induced by radiation there is a risk of cancer for Hanford exposures whose dose response is curvilinear with long latency and increasing effect with increasing exposure age. (author)

  14. Substance-related traffic-risk behaviors among college students

    Science.gov (United States)

    Arria, Amelia M.; Caldeira, Kimberly M.; Vincent, Kathryn B.; Garnier-Dykstra, Laura M.; O’Grady, Kevin E.

    2011-01-01

    Aims Drunk driving is a major public health concern, but drugged driving has received little attention. This study examines drugged driving and riding with a drugged driver in a college student sample, in terms of prevalence, age-related trends, race/sex differences, overlap with drunk driving, and risk for alcohol and marijuana dependence. Methods Students (N=1194) ages 19 to 22 were interviewed annually for three years about past-year frequency of drugged driving, riding with a drugged/drunk driver, drunk driving, access to a car, and alcohol/drug dependence. Annual follow-up rates were excellent (88% to 91%). Repeated measures analyses were conducted using generalized estimating equations (GEE). Results One in six (17%wt) 19-year-olds with access to a car drove drugged in the past year; prevalence remained stable through age 22. Drugged driving was more prevalent among males (pdrunk (ranges between 47% and 60%). Both drugged and drunk driving were independently associated with increased risk for alcohol dependence, holding constant age, sex, and race. Drunk driving did not add to the risk for marijuana dependence in the context of drugged driving. Conclusions The prevalence of drugged driving is similar to drunk driving among college students. Both are strongly associated with underlying alcohol and drug dependence. Prevention and treatment implications are discussed. PMID:21601379

  15. Challenges in risk estimation using routinely collected clinical data: The example of estimating cervical cancer risks from electronic health-records.

    Science.gov (United States)

    Landy, Rebecca; Cheung, Li C; Schiffman, Mark; Gage, Julia C; Hyun, Noorie; Wentzensen, Nicolas; Kinney, Walter K; Castle, Philip E; Fetterman, Barbara; Poitras, Nancy E; Lorey, Thomas; Sasieni, Peter D; Katki, Hormuzd A

    2018-06-01

    Electronic health-records (EHR) are increasingly used by epidemiologists studying disease following surveillance testing to provide evidence for screening intervals and referral guidelines. Although cost-effective, undiagnosed prevalent disease and interval censoring (in which asymptomatic disease is only observed at the time of testing) raise substantial analytic issues when estimating risk that cannot be addressed using Kaplan-Meier methods. Based on our experience analysing EHR from cervical cancer screening, we previously proposed the logistic-Weibull model to address these issues. Here we demonstrate how the choice of statistical method can impact risk estimates. We use observed data on 41,067 women in the cervical cancer screening program at Kaiser Permanente Northern California, 2003-2013, as well as simulations to evaluate the ability of different methods (Kaplan-Meier, Turnbull, Weibull and logistic-Weibull) to accurately estimate risk within a screening program. Cumulative risk estimates from the statistical methods varied considerably, with the largest differences occurring for prevalent disease risk when baseline disease ascertainment was random but incomplete. Kaplan-Meier underestimated risk at earlier times and overestimated risk at later times in the presence of interval censoring or undiagnosed prevalent disease. Turnbull performed well, though was inefficient and not smooth. The logistic-Weibull model performed well, except when event times didn't follow a Weibull distribution. We have demonstrated that methods for right-censored data, such as Kaplan-Meier, result in biased estimates of disease risks when applied to interval-censored data, such as screening programs using EHR data. The logistic-Weibull model is attractive, but the model fit must be checked against Turnbull non-parametric risk estimates. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  16. Future flood risk estimates along the river Rhine

    NARCIS (Netherlands)

    te Linde, A.H.; Bubeck, P.; Dekkers, J.E.C.; de Moel, H.; Aerts, J.C.J.H.

    2011-01-01

    In Europe, water management is moving from flood defence to a risk management approach, which takes both the probability and the potential consequences of flooding into account. It is expected that climate change and socio-economic development will lead to an increase in flood risk in the Rhine

  17. On accounting difficulties: Risks related to nuclear power

    International Nuclear Information System (INIS)

    Plot, Emmanuelle; Vidal, Olivier

    2014-01-01

    An extreme risk has a very slight probability but potentially heavy consequences. Despite the existence of three accountancy methods for dealing with them (provisions, contingent liabilities and insurance), the transposition of such risks into financial statements is based on a sequential analysis of both the probability of the risk happening and the ability to estimate the effects. This method keeps us from taking into account risks with a highly uncertain probability of occurrence, such as accidents at nuclear power plants - independently of the 'amount' at stake. As management reports from firms concerned by nuclear risks show, the diffusion of qualitative information does not offset this gap in bookkeeping

  18. On accounting difficulties: risks related to nuclear power

    International Nuclear Information System (INIS)

    Plot, E.; Vidal, O.

    2014-01-01

    An extreme risk has a very slight probability but potentially heavy consequences. Despite the existence of 3 accountancy methods for dealing with them (provisions, contingent liabilities and insurance), the transposition of such risks into financial statements is based on a sequential analysis of both the probability of the risk happening and the ability to estimate the effects. This method keeps us from taking into account risks with a highly uncertain probability of occurrence, such as accidents at nuclear power plants - independently of the 'amount' at stake. As management reports from firms concerned by nuclear risks show, the diffusion of qualitative information does not offset this gap in bookkeeping. (authors)

  19. CCSI Risk Estimation: An Application of Expert Elicitation

    Energy Technology Data Exchange (ETDEWEB)

    Engel, David W.; Dalton, Angela C.

    2012-10-01

    The Carbon Capture Simulation Initiative (CCSI) is a multi-laboratory simulation-driven effort to develop carbon capture technologies with the goal of accelerating commercialization and adoption in the near future. One of the key CCSI technical challenges is representing and quantifying the inherent uncertainty and risks associated with developing, testing, and deploying the technology in simulated and real operational settings. To address this challenge, the CCSI Element 7 team developed a holistic risk analysis and decision-making framework. The purpose of this report is to document the CCSI Element 7 structured systematic expert elicitation to identify additional risk factors. We review the significance of and established approaches to expert elicitation, describe the CCSI risk elicitation plan and implementation strategies, and conclude by discussing the next steps and highlighting the contribution of risk elicitation toward the achievement of the overarching CCSI objectives.

  20. Salmonella risk to consumers via pork is related to the Salmonella prevalence in pig feed.

    Science.gov (United States)

    Rönnqvist, M; Välttilä, V; Ranta, J; Tuominen, P

    2018-05-01

    Pigs are an important source of human infections with Salmonella, one of the most common causes of sporadic gastrointestinal infections and foodborne outbreaks in the European region. Feed has been estimated to be a significant source of Salmonella in piggeries in countries of a low Salmonella prevalence. To estimate Salmonella risk to consumers via the pork production chain, including feed production, a quantitative risk assessment model was constructed. The Salmonella prevalence in feeds and in animals was estimated to be generally low in Finland, but the relative importance of feed as a source of Salmonella in pigs was estimated as potentially high. Discontinuation of the present strict Salmonella control could increase the risk of Salmonella in slaughter pigs and consequent infections in consumers. The increased use of low risk and controlled feed ingredients could result in a consistently lower residual contamination in pigs and help the tracing and control of the sources of infections. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Estimation of second primary cancers risk based on the treatment planning system

    International Nuclear Information System (INIS)

    Jin Chufeng; Sun Guangyao; Liu Hui; Zheng Huaqing; Cheng Mengyun; Li Gui; Wu Yican; FDS Team

    2011-01-01

    Estimates of second primary cancers risk after radiotherapy has become increasingly important for comparative treatment planning. A new method based on the treatment planning system to estimate the risk of second primary cancers was introduced in this paper. Using the Advanced/Accurate Radiotherapy Treatment System(ARTS), a treatment planning system developed by the FDS team,the risk of second primary cancer was estimated over two treatment plans for a patient with pancreatic cancer. Based on the second primary cancer risk, the two plans were compared. It was found that,kidney and gall-bladder had higher risk to develop second primary cancer. A better plan was chosen by the analysis of second primary cancer risk. The results showed that this risk estimation method we developed could be used to evaluate treatment plans. (authors)

  2. Estimated risk contribution for dry spent fuel storage cask

    International Nuclear Information System (INIS)

    Santos, C.; Kirk, M.T.; Abramson, L.; Guttmann, J.; Hackett, E.; Simonen, F.A.

    2001-01-01

    The U.S. Nuclear Regulatory Commission (NRC) is pursuing means to risk-inform its regulations and programs for dry storage of spent nuclear fuel. In pursuit of this objective, the NRC will develop safety goals and probabilistic risk assessments for implementing risk-informed programs. This paper provides one example method for calculating the risk of a dry spent fuel storage cask under normal and accident conditions. The example is on the HI-STORM 100 cask at a proposed site containing four thousand such casks. The paper evaluates the risk to the public by determining the likelihood a welded stainless steel container will leak. In addition, the study addresses the risk at a site where 4,000 casks may be stored until the U.S. Department of Energy accepts the casks for placement in a repository. The methods used employ the PRODIGAL computer code to assess the probability of a faulty weld on a stainless steel-welded canister. These analyses are only the initial stages of a comprehensive risk study that the NRC is performing in support of its regulatory initiatives. (author)

  3. Cancer risk estimates from radiation therapy for heterotopic ossification prophylaxis after total hip arthroplasty

    Energy Technology Data Exchange (ETDEWEB)

    Mazonakis, Michalis; Berris, Theoharris; Damilakis, John [Department of Medical Physics, Faculty of Medicine, University of Crete, P.O. Box 2208, 71003 Iraklion, Crete (Greece); Lyraraki, Efrossyni [Department of Radiotherapy and Oncology, University Hospital of Iraklion, 71110 Iraklion, Crete (Greece)

    2013-10-15

    Purpose: Heterotopic ossification (HO) is a frequent complication following total hip arthroplasty. This study was conducted to calculate the radiation dose to organs-at-risk and estimate the probability of cancer induction from radiotherapy for HO prophylaxis.Methods: Hip irradiation for HO with a 6 MV photon beam was simulated with the aid of a Monte Carlo model. A realistic humanoid phantom representing an average adult patient was implemented in Monte Carlo environment for dosimetric calculations. The average out-of-field radiation dose to stomach, liver, lung, prostate, bladder, thyroid, breast, uterus, and ovary was calculated. The organ-equivalent-dose to colon, that was partly included within the treatment field, was also determined. Organ dose calculations were carried out using three different field sizes. The dependence of organ doses upon the block insertion into primary beam for shielding colon and prosthesis was investigated. The lifetime attributable risk for cancer development was estimated using organ, age, and gender-specific risk coefficients.Results: For a typical target dose of 7 Gy, organ doses varied from 1.0 to 741.1 mGy by the field dimensions and organ location relative to the field edge. Blocked field irradiations resulted in a dose range of 1.4–146.3 mGy. The most probable detriment from open field treatment of male patients was colon cancer with a high risk of 564.3 × 10{sup −5} to 837.4 × 10{sup −5} depending upon the organ dose magnitude and the patient's age. The corresponding colon cancer risk for female patients was (372.2–541.0) × 10{sup −5}. The probability of bladder cancer development was more than 113.7 × 10{sup −5} and 110.3 × 10{sup −5} for males and females, respectively. The cancer risk range to other individual organs was reduced to (0.003–68.5) × 10{sup −5}.Conclusions: The risk for cancer induction from radiation therapy for HO prophylaxis after total hip arthroplasty varies considerably by

  4. Cancer risk estimates from radiation therapy for heterotopic ossification prophylaxis after total hip arthroplasty

    International Nuclear Information System (INIS)

    Mazonakis, Michalis; Berris, Theoharris; Damilakis, John; Lyraraki, Efrossyni

    2013-01-01

    Purpose: Heterotopic ossification (HO) is a frequent complication following total hip arthroplasty. This study was conducted to calculate the radiation dose to organs-at-risk and estimate the probability of cancer induction from radiotherapy for HO prophylaxis.Methods: Hip irradiation for HO with a 6 MV photon beam was simulated with the aid of a Monte Carlo model. A realistic humanoid phantom representing an average adult patient was implemented in Monte Carlo environment for dosimetric calculations. The average out-of-field radiation dose to stomach, liver, lung, prostate, bladder, thyroid, breast, uterus, and ovary was calculated. The organ-equivalent-dose to colon, that was partly included within the treatment field, was also determined. Organ dose calculations were carried out using three different field sizes. The dependence of organ doses upon the block insertion into primary beam for shielding colon and prosthesis was investigated. The lifetime attributable risk for cancer development was estimated using organ, age, and gender-specific risk coefficients.Results: For a typical target dose of 7 Gy, organ doses varied from 1.0 to 741.1 mGy by the field dimensions and organ location relative to the field edge. Blocked field irradiations resulted in a dose range of 1.4–146.3 mGy. The most probable detriment from open field treatment of male patients was colon cancer with a high risk of 564.3 × 10 −5 to 837.4 × 10 −5 depending upon the organ dose magnitude and the patient's age. The corresponding colon cancer risk for female patients was (372.2–541.0) × 10 −5 . The probability of bladder cancer development was more than 113.7 × 10 −5 and 110.3 × 10 −5 for males and females, respectively. The cancer risk range to other individual organs was reduced to (0.003–68.5) × 10 −5 .Conclusions: The risk for cancer induction from radiation therapy for HO prophylaxis after total hip arthroplasty varies considerably by the treatment parameters, organ

  5. Estimating cancer risk from outdoor concentrations of hazardous air pollutants in 1990

    Energy Technology Data Exchange (ETDEWEB)

    Woodruff, T.J.; Caldwell, J.; Cogliano, V.J.; Axelrad, D.A.

    2000-03-01

    A public health concern regarding hazardous air pollutants (HAPs) is their potential to cause cancer. It has been difficult to assess potential cancer risks from HAPs, due primarily to lack of ambient concentration data for the general population. The Environmental Protection Agency's Cumulative Exposure Project modeled 1990 outdoor concentrations of HAPs across the United States, which were combined with inhalation unit risk estimates to estimate the potential increase in excess cancer risk for individual carcinogenic HAPs. These were summed3d to provide an estimate of cancer risk from multiple HAPs. The analysis estimates a median excess cancer risk of 18 lifetime cancer cases per 100,000 people for all HAP concentrations. About 75% of estimated cancer risk was attributable to exposure to polycyclic organic matter, 1,3-butadiene, formaldehyde, benzene, and chromium. Consideration of some specific uncertainties, including underestimation of ambient concentrations, combining upper 95% confidence bound potency estimates, and changes to potency estimates, found that cancer risk may be underestimated by 15% or overestimated by 40--50%. Other unanalyzed uncertainties could make these under- or overestimates larger. This analysis used 1990 estimates of concentrations and can be used to track progress toward reducing cancer risk to the general population.

  6. Estimating mortality risk reduction and economic benefits from controlling ozone air pollution

    National Research Council Canada - National Science Library

    Committee on Estimating Mortality Risk Reduction Benefits from Decreasing Tropospheric Ozone Exposure

    2008-01-01

    ... in life expectancy, and to assess methods for estimating the monetary value of the reduced risk of premature death and increased life expectancy in the context of health-benefits analysis. Estimating Mortality Risk Reduction and Economic Benefits from Controlling Ozone Air Pollution details the committee's findings and posits several recommendations to address these issues.

  7. Estimation of insurance premiums for coverage against natural disaster risk: an application of Bayesian Inference

    NARCIS (Netherlands)

    Paudel, Y.; Botzen, W.J.W.; Aerts, J.C.J.H.

    2013-01-01

    This study applies Bayesian Inference to estimate flood risk for 53 dyke ring areas in the Netherlands, and focuses particularly on the data scarcity and extreme behaviour of catastrophe risk. The probability density curves of flood damage are estimated through Monte Carlo simulations. Based on

  8. Option-Based Estimation of the Price of Co-Skewness and Co-Kurtosis Risk

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Fournier, Mathieu; Fournier, Mathieu

    -neutral second moments, and the price of co-kurtosis risk corresponds to the spread between the physical and the risk-neutral third moments. The option-based estimates of the prices of risk lead to reasonable values of the associated risk premia. An out-of-sample analysis of factor models with co-skewness and co......We show that the prices of risk for factors that are nonlinear in the market return are readily obtained using index option prices. We apply this insight to the price of co-skewness and co-kurtosis risk. The price of co-skewness risk corresponds to the spread between the physical and the risk......-kurtosis risk indicates that the new estimates of the price of risk improve the models performance. Models with higher-order market moments also robustly outperform standard competitors such as the CAPM and the Fama-French model....

  9. Option-Based Estimation of the Price of Co-Skewness and Co-Kurtosis Risk

    DEFF Research Database (Denmark)

    Christoffersen, Peter; Fournier, Mathieu; Jacobs, Kris

    -neutral second moments, and the price of co-kurtosis risk corresponds to the spread between the physical and the risk-neutral third moments. The option-based estimates of the prices of risk lead to reasonable values of the associated risk premia. An out-of-sample analysis of factor models with co-skewness and co......We show that the prices of risk for factors that are nonlinear in the market return are readily obtained using index option prices. We apply this insight to the price of co-skewness and co-kurtosis risk. The price of co-skewness risk corresponds to the spread between the physical and the risk......-kurtosis risk indicates that the new estimates of the price of risk improve the models' performance. Models with higher-order market moments also robustly outperform standard competitors such as the CAPM and the Fama-French model....

  10. Insulin Sensitivity and Mortality Risk Estimation in Patients with Type ...

    African Journals Online (AJOL)

    2016-07-15

    Jul 15, 2016 ... density lipoprotein cholesterol (LDL), triglycerides (TG), high‑density lipoprotein cholesterol (HDL), urinary albumin‑to‑creatinine ratio ... the mortality risk scores in patients with T2DM and its relationship with insulin resistance.

  11. The Program Module of Information Risk Numerical Estimation

    Directory of Open Access Journals (Sweden)

    E. S. Stepanova

    2011-03-01

    Full Text Available The algorithm of information risks analysis realized in the program module on the basis of threats matrixes and fuzzy cognitive maps describing potential threats on resources is offered in this paper.

  12. Association of type D personality with unhealthy lifestyle, and estimated risk of coronary events in the general Icelandic population.

    Science.gov (United States)

    Svansdottir, Erla; Denollet, Johan; Thorsson, Bolli; Gudnason, Thorarinn; Halldorsdottir, Sigrun; Gudnason, Vilmundur; van den Broek, Krista C; Karlsson, Hrobjartur D

    2013-04-01

    Type D personality is associated with an increased morbidity and mortality risk in cardiovascular disease patients, but the mechanisms explaining this risk are unclear. We examined whether Type D was associated with coronary artery disease (CAD) risk factors, estimated risk of developing CAD, and previous cardiac events. Cross-sectional study in the general Icelandic population. A random sample of 4753 individuals (mean age 49.1 ± 12.0 years; 49% men) from the REFINE-Reykjavik study completed assessments for Type D personality and conventional CAD risk factors. Ten-year risk of developing CAD was estimated with the Icelandic risk calculator. Type D personality (22% of sample) was associated with a higher prevalence of hypertension (35 vs. 31%, p = 0.009), but less use of hypertension medication (58 vs. 65%, p = 0.013) in hypertensives, more diabetes (6 vs. 4%, p = 0.023), wider waist circumference (p = 0.007), and elevated body mass index (p = 0.025) and blood lipids (p lifestyle-related CAD risk factors, a higher estimated risk of developing CAD, and higher incidence of previous cardiac events. Unhealthy lifestyles may partly explain the adverse cardiovascular effect of Type D personality.

  13. Prognostic risk estimates of patients with multiple sclerosis and their physicians: comparison to an online analytical risk counseling tool.

    Directory of Open Access Journals (Sweden)

    Christoph Heesen

    Full Text Available BACKGROUND: Prognostic counseling in multiple sclerosis (MS is difficult because of the high variability of disease progression. Simultaneously, patients and physicians are increasingly confronted with making treatment decisions at an early stage, which requires taking individual prognoses into account to strike a good balance between benefits and harms of treatments. It is therefore important to understand how patients and physicians estimate prognostic risk, and whether and how these estimates can be improved. An online analytical processing (OLAP tool based on pooled data from placebo cohorts of clinical trials offers short-term prognostic estimates that can be used for individual risk counseling. OBJECTIVE: The aim of this study was to clarify if personalized prognostic information as presented by the OLAP tool is considered useful and meaningful by patients. Furthermore, we used the OLAP tool to evaluate patients' and physicians' risk estimates. Within this evaluation process we assessed short-time prognostic risk estimates of patients with MS (final n = 110 and their physicians (n = 6 and compared them with the estimates of OLAP. RESULTS: Patients rated the OLAP tool as understandable and acceptable, but to be only of moderate interest. It turned out that patients, physicians, and the OLAP tool ranked patients similarly regarding their risk of disease progression. Both patients' and physicians' estimates correlated most strongly with those disease covariates that the OLAP tool's estimates also correlated with most strongly. Exposure to the OLAP tool did not change patients' risk estimates. CONCLUSION: While the OLAP tool was rated understandable and acceptable, it was only of modest interest and did not change patients' prognostic estimates. The results suggest, however, that patients had some idea regarding their prognosis and which factors were most important in this regard. Future work with OLAP should assess long-term prognostic

  14. Prognostic risk estimates of patients with multiple sclerosis and their physicians: comparison to an online analytical risk counseling tool.

    Science.gov (United States)

    Heesen, Christoph; Gaissmaier, Wolfgang; Nguyen, Franziska; Stellmann, Jan-Patrick; Kasper, Jürgen; Köpke, Sascha; Lederer, Christian; Neuhaus, Anneke; Daumer, Martin

    2013-01-01

    Prognostic counseling in multiple sclerosis (MS) is difficult because of the high variability of disease progression. Simultaneously, patients and physicians are increasingly confronted with making treatment decisions at an early stage, which requires taking individual prognoses into account to strike a good balance between benefits and harms of treatments. It is therefore important to understand how patients and physicians estimate prognostic risk, and whether and how these estimates can be improved. An online analytical processing (OLAP) tool based on pooled data from placebo cohorts of clinical trials offers short-term prognostic estimates that can be used for individual risk counseling. The aim of this study was to clarify if personalized prognostic information as presented by the OLAP tool is considered useful and meaningful by patients. Furthermore, we used the OLAP tool to evaluate patients' and physicians' risk estimates. Within this evaluation process we assessed short-time prognostic risk estimates of patients with MS (final n = 110) and their physicians (n = 6) and compared them with the estimates of OLAP. Patients rated the OLAP tool as understandable and acceptable, but to be only of moderate interest. It turned out that patients, physicians, and the OLAP tool ranked patients similarly regarding their risk of disease progression. Both patients' and physicians' estimates correlated most strongly with those disease covariates that the OLAP tool's estimates also correlated with most strongly. Exposure to the OLAP tool did not change patients' risk estimates. While the OLAP tool was rated understandable and acceptable, it was only of modest interest and did not change patients' prognostic estimates. The results suggest, however, that patients had some idea regarding their prognosis and which factors were most important in this regard. Future work with OLAP should assess long-term prognostic estimates and clarify its usefulness for patients and physicians

  15. Estimating Regional Scale Hydroclimatic Risk Conditions from the Soil Moisture Active-Passive (SMAP Satellite

    Directory of Open Access Journals (Sweden)

    Catherine Champagne

    2018-04-01

    Full Text Available Satellite soil moisture is a critical variable for identifying susceptibility to hydroclimatic risks such as drought, dryness, and excess moisture. Satellite soil moisture data from the Soil Moisture Active/Passive (SMAP mission was used to evaluate the sensitivity to hydroclimatic risk events in Canada. The SMAP soil moisture data sets in general capture relative moisture trends with the best estimates from the passive-only derived soil moisture and little difference between the data at different spatial resolutions. In general, SMAP data sets overestimated the magnitude of moisture at the wet extremes of wetting events. A soil moisture difference from average (SMDA was calculated from SMAP and historical Soil Moisture and Ocean Salinity (SMOS data showed a relatively good delineation of hydroclimatic risk events, although caution must be taken due to the large variability in the data within risk categories. Satellite soil moisture data sets are more sensitive to short term water shortages than longer term water deficits. This was not improved by adding “memory” to satellite soil moisture indices to improve the sensitivity of the data to drought, and there is a large variability in satellite soil moisture values with the same drought severity rating.

  16. Relative Hazard and Risk Measure Calculation Methodology Rev 1

    International Nuclear Information System (INIS)

    Stenner, Robert D.; White, Michael K.; Strenge, Dennis L.; Aaberg, Rosanne L.; Andrews, William B.

    2000-01-01

    Documentation of the methodology used to calculate relative hazard and risk measure results for the DOE complex wide risk profiles. This methodology is used on major site risk profiles. In February 1997, the Center for Risk Excellence (CRE) was created and charged as a technical, field-based partner to the Office of Science and Risk Policy (EM-52). One of the initial charges to the CRE is to assist the sites in the development of ''site risk profiles.'' These profiles are to be relatively short summaries (periodically updated) that present a broad perspective on the major risk related challenges that face the respective site. The risk profiles are intended to serve as a high-level communication tool for interested internal and external parties to enhance the understanding of these risk-related challenges. The risk profiles for each site have been designed to qualitatively present the following information: (1) a brief overview of the site, (2) a brief discussion on the historical mission of the site, (3) a quote from the site manager indicating the site's commitment to risk management, (4) a listing of the site's top risk-related challenges, (5) a brief discussion and detailed table presenting the site's current risk picture, (6) a brief discussion and detailed table presenting the site's future risk reduction picture, and (7) graphic illustrations of the projected management of the relative hazards at the site. The graphic illustrations were included to provide the reader of the risk profiles with a high-level mental picture to associate with all the qualitative information presented in the risk profile. Inclusion of these graphic illustrations presented the CRE with the challenge of how to fold this high-level qualitative risk information into a system to produce a numeric result that would depict the relative change in hazard, associated with each major risk management action, so it could be presented graphically. This report presents the methodology developed

  17. Estimating small area health-related characteristics of populations: a methodological review

    Directory of Open Access Journals (Sweden)

    Azizur Rahman

    2017-05-01

    Full Text Available Estimation of health-related characteristics at a fine local geographic level is vital for effective health promotion programmes, provision of better health services and population-specific health planning and management. Lack of a micro-dataset readily available for attributes of individuals at small areas negatively impacts the ability of local and national agencies to manage serious health issues and related risks in the community. A solution to this challenge would be to develop a method that simulates reliable small-area statistics. This paper provides a significant appraisal of the methodologies for estimating health-related characteristics of populations at geographical limited areas. Findings reveal that a range of methodologies are in use, which can be classified as three distinct set of approaches: i indirect standardisation and individual level modelling; ii multilevel statistical modelling; and iii micro-simulation modelling. Although each approach has its own strengths and weaknesses, it appears that microsimulation- based spatial models have significant robustness over the other methods and also represent a more precise means of estimating health-related population characteristics over small areas.

  18. Pregnancy-related venous thromboembolism and risk of occult cancer

    DEFF Research Database (Denmark)

    Tarp Hansen, Anette; Veres, Katalin; Horváth-Puhó, Erzsébet

    2017-01-01

    The cancer risk during the first year after a pregnancy-related venous thromboembolism episode is higher than expected.An aggressive search for cancer in women with pregnancy-related venous thromboembolism is probably not warranted, due to low absolute risk.......The cancer risk during the first year after a pregnancy-related venous thromboembolism episode is higher than expected.An aggressive search for cancer in women with pregnancy-related venous thromboembolism is probably not warranted, due to low absolute risk....

