Science.gov

Sample records for predicting internal exposure

  1. Predicting the radiation exposure of terrestrial wildlife in the Chernobyl exclusion zone : an international comparison of approaches.

    SciTech Connect

    Beresford, N. A.; Barnett, C. L.; Brown, J. E.; Cheng, J.-J.; Copplestone, D.; Gaschak, S.; Hosseini, A.; Howard, B. J.; Kamboj, S.; Nedveckaite, T.; Olyslaegers, G.; Smith, J. T.; Vives i Batlle, J.; Vives-Lynch, S.; Yu, C.; Environmental Science Division; Centre for Ecology and Hydrology; Norwegian Radiation Protection Authority; England and Wales Environment Agency; International Radioecology Lab.; Inst. of Physics, Radiation Protection,; Belgian Nuclear Research Centre; Univ. of Portsmouth; Westlakes Research Inst.

    2010-06-09

    There is now general acknowledgement that there is a requirement to demonstrate that species other than humans are protected from anthropogenic releases of radioactivity. A number of approaches have been developed for estimating the exposure of wildlife and some of these are being used to conduct regulatory assessments. There is a requirement to compare the outputs of such approaches against available data sets to ensure that they are robust and fit for purpose. In this paper we describe the application of seven approaches for predicting the whole-body ({sup 90}Sr, {sup 137}Cs, {sup 241}Am and Pu isotope) activity concentrations and absorbed dose rates for a range of terrestrial species within the Chernobyl exclusion zone. Predictions are compared against available measurement data, including estimates of external dose rate recorded by thermoluminescent dosimeters attached to rodent species. Potential reasons for differences between predictions between the various approaches and the available data are explored.

  2. Predicting positive mental health in internally displaced persons in Indonesia: the roles of economic improvement and exposure to violent conflict.

    PubMed

    Saragih Turnip, Sherly; Sörbom, Dag; Hauff, Edvard

    2016-01-01

    Positive mental health, rather than just the absence of mental illness, is rarely investigated among the internally displaced persons (IDPs) affected by violent conflict in low-income countries. The purpose of this study was to investigate a model that could explain the interrelationship between factors contributing to positive mental health in displaced populations. In a longitudinal study we examine poverty, exposure to traumatic events and the change of material well-being after one year. We collected data in two consecutive years (2005 and 2006) from a community-based sample of IDPs in Ambon, Indonesia, through face-to-face structured interviews with consenting adults. Participants of this study were IDPs lived in Ambon during the violent conflict period. We interviewed 471 IDPs in the first year and reinterviewed 399 (85%) of the same subjects in the second year. The IDPs possessed good sense of coherence and subjective well-being. Our final model, which was generated by the use of structural equation modeling, fits the data well (χ(2) = 52.51, df = 45, p = .21, CFI = .99, RMSEA = .019). Exposure to violent conflict had a negative impact on IDPs' mental health initially and better economic conditions improved it (r = -.30 and .29 respectively). Mental health status one year previously was a strong predictor of future mental health, followed by individual economic growth in the past year (r = .43 and .29 respectively). On a group level the IDPs were resilient and adaptive to survive in adverse living conditions after devastating violent conflict, and the economic improvement contributed to it. PMID:26059612

  3. Nevirapine exposure with WHO pediatric weight band dosing: enhanced therapeutic concentrations predicted based on extensive international pharmacokinetic experience.

    PubMed

    Nikanjam, Mina; Kabamba, Desiré; Cressey, Tim R; Burger, David; Aweeka, Francesca T; Acosta, Edward P; Spector, Stephen A; Capparelli, Edmund V

    2012-10-01

    Nevirapine (NVP) is a nonnucleoside reverse transcriptase inhibitor (NNRTI) used worldwide as part of combination antiretroviral therapy in infants and children to treat HIV infection. Dosing based on either weight or body surface area has been approved by the U.S. Food and Drug Administration (FDA) but can be difficult to implement in resource-limited settings. The World Health Organization (WHO) has developed simplified weight band dosing for NVP, but it has not been critically evaluated. NVP pharmacokinetic data were combined from eight pediatric clinical trials (Pediatric AIDS Clinical Trials Group [PACTG] studies 245, 356, 366, 377, 403, 1056, and 1069 and Children with HIV in Africa Pharmacokinetics and Adherence of Simple Antiretroviral Regimens [CHAPAS]) representing subjects from multiple continents and across the pediatric age continuum. A population pharmacokinetic model was developed to characterize developmental changes in NVP disposition, identify potential sources of NVP pharmacokinetic variability, and assess various pediatric dosing strategies and their impact on NVP exposure. Age, CYP2B6 genotype, and ritonavir were independent predictors of oral NVP clearance. The Triomune fixed-dose tablet was an independent predictor of bioavailability compared to the liquid and other tablet formulations. Monte Carlo simulations of the final model were used to assess WHO weight band dosing recommendations. The final pharmacokinetic model indicated that WHO weight band dosing is likely to result in a percentage of children with NVP exposure within the target range similar to that obtained with FDA dosing. Weight band dosing of NVP proposed by the WHO has the potential to provide a simple and effective dosing strategy for resource limited settings. PMID:22869579

  4. [Management of accidental internal exposure].

    PubMed

    Fatome, M

    1994-11-01

    Radionucleides can penetrate into the body via the lung, the digestive tract, wounds and sometimes through healthy skin. Once they have penetrated the body, they can either remain localized at the site of entry or be rapidly metabolized. The risk is late effects. Radioelements must be eliminated as rapidly as possible decreasing the exposure proportionally. The effectiveness of the treatment depends on early institution. Nevertheless, emergency intensive care or surgery may be required. As soon as possible, explorations must be carried out to evaluate the level of contamination (human spectrometry, radiotoxicological examinations) and to start treatment. Modalities include non-specific techniques (lavage, insolubilization, laxatives) and specific techniques such as complexation or isotopic dilution (iodine for iodine, Prussian blue for cesium, DTPA for plutonium, Diamox or sodium bicarbonate for uranium). Surgical cleaning of wounds and burns is an excellent means of decontamination. External contamination is often associated. Further contamination must be prevented immediately. PMID:7844774

  5. Does exposure prediction bias health effect estimation? The relationship between confounding adjustment and exposure prediction

    PubMed Central

    Dominici, Francesca

    2014-01-01

    In environmental epidemiology, we are often faced with two challenges. First, an exposure prediction model is needed to estimate the exposure to an agent of interest, ideally at the individual level. Second, when estimating the health-effect associated with the exposure, confounding adjustment is needed in the health-effects regression model. The current literature addresses these two challenges separately. That is, methods that account for measurement error in the predicted exposure often fail to acknowledge the possibility of confounding, while methods designed to control confounding often fail to acknowledge that the exposure has been predicted. In this paper, we consider exposure prediction and confounding adjustment in a health-effects regression model simultaneously. By using theoretical arguments and simulation studies, we show that the bias of a health-effect estimate is influenced by the exposure prediction model, the type of confounding adjustment used in the health-effects regression model, and the relationship between these two. Moreover, we argue that even with a health-effects regression model that properly adjusts for confounding, the use of a predicted exposure can bias the health-effect estimate unless all confounders included in the health-effects regression model are also included in the exposure prediction model. While these results of this paper were motivated by studies of environmental contaminants, they apply more broadly to any context where an exposure needs to be predicted. PMID:24815302

  6. Comparing prediction models for radiographic exposures

    NASA Astrophysics Data System (ADS)

    Ching, W.; Robinson, J.; McEntee, M. F.

    2015-03-01

    During radiographic exposures the milliampere-seconds (mAs), kilovoltage peak (kVp) and source-to-image distance can be adjusted for variations in patient thicknesses. Several exposure adjustment systems have been developed to assist with this selection. This study compares the accuracy of four systems to predict the required mAs for pelvic radiographs taken on a direct digital radiography system (DDR). Sixty radiographs were obtained by adjusting mAs to compensate for varying combinations of source-to-image distance (SID), kVp and patient thicknesses. The 25% rule, the DuPont Bit System and the DigiBit system were compared to determine which of these three most accurately predicted the mAs required for an increase in patient thickness. Similarly, the 15% rule, the DuPont Bit System and the DigiBit system were compared for an increase in kVp. The exposure index (EI) was used as an indication of exposure to the DDR. For each exposure combination the mAs was adjusted until an EI of 1500+/-2% was achieved. The 25% rule was the most accurate at predicting the mAs required for an increase in patient thickness, with 53% of the mAs predictions correct. The DigiBit system was the most accurate at predicting mAs needed for changes in kVp, with 33% of predictions correct. This study demonstrated that the 25% rule and DigiBit system were the most accurate predictors of mAs required for an increase in patient thickness and kVp respectively. The DigiBit system worked well in both scenarios as it is a single exposure adjustment system that considers a variety of exposure factors.

  7. LINKING EXPOSURES TO INTERNAL DOSES USING BIOMARKERS

    EPA Science Inventory

    Biomonitoring is a useful tool to help assess human exposures/internal doses to chemicals in the environment. This research contributes to EPA's mission to protect human health by understanding what chemicals people are exposed to in their daily environments. In this task, we wil...

  8. Predicting survival time for cold exposure

    NASA Astrophysics Data System (ADS)

    Tikuisis, Peter

    1995-06-01

    The prediction of survival time (ST) for cold exposure is speculative as reliable controlled data of deep hypothermia are unavailable. At best, guidance can be obtained from case histories of accidental exposure. This study describes the development of a mathematical model for the prediction of ST under sedentary conditions in the cold. The model is based on steady-state heat conduction in a single cylinder comprised of a core and two concentric annular shells representing the fat plus skin and the clothing plus still boundary layer, respectively. The ambient condition can be either air or water; the distinction is made by assigning different values of insulation to the still boundary layer. Metabolic heat production ( M) is comprised of resting and shivering components with the latter predicted by temperature signals from the core and skin. Where the cold exposure is too severe for M to balance heat loss, ST is largely determined by the rate of heat loss from the body. Where a balance occurs, ST is governed by the endurance time for shivering. End of survival is marked by the deep core temperature reaching a value of 30° C. The model was calibrated against survival data of cold water (0 to 20° C) immersion and then applied to cold air exposure. A sampling of ST predictions for the nude exposure of an average healthy male in relatively calm air (1 km/h wind speed) are the following: 1.8, 2.5, 4.1, 9.0, and >24 h for -30, -20, -10, 0, and 10° C, respectively. With two layers of loose clothing (average thickness of 1 mm each) in a 5 km/h wind, STs are 4.0, 5.6, 8.6, 15.4, and >24 h for -50, -40, -30, -20, and -10° C. The predicted STs must be weighted against the extrapolative nature of the model. At present, it would be prudent to use the predictions in a relative sense, that is, to compare or rank-order predicted STs for various combinations of ambient conditions and clothing protection.

  9. Status: Crewmember Noise Exposures on the International Space Station

    NASA Technical Reports Server (NTRS)

    Limardo-Rodriguez, Jose G.; Allen, Christopher S.; Danielson, Richard W.

    2015-01-01

    The International Space Station (ISS) provides a unique environment where crewmembers from the US and our international partners work and live for as long as 6 to 12 consecutive months. During these long-durations ISS missions, noise exposures from onboard equipment are posing concerns for human factors and crewmember health risks, such as possible reductions in hearing sensitivity, disruptions of crew sleep, interference with speech intelligibility and voice communications, interference with crew task performance, and reduced alarm audibility. It is crucial to control acoustical noise aboard ISS to acceptable noise exposure levels during the work-time period, and to also provide a restful sleep environment during the sleep-time period. Acoustic dosimeter measurements, obtained when the crewmember wears the dosimeter for 24-hour periods, are conducted onboard ISS every 60 days and compared to ISS flight rules. NASA personnel then assess the acoustic environment to which the crewmembers are exposed, and provide recommendations for hearing protection device usage. The purpose of this paper is to provide an update on the status of ISS noise exposure monitoring and hearing conservation strategies, as well as to summarize assessments of acoustic dosimeter data collected since the Increment 36 mission (April 2013). A description of the updated noise level constraints flight rule, as well as the Noise Exposure Estimation Tool and the Noise Hazard Inventory implementation for predicting crew noise exposures and recommending to ISS crewmembers when hearing protection devices are required, will be described.

  10. Critical Dose of Internal Organs Internal Exposure - 13471

    SciTech Connect

    Grigoryan, G.; Amirjanyan, A.; Grigoryan, N.

    2013-07-01

    The health threat posed by radionuclides has stimulated increased efforts to developed characterization on the biological behavior of radionuclides in humans in all ages. In an effort motivated largely by the Chernobyl nuclear accident, the International Commission on Radiological Protection (ICRP) is assembling a set of age specific biokinetic models for environmentally important radioelements. Radioactive substances in the air, mainly through the respiratory system and digestive tract, is inside the body. Radioactive substances are unevenly distributed in various organs and tissues. Therefore, the degree of damage will depend not only on the dose of radiation have but also on the critical organ, which is the most accumulation of radioactive substances, which leads to the defeat of the entire human body. The main objective of radiation protection, to avoid exceeding the maximum permissible doses of external and internal exposure of a person to prevent the physical and genetic damage people. The maximum tolerated dose (MTD) of radiation is called a dose of radiation a person in uniform getting her for 50 years does not cause changes in the health of the exposed individual and his progeny. The following classification of critical organs, depending on the category of exposure on their degree of sensitivity to radiation: First group: the whole body, gonads and red bone marrow; Second group: muscle, fat, liver, kidney, spleen, gastrointestinal tract, lungs and lens of the eye; The third group: bone, thyroid and skin; Fourth group: the hands, forearms, feet. MTD exposure whole body, gonads and bone marrow represent the maximum exposures (5 rem per year) experienced by people in their normal activities. The purpose of this article is intended dose received from various internal organs of the radionuclides that may enter the body by inhalation, and gastrointestinal tract. The biokinetic model describes the time dependent distribution and excretion of different

  11. Predicting Language Outcomes for Internationally Adopted Children

    ERIC Educational Resources Information Center

    Glennen, Sharon L.

    2007-01-01

    Purpose: Language and speech are difficult to assess in newly arrived internationally adopted children. The purpose of this study was to determine if assessments completed when toddlers were first adopted could predict language outcomes at age 2. Local norms were used to develop early intervention guidelines that were evaluated against age 2…

  12. A nozzle internal performance prediction method

    NASA Technical Reports Server (NTRS)

    Carlson, John R.

