Science.gov

Sample records for absolute risk estimates

  1. Comparison of two methods for estimating absolute risk of prostate cancer based on SNPs and family history

    PubMed Central

    Hsu, Fang-Chi; Sun, Jielin; Zhu, Yi; Kim, Seong-Tae; Jin, Tao; Zhang, Zheng; Wiklund, Fredrik; Kader, A. Karim; Zheng, S. Lilly; Isaacs, William; Grönberg, Henrik; Xu, Jianfeng

    2010-01-01

    Disease risk-associated single nucleotide polymorphisms (SNPs) identified from genome-wide association studies have the potential to be used for disease risk prediction. An important feature of these risk-associated SNPs is their weak individual effect but stronger cumulative effect on disease risk. Several approaches are commonly used to model the combined effect in risk prediction but their performance is unclear. We compared two methods to model the combined effect of 14 prostate cancer (PCa) risk-associated SNPs and family history for the estimation of absolute risk for PCa in a population-based case-control study in Sweden (2,899 cases and 1,722 controls). Method 1 weighs each risk allele equally using a simple method of counting the number of risk alleles while Method 2 weighs each risk SNP differently based on their respective Odds Ratios. We found considerable differences between the two methods. Absolute risk estimates from Method 1 were generally higher than that of Method 2, especially among men at higher risk. The difference in the overall discriminative performance, measured by area under the curve (AUC) of the receiver operating characteristic was small between Method 1 (0.614) and Method 2 (0.618), P = 0.20. However, the performance of these two methods in identifying high-risk individuals (two-fold or three-fold higher than average risk), measured by positive predictive values (PPV), was higher for Method 2 than Method 1. In conclusion, these results suggest that Method 2 is superior to Method 1 in estimating absolute risk if the purpose of risk prediction is to identify high-risk individuals. PMID:20332264

  2. Estimating the absolute wealth of households

    PubMed Central

    Gerkey, Drew; Hadley, Craig

    2015-01-01

    Abstract Objective To estimate the absolute wealth of households using data from demographic and health surveys. Methods We developed a new metric, the absolute wealth estimate, based on the rank of each surveyed household according to its material assets and the assumed shape of the distribution of wealth among surveyed households. Using data from 156 demographic and health surveys in 66 countries, we calculated absolute wealth estimates for households. We validated the method by comparing the proportion of households defined as poor using our estimates with published World Bank poverty headcounts. We also compared the accuracy of absolute versus relative wealth estimates for the prediction of anthropometric measures. Findings The median absolute wealth estimates of 1 403 186 households were 2056 international dollars per capita (interquartile range: 723–6103). The proportion of poor households based on absolute wealth estimates were strongly correlated with World Bank estimates of populations living on less than 2.00 United States dollars per capita per day (R2 = 0.84). Absolute wealth estimates were better predictors of anthropometric measures than relative wealth indexes. Conclusion Absolute wealth estimates provide new opportunities for comparative research to assess the effects of economic resources on health and human capital, as well as the long-term health consequences of economic change and inequality. PMID:26170506

  3. The performance of different propensity-score methods for estimating differences in proportions (risk differences or absolute risk reductions) in observational studies.

    PubMed

    Austin, Peter C

    2010-09-10

    Propensity score methods are increasingly being used to estimate the effects of treatments on health outcomes using observational data. There are four methods for using the propensity score to estimate treatment effects: covariate adjustment using the propensity score, stratification on the propensity score, propensity-score matching, and inverse probability of treatment weighting (IPTW) using the propensity score. When outcomes are binary, the effect of treatment on the outcome can be described using odds ratios, relative risks, risk differences, or the number needed to treat. Several clinical commentators suggested that risk differences and numbers needed to treat are more meaningful for clinical decision making than are odds ratios or relative risks. However, there is a paucity of information about the relative performance of the different propensity-score methods for estimating risk differences. We conducted a series of Monte Carlo simulations to examine this issue. We examined bias, variance estimation, coverage of confidence intervals, mean-squared error (MSE), and type I error rates. A doubly robust version of IPTW had superior performance compared with the other propensity-score methods. It resulted in unbiased estimation of risk differences, treatment effects with the lowest standard errors, confidence intervals with the correct coverage rates, and correct type I error rates. Stratification, matching on the propensity score, and covariate adjustment using the propensity score resulted in minor to modest bias in estimating risk differences. Estimators based on IPTW had lower MSE compared with other propensity-score methods. Differences between IPTW and propensity-score matching may reflect that these two methods estimate the average treatment effect and the average treatment effect for the treated, respectively.

  4. Estimating risk.

    PubMed

    2016-07-01

    A free mobile phone app has been launched providing nurses and other hospital clinicians with a simple way to identify high-risk surgical patients. The app is a phone version of the Surgical Outcome Risk Tool (SORT), originally developed for online use with computers by researchers from the National Confidential Enquiry into Patient Outcome and Death and the University College London Hospital Surgical Outcomes Research Centre. SORT uses information about patients' health and planned surgical procedures to estimate the risk of death within 30 days of an operation. The percentages are only estimates, taking into account the general risks of the procedures and some information about patients, and should not be confused with patient-specific estimates in individual cases. PMID:27369709

  5. Method for estimating absolute lung volumes at constant inflation pressure.

    PubMed

    Hills, B A; Barrow, R E

    1979-10-01

    A method has been devised for measuring functional residual capacity in the intact killed animal or absolute lung volumes in any excised lung preparation without changing the inflation pressure. This is achieved by titrating the absolute pressure of a chamber in which the preparation is compressed until a known volume of air has entered the lungs. This technique was used to estimate the volumes of five intact rabbit lungs and five rigid containers of known dimensions by means of Boyle's law. Results were found to agree to within +/- 1% with values determined by alternative methods. In the discussion the advantage of determining absolute lung volumes at almost any stage in a study of lung mechanics without the determination itself changing inflation pressure and, hence, lung volume is emphasized. PMID:511699

  6. Risk estimates for bone

    SciTech Connect

    Schlenker, R.A.

    1981-01-01

    The primary sources of information on the skeletal effects of internal emitters in humans are the US radium cases with occupational and medical exposures to /sup 226/ /sup 228/Ra and the German patients injected with /sup 224/Ra primarily for treatment of ankylosing spondylitis and tuberculosis. During the past decade, dose-response data from both study populations have been used by committees, e.g., the BEIR committees, to estimate risks at low dose levels. NCRP Committee 57 and its task groups are now engaged in making risk estimates for internal emitters. This paper presents brief discussions of the radium data, the results of some new analyses and suggestions for expressing risk estimates in a form appropriate to radiation protection.

  7. Common genetic polymorphisms modify the effect of smoking on absolute risk of bladder cancer

    PubMed Central

    Garcia-Closas, Montserrat; Rothman, Nathaniel; Figueroa, Jonine D.; Prokunina-Olsson, Ludmila; Han, Summer S.; Baris, Dalsu; Jacobs, Eric J; Malats, Nuria; De Vivo, Immaculata; Albanes, Demetrius; Purdue, Mark P; Sharma, Sapna; Fu, Yi-Ping; Kogevinas, Manolis; Wang, Zhaoming; Tang, Wei; Tardón, Adonina; Serra, Consol; Carrato, Alfredo; García-Closas, Reina; Lloreta, Josep; Johnson, Alison; Schwenn, Molly; Karagas, Margaret R; Schned, Alan; Andriole, Gerald; Grubb, Robert; Black, Amanda; Gapstur, Susan M; Thun, Michael; Diver, W Ryan; Weinstein, Stephanie J; Virtamo, Jarmo; Hunter, David J; Caporaso, Neil; Landi, Maria Teresa; Hutchinson, Amy; Burdett, Laurie; Jacobs, Kevin B; Yeager, Meredith; Fraumeni, Joseph F; Chanock, Stephen J; Silverman, Debra T; Chatterjee, Nilanjan

    2013-01-01

    Bladder cancer results from the combined effects of environmental and genetic factors, smoking being the strongest risk factor. Evaluating absolute risks resulting from the joint effects of smoking and genetic factors is critical to evaluate the public health relevance of genetic information. Analyses included up to 3,942 cases and 5,680 controls of European background in seven studies. We tested for multiplicative and additive interactions between smoking and 12 susceptibility loci, individually and combined as a polygenic risk score (PRS). Thirty-year absolute risks and risk differences by levels of the PRS were estimated for US-males aged 50-years. Six out of 12 variants showed significant additive gene-environment interactions, most notably NAT2 (P=7×10-4) and UGT1A6 (P=8×10-4). The 30-year absolute risk of bladder cancer in US males was 6.2% for all current smokers. This risk ranged from 2.9% for current smokers in the lowest quartile of the PRS to 9.9% for current smokers in the upper quartile. Risk difference estimates indicated that 8,200 cases would be prevented if elimination of smoking occurred in 100,000 men in the upper PRS quartile, compared to 2,000 cases prevented by a similar effort in the lowest PRS quartile (P-additive =1×10-4). The impact of eliminating smoking the on number of bladder cancer cases prevented is larger for individuals at higher than lower genetic risk. Our findings could have implications for targeted prevention strategies. However, other smoking-related diseases, as well as practical and ethical considerations, need to be considered before any recommendations could be made. PMID:23536561

  8. Common genetic polymorphisms modify the effect of smoking on absolute risk of bladder cancer.

    PubMed

    Garcia-Closas, Montserrat; Rothman, Nathaniel; Figueroa, Jonine D; Prokunina-Olsson, Ludmila; Han, Summer S; Baris, Dalsu; Jacobs, Eric J; Malats, Nuria; De Vivo, Immaculata; Albanes, Demetrius; Purdue, Mark P; Sharma, Sapna; Fu, Yi-Ping; Kogevinas, Manolis; Wang, Zhaoming; Tang, Wei; Tardón, Adonina; Serra, Consol; Carrato, Alfredo; García-Closas, Reina; Lloreta, Josep; Johnson, Alison; Schwenn, Molly; Karagas, Margaret R; Schned, Alan; Andriole, Gerald; Grubb, Robert; Black, Amanda; Gapstur, Susan M; Thun, Michael; Diver, William Ryan; Weinstein, Stephanie J; Virtamo, Jarmo; Hunter, David J; Caporaso, Neil; Landi, Maria Teresa; Hutchinson, Amy; Burdett, Laurie; Jacobs, Kevin B; Yeager, Meredith; Fraumeni, Joseph F; Chanock, Stephen J; Silverman, Debra T; Chatterjee, Nilanjan

    2013-04-01

    Bladder cancer results from the combined effects of environmental and genetic factors, smoking being the strongest risk factor. Evaluating absolute risks resulting from the joint effects of smoking and genetic factors is critical to assess the public health relevance of genetic information. Analyses included up to 3,942 cases and 5,680 controls of European background in seven studies. We tested for multiplicative and additive interactions between smoking and 12 susceptibility loci, individually and combined as a polygenic risk score (PRS). Thirty-year absolute risks and risk differences by levels of the PRS were estimated for U.S. males aged 50 years. Six of 12 variants showed significant additive gene-environment interactions, most notably NAT2 (P = 7 × 10(-4)) and UGT1A6 (P = 8 × 10(-4)). The 30-year absolute risk of bladder cancer in U.S. males was 6.2% for all current smokers. This risk ranged from 2.9% for current smokers in the lowest quartile of the PRS to 9.9% for current smokers in the upper quartile. Risk difference estimates indicated that 8,200 cases would be prevented if elimination of smoking occurred in 100,000 men in the upper PRS quartile compared with 2,000 cases prevented by a similar effort in the lowest PRS quartile (P(additive) = 1 × 10(-4)). Thus, the potential impact of eliminating smoking on the number of bladder cancer cases prevented is larger for individuals at higher than lower genetic risk. Our findings could have implications for targeted prevention strategies. However, other smoking-related diseases, as well as practical and ethical considerations, need to be considered before any recommendations could be made.

  9. Absolute and Comparative Cancer Risk Perceptions Among Smokers in Two Cities in China

    PubMed Central

    2014-01-01

    Introduction: Knowledge about health effects of smoking motivates quit attempts and sustained abstinence among smokers and also predicts greater acceptance of tobacco control efforts such as cigarette taxes and public smoking bans. We examined whether smokers in China, the world’s largest consumer of cigarettes, recognized their heightened personal risk of cancer relative to nonsmokers. Methods: A sample of Chinese people (N = 2,517; 555 current smokers) from 2 cities (Beijing and Hefei) estimated their personal risk of developing cancer, both in absolute terms (overall likelihood) and in comparative terms (relative to similarly aged people). Results: Controlling for demographics, smokers judged themselves to be at significantly lower risk of cancer than did nonsmokers on the comparative measure. No significant difference emerged between smokers and nonsmokers in absolute estimates. Conclusions: Smokers in China did not recognize their heightened personal risk of cancer, possibly reflecting ineffective warning labels on cigarette packs, a positive affective climate associated with smoking in China, and beliefs that downplay personal vulnerability among smokers (e.g., I don’t smoke enough to increase my cancer risk; I smoke high-quality cigarettes that won’t cause cancer). PMID:24668289

  10. Quantifying Cancer Absolute Risk and Cancer Mortality in the Presence of Competing Events after a Myotonic Dystrophy Diagnosis

    PubMed Central

    Gadalla, Shahinaz M.; Pfeiffer, Ruth M.; Kristinsson, Sigurdur Y.; Björkholm, Magnus; Hilbert, James E.; Moxley, Richard T.; Landgren, Ola; Greene, Mark H.

    2013-01-01

    Recent studies show that patients with myotonic dystrophy (DM) have an increased risk of specific malignancies, but estimates of absolute cancer risk accounting for competing events are lacking. Using the Swedish Patient Registry, we identified 1,081 patients with an inpatient and/or outpatient diagnosis of DM between 1987 and 2007. Date and cause of death and date of cancer diagnosis were extracted from the Swedish Cause of Death and Cancer Registries. We calculated non-parametric estimates of absolute cancer risk and cancer mortality accounting for the high non-cancer competing mortality associated with DM. Absolute cancer risk after DM diagnosis was 1.6% (95% CI=0.4-4%), 5% (95% CI=3-9%) and 9% (95% CI=6-13%) at ages 40, 50 and 60 years, respectively. Females had a higher absolute risk of all cancers combined than males: 9% (95% CI=4-14), and 13% (95% CI=9-20) vs. 2% (95%CI= 0.7-6) and 4% (95%CI=2-8) by ages 50 and 60 years, respectively) and developed cancer at younger ages (median age =51 years, range=22-74 vs. 57, range=43-84, respectively, p=0.02). Cancer deaths accounted for 10% of all deaths, with an absolute cancer mortality risk of 2% (95%CI=1-4.5%), 4% (95%CI=2-6%), and 6% (95%CI=4-9%) by ages 50, 60, and 70 years, respectively. No gender difference in cancer-specific mortality was observed (p=0.6). In conclusion, cancer significantly contributes to morbidity and mortality in DM patients, even after accounting for high competing DM mortality from non-neoplastic causes. It is important to apply population-appropriate, validated cancer screening strategies in DM patients. PMID:24236163

  11. Estimates of radiogenic cancer risks

    SciTech Connect

    Puskin, J.S.; Nelson, C.B.

    1995-07-01

    A methodology recently developed by the U.S. EPA for estimating the carcingenic risks from ionizing radiation is described. For most cancer sites, the risk model is one in which age-specific, relative risk coefficients are obtained by taking a geometric mean of the coefficients derived from the atomic bomb survivor data using two different methods for transporting risks from the Japanese to the U.S. population. The risk models are applied to estimate organ-specific risks per unit dose for a stationary population with mortality rates governed by 1980 U.S. vital statistics. With the exception of breast cancer, low-LET radiogenic cancer risk estimates are reduced by a factor of 2 at low doses and dose rates compared to acute high dose exposure conditions. For low dose (or dose rate) conditions, the risk of inducing a premature cancer death from uniform, whole body, low-LET irradiation is calculated to be 5.1 x 10{sup -2} Gy{sup -1}. Neglecting nonfatal skin cancers, the corresponding incidence risk is 7.6 x 10{sup -2} Gy{sup -1}. High-LET (alpha particle) risks are presumed to increase linearly with dose and to be independent of dose rate. High-LET risks are estimated to be 20 times the low-LET risks estimated under low dose rate conditions, except for leukemia and breast cancer where RBEs of 1 and 10 are adopted, respectively. 29 refs., 3 tabs.

  12. Global-Scale Location and Distance Estimates: Common Representations and Strategies in Absolute and Relative Judgments

    ERIC Educational Resources Information Center

    Friedman, Alinda; Montello, Daniel R.

    2006-01-01

    The authors examined whether absolute and relative judgments about global-scale locations and distances were generated from common representations. At the end of a 10-week class on the regional geography of the United States, participants estimated the latitudes of 16 North American cities and all possible pairwise distances between them. Although…

  13. [Medical insurance estimation of risks].

    PubMed

    Dunér, H

    1975-11-01

    The purpose of insurance medicine is to make a prognostic estimate of medical risk-factors in persons who apply for life, health, or accident insurance. Established risk-groups with a calculated average mortality and morbidity form the basis for premium rates and insurance terms. In most cases the applicant is accepted for insurance after a self-assessment of his health. Only around one per cent of the applications are refused, but there are cases in which the premium is raised, temporarily or permanently. It is often a matter of rough estimate, since the knowlege of the long-term prognosis for many diseases is incomplete. The insurance companies' rules for estimate of risk are revised at intervals of three or four years. The estimate of risk as regards life insurance has been gradually liberalised, while the medical conditions for health insurance have become stricter owing to an increase in the claims rate.

  14. Absolute magnitude estimation and relative judgement approaches to subjective workload assessment

    NASA Technical Reports Server (NTRS)

    Vidulich, Michael A.; Tsang, Pamela S.

    1987-01-01

    Two rating scale techniques employing an absolute magnitude estimation method, were compared to a relative judgment method for assessing subjective workload. One of the absolute estimation techniques used was an unidimensional overall workload scale and the other was the multidimensional NASA-Task Load Index technique. Thomas Saaty's Analytic Hierarchy Process was the unidimensional relative judgment method used. These techniques were used to assess the subjective workload of various single- and dual-tracking conditions. The validity of the techniques was defined as their ability to detect the same phenomena observed in the tracking performance. Reliability was assessed by calculating test-retest correlations. Within the context of the experiment, the Saaty Analytic Hierarchy Process was found to be superior in validity and reliability. These findings suggest that the relative judgment method would be an effective addition to the currently available subjective workload assessment techniques.

  15. Absolute value optimization to estimate phase properties of stochastic time series

    NASA Technical Reports Server (NTRS)

    Scargle, J. D.

    1977-01-01

    Most existing deconvolution techniques are incapable of determining phase properties of wavelets from time series data; to assure a unique solution, minimum phase is usually assumed. It is demonstrated, for moving average processes of order one, that deconvolution filtering using the absolute value norm provides an estimate of the wavelet shape that has the correct phase character when the random driving process is nonnormal. Numerical tests show that this result probably applies to more general processes.

  16. Reinforcing flood-risk estimation.

    PubMed

    Reed, Duncan W

    2002-07-15

    Flood-frequency estimation is inherently uncertain. The practitioner applies a combination of gauged data, scientific method and hydrological judgement to derive a flood-frequency curve for a particular site. The resulting estimate can be thought fully satisfactory only if it is broadly consistent with all that is reliably known about the flood-frequency behaviour of the river. The paper takes as its main theme the search for information to strengthen a flood-risk estimate made from peak flows alone. Extra information comes in many forms, including documentary and monumental records of historical floods, and palaeological markers. Meteorological information is also useful, although rainfall rarity is difficult to assess objectively and can be a notoriously unreliable indicator of flood rarity. On highly permeable catchments, groundwater levels present additional data. Other types of information are relevant to judging hydrological similarity when the flood-frequency estimate derives from data pooled across several catchments. After highlighting information sources, the paper explores a second theme: that of consistency in flood-risk estimates. Following publication of the Flood estimation handbook, studies of flood risk are now using digital catchment data. Automated calculation methods allow estimates by standard methods to be mapped basin-wide, revealing anomalies at special sites such as river confluences. Such mapping presents collateral information of a new character. Can this be used to achieve flood-risk estimates that are coherent throughout a river basin? PMID:12804255

  17. Reinforcing flood-risk estimation.

    PubMed

    Reed, Duncan W

    2002-07-15

    Flood-frequency estimation is inherently uncertain. The practitioner applies a combination of gauged data, scientific method and hydrological judgement to derive a flood-frequency curve for a particular site. The resulting estimate can be thought fully satisfactory only if it is broadly consistent with all that is reliably known about the flood-frequency behaviour of the river. The paper takes as its main theme the search for information to strengthen a flood-risk estimate made from peak flows alone. Extra information comes in many forms, including documentary and monumental records of historical floods, and palaeological markers. Meteorological information is also useful, although rainfall rarity is difficult to assess objectively and can be a notoriously unreliable indicator of flood rarity. On highly permeable catchments, groundwater levels present additional data. Other types of information are relevant to judging hydrological similarity when the flood-frequency estimate derives from data pooled across several catchments. After highlighting information sources, the paper explores a second theme: that of consistency in flood-risk estimates. Following publication of the Flood estimation handbook, studies of flood risk are now using digital catchment data. Automated calculation methods allow estimates by standard methods to be mapped basin-wide, revealing anomalies at special sites such as river confluences. Such mapping presents collateral information of a new character. Can this be used to achieve flood-risk estimates that are coherent throughout a river basin?

  18. Absolute probability estimates of lethal vessel strikes to North Atlantic right whales in Roseway Basin, Scotian Shelf.

    PubMed

    van der Hoop, Julie M; Vanderlaan, Angelia S M; Taggart, Christopher T

    2012-10-01

    Vessel strikes are the primary source of known mortality for the endangered North Atlantic right whale (Eubalaena glacialis). Multi-institutional efforts to reduce mortality associated with vessel strikes include vessel-routing amendments such as the International Maritime Organization voluntary "area to be avoided" (ATBA) in the Roseway Basin right whale feeding habitat on the southwestern Scotian Shelf. Though relative probabilities of lethal vessel strikes have been estimated and published, absolute probabilities remain unknown. We used a modeling approach to determine the regional effect of the ATBA, by estimating reductions in the expected number of lethal vessel strikes. This analysis differs from others in that it explicitly includes a spatiotemporal analysis of real-time transits of vessels through a population of simulated, swimming right whales. Combining automatic identification system (AIS) vessel navigation data and an observationally based whale movement model allowed us to determine the spatial and temporal intersection of vessels and whales, from which various probability estimates of lethal vessel strikes are derived. We estimate one lethal vessel strike every 0.775-2.07 years prior to ATBA implementation, consistent with and more constrained than previous estimates of every 2-16 years. Following implementation, a lethal vessel strike is expected every 41 years. When whale abundance is held constant across years, we estimate that voluntary vessel compliance with the ATBA results in an 82% reduction in the per capita rate of lethal strikes; very similar to a previously published estimate of 82% reduction in the relative risk of a lethal vessel strike. The models we developed can inform decision-making and policy design, based on their ability to provide absolute, population-corrected, time-varying estimates of lethal vessel strikes, and they are easily transported to other regions and situations.

  19. Mapping return levels of absolute NDVI variations for the assessment of drought risk in Ethiopia

    NASA Astrophysics Data System (ADS)

    Tonini, F.; Hochmair, H. H.; Jona Lasinio, G.

    2012-12-01

    The analysis and forecasting of extreme climatic events has become increasingly relevant to planning effective financial and food-related interventions in third-world countries. Natural disasters and climate change, both large and small scale, have a great impact on non-industrialized populations who rely exclusively on activities such as crop production, fishing, and similar livelihood activities. It is important to identify the extent of the areas prone to severe drought conditions in order to study the possible consequences of the drought on annual crop production. In this paper, we aim to identify such areas within the South Tigray zone, Ethiopia, using a transformation of the Normalized Difference Vegetation Index (NDVI) called Absolute Difference NDVI (ADVI). Negative NDVI shifts from the historical average can generally be linked to a reduction in the vigor of local vegetation. Drought is more likely to increase in areas where negative shifts occur more frequently and with high magnitude, making it possible to spot critical situations. We propose a new methodology for the assessment of drought risk in areas where crop production represents a primary source of livelihood for its inhabitants. We estimate ADVI return levels pixel per pixel by fitting extreme value models to independent monthly minima. The study is conducted using SPOT-Vegetation (VGT) ten-day composite (S10) images from April 1998 to March 2009. In all short-term and long-term predictions, we found that central and southern areas of the South Tigray zone are prone to a higher drought risk compared to other areas.; Temporal autocorrelation among monthly minima within the Alamata woreda. (a) ACF-Boxplot and (b) PACF-Boxplot. ; ADVI return level estimates. (a) 10-Month return levels. (b) 100-Month return levels. (c) 1000-Month return levels.

  20. Improving absolute gravity estimates by the L p -norm approximation of the ballistic trajectory

    NASA Astrophysics Data System (ADS)

    Nagornyi, V. D.; Svitlov, S.; Araya, A.

    2016-04-01

    Iteratively re-weighted least squares (IRLS) were used to simulate the L p -norm approximation of the ballistic trajectory in absolute gravimeters. Two iterations of the IRLS delivered sufficient accuracy of the approximation without a significant bias. The simulations were performed on different samplings and perturbations of the trajectory. For the platykurtic distributions of the perturbations, the L p -approximation with 3  <  p  <  4 was found to yield several times more precise gravity estimates compared to the standard least-squares. The simulation results were confirmed by processing real gravity observations performed at the excessive noise conditions.

  1. Absolute magnitudes of asteroids and a revision of asteroid albedo estimates from WISE thermal observations

    NASA Astrophysics Data System (ADS)

    Pravec, Petr; Harris, Alan W.; Kušnirák, Peter; Galád, Adrián; Hornoch, Kamil

    2012-09-01

    We obtained estimates of the Johnson V absolute magnitudes (H) and slope parameters (G) for 583 main-belt and near-Earth asteroids observed at Ondřejov and Table Mountain Observatory from 1978 to 2011. Uncertainties of the absolute magnitudes in our sample are <0.21 mag, with a median value of 0.10 mag. We compared the H data with absolute magnitude values given in the MPCORB, Pisa AstDyS and JPL Horizons orbit catalogs. We found that while the catalog absolute magnitudes for large asteroids are relatively good on average, showing only little biases smaller than 0.1 mag, there is a systematic offset of the catalog values for smaller asteroids that becomes prominent in a range of H greater than ∼10 and is particularly big above H ∼ 12. The mean (Hcatalog - H) value is negative, i.e., the catalog H values are systematically too bright. This systematic negative offset of the catalog values reaches a maximum around H = 14 where the mean (Hcatalog - H) is -0.4 to -0.5. We found also smaller correlations of the offset of the catalog H values with taxonomic types and with lightcurve amplitude, up to ∼0.1 mag or less. We discuss a few possible observational causes for the observed correlations, but the reason for the large bias of the catalog absolute magnitudes peaking around H = 14 is unknown; we suspect that the problem lies in the magnitude estimates reported by asteroid surveys. With our photometric H and G data, we revised the preliminary WISE albedo estimates made by Masiero et al. (Masired, J.R. et al. [2011]. Astrophys. J. 741, 68-89) and Mainzer et al. (Mainzer, A. et al. [2011b]. Astrophys. J. 743, 156-172) for asteroids in our sample. We found that the mean geometric albedo of Tholen/Bus/DeMeo C/G/B/F/P/D types with sizes of 25-300 km is pV = 0.057 with the standard deviation (dispersion) of the sample of 0.013 and the mean albedo of S/A/L types with sizes 0.6-200 km is 0.197 with the standard deviation of the sample of 0.051. The standard errors of the

  2. Estimation of absolute protein quantities of unlabeled samples by selected reaction monitoring mass spectrometry.

    PubMed

    Ludwig, Christina; Claassen, Manfred; Schmidt, Alexander; Aebersold, Ruedi

    2012-03-01

    For many research questions in modern molecular and systems biology, information about absolute protein quantities is imperative. This information includes, for example, kinetic modeling of processes, protein turnover determinations, stoichiometric investigations of protein complexes, or quantitative comparisons of different proteins within one sample or across samples. To date, the vast majority of proteomic studies are limited to providing relative quantitative comparisons of protein levels between limited numbers of samples. Here we describe and demonstrate the utility of a targeting MS technique for the estimation of absolute protein abundance in unlabeled and nonfractionated cell lysates. The method is based on selected reaction monitoring (SRM) mass spectrometry and the "best flyer" hypothesis, which assumes that the specific MS signal intensity of the most intense tryptic peptides per protein is approximately constant throughout a whole proteome. SRM-targeted best flyer peptides were selected for each protein from the peptide precursor ion signal intensities from directed MS data. The most intense transitions per peptide were selected from full MS/MS scans of crude synthetic analogs. We used Monte Carlo cross-validation to systematically investigate the accuracy of the technique as a function of the number of measured best flyer peptides and the number of SRM transitions per peptide. We found that a linear model based on the two most intense transitions of the three best flying peptides per proteins (TopPep3/TopTra2) generated optimal results with a cross-correlated mean fold error of 1.8 and a squared Pearson coefficient R(2) of 0.88. Applying the optimized model to lysates of the microbe Leptospira interrogans, we detected significant protein abundance changes of 39 target proteins upon antibiotic treatment, which correlate well with literature values. The described method is generally applicable and exploits the inherent performance advantages of SRM

  3. Greater absolute risk for all subtypes of breast cancer in the US than Malaysia.

    PubMed

    Horne, Hisani N; Beena Devi, C R; Sung, Hyuna; Tang, Tieng Swee; Rosenberg, Philip S; Hewitt, Stephen M; Sherman, Mark E; Anderson, William F; Yang, Xiaohong R

    2015-01-01

    Hormone receptor (HR) negative breast cancers are relatively more common in low-risk than high-risk countries and/or populations. However, the absolute variations between these different populations are not well established given the limited number of cancer registries with incidence rate data by breast cancer subtype. We, therefore, used two unique population-based resources with molecular data to compare incidence rates for the 'intrinsic' breast cancer subtypes between a low-risk Asian population in Malaysia and high-risk non-Hispanic white population in the National Cancer Institute's surveillance, epidemiology, and end results 18 registries database (SEER 18). The intrinsic breast cancer subtypes were recapitulated with the joint expression of the HRs (estrogen receptor and progesterone receptor) and human epidermal growth factor receptor-2 (HER2). Invasive breast cancer incidence rates overall were fivefold greater in SEER 18 than in Malaysia. The majority of breast cancers were HR-positive in SEER 18 and HR-negative in Malaysia. Notwithstanding the greater relative distribution for HR-negative cancers in Malaysia, there was a greater absolute risk for all subtypes in SEER 18; incidence rates were nearly 7-fold higher for HR-positive and 2-fold higher for HR-negative cancers in SEER 18. Despite the well-established relative breast cancer differences between low-risk and high-risk countries and/or populations, there was a greater absolute risk for HR-positive and HR-negative subtypes in the US than Malaysia. Additional analytical studies are sorely needed to determine the factors responsible for the elevated risk of all subtypes of breast cancer in high-risk countries like the United States.

  4. Mapping return levels of absolute NDVI variations for the assessment of drought risk in Ethiopia

    NASA Astrophysics Data System (ADS)

    Tonini, Francesco; Jona Lasinio, Giovanna; Hochmair, Hartwig H.

    2012-08-01

    The analysis and forecasting of extreme climatic events has become increasingly relevant to plan effective financial and food-related interventions in third-world countries. Natural disasters and climate change, both large and small scale, have a great impact on non-industrialized populations who rely exclusively on activities such as crop production, fishing, and similar livelihood activities. It is important to identify the extent of the areas prone to severe drought conditions in order to study the possible consequences of the drought on annual crop production. In this paper, we aim to identify such areas within the South Tigray zone, Ethiopia, using a transformation of the Normalized Difference Vegetation Index (NDVI) called Absolute Difference NDVI (ADVI). Negative NDVI shifts from the historical average can generally be linked to a reduction in the vigor of local vegetation. Drought is more likely to increase in areas where negative shifts occur more frequently and with high magnitude, making it possible to spot critical situations. We propose a new methodology for the assessment of drought risk in areas where crop production represents a primary source of livelihood for its inhabitants. We estimate ADVI return levels pixel per pixel by fitting extreme value models to independent monthly minima. The study is conducted using SPOT-Vegetation (VGT) ten-day composite (S10) images from April 1998 to March 2009. In all short-term and long-term predictions, we found that central and southern areas of the South Tigray zone are prone to a higher drought risk compared to other areas.

  5. A modified algorithm for estimating Absolute Salinity in the global ocean

    NASA Astrophysics Data System (ADS)

    Uchida, H.; Kawano, T.; Aoyama, M.; Wakita, M.; Nishino, S.; Ozawa, S.

    2012-04-01

    In 2010, the Intergovernmental Oceanographic Commission (IOC), International Association for the Physical Sciences of the Ocean (IAPSO) and the Scientific Committee on Oceanic Research (SCOR) adopted the new Thermodynamic Equation of Seawater - 2010 (TEOS-10). One of the substantial changes from previous practice is the use of Absolute Salinity (g/kg) instead of Practical Salinity in TEOS-10. Since there is no sensor that can precisely measure Absolute Salinity in situ, an algorithm to estimate Absolute Salinity was provided along with TEOS-10. The algorithm exploits the correlation between the Absolute Salinity anomaly (dSA) relative to the Reference-Composition Salinity and the silicate concentration, making use of the global atlas of silicate concentrations, and the correlation coefficient is a function of latitude determined for each ocean basin (McDougall et al., Ocean Sci. Discuss., 6, 215-242, 2009). However, the dSA shows latitude dependent systematic discrepancy from dSA estimated from another model which exploits more precisely the correlation between dSA and nutrient concentrations and carbonate system parameters based on mathematical investigation (Pawlowicz et al., Ocean Sci., 7, 363-387, 2011). These two models for estimating dSA were evaluated using measured dSA with an oscillation-type density meter for the North Pacific, the Bering Sea, and the Arctic Ocean. The measured dSA agreed well with the estimates of the multi-parameter model. These results suggest that the algorithm for estimating dSA used in TEOS-10 have latitude dependent systematic biases (~0.01 g/kg), probably due to systematic biases in density data used. To minimize these systematic biases, a simple relationship between dSA and silicate concentration was determined for the global ocean, regardless of latitude dependency, by combining previously used and newly obtained density data. For the surface water of the Arctic Ocean, however, dSA is related with alkalinity by the input of

  6. Global-scale location and distance estimates: common representations and strategies in absolute and relative judgments.

    PubMed

    Friedman, Alinda; Montello, Daniel R

    2006-03-01

    The authors examined whether absolute and relative judgments about global-scale locations and distances were generated from common representations. At the end of a 10-week class on the regional geography of the United States, participants estimated the latitudes of 16 North American cities and all possible pairwise distances between them. Although participants were relative experts, their latitude estimates revealed the presence of psychologically based regions with large gaps between them and a tendency to stretch North America southward toward the equator. The distance estimates revealed the same properties in the representation recovered via multidimensional scaling. Though the aggregated within- and between-regions distance estimates were fitted by Stevens's law (S. S. Stevens, 1957), this was an averaging artifact: The appropriateness of a power function to describe distance estimates depended on the regional membership of the cities. The authors conclude that plausible reasoning strategies, combined with regionalized representations and beliefs about the location of these relative to global landmarks, underlie global-scale latitude and distance judgments.

  7. Estimate of absolute geostrophic velocity from the density field in the northeastern Pacific Ocean

    SciTech Connect

    Coats, D.A.

    1981-09-20

    A pair of hydrographic sections (35/sup 0/N, 155/sup 0/W) were analyzed to compute absolute velocity by using a variation of the technique by Stommel and Schott (1977). Absolute velocity is determined from an integrated form of the potential vorticity equation by a technique suggested by Davis (1978). This study is the first application of this technique that allows a direct comparison between the uncertainty in estimating a smooth density field and the amount of imbalance in the system of model equations. Because the amount of incompatibility (imbalance) in the system of equations is far smaller than is allowed by the uncertainty in defining the smooth field, the model equation is considered adequate for this set of data. Below 400 m, the nearly constant zonal isopycnal slope indicates that potential vorticity is uniform on isopycnal surfaces. Since the method depends on resolving flow directions from the intersection of isopycnals and surfaces of constant potential vorticity, the absolute velocity is indeterminate in this region. The model equation does, however, constrain the structure of the meridional density field and requires a poleward shift in the latitude which successively deeper isopycnals reach their maximum depth. The fact that this poleward translation can be predicted over several degrees of latitude suggests potential vorticity is uniform over a substantial portion of the North Pacific subtropical gyre. This poleward translation of the density field is an aspect of subtropical density fields, in general, and occurs in conjunction with a translation in the field of geopotential anomaly. It is directly related to the curvature in the deep portion of the beta spiral.

  8. Estimating the absolute position of a mobile robot using position probability grids

    SciTech Connect

    Burgard, W.; Fox, D.; Hennig, D.; Schmidt, T.

    1996-12-31

    In order to re-use existing models of the environment mobile robots must be able to estimate their position and orientation in such models. Most of the existing methods for position estimation are based on special purpose sensors or aim at tracking the robot`s position relative to the known starting point. This paper describes the position probability grid approach to estimating the robot`s absolute position and orientation in a metric model of the environment. Our method is designed to work with standard sensors and is independent of any knowledge about the starting point. It is a Bayesian approach based on certainty grids. In each cell of such a grid we store the probability that this cell refers to the current position of the robot. These probabilities are obtained by integrating the likelihoods of sensor readings over time. Results described in this paper show that our technique is able to reliably estimate the position of a robot in complex environments. Our approach has proven to be robust with respect to inaccurate environmental models, noisy sensors, and ambiguous situations.

  9. Estimating Absolute Salinity (SA) in the World's Oceans Using Density and Composition

    NASA Astrophysics Data System (ADS)

    Woosley, R. J.; Huang, F.; Millero, F. J., Jr.

    2014-12-01

    The practical salinity (Sp), which is determined by the relationship of conductivity to the known proportions of the major components of seawater, and reference salinity (SR = (35.16504/35)*Sp), do not account for variations in physical properties such as density and enthalpy. Trace and minor components of seawater, such as nutrients or inorganic carbon and total alkalinity affect these properties and contribute to the absolute salinity (SA). This limitation has been recognized and several studies have been made to estimate the effect of these compositional changes on the conductivity-density relationship. These studies have been limited in number and geographic scope. Here, we combine the measurements of previous studies with new measurements for a total of 2,857 conductivity-density measurements covering all of the world's major oceans to derive empirical equations for the effect of silica and total alkalinity on the density and absolute salinity of the global oceans and recommend an equation applicable to most of the world oceans. The potential impact on salinity as a result of uptake of anthropogenic CO2 is also discussed.

  10. One idea of portfolio risk control for absolute return strategy risk adjustments by signals from correlation behavior

    NASA Astrophysics Data System (ADS)

    Nishiyama, N.

    2001-12-01

    Absolute return strategy provided from fund of funds (FOFs) investment schemes is the focus in Japanese Financial Community. FOFs investment mainly consists of hedge fund investment and it has two major characteristics which are low correlation against benchmark index and little impact from various external changes in the environment given maximizing return. According to the historical track record of survival hedge funds in this business world, they maintain a stable high return and low risk. However, one must keep in mind that low risk would not be equal to risk free. The failure of Long-term capital management (LTCM) that took place in the summer of 1998 was a symbolized phenomenon. The summer of 1998 exhibited a certain limitation of traditional value at risk (VaR) and some possibility that traditional VaR could be ineffectual to the nonlinear type of fluctuation in the market. In this paper, I try to bring self-organized criticality (SOC) into portfolio risk control. SOC would be well known as a model of decay in the natural world. I analyzed nonlinear type of fluctuation in the market as SOC and applied SOC to capture complicated market movement using threshold point of SOC and risk adjustments by scenario correlation as implicit signals. Threshold becomes the control parameter of risk exposure to set downside floor and forecast extreme nonlinear type of fluctuation under a certain probability. Simulation results would show synergy effect of portfolio risk control between SOC and absolute return strategy.

  11. Integrated Navigation System Design for Micro Planetary Rovers: Comparison of Absolute Heading Estimation Algorithms and Nonlinear Filtering.

    PubMed

    Ilyas, Muhammad; Hong, Beomjin; Cho, Kuk; Baeg, Seung-Ho; Park, Sangdeok

    2016-05-23

    This paper provides algorithms to fuse relative and absolute microelectromechanical systems (MEMS) navigation sensors, suitable for micro planetary rovers, to provide a more accurate estimation of navigation information, specifically, attitude and position. Planetary rovers have extremely slow speed (~1 cm/s) and lack conventional navigation sensors/systems, hence the general methods of terrestrial navigation may not be applicable to these applications. While relative attitude and position can be tracked in a way similar to those for ground robots, absolute navigation information is hard to achieve on a remote celestial body, like Moon or Mars, in contrast to terrestrial applications. In this study, two absolute attitude estimation algorithms were developed and compared for accuracy and robustness. The estimated absolute attitude was fused with the relative attitude sensors in a framework of nonlinear filters. The nonlinear Extended Kalman filter (EKF) and Unscented Kalman filter (UKF) were compared in pursuit of better accuracy and reliability in this nonlinear estimation problem, using only on-board low cost MEMS sensors. Experimental results confirmed the viability of the proposed algorithms and the sensor suite, for low cost and low weight micro planetary rovers. It is demonstrated that integrating the relative and absolute navigation MEMS sensors reduces the navigation errors to the desired level.

  12. Integrated Navigation System Design for Micro Planetary Rovers: Comparison of Absolute Heading Estimation Algorithms and Nonlinear Filtering

    PubMed Central

    Ilyas, Muhammad; Hong, Beomjin; Cho, Kuk; Baeg, Seung-Ho; Park, Sangdeok

    2016-01-01

    This paper provides algorithms to fuse relative and absolute microelectromechanical systems (MEMS) navigation sensors, suitable for micro planetary rovers, to provide a more accurate estimation of navigation information, specifically, attitude and position. Planetary rovers have extremely slow speed (~1 cm/s) and lack conventional navigation sensors/systems, hence the general methods of terrestrial navigation may not be applicable to these applications. While relative attitude and position can be tracked in a way similar to those for ground robots, absolute navigation information is hard to achieve on a remote celestial body, like Moon or Mars, in contrast to terrestrial applications. In this study, two absolute attitude estimation algorithms were developed and compared for accuracy and robustness. The estimated absolute attitude was fused with the relative attitude sensors in a framework of nonlinear filters. The nonlinear Extended Kalman filter (EKF) and Unscented Kalman filter (UKF) were compared in pursuit of better accuracy and reliability in this nonlinear estimation problem, using only on-board low cost MEMS sensors. Experimental results confirmed the viability of the proposed algorithms and the sensor suite, for low cost and low weight micro planetary rovers. It is demonstrated that integrating the relative and absolute navigation MEMS sensors reduces the navigation errors to the desired level. PMID:27223293

  13. Integrated Navigation System Design for Micro Planetary Rovers: Comparison of Absolute Heading Estimation Algorithms and Nonlinear Filtering.

    PubMed

    Ilyas, Muhammad; Hong, Beomjin; Cho, Kuk; Baeg, Seung-Ho; Park, Sangdeok

    2016-01-01

    This paper provides algorithms to fuse relative and absolute microelectromechanical systems (MEMS) navigation sensors, suitable for micro planetary rovers, to provide a more accurate estimation of navigation information, specifically, attitude and position. Planetary rovers have extremely slow speed (~1 cm/s) and lack conventional navigation sensors/systems, hence the general methods of terrestrial navigation may not be applicable to these applications. While relative attitude and position can be tracked in a way similar to those for ground robots, absolute navigation information is hard to achieve on a remote celestial body, like Moon or Mars, in contrast to terrestrial applications. In this study, two absolute attitude estimation algorithms were developed and compared for accuracy and robustness. The estimated absolute attitude was fused with the relative attitude sensors in a framework of nonlinear filters. The nonlinear Extended Kalman filter (EKF) and Unscented Kalman filter (UKF) were compared in pursuit of better accuracy and reliability in this nonlinear estimation problem, using only on-board low cost MEMS sensors. Experimental results confirmed the viability of the proposed algorithms and the sensor suite, for low cost and low weight micro planetary rovers. It is demonstrated that integrating the relative and absolute navigation MEMS sensors reduces the navigation errors to the desired level. PMID:27223293

  14. Estimation of absolute water surface temperature based on atmospherically corrected thermal infrared multispectral scanner digital data

    NASA Technical Reports Server (NTRS)

    Anderson, James E.

    1986-01-01

    Airborne remote sensing systems, as well as those on board Earth orbiting satellites, sample electromagnetic energy in discrete wavelength regions and convert the total energy sampled into data suitable for processing by digital computers. In general, however, the total amount of energy reaching a sensor system located at some distance from the target is composed not only of target related energy, but, in addition, contains a contribution originating from the atmosphere itself. Thus, some method must be devised for removing or at least minimizing the effects of the atmosphere. The LOWTRAN-6 Program was designed to estimate atmospheric transmittance and radiance for a given atmospheric path at moderate spectral resolution over an operational wavelength region from 0.25 to 28.5 microns. In order to compute the Thermal Infrared Multispectral Scanner (TIMS) digital values which were recorded in the absence of the atmosphere, the parameters derived from LOWTRAN-6 are used in a correction equation. The TIMS data were collected at 1:00 a.m. local time on November 21, 1983, over a recirculating cooling pond for a power plant in southeastern Mississippi. The TIMS data were analyzed before and after atmospheric corrections were applied using a band ratioing model to compute the absolute surface temperature of various points on the power plant cooling pond. The summarized results clearly demonstrate the desirability of applying atmospheric corrections.

  15. Realized Volatility and Absolute Return Volatility: A Comparison Indicating Market Risk

    PubMed Central

    Takaishi, Tetsuya; Stanley, H. Eugene; Li, Baowen

    2014-01-01

    Measuring volatility in financial markets is a primary challenge in the theory and practice of risk management and is essential when developing investment strategies. Although the vast literature on the topic describes many different models, two nonparametric measurements have emerged and received wide use over the past decade: realized volatility and absolute return volatility. The former is strongly favored in the financial sector and the latter by econophysicists. We examine the memory and clustering features of these two methods and find that both enable strong predictions. We compare the two in detail and find that although realized volatility has a better short-term effect that allows predictions of near-future market behavior, absolute return volatility is easier to calculate and, as a risk indicator, has approximately the same sensitivity as realized volatility. Our detailed empirical analysis yields valuable guidelines for both researchers and market participants because it provides a significantly clearer comparison of the strengths and weaknesses of the two methods. PMID:25054439

  16. A Concurrent Mixed Methods Approach to Examining the Quantitative and Qualitative Meaningfulness of Absolute Magnitude Estimation Scales in Survey Research

    ERIC Educational Resources Information Center

    Koskey, Kristin L. K.; Stewart, Victoria C.

    2014-01-01

    This small "n" observational study used a concurrent mixed methods approach to address a void in the literature with regard to the qualitative meaningfulness of the data yielded by absolute magnitude estimation scaling (MES) used to rate subjective stimuli. We investigated whether respondents' scales progressed from less to more and…

  17. A method for determining weights for excess relative risk and excess absolute risk when applied in the calculation of lifetime risk of cancer from radiation exposure.

    PubMed

    Walsh, Linda; Schneider, Uwe

    2013-03-01

    Radiation-related risks of cancer can be transported from one population to another population at risk, for the purpose of calculating lifetime risks from radiation exposure. Transfer via excess relative risks (ERR) or excess absolute risks (EAR) or a mixture of both (i.e., from the life span study (LSS) of Japanese atomic bomb survivors) has been done in the past based on qualitative weighting. Consequently, the values of the weights applied and the method of application of the weights (i.e., as additive or geometric weighted means) have varied both between reports produced at different times by the same regulatory body and also between reports produced at similar times by different regulatory bodies. Since the gender and age patterns are often markedly different between EAR and ERR models, it is useful to have an evidence-based method for determining the relative goodness of fit of such models to the data. This paper identifies a method, using Akaike model weights, which could aid expert judgment and be applied to help to achieve consistency of approach and quantitative evidence-based results in future health risk assessments. The results of applying this method to recent LSS cancer incidence models are that the relative EAR weighting by cancer solid cancer site, on a scale of 0-1, is zero for breast and colon, 0.02 for all solid, 0.03 for lung, 0.08 for liver, 0.15 for thyroid, 0.18 for bladder and 0.93 for stomach. The EAR weighting for female breast cancer increases from 0 to 0.3, if a generally observed change in the trend between female age-specific breast cancer incidence rates and attained age, associated with menopause, is accounted for in the EAR model. Application of this method to preferred models from a study of multi-model inference from many models fitted to the LSS leukemia mortality data, results in an EAR weighting of 0. From these results it can be seen that lifetime risk transfer is most highly weighted by EAR only for stomach cancer. However

  18. Indirectly estimated absolute lung cancer mortality rates by smoking status and histological type based on a systematic review

    PubMed Central

    2013-01-01

    Background National smoking-specific lung cancer mortality rates are unavailable, and studies presenting estimates are limited, particularly by histology. This hinders interpretation. We attempted to rectify this by deriving estimates indirectly, combining data from national rates and epidemiological studies. Methods We estimated study-specific absolute mortality rates and variances by histology and smoking habit (never/ever/current/former) based on relative risk estimates derived from studies published in the 20th century, coupled with WHO mortality data for age 70–74 for the relevant country and period. Studies with populations grossly unrepresentative nationally were excluded. 70–74 was chosen based on analyses of large cohort studies presenting rates by smoking and age. Variations by sex, period and region were assessed by meta-analysis and meta-regression. Results 148 studies provided estimates (Europe 59, America 54, China 22, other Asia 13), 54 providing estimates by histology (squamous cell carcinoma, adenocarcinoma). For all smoking habits and lung cancer types, mortality rates were higher in males, the excess less evident for never smokers. Never smoker rates were clearly highest in China, and showed some increasing time trend, particularly for adenocarcinoma. Ever smoker rates were higher in parts of Europe and America than in China, with the time trend very clear, especially for adenocarcinoma. Variations by time trend and continent were clear for current smokers (rates being higher in Europe and America than Asia), but less clear for former smokers. Models involving continent and trend explained much variability, but non-linearity was sometimes seen (with rates lower in 1991–99 than 1981–90), and there was regional variation within continent (with rates in Europe often high in UK and low in Scandinavia, and higher in North than South America). Conclusions The indirect method may be questioned, because of variations in definition of smoking and

  19. The performance of different propensity score methods for estimating absolute effects of treatments on survival outcomes: A simulation study

    PubMed Central

    Schuster, Tibor

    2014-01-01

    Observational studies are increasingly being used to estimate the effect of treatments, interventions and exposures on outcomes that can occur over time. Historically, the hazard ratio, which is a relative measure of effect, has been reported. However, medical decision making is best informed when both relative and absolute measures of effect are reported. When outcomes are time-to-event in nature, the effect of treatment can also be quantified as the change in mean or median survival time due to treatment and the absolute reduction in the probability of the occurrence of an event within a specified duration of follow-up. We describe how three different propensity score methods, propensity score matching, stratification on the propensity score and inverse probability of treatment weighting using the propensity score, can be used to estimate absolute measures of treatment effect on survival outcomes. These methods are all based on estimating marginal survival functions under treatment and lack of treatment. We then conducted an extensive series of Monte Carlo simulations to compare the relative performance of these methods for estimating the absolute effects of treatment on survival outcomes. We found that stratification on the propensity score resulted in the greatest bias. Caliper matching on the propensity score and a method based on earlier work by Cole and Hernán tended to have the best performance for estimating absolute effects of treatment on survival outcomes. When the prevalence of treatment was less extreme, then inverse probability of treatment weighting-based methods tended to perform better than matching-based methods. PMID:24463885

  20. Estimates of absolute flux and radiance factor of localized regions on Mars in the 2-4 micron wavelength region

    NASA Technical Reports Server (NTRS)

    Roush, Ted L.; Roush, Eileen A.; Singer, Robert B.; Lucey, Paul G.

    1992-01-01

    IRTF spectrophotometric observations of Mars obtained during the 1986 opposition are the bases for the present estimates of 2.0-4.15 micron absolute flux and radiance factor values. The bright/dark ratios obtained show a wavelength dependence similar to that observed by Bell and Crisp (1991) in 1990, but the spectral contrast for 1986 is lower than in those observations; this difference could be due to changes in the location, sample are size, and/or suspended atmospheric dust.

  1. Application of two versions of the WHO/international society of hypertension absolute cardiovascular risk assessment tools in a rural Bangladeshi population

    PubMed Central

    Fatema, Kaniz; Zwar, Nicholas Arnold; Milton, Abul Hasnat; Rahman, Bayzidur; Ali, Liaquat

    2015-01-01

    Objectives To estimate the absolute cardiovascular disease (CVD) risk burden in a remote rural Bangladeshi population using the ‘With’ and ‘Without’ Cholesterol versions of the WHO/International Society of Hypertension (WHO/ISH) CVD risk assessment chart (particularly suitable for low and middle-income countries due to less reliance on laboratory testing) and to evaluate the agreement between the two approaches. Design Cross-sectional study using data from a large prospective cohort of the North Bengal Non-Communicable Disease Programme (NB-NCDP) of Bangladesh. Setting General rural population from Thakurgaon district of Bangladesh. Participants 563 individuals who were categorised as having ‘no CVDs’ on screening by a questionnaire-based survey using the ‘WHO CVD-Risk Management Package’ developed in 2002. Main outcome measures Absolute CVD risk burden assessed using two versions of the WHO/ISH risk assessment charts for the South-East Asian Region-D. Results 10-year risk (moderate, high and very high) positivity was present among 21.5% and 20.2% of participants, respectively, using with and without cholesterol versions of the tool. The overall concordance rate for the two versions was 89.5% and they did not differ significantly in estimating the proportion of overall participants having higher levels of CVD. The projected drug requirement, however, showed a significant overestimation in the proportion of participants at both the threshold levels (p<0.002) on using ‘without’ as compared to ‘with’ cholesterol versions. Conclusions About one-fifth of the adult population in Bangladesh, even in a remote rural area, seem to be at risk of developing CVDs (25% of them at high risk and 25% at very high risk) within 10 years with males and females being almost equally vulnerable. PMID:26463220

  2. Procedure for estimating orbital debris risks

    NASA Technical Reports Server (NTRS)

    Crafts, J. L.; Lindberg, J. P.

    1985-01-01

    A procedure for estimating the potential orbital debris risk to the world's populace from payloads or spent stages left in orbit on future missions is presented. This approach provides a consistent, but simple, procedure to assess the risk due to random reentry with an adequate accuracy level for making programmatic decisions on planned low Earth orbit missions.

  3. Decision-making using absolute cardiovascular risk reduction and incremental cost-effectiveness ratios: a case study

    PubMed Central

    Ker, J A; Oosthuizen, H; Rheeder, P

    2008-01-01

    Summary Background Many clinical guidelines have adopted a multifactorial cardiovascular risk assessment to identify high-risk individuals for treatment. The Framingham risk chart is a widely used risk engine to calculate the absolute cardiovascular risk of an individual. Cost-effective analyses are typically used to evaluate therapeutic strategies, but it is more problematic for a clinician when faced with alternative therapeutic strategies to calculate cost effectiveness. Aim We used a single simulated-patient model to explore the effect of different drug treatments on the calculated absolute cardiovascular risk. Methods The Framingham risk score was calculated on a hypothetical patient, and drug treatment was initiated. After every drug introduced, the score was recalculated. Single-exit pricing of the various drugs in South Africa was used to calculate the cost of reducing predicted cardiovascular risk. Results The cost-effective ratio of an antihypertensive treatment strategy was calculated to be R21.35 per percentage of risk reduction. That of a statin treatment strategy was R22.93 per percentage of risk reduction. Using a high-dose statin, the cost-effective ratio was R12.81 per percentage of risk reduction. Combining the antihypertensive and statin strategy demonstrated a cost-effective ratio of R23.84 per percentage of risk reduction. A combination of several drugs enabled the hypothetical patient to reduce the risk to 14% at a cost-effective ratio of R17.18 per percentage of risk reduction. Conclusion This model demonstrates a method to compare different therapeutic strategies to reduce cardiovascular risk with their cost-effective ratios. PMID:18516355

  4. Predictors of indoor absolute humidity and estimated effects on influenza virus survival in grade schools

    PubMed Central

    2013-01-01

    Background Low absolute humidity (AH) has been associated with increased influenza virus survival and transmissibility and the onset of seasonal influenza outbreaks. Humidification of indoor environments may mitigate viral transmission and may be an important control strategy, particularly in schools where viral transmission is common and contributes to the spread of influenza in communities. However, the variability and predictors of AH in the indoor school environment and the feasibility of classroom humidification to levels that could decrease viral survival have not been studied. Methods Automated sensors were used to measure temperature, humidity and CO2 levels in two Minnesota grade schools without central humidification during two successive winters. Outdoor AH measurements were derived from the North American Land Data Assimilation System. Variability in indoor AH within classrooms, between classrooms in the same school, and between schools was assessed using concordance correlation coefficients (CCC). Predictors of indoor AH were examined using time-series Auto-Regressive Conditional Heteroskedasticity models. Classroom humidifiers were used when school was not in session to assess the feasibility of increasing indoor AH to levels associated with decreased influenza virus survival, as projected from previously published animal experiments. Results AH varied little within classrooms (CCC >0.90) but was more variable between classrooms in the same school (CCC 0.81 for School 1, 0.88 for School 2) and between schools (CCC 0.81). Indoor AH varied widely during the winter (range 2.60 to 10.34 millibars [mb]) and was strongly associated with changes in outdoor AH (p < 0.001). Changes in indoor AH on school weekdays were strongly associated with CO2 levels (p < 0.001). Over 4 hours, classroom humidifiers increased indoor AH by 4 mb, an increase sufficient to decrease projected 1-hour virus survival by an absolute value of 30% during winter months

  5. Accurate radiocarbon age estimation using "early" measurements: a new approach to reconstructing the Paleolithic absolute chronology

    NASA Astrophysics Data System (ADS)

    Omori, Takayuki; Sano, Katsuhiro; Yoneda, Minoru

    2014-05-01

    This paper presents new correction approaches for "early" radiocarbon ages to reconstruct the Paleolithic absolute chronology. In order to discuss time-space distribution about the replacement of archaic humans, including Neanderthals in Europe, by the modern humans, a massive data, which covers a wide-area, would be needed. Today, some radiocarbon databases focused on the Paleolithic have been published and used for chronological studies. From a viewpoint of current analytical technology, however, the any database have unreliable results that make interpretation of radiocarbon dates difficult. Most of these unreliable ages had been published in the early days of radiocarbon analysis. In recent years, new analytical methods to determine highly-accurate dates have been developed. Ultrafiltration and ABOx-SC methods, as new sample pretreatments for bone and charcoal respectively, have attracted attention because they could remove imperceptible contaminates and derive reliable accurately ages. In order to evaluate the reliability of "early" data, we investigated the differences and variabilities of radiocarbon ages on different pretreatments, and attempted to develop correction functions for the assessment of the reliability. It can be expected that reliability of the corrected age is increased and the age applied to chronological research together with recent ages. Here, we introduce the methodological frameworks and archaeological applications.

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

    PubMed

    Duarte, A S R; Nauta, M J

    2015-02-16

    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 of accounting for the Poisson randomness in counts, the difference between treating "true" zeroes as such or as censored below a limit of quantification (LOQ) and the importance of making the correct assumption about the underlying distribution of concentrations. By running a simulation experiment with zero-inflated Poisson-lognormal distributed data and an existing QMRA model from retail to consumer level, it was possible to assess the difference between expected risk and the risk estimated with using a lognormal, a zero-inflated lognormal, a Poisson-gamma, a zero-inflated Poisson-gamma and a zero-inflated Poisson-lognormal distribution. We show that the impact of the choice of different probability distributions to describe concentrations at retail on risk estimates is dependent both on concentration and prevalence levels. We also show that the use of an LOQ should be done consciously, especially when zero-inflation is not used. In general, zero-inflation does not necessarily improve the absolute risk estimation, but performance of zero-inflated distributions in QMRA tends to be

  7. Easy Absolute Values? Absolutely

    ERIC Educational Resources Information Center

    Taylor, Sharon E.; Mittag, Kathleen Cage

    2015-01-01

    The authors teach a problem-solving course for preservice middle-grades education majors that includes concepts dealing with absolute-value computations, equations, and inequalities. Many of these students like mathematics and plan to teach it, so they are adept at symbolic manipulations. Getting them to think differently about a concept that they…

  8. A methodological survey of the analysis, reporting and interpretation of Absolute Risk ReductiOn in systematic revieWs (ARROW): a study protocol

    PubMed Central

    2013-01-01

    Background Clinicians, providers and guideline panels use absolute effects to weigh the advantages and downsides of treatment alternatives. Relative measures have the potential to mislead readers. However, little is known about the reporting of absolute measures in systematic reviews. The objectives of our study are to determine the proportion of systematic reviews that report absolute measures of effect for the most important outcomes, and ascertain how they are analyzed, reported and interpreted. Methods/design We will conduct a methodological survey of systematic reviews published in 2010. We will conduct a 1:1 stratified random sampling of Cochrane vs. non-Cochrane systematic reviews. We will calculate the proportion of systematic reviews reporting at least one absolute estimate of effect for the most patient-important outcome for the comparison of interest. We will conduct multivariable logistic regression analyses with the reporting of an absolute estimate of effect as the dependent variable and pre-specified study characteristics as the independent variables. For systematic reviews reporting an absolute estimate of effect, we will document the methods used for the analysis, reporting and interpretation of the absolute estimate. Discussion Our methodological survey will inform current practices regarding reporting of absolute estimates in systematic reviews. Our findings may influence recommendations on reporting, conduct and interpretation of absolute estimates. Our results are likely to be of interest to systematic review authors, funding agencies, clinicians, guideline developers and journal editors. PMID:24330779

  9. Adaptive anisotropic kernels for nonparametric estimation of absolute configurational entropies in high-dimensional configuration spaces.

    PubMed

    Hensen, Ulf; Grubmüller, Helmut; Lange, Oliver F

    2009-07-01

    The quasiharmonic approximation is the most widely used estimate for the configurational entropy of macromolecules from configurational ensembles generated from atomistic simulations. This method, however, rests on two assumptions that severely limit its applicability, (i) that a principal component analysis yields sufficiently uncorrelated modes and (ii) that configurational densities can be well approximated by Gaussian functions. In this paper we introduce a nonparametric density estimation method which rests on adaptive anisotropic kernels. It is shown that this method provides accurate configurational entropies for up to 45 dimensions thus improving on the quasiharmonic approximation. When embedded in the minimally coupled subspace framework, large macromolecules of biological interest become accessible, as demonstrated for the 67-residue coldshock protein. PMID:19658735

  10. Estimating Terrorist Risk with Possibility Theory

    SciTech Connect

    J.L. Darby

    2004-11-30

    This report summarizes techniques that use possibility theory to estimate the risk of terrorist acts. These techniques were developed under the sponsorship of the Department of Homeland Security (DHS) as part of the National Infrastructure Simulation Analysis Center (NISAC) project. The techniques have been used to estimate the risk of various terrorist scenarios to support NISAC analyses during 2004. The techniques are based on the Logic Evolved Decision (LED) methodology developed over the past few years by Terry Bott and Steve Eisenhawer at LANL. [LED] The LED methodology involves the use of fuzzy sets, possibility theory, and approximate reasoning. LED captures the uncertainty due to vagueness and imprecision that is inherent in the fidelity of the information available for terrorist acts; probability theory cannot capture these uncertainties. This report does not address the philosophy supporting the development of nonprobabilistic approaches, and it does not discuss possibility theory in detail. The references provide a detailed discussion of these subjects. [Shafer] [Klir and Yuan] [Dubois and Prade] Suffice to say that these approaches were developed to address types of uncertainty that cannot be addressed by a probability measure. An earlier report discussed in detail the problems with using a probability measure to evaluate terrorist risk. [Darby Methodology]. Two related techniques are discussed in this report: (1) a numerical technique, and (2) a linguistic technique. The numerical technique uses traditional possibility theory applied to crisp sets, while the linguistic technique applies possibility theory to fuzzy sets. Both of these techniques as applied to terrorist risk for NISAC applications are implemented in software called PossibleRisk. The techniques implemented in PossibleRisk were developed specifically for use in estimating terrorist risk for the NISAC program. The LEDTools code can be used to perform the same linguistic evaluation as

  11. Estimating stellar atmospheric parameters, absolute magnitudes and elemental abundances from the LAMOST spectra with Kernel-based Principal Component Analysis

    NASA Astrophysics Data System (ADS)

    Xiang, M.-S.; Liu, X.-W.; Shi, J.-R.; Yuan, H.-B.; Huang, Y.; Luo, A.-L.; Zhang, H.-W.; Zhao, Y.-H.; Zhang, J.-N.; Ren, J.-J.; Chen, B.-Q.; Wang, C.; Li, J.; Huo, Z.-Y.; Zhang, W.; Wang, J.-L.; Zhang, Y.; Hou, Y.-H.; Wang, Y.-F.