  19. Estimating the concordance probability in a survival analysis with a discrete number of risk groups.

    Science.gov (United States)

    Heller, Glenn; Mo, Qianxing

    2016-04-01

    A clinical risk classification system is an important component of a treatment decision algorithm. A measure used to assess the strength of a risk classification system is discrimination, and when the outcome is survival time, the most commonly applied global measure of discrimination is the concordance probability. The concordance probability represents the pairwise probability of lower patient risk given longer survival time. The c-index and the concordance probability estimate have been used to estimate the concordance probability when patient-specific risk scores are continuous. In the current paper, the concordance probability estimate and an inverse probability censoring weighted c-index are modified to account for discrete risk scores. Simulations are generated to assess the finite sample properties of the concordance probability estimate and the weighted c-index. An application of these measures of discriminatory power to a metastatic prostate cancer risk classification system is examined.

  20. Relative Risks for Lethal Prostate Cancer Based on Complete Family History of Prostate Cancer Death.

    Science.gov (United States)

    Albright, Frederick S; Stephenson, Robert A; Agarwal, Neeraj; Cannon-Albright, Lisa A

    2017-01-01

    There are few published familial relative risks (RR) for lethal prostate cancer. This study estimates RRs for lethal prostate cancer based on comprehensive family history data, with the goal of improving identification of those men at highest risk of dying from prostate cancer. We used a population-based genealogical resource linked to a statewide electronic SEER cancer registry and death certificates to estimate relative risks (RR) for death from prostate cancer based upon family history. Over 600,000 male probands were analyzed, representing a variety of family history constellations of lethal prostate cancer. RR estimates were based on the ratio of the observed to the expected number of lethal prostate cancer cases using internal rates. RRs for lethal prostate cancer based on the number of affected first-degree relatives (FDR) ranged from 2.49 (95% CI: 2.27, 2.73) for exactly 1 FDR to 5.30 (2.13, 10.93) for ≥3 affected FDRs. In an absence of affected FDRs, increased risk was also significant for increasing numbers of affected second-degree or third degree relatives. Equivalent risks were observed for similar maternal and paternal family history. This study provides population-based estimates of lethal prostate cancer risk based on lethal prostate cancer family history. Many family history constellations associated with two to greater than five times increased risk for lethal prostate cancer were identified. These lethal prostate cancer risk estimates hold potential for use in identification, screening, early diagnosis, and treatment of men at high risk for death from prostate cancer. Prostate77:41-48, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  1. Estimation of risk map for cohort study of Hiroshima atomic bomb survivors. 1970-2010

    International Nuclear Information System (INIS)

    Tonda, Tetsuji; Satoh, Kenichi; Otani, Keiko; Sato, Yuya; Maruyama, Hirofomi; Kawakami, Hideshi; Tashiro, Satoshi; Hoshi, Masaharu; Ohtaki, Megu

    2012-01-01

    A risk map (map I) involving the effects of direct A-bomb exposure and of other confounding factors was estimated to analyze the death risk in the geographic distribution, and another risk map (map II) was also made by subtracting the direct exposure effect to see the confounder effect. The cohort was 37,382/157,327 survivors at Jan. 1, 1970, whose positional coordinates at the exposure were known, and was followed up until Dec. 31, 2009. For survival analysis, the endpoint was defined to be death (total 19,119) by regarding other 18,263 as censoring. Confounding factors were sex, age at the exposure, exposed dose and shielded condition. Maps I and II were depicted using the hazard ratio at the exposed position relative to the hypocenter, which was estimated by previously reported hazard model functions. Map I was found to be rather similar to concentric circle of the hypocenter, but to be tended a bit distorted toward northwest area. The distortion was clearer in the map II, indicating that death causes other than direct exposure existed. The confounder was thought to be the indirect exposure through the black rain, residual radiation and/or internal exposure, which awaiting future investigation. (T.T.)

  2. Radiation-Induced Leukemia at Doses Relevant to Radiation Therapy: Modeling Mechanisms and Estimating Risks

    Science.gov (United States)

    Shuryak, Igor; Sachs, Rainer K.; Hlatky, Lynn; Mark P. Little; Hahnfeldt, Philip; Brenner, David J.

    2006-01-01

    Because many cancer patients are diagnosed earlier and live longer than in the past, second cancers induced by radiation therapy have become a clinically significant issue. An earlier biologically based model that was designed to estimate risks of high-dose radiation induced solid cancers included initiation of stem cells to a premalignant state, inactivation of stem cells at high radiation doses, and proliferation of stem cells during cellular repopulation after inactivation. This earlier model predicted the risks of solid tumors induced by radiation therapy but overestimated the corresponding leukemia risks. Methods: To extend the model to radiation-induced leukemias, we analyzed in addition to cellular initiation, inactivation, and proliferation a repopulation mechanism specific to the hematopoietic system: long-range migration through the blood stream of hematopoietic stem cells (HSCs) from distant locations. Parameters for the model were derived from HSC biologic data in the literature and from leukemia risks among atomic bomb survivors v^ ho were subjected to much lower radiation doses. Results: Proliferating HSCs that migrate from sites distant from the high-dose region include few preleukemic HSCs, thus decreasing the high-dose leukemia risk. The extended model for leukemia provides risk estimates that are consistent with epidemiologic data for leukemia risk associated with radiation therapy over a wide dose range. For example, when applied to an earlier case-control study of 110000 women undergoing radiotherapy for uterine cancer, the model predicted an excess relative risk (ERR) of 1.9 for leukemia among women who received a large inhomogeneous fractionated external beam dose to the bone marrow (mean = 14.9 Gy), consistent with the measured ERR (2.0, 95% confidence interval [CI] = 0.2 to 6.4; from 3.6 cases expected and 11 cases observed). As a corresponding example for brachytherapy, the predicted ERR of 0.80 among women who received an inhomogeneous low

  3. Estimating cancer risks induced by CT screening for Korea population

    International Nuclear Information System (INIS)

    Yang, Hye Jeong; Yang, Won Seok

    2016-01-01

    Computed Tomography(CT) has been used to diagnose early stages of cancer and other diseases. Since the number of CT screening has been increasing, there is now a debate about the possible benefits and risks of CT screening on asymptomatic individuals. CT screening has definite benefits, however the radiation risk of screening an asymptomatic individual is a serious problem that cannot be overlooked. Despite its potential risks, CT screening for asymptomatic individual has been gradually increased in Korea and it is attributed to increase collective effective dose. Therefore, we reported the risk level of each organ which is included in scan field for CT screening and analyzed and then evaluated the risk level of Korean population comparison to others, Hong Kong, U.S. and U.K. populations. LARs are lower with older ages for all populations of both sexes. We recommend CT screening after the age of 40 because from that age, LAR decreases and the danger of top 5 cancer increases.

  4. Estimated daily salt intake in relation to blood pressure and blood lipids

    DEFF Research Database (Denmark)

    Thuesen, Betina H; Toft, Ulla; Buhelt, Lone P

    2015-01-01

    BACKGROUND: Excessive salt intake causes increased blood pressure which is considered the leading risk for premature death. One major challenge when evaluating associations between daily salt intake and markers of non-communicable diseases is that a high daily salt intake correlates with obesity...... 3294 men and women aged 18-69 years from a general population based study in Copenhagen, Denmark. Estimated 24-hour sodium excretion was calculated by measurements of creatinine and sodium concentration in spot urine in combination with information of sex, age, height and weight. The relations...

  5. Estimation of Esfarayen Farmers Risk Aversion Coefficient and Its Influencing Factors (Nonparametric Approach

    Directory of Open Access Journals (Sweden)

    Z. Nematollahi

    2016-03-01

    Full Text Available Introduction: Due to existence of the risk and uncertainty in agriculture, risk management is crucial for management in agriculture. Therefore the present study was designed to determine the risk aversion coefficient for Esfarayens farmers. Materials and Methods: The following approaches have been utilized to assess risk attitudes: (1 direct elicitation of utility functions, (2 experimental procedures in which individuals are presented with hypothetical questionnaires regarding risky alternatives with or without real payments and (3: Inference from observation of economic behavior. In this paper, we focused on approach (3: inference from observation of economic behavior, based on this assumption of existence of the relationship between the actual behavior of a decision maker and the behavior predicted from empirically specified models. A new non-parametric method and the QP method were used to calculate the coefficient of risk aversion. We maximized the decision maker expected utility with the E-V formulation (Freund, 1956. Ideally, in constructing a QP model, the variance-covariance matrix should be formed for each individual farmer. For this purpose, a sample of 100 farmers was selected using random sampling and their data about 14 products of years 2008- 2012 were assembled. The lowlands of Esfarayen were used since within this area, production possibilities are rather homogeneous. Results and Discussion: The results of this study showed that there was low correlation between some of the activities, which implies opportunities for income stabilization through diversification. With respect to transitory income, Ra, vary from 0.000006 to 0.000361 and the absolute coefficient of risk aversion in our sample were 0.00005. The estimated Ra values vary considerably from farm to farm. The results showed that the estimated Ra for the subsample existing of 'non-wealthy' farmers was 0.00010. The subsample with farmers in the 'wealthy' group had an

  6. Risk of Cardiovascular Morbidity and Mortality in Relation to Temperature

    Science.gov (United States)

    Mathes, Robert; Ito, Kazuhiko; Matte, Thomas

    2013-01-01

    Objective To examine the effects of temperature on cardiovascular-related (CVD) morbidity and mortality among New York City (NYC) residents. Introduction Extreme temperatures are consistently shown to have an effect on CVD-related mortality [1, 2]. A large multi-city study of mortality demonstrated a cold-day and hot-day weather effect on CVD-related deaths, with the larger impact occurring on the coldest days [3]. In contrast, the association between weather and CVD-related morbidity is less clear [4, 5]. The purpose of this study is to characterize the effect of temperature on CVD-related emergency department (ED) visits, hospitalizations, and mortality on a large, heterogeneous population. Additionally, we conducted a sensitivity analysis to determine the impact of air pollutants, specifically fine particulates (PM2.5) and ozone (O3), along with temperature, on CVD outcomes. Methods We analyzed daily weather conditions, ED visits classified as CVD-related based on chief complaint text, hospitalizations, and natural cause deaths that occurred in NYC between 2002 and 2006. ED visits were obtained from data reported daily to the city health department for syndromic surveillance. Inpatient admissions were obtained from the Statewide Planning and Research Cooperative System, a data reporting system developed by New York State. Mortality data were obtained from the NYC Office of Vital Statistics. Data for PM2.5 and O3 were obtained from all available air quality monitors within the five boroughs of NYC. To estimate risk of CVD morbidity and mortality, we used generalized linear models using a Poisson distribution to calculate relative risks (RR) and 95% confidence intervals (CI). A non-linear distributed lag was used to model mean temperature in order to allow for its effect on the same day and on subsequent days. Models were fit separately for cold season (October through March) and warm season (April through September) given season may modify the effect on CVD

  7. Estimating lung cancer risks of indoor radon: applications for prevention

    International Nuclear Information System (INIS)

    Klotz, J.B.

    1986-01-01

    The epidemiologic evidence for a serious lung cancer hazard from radon exposure is very strong, and cumulative exposures accrued in residences may frequently overlap those accrued in underground miners. However, many uncertainties exist in extrapolating from mining to indoor risks because of differences in the populations, in radon exposure variables, and in other exposures. Risks are also considered for indoor radon exposures outside the home. There is already suggestive evidence of an association of lung cancer with radon levels in community settings, and several large-scale investigations are in progress. Some important questions regarding quantifying risk may not be approached, however; some further research needs are outlined including development of techniques for preventing or postponing lung cancer in individuals previously exposed to high radon levels. 31 references, 2 tables

  8. Probabilistic methodology for estimating radiation-induced cancer risk

    International Nuclear Information System (INIS)

    Dunning, D.E. Jr.; Leggett, R.W.; Williams, L.R.

    1981-01-01

    The RICRAC computer code was developed at Oak Ridge National Laboratory to provide a versatile and convenient methodology for radiation risk assessment. The code allows as input essentially any dose pattern commonly encountered in risk assessments for either acute or chronic exposures, and it includes consideration of the age structure of the exposed population. Results produced by the analysis include the probability of one or more radiation-induced cancer deaths in a specified population, expected numbers of deaths, and expected years of life lost as a result of premature fatalities. These calculatons include consideration of competing risks of death from all other causes. The program also generates a probability frequency distribution of the expected number of cancers in any specified cohort resulting from a given radiation dose. The methods may be applied to any specified population and dose scenario

  9. Safety in relation to risk and benefit

    International Nuclear Information System (INIS)

    Siddall, E.

    1985-01-01

    The proper definition and quantification of human safety is discussed and from this basis the historical development of our present very high standard of safety is traced. It is shown that increased safety is closely associated with increased wealth, and the quantitative relationship between then is derived from different sources of evidence. When this factor is applied to the production of wealth by industry, a safety benefit is indicated which exceeds the asserted risks by orders of magnitude. It is concluded that present policies and attitudes in respect to the safety of industry may be diametrically wrong. (orig.) [de

  10. The effects of spatial population dataset choice on estimates of population at risk of disease

    Directory of Open Access Journals (Sweden)

    Gething Peter W

    2011-02-01

    Full Text Available Abstract Background The spatial modeling of infectious disease distributions and dynamics is increasingly being undertaken for health services planning and disease control monitoring, implementation, and evaluation. Where risks are heterogeneous in space or dependent on person-to-person transmission, spatial data on human population distributions are required to estimate infectious disease risks, burdens, and dynamics. Several different modeled human population distribution datasets are available and widely used, but the disparities among them and the implications for enumerating disease burdens and populations at risk have not been considered systematically. Here, we quantify some of these effects using global estimates of populations at risk (PAR of P. falciparum malaria as an example. Methods The recent construction of a global map of P. falciparum malaria endemicity enabled the testing of different gridded population datasets for providing estimates of PAR by endemicity class. The estimated population numbers within each class were calculated for each country using four different global gridded human population datasets: GRUMP (~1 km spatial resolution, LandScan (~1 km, UNEP Global Population Databases (~5 km, and GPW3 (~5 km. More detailed assessments of PAR variation and accuracy were conducted for three African countries where census data were available at a higher administrative-unit level than used by any of the four gridded population datasets. Results The estimates of PAR based on the datasets varied by more than 10 million people for some countries, even accounting for the fact that estimates of population totals made by different agencies are used to correct national totals in these datasets and can vary by more than 5% for many low-income countries. In many cases, these variations in PAR estimates comprised more than 10% of the total national population. The detailed country-level assessments suggested that none of the datasets was

  11. Estimating water equivalent snow depth from related meteorological variables

    International Nuclear Information System (INIS)

    Steyaert, L.T.; LeDuc, S.K.; Strommen, N.D.; Nicodemus, M.L.; Guttman, N.B.

    1980-05-01

    Engineering design must take into consideration natural loads and stresses caused by meteorological elements, such as, wind, snow, precipitation and temperature. The purpose of this study was to determine a relationship of water equivalent snow depth measurements to meteorological variables. Several predictor models were evaluated for use in estimating water equivalent values. These models include linear regression, principal component regression, and non-linear regression models. Linear, non-linear and Scandanavian models are used to generate annual water equivalent estimates for approximately 1100 cooperative data stations where predictor variables are available, but which have no water equivalent measurements. These estimates are used to develop probability estimates of snow load for each station. Map analyses for 3 probability levels are presented

  12. The current contribution of molecular factors to risk estimation in neuroblastoma patients.

    Science.gov (United States)

    Berthold, F; Sahin, K; Hero, B; Christiansen, H; Gehring, M; Harms, D; Horz, S; Lampert, F; Schwab, M; Terpe, J

    1997-10-01

    The association of molecular characteristics with prognosis has been reported, but not their relationship with each other and their impact in the context of known clinical risk factors. In this study, data of 1249 consecutive intent-to-treat-neuroblastoma patients with more than 1 year follow-up were examined by multivariate analysis using loglinear and Cox proportional hazard regression models on a stage-related basis (stages 1-3: 600, 4S: 116, 4: 533). In a first step, risk factors were identified from 18 selected clinical variables, and risk groups defined. The second step investigated whether molecular characteristics (MYCN, LOH 1p, del 1p, CD44, N-ras, NGF-R, bcl-2, APO-1 (CD95)) contributed additional prognostic information to the model. The loglinear model demonstrated several interactions between clinical factors. By the Cox regression model, seven independent clinical risk factors were found for stages 1-3, seven for stage 4 and two for stage 4S. By subsequent introduction of all molecular variables, MYCN amplification only added significant prognostic information to the clinical factors in localised and stage 4 neuroblastoma. The models allowed the definition of risk groups for stages 1-3 patients by age (e beta = 5.09) and MYCN (e beta = 4.26), for stage 4 by MYCN (e beta = 2.78) and number of symptoms (e beta = 2.44) and for stage 4S by platelet count (e beta = 3.91) and general condition (e beta = 2.99). Molecular factors and in particular MYCN contribute significantly to risk estimation. In conjunction with clinical factors, they are powerful tools to define risk groups in neuroblastoma.

  13. Potential Risk Estimation Drowning Index for Children (PREDIC): a pilot study from Matlab, Bangladesh.

    Science.gov (United States)

    Borse, N N; Hyder, A A; Bishai, D; Baker, T; Arifeen, S E

    2011-11-01

    Childhood drowning is a major public health problem that has been neglected in many low- and middle-income countries. In Matlab, rural Bangladesh, more than 40% of child deaths aged 1-4 years are due to drowning. The main objective of this paper was to develop and evaluate a childhood drowning risk prediction index. A literature review was carried out to document risk factors identified for childhood drowning in Bangladesh. The Newacheck model for special health care needs for children was adapted and applied to construct a childhood drowning risk index called "Potential Risk Estimation Drowning Index for Children" (PREDIC). Finally, the proposed PREDIC Index was applied to childhood drowning deaths and compared with the comparison group from children living in Matlab, Bangladesh. This pilot study used t-tests and Receiver Operating Characteristic (ROC) curve to analyze the results. The PREDIC index was applied to 302 drowning deaths and 624 children 0-4 years old living in Matlab. The results of t-test indicate that the drowned children had a statistically (t=-8.58, p=0.0001) significant higher mean PREDIC score (6.01) than those in comparison group (5.26). Drowning cases had a PREDIC score of 6 or more for 68% of the children however, the comparison group had 43% of the children with score of 6 or more which was statistically significant (t=-7.36, p<0.001). The area under the curve for the Receiver Operating Characteristic curve was 0.662. Index score construction was scientifically plausible; and the index is relatively complete, fairly accurate, and practical. The risk index can help identify and target high risk children with drowning prevention programs. PREDIC index needs to be further tested for its accuracy, feasibility and effectiveness in drowning risk reduction in Bangladesh and other countries. Copyright © 2011 Elsevier Ltd. All rights reserved.

  14. Patients with Testicular Cancer Undergoing CT Surveillance Demonstrate a Pitfall of Radiation-induced Cancer Risk Estimates: The Timing Paradox

    Science.gov (United States)

    Eisenberg, Jonathan D.; Lee, Richard J.; Gilmore, Michael E.; Turan, Ekin A.; Singh, Sarabjeet; Kalra, Mannudeep K.; Liu, Bob; Kong, Chung Yin; Gazelle, G. Scott

    2013-01-01

    Purpose: To demonstrate a limitation of lifetime radiation-induced cancer risk metrics in the setting of testicular cancer surveillance—in particular, their failure to capture the delayed timing of radiation-induced cancers over the course of a patient’s lifetime. Materials and Methods: Institutional review board approval was obtained for the use of computed tomographic (CT) dosimetry data in this study. Informed consent was waived. This study was HIPAA compliant. A Markov model was developed to project outcomes in patients with testicular cancer who were undergoing CT surveillance in the decade after orchiectomy. To quantify effects of early versus delayed risks, life expectancy losses and lifetime mortality risks due to testicular cancer were compared with life expectancy losses and lifetime mortality risks due to radiation-induced cancers from CT. Projections of life expectancy loss, unlike lifetime risk estimates, account for the timing of risks over the course of a lifetime, which enabled evaluation of the described limitation of lifetime risk estimates. Markov chain Monte Carlo methods were used to estimate the uncertainty of the results. Results: As an example of evidence yielded, 33-year-old men with stage I seminoma who were undergoing CT surveillance were projected to incur a slightly higher lifetime mortality risk from testicular cancer (598 per 100 000; 95% uncertainty interval [UI]: 302, 894) than from radiation-induced cancers (505 per 100 000; 95% UI: 280, 730). However, life expectancy loss attributable to testicular cancer (83 days; 95% UI: 42, 124) was more than three times greater than life expectancy loss attributable to radiation-induced cancers (24 days; 95% UI: 13, 35). Trends were consistent across modeled scenarios. Conclusion: Lifetime radiation risk estimates, when used for decision making, may overemphasize radiation-induced cancer risks relative to short-term health risks. © RSNA, 2012 Supplemental material: http

  15. Ethnic disparities in educational and occupational gradients of estimated cardiovascular disease risk: The Healthy Life in an Urban Setting study.

    Science.gov (United States)

    Perini, Wilco; Agyemang, Charles; Snijder, Marieke B; Peters, Ron J G; Kunst, Anton E

    2018-03-01

    European societies are becoming increasingly ethnically diverse. This may have important implications for socio-economic inequalities in health due to the often disadvantaged position of ethnic minority groups in both socio-economic status (SES) and disease, especially cardiovascular disease (CVD). The aim of this study was to determine whether the socio-economic gradient of estimated CVD risk differs between ethnic groups. Using the Healthy Life in an Urban Setting study, we obtained data on SES and CVD risk factors among participants from six ethnic backgrounds residing in Amsterdam. SES was measured using educational level and occupational level. CVD risk was estimated based on the occurrence of CVD risk factors using the Dutch version of the systematic coronary risk evaluation algorithm. Ethnic disparities in socio-economic gradients for estimated CVD risk were determined using the relative index of inequality (RII). Among Dutch-origin men, the RII for estimated CVD risk according to educational level was 6.15% (95% confidence interval [CI] 4.35-7.96%), indicating that those at the bottom of the educational hierarchy had a 6.15% higher estimated CVD risk relative than those at the top. Among Dutch-origin women, the RII was 4.49% (CI 2.45-6.52%). The RII was lower among ethnic minority groups, ranging from 0.83% to 3.13% among men and -0.29% to 5.12% among women, indicating weaker associations among these groups. Results were similar based on occupational level. Ethnic background needs to be considered in associations between SES and disease. The predictive value of SES varies between ethnic groups and may be quite poor for some groups.

  16. Estimating Bird / Aircraft Collision Probabilities and Risk Utilizing Spatial Poisson Processes

    Science.gov (United States)

    2012-06-10

    ESTIMATING BIRD/AIRCRAFT COLLISION PROBABILITIES AND RISK UTILIZING SPATIAL POISSON PROCESSES GRADUATE...AND RISK UTILIZING SPATIAL POISSON PROCESSES GRADUATE RESEARCH PAPER Presented to the Faculty Department of Operational Sciences...COLLISION PROBABILITIES AND RISK UTILIZING SPATIAL POISSON PROCESSES Brady J. Vaira, BS, MS Major, USAF Approved

  17. Estimated dietary dioxin exposure and breast cancer risk among women from the French E3N prospective cohort.

    Science.gov (United States)

    Danjou, Aurélie M N; Fervers, Béatrice; Boutron-Ruault, Marie-Christine; Philip, Thierry; Clavel-Chapelon, Françoise; Dossus, Laure

    2015-03-17

    Dioxins are environmental and persistent pollutants mostly emitted from combustion facilities (e.g. waste incinerators, metal and cement industries). Known to be endocrine disrupting chemicals, dioxins are suspected to increase breast cancer (BC) risk. Although diet is considered the primary source of dioxin exposure, no previous study has been published on dietary dioxin exposure in relation to BC risk. We aimed to assess dietary dioxin exposure among women from the E3N cohort and estimate BC risk associated with this exposure. The study included 63,830 women from the E3N cohort who completed a diet history questionnaire (DHQ) in 1993 and were followed until 2008. Dietary dioxin exposure was estimated by combining consumption data from the E3N DHQ and food dioxin contamination data from a French national monitoring program. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated by Cox models adjusted for BC risk factors. Mean dietary dioxin exposure was estimated at 1.3 ± 0.4 pg/kg body weight (BW)/day. A 0.4 pg/kg BW/d increase in dioxin intake was not associated with overall BC risk (HR = 1.00; 95% CI: 0.96, 1.05). A significant decrease in risk of estrogen receptor negative (ER-)/progesterone receptor negative (PR-) tumors was observed among post-menopausal women in the upper quartile of estimated dioxin intake (HR for Q4 vs. Q1: 0.65; 95% CI: 0.45, 0.96; P for trend across quartiles = 0.0463). Overall, no association between estimated dietary dioxin exposure and BC risk was found among E3N women. Further studies should include both dietary and environmental exposures to determine whether low-dose dioxin exposure is associated with BC risk.

  18. Estimating ToE Risk Level using CVSS

    NARCIS (Netherlands)

    Houmb, S.H.; Nunes Leal Franqueira, V.

    2009-01-01

    Security management is about calculated risk and requires continuous evaluation to ensure cost, time and resource effectiveness. Parts of which is to make future-oriented, cost-benefit investments in security. Security investments must adhere to healthy business principles where both security and

  19. Transfusion complications:Estimate of the residual risk of transfusion ...

    African Journals Online (AJOL)

    Background: Sub-Saharan Africa remains the epicenter of the human immunodeficiency virus (HIV) pan- demic. However, there is a lack of multicenter data on the risk of transfusion-transmitted HIV from blood centers in sub-Saharan Africa. Study design and methods: The incidence of HIV infections in the blood donations ...

  20. Estimation of risks associated to land transport of uranium hexafluoride

    International Nuclear Information System (INIS)

    Pages, P.; Tomachevsky, E.

    1987-01-01

    The system analysed concerns the packaging 48Y containing about 12 tons of hexafluoride, 1000 tons/year are forecasted for 1990 on the 900 km road Pierrelatte-Le Havre (France). Probabilities are given by the accident file, container failure by impact or fire and sanitary consequences are analysed. Risk is evaluated and discussed [fr

  1. The relation of risk assessment and health impact assessment

    DEFF Research Database (Denmark)

    Ádám, Balázs; Gulis, Gabriel

    2013-01-01

    than assessing a present situation. As part of this process, however, methods applied in risk assessment are used. Risk assessment typically characterises relation of a well-defined risk factor to a well-defined health outcome. Within HIA usually several individual risk assessments are needed...... of the causal chain from the proposal through related health determinants and risk factors to health outcomes. The stepwise analysis, systematic prioritization and consideration of horizontal interactions between the causal pathways make it feasible to use widely recognized risk assessment methods in the HIA......The level and distribution of health risks in a society is substantially influenced by measures of various policies, programmes or projects. Risk assessment can evaluate the nature, likelihood and severity of an adverse effect. Health impact assessment (HIA) provides similar function when used...

  2. A new estimation technique of sovereign default risk

    Directory of Open Access Journals (Sweden)

    Mehmet Ali Soytaş

    2016-12-01

    Full Text Available Using the fixed-point theorem, sovereign default models are solved by numerical value function iteration and calibration methods, which due to their computational constraints, greatly limits the models' quantitative performance and foregoes its country-specific quantitative projection ability. By applying the Hotz-Miller estimation technique (Hotz and Miller, 1993- often used in applied microeconometrics literature- to dynamic general equilibrium models of sovereign default, one can estimate the ex-ante default probability of economies, given the structural parameter values obtained from country-specific business-cycle statistics and relevant literature. Thus, with this technique we offer an alternative solution method to dynamic general equilibrium models of sovereign default to improve upon their quantitative inference ability.