    1992-01-01

    A prediction method was written and incorporated into a three-dimensional Navier-Stokes code (PAB3D) for the calculation of nozzle internal performance. The following quantities are calculated: (1) discharge coefficient; (2) normal, side, and axial thrust ratios; (3) rolling, pitching, and yawing moments; and (4) effective pitch and yaw vector angles. Four different case studies are presented to confirm the applicability of the methodology. Internal and, in most situations, external flow-field regions are required to be modeled. The computed nozzle discharge coefficient matches both the level and the trend of the experimental data within quoted experimental data accuracy (0.5 percent). Moment and force ratios are generally within 1 to 2 percent of the absolute level of experimental data, with the trends of data matched accurately.

  13. Identification of Gene Expression Biomarkers for Predicting Radiation Exposure

    PubMed Central

    Lu, Tzu-Pin; Hsu, Yi-Yao; Lai, Liang-Chuan; Tsai, Mong-Hsun; Chuang, Eric Y.

    2014-01-01

    A need for more accurate and reliable radiation dosimetry has become increasingly important due to the possibility of a large-scale radiation emergency resulting from terrorism or nuclear accidents. Although traditional approaches provide accurate measurements, such methods usually require tedious effort and at least two days to complete. Therefore, we provide a new method for rapid prediction of radiation exposure. Eleven microarray datasets were classified into two groups based on their radiation doses and utilized as the training samples. For the two groups, Student's t-tests and resampling tests were used to identify biomarkers, and their gene expression ratios were used to develop a prediction model. The performance of the model was evaluated in four independent datasets, and Ingenuity pathway analysis was performed to characterize the associated biological functions. Our meta-analysis identified 29 biomarkers, showing approximately 90% and 80% accuracy in the training and validation samples. Furthermore, the 29 genes significantly participated in the regulation of cell cycle, and 19 of them are regulated by three well-known radiation-modulated transcription factors: TP53, FOXM1 and ERBB2. In conclusion, this study demonstrates a reliable method for identifying biomarkers across independent studies and high and reproducible prediction accuracy was demonstrated in both internal and external datasets. PMID:25189756

  14. POPULATION EXPOSURES TO PARTICULATE MATTER: A COMPARISON OF EXPOSURE MODEL PREDICTIONS AND MEASUREMENT DATA

    EPA Science Inventory

    The US EPA National Exposure Research Laboratory (NERL) is currently developing an integrated human exposure source-to-dose modeling system (HES2D). This modeling system will incorporate models that use a probabilistic approach to predict population exposures to environmental ...

  15. Improving Undergraduate Learning for Employability through International Exposure

    ERIC Educational Resources Information Center

    Eaton, Tim V.; Kleshinski, Andrew S.

    2014-01-01

    The purpose of this study is to identify how undergraduate business programs can incorporate international exposure to increase employability among its graduates. We first examine how international opportunities in corporations have impacted the skills needed by employees to excel in a globalized work environment. From this, we identify desirable…

  16. Air pollution exposure prediction approaches used in air pollution epidemiology studies.

    PubMed

    Özkaynak, Halûk; Baxter, Lisa K; Dionisio, Kathie L; Burke, Janet

    2013-01-01

    Epidemiological studies of the health effects of outdoor air pollution have traditionally relied upon surrogates of personal exposures, most commonly ambient concentration measurements from central-site monitors. However, this approach may introduce exposure prediction errors and misclassification of exposures for pollutants that are spatially heterogeneous, such as those associated with traffic emissions (e.g., carbon monoxide, elemental carbon, nitrogen oxides, and particulate matter). We review alternative air quality and human exposure metrics applied in recent air pollution health effect studies discussed during the International Society of Exposure Science 2011 conference in Baltimore, MD. Symposium presenters considered various alternative exposure metrics, including: central site or interpolated monitoring data, regional pollution levels predicted using the national scale Community Multiscale Air Quality model or from measurements combined with local-scale (AERMOD) air quality models, hybrid models that include satellite data, statistically blended modeling and measurement data, concentrations adjusted by home infiltration rates, and population-based human exposure model (Stochastic Human Exposure and Dose Simulation, and Air Pollutants Exposure models) predictions. These alternative exposure metrics were applied in epidemiological applications to health outcomes, including daily mortality and respiratory hospital admissions, daily hospital emergency department visits, daily myocardial infarctions, and daily adverse birth outcomes. This paper summarizes the research projects presented during the symposium, with full details of the work presented in individual papers in this journal issue. PMID:23632992

  17. EPA perspective - exposure and effects prediction and monitoring

    EPA Science Inventory

    Risk-based decisions for environmental chemicals often rely on estimates of human exposure and biological response. Biomarkers have proven a useful empirical tool for evaluating exposure and hazard predictions. In the United States, the Centers for Disease Control and Preventio...

  18. Does Fear Reactivity during Exposure Predict Panic Symptom Reduction?

    ERIC Educational Resources Information Center

    Meuret, Alicia E.; Seidel, Anke; Rosenfield, Benjamin; Hofmann, Stefan G.; Rosenfield, David

    2012-01-01

    Objective: Fear reactivity during exposure is a commonly used indicator of learning and overall therapy outcome. The objective of this study was to assess the predictive value of fear reactivity during exposure using multimodal indicators and an advanced analytical design. We also investigated the degree to which treatment condition (cognitive…

  19. Validation of Aircraft Noise Prediction Models at Low Levels of Exposure

    NASA Technical Reports Server (NTRS)

    Page, Juliet A.; Hobbs, Christopher M.; Plotkin, Kenneth J.; Stusnick, Eric; Shepherd, Kevin P. (Technical Monitor)

    2000-01-01

    Aircraft noise measurements were made at Denver International Airport for a period of four weeks. Detailed operational information was provided by airline operators which enabled noise levels to be predicted using the FAA's Integrated Noise Model. Several thrust prediction techniques were evaluated. Measured sound exposure levels for departure operations were found to be 4 to 10 dB higher than predicted, depending on the thrust prediction technique employed. Differences between measured and predicted levels are shown to be related to atmospheric conditions present at the aircraft altitude.

  20. Uranium internal exposure evaluation based on urine assay data

    SciTech Connect

    Lawrence, J.N.P.

    1984-09-01

    The difficulties in assessing internal exposures to uranium from urine assay data are described. A simplified application of the ICRP-30 and ICRP Lung Model concepts to the estimation of uranium intake is presented. A discussion follows on the development of a computer code utilizing the ICRP-30-based uranium elimination model with the existing urine assay information. The calculated uranium exposures from 1949 through 1983 are discussed. 13 references, 1 table.

  1. Low Vagal Tone Magnifies the Association Between Psychosocial Stress Exposure and Internalizing Psychopathology in Adolescents

    PubMed Central

    McLaughlin, Katie A.; Rith-Najarian, Leslie; Dirks, Melanie A.; Sheridan, Margaret A.

    2014-01-01

    Vagal tone is a measure of cardiovascular function that facilitates adaptive responses to environmental challenge. Low vagal tone is associated with poor emotional and attentional regulation in children and has been conceptualized as a marker of sensitivity to stress. We investigated whether the associations of a wide range of psychosocial stressors with internalizing and externalizing psychopathology were magnified in adolescents with low vagal tone. Resting heart period data were collected from a diverse community sample of adolescents (ages 13–17; N =168). Adolescents completed measures assessing internalizing and externalizing psychopathology and exposure to stressors occurring in family, peer, and community contexts. Respiratory sinus arrhythmia (RSA) was calculated from the interbeat interval time series. We estimated interactions between RSA and stress exposure in predicting internalizing and externalizing symptoms and evaluated whether interactions differed by gender. Exposure to psychosocial stressors was associated strongly with psychopathology. RSA was unrelated to internalizing or externalizing problems. Significant interactions were observed between RSA and child abuse, community violence, peer victimization, and traumatic events in predicting internalizing but not externalizing symptoms. Stressors were positively associated with internalizing symptoms in adolescents with low RSA but not in those with high RSA. Similar patterns were observed for anxiety and depression. These interactions were more consistently observed for male than female individuals. Low vagal tone is associated with internalizing psychopathology in adolescents exposed to high levels of stressors. Measurement of vagal tone in clinical settings might provide useful information about sensitivity to stress in child and adolescent clients. PMID:24156380

  2. The Role of Stress Exposure and Family Functioning in Internalizing Outcomes of Urban Families

    PubMed Central

    Henry, David B.; Tolan, Patrick H.; Strachan, Martha K.

    2013-01-01

    Although research suggests that stress exposure and family functioning are associated with internalizing problems in adolescents and caregivers, surprisingly few studies have investigated the mechanisms that underlie this association. To determine whether family functioning buffers the development of internalizing problems in stress-exposed families, we assessed the relation between stress exposure, family functioning, and internalizing symptoms among a large sample of inner-city male youth and their caregivers living in poverty across five waves of data collection. We hypothesized that stress exposure and family functioning would predict development of subsequent youth and caregiver internalizing problems and that family functioning would moderate this relation, with higher functioning families demonstrating greater resiliency to stress exposure. We used a longitudinal, prospective design to evaluate whether family functioning (assessed at waves one through four) activated or buffered the effects of stress exposure (assessed at wave one) on subsequent internalizing symptoms (assessed at waves four and five). Stress from Developmental Transitions and family functioning were significant predictors of depressive symptoms and anxiety in youth; however, family functioning did not moderate the relation. Family functioning mediated the relation between stress from Daily Hassles and internalizing outcomes suggesting that poor parenting practices, low structure, and low emotional cohesion activate depression and anxiety in youth exposed to chronic and frequent everyday stressors. Surprisingly, only family functioning predicted depressive symptoms in caregivers. Results validate the use of a comprehensive, multi-informant assessment of stress when investigating internalizing outcomes in youth and support using family-based interventions in the treatment and prevention of internalizing. PMID:25601821

  3. 10 CFR 20.1204 - Determination of internal exposure.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Determination of internal exposure. 20.1204 Section 20.1204 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Occupational Dose... Commission, adjust the DAC or ALI values to reflect the actual physical and chemical characteristics...

  4. 10 CFR 20.1204 - Determination of internal exposure.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Determination of internal exposure. 20.1204 Section 20.1204 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION Occupational Dose... Commission, adjust the DAC or ALI values to reflect the actual physical and chemical characteristics...

  5. Prenatal substance exposure: What predicts behavioral resilience by early adolescence?

    PubMed

    Liebschutz, Jane M; Crooks, Denise; Rose-Jacobs, Ruth; Cabral, Howard J; Heeren, Timothy C; Gerteis, Jessie; Appugliese, Danielle P; Heymann, Orlaith D; Lange, Allison V; Frank, Deborah A

    2015-06-01

    Understanding behavioral resilience among at-risk adolescents may guide public policy decisions and future programs. We examined factors predicting behavioral resilience following intrauterine substance exposure in a prospective longitudinal birth-cohort study of 136 early adolescents (ages 12.4-15.9 years) at risk for poor behavioral outcomes. We defined behavioral resilience as a composite measure of lack of early substance use initiation (before age 14), lack of risky sexual behavior, or lack of delinquency. Intrauterine substance exposures included in this analysis were cocaine, tobacco, alcohol, and marijuana. We recruited participants from Boston Medical Center as mother-infant dyads between 1990 and 1993. The majority of the sample was African American/Caribbean (88%) and 49% female. In bivariate analyses, none and lower intrauterine cocaine exposure level predicted resilience compared with higher cocaine exposure, but this effect was not found in an adjusted model. Instead, strict caregiver supervision (adjusted odds ratio [AOR] = 6.02, 95% confidence interval (CI) [1.90, 19.00], p = .002), lower violence exposure (AOR = 4.07, 95% CI [1.77, 9.38], p < .001), and absence of intrauterine tobacco exposure (AOR = 3.71, 95% CI [1.28, 10.74], p = .02) predicted behavioral resilience. In conclusion, caregiver supervision in early adolescence, lower violence exposure in childhood, and lack of intrauterine tobacco exposure predicted behavioral resilience among a cohort of early adolescents with significant social and environmental risk. Future interventions should work to enhance parental supervision as a way to mitigate the effects of adversity on high-risk groups of adolescents. (PsycINFO Database Record PMID:26076097

  6. Exposure factors resources: contrasting EPA's Exposure Factors Handbook with international sources.

    PubMed

    Phillips, Linda J; Moya, Jacqueline

    2014-01-01

    Efforts to compile and standardize human exposure factors have resulted in the development of a variety of resources available to the scientific community. For example, the US Environmental Protection Agency (EPA) developed the Exposure Factors Handbook and Child-specific Exposure Factors Handbook to promote consistency among its various exposure-assessment activities. The US EPA handbooks are compilations of human exposure factors data, including anthropometric and sociocultural data (e.g., body weights, skin-surface areas, and life expectancy), behavioral data (e.g., non-dietary ingestion rates, activity/time use patterns, and consumer product use), factors that may be influenced by the physiological needs of the body, metabolic activity, and health and weight status (e.g., water and food intake, and inhalation rates), and other factors (e.g., building characteristics). Other countries have engaged in similar efforts to compile and standardize exposure factors for use in exposure and risk assessments. For example, the ExpoFacts database contains data for 30 European Union countries. Australia, Canada, Japan, Korea, and Taiwan have developed, or are developing, documents that provide exposure factors data relevant to their populations. The purpose of this paper is to provide an overview of some of the available exposure factors resources; to explore some of the similarities and differences between the US EPA Exposure Factors Handbook and selected other international resources, and to highlight data gaps and present some considerations for promoting consistency among these resources. PMID:23611905

  7. Prenatal and postnatal cocaine exposure predict teen cocaine use

    PubMed Central

    Delaney-Black, Virginia; Chiodo, Lisa M.; Hannigan, John H.; Greenwald, Mark K.; Janisse, James; Patterson, Grace; Huestis, Marilyn A.; Partridge, Robert T.; Ager, Joel; Sokol, Robert J.