    2016-10-01

    Accurate determination of stellar atmospheric parameters and elemental abundances is crucial for Galactic archeology via large-scale spectroscopic surveys. In this paper, we estimate stellar atmospheric parameters - effective temperature Teff, surface gravity log g and metallicity [Fe/H], absolute magnitudes MV and MKs, α-element to metal (and iron) abundance ratio [α/M] (and [α/Fe]), as well as carbon and nitrogen abundances [C/H] and [N/H] from the LAMOST spectra with a multivariate regression method based on kernel-based principal component analysis, using stars in common with other surveys (Hipparcos, Kepler, APOGEE) as training data sets. Both internal and external examinations indicate that given a spectral signal-to-noise ratio (SNR) better than 50, our method is capable of delivering stellar parameters with a precision of ˜100 K for Teff, ˜0.1 dex for log g, 0.3 - 0.4 mag for MV and MKs, 0.1 dex for [Fe/H], [C/H] and [N/H], and better than 0.05 dex for [α/M] ([α/Fe]). The results are satisfactory even for a spectral SNR of 20. The work presents first determinations of [C/H] and [N/H] abundances from a vast data set of LAMOST, and, to our knowledge, the first reported implementation of absolute magnitude estimation directly based on the observed spectra. The derived stellar parameters for millions of stars from the LAMOST surveys will be publicly available in the form of value-added catalogues.

  12. Absolute fracture risk assessment using lumbar spine and femoral neck bone density measurements: derivation and validation of a hybrid system.

    PubMed

    Leslie, William D; Lix, Lisa M

    2011-03-01

    The World Health Organization (WHO) Fracture Risk Assessment Tool (FRAX) computes 10-year probability of major osteoporotic fracture from multiple risk factors, including femoral neck (FN) T-scores. Lumbar spine (LS) measurements are not currently part of the FRAX formulation but are used widely in clinical practice, and this creates confusion when there is spine-hip discordance. Our objective was to develop a hybrid 10-year absolute fracture risk assessment system in which nonvertebral (NV) fracture risk was assessed from the FN and clinical vertebral (V) fracture risk was assessed from the LS. We identified 37,032 women age 45 years and older undergoing baseline FN and LS dual-energy X-ray absorptiometry (DXA; 1990-2005) from a population database that contains all clinical DXA results for the Province of Manitoba, Canada. Results were linked to longitudinal health service records for physician billings and hospitalizations to identify nontrauma vertebral and nonvertebral fracture codes after bone mineral density (BMD) testing. The population was randomly divided into equal-sized derivation and validation cohorts. Using the derivation cohort, three fracture risk prediction systems were created from Cox proportional hazards models (adjusted for age and multiple FRAX risk factors): FN to predict combined all fractures, FN to predict nonvertebral fractures, and LS to predict vertebral (without nonvertebral) fractures. The hybrid system was the sum of nonvertebral risk from the FN model and vertebral risk from the LS model. The FN and hybrid systems were both strongly predictive of overall fracture risk (p < .001). In the validation cohort, ROC analysis showed marginally better performance of the hybrid system versus the FN system for overall fracture prediction (p = .24) and significantly better performance for vertebral fracture prediction (p < .001). In a discordance subgroup with FN and LS T-score differences greater than 1 SD, there was a significant

  13. Evaluating methods for estimating existential risks.

    PubMed

    Tonn, Bruce; Stiefel, Dorian

    2013-10-01

    Researchers and commissions contend that the risk of human extinction is high, but none of these estimates have been based upon a rigorous methodology suitable for estimating existential risks. This article evaluates several methods that could be used to estimate the probability of human extinction. Traditional methods evaluated include: simple elicitation; whole evidence Bayesian; evidential reasoning using imprecise probabilities; and Bayesian networks. Three innovative methods are also considered: influence modeling based on environmental scans; simple elicitation using extinction scenarios as anchors; and computationally intensive possible-worlds modeling. Evaluation criteria include: level of effort required by the probability assessors; level of effort needed to implement the method; ability of each method to model the human extinction event; ability to incorporate scientific estimates of contributory events; transparency of the inputs and outputs; acceptability to the academic community (e.g., with respect to intellectual soundness, familiarity, verisimilitude); credibility and utility of the outputs of the method to the policy community; difficulty of communicating the method's processes and outputs to nonexperts; and accuracy in other contexts. The article concludes by recommending that researchers assess the risks of human extinction by combining these methods. PMID:23551083

  14. How to estimate your tolerance for risk

    SciTech Connect

    Mackay, J.A.

    1996-12-31

    Risk tolerance is used to calculate the Risk Adjusted Value (RAV) of a proposed investment. The RAV incorporates both the expected value and risk attitude for a particular investment, taking into consideration your concern for catastrophic financial loss, as well as chance of success, cost and value if successful. Uncertainty can be incorporated into all of the above variables. Often a project is more valuable to a corporation if a partial working interest is taken rather than the entire working interest. The RAV can be used to calculate the optimum working interest and the value of that diversification. To estimate the Apparent Risk Tolerance (ART) of an individual, division or corporation several methods can be employed: (1) ART can be calculated from the working interest selected in prior investment decisions. (2) ART can be estimated from a selection of working interests by the decision maker in a proposed portfolio of projects. (3) ART can be approximated from data released to the Security and Exchange Commission (SEC) in the annual 10K supplements (for both your company and possible partners). (4) ART can be assigned based on corporate size, budget, or activity. Examples are provided for the various methods to identify risk tolerance and apply it in making optimum working interest calculations for individual projects and portfolios.

  15. Risk Estimation Methodology for Launch Accidents.

    SciTech Connect

    Clayton, Daniel James; Lipinski, Ronald J.; Bechtel, Ryan D.

    2014-02-01

    As compact and light weight power sources with reliable, long lives, Radioisotope Power Systems (RPSs) have made space missions to explore the solar system possible. Due to the hazardous material that can be released during a launch accident, the potential health risk of an accident must be quantified, so that appropriate launch approval decisions can be made. One part of the risk estimation involves modeling the response of the RPS to potential accident environments. Due to the complexity of modeling the full RPS response deterministically on dynamic variables, the evaluation is performed in a stochastic manner with a Monte Carlo simulation. The potential consequences can be determined by modeling the transport of the hazardous material in the environment and in human biological pathways. The consequence analysis results are summed and weighted by appropriate likelihood values to give a collection of probabilistic results for the estimation of the potential health risk. This information is used to guide RPS designs, spacecraft designs, mission architecture, or launch procedures to potentially reduce the risk, as well as to inform decision makers of the potential health risks resulting from the use of RPSs for space missions.

  16. The Impact of Strategy Instruction and Timing of Estimates on Low and High Working-Memory Capacity Readers' Absolute Monitoring Accuracy

    ERIC Educational Resources Information Center

    Linderholm, Tracy; Zhao, Qin

    2008-01-01

    Working-memory capacity, strategy instruction, and timing of estimates were investigated for their effects on absolute monitoring accuracy, which is the difference between estimated and actual reading comprehension test performance. Participants read two expository texts under one of two randomly assigned reading strategy instruction conditions…

  17. Auditory risk estimates for youth target shooting

    PubMed Central

    Meinke, Deanna K.; Murphy, William J.; Finan, Donald S.; Lankford, James E.; Flamme, Gregory A.; Stewart, Michael; Soendergaard, Jacob; Jerome, Trevor W.

    2015-01-01

    Objective To characterize the impulse noise exposure and auditory risk for youth recreational firearm users engaged in outdoor target shooting events. The youth shooting positions are typically standing or sitting at a table, which places the firearm closer to the ground or reflective surface when compared to adult shooters. Design Acoustic characteristics were examined and the auditory risk estimates were evaluated using contemporary damage-risk criteria for unprotected adult listeners and the 120-dB peak limit suggested by the World Health Organization (1999) for children. Study sample Impulses were generated by 26 firearm/ammunition configurations representing rifles, shotguns, and pistols used by youth. Measurements were obtained relative to a youth shooter’s left ear. Results All firearms generated peak levels that exceeded the 120 dB peak limit suggested by the WHO for children. In general, shooting from the seated position over a tabletop increases the peak levels, LAeq8 and reduces the unprotected maximum permissible exposures (MPEs) for both rifles and pistols. Pistols pose the greatest auditory risk when fired over a tabletop. Conclusion Youth should utilize smaller caliber weapons, preferably from the standing position, and always wear hearing protection whenever engaging in shooting activities to reduce the risk for auditory damage. PMID:24564688

  18. Extreme Earthquake Risk Estimation by Hybrid Modeling

    NASA Astrophysics Data System (ADS)

    Chavez, M.; Cabrera, E.; Ashworth, M.; Garcia, S.; Emerson, D.; Perea, N.; Salazar, A.; Moulinec, C.

    2012-12-01

    The estimation of the hazard and the economical consequences i.e. the risk associated to the occurrence of extreme magnitude earthquakes in the neighborhood of urban or lifeline infrastructure, such as the 11 March 2011 Mw 9, Tohoku, Japan, represents a complex challenge as it involves the propagation of seismic waves in large volumes of the earth crust, from unusually large seismic source ruptures up to the infrastructure location. The large number of casualties and huge economic losses observed for those earthquakes, some of which have a frequency of occurrence of hundreds or thousands of years, calls for the development of new paradigms and methodologies in order to generate better estimates, both of the seismic hazard, as well as of its consequences, and if possible, to estimate the probability distributions of their ground intensities and of their economical impacts (direct and indirect losses), this in order to implement technological and economical policies to mitigate and reduce, as much as possible, the mentioned consequences. Herewith, we propose a hybrid modeling which uses 3D seismic wave propagation (3DWP) and neural network (NN) modeling in order to estimate the seismic risk of extreme earthquakes. The 3DWP modeling is achieved by using a 3D finite difference code run in the ~100 thousands cores Blue Gene Q supercomputer of the STFC Daresbury Laboratory of UK, combined with empirical Green function (EGF) techniques and NN algorithms. In particular the 3DWP is used to generate broadband samples of the 3D wave propagation of extreme earthquakes (plausible) scenarios corresponding to synthetic seismic sources and to enlarge those samples by using feed-forward NN. We present the results of the validation of the proposed hybrid modeling for Mw 8 subduction events, and show examples of its application for the estimation of the hazard and the economical consequences, for extreme Mw 8.5 subduction earthquake scenarios with seismic sources in the Mexican

  19. The Relative and Absolute Risks of Disadvantaged Family Background and Low Levels of School Resources on Student Literacy

    ERIC Educational Resources Information Center

    Nonoyama-Tarumi, Yuko; Willms, J. Douglas

    2010-01-01

    There has been a long-lasting debate of whether the effects of family background are larger than those of school resources, and whether these effects are a function of national income level. In this study, we bring a new perspective to the debate by using the concepts of relative risk and population attributable risk in estimating family and…

  20. Relating space radiation environments to risk estimates

    NASA Technical Reports Server (NTRS)

    Curtis, Stanley B.

    1993-01-01

    A number of considerations must go into the process of determining the risk of deleterious effects of space radiation to travelers. Among them are (1) determination of the components of the radiation environment (particle species, fluxes and energy spectra) which will encounter, (2) determination of the effects of shielding provided by the spacecraft and the bodies of the travelers which modify the incident particle spectra and mix of particles, and (3) determination of relevant biological effects of the radiation in the organs of interest. The latter can then lead to an estimation of risk from a given space scenario. Clearly, the process spans many scientific disciplines from solar and cosmic ray physics to radiation transport theeory to the multistage problem of the induction by radiation of initial lesions in living material and their evolution via physical, chemical, and biological processes at the molecular, cellular, and tissue levels to produce the end point of importance.

  1. Software risk estimation and management techniques at JPL

    NASA Technical Reports Server (NTRS)

    Hihn, J.; Lum, K.

    2002-01-01

    In this talk we will discuss how uncertainty has been incorporated into the JPL software model, probabilistic-based estimates, and how risk is addressed, how cost risk is currently being explored via a variety of approaches, from traditional risk lists, to detailed WBS-based risk estimates to the Defect Detection and Prevention (DDP) tool.

  2. IMPROVED RISK ESTIMATES FOR CARBON TETRACHLORIDE

    SciTech Connect

    Benson, Janet M.; Springer, David L.

    1999-12-31

    Carbon tetrachloride has been used extensively within the DOE nuclear weapons facilities. Rocky Flats was formerly the largest volume consumer of CCl4 in the United States using 5000 gallons in 1977 alone (Ripple, 1992). At the Hanford site, several hundred thousand gallons of CCl4 were discharged between 1955 and 1973 into underground cribs for storage. Levels of CCl4 in groundwater at highly contaminated sites at the Hanford facility have exceeded 8 the drinking water standard of 5 ppb by several orders of magnitude (Illman, 1993). High levels of CCl4 at these facilities represent a potential health hazard for workers conducting cleanup operations and for surrounding communities. The level of CCl4 cleanup required at these sites and associated costs are driven by current human health risk estimates, which assume that CCl4 is a genotoxic carcinogen. The overall purpose of these studies was to improve the scientific basis for assessing the health risk associated with human exposure to CCl4. Specific research objectives of this project were to: (1) compare the rates of CCl4 metabolism by rats, mice and hamsters in vivo and extrapolate those rates to man based on parallel studies on the metabolism of CCl4 by rat, mouse, hamster and human hepatic microsomes in vitro; (2) using hepatic microsome preparations, determine the role of specific cytochrome P450 isoforms in CCl4-mediated toxicity and the effects of repeated inhalation and ingestion of CCl4 on these isoforms; and (3) evaluate the toxicokinetics of inhaled CCl4 in rats, mice and hamsters. This information has been used to improve the physiologically based pharmacokinetic (PBPK) model for CCl4 originally developed by Paustenbach et al. (1988) and more recently revised by Thrall and Kenny (1996). Another major objective of the project was to provide scientific evidence that CCl4, like chloroform, is a hepatocarcinogen only when exposure results in cell damage, cell killing and regenerative proliferation. In

  3. Prediction of absolute risk of fragility fracture at 10 years in a Spanish population: validation of the WHO FRAX ™ tool in Spain

    PubMed Central

    2011-01-01

    Background Age-related bone loss is asymptomatic, and the morbidity of osteoporosis is secondary to the fractures that occur. Common sites of fracture include the spine, hip, forearm and proximal humerus. Fractures at the hip incur the greatest morbidity and mortality and give rise to the highest direct costs for health services. Their incidence increases exponentially with age. Independently changes in population demography, the age - and sex- specific incidence of osteoporotic fractures appears to be increasing in developing and developed countries. This could mean more than double the expected burden of osteoporotic fractures in the next 50 years. Methods/Design To assess the predictive power of the WHO FRAX™ tool to identify the subjects with the highest absolute risk of fragility fracture at 10 years in a Spanish population, a predictive validation study of the tool will be carried out. For this purpose, the participants recruited by 1999 will be assessed. These were referred to scan-DXA Department from primary healthcare centres, non hospital and hospital consultations. Study population: Patients attended in the national health services integrated into a FRIDEX cohort with at least one Dual-energy X-ray absorptiometry (DXA) measurement and one extensive questionnaire related to fracture risk factors. Measurements: At baseline bone mineral density measurement using DXA, clinical fracture risk factors questionnaire, dietary calcium intake assessment, history of previous fractures, and related drugs. Follow up by telephone interview to know fragility fractures in the 10 years with verification in electronic medical records and also to know the number of falls in the last year. The absolute risk of fracture will be estimated using the FRAX™ tool from the official web site. Discussion Since more than 10 years ago numerous publications have recognised the importance of other risk factors for new osteoporotic fractures in addition to low BMD. The extension of a

  4. Comparing paired vs non-paired statistical methods of analyses when making inferences about absolute risk reductions in propensity-score matched samples.

    PubMed

    Austin, Peter C

    2011-05-20

    Propensity-score matching allows one to reduce the effects of treatment-selection bias or confounding when estimating the effects of treatments when using observational data. Some authors have suggested that methods of inference appropriate for independent samples can be used for assessing the statistical significance of treatment effects when using propensity-score matching. Indeed, many authors in the applied medical literature use methods for independent samples when making inferences about treatment effects using propensity-score matched samples. Dichotomous outcomes are common in healthcare research. In this study, we used Monte Carlo simulations to examine the effect on inferences about risk differences (or absolute risk reductions) when statistical methods for independent samples are used compared with when statistical methods for paired samples are used in propensity-score matched samples. We found that compared with using methods for independent samples, the use of methods for paired samples resulted in: (i) empirical type I error rates that were closer to the advertised rate; (ii) empirical coverage rates of 95 per cent confidence intervals that were closer to the advertised rate; (iii) narrower 95 per cent confidence intervals; and (iv) estimated standard errors that more closely reflected the sampling variability of the estimated risk difference. Differences between the empirical and advertised performance of methods for independent samples were greater when the treatment-selection process was stronger compared with when treatment-selection process was weaker. We recommend using statistical methods for paired samples when using propensity-score matched samples for making inferences on the effect of treatment on the reduction in the probability of an event occurring.

  5. Estimation of health risks from radiation exposures

    SciTech Connect

    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.

  6. Mammographic breast density and breast cancer risk: interactions of percent density, absolute dense, and non-dense areas with breast cancer risk factors.

    PubMed

    Yaghjyan, Lusine; Colditz, Graham A; Rosner, Bernard; Tamimi, Rulla M

    2015-02-01

    We investigated if associations of breast density and breast cancer differ according to the level of other known breast cancer risk factors, including body mass index (BMI), age at menarche, parity, age at first child's birth, age at menopause, alcohol consumption, a family history of breast cancer, a history of benign breast disease, and physical activity. This study included 1,044 postmenopausal incident breast cancer cases diagnosed within the Nurses' Health Study cohort and 1,794 matched controls. Percent breast density, absolute dense, and non-dense areas were measured from digitized film images with computerized techniques. Information on breast cancer risk factors was obtained prospectively from biennial questionnaires. Percent breast density was more strongly associated with breast cancer risk in current postmenopausal hormone users (≥50 vs. 10 %: OR 5.34, 95 % CI 3.36-8.49) as compared to women with past (OR 2.69, 95 % CI 1.32-5.49) or no hormone history (OR 2.57, 95 % CI 1.18-5.60, p-interaction = 0.03). Non-dense area was inversely associated with breast cancer risk in parous women, but not in women without children (p-interaction = 0.03). Associations of density with breast cancer risk did not differ by the levels of BMI, age at menarche, parity, age at first child's birth, age at menopause, alcohol consumption, a family history of breast cancer, a history of benign breast disease, and physical activity. Women with dense breasts, who currently use menopausal hormone therapy are at a particularly high risk of breast cancer. Most breast cancer risk factors do not modify the association between mammographic breast density and breast cancer risk.

  7. Absolute quantification of the pretreatment PML-RARA transcript defines the relapse risk in acute promyelocytic leukemia.

    PubMed

    Albano, Francesco; Zagaria, Antonella; Anelli, Luisa; Coccaro, Nicoletta; Tota, Giuseppina; Brunetti, Claudia; Minervini, Crescenzio Francesco; Impera, Luciana; Minervini, Angela; Cellamare, Angelo; Orsini, Paola; Cumbo, Cosimo; Casieri, Paola; Specchia, Giorgina

    2015-05-30

    In this study we performed absolute quantification of the PML-RARA transcript by droplet digital polymerase chain reaction (ddPCR) in 76 newly diagnosed acute promyelocytic leukemia (APL) cases to verify the prognostic impact of the PML-RARA initial molecular burden. ddPCR analysis revealed that the amount of PML-RARA transcript at diagnosis in the group of patients who relapsed was higher than in that with continuous complete remission (CCR) (272 vs 89.2 PML-RARA copies/ng, p = 0.0004, respectively). Receiver operating characteristic analysis detected the optimal PML-RARA concentration threshold as 209.6 PML-RARA/ng (AUC 0.78; p < 0.0001) for discriminating between outcomes (CCR versus relapse). Among the 67 APL cases who achieved complete remission after the induction treatment, those with >209.6 PML-RARA/ng had a worse relapse-free survival (p = 0.0006). At 5-year follow-up, patients with >209.6 PML-RARA/ng had a cumulative incidence of relapse of 50.3% whereas 7.5% of the patients with suffered a relapse (p < 0.0001). Multivariate analysis identified the amount of PML-RARA before induction treatment as the sole independent prognostic factor for APL relapse.Our results show that the pretreatment PML-RARA molecular burden could therefore be used to improve risk stratification in order to develop more individualized treatment regimens for high-risk APL cases. PMID:25944686

  8. ON A NEW NEAR-INFRARED METHOD TO ESTIMATE THE ABSOLUTE AGES OF STAR CLUSTERS: NGC 3201 AS A FIRST TEST CASE

    SciTech Connect

    Bono, G.; Di Cecco, A.; Sanna, N.; Buonanno, R.; Stetson, P. B.; VandenBerg, D. A.; Calamida, A.; Amico, P.; Marchetti, E.; D'Odorico, S.; Gilmozzi, R.; Dall'Ora, M.; Iannicola, G.; Caputo, F.; Corsi, C. E.; Ferraro, I.; Monelli, M.; Walker, A. R.; Zoccali, M.; Degl'Innocenti, S.

    2010-01-10

    We present a new method to estimate the absolute ages of stellar systems. This method is based on the difference in magnitude between the main-sequence turnoff (MSTO) and a well-defined knee located along the lower main sequence (MSK). This feature is caused by the collisionally induced absorption of molecular hydrogen, and it can easily be identified in near-infrared (NIR) and in optical-NIR color-magnitude diagrams of stellar systems. We took advantage of deep and accurate NIR images collected with the Multi-Conjugate Adaptive Optics Demonstrator temporarily available on the Very Large Telescope and of optical images collected with the Advanced Camera for Surveys Wide Field Camera on the Hubble Space Telescope and with ground-based telescopes to estimate the absolute age of the globular NGC 3201 using both the MSTO and the {delta}(MSTO-MSK). We have adopted a new set of cluster isochrones, and we found that the absolute ages based on the two methods agree to within 1{sigma}. However, the errors of the ages based on the {delta}(MSTO-MSK) method are potentially more than a factor of 2 smaller, since they are not affected by uncertainties in cluster distance or reddening. Current isochrones appear to predict slightly bluer ({approx}0.05 mag) NIR and optical-NIR colors than observed for magnitudes fainter than the MSK.

  9. Relating space radiation environments to risk estimates

    SciTech Connect

    Curtis, S.B.

    1991-10-01

    This lecture will provide a bridge from the physical energy or LET spectra as might be calculated in an organ to the risk of carcinogenesis, a particular concern for extended missions to the moon or beyond to Mars. Topics covered will include (1) LET spectra expected from galactic cosmic rays, (2) probabilities that individual cell nuclei in the body will be hit by heavy galactic cosmic ray particles, (3) the conventional methods of calculating risks from a mixed environment of high and low LET radiation, (4) an alternate method which provides certain advantages using fluence-related risk coefficients (risk cross sections), and (5) directions for future research and development of these ideas.

  10. Exposure corrected risk estimates for childhood product related injuries.

    PubMed

    Senturia, Y D; Binns, H J; Christoffel, K K; Tanz, R R

    1993-08-01

    This study assesses the effect of exposure correction on injury risk estimates for children, using Chicago-area survey data on age-specific exposure of children to seven products: amusement park rides, sleds, bunkbeds, skateboards, fireworks, toboggans, and air guns and rifles. National Electronic Injury Surveillance System estimates for 1987 were used as numerators with two denominators: (i) uncorrected age-specific U.S. Census estimates for 1987 and (ii) these estimates corrected for exposure. Except for bunkbeds, skateboards and sleds, corrected injury risk decreased as age increased. Uncorrected population injury rates underestimated the risk posed to product-using children, especially those who are youngest and those who use skateboards.

  11. Absolute backscatter coefficient estimates of tissue-mimicking phantoms in the 5–50 MHz frequency range

    PubMed Central

    McCormick, Matthew M.; Madsen, Ernest L.; Deaner, Meagan E.; Varghese, Tomy

    2011-01-01

    Absolute backscatter coefficients in tissue-mimicking phantoms were experimentally determined in the 5–50 MHz frequency range using a broadband technique. A focused broadband transducer from a commercial research system, the VisualSonics Vevo 770, was used with two tissue-mimicking phantoms. The phantoms differed regarding the thin layers covering their surfaces to prevent desiccation and regarding glass bead concentrations and diameter distributions. Ultrasound scanning of these phantoms was performed through the thin layer. To avoid signal saturation, the power spectra obtained from the backscattered radio frequency signals were calibrated by using the signal from a liquid planar reflector, a water-brominated hydrocarbon interface with acoustic impedance close to that of water. Experimental values of absolute backscatter coefficients were compared with those predicted by the Faran scattering model over the frequency range 5–50 MHz. The mean percent difference and standard deviation was 54% ± 45% for the phantom with a mean glass bead diameter of 5.40 μm and was 47% ± 28% for the phantom with 5.16 μm mean diameter beads. PMID:21877789

  12. Political risk in fair market value estimates

    SciTech Connect

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

    1996-09-01

    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.

  13. Parametric Estimation in a Recurrent Competing Risks Model

    PubMed Central

    Peña, Edsel A.

    2014-01-01

    A resource-efficient approach to making inferences about the distributional properties of the failure times in a competing risks setting is presented. Efficiency is gained by observing recurrences of the competing risks over a random monitoring period. The resulting model is called the recurrent competing risks model (RCRM) and is coupled with two repair strategies whenever the system fails. Maximum likelihood estimators of the parameters of the marginal distribution functions associated with each of the competing risks and also of the system lifetime distribution function are presented. Estimators are derived under perfect and partial repair strategies. Consistency and asymptotic properties of the estimators are obtained. The estimation methods are applied to a data set of failures for cars under warranty. Simulation studies are used to ascertain the small sample properties and the efficiency gains of the resulting estimators. PMID:25346751

  14. Resources for global risk assessment: the International Toxicity Estimates for Risk (ITER) and Risk Information Exchange (RiskIE) databases.

    PubMed

    Wullenweber, Andrea; Kroner, Oliver; Kohrman, Melissa; Maier, Andrew; Dourson, Michael; Rak, Andrew; Wexler, Philip; Tomljanovic, Chuck

    2008-11-15

    The rate of chemical synthesis and use has outpaced the development of risk values and the resolution of risk assessment methodology questions. In addition, available risk values derived by different organizations may vary due to scientific judgments, mission of the organization, or use of more recently published data. Further, each organization derives values for a unique chemical list so it can be challenging to locate data on a given chemical. Two Internet resources are available to address these issues. First, the International Toxicity Estimates for Risk (ITER) database (www.tera.org/iter) provides chronic human health risk assessment data from a variety of organizations worldwide in a side-by-side format, explains differences in risk values derived by different organizations, and links directly to each organization's website for more detailed information. It is also the only database that includes risk information from independent parties whose risk values have undergone independent peer review. Second, the Risk Information Exchange (RiskIE) is a database of in progress chemical risk assessment work, and includes non-chemical information related to human health risk assessment, such as training modules, white papers and risk documents. RiskIE is available at http://www.allianceforrisk.org/RiskIE.htm, and will join ITER on National Library of Medicine's TOXNET (http://toxnet.nlm.nih.gov/). Together, ITER and RiskIE provide risk assessors essential tools for easily identifying and comparing available risk data, for sharing in progress assessments, and for enhancing interaction among risk assessment groups to decrease duplication of effort and to harmonize risk assessment procedures across organizations.

  15. Resources for global risk assessment: The International Toxicity Estimates for Risk (ITER) and Risk Information Exchange (RiskIE) databases

    SciTech Connect

    Wullenweber, Andrea Kroner, Oliver; Kohrman, Melissa; Maier, Andrew; Dourson, Michael; Rak, Andrew; Wexler, Philip; Tomljanovic, Chuck

    2008-11-15

    The rate of chemical synthesis and use has outpaced the development of risk values and the resolution of risk assessment methodology questions. In addition, available risk values derived by different organizations may vary due to scientific judgments, mission of the organization, or use of more recently published data. Further, each organization derives values for a unique chemical list so it can be challenging to locate data on a given chemical. Two Internet resources are available to address these issues. First, the International Toxicity Estimates for Risk (ITER) database ( (www.tera.org/iter)) provides chronic human health risk assessment data from a variety of organizations worldwide in a side-by-side format, explains differences in risk values derived by different organizations, and links directly to each organization's website for more detailed information. It is also the only database that includes risk information from independent parties whose risk values have undergone independent peer review. Second, the Risk Information Exchange (RiskIE) is a database of in progress chemical risk assessment work, and includes non-chemical information related to human health risk assessment, such as training modules, white papers and risk documents. RiskIE is available at (http://www.allianceforrisk.org/RiskIE.htm), and will join ITER on National Library of Medicine's TOXNET ( (http://toxnet.nlm.nih.gov/)). Together, ITER and RiskIE provide risk assessors essential tools for easily identifying and comparing available risk data, for sharing in progress assessments, and for enhancing interaction among risk assessment groups to decrease duplication of effort and to harmonize risk assessment procedures across organizations.

  16. Estimating Fire Risks at Industrial Nuclear Facilities

    SciTech Connect

    Coutts, D.A.

    1999-07-12

    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.

  17. Estimating Risk: Stereotype Amplification and the Perceived Risk of Criminal Victimization

    PubMed Central

    QUILLIAN, LINCOLN; PAGER, DEVAH

    2010-01-01

    This paper considers the process by which individuals estimate the risk of adverse events, with particular attention to the social context in which risk estimates are formed. We compare subjective probability estimates of crime victimization to actual victimization experiences among respondents from the 1994 to 2002 waves of the Survey of Economic Expectations (Dominitz and Manski 2002). Using zip code identifiers, we then match these survey data to local area characteristics from the census. The results show that: (1) the risk of criminal victimization is significantly overestimated relative to actual rates of victimization or other negative events; (2) neighborhood racial composition is strongly associated with perceived risk of victimization, whereas actual victimization risk is driven by nonracial neighborhood characteristics; and (3) white respondents appear more strongly affected by racial composition than nonwhites in forming their estimates of risk. We argue these results support a model of stereotype amplification in the formation of risk estimates. Implications for persistent racial inequality are considered. PMID:20686631

  18. Thinking Concretely Increases the Perceived Likelihood of Risks: The Effect of Construal Level on Risk Estimation.

    PubMed

    Lermer, Eva; Streicher, Bernhard; Sachs, Rainer; Raue, Martina; Frey, Dieter

    2016-03-01

    Recent findings on construal level theory (CLT) suggest that abstract thinking leads to a lower estimated probability of an event occurring compared to concrete thinking. We applied this idea to the risk context and explored the influence of construal level (CL) on the overestimation of small and underestimation of large probabilities for risk estimates concerning a vague target person (Study 1 and Study 3) and personal risk estimates (Study 2). We were specifically interested in whether the often-found overestimation of small probabilities could be reduced with abstract thinking, and the often-found underestimation of large probabilities was reduced with concrete thinking. The results showed that CL influenced risk estimates. In particular, a concrete mindset led to higher risk estimates compared to an abstract mindset for several adverse events, including events with small and large probabilities. This suggests that CL manipulation can indeed be used for improving the accuracy of lay people's estimates of small and large probabilities. Moreover, the results suggest that professional risk managers' risk estimates of common events (thus with a relatively high probability) could be improved by adopting a concrete mindset. However, the abstract manipulation did not lead managers to estimate extremely unlikely events more accurately. Potential reasons for different CL manipulation effects on risk estimates' accuracy between lay people and risk managers are discussed.

  19. Risk estimates for neonatal myotonic dystrophy.

    PubMed Central

    Glånz, A; Fråser, F C

    1984-01-01

    Children who inherit the autosomal dominant gene for myotonic dystrophy from their mother rather than their father may develop the severe neonatal type rather than the late onset type. The families of 22 neonatal type probands and 59 late onset type probands were studied to determine the risk of occurrence and recurrence of the neonatal type. The frequency of the neonatal type in sibs of neonatal type probands was 29%, or 37% if cases of neonatal deaths are counted as affected. This is significantly higher than the 6% of the neonatal type found in the offspring of affected women not ascertained through a child with the neonatal type. These data suggest that certain women carrying the gene for myotonic dystrophy are predisposed to have children affected with the neonatal type rather than the late onset type. The female near relatives of these women do not seem to share this predisposition. The data should be useful for genetic counseling. PMID:6748014

  20. Sensitivity of health risk estimates to air quality adjustment procedure

    SciTech Connect

    Whitfield, R.G.

    1997-06-30

    This letter is a summary of risk results associated with exposure estimates using two-parameter Weibull and quadratic air quality adjustment procedures (AQAPs). New exposure estimates were developed for children and child-occurrences, six urban areas, and five alternative air quality scenarios. In all cases, the Weibull and quadratic results are compared to previous results, which are based on a proportional AQAP.

  1. Absolute Summ

    NASA Astrophysics Data System (ADS)

    Phillips, Alfred, Jr.

    Summ means the entirety of the multiverse. It seems clear, from the inflation theories of A. Guth and others, that the creation of many universes is plausible. We argue that Absolute cosmological ideas, not unlike those of I. Newton, may be consistent with dynamic multiverse creations. As suggested in W. Heisenberg's uncertainty principle, and with the Anthropic Principle defended by S. Hawking, et al., human consciousness, buttressed by findings of neuroscience, may have to be considered in our models. Predictability, as A. Einstein realized with Invariants and General Relativity, may be required for new ideas to be part of physics. We present here a two postulate model geared to an Absolute Summ. The seedbed of this work is part of Akhnaton's philosophy (see S. Freud, Moses and Monotheism). Most important, however, is that the structure of human consciousness, manifest in Kenya's Rift Valley 200,000 years ago as Homo sapiens, who were the culmination of the six million year co-creation process of Hominins and Nature in Africa, allows us to do the physics that we do. .

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

    PubMed Central

    2012-01-01

    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. PMID:22776564

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

    Cancer.gov

    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.

  4. Estimating and Mapping the Population at Risk of Sleeping Sickness

    PubMed Central

    Franco, José R.; Paone, Massimo; Diarra, Abdoulaye; Ruiz-Postigo, José Antonio; Fèvre, Eric M.; Mattioli, Raffaele C.; Jannin, Jean G.

    2012-01-01

    Background 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. Results Approximately 70 million people distributed over a surface of 1.55 million km2 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. Discussion 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. PMID:23145192

  5. [Application of spatial relative risk estimation in communicable disease risk evaluation].

    PubMed

    Zhang, Yewu; Guo, Qing; Wang, Xiaofeng; Yu, Meng; Su, Xuemei; Dong, Yan; Zhang, Chunxi

    2015-05-01

    This paper summaries the application of adaptive kernel density algorithm in the spatial relative risk estimation of communicable diseases by using the reported data of infectious diarrhea (other than cholera, dysentery, typhoid and paratyphoid) in Ludian county and surrounding area in Yunnan province in 2013. Statistically significant fluctuations in an estimated risk function were identified through the use of asymptotic tolerance contours, and finally these data were visualized though disease mapping. The results of spatial relative risk estimation and disease mapping showed that high risk areas were in southeastern Shaoyang next to Ludian. Therefore, the spatial relative risk estimation of disease by using adaptive kernel density algorithm and disease mapping technique is a powerful method in identifying high risk population and areas.

  6. [Application of spatial relative risk estimation in communicable disease risk evaluation].

    PubMed

    Zhang, Yewu; Guo, Qing; Wang, Xiaofeng; Yu, Meng; Su, Xuemei; Dong, Yan; Zhang, Chunxi

    2015-05-01

    This paper summaries the application of adaptive kernel density algorithm in the spatial relative risk estimation of communicable diseases by using the reported data of infectious diarrhea (other than cholera, dysentery, typhoid and paratyphoid) in Ludian county and surrounding area in Yunnan province in 2013. Statistically significant fluctuations in an estimated risk function were identified through the use of asymptotic tolerance contours, and finally these data were visualized though disease mapping. The results of spatial relative risk estimation and disease mapping showed that high risk areas were in southeastern Shaoyang next to Ludian. Therefore, the spatial relative risk estimation of disease by using adaptive kernel density algorithm and disease mapping technique is a powerful method in identifying high risk population and areas. PMID:26080648

  7. On cancer risk estimation of urban air pollution.

    PubMed Central

    Törnqvist, M; Ehrenberg, L

    1994-01-01

    The usefulness of data from various sources for a cancer risk estimation of urban air pollution is discussed. Considering the irreversibility of initiations, a multiplicative model is preferred for solid tumors. As has been concluded for exposure to ionizing radiation, the multiplicative model, in comparison with the additive model, predicts a relatively larger number of cases at high ages, with enhanced underestimation of risks by short follow-up times in disease-epidemiological studies. For related reasons, the extrapolation of risk from animal tests on the basis of daily absorbed dose per kilogram body weight or per square meter surface area without considering differences in life span may lead to an underestimation, and agreements with epidemiologically determined values may be fortuitous. Considering these possibilities, the most likely lifetime risks of cancer death at the average exposure levels in Sweden were estimated for certain pollution fractions or indicator compounds in urban air. The risks amount to approximately 50 deaths per 100,000 for inhaled particulate organic material (POM), with a contribution from ingested POM about three times larger, and alkenes, and butadiene cause 20 deaths, respectively, per 100,000 individuals. Also, benzene and formaldehyde are expected to be associated with considerable risk increments. Comparative potency methods were applied for POM and alkenes. Due to incompleteness of the list of compounds considered and the uncertainties of the above estimates, the total risk calculation from urban air has not been attempted here. PMID:7821292

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

    PubMed

    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.

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

    PubMed Central

    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

  10. Absolute monocyte count trichotomizes chronic lymphocytic leukemia into high risk patients with immune dysregulation, disease progression and poor survival.

    PubMed

    Herishanu, Yair; Kay, Sigi; Sarid, Nadav; Kohan, Pedram; Braunstein, Rony; Rotman, Rachel; Deutsch, Varda; Ben-Ezra, Jonathan; Naparstek, Elizabeth; Perry, Chava; Katz, Ben-Zion

    2013-10-01

    Peripheral absolute monocyte count (AMC) has been reported to correlate with clinical outcome in different types of cancers. This association may relate to alteration in circulating monocytic subpopulations and tumor infiltrating macrophages. In this study we evaluated the clinical significance of peripheral AMC in 80 treatment naive patients with CLL. Measurement of AMC was based on direct morphological enumeration, due to our findings that complete blood count data may yield incorrect monocytes enumeration values in CLL. The median AMC in patients with CLL was within normal limits, however the AMC range exceeded the values of healthy individuals. The AMC trichotomized patients into 3 distinct sub-groups with different characteristics and outcomes. High AMC patients were younger and had higher absolute lymphocytes count, while patients with low AMC had prominent immune dysregulation (lower serum IgA levels, susceptibility to infections and a tendency for positive direct anti-globulin test). The low and high AMC patients had a shorter time to treatment compared to the intermediates AMC subgroups, whereas low AMC was associated with increased mortality caused by infectious complications. In conclusion, AMC quantification during the disease course classifies CLL patients into subgroups with unique clinical features and outcomes.

  11. Effects of exposure uncertainty on estimation of radon risks

    SciTech Connect

    Chambers, D.B.; Lowe, L.M.; Stager, R.H.; Reilly, P.M.; Duport, P.

    1992-12-31

    Estimates of lung-cancer risk from exposure to radon daughters are largely based on epidemiological studies of underground miners. The reliability of exposure data for these miners is a cause for concern, as actual workplace measurements of radon and/or radon-daughter levels are either sparse or absent for the early years of mining, when much of the exposure occurred.

  12. Estimates of endemic waterborne risks from community-intervention studies.

    PubMed

    Calderon, Rebecca L; Craun, Gunther F

    2006-01-01

    The nature and magnitude of endemic waterborne disease are not well characterized in the United States. Epidemiologic studies of various designs can provide an estimate of the waterborne attributable risk along with other types of information. Community drinking water systems frequently improve their operations and may change drinking water treatment and their major source of water. In the United States, many of these treatment changes are the result of regulations promulgated under the Safe Drinking Water Act. A community-intervention study design takes advantage of these "natural" experiments to assess changes in health risks. In this paper, we review the community-intervention studies that have assessed changes in waterborne gastroenteritis risks among immunocompetent populations in industrialized countries. Published results are available from two studies in Australia, one study in the United Kingdom, and one study in the United States. Preliminary results from two other US studies are also available. Although the current information is limited, the risks reported in these community-intervention studies can help inform the national estimate of endemic waterborne gastroenteritis. Information is provided about endemic waterborne risks for unfiltered surface water sources and a groundwater under the influence of surface water. Community-intervention studies with recommended study modifications should be conducted to better estimate the benefits associated with improved drinking water treatment. PMID:16895087

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

    SciTech Connect

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

    1984-12-01

    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. Estimation of myocardial volume at risk from CT angiography

    NASA Astrophysics Data System (ADS)

    Zhu, Liangjia; Gao, Yi; Mohan, Vandana; Stillman, Arthur; Faber, Tracy; Tannenbaum, Allen

    2011-03-01

    The determination of myocardial volume at risk distal to coronary stenosis provides important information for prognosis and treatment of coronary artery disease. In this paper, we present a novel computational framework for estimating the myocardial volume at risk in computed tomography angiography (CTA) imagery. Initially, epicardial and endocardial surfaces, and coronary arteries are extracted using an active contour method. Then, the extracted coronary arteries are projected onto the epicardial surface, and each point on this surface is associated with its closest coronary artery using the geodesic distance measurement. The likely myocardial region at risk on the epicardial surface caused by a stenosis is approximated by the region in which all its inner points are associated with the sub-branches distal to the stenosis on the coronary artery tree. Finally, the likely myocardial volume at risk is approximated by the volume in between the region at risk on the epicardial surface and its projection on the endocardial surface, which is expected to yield computational savings over risk volume estimation using the entire image volume. Furthermore, we expect increased accuracy since, as compared to prior work using the Euclidean distance, we employ the geodesic distance in this work. The experimental results demonstrate the effectiveness of the proposed approach on pig heart CTA datasets.

  15. Estimating Non-stationary Flood Risk in a Changing Climate

    NASA Astrophysics Data System (ADS)

    Yu, X.; Cohn, T. A.; Stedinger, J. R.

    2015-12-01

    Flood risk is usually described by a probability distribution for annual maximum streamflow which is assumed not to change with time. Federal, state and local governments in the United States are demanding guidance on flood frequency estimates that account for climate change. If a trend exists in peak flow series, ignoring it could result in large quantile estimator bias, while trying to estimate a trend will increase the flood quantile estimator's variance. Thus the issue is, what bias-variance tradeoff should we accept? This paper discusses approaches to flood frequency analysis (FFA) when flood series have trends. GCMs describe how annual runoff might vary over sub-continental scales, but this information is nearly useless for FFA in small watersheds. A LP3 Monte Carlo analysis and a re-sampling study of 100-year flood estimation (25- and 50-year projections) compares the performance of five methods: FFA as prescribed in national guidelines (Bulletin 17B), assumes the flood series is stationary and follows a log-Pearson type III (LP3) distribution; Fitting a LP3 distribution with time-varying parameters that include future trends in mean and perhaps variance, where slopes are assumed known; Fitting a LP3 distribution with time-varying parameters that capture future trends in mean and perhaps variance, where slopes are estimated from annual peak flow series; Employing only the most recent 30 years of flood records to fit a LP3 distribution; Applying a safety factor to the 100-year flood estimator (e.g. 25% increase). The 100-year flood estimator of method 2 has the smallest log-space mean squared error, though it is unlikely that the true trend would be known. Method 3 is only recommended over method 1 for large trends (≥ 0.5% per year). The 100-year flood estimators of method 1, 4, and 5 often have poor accuracy. Clearly, flood risk assessment will be a challenge in an uncertain world.

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

    PubMed

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

    1990-12-01

    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 risk of spontaneous abortion of 0.33.

  17. Flexible dose-response models for Japanese atomic bomb survivor data: Bayesian estimation and prediction of cancer risk.

    PubMed

    Bennett, James; Little, Mark P; Richardson, Sylvia

    2004-12-01

    Generalised absolute risk models were fitted to the latest Japanese atomic bomb survivor cancer incidence data using Bayesian Markov Chain Monte Carlo methods, taking account of random errors in the DS86 dose estimates. The resulting uncertainty distributions in the relative risk model parameters were used to derive uncertainties in population cancer risks for a current UK population. Because of evidence for irregularities in the low-dose dose response, flexible dose-response models were used, consisting of a linear-quadratic-exponential model, used to model the high-dose part of the dose response, together with piecewise-linear adjustments for the two lowest dose groups. Following an assumed administered dose of 0.001 Sv, lifetime leukaemia radiation-induced incidence risks were estimated to be 1.11 x 10(-2) Sv(-1) (95% Bayesian CI -0.61, 2.38) using this model. Following an assumed administered dose of 0.001 Sv, lifetime solid cancer radiation-induced incidence risks were calculated to be 7.28 x 10(-2) Sv(-1) (95% Bayesian CI -10.63, 22.10) using this model. Overall, cancer incidence risks predicted by Bayesian Markov Chain Monte Carlo methods are similar to those derived by classical likelihood-based methods and which form the basis of established estimates of radiation-induced cancer risk.

  18. NRC committee provides new risk estimates for exposure to radon

    SciTech Connect

    Not Available

    1988-03-01

    A new set of age-specific estimates describing the increased risk of lung cancer following exposure to radon was released in January by a National Research Council committee. The revised estimates result from new statistical techniques used to analyze previously collected data. In a study jointly sponsored by the Environmental Protection Agency (EPA) and the Nuclear Regulatory Commission, the committee concluded that lifetime exposure to one working level month (WLM) of radon per year, a standard measure used by radiation experts, increases an individual's chances of dying from lung cancer by 1.5 times compared with someone exposed only to background levels of radon. The committee estimated that, for every 1 million people exposed over a lifetime to one WLM of radon, about 350 additional deaths would occur due to lung cancer. The committee found that lung cancer risks associated with radon increased with increasing length of exposure. Moreover, it said that 15 years after exposure to radon has ended, the risk of lung cancer from the exposure declines to half the original risk.

  19. Estimating Skin Cancer Risk: Evaluating Mobile Computer-Adaptive Testing

    PubMed Central

    Djaja, Ngadiman; Janda, Monika; Olsen, Catherine M; Whiteman, David C

    2016-01-01

    Background Response burden is a major detriment to questionnaire completion rates. Computer adaptive testing may offer advantages over non-adaptive testing, including reduction of numbers of items required for precise measurement. Objective Our aim was to compare the efficiency of non-adaptive (NAT) and computer adaptive testing (CAT) facilitated by Partial Credit Model (PCM)-derived calibration to estimate skin cancer risk. Methods We used a random sample from a population-based Australian cohort study of skin cancer risk (N=43,794). All 30 items of the skin cancer risk scale were calibrated with the Rasch PCM. A total of 1000 cases generated following a normal distribution (mean [SD] 0 [1]) were simulated using three Rasch models with three fixed-item (dichotomous, rating scale, and partial credit) scenarios, respectively. We calculated the comparative efficiency and precision of CAT and NAT (shortening of questionnaire length and the count difference number ratio less than 5% using independent t tests). Results We found that use of CAT led to smaller person standard error of the estimated measure than NAT, with substantially higher efficiency but no loss of precision, reducing response burden by 48%, 66%, and 66% for dichotomous, Rating Scale Model, and PCM models, respectively. Conclusions CAT-based administrations of the skin cancer risk scale could substantially reduce participant burden without compromising measurement precision. A mobile computer adaptive test was developed to help people efficiently assess their skin cancer risk. PMID:26800642

  20. A Review of Expertise and Judgment Processes for Risk Estimation

    SciTech Connect

    R. L. Boring

    2007-06-01

    A major challenge of risk and reliability analysis for human errors or hardware failures is the need to enlist expert opinion in areas for which adequate operational data are not available. Experts enlisted in this capacity provide probabilistic estimates of reliability, typically comprised of a measure of central tendency and uncertainty bounds. While formal guidelines for expert elicitation are readily available, they largely fail to provide a theoretical basis for expertise and judgment. This paper reviews expertise and judgment in the context of risk analysis; overviews judgment biases, the role of training, and multivariate judgments; and provides guidance on the appropriate use of atomistic and holistic judgment processes.

  1. Using Mean Absolute Relative Phase, Deviation Phase and Point-Estimation Relative Phase to Measure Postural Coordination in a Serial Reaching Task.

    PubMed

    Galgon, Anne K; Shewokis, Patricia A

    2016-03-01

    The objectives of this communication are to present the methods used to calculate mean absolute relative phase (MARP), deviation phase (DP) and point estimate relative phase (PRP) and compare their utility in measuring postural coordination during the performance of a serial reaching task. MARP and DP are derived from continuous relative phase time series representing the relationship between two body segments or joints during movements. MARP is a single measure used to quantify the coordination pattern and DP measures the stability of the coordination pattern. PRP also quantifies coordination patterns by measuring the relationship between the timing of maximal or minimal angular displacements of two segments within cycles of movement. Seven young adults practiced a bilateral serial reaching task 300 times over 3 days. Relative phase measures were used to evaluate inter-joint relationships for shoulder-hip (proximal) and hip-ankle (distal) postural coordination at early and late learning. MARP, PRP and DP distinguished between proximal and distal postural coordination. There was no effect of practice on any of the relative phase measures for the group, but individual differences were seen over practice. Combined, MARP and DP estimated stability of in-phase and anti-phase postural coordination patterns, however additional qualitative movement analyses may be needed to interpret findings in a serial task. We discuss the strengths and limitations of using MARP and DP and compare MARP and DP to PRP measures in assessing coordination patterns in the context of various types of skillful tasks. Key pointsMARP, DP and PRP measures coordination between segments or joint anglesAdvantages and disadvantages of each measure should be considered in relationship to the performance taskMARP and DP may capture coordination patterns and stability of the patterns during discrete tasks or phases of movements within a taskPRP and SD or PRP may capture coordination patterns and

  2. Estimation of radiation risk for astronauts on the Moon

    NASA Astrophysics Data System (ADS)

    Kuznetsov, N. V.; Nymmik, R. A.; Panasyuk, M. I.; Denisov, A. N.; Sobolevsky, N. M.

    2012-05-01

    The problem of estimating the risk of radiation for humans on the Moon is discussed, taking into account the probabilistic nature of occurrence of solar particle events. Calculations of the expected values of tissue-averaged equivalent dose rates, which are created by galactic and solar cosmic-ray particle fluxes on the lunar surface behind shielding, are made for different durations of lunar missions.

  3. Estimating relative risks for common outcome using PROC NLP.

    PubMed

    Yu, Binbing; Wang, Zhuoqiao

    2008-05-01

    In cross-sectional or cohort studies with binary outcomes, it is biologically interpretable and of interest to estimate the relative risk or prevalence ratio, especially when the response rates are not rare. Several methods have been used to estimate the relative risk, among which the log-binomial models yield the maximum likelihood estimate (MLE) of the parameters. Because of restrictions on the parameter space, the log-binomial models often run into convergence problems. Some remedies, e.g., the Poisson and Cox regressions, have been proposed. However, these methods may give out-of-bound predicted response probabilities. In this paper, a new computation method using the SAS Nonlinear Programming (NLP) procedure is proposed to find the MLEs. The proposed NLP method was compared to the COPY method, a modified method to fit the log-binomial model. Issues in the implementation are discussed. For illustration, both methods were applied to data on the prevalence of microalbuminuria (micro-protein leakage into urine) for kidney disease patients from the Diabetes Control and Complications Trial. The sample SAS macro for calculating relative risk is provided in the appendix.

  4. Improved risk estimates for carbon tetrachloride. 1998 annual progress report

    SciTech Connect

    Benson, J.M.; Springer, D.L.; Thrall, K.D.

    1998-06-01

    'The overall purpose of these studies is to improve the scientific basis for assessing the cancer risk associated with human exposure to carbon tetrachloride. Specifically, the toxicokinetics of inhaled carbon tetrachloride is being determined in rats, mice and hamsters. Species differences in the metabolism of carbon tetrachloride by rats, mice and hamsters is being determined in vivo and in vitro using tissues and microsomes from these rodent species and man. Dose-response relationships will be determined in all studies. The information will be used to improve the current physiologically based pharmacokinetic model for carbon tetrachloride. The authors will also determine whether carbon tetrachloride is a hepatocarcinogen only when exposure results in cell damage, cell killing, and regenerative cell proliferation. In combination, the results of these studies will provide the types of information needed to enable a refined risk estimate for carbon tetrachloride under EPA''s new guidelines for cancer risk assessment.'

  5. Risk estimation based on chromosomal aberrations induced by radiation

    NASA Technical Reports Server (NTRS)

    Durante, M.; Bonassi, S.; George, K.; Cucinotta, F. A.

    2001-01-01

    The presence of a causal association between the frequency of chromosomal aberrations in peripheral blood lymphocytes and the risk of cancer has been substantiated recently by epidemiological studies. Cytogenetic analyses of crew members of the Mir Space Station have shown that a significant increase in the frequency of chromosomal aberrations can be detected after flight, and that such an increase is likely to be attributed to the radiation exposure. The risk of cancer can be estimated directly from the yields of chromosomal aberrations, taking into account some aspects of individual susceptibility and other factors unrelated to radiation. However, the use of an appropriate technique for the collection and analysis of chromosomes and the choice of the structural aberrations to be measured are crucial in providing sound results. Based on the fraction of aberrant lymphocytes detected before and after flight, the relative risk after a long-term Mir mission is estimated to be about 1.2-1.3. The new technique of mFISH can provide useful insights into the quantification of risk on an individual basis.

  6. Radiation carcinogenesis in man: influence of dose-response models and risk projection models in the estimation of risk coefficients following exposure to low-level radiation

    SciTech Connect

    Fabrikant, J.I.

    1982-02-01

    The somatic effects of concern in human populations exposed to low doses and low dose rates of ionizing radiations are those that may be induced by mutation in individual cells, singly or in small numbers. The most important of these is considered to be cancer induction. Current knowledge of the carcinogenic effect of radiation in man has been reviewed in two recent reports: the 1977 UNSCEAR Report; and the 1980 BEIR-III Report. Both reports emphasize that cancers of the breast, thyroid, hematopoietic tissues, lung, and bone can be induced by radiation. Other cancers, including the stomach, pancreas, pharynx, lymphatic, and perhaps all tissues of the body, may also be induced by radiation. Both reports calculate risk estimates in absolute and relative terms for low-dose, low-LET whole-body exposure, and for leukemia, breast cancer, thyroid cancer, lung cancer, and other cancers. These estimates derive from exposure and cancer incidence data at high doses and at high dose rates. There are no compelling scientific reasons to apply these values of risk to the very low doses and low dose rates of concern in human radiation protection. In the absence of reliable human data for calculating risk estimates, dose-response models have been constructed from extrapolations of animal data and high-dose-rate human data for projection of estimated risks at low doses and low dose rates. (ERB)

  7. A comparison of genetic risk score with family history for estimating prostate cancer risk

    PubMed Central

    Helfand, Brian T

    2016-01-01

    Prostate cancer (PCa) testing is recommended by most authoritative groups for high-risk men including those with a family history of the disease. However, family history information is often limited by patient knowledge and clinician intake, and thus, many men are incorrectly assigned to different risk groups. Alternate methods to assess PCa risk are required. In this review, we discuss how genetic variants, referred to as PCa-risk single-nucleotide polymorphisms, can be used to calculate a genetic risk score (GRS). GRS assigns a relatively unique value to all men based on the number of PCa-risk SNPs that an individual carries. This GRS value can provide a more precise estimate of a man's PCa risk. This is particularly relevant in situations when an individual is unaware of his family history. In addition, GRS has utility and can provide a more precise estimate of risk even among men with a positive family history. It can even distinguish risk among relatives with the same degree of family relationships. Taken together, this review serves to provide support for the clinical utility of GRS as an independent test to provide supplemental information to family history. As such, GRS can serve as a platform to help guide-shared decision-making processes regarding the timing and frequency of PCa testing and biopsies. PMID:27004541

  8. Seismic Risk Assessment and Loss Estimation for Tbilisi City

    NASA Astrophysics Data System (ADS)

    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.

  9. Risk cross sections and their application to risk estimation in the galactic cosmic-ray environment.

    PubMed

    Curtis, S B; Nealy, J E; Wilson, J W

    1995-01-01

    Radiation risk cross sections (i.e. risks per particle fluence) are discussed in the context of estimating the risk of radiation-induced cancer on long-term space flights from the galactic cosmic radiation outside the confines of the earth's magnetic field. Such quantities are useful for handling effects not seen after low-LET radiation. Since appropriate cross-section functions for cancer induction for each particle species are not yet available, the conventional quality factor is used as an approximation to obtain numerical results for risks of excess cancer mortality. Risks are obtained for seven of the most radiosensitive organs as determined by the ICRP [stomach, colon, lung, bone marrow (BFO), bladder, esophagus and breast], beneath 10 g/cm2 aluminum shielding at solar minimum. Spectra are obtained for excess relative risk for each cancer per LET interval by calculating the average fluence-LET spectrum for the organ and converting to risk by multiplying by a factor proportional to R gamma L Q(L) before integrating over L, the unrestricted LET. Here R gamma is the risk coefficient for low-LET radiation (excess relative mortality per Sv) for the particular organ in question. The total risks of excess cancer mortality obtained are 1.3 and 1.1% to female and male crew, respectively, for a 1-year exposure at solar minimum. Uncertainties in these values are estimated to range between factors of 4 and 15 and are dominated by the biological uncertainties in the risk coefficients for low-LET radiation and in the LET (or energy) dependence of the risk cross sections (as approximated by the quality factor). The direct substitution of appropriate risk cross sections will eventually circumvent entirely the need to calculate, measure or use absorbed dose, equivalent dose and quality factor for such a high-energy charged-particle environment. PMID:7997515

  10. Risk cross sections and their application to risk estimation in the galactic cosmic-ray environment

    NASA Technical Reports Server (NTRS)

    Curtis, S. B.; Nealy, J. E.; Wilson, J. W.; Chatterjee, A. (Principal Investigator)

    1995-01-01

    Radiation risk cross sections (i.e. risks per particle fluence) are discussed in the context of estimating the risk of radiation-induced cancer on long-term space flights from the galactic cosmic radiation outside the confines of the earth's magnetic field. Such quantities are useful for handling effects not seen after low-LET radiation. Since appropriate cross-section functions for cancer induction for each particle species are not yet available, the conventional quality factor is used as an approximation to obtain numerical results for risks of excess cancer mortality. Risks are obtained for seven of the most radiosensitive organs as determined by the ICRP [stomach, colon, lung, bone marrow (BFO), bladder, esophagus and breast], beneath 10 g/cm2 aluminum shielding at solar minimum. Spectra are obtained for excess relative risk for each cancer per LET interval by calculating the average fluence-LET spectrum for the organ and converting to risk by multiplying by a factor proportional to R gamma L Q(L) before integrating over L, the unrestricted LET. Here R gamma is the risk coefficient for low-LET radiation (excess relative mortality per Sv) for the particular organ in question. The total risks of excess cancer mortality obtained are 1.3 and 1.1% to female and male crew, respectively, for a 1-year exposure at solar minimum. Uncertainties in these values are estimated to range between factors of 4 and 15 and are dominated by the biological uncertainties in the risk coefficients for low-LET radiation and in the LET (or energy) dependence of the risk cross sections (as approximated by the quality factor). The direct substitution of appropriate risk cross sections will eventually circumvent entirely the need to calculate, measure or use absorbed dose, equivalent dose and quality factor for such a high-energy charged-particle environment.

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

    NASA Astrophysics Data System (ADS)

    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.

  12. Quasi-likelihood estimation for relative risk regression models.

    PubMed

    Carter, Rickey E; Lipsitz, Stuart R; Tilley, Barbara C

    2005-01-01

    For a prospective randomized clinical trial with two groups, the relative risk can be used as a measure of treatment effect and is directly interpretable as the ratio of success probabilities in the new treatment group versus the placebo group. For a prospective study with many covariates and a binary outcome (success or failure), relative risk regression may be of interest. If we model the log of the success probability as a linear function of covariates, the regression coefficients are log-relative risks. However, using such a log-linear model with a Bernoulli likelihood can lead to convergence problems in the Newton-Raphson algorithm. This is likely to occur when the success probabilities are close to one. A constrained likelihood method proposed by Wacholder (1986, American Journal of Epidemiology 123, 174-184), also has convergence problems. We propose a quasi-likelihood method of moments technique in which we naively assume the Bernoulli outcome is Poisson, with the mean (success probability) following a log-linear model. We use the Poisson maximum likelihood equations to estimate the regression coefficients without constraints. Using method of moment ideas, one can show that the estimates using the Poisson likelihood will be consistent and asymptotically normal. We apply these methods to a double-blinded randomized trial in primary biliary cirrhosis of the liver (Markus et al., 1989, New England Journal of Medicine 320, 1709-1713). PMID:15618526

  13. Leukemia risk associated with benzene exposure in the pliofilm cohort. II. Risk estimates.

    PubMed

    Paxton, M B; Chinchilli, V M; Brett, S M; Rodricks, J V

    1994-04-01

    The detailed work histories of the individual workers composing the Pliofilm cohort represent a unique resource for estimating the dose-response for leukemia that may follow occupational exposure to benzene. In this paper, we report the results of analyzing the updated Pliofilm cohort using the proportional hazards model, a more sophisticated technique that uses more of the available exposure data than the conditional logistic model used by Rinsky et al. The more rigorously defined exposure estimates derived by Paustenbach et al. are consistent with those of Crump and Allen in giving estimates of the slope of the leukemogenic dose-response that are not as steep as the slope resulting from the exposure estimates of Rinsky et al. We consider estimates of 0.3-0.5 additional leukemia deaths per thousand workers with 45 ppm-years of cumulative benzene exposure to be the best estimates currently available of leukemia risk from occupational exposure to benzene. These risks were estimated in the proportional hazards model when the exposure estimates of Crump and Allen or of Paustenbach et al. were used to derive a cumulative concentration-by-time metric. PMID:8008924

  14. Cancer Risk Estimates from Space Flight Estimated Using Yields of Chromosome Damage in Astronaut's Blood Lymphocytes

    NASA Technical Reports Server (NTRS)

    George, Kerry A.; Rhone, J.; Chappell, L. J.; Cucinotta, F. A.

    2011-01-01

    To date, cytogenetic damage has been assessed in blood lymphocytes from more than 30 astronauts before and after they participated in long-duration space missions of three months or more on board the International Space Station. Chromosome damage was assessed using fluorescence in situ hybridization whole chromosome analysis techniques. For all individuals, the frequency of chromosome damage measured within a month of return from space was higher than their preflight yield, and biodosimetry estimates were within the range expected from physical dosimetry. Follow up analyses have been performed on most of the astronauts at intervals ranging from around 6 months to many years after flight, and the cytogenetic effects of repeat long-duration missions have so far been assessed in four individuals. Chromosomal aberrations in peripheral blood lymphocytes have been validated as biomarkers of cancer risk and cytogenetic damage can therefore be used to characterize excess health risk incurred by individual crewmembers after their respective missions. Traditional risk assessment models are based on epidemiological data obtained on Earth in cohorts exposed predominantly to acute doses of gamma-rays, and the extrapolation to the space environment is highly problematic, involving very large uncertainties. Cytogenetic damage could play a key role in reducing uncertainty in risk estimation because it is incurred directly in the space environment, using specimens from the astronauts themselves. Relative cancer risks were estimated from the biodosimetry data using the quantitative approach derived from the European Study Group on Cytogenetic Biomarkers and Health database. Astronauts were categorized into low, medium, or high tertiles according to their yield of chromosome damage. Age adjusted tertile rankings were used to estimate cancer risk and results were compared with values obtained using traditional modeling approaches. Individual tertile rankings increased after space

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

    Cancer.gov

    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).

  16. Estimating Worker Risk Levels Using Accident/Incident Data

    SciTech Connect

    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.

  17. Estimation of Hail Risk in the UK and Europe

    NASA Astrophysics Data System (ADS)

    Robinson, Eric; Parker, Melanie; Higgs, Stephanie

    2016-04-01

    Observations of hail events in Europe, and the UK especially, are relatively limited. In order to determine hail risk it is therefore necessary to use information other than relying purely on the historical record. One such methodology is to leverage reanalysis data, in this case ERA-Interim, along with a numerical model (WRF) to recreate the past state of the atmosphere. Relevant atmospheric properties can be extracted and used in a regression model to determine hail probability for each day contained within the reanalyses. The results presented here show the results of using a regression model based on convective available potential energy, deep level shear and weather type. Combined these parameters represent the probability of severe thunderstorm, and in turn hail, activity. Once the probability of hail occurring on each day is determined this can be used as the basis of a stochastic catalogue which can be used in the estimation of hail risk.

  18. Global Building Inventory for Earthquake Loss Estimation and Risk Management

    USGS Publications Warehouse

    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.

  19. Estimation of risks associated with paediatric cochlear implantation.

    PubMed

    Johnston, J Cyne; Smith, Andrée Durieux; Fitzpatrick, Elizabeth; O'Connor, Annette; Angus, Douglas; Benzies, Karen; Schramm, David

    2010-09-01

    The objectives of this study were to estimate the rates of complications associated with paediatric cochlear implantation use: a) at one Canadian cochlear implant (CI) centre, and b) in the published literature. It comprised a retrospective hospital-based chart review and a concurrent review of complications in the published literature. There were 224 children who had undergone surgery from 1994 to June 2007. Results indicate that the rates of complications at the local Canadian paediatric CI centre are not significantly different from the literature rates for all examined complication types. This hospital-based retrospective chart review and review of the literature provide readers with an estimation of the risks to aid in evidence-based decision-making surrounding paediatric cochlear implantation.