  3. Estimated Perennial Streams of Idaho and Related Geospatial Datasets

    Science.gov (United States)

    Rea, Alan; Skinner, Kenneth D.

    2009-01-01

    The perennial or intermittent status of a stream has bearing on many regulatory requirements. Because of changing technologies over time, cartographic representation of perennial/intermittent status of streams on U.S. Geological Survey (USGS) topographic maps is not always accurate and (or) consistent from one map sheet to another. Idaho Administrative Code defines an intermittent stream as one having a 7-day, 2-year low flow (7Q2) less than 0.1 cubic feet per second. To establish consistency with the Idaho Administrative Code, the USGS developed regional regression equations for Idaho streams for several low-flow statistics, including 7Q2. Using these regression equations, the 7Q2 streamflow may be estimated for naturally flowing streams anywhere in Idaho to help determine perennial/intermittent status of streams. Using these equations in conjunction with a Geographic Information System (GIS) technique known as weighted flow accumulation allows for an automated and continuous estimation of 7Q2 streamflow at all points along a stream, which in turn can be used to determine if a stream is intermittent or perennial according to the Idaho Administrative Code operational definition. The selected regression equations were applied to create continuous grids of 7Q2 estimates for the eight low-flow regression regions of Idaho. By applying the 0.1 ft3/s criterion, the perennial streams have been estimated in each low-flow region. Uncertainty in the estimates is shown by identifying a 'transitional' zone, corresponding to flow estimates of 0.1 ft3/s plus and minus one standard error. Considerable additional uncertainty exists in the model of perennial streams presented in this report. The regression models provide overall estimates based on general trends within each regression region. These models do not include local factors such as a large spring or a losing reach that may greatly affect flows at any given point. Site-specific flow data, assuming a sufficient period of

  4. Estimates of lifetime infertility from three states: the behavioral risk factor surveillance system.

    Science.gov (United States)

    Crawford, Sara; Fussman, Chris; Bailey, Marie; Bernson, Dana; Jamieson, Denise J; Murray-Jordan, Melissa; Kissin, Dmitry M

    2015-07-01

    Knowledge of state-specific infertility is limited. The objectives of this study were to explore state-specific estimates of lifetime prevalence of having ever experienced infertility, sought treatment for infertility, types of treatments sought, and treatment outcomes. Male and female adult residents aged 18-50 years from three states involved in the States Monitoring Assisted Reproductive Technology Collaborative (Florida, Massachusetts, and Michigan) were asked state-added infertility questions as part of the 2012 Behavioral Risk Factor Surveillance System, a state-based, health-related telephone survey. Analysis involved estimation of lifetime prevalence of infertility. The estimated lifetime prevalence of infertility among 1,285 adults in Florida, 1,302 in Massachusetts, and 3,360 in Michigan was 9.7%, 6.0%, and 4.2%, respectively. Among 736 adults in Florida, 1,246 in Massachusetts, and 2,742 in Michigan that have ever tried to get pregnant, the lifetime infertility prevalence was 25.3% in Florida, 9.9% in Massachusetts, and 5.8% in Michigan. Among those with a history of infertility, over half sought treatment (60.7% in Florida, 70.6% in Massachusetts, and 51.6% in Michigan), the most common being non-assisted reproductive technology fertility treatments (61.3% in Florida, 66.0% in Massachusetts, and 75.9% in Michigan). State-specific estimates of lifetime infertility prevalence in Florida, Massachusetts, and Michigan varied. Variations across states are difficult to interpret, as they likely reflect both true differences in prevalence and differences in data collection questionnaires. State-specific estimates are needed for the prevention, detection, and management of infertility, but estimates should be based on a common set of questions appropriate for these goals.

  5. Risks of circulatory diseases among Mayak PA workers with radiation doses estimated using the improved Mayak Worker Dosimetry System 2008

    Energy Technology Data Exchange (ETDEWEB)

    Moseeva, Maria B.; Azizova, Tamara V.; Grigoryeva, Evgenia S. [Southern Urals Biophysics Institute (SUBI), Ozyorsk, Chelyabinsk Region (Russian Federation); Haylock, Richard [Public Health of England, London (United Kingdom)

    2014-05-15

    The new Mayak Worker Dosimetry System 2008 (MWDS-2008) was published in 2013 and supersedes the Doses-2005 dosimetry system for Mayak Production Association (PA) workers. It provides revised external and internal dose estimates based on the updated occupational history data. Using MWDS-2008, a cohort of 18,856 workers first employed at one of the main Mayak PA plants during 1948-1972 and followed up to 2005 was identified. Incidence and mortality risks from ischemic heart disease (IHD) (International Classification of Diseases (ICD)-9 codes 410-414) and from cerebrovascular diseases (CVD) (ICD-9 codes 430-438) were examined in this cohort and compared with previously published risk estimates in the same cohort based on the Doses-2005 dosimetry system. Significant associations were observed between doses from external gamma-rays and IHD and CVD incidence and also between internal doses from alpha-radiation and IHD mortality and CVD incidence. The estimates of excess relative risk (ERR)/Gy were consistent with those estimates from the previous studies based on Doses-2005 system apart from the relationship between CVD incidence and internal liver dose where the ERR/Gy based on MWDS-2008 was just over three times higher than the corresponding estimate based on Doses-2005 system. Adjustment for smoking status did not show any effect on the estimates of risk from internal alpha-particle exposure. (orig.)

  6. Humorous Relations: Attentiveness, Pleasure and Risk

    Science.gov (United States)

    Mayo, Cris

    2014-01-01

    This article focuses on the structures of humor and joke telling that require particular kinds of attentiveness and particular relationships between speaker and audience, or more specifically, between classmates. First, I will analyze the pedagogical and relational preconditions that are necessary for humor to work. If humor is to work well, the…

  7. Estimation of Uncertainty in Risk Assessment of Hydrogen Applications

    DEFF Research Database (Denmark)

    Markert, Frank; Krymsky, V.; Kozine, Igor

    2011-01-01

    Hydrogen technologies such as hydrogen fuelled vehicles and refuelling stations are being tested in practice in a number of projects (e.g. HyFleet-Cute and Whistler project) giving valuable information on the reliability and maintenance requirements. In order to establish refuelling stations the ...... probability and the NUSAP concept to quantify uncertainties of new not fully qualified hydrogen technologies and implications to risk management.......Hydrogen technologies such as hydrogen fuelled vehicles and refuelling stations are being tested in practice in a number of projects (e.g. HyFleet-Cute and Whistler project) giving valuable information on the reliability and maintenance requirements. In order to establish refuelling stations...... the permitting authorities request qualitative and quantitative risk assessments (QRA) to show the safety and acceptability in terms of failure frequencies and respective consequences. For new technologies not all statistical data might be established or are available in good quality causing assumptions...

  8. Elderly Taiwanese's Intrinsic Risk Factors for Fall-related Injuries

    OpenAIRE

    In-Fun Li; Yvonne Hsiung; Hui-Fen Hsing; Mei-Yu Lee; Te-Hsin Chang; Ming-Yuan Huang

    2016-01-01

    Background: As a vital issue in geriatric research, risk factors for falls were concluded to be multifactorial, and prevention has been mostly aimed at decreasing situational and environmental risks that cause and aggravate fall-related injuries, particularly within the institutions. While knowledge is limited about older patients' intrinsic determinants, the purpose of this study was to explore elderly Taiwanese's intrinsic risk factors associated with severe fall-related injuries. Method...

  9. Public attitudes towards industrial, work-related and other risks

    International Nuclear Information System (INIS)

    Prescott-Clarke, P.

    1982-01-01

    Two reports describing work sponsored by the Health and Safety Executive are presented. The first describes a study of public attitudes towards industrial, work related, nuclear industry related and other risks. The second report describes public attitudes towards the acceptability of risks. (U.K.)

  10. Brain tumour risk in relation to mobile telephone use

    DEFF Research Database (Denmark)

    Johansen, Christoffer

    2010-01-01

    The rapid increase in mobile telephone use has generated concern about possible health risks related to radiofrequency electromagnetic fields from this technology.......The rapid increase in mobile telephone use has generated concern about possible health risks related to radiofrequency electromagnetic fields from this technology....

  11. Estimation of embrittlement damage risk at neutron embrittled vessel constructions

    International Nuclear Information System (INIS)

    Staevski, K.; Madzharov, D.; Detistov, P.; Petrova, T.

    1998-01-01

    In this work a methodology based on Damage mechanics criteria is proposed. This methodology serves for probability assessment of the brittle damage risk for the neutron embrittled vessel elements. The developed methodology is realised in RISK code and has been verified on the base of tough reliability of the pressure vessel, 'Kozloduy' NPP Unit 2. This investigation has been carried out at the given parameters of the possible defects on the vessel's weld 4 taking into account requirements of the western and Russian standards. The obtained values for ductile to brittle transition temperatures, defining the equipment life-time in the presence of maximal defect, are in good consistence with the experimentally determined ones. The analyses of results show that the pressure vessel of 'Kozloduy' NPP Unit 2 has got a high level of reliability from brittle damage risk point of view and that the western standards give more conservative evaluation. On the bases of the results a conclusion is made that the developed methodology enables analysing the influence of possible defects in the neutron embrittled elements on their to reliability and their remained life-time

  12. Electricity markets volatility: estimates, regularities and risk management applications

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Masao [Sauder School of Business, University of British Columbia, 2053 Main Mall, Vancouver, BC, V6 T 1Z2 (Canada)]. E-mail: masao.nakamura@sauder.ubc.ca; Nakashima, Tomoaki [Powerex Corp., Vancouver, BC, V6C 2X8 (Canada); Niimura, Takahide [TNC Systems Technologies, Burnaby, BC, V5 H 2W4 (Canada)

    2006-09-15

    The recent deregulation of the market for electric power in many parts of the US and Canada has expanded the set of potential tools for managing the types of risks faced by both generators and consumers of electric power. In particular manufacturing and other firms whose operations are powered by electricity now face, on a continuing basis, the engineering management decisions concerning whether they should buy or produce electricity, and if they are to buy or sell electricity, what types of contracts are optimum. These types of risk management decisions typically involve futures, forwards, options and other financial derivatives. The price and volatility of electric power are known to play an essential role in determining which of these instruments should be used. However, electricity as a commodity possesses certain special features not shared by other commodities and hence its risk properties are not yet well understood. In this paper we consider and test certain hypotheses about the properties of electricity price using recent market data. We find that electricity prices possess certain volatility and other systematic properties that can be characterized by the type and method of delivery of electricity. These properties can be used by firms in formulating their optimal demand and supply schedules of electric power.

  13. Electricity markets volatility: estimates, regularities and risk management applications

    International Nuclear Information System (INIS)

    Nakamura, Masao; Nakashima, Tomoaki; Niimura, Takahide

    2006-01-01

    The recent deregulation of the market for electric power in many parts of the US and Canada has expanded the set of potential tools for managing the types of risks faced by both generators and consumers of electric power. In particular manufacturing and other firms whose operations are powered by electricity now face, on a continuing basis, the engineering management decisions concerning whether they should buy or produce electricity, and if they are to buy or sell electricity, what types of contracts are optimum. These types of risk management decisions typically involve futures, forwards, options and other financial derivatives. The price and volatility of electric power are known to play an essential role in determining which of these instruments should be used. However, electricity as a commodity possesses certain special features not shared by other commodities and hence its risk properties are not yet well understood. In this paper we consider and test certain hypotheses about the properties of electricity price using recent market data. We find that electricity prices possess certain volatility and other systematic properties that can be characterized by the type and method of delivery of electricity. These properties can be used by firms in formulating their optimal demand and supply schedules of electric power

  14. Impact of Hydrogeological Uncertainty on Estimation of Environmental Risks Posed by Hydrocarbon Transportation Networks

    Science.gov (United States)

    Ciriello, V.; Lauriola, I.; Bonvicini, S.; Cozzani, V.; Di Federico, V.; Tartakovsky, Daniel M.

    2017-11-01

    Ubiquitous hydrogeological uncertainty undermines the veracity of quantitative predictions of soil and groundwater contamination due to accidental hydrocarbon spills from onshore pipelines. Such predictions, therefore, must be accompanied by quantification of predictive uncertainty, especially when they are used for environmental risk assessment. We quantify the impact of parametric uncertainty on quantitative forecasting of temporal evolution of two key risk indices, volumes of unsaturated and saturated soil contaminated by a surface spill of light nonaqueous-phase liquids. This is accomplished by treating the relevant uncertain parameters as random variables and deploying two alternative probabilistic models to estimate their effect on predictive uncertainty. A physics-based model is solved with a stochastic collocation method and is supplemented by a global sensitivity analysis. A second model represents the quantities of interest as polynomials of random inputs and has a virtually negligible computational cost, which enables one to explore any number of risk-related contamination scenarios. For a typical oil-spill scenario, our method can be used to identify key flow and transport parameters affecting the risk indices, to elucidate texture-dependent behavior of different soils, and to evaluate, with a degree of confidence specified by the decision-maker, the extent of contamination and the correspondent remediation costs.

  15. Social and economic factors of the natural risk increasing: estimation of the Russian regions

    Directory of Open Access Journals (Sweden)

    E. Petrova

    2004-01-01

    Full Text Available This study is an attempt to assess quantitatively social and economic factors that determine vulnerability of Russian regions to natural risk, to trace the space differences of the considered factors, and to group the regions by their similarity. In order to indicate the regional differences in social and economic development, equipment condition, dangerous substances accumulation, and social trouble four the most suitable parameters were estimated, including the per capita production of Gross Regional Product (GRP, capital consumption, volume of total toxic waste, and crime rate. Increase of the first parameter causes vulnerability reducing, the increase of the last three causes its increasing. Using multidimensional cluster analysis five types of regions were found for Russia according to similarity of the considered parameters. These types are characterized with higher value of a single (rarely two chosen parameter, which seems to be sufficient enough to affect natural risks increasing in these regions in near future. Only few regions belonging to the fifth type proved to have rather high value of GRP and relatively low values of the other parameters. The negative correlation was found between a number of natural disasters (ND and the per capita GRP in case when some parameters reached anomalously high value. The distinctions between regions by prevailing different parameters, which result in natural risk increasing, help risk management to find directions where to focus on.

  16. ESTIMATING RISK ON THE CAPITAL MARKET WITH VaR METHOD

    Directory of Open Access Journals (Sweden)

    Sinisa Bogdan

    2015-06-01

    Full Text Available The two basic questions that every investor tries to answer before investment are questions about predicting return and risk. Risk and return are generally considered two positively correlated sizes, during the growth of risk it is expected increase of return to compensate the higher risk. The quantification of risk in the capital market represents the current topic since occurrence of securities. Together with estimated future returns it represents starting point of any investment. In this study it is described the history of the emergence of VaR methods, usefulness in assessing the risks of financial assets. Three main Value at Risk (VaR methodologies are decribed and explained in detail: historical method, parametric method and Monte Carlo method. After the theoretical review of VaR methods it is estimated risk of liquid stocks and portfolio from the Croatian capital market with historical and parametric VaR method, after which the results were compared and explained.

  17. Guidelines for estimating blowout rates and duration for environmental risk analysis purposes; Retningslinjer for beregning av utblaasningsrater og -varighet til bruk ved analyse av miljoerisiko

    Energy Technology Data Exchange (ETDEWEB)

    Nilsen, Thomas

    2007-01-15

    Risk assessment in relation to possible blowouts of oil and condensate is the main topic in this analysis. The estimated risk is evaluated against criteria for acceptable risk and is part of the foundation for dimensioning in oil spill preparedness. The report aims to contribute to the standardisation of the terminology, methodology and documentation for estimations of blowout rates, and thus to simplify communication of the analysis results and strengthen the decision makers' trust in these (ml)

  18. An exploration of spatial risk assessment for soil protection: estimating risk and establishing priority areas for soil protection.

    Science.gov (United States)

    Kibblewhite, M G; Bellamy, P H; Brewer, T R; Graves, A R; Dawson, C A; Rickson, R J; Truckell, I; Stuart, J

    2014-03-01

    Methods for the spatial estimation of risk of harm to soil by erosion by water and wind and by soil organic matter decline are explored. Rates of harm are estimated for combinations of soil type and land cover (as a proxy for hazard frequency) and used to estimate risk of soil erosion and loss of soil organic carbon (SOC) for 1 km(2)pixels. Scenarios are proposed for defining the acceptability of risk of harm to soil: the most precautionary one corresponds to no net harm after natural regeneration of soil (i.e. a 1 in 20 chance of exceeding an erosion rate of soils and a carbon stock decline of 0 tha(-1)y(-1) for organic soils). Areas at higher and lower than possible acceptable risk are mapped. The veracity of boundaries is compromised if areas of unacceptable risk are mapped to administrative boundaries. Errors in monitoring change in risk of harm to soil and inadequate information on risk reduction measures' efficacy, at landscape scales, make it impossible to use or monitor quantitative targets for risk reduction adequately. The consequences for priority area definition of expressing varying acceptable risk of harm to soil as a varying probability of exceeding a fixed level of harm, or, a varying level of harm being exceeded with a fixed probability, are discussed. Soil data and predictive models for rates of harm to soil would need considerable development and validation to implement a priority area approach robustly. Copyright © 2013 Elsevier B.V. All rights reserved.

  19. On the influence of uncertainties in estimating risk aversion and working interest

    International Nuclear Information System (INIS)

    MacKay, J.A.; Lerche, I.

    1996-01-01

    The influence of uncertainties in costs, value, success probability, risk tolerance and mandated working interest are evaluated for their impact on assessing probable ranges of uncertainty on risk adjusted value, RAV, using different models. The relative importance of different factors in contributing to the uncertainty in RAV is analyzed, as is the influence of different probability distributions for the intrinsic variables entering the RAV model formulae. Numerical illustrations indicate how the RAV probabilities depend not only on the model functions (Cozzolino, hyperbolic tangent) used to provide RAV estimates, but also on the intrinsic shapes of the probability distributions from which are drawn input parameter values for Monte Carlo simulations. In addition, a mandated range of working interest can be addressed as an extra variable contributing to the probabilistic range of RAV; while negative RAV values for high-cost project can be used to assess the probable buy-out amount one should be prepared to pay depending on corporate risk philosophy. Also, the procedures illustrate how the relative contributions of scientific factors influence uncertainty of reserve assessments, allowing one to determine where to concentrate effort to improve the ranges of uncertainty. (Author)

  20. Methodology for the Model-based Small Area Estimates of Cancer-Related Knowledge - Small Area Estimates

    Science.gov (United States)

    The HINTS is designed to produce reliable estimates at the national and regional levels. GIS maps using HINTS data have been used to provide a visual representation of possible geographic relationships in HINTS cancer-related variables.

  1. Jumps and Betas: A New Framework for Disentangling and Estimating Systematic Risks

    DEFF Research Database (Denmark)

    Todorov, Viktor; Bollerslev, Tim

    market portfolio, we find the estimated diffusive and jump betas with respect to the market to be quite dif- ferent for many of the stocks. Our findings have direct and important implications for empirical asset pricing finance and practical portfolio and risk management decisions.......We provide a new theoretical framework for disentangling and estimating sensitivity towards systematic diffusive and jump risks in the context of factor pricing models. Our estimates of the sensitivities towards systematic risks, or betas, are based on the notion of increasingly finer sampled...

  2. Estimation of insurance premiums for coverage against natural disaster risk: an application of Bayesian Inference

    Directory of Open Access Journals (Sweden)

    Y. Paudel

    2013-03-01

    Full Text Available This study applies Bayesian Inference to estimate flood risk for 53 dyke ring areas in the Netherlands, and focuses particularly on the data scarcity and extreme behaviour of catastrophe risk. The probability density curves of flood damage are estimated through Monte Carlo simulations. Based on these results, flood insurance premiums are estimated using two different practical methods that each account in different ways for an insurer's risk aversion and the dispersion rate of loss data. This study is of practical relevance because insurers have been considering the introduction of flood insurance in the Netherlands, which is currently not generally available.

  3. Estimation of insurance premiums for coverage against natural disaster risk: an application of Bayesian Inference

    Science.gov (United States)

    Paudel, Y.; Botzen, W. J. W.; Aerts, J. C. J. H.

    2013-03-01

    This study applies Bayesian Inference to estimate flood risk for 53 dyke ring areas in the Netherlands, and focuses particularly on the data scarcity and extreme behaviour of catastrophe risk. The probability density curves of flood damage are estimated through Monte Carlo simulations. Based on these results, flood insurance premiums are estimated using two different practical methods that each account in different ways for an insurer's risk aversion and the dispersion rate of loss data. This study is of practical relevance because insurers have been considering the introduction of flood insurance in the Netherlands, which is currently not generally available.

  4. State-Level Estimates of Cancer-Related Absenteeism Costs

    Science.gov (United States)

    Tangka, Florence K.; Trogdon, Justin G.; Nwaise, Isaac; Ekwueme, Donatus U.; Guy, Gery P.; Orenstein, Diane

    2016-01-01

    Background Cancer is one of the top five most costly diseases in the United States and leads to substantial work loss. Nevertheless, limited state-level estimates of cancer absenteeism costs have been published. Methods In analyses of data from the 2004–2008 Medical Expenditure Panel Survey, the 2004 National Nursing Home Survey, the U.S. Census Bureau for 2008, and the 2009 Current Population Survey, we used regression modeling to estimate annual state-level absenteeism costs attributable to cancer from 2004 to 2008. Results We estimated that the state-level median number of days of absenteeism per year among employed cancer patients was 6.1 days and that annual state-level cancer absenteeism costs ranged from $14.9 million to $915.9 million (median = $115.9 million) across states in 2010 dollars. Absenteeism costs are approximately 6.5% of the costs of premature cancer mortality. Conclusions The results from this study suggest that lost productivity attributable to cancer is a substantial cost to employees and employers and contributes to estimates of the overall impact of cancer in a state population. PMID:23969498

  5. The relative efficiency of three methods of estimating herbage mass ...

    African Journals Online (AJOL)

    The methods involved were randomly placed circular quadrats; randomly placed narrow strips; and disc meter sampling. Disc meter and quadrat sampling appear to be more efficient than strip sampling. In a subsequent small plot grazing trial the estimates of herbage mass, using the disc meter, had a consistent precision ...

  6. Measurement Error Affects Risk Estimates for Recruitment to the Hudson River Stock of Striped Bass

    Directory of Open Access Journals (Sweden)

    Dennis J. Dunning

    2002-01-01

    Full Text Available We examined the consequences of ignoring the distinction between measurement error and natural variability in an assessment of risk to the Hudson River stock of striped bass posed by entrainment at the Bowline Point, Indian Point, and Roseton power plants. Risk was defined as the probability that recruitment of age-1+ striped bass would decline by 80% or more, relative to the equilibrium value, at least once during the time periods examined (1, 5, 10, and 15 years. Measurement error, estimated using two abundance indices from independent beach seine surveys conducted on the Hudson River, accounted for 50% of the variability in one index and 56% of the variability in the other. If a measurement error of 50% was ignored and all of the variability in abundance was attributed to natural causes, the risk that recruitment of age-1+ striped bass would decline by 80% or more after 15 years was 0.308 at the current level of entrainment mortality (11%. However, the risk decreased almost tenfold (0.032 if a measurement error of 50% was considered. The change in risk attributable to decreasing the entrainment mortality rate from 11 to 0% was very small (0.009 and similar in magnitude to the change in risk associated with an action proposed in Amendment #5 to the Interstate Fishery Management Plan for Atlantic striped bass (0.006— an increase in the instantaneous fishing mortality rate from 0.33 to 0.4. The proposed increase in fishing mortality was not considered an adverse environmental impact, which suggests that potentially costly efforts to reduce entrainment mortality on the Hudson River stock of striped bass are not warranted.

  7. Estimates of cancer deaths attributable to behavioural risk factors in Italy, 2013.

    Science.gov (United States)

    Battisti, Francesca; Carreras, Giulia; Grassi, Tommaso; Chellini, Elisabetta; Gorini, Giuseppe

    2017-01-01

    "Non-communicable diseases cause more than 80% of deaths in europe and, among these, 20% are caused by cancer. Modifiable lifestyle factors considered in the italian national programme "Guadagnare salute" (Gaining health), such as tobacco smoking, unhealthy diet, physical inactivity, overweight, and excessive alcohol use, are amongst the major causes of cancer deaths. The aims of this study was to estimate the number of deaths attributable to lifestyle factors for italy and for italian regions in 2013 and to describe its variation in relation to the regional prevalence of risk factors exposure. For Italy and for each italian region, deaths attributable to lifestyle factors were estimated using the methodology of the Global Burden of disease (GBd) study. italian mortality data of 2013 and risks attributable to these lifestyle factors for each cancer site for italy from the GBd study were used. Prevalence of exposure to lifestyles in Italy and in each Italian Region was collected for the period 2008-2013. In 2013, at least 66,605 cancer deaths in italy were attributable to lifestyle factors, accounting for 37.9% of all cancer deaths: 34.1% of cancer deaths in men and 9.0% in women were attributable to smoking; in men and women, respectively, 3.3% and 2.8% were attributable to excessive alcohol consumption; 5.3 % and 6.7% to overweight; 10.1% and 7.1% to dietary risk factors; 1.9% and 4.2% to physical inactivity. A moderate variability of percentage of deaths attributable to modifi able lifestyle factors by region was also detected due to different prevalence values of exposure to lifestyles occurred in last decades. At least 45,000 cancer deaths in men and 21,000 in women occurred in 2013 were attributable to modifi able risk factors, whose prevalence varied by region and which could be averted through the implementation of primary prevention interventions."

  8. Assessing the risk of work-related international travel.

    Science.gov (United States)

    Druckman, Myles; Harber, Philip; Liu, Yihang; Quigley, Robert L

    2014-11-01

    To identify factors affecting the likelihood of requiring medical services during international business trips. Data from more than 800,000 international trips and medical assistance cases provided to 48 multinational corporations in 2009. Travel destination countries were grouped into four a priori risk-related categories. Travel to "low" medical risk countries in aggregate accounted for more hospitalizations and medical evacuations than travel to "high" medical risk countries. Nevertheless, the risk per trip was much higher for travel to higher medical risk countries. Corporations with employees on international travel should allocate sufficient resources to manage and ideally prevent medical issues during business travel. Travel medicine must focus on more than infectious diseases, and programs are necessary for both high- and low-risk regions. Improved understanding of travel-related needs determines resource allocation and risk mitigation efforts.

  9. Estimates of health risks associated with uranium transportation by air

    International Nuclear Information System (INIS)

    Elert, M.; Skagius, K.; Ericsson, A.M.; Karlsson, L.G.; Markstroem, A.

    1989-01-01

    There is today an increased interest for air transport of large quantities of uranium compounds. In this report the health risks from an aircrash where uraniumhexafluoride, uraniumdioxide powder, low enriched unirradiated fuel used in Swedish power reactors and unirradiated MTR-fuel used in the research reactor in Studsvik, is analysed. The radiation doses to personnel and the general public is calculated as well as the ground contamination from the spreaded material. Also air concentration of hydrogenflouride, from uraniumhexaflouride reacting with moisture in the air, is calculated. A number of intermediate results are presented. (authors) (69 refs.)