    2015-01-01

    Preclinical studies have identified alterations in cocaine and alcohol self-administration and behavioral responses to pharmacological challenges in adolescent offspring following prenatal exposure. To date, no published human studies have evaluated the relation between prenatal cocaine exposure and postnatal adolescent cocaine use. Human studies of prenatal cocaine-exposed children have also noted an increase in behaviors previously associated with substance use/abuse in teens and young adults, specifically childhood and teen externalizing behaviors, impulsivity, and attention problems. Despite these findings, human research has not addressed prior prenatal exposure as a potential predictor of teen drug use behavior. The purpose of this study was to evaluate the relations between prenatal cocaine exposure and teen cocaine use in a prospective longitudinal cohort (n = 316) that permitted extensive control for child, parent and community risk factors. Logistic regression analyses and Structural Equation Modeling revealed that both prenatal exposure and postnatal parent/caregiver cocaine use were uniquely related to teen use of cocaine at age 14 years. Teen cocaine use was also directly predicted by teen community violence exposure and caregiver negativity, and was indirectly related to teen community drug exposure. These data provide further evidence of the importance of prenatal exposure, family and community factors in the intergenerational transmission of teen/young adult substance abuse/use. PMID:20609384

  8. Adaptive plasticity in speech perception: Effects of external information and internal predictions.

    PubMed

    Guediche, Sara; Fiez, Julie A; Holt, Lori L

    2016-07-01

    When listeners encounter speech under adverse listening conditions, adaptive adjustments in perception can improve comprehension over time. In some cases, these adaptive changes require the presence of external information that disambiguates the distorted speech signals, whereas in other cases mere exposure is sufficient. Both external (e.g., written feedback) and internal (e.g., prior word knowledge) sources of information can be used to generate predictions about the correct mapping of a distorted speech signal. We hypothesize that these predictions provide a basis for determining the discrepancy between the expected and actual speech signal that can be used to guide adaptive changes in perception. This study provides the first empirical investigation that manipulates external and internal factors through (a) the availability of explicit external disambiguating information via the presence or absence of postresponse orthographic information paired with a repetition of the degraded stimulus, and (b) the accuracy of internally generated predictions; an acoustic distortion is introduced either abruptly or incrementally. The results demonstrate that the impact of external information on adaptive plasticity is contingent upon whether the intelligibility of the stimuli permits accurate internally generated predictions during exposure. External information sources enhance adaptive plasticity only when input signals are severely degraded and cannot reliably access internal predictions. This is consistent with a computational framework for adaptive plasticity in which error-driven supervised learning relies on the ability to compute sensory prediction error signals from both internal and external sources of information. (PsycINFO Database Record PMID:26854531

  9. Skin burns after laser exposure: histological analysis and predictive simulation.

    PubMed

    Museux, Nathanaëlle; Perez, Laetitia; Autrique, Laurent; Agay, Diane

    2012-08-01

    Thermal effects of laser irradiation on skin are investigated in this paper. The main purpose is to determine the damage level induced by a laser exposure. Potential burns induced by two lasers (wavelength 808nm and 1940nm) are studied and animal experimentations are performed. Several exposure durations and laser powers are tested. Based on previous works, a mathematical model dedicated to temperature prediction is proposed and finite-element method is implemented. This numerical predictive tool based on the bioheat equation takes into account heat losses due to the convection on skin surface, blood circulatory and also evaporation. Thermal behavior of each skin layer is also described considering distinct thermal and optical properties. Since the mathematical model is able to estimate damage levels, histological analyses were also carried through. It is confirmed that the mathematical model is an efficient predictive tool for estimation of damage caused by lasers and that thermal effects sharply depend on laser wavelength. PMID:22237052

  10. Prospective Effects of Violence Exposure across Multiple Contexts on Early Adolescents’ Internalizing and Externalizing Problems

    PubMed Central

    Mrug, Sylvie; Windle, Michael

    2013-01-01

    Background Violence exposure within each setting of community, school, or home has been linked with internalizing and externalizing problems. Although many children experience violence in multiple contexts, the effects of such cross-contextual exposure have not been studied. This study addresses this gap by examining independent and interactive effects of witnessing violence and victimization in the community, home, and school on subsequent internalizing and externalizing problems in early adolescence. Methods A community sample of 603 boys and girls (78% African American, 20% Caucasian) participated in a longitudinal study of youth violence. During two assessments 16 months apart, adolescents reported on witnessing violence and victimization in the community, school, and home, and their internalizing and externalizing problems. Results Multiple regressions tested the independent and interactive effects of witnessing violence or victimization across contexts on subsequent adjustment, after controlling for initial levels of internalizing and externalizing problems and demographic covariates. Witnessing violence at school predicted anxiety and depression; witnessing at home was related to anxiety and aggression; and witnessing community violence predicted delinquency. Victimization at home was related to subsequent anxiety, depression, and aggression; victimization at school predicted anxiety; and victimization in the community was not independently related to any outcomes. Finally, witnessing violence at home was associated with more anxiety, delinquency, and aggression only if adolescents reported no exposure to community violence. Conclusions Violence exposure at home and school had the strongest independent effects on internalizing and externalizing outcomes. Witnessing community violence attenuated the effects of witnessing home violence on anxiety and externalizing problems, perhaps due to desensitization or different norms or expectations regarding violence

  11. Perinatal Immunotoxicity: Why Adult Exposure Assessment Fails to Predict Risk

    PubMed Central

    Dietert, Rodney R.; Piepenbrink, Michael S.

    2006-01-01

    Recent research has pointed to the developing immune system as a remarkably sensitive toxicologic target for environmental chemicals and drugs. In fact, the perinatal period before and just after birth is replete with dynamic immune changes, many of which do not occur in adults. These include not only the basic maturation and distribution of immune cell types and selection against autoreactive lymphocytes but also changes designed specifically to protect the pregnancy against immune-mediated miscarriage. The newborn is then faced with critical immune maturational adjustments to achieve an immune balance necessary to combat myriad childhood and later-life diseases. All these processes set the fetus and neonate completely apart from the adult regarding immunotoxicologic risk. Yet for decades, safety evaluation has relied almost exclusively upon exposure of the adult immune system to predict perinatal immune risk. Recent workshops and forums have suggested a benefit in employing alternative exposures that include exposure throughout early life stages. However, issues remain concerning when and where such applications might be required. In this review we discuss the reasons why immunotoxic assessment is important for current childhood diseases and why adult exposure assessment cannot predict the effect of xenobiotics on the developing immune system. It also provides examples of developmental immunotoxicants where age-based risk appears to differ. Finally, it stresses the need to replace adult exposure assessment for immune evaluation with protocols that can protect the developing immune system. PMID:16581533

  12. Prenatal Substance Exposure: What Predicts Behavioral Resilience by Early Adolescence?

    PubMed Central

    Liebschutz, Jane; Crooks, Denise; Rose-Jacobs, Ruth; Cabral, Howard J; Heeren, Timothy C; Gerteis, Jessie; Appugliese, Danielle P.; Heymann, Orlaith D.; Lange, Allison V.; Frank, Deborah A.

    2015-01-01

    Understanding behavioral resilience among at-risk adolescents may guide public policy decisions and future programs. We examined factors predicting behavioral resilience following intrauterine substance exposure (IUSE) in a prospective longitudinal birth-cohort study of 136 early adolescents (age 12.4–15.9) at-risk for poor behavioral outcomes. We defined behavioral resilience as a composite measure of lack of early substance use initiation (before age 14), lack of risky sexual behavior, or lack of delinquency. IUSEs included in this analysis were cocaine (IUCE), tobacco (IUTE), alcohol (IUAE), and marijuana (IUME). We recruited participants from Boston Medical Center as mother-infant dyads between 1990 and 1993. The majority of the sample was African-American/Caribbean (88%) and 49% female. In bivariate analyses, none and lower IUCE level predicted resilience compared to higher IUCE, but this effect was not found in an adjusted model. Instead, strict caregiver supervision (adjusted odds ratio (AOR)=6.02, 95% confidence interval (CI)=1.90–19.00, p=0.002), lower violence exposure (AOR=4.07, 95% CI=1.77–9.38, p<0.001), and absence of intrauterine tobacco exposure (AOR=3.71, 95% CI= 1.28–10.74, p=0.02) predicted behavioral resilience. In conclusion, caregiver supervision in early adolescence, lower violence exposure in childhood, and lack of intrauterine tobacco exposure predict behavioral resilience among a cohort of early adolescents with significant social and environmental risk. Future interventions should work to enhance parental supervision as a way to mitigate the effects of adversity on high-risk groups of adolescents. PMID:26076097

  13. Underwater Sound Propagation Modeling Methods for Predicting Marine Animal Exposure.

    PubMed

    Hamm, Craig A; McCammon, Diana F; Taillefer, Martin L

    2016-01-01

    The offshore exploration and production (E&P) industry requires comprehensive and accurate ocean acoustic models for determining the exposure of marine life to the high levels of sound used in seismic surveys and other E&P activities. This paper reviews the types of acoustic models most useful for predicting the propagation of undersea noise sources and describes current exposure models. The severe problems caused by model sensitivity to the uncertainty in the environment are highlighted to support the conclusion that it is vital that risk assessments include transmission loss estimates with statistical measures of confidence. PMID:26610982

  14. 78 FR 68447 - Exposure Draft-Standards for Internal Control in the Federal Government

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-14

    ... OFFICE Exposure Draft--Standards for Internal Control in the Federal Government AGENCY: U.S. Government... 2013 Exposure Draft update to the Standards for Internal Control in the Federal Government reflect... Internal Control in the Federal Government, 2013 Exposure Draft, is available and can be downloaded...

  15. Predictive modeling of terrestrial radiation exposure from geologic materials

    NASA Astrophysics Data System (ADS)

    Haber, Daniel A.

    Aerial gamma ray surveys are an important tool for national security, scientific, and industrial interests in determining locations of both anthropogenic and natural sources of radioactivity. There is a relationship between radioactivity and geology and in the past this relationship has been used to predict geology from an aerial survey. The purpose of this project is to develop a method to predict the radiologic exposure rate of the geologic materials in an area by creating a model using geologic data, images from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), geochemical data, and pre-existing low spatial resolution aerial surveys from the National Uranium Resource Evaluation (NURE) Survey. Using these data, geospatial areas, referred to as background radiation units, homogenous in terms of K, U, and Th are defined and the gamma ray exposure rate is predicted. The prediction is compared to data collected via detailed aerial survey by our partner National Security Technologies, LLC (NSTec), allowing for the refinement of the technique. High resolution radiation exposure rate models have been developed for two study areas in Southern Nevada that include the alluvium on the western shore of Lake Mohave, and Government Wash north of Lake Mead; both of these areas are arid with little soil moisture and vegetation. We determined that by using geologic units to define radiation background units of exposed bedrock and ASTER visualizations to subdivide radiation background units of alluvium, regions of homogeneous geochemistry can be defined allowing for the exposure rate to be predicted. Soil and rock samples have been collected at Government Wash and Lake Mohave as well as a third site near Cameron, Arizona. K, U, and Th concentrations of these samples have been determined using inductively coupled mass spectrometry (ICP-MS) and laboratory counting using radiation detection equipment. In addition, many sample locations also have

  16. Air pollution dispersion models for human exposure predictions in London.

    PubMed

    Beevers, Sean D; Kitwiroon, Nutthida; Williams, Martin L; Kelly, Frank J; Ross Anderson, H; Carslaw, David C

    2013-01-01

    The London household survey has shown that people travel and are exposed to air pollutants differently. This argues for human exposure to be based upon space-time-activity data and spatio-temporal air quality predictions. For the latter, we have demonstrated the role that dispersion models can play by using two complimentary models, KCLurban, which gives source apportionment information, and Community Multi-scale Air Quality Model (CMAQ)-urban, which predicts hourly air quality. The KCLurban model is in close agreement with observations of NO(X), NO(2) and particulate matter (PM)(10/2.5), having a small normalised mean bias (-6% to 4%) and a large Index of Agreement (0.71-0.88). The temporal trends of NO(X) from the CMAQ-urban model are also in reasonable agreement with observations. Spatially, NO(2) predictions show that within 10's of metres of major roads, concentrations can range from approximately 10-20 p.p.b. up to 70 p.p.b. and that for PM(10/2.5) central London roadside concentrations are approximately double the suburban background concentrations. Exposure to different PM sources is important and we predict that brake wear-related PM(10) concentrations are approximately eight times greater near major roads than at suburban background locations. Temporally, we have shown that average NO(X) concentrations close to roads can range by a factor of approximately six between the early morning minimum and morning rush hour maximum periods. These results present strong arguments for the hybrid exposure model under development at King's and, in future, for in-building models and a model for the London Underground. PMID:23443237

  17. Internal exposure dynamics drive the Adverse Outcome Pathways of synthetic glucocorticoids in fish

    NASA Astrophysics Data System (ADS)

    Margiotta-Casaluci, Luigi; Owen, Stewart F.; Huerta, Belinda; Rodríguez-Mozaz, Sara; Kugathas, Subramanian; Barceló, Damià; Rand-Weaver, Mariann; Sumpter, John P.

    2016-02-01

    The Adverse Outcome Pathway (AOP) framework represents a valuable conceptual tool to systematically integrate existing toxicological knowledge from a mechanistic perspective to facilitate predictions of chemical-induced effects across species. However, its application for decision-making requires the transition from qualitative to quantitative AOP (qAOP). Here we used a fish model and the synthetic glucocorticoid beclomethasone dipropionate (BDP) to investigate the role of chemical-specific properties, pharmacokinetics, and internal exposure dynamics in the development of qAOPs. We generated a qAOP network based on drug plasma concentrations and focused on immunodepression, skin androgenisation, disruption of gluconeogenesis and reproductive performance. We showed that internal exposure dynamics and chemical-specific properties influence the development of qAOPs and their predictive power. Comparing the effects of two different glucocorticoids, we highlight how relatively similar in vitro hazard-based indicators can lead to different in vivo risk. This discrepancy can be predicted by their different uptake potential, pharmacokinetic (PK) and pharmacodynamic (PD) profiles. We recommend that the development phase of qAOPs should include the application of species-species uptake and physiologically-based PK/PD models. This integration will significantly enhance the predictive power, enabling a more accurate assessment of the risk and the reliable transferability of qAOPs across chemicals.