  20. 41 CFR 102-80.50 - Are Federal agencies responsible for identifying/estimating risks and for appropriate risk...

    Code of Federal Regulations, 2010 CFR

    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... environmental management risks and report or correct the situation, as appropriate. Federal agencies must...

  1. Estimate of the secondary cancer risk from megavoltage CT in tomotherapy

    NASA Astrophysics Data System (ADS)

    Kim, Dong Wook; Chung, Weon Kuu; Ahn, Sung Hwan; Yoon, Myonggeun

    2013-04-01

    We have assessed the radiation-induced excess cancer risk to organs from megavoltage computed tomography (MVCT). MVCT was performed in coarse, normal and fine scanning modes. Using a glass dosimeter, we measured the primary and the secondary doses inside a homemade phantom and at various distances from the imaging center. The organ-specific excess absolute risk (EAR) for cancer induction was estimated using an organ-equivalent dose (OED) based on the measured imaging doses. The average primary doses inside the phantom for the coarse, normal and fine scanning modes were 0.78, 1.15 and 2.15 cGy, respectively. The average secondary dose per scan, measured 20 to 60 cm from the imaging center, ranged from 0.044 to 0.008 cGy. The EAR for major organs indicated that when 30 MVCT scans are performed to position each patient during the course of radiation treatment, organ-specific cancers may develop in as many as 6 per 10,000 persons per year.

  2. Development and validation of risk prediction equations to estimate future risk of blindness and lower limb amputation in patients with diabetes: cohort study

    PubMed Central

    Coupland, Carol

    2015-01-01

    Study question Is it possible to develop and externally validate risk prediction equations to estimate the 10 year risk of blindness and lower limb amputation in patients with diabetes aged 25-84 years? Methods This was a prospective cohort study using routinely collected data from general practices in England contributing to the QResearch and Clinical Practice Research Datalink (CPRD) databases during the study period 1998-2014. The equations were developed using 763 QResearch practices (n=454 575 patients with diabetes) and validated in 254 different QResearch practices (n=142 419) and 357 CPRD practices (n=206 050). Cox proportional hazards models were used to derive separate risk equations for blindness and amputation in men and women that could be evaluated at 10 years. Measures of calibration and discrimination were calculated in the two validation cohorts. Study answer and limitations Risk prediction equations to quantify absolute risk of blindness and amputation in men and women with diabetes have been developed and externally validated. In the QResearch derivation cohort, 4822 new cases of lower limb amputation and 8063 new cases of blindness occurred during follow-up. The risk equations were well calibrated in both validation cohorts. Discrimination was good in men in the external CPRD cohort for amputation (D statistic 1.69, Harrell’s C statistic 0.77) and blindness (D statistic 1.40, Harrell’s C statistic 0.73), with similar results in women and in the QResearch validation cohort. The algorithms are based on variables that patients are likely to know or that are routinely recorded in general practice computer systems. They can be used to identify patients at high risk for prevention or further assessment. Limitations include lack of formally adjudicated outcomes, information bias, and missing data. What this study adds Patients with type 1 or type 2 diabetes are at increased risk of blindness and amputation but generally do not have accurate

  3. Low absolute lymphocyte count and addition of rituximab confer high risk for interstitial pneumonia in patients with diffuse large B-cell lymphoma.

    PubMed

    Huang, Yu-Chung; Liu, Chia-Jen; Liu, Chun-Yu; Pai, Jih-Tung; Hong, Ying-Chung; Teng, Hao-Wei; Hsiao, Liang-Tsai; Chao, Ta-Chung; Gau, Jyh-Pyng; Liu, Jin-Hwang; Hsu, Hui-Chi; Chiou, Tzeon-Jye; Chen, Po-Min; Yu, Yuan-Bin; Tzeng, Cheng-Hwai

    2011-10-01

    Several small-scale studies have reported pulmonary toxicity among patients with diffuse large B-cell lymphoma (DLBCL) receiving rituximab-containing chemotherapy, though whether the use of rituximab predisposes to interstitial pneumonia (IP) remains unclear. This retrospective study was intended to identify the characteristics and risk factors of IP in patients with DLBCL. Between 2000 and 2009, 529 consecutive patients with DLBCL receiving first-line tri-weekly COP- or CHOP-based chemotherapy with or without rituximab were enrolled as subjects. IP was defined as diffuse pulmonary interstitial infiltrates found on computed tomography scans in conjunction with respiratory symptoms. IP was observed in 26 patients (4.9%), six of whom were confirmed with Pneumocystis jirovecii pneumonia. The median number of chemotherapy courses before IP was four cycles. Using multivariate analysis, absolute lymphocyte count less than 1×10(9)/l at diagnosis [odds ratio (OR) 2.75, p=0.014] and the addition of rituximab to chemotherapy (OR 4.56, p=0.003) were identified as independent risk factors for IP. In conclusion, the incidence of IP is increased in patients with DLBCL receiving rituximab-containing chemotherapy. Specific subgroups with lymphopenia at diagnosis may justify close scrutiny to detect pulmonary complications. PMID:21647583

  4. Teaching Absolute Value Meaningfully

    ERIC Educational Resources Information Center

    Wade, Angela

    2012-01-01

    What is the meaning of absolute value? And why do teachers teach students how to solve absolute value equations? Absolute value is a concept introduced in first-year algebra and then reinforced in later courses. Various authors have suggested instructional methods for teaching absolute value to high school students (Wei 2005; Stallings-Roberts…

  5. Survivorship models for estimating the risk of decompression sickness.

    PubMed

    Kumar, K V; Powell, M R

    1994-07-01

    Several approaches have been used for modeling the incidence of decompression sickness (DCS) such as Hill's dose-response and logistic regression. Most of these methods do not include the time-to-onset information in the model. Survival analysis (failure time analysis) is appropriate when the time to onset of an event is of interest. The applicability of survival analysis for modeling the risk of DCS is illustrated by using data obtained from hypobaric chamber exposures simulating extravehicular activities (n = 426). Univariate analysis of incidence-free survival proportions were obtained for Doppler-detectable circulating microbubbles (CMB), symptoms of DCS and test aborts. A log-linear failure time regression model with 360-min half-time tissue ratio (TR) as covariate was constructed, and estimated probabilities for various TR values were calculated. Further regression analysis by including CMB status in this model showed significant improvement (p < 0.05) in the estimation of DCS over the previous model. Since DCS is dependent on the exposure pressure as well as the duration of exposure, we recommend the use of survival analysis for modeling the risk of DCS. PMID:7945136

  6. Health risks in wastewater irrigation: comparing estimates from quantitative microbial risk analyses and epidemiological studies.

    PubMed

    Mara, D D; Sleigh, P A; Blumenthal, U J; Carr, R M

    2007-03-01

    The combination of standard quantitative microbial risk analysis (QMRA) techniques and 10,000-trial Monte Carlo risk simulations was used to estimate the human health risks associated with the use of wastewater for unrestricted and restricted crop irrigation. A risk of rotavirus infection of 10(-2) per person per year (pppy) was used as the reference level of acceptable risk. Using the model scenario of involuntary soil ingestion for restricted irrigation, the risk of rotavirus infection is approximately 10(-2) pppy when the wastewater contains < or =10(6) Escherichia coli per 100ml and when local agricultural practices are highly mechanised. For labour-intensive agriculture the risk of rotavirus infection is approximately 10(-2) pppy when the wastewater contains < or = 10(5) E. coli per 100ml; however, the wastewater quality should be < or = 10(4) E. coli per 100ml when children under 15 are exposed. With the model scenario of lettuce consumption for unrestricted irrigation, the use of wastewaters containing < or =10(4) E. coli per 100ml results in a rotavirus infection risk of approximately 10(-2) pppy; however, again based on epidemiological evidence from Mexico, the current WHO guideline level of < or =1,000 E. coli per 100ml should be retained for root crops eaten raw. PMID:17402278

  7. Time-to-Compromise Model for Cyber Risk Reduction Estimation

    SciTech Connect

    Miles A. McQueen; Wayne F. Boyer; Mark A. Flynn; George A. Beitel

    2005-09-01

    We propose a new model for estimating the time to compromise a system component that is visible to an attacker. The model provides an estimate of the expected value of the time-to-compromise as a function of known and visible vulnerabilities, and attacker skill level. The time-to-compromise random process model is a composite of three subprocesses associated with attacker actions aimed at the exploitation of vulnerabilities. In a case study, the model was used to aid in a risk reduction estimate between a baseline Supervisory Control and Data Acquisition (SCADA) system and the baseline system enhanced through a specific set of control system security remedial actions. For our case study, the total number of system vulnerabilities was reduced by 86% but the dominant attack path was through a component where the number of vulnerabilities was reduced by only 42% and the time-to-compromise of that component was increased by only 13% to 30% depending on attacker skill level.

  8. [Absolute risk fracture prediction by risk factors validation and survey of osteoporosis in a Brussels cohort followed during 10 years (FRISBEE study)].

    PubMed

    Body, J J; Moreau, M; Bergmann, P; Paesmans, M; Dekelver, C; Lemaire, M L

    2008-09-01

    Osteoporosis is a major public health problem. For the time being, the diagnosis of osteoporosis relies on densitometry (T-score < -2.5 by DXA), although the risk of fracture depends also on other factors than the bone mass. Osteoporosis diagnosis (DXA) must be distinguished from the individual risk assessment of fracture. Different risk factors complementary to bone mass have been already validated in different populations. These include an old age, a history of fracture after the age of 50, a familial history of hip fracture (father or mother), a low BMI (< 20), corticoid treatment (> 3 months), tabagism and excessive alcohol consumption. A WHO taskforce has combined these different factors in order to integrate them in a 10-years predictive risk model of fracture (FRAX**). This model should still be validated in different populations, especially in populations not included in its development, which is the case for Belgium. We are evaluating these different risk factors for fracture in a Brussels population of 5000 women (60-80 years) who will be followed each year during 10 years. We also assess the predictive value of other risk factors for fracture not included in the WHO model (tendency to fall, use of sleeping pills, early non substituted menopause, sedentarity, ...). In an interim analysis of the first 452 women included and with data yet available at the time of this writing, we could find a significant (P < 0.05) relationship between diagnosis of osteoporosis at DXA and the number of risk factors, age > 70 years, a personal history of fracture after 50 years and a BMI < 20. PMID:18949979

  9. Moving towards a new paradigm for global flood risk estimation

    NASA Astrophysics Data System (ADS)

    Troy, Tara J.; Devineni, Naresh; Lima, Carlos; Lall, Upmanu

    2013-04-01

    model is implemented at a finer resolution (<=1km) in order to more accurately model streamflow under flood conditions and estimate inundation. This approach allows for efficient computational simulation of the hydrology when not under potential for flooding with high-resolution flood wave modeling when there is flooding potential. We demonstrate the results of this flood risk estimation system for the Ohio River basin in the United States, a large river basin that is historically prone to flooding, with the intention of using it to do global flood risk assessment.

  10. Declining bioavailability and inappropriate estimation of risk of persistent compounds

    SciTech Connect

    Kelsey, J.W.; Alexander, M.

    1997-03-01

    Earthworms (Eisenia foetida) assimilated decreasing amounts of atrazine, phenanthrene, and naphthalene that had been incubated for increasing periods of time in sterile soil. The amount of atrazine and phenanthrene removed from soil by mild extractants also decreased with time. The declines in bioavailability of the three compounds to earthworms and of naphthalene to bacteria were not reflected by analysis involving vigorous methods of solvent extraction; similar results for bioavailability of phenanthrene and 4-nitrophenol to bacteria were obtained in a previous study conducted at this laboratory. The authors suggest that regulations based on vigorous extractions for the analyses of persistent organic pollutants in soil do not appropriately estimate exposure or risk to susceptible populations.

  11. How do we measure dose and estimate risk?

    NASA Astrophysics Data System (ADS)

    Hoeschen, Christoph; Regulla, Dieter; Schlattl, Helmut; Petoussi-Henss, Nina; Li, Wei Bo; Zankl, Maria

    2011-03-01

    Radiation exposure due to medical imaging is a topic of emerging importance. In Europe this topic has been dealt with for a long time and in other countries it is getting more and more important and it gets an aspect of public interest in the latest years. This is mainly true due to the fact that the average dose per person in developed countries is increasing rapidly since threedimensional imaging is getting more and more available and useful for diagnosis. This paper introduces the most common dose quantities used in medical radiation exposure characterization, discusses usual ways for determination of such quantities as well as some considerations how these values are linked to radiation risk estimation. For this last aspect the paper will refer to the linear non threshold theory for an imaging application.

  12. 41 CFR 102-80.50 - Are Federal agencies responsible for identifying/estimating risks and for appropriate risk...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 80-SAFETY AND ENVIRONMENTAL MANAGEMENT Safety and 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...

  13. 41 CFR 102-80.50 - Are Federal agencies responsible for identifying/estimating risks and for appropriate risk...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 80-SAFETY AND ENVIRONMENTAL MANAGEMENT Safety and 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...

  14. 41 CFR 102-80.50 - Are Federal agencies responsible for identifying/estimating risks and for appropriate risk...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 80-SAFETY AND ENVIRONMENTAL MANAGEMENT Safety and 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...

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

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 80-SAFETY AND ENVIRONMENTAL MANAGEMENT Safety and 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...

  16. Estimation of Tsunami Risk for the Caribbean Coast

    NASA Astrophysics Data System (ADS)

    Zahibo, N.

    2004-05-01

    The tsunami problem for the coast of the Caribbean basin is discussed. Briefly the historical data of tsunami in the Caribbean Sea are presented. Numerical simulation of potential tsunamis in the Caribbean Sea is performed in the framework of the nonlinear-shallow theory. The tsunami wave height distribution along the Caribbean Coast is computed. These results are used to estimate the far-field tsunami potential of various coastal locations in the Caribbean Sea. In fact, five zones with tsunami low risk are selected basing on prognostic computations, they are: the bay "Golfo de Batabano" and the coast of province "Ciego de Avila" in Cuba, the Nicaraguan Coast (between Bluefields and Puerto Cabezas), the border between Mexico and Belize, the bay "Golfo de Venezuela" in Venezuela. The analysis of historical data confirms that there was no tsunami in the selected zones. Also, the wave attenuation in the Caribbean Sea is investigated; in fact, wave amplitude decreases in an order if the tsunami source is located on the distance up to 1000 km from the coastal location. Both factors wave attenuation and wave height distribution should be taken into account in the planned warning system for the Caribbean Sea. Specially the problem of tsunami risk for Lesser Antilles including Guadeloupe is discussed.

  17. Absolute transition probabilities of phosphorus.

    NASA Technical Reports Server (NTRS)

    Miller, M. H.; Roig, R. A.; Bengtson, R. D.

    1971-01-01

    Use of a gas-driven shock tube to measure the absolute strengths of 21 P I lines and 126 P II lines (from 3300 to 6900 A). Accuracy for prominent, isolated neutral and ionic lines is estimated to be 28 to 40% and 18 to 30%, respectively. The data and the corresponding theoretical predictions are examined for conformity with the sum rules.-

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

    PubMed Central

    Mastrandrea, Rossana; Barrat, Alain

    2016-01-01

    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. PMID:27341027

  19. Eosinophil count - absolute

    MedlinePlus

    Eosinophils; Absolute eosinophil count ... the white blood cell count to give the absolute eosinophil count. ... than 500 cells per microliter (cells/mcL). Normal value ranges may vary slightly among different laboratories. Talk ...

  20. Personalized Risk Estimator for Rheumatoid Arthritis (PRE-RA) Family Study: Rationale and design for a randomized controlled trial evaluating rheumatoid arthritis risk education to first-degree relatives

    PubMed Central

    Sparks, Jeffrey A.; Iversen, Maura D.; Kroouze, Rachel Miller; Mahmoud, Taysir G.; Triedman, Nellie A.; Kalia, Sarah S.; Atkinson, Michael L.; Lu, Bing; Deane, Kevin D.; Costenbader, Karen H.; Green, Robert C.; Karlson, Elizabeth W.

    2014-01-01

    We present the rationale, design features, and protocol of the Personalized Risk Estimator for Rheumatoid Arthritis (PRE-RA) Family Study (ClinicalTrials.gov NCT02046005). The PRE-RA Family Study is an NIH-funded prospective, randomized controlled trial designed to compare the willingness to change behaviors in first-degree relatives of rheumatoid arthritis (RA) patients without RA after exposure to RA risk educational programs. Consented subjects are randomized to receive education concerning their personalized RA risk based on demographics, RA-associated behaviors, genetics and biomarkers or to receive standard RA information. Four behavioral factors associated with RA risk were identified from prior studies for inclusion in the risk estimate: cigarette smoking, excess body weight, poor oral health, and low fish intake. Personalized RA risk information is presented through an online tool that collects data on an individual's specific age, gender, family history, and risk-related behaviors; presents genetic and biomarker results; displays relative and absolute risk of RA; and provides personalized feedback and education. The trial outcomes will be changes in willingness to alter behaviors from baseline to 6 weeks, 6 months, and 12 months in the three intervention groups. The design and execution of this trial that targets a special population at risk for RA, while incorporating varied risk factors into a single risk tool, offer distinct challenges. We provide the theoretical rationale for the PRE-RA Family Study and highlight particular design features of this trial that utilize personalized risk education as an intervention. PMID:25151341

  1. Personalized Risk Estimator for Rheumatoid Arthritis (PRE-RA) Family Study: rationale and design for a randomized controlled trial evaluating rheumatoid arthritis risk education to first-degree relatives.

    PubMed

    Sparks, Jeffrey A; Iversen, Maura D; Miller Kroouze, Rachel; Mahmoud, Taysir G; Triedman, Nellie A; Kalia, Sarah S; Atkinson, Michael L; Lu, Bing; Deane, Kevin D; Costenbader, Karen H; Green, Robert C; Karlson, Elizabeth W

    2014-09-01

    We present the rationale, design features, and protocol of the Personalized Risk Estimator for Rheumatoid Arthritis (PRE-RA) Family Study (ClinicalTrials.gov NCT02046005). The PRE-RA Family Study is an NIH-funded prospective, randomized controlled trial designed to compare the willingness to change behaviors in first-degree relatives of rheumatoid arthritis (RA) patients without RA after exposure to RA risk educational programs. Consented subjects are randomized to receive education concerning their personalized RA risk based on demographics, RA-associated behaviors, genetics, and biomarkers or to receive standard RA information. Four behavioral factors associated with RA risk were identified from prior studies for inclusion in the risk estimate: cigarette smoking, excess body weight, poor oral health, and low fish intake. Personalized RA risk information is presented through an online tool that collects data on an individual's specific age, gender, family history, and risk-related behaviors; presents genetic and biomarker results; displays relative and absolute risk of RA; and provides personalized feedback and education. The trial outcomes will be changes in willingness to alter behaviors from baseline to 6 weeks, 6 months, and 12 months in the three intervention groups. The design and the execution of this trial that targets a special population at risk for RA, while incorporating varied risk factors into a single risk tool, offer distinct challenges. We provide the theoretical rationale for the PRE-RA Family Study and highlight particular design features of this trial that utilize personalized risk education as an intervention.

  2. Soil-ecological risks for soil degradation estimation

    NASA Astrophysics Data System (ADS)

    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

  3. A weighted genetic risk score using all known susceptibility variants to estimate rheumatoid arthritis risk

    PubMed Central

    Yarwood, Annie; Han, Buhm; Raychaudhuri, Soumya; Bowes, John; Lunt, Mark; Pappas, Dimitrios A; Kremer, Joel; Greenberg, Jeffrey D; Plenge, Robert; Worthington, Jane; Barton, Anne; Eyre, Steve

    2015-01-01

    Background There is currently great interest in the incorporation of genetic susceptibility loci into screening models to identify individuals at high risk of disease. Here, we present the first risk prediction model including all 46 known genetic loci associated with rheumatoid arthritis (RA). Methods A weighted genetic risk score (wGRS) was created using 45 RA non-human leucocyte antigen (HLA) susceptibility loci, imputed amino acids at HLA-DRB1 (11, 71 and 74), HLA-DPB1 (position 9) HLA-B (position 9) and gender. The wGRS was tested in 11 366 RA cases and 15 489 healthy controls. The risk of developing RA was estimated using logistic regression by dividing the wGRS into quintiles. The ability of the wGRS to discriminate between cases and controls was assessed by receiver operator characteristic analysis and discrimination improvement tests. Results Individuals in the highest risk group showed significantly increased odds of developing anti-cyclic citrullinated peptide-positive RA compared to the lowest risk group (OR 27.13, 95% CI 23.70 to 31.05). The wGRS was validated in an independent cohort that showed similar results (area under the curve 0.78, OR 18.00, 95% CI 13.67 to 23.71). Comparison of the full wGRS with a wGRS in which HLA amino acids were replaced by a HLA tag single-nucleotide polymorphism showed a significant loss of sensitivity and specificity. Conclusions Our study suggests that in RA, even when using all known genetic susceptibility variants, prediction performance remains modest; while this is insufficiently accurate for general population screening, it may prove of more use in targeted studies. Our study has also highlighted the importance of including HLA variation in risk prediction models. PMID:24092415

  4. The Impact of Perceived Frailty on Surgeons’ Estimates of Surgical Risk

    PubMed Central

    Ferguson, Mark K.; Farnan, Jeanne; Hemmerich, Josh A.; Slawinski, Kris; Acevedo, Julissa; Small, Stephen

    2015-01-01

    Background Physicians are only moderately accurate in estimating surgical risk based on clinical vignettes. We assessed the impact of perceived frailty by measuring the influence of a short video of a standardized patient on surgical risk estimates. Methods Thoracic surgeons and cardiothoracic trainees estimated the risk of major complications for lobectomy based on clinical vignettes of varied risk categories (low, average, high). After each vignette, subjects viewed a randomly selected video of a standardized patient exhibiting either vigorous or frail behavior, then re-estimated risk. Subjects were asked to rate 5 vignettes paired with 5 different standardized patients. Results Seventy-one physicians participated. Initial risk estimates varied according to the vignette risk category: low, 15.2 ± 11.2% risk; average, 23.7 ± 16.1%; high, 37.3 ± 18.9%; p<0.001 by ANOVA. Concordant information in vignettes and videos moderately altered estimates (high risk vignette, frail video: 10.6 ± 27.5% increase in estimate, p=0.006; low risk vignette, vigorous video: 14.5 ± 45.0% decrease, p=0.009). Discordant findings influenced risk estimates more substantially (high risk vignette, vigorous video: 21.2 ± 23.5% decrease in second risk estimate, p<0.001; low risk vignette, frail video: 151.9 ± 209.8% increase, p<0.001). Conclusions Surgeons differentiated relative risk of lobectomy based on clinical vignettes. The effect of viewing videos was small when vignettes and videos were concordant; the effect was more substantial when vignettes and videos were discordant. The information will be helpful in training future surgeons in frailty recognition and risk estimation. PMID:24932570

  5. RADON EXPOSURE ASSESSMENT AND DOSIMETRY APPLIED TO EPIDEMIOLOGY AND RISK ESTIMATION

    EPA Science Inventory

    Epidemiological studies of underground miners provide the primary basis for radon risk estimates for indoor exposures as well as mine exposures. A major source of uncertainty in these risk estimates is the uncertainty in radon progeny exposure estimates for the miners. In addit...

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

    Cancer.gov

    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.

  7. The role of models in estimating consequences as part of the risk assessment process.

    PubMed

    Forde-Folle, K; Mitchell, D; Zepeda, C

    2011-08-01

    The degree of disease risk represented by the introduction, spread, or establishment of one or several diseases through the importation of animals and animal products is assessed by importing countries through an analysis of risk. The components of a risk analysis include hazard identification, risk assessment, risk management, and risk communication. A risk assessment starts with identification of the hazard(s) and then continues with four interrelated steps: release assessment, exposure assessment, consequence assessment, and risk estimation. Risk assessments may be either qualitative or quantitative. This paper describes how, through the integration of epidemiological and economic models, the potential adverse biological and economic consequences of exposure can be quantified.

  8. State Estimates of Adolescent Cigarette Use and Perceptions of Risk of Smoking: 2012 and 2013

    MedlinePlus

    ... 2015 STATE ESTIMATES OF ADOLESCENT CIGARETTE USE AND PERCEPTIONS OF RISK OF SMOKING: 2012 AND 2013 AUTHORS ... with an inverse association between use and risk perceptions (i.e., the prevalence of use is lower ...

  9. Cancer risk estimation caused by radiation exposure during endovascular procedure

    NASA Astrophysics Data System (ADS)

    Kang, Y. H.; Cho, J. H.; Yun, W. S.; Park, K. H.; Kim, H. G.; Kwon, S. M.

    2014-05-01

    The objective of this study was to identify the radiation exposure dose of patients, as well as staff caused by fluoroscopy for C-arm-assisted vascular surgical operation and to estimate carcinogenic risk due to such exposure dose. The study was conducted in 71 patients (53 men and 18 women) who had undergone vascular surgical intervention at the division of vascular surgery in the University Hospital from November of 2011 to April of 2012. It had used a mobile C-arm device and calculated the radiation exposure dose of patient (dose-area product, DAP). Effective dose was measured by attaching optically stimulated luminescence on the radiation protectors of staff who participates in the surgery to measure the radiation exposure dose of staff during the vascular surgical operation. From the study results, DAP value of patients was 308.7 Gy cm2 in average, and the maximum value was 3085 Gy cm2. When converted to the effective dose, the resulted mean was 6.2 m Gy and the maximum effective dose was 61.7 milliSievert (mSv). The effective dose of staff was 3.85 mSv; while the radiation technician was 1.04 mSv, the nurse was 1.31 mSv. All cancer incidences of operator are corresponding to 2355 persons per 100,000 persons, which deemed 1 of 42 persons is likely to have all cancer incidences. In conclusion, the vascular surgeons should keep the radiation protection for patient, staff, and all participants in the intervention in mind as supervisor of fluoroscopy while trying to understand the effects by radiation by themselves to prevent invisible danger during the intervention and to minimize the harm.

  10. Estimating Risk of Alcohol Dependence Using Alcohol Screening Scores*

    PubMed Central

    Rubinsky, Anna D.; Kivlahan, Daniel R.; Volk, Robert J.; Maynard, Charles; Bradley, Katharine A.

    2010-01-01

    Brief alcohol counseling interventions can reduce alcohol consumption and related morbidity among non-dependent risky drinkers, but more intensive alcohol treatment is recommended for persons with alcohol dependence. This study evaluated whether scores on common alcohol screening tests could identify patients likely to have current alcohol dependence so that more appropriate follow-up assessment and/or intervention could be offered. This cross-sectional study used secondary data from 392 male and 927 female adult family medicine outpatients (1993–1994). Likelihood ratios were used to empirically identify and evaluate ranges of scores of the AUDIT, the AUDIT-C, two single-item questions about frequency of binge drinking, and the CAGE questionnaire for detecting DSM-IV past-year alcohol dependence. Based on the prevalence of past-year alcohol dependence in this sample (men: 12.2%; women: 5.8%), zones of the AUDIT and AUDIT-C identified wide variability in the post-screening risk of alcohol dependence in men and women, even among those who screened positive for alcohol misuse. Among men, AUDIT zones 5–10, 11–14 and 15–40 were associated with post-screening probabilities of past-year alcohol dependence ranging from 18–87%, and AUDIT-C zones 5–6, 7–9 and 10–12 were associated with probabilities ranging from 22–75%. Among women, AUDIT zones 3–4, 5–8, 9–12 and 13–40 were associated with post-screening probabilities of past-year alcohol dependence ranging from 6–94%, and AUDIT-C zones 3, 4–6, 7–9 and 10–12 were associated with probabilities ranging from 9–88%. AUDIT or AUDIT-C scores could be used to estimate the probability of past-year alcohol dependence among patients who screen positive for alcohol misuse and inform clinical decision-making. PMID:20042299

  11. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2012-05-15

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  12. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K.; Snyderman, Neal J.; Rowland, Mark S.

    2010-07-13

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  13. Optomechanics for absolute rotation detection

    NASA Astrophysics Data System (ADS)

    Davuluri, Sankar

    2016-07-01

    In this article, we present an application of optomechanical cavity for the absolute rotation detection. The optomechanical cavity is arranged in a Michelson interferometer in such a way that the classical centrifugal force due to rotation changes the length of the optomechanical cavity. The change in the cavity length induces a shift in the frequency of the cavity mode. The phase shift corresponding to the frequency shift in the cavity mode is measured at the interferometer output to estimate the angular velocity of absolute rotation. We derived an analytic expression to estimate the minimum detectable rotation rate in our scheme for a given optomechanical cavity. Temperature dependence of the rotation detection sensitivity is studied.

  14. Solid cancer incidence among Chinese medical diagnostic x-ray workers, 1950-1995: Estimation of radiation-related risks.

    PubMed

    Sun, Zhijuan; Inskip, Peter D; Wang, Jixian; Kwon, Deukwoo; Zhao, Yongcheng; Zhang, Liangan; Wang, Qin; Fan, Saijun

    2016-06-15

    The objective of this study was to estimate solid cancer risk attributable to long-term, fractionated occupational exposure to low doses of ionizing radiation. Based on cancer incidence for the period 1950-1995 in a cohort of 27,011 Chinese medical diagnostic X-ray workers and a comparison cohort of 25,782 Chinese physicians who did not use X-ray equipment in their work, we used Poisson regression to fit excess relative risk (ERR) and excess absolute risk (EAR) dose-response models for incidence of all solid cancers combined. Radiation dose reconstruction was based on a previously published method that relied on simulating measurements for multiple X-ray machines, workplaces and working conditions, information about protective measures, including use of lead aprons, and work histories. The resulting model was used to estimate calendar year-specific badge dose calibrated as personal dose equivalent (Sv). To obtain calendar year-specific colon doses (Gy), we applied a standard organ conversion factor. A total of 1,643 cases of solid cancer were identified in 1.45 million person-years of follow-up. In both ERR and EAR models, a statistically significant radiation dose-response relationship was observed for solid cancers as a group. Averaged over both sexes, and using colon dose as the dose metric, the estimated ERR/Gy was 0.87 (95% CI: 0.48, 1.45), and the EAR was 22 per 10(4)PY-Gy (95% CI: 14, 32) at age 50. We obtained estimates of the ERR and EAR of solid cancers per unit dose that are compatible with those derived from other populations chronically exposed to low dose-rate occupational or environmental radiation.

  15. Solid cancer incidence among Chinese medical diagnostic x-ray workers, 1950-1995: Estimation of radiation-related risks.

    PubMed

    Sun, Zhijuan; Inskip, Peter D; Wang, Jixian; Kwon, Deukwoo; Zhao, Yongcheng; Zhang, Liangan; Wang, Qin; Fan, Saijun

    2016-06-15

    The objective of this study was to estimate solid cancer risk attributable to long-term, fractionated occupational exposure to low doses of ionizing radiation. Based on cancer incidence for the period 1950-1995 in a cohort of 27,011 Chinese medical diagnostic X-ray workers and a comparison cohort of 25,782 Chinese physicians who did not use X-ray equipment in their work, we used Poisson regression to fit excess relative risk (ERR) and excess absolute risk (EAR) dose-response models for incidence of all solid cancers combined. Radiation dose reconstruction was based on a previously published method that relied on simulating measurements for multiple X-ray machines, workplaces and working conditions, information about protective measures, including use of lead aprons, and work histories. The resulting model was used to estimate calendar year-specific badge dose calibrated as personal dose equivalent (Sv). To obtain calendar year-specific colon doses (Gy), we applied a standard organ conversion factor. A total of 1,643 cases of solid cancer were identified in 1.45 million person-years of follow-up. In both ERR and EAR models, a statistically significant radiation dose-response relationship was observed for solid cancers as a group. Averaged over both sexes, and using colon dose as the dose metric, the estimated ERR/Gy was 0.87 (95% CI: 0.48, 1.45), and the EAR was 22 per 10(4)PY-Gy (95% CI: 14, 32) at age 50. We obtained estimates of the ERR and EAR of solid cancers per unit dose that are compatible with those derived from other populations chronically exposed to low dose-rate occupational or environmental radiation. PMID:26860236

  16. State Estimates of Adolescent Marijuana Use and Perceptions of Risk of Harm from Marijuana Use: 2013 and 2014

    MedlinePlus

    ... 2014 estimates to 2012–2013 estimates). However, youth perceptions of great risk of harm from monthly marijuana ... change. State Estimates of Adolescent Marijuana Use and Perceptions of Risk of Harm From Marijuana Use: 2013 ...

  17. Indoor radon and lung cancer. Estimating the risks

    SciTech Connect

    Samet, J.M. )

    1992-01-01

    Radon is ubiquitous in indoor environments. Epidemiologic studies of underground miners with exposure to radon and experimental evidence have established that radon causes lung cancer. The finding that this naturally occurring carcinogen is present in the air of homes and other buildings has raised concern about the lung cancer risk to the general population from radon. I review current approaches for assessing the risk of indoor radon, emphasizing the extrapolation of the risks for miners to the general population. Although uncertainties are inherent in this risk assessment, the present evidence warrants identifying homes that have unacceptably high concentrations.23 references.

  18. Indoor radon and lung cancer. Estimating the risks.

    PubMed Central

    Samet, J. M.

    1992-01-01

    Radon is ubiquitous in indoor environments. Epidemiologic studies of underground miners with exposure to radon and experimental evidence have established that radon causes lung cancer. The finding that this naturally occurring carcinogen is present in the air of homes and other buildings has raised concern about the lung cancer risk to the general population from radon. I review current approaches for assessing the risk of indoor radon, emphasizing the extrapolation of the risks for miners to the general population. Although uncertainties are inherent in this risk assessment, the present evidence warrants identifying homes that have unacceptably high concentrations. PMID:1734594

  19. CCSI Risk Estimation: An Application of Expert Elicitation

    SciTech Connect

    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. Do We Know Whether Researchers and Reviewers are Estimating Risk and Benefit Accurately?

    PubMed

    Hey, Spencer Phillips; Kimmelman, Jonathan

    2016-10-01

    Accurate estimation of risk and benefit is integral to good clinical research planning, ethical review, and study implementation. Some commentators have argued that various actors in clinical research systems are prone to biased or arbitrary risk/benefit estimation. In this commentary, we suggest the evidence supporting such claims is very limited. Most prior work has imputed risk/benefit beliefs based on past behavior or goals, rather than directly measuring them. We describe an approach - forecast analysis - that would enable direct and effective measure of the quality of risk/benefit estimation. We then consider some objections and limitations to the forecasting approach. PMID:27197044

  1. Do We Know Whether Researchers and Reviewers are Estimating Risk and Benefit Accurately?

    PubMed

    Hey, Spencer Phillips; Kimmelman, Jonathan

    2016-10-01

    Accurate estimation of risk and benefit is integral to good clinical research planning, ethical review, and study implementation. Some commentators have argued that various actors in clinical research systems are prone to biased or arbitrary risk/benefit estimation. In this commentary, we suggest the evidence supporting such claims is very limited. Most prior work has imputed risk/benefit beliefs based on past behavior or goals, rather than directly measuring them. We describe an approach - forecast analysis - that would enable direct and effective measure of the quality of risk/benefit estimation. We then consider some objections and limitations to the forecasting approach.

  2. Estimation of radiation risk from screening mammography: Recent trends and comparison with expected benefits

    SciTech Connect

    Feig, S.A.; Ehrlich, S.M. )

    1990-03-01

    On the basis of recent epidemiologic studies, the National Institutes of Health in 1985 provided a new estimate for radiation risk to the breast that employed a relative risk model and acknowledged greater dependence on age at exposure. Lifetime risks from a single mammogram may be calculated from this estimate and are lower than those based on the previous 1977 National Cancer Institute estimate. Possible years of life expectancy lost from annual mammography beginning at age 40 years may also be calculated and are negligible compared with estimates for years of life expectancy gained from such screening.

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

    PubMed

    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.

  4. NEED FOR INDIVIDUAL CANCER RISK ESTIMATES IN X-RAY AND NUCLEAR MEDICINE IMAGING.

    PubMed

    Mattsson, Sören

    2016-06-01

    To facilitate the justification of an X-ray or nuclear medicine investigation and for informing patients, it is desirable that the individual patient's radiation dose and potential cancer risk can be prospectively assessed and documented. The current dose-reporting is based on effective dose, which ignores body size and does not reflect the strong dependence of risk on the age at exposure. Risk estimations should better be done through individual organ dose assessments, which need careful exposure characterisation as well as anatomical description of the individual patient. In nuclear medicine, reference biokinetic models should also be replaced with models describing individual physiological states and biokinetics. There is a need to adjust population-based cancer risk estimates to the possible risk of leukaemia and solid tumours for the individual depending on age and gender. The article summarises reasons for individual cancer risk estimates and gives examples of methods and results of such estimates. PMID:26994092

  5. Estimation of the Disease Burden Attributable to 11 Risk Factors in Hubei Province, China: A Comparative Risk Assessment.

    PubMed

    Cui, Fangfang; Zhang, Lan; Yu, Chuanhua; Hu, Songbo; Zhang, Yunquan

    2016-01-01

    In order to estimate the health losses caused by common risk factors in the Hubei province, China, we calculated the deaths and disability-adjusted life years (DALYs) attributable to 11 risk factors. We estimated the exposure distributions of risk factors in Hubei Province in 2013 from the monitoring system on chronic disease and related risk factors, combined with relative risk (RR) in order to calculate the population attributable fraction. Deaths and DALYs attributed to the selected risk factors were then estimated together with cause-specific deaths and DALYs. In total, 53.39% of the total deaths and 36.23% of the total DALYs in Hubei were a result of the 11 selected risk factors. The top five risk factors were high blood pressure, smoking, high body mass index, diet low in fruits and alcohol use, accounting for 14.68%, 12.57%, 6.03%, 3.90% and 3.19% of total deaths, respectively, and 9.41%, 7.22%, 4.42%, 2.51% and 2.44% of total DALYs, respectively. These risk factors, especially high blood pressure, smoking and high body mass index, significantly influenced quality of life, causing a large number of deaths and DALYs. The burden of chronic disease could be substantially reduced if these risk factors were effectively controlled, which would allow people to enjoy healthier lives. PMID:27669279

  6. Estimation of the Disease Burden Attributable to 11 Risk Factors in Hubei Province, China: A Comparative Risk Assessment

    PubMed Central

    Cui, Fangfang; Zhang, Lan; Yu, Chuanhua; Hu, Songbo; Zhang, Yunquan

    2016-01-01

    In order to estimate the health losses caused by common risk factors in the Hubei province, China, we calculated the deaths and disability-adjusted life years (DALYs) attributable to 11 risk factors. We estimated the exposure distributions of risk factors in Hubei Province in 2013 from the monitoring system on chronic disease and related risk factors, combined with relative risk (RR) in order to calculate the population attributable fraction. Deaths and DALYs attributed to the selected risk factors were then estimated together with cause-specific deaths and DALYs. In total, 53.39% of the total deaths and 36.23% of the total DALYs in Hubei were a result of the 11 selected risk factors. The top five risk factors were high blood pressure, smoking, high body mass index, diet low in fruits and alcohol use, accounting for 14.68%, 12.57%, 6.03%, 3.90% and 3.19% of total deaths, respectively, and 9.41%, 7.22%, 4.42%, 2.51% and 2.44% of total DALYs, respectively. These risk factors, especially high blood pressure, smoking and high body mass index, significantly influenced quality of life, causing a large number of deaths and DALYs. The burden of chronic disease could be substantially reduced if these risk factors were effectively controlled, which would allow people to enjoy healthier lives. PMID:27669279

  7. The Impact of a Frailty Education Module on Surgical Resident Estimates of Lobectomy Risk

    PubMed Central

    Ferguson, Mark K.; Thompson, Katherine; Huisingh-Scheetz, Megan; Farnan, Jeanne; Hemmerich, Joshua; Acevedo, Julissa; Small, Stephen

    2015-01-01

    Background Frailty is a risk factor for adverse events after surgery. Residents’ ability to recognize frailty is underdeveloped. We assessed the influence of a frailty education module on surgical residents’ estimates of lobectomy risk. Methods Traditional track cardiothoracic surgery residents were randomized to take an on-line short course on frailty (experimental group) or to receive no training (control group). Residents read a clinical vignette, made an initial risk estimate of major complications for lobectomy, and rated clinical factors on their importance to their estimates. They viewed a video of a standardized patient portraying the patient in the vignette, randomly selected to exhibit either vigorous or frail behavior, and provided a final risk estimate. After rating 5 vignettes, they completed a test on their frailty knowledge. Results Forty-one residents participated (20 in the experimental group). Initial risk estimates were similar between the groups. The experimental group rated clinical factors as “very important” in their initial risk estimates more often than did the control group (47.6% vs 38.5%; p<0.001). Viewing videos resulted in a significant change from initial to final risk estimates (frail: 50±75% increase, p=0.008; vigorous: 14±32% decrease, p=0.043). The magnitude of change in risk estimates was greater for the experimental group (10.0±8.1 vs 5.1±7.7; p<0.001). The experimental group answered more frailty test questions correctly (93.7% vs 75.2%; p<0.001). Conclusions A frailty education module improved resident knowledge of frailty and influenced surgical risk estimates. Training in frailty may help educate residents in frailty recognition and surgical risk assessment. PMID:26004924

  8. Estimating the subjective risks of driving simulator accidents.

    PubMed

    Dixit, Vinayak; Harrison, Glenn W; Rutström, E Elisabet

    2014-01-01

    We examine the subjective risks of driving behavior using a controlled virtual reality experiment. Use of a driving simulator allows us to observe choices over risky alternatives that are presented to the individual in a naturalistic manner, with many of the cues one would find in the field. However, the use of a simulator allows us the type of controls one expects from a laboratory environment. The subject was tasked with making a left-hand turn into incoming traffic, and the experimenter controlled the headways of oncoming traffic. Subjects were rewarded for making a successful turn, and lost income if they crashed. The experimental design provided opportunities for subjects to develop subjective beliefs about when it would be safe to turn, and it also elicited their attitudes towards risk. A simple structural model explains behavior, and showed evidence of heterogeneity in both the subjective beliefs that subjects formed and their risk attitudes. We find that subjective beliefs change with experience in the task and the driver's skill. A significant difference was observed in the perceived probability to successfully turn among the inexperienced drivers who did and did not crash even though there was no significant difference in drivers' risk attitudes among the two groups. We use experimental economics to design controlled, incentive compatible tasks that provide an opportunity to evaluate the impact on driver safety of subject's subjective beliefs about when it would be safe to turn as well as their attitudes towards risk. This method could be used to help insurance companies determine risk premia associated with risk attitudes or beliefs of crashing, to better incentivize safe driving.

  9. Biomechanical Risk Estimates for Mild Traumatic Brain Injury

    PubMed Central

    Funk, J. R.; Duma, S. M.; Manoogian, S. J.; Rowson, S.

    2007-01-01

    The objective of this study was to characterize the risk of mild traumatic brain injury (MTBI) in living humans based on a large set of head impact data taken from American football players at the collegiate level. Real-time head accelerations were recorded from helmet-mounted accelerometers designed to stay in contact with the player’s head. Over 27,000 head impacts were recorded, including four impacts resulting in MTBI. Parametric risk curves were developed by normalizing MTBI incidence data by head impact exposure data. An important finding of this research is that living humans, at least in the setting of collegiate football, sustain much more significant head impacts without apparent injury than previously thought. The following preliminary nominal injury assessment reference values associated with a 10% risk of MTBI are proposed: a peak linear head acceleration of 165 g, a HIC of 400, and a peak angular head acceleration of 9000 rad/s2. PMID:18184501

  10. Probabilistic methodology for estimating radiation-induced cancer risk

    SciTech Connect

    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.

  11. Absolute biological needs.

    PubMed

    McLeod, Stephen

    2014-07-01

    Absolute needs (as against instrumental needs) are independent of the ends, goals and purposes of personal agents. Against the view that the only needs are instrumental needs, David Wiggins and Garrett Thomson have defended absolute needs on the grounds that the verb 'need' has instrumental and absolute senses. While remaining neutral about it, this article does not adopt that approach. Instead, it suggests that there are absolute biological needs. The absolute nature of these needs is defended by appeal to: their objectivity (as against mind-dependence); the universality of the phenomenon of needing across the plant and animal kingdoms; the impossibility that biological needs depend wholly upon the exercise of the abilities characteristic of personal agency; the contention that the possession of biological needs is prior to the possession of the abilities characteristic of personal agency. Finally, three philosophical usages of 'normative' are distinguished. On two of these, to describe a phenomenon or claim as 'normative' is to describe it as value-dependent. A description of a phenomenon or claim as 'normative' in the third sense does not entail such value-dependency, though it leaves open the possibility that value depends upon the phenomenon or upon the truth of the claim. It is argued that while survival needs (or claims about them) may well be normative in this third sense, they are normative in neither of the first two. Thus, the idea of absolute need is not inherently normative in either of the first two senses. PMID:23586876

  12. Absolute biological needs.

    PubMed

    McLeod, Stephen

    2014-07-01

    Absolute needs (as against instrumental needs) are independent of the ends, goals and purposes of personal agents. Against the view that the only needs are instrumental needs, David Wiggins and Garrett Thomson have defended absolute needs on the grounds that the verb 'need' has instrumental and absolute senses. While remaining neutral about it, this article does not adopt that approach. Instead, it suggests that there are absolute biological needs. The absolute nature of these needs is defended by appeal to: their objectivity (as against mind-dependence); the universality of the phenomenon of needing across the plant and animal kingdoms; the impossibility that biological needs depend wholly upon the exercise of the abilities characteristic of personal agency; the contention that the possession of biological needs is prior to the possession of the abilities characteristic of personal agency. Finally, three philosophical usages of 'normative' are distinguished. On two of these, to describe a phenomenon or claim as 'normative' is to describe it as value-dependent. A description of a phenomenon or claim as 'normative' in the third sense does not entail such value-dependency, though it leaves open the possibility that value depends upon the phenomenon or upon the truth of the claim. It is argued that while survival needs (or claims about them) may well be normative in this third sense, they are normative in neither of the first two. Thus, the idea of absolute need is not inherently normative in either of the first two senses.

  13. CubeSat mission design software tool for risk estimating relationships

    NASA Astrophysics Data System (ADS)

    Gamble, Katharine Brumbaugh; Lightsey, E. Glenn

    2014-09-01

    In an effort to make the CubeSat risk estimation and management process more scientific, a software tool has been created that enables mission designers to estimate mission risks. CubeSat mission designers are able to input mission characteristics, such as form factor, mass, development cycle, and launch information, in order to determine the mission risk root causes which historically present the highest risk for their mission. Historical data was collected from the CubeSat community and analyzed to provide a statistical background to characterize these Risk Estimating Relationships (RERs). This paper develops and validates the mathematical model based on the same cost estimating relationship methodology used by the Unmanned Spacecraft Cost Model (USCM) and the Small Satellite Cost Model (SSCM). The RER development uses general error regression models to determine the best fit relationship between root cause consequence and likelihood values and the input factors of interest. These root causes are combined into seven overall CubeSat mission risks which are then graphed on the industry-standard 5×5 Likelihood-Consequence (L-C) chart to help mission designers quickly identify areas of concern within their mission. This paper is the first to document not only the creation of a historical database of CubeSat mission risks, but, more importantly, the scientific representation of Risk Estimating Relationships.

  14. Estimate of the risk of radiation-induced cancers after linear-accelerator-based breast-cancer radiotherapy

    NASA Astrophysics Data System (ADS)

    Koh, Eui Kwan; Seo, Jungju; Baek, Tae Seong; Chung, Eun Ji; Yoon, Myonggeun; Lee, Hyun-ho

    2013-07-01

    The aim of this study is to assess and compare the excess absolute risks (EARs) of radiation-induced cancers following conformal (3D-CRT), fixed-field intensity-modulated (IMRT) and volumetric modulated arc (RapidArc) radiation therapy in patients with breast cancer. 3D-CRT, IMRT and RapidArc were planned for 10 breast cancer patients. The organ-specific EAR for cancer induction was estimated using the organ equivalent dose (OED) based on computed dose volume histograms (DVHs) and the secondary doses measured at various points from the field edge. The average secondary dose per Gy treatment dose from 3D-CRT, measured 10 to 50 cm from the field edge, ranged from 8.27 to 1.04 mGy. The secondary doses per Gy from IMRT and RapidArc, however, ranged between 5.86 and 0.54 mGy, indicating that IMRT and RapidArc are associated with smaller doses of secondary radiation than 3D-CRT. The organ specific EARs for out-of-field organs, such as the thyroid, liver and colon, were higher with 3D-CRT than with IMRT or RapidArc. In contrast, EARs for in-field organs were much lower with 3D-CRT than with IMRT or RapidArc. The overall estimate of EAR indicated that the radiation-induced cancer risk was 1.8-2.0 times lower with 3D-CRT than with IMRT or RapidArc. Comparisons of EARs during breast irradiation suggested that the predicted risk of secondary cancers was lower with 3D-CRT than with IMRT or RapidArc.

  15. Assessing uncertainty in published risk estimates using hexavalent chromium and lung cancer mortality as an example

    EPA Science Inventory

    Introduction: The National Research Council recommended quantitative evaluation of uncertainty in effect estimates for risk assessment. This analysis considers uncertainty across model forms and model parameterizations with hexavalent chromium [Cr(VI)] and lung cancer mortality a...

  16. Estimation of the burden of cardiovascular disease attributable to modifiable risk factors and cost-effectiveness analysis of preventative interventions to reduce this burden in Argentina

    PubMed Central

    2010-01-01

    Background Cardiovascular disease (CVD) is the primary cause of mortality and morbidity in Argentina representing 34.2% of deaths and 12.6% of potential years of life lost (PYLL). The aim of the study was to estimate the burden of acute coronary heart disease (CHD) and stroke and the cost-effectiveness of preventative population-based and clinical interventions. Methods An epidemiological model was built incorporating prevalence and distribution of high blood pressure, high cholesterol, hyperglycemia, overweight and obesity, smoking, and physical inactivity, obtained from the Argentine Survey of Risk Factors dataset. Population Attributable Fraction (PAF) of each risk factor was estimated using relative risks from international sources. Total fatal and non-fatal events, PYLL and Disability Adjusted Life Years (DALY) were estimated. Costs of event were calculated from local utilization databases and expressed in international dollars (I$). Incremental cost-effectiveness ratios (ICER) were estimated for six interventions: reducing salt in bread, mass media campaign to promote tobacco cessation, pharmacological therapy of high blood pressure, pharmacological therapy of high cholesterol, tobacco cessation therapy with bupropion, and a multidrug strategy for people with an estimated absolute risk > 20% in 10 years. Results An estimated total of 611,635 DALY was lost due to acute CHD and stroke for 2005. Modifiable risk factors explained 71.1% of DALY and more than 80% of events. Two interventions were cost-saving: lowering salt intake in the population through reducing salt in bread and multidrug therapy targeted to persons with an absolute risk above 20% in 10 years; three interventions had very acceptable ICERs: drug therapy for high blood pressure in hypertensive patients not yet undergoing treatment (I$ 2,908 per DALY saved), mass media campaign to promote tobacco cessation amongst smokers (I$ 3,186 per DALY saved), and lowering cholesterol with statin drug therapy

  17. Estimated exposure to phthalates in cosmetics and risk assessment.

    PubMed

    Koo, Hyun Jung; Lee, Byung Mu

    2004-12-01

    Some phthalates such as di(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP) and their metabolites are suspected of producing teratogenic or endocrine-disrupting effects. To predict possible human exposure to phthalates in cosmetics, the levels of DEHP, diethyl phthalate (DEP), DBP, and butylbenzyl phthalate (BBP) were determined by high-performance liquid chromatography (HPLC) in 102 branded hair sprays, perfumes, deodorants, and nail polishes. DBP was detected in 19 of the 21 nail polishes and in 11 of the 42 perfumes, and DEP was detected in 24 of the 42 perfumes and 2 of the 8 deodorants. Median exposure levels to phthalates in cosmetics by dermal absorption were estimated to be 0.0006 g/kg body weight (bw)/d for DEHP, 0.6 g/kg bw/d for DEP, and 0.103 g/kg bw/d for DBP. Furthermore, if phthalates in cosmetics were assumed to be absorbed exclusively via 100% inhalation, the median daily exposure levels to phthalates in cosmetics were estimated to be 0.026 g/kg bw/d for DEHP, 81.471 g/kg bw/d for DEP, and 22.917 g/kg bw/d for DBP, which are far lower than the regulation levels set buy the Scientific Committee on Toxicity, Ecotoxicity, and the Environment (CSTEE) (37 g/kg bw/d, DEHP), Agency for Toxic Substances and Disease Registry (ATSDR) (7000 g/kg bw/d, DEP), and International Programme on Chemical Safety (IPCS) (66 g/kg bw/d, DBP), respectively. Based on these data, hazard indices (HI, daily exposure level/regulation level) were calculated to be 0.0007 for DEHP, 0.012 for DEP, and 0.347 for DBP. These data suggest that estimated exposure to-phthalates in the cosmetics mentioned are relatively small. However, total exposure levels from several sources may be greater and require further investigation.

  18. Estimation of the reaction times in tasks of varying difficulty from the phase coherence of the auditory steady-state response using the least absolute shrinkage and selection operator analysis.

    PubMed

    Yokota, Yusuke; Igarashi, Yasuhiko; Okada, Masato; Naruse, Yasushi

    2015-01-01

    Quantitative estimation of the workload in the brain is an important factor for helping to predict the behavior of humans. The reaction time when performing a difficult task is longer than that when performing an easy task. Thus, the reaction time reflects the workload in the brain. In this study, we employed an N-back task in order to regulate the degree of difficulty of the tasks, and then estimated the reaction times from the brain activity. The brain activity that we used to estimate the reaction time was the auditory steady-state response (ASSR) evoked by a 40-Hz click sound. Fifteen healthy participants participated in the present study and magnetoencephalogram (MEG) responses were recorded using a 148-channel magnetometer system. The least absolute shrinkage and selection operator (LASSO), which is a type of sparse modeling, was employed to estimate the reaction times from the ASSR recorded by MEG. The LASSO showed higher estimation accuracy than the least squares method. This result indicates that LASSO overcame the over-fitting to the learning data. Furthermore, the LASSO selected channels in not only the parietal region, but also in the frontal and occipital regions. Since the ASSR is evoked by auditory stimuli, it is usually large in the parietal region. However, since LASSO also selected channels in regions outside the parietal region, this suggests that workload-related neural activity occurs in many brain regions. In the real world, it is more practical to use a wearable electroencephalography device with a limited number of channels than to use MEG. Therefore, determining which brain areas should be measured is essential. The channels selected by the sparse modeling method are informative for determining which brain areas to measure. PMID:26737821

  19. Cardiovascular risk factors and estimated 10-year risk of fatal cardiovascular events using various equations in Greeks with metabolic syndrome.

    PubMed

    Chimonas, Theodoros; Athyros, Vassilios G; Ganotakis, Emmanouel; Nicolaou, Vassilios; Panagiotakos, Demosthenes B; Mikhailidis, Dimitri P; Elisaf, Moses

    2010-01-01

    We investigated cardiovascular disease (CVD) risk factors in 1501 Greeks (613 men and 888 women, aged 40-65 years) referred to outpatients with metabolic syndrome (MetS) and without diabetes mellitus or CVD. The 10-year risk of fatal CVD events was calculated using European Society of Cardiology Systematic Coronary Risk Estimation (ESC SCORE), Hellenic-SCORE, and Framingham equations. Raised blood pressure (BP) and hypertriglyceridemia were more common in men (89.6% vs 84.2% and 86.8% vs 74.2%, respectively; P < .001). Low high-density lipoprotein cholesterol (HDL-C) and abdominal obesity were more common in women (58.2% vs 66.2% and 85.8% vs 97.1%, respectively; P < .001). The 10-year risk of fatal CVD events using HellenicSCORE was higher in men (6.3% +/- 4.3% vs 2.7% +/- 2.1%; P < .001). European Society of Cardiology Systematic Coronary Risk Estimation and Framingham yielded similar results. The risk equations gave similar assessments in a European Mediterranean population except for HellenicSCORE that calculated more MetS women requiring risk modification. This might justify local risk engine evaluation in event-based studies. (Clinical-Trials.gov ID: NCT00416741).

  20. The absolute path command

    2012-05-11

    The ap command traveres all symlinks in a given file, directory, or executable name to identify the final absolute path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it canmore » provide the absolute path to a relative directory from the current working directory.« less

  1. The absolute path command

    SciTech Connect

    Moody, A.

    2012-05-11

    The ap command traveres all symlinks in a given file, directory, or executable name to identify the final absolute path. It can print just the final path, each intermediate link along with the symlink chan, and the permissions and ownership of each directory component in the final path. It has functionality similar to "which", except that it shows the final path instead of the first path. It is also similar to "pwd", but it can provide the absolute path to a relative directory from the current working directory.

  2. Disease Risk Estimation by Combining Case–Control Data with Aggregated Information on the Population at Risk

    PubMed Central

    Chang, Xiaohui; Waagepetersen, Rasmus; Yu, Herbert; Ma, Xiaomei; Holford, Theodore R.; Wang, Rong; Guan, Yongtao

    2016-01-01

    Summary We propose a novel statistical framework by supplementing case–control data with summary statistics on the population at risk for a subset of risk factors. Our approach is to first form two unbiased estimating equations, one based on the case–control data and the other on both the case data and the summary statistics, and then optimally combine them to derive another estimating equation to be used for the estimation. The proposed method is computationally simple and more efficient than standard approaches based on case–control data alone. We also establish asymptotic properties of the resulting estimator, and investigate its finite-sample performance through simulation. As a substantive application, we apply the proposed method to investigate risk factors for endometrial cancer, by using data from a recently completed population-based case–control study and summary statistics from the Behavioral Risk Factor Surveillance System, the Population Estimates Program of the US Census Bureau, and the Connecticut Department of Transportation. PMID:25351292

  3. Estimated occupational risk from bioaerosols generated during land application of Class B biosolids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It has been speculated that bioaerosols generated during land application of biosolids pose a serious occupational risk, but few scientific studies have been performed to assess levels of aerosolization of microorganisms from biosolids and to estimate the occupational risks of infection. This study ...

  4. Bayesian Framework for Water Quality Model Uncertainty Estimation and Risk Management

    EPA Science Inventory

    A formal Bayesian methodology is presented for integrated model calibration and risk-based water quality management using Bayesian Monte Carlo simulation and maximum likelihood estimation (BMCML). The primary focus is on lucid integration of model calibration with risk-based wat...

  5. Estimating risks to aquatic life using quantile regression

    USGS Publications Warehouse

    Schmidt, Travis S.; Clements, William H.; Cade, Brian S.

    2012-01-01

    One of the primary goals of biological assessment is to assess whether contaminants or other stressors limit the ecological potential of running waters. It is important to interpret responses to contaminants relative to other environmental factors, but necessity or convenience limit quantification of all factors that influence ecological potential. In these situations, the concept of limiting factors is useful for data interpretation. We used quantile regression to measure risks to aquatic life exposed to metals by including all regression quantiles (τ  =  0.05–0.95, by increments of 0.05), not just the upper limit of density (e.g., 90th quantile). We measured population densities (individuals/0.1 m2) of 2 mayflies (Rhithrogena spp., Drunella spp.) and a caddisfly (Arctopsyche grandis), aqueous metal mixtures (Cd, Cu, Zn), and other limiting factors (basin area, site elevation, discharge, temperature) at 125 streams in Colorado. We used a model selection procedure to test which factor was most limiting to density. Arctopsyche grandis was limited by other factors, whereas metals limited most quantiles of density for the 2 mayflies. Metals reduced mayfly densities most at sites where other factors were not limiting. Where other factors were limiting, low mayfly densities were observed despite metal concentrations. Metals affected mayfly densities most at quantiles above the mean and not just at the upper limit of density. Risk models developed from quantile regression showed that mayfly densities observed at background metal concentrations are improbable when metal mixtures are at US Environmental Protection Agency criterion continuous concentrations. We conclude that metals limit potential density, not realized average density. The most obvious effects on mayfly populations were at upper quantiles and not mean density. Therefore, we suggest that policy developed from mean-based measures of effects may not be as useful as policy based on the concept of

  6. Uncertainties in Estimates of the Risks of Late Effects from Space Radiation

    NASA Technical Reports Server (NTRS)

    Cucinotta, F. A.; Schimmerling, W.; Wilson, J. W.; Peterson, L. E.; Saganti, P.; Dicelli, J. F.

    2002-01-01

    The health risks faced by astronauts from space radiation include cancer, cataracts, hereditary effects, and non-cancer morbidity and mortality risks related to the diseases of the old age. Methods used to project risks in low-Earth orbit are of questionable merit for exploration missions because of the limited radiobiology data and knowledge of galactic cosmic ray (GCR) heavy ions, which causes estimates of the risk of late effects to be highly uncertain. Risk projections involve a product of many biological and physical factors, each of which has a differential range of uncertainty due to lack of data and knowledge. Within the linear-additivity model, we use Monte-Carlo sampling from subjective uncertainty distributions in each factor to obtain a Maximum Likelihood estimate of the overall uncertainty in risk projections. The resulting methodology is applied to several human space exploration mission scenarios including ISS, lunar station, deep space outpost, and Mar's missions of duration of 360, 660, and 1000 days. The major results are the quantification of the uncertainties in current risk estimates, the identification of factors that dominate risk projection uncertainties, and the development of a method to quantify candidate approaches to reduce uncertainties or mitigate risks. The large uncertainties in GCR risk projections lead to probability distributions of risk that mask any potential risk reduction using the "optimization" of shielding materials or configurations. In contrast, the design of shielding optimization approaches for solar particle events and trapped protons can be made at this time, and promising technologies can be shown to have merit using our approach. The methods used also make it possible to express risk management objectives in terms of quantitative objective's, i.e., the number of days in space without exceeding a given risk level within well defined confidence limits.

  7. REVIEW OF DRAFT REVISED BLUE BOOK ON ESTIMATING CANCER RISKS FROM EXPOSURE TO IONIZING RADIATION

    EPA Science Inventory

    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...

  8. ASSESSMENT OF METHODS FOR ESTIMATING RISK TO BIRDS FROM INGESTION OF CONTAMINATED GRIT PARTICLES (FINAL REPORT)

    EPA Science Inventory

    The 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 mo...

  9. Estimating Toxicity Pathway Activating Doses for High Throughput Chemical Risk Assessments

    EPA Science Inventory

    Estimating a Toxicity Pathway Activating Dose (TPAD) from in vitro assays as an analog to a reference dose (RfD) derived from in vivo toxicity tests would facilitate high throughput risk assessments of thousands of data-poor environmental chemicals. Estimating a TPAD requires def...

  10. Risk estimations, risk factors, and genetic variants associated with Alzheimer's disease in selected publications from the Framingham Heart Study.

    PubMed

    Weinstein, Galit; Wolf, Philip A; Beiser, Alexa S; Au, Rhoda; Seshadri, Sudha

    2013-01-01

    The study of Alzheimer's disease (AD) in the Framingham Heart Study (FHS), a multi-generational, community-based population study, began nearly four decades ago. In this overview, we highlight findings from seven prior publications that examined lifetime risk estimates for AD, environmental risk factors for AD, circulating and imaging markers of aging-related brain injury, and explorations on the genetics underlying AD. First, we describe estimations of the lifetime risk of AD. These estimates are distinguished from other measures of disease burden and have substantial public health implications. We then describe prospective studies of environmental AD risk factors: one examined the association between plasma levels of omega-3 fatty-acid and risk of incident AD, the other explored the association of diabetes to this risk in subsamples with specific characteristics. With evidence of inflammation as an underlying mechanism, we also describe findings from a study that compared the effects of serum cytokines and spontaneous production of peripheral blood mononuclear cell cytokines on AD risk. Investigating AD related endophenotypes increases sensitivity in identifying risk factors and can be used to explore pathophysiologic pathways between a risk factor and the disease. We describe findings of an association between large volume of white matter hyperintensities and a specific pattern of cognitive deficits in non-demented participants. Finally, we summarize our findings from two genetic studies: The first used genome-wide association (GWA) and family-based association methods to explore the genetic basis of cognitive and structural brain traits. The second is a large meta-analysis GWA study of AD, in which novel loci of AD susceptibility were found. Together, these findings demonstrate the FHS multi-directional efforts in investigating dementia and AD. PMID:22796871

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

    PubMed

    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 <1 tha(-1)y(-1) and SOC content decline of 0 kg t(-1)y(-1) for mineral 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. PMID:24412915

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

    PubMed

    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 <1 tha(-1)y(-1) and SOC content decline of 0 kg t(-1)y(-1) for mineral 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.