  10. Multifactorial diseases and risk estimations: special reference of mutation component

    International Nuclear Information System (INIS)

    Yasuda, Norikazu

    1995-01-01

    Genetic effects of radiation in man have been tractable such aspects as genes, chromosomes, genomes, individuals and populations. In spite of enormous interest from an academic view point on the mechanism studies, it is rather a little study on incidence or prevalence of genetic diseases as hereditary effects when human population in general have been exposed by radiation. Such studies are valuable for radiation protection as well as radiation public health. In this review, I have attempted to reconcile some fragments evidences to derive an important conclusion: the hereditary effects of radiation could not be detected from examination of disease incidence (or prevalence) for the genetic risk. (J.P.N.)

  11. Estimating the risk-return tradeoff in MENA Stock Markets

    Directory of Open Access Journals (Sweden)

    Salim Lahmiri

    2013-04-01

    Full Text Available This study employs the generalized autoregressive conditionally heteroskedastic in the mean (GARCH-M methodology to investigate the return generating process of Jordan, Kingdom of Saudi Arabia (KSA, Kuwait, and Morocco stock market indices. The tradeoff between returns and the conditional variance is found to be positive in all markets. In other words, the empirical findings show that investors are rewarded for their exposure to more risk in these financial markets. This result is consistent with both financial theory and empirical finance.

  12. Comparison of prospective risk estimates for postoperative complications: human vs computer model.

    Science.gov (United States)

    Glasgow, Robert E; Hawn, Mary T; Hosokawa, Patrick W; Henderson, William G; Min, Sung-Joon; Richman, Joshua S; Tomeh, Majed G; Campbell, Darrell; Neumayer, Leigh A

    2014-02-01

    Surgical quality improvement tools such as NSQIP are limited in their ability to prospectively affect individual patient care by the retrospective audit and feedback nature of their design. We hypothesized that statistical models using patient preoperative characteristics could prospectively provide risk estimates of postoperative adverse events comparable to risk estimates provided by experienced surgeons, and could be useful for stratifying preoperative assessment of patient risk. This was a prospective observational cohort. Using previously developed models for 30-day postoperative mortality, overall morbidity, cardiac, thromboembolic, pulmonary, renal, and surgical site infection (SSI) complications, model and surgeon estimates of risk were compared with each other and with actual 30-day outcomes. The study cohort included 1,791 general surgery patients operated on between June 2010 and January 2012. Observed outcomes were mortality (0.2%), overall morbidity (8.2%), and pulmonary (1.3%), cardiac (0.3%), thromboembolism (0.2%), renal (0.4%), and SSI (3.8%) complications. Model and surgeon risk estimates showed significant correlation (p risk for overall morbidity to be low, the model-predicted risk and observed morbidity rates were 2.8% and 4.1%, respectively, compared with 10% and 18% in perceived high risk patients. Patients in the highest quartile of model-predicted risk accounted for 75% of observed mortality and 52% of morbidity. Across a broad range of general surgical operations, we confirmed that the model risk estimates are in fairly good agreement with risk estimates of experienced surgeons. Using these models prospectively can identify patients at high risk for morbidity and mortality, who could then be targeted for intervention to reduce postoperative complications. Published by Elsevier Inc.

  13. Estimation of effective dose and lifetime attributable risk from multiple head CT scans in ventriculoperitoneal shunted children

    International Nuclear Information System (INIS)

    Aw-Zoretic, J.; Seth, D.; Katzman, G.; Sammet, S.

    2014-01-01

    Purpose: The purpose of this review is to determine the averaged effective dose and lifetime attributable risk factor from multiple head computed tomography (CT) dose data on children with ventriculoperitoneal shunts (VPS). Method and materials: A total of 422 paediatric head CT exams were found between October 2008 and January 2011 and retrospectively reviewed. The CT dose data was weighted with the latest IRCP 103 conversion factor to obtain the effective dose per study and the averaged effective dose was calculated. Estimates of the lifetime attributable risk were also calculated from the averaged effective dose using a conversion factor from the latest BEIR VII report. Results: Our study found the highest effective doses in neonates and the lowest effective doses were observed in the 10–18 years age group. We estimated a 0.007% potential increase risk in neonates and 0.001% potential increased risk in teenagers over the base risk. Conclusion: Multiple head CTs in children equates to a slight potential increase risk in lifetime attributable risk over the baseline risk for cancer, slightly higher in neonates relative to teenagers. The potential risks versus clinical benefit must be assessed

  14. High resolution estimates of the corrosion risk for cultural heritage in Italy

    International Nuclear Information System (INIS)

    De Marco, Alessandra; Screpanti, Augusto; Mircea, Mihaela; Piersanti, Antonio; Proietti, Chiara; Fornasier, M. Francesca

    2017-01-01

    Air pollution plays a pivotal role in the deterioration of many materials used in buildings and cultural monuments causing an inestimable damage. This study aims to estimate the impacts of air pollution (SO 2 , HNO 3 , O 3 , PM 10 ) and meteorological conditions (temperature, precipitation, relative humidity) on limestone, copper and bronze based on high resolution air quality data-base produced with AMS-MINNI modelling system over the Italian territory over the time period 2003–2010. A comparison between high resolution data (AMS-MINNI grid, 4 × 4 km) and low resolution data (EMEP grid, 50 × 50 km) has been performed. Our results pointed out that the corrosion levels for limestone, copper and bronze are decreased in Italy from 2003 to 2010 in relation to decrease of pollutant concentrations. However, some problem related to air pollution persists especially in Northern and Southern Italy. In particular, PM 10 and HNO 3 are considered the main responsible for limestone corrosion. Moreover, the high resolution data (AMS-MINNI) allowed the identification of risk areas that are not visible with the low resolution data (EMEP modelling system) in all considered years and, especially, in the limestone case. Consequently, high resolution air quality simulations are suitable to provide concrete benefits in providing information for national effective policy against corrosion risk for cultural heritage, also in the context of climate changes that are affecting strongly Mediterranean basin. - Highlights: • Air pollution plays a pivotal role in the deterioration of cultural materials. • Limestone, copper and bronze corrosion levels decreased in Italy from 2003 to 2010. • PM 10 is considered the main responsible for limestone corrosion in Northern Italy. • HNO3 is considered the main responsible for limestone corrosion in all analyzed years. • High-resolution data are particularly useful to define area at risk for corrosion. - Importance of the high

  15. A Comparison Study on the Integrated Risk Estimation for Various Power Systems

    International Nuclear Information System (INIS)

    Kim, Tae Woon; Ha, J. J.; Kim, S. H.; Jeong, J. T.; Min, K. R.; Kim, K. Y.

    2007-06-01

    The objective of this study is to establish a system for the comparative analysis of the environmental impacts, risks, health effects, and social acceptance for various electricity generation systems and a computational framework and necessary databases. In this study, the second phase of the nuclear research and development program(2002-2004), the methodologies for the comparative analysis of the environmental impacts, risks, and health effects for various electricity generation systems was investigated and applied to reference power plants. The life cycle assessment (LCA) methodology as a comparative analysis tool for the environmental impacts was adopted and applied to fossil-fueled and nuclear power plants. The scope of the analysis considered in this study are the construction, operation/fuel cycle), and demolition of each power generation system. In the risk analysis part, the empirical and analytical methods were adopted and applied to fossil-fueled and nuclear power plants. In the empirical risk assessment part, we collected historical experiences of worldwide energy-related accidents with fatalities over the last 30 years. The scope of the analysis considered in this study are the construction, operation (fuel cycle), and demolition stages of each power generation systems. The risks for the case of nuclear power plants which have potential releases of radioactive materials were estimated In a probabilistic way (PSA) by considering the occurrence of severe accidents and compared with the risks of other electricity generation systems. The health effects testimated as external cost) resulting from the operation of nuclear, coal, and hydro power systems were estimated and compared by using the program developed by the IAEA. Regarding a comprehensive comparison of the various power systems, the analytic hierarchy process (AHP) method is introduced to aggregate the diverse information under conflicting decision criteria. Social aspect is treated by a web

  16. Risk related behaviour under different ambient scent conditions

    Directory of Open Access Journals (Sweden)

    Alina Gagarina

    2016-09-01

    Full Text Available The article analyses the effect of two ambient scents (peppermint and vanilla and their intensiveness on risk related behaviour that is expressed through selected decision making heuristics. Purpose of the article: The purpose of this article is to identify the relationship of ambient scent type and intensiveness with risk related behaviour that is expressed through selected decision making heuristics. Methodology/methods: 2×2 factorial experiment with control group was run. Ambient scent type (vanilla vs. peppermint and intensiveness (8 (1mg vs. 16 sprays (2mg of scent concentrate in the same room were manipulated as between subject variables. Risk aversion, effect of anchoring heuristic on bidding, and affect (risk and benefit heuristics were tracked as dependent variables. Scientific aim: To identify whether ambient scent type and intensiveness have effect on risk related behaviour. Findings: Evidence suggests that there are effects of ambient scent on risk related behaviour, thus fulfilling the missing gap to relate ambient environment to decision making heuristics when risks are involved. However, not all heuristics were affected by experimental conditions. Subjects were bidding significantly higher amounts under low anchor conditions, when peppermint scent was around (if compared to vanilla group. Affect risk was perceived as lower in peppermint ambient scent conditions, if compared to the control group. Intensity of ambient scent also had influence on affect risk: subjects perceived less risk under high scent intensity conditions. Conclusions: By manipulating ambient scent, marketers may reduce or increase consumers risk perception and behaviour and as a consequence influence their purchase decisions. Marketers could use peppermint scent in high intensiveness in the situations where they want consumers to undertake higher risks (expensive purchases, gambling, insurance, since stakes were higher under peppermint ambient scent condition

  17. Climate Change and Risk Management: Challenges for Insurance, Adaptation, and Loss Estimation

    OpenAIRE

    Kousky, Carolyn; Cooke, Roger

    2009-01-01

    Adapting to climate change will not only require responding to the physical effects of global warming, but will also require adapting the way we conceptualize, measure, and manage risks. Climate change is creating new risks, altering the risks we already face, and also, importantly, impacting the interdependencies between these risks. In this paper we focus on three particular phenomena of climate related risks that will require a change in our thinking about risk management: global micro-cor...

  18. Risk and return: Long-run relations, fractional cointegration, and return predictability

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Osterrieder, Daniela; Sizova, Natalia

    2013-01-01

    Univariate dependencies in market volatility, both objective and risk neutral, are best described by long-memory fractionally integrated processes. Meanwhile, the ex post difference, or the variance swap payoff reflecting the reward for bearing volatility risk, displays far less persistent dynamics...... are consistent with generalized long-run risk models and help explain why classical efforts of establishing a naïve return-volatility relation fail. We also estimate a fractionally cointegrated vector autoregression (CFVAR). The model-implied long-run equilibrium relation between the two variance variables...

  19. Uncertainty Estimation Cheat Sheet for Probabilistic Risk Assessment

    Science.gov (United States)

    Britton, Paul T.; Al Hassan, Mohammad; Ring, Robert W.

    2017-01-01

    "Uncertainty analysis itself is uncertain, therefore, you cannot evaluate it exactly," Source Uncertain Quantitative results for aerospace engineering problems are influenced by many sources of uncertainty. Uncertainty analysis aims to make a technical contribution to decision-making through the quantification of uncertainties in the relevant variables as well as through the propagation of these uncertainties up to the result. Uncertainty can be thought of as a measure of the 'goodness' of a result and is typically represented as statistical dispersion. This paper will explain common measures of centrality and dispersion; and-with examples-will provide guidelines for how they may be estimated to ensure effective technical contributions to decision-making.

  20. An Estimation of Risk Impact of Anticipated Transients without Scram for a KSNP

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seok Jung; Yang Joon Eon

    2006-07-15

    Anticipated transient without scram (ATWS) event is an accident sequence with large risk impact, while it is a beyond design basis accident (BDBA). We have estimated a risk due to an ATWS accident sequence for the KSNP in consideration of the recent accident analysis results. The SECY-83-293's model for the CE type plants has been used in a risk estimation of ATWS. A risk estimation due to an ATWS for the KSNP has been performed in consideration of the recent ATWS accident analysis results and plant information. We reviewed influence factors in the SECY-83-293's model, these factors have been re-estimated by using current information and PSA results for a KSNP. A risk due to an ATWS has been estimated as 3.6E-6/yr of CDF by using domestic aspect and recent KSNP information. A sensitivity study for the UET variation has been performed. As the results of the sensitivity analysis, the overall risk spectrum by the UET variation is bounded between 7.80E-7/yr to 8.00E-6/yr of CDF. As the result of the current study, the risk due to an ATWS accident sequence has been identified as a considerable impact on the entire risk of a KSNP, so the risk estimation of that plant should be upgraded by considering the recent information like the ATWS accident analysis results. Finally, we expect that this study can become a basis for the entire risk estimation of the referred plant.

  1. The perception of risks related to electricity generation

    Energy Technology Data Exchange (ETDEWEB)

    Midden, C J; Daamen, D D; Verplanken, B

    1987-01-01

    Some of the key findings are discussed of psychological research on the perception of risks and attitudes with respect to the use of uranium and coal for electricity generation. It appears that attitudes are mostly not based on ideology but rather determined by a trade-off of expected risks and advantages. Lay estimates of probabilities are compared with expert judgements. In the last section attitudes of people living near existing or planned power plants are analyzed. Serious doubts are raised about the possibilities to give residents economic compensation for exposure to risks. 1 fig., 29 refs.

  2. Improving Relative Combat Power Estimation: The Road to Victory

    Science.gov (United States)

    2014-06-13

    was unthinkable before. Napoleon Bonaparte achieved a superior warfighting system compared to his opponents, which resulted in SOF. Napoleon’s...observations about combat power estimation and force empoloyment, remain valid. Napoleon also offered thoughts about combat power and superiority whe he...force. However, Napoleon did not think one- sidedly about the problem. He also said: “The moral is to the physical as three to one.”11 This dual

  3. Patient absorbed radiation doses estimation related to irradiation anatomy

    International Nuclear Information System (INIS)

    Soares, Flavio Augusto Penna; Soares, Amanda Anastacio; Kahl, Gabrielly Gomes

    2014-01-01

    Developed a direct equation to estimate the absorbed dose to the patient in x-ray examinations, using electric, geometric parameters and filtering combined with data from irradiated anatomy. To determine the absorbed dose for each examination, the entrance skin dose (ESD) is adjusted to the thickness of the patient's specific anatomy. ESD is calculated from the estimated KERMA greatness in the air. Beer-Lambert equations derived from power data mass absorption coefficients obtained from the NIST / USA, were developed for each tissue: bone, muscle, fat and skin. Skin thickness was set at 2 mm and the bone was estimated in the central ray of the site, in the anteroposterior view. Because they are similar in density and attenuation coefficients, muscle and fat are treated as a single tissue. For evaluation of the full equations, we chose three different anatomies: chest, hand and thigh. Although complex in its shape, the equations simplify direct determination of absorbed dose from the characteristics of the equipment and patient. The input data is inserted at a single time and total absorbed dose (mGy) is calculated instantly. The average error, when compared with available data, is less than 5% in any combination of device data and exams. In calculating the dose for an exam and patient, the operator can choose the variables that will deposit less radiation to the patient through the prior analysis of each combination of variables, using the ALARA principle in routine diagnostic radiology sector

  4. High resolution estimates of the corrosion risk for cultural heritage in Italy.

    Science.gov (United States)

    De Marco, Alessandra; Screpanti, Augusto; Mircea, Mihaela; Piersanti, Antonio; Proietti, Chiara; Fornasier, M Francesca

    2017-07-01

    Air pollution plays a pivotal role in the deterioration of many materials used in buildings and cultural monuments causing an inestimable damage. This study aims to estimate the impacts of air pollution (SO 2 , HNO 3 , O 3 , PM 10 ) and meteorological conditions (temperature, precipitation, relative humidity) on limestone, copper and bronze based on high resolution air quality data-base produced with AMS-MINNI modelling system over the Italian territory over the time period 2003-2010. A comparison between high resolution data (AMS-MINNI grid, 4 × 4 km) and low resolution data (EMEP grid, 50 × 50 km) has been performed. Our results pointed out that the corrosion levels for limestone, copper and bronze are decreased in Italy from 2003 to 2010 in relation to decrease of pollutant concentrations. However, some problem related to air pollution persists especially in Northern and Southern Italy. In particular, PM 10 and HNO 3 are considered the main responsible for limestone corrosion. Moreover, the high resolution data (AMS-MINNI) allowed the identification of risk areas that are not visible with the low resolution data (EMEP modelling system) in all considered years and, especially, in the limestone case. Consequently, high resolution air quality simulations are suitable to provide concrete benefits in providing information for national effective policy against corrosion risk for cultural heritage, also in the context of climate changes that are affecting strongly Mediterranean basin. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Use of doubling doses for the estimation of genetic risks

    International Nuclear Information System (INIS)

    Searle, A.G.

    1977-01-01

    Doubling dose estimates derived from radiation experiments in mice are proving of great value for the assessment of genetic hazards to man from extra radiation exposure because they allow the latest information on mutation frequencies and the incidence of genetic disease in man to be used in the assessment process. The similarity in spectra of 'spontaneous' and induced mutations increases coincidence in the validity of this approach. Data on rates of induction of dominant and recessive mutations, translocations and X-chromosome loss are used to derive doubling doses for chronic exposures to both low and high-LET radiations. Values for γ and X-rays, derived from both male and female germ-cells, fall inside a fairly small range and it is felt that the use of an overall figure of 100 rads is justifiable for protection purposes. Values for neutrons and α-particles, obtained from male germ-cells, varied according to neutron energy etc. but clustered around a value of 5 rads for fission neutrons

  6. Does Implementation of Biomathematical Models Mitigate Fatigue and Fatigue-related Risks in Emergency Medical Services Operations? A Systematic Review

    Science.gov (United States)

    2018-01-11

    Background: Work schedules like those of Emergency Medical Services (EMS) personnel have been associated with increased risk of fatigue-related impairment. Biomathematical modeling is a means of objectively estimating the potential impacts of fatigue...

  7. Varied definitions of risk related to sensation seeking trait

    International Nuclear Information System (INIS)

    Daastoel, P.Oe.U.; Drottz-Sjoeberg, B.M.

    1999-01-01

    This pilot study is based on the assumption and the knowledge that previous results show that the normal use of the word risk varies across subjects. The risk definitions the subjects use have also been shown to be related to various educational interests. A related field of research has developed measures for Sensation Seeking personality trait, with four facets. Three independent groups of first year psychology students reported their normal definition of the word risk using one of three measurement formats. The results showed, e.g. that the typical open-ended response to the personal definition of risk was danger. Subjects who defined risk as the combination of probability and consequences tended to score higher on the total Sensation Seeking Scale, as compared to those defining risk as the probability of an event

  8. Varied definitions of risk related to sensation seeking trait

    Energy Technology Data Exchange (ETDEWEB)

    Daastoel, P.Oe.U.; Drottz-Sjoeberg, B.M. [Norwegian Univ. of Science and Technology, Trondheim (Norway). Dept. of Psychology

    1999-12-01

    This pilot study is based on the assumption and the knowledge that previous results show that the normal use of the word risk varies across subjects. The risk definitions the subjects use have also been shown to be related to various educational interests. A related field of research has developed measures for Sensation Seeking personality trait, with four facets. Three independent groups of first year psychology students reported their normal definition of the word risk using one of three measurement formats. The results showed, e.g. that the typical open-ended response to the personal definition of risk was danger. Subjects who defined risk as the combination of probability and consequences tended to score higher on the total Sensation Seeking Scale, as compared to those defining risk as the probability of an event.

  9. Female Genital Mutilation/Cutting in the United States: Updated Estimates of Women and Girls at Risk, 2012.

    Science.gov (United States)

    Goldberg, Howard; Stupp, Paul; Okoroh, Ekwutosi; Besera, Ghenet; Goodman, David; Danel, Isabella

    2016-01-01

    In 1996, the U.S. Congress passed legislation making female genital mutilation/cutting (FGM/C) illegal in the United States. CDC published the first estimates of the number of women and girls at risk for FGM/C in 1997. Since 2012, various constituencies have again raised concerns about the practice in the United States. We updated an earlier estimate of the number of women and girls in the United States who were at risk for FGM/C or its consequences. We estimated the number of women and girls who were at risk for undergoing FGM/C or its consequences in 2012 by applying country-specific prevalence of FGM/C to the estimated number of women and girls living in the United States who were born in that country or who lived with a parent born in that country. Approximately 513,000 women and girls in the United States were at risk for FGM/C or its consequences in 2012, which was more than three times higher than the earlier estimate, based on 1990 data. The increase in the number of women and girls younger than 18 years of age at risk for FGM/C was more than four times that of previous estimates. The estimated increase was wholly a result of rapid growth in the number of immigrants from FGM/C-practicing countries living in the United States and not from increases in FGM/C prevalence in those countries. Scientifically valid information regarding whether women or their daughters have actually undergone FGM/C and related information that can contribute to efforts to prevent the practice in the United States and provide needed health services to women who have undergone FGM/C are needed.

  10. Model-Based Estimation of Collision Risks of Predatory Birds with Wind Turbines

    Directory of Open Access Journals (Sweden)

    Marcus Eichhorn

    2012-06-01

    Full Text Available The expansion of renewable energies, such as wind power, is a promising way of mitigating climate change. Because of the risk of collision with rotor blades, wind turbines have negative effects on local bird populations, particularly on raptors such as the Red Kite (Milvus milvus. Appropriate assessment tools for these effects have been lacking. To close this gap, we have developed an agent-based, spatially explicit model that simulates the foraging behavior of the Red Kite around its aerie in a landscape consisting of different land-use types. We determined the collision risk of the Red Kite with the turbine as a function of the distance between the wind turbine and the aerie and other parameters. The impact function comprises the synergistic effects of species-specific foraging behavior and landscape structure. The collision risk declines exponentially with increasing distance. The strength of this decline depends on the raptor's foraging behavior, its ability to avoid wind turbines, and the mean wind speed in the region. The collision risks, which are estimated by the simulation model, are in the range of values observed in the field. The derived impact function shows that the collision risk can be described as an aggregated function of distance between the wind turbine and the raptor's aerie. This allows an easy and rapid assessment of the ecological impacts of (existing or planned wind turbines in relation to their spatial location. Furthermore, it implies that minimum buffer zones for different landscapes can be determined in a defensible way. This modeling approach can be extended to other bird species with central-place foraging behavior. It provides a helpful tool for landscape planning aimed at minimizing the impacts of wind power on biodiversity.

  11. Quantifying risk over the life course - latency, age-related susceptibility, and other time-varying exposure metrics.

    Science.gov (United States)

    Wang, Molin; Liao, Xiaomei; Laden, Francine; Spiegelman, Donna

    2016-06-15

    Identification of the latency period and age-related susceptibility, if any, is an important aspect of assessing risks of environmental, nutritional, and occupational exposures. We consider estimation and inference for latency and age-related susceptibility in relative risk and excess risk models. We focus on likelihood-based methods for point and interval estimation of the latency period and age-related windows of susceptibility coupled with several commonly considered exposure metrics. The method is illustrated in a study of the timing of the effects of constituents of air pollution on mortality in the Nurses' Health Study. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  12. Quantifying Risk Over the Life Course – Latency, Age-Related Susceptibility, and Other Time-Varying Exposure Metrics

    Science.gov (United States)

    Wang, Molin; Liao, Xiaomei; Laden, Francine; Spiegelman, Donna

    2016-01-01

    Identification of the latency period and age-related susceptibility, if any, is an important aspect of assessing risks of environmental, nutritional and occupational exposures. We consider estimation and inference for latency and age-related susceptibility in relative risk and excess risk models. We focus on likelihood-based methods for point and interval estimation of the latency period and age-related windows of susceptibility coupled with several commonly considered exposure metrics. The method is illustrated in a study of the timing of the effects of constituents of air pollution on mortality in the Nurses’ Health Study. PMID:26750582

  13. Uncertainty in estimating and mitigating industrial related GHG emissions

    International Nuclear Information System (INIS)

    El-Fadel, M.; Zeinati, M.; Ghaddar, N.; Mezher, T.

    2001-01-01

    Global climate change has been one of the challenging environmental concerns facing policy makers in the past decade. The characterization of the wide range of greenhouse gas emissions sources and sinks as well as their behavior in the atmosphere remains an on-going activity in many countries. Lebanon, being a signatory to the Framework Convention on Climate Change, is required to submit and regularly update a national inventory of greenhouse gas emissions sources and removals. Accordingly, an inventory of greenhouse gases from various sectors was conducted following the guidelines set by the United Nations Intergovernmental Panel on Climate Change (IPCC). The inventory indicated that the industrial sector contributes about 29% to the total greenhouse gas emissions divided between industrial processes and energy requirements at 12 and 17%, respectively. This paper describes major mitigation scenarios to reduce emissions from this sector based on associated technical, economic, environmental, and social characteristics. Economic ranking of these scenarios was conducted and uncertainty in emission factors used in the estimation process was emphasized. For this purpose, theoretical and experimental emission factors were used as alternatives to default factors recommended by the IPCC and the significance of resulting deviations in emission estimation is presented. (author)

  14. Heritability estimates for yield and related traits in bread wheat

    International Nuclear Information System (INIS)

    Din, R.; Jehan, S.; Ibraullah, A.

    2009-01-01

    A set of 22 experimental wheat lines along with four check cultivars were evaluated in in-irrigated and unirrgated environments with objectives to determine genetic and phenotypic variation and heritability estimates for yield and its traits- The two environments were statistically at par for physiological maturity, plant height, spikes m/sub -2/. spike lets spike/sup -1/ and 1000-grain weight. Highly significant genetic variability existed among wheat lines (P < 0.0 I) in the combined analysis across two test environments for traits except 1000- grain weight. Genotypes x environment interactions were non-significant for traits indicating consistent performance of lines in two test environments. However lines and check cultivars were two to five days early in maturity under unirrigated environment. Plant height, spikes m/sup -2/ and 1000-grain weight also reduced under unirrigated environments. Genetic variances were greater than Environmental variances for most of traits- Heritability estimates were of higher magnitude (0.74 to 0.96) for plant height, medium (0.31 to 0.56) for physiological maturity. spikelets spike/sup -1/ (unirrigated) and 1000-grain weight, and low for spikes m/sup -2/. (author)

  15. The estimation of time-varying risks in asset pricing modelling using B-Spline method

    Science.gov (United States)

    Nurjannah; Solimun; Rinaldo, Adji

    2017-12-01

    Asset pricing modelling has been extensively studied in the past few decades to explore the risk-return relationship. The asset pricing literature typically assumed a static risk-return relationship. However, several studies found few anomalies in the asset pricing modelling which captured the presence of the risk instability. The dynamic model is proposed to offer a better model. The main problem highlighted in the dynamic model literature is that the set of conditioning information is unobservable and therefore some assumptions have to be made. Hence, the estimation requires additional assumptions about the dynamics of risk. To overcome this problem, the nonparametric estimators can also be used as an alternative for estimating risk. The flexibility of the nonparametric setting avoids the problem of misspecification derived from selecting a functional form. This paper investigates the estimation of time-varying asset pricing model using B-Spline, as one of nonparametric approach. The advantages of spline method is its computational speed and simplicity, as well as the clarity of controlling curvature directly. The three popular asset pricing models will be investigated namely CAPM (Capital Asset Pricing Model), Fama-French 3-factors model and Carhart 4-factors model. The results suggest that the estimated risks are time-varying and not stable overtime which confirms the risk instability anomaly. The results is more pronounced in Carhart’s 4-factors model.