  18. Internal exposure dynamics drive the Adverse Outcome Pathways of synthetic glucocorticoids in fish

    PubMed Central

    Margiotta-Casaluci, Luigi; Owen, Stewart F.; Huerta, Belinda; Rodríguez-Mozaz, Sara; Kugathas, Subramanian; Barceló, Damià; Rand-Weaver, Mariann; Sumpter, John P.

    2016-01-01

    The Adverse Outcome Pathway (AOP) framework represents a valuable conceptual tool to systematically integrate existing toxicological knowledge from a mechanistic perspective to facilitate predictions of chemical-induced effects across species. However, its application for decision-making requires the transition from qualitative to quantitative AOP (qAOP). Here we used a fish model and the synthetic glucocorticoid beclomethasone dipropionate (BDP) to investigate the role of chemical-specific properties, pharmacokinetics, and internal exposure dynamics in the development of qAOPs. We generated a qAOP network based on drug plasma concentrations and focused on immunodepression, skin androgenisation, disruption of gluconeogenesis and reproductive performance. We showed that internal exposure dynamics and chemical-specific properties influence the development of qAOPs and their predictive power. Comparing the effects of two different glucocorticoids, we highlight how relatively similar in vitro hazard-based indicators can lead to different in vivo risk. This discrepancy can be predicted by their different uptake potential, pharmacokinetic (PK) and pharmacodynamic (PD) profiles. We recommend that the development phase of qAOPs should include the application of species-species uptake and physiologically-based PK/PD models. This integration will significantly enhance the predictive power, enabling a more accurate assessment of the risk and the reliable transferability of qAOPs across chemicals. PMID:26917256

  19. Internal exposure dynamics drive the Adverse Outcome Pathways of synthetic glucocorticoids in fish.

    PubMed

    Margiotta-Casaluci, Luigi; Owen, Stewart F; Huerta, Belinda; Rodríguez-Mozaz, Sara; Kugathas, Subramanian; Barceló, Damià; Rand-Weaver, Mariann; Sumpter, John P

    2016-01-01

    The Adverse Outcome Pathway (AOP) framework represents a valuable conceptual tool to systematically integrate existing toxicological knowledge from a mechanistic perspective to facilitate predictions of chemical-induced effects across species. However, its application for decision-making requires the transition from qualitative to quantitative AOP (qAOP). Here we used a fish model and the synthetic glucocorticoid beclomethasone dipropionate (BDP) to investigate the role of chemical-specific properties, pharmacokinetics, and internal exposure dynamics in the development of qAOPs. We generated a qAOP network based on drug plasma concentrations and focused on immunodepression, skin androgenisation, disruption of gluconeogenesis and reproductive performance. We showed that internal exposure dynamics and chemical-specific properties influence the development of qAOPs and their predictive power. Comparing the effects of two different glucocorticoids, we highlight how relatively similar in vitro hazard-based indicators can lead to different in vivo risk. This discrepancy can be predicted by their different uptake potential, pharmacokinetic (PK) and pharmacodynamic (PD) profiles. We recommend that the development phase of qAOPs should include the application of species-species uptake and physiologically-based PK/PD models. This integration will significantly enhance the predictive power, enabling a more accurate assessment of the risk and the reliable transferability of qAOPs across chemicals. PMID:26917256

  20. Predictive modeling of nanomaterial exposure effects in biological systems

    PubMed Central

    Liu, Xiong; Tang, Kaizhi; Harper, Stacey; Harper, Bryan; Steevens, Jeffery A; Xu, Roger

    2013-01-01

    Background Predictive modeling of the biological effects of nanomaterials is critical for industry and policymakers to assess the potential hazards resulting from the application of engineered nanomaterials. Methods We generated an experimental dataset on the toxic effects experienced by embryonic zebrafish due to exposure to nanomaterials. Several nanomaterials were studied, such as metal nanoparticles, dendrimer, metal oxide, and polymeric materials. The embryonic zebrafish metric (EZ Metric) was used as a screening-level measurement representative of adverse effects. Using the dataset, we developed a data mining approach to model the toxic endpoints and the overall biological impact of nanomaterials. Data mining techniques, such as numerical prediction, can assist analysts in developing risk assessment models for nanomaterials. Results We found several important attributes that contribute to the 24 hours post-fertilization (hpf) mortality, such as dosage concentration, shell composition, and surface charge. These findings concur with previous studies on nanomaterial toxicity using embryonic zebrafish. We conducted case studies on modeling the overall effect/impact of nanomaterials and the specific toxic endpoints such as mortality, delayed development, and morphological malformations. The results show that we can achieve high prediction accuracy for certain biological effects, such as 24 hpf mortality, 120 hpf mortality, and 120 hpf heart malformation. The results also show that the weighting scheme for individual biological effects has a significant influence on modeling the overall impact of nanomaterials. Sample prediction models can be found at http://neiminer.i-a-i.com/nei_models. Conclusion The EZ Metric-based data mining approach has been shown to have predictive power. The results provide valuable insights into the modeling and understanding of nanomaterial exposure effects. PMID:24098077

  1. International Symposia on Integrated Exposure Assessment for Hazardous Materials

    PubMed Central

    Kwon, Ho-Jang; Ha, Mina

    2012-01-01

    Objectives On September 2, 2010 and November 25, 2011, the Korean Research Project on Integrated Exposure Assessment to Hazardous Materials for Food Safety (KRIEFS) organized two international symposia in Seoul, Korea. KRIEFS, established by the Korean Food and Drug Administration in March 2010, envisioned these international symposia as means to obtain advanced experiences from other countries and to reflect on and refine the KRIEFS's survey design and methods. Methods For the first symposium KRIEFS invited human biomonitoring (HBM) experts from Germany, the US, and Canada. The visiting HBM experts shared the details of their national studies while the KRIEFS discussed study design, as well as the methods, results and policymaking processes of the KRIEFS project. The second symposium was organized to share the survey design and results on endocrine disruptors from Taiwan. Results The Speaker from Germany introduced the German Environmental Survey and shared their experiences in HBM design, such as the process of developing reference values, and discussed the new HBM plan in Germany and the European Union. The Representative from Canada shared insights from national HBM approach. In the case of the US, the speaker focused on risk communication with subjects in epidemiological studies. In the second international symposium, the speaker shared the experience of endocrine disruptors'studies from Taiwan. Conclusions KRIEFS was able to better understand previous nationwide HBM research designs, policy making process, and risk communication with research subjects.

  2. Learning to predict: Exposure to temporal sequences facilitates prediction of future events

    PubMed Central

    Baker, Rosalind; Dexter, Matthew; Hardwicke, Tom E.; Goldstone, Aimee; Kourtzi, Zoe

    2014-01-01

    Previous experience is thought to facilitate our ability to extract spatial and temporal regularities from cluttered scenes. However, little is known about how we may use this knowledge to predict future events. Here we test whether exposure to temporal sequences facilitates the visual recognition of upcoming stimuli. We presented observers with a sequence of leftwards and rightwards oriented gratings that was interrupted by a test stimulus. Observers were asked to indicate whether the orientation of the test stimulus matched their expectation based on the preceding sequence. Our results demonstrate that exposure to temporal sequences without feedback facilitates our ability to predict an upcoming stimulus. In particular, observers’ performance improved following exposure to structured but not random sequences. Improved performance lasted for a prolonged period and generalized to untrained stimulus orientations rather than sequences of different global structure, suggesting that observers acquire knowledge of the sequence structure rather than its items. Further, this learning was compromised when observers performed a dual task resulting in increased attentional load. These findings suggest that exposure to temporal regularities in a scene allows us to accumulate knowledge about its global structure and predict future events. PMID:24231115

  3. 75 FR 44304 - Noise Exposure Map Notice, Portland International Airport, Portland, OR

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-28

    ... Noise Exposure Map Notice, Portland International Airport, Portland, OR AGENCY: Federal Aviation... determination that the noise exposure maps submitted by Port of Portland for Portland International Airport... the FAA's determination on the noise exposure maps is July 21, 2010. FOR FURTHER INFORMATION...

  4. 78 FR 25523 - Acceptance of Noise Exposure Map Notice for Oakland County International Airport, Pontiac, Michigan

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-01

    ... Federal Aviation Administration Acceptance of Noise Exposure Map Notice for Oakland County International...: The FAA announces its determination that the noise exposure maps submitted by Oakland County, for the... exposure maps submitted for Oakland County International Airport are in compliance with...

  5. 78 FR 41184 - Noise Exposure Map Notice for Hilo International Airport, Hilo, Hawaii

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-09

    ... Federal Aviation Administration Noise Exposure Map Notice for Hilo International Airport, Hilo, Hawaii... determination that the noise exposure maps submitted by Hawaii State Department of Transportation, Airports... announces that the FAA finds that the noise exposure maps submitted for Hilo International Airport are...

  6. 77 FR 36331 - Noise Exposure Maps; Cleveland Hopkins International Airport, Cleveland, OH

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-18

    ... Noise Exposure Maps; Cleveland Hopkins International Airport, Cleveland, OH AGENCY: Federal Aviation... determination that the noise exposure maps submitted by the City of Cleveland for Cleveland Hopkins... International Airport under Part 150 in conjunction with the noise exposure map, and that this program will...

  7. Internal performance predictions for Langley scramjet engine module

    NASA Technical Reports Server (NTRS)

    Pinckney, S. Z.

    1978-01-01

    A one dimensional theoretical method for the prediction of the internal performance of a scramjet engine is presented. The effects of changes in vehicle forebody flow parameters and characteristics on predicted thrust for the scramjet engine were evaluated using this method, and results are presented. A theoretical evaluation of the effects of changes in the scramjet engine's internal parameters is also presented. Theoretical internal performance predictions, in terms thrust coefficient and specific impulse, are provided for the scramjet engine for free stream Mach numbers of 5, 6, and 7 free stream dynamic pressure of 23,940 N/sq m forebody surface angles of 4.6 deg to 14.6 deg, and fuel equivalence ratio of 1.0.

  8. Kantian fractionalization predicts the conflict propensity of the international system

    PubMed Central

    Cranmer, Skyler J.; Menninga, Elizabeth J.; Mucha, Peter J.

    2015-01-01

    Network science has spurred a reexamination of relational phenomena in political science, including the study of international conflict. We introduce a new direction to the study of conflict by showing that the multiplex fractionalization of the international system along three key dimensions is a powerful predictor of the propensity for violent interstate conflict. Even after controlling for well-established conflict indicators, our new measure contributes more to model fit for interstate conflict than all of the previously established measures combined. Moreover, joint democracy plays little, if any, role in predicting system stability, thus challenging perhaps the major empirical finding of the international relations literature. Lastly, the temporal variability of our measure with conflict is consistent with a causal relationship. Our results have real-world policy implications as changes in our fractionalization measure substantially aid the prediction of conflict up to 10 years into the future, allowing it to serve as an early warning sign of international instability. PMID:26338977

  9. Kantian fractionalization predicts the conflict propensity of the international system.

    PubMed

    Cranmer, Skyler J; Menninga, Elizabeth J; Mucha, Peter J

    2015-09-22

    Network science has spurred a reexamination of relational phenomena in political science, including the study of international conflict. We introduce a new direction to the study of conflict by showing that the multiplex fractionalization of the international system along three key dimensions is a powerful predictor of the propensity for violent interstate conflict. Even after controlling for well-established conflict indicators, our new measure contributes more to model fit for interstate conflict than all of the previously established measures combined. Moreover, joint democracy plays little, if any, role in predicting system stability, thus challenging perhaps the major empirical finding of the international relations literature. Lastly, the temporal variability of our measure with conflict is consistent with a causal relationship. Our results have real-world policy implications as changes in our fractionalization measure substantially aid the prediction of conflict up to 10 years into the future, allowing it to serve as an early warning sign of international instability. PMID:26338977

  10. A Comparison of Two Strategies for Building an Exposure Prediction Model.

    PubMed

    Heiden, Marina; Mathiassen, Svend Erik; Garza, Jennifer; Liv, Per; Wahlström, Jens

    2016-01-01

    Cost-efficient assessments of job exposures in large populations may be obtained from models in which 'true' exposures assessed by expensive measurement methods are estimated from easily accessible and cheap predictors. Typically, the models are built on the basis of a validation study comprising 'true' exposure data as well as an extensive collection of candidate predictors from questionnaires or company data, which cannot all be included in the models due to restrictions in the degrees of freedom available for modeling. In these situations, predictors need to be selected using procedures that can identify the best possible subset of predictors among the candidates. The present study compares two strategies for selecting a set of predictor variables. One strategy relies on stepwise hypothesis testing of associations between predictors and exposure, while the other uses cluster analysis to reduce the number of predictors without relying on empirical information about the measured exposure. Both strategies were applied to the same dataset on biomechanical exposure and candidate predictors among computer users, and they were compared in terms of identified predictors of exposure as well as the resulting model fit using bootstrapped resamples of the original data. The identified predictors were, to a large part, different between the two strategies, and the initial model fit was better for the stepwise testing strategy than for the clustering approach. Internal validation of the models using bootstrap resampling with fixed predictors revealed an equally reduced model fit in resampled datasets for both strategies. However, when predictor selection was incorporated in the validation procedure for the stepwise testing strategy, the model fit was reduced to the extent that both strategies showed similar model fit. Thus, the two strategies would both be expected to perform poorly with respect to predicting biomechanical exposure in other samples of computer users. PMID

  11. TIME-INTEGRATED EXPOSURE MEASURES TO IMPROVE THE PREDICTIVE POWER OF EXPOSURE CLASSIFICATION FOR EPIDEMIOLOGIC STUDIES

    EPA Science Inventory

    Accurate exposure classification tools are required to link exposure with health effects in epidemiological studies. Although long-term integrated exposure measurements are a critical component of exposure assessment, the ability to include these measurements into epidemiologic...

  12. ASSESSING A COMPUTER MODEL FOR PREDICTING HUMAN EXPOSURE TO PM2.5

    EPA Science Inventory

    This paper compares outputs of a model for predicting PM2.5 exposure with experimental data obtained from exposure studies of selected subpopulations. The exposure model is built on a WWW platform called pCNEM, "A PC Version of pNEM." Exposure models created by pCNEM are sim...

  13. Air pollution exposure prediction approaches used in air pollution epidemiology studies

    EPA Science Inventory

    Epidemiological studies of the health effects of air pollution have traditionally relied upon surrogates of personal exposures, most commonly ambient concentration measurements from central-site monitors. However, this approach may introduce exposure prediction errors and miscla...