  13. Overview of Risk-Estimation Tools for Primary Prevention of Cardiovascular Diseases in European Populations.

    PubMed

    Gorenoi, Vitali; Hagen, Anja

    2015-06-01

    To identify persons with a high risk for cardiovascular diseases (CVD) special tools (scores, charts, graphics or computer programs) for CVD-risk assessment based on levels of the certain risk factors have been constructed. The applicability of these instruments depends on the derivation cohorts, considered risk factors and endpoints, applied statistical methods as well as used formats. The review addresses the risk-estimation tools for primary prevention of CVD potentially relevant for European populations. The risk-estimation tools were identified using two previously published systematic reviews as well as conducting a literature search in MEDLINE and a manual search. Only instruments were considered which were derived from cohorts of at least 1,000 participants of one gender without pre-existing CVD, enable risk assessment for a period of at least 5 years, were designed for an age-range of at least 25 years and published after the year 2000. A number of risk-estimation tools for CVD derived from single European, several European and from non-European cohorts were identified. From a clinical perspective, seem to be preferable instruments for risk of CVD contemporary developed for the population of interest, which use easily accessible measures and show a high discriminating ability. Instruments, restricting risk-estimation to certain cardiovascular events, recalibrated high-accuracy tools or tools derived from European populations with similar risk factors distribution and CVD-incidence are the second choice. In younger people, calculating the relative risk or cardiovascular age equivalence measures may be of more benefit.

  14. Quantitative Risk reduction estimation Tool For Control Systems, Suggested Approach and Research Needs

    SciTech Connect

    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.

  15. Space Radiation Heart Disease Risk Estimates for Lunar and Mars Missions

    NASA Technical Reports Server (NTRS)

    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.

  16. Uncertainties in estimates of the risks of late effects from space radiation.

    PubMed

    Cucinotta, F A; Schimmerling, W; Wilson, J W; Peterson, L E; Saganti, P B; Dicello, J F

    2004-01-01

    Methods used to project risks in low-Earth orbit are of questionable merit for exploration missions because of the limited radiobiology data and knowledge of galactic cosmic ray (GCR) heavy ions, which causes estimates of the risk of late effects to be highly uncertain. Risk projections involve a product of many biological and physical factors, each of which has a differential range of uncertainty due to lack of data and knowledge. Using the linear-additivity model for radiation risks, we use Monte-Carlo sampling from subjective uncertainty distributions in each factor to obtain an estimate of the overall uncertainty in risk projections. The resulting methodology is applied to several human space exploration mission scenarios including a deep space outpost and Mars missions of duration of 360, 660, and 1000 days. The major results are the quantification of the uncertainties in current risk estimates, the identification of factors that dominate risk projection uncertainties, and the development of a method to quantify candidate approaches to reduce uncertainties or mitigate risks. The large uncertainties in GCR risk projections lead to probability distributions of risk that mask any potential risk reduction using the "optimization" of shielding materials or configurations. In contrast, the design of shielding optimization approaches for solar particle events and trapped protons can be made at this time and promising technologies can be shown to have merit using our approach. The methods used also make it possible to express risk management objectives in terms of quantitative metrics, e.g., the number of days in space without exceeding a given risk level within well-defined confidence limits.

  17. Uncertainties in estimates of the risks of late effects from space radiation

    NASA Technical Reports Server (NTRS)

    Cucinotta, F. A.; Schimmerling, W.; Wilson, J. W.; Peterson, L. E.; Saganti, P. B.; Dicello, J. F.

    2004-01-01

    Methods used to project risks in low-Earth orbit are of questionable merit for exploration missions because of the limited radiobiology data and knowledge of galactic cosmic ray (GCR) heavy ions, which causes estimates of the risk of late effects to be highly uncertain. Risk projections involve a product of many biological and physical factors, each of which has a differential range of uncertainty due to lack of data and knowledge. Using the linear-additivity model for radiation risks, we use Monte-Carlo sampling from subjective uncertainty distributions in each factor to obtain an estimate of the overall uncertainty in risk projections. The resulting methodology is applied to several human space exploration mission scenarios including a deep space outpost and Mars missions of duration of 360, 660, and 1000 days. The major results are the quantification of the uncertainties in current risk estimates, the identification of factors that dominate risk projection uncertainties, and the development of a method to quantify candidate approaches to reduce uncertainties or mitigate risks. The large uncertainties in GCR risk projections lead to probability distributions of risk that mask any potential risk reduction using the "optimization" of shielding materials or configurations. In contrast, the design of shielding optimization approaches for solar particle events and trapped protons can be made at this time and promising technologies can be shown to have merit using our approach. The methods used also make it possible to express risk management objectives in terms of quantitative metrics, e.g., the number of days in space without exceeding a given risk level within well-defined confidence limits. Published by Elsevier Ltd on behalf of COSPAR.

  18. A simple procedure for estimating pseudo risk ratios from exposure to non-carcinogenic chemical mixtures.

    PubMed

    Scinicariello, Franco; Portier, Christopher

    2016-03-01

    Non-cancer risk assessment traditionally assumes a threshold of effect, below which there is a negligible risk of an adverse effect. The Agency for Toxic Substances and Disease Registry derives health-based guidance values known as Minimal Risk Levels (MRLs) as estimates of the toxicity threshold for non-carcinogens. Although the definition of an MRL, as well as EPA reference dose values (RfD and RfC), is a level that corresponds to "negligible risk," they represent daily exposure doses or concentrations, not risks. We present a new approach to calculate the risk at exposure to specific doses for chemical mixtures, the assumption in this approach is to assign de minimis risk at the MRL. The assigned risk enables the estimation of parameters in an exponential model, providing a complete dose-response curve for each compound from the chosen point of departure to zero. We estimated parameters for 27 chemicals. The value of k, which determines the shape of the dose-response curve, was moderately insensitive to the choice of the risk at the MRL. The approach presented here allows for the calculation of a risk from a single substance or the combined risk from multiple chemical exposures in a community. The methodology is applicable from point of departure data derived from quantal data, such as data from benchmark dose analyses or from data that can be transformed into probabilities, such as lowest-observed-adverse-effect level. The individual risks are used to calculate risk ratios that can facilitate comparison and cost-benefit analyses of environmental contamination control strategies. PMID:25667015

  19. Uncertainties in estimates of the risks of late effects from space radiation.

    PubMed

    Cucinotta, F A; Schimmerling, W; Wilson, J W; Peterson, L E; Saganti, P B; Dicello, J F

    2004-01-01

    Methods used to project risks in low-Earth orbit are of questionable merit for exploration missions because of the limited radiobiology data and knowledge of galactic cosmic ray (GCR) heavy ions, which causes estimates of the risk of late effects to be highly uncertain. Risk projections involve a product of many biological and physical factors, each of which has a differential range of uncertainty due to lack of data and knowledge. Using the linear-additivity model for radiation risks, we use Monte-Carlo sampling from subjective uncertainty distributions in each factor to obtain an estimate of the overall uncertainty in risk projections. The resulting methodology is applied to several human space exploration mission scenarios including a deep space outpost and Mars missions of duration of 360, 660, and 1000 days. The major results are the quantification of the uncertainties in current risk estimates, the identification of factors that dominate risk projection uncertainties, and the development of a method to quantify candidate approaches to reduce uncertainties or mitigate risks. The large uncertainties in GCR risk projections lead to probability distributions of risk that mask any potential risk reduction using the "optimization" of shielding materials or configurations. In contrast, the design of shielding optimization approaches for solar particle events and trapped protons can be made at this time and promising technologies can be shown to have merit using our approach. The methods used also make it possible to express risk management objectives in terms of quantitative metrics, e.g., the number of days in space without exceeding a given risk level within well-defined confidence limits. PMID:15881779

  20. A simple procedure for estimating pseudo risk ratios from exposure to non-carcinogenic chemical mixtures.

    PubMed

    Scinicariello, Franco; Portier, Christopher

    2016-03-01

    Non-cancer risk assessment traditionally assumes a threshold of effect, below which there is a negligible risk of an adverse effect. The Agency for Toxic Substances and Disease Registry derives health-based guidance values known as Minimal Risk Levels (MRLs) as estimates of the toxicity threshold for non-carcinogens. Although the definition of an MRL, as well as EPA reference dose values (RfD and RfC), is a level that corresponds to "negligible risk," they represent daily exposure doses or concentrations, not risks. We present a new approach to calculate the risk at exposure to specific doses for chemical mixtures, the assumption in this approach is to assign de minimis risk at the MRL. The assigned risk enables the estimation of parameters in an exponential model, providing a complete dose-response curve for each compound from the chosen point of departure to zero. We estimated parameters for 27 chemicals. The value of k, which determines the shape of the dose-response curve, was moderately insensitive to the choice of the risk at the MRL. The approach presented here allows for the calculation of a risk from a single substance or the combined risk from multiple chemical exposures in a community. The methodology is applicable from point of departure data derived from quantal data, such as data from benchmark dose analyses or from data that can be transformed into probabilities, such as lowest-observed-adverse-effect level. The individual risks are used to calculate risk ratios that can facilitate comparison and cost-benefit analyses of environmental contamination control strategies.

  1. ESTIMATING RISK TO CALIFORNIA ENERGY INFRASTRUCTURE FROM PROJECTED CLIMATE CHANGE

    SciTech Connect

    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.

  2. Comparison of Paper-and-Pencil versus Web Administration of the Youth Risk Behavior Survey (YRBS): Risk Behavior Prevalence Estimates

    ERIC Educational Resources Information Center

    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…

  3. Estimation of cancer risks and benefits associated with a potential increased consumption of fruits and vegetables.

    PubMed

    Reiss, Richard; Johnston, Jason; Tucker, Kevin; DeSesso, John M; Keen, Carl L

    2012-12-01

    The current paper provides an analysis of the potential number of cancer cases that might be prevented if half the U.S. population increased its fruit and vegetable consumption by one serving each per day. This number is contrasted with an upper-bound estimate of concomitant cancer cases that might be theoretically attributed to the intake of pesticide residues arising from the same additional fruit and vegetable consumption. The cancer prevention estimates were derived using a published meta-analysis of nutritional epidemiology studies. The cancer risks were estimated using U.S. Environmental Protection Agency (EPA) methods, cancer potency estimates from rodent bioassays, and pesticide residue sampling data from the U.S. Department of Agriculture (USDA). The resulting estimates are that approximately 20,000 cancer cases per year could be prevented by increasing fruit and vegetable consumption, while up to 10 cancer cases per year could be caused by the added pesticide consumption. These estimates have significant uncertainties (e.g., potential residual confounding in the fruit and vegetable epidemiologic studies and reliance on rodent bioassays for cancer risk). However, the overwhelming difference between benefit and risk estimates provides confidence that consumers should not be concerned about cancer risks from consuming conventionally-grown fruits and vegetables.

  4. Assessment of the value of a genetic risk score in improving the estimation of coronary risk

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The American Heart Association has established criteria for the evaluation of novel markers of cardiovascular risk. In accordance with these criteria, we assessed the association between a multi-locus genetic risk score (GRS) and incident coronary heart disease (CHD), and evaluated whether this GRS ...

  5. Mobile Applications for Type 2 Diabetes Risk Estimation: a Systematic Review.

    PubMed

    Fijacko, Nino; Brzan, Petra Povalej; Stiglic, Gregor

    2015-10-01

    Screening for chronical diseases like type 2 diabetes can be done using different methods and various risk tests. This study present a review of type 2 diabetes risk estimation mobile applications focusing on their functionality and availability of information on the underlying risk calculators. Only 9 out of 31 reviewed mobile applications, featured in three major mobile application stores, disclosed the name of risk calculator used for assessing the risk of type 2 diabetes. Even more concerning, none of the reviewed applications mentioned that they are collecting the data from users to improve the performance of their risk estimation calculators or offer users the descriptive statistics of the results from users that already used the application. For that purpose the questionnaires used for calculation of risk should be upgraded by including the information on the most recent blood sugar level measurements from users. Although mobile applications represent a great future potential for health applications, developers still do not put enough emphasis on informing the user of the underlying methods used to estimate the risk for a specific clinical condition. PMID:26303152

  6. Mobile Applications for Type 2 Diabetes Risk Estimation: a Systematic Review.

    PubMed

    Fijacko, Nino; Brzan, Petra Povalej; Stiglic, Gregor

    2015-10-01

    Screening for chronical diseases like type 2 diabetes can be done using different methods and various risk tests. This study present a review of type 2 diabetes risk estimation mobile applications focusing on their functionality and availability of information on the underlying risk calculators. Only 9 out of 31 reviewed mobile applications, featured in three major mobile application stores, disclosed the name of risk calculator used for assessing the risk of type 2 diabetes. Even more concerning, none of the reviewed applications mentioned that they are collecting the data from users to improve the performance of their risk estimation calculators or offer users the descriptive statistics of the results from users that already used the application. For that purpose the questionnaires used for calculation of risk should be upgraded by including the information on the most recent blood sugar level measurements from users. Although mobile applications represent a great future potential for health applications, developers still do not put enough emphasis on informing the user of the underlying methods used to estimate the risk for a specific clinical condition.

  7. Mathematical Models for Estimating the Risks of Bovine Spongiform Encephalopathy (BSE).

    PubMed

    Al-Zoughool, Mustafa; Cottrell, David; Elsaadany, Susie; Murray, Noel; Oraby, Tamer; Smith, Robert; Krewski, Daniel

    2015-01-01

    When the bovine spongiform encephalopathy (BSE) epidemic first emerged in the United Kingdom in the mid 1980s, the etiology of animal prion diseases was largely unknown. Risk management efforts to control the disease were also subject to uncertainties regarding the extent of BSE infections and future course of the epidemic. As understanding of BSE increased, mathematical models were developed to estimate risk of BSE infection and to predict reductions in risk in response to BSE control measures. Risk models of BSE-transmission dynamics determined disease persistence in cattle herds and relative infectivity of cattle prior to onset of clinical disease. These BSE models helped in understanding key epidemiological features of BSE transmission and dynamics, such as incubation period distribution and age-dependent infection susceptibility to infection with the BSE agent. This review summarizes different mathematical models and methods that have been used to estimate risk of BSE, and discusses how such risk projection models have informed risk assessment and management of BSE. This review also provides some general insights on how mathematical models of the type discussed here may be used to estimate risks of emerging zoonotic diseases when biological data on transmission of the etiological agent are limited.

  8. Mathematical Models for Estimating the Risks of Bovine Spongiform Encephalopathy (BSE).

    PubMed

    Al-Zoughool, Mustafa; Cottrell, David; Elsaadany, Susie; Murray, Noel; Oraby, Tamer; Smith, Robert; Krewski, Daniel

    2015-01-01

    When the bovine spongiform encephalopathy (BSE) epidemic first emerged in the United Kingdom in the mid 1980s, the etiology of animal prion diseases was largely unknown. Risk management efforts to control the disease were also subject to uncertainties regarding the extent of BSE infections and future course of the epidemic. As understanding of BSE increased, mathematical models were developed to estimate risk of BSE infection and to predict reductions in risk in response to BSE control measures. Risk models of BSE-transmission dynamics determined disease persistence in cattle herds and relative infectivity of cattle prior to onset of clinical disease. These BSE models helped in understanding key epidemiological features of BSE transmission and dynamics, such as incubation period distribution and age-dependent infection susceptibility to infection with the BSE agent. This review summarizes different mathematical models and methods that have been used to estimate risk of BSE, and discusses how such risk projection models have informed risk assessment and management of BSE. This review also provides some general insights on how mathematical models of the type discussed here may be used to estimate risks of emerging zoonotic diseases when biological data on transmission of the etiological agent are limited. PMID:26158300

  9. Effect of induction chemotherapy on estimated risk of radiation pneumonitis in bulky non–small cell lung cancer

    SciTech Connect

    Amin, Neha P.; Miften, Moyed; Thornton, Dale; Ryan, Nicole; Kavanagh, Brian; Gaspar, Laurie E

    2013-10-01

    Patients with bulky non–small cell lung cancer (NSCLC) may be at a high risk for radiation pneumonitis (RP) if treated with up-front concurrent chemoradiation. There is limited information about the effect of induction chemotherapy on the volume of normal lung subsequently irradiated. This study aims to estimate the reduction in risk of RP in patients with NSCLC after receiving induction chemotherapy. Between 2004 and 2009, 25 patients with Stage IV NSCLC were treated with chemotherapy alone (no surgery or radiation therapy [RT]) and had computed tomography (CT) scans before and after 2 cycles of chemotherapy. Simulated RT plans were created for the prechemotherapy and postchemotherapy scans so as to deliver 60 Gy to the thoracic disease in patients who had either a >20% volumetric increase or decrease in gross tumor volume (GTV) from chemotherapy. The prechemotherapy and postchemotherapy scans were analyzed to compare the percentage of lung volume receiving≥20 Gy (V20), mean lung dose (MLD), and normal tissue complication probability (NTCP). Eight patients (32%) had a GTV reduction >20%, 2 (8%) had GTV increase >20%, and 15 (60%) had stable GTV. In the 8 responders, there was an absolute median GTV decrease of 88.1 cc (7.3 to 351.6 cc) or a 48% (20% to 62%) relative reduction in tumor burden. One had >20% tumor progression during chemotherapy, yet had an improvement in dosimetric parameters postchemotherapy. Among these 9 patients, the median decrease in V20, MLD, and NTCP was 2.6% (p<0.01), 2.1 Gy (p<0.01), and 5.6% (p<0.01), respectively. Less than one-third of patients with NSCLC obtain >20% volumetric tumor reduction from chemotherapy alone. Even with that amount of volumetric reduction, the 5% reduced risk of RP was only modest and did not convert previously ineligible patients to safely receive definitive thoracic RT.

  10. Prophylactic radiotherapy against heterotopic ossification following internal fixation of acetabular fractures: a comparative estimate of risk

    PubMed Central

    Nasr, P; Yip, G; Scaife, J E; House, T; Thomas, S J; Harris, F; Owen, P J; Hull, P

    2014-01-01

    Objective: Radiotherapy (RT) is effective in preventing heterotopic ossification (HO) around acetabular fractures requiring surgical reconstruction. We audited outcomes and estimated risks from RT prophylaxis, and alternatives of indometacin or no prophylaxis. Methods: 34 patients underwent reconstruction of acetabular fractures through a posterior approach, followed by a 8-Gy single fraction. The mean age was 44 years. The mean time from surgery to RT was 1.1 days. The major RT risk is radiation-induced fatal cancer. The International Commission on Radiological Protection (ICRP) method was used to estimate risk, and compared with a method (Trott and Kemprad) specifically for estimating RT risk for benign disease. These were compared with risks associated with indometacin and no prophylaxis. Results: 28 patients (82%) developed no HO; 6 developed Brooker Class I; and none developed Class II–IV HO. The ICRP method suggests a risk of fatal cancer in the range of 1 in 1000 to 1 in 10,000; the Trott and Kemprad method suggests 1 in 3000. For younger patients, this may rise to 1 in 2000; and for elderly patients, it may fall to 1 in 6000. The risk of death from gastric bleeding or perforation from indometacin is 1 in 180 to 1 in 900 in older patients. Without prophylaxis risk of death from reoperation to remove HO is 1 in 4000 to 1 in 30,000. Conclusion: These results are encouraging, consistent with much larger series and endorse our multidisciplinary management. Risk estimates can be used in discussion with patients. Advances in knowledge: The risk from RT prophylaxis is small, it is safer than indometacin and substantially overlaps with the range for no prophylaxis. PMID:25089852

  11. Estimating risk at a Superfund site using passive sampling devices as biological surrogates in human health risk models.

    PubMed

    Allan, Sarah E; Sower, Gregory J; Anderson, Kim A

    2011-10-01

    Passive sampling devices (PSDs) sequester the freely dissolved fraction of lipophilic contaminants, mimicking passive chemical uptake and accumulation by biomembranes and lipid tissues. Public Health Assessments that inform the public about health risks from exposure to contaminants through consumption of resident fish are generally based on tissue data, which can be difficult to obtain and requires destructive sampling. The purpose of this study is to apply PSD data in a Public Health Assessment to demonstrate that PSDs can be used as a biological surrogate to evaluate potential human health risks and elucidate spatio-temporal variations in risk. PSDs were used to measure polycyclic aromatic hydrocarbons (PAHs) in the Willamette River; upriver, downriver and within the Portland Harbor Superfund megasite for 3 years during wet and dry seasons. Based on an existing Public Health Assessment for this area, concentrations of PAHs in PSDs were substituted for fish tissue concentrations. PSD measured PAH concentrations captured the magnitude, range and variability of PAH concentrations reported for fish/shellfish from Portland Harbor. Using PSD results in place of fish data revealed an unacceptable risk level for cancer in all seasons but no unacceptable risk for non-cancer endpoints. Estimated cancer risk varied by several orders of magnitude based on season and location. Sites near coal tar contamination demonstrated the highest risk, particularly during the dry season and remediation activities. Incorporating PSD data into Public Health Assessments provides specific spatial and temporal contaminant exposure information that can assist public health professionals in evaluating human health risks.

  12. Estimating risk at a Superfund site using passive sampling devices as biological surrogates in human health risk models

    PubMed Central

    Allan, Sarah E.; Sower, Gregory J.; Anderson, Kim A.

    2013-01-01

    Passive sampling devices (PSDs) sequester the freely dissolved fraction of lipophilic contaminants, mimicking passive chemical uptake and accumulation by biomembranes and lipid tissues. Public Health Assessments that inform the public about health risks from exposure to contaminants through consumption of resident fish are generally based on tissue data, which can be difficulties to obtain and requires destructive sampling. The purpose of this study is to apply PSD data in a Public Health Assessment to demonstrate that PSDs can be used as a biological surrogate to evaluate potential human health risks and elucidate spatio-temporal variations in risk. PSDs were used to measure polycyclic aromatic hydrocarbons (PAHs) in the Willamette River; upriver, downriver and within the Portland Harbor Superfund megasite for three years during wet and dry seasons. Based on an existing Public Health Assessment for this area, concentrations of PAHs in PSDs were substituted for fish tissue concentrations. PSD measured PAH concentrations captured the magnitude, range and variability of PAH concentrations reported for fish/shellfish from Portland Harbor. Using PSD results in place of fish data revealed an unacceptable risk level for cancer in all seasons but no unacceptable risk for non-cancer endpoints. Estimated cancer risk varied by several orders of magnitude based on season and location. Sites near coal tar contamination demonstrated the highest risk, particularly during the dry season and remediation activities. Incorporating PSD data into Public Health Assessments provides specific spatial and temporal contaminant exposure information that can assist public health professionals in evaluating human health risks. PMID:21741671

  13. Inhalation exposure or body burden? Better way of estimating risk--An application of PBPK model.

    PubMed

    Majumdar, Dipanjali; Dutta, Chirasree; Sen, Subha

    2016-01-01

    We aim to establish a new way for estimating the risk from internal dose or body burden due to exposure of benzene in human subject utilizing physiologically based pharmacokinetic (PBPK) model. We also intend to verify its applicability on human subjects exposed to different levels of benzene. We estimated personal inhalation exposure of benzene for two occupational groups namely petrol pump workers and car drivers with respect to a control group, only environmentally exposed. Benzene in personal air was pre-concentrated on charcoal followed by chemical desorption and analysis by gas chromatography equipped with flame ionization detector (GC-FID). We selected urinary trans,trans-muconic acid (t,t-MA) as biomarker of benzene exposure and measured its concentration using solid phase extraction followed by high performance liquid chromatography (HPLC). Our estimated inhalation exposure of benzene was 137.5, 97.9 and 38.7 μg/m(3) for petrol pump workers, car drivers and environmentally exposed control groups respectively which resulted in urinary t,t-MA levels of 145.4±55.3, 112.6±63.5 and 60.0±34.9 μg g(-1) of creatinine, for the groups in the same order. We deduced a derivation for estimation of body burden from urinary metabolite concentration using PBPK model. Estimation of the internal dose or body burden of benzene in human subject has been made for the first time by the measurement of t,t-MA as a urinary metabolite using physiologically based pharmacokinetic (PBPK) model as a tool. The weight adjusted total body burden of benzene was estimated to be 17.6, 11.1 and 5.0 μg kg(-1) of body weight for petrol pump workers, drivers and the environmentally exposed control group, respectively using this method. We computed the carcinogenic risk using both the estimated internal benzene body burden and external exposure values using conventional method. Our study result shows that internal dose or body burden is not proportional to level of exposure rather have a

  14. Inhalation exposure or body burden? Better way of estimating risk--An application of PBPK model.

    PubMed

    Majumdar, Dipanjali; Dutta, Chirasree; Sen, Subha

    2016-01-01

    We aim to establish a new way for estimating the risk from internal dose or body burden due to exposure of benzene in human subject utilizing physiologically based pharmacokinetic (PBPK) model. We also intend to verify its applicability on human subjects exposed to different levels of benzene. We estimated personal inhalation exposure of benzene for two occupational groups namely petrol pump workers and car drivers with respect to a control group, only environmentally exposed. Benzene in personal air was pre-concentrated on charcoal followed by chemical desorption and analysis by gas chromatography equipped with flame ionization detector (GC-FID). We selected urinary trans,trans-muconic acid (t,t-MA) as biomarker of benzene exposure and measured its concentration using solid phase extraction followed by high performance liquid chromatography (HPLC). Our estimated inhalation exposure of benzene was 137.5, 97.9 and 38.7 μg/m(3) for petrol pump workers, car drivers and environmentally exposed control groups respectively which resulted in urinary t,t-MA levels of 145.4±55.3, 112.6±63.5 and 60.0±34.9 μg g(-1) of creatinine, for the groups in the same order. We deduced a derivation for estimation of body burden from urinary metabolite concentration using PBPK model. Estimation of the internal dose or body burden of benzene in human subject has been made for the first time by the measurement of t,t-MA as a urinary metabolite using physiologically based pharmacokinetic (PBPK) model as a tool. The weight adjusted total body burden of benzene was estimated to be 17.6, 11.1 and 5.0 μg kg(-1) of body weight for petrol pump workers, drivers and the environmentally exposed control group, respectively using this method. We computed the carcinogenic risk using both the estimated internal benzene body burden and external exposure values using conventional method. Our study result shows that internal dose or body burden is not proportional to level of exposure rather have a

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

    PubMed

    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.

  16. FY 2000 Buildings Energy Savings Estimates under Uncertainty: Developing Approaches for Incorporating Risk into Buildings Program Energy Efficiency Estimates

    SciTech Connect

    Anderson, Dave M.

    2002-11-18

    This report is one of two that re-examines the forecasted impact of individual programs currently within the Buildings Technology Program (BT) and the Weatherization and Intergovernmental Program (WIP) that appeared in the FY2000 Presidential Budget request. This report develops potential methods for allowing inherent risk to be captured in the program benefits analysis. Note that the FY2000 budget request was originally analyzed under the former Office of Building Technology, State and Community Programs (BTS), where BT and WIP were previously combined. Throughout the document, reference will be made to the predecessor of the BT and WIP programs, BTS, as FY2000 reflected that organization. A companion report outlines the effects of re-estimating the FY 2000 budget request based on overlaying program data from subsequent years, essentially revised out-year forecasts. That report shows that year-to-year long-term projections of primary energy savings can vary widely as models improve and programs change. Those point estimates are not influenced by uncertainty or risk. This report develops potential methods for allowing inherent risk to affect the benefits analysis via Monte Carlo simulation.

  17. A comparative study of volumetric breast density estimation in digital mammography and magnetic resonance imaging: results from a high-risk population

    NASA Astrophysics Data System (ADS)

    Kontos, Despina; Xing, Ye; Bakic, Predrag R.; Conant, Emily F.; Maidment, Andrew D. A.

    2010-03-01

    We performed a study to compare methods for volumetric breast density estimation in digital mammography (DM) and magnetic resonance imaging (MRI) for a high-risk population of women. DM and MRI images of the unaffected breast from 32 women with recently detected abnormalities and/or previously diagnosed breast cancer (age range 31-78 yrs, mean 50.3 yrs) were retrospectively analyzed. DM images were analyzed using QuantraTM (Hologic Inc). The MRI images were analyzed using a fuzzy-C-means segmentation algorithm on the T1 map. Both methods were compared to Cumulus (Univ. Toronto). Volumetric breast density estimates from DM and MRI are highly correlated (r=0.90, p<=0.001). The correlation between the volumetric and the area-based density measures is lower and depends on the training background of the Cumulus software user (r=0.73-84, p<=0.001). In terms of absolute values, MRI provides the lowest volumetric estimates (mean=14.63%), followed by the DM volumetric (mean=22.72%) and area-based measures (mean=29.35%). The MRI estimates of the fibroglandular volume are statistically significantly lower than the DM estimates for women with very low-density breasts (p<=0.001). We attribute these differences to potential partial volume effects in MRI and differences in the computational aspects of the image analysis methods in MRI and DM. The good correlation between the volumetric and the area-based measures, shown to correlate with breast cancer risk, suggests that both DM and MRI volumetric breast density measures can aid in breast cancer risk assessment. Further work is underway to fully-investigate the association between volumetric breast density measures and breast cancer risk.

  18. Probabilistic modelling for estimating gas kinetics and decompression sickness risk in pigs during H2 biochemical decompression.

    PubMed

    Fahlman, Andreas; Kayar, Susan R

    2003-07-01

    We modelled the kinetics of H2 flux during gas uptake and elimination in conscious pigs exposed to hyperbaric H2. The model used a physiological description of gas flux fitted to the observed decompression sickness (DCS) incidence in two groups of pigs: untreated controls, and animals that had received intestinal injections of H2-metabolizing microbes that biochemically eliminated some of the H2 stored in the pigs' tissues. To analyse H2 flux during gas uptake, animals were compressed in a dry chamber to 24 atm (ca 88% H2, 9% He, 2% O2, 1% N2) for 30-1440 min and decompressed at 0.9 atm min(-1) (n = 70). To analyse H2 flux during gas elimination, animals were compressed to 24 atm for 3 h and decompressed at 0.45-1.8 atm min(-1) (n = 58). Animals were closely monitored for 1 h post-decompression for signs of DCS. Probabilistic modelling was used to estimate that the exponential time constant during H2 uptake (tau(in)) and H2 elimination (tau(out)) were 79 +/- 25 min and 0.76 +/- 0.14 min, respectively. Thus, the gas kinetics affecting DCS risk appeared to be substantially faster for elimination than uptake, which is contrary to customary assumptions of gas uptake and elimination kinetic symmetry. We discuss the possible reasons for this asymmetry, and why absolute values of H2 kinetics cannot be obtained with this approach.

  19. Estimated Risk Level of Unified Stereotactic Body Radiation Therapy Dose Tolerance Limits for Spinal Cord.

    PubMed

    Grimm, Jimm; Sahgal, Arjun; Soltys, Scott G; Luxton, Gary; Patel, Ashish; Herbert, Scott; Xue, Jinyu; Ma, Lijun; Yorke, Ellen; Adler, John R; Gibbs, Iris C

    2016-04-01

    A literature review of more than 200 stereotactic body radiation therapy spine articles from the past 20 years found only a single article that provided dose-volume data and outcomes for each spinal cord of a clinical dataset: the Gibbs 2007 article (Gibbs et al, 2007(1)), which essentially contains the first 100 stereotactic body radiation therapy (SBRT) spine treatments from Stanford University Medical Center. The dataset is modeled and compared in detail to the rest of the literature review, which found 59 dose tolerance limits for the spinal cord in 1-5 fractions. We partitioned these limits into a unified format of high-risk and low-risk dose tolerance limits. To estimate the corresponding risk level of each limit we used the Gibbs 2007 clinical spinal cord dose-volume data for 102 spinal metastases in 74 patients treated by spinal radiosurgery. In all, 50 of the patients were previously irradiated to a median dose of 40Gy in 2-3Gy fractions and 3 patients developed treatment-related myelopathy. These dose-volume data were digitized into the dose-volume histogram (DVH) Evaluator software tool where parameters of the probit dose-response model were fitted using the maximum likelihood approach (Jackson et al, 1995(3)). Based on this limited dataset, for de novo cases the unified low-risk dose tolerance limits yielded an estimated risk of spinal cord injury of ≤1% in 1-5 fractions, and the high-risk limits yielded an estimated risk of ≤3%. The QUANTEC Dmax limits of 13Gy in a single fraction and 20Gy in 3 fractions had less than 1% risk estimated from this dataset, so we consider these among the low-risk limits. In the previously irradiated cohort, the estimated risk levels for 10 and 14Gy maximum cord dose limits in 5 fractions are 0.4% and 0.6%, respectively. Longer follow-up and more patients are required to improve the risk estimates and provide more complete validation. PMID:27000514

  20. Estimated Risk Level of Unified Stereotactic Body Radiation Therapy Dose Tolerance Limits for Spinal Cord.

    PubMed

    Grimm, Jimm; Sahgal, Arjun; Soltys, Scott G; Luxton, Gary; Patel, Ashish; Herbert, Scott; Xue, Jinyu; Ma, Lijun; Yorke, Ellen; Adler, John R; Gibbs, Iris C

    2016-04-01

    A literature review of more than 200 stereotactic body radiation therapy spine articles from the past 20 years found only a single article that provided dose-volume data and outcomes for each spinal cord of a clinical dataset: the Gibbs 2007 article (Gibbs et al, 2007(1)), which essentially contains the first 100 stereotactic body radiation therapy (SBRT) spine treatments from Stanford University Medical Center. The dataset is modeled and compared in detail to the rest of the literature review, which found 59 dose tolerance limits for the spinal cord in 1-5 fractions. We partitioned these limits into a unified format of high-risk and low-risk dose tolerance limits. To estimate the corresponding risk level of each limit we used the Gibbs 2007 clinical spinal cord dose-volume data for 102 spinal metastases in 74 patients treated by spinal radiosurgery. In all, 50 of the patients were previously irradiated to a median dose of 40Gy in 2-3Gy fractions and 3 patients developed treatment-related myelopathy. These dose-volume data were digitized into the dose-volume histogram (DVH) Evaluator software tool where parameters of the probit dose-response model were fitted using the maximum likelihood approach (Jackson et al, 1995(3)). Based on this limited dataset, for de novo cases the unified low-risk dose tolerance limits yielded an estimated risk of spinal cord injury of ≤1% in 1-5 fractions, and the high-risk limits yielded an estimated risk of ≤3%. The QUANTEC Dmax limits of 13Gy in a single fraction and 20Gy in 3 fractions had less than 1% risk estimated from this dataset, so we consider these among the low-risk limits. In the previously irradiated cohort, the estimated risk levels for 10 and 14Gy maximum cord dose limits in 5 fractions are 0.4% and 0.6%, respectively. Longer follow-up and more patients are required to improve the risk estimates and provide more complete validation.

  1. Measurement of natural radionuclides in Malaysian bottled mineral water and consequent health risk estimation

    SciTech Connect

    Priharti, W.; Samat, S. B.; Yasir, M. S.

    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.

  2. Measurement of natural radionuclides in Malaysian bottled mineral water and consequent health risk estimation

    NASA Astrophysics Data System (ADS)

    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.

  3. Consolidating Risk Estimates for Radiation-Induced Complications in Individual Patient: Late Rectal Toxicity

    SciTech Connect

    Prior, Phillip; Devisetty, Kiran; Tarima, Sergey S.; Lawton, Colleen A.F.; Semenenko, Vladimir A.

    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.

  4. The Estimate of Risk of Adolescent Sexual Offense Recidivism (ERASOR): preliminary psychometric data.

    PubMed

    Worling, James R

    2004-06-01

    The Estimate of Risk of Adolescent Sexual Offense Recidivism (ERASOR) is an empirically guided checklist designed to assist clinicians to estimate the short-term risk of a sexual reoffense for youth aged 12-18 years of age. The ERASOR provides objective coding instructions for 25 risk factors (16 dynamic and 9 static). To investigate the psychometric properties, risk ratings were collected from 28 clinicians who evaluated 136 adolescent males (aged 12-18 years) following comprehensive, clinical assessments. Preliminary psychometric data (i.e., interrater agreement, item-total correlation, internal consistency) were found to be supportive of the reliability and item composition of the tool. ERASOR ratings also significantly discriminated adolescents based on whether or not they had previously been sanctioned for a prior sexual offense. PMID:15326883

  5. Performance of default risk model with barrier option framework and maximum likelihood estimation: Evidence from Taiwan

    NASA Astrophysics Data System (ADS)

    Chou, Heng-Chih; Wang, David

    2007-11-01

    We investigate the performance of a default risk model based on the barrier option framework with maximum likelihood estimation. We provide empirical validation of the model by showing that implied default barriers are statistically significant for a sample of construction firms in Taiwan over the period 1994-2004. We find that our model dominates the commonly adopted models, Merton model, Z-score model and ZETA model. Moreover, we test the n-year-ahead prediction performance of the model and find evidence that the prediction accuracy of the model improves as the forecast horizon decreases. Finally, we assess the effect of estimated default risk on equity returns and find that default risk is able to explain equity returns and that default risk is a variable worth considering in asset-pricing tests, above and beyond size and book-to-market.

  6. A methodology for estimating risks associated with landslides of contaminated soil into rivers.

    PubMed

    Göransson, Gunnel; Norrman, Jenny; Larson, Magnus; Alén, Claes; Rosén, Lars

    2014-02-15

    Urban areas adjacent to surface water are exposed to soil movements such as erosion and slope failures (landslides). A landslide is a potential mechanism for mobilisation and spreading of pollutants. This mechanism is in general not included in environmental risk assessments for contaminated sites, and the consequences associated with contamination in the soil are typically not considered in landslide risk assessments. This study suggests a methodology to estimate the environmental risks associated with landslides in contaminated sites adjacent to rivers. The methodology is probabilistic and allows for datasets with large uncertainties and the use of expert judgements, providing quantitative estimates of probabilities for defined failures. The approach is illustrated by a case study along the river Göta Älv, Sweden, where failures are defined and probabilities for those failures are estimated. Failures are defined from a pollution perspective and in terms of exceeding environmental quality standards (EQSs) and acceptable contaminant loads. Models are then suggested to estimate probabilities of these failures. A landslide analysis is carried out to assess landslide probabilities based on data from a recent landslide risk classification study along the river Göta Älv. The suggested methodology is meant to be a supplement to either landslide risk assessment (LRA) or environmental risk assessment (ERA), providing quantitative estimates of the risks associated with landslide in contaminated sites. The proposed methodology can also act as a basis for communication and discussion, thereby contributing to intersectoral management solutions. From the case study it was found that the defined failures are governed primarily by the probability of a landslide occurring. The overall probabilities for failure are low; however, if a landslide occurs the probabilities of exceeding EQS are high and the probability of having at least a 10% increase in the contamination load

  7. A methodology for estimating risks associated with landslides of contaminated soil into rivers.

    PubMed

    Göransson, Gunnel; Norrman, Jenny; Larson, Magnus; Alén, Claes; Rosén, Lars

    2014-02-15

    Urban areas adjacent to surface water are exposed to soil movements such as erosion and slope failures (landslides). A landslide is a potential mechanism for mobilisation and spreading of pollutants. This mechanism is in general not included in environmental risk assessments for contaminated sites, and the consequences associated with contamination in the soil are typically not considered in landslide risk assessments. This study suggests a methodology to estimate the environmental risks associated with landslides in contaminated sites adjacent to rivers. The methodology is probabilistic and allows for datasets with large uncertainties and the use of expert judgements, providing quantitative estimates of probabilities for defined failures. The approach is illustrated by a case study along the river Göta Älv, Sweden, where failures are defined and probabilities for those failures are estimated. Failures are defined from a pollution perspective and in terms of exceeding environmental quality standards (EQSs) and acceptable contaminant loads. Models are then suggested to estimate probabilities of these failures. A landslide analysis is carried out to assess landslide probabilities based on data from a recent landslide risk classification study along the river Göta Älv. The suggested methodology is meant to be a supplement to either landslide risk assessment (LRA) or environmental risk assessment (ERA), providing quantitative estimates of the risks associated with landslide in contaminated sites. The proposed methodology can also act as a basis for communication and discussion, thereby contributing to intersectoral management solutions. From the case study it was found that the defined failures are governed primarily by the probability of a landslide occurring. The overall probabilities for failure are low; however, if a landslide occurs the probabilities of exceeding EQS are high and the probability of having at least a 10% increase in the contamination load

  8. Estimated human health risks of disposing of nonhazardous oil field waste in salt caverns

    SciTech Connect

    Tomasko, D.; Elcock, D.; Veil, J.

    1997-09-01

    Argonne National Laboratory (ANL) has completed an evaluation of the possibility that adverse human health effects (carcinogenic and noncarcinogenic) could result from exposure to contaminants released from nonhazardous oil field wastes (NOW) disposed in domal salt caverns. In this assessment, several steps were used to evaluate potential human health risks: identifying potential contaminants of concern, determining how humans could be exposed to these contaminants, assessing the contaminants` toxicities, estimating contaminant intakes, and, finally, calculating human cancer and noncancer risks.

  9. Urban micro-scale flood risk estimation with parsimonious hydraulic modelling and census data

    NASA Astrophysics Data System (ADS)

    Arrighi, C.; Brugioni, M.; Castelli, F.; Franceschini, S.; Mazzanti, B.

    2013-05-01

    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 function, for the main

  10. Risk analysis and Monte Carlo simulation applied to the generation of drilling AFE estimates

    SciTech Connect

    Peterson, S.K.; Murtha, J.A.; Schneider, F.F.

    1995-06-01

    This paper presents a method for developing an authorization-for-expenditure (AFE)-generating model and illustrates the technique with a specific offshore field development case study. The model combines Monte Carlo simulation and statistical analysis of historical drilling data to generate more accurate, risked, AFE estimates. In addition to the general method, two examples of making AFE time estimates for North Sea wells with the presented techniques are given.

  11. Examining the effects of air pollution composition on within region differences in PM2.5 mortality risk estimates

    EPA Science Inventory

    Multi-city population-based epidemiological studies have observed significant heterogeneity in both the magnitude and direction of city-specific risk estimates, but tended to focus on regional differences in PM2.5 mortality risk estimates. Interpreting differences in risk estimat...

  12. Estimation of flood risk for cultural heritage in an art city

    NASA Astrophysics Data System (ADS)

    Arrighi, Chiara; Brugioni, Marcello; Franceschini, Serena; Castelli, Fabio; Mazzanti, Bernardo

    2015-04-01

    Flood risk assessment in art cities poses many challenges for the presence of cultural heritage at risk, which is a damage category whose value is hardly monetizable. In fact, valuing cultural asset is a complex task, usually requiring more effort than a rough estimation of restoration costs. The lack of an adequate risk evaluation of the cultural asset may also lead to enormous difficulties and political problems for the accomplishment of the structural mitigation solutions. The aim of the work is to perform a first analysis of the risk to cultural heritage avoiding a full quantification of exposure. Here we present a case study of broad importance, which is the art city of Florence (Italy), affected by a devastating flood in 1966. In previous studies the estimated flood risk, neglecting damages to cultural heritage, was about 53 Mio€ /year. Nevertheless, Florence hosts 176 buildings officially classified as cultural heritage and thousands of paintings, sculptures and ancient books. Proceeding similarly to the commonly accepted flood risk assessment method, the annual expected loss in terms of cultural heritage/artworks is estimated.

  13. Estimate of Space Radiation-Induced Cancer Risks for International Space Station Orbits

    SciTech Connect

    Wu, H.; Atwell, W.; Cucinotta, F.A.; Yang, C.

    1996-03-01

    Excess cancer risks from exposures to space radiation are estimated for various orbits of the International Space Station (ISS). Organ exposures are computed with the transport codes, BRYNTRN and HZETRN, and the computerized anatomical male and computerized anatomical female models. Cancer risk coefficients in the National Council on Radiation Protection and Measurements report No. 98 are used to generate lifetime excess cancer incidence and cancer mortality after a one-month mission to ISS. The generated data are tabulated to serve as a quick reference for assessment of radiation risk to astronauts on ISS missions.

  14. Estimate of Space Radiation-Induced Cancer Risks for International Space Station Orbits

    NASA Technical Reports Server (NTRS)

    Wu, Honglu; Atwell, William; Cucinotta, Francis A.; Yang, Chui-hsu

    1996-01-01

    Excess cancer risks from exposures to space radiation are estimated for various orbits of the International Space Station (ISS). Organ exposures are computed with the transport codes, BRYNTRN and HZETRN, and the computerized anatomical male and computerized anatomical female models. Cancer risk coefficients in the National Council on Radiation Protection and Measurements report No. 98 are used to generate lifetime excess cancer incidence and cancer mortality after a one-month mission to ISS. The generated data are tabulated to serve as a quick reference for assessment of radiation risk to astronauts on ISS missions.

  15. Estimated occupational risk from bioaerosols generated during land application of class B biosolids.

    PubMed

    Tanner, Benjamin D; Brooks, John P; Gerba, Charles P; Haas, Charles N; Josephson, Karen L; Pepper, Ian L

    2008-01-01

    Some speculate that bioaerosols from land application of biosolids pose occupational risks, but few studies have assessed aerosolization of microorganisms from biosolids or estimated occupational risks of infection. This study investigated levels of microorganisms in air immediately downwind of land application operations and estimated occupational risks from aerosolized microorganisms. In all, more than 300 air samples were collected downwind of biosolids application sites at various locations within the United States. Coliform bacteria, coliphages, and heterotrophic plate count (HPC) bacteria were enumerated from air and biosolids at each site. Concentrations of coliforms relative to Salmonella and concentrations of coliphage relative to enteroviruses in biosolids were used, in conjunction with levels of coliforms and coliphages measured in air during this study, to estimate exposure to Salmonella and enteroviruses in air. The HPC bacteria were ubiquitous in air near land application sites whether or not biosolids were being applied, and concentrations were positively correlated to windspeed. Coliform bacteria were detected only when biosolids were being applied to land or loaded into land applicators. Coliphages were detected in few air samples, and only when biosolids were being loaded into land applicators. In general, environmental parameters had little impact on concentrations of microorganisms in air immediately downwind of land application. The method of land application was most correlated to aerosolization. From this large body of data, the occupational risk of infection from bioaerosols was estimated to be 0.78 to 2.1%/yr. Extraordinary exposure scenarios carried an estimated annual risk of infection of up to 34%, with viruses posing the greatest threat. Risks from aerosolized microorganisms at biosolids land application sites appear to be lower than those at wastewater treatment plants, based on previously reported literature. PMID:18948485

  16. Estimating cancer risk from dental cone-beam CT exposures based on skin dosimetry

    NASA Astrophysics Data System (ADS)

    Pauwels, Ruben; Cockmartin, Lesley; Ivanauskaité, Deimante; Urbonienė, Ausra; Gavala, Sophia; Donta, Catherine; Tsiklakis, Kostas; Jacobs, Reinhilde; Bosmans, Hilde; Bogaerts, Ria; Horner, Keith; SEDENTEXCT Project Consortium, The

    2014-07-01

    The aim of this study was to measure entrance skin doses on patients undergoing cone-beam computed tomography (CBCT) examinations, to establish conversion factors between skin and organ doses, and to estimate cancer risk from CBCT exposures. 266 patients (age 8-83) were included, involving three imaging centres. CBCT scans were acquired using the SCANORA 3D (Soredex, Tuusula, Finland) and NewTom 9000 (QR, Verona, Italy). Eight thermoluminescent dosimeters were attached to the patient's skin at standardized locations. Using previously published organ dose estimations on various CBCTs with an anthropomorphic phantom, correlation factors to convert skin dose to organ doses were calculated and applied to estimate patient organ doses. The BEIR VII age- and gender-dependent dose-risk model was applied to estimate the lifetime attributable cancer risk. For the SCANORA 3D, average skin doses over the eight locations varied between 484 and 1788 µGy. For the NewTom 9000 the range was between 821 and 1686 µGy for Centre 1 and between 292 and 2325 µGy for Centre 2. Entrance skin dose measurements demonstrated the combined effect of exposure and patient factors on the dose. The lifetime attributable cancer risk, expressed as the probability to develop a radiation-induced cancer, varied between 2.7 per million (age >60) and 9.8 per million (age 8-11) with an average of 6.0 per million. On average, the risk for female patients was 40% higher. The estimated radiation risk was primarily influenced by the age at exposure and the gender, pointing out the continuing need for justification and optimization of CBCT exposures, with a specific focus on children.

  17. Heritability Estimates Identify a Substantial Genetic Contribution to Risk and Outcome of Intracerebral Hemorrhage

    PubMed Central

    Devan, William J.; Falcone, Guido J.; Anderson, Christopher D.; Jagiella, Jeremiasz M.; Schmidt, Helena; Hansen, Björn M.; Jimenez-Conde, Jordi; Giralt-Steinhauer, Eva; Cuadrado-Godia, Elisa; Soriano, Carolina; Ayres, Alison M.; Schwab, Kristin; Kassis, Sylvia Baedorf; Valant, Valerie; Pera, Joanna; Urbanik, Andrzej; Viswanathan, Anand; Rost, Natalia S.; Goldstein, Joshua N.; Freudenberger, Paul; Stögerer, Eva-Maria; Norrving, Bo; Tirschwell, David L.; Selim, Magdy; Brown, Devin L.; Silliman, Scott L.; Worrall, Bradford B.; Meschia, James F.; Kidwell, Chelsea S.; Montaner, Joan; Fernandez-Cadenas, Israel; Delgado, Pilar; Greenberg, Steven M.; Roquer, Jaume; Lindgren, Arne; Slowik, Agnieszka; Schmidt, Reinhold; Woo, Daniel; Rosand, Jonathan; Biffi, Alessandro

    2013-01-01

    Background and Purpose Previous studies suggest that genetic variation plays a substantial role in occurrence and evolution of intracerebral hemorrhage (ICH). Genetic contribution to disease can be determined by calculating heritability using family-based data, but such an approach is impractical for ICH because of lack of large pedigree-based studies. However, a novel analytic tool based on genome-wide data allows heritability estimation from unrelated subjects. We sought to apply this method to provide heritability estimates for ICH risk, severity, and outcome. Methods We analyzed genome-wide genotype data for 791 ICH cases and 876 controls, and determined heritability as the proportion of variation in phenotype attributable to captured genetic variants. Contribution to heritability was separately estimated for the APOE (encoding apolipoprotein E) gene, an established genetic risk factor, and for the rest of the genome. Analyzed phenotypes included ICH risk, admission hematoma volume, and 90-day mortality. Results ICH risk heritability was estimated at 29% (SE, 11%) for non-APOE loci and at 15% (SE, 10%) for APOE. Heritability for 90-day ICH mortality was 41% for non-APOE loci and 10% (SE, 9%) for APOE. Genetic influence on hematoma volume was also substantial: admission volume heritability was estimated at 60% (SE, 70%) for non-APOE loci and at 12% (SE, 4%) for APOE. Conclusions Genetic variation plays a substantial role in ICH risk, outcome, and hematoma volume. Previously reported risk variants account for only a portion of inherited genetic influence on ICH pathophysiology, pointing to additional loci yet to be identified. PMID:23559261

  18. Estimating cancer risk from dental cone-beam CT exposures based on skin dosimetry.

    PubMed

    Pauwels, Ruben; Cockmartin, Lesley; Ivanauskaité, Deimante; Urbonienė, Ausra; Gavala, Sophia; Donta, Catherine; Tsiklakis, Kostas; Jacobs, Reinhilde; Bosmans, Hilde; Bogaerts, Ria; Horner, Keith

    2014-07-21

    The aim of this study was to measure entrance skin doses on patients undergoing cone-beam computed tomography (CBCT) examinations, to establish conversion factors between skin and organ doses, and to estimate cancer risk from CBCT exposures. 266 patients (age 8-83) were included, involving three imaging centres. CBCT scans were acquired using the SCANORA 3D (Soredex, Tuusula, Finland) and NewTom 9000 (QR, Verona, Italy). Eight thermoluminescent dosimeters were attached to the patient's skin at standardized locations. Using previously published organ dose estimations on various CBCTs with an anthropomorphic phantom, correlation factors to convert skin dose to organ doses were calculated and applied to estimate patient organ doses. The BEIR VII age- and gender-dependent dose-risk model was applied to estimate the lifetime attributable cancer risk. For the SCANORA 3D, average skin doses over the eight locations varied between 484 and 1788 µGy. For the NewTom 9000 the range was between 821 and 1686 µGy for Centre 1 and between 292 and 2325 µGy for Centre 2. Entrance skin dose measurements demonstrated the combined effect of exposure and patient factors on the dose. The lifetime attributable cancer risk, expressed as the probability to develop a radiation-induced cancer, varied between 2.7 per million (age >60) and 9.8 per million (age 8-11) with an average of 6.0 per million. On average, the risk for female patients was 40% higher. The estimated radiation risk was primarily influenced by the age at exposure and the gender, pointing out the continuing need for justification and optimization of CBCT exposures, with a specific focus on children. PMID:24957710

  19. Micro-scale flood risk estimation in historic centres: a case study in Florence, Italy

    NASA Astrophysics Data System (ADS)

    Castelli, Fabio; Arrighi, Chiara; Brugioni, Marcello; Franceschini, Serena; Mazzanti, Bernardo

    2013-04-01

    The route to flood risk assessment is much more than hydraulic modelling of inundation, that is hazard mapping. Flood risk is the product of flood hazard, vulnerability and exposure, all the three to be estimated with comparable level of accuracy. While hazard maps have already been implemented in many countries, quantitative damage and risk maps are still at a preliminary level. Currently one of the main challenges in flood damage estimation resides in the scarce availability of socio-economic data characterizing the monetary value of the exposed assets. When these public-open data are available, the variability of their level of detail drives the need of merging different sources and of selecting an appropriate scale of analysis. In this work a parsimonious quasi-2D hydraulic model is adopted, having many advantages in terms of easy set-up. In order to represent the geometry of the study domain an high-resolution and up-to-date Digital Surface Model (DSM) is used. The accuracy in flood depth estimation is evaluated by comparison with marble-plate records of a historic flood in the city of Florence (Italy). The accuracy is characterized in the downtown 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 €/m2•year, corresponding to about 8.3% of residents income. The spatial distribution of estimated risk highlights a complex interaction between the flood pattern and the buildings characteristics. Proceeding through the risk estimation steps, a new micro-scale potential damage assessment method is proposed. This method is based on the georeferenced census system considered as optimal compromise between spatial detail and open availability of socio-economic data. The census sections system consist of geographically contiguous polygons that usually coincide with building blocks in dense urban areas. The results of flood risk assessment at the census section scale resolve most of

  20. Combined Use of Absolute and Differential Seismic Arrival Time Data to Improve Absolute Event Location

    NASA Astrophysics Data System (ADS)

    Myers, S.; Johannesson, G.

    2012-12-01

    Arrival time measurements based on waveform cross correlation are becoming more common as advanced signal processing methods are applied to seismic data archives and real-time data streams. Waveform correlation can precisely measure the time difference between the arrival of two phases, and differential time data can be used to constrain relative location of events. Absolute locations are needed for many applications, which generally requires the use of absolute time data. Current methods for measuring absolute time data are approximately two orders of magnitude less precise than differential time measurements. To exploit the strengths of both absolute and differential time data, we extend our multiple-event location method Bayesloc, which previously used absolute time data only, to include the use of differential time measurements that are based on waveform cross correlation. Fundamentally, Bayesloc is a formulation of the joint probability over all parameters comprising the multiple event location system. The Markov-Chain Monte Carlo method is used to sample from the joint probability distribution given arrival data sets. The differential time component of Bayesloc includes scaling a stochastic estimate of differential time measurement precision based the waveform correlation coefficient for each datum. For a regional-distance synthetic data set with absolute and differential time measurement error of 0.25 seconds and 0.01 second, respectively, epicenter location accuracy is improved from and average of 1.05 km when solely absolute time data are used to 0.28 km when absolute and differential time data are used jointly (73% improvement). The improvement in absolute location accuracy is the result of conditionally limiting absolute location probability regions based on the precise relative position with respect to neighboring events. Bayesloc estimates of data precision are found to be accurate for the synthetic test, with absolute and differential time measurement

  1. Estimated risk from exposure to radon decay products in US homes

    SciTech Connect

    Nero, A.V. Jr.

    1986-05-01

    Recent analyses now permit direct estimation of the risks of lung cancer from radon decay products in US homes. Analysis of data from indoor monitoring in single-family homes yields a tentative frequency distribution of annual-average /sup 222/Rn concentrations averaging 55 Bq m/sup -3/ and having 2% of homes exceeding 300 Bq m/sup -3/. Application of the results of occupational epidemiological studies, either directly or using recent advances in lung dosimetry, to indoor exposures suggests that the average indoor concentration entails a lifetime risk of lung cancer of 0.3% or about 10% of the total risk of lung cancer. The risk to individuals occupying the homes with 300 Bq m/sup -3/ or more for their lifetimes is estimated to exceed 2%, with risks from the homes with thousands of Bq m/sup -3/ correspondingly higher, even exceeding the total risk of premature death due to cigarette smoking. The potential for such average and high-level risks in ordinary homes forces development of a new perspective on environmental exposures.

  2. An Evidenced-Based Approach for Estimating Decompression Sickness Risk in Aircraft Operations

    NASA Technical Reports Server (NTRS)

    Robinson, Ronald R.; Dervay, Joseph P.; Conkin, Johnny

    1999-01-01

    Estimating the risk of decompression Sickness (DCS) in aircraft operations remains a challenge, making the reduction of this risk through the development of operationally acceptable denitrogenation schedules difficult. In addition, the medical recommendations which are promulgated are often not supported by rigorous evaluation of the available data, but are instead arrived at by negotiation with the aircraft operations community, are adapted from other similar aircraft operations, or are based upon the opinion of the local medical community. We present a systematic approach for defining DCS risk in aircraft operations by analyzing the data available for a specific aircraft, flight profile, and aviator population. Once the risk of DCS in a particular aircraft operation is known, appropriate steps can be taken to reduce this risk to a level acceptable to the applicable aviation community. Using this technique will allow any aviation medical community to arrive at the best estimate of DCS risk for its specific mission and aviator population and will allow systematic reevaluation of the decisions regarding DCS risk reduction when additional data are available.

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

    SciTech Connect

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

    2000-02-01

    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 < 1.03 x 10{sup {minus}4} (ppm coal tar in total diet) + 240 x 10{sup {minus}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 < 2.55 x 10{sup {minus}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{sup {minus}3} per {micro}g per kg body weight per day from this Good Laboratory Practice (GLP) study compared with the current value of 7.3 x 10{sup {minus}3} per {micro}g per kg body weight per day listed in the US EPA Integrated Risk Information System.

  4. Estimation of Hypertension Risk from Lifestyle Factors and Health Profile: A Case Study

    PubMed Central

    2014-01-01

    Hypertension is a highly prevalent risk factor for cardiovascular disease and it can also lead to other diseases which seriously harm the human health. Screening the risks and finding a clinical model for estimating the risk of onset, maintenance, or the prognosis of hypertension are of great importance to the prevention or treatment of the disease, especially if the indicator can be derived from simple health profile. In this study, we investigate a chronic disease questionnaire data set of 6563 rural citizens in East China and find out a clinical signature that can assess the risk of hypertension easily and accurately. The signature achieves an accuracy of about 83% on the external test dataset, with an AUC of 0.91. Our study demonstrates that a combination of simple lifestyle features can sufficiently reflect the risk of hypertension onset. This finding provides potential guidance for disease prevention and control as well as development of home care and home-care technologies. PMID:25019099

  5. ABSOLUTE POLARIMETRY AT RHIC.

    SciTech Connect

    OKADA; BRAVAR, A.; BUNCE, G.; GILL, R.; HUANG, H.; MAKDISI, Y.; NASS, A.; WOOD, J.; ZELENSKI, Z.; ET AL.

    2007-09-10

    Precise and absolute beam polarization measurements are critical for the RHIC spin physics program. Because all experimental spin-dependent results are normalized by beam polarization, the normalization uncertainty contributes directly to final physics uncertainties. We aimed to perform the beam polarization measurement to an accuracy Of {Delta}P{sub beam}/P{sub beam} < 5%. The absolute polarimeter consists of Polarized Atomic Hydrogen Gas Jet Target and left-right pairs of silicon strip detectors and was installed in the RHIC-ring in 2004. This system features proton-proton elastic scattering in the Coulomb nuclear interference (CNI) region. Precise measurements of the analyzing power A{sub N} of this process has allowed us to achieve {Delta}P{sub beam}/P{sub beam} = 4.2% in 2005 for the first long spin-physics run. In this report, we describe the entire set up and performance of the system. The procedure of beam polarization measurement and analysis results from 2004-2005 are described. Physics topics of AN in the CNI region (four-momentum transfer squared 0.001 < -t < 0.032 (GeV/c){sup 2}) are also discussed. We point out the current issues and expected optimum accuracy in 2006 and the future.

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

    PubMed

    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.

  7. A review of methods to estimate cause-specific mortality in presence of competing risks

    USGS Publications Warehouse

    Heisey, Dennis M.; Patterson, Brent R.

    2006-01-01

    Estimating cause-specific mortality is often of central importance for understanding the dynamics of wildlife populations. Despite such importance, methodology for estimating and analyzing cause-specific mortality has received little attention in wildlife ecology during the past 20 years. The issue of analyzing cause-specific, mutually exclusive events in time is not unique to wildlife. In fact, this general problem has received substantial attention in human biomedical applications within the context of biostatistical survival analysis. Here, we consider cause-specific mortality from a modern biostatistical perspective. This requires carefully defining what we mean by cause-specific mortality and then providing an appropriate hazard-based representation as a competing risks problem. This leads to the general solution of cause-specific mortality as the cumulative incidence function (CIF). We describe the appropriate generalization of the fully nonparametric staggered-entry Kaplan–Meier survival estimator to cause-specific mortality via the nonparametric CIF estimator (NPCIFE), which in many situations offers an attractive alternative to the Heisey–Fuller estimator. An advantage of the NPCIFE is that it lends itself readily to risk factors analysis with standard software for Cox proportional hazards model. The competing risks–based approach also clarifies issues regarding another intuitive but erroneous "cause-specific mortality" estimator based on the Kaplan–Meier survival estimator and commonly seen in the life sciences literature.

  8. Estimators of annual probability of infection for quantitative microbial risk assessment.

    PubMed

    Karavarsamis, N; Hamilton, A J

    2010-06-01

    Four estimators of annual infection probability were compared pertinent to Quantitative Microbial Risk Analysis (QMRA). A stochastic model, the Gold Standard, was used as the benchmark. It is a product of independent daily infection probabilities which in turn are based on daily doses. An alternative and commonly-used estimator, here referred to as the Naïve, assumes a single daily infection probability from a single value of daily dose. The typical use of this estimator in stochastic QMRA involves the generation of a distribution of annual infection probabilities, but since each of these is based on a single realisation of the dose distribution, the resultant annual infection probability distribution simply represents a set of inaccurate estimates. While the medians of both distributions were within an order of magnitude for our test scenario, the 95th percentiles, which are sometimes used in QMRA as conservative estimates of risk, differed by around one order of magnitude. The other two estimators examined, the Geometric and Arithmetic, were closely related to the Naïve and use the same equation, and both proved to be poor estimators. Lastly, this paper proposes a simple adjustment to the Gold Standard equation accommodating periodic infection probabilities when the daily infection probabilities are unknown.

  9. Prevalence Estimates of Health Risk Behaviors of Immigrant Latino Men Who Have Sex with Men

    ERIC Educational Resources Information Center

    Rhodes, Scott D.; McCoy, Thomas P.; Hergenrather, Kenneth C.; Vissman, Aaron T.; Wolfson, Mark; Alonzo, Jorge; Bloom, Fred R.; Alegria-Ortega, Jose; Eng, Eugenia

    2012-01-01

    Purpose: Little is known about the health status of rural immigrant Latino men who have sex with men (MSM). These MSM comprise a subpopulation that tends to remain "hidden" from both researchers and practitioners. This study was designed to estimate the prevalence of tobacco, alcohol, and drug use, and sexual risk behaviors of Latino MSM living in…

  10. AN INFORMATIC APPROACH TO ESTIMATING ECOLOGICAL RISKS POSED BY PHARMACEUTICAL USE

    EPA Science Inventory

    A new method for estimating risks of human prescription pharmaceuticals based on information found in regulatory filings as well as scientific and trade literature is described in a presentation at the Pharmaceuticals in the Environment Workshop in Las Vegas, NV, August 23-25, 20...

  11. Risk estimates for radiation-induced cancer and radiation protection standards

    SciTech Connect

    Sinclair, W.K. )

    1989-11-01

    At low doses, the primary biological effects of concern are stochastic in nature, i.e., they are more probable at higher doses, but their severity is independent of the dose. In the last decade, a new epidemiological information on radiation-induced cancer in humans has become available. In the Japanese survivors three new cycles of data (11 yr of experience) have accumulated, and a revised dosimetry system (DS86) has been introduced. UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation) reevaluated the risk of cancer from all human sources, which include other human populations such as those treated for ankylosing spondylitis and for cancer of the cervix. UNSCEAR has also evaluated the cancer risk for each of nine organs. For radiation protection purposes (low doses and dose rates, adult populations mainly), nominal values of risk since the 1977-80 period have been {approximately}1%/Sv. This value will need to be increased in the light of the new estimates. Also, risk estimates for various tissues must be reconsidered, and weighting factors used by International Commission on Radiological Protection need to be reexamined. Recommendations on occupational and public dose limits must also be reconsidered. The National Council on Radiation Protection and Measurements is in a comparatively good position with a recently produced set of recommendations that had higher cancer risk estimates in mind.

  12. Estimate of the risk in radiation therapy due to unwanted neutrons

    SciTech Connect

    Swanson, W.P.

    1980-03-01

    The integral dose of accelerator-produced leakage neutrons to patients undergoing high-energy photon therapy is estimated and compared to other sources of integral dose. The leakage neutron component contributes about 5 g rad (1 rad=10/sup -2/ Gy) for a typical treatment course of 5000 rad. When averaged over a 70-kg tissue volume, the corresponding dose amounts to only 0.36 rad. From this, the risk of inducing fatal malignancies by leakage neutrons is estimated to be about 50 x 10/sup -6/ per year following treatment. This is compared to other risks to which the patient is unavoidably exposed, and it is argued that the unwanted neutrons pose such small additional risk that regulatory intervention is not warranted. This assessment is performed without reference to neutron RBE or quality factor.