  16. Crossover effect of spouse weekly working hours on estimated 10-years risk of cardiovascular disease.

    Directory of Open Access Journals (Sweden)

    Mo-Yeol Kang

    Full Text Available To investigate the association between spouse weekly working hours (SWWH and the estimated 10-years risk of cardiovascular disease (CVD.This cross-sectional study was based on the data obtained from the Korean National Health and Nutrition Examination Survey 2007-2012. Data of 16,917 participants (8,330 husbands, 8,587 wives were used for this analysis. The participants' clinical data were collected to estimate the 10-years risk of CVD, as well as weekly working hours. Multiple logistic regression was conducted to investigate the association between SWWH and the estimated 10-years risk of CVD. We also performed a stratified analysis according to each participant's and their spouse's employment status.Compared to those whose spouses worked 30 hours per week, estimated 10-years risk of CVD was significantly higher as SWWH increase among those whose spouses worked >30 hours per week. After adjusting for covariates, the odds ratio for high CVD risk was found to increase as SWWH increased, up to 2.52 among husbands and 2.43 among wives. We also found that the association between SWWH and the estimated 10-years risk of CVD varied according to the employment status. Analysis of each component included in the CVD appraisal model showed that SWWH had close relationship with diabetes in men, and smoking habits in women.Spouse's long working hours are associated with individual's risk of CVD in future, especially among husbands.

  17. ESTIMATING RISK TO CALIFORNIA ENERGY INFRASTRUCTURE FROM PROJECTED CLIMATE CHANGE

    Energy Technology Data Exchange (ETDEWEB)

    Sathaye, Jayant; Dale, Larry; Larsen, Peter; Fitts, Gary; Koy, Kevin; Lewis, Sarah; Lucena, Andre

    2011-06-22

    This report outlines the results of a study of the impact of climate change on the energy infrastructure of California and the San Francisco Bay region, including impacts on power plant generation; transmission line and substation capacity during heat spells; wildfires near transmission lines; sea level encroachment upon power plants, substations, and natural gas facilities; and peak electrical demand. Some end-of-century impacts were projected:Expected warming will decrease gas-fired generator efficiency. The maximum statewide coincident loss is projected at 10.3 gigawatts (with current power plant infrastructure and population), an increase of 6.2 percent over current temperature-induced losses. By the end of the century, electricity demand for almost all summer days is expected to exceed the current ninetieth percentile per-capita peak load. As much as 21 percent growth is expected in ninetieth percentile peak demand (per-capita, exclusive of population growth). When generator losses are included in the demand, the ninetieth percentile peaks may increase up to 25 percent. As the climate warms, California's peak supply capacity will need to grow faster than the population.Substation capacity is projected to decrease an average of 2.7 percent. A 5C (9F) air temperature increase (the average increase predicted for hot days in August) will diminish the capacity of a fully-loaded transmission line by an average of 7.5 percent.The potential exposure of transmission lines to wildfire is expected to increase with time. We have identified some lines whose probability of exposure to fire are expected to increase by as much as 40 percent. Up to 25 coastal power plants and 86 substations are at risk of flooding (or partial flooding) due to sea level rise.

  18. An update on standards for radiation in the environment and associated estimates of risk

    International Nuclear Information System (INIS)

    Kocher, D.C.

    1989-01-01

    This presentation reviews current and proposed standards, recommendations, and guidances for limiting routine radiation exposures of the public, and estimates the risk corresponding to standards, recommendations, and guidances. These estimates provide a common basis for comparing different criteria for limiting public exposures to radiation, as well as hazardous chemicals

  19. REVIEW OF DRAFT REVISED BLUE BOOK ON ESTIMATING CANCER RISKS FROM EXPOSURE TO IONIZING RADIATION

    Science.gov (United States)

    In 1994, EPA published a report, referred to as the “Blue Book,” which lays out EPA’s current methodology for quantitatively estimating radiogenic cancer risks. A follow-on report made minor adjustments to the previous estimates and presented a partial analysis of the uncertainti...

  20. Effects of trust and governance on relational risk

    NARCIS (Netherlands)

    Nooteboom, B.; Berger, J.; Noorderhaven, N.G.

    In transaction cost economics, foist has been treated as redundant or even misleading. This study tested the effects of governance and trust the risk perceived by agents of firms in alliances. Two dimensions of relational risk were assessed: the probability that something will go wrong and the size

  1. Beyond the contract: managing risk in supply chain relations

    NARCIS (Netherlands)

    Dekker, H.C.; Sakaguchi, J.; Kawai, T.

    2013-01-01

    As a consequence of the development of intensified relations with suppliers, for many firms the supply chain has become a significant source of risk exposure. In this paper we examine firms' use of control practices to manage risks associated with intensified collaboration with supply chain

  2. Estimating adolescent risk for hearing loss based on data from a large school-based survey.

    Science.gov (United States)

    Vogel, Ineke; Verschuure, Hans; van der Ploeg, Catharina P B; Brug, Johannes; Raat, Hein

    2010-06-01

    We estimated whether and to what extent a group of adolescents were at risk of developing permanent hearing loss as a result of voluntary exposure to high-volume music, and we assessed whether such exposure was associated with hearing-related symptoms. In 2007, 1512 adolescents (aged 12-19 years) in Dutch secondary schools completed questionnaires about their music-listening behavior and whether they experienced hearing-related symptoms after listening to high-volume music. We used their self-reported data in conjunction with published average sound levels of music players, discotheques, and pop concerts to estimate their noise exposure, and we compared that exposure to our own "loosened" (i.e., less strict) version of current European safety standards for occupational noise exposure. About half of the adolescents exceeded safety standards for occupational noise exposure. About one third of the respondents exceeded safety standards solely as a result of listening to MP3 players. Hearing symptoms that occurred after using an MP3 player or going to a discotheque were associated with exposure to high-volume music. Adolescents often exceeded current occupational safety standards for noise exposure, highlighting the need for specific safety standards for leisure-time noise exposure.

  3. Topics on the problem of genetic risk estimates health research foundation

    International Nuclear Information System (INIS)

    Nakai, Sayaka

    1995-01-01

    Reanalysis of the data on untoward pregnancy outcome (UPO) for atomic bomb survivors was undertaken based on following current results of cytogenetic studies obtained in Japan: 1) Human gametes were very sensitive to the production of chromosome aberrations either spontaneous or radiation induced origin. 2) The shape of dose-response relations against to radiations showed humped curve at relatively low dose-range below 3Gy. 3) Existence of very severe selection to the embryo having chromosome aberrations represented during fetus development before the birth. It was concluded that 1) Humped dose-response model was more fitted than the linear dose model. 2) Regression coefficient for the slope of UPO at low doses derived from humped dose model was about 6 times more higher than the previous value based on linear model. 3) Risk factor for genetic detriment in term of UPO was estimated as 0.015/Gy under the condition exposed radiation below 1Gy. 4) It was difficult to find out positive evidence supporting the view which is given by Neel et al. that present estimates of doubling dose based on mouse data thought to be underestimated figure. (author)

  4. Psychological impact of providing women with personalised 10-year breast cancer risk estimates.

    Science.gov (United States)

    French, David P; Southworth, Jake; Howell, Anthony; Harvie, Michelle; Stavrinos, Paula; Watterson, Donna; Sampson, Sarah; Evans, D Gareth; Donnelly, Louise S

    2018-05-08

    The Predicting Risk of Cancer at Screening (PROCAS) study estimated 10-year breast cancer risk for 53,596 women attending NHS Breast Screening Programme. The present study, nested within the PROCAS study, aimed to assess the psychological impact of receiving breast cancer risk estimates, based on: (a) the Tyrer-Cuzick (T-C) algorithm including breast density or (b) T-C including breast density plus single-nucleotide polymorphisms (SNPs), versus (c) comparison women awaiting results. A sample of 2138 women from the PROCAS study was stratified by testing groups: T-C only, T-C(+SNPs) and comparison women; and by 10-year risk estimates received: 'moderate' (5-7.99%), 'average' (2-4.99%) or 'below average' (<1.99%) risk. Postal questionnaires were returned by 765 (36%) women. Overall state anxiety and cancer worry were low, and similar for women in T-C only and T-C(+SNPs) groups. Women in both T-C only and T-C(+SNPs) groups showed lower-state anxiety but slightly higher cancer worry than comparison women awaiting results. Risk information had no consistent effects on intentions to change behaviour. Most women were satisfied with information provided. There was considerable variation in understanding. No major harms of providing women with 10-year breast cancer risk estimates were detected. Research to establish the feasibility of risk-stratified breast screening is warranted.

  5. Cancer risks in BRCA2 families: estimates for sites other than breast and ovary

    NARCIS (Netherlands)

    van Asperen, C. J.; Brohet, R. M.; Meijers-Heijboer, E. J.; Hoogerbrugge, N.; Verhoef, S.; Vasen, H. F. A.; Ausems, M. G. E. M.; Menko, F. H.; Gomez Garcia, E. B.; Klijn, J. G. M.; Hogervorst, F. B. L.; van Houwelingen, J. C.; van't Veer, L. J.; Rookus, M. A.; van Leeuwen, F. E.

    2005-01-01

    In BRCA2 mutation carriers, increased risks have been reported for several cancer sites besides breast and ovary. As most of the families included in earlier reports were selected on the basis of multiple breast/ovarian cancer cases, it is possible that risk estimates may differ in mutation carriers

  6. Stroke risk estimation across nine European countries in the MORGAM project

    DEFF Research Database (Denmark)

    Borglykke, Anders; Andreasen, Anne H; Kuulasmaa, Kari

    2010-01-01

    Previous tools for stroke risk assessment have either been developed for specific populations or lack data on non-fatal events or uniform data collection. The purpose of this study was to develop a stepwise model for the estimation of 10 year risk of stroke in nine different countries across Europe....

  7. Insulin sensitivity and mortality risk estimation in patients with type 2 ...

    African Journals Online (AJOL)

    Background: There is at present the dearth of information on the possible contribution of insulin resistance to scores obtained from mortality risk estimation in patients with type 2 diabetes mellitus (T2DM). Aim: This study determined the mortality risk scores in patients with T2DM and its relationship with insulin resistance.

  8. Risk of abdominal aortic aneurysm (AAA) among male and female relatives of AAA patients.

    Science.gov (United States)

    van de Luijtgaarden, Koen M; Rouwet, Ellen V; Hoeks, Sanne E; Stolker, Robert J; Verhagen, Hence Jm; Majoor-Krakauer, Danielle

    2017-04-01

    Sex affects the presentation, treatment, and outcomes of abdominal aortic aneurysm (AAA). Although AAAs are less prevalent in women, at least in the general population, women with an AAA have a poorer prognosis in comparison to men. Sex differences in the genetic predisposition for aneurysm disease remain to be established. In this study we investigated the familial risk of AAA for women compared to men. All living AAA patients included in a 2004-2012 prospective database were invited to the multidisciplinary vascular/genetics outpatient clinic between 2009 and 2012 for assessment of family history using detailed questionnaires. AAA risk for male and female relatives was calculated separately and stratified by sex of the AAA patients. Families of 568 AAA patients were investigated and 22.5% of the patients had at least one affected relative. Female relatives had a 2.8-fold and male relatives had a 1.7-fold higher risk than the estimated sex-specific population risk. Relatives of female AAA patients had a higher aneurysm risk than relatives of male patients (9.0 vs 5.9%, p = 0.022), corresponding to 5.5- and 2.0-fold increases in aneurysm risk in the female and male relatives, respectively. The risk for aortic aneurysm in relatives of AAA patients is higher than expected from population risk. The excess risk is highest for the female relatives of AAA patients and for the relatives of female AAA patients. These findings endorse targeted AAA family screening for female and male relatives of all AAA patients.

  9. Relative estimation of the mineral ages using uranium migration

    International Nuclear Information System (INIS)

    Danis, A.

    1990-01-01

    Using the uranium fission track micro mapping technique the correlation between the age and uranium migration from inclusions was studied. It is shown that during geological time, as function of the mineral, its age and its uranium migration speed, the pattern of the track, clusters corresponding to the uranium inclusions got a typical feature. Thus for a bulk polished geological sample it is possible to establish an age succession of the constituent minerals as a function of the track cluster patterns. Also, it is shown that knowing the migration speed of the uranium in a mineral it is possible to estimate the age of this mineral by measuring the migration distance on the micro mapping. (Author)

  10. 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

  11. Excess relative risk of solid cancer mortality after prolonged exposure to naturally occurring high background radiation in Yangjiang, China

    Energy Technology Data Exchange (ETDEWEB)

    Sun Quanfu; Tao Zufan [Ministry of Health, Beijing (China). Lab. of Industrial Hygiene; Akiba, Suminori (and others)

    2000-10-01

    A study was made on cancer mortality in the high-background radiation areas of Yangjiang, China. Based on hamlet-specific environmental doses and sex- and age-specific occupancy factors, cumulative doses were calculated for each subject. In this article, we describe how the indirect estimation was made on individual dose and the methodology used to estimate radiation risk. Then, assuming a linear dose response relationship and using cancer mortality data for the period 1979-1995, we estimate the excess relative risk per Sievert for solid cancer to be -0.11 (95% CI, -0.67, 0.69). Also, we estimate the excess relative risks of four leading cancers in the study areas, i.e., cancers of the liver, nasopharynx, lung and stomach. In addition, we evaluate the effects of possible bias on our risk estimation. (author)

  12. Improved Radiation Dosimetry/Risk Estimates to Facilitate Environmental Management of Plutonium-Contaminated Sites

    Energy Technology Data Exchange (ETDEWEB)

    Scott, Bobby R.; Tokarskaya, Zoya B.; Zhuntova, Galina V.; Osovets, Sergey V.; Syrchikov, Victor A., Belyaeva, Zinaida D.

    2007-12-14

    This report summarizes 4 years of research achievements in this Office of Science (BER), U.S. Department of Energy (DOE) project. The research described was conducted by scientists and supporting staff at Lovelace Respiratory Research Institute (LRRI)/Lovelace Biomedical and Environmental Research Institute (LBERI) and the Southern Urals Biophysics Institute (SUBI). All project objectives and goals were achieved. A major focus was on obtaining improved cancer risk estimates for exposure via inhalation to plutonium (Pu) isotopes in the workplace (DOE radiation workers) and environment (public exposures to Pu-contaminated soil). A major finding was that low doses and dose rates of gamma rays can significantly suppress cancer induction by alpha radiation from inhaled Pu isotopes. The suppression relates to stimulation of the body's natural defenses, including immunity against cancer cells and selective apoptosis which removes precancerous and other aberrant cells.

  13. Improved Radiation Dosimetry/Risk Estimates to Facilitate Environmental Management of Plutonium-Contaminated Sites

    International Nuclear Information System (INIS)

    Scott, Bobby R.; Tokarskaya, Zoya B.; Zhuntova, Galina V.; Osovets, Sergey V.; Syrchikov, Victor A.; Belyaeva, Zinaida D.

    2007-01-01

    This report summarizes 4 years of research achievements in this Office of Science (BER), U.S. Department of Energy (DOE) project. The research described was conducted by scientists and supporting staff at Lovelace Respiratory Research Institute (LRRI)/Lovelace Biomedical and Environmental Research Institute (LBERI) and the Southern Urals Biophysics Institute (SUBI). All project objectives and goals were achieved. A major focus was on obtaining improved cancer risk estimates for exposure via inhalation to plutonium (Pu) isotopes in the workplace (DOE radiation workers) and environment (public exposures to Pu-contaminated soil). A major finding was that low doses and dose rates of gamma rays can significantly suppress cancer induction by alpha radiation from inhaled Pu isotopes. The suppression relates to stimulation of the body's natural defenses, including immunity against cancer cells and selective apoptosis which removes precancerous and other aberrant cells

  14. Value-at-Risk analysis using ARMAX GARCHX approach for estimating risk of banking subsector stock return’s

    Science.gov (United States)

    Dewi Ratih, Iis; Sutijo Supri Ulama, Brodjol; Prastuti, Mike

    2018-03-01

    Value at Risk (VaR) is one of the statistical methods used to measure market risk by estimating the worst losses in a given time period and level of confidence. The accuracy of this measuring tool is very important in determining the amount of capital that must be provided by the company to cope with possible losses. Because there is a greater losses to be faced with a certain degree of probability by the greater risk. Based on this, VaR calculation analysis is of particular concern to researchers and practitioners of the stock market to be developed, thus getting more accurate measurement estimates. In this research, risk analysis of stocks in four banking sub-sector, Bank Rakyat Indonesia, Bank Mandiri, Bank Central Asia and Bank Negara Indonesia will be done. Stock returns are expected to be influenced by exogenous variables, namely ICI and exchange rate. Therefore, in this research, stock risk estimation are done by using VaR ARMAX-GARCHX method. Calculating the VaR value with the ARMAX-GARCHX approach using window 500 gives more accurate results. Overall, Bank Central Asia is the only bank had the estimated maximum loss in the 5% quantile.

  15. Recent estimates of the risk of childhood cancer following irradiation of the fetus

    International Nuclear Information System (INIS)

    Gilman, E.A.; Kneale, G.W.; Knox, E.G.; Stewart, A.M.

    1989-01-01

    For children born during the period 1939-1979 the authors estimate that 7% of childhood cancers were caused by prenatal X-ray (Knox et al., 1987). The decline in relative risk from the high values of the 1940s to the lower values seen in the late 1960s is probably due to improvements in X-ray techniques and equipment, together with a decline in the number of films used per examination, which resulted in a reduction in dose per examination from a mean of 9 mGy to 3 mGy in 1960. The reason for apparent increase in relative risk in recent years is not clear. The finding that the dose response from terrestrial gamma radiation was three times as great as for prenatal X-ray may be due to exposures from TGR being received throughout pregnancy, including the more sensitive first trimester,. It is also likely that the outdoor TGR measurements used in the analysis are correlated with, and act as an indicator of, level of exposure due to other sources of natural radiation (e.g. indoor gamma and radon). The discrepancy between the findings from the atomic bomb survivors irradiated in utero and those of case/control studies of childhood cancer is discussed. (author)

  16. Risk related behaviour under different ambient scent conditions

    OpenAIRE

    Alina Gagarina; Indre Pikturniene

    2016-01-01

    The article analyses the effect of two ambient scents (peppermint and vanilla) and their intensiveness on risk related behaviour that is expressed through selected decision making heuristics. Purpose of the article: The purpose of this article is to identify the relationship of ambient scent type and intensiveness with risk related behaviour that is expressed through selected decision making heuristics. Methodology/methods: 2×2 factorial experiment with control group was run. Ambi...

  17. Assessing the risk of Legionnaires' disease: the inhalation exposure model and the estimated risk in residential bathrooms.

    Science.gov (United States)

    Azuma, Kenichi; Uchiyama, Iwao; Okumura, Jiro

    2013-02-01

    Legionella are widely found in the built environment. Patients with Legionnaires' disease have been increasing in Japan; however, health risks from Legionella bacteria in the environment are not appropriately assessed. We performed a quantitative health risk assessment modeled on residential bathrooms in the Adachi outbreak area and estimated risk levels. The estimated risks in the Adachi outbreak approximately corresponded to the risk levels exponentially extrapolated into lower levels on the basis of infection and mortality rates calculated from actual outbreaks, suggesting that the model of Legionnaires' disease in residential bathrooms was adequate to predict disease risk for the evaluated outbreaks. Based on this model, the infection and mortality risk levels per year in 10 CFU/100 ml (100 CFU/L) of the Japanese water quality guideline value were approximately 10(-2) and 10(-5), respectively. However, acceptable risk levels of infection and mortality from Legionnaires' disease should be adjusted to approximately 10(-4) and 10(-7), respectively, per year. Therefore, a reference value of 0.1 CFU/100 ml (1 CFU/L) as a water quality guideline for Legionella bacteria is recommended. This value is occasionally less than the actual detection limit. Legionella levels in water system should be maintained as low as reasonably achievable (<1 CFU/L). Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Analytical Estimation of Water-Oil Relative Permeabilities through Fractures

    Directory of Open Access Journals (Sweden)

    Saboorian-Jooybari Hadi

    2016-05-01

    Full Text Available Modeling multiphase flow through fractures is a key issue for understanding flow mechanism and performance prediction of fractured petroleum reservoirs, geothermal reservoirs, underground aquifers and carbon-dioxide sequestration. One of the most challenging subjects in modeling of fractured petroleum reservoirs is quantifying fluids competition for flow in fracture network (relative permeability curves. Unfortunately, there is no standard technique for experimental measurement of relative permeabilities through fractures and the existing methods are very expensive, time consuming and erroneous. Although, several formulations were presented to calculate fracture relative permeability curves in the form of linear and power functions of flowing fluids saturation, it is still unclear what form of relative permeability curves must be used for proper modeling of flow through fractures and consequently accurate reservoir simulation. Basically, the classic linear relative permeability (X-type curves are used in almost all of reservoir simulators. In this work, basic fluid flow equations are combined to develop a new simple analytical model for water-oil two phase flow in a single fracture. The model gives rise to simple analytic formulations for fracture relative permeabilities. The model explicitly proves that water-oil relative permeabilities in fracture network are functions of fluids saturation, viscosity ratio, fluids density, inclination of fracture plane from horizon, pressure gradient along fracture and rock matrix wettability, however they were considered to be only functions of saturations in the classic X-type and power (Corey [35] and Honarpour et al. [28, 29] models. Eventually, validity of the proposed formulations is checked against literature experimental data. The proposed fracture relative permeability functions have several advantages over the existing ones. Firstly, they are explicit functions of the parameters which are known for

  19. The Boehringer Ingelheim employee study (Part 2): 10-year cardiovascular diseases risk estimation.

    Science.gov (United States)

    Kempf, K; Martin, S; Döhring, C; Dugi, K; Haastert, B; Schneider, M

    2016-10-01

    Cardiovascular disease (CVD) may cause an economic burden to companies, but CVD risk estimations specific to working populations are lacking. To estimate the 10-year CVD risk in the Boehringer Ingelheim (BI) employee cohort and analyse the potential effect of hypothetical risk reduction interventions. We estimated CVD risk using the Framingham (FRS), PROCAM (PRS) and Reynolds (RRS) risk scores, using cross-sectional baseline data on BI Pharma employees collected from 2005 to 2011. Results were compared using Fisher's exact and Wilcoxon tests. The predictive ability of the score estimates was assessed using receiver-operating characteristics analyses. Among the 4005 study subjects, we estimated 10-year CVD risks of 35% (FRS), 9% (PRS) and 6% (RRS) for men and 10% (FRS), 4% (PRS) and 1% (RRS) for women. One hundred and thirty-four (6%) men and 111 (6%) women employees had current CVD. The best predictors of prevalent CVD were the FRS and the RRS for men [area-under-the-curve 0.62 (0.57-0.67) for both]. A hypothetical intervention that would improve systolic blood pressure, HbA1c (for diabetes), C-reactive protein, triglycerides and total and high-density lipoprotein cholesterol by 10% each would potentially reduce expected CVD cases by 36-41% in men and 30-45% in women, and if smoking cessation is incorporated, by 39-45% and 30-55%, respectively, depending on the pre-intervention risk score. There was a substantial risk of developing CVD in this working cohort. Occupational health programmes with lifestyle interventions for high-risk individuals may be an effective risk reduction measure. © The Author 2016. Published by Oxford University Press on behalf of the Society of Occupational Medicine. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  20. Improved Radiation Dosimetry/Risk Estimates to Facilitate Environmental Management Of Plutonium Contaminated Sites

    International Nuclear Information System (INIS)

    Scott, B.R.

    2001-01-01

    Currently available radiation dosimetry/health-risk models for inhalation exposure to radionuclides are based on deterministic radiation intake and deterministic radiation doses (local and global). These models are not adequate for brief plutonium (Pu) exposure scenarios related to Department of Energy (DOE) decontamination/decommissioning (D and D) operations because such exposures involve the stochastic-intake (StI) paradigm. For this paradigm, small or moderate numbers of airborne, pure, highly radioactive PuO2 particles could be inhaled and deposited in the respiratory tract in unpredictable numbers (stochastic) during D and D incidents. Probabilistic relationships govern intake via the respiratory tract for the StI paradigm. An StIparadigm incident occurred on March 16, 2000, at Los Alamos National Laboratory. It involved eight workers who inhaled high-specific-activity, alpha-emitting (HSA-aE) 238PuO2-contaminated room air (glovebox-failure incident). Health-risk estimation is not trivial for the StI-exposure paradigm, especially for HSA-aE 238PuO2, as different individuals can have very different and uncertain radioactivity intakes for the same exposure duration and same incident. Indeed, this occurred in the Los Alamos incident. Rather than inappropriate point estimates of intake, dose, and risk, more appropriate probability distributions are needed. A main objective of this project has been to develop a stochastic dosimetry/risk computer model for evaluating radioactivity intake (by inhalation) distributions, organ dose distributions, and health risk distributions for DOE workers who may inhale airborne, alpha-emitting, pure PuO2 at DOE sites such as Rocky Flats. Another objective of this project has been to address the deterministic intake (DI) paradigm where members of the public could inhale, over years, millions and more resuspended, air-transported, PuO2-contaminated dust particles while residing (e.g., farmer) or working (e.g., office worker) at a

  1. Improving the estimation of celiac disease sibling risk by non-HLA genes.

    Directory of Open Access Journals (Sweden)

    Valentina Izzo

    Full Text Available Celiac Disease (CD is a polygenic trait, and HLA genes explain less than half of the genetic variation. Through large GWAs more than 40 associated non-HLA genes were identified, but they give a small contribution to the heritability of the disease. The aim of this study is to improve the estimate of the CD risk in siblings, by adding to HLA a small set of non-HLA genes. One-hundred fifty-seven Italian families with a confirmed CD case and at least one other sib and both parents were recruited. Among 249 sibs, 29 developed CD in a 6 year follow-up period. All individuals were typed for HLA and 10 SNPs in non-HLA genes: CCR1/CCR3 (rs6441961, IL12A/SCHIP1 and IL12A (rs17810546 and rs9811792, TAGAP (rs1738074, RGS1 (rs2816316, LPP (rs1464510, OLIG3 (rs2327832, REL (rs842647, IL2/IL21 (rs6822844, SH2B3 (rs3184504. Three associated SNPs (in LPP, REL, and RGS1 genes were identified through the Transmission Disequilibrium Test and a Bayesian approach was used to assign a score (BS to each detected HLA+SNPs genotype combination. We then classified CD sibs as at low or at high risk if their BS was respectively < or ≥ median BS value within each HLA risk group. A larger number (72% of CD sibs showed a BS ≥ the median value and had a more than two fold higher OR than CD sibs with a BS value < the median (O.R = 2.53, p = 0.047. Our HLA+SNPs genotype classification, showed both a higher predictive negative value (95% vs 91% and diagnostic sensitivity (79% vs 45% than the HLA only. In conclusion, the estimate of the CD risk by HLA+SNPs approach, even if not applicable to prevention, could be a precious tool to improve the prediction of the disease in a cohort of first degree relatives, particularly in the low HLA risk groups.