  14. Change in BMI Accurately Predicted by Social Exposure to Acquaintances

    PubMed Central

    Oloritun, Rahman O.; Ouarda, Taha B. M. J.; Moturu, Sai; Madan, Anmol; Pentland, Alex (Sandy); Khayal, Inas

    2013-01-01

    Research has mostly focused on obesity and not on processes of BMI change more generally, although these may be key factors that lead to obesity. Studies have suggested that obesity is affected by social ties. However these studies used survey based data collection techniques that may be biased toward select only close friends and relatives. In this study, mobile phone sensing techniques were used to routinely capture social interaction data in an undergraduate dorm. By automating the capture of social interaction data, the limitations of self-reported social exposure data are avoided. This study attempts to understand and develop a model that best describes the change in BMI using social interaction data. We evaluated a cohort of 42 college students in a co-located university dorm, automatically captured via mobile phones and survey based health-related information. We determined the most predictive variables for change in BMI using the least absolute shrinkage and selection operator (LASSO) method. The selected variables, with gender, healthy diet category, and ability to manage stress, were used to build multiple linear regression models that estimate the effect of exposure and individual factors on change in BMI. We identified the best model using Akaike Information Criterion (AIC) and R2. This study found a model that explains 68% (p<0.0001) of the variation in change in BMI. The model combined social interaction data, especially from acquaintances, and personal health-related information to explain change in BMI. This is the first study taking into account both interactions with different levels of social interaction and personal health-related information. Social interactions with acquaintances accounted for more than half the variation in change in BMI. This suggests the importance of not only individual health information but also the significance of social interactions with people we are exposed to, even people we may not consider as close friends. PMID

  15. A practical approach to helicopter internal noise prediction

    NASA Technical Reports Server (NTRS)

    Levine, L. S.; Defelice, J. J.

    1978-01-01

    A practical and well correlated procedure for predicting helicopter internal noise is presented. It accounts for the propagation of noise along multiple paths on an octave by octave basis. The method is sufficiently general to be applicable to conventional helicopters as well as other aircraft types, when the appropriate structural geometry, noise source strengths, and material acoustic properties are defined. A guide is provided for the prediction of various helicopter noise sources over a wide range of horsepower for use when measured data are not available. The method is applied to the prediction of the interior levels of the Civil Helicopter Research Aircraft (CHRA), both with and without soundproofing installed. Results include good correlation with measured levels and prediction of the speech interference level within 1.5 db at all conditions. A sample problem is also shown illustrating the use of the procedure. This example calculates the engine casing noise observed in the passenger cabin of the CHRA.

  16. A PROBABILISTIC MODELING FRAMEWORK FOR PREDICTING POPULATION EXPOSURES TO BENZENE

    EPA Science Inventory

    The US Environmental Protection Agency (EPA) is modifying their probabilistic Stochastic Human Exposure Dose Simulation (SHEDS) model to assess aggregate exposures to air toxics. Air toxics include urban Hazardous Air Pollutants (HAPS) such as benzene from mobile sources, part...

  17. Predicting Maternal Rat and Pup Exposures: How Different Are They?

    EPA Science Inventory

    Risk and safety assessments for early life exposures to environmental chemicals or pharmaceuticals based on cross-species extrapolation would greatly benefit from information on chemical dosimetry in the young. Although relevant toxicity studies involve exposures during multiple ...

  18. 78 FR 71706 - Noise Exposure Map Notice for Laughlin/Bullhead International Airport, Bullhead City, Arizona

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-29

    ... Federal Aviation Administration Noise Exposure Map Notice for Laughlin/Bullhead International Airport... Aviation Administration (FAA) announces its determination that the noise exposure maps submitted by Mohave... INFORMATION: This notice announces that the FAA finds that the noise exposure maps submitted for...

  19. 77 FR 834 - Noise Exposure Map Update for Albany International Airport, Albany, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-06

    ... Federal Aviation Administration Noise Exposure Map Update for Albany International Airport, Albany, NY... Administration (FAA) announces its determination that the updated noise exposure maps submitted by the Albany... exposure maps is December 19, 2011. FOR FURTHER INFORMATION CONTACT: Ms. Suki Gill,...

  20. 76 FR 12404 - Noise Exposure Map Notice; Jackson-Evers International Airport, Jackson, MS

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-07

    ... Federal Aviation Administration Noise Exposure Map Notice; Jackson-Evers International Airport, Jackson... Administration (FAA) announces its determination that the noise exposure maps submitted by the Jackson Municipal.... DATES: Effective Date: The effective date of the FAA's determination on the noise exposure maps...

  1. 75 FR 54695 - Noise Exposure Map Notice; Brownsville South Padre Island International Airport, Brownsville, TX

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-08

    ... Federal Aviation Administration Noise Exposure Map Notice; Brownsville South Padre Island International... Federal Aviation Administration (FAA) announces its determination that the noise exposure maps submitted... on the noise exposure maps is August 30, 2010. FOR FURTHER INFORMATION CONTACT: Lance E. Key,...

  2. 3D protein structure prediction using Imperialist Competitive algorithm and half sphere exposure prediction.

    PubMed

    Khaji, Erfan; Karami, Masoumeh; Garkani-Nejad, Zahra

    2016-02-21

    Predicting the native structure of proteins based on half-sphere exposure and contact numbers has been studied deeply within recent years. Online predictors of these vectors and secondary structures of amino acids sequences have made it possible to design a function for the folding process. By choosing variant structures and directs for each secondary structure, a random conformation can be generated, and a potential function can then be assigned. Minimizing the potential function utilizing meta-heuristic algorithms is the final step of finding the native structure of a given amino acid sequence. In this work, Imperialist Competitive algorithm was used in order to accelerate the process of minimization. Moreover, we applied an adaptive procedure to apply revolutionary changes. Finally, we considered a more accurate tool for prediction of secondary structure. The results of the computational experiments on standard benchmark show the superiority of the new algorithm over the previous methods with similar potential function. PMID:26718864

  3. In-depth methods for systemic exposure predictions

    EPA Science Inventory

    Exposure to a wide range of chemicals is ubiquitous and largely unavoidable within modern society. The potential for human exposure, however, has not been quantified for the vast majority of chemicals with wide commercial use. Creative advances in exposure science are needed to s...

  4. Identity Distress among Youth Exposed to Natural Disasters: Associations with Level of Exposure, Posttraumatic Stress, and Internalizing Problems

    PubMed Central

    Scott, Brandon G.; Sanders, Ashley F. P.; Graham, Rebecca A.; Banks, Donice M.; Russell, Justin D.; Berman, Steven L.; Weems, Carl F.

    2014-01-01

    Identity distress involves intense or prolonged upset or worry about personal identity issues including long-term goals, career choice, friendships, sexual orientation and behavior, religion, values and beliefs, and group loyalties. Research suggests that trauma exposure and subsequent PTSD symptoms may negatively impact identity development and psychological adjustment. However, little is known about their specific associations with identity distress and internalizing problems among disaster-exposed adolescents. The purpose of this study was to examine these relationships in a sample of 325 adolescents (60% female; 89% African American) who experienced a major natural disaster and its aftermath. The results indicated that identity distress was positively associated with age, hurricane exposure, PTSD symptoms, and internalizing problems. Linear regression analyses also showed that identity distress was uniquely associated with internalizing symptoms and that there was an indirect effect of hurricane exposure on identity distress via PTSD symptoms. Finally, PTSD symptoms moderated the link between identity distress and internalizing symptoms, with a significant positive slope found for youth with more PTSD symptoms. Findings were generally consistent with previous work and predictions, and add to the extant knowledge about identity distress by providing data on the linkages between disaster exposure, posttraumatic stress and internalizing problems in adolescents. PMID:25505851

  5. Minimal Internal Radiation Exposure in Residents Living South of the Fukushima Daiichi Nuclear Power Plant Disaster

    PubMed Central

    Akiyama, Junichi; Kato, Shigeaki; Tsubokura, Masaharu; Mori, Jinichi; Tanimoto, Tetsuya; Abe, Koichiro; Sakai, Shuji; Hayano, Ryugo; Tokiwa, Michio; Shimmura, Hiroaki

    2015-01-01

    Following the Fukushima nuclear power plant disaster, assessment of internal radiation exposure was indispensable to predict radiation-related health threats to residents of neighboring areas. Although many evaluations of internal radiation in residents living north and west of the crippled Fukushima nuclear power plant are available, there is little information on residents living in areas south of the plant, which were similarly affected by radio-contamination from the disaster. To assess the internal radio-contamination in residents living in affected areas to the south of the plant or who were evacuated into Iwaki city, a whole body counter (WBC) screening program of internal radio-contamination was performed on visitors to the Jyoban hospital in Iwaki city, which experienced less contamination than southern areas adjacent to the nuclear plant. The study included 9,206 volunteer subjects, of whom 6,446 were schoolchildren aged 4–15 years. Measurements began one year after the incident and were carried out over the course of two years. Early in the screening period only two schoolchildren showed Cs-137 levels that were over the detection limit (250 Bq/body), although their Cs-134 levels were below the detection limit (220 Bq/body). Among the 2,760 adults tested, 35 (1.3%) had detectable internal radio-contamination, but only for Cs-137 (range: 250 Bq/body to 859 Bq/body), and not Cs-134. Of these 35 subjects, nearly all (34/35) showed elevated Cs-137 levels only during the first year of the screening. With the exception of potassium 40, no other radionuclides were detected during the screening period. The maximum annual effective dose calculated from the detected Cs-137 levels was 0.029 and 0.028 mSv/year for the schoolchildren and adults, respectively, which is far below the 1 mSv/year limit set by the government of Japan. Although the data for radiation exposure during the most critical first year after the incident are unavailable due to a lack of systemic

  6. Minimal Internal Radiation Exposure in Residents Living South of the Fukushima Daiichi Nuclear Power Plant Disaster.

    PubMed

    Akiyama, Junichi; Kato, Shigeaki; Tsubokura, Masaharu; Mori, Jinichi; Tanimoto, Tetsuya; Abe, Koichiro; Sakai, Shuji; Hayano, Ryugo; Tokiwa, Michio; Shimmura, Hiroaki

    2015-01-01

    Following the Fukushima nuclear power plant disaster, assessment of internal radiation exposure was indispensable to predict radiation-related health threats to residents of neighboring areas. Although many evaluations of internal radiation in residents living north and west of the crippled Fukushima nuclear power plant are available, there is little information on residents living in areas south of the plant, which were similarly affected by radio-contamination from the disaster. To assess the internal radio-contamination in residents living in affected areas to the south of the plant or who were evacuated into Iwaki city, a whole body counter (WBC) screening program of internal radio-contamination was performed on visitors to the Jyoban hospital in Iwaki city, which experienced less contamination than southern areas adjacent to the nuclear plant. The study included 9,206 volunteer subjects, of whom 6,446 were schoolchildren aged 4-15 years. Measurements began one year after the incident and were carried out over the course of two years. Early in the screening period only two schoolchildren showed Cs-137 levels that were over the detection limit (250 Bq/body), although their Cs-134 levels were below the detection limit (220 Bq/body). Among the 2,760 adults tested, 35 (1.3%) had detectable internal radio-contamination, but only for Cs-137 (range: 250 Bq/body to 859 Bq/body), and not Cs-134. Of these 35 subjects, nearly all (34/35) showed elevated Cs-137 levels only during the first year of the screening. With the exception of potassium 40, no other radionuclides were detected during the screening period. The maximum annual effective dose calculated from the detected Cs-137 levels was 0.029 and 0.028 mSv/year for the schoolchildren and adults, respectively, which is far below the 1 mSv/year limit set by the government of Japan. Although the data for radiation exposure during the most critical first year after the incident are unavailable due to a lack of systemic

  7. Developmental Trajectories of Internally and Externally Driven Temporal Prediction

    PubMed Central

    Mento, Giovanni; Tarantino, Vincenza

    2015-01-01

    The ability to generate temporal prediction (TP) is fundamental to our survival since it allows us to selectively orient our attention in time in order to prioritize relevant environmental information. Studies on adult participants showed that externally and internally driven mechanisms can be engaged to establish TP, both resulting in better behavioural performance. However, few studies on children have investigated the ability to engage internally and externally driven TP, especially in relation to how these mechanisms change across development. In this study, 111 participants (88 children between six and eleven years of age, and 23 adults) were tested by means of a simple reaction time paradigm, in which temporal cueing and neutral conditions were orthogonally manipulated to induce externally and internally driven TP mechanisms, as well as an interaction between the two. Sequential effects (SEs) relative to both tasks were also investigated. Results showed that all children participating in the study were able to implement both external and internal TP in an independent fashion. However, children younger than eight years were not able to combine both strategies. Furthermore, in the temporal cueing blocks they did not show the typically-observed asymmetric SE pattern. These results suggest that children can flexibly use both external and internal TP mechanisms to optimise their behaviour, although their successful combined use develops only after eight years of age. PMID:26262878

  8. ERPs recorded during early second language exposure predict syntactic learning.

    PubMed

    Batterink, Laura; Neville, Helen J

    2014-09-01

    Millions of adults worldwide are faced with the task of learning a second language (L2). Understanding the neural mechanisms that support this learning process is an important area of scientific inquiry. However, most previous studies on the neural mechanisms underlying L2 acquisition have focused on characterizing the results of learning, relying upon end-state outcome measures in which learning is assessed after it has occurred, rather than on the learning process itself. In this study, we adopted a novel and more direct approach to investigate neural mechanisms engaged during L2 learning, in which we recorded ERPs from beginning adult learners as they were exposed to an unfamiliar L2 for the first time. Learners' proficiency in the L2 was then assessed behaviorally using a grammaticality judgment task, and ERP data acquired during initial L2 exposure were sorted as a function of performance on this task. High-proficiency learners showed a larger N100 effect to open-class content words compared with closed-class function words, whereas low-proficiency learners did not show a significant N100 difference between open- and closed-class words. In contrast, amplitude of the N400 word category effect correlated with learners' L2 comprehension, rather than predicting syntactic learning. Taken together, these results indicate that learners who spontaneously direct greater attention to open- rather than closed-class words when processing L2 input show better syntactic learning, suggesting a link between selective attention to open-class content words and acquisition of basic morphosyntactic rules. These findings highlight the importance of selective attention mechanisms for L2 acquisition. PMID:24666165

  9. ERPs Recorded During Early Second Language Exposure Predict Syntactic Learning

    PubMed Central

    Batterink, Laura; Neville, Helen J.