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

    NASA Astrophysics Data System (ADS)

    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.

  14. Prevalence Estimates of Health Risk Behaviors of Immigrant Latino Men Who Have Sex With Men

    PubMed Central

    Rhodes, Scott D.; McCoy, Thomas P.; Hergenrather, Kenneth C.; Vissman, Aaron T.; Wolfson, Mark; Alonzo, Jorge; Bloom, Fred R.; Alegría-Ortega, Jose; Eng, Eugenia

    2011-01-01

    Purpose Little is known about the health status of rural immigrant Latino men who have sex with men (MSM). These MSM comprise a subpopulation that tends to remain “hidden” from both researchers and practitioners. This study was designed to estimate the prevalence of tobacco, alcohol, and drug use, and sexual risk behaviors of Latino MSM living in rural North Carolina. Methods A community-based participatory research (CBPR) partnership used respondent-driven sampling (RDS) to identify, recruit, and enroll Latino MSM to participate in an interviewer-administered behavioral assessment. RDS weighted prevalence of risk behaviors was estimated using the RDS Analysis Tool. Data collection occurred in 2008. Results A total of 190 Latino MSM was reached; the average age was 25.5 years old and nearly 80% reported being from Mexico. Prevalence estimates of smoking everyday and past 30-day heavy episodic drinking were 6.5% and 35.0%, respectively. Prevalence estimates of past 12-month marijuana and cocaine use were 56.0% and 27.1%, respectively. Past 3-month prevalence estimates of sex with at least one woman, multiple male partners, and inconsistent condom use were 21.2%, 88.9%, and 54.1%, respectively. Conclusions Respondents had low rates of tobacco use and club drug use, and high rates of sexual risk behaviors. Although this study represents an initial step in documenting the health risk behaviors of immigrant Latino MSM who are part of a new trend in Latino immigration to the southeastern US, a need exists for further research, including longitudinal studies to understand the trajectory of risk behavior among immigrant Latino MSM. PMID:22236317

  15. Quantitative microbial risk assessment combined with hydrodynamic modelling to estimate the public health risk associated with bathing after rainfall events.

    PubMed

    Eregno, Fasil Ejigu; Tryland, Ingun; Tjomsland, Torulv; Myrmel, Mette; Robertson, Lucy; Heistad, Arve

    2016-04-01

    This study investigated the public health risk from exposure to infectious microorganisms at Sandvika recreational beaches, Norway and dose-response relationships by combining hydrodynamic modelling with Quantitative Microbial Risk Assessment (QMRA). Meteorological and hydrological data were collected to produce a calibrated hydrodynamic model using Escherichia coli as an indicator of faecal contamination. Based on average concentrations of reference pathogens (norovirus, Campylobacter, Salmonella, Giardia and Cryptosporidium) relative to E. coli in Norwegian sewage from previous studies, the hydrodynamic model was used for simulating the concentrations of pathogens at the local beaches during and after a heavy rainfall event, using three different decay rates. The simulated concentrations were used as input for QMRA and the public health risk was estimated as probability of infection from a single exposure of bathers during the three consecutive days after the rainfall event. The level of risk on the first day after the rainfall event was acceptable for the bacterial and parasitic reference pathogens, but high for the viral reference pathogen at all beaches, and severe at Kalvøya-small and Kalvøya-big beaches, supporting the advice of avoiding swimming in the day(s) after heavy rainfall. The study demonstrates the potential of combining discharge-based hydrodynamic modelling with QMRA in the context of bathing water as a tool to evaluate public health risk and support beach management decisions. PMID:26802355

  16. Estimated GFR associates with cardiovascular risk factors independently of measured GFR.

    PubMed

    Mathisen, Ulla Dorte; Melsom, Toralf; Ingebretsen, Ole C; Jenssen, Trond; Njølstad, Inger; Solbu, Marit D; Toft, Ingrid; Eriksen, Bjørn O

    2011-05-01

    Estimation of the GFR (eGFR) using creatinine- or cystatin C-based equations is imperfect, especially when the true GFR is normal or near-normal. Modest reductions in eGFR from the normal range variably predict cardiovascular morbidity. If eGFR associates not only with measured GFR (mGFR) but also with cardiovascular risk factors, the effects of these non-GFR-related factors might bias the association between eGFR and outcome. To investigate these potential non-GFR-related associations between eGFR and cardiovascular risk factors, we measured GFR by iohexol clearance in a sample from the general population (age 50 to 62 years) without known cardiovascular disease, diabetes, or kidney disease. Even after adjustment for mGFR, eGFR associated with traditional cardiovascular risk factors in multiple regression analyses. More risk factors influenced cystatin C-based eGFR than creatinine-based eGFR, adjusted for mGFR, and some of the risk factors exhibited nonlinear effects in generalized additive models (P<0.05). These results suggest that eGFR, calculated using standard creatinine- or cystatin C-based equations, partially depends on factors other than the true GFR. Thus, estimates of cardiovascular risk associated with small changes in eGFR must be interpreted with caution.

  17. Estimates of prevalence and risk associated with inattention and distraction based upon in situ naturalistic data.

    PubMed

    Dingus, Thomas A

    2014-01-01

    By using in situ naturalistic driving data, estimates of prevalence and risk can be made regarding driver populations' secondary task distractions and crash rates. Through metadata analysis, three populations of drivers (i.e., adult light vehicle, teenaged light vehicle, and adult heavy vehicle) were compared regarding frequency of secondary task behavior and the associated risk for safety-critical incidents. Relative risk estimates provide insight into the risk associated with engaging in a single task. When such risk is considered in combination with frequency of use, it sheds additional light on those secondary tasks that create the greatest overall risk to driving safety. The results show that secondary tasks involving manual typing, texting, dialing, reaching for an object, or reading are dangerous for all three populations. Additionally, novice teen drivers have difficulty in several tasks that the other two populations do not, including eating and external distractions. Truck drivers also perform a number of risky "mobile office" types of tasks, including writing, not seen in the other populations. Implications are described for policy makers and designers of in-vehicle and nomadic, portable systems. PMID:24776227

  18. Estimates of auditory risk from outdoor impulse noise. II: Civilian firearms.

    PubMed

    Flamme, Gregory A; Wong, Adam; Liebe, Kevin; Lynd, James

    2009-01-01

    Firearm impulses are common noise exposures in the United States. This study records, describes and analyzes impulses produced outdoors by civilian firearms with respect to the amount of auditory risk they pose to the unprotected listener under various listening conditions. Risk estimates were obtained using three contemporary damage risk criteria (DRC) including a waveform parameter-based approach (peak SPL and B-duration), an energy-based criterion (A-weighted SEL and equivalent continuous level) and a physiological model (AHAAH). Results from these DRC were converted into a number of maximum permissible unprotected exposures to facilitate interpretation. Acoustic characteristics of firearm impulses differed substantially across guns, ammunition, and microphone location. The type of gun, ammunition and the microphone location all significantly affected estimates of auditory risk from firearms. Vast differences in maximum permissible exposures were observed; the rank order of the differences varied with the source of the impulse. Unprotected exposure to firearm noise is not recommended, but people electing to fire a gun without hearing protection should be advised to minimize auditory risk through careful selection of ammunition and shooting environment. Small-caliber guns with long barrels and guns loaded with the least powerful ammunition tend to be associated with the least auditory risk. PMID:19805933

  19. Absolute Equilibrium Entropy

    NASA Technical Reports Server (NTRS)

    Shebalin, John V.

    1997-01-01

    The entropy associated with absolute equilibrium ensemble theories of ideal, homogeneous, fluid and magneto-fluid turbulence is discussed and the three-dimensional fluid case is examined in detail. A sigma-function is defined, whose minimum value with respect to global parameters is the entropy. A comparison is made between the use of global functions sigma and phase functions H (associated with the development of various H-theorems of ideal turbulence). It is shown that the two approaches are complimentary though conceptually different: H-theorems show that an isolated system tends to equilibrium while sigma-functions allow the demonstration that entropy never decreases when two previously isolated systems are combined. This provides a more complete picture of entropy in the statistical mechanics of ideal fluids.

  20. Estimating risks of heat strain by age and sex: a population-level simulation model.

    PubMed

    Glass, Kathryn; Tait, Peter W; Hanna, Elizabeth G; Dear, Keith

    2015-05-18

    Individuals living in hot climates face health risks from hyperthermia due to excessive heat. Heat strain is influenced by weather exposure and by individual characteristics such as age, sex, body size, and occupation. To explore the population-level drivers of heat strain, we developed a simulation model that scales up individual risks of heat storage (estimated using Myrup and Morgan's man model "MANMO") to a large population. Using Australian weather data, we identify high-risk weather conditions together with individual characteristics that increase the risk of heat stress under these conditions. The model identifies elevated risks in children and the elderly, with females aged 75 and older those most likely to experience heat strain. Risk of heat strain in males does not increase as rapidly with age, but is greatest on hot days with high solar radiation. Although cloudy days are less dangerous for the wider population, older women still have an elevated risk of heat strain on hot cloudy days or when indoors during high temperatures. Simulation models provide a valuable method for exploring population level risks of heat strain, and a tool for evaluating public health and other government policy interventions.

  1. Cancer risk estimation in Digital Breast Tomosynthesis using GEANT4 Monte Carlo simulations and voxel phantoms.

    PubMed

    Ferreira, P; Baptista, M; Di Maria, S; Vaz, P

    2016-05-01

    The aim of this work was to estimate the risk of radiation induced cancer following the Portuguese breast screening recommendations for Digital Mammography (DM) when applied to Digital Breast Tomosynthesis (DBT) and to evaluate how the risk to induce cancer could influence the energy used in breast diagnostic exams. The organ doses were calculated by Monte Carlo simulations using a female voxel phantom and considering the acquisition of 25 projection images. Single organ cancer incidence risks were calculated in order to assess the total effective radiation induced cancer risk. The screening strategy techniques considered were: DBT in Cranio-Caudal (CC) view and two-view DM (CC and Mediolateral Oblique (MLO)). The risk of cancer incidence following the Portuguese screening guidelines (screening every two years in the age range of 50-80years) was calculated by assuming a single CC DBT acquisition view as standalone screening strategy and compared with two-view DM. The difference in the total effective risk between DBT and DM is quite low. Nevertheless in DBT an increase of risk for the lung is observed with respect to DM. The lung is also the organ that is mainly affected when non-optimal beam energy (in terms of image quality and absorbed dose) is used instead of an optimal one. The use of non-optimal energies could increase the risk of lung cancer incidence by a factor of about 2. PMID:27133140

  2. Estimating Risks of Heat Strain by Age and Sex: A Population-Level Simulation Model

    PubMed Central

    Glass, Kathryn; Tait, Peter W.; Hanna, Elizabeth G.; Dear, Keith

    2015-01-01

    Individuals living in hot climates face health risks from hyperthermia due to excessive heat. Heat strain is influenced by weather exposure and by individual characteristics such as age, sex, body size, and occupation. To explore the population-level drivers of heat strain, we developed a simulation model that scales up individual risks of heat storage (estimated using Myrup and Morgan’s man model “MANMO”) to a large population. Using Australian weather data, we identify high-risk weather conditions together with individual characteristics that increase the risk of heat stress under these conditions. The model identifies elevated risks in children and the elderly, with females aged 75 and older those most likely to experience heat strain. Risk of heat strain in males does not increase as rapidly with age, but is greatest on hot days with high solar radiation. Although cloudy days are less dangerous for the wider population, older women still have an elevated risk of heat strain on hot cloudy days or when indoors during high temperatures. Simulation models provide a valuable method for exploring population level risks of heat strain, and a tool for evaluating public health and other government policy interventions. PMID:25993102

  3. Molecular iodine absolute frequencies. Final report

    SciTech Connect

    Sansonetti, C.J.

    1990-06-25

    Fifty specified lines of {sup 127}I{sub 2} were studied by Doppler-free frequency modulation spectroscopy. For each line the classification of the molecular transition was determined, hyperfine components were identified, and one well-resolved component was selected for precise determination of its absolute frequency. In 3 cases, a nearby alternate line was selected for measurement because no well-resolved component was found for the specified line. Absolute frequency determinations were made with an estimated uncertainty of 1.1 MHz by locking a dye laser to the selected hyperfine component and measuring its wave number with a high-precision Fabry-Perot wavemeter. For each line results of the absolute measurement, the line classification, and a Doppler-free spectrum are given.

  4. Vertebral Strength and Estimated Fracture Risk Across the BMI Spectrum in Women.

    PubMed

    Bachmann, Katherine N; Bruno, Alexander G; Bredella, Miriam A; Schorr, Melanie; Lawson, Elizabeth A; Gill, Corey M; Singhal, Vibha; Meenaghan, Erinne; Gerweck, Anu V; Eddy, Kamryn T; Ebrahimi, Seda; Koman, Stuart L; Greenblatt, James M; Keane, Robert J; Weigel, Thomas; Dechant, Esther; Misra, Madhusmita; Klibanski, Anne; Bouxsein, Mary L; Miller, Karen K

    2016-02-01

    Somewhat paradoxically, fracture risk, which depends on applied loads and bone strength, is elevated in both anorexia nervosa and obesity at certain skeletal sites. Factor-of-risk (Φ), the ratio of applied load to bone strength, is a biomechanically based method to estimate fracture risk; theoretically, higher Φ reflects increased fracture risk. We estimated vertebral strength (linear combination of integral volumetric bone mineral density [Int.vBMD] and cross-sectional area from quantitative computed tomography [QCT]), vertebral compressive loads, and Φ at L4 in 176 women (65 anorexia nervosa, 45 lean controls, and 66 obese). Using biomechanical models, applied loads were estimated for: 1) standing; 2) arms flexed 90°, holding 5 kg in each hand (holding); 3) 45° trunk flexion, 5 kg in each hand (lifting); 4) 20° trunk right lateral bend, 10 kg in right hand (bending). We also investigated associations of Int.vBMD and vertebral strength with lean mass (from dual-energy X-ray absorptiometry [DXA]) and visceral adipose tissue (VAT, from QCT). Women with anorexia nervosa had lower, whereas obese women had similar, Int.vBMD and estimated vertebral strength compared with controls. Vertebral loads were highest in obesity and lowest in anorexia nervosa for standing, holding, and lifting (p < 0.0001) but were highest in anorexia nervosa for bending (p < 0.02). Obese women had highest Φ for standing and lifting, whereas women with anorexia nervosa had highest Φ for bending (p < 0.0001). Obese and anorexia nervosa subjects had higher Φ for holding than controls (p < 0.03). Int.vBMD and estimated vertebral strength were associated positively with lean mass (R = 0.28 to 0.45, p ≤ 0.0001) in all groups combined and negatively with VAT (R = -[0.36 to 0.38], p < 0.003) within the obese group. Therefore, women with anorexia nervosa had higher estimated vertebral fracture risk (Φ) for holding and bending because of inferior vertebral strength. Despite similar

  5. Bayesian estimation of the relative toxicity of (239)Pu and (226)Ra with dependent competing risks

    NASA Astrophysics Data System (ADS)

    Xiao, Shili

    The purpose of this dissertation research is to compare the toxicity of the alpha-emitting, bone-seeking radionuclides sp{239}Pu and sp{226}Ra, develop a model for radiation induced osteosarcomas, and analyze the survival data of beagles exposed to these radionuclides. This research integrates the knowledge of radiation protection, survival theory and methods (competing risks, maximum likelihood estimation, and Bayesian techniques), numerical integration techniques (Monte Carlo, Lattice rule and Gauss-quadrature) and object-oriented programming in C++. The outline of this research is: (1) survival data preprocessing, (2) model identification and selection, (3) introduction of FGM model, the dependent competing risk model created by Farlie, Gumbel and Morgenstern, to the study of survival data with dependent competing risks: osteosarcomas and other diseases, development of the crude density of the FGM model and construction of the likelihood function for the FGM model, (4) Bayesian estimates of the posterior marginal density of the toxicity ratio in the FGM model using several numerical integration techniques (Monte Carlo, Lattice rule and Gaussian Quadrature), (5) construction of the likelihood function for the independent competing risk model, Bayesian estimate of the posterior marginal density of toxicity ratio in the model using Monte Carlo method, which is compared with the posterior marginal densities for the toxicity ratio obtained from the FGM model, (6) Bayesian estimates of all other parameters in the FGM model using Monte Carlo method, (7) Comparison of the cumulative hazard for sp{239}Pu calculated according to the model with Nelson's cumulative hazard plot under Bayesian point estimates of parameters and the mean activity in each injection level, (8) Comparison of the toxicity of plutonium in osteosarcoma with that of radium under Bayesian point estimates of parameters an d the selected activit of 0.85 muCsbi, (7) discuss Bayesian prediction of the

  6. Impact of provision of cardiovascular disease risk estimates to healthcare professionals and patients: a systematic review

    PubMed Central

    Usher-Smith, Juliet A; Silarova, Barbora; Schuit, Ewoud; GM Moons, Karel; Griffin, Simon J

    2015-01-01

    Objective To systematically review whether the provision of information on cardiovascular disease (CVD) risk to healthcare professionals and patients impacts their decision-making, behaviour and ultimately patient health. Design A systematic review. Data sources An electronic literature search of MEDLINE and PubMed from 01/01/2004 to 01/06/2013 with no language restriction and manual screening of reference lists of systematic reviews on similar topics and all included papers. Eligibility criteria for selecting studies (1) Primary research published in a peer-reviewed journal; (2) inclusion of participants with no history of CVD; (3) intervention strategy consisted of provision of a CVD risk model estimate to either professionals or patients; and (4) the only difference between the intervention group and control group (or the only intervention in the case of before-after studies) was the provision of a CVD risk model estimate. Results After duplicates were removed, the initial electronic search identified 9671 papers. We screened 196 papers at title and abstract level and included 17 studies. The heterogeneity of the studies limited the analysis, but together they showed that provision of risk information to patients improved the accuracy of risk perception without decreasing quality of life or increasing anxiety, but had little effect on lifestyle. Providing risk information to physicians increased prescribing of lipid-lowering and blood pressure medication, with greatest effects in those with CVD risk >20% (relative risk for change in prescribing 2.13 (1.02 to 4.63) and 2.38 (1.11 to 5.10) respectively). Overall, there was a trend towards reductions in cholesterol and blood pressure and a statistically significant reduction in modelled CVD risk (−0.39% (−0.71 to −0.07)) after, on average, 12 months. Conclusions There seems evidence that providing CVD risk model estimates to professionals and patients improves perceived CVD risk and medical prescribing

  7. Validation of model-based estimates (synthetic estimates) of the prevalence of risk factors for coronary heart disease for wards in England.

    PubMed

    Scarborough, Peter; Allender, Steven; Rayner, Mike; Goldacre, Michael

    2009-06-01

    Several sets of model-based estimates (synthetic estimates) of the prevalence of risk factors for coronary heart disease for small areas in England have been developed. These have been used in policy documents to indicate which areas are in need of intervention. In general, these models have not been subjected to validity assessment. This paper describes a validity assessment of 16 sets of synthetic estimates, by comparison of the models with national, regional and local survey-based estimates, and local mortality rate estimates. Model-based estimates of the prevalence of smoking, low fruit and vegetable consumption, obesity, hypertension and raised cholesterol are found to be valid.

  8. Health risk estimates for groundwater and soil contamination in the Slovak Republic: a convenient tool for identification and mapping of risk areas.

    PubMed

    Fajčíková, K; Cvečková, V; Stewart, A; Rapant, S

    2014-10-01

    We undertook a quantitative estimation of health risks to residents living in the Slovak Republic and exposed to contaminated groundwater (ingestion by adult population) and/or soils (ingestion by adult and child population). Potential risk areas were mapped to give a visual presentation at basic administrative units of the country (municipalities, districts, regions) for easy discussion with policy and decision-makers. The health risk estimates were calculated by US EPA methods, applying threshold values for chronic risk and non-threshold values for cancer risk. The potential health risk was evaluated for As, Ba, Cd, Cu, F, Hg, Mn, NO3 (-), Pb, Sb, Se and Zn for groundwater and As, B, Ba, Be, Cd, Cu, F, Hg, Mn, Mo, Ni, Pb, Sb, Se and Zn for soils. An increased health risk was identified mainly in historical mining areas highly contaminated by geogenic-anthropogenic sources (ore deposit occurrence, mining, metallurgy). Arsenic and antimony were the most significant elements in relation to health risks from groundwater and soil contamination in the Slovak Republic contributing a significant part of total chronic risk levels. Health risk estimation for soil contamination has highlighted the significance of exposure through soil ingestion in children. Increased cancer risks from groundwater and soil contamination by arsenic were noted in several municipalities and districts throughout the country in areas with significantly high arsenic levels in the environment. This approach to health risk estimations and visualization represents a fast, clear and convenient tool for delineation of risk areas at national and local levels.

  9. European risk assessment of LAS in agricultural soil revisited: species sensitivity distribution and risk estimates.

    PubMed

    Jensen, John; Smith, Stephen R; Krogh, Paul Henning; Versteeg, Donald J; Temara, Ali

    2007-10-01

    Linear alkylbenzene sulphonate (LAS) is used at a rate of approximately 430,000 tons/y in Western Europe, mainly in laundry detergents. It is present in sewage sludge (70-5,600 mg/kg; 5-95th percentile) because of its high usage per capita, its sorption and precipitation in primary settlers, and its lack of degradation in anaerobic digesters. Immediately after amendment, calculated and measured concentrations are <1 to 60 mg LAS/kg soil. LAS biodegrades rapidly in soil with primary and ultimate half-lives of up to 7 and 30 days, respectively. Calculated residual concentrations after the averaging time (30 days) are 0.24-18 mg LAS/kg soil. The long-term ecotoxicity to soil microbiota is relatively low (EC10 >or=26 mg sludge-associated LAS/kg soil). An extensive review of the invertebrate and plant ecotoxicological data, combined with a probabilistic assessment approach, led to a PNEC value of 35 mg LAS/kg soil, i.e. the 5th percentile (HC5) of the species sensitivity distribution (lognormal distribution of the EC10 and NOEC values). Risk ratios were identified to fall within a range of 0.01 (median LAS concentration in sludge) to 0.1 (95th percentile) and always below 0.5 (maximum LAS concentration measured in sludge) according to various scenarios covering different factors such as local sewage influent concentration, water hardness, and sewage sludge stabilisation process. Based on the present information, it can be concluded that LAS does not represent an ecological risk in Western Europe when applied via normal sludge amendment to agricultural soil. PMID:17765285

  10. Radiobiologic risk estimation from dental radiology. Part II. Cancer incidence and fatality

    SciTech Connect

    Underhill, T.E.; Kimura, K.; Chilvarquer, I.; McDavid, W.D.; Langlais, R.P.; Preece, J.W.; Barnwell, G.

    1988-08-01

    With the use of the measured absorbed doses from part I of this article, the specific radiobiologic risk to the patient from (1) five different panoramic machines with rare-earth screens, (2) a 20-film complete-mouth survey with E-speed film, long round cone, (3) a 20-film complete-mouth survey with E-speed film, long rectangular cone, (4) a 4-film interproximal survey with E-speed film, long round cone, and (5) a 4-film interproximal survey with E-speed film, long rectangular cone, was calculated. The estimated risks are expressed in two ways: the probability of radiation-induced cancer in specific organs per million examinations and the probability of expression of a fatal cancer per million examinations. The highest risks calculated were from the complete-mouth survey with the use of round collimation. The lowest risks calculated were from panoramic radiography and four interproximal radiographs with rectangular collimation.

  11. Radiobiologic risk estimation from dental radiology. Part II. Cancer incidence and fatality.

    PubMed

    Underhill, T E; Kimura, K; Chilvarquer, I; McDavid, W D; Langlais, R P; Preece, J W; Barnwell, G

    1988-08-01

    With the use of the measured absorbed doses from part I of this article, the specific radiobiologic risk to the patient from (1) five different panoramic machines with rare-earth screens, (2) a 20-film complete-mouth survey with E-speed film, long round cone, (3) a 20-film complete-mouth survey with E-speed film, long rectangular cone, (4) a 4-film interproximal survey with E-speed film, long round cone, and (5) a 4-film interproximal survey with E-speed film, long rectangular cone, was calculated. The estimated risks are expressed in two ways: the probability of radiation-induced cancer in specific organs per million examinations and the probability of expression of a fatal cancer per million examinations. The highest risks calculated were from the complete-mouth survey with the use of round collimation. The lowest risks calculated were from panoramic radiography and four interproximal radiographs with rectangular collimation.

  12. A Methodological Approach to Small Area Estimation for the Behavioral Risk Factor Surveillance System.

    PubMed

    Pierannunzi, Carol; Xu, Fang; Wallace, Robyn C; Garvin, William; Greenlund, Kurt J; Bartoli, William; Ford, Derek; Eke, Paul; Town, G Machell

    2016-07-14

    Public health researchers have used a class of statistical methods to calculate prevalence estimates for small geographic areas with few direct observations. Many researchers have used Behavioral Risk Factor Surveillance System (BRFSS) data as a basis for their models. The aims of this study were to 1) describe a new BRFSS small area estimation (SAE) method and 2) investigate the internal and external validity of the BRFSS SAEs it produced. The BRFSS SAE method uses 4 data sets (the BRFSS, the American Community Survey Public Use Microdata Sample, Nielsen Claritas population totals, and the Missouri Census Geographic Equivalency File) to build a single weighted data set. Our findings indicate that internal and external validity tests were successful across many estimates. The BRFSS SAE method is one of several methods that can be used to produce reliable prevalence estimates in small geographic areas.

  13. A Methodological Approach to Small Area Estimation for the Behavioral Risk Factor Surveillance System

    PubMed Central

    Xu, Fang; Wallace, Robyn C.; Garvin, William; Greenlund, Kurt J.; Bartoli, William; Ford, Derek; Eke, Paul; Town, G. Machell

    2016-01-01

    Public health researchers have used a class of statistical methods to calculate prevalence estimates for small geographic areas with few direct observations. Many researchers have used Behavioral Risk Factor Surveillance System (BRFSS) data as a basis for their models. The aims of this study were to 1) describe a new BRFSS small area estimation (SAE) method and 2) investigate the internal and external validity of the BRFSS SAEs it produced. The BRFSS SAE method uses 4 data sets (the BRFSS, the American Community Survey Public Use Microdata Sample, Nielsen Claritas population totals, and the Missouri Census Geographic Equivalency File) to build a single weighted data set. Our findings indicate that internal and external validity tests were successful across many estimates. The BRFSS SAE method is one of several methods that can be used to produce reliable prevalence estimates in small geographic areas. PMID:27418213

  14. Underestimating the Alcohol Content of a Glass of Wine: The Implications for Estimates of Mortality Risk

    PubMed Central

    Britton, Annie; O’Neill, Darragh; Bell, Steven

    2016-01-01

    Aims Increases in glass sizes and wine strength over the last 25 years in the UK are likely to have led to an underestimation of alcohol intake in population studies. We explore whether this probable misclassification affects the association between average alcohol intake and risk of mortality from all causes, cardiovascular disease and cancer. Methods Self-reported alcohol consumption in 1997–1999 among 7010 men and women in the Whitehall II cohort of British civil servants was linked to the risk of mortality until mid-2015. A conversion factor of 8 g of alcohol per wine glass (1 unit) was compared with a conversion of 16 g per wine glass (2 units). Results When applying a higher alcohol content conversion for wine consumption, the proportion of heavy/very heavy drinkers increased from 28% to 41% for men and 15% to 28% for women. There was a significantly increased risk of very heavy drinking compared with moderate drinking for deaths from all causes and cancer before and after change in wine conversion; however, the hazard ratios were reduced when a higher wine conversion was used. Conclusions In this population-based study, assuming higher alcohol content in wine glasses changed the estimates of mortality risk. We propose that investigator-led cohorts need to revisit conversion factors based on more accurate estimates of alcohol content in wine glasses. Prospectively, researchers need to collect more detailed information on alcohol including serving sizes and strength. Short summary The alcohol content in a wine glass is likely to be underestimated in population surveys as wine strength and serving size have increased in recent years. We demonstrate that in a large cohort study, this underestimation affects estimates of mortality risk. Investigator-led cohorts need to revisit conversion factors based on more accurate estimates of alcohol content in wine glasses. PMID:27261472

  15. Risk estimates for deterministic health effects of inhaled weapons grade plutonium.

    PubMed

    Scott, Bobby R; Peterson, Vern L

    2003-09-01

    Risk estimates for deterministic effects of inhaled weapons-grade plutonium (WG Pu) are needed to evaluate potential serious harm to (1) U.S. Department of Energy nuclear workers from accidental or other work-place releases of WG Pu; and (2) the public from terrorist actions resulting in the release of WG Pu to the environment. Deterministic health effects (the most serious radiobiological consequences to humans) can arise when large amounts of WG Pu are taken into the body. Inhalation is considered the most likely route of intake during work-place accidents or during a nuclear terrorism incident releasing WG Pu to the environment. Our current knowledge about radiation-related harm is insufficient for generating precise estimates of risk for a given WG Pu exposure scenario. This relates largely to uncertainties associated with currently available risk and dosimetry models. Thus, rather than generating point estimates of risk, distributions that account for variability/uncertainty are needed to properly characterize potential harm to humans from a given WG Pu exposure scenario. In this manuscript, we generate and summarize risk distributions for deterministic radiation effects in the lungs of nuclear workers from inhaled WG Pu particles (standard isotopic mix). These distributions were developed using NUREG/CR-4214 risk models and time-dependent, dose conversion factor data based on Publication 30 of the International Commission on Radiological Protection. Dose conversion factors based on ICRP Publication 30 are more relevant to deterministic effects than are the dose conversion factors based on ICRP Publication 66, which relate to targets for stochastic effects. Risk distributions that account for NUREG/CR-4214 parameter and model uncertainties were generated using the Monte Carlo method. Risks were evaluated for both lethality (from radiation pneumonitis) and morbidity (due to radiation-induced respiratory dysfunction) and were found to depend strongly on absorbed

  16. Estimating Risk of Natural Gas Portfolios by Using GARCH-EVT-Copula Model.

    PubMed

    Tang, Jiechen; Zhou, Chao; Yuan, Xinyu; Sriboonchitta, Songsak

    2015-01-01

    This paper concentrates on estimating the risk of Title Transfer Facility (TTF) Hub natural gas portfolios by using the GARCH-EVT-copula model. We first use the univariate ARMA-GARCH model to model each natural gas return series. Second, the extreme value distribution (EVT) is fitted to the tails of the residuals to model marginal residual distributions. Third, multivariate Gaussian copula and Student t-copula are employed to describe the natural gas portfolio risk dependence structure. Finally, we simulate N portfolios and estimate value at risk (VaR) and conditional value at risk (CVaR). Our empirical results show that, for an equally weighted portfolio of five natural gases, the VaR and CVaR values obtained from the Student t-copula are larger than those obtained from the Gaussian copula. Moreover, when minimizing the portfolio risk, the optimal natural gas portfolio weights are found to be similar across the multivariate Gaussian copula and Student t-copula and different confidence levels. PMID:26351652

  17. Estimating Risk of Natural Gas Portfolios by Using GARCH-EVT-Copula Model

    PubMed Central

    Tang, Jiechen; Zhou, Chao; Yuan, Xinyu; Sriboonchitta, Songsak

    2015-01-01

    This paper concentrates on estimating the risk of Title Transfer Facility (TTF) Hub natural gas portfolios by using the GARCH-EVT-copula model. We first use the univariate ARMA-GARCH model to model each natural gas return series. Second, the extreme value distribution (EVT) is fitted to the tails of the residuals to model marginal residual distributions. Third, multivariate Gaussian copula and Student t-copula are employed to describe the natural gas portfolio risk dependence structure. Finally, we simulate N portfolios and estimate value at risk (VaR) and conditional value at risk (CVaR). Our empirical results show that, for an equally weighted portfolio of five natural gases, the VaR and CVaR values obtained from the Student t-copula are larger than those obtained from the Gaussian copula. Moreover, when minimizing the portfolio risk, the optimal natural gas portfolio weights are found to be similar across the multivariate Gaussian copula and Student t-copula and different confidence levels. PMID:26351652

  18. Estimating Risk of Natural Gas Portfolios by Using GARCH-EVT-Copula Model.

    PubMed

    Tang, Jiechen; Zhou, Chao; Yuan, Xinyu; Sriboonchitta, Songsak

    2015-01-01

    This paper concentrates on estimating the risk of Title Transfer Facility (TTF) Hub natural gas portfolios by using the GARCH-EVT-copula model. We first use the univariate ARMA-GARCH model to model each natural gas return series. Second, the extreme value distribution (EVT) is fitted to the tails of the residuals to model marginal residual distributions. Third, multivariate Gaussian copula and Student t-copula are employed to describe the natural gas portfolio risk dependence structure. Finally, we simulate N portfolios and estimate value at risk (VaR) and conditional value at risk (CVaR). Our empirical results show that, for an equally weighted portfolio of five natural gases, the VaR and CVaR values obtained from the Student t-copula are larger than those obtained from the Gaussian copula. Moreover, when minimizing the portfolio risk, the optimal natural gas portfolio weights are found to be similar across the multivariate Gaussian copula and Student t-copula and different confidence levels.

  19. Absolute neutrino mass measurements

    SciTech Connect

    Wolf, Joachim

    2011-10-06

    The neutrino mass plays an important role in particle physics, astrophysics and cosmology. In recent years the detection of neutrino flavour oscillations proved that neutrinos carry mass. However, oscillation experiments are only sensitive to the mass-squared difference of the mass eigenvalues. In contrast to cosmological observations and neutrino-less double beta decay (0v2{beta}) searches, single {beta}-decay experiments provide a direct, model-independent way to determine the absolute neutrino mass by measuring the energy spectrum of decay electrons at the endpoint region with high accuracy.Currently the best kinematic upper limits on the neutrino mass of 2.2eV have been set by two experiments in Mainz and Troitsk, using tritium as beta emitter. The next generation tritium {beta}-experiment KATRIN is currently under construction in Karlsruhe/Germany by an international collaboration. KATRIN intends to improve the sensitivity by one order of magnitude to 0.2eV. The investigation of a second isotope ({sup 137}Rh) is being pursued by the international MARE collaboration using micro-calorimeters to measure the beta spectrum. The technology needed to reach 0.2eV sensitivity is still in the R and D phase. This paper reviews the present status of neutrino-mass measurements with cosmological data, 0v2{beta} decay and single {beta}-decay.

  20. 49 CFR Appendix G to Part 222 - Excess Risk Estimates for Public Highway-Rail Grade Crossings

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Grade Crossings G Appendix G to Part 222 Transportation Other Regulations Relating to Transportation... HIGHWAY-RAIL GRADE CROSSINGS Pt. 222, App. G Appendix G to Part 222—Excess Risk Estimates for Public Highway-Rail Grade Crossings Ban Effects/Train Horn Effectiveness Warning type Excess risk estimate...

  1. 49 CFR Appendix G to Part 222 - Excess Risk Estimates for Public Highway-Rail Grade Crossings

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Grade Crossings G Appendix G to Part 222 Transportation Other Regulations Relating to Transportation... HIGHWAY-RAIL GRADE CROSSINGS Pt. 222, App. G Appendix G to Part 222—Excess Risk Estimates for Public Highway-Rail Grade Crossings Ban Effects/Train Horn Effectiveness Warning type Excess risk estimate...

  2. 49 CFR Appendix G to Part 222 - Excess Risk Estimates for Public Highway-Rail Grade Crossings

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Grade Crossings G Appendix G to Part 222 Transportation Other Regulations Relating to Transportation... HIGHWAY-RAIL GRADE CROSSINGS Pt. 222, App. G Appendix G to Part 222—Excess Risk Estimates for Public Highway-Rail Grade Crossings Ban Effects/Train Horn Effectiveness Warning type Excess risk estimate...

  3. 49 CFR Appendix G to Part 222 - Excess Risk Estimates for Public Highway-Rail Grade Crossings

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Excess Risk Estimates for Public Highway-Rail Grade Crossings G Appendix G to Part 222 Transportation Other Regulations Relating to Transportation... HIGHWAY-RAIL GRADE CROSSINGS Pt. 222, App. G Appendix G to Part 222—Excess Risk Estimates for...

  4. Estimating the risks of cancer mortality and genetic defects resulting from exposures to low levels of ionizing radiation

    SciTech Connect

    Buhl, T.E.; Hansen, W.R.

    1984-05-01

    Estimators for calculating the risk of cancer and genetic disorders induced by exposure to ionizing radiation have been recommended by the US National Academy of Sciences Committee on the Biological Effects of Ionizing Radiations, the UN Scientific Committee on the Effects of Atomic Radiation, and the International Committee on Radiological Protection. These groups have also considered the risks of somatic effects other than cancer. The US National Council on Radiation Protection and Measurements has discussed risk estimate procedures for radiation-induced health effects. The recommendations of these national and international advisory committees are summarized and compared in this report. Based on this review, two procedures for risk estimation are presented for use in radiological assessments performed by the US Department of Energy under the National Environmental Policy Act of 1969 (NEPA). In the first procedure, age- and sex-averaged risk estimators calculated with US average demographic statistics would be used with estimates of radiation dose to calculate the projected risk of cancer and genetic disorders that would result from the operation being reviewed under NEPA. If more site-specific risk estimators are needed, and the demographic information is available, a second procedure is described that would involve direct calculation of the risk estimators using recommended risk-rate factors. The computer program REPCAL has been written to perform this calculation and is described in this report. 25 references, 16 tables.

  5. Predicting 10-Year Risk of Fatal Cardiovascular Disease in Germany: An Update Based on the SCORE-Deutschland Risk Charts

    PubMed Central

    Rücker, Viktoria; Keil, Ulrich; Fitzgerald, Anthony P; Malzahn, Uwe; Prugger, Christof; Ertl, Georg; Heuschmann, Peter U; Neuhauser, Hannelore

    2016-01-01

    Estimation of absolute risk of cardiovascular disease (CVD), preferably with population-specific risk charts, has become a cornerstone of CVD primary prevention. Regular recalibration of risk charts may be necessary due to decreasing CVD rates and CVD risk factor levels. The SCORE risk charts for fatal CVD risk assessment were first calibrated for Germany with 1998 risk factor level data and 1999 mortality statistics. We present an update of these risk charts based on the SCORE methodology including estimates of relative risks from SCORE, risk factor levels from the German Health Interview and Examination Survey for Adults 2008–11 (DEGS1) and official mortality statistics from 2012. Competing risks methods were applied and estimates were independently validated. Updated risk charts were calculated based on cholesterol, smoking, systolic blood pressure risk factor levels, sex and 5-year age-groups. The absolute 10-year risk estimates of fatal CVD were lower according to the updated risk charts compared to the first calibration for Germany. In a nationwide sample of 3062 adults aged 40–65 years free of major CVD from DEGS1, the mean 10-year risk of fatal CVD estimated by the updated charts was lower by 29% and the estimated proportion of high risk people (10-year risk > = 5%) by 50% compared to the older risk charts. This recalibration shows a need for regular updates of risk charts according to changes in mortality and risk factor levels in order to sustain the identification of people with a high CVD risk. PMID:27612145

  6. Predicting 10-Year Risk of Fatal Cardiovascular Disease in Germany: An Update Based on the SCORE-Deutschland Risk Charts.

    PubMed

    Rücker, Viktoria; Keil, Ulrich; Fitzgerald, Anthony P; Malzahn, Uwe; Prugger, Christof; Ertl, Georg; Heuschmann, Peter U; Neuhauser, Hannelore

    2016-01-01

    Estimation of absolute risk of cardiovascular disease (CVD), preferably with population-specific risk charts, has become a cornerstone of CVD primary prevention. Regular recalibration of risk charts may be necessary due to decreasing CVD rates and CVD risk factor levels. The SCORE risk charts for fatal CVD risk assessment were first calibrated for Germany with 1998 risk factor level data and 1999 mortality statistics. We present an update of these risk charts based on the SCORE methodology including estimates of relative risks from SCORE, risk factor levels from the German Health Interview and Examination Survey for Adults 2008-11 (DEGS1) and official mortality statistics from 2012. Competing risks methods were applied and estimates were independently validated. Updated risk charts were calculated based on cholesterol, smoking, systolic blood pressure risk factor levels, sex and 5-year age-groups. The absolute 10-year risk estimates of fatal CVD were lower according to the updated risk charts compared to the first calibration for Germany. In a nationwide sample of 3062 adults aged 40-65 years free of major CVD from DEGS1, the mean 10-year risk of fatal CVD estimated by the updated charts was lower by 29% and the estimated proportion of high risk people (10-year risk > = 5%) by 50% compared to the older risk charts. This recalibration shows a need for regular updates of risk charts according to changes in mortality and risk factor levels in order to sustain the identification of people with a high CVD risk. PMID:27612145

  7. [Estimation of the risk of Alzheimer type dementia based on "Prognostic Questionnaire"].

    PubMed

    Bidzan, Leszek; Bidzan, Mariola

    2002-01-01

    The aim of undertaken studies was verification of usefulness of "Prognostic Questionnaire" for estimations of risk of Alzheimer type dementia. In support for own base were included 286 persons, which were investigated by scales creating of "Prognostic Questionnaire" in years 1991-1993. From among 286 persons originally classified to renewed study one surrendered 163 persons. Result in investigation MMSE equal or lower from 25 points was base to removal full psychiatric investigations which had in view recognition of Alzheimer type dementia or its exclusion. Possible Alzheimer disease were recognized at 23 persons. Sensitivity and specificity for "Prognostic Questionnaire" obtained for several critical values were marked. The study showed usefulness of joint interpretation of results of several clinical scales creating "Prognostic Questionnaire" for estimations of risk of Alzheimer type dementia. PMID:12647439

  8. Quantitative Cyber Risk Reduction Estimation Methodology for a Small Scada Control System

    SciTech Connect

    Miles A. McQueen; Wayne F. Boyer; Mark A. Flynn; George A. Beitel

    2006-01-01

    We propose a new methodology for obtaining a quick quantitative measurement of the risk reduction achieved when a control system is modified with the intent to improve cyber security defense against external attackers. The proposed methodology employs a directed graph called a compromise graph, where the nodes represent stages of a potential attack and the edges represent the expected time-to-compromise for differing attacker skill levels. Time-to-compromise is modeled as a function of known vulnerabilities and attacker skill level. The methodology was used to calculate risk reduction estimates for a specific SCADA system and for a specific set of control system security remedial actions. Despite an 86% reduction in the total number of vulnerabilities, the estimated time-to-compromise was increased only by about 3 to 30% depending on target and attacker skill level.

  9. Uncertainties in estimating health risks associated with exposure to ionising radiation.

    PubMed

    Preston, R Julian; Boice, John D; Brill, A Bertrand; Chakraborty, Ranajit; Conolly, Rory; Hoffman, F Owen; Hornung, Richard W; Kocher, David C; Land, Charles E; Shore, Roy E; Woloschak, Gayle E

    2013-09-01

    The information for the present discussion on the uncertainties associated with estimation of radiation risks and probability of disease causation was assembled for the recently published NCRP Report No. 171 on this topic. This memorandum provides a timely overview of the topic, given that quantitative uncertainty analysis is the state of the art in health risk assessment and given its potential importance to developments in radiation protection. Over the past decade the increasing volume of epidemiology data and the supporting radiobiology findings have aided in the reduction of uncertainty in the risk estimates derived. However, it is equally apparent that there remain significant uncertainties related to dose assessment, low dose and low dose-rate extrapolation approaches (e.g. the selection of an appropriate dose and dose-rate effectiveness factor), the biological effectiveness where considerations of the health effects of high-LET and lower-energy low-LET radiations are required and the transfer of risks from a population for which health effects data are available to one for which such data are not available. The impact of radiation on human health has focused in recent years on cancer, although there has been a decided increase in the data for noncancer effects together with more reliable estimates of the risk following radiation exposure, even at relatively low doses (notably for cataracts and cardiovascular disease). New approaches for the estimation of hereditary risk have been developed with the use of human data whenever feasible, although the current estimates of heritable radiation effects still are based on mouse data because of an absence of effects in human studies. Uncertainties associated with estimation of these different types of health effects are discussed in a qualitative and semi-quantitative manner as appropriate. The way forward would seem to require additional epidemiological studies, especially studies of low dose and low dose

  10. Uncertainties in estimating health risks associated with exposure to ionising radiation.

    PubMed

    Preston, R Julian; Boice, John D; Brill, A Bertrand; Chakraborty, Ranajit; Conolly, Rory; Hoffman, F Owen; Hornung, Richard W; Kocher, David C; Land, Charles E; Shore, Roy E; Woloschak, Gayle E

    2013-09-01

    The information for the present discussion on the uncertainties associated with estimation of radiation risks and probability of disease causation was assembled for the recently published NCRP Report No. 171 on this topic. This memorandum provides a timely overview of the topic, given that quantitative uncertainty analysis is the state of the art in health risk assessment and given its potential importance to developments in radiation protection. Over the past decade the increasing volume of epidemiology data and the supporting radiobiology findings have aided in the reduction of uncertainty in the risk estimates derived. However, it is equally apparent that there remain significant uncertainties related to dose assessment, low dose and low dose-rate extrapolation approaches (e.g. the selection of an appropriate dose and dose-rate effectiveness factor), the biological effectiveness where considerations of the health effects of high-LET and lower-energy low-LET radiations are required and the transfer of risks from a population for which health effects data are available to one for which such data are not available. The impact of radiation on human health has focused in recent years on cancer, although there has been a decided increase in the data for noncancer effects together with more reliable estimates of the risk following radiation exposure, even at relatively low doses (notably for cataracts and cardiovascular disease). New approaches for the estimation of hereditary risk have been developed with the use of human data whenever feasible, although the current estimates of heritable radiation effects still are based on mouse data because of an absence of effects in human studies. Uncertainties associated with estimation of these different types of health effects are discussed in a qualitative and semi-quantitative manner as appropriate. The way forward would seem to require additional epidemiological studies, especially studies of low dose and low dose

  11. Estimating risks of importation and local transmission of Zika virus infection

    PubMed Central

    Nah, Kyeongah; Mizumoto, Kenji; Miyamatsu, Yuichiro; Yasuda, Yohei; Kinoshita, Ryo

    2016-01-01

    Background. An international spread of Zika virus (ZIKV) infection has attracted global attention. ZIKV is conveyed by a mosquito vector, Aedes species, which also acts as the vector species of dengue and chikungunya viruses. Methods. Arrival time of ZIKV importation (i.e., the time at which the first imported case was diagnosed) in each imported country was collected from publicly available data sources. Employing a survival analysis model in which the hazard is an inverse function of the effective distance as informed by the airline transportation network data, and using dengue and chikungunya virus transmission data, risks of importation and local transmission were estimated. Results. A total of 78 countries with imported case(s) have been identified, with the arrival time ranging from 1 to 44 weeks since the first ZIKV was identified in Brazil, 2015. Whereas the risk of importation was well explained by the airline transportation network data, the risk of local transmission appeared to be best captured by additionally accounting for the presence of dengue and chikungunya viruses. Discussion. The risk of importation may be high given continued global travel of mildly infected travelers but, considering that the public health concerns over ZIKV infection stems from microcephaly, it is more important to focus on the risk of local and widespread transmission that could involve pregnant women. The predicted risk of local transmission was frequently seen in tropical and subtropical countries with dengue or chikungunya epidemic experience. PMID:27069825

  12. Estimating risks of importation and local transmission of Zika virus infection.

    PubMed

    Nah, Kyeongah; Mizumoto, Kenji; Miyamatsu, Yuichiro; Yasuda, Yohei; Kinoshita, Ryo; Nishiura, Hiroshi

    2016-01-01

    Background. An international spread of Zika virus (ZIKV) infection has attracted global attention. ZIKV is conveyed by a mosquito vector, Aedes species, which also acts as the vector species of dengue and chikungunya viruses. Methods. Arrival time of ZIKV importation (i.e., the time at which the first imported case was diagnosed) in each imported country was collected from publicly available data sources. Employing a survival analysis model in which the hazard is an inverse function of the effective distance as informed by the airline transportation network data, and using dengue and chikungunya virus transmission data, risks of importation and local transmission were estimated. Results. A total of 78 countries with imported case(s) have been identified, with the arrival time ranging from 1 to 44 weeks since the first ZIKV was identified in Brazil, 2015. Whereas the risk of importation was well explained by the airline transportation network data, the risk of local transmission appeared to be best captured by additionally accounting for the presence of dengue and chikungunya viruses. Discussion. The risk of importation may be high given continued global travel of mildly infected travelers but, considering that the public health concerns over ZIKV infection stems from microcephaly, it is more important to focus on the risk of local and widespread transmission that could involve pregnant women. The predicted risk of local transmission was frequently seen in tropical and subtropical countries with dengue or chikungunya epidemic experience.

  13. Estimating risks of importation and local transmission of Zika virus infection.

    PubMed

    Nah, Kyeongah; Mizumoto, Kenji; Miyamatsu, Yuichiro; Yasuda, Yohei; Kinoshita, Ryo; Nishiura, Hiroshi

    2016-01-01

    Background. An international spread of Zika virus (ZIKV) infection has attracted global attention. ZIKV is conveyed by a mosquito vector, Aedes species, which also acts as the vector species of dengue and chikungunya viruses. Methods. Arrival time of ZIKV importation (i.e., the time at which the first imported case was diagnosed) in each imported country was collected from publicly available data sources. Employing a survival analysis model in which the hazard is an inverse function of the effective distance as informed by the airline transportation network data, and using dengue and chikungunya virus transmission data, risks of importation and local transmission were estimated. Results. A total of 78 countries with imported case(s) have been identified, with the arrival time ranging from 1 to 44 weeks since the first ZIKV was identified in Brazil, 2015. Whereas the risk of importation was well explained by the airline transportation network data, the risk of local transmission appeared to be best captured by additionally accounting for the presence of dengue and chikungunya viruses. Discussion. The risk of importation may be high given continued global travel of mildly infected travelers but, considering that the public health concerns over ZIKV infection stems from microcephaly, it is more important to focus on the risk of local and widespread transmission that could involve pregnant women. The predicted risk of local transmission was frequently seen in tropical and subtropical countries with dengue or chikungunya epidemic experience. PMID:27069825

  14. Improved Strategies and Optimization of Calibration Models for Real-time PCR Absolute Quantification

    EPA Science Inventory

    Real-time PCR absolute quantification applications rely on the use of standard curves to make estimates of DNA target concentrations in unknown samples. Traditional absolute quantification approaches dictate that a standard curve must accompany each experimental run. However, t...

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

    SciTech Connect

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

    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 the

  16. The economic value of reducing environmental health risks: Contingent valuation estimates of the value of information

    SciTech Connect

    Krieger, D.J.; Hoehn, J.P.

    1999-05-01

    Obtaining economically consistent values for changes in low probability health risks continues to be a challenge for contingent valuation (CV) as well as for other valuation methods. One of the cited condition for economic consistency is that estimated values be sensitive to the scope (differences in quantity or quality) of a good described in a CV application. The alleged limitations of CV pose a particular problem for environmental managers who must often make decisions that affect human health risks. This paper demonstrates that a well-designed CV application can elicit scope sensitive values even for programs that provide conceptually complex goods such as risk reduction. Specifically, it finds that the amount sport anglers are willing to pay for information about chemical residues in fish varies systematically with informativeness--a relationship suggested by the theory of information value.

  17. Recent estimates of cancer risk from low-let ionizing radiation and radiation protection limits

    NASA Astrophysics Data System (ADS)

    Sinclair, Warren K.

    1992-07-01

    Estimates of the risk of cancer induction, formerly about 1%/Sv, formed the basis of ICRP radiation protection limits in 1977. They have now increased to about 4-5%/Sv for low doses. These increases are based mainly on new data for the Japanese survivors of the A-bombs of 1945. They result from the accumulation of 11 years more of data on solid tumors, the revisions in the dosimetry of those exposed and improvement in statistical methods and projections. The application of a dose rate effectiveness factor between effects at high dose rate and those at low dose and dose rate is also an important consideration. Not only has the total risk changed but also the distribution of risk among organs. Thus the effective dose equivalent may require modification. These changes are modifying ICRP and NCRP thinking about recommendations on protection limits, especially for radiation workers.

  18. Forest fire risk estimation from time series analisys of NOAA NDVI data

    NASA Astrophysics Data System (ADS)

    Gabban, Andrea; Liberta, Giorgio; San-Miguel-Ayanz, Jesus; Barbosa, Paulo

    2004-02-01

    The values of the Normalized Difference Vegetation Index obtained from NOAA Advanced Very High Resolution Radiometer (AVHRR) have often been used for forestry application, including the assessment of fire risk. Forest fire risk estimates were based mainly on the decrease of NDVI values during the summer in areas subject to summer drought. However, the inter-annual variability of the vegetation response has never been extensively taken into account. The present work was based on the assumption that Mediterranean vegetation is adapted to summer drought and one possible estimator of the vegetation stress was the inter-annual variability of the vegetation status, as reflected by NDVI values. This article presents a novel methodology for the assessment of fire risk based on the comparison of the current NDVI values, on a given area, with the historical values along a time series of 13 years. The first part of the study is focused on the characterization of the Minimum and Maximum long term daily images. The second part is centered on the best method to compare the long term Maximum and Minimum with the current NDVI. A statistical index, Dynamic Relative Greenness, DRG, was tested on as a novel potential fire risk indicator.

  19. Estimates of Radiation Doses and Cancer Risk from Food Intake in Korea.

    PubMed

    Moon, Eun-Kyeong; Ha, Wi-Ho; Seo, Songwon; Jin, Young Woo; Jeong, Kyu Hwan; Yoon, Hae-Jung; Kim, Hyoung-Soo; Hwang, Myung-Sil; Choi, Hoon; Lee, Won Jin

    2016-01-01

    The aim of this study was to estimate internal radiation doses and lifetime cancer risk from food ingestion. Radiation doses from food intake were calculated using the Korea National Health and Nutrition Examination Survey and the measured radioactivity of (134)Cs, (137)Cs, and (131)I from the Ministry of Food and Drug Safety in Korea. Total number of measured data was 8,496 (3,643 for agricultural products, 644 for livestock products, 43 for milk products, 3,193 for marine products, and 973 for processed food). Cancer risk was calculated by multiplying the estimated committed effective dose and the detriment adjusted nominal risk coefficients recommended by the International Commission on Radiation Protection. The lifetime committed effective doses from the daily diet are ranged 2.957-3.710 mSv. Excess lifetime cancer risks are 14.4-18.1, 0.4-0.5, and 1.8-2.3 per 100,000 for all solid cancers combined, thyroid cancer, and leukemia, respectively.

  20. Genetic risk and longitudinal disease activity in systemic lupus erythematosus using targeted maximum likelihood estimation.

    PubMed

    Gianfrancesco, M A; Balzer, L; Taylor, K E; Trupin, L; Nititham, J; Seldin, M F; Singer, A W; Criswell, L A; Barcellos, L F

    2016-09-01

    Systemic lupus erythematous (SLE) is a chronic autoimmune disease associated with genetic and environmental risk factors. However, the extent to which genetic risk is causally associated with disease activity is unknown. We utilized longitudinal-targeted maximum likelihood estimation to estimate the causal association between a genetic risk score (GRS) comprising 41 established SLE variants and clinically important disease activity as measured by the validated Systemic Lupus Activity Questionnaire (SLAQ) in a multiethnic cohort of 942 individuals with SLE. We did not find evidence of a clinically important SLAQ score difference (>4.0) for individuals with a high GRS compared with those with a low GRS across nine time points after controlling for sex, ancestry, renal status, dialysis, disease duration, treatment, depression, smoking and education, as well as time-dependent confounding of missing visits. Individual single-nucleotide polymorphism (SNP) analyses revealed that 12 of the 41 variants were significantly associated with clinically relevant changes in SLAQ scores across time points eight and nine after controlling for multiple testing. Results based on sophisticated causal modeling of longitudinal data in a large patient cohort suggest that individual SLE risk variants may influence disease activity over time. Our findings also emphasize a role for other biological or environmental factors. PMID:27467283

  1. Estimates of Radiation Doses and Cancer Risk from Food Intake in Korea

    PubMed Central

    2016-01-01

    The aim of this study was to estimate internal radiation doses and lifetime cancer risk from food ingestion. Radiation doses from food intake were calculated using the Korea National Health and Nutrition Examination Survey and the measured radioactivity of 134Cs, 137Cs, and 131I from the Ministry of Food and Drug Safety in Korea. Total number of measured data was 8,496 (3,643 for agricultural products, 644 for livestock products, 43 for milk products, 3,193 for marine products, and 973 for processed food). Cancer risk was calculated by multiplying the estimated committed effective dose and the detriment adjusted nominal risk coefficients recommended by the International Commission on Radiation Protection. The lifetime committed effective doses from the daily diet are ranged 2.957-3.710 mSv. Excess lifetime cancer risks are 14.4-18.1, 0.4-0.5, and 1.8-2.3 per 100,000 for all solid cancers combined, thyroid cancer, and leukemia, respectively. PMID:26770031

  2. Injury Risk Estimation Expertise: Cognitive-Perceptual Mechanisms of ACL-IQ.

    PubMed

    Petushek, Erich J; Cokely, Edward T; Ward, Paul; Myer, Gregory D

    2015-06-01

    Instrument-based biomechanical movement analysis is an effective injury screening method but relies on expensive equipment and time-consuming analysis. Screening methods that rely on visual inspection and perceptual skill for prognosticating injury risk provide an alternative approach that can significantly reduce cost and time. However, substantial individual differences exist in skill when estimating injury risk performance via observation. The underlying perceptual-cognitive mechanisms of injury risk identification were explored to better understand the nature of this skill and provide a foundation for improving performance. Quantitative structural and process modeling of risk estimation indicated that superior performance was largely mediated by specific strategies and skills (e.g., irrelevant information reduction), and independent of domain-general cognitive abilities (e.g., mental rotation, general decision skill). These cognitive models suggest that injury prediction expertise (i.e., ACL-IQ) is a trainable skill, and provide a foundation for future research and applications in training, decision support, and ultimately clinical screening investigations.

  3. Estimates of Radiation Doses and Cancer Risk from Food Intake in Korea.

    PubMed

    Moon, Eun-Kyeong; Ha, Wi-Ho; Seo, Songwon; Jin, Young Woo; Jeong, Kyu Hwan; Yoon, Hae-Jung; Kim, Hyoung-Soo; Hwang, Myung-Sil; Choi, Hoon; Lee, Won Jin

    2016-01-01

    The aim of this study was to estimate internal radiation doses and lifetime cancer risk from food ingestion. Radiation doses from food intake were calculated using the Korea National Health and Nutrition Examination Survey and the measured radioactivity of (134)Cs, (137)Cs, and (131)I from the Ministry of Food and Drug Safety in Korea. Total number of measured data was 8,496 (3,643 for agricultural products, 644 for livestock products, 43 for milk products, 3,193 for marine products, and 973 for processed food). Cancer risk was calculated by multiplying the estimated committed effective dose and the detriment adjusted nominal risk coefficients recommended by the International Commission on Radiation Protection. The lifetime committed effective doses from the daily diet are ranged 2.957-3.710 mSv. Excess lifetime cancer risks are 14.4-18.1, 0.4-0.5, and 1.8-2.3 per 100,000 for all solid cancers combined, thyroid cancer, and leukemia, respectively. PMID:26770031

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

    SciTech Connect

    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.

  5. Estimating the risks of smoking, air pollution, and passive smoke on acute respiratory conditions

    SciTech Connect

    Ostro, B.D. )

    1989-06-01

    Five years of the annual Health Interview Survey, conducted by the National Center for Health Statistics, are used to estimate the effects of air pollution, smoking, and environmental tobacco smoke on respiratory restrictions in activity for adults, and bed disability for children. After adjusting for several socioeconomic factors, the multiple regression estimates indicate that an independent and statistically significant association exists between these three forms of air pollution and respiratory morbidity. The comparative risks of these exposures are computed and the plausibility of the relative risks is examined by comparing the equivalent doses with actual measurements of exposure taken in the homes of smokers. The results indicate that: (1) smokers will have a 55-75% excess in days with respiratory conditions severe enough to cause reductions in normal activity; (2) a 1 microgram increase in fine particulate matter air pollution is associated with a 3% excess in acute respiratory disease; and (3) a pack-a-day smoker will increase respiratory restricted days for a nonsmoking spouse by 20% and increase the number of bed disability days for young children living in the household by 20%. The results also indicate that the estimates of the effects of secondhand smoking on children are improved when the mother's work status is known and incorporated into the exposure estimate.

  6. Estimating the risks of smoking, air pollution, and passive smoke on acute respiratory conditions.

    PubMed

    Ostro, B D

    1989-06-01

    Five years of the annual Health Interview Survey, conducted by the National Center for Health Statistics, are used to estimate the effects of air pollution, smoking, and environmental tobacco smoke on respiratory restrictions in activity for adults, and bed disability for children. After adjusting for several socioeconomic factors, the multiple regression estimates indicate that an independent and statistically significant association exists between these three forms of air pollution and respiratory morbidity. The comparative risks of these exposures are computed and the plausibility of the relative risks is examined by comparing the equivalent doses with actual measurements of exposure taken in the homes of smokers. The results indicate that: (1) smokers will have a 55-75% excess in days with respiratory conditions severe enough to cause reductions in normal activity; (2) a 1 microgram increase in fine particulate matter air pollution is associated with a 3% excess in acute respiratory disease; and (3) a pack-a-day smoker will increase respiratory restricted days for a nonsmoking spouse by 20% and increase the number of bed disability days for young children living in the household by 20%. The results also indicate that the estimates of the effects of secondhand smoking on children are improved when the mother's work status is known and incorporated into the exposure estimate.

  7. Problems and solutions in the estimation of genetic risks from radiation and chemicals

    SciTech Connect

    Russell, W. L.

    1980-01-01

    Extensive investigations with mice on the effects of various physical and biological factors, such as dose rate, sex and cell stage, on radiation-induced mutation have provided an evaluation of the genetics hazards of radiation in man. The mutational results obtained in both sexes with progressive lowering of the radiation dose rate have permitted estimation of the mutation frequency expected under the low-level radiation conditions of most human exposure. Supplementing the studies on mutation frequency are investigations on the phenotypic effects of mutations in mice, particularly anatomical disorders of the skeleton, which allow an estimation of the degree of human handicap associated with the occurrence of parallel defects in man. Estimation of the genetic risk from chemical mutagens is much more difficult, and the research is much less advanced. Results on transmitted mutations in mice indicate a poor correlation with mutation induction in non-mammalian organisms.

  8. Estimate of the risks of disposing nonhazardous oil field wastes into salt caverns

    SciTech Connect

    Tomasko, D.; Elcock, D.; Veil, J.

    1997-12-31

    Argonne National Laboratory (ANL) has completed an evaluation of the possibility that adverse human health effects (carcinogenic and noncarcinogenic) could result from exposure to contaminants released from nonhazardous oil field wastes (NOW) disposed in domal salt caverns. Potential human health risks associated with hazardous substances (arsenic, benzene, cadmium, and chromium) in NOW were assessed under four postclosure cavern release scenarios: inadvertent cavern intrusion, failure of the cavern seal, failure of the cavern through cracks or leaky interbeds, and a partial collapse of the cavern roof. To estimate potential human health risks for these scenarios, contaminant concentrations at the receptor were calculated using a one-dimensional solution to an advection/dispersion equation that included first order degradation. Assuming a single, generic salt cavern and generic oil-field wastes, the best-estimate excess cancer risks ranged from 1.7 {times} 10{sup {minus}12} to 1.1 {times} 10{sup {minus}8} and hazard indices (referring to noncancer health effects) ranged from 7 {times} 10{sup {minus}9} to 7 {times} 10{sup {minus}4}. Under worse-case conditions in which the probability of cavern failure is 1.0, excess cancer risks ranged from 4.9 {times} 10{sup {minus}9} to 1.7 {times} 10{sup {minus}5} and hazard indices ranged from 7.0 {times} 10{sup {minus}4} to 0.07. Even under worst-case conditions, the risks are within the US Environmental Protection Agency (EPA) target range for acceptable exposure levels. From a human health risk perspective, salt caverns can, therefore, provide an acceptable disposal method for NOW.

  9. Risk estimation for future glacier lake outburst floods based on local land-use changes

    NASA Astrophysics Data System (ADS)

    Nussbaumer, S.; Schaub, Y.; Huggel, C.; Walz, A.

    2014-06-01

    Effects of climate change are particularly strong in high-mountain regions. Most visibly, glaciers are shrinking at a rapid pace, and as a consequence, glacier lakes are forming or growing. At the same time the stability of mountain slopes is reduced by glacier retreat, permafrost thaw and other factors, resulting in an increasing landslide hazard which can potentially impact lakes and therewith trigger far-reaching and devastating outburst floods. To manage risks from existing or future lakes, strategies need to be developed to plan in time for adequate risk reduction measures at a local level. However, methods to assess risks from future lake outbursts are not available and need to be developed to evaluate both future hazard and future damage potential. Here a method is presented to estimate future risks related to glacier lake outbursts for a local site in southern Switzerland (Naters, Valais). To generate two hazard scenarios, glacier shrinkage and lake formation modelling was applied, combined with simple flood modelling and field work. Furthermore, a land-use model was developed to quantify and allocate land-use changes based on local-to-regional storylines and three scenarios of land-use driving forces. Results are conceptualized in a matrix of three land-use and two hazard scenarios for the year 2045, and show the distribution of risk in the community of Naters, including high and very high risk areas. The study underlines the importance of combined risk management strategies focusing on land-use planning, on vulnerability reduction, as well as on structural measures (where necessary) to effectively reduce future risks related to lake outburst floods.