  2. Space Radiation Heart Disease Risk Estimates for Lunar and Mars Missions

    Science.gov (United States)

    Cucinotta, Francis A.; Chappell, Lori; Kim, Myung-Hee

    2010-01-01

    The NASA Space Radiation Program performs research on the risks of late effects from space radiation for cancer, neurological disorders, cataracts, and heart disease. For mortality risks, an aggregate over all risks should be considered as well as projection of the life loss per radiation induced death. We report on a triple detriment life-table approach to combine cancer and heart disease risks. Epidemiology results show extensive heterogeneity between populations for distinct components of the overall heart disease risks including hypertension, ischaemic heart disease, stroke, and cerebrovascular diseases. We report on an update to our previous heart disease estimates for Heart disease (ICD9 390-429) and Stroke (ICD9 430-438), and other sub-groups using recent meta-analysis results for various exposed radiation cohorts to low LET radiation. Results for multiplicative and additive risk transfer models are considered using baseline rates for US males and female. Uncertainty analysis indicated heart mortality risks as low as zero, assuming a threshold dose for deterministic effects, and projections approaching one-third of the overall cancer risk. Medan life-loss per death estimates were significantly less than that of solid cancer and leukemias. Critical research questions to improve risks estimates for heart disease are distinctions in mechanisms at high doses (>2 Gy) and low to moderate doses (<2 Gy), and data and basic understanding of radiation doserate and quality effects, and individual sensitivity.

  3. Climate risk assessment in museums : degradation risks determined from temperature and relative humidity data

    NARCIS (Netherlands)

    Martens, M.H.J.

    2012-01-01

    The main subject of this thesis is the determination of climate risks to objects in museums on the basis of measured and/or simulated temperature and relative humidity data. The focus is on the quantification of climate related risks for the preservation quality of indoor climate in Dutch museums.

  4. A risk adjustment approach to estimating the burden of skin disease in the United States.

    Science.gov (United States)

    Lim, Henry W; Collins, Scott A B; Resneck, Jack S; Bolognia, Jean; Hodge, Julie A; Rohrer, Thomas A; Van Beek, Marta J; Margolis, David J; Sober, Arthur J; Weinstock, Martin A; Nerenz, David R; Begolka, Wendy Smith; Moyano, Jose V

    2018-01-01

    Direct insurance claims tabulation and risk adjustment statistical methods can be used to estimate health care costs associated with various diseases. In this third manuscript derived from the new national Burden of Skin Disease Report from the American Academy of Dermatology, a risk adjustment method that was based on modeling the average annual costs of individuals with or without specific diseases, and specifically tailored for 24 skin disease categories, was used to estimate the economic burden of skin disease. The results were compared with the claims tabulation method used in the first 2 parts of this project. The risk adjustment method estimated the direct health care costs of skin diseases to be $46 billion in 2013, approximately $15 billion less than estimates using claims tabulation. For individual skin diseases, the risk adjustment cost estimates ranged from 11% to 297% of those obtained using claims tabulation for the 10 most costly skin disease categories. Although either method may be used for purposes of estimating the costs of skin disease, the choice of method will affect the end result. These findings serve as an important reference for future discussions about the method chosen in health care payment models to estimate both the cost of skin disease and the potential cost impact of care changes. Copyright © 2017 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  5. The use of chemical and radionuclide risk estimates in site performance evaluation of mixed waste sites

    International Nuclear Information System (INIS)

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

    1988-01-01

    Many radioactive waste sites contain not only radioactive material but also varying amounts of chemical waste. The use of such procedures implies some risk at any exposure level, and thus requires that an exposure level be determined that corresponds to an acceptable risk to an individual or a population. Although the uncertainties and limitations of these methods are of concern, the assumption has been generally adopted that the human dose response for all carcinogens is linear, with no threshold occurring at low levels of exposure. With the move toward decontamination programs and clean-up of various mixed waste sites throughout the US, there is interest in the possibility that risk estimates calculated individually for radionuclides and for chemicals may be combined to reflect the total risk for each site. The purpose of this paper is to examine the feasibility of combining risk estimates during risk/benefit analyses. For a variety of reasons, the state of radiation risk assessment is more advanced than that of chemical risk assessment. The reasons for this disparity are summarized in this paper. Quantitative radiation risk assessment is currently being performed, but involves a high degree of uncertainty. Chemical risk assessment in general does not allow quantitative results bracketed by uncertainty analysis. Therefore, it is concluded that it is currently not possible to develop a useful, quantitative combined risk assessment for a mixed waste site, but that it may be possible to develop such a capability in the future

  6. Quantitative Risk reduction estimation Tool For Control Systems, Suggested Approach and Research Needs

    Energy Technology Data Exchange (ETDEWEB)

    Miles McQueen; Wayne Boyer; Mark Flynn; Sam Alessi

    2006-03-01

    For the past year we have applied a variety of risk assessment technologies to evaluate the risk to critical infrastructure from cyber attacks on control systems. More recently, we identified the need for a stand alone control system risk reduction estimation tool to provide owners and operators of control systems with a more useable, reliable, and credible method for managing the risks from cyber attack. Risk is defined as the probability of a successful attack times the value of the resulting loss, typically measured in lives and dollars. Qualitative and ad hoc techniques for measuring risk do not provide sufficient support for cost benefit analyses associated with cyber security mitigation actions. To address the need for better quantitative risk reduction models we surveyed previous quantitative risk assessment research; evaluated currently available tools; developed new quantitative techniques [17] [18]; implemented a prototype analysis tool to demonstrate how such a tool might be used; used the prototype to test a variety of underlying risk calculational engines (e.g. attack tree, attack graph); and identified technical and research needs. We concluded that significant gaps still exist and difficult research problems remain for quantitatively assessing the risk to control system components and networks, but that a useable quantitative risk reduction estimation tool is not beyond reach.

  7. The impact of advances in human molecular biology on radiation genetic risk estimation in man

    International Nuclear Information System (INIS)

    Sankaranarayanan, K.

    1996-01-01

    This paper provides an overview of the conceptual framework, the data base, methods and assumptions used thus far to assess the genetic risks of exposure of human populations to ionising radiation. These are then re-examined in the contemporary context of the rapidly expanding knowledge of the molecular biology of human mendelian diseases. This re-examination reveals that (i) many of the assumptions used thus far in radiation genetic risk estimation may not be fully valid and (ii) the current genetic risk estimates are probably conservative, but provide an adequate margin of safety for radiological protection. The view is expressed that further advances in the field of genetic risk estimation will be largely driven by advances in the molecular biology of human genetic diseases. (author). 37 refs., 5 tabs

  8. Waterborne disease-related risk perceptions in the Sonora River basin, Mexico.

    Science.gov (United States)

    Morua, Agustin Robles; Halvorsen, Kathleen E; Mayer, Alex S

    2011-05-01

    Waterborne disease is estimated to cause about 10% of all diseases worldwide. However, related risk perceptions are not well understood, particularly in the developing world where waterborne disease is an enormous problem. We focus on understanding risk perceptions related to these issues in a region within northern Mexico. Our findings show how waterborne disease problems and solutions are understood in eight small communities along a highly contaminated river system. We found major differences in risk perceptions between health professionals, government officials, and lay citizens. Health professionals believed that a high level of human-waste-related risk existed within the region. Few officials and lay citizens shared this belief. In addition, few officials and lay citizens were aware of poor wastewater-management-related disease outbreaks and water contamination. Finally, aside from health professionals, a few interviewees understood the importance of basic hygiene and water treatment measures that could help to prevent disease. Our results add to the literature on environmentally-related risk perceptions in the developing world. We discuss recommendations for improving future human-wastewater-related risk communication within the region. © 2011 Society for Risk Analysis.

  9. Risk communication related to animal products derived from biotechnology.

    Science.gov (United States)

    McCrea, D

    2005-04-01

    Previous chapters of this review have dealt with the key considerations related to the application of biotechnology in veterinary science and animal production. This article explores the theory and practice of risk communication and sets out the basic principles for good risk communication when dealing with new technologies, uncertainty, and cautious and sceptical consumers. After failure to communicate with consumers and stakeholders about the risk to human health from bovine spongiform encephalopathy (BSE) in the 1990s, Government Agencies in the United Kingdom have made significant improvements in risk communication. The official inquiry that followed the BSE crisis concluded that a policy of openness was the correct approach, and this article emphasises the importance of consultation, consistency and transparency. There are, however, many different factors that affect public perception of risk (religious, political, social, cultural, etc.) and developing effective risk communication strategies must take all of these complex issues into consideration.

  10. Occupational and consumer risk estimates for nanoparticles emitted by laser printers

    International Nuclear Information System (INIS)

    Haenninen, Otto; Brueske-Hohlfeld, Irene; Loh, Miranda; Stoeger, Tobias; Kreyling, Wolfgang; Schmid, Otmar; Peters, Annette

    2010-01-01

    Several studies have reported laser printers as significant sources of nanosized particles ( -1 ; particle number 1.1-3.1 x 10 9 d -1 ) were estimated to correspond to 4-13 (mass) or 12-34 (number) deaths per million persons exposed on the basis of epidemiological risk estimates for ambient particles. These risks are higher than the generally used definition of acceptable risk of 1 x 10 -6 , but substantially lower than the estimated risks due to ambient particles. Toxicological studies on ambient particles revealed consistent values for lowest observed effect levels (LOELs) which were converted into equivalent daily uptakes using allometric scaling. These LOEL uptakes were by a factor of about 330-1,000 (mass) and 1,000-2,500 (particle surface area) higher than estimated uptakes from printers. This toxicological assessment would indicate no significant health risks due to printer particles. Finally, our study suggests that particle number (not mass) and mass (not surface area) are the most conservative risk metrics for the epidemiological and toxicological risks presented here, respectively.

  11. Effects of risk estimation tendency on risk perception at the Tohoku Disaster

    International Nuclear Information System (INIS)

    Nakagawa, Yuri; Tsuchida, Shoji; Tsujikawa, Norifumi; Shiotani, Takamasa

    2012-01-01

    The Tohoku Disaster showed the underlying risks of earthquake, tsunami, nuclear power plant accidents and debris removal. The ability to understand the risk and act appropriately has been widely discussed among the professionals as well within the community. In Oct 2011, an Online survey. Using the correspondence analysis approach, the data collected the free-answer question 'What do you remember most regarding news on the Tohoku Disaster' was analyzed. The relationship between the cognitive trade-off factors, zero-risk factors and elaboration tendency factors, and risk perception among the people following the Tohoku Disaster were discussed. (author)

  12. Urban-hazard risk analysis: mapping of heat-related risks in the elderly in major Italian cities.

    Directory of Open Access Journals (Sweden)

    Marco Morabito

    Full Text Available Short-term impacts of high temperatures on the elderly are well known. Even though Italy has the highest proportion of elderly citizens in Europe, there is a lack of information on spatial heat-related elderly risks.Development of high-resolution, heat-related urban risk maps regarding the elderly population (≥ 65.A long time-series (2001-2013 of remote sensing MODIS data, averaged over the summer period for eleven major Italian cities, were downscaled to obtain high spatial resolution (100 m daytime and night-time land surface temperatures (LST. LST was estimated pixel-wise by applying two statistical model approaches: 1 the Linear Regression Model (LRM; 2 the Generalized Additive Model (GAM. Total and elderly population density data were extracted from the Joint Research Centre population grid (100 m from the 2001 census (Eurostat source, and processed together using "Crichton's Risk Triangle" hazard-risk methodology for obtaining a Heat-related Elderly Risk Index (HERI.The GAM procedure allowed for improved daytime and night-time LST estimations compared to the LRM approach. High-resolution maps of daytime and night-time HERI levels were developed for inland and coastal cities. Urban areas with the hazardous HERI level (very high risk were not necessarily characterized by the highest temperatures. The hazardous HERI level was generally localized to encompass the city-centre in inland cities and the inner area in coastal cities. The two most dangerous HERI levels were greater in the coastal rather than inland cities.This study shows the great potential of combining geospatial technologies and spatial demographic characteristics within a simple and flexible framework in order to provide high-resolution urban mapping of daytime and night-time HERI. In this way, potential areas for intervention are immediately identified with up-to-street level details. This information could support public health operators and facilitate coordination for heat-related

  13. Urban-hazard risk analysis: mapping of heat-related risks in the elderly in major Italian cities.

    Science.gov (United States)

    Morabito, Marco; Crisci, Alfonso; Gioli, Beniamino; Gualtieri, Giovanni; Toscano, Piero; Di Stefano, Valentina; Orlandini, Simone; Gensini, Gian Franco

    2015-01-01

    Short-term impacts of high temperatures on the elderly are well known. Even though Italy has the highest proportion of elderly citizens in Europe, there is a lack of information on spatial heat-related elderly risks. Development of high-resolution, heat-related urban risk maps regarding the elderly population (≥ 65). A long time-series (2001-2013) of remote sensing MODIS data, averaged over the summer period for eleven major Italian cities, were downscaled to obtain high spatial resolution (100 m) daytime and night-time land surface temperatures (LST). LST was estimated pixel-wise by applying two statistical model approaches: 1) the Linear Regression Model (LRM); 2) the Generalized Additive Model (GAM). Total and elderly population density data were extracted from the Joint Research Centre population grid (100 m) from the 2001 census (Eurostat source), and processed together using "Crichton's Risk Triangle" hazard-risk methodology for obtaining a Heat-related Elderly Risk Index (HERI). The GAM procedure allowed for improved daytime and night-time LST estimations compared to the LRM approach. High-resolution maps of daytime and night-time HERI levels were developed for inland and coastal cities. Urban areas with the hazardous HERI level (very high risk) were not necessarily characterized by the highest temperatures. The hazardous HERI level was generally localized to encompass the city-centre in inland cities and the inner area in coastal cities. The two most dangerous HERI levels were greater in the coastal rather than inland cities. This study shows the great potential of combining geospatial technologies and spatial demographic characteristics within a simple and flexible framework in order to provide high-resolution urban mapping of daytime and night-time HERI. In this way, potential areas for intervention are immediately identified with up-to-street level details. This information could support public health operators and facilitate coordination for heat-related

  14. Association between subjective risk perception and objective risk estimation in patients with atrial fibrillation: a cross-sectional study.

    Science.gov (United States)

    Zweiker, David; Zweiker, Robert; Winkler, Elisabeth; Roesch, Konstantina; Schumacher, Martin; Stepan, Vinzenz; Krippl, Peter; Bauer, Norbert; Heine, Martin; Reicht, Gerhard; Zweiker, Gudrun; Sprenger, Martin; Watzinger, Norbert

    2017-09-25

    Oral anticoagulation (OAC) is state-of-the-art therapy for atrial fibrillation (AF), the most common arrhythmia worldwide. However, little is known about the perception of patients with AF and how it correlates with risk scores used by their physicians. Therefore, we correlated patients' estimates of their own stroke and bleeding risk with the objectively predicted individual risk using CHA 2 DS 2 -VASc and HAS-BLED scores. Cross-sectional prevalence study using convenience sampling and telephone follow-up. Eight hospital departments and one general practitioner in Austria. Patients' perception of stroke and bleeding risk was opposed to commonly used risk scoring. Patients with newly diagnosed AF and indication for anticoagulation. Comparison of subjective risk perception with CHA 2 DS 2 -VASc and HAS-BLED scores showing possible discrepancies between subjective and objective risk estimation. Patients' judgement of their own knowledge on AF and education were also correlated with accuracy of subjective risk appraisal. Ninety-one patients (age 73±11 years, 45% female) were included in this study. Subjective stroke and bleeding risk estimation did not correlate with risk scores (ρ=0.08 and ρ=0.17). The majority of patients (57%) underestimated the individual stroke risk. Patients feared stroke more than bleeding (67% vs 10%). There was no relationship between accurate perception of stroke and bleeding risks and education level. However, we found a correlation between the patients' judgement of their own knowledge of AF and correct assessment of individual stroke risk (ρ=0.24, p=0.02). During follow-up, patients experienced the following events: death (n=5), stroke (n=2), bleeding (n=1). OAC discontinuation rate despite indication was 3%. In this cross-sectional analysis of OAC-naive patients with AF, we found major differences between patients' perceptions and physicians' assessments of risks and benefits of OAC. To ensure shared decision-making and informed

  15. Study of dose and relative risk of occupationally exposed individuals in interventional procedures

    International Nuclear Information System (INIS)

    Silveira Filho, Jose A.M.; Reis, Charlene O.; Taniguti, Lana T.; Pacifico, Leonardo C.; SaintYves, Thalis L.A.; Mecca, Fernando A.

    2012-01-01

    This paper estimates the occupational effective dose and the relative risk of leukemia and cancers of the digestive tract mortality through dose study of the most radiosensitive anatomical regions (lens, thyroid, chest and gonads) of the professionals involved in interventional gonad procedures. It was considered a cumulative exposure time of 10,000 hours, which is the occupational exposure time of an IOE in throughout his professional life. It was also considered that they always use Personal Protective Equipment (PPE). Mathematical models derived from epidemiological data contained in the BEIR V and in the IAEA’s TECDOC 870 are used to estimate the relative risk. The results show a significant increase in mortality risk for these types of cancer for individuals occupationally exposed to three different distances from the x-ray beam, and reinforces that radiation protection measures are essential. (author)

  16. Relative risk of visceral leishmaniasis in Brazil: a spatial analysis in urban area.

    Directory of Open Access Journals (Sweden)

    Valdelaine Etelvina Miranda de Araújo

    2013-11-01

    Full Text Available BACKGROUND: Visceral leishmaniasis (VL is a vector-borne disease whose factors involved in transmission are poorly understood, especially in more urban and densely populated counties. In Brazil, the VL urbanization is a challenge for the control program. The goals were to identify the greater risk areas for human VL and the risk factors involved in transmission. METHODOLOGY: This is an ecological study on the relative risk of human VL. Spatial units of analysis were the coverage areas of the Basic Health Units (146 small-areas of Belo Horizonte, Minas Gerais State, Brazil. Human VL cases, from 2007 to 2009 (n = 412, were obtained in the Brazilian Reportable Disease Information System. Bayesian approach was used to model the relative risk of VL including potential risk factors involved in transmission (canine infection, socioeconomic and environmental features and to identify the small-areas of greater risk to human VL. PRINCIPAL FINDINGS: The relative risk of VL was shown to be correlated with income, education, and the number of infected dogs per inhabitants. The estimates of relative risk of VL were higher than 1.0 in 54% of the areas (79/146. The spatial modeling highlighted 14 areas with the highest relative risk of VL and 12 of them are concentrated in the northern region of the city. CONCLUSIONS: The spatial analysis used in this study is useful for the identification of small-areas according to risk of human VL and presents operational applicability in control and surveillance program in an urban environment with an unequal spatial distribution of the disease. Thus the frequent monitoring of relative risk of human VL in small-areas is important to direct and prioritize the actions of the control program in urban environment, especially in big cities.

  17. Relative risk models of lung cancer in uranium miners

    Energy Technology Data Exchange (ETDEWEB)

    Tomasek, L [National Radiation Protection Institute, Prague (Czech Republic); Placek, V [Inst. for Expertises and Emergencies, Pribram-Kamenna (Czech Republic)

    1996-12-31

    The study population of the S cohort (studies of underground miners of uranium and other substances as the source of information on long term effects of exposure to radon and its progeny) involve uranium miners, that started underground work at the Jachymov and Horni Slavkov mines in the period 1978-1959, and had worked at least for four years. A total 4320 men satisfied these criteria. During the decade up to 1990, follow-up of the cohort mainly relied on the national population registry. In order to improve the follow-u, a series of additional checks were conducted: in the files of the Czech and Slovak Pensions Offices, by local enquires, and by direct correspondence. These additional efforts resulted in an increase of more than 10% in the numbers of known men to have died or emigrated. An exceptional feature of the S study is the large number of measurements of radon concentrations made in each mine-shaft (mean number per year and shaft was 223 in the period 1949-1960). Each man`s annual exposures to radon progeny in terms of working levels were estimated combining measurement data with men`s employment details. The excess relative risk models were used in the form RR = c(1 + ERR(w,x)), where ERR is excess relative risk, w and x denote exposure history and modifying variable, and c is an intercept term that allows the mortality rate for `unexposed` cohort to differ from that in the general population. The increased mortality (O/E=1.58; where O is observed and E is expected cases among collected death cases in the cohort) in the cohort, generally, somewhat lower ratios than one reflect the non-industrial character of the region, with the exception of lung cancer in man. The differences in the O/E ratios for lung cancer among the separate communities indicate that even in the situation of generally lower mortality, the dependence of lung cancer mortality on radon exposure cannot be excluded. 3 tabs., 6 refs.

  18. Comparison of Paper-and-Pencil versus Web Administration of the Youth Risk Behavior Survey (YRBS): Risk Behavior Prevalence Estimates

    Science.gov (United States)

    Eaton, Danice K.; Brener, Nancy D.; Kann, Laura; Denniston, Maxine M.; McManus, Tim; Kyle, Tonja M.; Roberts, Alice M.; Flint, Katherine H.; Ross, James G.

    2010-01-01

    The authors examined whether paper-and-pencil and Web surveys administered in the school setting yield equivalent risk behavior prevalence estimates. Data were from a methods study conducted by the Centers for Disease Control and Prevention (CDC) in spring 2008. Intact classes of 9th- or 10th-grade students were assigned randomly to complete a…

  19. Dynamic Estimation of Volatility Risk Premia and Investor Risk Aversion from Option-Implied and Realized Volatilities

    DEFF Research Database (Denmark)

    Bollerslev, Tim; Gibson, Michael; Zhou, Hao

    experiment confirms that the procedure works well in practice. Implementing the procedure with actual S&P500 option-implied volatilities and high-frequency five-minute-based realized volatilities indicates significant temporal dependencies in the estimated stochastic volatility risk premium, which we in turn...

  20. Geostatistical risk estimation at waste disposal sites in the presence of hot spots

    International Nuclear Information System (INIS)

    Komnitsas, Kostas; Modis, Kostas

    2009-01-01

    The present paper aims to estimate risk by using geostatistics at the wider coal mining/waste disposal site of Belkovskaya, Tula region, in Russia. In this area the presence of hot spots causes a spatial trend in the mean value of the random field and a non-Gaussian data distribution. Prior to application of geostatistics, subtraction of trend and appropriate smoothing and transformation of the data into a Gaussian form were carried out; risk maps were then generated for the wider study area in order to assess the probability of exceeding risk thresholds. Finally, the present paper discusses the need for homogenization of soil risk thresholds regarding hazardous elements that will enhance reliability of risk estimation and enable application of appropriate rehabilitation actions in contaminated areas.

  1. Scoring Systems for Estimating the Risk of Anticoagulant-Associated Bleeding.

    Science.gov (United States)

    Parks, Anna L; Fang, Margaret C

    2017-07-01

    Anticoagulant medications are frequently used to prevent and treat thromboembolic disease. However, the benefits of anticoagulants must be balanced with a careful assessment of the risk of bleeding complications that can ensue from their use. Several bleeding risk scores are available, including the Outpatient Bleeding Risk Index, HAS-BLED, ATRIA, and HEMORR 2 HAGES risk assessment tools, and can be used to help estimate patients' risk for bleeding on anticoagulants. These tools vary by their individual risk components and in how they define and weigh clinical factors. However, it is not yet clear how best to integrate bleeding risk tools into clinical practice. Current bleeding risk scores generally have modest predictive ability and limited ability to predict the most devastating complication of anticoagulation, intracranial hemorrhage. In clinical practice, bleeding risk tools should be paired with a formal determination of thrombosis risk, as their results may be most influential for patients at the lower end of thrombosis risk, as well as for highlighting potentially modifiable risk factors for bleeding. Use of bleeding risk scores may assist clinicians and patients in making informed and individualized anticoagulation decisions. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  2. Cardiovascular risk estimation by professionally active cardiovascular nurses: results from the Basel 2005 Nurses Cohort.

    Science.gov (United States)

    Scholte op Reimer, Wilma J M; Moons, Philip; De Geest, Sabina; Fridlund, Bengt; Heikkilä, Johanna; Jaarsma, Tiny; Lenzen, Mattie; Martensson, Jan; Norekvål, Tone M; Smith, Karen; Stewart, Simon; Strömberg, Anna; Thompson, David R

    2006-12-01

    Nurses play a key role in the prevention of cardiovascular disease (CVD) and one would, therefore, expect them to have a heightened awareness of the need for systematic screening and their own CVD risk profile. The aim of this study was to examine personal awareness of CVD risk among a cohort of cardiovascular nurses attending a European conference. Of the 340 delegates attending the 5th annual Spring Meeting on Cardiovascular Nursing (Basel, Switzerland, 2005), 287 (83%) completed a self-report questionnaire to assess their own risk factors for CVD. Delegates were also asked to give an estimation of their absolute total risk of experiencing a fatal CVD event in the next 10 years. Level of agreement between self-reported CVD risk estimation and their actual risk according to the SCORE risk assessment system was compared by calculating weighted Kappa (kappa(w)). Overall, 109 responders (38%) self-reported having either pre-existing CVD (only 2%), one or more markedly raised CVD risk factors, a high total risk of fatal CVD (> or =5% in 10 years) or a strong family history of CVD. About half of this cohort (53%) did not know their own total cholesterol level. Less than half (45%) reported having a 10-year risk of fatal CVD of or =5%. Based on the SCORE risk function, the estimated 10-year risk of a fatal CVD event was or =5% risk of such an event. Overall, less than half (46%) of this cohort's self-reported CVD risk corresponded with that calculated using the SCORE risk function (kappa(w)=0.27). Most cardiovascular nurses attending a European conference in 2005 poorly understood their own CVD risk profile, and the agreement between their self-reported 10-year risk of a fatal CVD and their CVD risk using SCORE was only fair. Given the specialist nature of this conference, our findings clearly demonstrate a need to improve overall nursing awareness of the role and importance of systematic CVD risk assessment.

  3. Alcohol-Related Problems And High Risk Sexual Behaviour In ...

    African Journals Online (AJOL)

    There was a significant association between alcohol-related problems and risky sexual behavior. Alcohol-related problems are fairly common in people already infected with HIV/AIDS and are associated with high-risk sexual behavior. Thus, screening and treatment should be part of an effective HIV intervention program.

  4. Risk of cancer in relatives of patients with myotonic dystrophy

    DEFF Research Database (Denmark)

    Lund, M; Diaz, L J; Gørtz, S

    2014-01-01

    BACKGROUND AND PURPOSE: Myotonic dystrophies (DM) are autosomal dominantly inherited neuromuscular disorders caused by unstable nucleotide repeat expansions. DM and cancer have been associated, but the pathogenesis behind the association remains unclear. It could relate to derived effects of the DM...... genotype in which case non-DM relatives of DM patients would not be expected to be at increased risk of cancer. To elucidate this, a population-based cohort study investigating risk of cancer in relatives of DM patients was conducted. METHODS: DM was identified using the National Danish Patient Registry...

  5. New Estimates of Numerical Values Related to a Simplex

    Directory of Open Access Journals (Sweden)

    Mikhail V. Nevskii

    2017-01-01

    if \\(\\xi_n=n.\\ This statement is valid only in one direction. There exists a simplex \\(S\\subset Q_5\\ such that the boundary of the simplex \\(5S\\ contains all the vertices of the cube \\(Q_5\\. We describe a one-parameter family of simplices contained in \\(Q_5\\ with the property \\(\\alpha(S=\\xi(S=5.\\ These simplices were found with the use of numerical and symbolic computations. %Numerical experiments allow to discover Another new result is an inequality \\(\\xi_6\\ <6.0166\\. %Прежняя оценка имела вид \\(6\\leq \\xi_6\\leq 6.6\\. We also systematize some of our estimates of numbers \\(\\xi_n\\, \\(\\theta_n\\, \\(\\varkappa_n\\ derived by~now. The symbol \\(\\theta_n\\ denotes the minimal norm of interpolation projection on the space of linear functions of \\(n\\ variables as~an~operator from \\(C(Q_n\\ to~\\(C(Q_n\\.