    2015-01-01

    Millions of adults worldwide are faced with the task of learning a second language (L2). Understanding the neural mechanisms that support this learning process is an important area of scientific inquiry. However, most previous studies on the neural mechanisms underlying L2 acquisition have focused on characterizing the results of learning, relying upon end-state outcome measures in which learning is assessed after it has occurred, rather than on the learning process itself. In the present study, we adopted a novel and more direct approach to investigate neural mechanisms engaged during L2 learning, in which we recorded ERPs from beginning adult learners as they were exposed to an unfamiliar L2 for the first time. Learners’ proficiency in the L2 was then assessed behaviorally using a grammaticality judgment task, and ERP data acquired during initial L2 exposure were sorted as a function of performance on this task. High proficiency learners showed a larger N100 effect to open-class content words compared to closed-class function words, while low proficiency learners did not show a significant N100 difference between open- and closed-class words. In contrast, amplitude of the N400 word category effect correlated with learners’ L2 comprehension, rather than predicting syntactic learning. Taken together, these results indicate that learners who spontaneously direct greater attention to open- rather than closed-class words when processing L2 input show better syntactic learning, suggesting a link between selective attention to open-class content words and acquisition of basic morphosyntactic rules. These findings highlight the importance of selective attention mechanisms for L2 acquisition. PMID:24666165

  10. Exposure factors resources: contrasting EPA’s Exposure Factors Handbook with international sources(journal article)

    EPA Science Inventory

    Efforts to compile and standardize exposure human factors have resulted in the development of a variety of resources available to the scientific community. For example, the U.S. EPA developed the Exposure Factors Handbook and Child-specific Exposure Factors Handbook to promote c...

  11. 78 FR 52532 - Exposure Draft-Standards for Internal Control in the Federal Government

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-23

    ... OFFICE Exposure Draft--Standards for Internal Control in the Federal Government AGENCY: U.S. Government... Office (GAO) is seeking public comments on the proposed revisions to the Standards for Internal Control... Internal Control in the Federal Government reflect major developments in the accountability and...

  12. Incorporating High-Throughput Exposure Predictions With Dosimetry-Adjusted In Vitro Bioactivity to Inform Chemical Toxicity Testing

    PubMed Central

    Wetmore, Barbara A.; Wambaugh, John F.; Allen, Brittany; Ferguson, Stephen S.; Sochaski, Mark A.; Setzer, R. Woodrow; Houck, Keith A.; Strope, Cory L.; Cantwell, Katherine; Judson, Richard S.; LeCluyse, Edward; Clewell, Harvey J.; Thomas, Russell S.; Andersen, Melvin E.

    2015-01-01

    We previously integrated dosimetry and exposure with high-throughput screening (HTS) to enhance the utility of ToxCast HTS data by translating in vitro bioactivity concentrations to oral equivalent doses (OEDs) required to achieve these levels internally. These OEDs were compared against regulatory exposure estimates, providing an activity-to-exposure ratio (AER) useful for a risk-based ranking strategy. As ToxCast efforts expand (ie, Phase II) beyond food-use pesticides toward a wider chemical domain that lacks exposure and toxicity information, prediction tools become increasingly important. In this study, in vitro hepatic clearance and plasma protein binding were measured to estimate OEDs for a subset of Phase II chemicals. OEDs were compared against high-throughput (HT) exposure predictions generated using probabilistic modeling and Bayesian approaches generated by the U.S. Environmental Protection Agency (EPA) ExpoCast program. This approach incorporated chemical-specific use and national production volume data with biomonitoring data to inform the exposure predictions. This HT exposure modeling approach provided predictions for all Phase II chemicals assessed in this study whereas estimates from regulatory sources were available for only 7% of chemicals. Of the 163 chemicals assessed in this study, 3 or 13 chemicals possessed AERs < 1 or < 100, respectively. Diverse bioactivities across a range of assays and concentrations were also noted across the wider chemical space surveyed. The availability of HT exposure estimation and bioactivity screening tools provides an opportunity to incorporate a risk-based strategy for use in testing prioritization. PMID:26251325

  13. Incorporating High-Throughput Exposure Predictions With Dosimetry-Adjusted In Vitro Bioactivity to Inform Chemical Toxicity Testing.

    PubMed

    Wetmore, Barbara A; Wambaugh, John F; Allen, Brittany; Ferguson, Stephen S; Sochaski, Mark A; Setzer, R Woodrow; Houck, Keith A; Strope, Cory L; Cantwell, Katherine; Judson, Richard S; LeCluyse, Edward; Clewell, Harvey J; Thomas, Russell S; Andersen, Melvin E

    2015-11-01

    We previously integrated dosimetry and exposure with high-throughput screening (HTS) to enhance the utility of ToxCast HTS data by translating in vitro bioactivity concentrations to oral equivalent doses (OEDs) required to achieve these levels internally. These OEDs were compared against regulatory exposure estimates, providing an activity-to-exposure ratio (AER) useful for a risk-based ranking strategy. As ToxCast efforts expand (ie, Phase II) beyond food-use pesticides toward a wider chemical domain that lacks exposure and toxicity information, prediction tools become increasingly important. In this study, in vitro hepatic clearance and plasma protein binding were measured to estimate OEDs for a subset of Phase II chemicals. OEDs were compared against high-throughput (HT) exposure predictions generated using probabilistic modeling and Bayesian approaches generated by the U.S. Environmental Protection Agency (EPA) ExpoCast program. This approach incorporated chemical-specific use and national production volume data with biomonitoring data to inform the exposure predictions. This HT exposure modeling approach provided predictions for all Phase II chemicals assessed in this study whereas estimates from regulatory sources were available for only 7% of chemicals. Of the 163 chemicals assessed in this study, 3 or 13 chemicals possessed AERs < 1 or < 100, respectively. Diverse bioactivities across a range of assays and concentrations were also noted across the wider chemical space surveyed. The availability of HT exposure estimation and bioactivity screening tools provides an opportunity to incorporate a risk-based strategy for use in testing prioritization. PMID:26251325

  14. PREDICTING POPULATION EXPOSURES TO PM: THE IMPORTANCE OF MICROENVIRONMENTAL CONCENTRATIONS AND HUMAN ACTIVITIES

    EPA Science Inventory

    The Stochastic Human Exposure and Dose Simulation (SHEDS) models being developed by the US EPA/NERL use a probabilistic approach to predict population exposures to pollutants. The SHEDS model for particulate matter (SHEDS-PM) estimates the population distribution of PM exposure...

  15. Positive interpretation bias predicts well-being in medical interns

    PubMed Central

    Kleim, Birgit; Thörn, Hanna A.; Ehlert, Ulrike

    2014-01-01

    Cognitive theories of emotion posit that affective responses may be shaped by how individuals interpret emotion-eliciting situations. This study tested whether individual differences in interpretation bias (i.e., interpreting ambiguous scenarios in a more negative or positive manner) independently predict trait resilience and depression in medical interns. Interpretation bias and trait resilience scores were assessed in 47 interns prior to their first internship. Depressive symptoms were assessed twice during internship. Nearly half of the sample (42%) scored above the cut-off for mild depressive symptoms during internship, a significant rise compared to the initial assessment. Those with a more positive interpretation bias had higher trait resilience (β = 0.44, p = 0.004) and a 6-fold decreased depressive symptom risk during internship (OR = 6.41, p = 0.027). The predictive power of a positive interpretation bias for decreased depression symptoms held over and above initial depressive symptoms, demographics and trait reappraisal. Assessing positive interpretation bias may have practical utility for predicting future well-being in at risk-populations. PMID:25009521

  16. Prediction of strongly-heated internal gas flows

    SciTech Connect

    McEligot, D.M. ||; Shehata, A.M.; Kunugi, Tomoaki |

    1997-12-31

    The purposes of the present article are to remind practitioners why the usual textbook approaches may not be appropriate for treating gas flows heated from the surface with large heat fluxes and to review the successes of some recent applications of turbulence models to this case. Simulations from various turbulence models have been assessed by comparison to the measurements of internal mean velocity and temperature distributions by Shehata for turbulent, laminarizing and intermediate flows with significant gas property variation. Of about fifteen models considered, five were judged to provide adequate predictions.

  17. Noise prediction and control of Pudong International Airport expansion project.

    PubMed

    Lei, Bin; Yang, Xin; Yang, Jianguo

    2009-04-01

    The Environmental Impact Assessment (EIA) process of the third runway building project of Pudong International Airport is briefly introduced in the paper. The basic principle, the features, and the operation steps of newly imported FAA's Integrated Noise Model (INM) are discussed for evaluating the aircraft noise impacts. The prediction of the aircraft noise and the countermeasures for the noise mitigation are developed, which includes the reasonable runway location, the optimized land use, the selection of low noise aircrafts, the Fly Quit Program, the relocation of sensitive receptors and the noise insulation of sensitive buildings. Finally, the expansion project is justified and its feasibility is confirmed. PMID:18373206

  18. International perspectives of lead exposure and lead toxicity.

    PubMed

    Grandjean, P

    1993-01-01

    Three approaches have been used to examine how human body burdens of lead depend on different environments: (1) In paleopathologic studies, lead concentrations have been determined in well-preserved human bones or teeth, and pre-pollution samples generally show lead concentrations of about 1% of current levels in industrialized countries. (2) Geographic comparisons of blood-lead concentrations show low levels in, Nepal, Faroe Islands, and Sweden, while high levels occur in Mexico and Malta; average blood-lead levels may vary by a factor of 10 or more. (3) In analytical epidemiology, major exposure sources have been related to lead levels in blood, by either prospective or cross-sectional design. Increased blood-lead concentrations are related to smoking, drinking alcoholic beverages, eating vegetables for dinner, urban residence, and exposure from lead-using industries; average blood-lead values of subgroups within well-defined populations may vary by a factor of 3 or more. The dose-relationships for lead-induced neurotoxicity will depend on the sensitivity of the parameters chosen as indicators of lead exposure and of neurotoxicity. The temporal relationship between lead exposures and the development of deficits must be ascertained. Individual susceptibility and interacting factors must also be taken into account. Differences in addressing these issues impede the comparison between studies. Recently neonatal jaundice has been found to be a risk factor for subsequent neurobehavioral dysfunction in children with a birth weight above 2500 g, but only in children with increased lead exposure. Lead exposure may act in combination with several other factors and result in additive, or synergistic effects.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8247415

  19. EXPOSURES AND INTERNAL DOSES OF TRIHALOMETHANES IN HUMANS: MULTI-ROUTE CONTRIBUTIONS FROM DRINKING WATER (FINAL)

    EPA Science Inventory

    The National Center for Environmental Assessment (NCEA) has released a final report that presents and applies a method to estimate distributions of internal concentrations of trihalomethanes (THMs) in humans resulting from a residential drinking water exposure. The report presen...

  20. Prospective Effects of Violence Exposure across Multiple Contexts on Early Adolescents' Internalizing and Externalizing Problems

    ERIC Educational Resources Information Center

    Mrug, Sylvie; Windle, Michael

    2010-01-01

    Background: Violence exposure within each setting of community, school, or home has been linked with internalizing and externalizing problems. Although many children experience violence in multiple contexts, the effects of such cross-contextual exposure have not been studied. This study addresses this gap by examining independent and interactive…

  1. Harmonization of exposure assessment for food chemicals: the international perspective.

    PubMed

    Luetzow, Manfred

    2003-04-11

    The assessment of human exposure to chemicals present in the diet is a rapidly developing discipline. The formulation of the "risk analysis paradigm" by the Codex Alimentarius Commission in 1994 defined the exposure assessment as an essential step of the risk assessment process. This has re-enforced demands to those joint FAO/WHO scientific bodies who evaluate the safety of chemicals in foods to estimate routinely intakes for food additives, flavors, contaminants, and residues of pesticides and veterinary drugs as part of their safety assessments. The approaches chosen by the Joint FAO/WHO Expert Committee for Food Additives (JECFA) and the Joint FAO/WHO Expert Meeting on Pesticide Residues (JMPR) for these compounds are considerably different. These differences can only be understood when considering the different risk policies of the Codex Alimentarius Committees involved. Specific problems emerge if global intake assessments are requested; lack of representative regional data for consumption patterns and insufficient knowledge about levels of chemicals occurring in foods in many countries bear the risk that exposure assessments do not provide risk managers with a true global picture. There is a need to improve the collection and dissemination of such data. PMID:12676490

  2. Assessing Occupational Exposure to Chemicals in an International Epidemiological Study of Brain Tumours

    PubMed Central

    van Tongeren, Martie

    2013-01-01

    The INTEROCC project is a multi-centre case–control study investigating the risk of developing brain cancer due to occupational chemical and electromagnetic field exposures. To estimate chemical exposures, the Finnish Job Exposure Matrix (FINJEM) was modified to improve its performance in the INTEROCC study and to address some of its limitations, resulting in the development of the INTEROCC JEM. An international team of occupational hygienists developed a crosswalk between the Finnish occupational codes used in FINJEM and the International Standard Classification of Occupations 1968 (ISCO68). For ISCO68 codes linked to multiple Finnish codes, weighted means of the exposure estimates were calculated. Similarly, multiple ISCO68 codes linked to a single Finnish code with evidence of heterogeneous exposure were refined. One of the key time periods in FINJEM (1960–1984) was split into two periods (1960–1974 and 1975–1984). Benzene exposure estimates in early periods were modified upwards. The internal consistency of hydrocarbon exposures and exposures to engine exhaust fumes was improved. Finally, exposure to polycyclic aromatic hydrocarbon and benzo(a)pyrene was modified to include the contribution from second-hand smoke. The crosswalk ensured that the FINJEM exposure estimates could be applied to the INTEROCC study subjects. The modifications generally resulted in an increased prevalence of exposure to chemical agents. This increased prevalence of exposure was not restricted to the lowest categories of cumulative exposure, but was seen across all levels for some agents. Although this work has produced a JEM with important improvements compared to FINJEM, further improvements are possible with the expansion of agents and additional external data. PMID:23467593

  3. Shadow prediction model for the International Space Station Alpha

    SciTech Connect

    Chung, D.K.