  10. Local land-use change based risk estimation for future glacier lake outburst flood

    NASA Astrophysics Data System (ADS)

    Nussbaumer, S.; Huggel, C.; Schaub, Y.; Walz, A.

    2013-08-01

    Effects of climate change are particularly strong in high-mountain regions. Most visibly, glaciers are shrinking at a rapid pace, and as a consequence, glacier lakes are forming or growing. At the same time the stability of mountain slopes is reduced by glacier retreat, permafrost thaw and other factors, resulting in an increasing risk of landslides which can potentially impact lakes and therewith trigger far reaching and devastating outburst floods. To manage risks from existing or future lakes, strategies need to be developed to plan in time for adequate risk reduction measures at a local level. However, methods to assess risks from future lake outbursts are not available. It is actually a challenge to develop methods to evaluate both, future hazard potential and future damage potential. Here we present an analysis of future risks related to glacier lake outbursts for a local site in southern Switzerland (Naters, Valais). To estimate two hazard scenarios, we used glacier shrinkage and lake formation modelling, simple flood modelling and field work. Further we developed a land-use model to quantify and allocate land-use changes based on local-to-regional storylines and three scenarios of land-use driving forces. Results are conceptualized in a matrix of three land-use and two hazard scenarios for a time period of 2045, and show the distribution of risk in the community of Naters, including high and very high risk areas. The study corroborates the importance of land-use planning to effectively reduce future risks related to lake outburst floods.

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

    NASA Technical Reports Server (NTRS)

    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

  12. Sensitivity Analysis of Median Lifetime on Radiation Risks Estimates for Cancer and Circulatory Disease amongst Never-Smokers

    NASA Technical Reports Server (NTRS)

    Chappell, Lori J.; Cucinotta, Francis A.

    2011-01-01

    Radiation risks are estimated in a competing risk formalism where age or time after exposure estimates of increased risks for cancer and circulatory diseases are folded with a probability to survive to a given age. The survival function, also called the life-table, changes with calendar year, gender, smoking status and other demographic variables. An outstanding problem in risk estimation is the method of risk transfer between exposed populations and a second population where risks are to be estimated. Approaches used to transfer risks are based on: 1) Multiplicative risk transfer models -proportional to background disease rates. 2) Additive risk transfer model -risks independent of background rates. In addition, a Mixture model is often considered where the multiplicative and additive transfer assumptions are given weighted contributions. We studied the influence of the survival probability on the risk of exposure induced cancer and circulatory disease morbidity and mortality in the Multiplicative transfer model and the Mixture model. Risks for never-smokers (NS) 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 NS, with additional contributions from circulatory diseases and cancers of the stomach, liver, bladder, oral cavity, esophagus, colon, a portion of the solid cancer remainder, and leukemia. Greater improvements in risk estimates for NS s 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).

  13. Biokinetic and dosimetric modelling in the estimation of radiation risks from internal emitters.

    PubMed

    Harrison, John

    2009-06-01

    The International Commission on Radiological Protection (ICRP) has developed biokinetic and dosimetric models that enable the calculation of organ and tissue doses for a wide range of radionuclides. These are used to calculate equivalent and effective dose coefficients (dose in Sv Bq(-1) intake), considering occupational and environmental exposures. Dose coefficients have also been given for a range of radiopharmaceuticals used in diagnostic medicine. Using equivalent and effective dose, exposures from external sources and from different radionuclides can be summed for comparison with dose limits, constraints and reference levels that relate to risks from whole-body radiation exposure. Risk estimates are derived largely from follow-up studies of the survivors of the atomic bombings at Hiroshima and Nagasaki in 1945. New dose coefficients will be required following the publication in 2007 of new ICRP recommendations. ICRP biokinetic and dosimetric models are subject to continuing review and improvement, although it is arguable that the degree of sophistication of some of the most recent models is greater than required for the calculation of effective dose to a reference person for the purposes of regulatory control. However, the models are also used in the calculation of best estimates of doses and risks to individuals, in epidemiological studies and to determine probability of cancer causation. Models are then adjusted to best fit the characteristics of the individuals and population under consideration. For example, doses resulting from massive discharges of strontium-90 and other radionuclides to the Techa River from the Russian Mayak plutonium plant in the early years of its operation are being estimated using models adapted to take account of measurements on local residents and other population-specific data. Best estimates of doses to haemopoietic bone marrow, in utero and postnatally, are being used in epidemiological studies of radiation-induced leukaemia

  14. Absolute Identification by Relative Judgment

    ERIC Educational Resources Information Center

    Stewart, Neil; Brown, Gordon D. A.; Chater, Nick

    2005-01-01

    In unidimensional absolute identification tasks, participants identify stimuli that vary along a single dimension. Performance is surprisingly poor compared with discrimination of the same stimuli. Existing models assume that identification is achieved using long-term representations of absolute magnitudes. The authors propose an alternative…

  15. Be Resolute about Absolute Value

    ERIC Educational Resources Information Center

    Kidd, Margaret L.

    2007-01-01

    This article explores how conceptualization of absolute value can start long before it is introduced. The manner in which absolute value is introduced to students in middle school has far-reaching consequences for their future mathematical understanding. It begins to lay the foundation for students' understanding of algebra, which can change…

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

    PubMed

    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 < 5 mSv), or population exposure by water-independent pathways (50-y CEDE < 80 mSv). The greatest hazard is related to the water contamination in conditions of effective leaching of uranium in the groundwater (50-y CEDE < 400 mSv). Even in this worst case scenario, the chemical toxicity largely predominates over radiological risk. These computer simulations suggest that little radiological risk is associated to the use of depleted uranium weapons.

  17. Estimated Insulin Sensitivity and Cardiovascular Disease Risk Factors in Adolescents with and without Type 1 Diabetes

    PubMed Central

    Specht, Brian J; Wadwa, R Paul; Snell-Bergeon, Janet K; Nadeau, Kristen J; Bishop, Franziska K; Maahs, David M.

    2012-01-01

    Objective To test the hypothesis that cardiovascular disease (CVD) risk factors are similar in adolescents with and without diabetes (T1D) in the most insulin sensitive (IS) tertile and CVD risk factors are more atherogenic with decreasing IS in adolescents with T1D. Study design Adolescents with IS T1D (n=292; age=15.4±2.1 years; duration=8.8±3.0 years, HbA1c=8.9±1.6%) and non-diabetic (non-DM) controls (n=89; age=15.4±2.1 years) was estimated using the model: logeIS=4.64725 – 0.02032(waist, cm) – 0.09779(HbA1c, %) – 0.00235(triglycerides, mg/dl). CVD risk factors (blood pressure, fasting total, LDL and HDL-cholesterol, hs-CRP, and BMI Z-score) were compared between all non-DM adolescents and those with T1D in the most IS tertile, and then examined for a linear trend by IS tertile in adolescents with T1D, adjusted for sex, race/ethnicity and Tanner Stage. Results Estimated IS was significantly lower in adolescents with T1D compared with those without (T1D=7.8±2.4, non-DM=11.5±2.9; p<0.0001). CVD risk factors were similar for non-DM compared with the adolescents with most IS T1D, except for higher HDL-c and DBP in adolescents with T1D (p<0.05). Among adolescents with T1D, all CVD risk factors except for HDL-c, were more atherogenic across decreasing IS tertiles in linear regression analysis (p<0.05). Conclusion Adolescents with T1D who are the most IS have similar CVD risk factors compared with non-DM adolescents. CVD risk factors are inversely associated with adolescents with IS T1D. IS may be an important therapeutic target for reducing CVD risk factors in adolescents with T1D. PMID:22921593

  18. Risk of water contamination by nitrogen in Canada as estimated by the IROWC-N model.

    PubMed

    De Jong, R; Drury, C F; Yang, J Y; Campbell, C A

    2009-07-01

    With increasing amounts of nitrogen (N) being added to farmland in the form of fertilizer and manure to optimize crop yields, and more broadly, to meet the growing demands for food, feed and energy, there are public concerns regarding its possible negative impact on the environment. An optimal balance between N requirements for production versus efficient N use is required, so as to minimize N losses from the agricultural system. An agri-environmental indicator i.e., the Indicator of the Risk of Water Contamination by Nitrogen (IROWC-N) was developed to assess the risk of N moving from agricultural areas into groundwater and/or nearby surface water bodies. The indicator linked the quantity of mineral nitrogen remaining in the soil at harvest, i.e., the Residual Soil Nitrogen (RSN) indicator, and the subsequent climatic conditions during the winter period. The results were assessed in terms of nitrate lost through leaching and nitrate concentration in the drainage water, expressed in five IROWC-N risk classes. Unlike previous versions of the indicator, the current model provided a more complete description of the soil-water balance, including the calculation of rainfall interception by crops, surface runoff, actual evapotranspiration and soil-water contents. Consequently, the current IROWC-N estimates differed markedly from those obtained previously. Between 1981 and 2006, the risk of water contamination by N in Canada was small, and reflected what was happening in the three Prairie provinces where 85% of Canada's farmland is located. However, the aggregated IROWC-N index, which is a combination of all five risk classes, increased steadily by 2.3% per year, from 6.7 in 1981 to 10.6 in 2006. The proportion of farmland in the very low IROWC-N risk class decreased from 88 to 78%; correspondingly, the proportion in the low risk class increased from 2 to 12%. The proportion of farmland in the moderate-, high- and very high-risk classes changed by less than 3% over time

  19. Risk of water contamination by nitrogen in Canada as estimated by the IROWC-N model.

    PubMed

    De Jong, R; Drury, C F; Yang, J Y; Campbell, C A

    2009-07-01

    With increasing amounts of nitrogen (N) being added to farmland in the form of fertilizer and manure to optimize crop yields, and more broadly, to meet the growing demands for food, feed and energy, there are public concerns regarding its possible negative impact on the environment. An optimal balance between N requirements for production versus efficient N use is required, so as to minimize N losses from the agricultural system. An agri-environmental indicator i.e., the Indicator of the Risk of Water Contamination by Nitrogen (IROWC-N) was developed to assess the risk of N moving from agricultural areas into groundwater and/or nearby surface water bodies. The indicator linked the quantity of mineral nitrogen remaining in the soil at harvest, i.e., the Residual Soil Nitrogen (RSN) indicator, and the subsequent climatic conditions during the winter period. The results were assessed in terms of nitrate lost through leaching and nitrate concentration in the drainage water, expressed in five IROWC-N risk classes. Unlike previous versions of the indicator, the current model provided a more complete description of the soil-water balance, including the calculation of rainfall interception by crops, surface runoff, actual evapotranspiration and soil-water contents. Consequently, the current IROWC-N estimates differed markedly from those obtained previously. Between 1981 and 2006, the risk of water contamination by N in Canada was small, and reflected what was happening in the three Prairie provinces where 85% of Canada's farmland is located. However, the aggregated IROWC-N index, which is a combination of all five risk classes, increased steadily by 2.3% per year, from 6.7 in 1981 to 10.6 in 2006. The proportion of farmland in the very low IROWC-N risk class decreased from 88 to 78%; correspondingly, the proportion in the low risk class increased from 2 to 12%. The proportion of farmland in the moderate-, high- and very high-risk classes changed by less than 3% over time

  20. Examining the effects of air pollution composition on within region differences in PM2.5 mortality risk estimates.

    PubMed

    Baxter, Lisa K; Duvall, Rachelle M; Sacks, Jason

    2013-01-01

    Multi-city population-based epidemiological studies have observed significant heterogeneity in both the magnitude and direction of city-specific risk estimates, but tended to focus on regional differences in PM2.5 mortality risk estimates. Interpreting differences in risk estimates is complicated by city-to-city heterogeneity observed within regions due to city-to-city variations in the PM2.5 composition and the concentration of gaseous pollutants. We evaluate whether variations in PM2.5 composition and gaseous pollutant concentrations have a role in explaining the heterogeneity in PM2.5 mortality risk estimates observed in 27 US cities from 1997 to 2002. Within each region, we select the two cities with the largest and smallest mortality risk estimate. We compare for each region the within- and between-city concentrations and correlations of PM2.5 constituents and gaseous pollutants. We also attempt to identify source factors through principal component analysis (PCA) for each city. The results of this analysis indicate that identifying a PM constituent(s) that explains the differences in the PM2.5 mortality risk estimates is not straightforward. The difference in risk estimates between cities in the same region may be attributed to a group of pollutants, possibly those related to local sources such as traffic.

  1. Longer genotypically-estimated leukocyte telomere length is associated with increased adult glioma risk.

    PubMed

    Walsh, Kyle M; Codd, Veryan; Rice, Terri; Nelson, Christopher P; Smirnov, Ivan V; McCoy, Lucie S; Hansen, Helen M; Elhauge, Edward; Ojha, Juhi; Francis, Stephen S; Madsen, Nils R; Bracci, Paige M; Pico, Alexander R; Molinaro, Annette M; Tihan, Tarik; Berger, Mitchel S; Chang, Susan M; Prados, Michael D; Jenkins, Robert B; Wiemels, Joseph L; Samani, Nilesh J; Wiencke, John K; Wrensch, Margaret R

    2015-12-15

    Telomere maintenance has emerged as an important molecular feature with impacts on adult glioma susceptibility and prognosis. Whether longer or shorter leukocyte telomere length (LTL) is associated with glioma risk remains elusive and is often confounded by the effects of age and patient treatment. We sought to determine if genotypically-estimated LTL is associated with glioma risk and if inherited single nucleotide polymorphisms (SNPs) that are associated with LTL are glioma risk factors. Using a Mendelian randomization approach, we assessed differences in genotypically-estimated relative LTL in two independent glioma case-control datasets from the UCSF Adult Glioma Study (652 patients and 3735 controls) and The Cancer Genome Atlas (478 non-overlapping patients and 2559 controls). LTL estimates were based on a weighted linear combination of subject genotype at eight SNPs, previously associated with LTL in the ENGAGE Consortium Telomere Project. Mean estimated LTL was 31bp (5.7%) longer in glioma patients than controls in discovery analyses (P = 7.82x10-8) and 27bp (5.0%) longer in glioma patients than controls in replication analyses (1.48x10-3). Glioma risk increased monotonically with each increasing septile of LTL (O.R.=1.12; P = 3.83x10-12). Four LTL-associated SNPs were significantly associated with glioma risk in pooled analyses, including those in the telomerase component genes TERC (O.R.=1.14; 95% C.I.=1.03-1.28) and TERT (O.R.=1.39; 95% C.I.=1.27-1.52), and those in the CST complex genes OBFC1 (O.R.=1.18; 95% C.I.=1.05-1.33) and CTC1 (O.R.=1.14; 95% C.I.=1.02-1.28). Future work is needed to characterize the role of the CST complex in gliomagenesis and further elucidate the complex balance between ageing, telomere length, and molecular carcinogenesis.

  2. Longer genotypically-estimated leukocyte telomere length is associated with increased adult glioma risk

    PubMed Central

    Walsh, Kyle M.; Codd, Veryan; Rice, Terri; Nelson, Christopher P.; Smirnov, Ivan V.; McCoy, Lucie S.; Hansen, Helen M.; Elhauge, Edward; Ojha, Juhi; Francis, Stephen S.; Madsen, Nils R.; Bracci, Paige M.; Pico, Alexander R.; Molinaro, Annette M.; Tihan, Tarik; Berger, Mitchel S.; Chang, Susan M.; Prados, Michael D.; Jenkins, Robert B.; Wiemels, Joseph L.; Samani, Nilesh J.; Wiencke, John K.; Wrensch, Margaret R.

    2015-01-01

    Telomere maintenance has emerged as an important molecular feature with impacts on adult glioma susceptibility and prognosis. Whether longer or shorter leukocyte telomere length (LTL) is associated with glioma risk remains elusive and is often confounded by the effects of age and patient treatment. We sought to determine if genotypically-estimated LTL is associated with glioma risk and if inherited single nucleotide polymorphisms (SNPs) that are associated with LTL are glioma risk factors. Using a Mendelian randomization approach, we assessed differences in genotypically-estimated relative LTL in two independent glioma case-control datasets from the UCSF Adult Glioma Study (652 patients and 3735 controls) and The Cancer Genome Atlas (478 non-overlapping patients and 2559 controls). LTL estimates were based on a weighted linear combination of subject genotype at eight SNPs, previously associated with LTL in the ENGAGE Consortium Telomere Project. Mean estimated LTL was 31bp (5.7%) longer in glioma patients than controls in discovery analyses (P = 7.82×10-8) and 27bp (5.0%) longer in glioma patients than controls in replication analyses (1.48×10-3). Glioma risk increased monotonically with each increasing septile of LTL (O.R.=1.12; P = 3.83×10-12). Four LTL-associated SNPs were significantly associated with glioma risk in pooled analyses, including those in the telomerase component genes TERC (O.R.=1.14; 95% C.I.=1.03-1.28) and TERT (O.R.=1.39; 95% C.I.=1.27-1.52), and those in the CST complex genes OBFC1 (O.R.=1.18; 95% C.I.=1.05-1.33) and CTC1 (O.R.=1.14; 95% C.I.=1.02-1.28). Future work is needed to characterize the role of the CST complex in gliomagenesis and further elucidate the complex balance between ageing, telomere length, and molecular carcinogenesis. PMID:26646793

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

    NASA Astrophysics Data System (ADS)

    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.

  4. Prospect theory based estimation of drivers' risk attitudes in route choice behaviors.

    PubMed

    Zhou, Lizhen; Zhong, Shiquan; Ma, Shoufeng; Jia, Ning

    2014-12-01

    This paper applied prospect theory (PT) to describe drivers' route choice behavior under Variable Message Sign (VMS), which presented visual traffic information to assist them to make route choice decisions. A quite rich empirical data from questionnaire and field spot was used to estimate parameters of PT. In order to make the parameters more realistic with drivers' attitudes, they were classified into different types by significant factors influencing their behaviors. Based on the travel time distribution of alternative routes and route choice results from questionnaire, the parameterized value function of each category was figured out, which represented drivers' risk attitudes and choice characteristics. The empirical verification showed that the estimates were acceptable and effective. The result showed drivers' risk attitudes and route choice characteristics could be captured by PT under real-time information shown on VMS. For practical application, once drivers' route choice characteristics and parameters were identified, their route choice behavior under different road conditions could be predicted accurately, which was the basis of traffic guidance measures formulation and implementation for targeted traffic management. Moreover, the heterogeneous risk attitudes among drivers should be considered when releasing traffic information and regulating traffic flow.

  5. Developing a utility decision framework to evaluate predictive models in breast cancer risk estimation

    PubMed Central

    Wu, Yirong; Abbey, Craig K.; Chen, Xianqiao; Liu, Jie; Page, David C.; Alagoz, Oguzhan; Peissig, Peggy; Onitilo, Adedayo A.; Burnside, Elizabeth S.

    2015-01-01

    Abstract. Combining imaging and genetic information to predict disease presence and progression is being codified into an emerging discipline called “radiogenomics.” Optimal evaluation methodologies for radiogenomics have not been well established. We aim to develop a decision framework based on utility analysis to assess predictive models for breast cancer diagnosis. We garnered Gail risk factors, single nucleotide polymorphisms (SNPs), and mammographic features from a retrospective case-control study. We constructed three logistic regression models built on different sets of predictive features: (1) Gail, (2) Gail + Mammo, and (3) Gail + Mammo + SNP. Then we generated receiver operating characteristic (ROC) curves for three models. After we assigned utility values for each category of outcomes (true negatives, false positives, false negatives, and true positives), we pursued optimal operating points on ROC curves to achieve maximum expected utility of breast cancer diagnosis. We performed McNemar’s test based on threshold levels at optimal operating points, and found that SNPs and mammographic features played a significant role in breast cancer risk estimation. Our study comprising utility analysis and McNemar’s test provides a decision framework to evaluate predictive models in breast cancer risk estimation. PMID:26835489

  6. Estimating the Risk of ABO Hemolytic Disease of the Newborn in Lagos

    PubMed Central

    Akanmu, Alani Sulaimon; Oyedeji, Olufemi Abiola; Adeyemo, Titilope Adenike; Ogbenna, Ann Abiola

    2015-01-01

    Background. ABO hemolytic disease of the newborn is the most common hemolytic consequence of maternofetal blood group incompatibility restricted mostly to non-group-O babies of group O mothers with immune anti-A or anti-B antibodies. Aim. We estimated the risk of ABO HDN with view to determining need for routine screening for ABO incompatibility between mother and fetus. Materials and Methods. Prevalence of ABO blood group phenotypes in blood donors at the donor clinic of the Lagos University Teaching Hospital and arithmetic methods were used to determine population prevalence of ABO genes. We then estimated proportion of pregnancies of group O mothers carrying a non-group-O baby and the risk that maternofetal ABO incompatibility will cause clinical ABO HDN. Results. Blood from 9138 donors was ABO typed. 54.3%, 23%, 19.4%, and 3.3% were blood groups O, A, B, and AB, respectively. Calculated gene frequencies were 0.1416, 0.1209, and 0.7375 for A, B, and O genes, respectively. It was estimated that 14.3% of deliveries will result in a blood group O woman giving birth to a child who is non-group-O. Approximately 4.3% of deliveries are likely to suffer ABO HDN with 2.7% prone to suffer from moderately severe to severe hemolysis. PMID:26491605

  7. Estimating the Size of Populations at High Risk for HIV Using Respondent-Driven Sampling Data

    PubMed Central

    Handcock, Mark S.; Gile, Krista J.; Mar, Corinne M.

    2015-01-01

    Summary The study of hard-to-reach populations presents significant challenges. Typically, a sampling frame is not available, and population members are difficult to identify or recruit from broader sampling frames. This is especially true of populations at high risk for HIV/AIDS. Respondent-driven sampling (RDS) is often used in such settings with the primary goal of estimating the prevalence of infection. In such populations, the number of people at risk for infection and the number of people infected are of fundamental importance. This article presents a case-study of the estimation of the size of the hard-to-reach population based on data collected through RDS. We study two populations of female sex workers and men-who-have-sex-with-men in El Salvador. The approach is Bayesian and we consider different forms of prior information, including using the UNAIDS population size guidelines for this region. We show that the method is able to quantify the amount of information on population size available in RDS samples. As separate validation, we compare our results to those estimated by extrapolating from a capture–recapture study of El Salvadorian cities. The results of our case-study are largely comparable to those of the capture–recapture study when they differ from the UNAIDS guidelines. Our method is widely applicable to data from RDS studies and we provide a software package to facilitate this. PMID:25585794

  8. Patient-specific radiation dose and cancer risk estimation in CT: Part II. Application to patients

    SciTech Connect

    Li Xiang; Samei, Ehsan; Segars, W. Paul; Sturgeon, Gregory M.; Colsher, James G.; Toncheva, Greta; Yoshizumi, Terry T.; Frush, Donald P.

    2011-01-15

    Purpose: Current methods for estimating and reporting radiation dose from CT examinations are largely patient-generic; the body size and hence dose variation from patient to patient is not reflected. Furthermore, the current protocol designs rely on dose as a surrogate for the risk of cancer incidence, neglecting the strong dependence of risk on age and gender. The purpose of this study was to develop a method for estimating patient-specific radiation dose and cancer risk from CT examinations. Methods: The study included two patients (a 5-week-old female patient and a 12-year-old male patient), who underwent 64-slice CT examinations (LightSpeed VCT, GE Healthcare) of the chest, abdomen, and pelvis at our institution in 2006. For each patient, a nonuniform rational B-spine (NURBS) based full-body computer model was created based on the patient's clinical CT data. Large organs and structures inside the image volume were individually segmented and modeled. Other organs were created by transforming an existing adult male or female full-body computer model (developed from visible human data) to match the framework defined by the segmented organs, referencing the organ volume and anthropometry data in ICRP Publication 89. A Monte Carlo program previously developed and validated for dose simulation on the LightSpeed VCT scanner was used to estimate patient-specific organ dose, from which effective dose and risks of cancer incidence were derived. Patient-specific organ dose and effective dose were compared with patient-generic CT dose quantities in current clinical use: the volume-weighted CT dose index (CTDI{sub vol}) and the effective dose derived from the dose-length product (DLP). Results: The effective dose for the CT examination of the newborn patient (5.7 mSv) was higher but comparable to that for the CT examination of the teenager patient (4.9 mSv) due to the size-based clinical CT protocols at our institution, which employ lower scan techniques for smaller

  9. Estimating the Risk of Renal Stone Events During Long-Duration Spaceflight

    NASA Technical Reports Server (NTRS)

    Reyes, David; Kerstman, Eric; Locke, James

    2014-01-01

    Introduction: Given the bone loss and increased urinary calcium excretion in the microgravity environment, persons participating in long-duration spaceflight may have an increased risk for renal stone formation. Renal stones are often an incidental finding of abdominal imaging studies done for other reasons. Thus, some crewmembers may have undiscovered, asymptomatic stones prior to their mission. Methods: An extensive literature search was conducted concerning the natural history of asymptomatic renal stones. For comparison, simulations were done using the Integrated Medical Model (IMM). The IMM is an evidence-based decision support tool that provides risk analysis and has the capability to optimize medical systems for missions by minimizing the occurrence of adverse mission outcomes such as evacuation and loss of crew life within specified mass and volume constraints. Results: The literature of the natural history of asymptomatic renal stones in the general medical population shows that the probability of symptomatic event is 8% to 34% at 1 to 3 years for stones < 7 mm. Extrapolated to a 6-month mission, for stones < 5 to 7 mm, the risk for any stone event is about 4 to 6%, with a 0.7% to 4% risk for intervention, respectively. IMM simulations compare favorably with risk estimates garnered from the terrestrial literature. The IMM forecasts that symptomatic renal stones may be one of the top drivers for medical evacuation of an International Space Station (ISS) mission. Discussion: Although the likelihood of a stone event is low, the consequences could be severe due to limitations of current ISS medical capabilities. Therefore, these risks need to be quantified to aid planning, limit crew morbidity and mitigate mission impacts. This will be especially critical for missions beyond earth orbit, where evacuation may not be an option.

  10. Measurement error affects risk estimates for recruitment to the Hudson River stock of striped bass.

    PubMed

    Dunning, Dennis J; Ross, Quentin E; Munch, Stephan B; Ginzburg, Lev R

    2002-06-01

    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.

  11. Estimating drought risk across Europe from reported drought impacts, drought indices, and vulnerability factors

    NASA Astrophysics Data System (ADS)

    Blauhut, Veit; Stahl, Kerstin; Stagge, James Howard; Tallaksen, Lena M.; De Stefano, Lucia; Vogt, Jürgen

    2016-07-01

    Drought is one of the most costly natural hazards in Europe. Due to its complexity, drought risk, meant as the combination of the natural hazard and societal vulnerability, is difficult to define and challenging to detect and predict, as the impacts of drought are very diverse, covering the breadth of socioeconomic and environmental systems. Pan-European maps of drought risk could inform the elaboration of guidelines and policies to address its documented severity and impact across borders. This work tests the capability of commonly applied drought indices and vulnerability factors to predict annual drought impact occurrence for different sectors and macro regions in Europe and combines information on past drought impacts, drought indices, and vulnerability factors into estimates of drought risk at the pan-European scale. This hybrid approach bridges the gap between traditional vulnerability assessment and probabilistic impact prediction in a statistical modelling framework. Multivariable logistic regression was applied to predict the likelihood of impact occurrence on an annual basis for particular impact categories and European macro regions. The results indicate sector- and macro-region-specific sensitivities of drought indices, with the Standardized Precipitation Evapotranspiration Index (SPEI) for a 12-month accumulation period as the overall best hazard predictor. Vulnerability factors have only limited ability to predict drought impacts as single predictors, with information about land use and water resources being the best vulnerability-based predictors. The application of the hybrid approach revealed strong regional and sector-specific differences in drought risk across Europe. The majority of the best predictor combinations rely on a combination of SPEI for shorter and longer accumulation periods, and a combination of information on land use and water resources. The added value of integrating regional vulnerability information with drought risk prediction

  12. Estimating drought risk across Europe from reported drought impacts, hazard indicators and vulnerability factors

    NASA Astrophysics Data System (ADS)

    Blauhut, V.; Stahl, K.; Stagge, J. H.; Tallaksen, L. M.; De Stefano, L.; Vogt, J.

    2015-12-01

    Drought is one of the most costly natural hazards in Europe. Due to its complexity, drought risk, the combination of the natural hazard and societal vulnerability, is difficult to define and challenging to detect and predict, as the impacts of drought are very diverse, covering the breadth of socioeconomic and environmental systems. Pan-European maps of drought risk could inform the elaboration of guidelines and policies to address its documented severity and impact across borders. This work (1) tests the capability of commonly applied hazard indicators and vulnerability factors to predict annual drought impact occurrence for different sectors and macro regions in Europe and (2) combines information on past drought impacts, drought hazard indicators, and vulnerability factors into estimates of drought risk at the pan-European scale. This "hybrid approach" bridges the gap between traditional vulnerability assessment and probabilistic impact forecast in a statistical modelling framework. Multivariable logistic regression was applied to predict the likelihood of impact occurrence on an annual basis for particular impact categories and European macro regions. The results indicate sector- and macro region specific sensitivities of hazard indicators, with the Standardised Precipitation Evapotranspiration Index for a twelve month aggregation period (SPEI-12) as the overall best hazard predictor. Vulnerability factors have only limited ability to predict drought impacts as single predictor, with information about landuse and water resources as best vulnerability-based predictors. (3) The application of the "hybrid approach" revealed strong regional (NUTS combo level) and sector specific differences in drought risk across Europe. The majority of best predictor combinations rely on a combination of SPEI for shorter and longer aggregation periods, and a combination of information on landuse and water resources. The added value of integrating regional vulnerability information

  13. Uncertainty in the estimation of benzene risks: application of an uncertainty taxonomy to risk assessments based on an epidemiology study of rubber hydrochloride workers.

    PubMed Central

    Byrd, D M; Barfield, E T

    1989-01-01

    This paper reviews 14 risk assessments that use the data from descriptions by Rinsky, Young, and co-workers of benzene-associated leukemias among a group of rubber hydrochloride workers in Ohio. The leukemogenic risks of benzene estimated in these assessments differ. The assessors use different assumptions (parameters, confounding factors, or formulas), which account for the differences in risk. The purpose of the review is to determine whether the major source of uncertainty in assessments of benzene risk arises from data, method, or concept. The results show that methodological differences dominate the other two potential sources with respect to impact on risk magnitude. PMID:2792047

  14. Estimating the risk of collisions between bicycles and motor vehicles at signalized intersections.

    PubMed

    Wang, Yinhai; Nihan, Nancy L

    2004-05-01

    Collisions between bicycles and motor vehicles have caused severe life and property losses in many countries. The majority of bicycle-motor vehicle (BMV) accidents occur at intersections. In order to reduce the number of BMV accidents at intersections, a substantial understanding of the causal factors for the collisions is required. In this study, intersection BMV accidents were classified into three types based on the movements of the involved motor vehicles and bicycles. The three BMV accident classifications were through motor vehicle related collisions, left-turn motor vehicle related collisions, and right-turn motor vehicle related collisions. A methodology for estimating these BMV accident risks was developed based on probability theory. A significant difference between this proposed methodology and most current approaches is that the proposed approach explicitly relates the risk of each specific BMV accident type to its related flows. The methodology was demonstrated using a 4-year (1992-1995) data set collected from 115 signalized intersections in the Tokyo Metropolitan area. This data set contains BMV accident data, bicycle flow data, motor vehicle flow data, traffic control data, and geometric data for each intersection approach. For each BMV risk model, an independent explanatory variable set was chosen according to the characteristics of the accident type. Three negative binomial regression models (one corresponding to each BMV accident type) were estimated using the maximum likelihood method. The coefficient value and its significance level were estimated for each selected variable. The negative binomial dispersion parameters for all the three models were significant at 0.01 levels. This supported the choice of the negative binomial regression over the Poisson regression for the quantitative analyses in this study.

  15. Estimates of coextinction risk: how anuran parasites respond to the extinction of their hosts.

    PubMed

    Campião, Karla Magalhães; de Aquino Ribas, Augusto Cesar; Cornell, Stephen J; Begon, Michael; Tavares, Luiz Eduardo Roland

    2015-12-01

    Amphibians are known as the most threatened vertebrate group. One of the outcomes of a species' extinction is the coextinction of its dependents. Here, we estimate the extinction risk of helminth parasites of South America anurans. Parasite coextinction probabilities were modeled, assuming parasite specificity and host vulnerability to extinction as determinants. Parasite species associated with few hosts were the most prone to extinction, and extinction risk varied amongst helminth species of different taxonomic groups and life cycle complexity. Considering host vulnerability in the model decreased the extinction probability of most parasites species. However, parasite specificity and host vulnerability combined to increase the extinction probabilities of 44% of the helminth species reported in a single anuran species.

  16. Risk estimation of infectious diseases determines the effectiveness of the control strategy

    NASA Astrophysics Data System (ADS)

    Zhang, Haifeng; Zhang, Jie; Li, Ping; Small, Michael; Wang, Binghong

    2011-05-01

    Usually, whether to take vaccination or not is a voluntary decision, which is determined by many factors, from societal factors (such as religious belief and human rights) to individual preferences (including psychology and altruism). Facing the outbreaks of infectious diseases, different people often have different estimations on the risk of infectious diseases. So, some persons are willing to vaccinate, but other persons are willing to take risks. In this paper, we establish two different risk assessment systems using the technique of dynamic programming, and then compare the effects of the two different systems on the prevention of diseases on complex networks. One is that the perceived probability of being infected for each individual is the same (uniform case). The other is that the perceived probability of being infected is positively correlated to individual degrees (preferential case). We show that these two risk assessment systems can yield completely different results, such as, the effectiveness of controlling diseases, the time evolution of the number of infections, and so on.

  17. Risk information in support of cost estimates for the Baseline Environmental Management Report (BEMR). Section 1

    SciTech Connect

    Gelston, G.M.; Jarvis, M.F.; Warren, B.R.; Von Berg, R.

    1995-06-01

    The Pacific Northwest Laboratory (PNL)(1) effort on the overall Baseline Environmental Management Report (BEMR) project consists of four installation-specific work components performed in succession. These components include (1) development of source terms, 92) collection of data and preparation of environmental settings reports, (3) calculation of unit risk factors, and (4) utilization of the unit risk factors in Automated Remedial Action Methodology (ARAM) for computation of target concentrations and cost estimates. This report documents work completed for the Nevada Test Site, Nevada, for components 2 and 3. The product of this phase of the BEMR project is the development of unit factors (i.e., unit transport factors, unit exposure factors, and unit risk factors). Thousands of these unit factors are gene rated and fill approximately one megabyte of computer information per installation. The final unit risk factors (URF) are transmitted electronically to BEMR-Cost task personnel as input to a computer program (ARAM). Abstracted files and exhibits of the URF information are included in this report. These visual formats are intended to provide a sample of the final task deliverable (the URF files) which can be easily read without a computer.

  18. Waste management programmatic environmental impact statement methodology for estimating human health risks

    SciTech Connect

    Bergenback, B.; Blaylock, B.P.; Legg, J.L.

    1995-05-01

    The US Department of Energy (DOE) has produced large quantities of radioactive and hazardous waste during years of nuclear weapons production. As a result, a large number of sites across the DOE Complex have become chemically and/or radiologically contaminated. In 1990, the Secretary of Energy charged the DOE Office of Environmental Restoration and Waste management (EM) with the task of preparing a Programmatic Environmental Impact Statement (PEIS). The PEIS should identify and assess the potential environmental impacts of implementing several integrated Environmental Restoration (ER) and Waste Management (WM) alternatives. The determination and integration of appropriate remediation activities and sound waste management practices is vital for ensuring the diminution of adverse human health impacts during site cleanup and waste management programs. This report documents the PEIS risk assessment methodology used to evaluate human health risks posed by WM activities. The methodology presents a programmatic cradle to grave risk assessment for EM program activities. A unit dose approach is used to estimate risks posed by WM activities and is the subject of this document.

  19. Arsenic risk mapping in Bangladesh: a simulation technique of cokriging estimation from regional count data.

    PubMed

    Hassan, M Manzurul; Atkins, Peter J

    2007-10-01

    Risk analysis with spatial interpolation methods from a regional database on to a continuous surface is of contemporary interest. Groundwater arsenic poisoning in Bangladesh and its impact on human health has been one of the "biggest environmental health disasters" in current years. It is ironic that so many tubewells have been installed in recent times for pathogen-free drinking water but the water pumped is often contaminated with toxic levels of arsenic. This paper seeks to analyse the spatial pattern of arsenic risk by mapping composite "problem regions" in southwest Bangladesh. It also examines the cokriging interpolation method in analysing the suitability of isopleth maps for different risk areas. GIS-based data processing and spatial analysis were used for this research, along with state-of-the-art decision-making techniques. Apart from the GIS-based buffering and overlay mapping operations, a cokriging interpolation method was adopted because of its exact interpolation capacity. The paper presents an interpolation of regional estimates of arsenic data for spatial risk mapping that overcomes the areal bias problem for administrative boundaries. Moreover, the functionality of the cokriging method demonstrates the suitability of isopleth maps that are easy to read.

  20. Use of binary logistic regression technique with MODIS data to estimate wild fire risk

    NASA Astrophysics Data System (ADS)

    Fan, Hong; Di, Liping; Yang, Wenli; Bonnlander, Brian; Li, Xiaoyan

    2007-11-01

    Many forest fires occur across the globe each year, which destroy life and property, and strongly impact ecosystems. In recent years, wildland fires and altered fire disturbance regimes have become a significant management and science problem affecting ecosystems and wildland/urban interface cross the United States and global. In this paper, we discuss the estimation of 504 probability models for forecasting fire risk for 14 fuel types, 12 months, one day/week/month in advance, which use 19 years of historical fire data in addition to meteorological and vegetation variables. MODIS land products are utilized as a major data source, and a logistical binary regression was adopted to solve fire forecast probability. In order to better modeling the change of fire risk along with the transition of seasons, some spatial and temporal stratification strategies were applied. In order to explore the possibilities of real time prediction, the Matlab distributing computing toolbox was used to accelerate the prediction. Finally, this study give an evaluation and validation of predict based on the ground truth collected. Validating results indicate these fire risk models have achieved nearly 70% accuracy of prediction and as well MODIS data are potential data source to implement near real-time fire risk prediction.

  1. Estimating wildfire risk on a Mojave Desert landscape using remote sensing and field sampling

    USGS Publications Warehouse

    Van Linn, Peter F.; Nussear, Kenneth E.; Esque, Todd C.; DeFalco, Lesley A.; Inman, Richard D.; Abella, Scott R.

    2013-01-01

    Predicting wildfires that affect broad landscapes is important for allocating suppression resources and guiding land management. Wildfire prediction in the south-western United States is of specific concern because of the increasing prevalence and severe effects of fire on desert shrublands and the current lack of accurate fire prediction tools. We developed a fire risk model to predict fire occurrence in a north-eastern Mojave Desert landscape. First we developed a spatial model using remote sensing data to predict fuel loads based on field estimates of fuels. We then modelled fire risk (interactions of fuel characteristics and environmental conditions conducive to wildfire) using satellite imagery, our model of fuel loads, and spatial data on ignition potential (lightning strikes and distance to roads), topography (elevation and aspect) and climate (maximum and minimum temperatures). The risk model was developed during a fire year at our study landscape and validated at a nearby landscape; model performance was accurate and similar at both sites. This study demonstrates that remote sensing techniques used in combination with field surveys can accurately predict wildfire risk in the Mojave Desert and may be applicable to other arid and semiarid lands where wildfires are prevalent.

  2. The new risk estimates and exposures to radon in high grade uranium mines

    SciTech Connect

    Brown, L.D. )

    1992-09-01

    The DS86 dosimetry used by the Radiation Effects Research Foundation, in re-evaluating radiation exposure risks from the atom bomb survivor lifespan studies, has led directly to a significant reduction in the maximum permissible dose recommended by the International Commission on Radiological Protection. In the case of uranium miners the contribution to the total dose resulting from the inhalation of radon daughters continues to be assessed in accordance with the procedures recommended in ICRP Report 47, which means that there has been no change in the maximum permissible radon daughter exposure limit. ICRP intends to review this situation once the new report of their task force on lung dosimetry has been adopted. This paper suggests that the direct epidemiological data on the risks of radon daughter inhalation is more satisfactory than indirect estimates of risk based on a lung dosimetry model, and that this direct evidence does not justify any increase in the presently accepted risk factor associated with radon daughter inhalation.

  3. Overall risk estimation for nonreactor nuclear facilities and implementation of safety goals

    SciTech Connect

    Kim, K.S.; Bradley, R.F.

    1993-06-01

    A typical safety analysis report (SAR) contains estimated frequencies.and consequences of various design basis accidents (DBA). However, the results are organized and presented in such a way that they are not conducive for summing up with mathematical rigor to express total or overall risk. This paper describes a mathematical formalism for deriving total risk indicators. The mathematical formalism is based on the complementary cumulative distribution function (CCDF) or exceedance probability of radioactivity release fraction and individual radiation dose. A simple protocol is presented for establishing exceedance probabilities from the results of DBA analyses typically available from an SAR. The exceedance probability of release fraction can be a useful indicator for gaining insights into the capability of confinement barriers, characteristics of source terms, and scope of the SAR. Fatality risks comparable to the DOE Safety Goals can be derived from the exceedance probability of individual doses. Example case analyses are presented to illustrate the use of the proposed protocol and mathematical formalism. The methodology is finally applied to proposed risk guidelines for individual accident events to show that these guidelines would be within the DOE Safety Goals.

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

    NASA Astrophysics Data System (ADS)

    Petrova, E.

    2004-04-01

    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.

  5. A global building inventory for earthquake loss estimation and risk management

    USGS Publications Warehouse

    Jaiswal, K.; Wald, D.; Porter, K.

    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. ?? 2010, Earthquake Engineering Research Institute.

  6. Spatially interpolated disease prevalence estimation using collateral indicators of morbidity and ecological risk.

    PubMed

    Congdon, Peter

    2013-10-01

    This paper considers estimation of disease prevalence for small areas (neighbourhoods) when the available observations on prevalence are for an alternative partition of a region, such as service areas. Interpolation to neighbourhoods uses a kernel method extended to take account of two types of collateral information. The first is morbidity and service use data, such as hospital admissions, observed for neighbourhoods. Variations in morbidity and service use are expected to reflect prevalence. The second type of collateral information is ecological risk factors (e.g., pollution indices) that are expected to explain variability in prevalence in service areas, but are typically observed only for neighbourhoods. An application involves estimating neighbourhood asthma prevalence in a London health region involving 562 neighbourhoods and 189 service (primary care) areas. PMID:24129116

  7. Nonparametric estimation and classification using radial basis function nets and empirical risk minimization.

    PubMed

    Krzyzak, A; Linder, T; Lugosi, C

    1996-01-01

    Studies convergence properties of radial basis function (RBF) networks for a large class of basis functions, and reviews the methods and results related to this topic. The authors obtain the network parameters through empirical risk minimization. The authors show the optimal nets to be consistent in the problem of nonlinear function approximation and in nonparametric classification. For the classification problem the authors consider two approaches: the selection of the RBF classifier via nonlinear function estimation and the direct method of minimizing the empirical error probability. The tools used in the analysis include distribution-free nonasymptotic probability inequalities and covering numbers for classes of functions.

  8. Risk estimation of HNA-3 incompatibility and alloimmunization in Thai populations.

    PubMed

    Nathalang, Oytip; Intharanut, Kamphon; Siriphanthong, Kanokpol; Nathalang, Siriporn; Leetrakool, Nipapan

    2015-01-01

    Severe transfusion-related acute lung injury (TRALI) is often due to antibodies in blood components directed against human neutrophil antigen (HNA)-3a. This study aimed to report the genotype frequencies of the HNA-3 system and to estimate the potential risk of HNA-3 incompatibility and alloimmunization in two Thai populations. Eight hundred DNA samples obtained from 500 unrelated healthy blood donors at the National Blood Centre, Thai Red Cross Society, Bangkok and 300 samples from the Blood Bank, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand were included. HNA-3 genotyping was performed using an in-house polymerase chain reaction with sequence-specific primer (PCR-SSP) technique. The observed frequencies of the HNA-3a/3a, HNA-3a/3b, and HNA-3b/3b genotypes were 0.528, 0.380, and 0.092 in central Thais and 0.600, 0.350, and 0.050 in northern Thais, respectively. The frequencies were used to estimate HNA-3 incompatibility and risk of HNA-3a alloimmunization. The HNA-3 incompatibility in central Thais (33.28%) was higher than northern Thais (28.75%), corresponding to a significantly higher probability of HNA-3a alloimmunization (P<0.05) similar to Japanese and Chinese populations. This study showed the high risk of HNA-3 incompatibility and alloimmunization, especially in central Thai blood donors. A molecular-based identification of the HNA-3 genotype of female donors is suggested to reduce the risk of TRALI following plasma and whole blood allogeneic transfusion.

  9. Estimation of mortality and morbidity risk of radical cystectomy using POSSUM and the Portsmouth predictor equation

    PubMed Central

    Morizane, Shuichi; Honda, Masashi; Isoyama, Tadahiro; Koumi, Tsutomu; Ono, Kouji; Kadowaki, Hiroyuki; Sejima, Takehiro; Takenaka, Atsushi

    2015-01-01

    Introduction The Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity (POSSUM) and the Portsmouth predictor equation (P-POSSUM) are simple scoring systems used to estimate the risk of complications and death postoperatively. We investigated the use of these scores to predict the postoperative risk in patients undergoing radical cystectomy (RC). Material and methods In this retrospective study, we enrolled 280 patients who underwent RC for invasive bladder cancer between January 2003 and December 2011. Morbidity and mortality were predicted using the POSSUM and P-POSSUM equations. We further assessed the ability of the POSSUM and P-POSSUM to predict the mortality and morbidity risk in RC patients with a Clavien–Dindo classification of surgical complications of grade II or higher. Results The observed morbidity and mortality rates were 58.9% (165 patients) and 1.8% (5 patients), respectively. Predicted morbidity using POSSUM was 49.2% (138 patients) compared to the 58.9% (165 patients) observed (P <0.0001). Compared to the observed death rate of 1.8% (5 patients), predicted mortality using POSSUM and P-POSSUM was 12.1% (34 patients) and 3.9% (11 patients), respectively (P <0.0001 and P = 0.205). The mortality risk estimated by P-POSSUM was not significantly different from the observed mortality rate. Conclusions The results of this study supported the efficacy of POSSUM combined with P-POSSUM to predict morbidity and mortality in patients undergoing RC. Further prospective studies are needed to better determine the usefulness of POSSUM and P-POSSUM for a comparative audit in urological patients undergoing RC. PMID:26568864

  10. Impact of Winko on absolute discharges.

    PubMed

    Balachandra, Krishna; Swaminath, Sam; Litman, Larry C

    2004-01-01

    In Canada, case laws have had a significant impact on the way mentally ill offenders are managed, both in the criminal justice system and in the forensic mental health system. The Supreme Court of Canada's decision with respect to Winko has set a major precedent in the application of the test of significant risk to the safety of the public in making dispositions by the Ontario Review Board and granting absolute discharges to the mentally ill offenders in the forensic health system. Our study examines the impact of the Supreme Court of Canada's decision before and after Winko. The results show that the numbers of absolute discharges have increased post-Winko, which was statistically significant, but there could be other factors influencing this increase.

  11. Daily salt intake estimated by overnight urine collections indicates a high cardiovascular disease risk in Thailand.

    PubMed

    Yokokawa, Hirohide; Yuasa, Motoyuki; Nedsuwan, Supalert; Moolphate, Saiyud; Fukuda, Hiroshi; Kitajima, Tsutomu; Minematsu, Kazuo; Tanimura, Susumu; Marui, Eiji

    2016-01-01

    This cross-sectional study (February 2012 to March 2013) was conducted to estimate daily salt intake and basic characteristics among 793 community-dwelling participants at high risk of cardiovascular disease (Framingham risk score >15%), who had visited diabetes or hypertension clinics at health centres in the Muang district, Chiang Rai, Thailand. We performed descriptive analysis of baseline data and used an automated analyser to estimate the average of 24-hour salt intake estimated from 3 days overnight urine collection. Participants were divided into two groups based on median estimated daily salt intake. Mean age and proportion of males were 65.2 years and 37.6% in the higher salt intake group (>=10.0 g/day, n=362), and 67.5 years and 42.7% in the lower salt intake group (<10.0 g/day, n=431), respectively (p=0.01, p<0.01). The higher salt intake group comprised more patients with a family history of hypertension, antihypertensive drug use, less ideal body mass index (18.5-24.9), higher exercise frequency (>=2 times weekly) and lower awareness of high salt intake. Among higher salt intake participants, those with lower awareness of high salt intake were younger and more often had a family history of hypertension, relative to those with more awareness. Our data indicated that families often share lifestyles involving high salt intake, and discrepancies between actual salt intake and awareness of high salt intake may represent a need for salt reduction intervention aiming at family level. Awareness of actual salt intake should be improved for each family. PMID:26965760

  12. Impact of alternative metrics on estimates of extent of occurrence for extinction risk assessment.

    PubMed

    Joppa, Lucas N; Butchart, Stuart H M; Hoffmann, Michael; Bachman, Steve P; Akçakaya, H Resit; Moat, Justin F; Böhm, Monika; Holland, Robert A; Newton, Adrian; Polidoro, Beth; Hughes, Adrian

    2016-04-01

    In International Union for Conservation of Nature (IUCN) Red List assessments, extent of occurrence (EOO) is a key measure of extinction risk. However, the way assessors estimate EOO from maps of species' distributions is inconsistent among assessments of different species and among major taxonomic groups. Assessors often estimate EOO from the area of mapped distribution, but these maps often exclude areas that are not habitat in idiosyncratic ways and are not created at the same spatial resolutions. We assessed the impact on extinction risk categories of applying different methods (minimum convex polygon, alpha hull) for estimating EOO for 21,763 species of mammals, birds, and amphibians. Overall, the percentage of threatened species requiring down listing to a lower category of threat (taking into account other Red List criteria under which they qualified) spanned 11-13% for all species combined (14-15% for mammals, 7-8% for birds, and 12-15% for amphibians). These down listings resulted from larger estimates of EOO and depended on the EOO calculation method. Using birds as an example, we found that 14% of threatened and near threatened species could require down listing based on the minimum convex polygon (MCP) approach, an approach that is now recommended by IUCN. Other metrics (such as alpha hull) had marginally smaller impacts. Our results suggest that uniformly applying the MCP approach may lead to a one-time down listing of hundreds of species but ultimately ensure consistency across assessments and realign the calculation of EOO with the theoretical basis on which the metric was founded.

  13. Impact of alternative metrics on estimates of extent of occurrence for extinction risk assessment.

    PubMed

    Joppa, Lucas N; Butchart, Stuart H M; Hoffmann, Michael; Bachman, Steve P; Akçakaya, H Resit; Moat, Justin F; Böhm, Monika; Holland, Robert A; Newton, Adrian; Polidoro, Beth; Hughes, Adrian

    2016-04-01

    In International Union for Conservation of Nature (IUCN) Red List assessments, extent of occurrence (EOO) is a key measure of extinction risk. However, the way assessors estimate EOO from maps of species' distributions is inconsistent among assessments of different species and among major taxonomic groups. Assessors often estimate EOO from the area of mapped distribution, but these maps often exclude areas that are not habitat in idiosyncratic ways and are not created at the same spatial resolutions. We assessed the impact on extinction risk categories of applying different methods (minimum convex polygon, alpha hull) for estimating EOO for 21,763 species of mammals, birds, and amphibians. Overall, the percentage of threatened species requiring down listing to a lower category of threat (taking into account other Red List criteria under which they qualified) spanned 11-13% for all species combined (14-15% for mammals, 7-8% for birds, and 12-15% for amphibians). These down listings resulted from larger estimates of EOO and depended on the EOO calculation method. Using birds as an example, we found that 14% of threatened and near threatened species could require down listing based on the minimum convex polygon (MCP) approach, an approach that is now recommended by IUCN. Other metrics (such as alpha hull) had marginally smaller impacts. Our results suggest that uniformly applying the MCP approach may lead to a one-time down listing of hundreds of species but ultimately ensure consistency across assessments and realign the calculation of EOO with the theoretical basis on which the metric was founded. PMID:26183938

  14. How accurately are maximal metabolic equivalents estimated based on the treadmill workload in healthy people and asymptomatic subjects with cardiovascular risk factors?

    PubMed

    Maeder, M T; Muenzer, T; Rickli, H; Brunner-La Rocca, H P; Myers, J; Ammann, P

    2008-08-01

    Maximal exercise capacity expressed as metabolic equivalents (METs) is rarely directly measured (measured METs; mMETs) but estimated from maximal workload (estimated METs; eMETs). We assessed the accuracy of predicting mMETs by eMETs in asymptomatic subjects. Thirty-four healthy volunteers without cardiovascular risk factors (controls) and 90 patients with at least one risk factor underwent cardiopulmonary exercise testing using individualized treadmill ramp protocols. The equation of the American College of Sports Medicine (ACSM) was employed to calculate eMETs. Despite a close correlation between eMETs and mMETs (patients: r = 0.82, controls: r = 0.88; p < 0.001 for both), eMETs were higher than mMETs in both patients [11.7 (8.9 - 13.4) vs. 8.2 (7.0 - 10.6) METs; p < 0.001] and controls [17.0 (16.2 - 18.2) vs. 15.6 (14.2 - 17.0) METs; p < 0.001]. The absolute [2.5 (1.6 - 3.7) vs. 1.3 (0.9 - 2.1) METs; p < 0.001] and the relative [28 (19 - 47) vs. 9 (6 - 14) %; p < 0.001] difference between eMETs and mMETs was higher in patients. In patients, ratio limits of agreement of 1.33 (*/ divided by 1.40) between eMETs and mMETs were obtained, whereas the ratio limits of agreement were 1.09 (*/ divided by 1.13) in controls. The ACSM equation is associated with a significant overestimation of mMETs in young and fit subjects, which is markedly more pronounced in older and less fit subjects with cardiovascular risk factors.

  15. Assessing uncertainty in published risk estimates using hexavalent chromium and lung cancer mortality as an example [Presentation 2015

    EPA Science Inventory

    Introduction: The National Research Council recommended quantitative evaluation of uncertainty in effect estimates for risk assessment. This analysis considers uncertainty across model forms and model parameterizations with hexavalent chromium [Cr(VI)] and lung cancer mortality a...

  16. Singular perturbation of absolute stability.

    NASA Technical Reports Server (NTRS)

    Siljak, D. D.

    1972-01-01

    It was previously shown (author, 1969) that the regions of absolute stability in the parameter space can be determined when the parameters appear on the right-hand side of the system equations, i.e., the regular case. Here, the effect on absolute stability of a small parameter attached to higher derivatives in the equations (the singular case) is studied. The Lur'e-Postnikov class of nonlinear systems is considered.

  17. Estimating Geographical Variation in the Risk of Zoonotic Plasmodium knowlesi Infection in Countries Eliminating Malaria

    PubMed Central

    Shearer, Freya M.; Huang, Zhi; Weiss, Daniel J.; Wiebe, Antoinette; Gibson, Harry S.; Battle, Katherine E.; Pigott, David M.; Brady, Oliver J.; Putaporntip, Chaturong; Jongwutiwes, Somchai; Lau, Yee Ling; Manske, Magnus; Amato, Roberto; Elyazar, Iqbal R. F.; Vythilingam, Indra; Bhatt, Samir; Gething, Peter W.; Singh, Balbir; Golding, Nick; Hay, Simon I.

    2016-01-01

    Background Infection by the simian malaria parasite, Plasmodium knowlesi, can lead to severe and fatal disease in humans, and is the most common cause of malaria in parts of Malaysia. Despite being a serious public health concern, the geographical distribution of P. knowlesi malaria risk is poorly understood because the parasite is often misidentified as one of the human malarias. Human cases have been confirmed in at least nine Southeast Asian countries, many of which are making progress towards eliminating the human malarias. Understanding the geographical distribution of P. knowlesi is important for identifying areas where malaria transmission will continue after the human malarias have been eliminated. Methodology/Principal Findings A total of 439 records of P. knowlesi infections in humans, macaque reservoir and vector species were collated. To predict spatial variation in disease risk, a model was fitted using records from countries where the infection data coverage is high. Predictions were then made throughout Southeast Asia, including regions where infection data are sparse. The resulting map predicts areas of high risk for P. knowlesi infection in a number of countries that are forecast to be malaria-free by 2025 (Malaysia, Cambodia, Thailand and Vietnam) as well as countries projected to be eliminating malaria (Myanmar, Laos, Indonesia and the Philippines). Conclusions/Significance We have produced the first map of P. knowlesi malaria risk, at a fine-scale resolution, to identify priority areas for surveillance based on regions with sparse data and high estimated risk. Our map provides an initial evidence base to better understand the spatial distribution of this disease and its potential wider contribution to malaria incidence. Considering malaria elimination goals, areas for prioritised surveillance are identified. PMID:27494405

  18. The potential of plasma miRNAs for diagnosis and risk estimation of colorectal cancer.

    PubMed

    Chen, Wang-Yang; Zhao, Xiao-Juan; Yu, Zhi-Fu; Hu, Fu-Lan; Liu, Yu-Peng; Cui, Bin-Bin; Dong, Xin-Shu; Zhao, Ya-Shuang

    2015-01-01

    Circulating microRNAs (miRNAs) were recognized to be potential non-invasive biomarkers for colorectal cancer (CRC) detection and prediction. Meanwhile, the association of the expression of plasma miRNAs with the risk of CRC patients has rarely been analyzed. Therefore, we conducted this study to evaluate the value of plasma miRNAs for CRC diagnosis and risk estimation. Fasting blood samples from 100 CRC patients and 79 cancer-free controls were collected. Plasma miR-106a, miR-20a, miR-27b, miR-92a and miR-29a levels were detected by RT-qPCR. Sensitivity and specificity were employed to evaluate the diagnostic value of miRNAs for CRC. Univariate and multivariate logistic regression were employed to analyze the association between miRNAs expression and CRC risk. As results, miR-106a and miR-20a were elevated in the patients with CRC. The sensitivity of miR-106a was 74.00% and the specificity was 44.40%, while the cutoff value was 2.03. As for miR-20a, the sensitivity was 46.00% and specificity was 73.42% when employed 2.44 as cutoff value. High expression of plasma miR-106a increased CRC risk by 1.80 -fold. Plasma miR-106a and miR-20a may as noninvasive biomarkers for detecting the CRC. High expression of miR-106a associated with CRC risk. PMID:26261602

  19. Semi-analytical estimation of wellbore leakage risk during CO2 sequestration in Ottawa County, Michigan

    NASA Astrophysics Data System (ADS)

    Guo, B.; Matteo, E. N.; Elliot, T. R.; Nogues, J. P.; Deng, H.; Fitts, J. P.; Pollak, M.; Bielicki, J.; Wilson, E.; Celia, M. A.; Peters, C. A.

    2011-12-01

    Using the semi-analytical ELSA model, wellbore leakage risk is estimated for CO2 injection into either the Mt. Simon or St. Peter formations, which are part of the Michigan Sedimentary Basin that lies beneath Ottawa County, MI. ELSA is a vertically integrated subsurface modeling tool that can be used to simulate both supercritical CO2 plume distribution/migration and pressure- induced brine displacement during CO2 injection. A composite 3D subsurface domain was constructed for the ELSA simulations based on estimated permeabilities for formation layers, as well as GIS databases containing subsurface stratigraphy, active and inactive and inactive wells, and potential interactions with subsurface activities. These activities include potable aquifers, oil and gas reservoirs, and waste injection sites, which represent potential liabilities if encountered by brine or supercritical CO2 displaced from the injection formation. Overall, the 3D subsurface domain encompasses an area of 1500 km2 to a depth of 2 km and contains over 3,000 wells. The permeabilities for abandoned wells are derived from a ranking system based on available well data including historical records and well logs. This distribution is then randomly sampled in Monte Carlo simulations that are used to generate a probability map for subsurface interferences or atmospheric release resulting from leakage of CO2 and /or brine from the injection formation. This method serves as the basis for comparative testing between various scenarios for injection, as well as for comparing the relative risk of leakage between injection formations or storage sites.

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

    PubMed

    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

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

    PubMed

    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

  2. Estimation of Wild Fire Risk Area based on Climate and Maximum Entropy in Korean Peninsular

    NASA Astrophysics Data System (ADS)

    Kim, T.; Lim, C. H.; Song, C.; Lee, W. K.

    2015-12-01

    The number of forest fires and accompanying human injuries and physical damages has been increased by frequent drought. In this study, forest fire danger zone of Korea is estimated to predict and prepare for future forest fire hazard regions. The MaxEnt (Maximum Entropy) model is used to estimate the forest fire hazard region which estimates the probability distribution of the status. The MaxEnt model is primarily for the analysis of species distribution, but its applicability for various natural disasters is getting recognition. The detailed forest fire occurrence data collected by the MODIS for past 5 years (2010-2014) is used as occurrence data for the model. Also meteorology, topography, vegetation data are used as environmental variable. In particular, various meteorological variables are used to check impact of climate such as annual average temperature, annual precipitation, precipitation of dry season, annual effective humidity, effective humidity of dry season, aridity index. Consequently, the result was valid based on the AUC(Area Under the Curve) value (= 0.805) which is used to predict accuracy in the MaxEnt model. Also predicted forest fire locations were practically corresponded with the actual forest fire distribution map. Meteorological variables such as effective humidity showed the greatest contribution, and topography variables such as TWI (Topographic Wetness Index) and slope also contributed on the forest fire. As a result, the east coast and the south part of Korea peninsula were predicted to have high risk on the forest fire. In contrast, high-altitude mountain area and the west coast appeared to be safe with the forest fire. The result of this study is similar with former studies, which indicates high risks of forest fire in accessible area and reflects climatic characteristics of east and south part in dry season. To sum up, we estimated the forest fire hazard zone with existing forest fire locations and environment variables and had

  3. Improving the Estimation of Celiac Disease Sibling Risk by Non-HLA Genes

    PubMed Central

    Izzo, Valentina; Pinelli, Michele; Tinto, Nadia; Esposito, Maria Valeria; Cola, Arturo; Sperandeo, Maria Pia; Tucci, Francesca; Cocozza, Sergio; Greco, Luigi; Sacchetti, Lucia

    2011-01-01

    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. PMID:22087237

  4. Estimation of wildfire size and risk changes due to fuels treatments

    USGS Publications Warehouse

    Cochrane, M.A.; Moran, C.J.; Wimberly, M.C.; Baer, A.D.; Finney, M.A.; Beckendorf, K.L.; Eidenshink, J.; Zhu, Z.

    2012-01-01

    Human land use practices, altered climates, and shifting forest and fire management policies have increased the frequency of large wildfires several-fold. Mitigation of potential fire behaviour and fire severity have increasingly been attempted through pre-fire alteration of wildland fuels using mechanical treatments and prescribed fires. Despite annual treatment of more than a million hectares of land, quantitative assessments of the effectiveness of existing fuel treatments at reducing the size of actual wildfires or how they might alter the risk of burning across landscapes are currently lacking. Here, we present a method for estimating spatial probabilities of burning as a function of extant fuels treatments for any wildland fire-affected landscape. We examined the landscape effects of more than 72 000 ha of wildland fuel treatments involved in 14 large wildfires that burned 314 000 ha of forests in nine US states between 2002 and 2010. Fuels treatments altered the probability of fire occurrence both positively and negatively across landscapes, effectively redistributing fire risk by changing surface fire spread rates and reducing the likelihood of crowning behaviour. Trade offs are created between formation of large areas with low probabilities of increased burning and smaller, well-defined regions with reduced fire risk.

  5. Estimation of the Transportation Risks for the Spent Fuel in Korea for Various Transportation Scenarios

    SciTech Connect

    Jongtae, Jeong; Cho, D.K.; Choi, H.J.; Choi, J.W.

    2008-07-01

    According to the long term management strategy for spent fuels in Korea, they will be transported from the spent fuel pools in each nuclear power plant to the central interim storage facility (CISF) which is to start operation in 2016. Therefore, we have to determine the safe and economical logistics for the transportation of these spent fuels by considering their transportation risks and costs. In this study, we developed four transportation scenarios by considering the type of transportation casks and transport means in order to suggest safe and economical transportation logistics for the spent fuels in Korea. Also, we estimated and compared the transportation risks for these four transportation scenarios. From the results of this study, we found that these four transportation scenarios for spent fuels have a very low radiological risk activity with a manageable safety and health consequences. The results of this study can be used as basic data for the development of safe and economical logistics for a transportation of the spent fuels in Korea by considering the transportation costs for the four scenarios which will be needed in the near future. (authors)

  6. Identification and estimation of socioeconomic impacts resulting from perceived risks and changing images; An annotated bibliography

    SciTech Connect

    Nieves, L.A.; Wernette, D.R.; Hemphill, R.C.; Mohiudden, S.; Corso, J.