  6. Value-at-risk estimation with wavelet-based extreme value theory: Evidence from emerging markets

    Science.gov (United States)

    Cifter, Atilla

    2011-06-01

    This paper introduces wavelet-based extreme value theory (EVT) for univariate value-at-risk estimation. Wavelets and EVT are combined for volatility forecasting to estimate a hybrid model. In the first stage, wavelets are used as a threshold in generalized Pareto distribution, and in the second stage, EVT is applied with a wavelet-based threshold. This new model is applied to two major emerging stock markets: the Istanbul Stock Exchange (ISE) and the Budapest Stock Exchange (BUX). The relative performance of wavelet-based EVT is benchmarked against the Riskmetrics-EWMA, ARMA-GARCH, generalized Pareto distribution, and conditional generalized Pareto distribution models. The empirical results show that the wavelet-based extreme value theory increases predictive performance of financial forecasting according to number of violations and tail-loss tests. The superior forecasting performance of the wavelet-based EVT model is also consistent with Basel II requirements, and this new model can be used by financial institutions as well.

  7. Urbanization and traffic related exposures as risk factors for Schizophrenia

    DEFF Research Database (Denmark)

    Pedersen, Carsten Bøcker; Mortensen, Preben Bo

    2006-01-01

    to nearest major road had no significant effect. CONCLUSIONS: The cause(s) or exposure(s) responsible for the urban-rural differences in schizophrenia risk were closer related to the degree of urbanization than to the geographical distance to nearest major road. Traffic related exposures might thus be less......BACKGROUND: Urban birth or upbringing increase schizophrenia risk. Though unknown, the causes of these urban-rural differences have been hypothesized to include, e.g., infections, diet, toxic exposures, social class, or an artefact due to selective migration. METHODS: We investigated the hypothesis...... that traffic related exposures affect schizophrenia risk and that this potential effect is responsible for the urban-rural differences. The geographical distance from place of residence to nearest major road was used as a proxy variable for traffic related exposures. We used a large population-based sample...

  8. Estimating oil price 'Value at Risk' using the historical simulation approach

    International Nuclear Information System (INIS)

    Cabedo, J.D.; Moya, I.

    2003-01-01

    In this paper we propose using Value at Risk (VaR) for oil price risk quantification. VaR provides an estimation for the maximum oil price change associated with a likelihood level, and can be used for designing risk management strategies. We analyse three VaR calculation methods: the historical simulation standard approach, the historical simulation with ARMA forecasts (HSAF) approach. developed in this paper, and the variance-covariance method based on autoregressive conditional heteroskedasticity models forecasts. The results obtained indicate that HSAF methodology provides a flexible VaR quantification, which fits the continuous oil price movements well and provides an efficient risk quantification. (author)

  9. Estimating oil price 'Value at Risk' using the historical simulation approach

    International Nuclear Information System (INIS)

    David Cabedo, J.; Moya, Ismael

    2003-01-01

    In this paper we propose using Value at Risk (VaR) for oil price risk quantification. VaR provides an estimation for the maximum oil price change associated with a likelihood level, and can be used for designing risk management strategies. We analyse three VaR calculation methods: the historical simulation standard approach, the historical simulation with ARMA forecasts (HSAF) approach, developed in this paper, and the variance-covariance method based on autoregressive conditional heteroskedasticity models forecasts. The results obtained indicate that HSAF methodology provides a flexible VaR quantification, which fits the continuous oil price movements well and provides an efficient risk quantification

  10. Estimation of transient increases in bleeding risk associated with physical activity in children with haemophilia

    Directory of Open Access Journals (Sweden)

    Latimer Jane

    2008-06-01

    Full Text Available Abstract Background Although it is widely appreciated that vigorous physical activity can increase the risk of bleeding episodes in children with haemophilia, the magnitude of the increase in risk is not known. Accurate risk estimates could inform decisions made by children with haemophilia and their parents about participation in physical activity and aid the development of optimal prophylactic schedules. The aim of this study is to provide an accurate estimate of the risks of bleeding associated with vigorous physical activity in children with haemophilia. Methods/Design The study will be a case-crossover study nested within a prospective cohort study. Children with moderate or severe haemophilia A or B, recruited from two paediatric haematology departments in Australia, will participate in the study. The child, or the child's parent or guardian, will report bleeding episodes experienced over a 12-month period. Following a bleeding episode, the participant will be interviewed by telephone about exposures to physical activity in the case period (8 hours before the bleed and 2 control periods (an 8 hour period at the same time on the day preceding the bleed and an 8 hour period two days preceding the bleed. Conditional logistic regression will be used to estimate the risk of participating in vigorous physical activity from measures of exposure to physical activity in the case and control periods. Discussion This case-control study will provide estimates of the risk of participation in vigorous physical activity in children with haemophilia.

  11. Report on some methods of determining the state of convergence of Monte Carlo risk estimates

    International Nuclear Information System (INIS)

    Orford, J.L.; Hufton, D.; Johnson, K.

    1991-05-01

    The Department of the Environment is developing a methodology for assessing potential sites for the disposal of low and intermediate level radioactive wastes. Computer models are used to simulate the groundwater transport of radioactive materials from a disposal facility back to man. Monte Carlo methods are being employed to conduct a probabilistic risk assessment (pra) of potential sites. The models calculate time histories of annual radiation dose to the critical group population. The annual radiation dose to the critical group in turn specifies the annual individual risk. The distribution of dose is generally highly skewed and many simulation runs are required to predict the level of confidence in the risk estimate i.e. to determine whether the risk estimate is converged. This report describes some statistical methods for determining the state of convergence of the risk estimate. The methods described include the Shapiro-Wilk test, calculation of skewness and kurtosis and normal probability plots. A method for forecasting the number of samples needed before the risk estimate is converged is presented. Three case studies were conducted to examine the performance of some of these techniques. (author)

  12. Estimation of breast dose and cancer risk in chest and abdomen CT procedures

    International Nuclear Information System (INIS)

    Eltahir, Suha Abubaker Ali

    2013-05-01

    The use of CT in medical diagnosis delivers radiation doses to patents that are higher than those from other radiological procedures. Lack of optimized protocols be an additional source of increased dose in developing countries. The aims of this study are first, to measure patient doses during CT chest and abdomen procedures, second, to estimate the radiation dose to the breast, and third to quantify the radiation risks during the procedures. Patient doses from two common CT examinations were obtained from four hospitals in Khartoum.The patient doses were estimated using measurement of CT dose indexes (CTDI), exposure-related parameters, and the IMPACT spreadsheet based on NRPB conversion factors. A large variation of mean organ doses among hospitals was observed for similar CT examinations. These variations largely originated from different CT scanning protocols used in different hospitals and scanner type. The largest range was found for CT of the chest, for which the dose varied from 2.3 to 47 (average 24.7) mSv and for abdomen CT, it was 1.6 to 18.8 (average 10.2) mSv. Radiation dose to the breast ranged from 1.6 to 32.9 mSv for the chest and 1.1 to 13.2 mSv for the abdomen. The radiation risk per procedure was high. The obtained values were mostly higher than the values of organ doses reported from the other studies. It was concluded that current clinical chest and abdomen protocols result in variable radiation doses to the breast. The magnitude of exposure may have implications for imaging strategies.(Author)

  13. Estimation of risks by chemicals produced during laser pyrolysis of tissues

    Science.gov (United States)

    Weber, Lothar W.; Spleiss, Martin

    1995-01-01

    Use of laser systems in minimal invasive surgery results in formation of laser aerosol with volatile organic compounds of possible health risk. By use of currently identified chemical substances an overview on possibly associated risks to human health is given. The class of the different identified alkylnitriles seem to be a laser specific toxicological problem. Other groups of chemicals belong to the Maillard reaction type, the fatty acid pyrolysis type, or even the thermally activated chemolysis. In relation to the available different threshold limit values the possible exposure ranges of identified substances are discussed. A rough estimation results in an exposure range of less than 1/100 for almost all substances with given human threshold limit values without regard of possible interactions. For most identified alkylnitriles, alkenes, and heterocycles no threshold limit values are given for lack of, until now, practical purposes. Pyrolysis of anaesthetized organs with isoflurane gave no hints for additional pyrolysis products by fragment interactions with resulting VOCs. Measurements of pyrolysis gases resulted in detection of small amounts of NO additionally with NO2 formation at plasma status.

  14. Clinical risk factors for age-related macular degeneration: a systematic review and meta-analysis

    Directory of Open Access Journals (Sweden)

    Evans Christopher

    2010-12-01

    Full Text Available Abstract Background Age-related macular degeneration (AMD is the leading cause of blindness in Western countries. Numerous risk factors have been reported but the evidence and strength of association is variable. We aimed to identify those risk factors with strong levels of evidence which could be easily assessed by physicians or ophthalmologists to implement preventive interventions or address current behaviours. Methods A systematic review identified 18 prospective and cross-sectional studies and 6 case control studies involving 113,780 persons with 17,236 cases of late AMD that included an estimate of the association between late AMD and at least one of 16 pre-selected risk factors. Fixed-effects meta-analyses were conducted for each factor to combine odds ratio (OR and/or relative risk (RR outcomes across studies by study design. Overall raw point estimates of each risk factor and associated 95% confidence intervals (CI were calculated. Results Increasing age, current cigarette smoking, previous cataract surgery, and a family history of AMD showed strong and consistent associations with late AMD. Risk factors with moderate and consistent associations were higher body mass index, history of cardiovascular disease, hypertension, and higher plasma fibrinogen. Risk factors with weaker and inconsistent associations were gender, ethnicity, diabetes, iris colour, history of cerebrovascular disease, and serum total and HDL cholesterol and triglyceride levels. Conclusions Smoking, previous cataract surgery and a family history of AMD are consistent risk factors for AMD. Cardiovascular risk factors are also associated with AMD. Knowledge of these risk factors that may be easily assessed by physicians and general ophthalmologists may assist in identification and appropriate referral of persons at risk of AMD.

  15. Relations between radiation risks and radiation protection measuring techniques

    International Nuclear Information System (INIS)

    Herrmann, K.; Kraus, W.

    Relations between radiation risks and radiation protection measuring techniques are considered as components of the radiation risk. The influence of the exposure risk on type and extent of radiation protection measurements is discussed with regard to different measuring tasks. Based upon measuring results concerning the frequency of certain external and internal occupational exposures in the GDR, it has been shown that only a small fraction of the monitored persons are subjected to a high exposure risk. As a consequence the following recommendations are presented: occupationally exposed persons with small exposure risk should be monitored using only a long-term desimeter (for instance a thermoluminescence desimeter). In the case of internal exposure, the surface and air contamination levels should be controlled so strictly that routine measurements of internal contamination need not be performed

  16. Nighttime parenting strategies and sleep-related risks to infants.

    Science.gov (United States)

    Volpe, Lane E; Ball, Helen L; McKenna, James J

    2013-02-01

    A large social science and public health literature addresses infant sleep safety, with implications for infant mortality in the context of accidental deaths and Sudden Infant Death Syndrome (SIDS). As part of risk reduction campaigns in the USA, parents are encouraged to place infants supine and to alter infant bedding and elements of the sleep environment, and are discouraged from allowing infants to sleep unsupervised, from bed-sharing either at all or under specific circumstances, or from sofa-sharing. These recommendations are based on findings from large-scale epidemiological studies that generate odds ratios or relative risk statistics for various practices; however, detailed behavioural data on nighttime parenting and infant sleep environments are limited. To address this issue, this paper presents and discusses the implications of four case studies based on overnight observations conducted with first-time mothers and their four-month old infants. These case studies were collected at the Mother-Baby Behavioral Sleep Lab at the University of Notre Dame USA between September 2002 and June 2004. Each case study provides a detailed description based on video analysis of sleep-related risks observed while mother-infant dyads spent the night in a sleep lab. The case studies provide examples of mothers engaged in the strategic management of nighttime parenting for whom sleep-related risks to infants arose as a result of these strategies. Although risk reduction guidelines focus on eliminating potentially risky infant sleep practices as if the probability of death from each were equal, the majority of instances in which these occur are unlikely to result in infant mortality. Therefore, we hypothesise that mothers assess potential costs and benefits within margins of risk which are not acknowledged by risk-reduction campaigns. Exploring why mothers might choose to manage sleep and nighttime parenting in ways that appear to increase potential risks to infants may

  17. Estimating risk at a Superfund site contaminated with radiological and chemical wastes

    International Nuclear Information System (INIS)

    Temeshy, A.; Liedle, J.M.; Sims, L.M.; Efird, C.R.

    1992-01-01

    This paper describes the method and results for estimating carcinogenic and noncarcinogenic effects at a Superfund site that is radiologically and chemically contaminated. Risk to receptors from disposal of waste in soil and resulting contamination of groundwater, air, surface water, and sediment is quantified. Specific risk assessment components which are addressed are the exposure assessment, toxicity assessment, and the resulting risk characterization. In the exposure assessment, potential exposure pathways are identified using waste disposal inventory information for soil and modeled information for other media. Models are used to calculate future radionuclide concentrations in groundwater, soil, surface water and air. Chemical exposure concentrations are quantified using site characterization data. Models are used to determine concentrations of chemicals in surface water and in air. Toxicity parameters used to quantify the dose-response relationship associated with the carcinogenic contaminants are slope factors and with noncarcinogenic contaminants are reference doses. In the risk characterization step, results from the exposure assessment and toxicity assessment are summarized and integrated into quantitative risk estimates for carcinogens and hazard induces for noncarcinogens. Calculated risks for carcinogenic contaminants are compared with EPA's target risk range. At WAG 6, the risk from radionuclides and chemicals for an on-WAG homesteader exceeds EPA's target risk range. Hazard indices are compared to unity for noncarcinogenic contaminants. At WAG 6, the total pathway hazard index for the on-WAG homesteader exceeds unity

  18. Estimating the Health Risk Associated with the Use of Ecological Sanitation Toilets in Malawi

    Directory of Open Access Journals (Sweden)

    Save Kumwenda

    2017-01-01

    Full Text Available Use of Ecological Sanitation (EcoSan sludge is becoming popular due to increasing price of organic fertilizers in Malawi; however, there is little evidence on the associated risks. Quantitative microbiological risk assessment (QMRA was done to determine health risks associated with use of EcoSan. Pathogens considered included Escherichia coli (E. coli, Salmonella, and soil transmitted helminths (STHs. Exponential and Beta Poisson models were used to estimate the risk from helminthic and bacterial pathogens, respectively. Main exposure pathways were through poor storage of sludge, contamination of foods during drying, walking barefoot on the ground contaminated with sludge, pit emptying without protection, and application of sludge in the fields. Estimated annual risk for Ascaris lumbricoides, Taenia, and hookworms was approximately over 5.6 × 10−1 for both Fossa Alternas (FAs and Urine Diverting Dry Toilet (UDDTs. Risk from E. coli and Salmonella was 8.9 × 10−2 and above. The risks were higher than WHO acceptable risk for use of faecal sludge in crops of 10−4 infections per year. Promoters and users of EcoSan latrines need to consider advocating for strict guidelines to reduce the risk.

  19. Flood risk assessment in France: comparison of extreme flood estimation methods (EXTRAFLO project, Task 7)

    Science.gov (United States)

    Garavaglia, F.; Paquet, E.; Lang, M.; Renard, B.; Arnaud, P.; Aubert, Y.; Carre, J.

    2013-12-01

    In flood risk assessment the methods can be divided in two families: deterministic methods and probabilistic methods. In the French hydrologic community the probabilistic methods are historically preferred to the deterministic ones. Presently a French research project named EXTRAFLO (RiskNat Program of the French National Research Agency, https://extraflo.cemagref.fr) deals with the design values for extreme rainfall and floods. The object of this project is to carry out a comparison of the main methods used in France for estimating extreme values of rainfall and floods, to obtain a better grasp of their respective fields of application. In this framework we present the results of Task 7 of EXTRAFLO project. Focusing on French watersheds, we compare the main extreme flood estimation methods used in French background: (i) standard flood frequency analysis (Gumbel and GEV distribution), (ii) regional flood frequency analysis (regional Gumbel and GEV distribution), (iii) local and regional flood frequency analysis improved by historical information (Naulet et al., 2005), (iv) simplify probabilistic method based on rainfall information (i.e. Gradex method (CFGB, 1994), Agregee method (Margoum, 1992) and Speed method (Cayla, 1995)), (v) flood frequency analysis by continuous simulation approach and based on rainfall information (i.e. Schadex method (Paquet et al., 2013, Garavaglia et al., 2010), Shyreg method (Lavabre et al., 2003)) and (vi) multifractal approach. The main result of this comparative study is that probabilistic methods based on additional information (i.e. regional, historical and rainfall information) provide better estimations than the standard flood frequency analysis. Another interesting result is that, the differences between the various extreme flood quantile estimations of compared methods increase with return period, staying relatively moderate up to 100-years return levels. Results and discussions are here illustrated throughout with the example

  20. Quantifying the underestimation of relative risks from genome-wide association studies.

    Directory of Open Access Journals (Sweden)

    Chris Spencer

    2011-03-01

    Full Text Available Genome-wide association studies (GWAS have identified hundreds of associated loci across many common diseases. Most risk variants identified by GWAS will merely be tags for as-yet-unknown causal variants. It is therefore possible that identification of the causal variant, by fine mapping, will identify alleles with larger effects on genetic risk than those currently estimated from GWAS replication studies. We show that under plausible assumptions, whilst the majority of the per-allele relative risks (RR estimated from GWAS data will be close to the true risk at the causal variant, some could be considerable underestimates. For example, for an estimated RR in the range 1.2-1.3, there is approximately a 38% chance that it exceeds 1.4 and a 10% chance that it is over 2. We show how these probabilities can vary depending on the true effects associated with low-frequency variants and on the minor allele frequency (MAF of the most associated SNP. We investigate the consequences of the underestimation of effect sizes for predictions of an individual's disease risk and interpret our results for the design of fine mapping experiments. Although these effects mean that the amount of heritability explained by known GWAS loci is expected to be larger than current projections, this increase is likely to explain a relatively small amount of the so-called "missing" heritability.

  1. Risk of bleeding related to antithrombotic treatment in cardiovascular disease

    DEFF Research Database (Denmark)

    Sørensen, Rikke; Olesen, Jonas B; Charlot, Mette

    2012-01-01

    Antithrombotic therapy is a cornerstone of treatment in patients with cardiovascular disease with bleeding being the most feared complication. This review describes the risk of bleeding related to different combinations of antithrombotic drugs used for cardiovascular disease: acute coronary...... syndrome (ACS), atrial fibrillation (AF), cerebrovascular (CVD) and peripheral arterial disease (PAD). Different risk assessment schemes and bleeding definitions are compared. The HAS-BLED risk score is recommended in patients with AF and in ACS patients with AF. In patients with ACS with or without...

  2. Measurement of natural radionuclides in Malaysian bottled mineral water and consequent health risk estimation

    Energy Technology Data Exchange (ETDEWEB)

    Priharti, W.; Samat, S. B.; Yasir, M. S. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2015-09-25

    The radionuclides of {sup 226}Ra, {sup 232}Th and {sup 40}K were measured in ten mineral water samples, of which from the radioactivity obtained, the ingestion doses for infants, children and adults were calculated and the cancer risk for the adult was estimated. Results showed that the calculated ingestion doses for the three age categories are much lower than the average worldwide ingestion exposure of 0.29 mSv/y and the estimated cancer risk is much lower than the cancer risk of 8.40 × 10{sup −3} (estimated from the total natural radiation dose of 2.40 mSv/y). The present study concludes that the bottled mineral water produced in Malaysia is safe for daily human consumption.

  3. Measurement of natural radionuclides in Malaysian bottled mineral water and consequent health risk estimation

    Science.gov (United States)

    Priharti, W.; Samat, S. B.; Yasir, M. S.

    2015-09-01

    The radionuclides of 226Ra, 232Th and 40K were measured in ten mineral water samples, of which from the radioactivity obtained, the ingestion doses for infants, children and adults were calculated and the cancer risk for the adult was estimated. Results showed that the calculated ingestion doses for the three age categories are much lower than the average worldwide ingestion exposure of 0.29 mSv/y and the estimated cancer risk is much lower than the cancer risk of 8.40 × 10-3 (estimated from the total natural radiation dose of 2.40 mSv/y). The present study concludes that the bottled mineral water produced in Malaysia is safe for daily human consumption.

  4. Decline in estimated glomerular filtration rate and subsequent risk of end-stage renal disease and mortality.

    Science.gov (United States)

    Coresh, Josef; Turin, Tanvir Chowdhury; Matsushita, Kunihiro; Sang, Yingying; Ballew, Shoshana H; Appel, Lawrence J; Arima, Hisatomi; Chadban, Steven J; Cirillo, Massimo; Djurdjev, Ognjenka; Green, Jamie A; Heine, Gunnar H; Inker, Lesley A; Irie, Fujiko; Ishani, Areef; Ix, Joachim H; Kovesdy, Csaba P; Marks, Angharad; Ohkubo, Takayoshi; Shalev, Varda; Shankar, Anoop; Wen, Chi Pang; de Jong, Paul E; Iseki, Kunitoshi; Stengel, Benedicte; Gansevoort, Ron T; Levey, Andrew S

    2014-06-25

    The established chronic kidney disease (CKD) progression end point of end-stage renal disease (ESRD) or a doubling of serum creatinine concentration (corresponding to a change in estimated glomerular filtration rate [GFR] of −57% or greater) is a late event. To characterize the association of decline in estimated GFR with subsequent progression to ESRD with implications for using lesser declines in estimated GFR as potential alternative end points for CKD progression. Because most people with CKD die before reaching ESRD, mortality risk also was investigated. Individual meta-analysis of 1.7 million participants with 12,344 ESRD events and 223,944 deaths from 35 cohorts in the CKD Prognosis Consortium with a repeated measure of serum creatinine concentration over 1 to 3 years and outcome data. Transfer of individual participant data or standardized analysis of outputs for random-effects meta-analysis conducted between July 2012 and September 2013, with baseline estimated GFR values collected from 1975 through 2012. End-stage renal disease (initiation of dialysis or transplantation) or all-cause mortality risk related to percentage change in estimated GFR over 2 years, adjusted for potential confounders and first estimated GFR. The adjusted hazard ratios (HRs) of ESRD and mortality were higher with larger estimated GFR decline. Among participants with baseline estimated GFR of less than 60 mL/min/1.73 m2, the adjusted HRs for ESRD were 32.1 (95% CI, 22.3-46.3) for changes of −57% in estimated GFR and 5.4 (95% CI, 4.5-6.4) for changes of −30%. However, changes of −30% or greater (6.9% [95% CI, 6.4%-7.4%] of the entire consortium) were more common than changes of −57% (0.79% [95% CI, 0.52%-1.06%]). This association was strong and consistent across the length of the baseline period (1 to 3 years), baseline estimated GFR, age, diabetes status, or albuminuria. Average adjusted 10-year risk of ESRD (in patients with a baseline estimated GFR of 35 mL/min/1.73 m2

  5. Use of risk projection models to estimate mortality and incidence from radiation-induced breast cancer in screening programs

    International Nuclear Information System (INIS)

    Ramos, M; Ferrer, S; Villaescusa, J I; Verdu, G; Salas, M D; Cuevas, M D

    2005-01-01

    The authors report on a method to calculate radiological risks, applicable to breast screening programs and other controlled medical exposures to ionizing radiation. In particular, it has been applied to make a risk assessment in the Valencian Breast Cancer Early Detection Program (VBCEDP) in Spain. This method is based on a parametric approach, through Markov processes, of hazard functions for radio-induced breast cancer incidence and mortality, with mean glandular breast dose, attained age and age-at-exposure as covariates. Excess relative risk functions of breast cancer mortality have been obtained from two different case-control studies exposed to ionizing radiation, with different follow-up time: the Canadian Fluoroscopy Cohort Study (1950-1987) and the Life Span Study (1950-1985 and 1950-1990), whereas relative risk functions for incidence have been obtained from the Life Span Study (1958-1993), the Massachusetts tuberculosis cohorts (1926-1985 and 1970-1985), the New York post-partum mastitis patients (1930-1981) and the Swedish benign breast disease cohort (1958-1987). Relative risks from these cohorts have been transported to the target population undergoing screening in the Valencian Community, a region in Spain with about four and a half million inhabitants. The SCREENRISK software has been developed to estimate radiological detriments in breast screening. Some hypotheses corresponding to different screening conditions have been considered in order to estimate the total risk associated with a woman who takes part in all screening rounds. In the case of the VBCEDP, the total radio-induced risk probability for fatal breast cancer is in a range between [5 x 10 -6 , 6 x 10 -4 ] versus the natural rate of dying from breast cancer in the Valencian Community which is 9.2 x 10 -3 . The results show that these indicators could be included in quality control tests and could be adequate for making comparisons between several screening programs

  6. Cross-property relations and permeability estimation in model porous media

    International Nuclear Information System (INIS)

    Schwartz, L.M.; Martys, N.; Bentz, D.P.; Garboczi, E.J.; Torquato, S.

    1993-01-01

    Results from a numerical study examining cross-property relations linking fluid permeability to diffusive and electrical properties are presented. Numerical solutions of the Stokes equations in three-dimensional consolidated granular packings are employed to provide a basis of comparison between different permeability estimates. Estimates based on the Λ parameter (a length derived from electrical conduction) and on d c (a length derived from immiscible displacement) are found to be considerably more reliable than estimates based on rigorous permeability bounds related to pore space diffusion. We propose two hybrid relations based on diffusion which provide more accurate estimates than either of the rigorous permeability bounds

  7. Binomial Distribution Sample Confidence Intervals Estimation 7. Absolute Risk Reduction and ARR-like Expressions

    Directory of Open Access Journals (Sweden)

    Andrei ACHIMAŞ CADARIU

    2004-08-01

    Full Text Available Assessments of a controlled clinical trial suppose to interpret some key parameters as the controlled event rate, experimental event date, relative risk, absolute risk reduction, relative risk reduction, number needed to treat when the effect of the treatment are dichotomous variables. Defined as the difference in the event rate between treatment and control groups, the absolute risk reduction is the parameter that allowed computing the number needed to treat. The absolute risk reduction is compute when the experimental treatment reduces the risk for an undesirable outcome/event. In medical literature when the absolute risk reduction is report with its confidence intervals, the method used is the asymptotic one, even if it is well know that may be inadequate. The aim of this paper is to introduce and assess nine methods of computing confidence intervals for absolute risk reduction and absolute risk reduction – like function.Computer implementations of the methods use the PHP language. Methods comparison uses the experimental errors, the standard deviations, and the deviation relative to the imposed significance level for specified sample sizes. Six methods of computing confidence intervals for absolute risk reduction and absolute risk reduction-like functions were assessed using random binomial variables and random sample sizes.The experiments shows that the ADAC, and ADAC1 methods obtains the best overall performance of computing confidence intervals for absolute risk reduction.

  8. Consolidating Risk Estimates for Radiation-Induced Complications in Individual Patient: Late Rectal Toxicity

    International Nuclear Information System (INIS)

    Prior, Phillip; Devisetty, Kiran; Tarima, Sergey S.; Lawton, Colleen A.F.; Semenenko, Vladimir A.