    1995-12-31

    A Fortran computer model, SHADOW5, was developed to predict shadows on the solar arrays of the International Space Station Alpha (ISSA) for general flight modes. This shadow model was incorporated into the EPSOP-F (Electrical Power System On-Orbit Performance) program to conduct ISSA power analyses for various operating conditions. This paper describes the mathematical methods of the model and shows the typical results predicted with the model. Vector analyses with coordinate transformations were used to trace the shadows between the potential shadowing and shadowed components of the station during the sun portion of the orbit. Including the space shuttle orbiter, 40 components were modeled. The basic shapes of the components were assumed to be either planar or cylindrical. The elemental areas obtained from the Cartesian grid lines allocated on the component surfaces were projected in the sun vector direction to reconstruct shadows on the shadowed planar surface. Comparison of predicted results with other models showed good agreement. Ease of preparing input data and relatively short CPU time make this model suitable for shadow analyses required for the many design and flight configurations of the space station.

  4. Prediction of thermal strains in fibre reinforced plastic matrix by discretisation of the temperature exposure history

    NASA Astrophysics Data System (ADS)

    Ngoy, E. K.

    2016-07-01

    Prediction of environmental effects on fibre reinforced plastics habitually is made difficult due to the complex variability of the natural service environment. This paper suggests a method to predict thermal strain distribution over the material lifetime by discretisation of the exposure history. Laboratory results show a high correlation between predicted and experimentally measured strain distribution

  5. Documentation of quality improvement exposure by internal medicine residency applicants

    PubMed Central

    Kolade, Victor O.; Sethi, Anuradha

    2016-01-01

    Background Quality improvement (QI) has become an essential component of medical care in the United States. In residency programs, QI is a focus area of the Clinical Learning Environment Review visits conducted by the Accreditation Council for Graduate Medical Education. The readiness of applicants to internal medicine residency to engage in QI on day one is unknown. Purpose To document the reporting of QI training or experience in residency applications. Methods Electronic Residency Application Service applications to a single internal medicine program were reviewed individually looking for reported QI involvement or actual projects in the curriculum vitae (CVs), personal statements (PSs), and letters of recommendation (LORs). CVs were also reviewed for evidence of education in QI such as completion of Institute for Healthcare Improvement (IHI) modules. Results Of 204 candidates shortlisted for interview, seven had QI items on their CVs, including one basic IHI certificate. Three discussed their QI work in their PSs, and four had recommendation letters describing their involvement in QI. One applicant had both CV and LOR evidence, so that 13 (6%) documented QI engagement. Conclusion Practice of or instruction in QI is rarely mentioned in application documents of prospective internal medicine interns. PMID:26908376

  6. Predicting Later-Life Outcomes of Early-Life Exposures

    EPA Science Inventory

    Background: In utero exposure of the fetus to a stressor can lead to disease in later life. Epigenetic mechanisms are likely mediators of later-life expression of early-life events.Objectives: We examined the current state of understanding of later-life diseases resulting from ea...

  7. International Test Program for Synergistic Atomic Oxygen and Vacuum Ultraviolet Radiation Exposure of Spacecraft Materials

    NASA Technical Reports Server (NTRS)

    Miller, Sharon K.

    2001-01-01

    The components and materials of spacecraft in low Earth orbit can degrade in thermal and optical performance through interaction with atomic oxygen and vacuum ultraviolet (VUV) radiation, which are predominant in low Earth orbit. Because of the importance of low Earth orbit durability and performance to manufacturers and users, an international test program for assessing the durability of spacecraft materials and components was initiated. Initial tests at the NASA Glenn Research Center consisted of exposure of samples representing a variety of thermal control paints, multilayer insulation materials, and Sun sensors that have been used in space. Materials donated from various international sources were tested alongside materials whose performance is well known, such as Teflon FEP, Kapton H, or Z-93-P white paint. The optical, thermal, or mass loss data generated during the tests were then provided to the participating material suppliers. Data were not published unless the participant donating the material consented to publication. The test program is intended to give spacecraft builders and users a better understanding of degradation processes and effects so that they can improve their predictions of spacecraft performance.

  8. International Test Program for Synergistic Atomic Oxygen and VUV Exposure of Spacecraft Materials

    NASA Technical Reports Server (NTRS)

    Rutledge, Sharon; Banks, Bruce; Dever, Joyce; Savage, William

    2000-01-01

    Spacecraft in low Earth orbit (LEO) are subject to degradation in thermal and optical performance of components and materials through interaction with atomic oxygen and vacuum ultraviolet radiation which are predominant in LEO. Due to the importance of LEO durability and performance to manufacturers and users, an international test program for assessing the durability of spacecraft materials and components was initiated. Initial tests consisted of exposure of samples representing a variety of thermal control paints and multilayer insulation materials that have been used in space. Materials donated from various international sources were tested alongside a material whose performance is well known such as Teflon FEP or Kapton H for multilayer insulation, or Z-93-P for white thermal control paints. The optical, thermal or mass loss data generated during the test was then provided to the participating material supplier. Data was not published unless the participant donating the material consented to publication. This paper presents a description of the types of tests and facilities that have been used for the test program as well as some examples of data that have been generated. The test program is intended to give spacecraft builders and users a better understanding of degradation processes and effects to enable improved prediction of spacecraft performance.

  9. Brief Report: Do Delinquency and Community Violence Exposure Explain Internalizing Problems in Early Adolescent Gang Members?

    ERIC Educational Resources Information Center

    Madan, Anjana; Mrug, Sylvie; Windle, Michael

    2011-01-01

    Adolescent gang members are at higher risk for internalizing problems as well as exposure to community violence and delinquency. This study examined whether gang membership in early adolescence is associated with internalizing problems (depression, anxiety, and suicidal behavior) and whether these associations are mediated by delinquency and…

  10. 77 FR 50759 - Noise Exposure Map Notice, Orlando Sanford International Airport, Sanford, FL

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-22

    ... Federal Aviation Administration Noise Exposure Map Notice, Orlando Sanford International Airport, Sanford... Authority for Orlando Sanford International Airport under the provisions of 49 U.S.C. 47501 et seq... August 16, 2012. FOR FURTHER INFORMATION CONTACT: Allan Nagy, Federal Aviation Administration,...

  11. Medial prefrontal cortex predicts internally driven strategy shifts

    PubMed Central

    Schuck, Nicolas W.; Gaschler, Robert; Wenke, Dorit; Heinzle, Jakob; Frensch, Peter A.; Haynes, John-Dylan; Reverberi, Carlo

    2015-01-01

    Summary Many daily behaviors require us to actively focus on the current task and ignore all other distractions. Yet, ignoring everything else might hinder the ability to discover new ways to achieve the same goal. Here, we studied the neural mechanisms that support the spontaneous change to better strategies while an established strategy is executed. Multivariate neuroimaging analysis showed that before the spontaneous change to an alternative strategy, medial prefrontal cortex (MPFC) encoded information that was irrelevant for the current strategy but necessary for the later strategy. Importantly, this neural effect was related to future behavioral changes: information encoding in MPFC was changed only in participants who eventually switched their strategy and started before the actual strategy change. This allowed us to predict spontaneous strategy shifts ahead of time. These findings suggest that MPFC might internally simulate alternative strategies and sheds new light on the organization of PFC. PMID:25819613

  12. Microcomputer programs for the evaluation of predictable long-term exposure.

    PubMed

    Re, M

    1985-07-01

    Some methods proposed for evaluation of predictable long-term exposure by statistical treatment of workshift exposure values are considered. Predictable long-term exposure is a useful parameter for risk assessment procedures, as it allows the evaluation of workplace hazards by taking into account interday variability of exposure to air contaminants. Statistical calculations required for evaluating predictable long-term exposure may be performed easily by hand-held programmable calculators. The programs reported here are for use with a Texas Instruments TI-59 hand-held programmable calculator equipped with a PC-100 C thermal printer. They are designed for users inexperienced in programming, since an interactive approach has been adopted that helps communication between user and computer. PMID:3880190

  13. The effects of internal radiation exposure on cancer mortality in nuclear workers at Rocketdyne/Atomics International.

    PubMed Central

    Ritz, B; Morgenstern, H; Crawford-Brown, D; Young, B

    2000-01-01

    We examined the effects of chronic exposure to radionuclides, primarily uranium and mixed-fission products, on cancer mortality in a retrospective cohort study of workers enrolled in the radiation-monitoring program of a nuclear research and development facility. Between 1950 and 1994, 2,297 workers were monitored for internal radiation exposures, and 441 workers died, 134 (30.4%) of them from cancer as the underlying cause. We calculated internal lung-dose estimates based on urinalysis and whole-body and lung counts reported for individual workers. We examined cancer mortality of workers exposed at different cumulative lung-dose levels using complete risk-set analysis for cohort data, adjusting for age, pay type, time since first radiation monitored, and external radiation. In addition, we examined the potential for confounding due to chemical exposures and smoking, explored whether external radiation exposure modifies the effects of internal exposure, and estimated effects after excluding exposures likely to have been unrelated to disease onset. Dose-response relations were observed for death from hemato- and lymphopoietic cancers and from upper aerodigestive tract cancers, adjusting for age, time since first monitored, pay type, and external (gamma) radiation dose. No association was found for other cancers, including cancers of the lung. Despite the small number of exposed deaths from specific cancer types and possible bias due to measurement error and confounding, the positive findings and strong dose-response gradients observed suggest carcinogenic effects of internal radiation to the upper aerodigestive tract and the blood and lymph system in this occupational cohort. However, causal inferences require replication of our results in other populations or confirmation with an extended follow-up of this cohort. PMID:10964795

  14. Invited Commentary: Use of Arsenical Skin Lesions to Predict Risk of Internal Cancer—Implications for Prevention and Future Research

    PubMed Central

    Ahsan, Habibul; Steinmaus, Craig

    2013-01-01

    Arsenic exposure affects millions of people worldwide, causing substantial mortality and morbidity from cancers and cardiovascular and respiratory diseases. An article in the current issue (Am J Epidemiol. 2013;177(3):202–212) reports that classic dermatological manifestations, typically associated with chronic arsenic exposure, are predictive of internal cancers among Taiwanese decades after the cessation of exposure. Specifically, the risk of lung and urothelial cancers was elevated, which was evident regardless of arsenic dose, smoking, and age. There was also an unexpected elevated risk of prostate cancer. Despite some methodological limitations, these findings underscore the need for assessing whether dermatological manifestations are also predictive of cardiovascular, respiratory, and other arsenic-related, long-term health consequences. Given the emerging evidence of arsenic exposure from dietary sources beyond contaminated drinking water and occupational and environmental settings, and also because the vast majority of diseases and deaths among exposed populations do not show classic dermatological manifestations, larger and more comprehensive investigations of the health effects of arsenic exposure, especially at lower doses, are needed. In parallel, because the risk of known arsenic-related health outcomes remains elevated decades after exposure cessation, research toward identification of early clinical and biological markers of long-term risk as well as avenues for prevention, in addition to policy actions for exposure reductions, is warranted. PMID:23299696

  15. MEDIA EXPOSURE AND SYMPATHETIC NERVOUS SYSTEM REACTIVITY PREDICT PTSD SYMPTOMS AFTER THE BOSTON MARATHON BOMBINGS

    PubMed Central

    Busso, Daniel S.; McLaughlin, Katie A.; Sheridan, Margaret A.

    2014-01-01

    Background Terrorist attacks have been shown to precipitate posttraumatic stress disorder (PTSD) symptomatology in children and adolescents, particularly among youths with high exposure to media coverage surrounding such events. Media exposure may be particularly likely to trigger PTSD symptoms in youths with high physiological reactivity to stress or with prior psychopathology or exposure to violence. We examined the interplay between media exposure, preattack psychopathology, autonomic nervous system (ANS) reactivity, and prior violence exposure in predicting PTSD symptom onset following the terrorist attack at the 2013 Boston Marathon. Methods A community sample of 78 adolescents (mean age = 16.7 years, 65% female) completed a survey about the bombings, including media exposure to the event and PTSD symptoms. All respondents participated in a study assessing psychopathology prior to the attack, and sympathetic and parasympathetic reactivity to a laboratory-based stressor was assessed in a subset (N = 44) of this sample. We examined the associations of media exposure, ANS reactivity, preattack psychopathology, and prior violence exposure with onset of PTSD symptoms related to the bombings. Results Media exposure, preattack psychopathology, and prior violence exposure were associated with PTSD symptoms. Moreover, media exposure interacted with sympathetic reactivity to predict PTSD symptom onset, such that adolescents with lower levels of sympathetic reactivity developed PTSD symptoms only following high exposure to media coverage of the attack. Conclusions We provide novel evidence that physiological reactivity prior to exposure to an unpredictable traumatic stressor predicts PTSD symptom onset. These findings have implications for identifying youths most vulnerable to PTSD following wide-scale trauma. PMID:24995832

  16. Monitoring methylmercury during pregnancy: maternal hair predicts fetal brain exposure.

    PubMed

    Cernichiari, E; Brewer, R; Myers, G J; Marsh, D O; Lapham, L W; Cox, C; Shamlaye, C F; Berlin, M; Davidson, P W; Clarkson, T W

    1995-01-01

    Autopsy brains were obtained from infants dying from a variety of causes within a few days of birth in a population exposed to methylmercury in fish. Infant and maternal blood and hair samples were also obtained. The concentration of total mercury in 6 major brain regions were highly correlated with maternal hair levels. This correlation was confirmed by a sequence of comparisons of maternal hair to maternal blood to infant blood and finally to infant brain. The results lend support to the use of maternal hair in assessing fetal exposure to methylmercury in fish-eating populations. PMID:8714874

  17. Late biological effects from internal and external exposure

    SciTech Connect

    Adams, W.H.

    1985-01-01

    Information on late biological effects of radiation was obtained from the long-term medical followup of a small population of Marshallese accidentally exposed to radioactive fallout from a thermonuclear test in 1954. Endocrine data are compatible with a sequence of nonstochastic radiation effects. The ingestion of radioisotopes of iodine produced clinical thyroid hypofunction in children, biochemical evidence of thyroid dysfunction in some adults, thyroid adenomatous module formation, and, as a possible indirect effect of thyroid damage, at least two cases of pituitary adenoma. In contrast, the only evidence of a stochastic effect has been a real increase in thyroid cancers among the more highly exposed people of Rongelap, none of whom have evidence of residual disease. While three nonthyroidal cancers which are known to be inducible in humans by external irradiation have been documented in the exposed population, three similar cancers have occurred in an unexposed comparison population of Marshallese. Nonstochastic effects of radiation exposure may be common but subtle. In the Marshallese experience the morbidity of delayed nonstochastic effects far exceeds that of the stochastic. 20 refs., 5 figs., 1 tab.