    1990-02-01

    In 1982, the US Congress passed the Nuclear Waste Policy Act to initiate the process of choosing a location to permanently store high-level nuclear waste from the designated Yucca Mountain, Nevada, as the only location to be studied as a candidate site for such a repository. The original acts and its amendments had established the grant mechanism by which the state of Nevada could finance an investigation of the potential socioeconomic impacts that could result from the installation and operation of this facility. Over the past three years, the Office of Civilian Radioactive Waste Management (OCRWM or RW) in the US Department of Energy (DOE) has approved grant requests by Nevada to perform this investigation. This report is intended to update and enhance a literature review conducted by the Human Affairs Research Center (HARC) for the Basalt Waste Isolation Project that dealt with the psychological and sociological processes underlying risk perception. It provides addition information on the HARC work, covers a subsequent step in the impact-estimation process, and translates risk perception into decisions and behaviors with economic consequences. It also covers recently developed techniques for assessing the nature and magnitude of impacts caused by environmental changes focusing on those impacts caused by changes in perceived risks.

  7. Towards a US national estimate of the risk of endemic waterborne disease--sero-epidemiologic studies.

    PubMed

    Casemore, David

    2006-01-01

    Worldwide literature on serological methods and sero-surveys on waterborne pathogens has been reviewed. Outbreak investigation and research reports have also been examined to aid understanding of the serological response and transmission dynamics. The aim was to seek an estimate of seroprevalence and to determine if this could inform the US national estimate of risk for endemic waterborne infection associated with public water supplies. Antibody responses indicate infection, both symptomatic and asymptomatic, so probably give a truer indication of prevalence. Outbreak data can probably be regarded as the upper bound for seroprevalence estimations. Antibody is not necessarily protective per se but is a good indicator for at least partial resistance to symptomatic infection; absence of antibody will normally imply susceptibility. Pathogens transmitted by water are commonly transmitted by other routes. However, the fact that other transmission routes are more common does not detract from the potential protective effect of immunity when waterborne transmission occurs. Data indicate that seroprevalence varies widely, reflecting geographic, social and hygiene factors, but is generally greater where surface water sources are used rather than groundwater. Areas of low seroprevalence may expect a high attack rate in the event of contamination of their water supply.

  8. Use of health effect risk estimates and uncertainty in formal regulatory proceedings: a case study involving atmospheric particulates

    SciTech Connect

    Habegger, L.J.; Oezkaynak, A.H.

    1984-01-01

    Coal combustion particulates are released to the atmosphere by power plants supplying electrical to the nuclear fuel cycle. This paper presents estimates of the public health risks associated with the release of these particulates at a rate associated with the annual nuclear fuel production requirements for a nuclear power plan. Utilization of these risk assessments as a new component in the formal evaluation of total risks from nuclear power plants is discussed. 23 references, 3 tables.

  9. Estimated Reduction in Cancer Risk due to PAH Exposures If Source Control Measures during the 2008 Beijing Olympics Were Sustained

    PubMed Central

    Jia, Yuling; Stone, Dave; Wang, Wentao; Schrlau, Jill; Tao, Shu; Massey Simonich, Staci L.

    2011-01-01

    Background The 2008 Beijing Olympic Games provided a unique case study to investigate the effect of source control measures on the reduction in air pollution, and associated inhalation cancer risk, in a Chinese megacity. Objectives We measured 17 carcinogenic polycyclic aromatic hydrocarbons (PAHs) and estimated the lifetime excess inhalation cancer risk during different periods of the Beijing Olympic Games, to assess the effectiveness of source control measures in reducing PAH-induced inhalation cancer risks. Methods PAH concentrations were measured in samples of particulate matter ≤ 2.5 μm in aerodynamic diameter (PM2.5) collected during the Beijing Olympic Games, and the associated inhalation cancer risks were estimated using a point-estimate approach based on relative potency factors. Results We estimated the number of lifetime excess cancer cases due to exposure to the 17 carcinogenic PAHs [12 priority pollutant PAHs and five high-molecular-weight (302 Da) PAHs (MW 302 PAHs)] to range from 6.5 to 518 per million people for the source control period concentrations and from 12.2 to 964 per million people for the nonsource control period concentrations. This would correspond to a 46% reduction in estimated inhalation cancer risk due to source control measures, if these measures were sustained over time. Benzo[b]fluoranthene, dibenz[a,h]anthracene, benzo[a]pyrene, and dibenzo[a,l]pyrene were the most carcinogenic PAH species evaluated. Total excess inhalation cancer risk would be underestimated by 23% if we did not include the five MW 302 PAHs in the risk calculation. Conclusions Source control measures, such as those imposed during the 2008 Beijing Olympics, can significantly reduce the inhalation cancer risk associated with PAH exposure in Chinese megacities similar to Beijing. MW 302 PAHs are a significant contributor to the estimated overall inhalation cancer risk. PMID:21632310

  10. Dementia risk estimates associated with measures of depression: a systematic review and meta-analysis

    PubMed Central

    Anstey, Kaarin J

    2015-01-01

    Objectives To perform a systematic review of reported HRs of all cause dementia, Alzheimer's disease (AD) and vascular dementia (VaD) for late-life depression and depressive symptomatology on specific screening instruments at specific thresholds. Design Meta-analysis with meta-regression. Setting and participants PubMed, PsycInfo, and Cochrane databases were searched through 28 February 2014. Articles reporting HRs for incident all-cause dementia, AD and VaD based on published clinical criteria using validated measures of clinical depression or symptomatology from prospective studies of general population of adults were selected by consensus among multiple reviewers. Studies that did not use clinical dementia diagnoses or validated instruments for the assessment of depression were excluded. Data were extracted by two reviewers and reviewed by two other independent reviewers. The most specific analyses possible using continuous symptomatology ratings and categorical measures of clinical depression focusing on single instruments with defined reported cut-offs were conducted. Primary outcome measures HRs for all-cause dementia, AD, and VaD were computed where possible for continuous depression scores, or for major depression assessed with single or comparable validated instruments. Results Searches yielded 121 301 articles, of which 36 (0.03%) were eligible. Included studies provided a combined sample size of 66 532 individuals including 6593 cases of dementia, 2797 cases of AD and 585 cases of VaD. The increased risk associated with depression did not significantly differ by type of dementia and ranged from 83% to 104% for diagnostic thresholds consistent with major depression. Risk associated with continuous depression symptomatology measures were consistent with those for clinical thresholds. Conclusions Late-life depression is consistently and similarly associated with a twofold increased risk of dementia. The precise risk estimates produced in this study for

  11. Chemical composition of French mimosa absolute oil.

    PubMed

    Perriot, Rodolphe; Breme, Katharina; Meierhenrich, Uwe J; Carenini, Elise; Ferrando, Georges; Baldovini, Nicolas

    2010-02-10

    Since decades mimosa (Acacia dealbata) absolute oil has been used in the flavor and perfume industry. Today, it finds an application in over 80 perfumes, and its worldwide industrial production is estimated five tons per year. Here we report on the chemical composition of French mimosa absolute oil. Straight-chain analogues from C6 to C26 with different functional groups (hydrocarbons, esters, aldehydes, diethyl acetals, alcohols, and ketones) were identified in the volatile fraction. Most of them are long-chain molecules: (Z)-heptadec-8-ene, heptadecane, nonadecane, and palmitic acid are the most abundant, and constituents such as 2-phenethyl alcohol, methyl anisate, and ethyl palmitate are present in smaller amounts. The heavier constituents were mainly triterpenoids such as lupenone and lupeol, which were identified as two of the main components. (Z)-Heptadec-8-ene, lupenone, and lupeol were quantified by GC-MS in SIM mode using external standards and represents 6%, 20%, and 7.8% (w/w) of the absolute oil. Moreover, odorant compounds were extracted by SPME and analyzed by GC-sniffing leading to the perception of 57 odorant zones, of which 37 compounds were identified by their odorant description, mass spectrum, retention index, and injection of the reference compound. PMID:20070087

  12. Chemical composition of French mimosa absolute oil.

    PubMed

    Perriot, Rodolphe; Breme, Katharina; Meierhenrich, Uwe J; Carenini, Elise; Ferrando, Georges; Baldovini, Nicolas

    2010-02-10

    Since decades mimosa (Acacia dealbata) absolute oil has been used in the flavor and perfume industry. Today, it finds an application in over 80 perfumes, and its worldwide industrial production is estimated five tons per year. Here we report on the chemical composition of French mimosa absolute oil. Straight-chain analogues from C6 to C26 with different functional groups (hydrocarbons, esters, aldehydes, diethyl acetals, alcohols, and ketones) were identified in the volatile fraction. Most of them are long-chain molecules: (Z)-heptadec-8-ene, heptadecane, nonadecane, and palmitic acid are the most abundant, and constituents such as 2-phenethyl alcohol, methyl anisate, and ethyl palmitate are present in smaller amounts. The heavier constituents were mainly triterpenoids such as lupenone and lupeol, which were identified as two of the main components. (Z)-Heptadec-8-ene, lupenone, and lupeol were quantified by GC-MS in SIM mode using external standards and represents 6%, 20%, and 7.8% (w/w) of the absolute oil. Moreover, odorant compounds were extracted by SPME and analyzed by GC-sniffing leading to the perception of 57 odorant zones, of which 37 compounds were identified by their odorant description, mass spectrum, retention index, and injection of the reference compound.

  13. Improved risk estimated from carbon tetrachloride. Annual progress report, October 1, 1996--September 30, 1997

    SciTech Connect

    Benson, J.M.

    1997-10-27

    'Carbon tetrachloride (CCl{sub 4}) has been used extensively within the Department of Energy (DOE) nuclear weapons facilities. Rocky Flats was formerly the largest volume user of CCl{sub 4} in the US, with 5,000 gallons used there in 1977 alone. At the Hanford site, several hundred thousand gallons of CCl{sub 4} were discharged between 1955 and 1973 into underground cribs for storage. Levels of CCl{sub 4} in groundwater at highly contaminated sites at the Hanford. facility have exceeded the drinking water standard of 5 ppb by several orders of magnitude. High levels of CCl{sub 4} at these facilities represent a potential health hazard for workers conducting cleanup operations and for surrounding communities. The level of CCl{sub 4} cleanup required at these sites and associated costs are driven by current human health risk estimates which assume that CCl{sub 4} is a genotoxic carcinogen. The overall purpose of these studies is to improve the scientific basis for assessing the health risk associated with human exposure to CCl{sub 4}. Specifically, the authors will determine the toxicokinetics of inhaled and ingested CCl{sub 4} in F344/Crl rats, B6C3F1 mice, and Syrian hamsters. They will also evaluate species differences in the metabolism of CCl{sub 4} by rats, mice, hamsters, and man. Dose-response relationships will be determined in all these studies. This information will be used to improve the physiologically based pharmacokinetic (PBPK) model for CCl4 originally developed by Paustenbach et al. (1988) and more recently revised by Thrall and Kenny (1996). They will also provide scientific evidence that CCl{sub 4} , like chloroform, is a hepatocarcinogen only when exposure results in cell damage, cell killing, and regenerative cell proliferation. In combination, the studies outlined in this proposal will provide the exact types of information needed to enable refined cancer risk estimates for CCl{sub 4} under the new guidelines for risk assessment proposed by the

  14. Exploration of diffusion kernel density estimation in agricultural drought risk analysis: a case study in Shandong, China

    NASA Astrophysics Data System (ADS)

    Chen, W.; Shao, Z.; Tiong, L. K.

    2015-11-01

    Drought caused the most widespread damage in China, making up over 50 % of the total affected area nationwide in recent decades. In the paper, a Standardized Precipitation Index-based (SPI-based) drought risk study is conducted using historical rainfall data of 19 weather stations in Shandong province, China. Kernel density based method is adopted to carry out the risk analysis. Comparison between the bivariate Gaussian kernel density estimation (GKDE) and diffusion kernel density estimation (DKDE) are carried out to analyze the effect of drought intensity and drought duration. The results show that DKDE is relatively more accurate without boundary-leakage. Combined with the GIS technique, the drought risk is presented which reveals the spatial and temporal variation of agricultural droughts for corn in Shandong. The estimation provides a different way to study the occurrence frequency and severity of drought risk from multiple perspectives.

  15. Absolute flux scale for radioastronomy

    SciTech Connect

    Ivanov, V.P.; Stankevich, K.S.

    1986-07-01

    The authors propose and provide support for a new absolute flux scale for radio astronomy, which is not encumbered with the inadequacies of the previous scales. In constructing it the method of relative spectra was used (a powerful tool for choosing reference spectra). A review is given of previous flux scales. The authors compare the AIS scale with the scale they propose. Both scales are based on absolute measurements by the ''artificial moon'' method, and they are practically coincident in the range from 0.96 to 6 GHz. At frequencies above 6 GHz, 0.96 GHz, the AIS scale is overestimated because of incorrect extrapolation of the spectra of the primary and secondary standards. The major results which have emerged from this review of absolute scales in radio astronomy are summarized.

  16. Flood risk assessment in France: comparison of extreme flood estimation methods (EXTRAFLO project, Task 7)

    NASA Astrophysics Data System (ADS)

    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

  17. Combining Radiation Epidemiology With Molecular Biology-Changing From Health Risk Estimates to Therapeutic Intervention.

    PubMed

    Abend, Michael; Port, Matthias

    2016-08-01

    The authors herein summarize six presentations dedicated to the key session "molecular radiation epidemiology" of the ConRad meeting 2015. These presentations were chosen in order to highlight the promise when combining conventional radiation epidemiology with molecular biology. Conventional radiation epidemiology uses dose estimates for risk predictions on health. However, combined with molecular biology, dose-dependent bioindicators of effect hold the promise to improve clinical diagnostics and to provide target molecules for potential therapeutic intervention. One out of the six presentations exemplified the use of radiation-induced molecular changes as biomarkers of exposure by measuring stabile chromosomal translocations. The remaining five presentations focused on molecular changes used as bioindicators of the effect. These bioindicators of the effect could be used for diagnostic purposes on colon cancers (genomic instability), thyroid cancer (CLIP2), or head and neck squamous cell cancers. Therapeutic implications of gene expression changes were examined in Chernobyl thyroid cancer victims and Mayak workers. PMID:27356062

  18. Schistosomiasis risk estimation in Minas Gerais State, Brazil, using environmental data and GIS techniques.

    PubMed

    Guimarães, Ricardo J P S; Freitas, Corina C; Dutra, Luciano V; Moura, Ana C M; Amaral, Ronaldo S; Drummond, Sandra C; Scholte, Ronaldo G C; Carvalho, Omar S

    2008-01-01

    The influence of climate and environmental variables to the distribution of schistosomiasis has been assessed in several previous studies. Also Geographical Information System (GIS), is a tool that has been recently tested for better understanding the spatial disease distribution. The objective of this paper is to further develop the GIS technology for modeling and control of schistosomiasis using meteorological and social variables and introducing new potential environmental-related variables, particularly those produced by recently launched orbital sensors like the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Shuttle Radar Topography Mission (SRTM). Three different scenarios have been analyzed, and despite of not quite large determination factor, the standard deviation of risk estimates was considered adequate for public health needs. The main variables selected as important for modeling purposes was topographic elevation, summer minimum temperature, the NDVI vegetation index, and the social index HDI91. PMID:18692017

  19. Combining Radiation Epidemiology With Molecular Biology-Changing From Health Risk Estimates to Therapeutic Intervention.

    PubMed

    Abend, Michael; Port, Matthias

    2016-08-01

    The authors herein summarize six presentations dedicated to the key session "molecular radiation epidemiology" of the ConRad meeting 2015. These presentations were chosen in order to highlight the promise when combining conventional radiation epidemiology with molecular biology. Conventional radiation epidemiology uses dose estimates for risk predictions on health. However, combined with molecular biology, dose-dependent bioindicators of effect hold the promise to improve clinical diagnostics and to provide target molecules for potential therapeutic intervention. One out of the six presentations exemplified the use of radiation-induced molecular changes as biomarkers of exposure by measuring stabile chromosomal translocations. The remaining five presentations focused on molecular changes used as bioindicators of the effect. These bioindicators of the effect could be used for diagnostic purposes on colon cancers (genomic instability), thyroid cancer (CLIP2), or head and neck squamous cell cancers. Therapeutic implications of gene expression changes were examined in Chernobyl thyroid cancer victims and Mayak workers.

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

    SciTech Connect

    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.

  1. An assessment of ecological and case-control methods for estimating lung cancer risk due to indoor radon

    SciTech Connect

    Stidley, C.A.; Samet, J.M.

    1992-12-31

    Studies of underground miners indicate that indoor radon is an important cause of lung cancer. This finding has raised concern that exposure to radon also causes lung cancer in the general population. Epidemiological studies, including both case-control and ecological approaches, have directly addressed the risks of indoor residential radon; many more case-control studies are in progress. Ecological studies that associate lung-cancer rates with typical indoor radon levels in various geographic areas have not consistently shown positive associations. The results of purportedly negative ecological studies have been used as a basis for questioning the hazards of indoor radon exposure. Because of potentially serious methodologic flaws for testing hypotheses, we examined the ecological method as a tool for assessing lung-cancer risk from indoor radon exposure. We developed a simulation approach that utilizes the Environmental Protection Agency (EPA) radon survey data to assign exposures to individuals within counties. Using the computer-generated data, we compared risk estimates obtained by ecological regression methods with those obtained from other regression methods and with the {open_quotes}true{close_quotes} risks used to generate the data. For many of these simulations, the ecological models, while fitting the summary data well, gave risk estimates that differed considerably from the true risks. For some models, the risk estimates were negatively correlated with exposure, although the assumed relationship was positive. Attempts to improve the ecological models by adding smoking variables, including interaction terms, did not always improve the estimates of risk, which are easily affected by model misspecification. Because exposure situations used in the simulations are realistic, our results show that ecological methods may not accurately estimate the lung-cancer risk associated with indoor radon exposure.

  2. Effect of water resource development and management on lymphatic filariasis, and estimates of populations at risk.

    PubMed

    Erlanger, Tobias E; Keiser, Jennifer; Caldas De Castro, Marcia; Bos, Robert; Singer, Burton H; Tanner, Marcel; Utzinger, Jürg

    2005-09-01

    Lymphatic filariasis (LF) is a debilitating disease overwhelmingly caused by Wuchereria bancrofti, which is transmitted by various mosquito species. Here, we present a systematic literature review with the following objectives: (i) to establish global and regional estimates of populations at risk of LF with particular consideration of water resource development projects, and (ii) to assess the effects of water resource development and management on the frequency and transmission dynamics of the disease. We estimate that globally, 2 billion people are at risk of LF. Among them, there are 394.5 million urban dwellers without access to improved sanitation and 213 million rural dwellers living in close proximity to irrigation. Environmental changes due to water resource development and management consistently led to a shift in vector species composition and generally to a strong proliferation of vector populations. For example, in World Health Organization (WHO) subregions 1 and 2, mosquito densities of the Anopheles gambiae complex and Anopheles funestus were up to 25-fold higher in irrigated areas when compared with irrigation-free sites. Although the infection prevalence of LF often increased after the implementation of a water project, there was no clear association with clinical symptoms. Concluding, there is a need to assess and quantify changes of LF transmission parameters and clinical manifestations over the entire course of water resource developments. Where resources allow, integrated vector management should complement mass drug administration, and broad-based monitoring and surveillance of the disease should become an integral part of large-scale waste management and sanitation programs, whose basic rationale lies in a systemic approach to city, district, and regional level health services and disease prevention.

  3. Regression models and risk estimation for mixed discrete and continuous outcomes in developmental toxicology.

    PubMed

    Regan, M M; Catalano, P J

    2000-06-01

    Multivariate dose-response models have recently been proposed for developmental toxicity data to simultaneously model malformation incidence (a binary outcome), and reductions in fetal weight (a continuous outcome). In this and other applications, the binary outcome often represents a dichotomization of another outcome or a composite of outcomes, which facilitates analysis. For example, in Segment II developmental toxicology studies, multiple malformation types (i.e., external, visceral, skeletal) are evaluated on each fetus; malformation status may also be ordinally measured (e.g., normal, signs of variation, full malformation). A model is proposed is for fetal weight and multiple malformation variables measured on an ordinal scale, where the correlations between the outcomes and between the offspring within a litter are taken into account. Fully specifying the joint distribution of outcomes within a litter is avoided by specifying only the distribution of the multivariate outcome for each fetus and using generalized estimating equation methodology to account for correlations due to litter clustering. The correlations between the outcomes are required to characterize joint risk to the fetus, and are therefore a focus of inference. Dose-response models and their application to quantitative risk assessment are illustrated using data from a recent developmental toxicology experiment of ethylene oxide in mice. PMID:10949415

  4. Be rich or don't be sick: estimating Vietnamese patients' risk of falling into destitution.

    PubMed

    Vuong, Quan Hoang

    2015-01-01

    This paper represents the first research attempt to estimate the probabilities of Vietnamese patients falling into destitution due to financial burdens occurring during a curative hospital stay. The study models risk against such factors as level of insurance coverage, residency status of patient, and cost of treatment, among others. The results show that very high probabilities of destitution, approximately 70 %, apply to a large group of patients, who are non-residents, poor and ineligible for significant insurance coverage. There is also a probability of 58 % that seriously ill low-income patients who face higher health care costs would quit their treatment. These facts put the Vietnamese government's ambitious plan of increasing both universal coverage (UC) to 100 % of expenditure and the rate of UC beneficiaries to 100 %, to a serious test. The current study also raises issues of asymmetric information and alternative financing options for the poor, who are most exposed to risk of destitution following market-based health care reforms. PMID:26413435

  5. Update of identification and estimation of socioeconomic impacts resulting from perceived risks and changing images: An annotated bibliography

    SciTech Connect

    Nieves, L.A.; Clark, D.E.; Wernette, D.

    1991-08-01

    This annotated bibliography reviews selected literature published through August 1991 on the identification of perceived risks and methods for estimating the economic impacts of risk perception. It updates the literature review found in Argonne National Laboratory report ANL/EAIS/TM-24 (February 1990). Included in this update are (1) a literature review of the risk perception process, of the relationship between risk perception and economic impacts, of economic methods and empirical applications, and interregional market interactions and adjustments; (2) a working bibliography (that includes the documents abstracted in the 1990 report); (3) a topical index to the abstracts found in both reports; and (4) abstracts of selected articles found in this update.

  6. Estimating the pollution risk of cadmium in soil using a composite soil environmental quality standard.

    PubMed

    Qu, Mingkai; Li, Weidong; Zhang, Chuanrong; Huang, Biao; Zhao, Yongcun

    2014-01-01

    Estimating standard-exceeding probabilities of toxic metals in soil is crucial for environmental evaluation. Because soil pH and land use types have strong effects on the bioavailability of trace metals in soil, they were taken into account by some environmental protection agencies in making composite soil environmental quality standards (SEQSs) that contain multiple metal thresholds under different pH and land use conditions. This study proposed a method for estimating the standard-exceeding probability map of soil cadmium using a composite SEQS. The spatial variability and uncertainty of soil pH and site-specific land use type were incorporated through simulated realizations by sequential Gaussian simulation. A case study was conducted using a sample data set from a 150 km(2) area in Wuhan City and the composite SEQS for cadmium, recently set by the State Environmental Protection Administration of China. The method may be useful for evaluating the pollution risks of trace metals in soil with composite SEQSs.

  7. Estimating the Pollution Risk of Cadmium in Soil Using a Composite Soil Environmental Quality Standard

    PubMed Central

    Huang, Biao; Zhao, Yongcun

    2014-01-01

    Estimating standard-exceeding probabilities of toxic metals in soil is crucial for environmental evaluation. Because soil pH and land use types have strong effects on the bioavailability of trace metals in soil, they were taken into account by some environmental protection agencies in making composite soil environmental quality standards (SEQSs) that contain multiple metal thresholds under different pH and land use conditions. This study proposed a method for estimating the standard-exceeding probability map of soil cadmium using a composite SEQS. The spatial variability and uncertainty of soil pH and site-specific land use type were incorporated through simulated realizations by sequential Gaussian simulation. A case study was conducted using a sample data set from a 150 km2 area in Wuhan City and the composite SEQS for cadmium, recently set by the State Environmental Protection Administration of China. The method may be useful for evaluating the pollution risks of trace metals in soil with composite SEQSs. PMID:24672364

  8. Value-at-risk estimation with wavelet-based extreme value theory: Evidence from emerging markets

    NASA Astrophysics Data System (ADS)

    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.

  9. Estimating the Influence of Oil and Gas Emissions on Urban Ozone and Associated Health Risks

    NASA Astrophysics Data System (ADS)

    Capps, S.; Nsanzineza, R.; Turner, M. D.; Henze, D. K.; Zhao, S.; Russell, M. G.; Hakami, A.; Milford, J. B.

    2015-12-01

    Tropospheric ozone (O3) degrades air quality, impacting human health and public welfare. The National Ambient Air Quality Standard (NAAQS) is designed to limit these impacts, but certain areas in the continental U.S. exceed this standard. Mitigating O3 NAAQS exceedances by designing emissions controls can be complicated in urban areas because of the long-range transport of ozone and its gaseous precursors as well as the complex mix of local emissions sources. Recent growth of unconventional oil and gas development near urban areas in Colorado, Texas, and the northeastern corridor has exacerbated this problem. To estimate the contribution of emissions from oil and gas development to urban O3 issues, we apply the CMAQ adjoint, which efficiently elucidates the relative influence of emissions sources on select concentration-based metrics. Specifically, the adjoint is used to calculate the spatially-specific relative contributions of emissions of oxides of nitrogen (NOx) and volatile organic compounds (VOCs) throughout the continental U.S. to O3 NAAQS exceedances and to ozone-related health risks in select urban areas. By evaluating these influences for different urban areas, including one in California that has been managing air quality with adjacent oil and gas development for a longer period of time, we are able to compare and contrast the emissions control strategies that may be more effective in particular regions. Additionally, the resulting relationships between emissions and concentrations provide a way to project ozone impacts when measurements provide refined estimates of emissions from this sector.

  10. Estimating functional connectivity of wildlife habitat and its relevance to ecological risk assessment

    USGS Publications Warehouse

    Johnson, A.R.; Allen, C.R.; Simpson, K.A.N.

    2004-01-01

    Habitat fragmentation is a major threat to the viability of wildlife populations and the maintenance of biodiversity. Fragmentation relates to the sub-division of habitat intq disjunct patches. Usually coincident with fragmentation per se is loss of habitat, a reduction in the size of the remnant patches, and increasing distance between patches. Natural and anthropogenic processes leading to habitat fragmentation occur at many spatial scales, and their impacts on wildlife depend on the scales at which species interact with the landscape. The concept of functional connectivity captures this organism-based view of the relative ease of movement or degree of exchange between physically disjunct habitat patches. Functional connectivity of a given habitat arrangement for a given wildlife species depends on details of the organism's life history and behavioral ecology, but, for broad categories of species, quantities such as home range size and dispersal distance scale allometrically with body mass. These relationships can be incorporated into spatial analyses of functional connectivity, which can be quantified by indices or displayed graphically in maps. We review indices and GIS-based approaches to estimating functional connectivity, presenting examples from the literature and our own work on mammalian distributions. Such analyses can be readily incorporated within an ecological risk framework. Estimates of functional connectivity may be useful in a screening-level assessment of the impact of habitat fragmentation relative to other stressors, and may be crucial in detailed population modeling and viability analysis.

  11. Radiation dose measurement and risk estimation for paediatric patients undergoing micturating cystourethrography.

    PubMed

    Sulieman, A; Theodorou, K; Vlychou, M; Topaltzikis, T; Kanavou, D; Fezoulidis, I; Kappas, C

    2007-09-01

    Micturating cystourethrography (MCU) is considered to be the gold-standard method used to detect and grade vesicoureteric reflux (VUR) and show urethral and bladder abnormalities. It accounts for 30-50% of all fluoroscopic examinations in children. Therefore, it is crucial to define and optimize the radiation dose received by a child during MCU examination, taking into account that children have a higher risk of developing radiation-induced cancer than adults. This study aims to quantify and evaluate, by means of thermoluminescence dosimetry (TLD), the radiation dose to the newborn and paediatric populations undergoing MCU using fluoroscopic imaging. Evaluation of entrance surface dose (ESD), organ and surface dose to specific radiosensitive organs was carried out. Furthermore, the surface dose to the co-patient, i.e. individuals helping in the support, care and comfort of the children during the examination, was evaluated in order to estimate the level of risk. 52 patients with mean age of 0.36 years who had undergone MCU using digital fluoroscopy were studied. ESD, surface doses to thyroid, testes/ovaries and co-patients were measured with TLDs. MCU with digital equipment and fluoroscopy-captured image technique can reduce the radiation dose by approximately 50% while still obtaining the necessary diagnostic information. Radiographic exposures were made in cases of the presence of reflux or of the difficulty in evaluating a finding. The radiation surface doses to the thyroid and testes are relatively low, whereas the radiation dose to the co-patient is negligible. The risks associated with MCU for patients and co-patients are negligible. The results of this study provide baseline data to establish reference dose levels for MCU examination in very young patients.

  12. Classification of Kidney Transplant Recipients Using a Combination of Estimated GFR and Albuminuria Reflects Risk

    PubMed Central

    White, Christine A.; Akbari, Ayub; Talreja, Hari; Lalani, Neha; Knoll, Greg A.

    2016-01-01

    Background The 2012 Kidney Dialysis Initiative Global Outcomes chronic kidney disease (CKD) classification scheme subdivides stage 3 CKD and incorporates the urinary albumin-to-creatinine ratio (ACR). The aim of this study was to evaluate whether the novel scheme provides graded risk in kidney transplant recipients (KTRs). Methods Prevalent KTRs with available laboratory data were included. The primary outcome was a composite of doubling of serum creatinine, graft failure, or death. Patients were stratified using the CKD-Epidemiolgic Collaboration equation, and ACR and the event rate per 1000 patient-years in each CKD category were calculated. Results There were 269 KTRs with a mean follow-up of 4.5 ± 2.0 years. There was a graded increase in outcomes with increasing ACR and decreasing estimated glomerular filtration rate (eGFR). For the primary outcome, the event rate was 15.3 (95% confidence interval, 4.2-39.2) per 1000 patient-years for those with an eGFR greater than 60 mL/min per 1.73 m2 and an ACR less than 30 mg/g, whereas it was 375 (95% confidence interval, 193.8-655.1) for those with an eGFR less than 30 mL/min per 1.73 m2 and an ACR greater than 300 mg/g. Conclusions The novel Kidney Dialysis Initiative Global Outcomes classification scheme provides graded risk for important clinical events in KTRs. This information can be used to identify high-risk patients and to tailor follow-up and management strategies aimed at improving outcomes.

  13. Exposure Estimation for Risk Assessment of the Phthalate Incident in Taiwan

    PubMed Central

    Chen, Chu-Chih; Wang, Shu-Li; Wu, Ming-Tsang; Wang, Yin-Han; Huang, Po-Chin; Chen, Bai-Hsiun; Sun, Chien-Wen; Ho, Chi-Kung; Shih, Yang-Chih; Shiu, Ming-Neng; Pan, Wen-Harn; Chen, Mei-Lien; Lee, Ching-Chang; Hsiung, Chao A.

    2016-01-01

    Background In May 2011, di(2-ethylhexyl) phthalates (DEHP) and, to a lesser extent, di-iso-nonyl phthalate (DiNP) were found to have been illegally used for many years in Taiwan as clouding agents in foods including sports drinks, juice beverages, tea drinks, fruit jam/nectar/jelly, and health or nutrient supplements. Objective To estimate the DEHP exposure for the study participants for the follow-up epidemiological study and health risk assessment. Methods A total of 347 individuals possibly highly exposed to phthalate-tainted foods participated in the study. Exposure assessment was performed based on the participants' responses to a structured questionnaire, self-report of exposure history, urinary metabolite concentrations, and DEHP concentration information in 2449 food records. A Bayesian statistical approach using Markov chain Monte Carlo simulation was employed to deal with the uncertainties in the DEHP concentrations of the contaminated foods and the participants' likelihood of being exposed. Results An estimated 37% and 15% of children younger than 12 years old were exposed to DEHP at medium (20–50 μg / kg_bw / day) and high AvDIs (50–100 μg / kg_bw / day), respectively, prior to the episode (9% and 3% in adults, respectively). Moreover, 11% of children and 1% of adults were highly exposed (> 100 μg / kg_bw / day), with a maximum of 414.1 μg / kg_bw / day and 126.4 μg / kg_bw / day, respectively. Conclusions The phthalate exposure-associated adverse health effects for these participants warrant further investigation. The estimation procedure may be applied to other exposure assessment with various sources of uncertainties. PMID:26960145

  14. Estimation of costs for control of Salmonella in high-risk feed materials and compound feed

    PubMed Central

    Wierup, Martin; Widell, Stig

    2014-01-01

    Introduction Feed is a potential and major source for introducing Salmonella into the animal-derived food chain. This is given special attention in the European Union (EU) efforts to minimize human food-borne Salmonella infections from animal-derived food. The objective of this study was to estimate the total extra cost for preventing Salmonella contamination of feed above those measures required to produce commercial feed according to EU regulation (EC) No 183/2005. The study was carried out in Sweden, a country where Salmonella infections in food-producing animals from feed have largely been eliminated. Methods On the initiative and leadership of the competent authority, the different steps of feed production associated with control of Salmonella contamination were identified. Representatives for the major feed producers operating in the Swedish market then independently estimated the annual mean costs during the years 2009 and 2010. The feed producers had no known incentives to underestimate the costs. Results and discussion The total cost for achieving a Salmonella-safe compound feed, when such a control is established, was estimated at 1.8–2.3 € per tonne of feed. Of that cost, 25% relates to the prevention of Salmonella contaminated high-risk vegetable feed materials (mainly soybean meal and rapeseed meal) from entering feed mills, and 75% for measures within the feed mills. Based on the feed formulations applied, those costs in relation to the farmers’ 2012 price for compound feed were almost equal for broilers and dairy cows (0.7%). Due to less use of protein concentrate to fatten pigs, the costs were lower (0.6%). These limited costs suggest that previous recommendations to enforce a Salmonella-negative policy for animal feed are realistic and economically feasible to prevent a dissemination of the pathogen to animal herds, their environment, and potentially to human food products. PMID:24959328

  15. Risk estimates for hip fracture from clinical and densitometric variables and impact of database selection in Lebanese subjects.

    PubMed

    Badra, Mohammad; Mehio-Sibai, Abla; Zeki Al-Hazzouri, Adina; Abou Naja, Hala; Baliki, Ghassan; Salamoun, Mariana; Afeiche, Nadim; Baddoura, Omar; Bulos, Suhayl; Haidar, Rachid; Lakkis, Suhayl; Musharrafieh, Ramzi; Nsouli, Afif; Taha, Assaad; Tayim, Ahmad; El-Hajj Fuleihan, Ghada

    2009-01-01

    Bone mineral density (BMD) and fracture incidence vary greatly worldwide. The data, if any, on clinical and densitometric characteristics of patients with hip fractures from the Middle East are scarce. The objective of the study was to define risk estimates from clinical and densitometric variables and the impact of database selection on such estimates. Clinical and densitometric information were obtained in 60 hip fracture patients and 90 controls. Hip fracture subjects were 74 yr (9.4) old, were significantly taller, lighter, and more likely to be taking anxiolytics and sleeping pills than controls. National Health and Nutrition Examination Survey (NHANES) database selection resulted in a higher sensitivity and almost equal specificity in identifying patients with a hip fracture compared with the Lebanese database. The odds ratio (OR) and its confidence interval (CI) for hip fracture per standard deviation (SD) decrease in total hip BMD was 2.1 (1.45-3.05) with the NHANES database, and 2.11 (1.36-2.37) when adjusted for age and body mass index (BMI). Risk estimates were higher in male compared with female subjects. In Lebanese subjects, BMD- and BMI-derived hip fracture risk estimates are comparable to western standards. The study validates the universal use of the NHANES database, and the applicability of BMD- and BMI-derived risk fracture estimates in the World Health Organization (WHO) global fracture risk model, to the Lebanese. PMID:19246223

  16. Relativistic Absolutism in Moral Education.

    ERIC Educational Resources Information Center

    Vogt, W. Paul

    1982-01-01

    Discusses Emile Durkheim's "Moral Education: A Study in the Theory and Application of the Sociology of Education," which holds that morally healthy societies may vary in culture and organization but must possess absolute rules of moral behavior. Compares this moral theory with current theory and practice of American educators. (MJL)

  17. Apples to apples: the origin and magnitude of differences in asbestos cancer risk estimates derived using varying protocols.

    PubMed

    Berman, D Wayne

    2011-08-01

    Given that new protocols for assessing asbestos-related cancer risk have recently been published, questions arise concerning how they compare to the "IRIS" protocol currently used by regulators. The newest protocols incorporate findings from 20 additional years of literature. Thus, differences between the IRIS and newer Berman and Crump protocols are examined to evaluate whether these protocols can be reconciled. Risks estimated by applying these protocols to real exposure data from both laboratory and field studies are also compared to assess the relative health protectiveness of each protocol. The reliability of risks estimated using the two protocols are compared by evaluating the degree with which each potentially reproduces the known epidemiology study risks. Results indicate that the IRIS and Berman and Crump protocols can be reconciled; while environment-specific variation within fiber type is apparently due primarily to size effects (not addressed by IRIS), the 10-fold (average) difference between amphibole asbestos risks estimated using each protocol is attributable to an arbitrary selection of the lowest of available mesothelioma potency factors in the IRIS protocol. Thus, the IRIS protocol may substantially underestimate risk when exposure is primarily to amphibole asbestos. Moreover, while the Berman and Crump protocol is more reliable than the IRIS protocol overall (especially for predicting amphibole risk), evidence is presented suggesting a new fiber-size-related adjustment to the Berman and Crump protocol may ultimately succeed in reconciling the entire epidemiology database. However, additional data need to be developed before the performance of the adjusted protocol can be fully validated.

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

    PubMed

    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.

  19. Cancer risk estimation in Belarussian children due to thyroid irradiation as a consequence of the Chernobyl nuclear accident

    SciTech Connect

    Buglova, E.; Kenigsberg, J.E.; Sergeeva, N.V.

    1996-07-01

    The thyroid doses received by the juvenile population of Belarus following the Chernobyl accident ranged up to about 10 Gy. The thyroid cancer risk estimate recommended in NCRP Report No. 80 was used to predict the number of thyroid cancer cases among children during 1990-1992 in selected Belarussian regions and cities. The results obtained using this risk estimate show an excess of thyroid cancer cases being registered vs. the predicted cases. Thyroid cancer incidence rate among boys under investigation is higher than among girls in the postaccident period. The excess of the observed over the expected incidence in the general juvenile population is caused by the high thyroid cancer incidence rate among boys. These results, which can be considered part of the first stage of a thorough thyroid cancer risk estimation after the Chernobyl accident, demonstrate the critical need to complete these studies in depth. 6 refs., 5 figs., 3 tabs.

  20. Chronic beryllium disease and cancer risk estimates with uncertainty for beryllium released to the air from the Rocky Flats Plant.

    PubMed Central

    McGavran, P D; Rood, A S; Till, J E

    1999-01-01

    Beryllium was released into the air from routine operations and three accidental fires at the Rocky Flats Plant (RFP) in Colorado from 1958 to 1989. We evaluated environmental monitoring data and developed estimates of airborne concentrations and their uncertainties and calculated lifetime cancer risks and risks of chronic beryllium disease to hypothetical receptors. This article discusses exposure-response relationships for lung cancer and chronic beryllium disease. We assigned a distribution to cancer slope factor values based on the relative risk estimates from an occupational epidemiologic study used by the U.S. Environmental Protection Agency (EPA) to determine the slope factors. We used the regional atmospheric transport code for Hanford emission tracking atmospheric transport model for exposure calculations because it is particularly well suited for long-term annual-average dispersion estimates and it incorporates spatially varying meteorologic and environmental parameters. We accounted for model prediction uncertainty by using several multiplicative stochastic correction factors that accounted for uncertainty in the dispersion estimate, the meteorology, deposition, and plume depletion. We used Monte Carlo techniques to propagate model prediction uncertainty through to the final risk calculations. We developed nine exposure scenarios of hypothetical but typical residents of the RFP area to consider the lifestyle, time spent outdoors, location, age, and sex of people who may have been exposed. We determined geometric mean incremental lifetime cancer incidence risk estimates for beryllium inhalation for each scenario. The risk estimates were < 10(-6). Predicted air concentrations were well below the current reference concentration derived by the EPA for beryllium sensitization. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:10464074

  1. Chronic beryllium disease and cancer risk estimates with uncertainty for beryllium released to the air from the Rocky Flats Plant.

    PubMed

    McGavran, P D; Rood, A S; Till, J E

    1999-09-01

    Beryllium was released into the air from routine operations and three accidental fires at the Rocky Flats Plant (RFP) in Colorado from 1958 to 1989. We evaluated environmental monitoring data and developed estimates of airborne concentrations and their uncertainties and calculated lifetime cancer risks and risks of chronic beryllium disease to hypothetical receptors. This article discusses exposure-response relationships for lung cancer and chronic beryllium disease. We assigned a distribution to cancer slope factor values based on the relative risk estimates from an occupational epidemiologic study used by the U.S. Environmental Protection Agency (EPA) to determine the slope factors. We used the regional atmospheric transport code for Hanford emission tracking atmospheric transport model for exposure calculations because it is particularly well suited for long-term annual-average dispersion estimates and it incorporates spatially varying meteorologic and environmental parameters. We accounted for model prediction uncertainty by using several multiplicative stochastic correction factors that accounted for uncertainty in the dispersion estimate, the meteorology, deposition, and plume depletion. We used Monte Carlo techniques to propagate model prediction uncertainty through to the final risk calculations. We developed nine exposure scenarios of hypothetical but typical residents of the RFP area to consider the lifestyle, time spent outdoors, location, age, and sex of people who may have been exposed. We determined geometric mean incremental lifetime cancer incidence risk estimates for beryllium inhalation for each scenario. The risk estimates were < 10(-6). Predicted air concentrations were well below the current reference concentration derived by the EPA for beryllium sensitization. PMID:10464074

  2. Estimated risk of lung cancer from exposure to radon decay products in U.S. homes: A brief review

    NASA Astrophysics Data System (ADS)

    Nero, Anthony V.

    Recent analyses now permit direct estimation of the risks of lung cancer from radon decay products in U.S. homes. Analysis of data from indoor monitoring in single-family homes yields a tentative frequency distribution of annual-average 222Rn concentrations with an arithmetic mean of 55 Bq m -3 and approximately 2% of homes having 300 Bq m -3 or more. Application of the results of occupational epidemiological studies to indoor exposures, either directly or using recent advances in lung dosimetry, suggests that the average indoor concentration entails a lifetime risk of lung cancer of about 0.4%, contributing about 10% of the total risk of lung cancer. The risk to individuals occupying the homes with 300 Bq m -3 or more for their lifetimes is estimated to exceed 2%, with risks from the homes with thousands of Bq m -3 correspondingly higher, even exceeding the total risk of premature death due to cigarette smoking. Such average and high-level risks greatly exceed ordinarily-considered environmental risks, forcing development of a new perspective on environmental exposures.

  3. IT-OSRA: applying ensemble simulations to estimate the oil spill risk associated to operational and accidental oil spills

    NASA Astrophysics Data System (ADS)

    Sepp Neves, Antonio Augusto; Pinardi, Nadia; Martins, Flavio

    2016-08-01

    Oil Spill Risk Assessments (OSRAs) are widely employed to support decision making regarding oil spill risks. This article adapts the ISO-compliant OSRA framework developed by Sepp Neves et al. (J Environ Manag 159:158-168, 2015) to estimate risks in a complex scenario where uncertainties related to the meteo-oceanographic conditions, where and how a spill could happen exist and the risk computation methodology is not yet well established (ensemble oil spill modeling). The improved method was applied to the Algarve coast, Portugal. Over 50,000 simulations were performed in 2 ensemble experiments to estimate the risks due to operational and accidental spill scenarios associated with maritime traffic. The level of risk was found to be important for both types of scenarios, with significant seasonal variations due to the the currents and waves variability. Higher frequency variability in the meteo-oceanographic variables were also found to contribute to the level of risk. The ensemble results show that the distribution of oil concentrations found on the coast is not Gaussian, opening up new fields of research on how to deal with oil spill risks and related uncertainties.

  4. Ionizing radiation and genetic risks. VIII. The concept of mutation component and its use in risk estimation for multifactorial diseases.

    PubMed

    Denniston, C; Chakraborty, R; Sankaranarayanan, K

    1998-08-31

    Multifactorial diseases, which include the common congenital abnormalities (incidence: 6%) and chronic diseases with onset predominantly in adults (population prevalence: 65%), contribute substantially to human morbidity and mortality. Their transmission patterns do not conform to Mendelian expectations. The model most frequently used to explain their inheritance and to estimate risks to relatives is a Multifactorial Threshold Model (MTM) of disease liability. The MTM assumes that: (i) the disease is due to the joint action of a large number of genetic and environmental factors, each of which contributing a small amount of liability, (ii) the distribution of liability in the population is Gaussian and (iii) individuals whose liability exceeds a certain threshold value are affected by the disease. For most of these diseases, the number of genes involved or the environmental factors are not fully known. In the context of radiation exposures of the population, the question of the extent to which induced mutations will cause an increase in the frequencies of these diseases has remained unanswered. In this paper, we address this problem by using a modified version of MTM which incorporates mutation and selection as two additional parameters. The model assumes a finite number of gene loci and threshold of liability (hence, the designation, Finite-Locus Threshold Model or FLTM). The FLTM permits one to examine the relationship between broad-sense heritability of disease liability and mutation component (MC), the responsiveness of the disease to a change in mutation rate. Through the use of a computer program (in which mutation rate, selection, threshold, recombination rate and environmental variance are input parameters and MC and heritability of liability are output estimates), we studied the MC-heritability relationship for (i) a permanent increase in mutation rate (e.g., when the population sustains radiation exposure in every generation) and (ii) a one-time increase

  5. Methodological extensions of meta-analysis with excess relative risk estimates: application to risk of second malignant neoplasms among childhood cancer survivors treated with radiotherapy.

    PubMed

    Doi, Kazutaka; Mieno, Makiko N; Shimada, Yoshiya; Yonehara, Hidenori; Yoshinaga, Shinji

    2014-09-01

    Although radiotherapy is recognized as an established risk factor for second malignant neoplasms (SMNs), the dose response of SMNs following radiotherapy has not been well characterized. In our previous meta-analysis of the risks of SMNs occurring among children who have received radiotherapy, the small number of eligible studies precluded a detailed evaluation. Therefore, to increase the number of eligible studies, we developed a method of calculating excess relative risk (ERR) per Gy estimates from studies for which the relative risk estimates for several dose categories were available. Comparing the calculated ERR with that described in several original papers validated the proposed method. This enabled us to increase the number of studies, which we used to conduct a meta-analysis. The overall ERR per Gy estimate of radiotherapy over 26 relevant studies was 0.60 (95%CI: 0.30-1.20), which is smaller than the corresponding estimate for atomic bomb survivors exposed to radiation as young children (1.7; 95% CI: 1.1-2.5). A significant decrease in ERR per Gy with increase in age at exposure (0.85 times per annual increase) was observed in the meta-regression. Heterogeneity was suggested by Cochran's Q statistic (P < 0.001), which may be partly accounted for by age at exposure. PMID:25037101

  6. Methodological extensions of meta-analysis with excess relative risk estimates: application to risk of second malignant neoplasms among childhood cancer survivors treated with radiotherapy

    PubMed Central

    Doi, Kazutaka; Mieno, Makiko N.; Shimada, Yoshiya; Yonehara, Hidenori; Yoshinaga, Shinji

    2014-01-01

    Although radiotherapy is recognized as an established risk factor for second malignant neoplasms (SMNs), the dose response of SMNs following radiotherapy has not been well characterized. In our previous meta-analysis of the risks of SMNs occurring among children who have received radiotherapy, the small number of eligible studies precluded a detailed evaluation. Therefore, to increase the number of eligible studies, we developed a method of calculating excess relative risk (ERR) per Gy estimates from studies for which the relative risk estimates for several dose categories were available. Comparing the calculated ERR with that described in several original papers validated the proposed method. This enabled us to increase the number of studies, which we used to conduct a meta-analysis. The overall ERR per Gy estimate of radiotherapy over 26 relevant studies was 0.60 (95%CI: 0.30–1.20), which is smaller than the corresponding estimate for atomic bomb survivors exposed to radiation as young children (1.7; 95% CI: 1.1–2.5). A significant decrease in ERR per Gy with increase in age at exposure (0.85 times per annual increase) was observed in the meta-regression. Heterogeneity was suggested by Cochran's Q statistic (P < 0.001), which may be partly accounted for by age at exposure. PMID:25037101

  7. Improved seismic risk estimation for Bucharest, based on multiple hazard scenarios, analytical methods and new techniques

    NASA Astrophysics Data System (ADS)

    Toma-Danila, Dragos; Florinela Manea, Elena; Ortanza Cioflan, Carmen

    2014-05-01

    Bucharest, capital of Romania (with 1678000 inhabitants in 2011), is one of the most exposed big cities in Europe to seismic damage. The major earthquakes affecting the city have their origin in the Vrancea region. The Vrancea intermediate-depth source generates, statistically, 2-3 shocks with moment magnitude >7.0 per century. Although the focal distance is greater than 170 km, the historical records (from the 1838, 1894, 1908, 1940 and 1977 events) reveal severe effects in the Bucharest area, e.g. intensities IX (MSK) for the case of 1940 event. During the 1977 earthquake, 1420 people were killed and 33 large buildings collapsed. The nowadays building stock is vulnerable both due to construction (material, age) and soil conditions (high amplification, generated within the weak consolidated Quaternary deposits, their thickness is varying 250-500m throughout the city). A number of 373 old buildings, out of 2563, evaluated by experts are more likely to experience severe damage/collapse in the next major earthquake. The total number of residential buildings, in 2011, was 113900. In order to guide the mitigation measures, different studies tried to estimate the seismic risk of Bucharest, in terms of buildings, population or economic damage probability. Unfortunately, most of them were based on incomplete sets of data, whether regarding the hazard or the building stock in detail. However, during the DACEA Project, the National Institute for Earth Physics, together with the Technical University of Civil Engineering Bucharest and NORSAR Institute managed to compile a database for buildings in southern Romania (according to the 1999 census), with 48 associated capacity and fragility curves. Until now, the developed real-time estimation system was not implemented for Bucharest. This paper presents more than an adaptation of this system to Bucharest; first, we analyze the previous seismic risk studies, from a SWOT perspective. This reveals that most of the studies don't use

  8. Estimation of the health risks associated with polychlorinated biphenyl (PCB) concentrations found onboard older U.S. Navy vessels.

    PubMed

    Still, K R; Arfsten, D P; Jederberg, W W; Kane, L V; Larcom, B J

    2003-10-01

    PCBs have been identified on surfaces and in component materials and equipment from inactive U.S. Navy nuclear submarines commissioned prior to 1970. Health risks associated with PCBs present onboard submarines were estimated for hypothetical crew members and shipyard workers. Median non-cancer hazard quotients for shipyard workers and submarine crew ranged between 0.4-54.6, with the highest quotients estimated for unprotected shipyard workers. Median cancer risk estimates ranged from 7.3 x 10(-6) to 1.1 x 10(-3) with the highest estimated risk calculated for unprotected shipyard workers. Our findings suggest that PCB surface concentrations found onboard inactive nuclear submarines commissioned prior to 1970 may be high enough to constitute a possible risk to the health of persons involved in dismantling of Navy submarines if PCB exposure is not minimized. Potential sources of uncertainty in our risk assessment include the correlation between PCB contamination levels on inactive versus active nuclear submarine vessels, the relationship between wipe sample concentrations and human exposure, dermal contact frequency with PCB-contaminated surfaces, carcinogenicity of PCBs in humans, and uncertainties inherent with the PCB cancer slope factor and oral RfD. Our findings support Navy policy that shipyard workers should wear personal protective equipment when PCB contamination is suspected or has been identified and that IH surveys should continue to identify sources of PCB contamination onboard vessels and reduce PCB contamination to concentrations that are reasonably achievable.

  9. Radiation risk estimation: Modelling approaches for “targeted” and “non-targeted” effects

    NASA Astrophysics Data System (ADS)

    Ballarini, Francesca; Alloni, Daniele; Facoetti, Angelica; Mairani, Andrea; Nano, Rosanna; Ottolenghi, Andrea

    The estimation of the risks from low doses of ionizing radiation - including heavy ions - is still a debated question. In particular, the action of heavy ions on biological targets needs further investigation. In this framework, we present a mechanistic model and a Monte Carlo simulation code for the induction of different types of chromosome aberrations. The model, previously validated for gamma rays and light ions, has recently started to be extended to heavy ions such as Iron and Carbon, which are of interest both for space radiation protection and for hadrontherapy. Preliminary results were found to be in agreement with experimental dose-response curves for aberration yields observed following heavy-ion irradiation of human lymphocytes treated with the Premature Chromosome Condensation technique. During the last 10 years, the "Linear No Threshold" hypothesis has been challenged by a large number of observations on the so-called "non-targeted effects" including bystander effect, which consists of the induction of cytogenetic damage in cells not directly traversed by radiation, most likely as a response to molecular messengers released by directly irradiated cells. Although it is now clear that cellular communication plays a fundamental role, our knowledge on the mechanisms underlying bystander effects is still poor, and would largely benefit from further investigations including theoretical models and simulation codes. In the present paper we will review different modelling approaches, including one that is being developed at the University of Pavia, focusing on the assumptions adopted by the various authors and on their implications in terms of low-dose radiation risk, as well as on the identification of "critical" parameters that can modulate the model outcomes.

  10. Quantification and Radiological Risk Estimation Due to the Presence of Natural Radionuclides in Maiganga Coal, Nigeria.

    PubMed

    Kolo, Matthew Tikpangi; Khandaker, Mayeen Uddin; Amin, Yusoff Mohd; Abdullah, Wan Hasiah Binti

    2016-01-01

    Following the increasing demand of coal for power generation, activity concentrations of primordial radionuclides were determined in Nigerian coal using the gamma spectrometric technique with the aim of evaluating the radiological implications of coal utilization and exploitation in the country. Mean activity concentrations of 226Ra, 232Th, and 40K were 8.18±0.3, 6.97±0.3, and 27.38±0.8 Bq kg-1, respectively. These values were compared with those of similar studies reported in literature. The mean estimated radium equivalent activity was 20.26 Bq kg-1 with corresponding average external hazard index of 0.05. Internal hazard index and representative gamma index recorded mean values of 0.08 and 0.14, respectively. These values were lower than their respective precautionary limits set by UNSCEAR. Average excess lifetime cancer risk was calculated to be 0.04×10-3, which was insignificant compared with 0.05 prescribed by ICRP for low level radiation. Pearson correlation matrix showed significant positive relationship between 226Ra and 232Th, and with other estimated hazard parameters. Cumulative mean occupational dose received by coal workers via the three exposure routes was 7.69 ×10-3 mSv y-1, with inhalation pathway accounting for about 98%. All radiological hazard indices evaluated showed values within limits of safety. There is, therefore, no likelihood of any immediate radiological health hazards to coal workers, final users, and the environment from the exploitation and utilization of Maiganga coal. PMID:27348624

  11. Quantification and Radiological Risk Estimation Due to the Presence of Natural Radionuclides in Maiganga Coal, Nigeria

    PubMed Central

    Kolo, Matthew Tikpangi; Khandaker, Mayeen Uddin; Amin, Yusoff Mohd; Abdullah, Wan Hasiah Binti

    2016-01-01

    Following the increasing demand of coal for power generation, activity concentrations of primordial radionuclides were determined in Nigerian coal using the gamma spectrometric technique with the aim of evaluating the radiological implications of coal utilization and exploitation in the country. Mean activity concentrations of 226Ra, 232Th, and 40K were 8.18±0.3, 6.97±0.3, and 27.38±0.8 Bq kg-1, respectively. These values were compared with those of similar studies reported in literature. The mean estimated radium equivalent activity was 20.26 Bq kg-1 with corresponding average external hazard index of 0.05. Internal hazard index and representative gamma index recorded mean values of 0.08 and 0.14, respectively. These values were lower than their respective precautionary limits set by UNSCEAR. Average excess lifetime cancer risk was calculated to be 0.04×10−3, which was insignificant compared with 0.05 prescribed by ICRP for low level radiation. Pearson correlation matrix showed significant positive relationship between 226Ra and 232Th, and with other estimated hazard parameters. Cumulative mean occupational dose received by coal workers via the three exposure routes was 7.69 ×10−3 mSv y-1, with inhalation pathway accounting for about 98%. All radiological hazard indices evaluated showed values within limits of safety. There is, therefore, no likelihood of any immediate radiological health hazards to coal workers, final users, and the environment from the exploitation and utilization of Maiganga coal. PMID:27348624

  12. Stochastic estimates of exposure and cancer risk from carbon tetrachloride released to the air from the rocky flats plant.

    PubMed

    Rood, A S; McGavran, P D; Aanenson, J W; Till, J E

    2001-08-01

    Carbon tetrachloride is a degreasing agent that was used at the Rocky Flats Plant (RFP) in Colorado to clean product components and equipment. The chemical is considered a volatile organic compound and a probable human carcinogen. During the time the plant operated (1953-1989), most of the carbon tetrachloride was released to the atmosphere through building exhaust ducts. A smaller amount was released to the air via evaporation from open-air burn pits and ground-surface discharge points. Airborne releases from the plant were conservatively estimated to be equivalent to the amount of carbon tetrachloride consumed annually by the plant, which was estimated to be between 3.6 and 180 Mg per year. This assumption was supported by calculations that showed that most of the carbon tetrachloride discharged to the ground surface would subsequently be released to the atmosphere. Atmospheric transport of carbon tetrachloride from the plant to the surrounding community was estimated using a Gaussian Puff dispersion model (RATCHET). Time-integrated concentrations were estimated for nine hypothetical but realistic exposure scenarios that considered variation in lifestyle, location, age, and gender. Uncertainty distributions were developed for cancer slope factors and atmospheric dispersion factors. These uncertainties were propagated through to the final risk estimate using Monte Carlo techniques. The geometric mean risk estimates varied from 5.2 x 10(-6) for a hypothetical rancher or laborer working near the RFP to 3.4 x 10(-9) for an infant scenario. The distribution of incremental lifetime cancer incidence risk for the hypothetical rancher was between 1.3 x 10(-6) (5% value) and 2.1 x 10(-5) (95% value). These estimates are similar to or exceed estimated cancer risks posed by releases of radionuclides from the site. PMID:11726020

  13. Incidence of viral markers and evaluation of the estimated risk in the Swiss blood donor population from 1996 to 2003.

    PubMed

    Niederhauser, C; Schneider, P; Fopp, M; Ruefer, A; Lévy, G

    2005-02-01

    Among the well known transfusion-associated risks, the transmission of pathogenic viruses is regarded as one of the most serious. Over the past two decades, a series of overlapping safety procedures have been successively implemented to minimise this risk. It is now generally considered that the risk of transmitting viral infections via blood products is very low in developed countries. The present study analyses the incidence of the key infectious diseases HIV, hepatitis B virus (HBV) and hepatitis C virus (HCV) between 1996 and 2003 from 99% of voluntary repeat blood donors visiting the blood transfusion service of the Swiss Red Cross. Furthermore the estimated risk of these viral markers was calculated. From 1996 to 2003 the incidence rate for HCV decreased continuously, whereas no significant decrease in the incidence rate of HIV and HBV was observed. From 2001 to 2003, the last calculated period, the residual risk was estimated to be 1 in 1,900,000 for HIV, 1 in 2,200,0000 for HCV and 1 in 115,000 for HBV, respectively. This agrees with international studies, which have been shown that the estimated residual risk for HBV between 1996 and 2003 is higher than that of HCV and HIV.

  14. Derivation and validation of a prediction rule for estimating advanced colorectal neoplasm risk in average-risk Chinese.

    PubMed

    Cai, Quan-Cai; Yu, En-Da; Xiao, Yi; Bai, Wen-Yuan; Chen, Xing; He, Li-Ping; Yang, Yu-Xiu; Zhou, Ping-Hong; Jiang, Xue-Liang; Xu, Hui-Min; Fan, Hong; Ge, Zhi-Zheng; Lv, Nong-Hua; Huang, Zhi-Gang; Li, You-Ming; Ma, Shu-Ren; Chen, Jie; Li, Yan-Qing; Xu, Jian-Ming; Xiang, Ping; Yang, Li; Lin, Fu-Lin; Li, Zhao-Shen

    2012-03-15

    No prediction rule is currently available for advanced colorectal neoplasms, defined as invasive cancer, an adenoma of 10 mm or more, a villous adenoma, or an adenoma with high-grade dysplasia, in average-risk Chinese. In this study between 2006 and 2008, a total of 7,541 average-risk Chinese persons aged 40 years or older who had complete colonoscopy were included. The derivation and validation cohorts consisted of 5,229 and 2,312 persons, respectively. A prediction rule was developed from a logistic regression model and then internally and externally validated. The prediction rule comprised 8 variables (age, sex, smoking, diabetes mellitus, green vegetables, pickled food, fried food, and white meat), with scores ranging from 0 to 14. Among the participants with low-risk (≤3) or high-risk (>3) scores in the validation cohort, the risks of advanced neoplasms were 2.6% and 10.0% (P < 0.001), respectively. If colonoscopy was used only for persons with high risk, 80.3% of persons with advanced neoplasms would be detected while the number of colonoscopies would be reduced by 49.2%. The prediction rule had good discrimination (area under the receiver operating characteristic curve = 0.74, 95% confidence interval: 0.70, 0.78) and calibration (P = 0.77) and, thus, provides accurate risk stratification for advanced neoplasms in average-risk Chinese. PMID:22328705

  15. Moral absolutism and ectopic pregnancy.

    PubMed

    Kaczor, C

    2001-02-01

    If one accepts a version of absolutism that excludes the intentional killing of any innocent human person from conception to natural death, ectopic pregnancy poses vexing difficulties. Given that the embryonic life almost certainly will die anyway, how can one retain one's moral principle and yet adequately respond to a situation that gravely threatens the life of the mother and her future fertility? The four options of treatment most often discussed in the literature are non-intervention, salpingectomy (removal of tube with embryo), salpingostomy (removal of embryo alone), and use of methotrexate (MXT). In this essay, I review these four options and introduce a fifth (the milking technique). In order to assess these options in terms of the absolutism mentioned, it will also be necessary to discuss various accounts of the intention/foresight distinction. I conclude that salpingectomy, salpingostomy, and the milking technique are compatible with absolutist presuppositions, but not the use of methotrexate.

  16. Moral absolutism and ectopic pregnancy.

    PubMed

    Kaczor, C

    2001-02-01

    If one accepts a version of absolutism that excludes the intentional killing of any innocent human person from conception to natural death, ectopic pregnancy poses vexing difficulties. Given that the embryonic life almost certainly will die anyway, how can one retain one's moral principle and yet adequately respond to a situation that gravely threatens the life of the mother and her future fertility? The four options of treatment most often discussed in the literature are non-intervention, salpingectomy (removal of tube with embryo), salpingostomy (removal of embryo alone), and use of methotrexate (MXT). In this essay, I review these four options and introduce a fifth (the milking technique). In order to assess these options in terms of the absolutism mentioned, it will also be necessary to discuss various accounts of the intention/foresight distinction. I conclude that salpingectomy, salpingostomy, and the milking technique are compatible with absolutist presuppositions, but not the use of methotrexate. PMID:11262641

  17. The Absolute Spectrum Polarimeter (ASP)

    NASA Technical Reports Server (NTRS)

    Kogut, A. J.

    2010-01-01

    The Absolute Spectrum Polarimeter (ASP) is an Explorer-class mission to map the absolute intensity and linear polarization of the cosmic microwave background and diffuse astrophysical foregrounds over the full sky from 30 GHz to 5 THz. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r much greater than 1O(raised to the power of { -3}) and Compton distortion y < 10 (raised to the power of{-6}). We describe the ASP instrument and mission architecture needed to detect the signature of an inflationary epoch in the early universe using only 4 semiconductor bolometers.

  18. Classification images predict absolute efficiency.

    PubMed

    Murray, Richard F; Bennett, Patrick J; Sekuler, Allison B

    2005-02-24

    How well do classification images characterize human observers' strategies in perceptual tasks? We show mathematically that from the classification image of a noisy linear observer, it is possible to recover the observer's absolute efficiency. If we could similarly predict human observers' performance from their classification images, this would suggest that the linear model that underlies use of the classification image method is adequate over the small range of stimuli typically encountered in a classification image experiment, and that a classification image captures most important aspects of human observers' performance over this range. In a contrast discrimination task and in a shape discrimination task, we found that observers' absolute efficiencies were generally well predicted by their classification images, although consistently slightly (approximately 13%) higher than predicted. We consider whether a number of plausible nonlinearities can account for the slight under prediction, and of these we find that only a form of phase uncertainty can account for the discrepancy.

  19. Absolute calibration of optical flats

    DOEpatents

    Sommargren, Gary E.