    2012-01-01

    Purpose: To test the feasibility of a new approach to synthesize published normal tissue complication data using late rectal toxicity in prostate cancer as an example. Methods and Materials: A data survey was performed to identify the published reports on the dose–response relationships for late rectal toxicity. The risk estimates for Grade 1 or greater, Grade 2 or greater, and Grade 3 or greater toxicity were obtained for a test cohort of patients treated at our institution. The influence of the potential factors that might have affected the reported toxicity levels was investigated. The studies that did not conform to the general data trends were excluded, and single, combined risk estimates were derived for each patient and toxicity level. Results: A total of 21 studies of nonoverlapping patient populations were identified. Three studies provided dose–response models for more than one level of toxicity. Of these 21 studies, 6, 14, and 5 were used to derive the initial risk estimates for Grade 1, 2, and 3 or greater toxicity, respectively. A comparison of risk estimates between the studies reporting rectal bleeding and rectal toxicity (bleeding plus other symptoms) or between studies with follow-up <36 months and ≥36 months did not reveal significant differences (p ≥ .29 for all comparisons). After excluding three reports that did not conform to the general data trends, the combined risk estimates were derived from 5 reports (647 patients), 11 reports (3,369 patients), and 5 reports (1,330 patients) for Grade 1, 2, and 3 or greater toxicity, respectively. Conclusions: The proposed approach is feasible and allows for more systematic use of published dose–response data to estimate the complication risks for the individual patient.

  9. Consolidating Risk Estimates for Radiation-Induced Complications in Individual Patient: Late Rectal Toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Prior, Phillip; Devisetty, Kiran [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Tarima, Sergey S. [Division of Biostatistics, Institute for Health and Society, Medical College of Wisconsin, Milwaukee, WI (United States); Lawton, Colleen A.F. [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States); Semenenko, Vladimir A., E-mail: vsemenenko@mcw.edu [Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI (United States)

    2012-05-01

    Purpose: To test the feasibility of a new approach to synthesize published normal tissue complication data using late rectal toxicity in prostate cancer as an example. Methods and Materials: A data survey was performed to identify the published reports on the dose-response relationships for late rectal toxicity. The risk estimates for Grade 1 or greater, Grade 2 or greater, and Grade 3 or greater toxicity were obtained for a test cohort of patients treated at our institution. The influence of the potential factors that might have affected the reported toxicity levels was investigated. The studies that did not conform to the general data trends were excluded, and single, combined risk estimates were derived for each patient and toxicity level. Results: A total of 21 studies of nonoverlapping patient populations were identified. Three studies provided dose-response models for more than one level of toxicity. Of these 21 studies, 6, 14, and 5 were used to derive the initial risk estimates for Grade 1, 2, and 3 or greater toxicity, respectively. A comparison of risk estimates between the studies reporting rectal bleeding and rectal toxicity (bleeding plus other symptoms) or between studies with follow-up <36 months and {>=}36 months did not reveal significant differences (p {>=} .29 for all comparisons). After excluding three reports that did not conform to the general data trends, the combined risk estimates were derived from 5 reports (647 patients), 11 reports (3,369 patients), and 5 reports (1,330 patients) for Grade 1, 2, and 3 or greater toxicity, respectively. Conclusions: The proposed approach is feasible and allows for more systematic use of published dose-response data to estimate the complication risks for the individual patient.

  10. Anesthesiologist- and System-Related Risk Factors for Risk-Adjusted Pediatric Anesthesia-Related Cardiac Arrest.

    Science.gov (United States)

    Zgleszewski, Steven E; Graham, Dionne A; Hickey, Paul R; Brustowicz, Robert M; Odegard, Kirsten C; Koka, Rahul; Seefelder, Christian; Navedo, Andres T; Randolph, Adrienne G

    2016-02-01

    Pediatric anesthesia-related cardiac arrest (ARCA) is an uncommon but potentially preventable adverse event. Infants and children with more severe underlying disease are at highest risk. We aimed to identify system- and anesthesiologist-related risk factors for ARCA. We analyzed a prospectively collected patient cohort data set of anesthetics administered from 2000 to 2011 to children at a large tertiary pediatric hospital. Pre-procedure systemic disease level was characterized by ASA physical status (ASA-PS). Two reviewers independently reviewed cardiac arrests and categorized their anesthesia relatedness. Factors associated with ARCA in the univariate analyses were identified for reevaluation after adjustment for patient age and ASA-PS. Cardiac arrest occurred in 142 of 276,209 anesthetics (incidence 5.1/10,000 anesthetics); 72 (2.6/10,000 anesthetics) were classified as anesthesia-related. In the univariate analyses, risk of ARCA was much higher in cardiac patients and for anesthesiologists with lower annual caseload and/or fewer annual days delivering anesthetics (all P risk adjustment for ASA-PS ≥ III and age ≤ 6 months, however, the association with lower annual days delivering anesthetics remained (P = 0.03), but the other factors were no longer significant. Case-mix explained most associations between higher risk of pediatric ARCA and anesthesiologist-related variables at our institution, but the association with fewer annual days delivering anesthetics remained. Our findings highlight the need for rigorous adjustment for patient risk factors in anesthesia patient safety studies.

  11. Structural equation models to estimate risk of infection and tolerance to bovine mastitis.

    Science.gov (United States)

    Detilleux, Johann; Theron, Léonard; Duprez, Jean-Noël; Reding, Edouard; Humblet, Marie-France; Planchon, Viviane; Delfosse, Camille; Bertozzi, Carlo; Mainil, Jacques; Hanzen, Christian

    2013-03-06

    One method to improve durably animal welfare is to select, as reproducers, animals with the highest ability to resist or tolerate infection. To do so, it is necessary to distinguish direct and indirect mechanisms of resistance and tolerance because selection on these traits is believed to have different epidemiological and evolutionary consequences. We propose structural equation models with latent variables (1) to quantify the latent risk of infection and to identify, among the many potential mediators of infection, the few ones that influence it significantly and (2) to estimate direct and indirect levels of tolerance of animals infected naturally with pathogens. We applied the method to two surveys of bovine mastitis in the Walloon region of Belgium, in which we recorded herd management practices, mastitis frequency, and results of bacteriological analyses of milk samples. Structural equation models suggested that, among more than 35 surveyed herd characteristics, only nine (age, addition of urea in the rations, treatment of subclinical mastitis, presence of dirty liner, cows with hyperkeratotic teats, machine stripping, pre- and post-milking teat disinfection, and housing of milking cows in cubicles) were directly and significantly related to a latent measure of bovine mastitis, and that treatment of subclinical mastitis was involved in the pathway between post-milking teat disinfection and latent mastitis. These models also allowed the separation of direct and indirect effects of bacterial infection on milk productivity. Results suggested that infected cows were tolerant but not resistant to mastitis pathogens. We revealed the advantages of structural equation models, compared to classical models, for dissecting measurements of resistance and tolerance to infectious diseases, here bovine mastitis. Using our method, we identified nine major risk factors that were directly associated with an increased risk of mastitis and suggested that cows were tolerant but

  12. Estimates of radiation doses and cancer risk from food intake in Korea

    International Nuclear Information System (INIS)

    Moon, Eun Kyeong; Lee, Won Jin; Ha, Wi Ho; Seo, Song Won; Jin, Young Woo; Jeong, Kyu Hwan; Yoon, Hae Jung; Kim, Hyoung Soo; Hwang, Myung Sil; Choi, Hoon

    2016-01-01

    After the Fukushima Daiichi nuclear power plant accident, a widespread public concern for radiation exposure through the contamination of domestic or imported food has continued worldwide. Because the internal exposure from contaminated food is an important consideration for human health effect, some studies for estimating radiation doses and cancer risk from the Fukushima nuclear accident have been conducted in several countries (1). The aims of the study is to estimate internal radiation dose and lifetime risks of cancer from food ingestion in Korean population. Our findings suggest no discernible increase n radiation doses or excess fatal cancer risk from food ingestion at this stage in Korea, and provide scientific evidence of the risk communication with general public associated with low-dose radiation exposure.

  13. RiD: A New Approach to Estimate the Insolvency Risk

    Directory of Open Access Journals (Sweden)

    Marco Aurélio dos Santos Sanfins

    2014-10-01

    Full Text Available Given the recent international crises and the increasing number of defaults, several researchers have attempted to develop metrics that calculate the probability of insolvency with higher accuracy. The approaches commonly used, however, do not consider the credit risk nor the severity of the distance between receivables and obligations among different periods. In this paper we mathematically present an approach that allow us to estimate the insolvency risk by considering not only future receivables and obligations, but the severity of the distance between them and the quality of the respective receivables. Using Monte Carlo simulations and hypothetical examples, we show that our metric is able to estimate the insolvency risk with high accuracy. Moreover, our results suggest that in the absence of a smooth distribution between receivables and obligations, there is a non-null insolvency risk even when the present value of receivables is larger than the present value of the obligations.

  14. Estimates of radiation doses and cancer risk from food intake in Korea

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Eun Kyeong; Lee, Won Jin [Korea University, Seoul (Korea, Republic of); Ha, Wi Ho; Seo, Song Won; Jin, Young Woo [Korea Institute of Radiological and Medical Sciences, Seoul (Korea, Republic of); Jeong, Kyu Hwan [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of); Yoon, Hae Jung; Kim, Hyoung Soo; Hwang, Myung Sil [Ministry of Food and Drug Safety, Cheongju (Korea, Republic of); Choi, Hoon [Wonkwang University, Iksan (Korea, Republic of)

    2016-04-15

    After the Fukushima Daiichi nuclear power plant accident, a widespread public concern for radiation exposure through the contamination of domestic or imported food has continued worldwide. Because the internal exposure from contaminated food is an important consideration for human health effect, some studies for estimating radiation doses and cancer risk from the Fukushima nuclear accident have been conducted in several countries (1). The aims of the study is to estimate internal radiation dose and lifetime risks of cancer from food ingestion in Korean population. Our findings suggest no discernible increase n radiation doses or excess fatal cancer risk from food ingestion at this stage in Korea, and provide scientific evidence of the risk communication with general public associated with low-dose radiation exposure.

  15. Estimation of stochastic effects risk in children from areas affected by the Chernobyl accident

    International Nuclear Information System (INIS)

    Jova S, L.; Garcia L, O.; Valdes R, M.

    1996-01-01

    Radiation risk estimation of stochastic effect was evaluated in a group of children assisted in the Cuba Republic as part of the program for medical attention with children from areas affected by the Chernobyl accident . Doses, received from different sources, were estimated for risk evaluation. The study shows total detrimental effects between 0,02 - 0,01% for different groups; values lower than expected for developed country (17-20%). Fatal thyroid cancer increased up to 0,07% in one of the studied groups. (authors). 8 refs., 4 tabs

  16. Estimating and controlling workplace risk: an approach for occupational hygiene and safety professionals.

    Science.gov (United States)

    Toffel, Michael W; Birkner, Lawrence R

    2002-07-01

    The protection of people and physical assets is the objective of health and safety professionals and is accomplished through the paradigm of anticipation, recognition, evaluation, and control of risks in the occupational environment. Risk assessment concepts are not only used by health and safety professionals, but also by business and financial planners. Since meeting health and safety objectives requires financial resources provided by business and governmental managers, the hypothesis addressed here is that health and safety risk decisions should be made with probabilistic processes used in financial decision-making and which are familiar and recognizable to business and government planners and managers. This article develops the processes and demonstrates the use of incident probabilities, historic outcome information, and incremental impact analysis to estimate risk of multiple alternatives in the chemical process industry. It also analyzes how the ethical aspects of decision-making can be addressed in formulating health and safety risk management plans. It is concluded that certain, easily understood, and applied probabilistic risk assessment methods used by business and government to assess financial and outcome risk have applicability to improving workplace health and safety in three ways: 1) by linking the business and health and safety risk assessment processes to securing resources, 2) by providing an additional set of tools for health and safety risk assessment, and 3) by requiring the risk assessor to consider multiple risk management alternatives.

  17. Common pitfalls in statistical analysis: Absolute risk reduction, relative risk reduction, and number needed to treat

    Science.gov (United States)

    Ranganathan, Priya; Pramesh, C. S.; Aggarwal, Rakesh

    2016-01-01

    In the previous article in this series on common pitfalls in statistical analysis, we looked at the difference between risk and odds. Risk, which refers to the probability of occurrence of an event or outcome, can be defined in absolute or relative terms. Understanding what these measures represent is essential for the accurate interpretation of study results. PMID:26952180

  18. Development and prospective validation of a model estimating risk of readmission in cancer patients.

    Science.gov (United States)

    Schmidt, Carl R; Hefner, Jennifer; McAlearney, Ann S; Graham, Lisa; Johnson, Kristen; Moffatt-Bruce, Susan; Huerta, Timothy; Pawlik, Timothy M; White, Susan

    2018-02-26

    Hospital readmissions among cancer patients are common. While several models estimating readmission risk exist, models specific for cancer patients are lacking. A logistic regression model estimating risk of unplanned 30-day readmission was developed using inpatient admission data from a 2-year period (n = 18 782) at a tertiary cancer hospital. Readmission risk estimates derived from the model were then calculated prospectively over a 10-month period (n = 8616 admissions) and compared with actual incidence of readmission. There were 2478 (13.2%) unplanned readmissions. Model factors associated with readmission included: emergency department visit within 30 days, >1 admission within 60 days, non-surgical admission, solid malignancy, gastrointestinal cancer, emergency admission, length of stay >5 days, abnormal sodium, hemoglobin, or white blood cell count. The c-statistic for the model was 0.70. During the 10-month prospective evaluation, estimates of readmission from the model were associated with higher actual readmission incidence from 20.7% for the highest risk category to 9.6% for the lowest. An unplanned readmission risk model developed specifically for cancer patients performs well when validated prospectively. The specificity of the model for cancer patients, EMR incorporation, and prospective validation justify use of the model in future studies designed to reduce and prevent readmissions. © 2018 Wiley Periodicals, Inc.

  19. The use of importance sampling in a trial assessment to obtain converged estimates of radiological risk

    International Nuclear Information System (INIS)

    Johnson, K.; Lucas, R.

    1986-12-01

    In developing a methodology for assessing potential sites for the disposal of radioactive wastes, the Department of the Environment has conducted a series of trial assessment exercises. In order to produce converged estimates of radiological risk using the SYVAC A/C simulation system an efficient sampling procedure is required. Previous work has demonstrated that importance sampling can substantially increase sampling efficiency. This study used importance sampling to produce converged estimates of risk for the first DoE trial assessment. Four major nuclide chains were analysed. In each case importance sampling produced converged risk estimates with between 10 and 170 times fewer runs of the SYVAC A/C model. This increase in sampling efficiency can reduce the total elapsed time required to obtain a converged estimate of risk from one nuclide chain by a factor of 20. The results of this study suggests that the use of importance sampling could reduce the elapsed time required to perform a risk assessment of a potential site by a factor of ten. (author)

  20. Estimation of the value-at-risk parameter: Econometric analysis and the extreme value theory approach

    Directory of Open Access Journals (Sweden)

    Mladenović Zorica

    2006-01-01

    Full Text Available In this paper different aspects of value-at-risk estimation are considered. Daily returns of CISCO, INTEL and NASDAQ stock indices are analyzed for period: September 1996 - September 2006. Methods that incorporate time varying variability and heavy tails of the empirical distributions of returns are implemented. The main finding of the paper is that standard econometric methods underestimate the value-at-risk parameter if heavy tails of the empirical distribution are not explicitly taken into account. .

  1. Estimators of the Relations of Equivalence, Tolerance and Preference Based on Pairwise Comparisons with Random Errors

    Directory of Open Access Journals (Sweden)

    Leszek Klukowski

    2012-01-01

    Full Text Available This paper presents a review of results of the author in the area of estimation of the relations of equivalence, tolerance and preference within a finite set based on multiple, independent (in a stochastic way pairwise comparisons with random errors, in binary and multivalent forms. These estimators require weaker assumptions than those used in the literature on the subject. Estimates of the relations are obtained based on solutions to problems from discrete optimization. They allow application of both types of comparisons - binary and multivalent (this fact relates to the tolerance and preference relations. The estimates can be verified in a statistical way; in particular, it is possible to verify the type of the relation. The estimates have been applied by the author to problems regarding forecasting, financial engineering and bio-cybernetics. (original abstract

  2. Urban micro-scale flood risk estimation with parsimonious hydraulic modelling and census data

    Directory of Open Access Journals (Sweden)

    C. Arrighi

    2013-05-01

    Full Text Available The adoption of 2007/60/EC Directive requires European countries to implement flood hazard and flood risk maps by the end of 2013. Flood risk is the product of flood hazard, vulnerability and exposure, all three to be estimated with comparable level of accuracy. The route to flood risk assessment is consequently much more than hydraulic modelling of inundation, that is hazard mapping. While hazard maps have already been implemented in many countries, quantitative damage and risk maps are still at a preliminary level. A parsimonious quasi-2-D hydraulic model is here adopted, having many advantages in terms of easy set-up. It is here evaluated as being accurate in flood depth estimation in urban areas with a high-resolution and up-to-date Digital Surface Model (DSM. The accuracy, estimated by comparison with marble-plate records of a historic flood in the city of Florence, is characterized in the downtown's most flooded area by a bias of a very few centimetres and a determination coefficient of 0.73. The average risk is found to be about 14 € m−2 yr−1, corresponding to about 8.3% of residents' income. The spatial distribution of estimated risk highlights a complex interaction between the flood pattern and the building characteristics. As a final example application, the estimated risk values have been used to compare different retrofitting measures. Proceeding through the risk estimation steps, a new micro-scale potential damage assessment method is proposed. This is based on the georeferenced census system as the optimal compromise between spatial detail and open availability of socio-economic data. The results of flood risk assessment at the census section scale resolve most of the risk spatial variability, and they can be easily aggregated to whatever upper scale is needed given that they are geographically defined as contiguous polygons. Damage is calculated through stage–damage curves, starting from census data on building type and

  3. Uncertainty in exposure of underground miners to radon daughters and the effect of uncertainty on risk estimates

    International Nuclear Information System (INIS)

    1989-10-01

    Studies of underground miners provide the principal basis for assessing the risk from radon daughter exposure. An important problem in all epidemiological studies of underground miners is the reliability of the estimates of the miners' exposures. This study examines the various sources of uncertainty in exposure estimation for the principal epidemiologic studies reported in the literature including the temporal and spatial variability of radon sources and, with the passage of time, changes to both mining methods and ventilation conditions. Uncertainties about work histories and the role of other hard rock mining experience are also discussed. The report also describes two statistical approaches, both based on Bayesian methods, by which the effects on the estimated risk coefficient of uncertainty in exposure (WLM) can be examined. One approach requires only an estimate of the cumulative WLM exposure of a group of miners, an estimate of the number of (excess) lung cancers potentially attributable to that exposure, and a specification of the uncertainty about the cumulative exposure of the group. The second approach is based on a linear regression model which incorporates errors (uncertainty) in the independent variable (WLM) and allows the dependent variable (cases) to be Poisson distributed. The method permits the calculation of marginal probability distributions for either slope (risk coefficient) or intercept. The regression model approach is applied to several published data sets from epidemiological studies of miners. Specific results are provided for each data set and apparent differences in risk coefficients are discussed. The studies of U.S. uranium miners, Ontario uranium miners and Czechoslovakian uranium miners are argued to provide the best basis for risk estimation at this time. In general terms, none of the analyses performed are inconsistent with a linear exposure-effect relation. Based on analyses of the overall miner groups, the most likely ranges

  4. Space Radiation Cancer, Circulatory Disease and CNS Risks for Near Earth Asteroid and Mars Missions: Uncertainty Estimates for Never-Smokers

    Science.gov (United States)

    Cucinotta, Francis A.; Chappell, Lori J.; Wang, Minli; Kim, Myung-Hee

    2011-01-01

    history of smoking exposure has a larger impact on GCR risk estimates than amounts of radiation shielding or age at exposure (amongst adults). Risks for never-smokers compared to the average U.S. population are estimated to be reduced between 30% and 60% dependent on model assumptions. Lung cancer is the major contributor to the reduction for never-smokers, with additional contributions from circulatory diseases and cancers of the stomach, liver, bladder, oral cavity and esophagus, and leukemia. The relative contribution of CNS risks to the overall space radiation detriment is potentially increased for never-smokers such as most astronauts. Problems in estimating risks for former smokers and the influence of second-hand smoke are discussed. Compared to the LET approximation, the new track structure derived radiation quality functions lead to a reduced risk for relativistic energy particles and increased risks for intermediate energy particles. Revised estimates for the number of safe days in space at solar minimum for heavy shielding conditions are described for never-smokers and the average U.S. population. Results show that missions to near Earth asteroids (NEA) or Mars violate NASA's radiation safety standards with the current levels of uncertainties. Greater improvements in risk estimates for never-smokers are possible, and would be dependent on improved understanding of risk transfer models, and elucidating the role of space radiation on the various stages of disease formation (e.g. initiation, promotion, and progression).

  5. Cancer-related fatigue: Mechanisms, risk factors, and treatments

    Science.gov (United States)

    Bower, Julienne E.

    2015-01-01

    Fatigue is one of the most common and distressing side effects of cancer and its treatment, and may persist for years after treatment completion in otherwise healthy survivors. Cancer-related fatigue causes disruption in all aspects of quality of life and may be a risk factor for reduced survival. The prevalence and course of fatigue in cancer patients has been well characterized, and there is growing understanding of underlying biological mechanisms. Inflammation has emerged as a key biological pathway for cancer-related fatigue, with studies documenting links between markers of inflammation and fatigue before, during, and particularly after treatment. There is considerable variability in the experience of cancer-related fatigue that is not explained by disease- or treatment-related characteristics, suggesting that host factors may play an important role in the development and persistence of this symptom. Indeed, longitudinal studies have begun to identify genetic, biological, psychosocial, and behavioral risk factors for cancer-related fatigue. Given the multi-factorial nature of cancer-related fatigue, a variety of intervention approaches have been examined in randomized controlled trials, including physical activity, psychosocial, mind-body, and pharmacological treatments. Although there is currently no gold standard for treating fatigue, several of these approaches have shown beneficial effects and can be recommended to patients. This report provides a state of the science review of mechanisms, risk factors, and interventions for cancer-related fatigue, with a focus on recent longitudinal studies and randomized trials that have targeted fatigued patients. PMID:25113839

  6. Are we overestimating the stroke risk related to contraceptive pills?

    Science.gov (United States)

    Gompel, Anne; Plu-Bureau, Genevieve

    2014-02-01

    Hormonal contraceptives are used by million of women worldwide. Ischemic stroke is one of the major harmful effects of hormonal contraceptives, but remains a very uncommon disease before menopause. The increased risk of stroke under third and fourth-generation contraceptive pills and nonoral contraceptives has been recently highlighted. Given the benefits associated with combined hormonal contraceptives (COCs), it is important to properly evaluate their risks in order to provide a better benefit/risk balance to young women. Scarce studies addressing the rates of stroke in young women suggest that the fraction attributable to the contraceptive pill remains low. In contrast, there is abundant literature on the relative risks of stroke under COCs. The risk of arterial disease seems to be similar among users of second and third-generation pills, drospirenone-containing pills and nonoral hormonal contraceptives. Progestin-only contraceptives do not appear to be associated with an increased risk of stroke. New formulations of hormonal contraceptives are not safer than second-generation COCs. Even if the absolute numbers of strokes attributable to hormonal contraceptives is very low, stringent selection of patients should help to reduce the events still more, and progestin-only contraceptives/nonhormonal methods should be preferred in cases of associated risk factors.

  7. Risk of bleeding related to antithrombotic treatment in cardiovascular disease

    DEFF Research Database (Denmark)

    Sørensen, Rikke; Olesen, Jonas B; Charlot, Mette

    2012-01-01

    Antithrombotic therapy is a cornerstone of treatment in patients with cardiovascular disease with bleeding being the most feared complication. This review describes the risk of bleeding related to different combinations of antithrombotic drugs used for cardiovascular disease: acute coronary...... syndrome (ACS), atrial fibrillation (AF), cerebrovascular (CVD) and peripheral arterial disease (PAD). Different risk assessment schemes and bleeding definitions are compared. The HAS-BLED risk score is recommended in patients with AF and in ACS patients with AF. In patients with ACS with or without...... a stent dual antiplatelet therapy with a P2Y12 receptor antagonist and acetylsalicylic acid (ASA) is recommended for 12 months, preferable with prasugrel or ticagrelor unless there is an additional indication of warfarin or increased risk of bleeding. In patients with AF, warfarin is recommended...

  8. Human capital and risk aversion in relational incentive contracts

    International Nuclear Information System (INIS)

    Kvaloey, Ola

    2003-01-01

    This paper examines a self-enforced relational incentive contract between a risk neutral principal and a risk averse agent where the agent's human capital is essential in ex post realization of values. I analyse the effect of outside options on the optimal bonus level, showing how the presence of ex post outside options may impede desirable degrees of performance pay. The effect of risk aversion and incentive responsiveness is analysed by allowing for linear contracts. I show that the first order effect of these parameters are the same as in verifiable contracts, but second order effects show that the optimal bonus level's sensitivity to risk aversion and incentive responsiveness increases with the discount factor. The analysis has interesting implications on firm boundaries and specificity choices. (author)

  9. Elite athletes experiences with risk related to cardiac screening

    DEFF Research Database (Denmark)

    Christensen, Jonas Schmidt; Thing, Lone Friis

    Society of Cardiology as well as major sports federations such as the International Olympic Committee, however, these recommendations seem to be based on an inadequate empirical foundation, just as the costs of performing cardiac screening on a larger scale seem out of proportion. Additionally, the field...... perspective on risk (Foucault 1988). For most elite athletes participation in cardiac screening is done out of a wish to obtain an acquittal from risks. Symptomatic of the risk society cardiac screening can from an athlete perspective at the same time be seen as an attempt to gain control over......Elite Athletes experiences with risks related to Cardiac Screening Jonas Schmidt Christensen1, Lone Friis Thing1 1University of Copenhagen - Department of Nutrition, Exercise and Sports (NEXS), Cardiac screening of elite athletes are recommended by both the American Heart Association & the European...

  10. Temperature-related mortality estimates after accounting for the cumulative effects of air pollution in an urban area.

    Science.gov (United States)

    Stanišić Stojić, Svetlana; Stanišić, Nemanja; Stojić, Andreja

    2016-07-11

    To propose a new method for including the cumulative mid-term effects of air pollution in the traditional Poisson regression model and compare the temperature-related mortality risk estimates, before and after including air pollution data. The analysis comprised a total of 56,920 residents aged 65 years or older who died from circulatory and respiratory diseases in Belgrade, Serbia, and daily mean PM10, NO2, SO2 and soot concentrations obtained for the period 2009-2014. After accounting for the cumulative effects of air pollutants, the risk associated with cold temperatures was significantly lower and the overall temperature-attributable risk decreased from 8.80 to 3.00 %. Furthermore, the optimum range of temperature, within which no excess temperature-related mortality is expected to occur, was very broad, between -5 and 21 °C, which differs from the previous findings that most of the attributable deaths were associated with mild temperatures. These results suggest that, in polluted areas of developing countries, most of the mortality risk, previously attributed to cold temperatures, can be explained by the mid-term effects of air pollution. The results also showed that the estimated relative importance of PM10 was the smallest of four examined pollutant species, and thus, including PM10 data only is clearly not the most effective way to control for the effects of air pollution.

  11. A practical approach to risk-benefit estimation in pediatric drug research.

    Science.gov (United States)

    Koren, Gideon

    2015-02-01

    One of the most difficult challenges in pediatric drug research is in exposing children to risk, often without a balanced chance of benefits. While the concept of risk is similar in adult research, the adult patient can decide for himself/herself on an acceptable level of risk, whereas children have to accept the decisions of their guardians. This paper attempts to put the complexities of estimating risk in pediatric drug research into their practical perspective, and to familiarize the reader with the way such processes are conducted in different parts of the world. Although there are regional differences, all authorities typically quantify risks of pediatric research in general, and drug research in particular, in three levels: those experienced in day-to-day life; risks slightly above this