    2005-04-05

    The invention uses the phase shifting diffraction interferometer (PSDI) to provide a true point-by-point measurement of absolute flatness over the surface of optical flats. Beams exiting the fiber optics in a PSDI have perfect spherical wavefronts. The measurement beam is reflected from the optical flat and passed through an auxiliary optic to then be combined with the reference beam on a CCD. The combined beams include phase errors due to both the optic under test and the auxiliary optic. Standard phase extraction algorithms are used to calculate this combined phase error. The optical flat is then removed from the system and the measurement fiber is moved to recombine the two beams. The newly combined beams include only the phase errors due to the auxiliary optic. When the second phase measurement is subtracted from the first phase measurement, the absolute phase error of the optical flat is obtained.

  20. Structural equation models to estimate risk of infection and tolerance to bovine mastitis

    PubMed Central

    2013-01-01

    Background 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. Methods 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. Results and discussion 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. Conclusions 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

  1. Breast Cancer Risk Estimation Using Parenchymal Texture Analysis in Digital Breast Tomosynthesis

    SciTech Connect

    Ikejimba, Lynda C.; Kontos, Despina; Maidment, Andrew D. A.

    2010-10-11

    Mammographic parenchymal texture has been shown to correlate with genetic markers of developing breast cancer. Digital breast tomosynthesis (DBT) is a novel x-ray imaging technique in which tomographic images of the breast are reconstructed from multiple source projections acquired at different angles of the x-ray tube. Compared to digital mammography (DM), DBT eliminates breast tissue overlap, offering superior parenchymal tissue visualization. We hypothesize that texture analysis in DBT could potentially provide a better assessment of parenchymal texture and ultimately result in more accurate assessment of breast cancer risk. As a first step towards validating this hypothesis, we investigated the association between DBT parenchymal texture and breast percent density (PD), a known breast cancer risk factor, and compared it to DM. Bilateral DBT and DM images from 71 women participating in a breast cancer screening trial were analyzed. Filtered-backprojection was used to reconstruct DBT tomographic planes in 1 mm increments with 0.22 mm in-plane resolution. Corresponding DM images were acquired at 0.1 mm pixel resolution. Retroareolar regions of interest (ROIs) equivalent to 2.5 cm{sup 3} were segmented from the DBT images and corresponding 2.5 cm{sup 2} ROIs were segmented from the DM images. Breast PD was mammographically estimated using the Cumulus scale. Overall, DBT texture features demonstrated a stronger correlation than DM to PD. The Pearson correlation coefficients for DBT were r = 0.40 (p<0.001) for contrast and r = -0.52 (p<0.001) for homogeneity; the corresponding DM correlations were r = 0.26 (p = 0.002) and r = -0.33 (p<0.001). Multiple linear regression of the texture features versus breast PD also demonstrated significantly stronger associations in DBT (R{sup 2} = 0.39) compared to DM (R{sup 2} = 0.33). We attribute these observations to the superior parenchymal tissue visualization in DBT. Our study is the first to perform DBT texture analysis in a

  2. Spatial Estimation of Populations at Risk from Radiological Dispersion Device Terrorism Incidents

    SciTech Connect

    Regens, J.L.; Gunter, J.T.

    2008-07-01

    Delineation of the location and size of the population potentially at risk of exposure to ionizing radiation is one of the key analytical challenges in estimating accurately the severity of the potential health effects associated with a radiological terrorism incident. Regardless of spatial scale, the geographical units for which population data commonly are collected rarely coincide with the geographical scale necessary for effective incident management and medical response. This paper identifies major government and commercial open sources of U.S. population data and presents a GIS-based approach for allocating publicly available population data, including age distributions, to geographical units appropriate for planning and implementing incident management and medical response strategies. In summary: The gravity model offers a straight-forward, empirical tool for estimating population flows, especially when geographical areas are relatively well-defined in terms of accessibility and spatial separation. This is particularly important for several reasons. First, the spatial scale for the area impacted by a RDD terrorism event is unlikely to match fully the spatial scale of available population data. That is, the plume spread typically will not uniformly overlay the impacted area. Second, the number of people within the impacted area varies as a function whether an attack occurs during the day or night. For example, the population of a central business district or industrial area typically is larger during the day while predominately residential areas have larger night time populations. As a result, interpolation techniques that link population data to geographical units and allocate those data based on time-frame at a spatial scale that is relevant to enhancing preparedness and response. The gravity model's main advantage is that it efficiently allocates readily available, open source population data to geographical units appropriate for planning and implementing

  3. A vibroseismic method for estimation of the ecological risk of powerful technogenic and natural explosions

    NASA Astrophysics Data System (ADS)

    Khairetdinov, Marat; Voskoboynikova, Gyulnara; Sedukhina, Galina

    2016-04-01

    This paper presents the results of experimental investigations of an original ecologically safe approach, proposed by the authors, to assessment of the geoecological risk from powerful mass explosions for the social and natural environment. In this approach, seismic vibrators are used as sources imitating explosions but having, in contrast to them, a much smaller power. Such sources can simultaneously excite in the medium seismic and acoustic (vibro-seismo-acoustic) oscillations with precision power and frequency-time characteristics. A comparative analysis of seismic and acoustic wave levels allows us to conclude that the major ecologically dangerous effect of ground-based test site explosions is due to acoustic waves whose energy is an order of magnitude greater than that of seismic waves. Calculated azimuthal dependencies of the focusing effect of acoustic waves in the infralow frequency range at different wind velocities and "source-receiver" distances by vibrator CV-40 were obtained . It was found that meteorological conditions have a greater influence on acoustic wave focusing in experiments that according to theoretical results. The effects of focusing of acoustic oscillations in space were revealed and estimated quantitatively. Specifically, it was proved that even at a weak wind of 2-4 m/s the ratio between the maximal and minimal acoustic wave levels depending on the azimuthal direction can reach 50. This can be a reason for great ecological hazard of technogenic explosions. The received results are new and original. The received results are new and original.

  4. Significance of model credibility in estimating climate projection distributions for regional hydroclimatological risk assessments

    USGS Publications Warehouse

    Brekke, L.D.; Dettinger, M.D.; Maurer, E.P.; Anderson, M.

    2008-01-01

    Ensembles of historical climate simulations and climate projections from the World Climate Research Programme's (WCRP's) Coupled Model Intercomparison Project phase 3 (CMIP3) multi-model dataset were investigated to determine how model credibility affects apparent relative scenario likelihoods in regional risk assessments. Methods were developed and applied in a Northern California case study. An ensemble of 59 twentieth century climate simulations from 17 WCRP CMIP3 models was analyzed to evaluate relative model credibility associated with a 75-member projection ensemble from the same 17 models. Credibility was assessed based on how models realistically reproduced selected statistics of historical climate relevant to California climatology. Metrics of this credibility were used to derive relative model weights leading to weight-threshold culling of models contributing to the projection ensemble. Density functions were then estimated for two projected quantities (temperature and precipitation), with and without considering credibility-based ensemble reductions. An analysis for Northern California showed that, while some models seem more capable at recreating limited aspects twentieth century climate, the overall tendency is for comparable model performance when several credibility measures are combined. Use of these metrics to decide which models to include in density function development led to local adjustments to function shapes, but led to limited affect on breadth and central tendency, which were found to be more influenced by 'completeness' of the original ensemble in terms of models and emissions pathways. ?? 2007 Springer Science+Business Media B.V.

  5. [Estimation of livestock manure nitrogen load and pollution risk evaluation of farmland in Daxing District].

    PubMed

    Yan, Bo-jie; Zhao, Chun-jiang; Pan, Yu-chun; Yan, Jing-jie; Guo, Xin

    2010-02-01

    Based on the livestock statistical data, the nutrient content of livestock manure was calculated and the nutrient transformation from livestock manure to farmland was realized by using the method of spatializing livestock manure nutrient. On this basis, this paper calculated nitrogen load of livestock manure combining with the area of farmland and realized the estimation of nitrogen load of livestock manure and potential pollution evaluation in landmass for unit taking Daxing District in Beijing as an example. The result showed that the average, minimum and maximum nitrogen loads of farmland were 214.02 kg/hm2, 10.64 kg/hm2 and 5996.26 kg/hm2 respectively and near half of farmland was threaten by nitrogen load of livestock manure, accounting for 42.14% of the total farmland. These farmland threaten to polluted had the characters of small area and few nutrient demand and mainly located nearby the inhabitant and the scale raising. The coefficients of variation and average of available nitrogen in topsoil and subsoil were 64.3%, 53.65% and 65.93 microg/g, 45.25 microg/g respectively and the enrichment coefficient was 1.46, which explained the existing pollution risk and the influence degree of livestock manure to soil environment pollution.

  6. Utility of Recent Studies to Assess the National Research Council 2001 Estimates of Cancer Risk from Ingested Arsenic

    PubMed Central

    Gibb, Herman; Haver, Cary; Gaylor, David; Ramasamy, Santhini; Lee, Janice S.; Lobdell, Danelle; Wade, Timothy; Chen, Chao; White, Paul; Sams, Reeder

    2011-01-01

    Objective The purpose of this review is to evaluate the impact of recent epidemiologic literature on the National Research Council (NRC) assessment of the lung and bladder cancer risks from ingesting low concentrations (< 100 μg/L) of arsenic-contaminated water. Data sources, extraction, and synthesis PubMed was searched for epidemiologic studies pertinent to the lung and bladder cancer risk estimates from low-dose arsenic exposure. Articles published from 2001, the date of the NRC assessment, through September 2010 were included. Fourteen epidemiologic studies on lung and bladder cancer risk were identified as potentially useful for the analysis. Conclusions Recent epidemiologic studies that have investigated the risk of lung and bladder cancer from low arsenic exposure are limited in their ability to detect the NRC estimates of excess risk because of sample size and less than lifetime exposure. Although the ecologic nature of the Taiwanese studies on which the NRC estimates are based present certain limitations, the data from these studies have particular strengths in that they describe lung and bladder cancer risks resulting from lifetime exposure in a large population and remain the best data on which to conduct quantitative risk assessment. Continued follow-up of a population in northeastern Taiwan, however, offers the best opportunity to improve the cancer risk assessment for arsenic in drinking water. Future studies of arsenic < 100 μg/L in drinking water and lung and bladder cancer should consider adequacy of the sample size, the synergistic relationship of arsenic and smoking, duration of arsenic exposure, age when exposure began and ended, and histologic subtype. PMID:21030336

  7. Does the Honey Bee "Risk Cup" Runneth Over? Estimating Aggregate Exposures for Assessing Pesticide Risks to Honey Bees in Agroecosystems.

    PubMed

    Berenbaum, May R

    2016-01-13

    Honey bees (Apis mellifera) are uniquely vulnerable to nontarget pesticide impacts because, as ubiquitous managed pollinators, they are deliberately transported into areas where crops are grown with pesticides. Moreover, attributes making them excellent managed pollinators, including large long-lived colonies and complex behavior, also make them challenging subjects for toxicity bioassays. For over 150 years, improvements in formulation and delivery of pesticides, increasing their environmental and temporal presence, have had unintended consequences for honey bees. Since 1996, the Environmental Protection Agency has used "aggregate risk"--exposure risks to all possible sources--to set tolerances; once a "risk cup" is filled, no new pesticide or use can be approved unless risks are reduced elsewhere. The EPA now recommends a modeling approach for aggregating all exposure risks for bees, with differential lifestage sensitivity and exposure probabilities. Thus, the honey bee is the first insect with its own "risk cup"--a technological innovation that may not have unintended consequences for this beleaguered beneficial species.

  8. Does the Honey Bee "Risk Cup" Runneth Over? Estimating Aggregate Exposures for Assessing Pesticide Risks to Honey Bees in Agroecosystems.

    PubMed

    Berenbaum, May R

    2016-01-13

    Honey bees (Apis mellifera) are uniquely vulnerable to nontarget pesticide impacts because, as ubiquitous managed pollinators, they are deliberately transported into areas where crops are grown with pesticides. Moreover, attributes making them excellent managed pollinators, including large long-lived colonies and complex behavior, also make them challenging subjects for toxicity bioassays. For over 150 years, improvements in formulation and delivery of pesticides, increasing their environmental and temporal presence, have had unintended consequences for honey bees. Since 1996, the Environmental Protection Agency has used "aggregate risk"--exposure risks to all possible sources--to set tolerances; once a "risk cup" is filled, no new pesticide or use can be approved unless risks are reduced elsewhere. The EPA now recommends a modeling approach for aggregating all exposure risks for bees, with differential lifestage sensitivity and exposure probabilities. Thus, the honey bee is the first insect with its own "risk cup"--a technological innovation that may not have unintended consequences for this beleaguered beneficial species. PMID:25885594

  9. Violence and Drug Use in Rural Teens: National Prevalence Estimates from the 2003 Youth Risk Behavior Survey

    ERIC Educational Resources Information Center

    Johnson, Andrew O.; Mink, Michael D.; Harun, Nusrat; Moore, Charity G.; Martin, Amy B.; Bennett, Kevin J.

    2008-01-01

    Objectives: The purpose of this study was to compare national estimates of drug use and exposure to violence between rural and urban teens. Methods: Twenty-eight dependent variables from the 2003 Youth Risk Behavior Survey were used to compare violent activities, victimization, suicidal behavior, tobacco use, alcohol use, and illegal drug use…

  10. Incorporating variability in point estimates in risk assessment: Bridging the gap between LC50 and population endpoints.

    PubMed

    Stark, John D; Vargas, Roger I; Banks, John E

    2015-07-01

    Historically, point estimates such as the median lethal concentration (LC50) have been instrumental in assessing risks associated with toxicants to rare or economically important species. In recent years, growing awareness of the shortcomings of this approach has led to an increased focus on analyses using population endpoints. However, risk assessment of pesticides still relies heavily on large amounts of LC50 data amassed over decades in the laboratory. Despite the fact that these data are generally well replicated, little or no attention has been given to the sometime high levels of variability associated with the generation of point estimates. This is especially important in agroecosystems where arthropod predator-prey interactions are often disrupted by the use of pesticides. Using laboratory derived data of 4 economically important species (2 fruit fly pest species and 2 braconid parasitoid species) and matrix based population models, the authors demonstrate in the present study a method for bridging traditional point estimate risk assessments with population outcomes. The results illustrate that even closely related species can show strikingly divergent responses to the same exposures to pesticides. Furthermore, the authors show that using different values within the 95% confidence intervals of LC50 values can result in very different population outcomes, ranging from quick recovery to extinction for both pest and parasitoid species. The authors discuss the implications of these results and emphasize the need to incorporate variability and uncertainty in point estimates for use in risk assessment.

  11. Incorporating variability in point estimates in risk assessment: bridging the gap between LC50 and population endpoints

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Historically, the use of point estimates such as the LC50 has been instrumental in assessing the risk associated with toxicants to rare or economically important species. In recent years, growing awareness of the shortcomings of this approach has led to an increased focus on analyses using populatio...

  12. 49 CFR Appendix G to Part 222 - Excess Risk Estimates for Public Highway-Rail Grade Crossings

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Grade Crossings G Appendix G to Part 222 Transportation Other Regulations Relating to Transportation... HIGHWAY-RAIL GRADE CROSSINGS Pt. 222, App. G Appendix G to Part 222—Excess Risk Estimates for Public Highway-Rail Grade Crossings Ban Effects/Train Horn Effectiveness [Summary table] Warning type Excess...

  13. Estimated Risk of Developing Selected DSM-IV Disorders among 5-Year-Old Children with Prenatal Cocaine Exposure

    ERIC Educational Resources Information Center

    Morrow, Connie E.; Accornero, Veronica H.; Xue, Lihua; Manjunath, Sudha; Culbertson, Jan L.; Anthony, James C.; Bandstra, Emmalee S.

    2009-01-01

    We estimated childhood risk of developing selected DSM-IV Disorders, including Attention-Deficit Hyperactivity Disorder (ADHD), Oppositional Defiant Disorder (ODD), and Separation Anxiety Disorder (SAD), in children with prenatal cocaine exposure (PCE). Children were enrolled prospectively at birth (n = 476) with prenatal drug exposures documented…

  14. Cognitive Predictors of Calculations and Number Line Estimation with Whole Numbers and Fractions among At-Risk Students

    ERIC Educational Resources Information Center

    Namkung, Jessica M.; Fuchs, Lynn S.

    2015-01-01

    The purpose of this study was to examine the cognitive predictors of calculations and number line estimation with whole numbers and fractions. At-risk 4th-grade students (N = 139) were assessed on 7 domain-general abilities (i.e., working memory, processing speed, concept formation, language, attentive behavior, and nonverbal reasoning) and…

  15. Cognitive Predictors of Calculations and Number Line Estimation with Whole Numbers and Fractions among At-Risk Students

    ERIC Educational Resources Information Center

    Namkung, Jessica M.; Fuchs, Lynn S.

    2016-01-01

    The purpose of this study was to examine the cognitive predictors of calculations and number line estimation with whole numbers and fractions. At-risk 4th-grade students (N = 139) were assessed on 6 domain-general abilities (i.e., working memory, processing speed, concept formation, language, attentive behavior, and nonverbal reasoning) and…

  16. Risk Factors for Learning-Related Behavior Problems at 24 Months of Age: Population-Based Estimates

    ERIC Educational Resources Information Center

    Morgan, Paul L.; Farkas, George; Hillemeier, Marianne M.; Maczuga, Steven

    2009-01-01

    We used a large sample of singleton children to estimate the effects of socioeconomic status (SES), race/ethnicity, gender, additional socio-demographics, gestational and birth factors, and parenting on children's risk for learning-related behavior problems at 24 months of age. We investigated to what extent these factors increased a child's risk…

  17. Improving the accuracy of risk prediction from particle-based breakthrough curves reconstructed with kernel density estimators

    NASA Astrophysics Data System (ADS)

    Siirila-Woodburn, Erica R.; Fernández-Garcia, Daniel; Sanchez-Vila, Xavier

    2015-06-01

    While particle tracking techniques are often used in risk frameworks, the number of particles needed to properly derive risk metrics such as average concentration for a given exposure duration is often unknown. If too few particles are used, error may propagate into the risk estimate. In this work, we provide a less error-prone methodology for the direct reconstruction of exposure duration averaged concentration versus time breakthrough curves from particle arrival times at a compliance surface. The approach is based on obtaining a suboptimal kernel density estimator that is applied to the sampled particle arrival times. The corresponding estimates of risk metrics obtained with this method largely outperform those by means of traditional methods (reconstruction of the breakthrough curve followed by the integration of concentration in time over the exposure duration). This is particularly true when the number of particles used in the numerical simulation is small (<105), and for small exposure times. Percent error in the peak of averaged breakthrough curves is approximately zero for all scenarios and all methods tested when the number of particles is ≥105. Our results illustrate that obtaining a representative average exposure concentration is reliant on the information contained in each individual tracked particle, more so when the number of particles is small. They further illustrate the usefulness of defining problem-specific kernel density estimators to properly reconstruct the observables of interest in a particle tracking framework without relying on the use of an extremely large number of particles.

  18. Effects of exposure model resolution on seismic risk estimates - Examples from the cities of Kerak and Madaba in Jordan

    NASA Astrophysics Data System (ADS)

    Haas, Michael; Al-Qaryouti, Mahmoud; Ashour, Anas; Daoud, Nazar; Pittore, Massimiliano; Sarayrah, Abdullah; Sawarieh, Ali; Wieland, Marc

    2016-04-01

    Seismic risk is composed of the three components seismic hazard, exposed structures and the structures' vulnerability with respect to ground motion. Seismic risk estimates are subject to often large uncertainties, whose precise quantification remain a challenge. In general the largest uncertainties are considered to stem from the seismic hazard component, followed by the uncertainties in the vulnerability models. The importance of uncertainties in the exposure component are often regarded as of minor importance. This is obvious in the case the seismic risk assessment is carried out for a set of specific structures, but in case of risk estimates at city- or regional-scale the importance of uncertainties in the exposure model strongly increases. In this presentation exposure models derived from census data, remote sensing data and panoramic images obtained by a mobile mapping system for the two cities of Kerak and Madaba in Jordan and their uncertainties are discussed. Furthermore, the presentation aims to provide an insight on the effects of using these exposure models, derived from different data with varying resolution and different model assumptions on the uncertainties of seismic risk estimates for the two considered locations.

  19. Estimated cancer risk of dioxins to humans using a bioassay and physiologically based pharmacokinetic model

    SciTech Connect

    Maruyama, Wakae . E-mail: maruw@nies.go.jp; Aoki, Yasunobu

    2006-07-15

    The health risk of dioxins and dioxin-like compounds to humans was analyzed quantitatively using experimental data and mathematical models. To quantify the toxicity of a mixture of three dioxin congeners, we calculated the new relative potencies (REPs) for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PeCDD), and 2,3,4,7,8- pentachlorodibenzofuran (PeCDF), focusing on their tumor promotion activity. We applied a liver foci formation assay to female SD rats after repeated oral administration of dioxins. The REP of dioxin for a rat was determined using dioxin concentration and the number of the foci in rat liver. A physiologically based pharmacokinetic model (PBPK model) was used for interspecies extrapolation targeting on dioxin concentration in liver. Toxic dose for human was determined by back-estimation with a human PBPK model, assuming that the same concentration in the target tissue may cause the same level of effect in rats and humans, and the REP for human was determined by the toxic dose obtained. The calculated REPs for TCDD, PeCDD, and PeCDF were 1.0, 0.34, and 0.05 for rats, respectively, and the REPs for humans were almost the same as those for rats. These values were different from the toxic equivalency factors (TEFs) presented previously (Van den Berg, M., Birnbaum, L., Bosveld, A.T.C., Brunstrom, B., Cook, P., Feeley, M., Giesy, J.P., Hanberg, A., Hasegawa, R., Kennedy, S.W., Kubiak, T., Larsen, J.C., Rolaf van Leeuwen, F.X., Liem, A.K.D., Nolt, C., Peterson, R.E., Poellinger. L., Safe, S., Schrenk, D., Tillitt, D, Tysklind, M., Younes, M., Waern, F., Zacharewski, T., 1998. Toxic equivalency factors (TEFs) for PCBs, PCDDs, PCDFs for humans and wildlife. Environ. Health Perspect. 106, 775-792). The relative risk of excess liver cancer for Japanese people in general was 1.7-6.5 x 10{sup -7} by TCDD only, and 2.9-11 x 10{sup -7} by the three dioxins at the present level of contamination.

  20. Estimating the risk of cardiovascular disease using an obese-years metric

    PubMed Central

    Abdullah, Asnawi; Amin, Fauzi Ali; Stoelwinder, Johannes; Tanamas, Stephanie K; Wolfe, Rory; Barendregt, Jan; Peeters, Anna

    2014-01-01

    Objective To examine the association between obese-years and the risk of cardiovascular disease (CVD). Study design Prospective cohort study. Setting Boston, USA. Participants 5036 participants of the Framingham Heart Study were examined. Methods Obese-years was calculated by multiplying for each participant the number of body mass index (BMI) units above 29 kg/m2 by the number of years lived at that BMI during approximately 50 years of follow-up. The association between obese-years and CVD was analysed using time-dependent Cox regression adjusted for potential confounders and compared with other models using the Akaike information criterion (AIC). The lowest AIC indicated better fit. Primary outcome CVD. Results The median cumulative obese-years was 24 (range 2–556 obese-years). During 138 918 person-years of follow-up, 2753 (55%) participants were diagnosed with CVD. The incidence rates and adjusted HR (AHR) for CVD increased with an increase in the number of obese-years. AHR for the categories 1–24.9, 25–49.9, 50–74.9 and ≥75 obese-years were, respectively, 1.31 (95% CI 1.15 to 1.48), 1.37 (95% CI 1.14 to 1.65), 1.62 (95% CI 1.32 to 1.99) and 1.80 (95% CI 1.54 to 2.10) compared with those who were never obese (ie, had zero obese-years). The effect of obese-years was stronger in males than females. For every 10 unit increase in obese-years, the AHR of CVD increased by 6% (95% CI 4% to 8%) for males and 3% (95% CI 2% to 4%) for females. The AIC was lowest for the model containing obese-years compared with models containing either the level of BMI or the duration of obesity alone. Conclusions This study demonstrates that obese-years metric conceptually captures the cumulative damage of obesity on body systems, and is found to provide slightly more precise estimation of the risk of CVD than the level or duration of obesity alone. PMID:25231490

  1. Estimating the risks of multiple, covarying stressors in the National Lakes Assessment

    EPA Science Inventory

    The National Lakes Assessment (NLA) used relative and attributable risks to measure the apparent nationwide effects of excess nitrogen, reduced lakeshore habitat, and other stressors, on planktonic assemblages in lakes. The risk measures, borrowed from human health research,...

  2. The Geophysical, Anthropogenic, and Social Dimensions of Delta Risk: Estimating Contemporary and Future Risks at the Global Scale

    NASA Astrophysics Data System (ADS)

    Tessler, Z. D.; Vorosmarty, C. J.; Grossberg, M.; Gladkova, I.; Aizenman, H.; Syvitski, J. P.; Foufoula-Georgiou, E.

    2015-12-01

    Deltas are highly sensitive to increasing risks arising from local humanactivities, land subsidence, regional water management, global sea-level rise,and climate extremes. We extended a delta risk framework to include the impactof relative sea-level rise on exposure to flood conditions. We apply thisframework to an integrated set of global environmental, geophysical, and socialindicators over 48 major deltas to quantify how delta flood risk due to extremeevents is changing over time. Although geophysical and relative sea-level risederived risks are distributed across all levels of economic development, wealthycountries effectively limit their present-day threat by gross domesticproduct-enabled infrastructure and coastal defense investments. However, wheninvestments do not address the long-term drivers of land subsidence and relativesea-level rise, overall risk can be very sensitive to changes in protectivecapability. For instance, we show how in an energy-constrained future scenario,such protections will probably prove to be unsustainable, raising relative risksby four to eight times in the Mississippi and Rhine deltas and by one-and-a-halfto four times in the Chao Phraya and Yangtze deltas. The current emphasis onshort-term solutions on the world's deltas will greatly constrain options fordesigning sustainable solutions in the long term.

  3. Contribution of Company Affiliation and Social Contacts to Risk Estimates of Between-Farm Transmission of Avian Influenza

    PubMed Central

    Leibler, Jessica H.; Carone, Marco; Silbergeld, Ellen K.

    2010-01-01

    Background Models of between-farm transmission of pathogens have identified service vehicles and social groups as risk factors mediating the spread of infection. Because of high levels of economic organization in much of the poultry industry, we examined the importance of company affiliation, as distinct from social contacts, in a model of the potential spread of avian influenza among broiler poultry farms in a poultry-dense region in the United States. The contribution of company affiliation to risk of between-farm disease transmission has not been previously studied. Methodology/Principal Findings We obtained data on the nature and frequency of business and social contacts through a national survey of broiler poultry growers in the United States. Daily rates of contact were estimated using Monte Carlo analysis. Stochastic modeling techniques were used to estimate the exposure risk posed by a single infectious farm to other farms in the region and relative risk of exposure for farms under different scenarios. The mean daily rate of vehicular contact was 0.82 vehicles/day. The magnitude of exposure risk ranged from <1% to 25% under varying parameters. Risk of between-farm transmission was largely driven by company affiliation, with farms in the same company group as the index farm facing as much as a 5-fold increase in risk compared to farms contracted with different companies. Employment of part-time workers contributed to significant increases in risk in most scenarios, notably for farms who hired day-laborers. Social visits were significantly less important in determining risk. Conclusions/Significance Biosecurity interventions should be based on information on industry structure and company affiliation, and include part-time workers as potentially unrecognized sources of viral transmission. Modeling efforts to understand pathogen transmission in the context of industrial food animal production should consider company affiliation in addition to geospatial

  4. The AFGL absolute gravity program

    NASA Technical Reports Server (NTRS)

    Hammond, J. A.; Iliff, R. L.

    1978-01-01

    A brief discussion of the AFGL's (Air Force Geophysics Laboratory) program in absolute gravity is presented. Support of outside work and in-house studies relating to gravity instrumentation are discussed. A description of the current transportable system is included and the latest results are presented. These results show good agreement with measurements at the AFGL site by an Italian system. The accuracy obtained by the transportable apparatus is better than 0.1 microns sq sec 10 microgal and agreement with previous measurements is within the combined uncertainties of the measurements.

  5. Familial Aggregation of Absolute Pitch

    PubMed Central

    Baharloo, Siamak; Service, Susan K.; Risch, Neil; Gitschier, Jane; Freimer, Nelson B.

    2000-01-01

    Absolute pitch (AP) is a behavioral trait that is defined as the ability to identify the pitch of tones in the absence of a reference pitch. AP is an ideal phenotype for investigation of gene and environment interactions in the development of complex human behaviors. Individuals who score exceptionally well on formalized auditory tests of pitch perception are designated as “AP-1.” As described in this report, auditory testing of siblings of AP-1 probands and of a control sample indicates that AP-1 aggregates in families. The implications of this finding for the mapping of loci for AP-1 predisposition are discussed. PMID:10924408

  6. A competing risks approach for time estimation of household WEEE disposal

    SciTech Connect

    Gutierrez, E.; Adenso-Diaz, B.; Lozano, S.; Gonzalez-Torre, P.

    2010-08-15

    The recent growth in the number of electrical and electronic devices is viewed as one the priority waste streams in European Union waste management policy. This paper presents the findings of a survey to study domestic habits with respect to Waste Electrical and Electronic Equipment (WEEE) in Spain. A specific problem when performing this estimation arises from the fact that consumers quite often store old appliances at home when they are no longer used. Focusing on four different types of appliance, survival analysis (SA) is used to study both the usage span and the reasons for no longer using each device. The time that the discarded products were kept at home before being disposed of was studied using competing risks (CR) analysis. The results of the analysis provide information on the distribution of the studied variables for the different outcomes as well as the influence exerted by the socio-demographic variables considered. Relations between these characteristics and the storage time of the appliances before disposal emerge based on survey data. For instance, the CR model finds that the storage time of the some appliances (i.e. refrigerator) is related to these social-demographics factors. However, other appliances (i.e. microwave oven) are less influenced by these factors. The attitude and motivation of the respondents to the survey as regards the End-of-Life of appliances were also analysed. A majority of respondents do not store discarded appliances at home. The first reason for storing appliances at home is the possibility of it being useful in the future and the second that the respondents did not know what to do with them.

  7. A competing risks approach for time estimation of household WEEE disposal.

    PubMed

    Gutiérrez, E; Adenso-Díaz, B; Lozano, S; González-Torre, P

    2010-01-01

    The recent growth in the number of electrical and electronic devices is viewed as one the priority waste streams in European Union waste management policy. This paper presents the findings of a survey to study domestic habits with respect to Waste Electrical and Electronic Equipment (WEEE) in Spain. A specific problem when performing this estimation arises from the fact that consumers quite often store old appliances at home when they are no longer used. Focusing on four different types of appliance, survival analysis (SA) is used to study both the usage span and the reasons for no longer using each device. The time that the discarded products were kept at home before being disposed of was studied using competing risks (CR) analysis. The results of the analysis provide information on the distribution of the studied variables for the different outcomes as well as the influence exerted by the socio-demographic variables considered. Relations between these characteristics and the storage time of the appliances before disposal emerge based on survey data. For instance, the CR model finds that the storage time of the some appliances (i.e. refrigerator) is related to these social-demographics factors. However, other appliances (i.e. microwave oven) are less influenced by these factors. The attitude and motivation of the respondents to the survey as regards the End-of-Life of appliances were also analysed. A majority of respondents do not store discarded appliances at home. The first reason for storing appliances at home is the possibility of it being useful in the future and the second that the respondents did not know what to do with them.

  8. Estimation of risk based on multiple events in radiation carcinogenesis of rat skin

    NASA Astrophysics Data System (ADS)

    Burns, F. J.; Jin, Y.; Garte, S. J.; Hosselet, S.

    1994-10-01

    In the multistage theory of carcinogenesis, cells progress to cancer through a series of discrete, irreversible, heritable genetic alterations or mutations. However data on radiation-induced cancer incidence in rat skin suggests that some part of an intermediate repairable alteration may occur. Data are presented on cancer induction in rat skin exposed to the following radiations: 1. an electron beam (LET = 0.34 keV/um, 2. a neon ion beam (LET = 25 keV/um and 3. an argon ion beam (LET = 125 keV/um. The latter 2 beams were generated by the Bevalac at the Lawrence Berkeley Laboratory, Berkeley, CA. About 6.0 cm2 of skin was irradiated per rat. The rats were observed every 6 weeks for at least 78 weeks and tumors were scored at first occurrence. Several histological types of cancer, including squamous and basal cell carcinomas, were induced. The cancer yield versus radiation dose was fitted by the quadratic equation (Y (D) = CLD + BD2), and the parameters C and B were estimated for each type of radiation. Analysis of the DNA from the electron-induced carcinomas indicated that K-ras and/or c-myc oncogenes were activated in all tumors tested, although only a small proportion of neon-induced tumors showed similar activation. In situ hybridization indicated that the cancers contain subpopulations of cells with differing amounts of c-myc and H-ras amplification. The results are consistent with the idea that ionizing radiation produces carcinogenically relevant lesions via 2 repairable events at low LET and via a non-repairable, linked event pathway at high LET; either pathway may advance the cell by 1 stage in the multistage model. The model, if validated, permits the direct calculation of cancer risk in rat skin in a way that can be subjected to experimental testing.

  9. Social and economic factors of the natural risk growth: estimation of the Russian regions

    NASA Astrophysics Data System (ADS)

    Petrova, E.

    2003-04-01

    Òhe vulnerability of the population and economy territorial complexes (PETC) to the influence of unfavorable and dangerous natural processes and events is determined not only by the physical parameters of natural hazards in the given region, but also by economic and social peculiarities of the PETC by itself. It depends on economy type, on PETC’s age, structure and dimensions as well as on degree of its participation in the territorial division of labor. PETC would be more vulnerable to the natural hazards impact if its population density, concentration of the industrial capacities (especially of the objects that additionally create the potential danger of the man-caused catastrophes such as nuclear-power stations, chemical enterprises, oil refineries and so on), concentration of transport and other means of communication, the technological complexity, the originality of the objects included in it as well as the originality of PETC by itself would be higher. The PETC with the unfavorable socio-political and ecological situation and underdeveloped management structures are more vulnerable. The estimation of regions by PETC vulnerability degree to the natural hazards were marked out on a base of data about the actual distribution of the natural hazards in Russia and analysis of the economic indices of the Russian Federation subjects. Among the economic indexes the per capita production of Gross Regional Product (GRP), population density, road density, the degree of appraisal depreciation of the fixed assets, the land cultivation degree of the territory, forest share and so on were taken into account. As the analysis showed, the economic and social factors of the natural risk growth are active in the majority of the regions of the Russian Federation. Such a situation demands the increased attention of state and local authorities to this problem for lowering the economic and social constituents of the growth of natural hazards.

  10. Ryegrass cv. Lema and guava cv. Paluma biomonitoring suitability for estimating nutritional contamination risks under seasonal climate in Southeastern Brazil.

    PubMed

    Bulbovas, Patricia; Camargo, Carla Z S; Domingos, Marisa

    2015-08-01

    The risks posed by nutrient deposition due to air pollution on ecosystems and their respective services to human beings can be appropriately estimated by bioindicator plants when they are well acclimated to the study region environmental conditions. This assumption encouraged us to comparatively evaluate the accumulation potential of ryegrass cv. Lema and guava cv. Paluma macro and micronutrients. We also indicated the most appropriate species for biomonitoring nutrient contamination risks in tropical areas of Southeastern Brazil, which are characterized by marked dry and wet seasons and complex mixtures of air pollutants from different sources (industries, vehicle traffic and agriculture). The study was conducted in 14 sites with different neighboring land uses, within the Metropolitan Region of Campinas, central-eastern region of São Paulo State. The exposure experiments with ryegrass and guava were consecutively repeated 40 (28 days each) and 12 (84 days each) times, respectively, from Oct/2010 to Sept/2013. Macro and micronutrients were analyzed and background concentrations and enrichment ratios (ER) were estimated to classify the contamination risk within the study region. Significantly higher ER suggested that ryegrass were the most appropriate accumulator species for N, S, Mg, Fe, Mn, Cu and Zn deposition and guava for K, Ca, P and B deposition. Based on these biomonitoring adjustments, we concluded that the nutrient deposition was spatially homogeneous in the study area, but clear seasonality in the contamination risk by nutritional inputs was evidenced. Significantly higher contamination risk by S, Fe, K and B occurred during the dry season and enhanced contamination risk by Mn, Cu and Zn were highlighted during the wet season. Distinctly high contamination risk was estimated for S, Fe and Mn in several exposure experiments.

  11. Eruptive history, current activity and risk estimation using geospatial information in the Colima volcano, Mexico

    NASA Astrophysics Data System (ADS)

    Suarez-Plascencia, C.; Camarena-Garcia, M.; Nunez-Cornu, F. J.; Flores-Peña, S.

    2013-12-01

    Colima volcano, also known as Volcan de Fuego (19 30.696 N, 103 37.026 W), is located on the border between the states of Jalisco and Colima, and is the most active volcano in Mexico. In January 20, 1913, Colima had its biggest explosion of the twentieth century, with VEI 4, after the volcano had been dormant for almost 40 years. In 1961, a dome reached the northeastern edge of the crater and started a new lava flow, and from this date maintains constant activity. In February 10, 1999, a new explosion occurred at the summit dome. The activity during the 2001-2005 period was the most intense, but did not exceed VEI 3. The activity resulted in the formation of domes and their destruction after explosive events. The explosions originated eruptive columns, reaching altitudes between 4,500 and 9,000 masl, further pyroclastic flows reaching distances up to 3.5 km from the crater. During the explosive events, ash emissions were generated in all directions reaching distances up to 100 km, slightly affecting the nearby villages: Tuxpan, Tonila, Zapotlan, Cuauhtemoc, Comala, Zapotitlan de Vadillo and Toliman. During 2005 to July 2013, this volcano has had an intense effusive-explosive activity; similar to the one that took place during the period of 1890 through 1905. That was before the Plinian eruption of 1913, where pyroclastic flows reached a distance of 15 km from the crater. In this paper we estimate the risk of Colima volcano through the analysis of the vulnerability variables, hazard and exposure, for which we use: satellite imagery, recurring Fenix helicopter over flights of the state government of Jalisco, the use of the images of Google Earth and the population census 2010 INEGI. With this information and data identified changes in economic activities, development, and use of land. The expansion of the agricultural frontier in the lower sides of the volcano Colima, and with the advancement of traditional crops of sugar cane and corn, increased the growth of

  12. Estimation of human health risk associated with the consumption of pesticide-contaminated vegetables from Kumasi, Ghana.

    PubMed

    Akoto, Osei; Gavor, Sandra; Appah, Martin K; Apau, Joseph

    2015-05-01

    Analysis of pesticides consisting of 12 organophosphates (OPs), 10 organochlorines (OCs), and 6 pyrethroids in vegetables from Kumasi was conducted. Vegetable samples comprising 20 each of eggplants, okra, and tomatoes were analyzed. The method involves solvent extraction of pesticide residues followed by cleanup using silica gel. Residue analysis was carried out using a GC equipped with pulsed flame photometric detector for OP residues and electron capture detector for OC and pyrethroid residues. The results revealed that methamidophos exceeded the maximum residue limits (MRLs) in all vegetable commodities. Levels of malathion and dimethoate also exceeded the MRLs in eggplant and tomato samples. Endrin, α-endosulfan, γ-hexachlorocyclohexane (HCH), γ-chlordane, and heptachlor exceeded their MRLs in okra samples whereas methoxychlor, allethrin, and deltamethrin exceeded in eggplant samples. Health risk estimation revealed that dimethoate in tomato and endrin, heptachlor, γ-HCH, and γ-chlordane in okra could not pose potential toxicity to the consumer. The combined risk index showed no health risk to consumers due to intake of pyrethroid OC and OP residue on these vegetables. The overall risk index for combined pesticides due to consumption of all the vegetables was higher than 1, which signifies potential health risk to consumers. OPs were the major risk contributor for both eggplant and tomatoes which accounted for 87.78 and 95.84%, respectively, of the combined risk of pesticides in the vegetables. However, OC with 97.94% of the combined risk index was the major risk contributor for the okra. The carcinogenic risk of the OCs in okra was of no concern since their carcinogenic rates were below the acceptable risk level. PMID:25864079

  13. Using the USGS Seismic Risk Web Application to estimate aftershock damage

    USGS Publications Warehouse

    McGowan, Sean M.; Luco, Nicolas

    2014-01-01

    The U.S. Geological Survey (USGS) Engineering Risk Assessment Project has developed the Seismic Risk Web Application to combine earthquake hazard and structural fragility information in order to calculate the risk of earthquake damage to structures. Enabling users to incorporate their own hazard and fragility information into the calculations will make it possible to quantify (in near real-time) the risk of additional damage to structures caused by aftershocks following significant earthquakes. Results can quickly be shared with stakeholders to illustrate the impact of elevated ground motion hazard and earthquake-compromised structural integrity on the risk of damage during a short-term, post-earthquake time horizon.

  14. Quantitative estimation of landslide risk from rapid debris slides on natural slopes in the Nilgiri hills, India

    NASA Astrophysics Data System (ADS)

    Jaiswal, P.; van Westen, C. J.; Jetten, V.

    2011-06-01

    A quantitative procedure for estimating landslide risk to life and property is presented and applied in a mountainous area in the Nilgiri hills of southern India. Risk is estimated for elements at risk located in both initiation zones and run-out paths of potential landslides. Loss of life is expressed as individual risk and as societal risk using F-N curves, whereas the direct loss of properties is expressed in monetary terms. An inventory of 1084 landslides was prepared from historical records available for the period between 1987 and 2009. A substantially complete inventory was obtained for landslides on cut slopes (1042 landslides), while for natural slopes information on only 42 landslides was available. Most landslides were shallow translational debris slides and debris flowslides triggered by rainfall. On natural slopes most landslides occurred as first-time failures. For landslide hazard assessment the following information was derived: (1) landslides on natural slopes grouped into three landslide magnitude classes, based on landslide volumes, (2) the number of future landslides on natural slopes, obtained by establishing a relationship between the number of landslides on natural slopes and cut slopes for different return periods using a Gumbel distribution model, (3) landslide susceptible zones, obtained using a logistic regression model, and (4) distribution of landslides in the susceptible zones, obtained from the model fitting performance (success rate curve). The run-out distance of landslides was assessed empirically using landslide volumes, and the vulnerability of elements at risk was subjectively assessed based on limited historic incidents. Direct specific risk was estimated individually for tea/coffee and horticulture plantations, transport infrastructures, buildings, and people both in initiation and run-out areas. Risks were calculated by considering the minimum, average, and maximum landslide volumes in each magnitude class and the

  15. Estimating the risks of acquiring a kidney abroad: a meta-analysis of complications following participation in transplant tourism.

    PubMed

    Anker, Ashley E; Feeley, Thomas H

    2012-01-01

    A meta-analysis of odds ratios comparing the risks of participating in transplant tourism by acquiring a kidney abroad to the risks associated with domestic kidney transplant was undertaken. Comparison across 12 medical outcomes indicates transplant tourists are significantly more likely to contract cytomegalovirus, hepatitis B, HIV, post-transplantation diabetes mellitus, and wound infection than those receiving domestic kidney transplant. Results also indicate that domestic kidney transplant recipients experience significantly higher one-yr patient- and graft-survival rates. Analyses are supplemented by independent comparisons of outcomes and provide practitioners with weighted estimates of the proportion of transplant recipients experiencing 15 medical outcomes. Practitioners are encouraged to caution patients of the medical risks associated with transplant tourism. Despite the illegal and unethical nature of transplant tourism, additional efforts are indicated to eliminate the organ trade and to educate wait-listed patients about the risks of transplant tourism.

  16. A threshold hazard model for estimating serious infection risk following anti-tumor necrosis factor therapy in rheumatoid arthritis patients.

    PubMed

    Fu, Bo; Lunt, Mark; Galloway, James; Dixon, Will; Hyrich, Kimme; Symmons, Deborah

    2013-03-11

    Over recent years novel biologic agents have been developed for the treatment of rheumatoid arthritis. The most common type of biologic agent in use in the United Kingdom is the anti-tumor necrosis factor inhibitor class. To fully appreciate the potential risks of anti-tumor necrosis factor therapy in patients, knowledge about the baseline hazard (risk pattern) and the characteristics of patients associated with serious infection is important. We propose a nonproportional hazard model for estimating the infection risk, by including the drug exposure history information into the baseline hazard. We found that the infection risk reaches a peak within 1 month after drug exposure starts and then declines steadily for nearly 2 years before stabilizing out.

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

    PubMed

    Pouillot, Régis; Chen, Yuhuan; Hoelzer, Karin

    2015-02-01

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

  18. Estimated Risk of Developing Selected DSM-IV Disorders Among 5-Year-Old Children with Prenatal Cocaine Exposure

    PubMed Central

    Morrow, Connie E.; Xue, Lihua; Manjunath, Sudha; Culbertson, Jan C.; Accornero, Veronica H.; Anthony, James C.; Bandstra, Emmalee S.

    2016-01-01

    This study estimated childhood risk of developing selected DSM-IV Disorders, including Attention-Deficit Hyperactivity Disorder (ADHD), Oppositional Defiant Disorder (ODD), and Separation Anxiety Disorder (SAD), in children with prenatal cocaine exposure (PCE). Children were enrolled prospectively at birth (n=476) with prenatal drug exposures documented by maternal interview, urine and meconium assays. Study participants included 400 African-American children from the birth cohort, 208 cocaine-exposed (CE) and 192 non-cocaine-exposed (NCE) who attended a 5-year follow-up assessment and whose caregiver completed the Computerized Diagnostic Interview Schedule for Children. Under a generalized linear model (logistic link), Fisher’s exact methods were used to estimate the CE-associated relative risk (RR) of these disorders. Results indicated a modest but statistically robust elevation of ADHD risk associated with increasing levels of PCE (p<0.05). Binary comparison of CE versus NCE children indicated no CE-associated RR. Estimated cumulative incidence proportions among CE children were 2.9% for ADHD (vs 3.1% NCE); 1.4% for SAD (vs 1.6% NCE); and 4.3% for ODD (vs 6.8% NCE). Findings offer suggestive evidence of increased risk of ADHD (but not ODD or SAD) in relation to an increasing gradient of PCE during gestation. PMID:27761099

  19. Estimating Potential Increased Bladder Cancer Risk Due to Increased Bromide Concentrations in Sources of Disinfected Drinking Waters.

    PubMed

    Regli, Stig; Chen, Jimmy; Messner, Michael; Elovitz, Michael S; Letkiewicz, Frank J; Pegram, Rex A; Pepping, T J; Richardson, Susan D; Wright, J Michael

    2015-11-17

    Public water systems are increasingly facing higher bromide levels in their source waters from anthropogenic contamination through coal-fired power plants, conventional oil and gas extraction, textile mills, and hydraulic fracturing. Climate change is likely to exacerbate this in coming years. We estimate bladder cancer risk from potential increased bromide levels in source waters of disinfecting public drinking water systems in the United States. Bladder cancer is the health end point used by the United States Environmental Protection Agency (EPA) in its benefits analysis for regulating disinfection byproducts in drinking water. We use estimated increases in the mass of the four regulated trihalomethanes (THM4) concentrations (due to increased bromide incorporation) as the surrogate disinfection byproduct (DBP) occurrence metric for informing potential bladder cancer risk. We estimate potential increased excess lifetime bladder cancer risk as a function of increased source water bromide levels. Results based on data from 201 drinking water treatment plants indicate that a bromide increase of 50 μg/L could result in a potential increase of between 10(-3) and 10(-4) excess lifetime bladder cancer risk in populations served by roughly 90% of these plants. PMID:26489011

  20. Estimating Potential Increased Bladder Cancer Risk Due to Increased Bromide Concentrations in Sources of Disinfected Drinking Waters.

    PubMed

    Regli, Stig; Chen, Jimmy; Messner, Michael; Elovitz, Michael S; Letkiewicz, Frank J; Pegram, Rex A; Pepping, T J; Richardson, Susan D; Wright, J Michael

    2015-11-17

    Public water systems are increasingly facing higher bromide levels in their source waters from anthropogenic contamination through coal-fired power plants, conventional oil and gas extraction, textile mills, and hydraulic fracturing. Climate change is likely to exacerbate this in coming years. We estimate bladder cancer risk from potential increased bromide levels in source waters of disinfecting public drinking water systems in the United States. Bladder cancer is the health end point used by the United States Environmental Protection Agency (EPA) in its benefits analysis for regulating disinfection byproducts in drinking water. We use estimated increases in the mass of the four regulated trihalomethanes (THM4) concentrations (due to increased bromide incorporation) as the surrogate disinfection byproduct (DBP) occurrence metric for informing potential bladder cancer risk. We estimate potential increased excess lifetime bladder cancer risk as a function of increased source water bromide levels. Results based on data from 201 drinking water treatment plants indicate that a bromide increase of 50 μg/L could result in a potential increase of between 10(-3) and 10(-4) excess lifetime bladder cancer risk in populations served by roughly 90% of these plants.

  1. Commissioning the neutron production of a Linac: Development of a simple tool for second cancer risk estimation

    SciTech Connect

    Romero-Expósito, M.; Sánchez-Nieto, B.; Terrón, J. A.; Lopes, M. C.; Ferreira, B. C.; Grishchuk, D.; Sandín, C.; Moral-Sánchez, S.; Melchor, M.; Domingo, C.; and others

    2015-01-15

    Purpose: Knowing the contribution of neutron to collateral effects in treatments is both a complex and a mandatory task. This work aims to present an operative procedure for neutron estimates in any facility using a neutron digital detector. Methods: The authors’ previous work established a linear relationship between the total second cancer risk due to neutrons (TR{sup n}) and the number of MU of the treatment. Given that the digital detector also presents linearity with MU, its response can be used to determine the TR{sup n} per unit MU, denoted as m, normally associated to a generic Linac model and radiotherapy facility. Thus, from the number of MU of each patient treatment, the associated risk can be estimated. The feasibility of the procedure was tested by applying it in eight facilities; patients were evaluated as well. Results: From the reading of the detector under selected irradiation conditions, m values were obtained for different machines, ranging from 0.25 × 10{sup −4}% per MU for an Elekta Axesse at 10 MV to 6.5 × 10{sup −4}% per MU for a Varian Clinac at 18 MV. Using these values, TR{sup n} of patients was estimated in each facility and compared to that from the individual evaluation. Differences were within the range of uncertainty of the authors’ methodology of equivalent dose and risk estimations. Conclusions: The procedure presented here allows an easy estimation of the second cancer risk due to neutrons for any patient, given the number of MU of the treatment. It will enable the consideration of this information when selecting the optimal treatment for a patient by its implementation in the treatment planning system.

  2. Estimating the risk of type-2 diabetes using obese-years in a contemporary population of the Framingham Study

    PubMed Central

    Abdullah, Asnawi; Amin, Fauzi Ali; Hanum, Farida; Stoelwinder, Johannes; Tanamas, Stephanie; Wolf, Rory; Wong, Evelyn; Peeters, Anna

    2016-01-01

    Background We have recently demonstrated that an obese-years construct is a better predictor of the risk of diabetes than the severity of body weight alone. However, these risk estimates were derived from a population cohort study initiated in 1948 that might not apply to the current population. Objective To validate an obese-years construct in estimating the risk of type-2 diabetes in a more contemporary cohort study. Design A total of 5,132 participants of the Framingham Offspring Study, initiated in 1972, were followed up for 45 years. Body mass index (BMI) above 29 kg/m2 was multiplied by the number of years lived with obesity at that BMI to define the number of obese-years. Time-dependent Cox regression was used to explore the association. Results The risk of type-2 diabetes increased significantly with increase in obese-years. Adjusted hazard ratios increased by 6% (95% CI: 5–7%) per additional 10 points of obese-years. This ratio was observed to be similar in both men and women, but was 4% higher in current smokers than in never/ex-smokers. The Akaike Information Criterion confirmed that the Cox regression model with the obese-years construct was a stronger predictor of the risk of diabetes than a model including either BMI or the duration of obesity alone. Conclusions In a contemporary cohort population, it was confirmed that the obese-years construct is strongly associated with an increased risk of type-2 diabetes. This suggests that both severity and the duration of obesity should be considered in future estimations of the burden of disease associated with obesity. PMID:27369220

  3. How do we best estimate fluvial flood risk in urban environments? : The case of the city of Eilenburg, Germany

    NASA Astrophysics Data System (ADS)

    Longo, Elisa; Tito Aronica, Giuseppe; Di Baldassarre, Giuliano; Mukolwe, Micah

    2015-04-01

    Flooding is one of the most impactful natural hazards. In particular, by looking at the data of damages from natural hazards in Europe collected in the International Disaster Database (EM-DAT) one can see a significant increase over the past four decades of both frequency of floods and associated economic damages. Similarly, dramatic trends are also found by analyzing other types of flood losses, such as the number of people affected by floods, homeless, injured or killed. To deal with the aforementioned increase of flood risk, more and more efforts are being made to promote integrated flood risk management, for instance, at the end of 2007, the European Community (EC) issued the Flood Directive (F.D.) 2007/60/EC. One of the major innovations was that the F.D. 2007/60/C requires Member State to carry out risk maps and then take appropriate measures to reduce the evaluated risk. The main goal of this research was to estimate flood damaging using a computer code based on a recently developed method (KULTURisk, www.kulturisk.eu) and to compare the estimated damage with the observed one. The study area was the municipality of Eilenburg, which in 2002 was subjected to a destructive flood event. Were produced flood damage maps with new procedures (e.g. KULTURisk) and compared the estimates with observed data. This study showed the possibility to extend the lesson learned with the Eilenburg case study in other similar contexts. The outcomes of this test provided interesting insights about the flood risk mapping, which are expected to contribute to raise awareness to the flooding issues,to plan (structural and/or non-structural) measures of flood risk reduction and to support better land-use and urban planning.

  4. Estimation of infectious risks in residential populations exposed to airborne pathogens during center pivot irrigation of dairy wastewaters.

    PubMed

    Dungan, Robert Stephen

    2014-05-01

    In the western United States where dairy wastewaters are commonly land applied, there are concerns over individuals being exposed to airborne pathogens. In response, a quantitative microbial risk assessment (QMRA) was performed to estimate infectious risks after inhalation exposure of pathogens aerosolized during center pivot irrigation of diluted dairy wastewaters. The dispersion of pathogens (Campylobacter jejuni, Escherichia coli O157:H7, non-O157 E. coli, Listeria monocytogenes, and Salmonella spp.) was modeled using the atmospheric dispersion model, AERMOD. Pathogen concentrations at downwind receptors were used to calculate infectious risks during one-time (1, 8, and 24 h) and multiday (7 d at 1 h d(-1)) exposure events using a β-Poisson dose-response model. This assessment considered risk of infection in residential populations that were 1 to 10 km from a center pivot operation. In the simulations, infectious risks were estimated to be the greatest in individuals closest to the center pivot, as a result of a higher pathogen dose. On the basis of the results from this QMRA, it is recommended that wastewaters only be applied during daylight hours when inactivation and dilution of airborne pathogens is highest. Further refinement of the dispersion and dose-response models should be considered to increase the utility of this QMRA. PMID:24697271

  5. MITRA Virtual laboratory for operative application of satellite time series for land degradation risk estimation

    NASA Astrophysics Data System (ADS)

    Nole, Gabriele; Scorza, Francesco; Lanorte, Antonio; Manzi, Teresa; Lasaponara, Rosa

    2015-04-01

    This paper aims to present the development of a tool to integrate time series from active and passive satellite sensors (such as of MODIS, Vegetation, Landsat, ASTER, COSMO, Sentinel) into a virtual laboratory to support studies on landscape and archaeological landscape, investigation on environmental changes, estimation and monitoring of natural and anthropogenic risks. The virtual laboratory is composed by both data and open source tools specifically developed for the above mentioned applications. Results obtained for investigations carried out using the implemented tools for monitoring land degradation issues and subtle changes ongoing on forestry and natural areas are herein presented. In detail MODIS, SPOT Vegetation and Landsat time series were analyzed comparing results of different statistical analyses and the results integrated with ancillary data and evaluated with field survey. The comparison of the outputs we obtained for the Basilicata Region from satellite data analyses and independent data sets clearly pointed out the reliability for the diverse change analyses we performed, at the pixel level, using MODIS, SPOT Vegetation and Landsat TM data. Next steps are going to be implemented to further advance the current Virtual Laboratory tools, by extending current facilities adding new computational algorithms and applying to other geographic regions. Acknowledgement This research was performed within the framework of the project PO FESR Basilicata 2007/2013 - Progetto di cooperazione internazionale MITRA "Remote Sensing tecnologies for Natural and Cultural heritage Degradation Monitoring for Preservation and valorization" funded by Basilicata Region Reference 1. A. Lanorte, R Lasaponara, M Lovallo, L Telesca 2014 Fisher-Shannon information plane analysis of SPOT/VEGETATION Normalized Difference Vegetation Index (NDVI) time series to characterize vegetation recovery after fire disturbance International Journal of Applied Earth Observation and

  6. Estimation of risk probability for gravity-driven pyroclastic flows at Volcan Colima, Mexico

    NASA Astrophysics Data System (ADS)

    Sheridan, Michael F.; Macías, JoséLuis

    1995-07-01

    Mapped pyroclastic flow terminations at Colima volcano were used to determine energy lines. We assumed straight energy lines, initial flow velocities of zero and flow movement starting from the volcano summit. Heim coefficients ( H/L) of the flows plotted on a histogram cluster in two distinct modes. One corresponds to large pyroclastic flows (pumice flows and block-and-ash flows) for which Heim coefficients range from 0.22 to 0.28. This group has a mean value of 0.24 and a standard deviation of 0.021. The other mode corresponds to small block-and-ash avalanches which have Heim coefficients that range from 0.33 to 0.38, a mean value of 0.35 and a standard deviation of 0.025. No flow terminations yield Heim coefficients in the range from 0.28 to 0.33. This break probably separates fluidized pyroclastic flows from less mobile hot rock avalanches. Plots of Heim coefficients on arithmetic probability paper are approximate probability functions for the two types of flows. Heim coefficients calculated for straight lines that connect population centers with the volcano summit can be used with this type of graph to estimate the probability that either type of pyroclastic flow would reach the site. We used this technique to determine risk probabilities for various localities around Colima volcano. These calculations indicate that Laguna Verde, Yerbabuena, Cofradia-El Fresnal, El Naranjal, Atenguillo, La Becerrera, Montitlan and San Antonio have a probability ranging from 99 to 6% of being covered by large pyroclastic flows. Laguna Verde and Yerbabuena are the sites with the highest probability of being reached by small block-and-ash avalanches. The depression situated south-southwest of Colima volcano is an area with a very high probability of being affected by the pyroclastic phenomena considered above. The small avalanche produced by dome collapse of Colima on April 16, 1991 traveled along the barranca El Cordobán toward the area of the highest probability on our map.

  7. Cosmology with negative absolute temperatures

    NASA Astrophysics Data System (ADS)

    Vieira, J. P. P.; Byrnes, Christian T.; Lewis, Antony

    2016-08-01

    Negative absolute temperatures (NAT) are an exotic thermodynamical consequence of quantum physics which has been known since the 1950's (having been achieved in the lab on a number of occasions). Recently, the work of Braun et al. [1] has rekindled interest in negative temperatures and hinted at a possibility of using NAT systems in the lab as dark energy analogues. This paper goes one step further, looking into the cosmological consequences of the existence of a NAT component in the Universe. NAT-dominated expanding Universes experience a borderline phantom expansion (w < ‑1) with no Big Rip, and their contracting counterparts are forced to bounce after the energy density becomes sufficiently large. Both scenarios might be used to solve horizon and flatness problems analogously to standard inflation and bouncing cosmologies. We discuss the difficulties in obtaining and ending a NAT-dominated epoch, and possible ways of obtaining density perturbations with an acceptable spectrum.

  8. Apparatus for absolute pressure measurement

    NASA Technical Reports Server (NTRS)

    Hecht, R. (Inventor)

    1969-01-01

    An absolute pressure sensor (e.g., the diaphragm of a capacitance manometer) was subjected to a superimposed potential to effectively reduce the mechanical stiffness of the sensor. This substantially increases the sensitivity of the sensor and is particularly useful in vacuum gauges. An oscillating component of the superimposed potential induced vibrations of the sensor. The phase of these vibrations with respect to that of the oscillating component was monitored, and served to initiate an automatic adjustment of the static component of the superimposed potential, so as to bring the sensor into resonance at the frequency of the oscillating component. This establishes a selected sensitivity for the sensor, since a definite relationship exists between resonant frequency and sensitivity.

  9. Cosmology with negative absolute temperatures

    NASA Astrophysics Data System (ADS)

    Vieira, J. P. P.; Byrnes, Christian T.; Lewis, Antony

    2016-08-01

    Negative absolute temperatures (NAT) are an exotic thermodynamical consequence of quantum physics which has been known since the 1950's (having been achieved in the lab on a number of occasions). Recently, the work of Braun et al. [1] has rekindled interest in negative temperatures and hinted at a possibility of using NAT systems in the lab as dark energy analogues. This paper goes one step further, looking into the cosmological consequences of the existence of a NAT component in the Universe. NAT-dominated expanding Universes experience a borderline phantom expansion (w < -1) with no Big Rip, and their contracting counterparts are forced to bounce after the energy density becomes sufficiently large. Both scenarios might be used to solve horizon and flatness problems analogously to standard inflation and bouncing cosmologies. We discuss the difficulties in obtaining and ending a NAT-dominated epoch, and possible ways of obtaining density perturbations with an acceptable spectrum.

  10. The influence of spatial resolution on human health risk co-benefit estimates for global climate policy assessments.

    PubMed

    Shih, Hsiu-Ching; Crawford-Brown, Douglas; Ma, Hwong-wen

    2015-03-15

    Assessment of the ability of climate policies to produce desired improvements in public health through co-benefits of air pollution reduction can consume resources in both time and research funds. These resources increase significantly as the spatial resolution of models increases. In addition, the level of spatial detail available in macroeconomic models at the heart of climate policy assessments is much lower than that available in traditional human health risk modeling. It is therefore important to determine whether increasing spatial resolution considerably affects risk-based decisions; which kinds of decisions might be affected; and under what conditions they will be affected. Human health risk co-benefits from carbon emissions reductions that bring about concurrent reductions in Particulate Matter (PM10) emissions is therefore examined here at four levels of spatial resolution (Uniform Nation, Uniform Region, Uniform County/city, Health Risk Assessment) in a case study of Taiwan as one of the geographic regions of a global macroeceonomic model, with results that are representative of small, industrialized nations within that global model. A metric of human health risk mortality (YOLL, years of life lost in life expectancy) is compared under assessments ranging from a "uniform simulation" in which there is no spatial resolution of changes in ambient air concentration under a policy to a "highly spatially resolved simulation" (called here Health Risk Assessment). PM10 is chosen in this study as the indicator of air pollution for which risks are assessed due to its significance as a co-benefit of carbon emissions reductions within climate mitigation policy. For the policy examined, the four estimates of mortality in the entirety of Taiwan are 747 YOLL, 834 YOLL, 984 YOLL and 916 YOLL, under Uniform Taiwan, Uniform Region, Uniform County and Health Risk Assessment respectively; or differences of 18%, 9%, 7% if the HRA methodology is taken as the baseline. While

  11. The influence of spatial resolution on human health risk co-benefit estimates for global climate policy assessments.

    PubMed

    Shih, Hsiu-Ching; Crawford-Brown, Douglas; Ma, Hwong-wen

    2015-03-15

    Assessment of the ability of climate policies to produce desired improvements in public health through co-benefits of air pollution reduction can consume resources in both time and research funds. These resources increase significantly as the spatial resolution of models increases. In addition, the level of spatial detail available in macroeconomic models at the heart of climate policy assessments is much lower than that available in traditional human health risk modeling. It is therefore important to determine whether increasing spatial resolution considerably affects risk-based decisions; which kinds of decisions might be affected; and under what conditions they will be affected. Human health risk co-benefits from carbon emissions reductions that bring about concurrent reductions in Particulate Matter (PM10) emissions is therefore examined here at four levels of spatial resolution (Uniform Nation, Uniform Region, Uniform County/city, Health Risk Assessment) in a case study of Taiwan as one of the geographic regions of a global macroeceonomic model, with results that are representative of small, industrialized nations within that global model. A metric of human health risk mortality (YOLL, years of life lost in life expectancy) is compared under assessments ranging from a "uniform simulation" in which there is no spatial resolution of changes in ambient air concentration under a policy to a "highly spatially resolved simulation" (called here Health Risk Assessment). PM10 is chosen in this study as the indicator of air pollution for which risks are assessed due to its significance as a co-benefit of carbon emissions reductions within climate mitigation policy. For the policy examined, the four estimates of mortality in the entirety of Taiwan are 747 YOLL, 834 YOLL, 984 YOLL and 916 YOLL, under Uniform Taiwan, Uniform Region, Uniform County and Health Risk Assessment respectively; or differences of 18%, 9%, 7% if the HRA methodology is taken as the baseline. While

  12. Use of risk projection models to estimate mortality and incidence from radiation-induced breast cancer in screening programs

    NASA Astrophysics Data System (ADS)

    Ramos, M.; Ferrer, S.; Villaescusa, J. I.; Verdú, G.; Salas, M. D.; Cuevas, M.