  18. Radiation exposure predictions for short-duration stay Mars missions.

    PubMed

    Striepe, S A; Nealy, J E; Simonsen, L C

    1992-01-01

    The human radiation environment for several short-duration stay manned Mars missions is predicted using the Mission Radiation Calculation (MIRACAL) program, which was developed at NASA Langley Research Center. This program provides dose estimates for galactic cosmic rays (GCR) and large and ordinary solar proton flare events for various amounts of effective spacecraft shielding (both operational and storm shelter thicknesses) and a given time history of the spacecraft's heliocentric position. The results of this study show that most of the missions can survive the most recent large flares (if they were to occur at the missions' perihelion) if a 25 g/cm2 storm shelter is assumed. The dose predictions show that missions during solar minima (when solar flare activity is the lowest) are not necessarily the minimum dose cases, due to increased GCR contribution during this time period. The direct transfer mission studied has slightly lower doses than the outbound Venus swingby mission [on the order of 10-20 centi-Sieverts (cSv) lower], with the greatest dose differences for the assumed worst case scenario (when the large flares occur at perihelion). The GCR dose for a mission can be reduced by having the crew spend some fraction of its day nominally in the storm shelter (other than during flare events). PMID:11538210

  19. Impact of subspecialty elective exposures on outcomes on the American board of internal medicine certification examination

    PubMed Central

    2012-01-01

    Background The American Board of Internal Medicine Certification Examination (ABIM-CE) is one of several methods used to assess medical knowledge, an Accreditation Council for Graduate Medical Education (ACGME) core competency for graduating internal medicine residents. With recent changes in graduate medical education program directors and internal medicine residents are seeking evidence to guide decisions regarding residency elective choices. Prior studies have shown that formalized elective curricula improve subspecialty ABIM-CE scores. The primary aim of this study was to evaluate whether the number of subspecialty elective exposures or the specific subspecialties which residents complete electives in impact ABIM-CE scores. Methods ABIM-CE scores, elective exposures and demographic characteristics were collected for MedStar Georgetown University Hospital internal medicine residents who were first-time takers of the ABIM-CE in 2006–2010 (n=152). Elective exposures were defined as a two-week period assigned to the respective subspecialty. ABIM-CE score was analyzed using the difference between the ABIM-CE score and the standardized passing score (delta-SPS). Subspecialty scores were analyzed using percentage of correct responses. Data was analyzed using GraphPad Prism version 5.00 for Windows. Results Paired elective exposure and ABIM-CE scores were available in 131 residents. There was no linear correlation between ABIM-CE mean delta-SPS and the total number of electives or the number of unique elective exposures. Residents with ≤14 elective exposures had higher ABIM-CE mean delta-SPS than those with ≥15 elective exposures (143.4 compared to 129.7, p=0.051). Repeated electives in individual subspecialties were not associated with significant difference in mean ABIM-CE delta-SPS. Conclusions This study did not demonstrate significant positive associations between individual subspecialty elective exposures and ABIM-CE mean delta-SPS score. Residents with

  20. Using Poison Center Exposure Calls to Predict Methadone Poisoning Deaths

    PubMed Central

    Dasgupta, Nabarun; Davis, Jonathan; Jonsson Funk, Michele; Dart, Richard

    2012-01-01

    Purpose There are more drug overdose deaths in the Untied States than motor vehicle fatalities. Yet the US vital statistics reporting system is of limited value because the data are delayed by four years. Poison centers report data within an hour of the event, but previous studies suggested a small proportion of poisoning deaths are reported to poison centers (PC). In an era of improved electronic surveillance capabilities, exposure calls to PCs may be an alternate indicator of trends in overdose mortality. Methods We used PC call counts for methadone that were reported to the Researched Abuse, Diversion and Addiction-Related Surveillance (RADARS®) System in 2006 and 2007. US death certificate data were used to identify deaths due to methadone. Linear regression was used to quantify the relationship of deaths and poison center calls. Results Compared to decedents, poison center callers tended to be younger, more often female, at home and less likely to require medical attention. A strong association was found with PC calls and methadone mortality (b = 0.88, se = 0.42, t = 9.5, df = 1, p<0.0001, R2 = 0.77). These findings were robust to large changes in a sensitivity analysis assessing the impact of underreporting of methadone overdose deaths. Conclusions Our results suggest that calls to poison centers for methadone are correlated with poisoning mortality as identified on death certificates. Calls received by poison centers may be used for timely surveillance of mortality due to methadone. In the midst of the prescription opioid overdose epidemic, electronic surveillance tools that report in real-time are powerful public health tools. PMID:22829925

  1. Predictive Modeling of Terrestrial Radiation Exposure from Geologic Materials

    SciTech Connect

    Malchow, Russell L.; Haber, Daniel University of Nevada, Las Vegas; Burnley, Pamela; Marsac, Kara; Hausrath, Elisabeth; Adcock, Christopher

    2015-01-01

    Aerial gamma ray surveys are important for those working in nuclear security and industry for determining locations of both anthropogenic radiological sources and natural occurrences of radionuclides. During an aerial gamma ray survey, a low flying aircraft, such as a helicopter, flies in a linear pattern across the survey area while measuring the gamma emissions with a sodium iodide (NaI) detector. Currently, if a gamma ray survey is being flown in an area, the only way to correct for geologic sources of gamma rays is to have flown the area previously. This is prohibitively expensive and would require complete national coverage. This project’s goal is to model the geologic contribution to radiological backgrounds using published geochemical data, GIS software, remote sensing, calculations, and modeling software. K, U and Th are the three major gamma emitters in geologic material. U and Th are assumed to be in secular equilibrium with their daughter isotopes. If K, U, and Th abundance values are known for a given geologic unit the expected gamma ray exposure rate can be calculated using the Grasty equation or by modeling software. Monte Carlo N-Particle Transport software (MCNP), developed by Los Alamos National Laboratory, is modeling software designed to simulate particles and their interactions with matter. Using this software, models have been created that represent various lithologies. These simulations randomly generate gamma ray photons at energy levels expected from natural radiologic sources. The photons take a random path through the simulated geologic media and deposit their energy at the end of their track. A series of nested spheres have been created and filled with simulated atmosphere to record energy deposition. Energies deposited are binned in the same manner as the NaI detectors used during an aerial survey. These models are used in place of the simplistic Grasty equation as they take into account absorption properties of the lithology which the

  2. Prediction of frequency and exposure level of solar particle events.

    PubMed

    Kim, Myung-Hee Y; Hayat, Matthew J; Feiveson, Alan H; Cucinotta, Francis A

    2009-07-01

    For future space missions outside of the Earth's magnetic field, the risk of radiation exposure from solar particle events (SPEs) during extra-vehicular activities (EVAs) or in lightly shielded vehicles is a major concern when designing radiation protection including determining sufficient shielding requirements for astronauts and hardware. While the expected frequency of SPEs is strongly influenced by solar modulation, SPE occurrences themselves are chaotic in nature. We report on a probabilistic modeling approach, where a cumulative expected occurrence curve of SPEs for a typical solar cycle was formed from a non-homogeneous Poisson process model fitted to a database of proton fluence measurements of SPEs that occurred during the past 5 solar cycles (19-23) and those of large SPEs identified from impulsive nitrate enhancements in polar ice. From the fitted model, we then estimated the expected frequency of SPEs at any given proton fluence threshold with energy >30 MeV (Phi(30)) during a defined space mission period. Analytic energy spectra of 34 large SPEs observed in the space era were fitted over broad energy ranges extending to GeV, and subsequently used to calculate the distribution of mGy equivalent (mGy-Eq) dose for a typical blood-forming organ (BFO) inside a spacecraft as a function of total Phi(30) fluence. This distribution was combined with a simulation of SPE events using the Poisson model to estimate the probability of the BFO dose exceeding the NASA 30-d limit of 250 mGy-Eq per 30 d. These results will be useful in implementing probabilistic risk assessment approaches at NASA and guidelines for protection systems for astronauts on future space exploration missions. PMID:19509510

  3. Exposure prediction approaches used in air pollution epidemiology studies: Key findings and future recommendations

    PubMed Central

    Baxter, Lisa K.; Dionisio, Kathie L.; Burke, Janet; Sarnat, Stefanie Ebelt; Sarnat, Jeremy A.; Hodas, Natasha; Rich, David Q.; Turpin, Barbara J.; Jones, Rena R.; Mannshardt, Elizabeth; Kumar, Naresh; Beevers, Sean D.; Özkaynak, Halûk

    2014-01-01

    Many epidemiologic studies of the health effects of exposure to ambient air pollution use measurements from central-site monitors as their exposure estimate. However, measurements from central-site monitors may lack the spatial and temporal resolution required to capture exposure variability in a study population, thus resulting in exposure error and biased estimates. Articles in this dedicated issue examine various approaches to predict or assign exposures to ambient pollutants. These methods include: combining existing central-site pollution measurements with local- and/or regional-scale air quality models to create new or “hybrid” models for pollutant exposure estimates, and using exposure models to account for factors such as infiltration of pollutants indoors and human activity patterns. Key findings from these articles are summarized to provide lessons learned and recommendations for additional research on improving exposure estimation approaches for future epidemiological studies. In summary, when compared to use of central-site monitoring data, the enhanced spatial resolution of air quality or exposure models can have an impact on resultant health effect estimates, especially for pollutants derived from local sources such as traffic (e.g. EC, CO, and NOx). In addition, the optimal exposure estimation approach also depends upon the epidemiological study design. We recommend that future research develop pollutant-specific infiltration data (including for PM species), and improve existing data on human time-activity patterns, and exposure to local source (e.g. traffic), in order to enhance human exposure modeling estimates. We also recommend comparing how various approaches to exposure estimation characterize relationships between multiple pollutants in time and space, and investigating the impact of improved exposure estimates in chronic health studies. PMID:24084756

  4. Predicting adult pulmonary ventilation volume and wearing complianceby on-board accelerometry during personal level exposure assessments

    NASA Astrophysics Data System (ADS)

    Rodes, C. E.; Chillrud, S. N.; Haskell, W. L.; Intille, S. S.; Albinali, F.; Rosenberger, M. E.

    2012-09-01

    BackgroundMetabolic functions typically increase with human activity, but optimal methods to characterize activity levels for real-time predictions of ventilation volume (l min-1) during exposure assessments have not been available. Could tiny, triaxial accelerometers be incorporated into personal level monitors to define periods of acceptable wearing compliance, and allow the exposures (μg m-3) to be extended to potential doses in μg min-1 kg-1 of body weight? ObjectivesIn a pilot effort, we tested: 1) whether appropriately-processed accelerometer data could be utilized to predict compliance and in linear regressions to predict ventilation volumes in real-time as an on-board component of personal level exposure sensor systems, and 2) whether locating the exposure monitors on the chest in the breathing zone, provided comparable accelerometric data to other locations more typically utilized (waist, thigh, wrist, etc.). MethodsPrototype exposure monitors from RTI International and Columbia University were worn on the chest by a pilot cohort of adults while conducting an array of scripted activities (all <10 METS), spanning common recumbent, sedentary, and ambulatory activity categories. Referee Wocket accelerometers that were placed at various body locations allowed comparison with the chest-located exposure sensor accelerometers. An Oxycon Mobile mask was used to measure oral-nasal ventilation volumes in-situ. For the subset of participants with complete data (n = 22), linear regressions were constructed (processed accelerometric variable versus ventilation rate) for each participant and exposure monitor type, and Pearson correlations computed to compare across scenarios. ResultsTriaxial accelerometer data were demonstrated to be adequately sensitive indicators for predicting exposure monitor wearing compliance. Strong linear correlations (R values from 0.77 to 0.99) were observed for all participants for both exposure sensor accelerometer variables against

  5. Beyond Host Language Proficiency: Coping Resources Predicting International Students' Satisfaction

    ERIC Educational Resources Information Center

    Mak, Anita S.; Bodycott, Peter; Ramburuth, Prem

    2015-01-01

    As international students navigate in a foreign educational environment, having higher levels of coping or stress-resistance resources--both internal and external--could be related to increased satisfaction with personal and university life. The internal coping resources examined in this study were host language proficiency, self-esteem,…

  6. Predicting Supervisor, Peer, and Self Ratings of Intern Performance

    ERIC Educational Resources Information Center

    Kegel-Flom, Penelope

    1975-01-01

    Relationships between the ratings of interns by their supervisors, their peers, and the interns themselves on four dimensions are compared and analyzed in relationship to earlier measures of aptitude, achievement, and personality. Findings reported show supervisor ratings to be highest and admission variables to be unrelated to intern performance.…

  7. [Predictive models for the assessment of occupational exposure to chemicals: a new challenge for employers].

    PubMed

    Gromiec, Jan Piotr; Kupczewska-Dobecka, Małgorzata; Jankowska, Agnieszka; Czerczak, Sławomir

    2013-01-01

    Employers are obliged to carry out and document the risk associated with the use of chemical substances. The best but the most expensive method is to measure workplace concentrations of chemicals. At present no "measureless" method for risk assessment is available in Poland, but predictive models for such assessments have been developed in some countries. The purpose of this work is to review and evaluate the applicability of selected predictive methods for assessing occupational inhalation exposure and related risk to check the compliance with Occupational Exposure Limits (OELs), as well as the compliance with REACH obligations. Based on the literature data HSE COSHH Essentials, EASE, ECETOC TRA, Stoffenmanager, and EMKG-Expo-Tool were evaluated. The data on validation of predictive models were also examined. It seems that predictive models may be used as a useful method for Tier 1 assessment of occupational exposure by inhalation. Since the levels of exposure are frequently overestimated, they should be considered as "rational worst cases" for selection of proper control measures. Bearing in mind that the number of available exposure scenarios and PROC categories is limited, further validation by field surveys is highly recommended. Predictive models may serve as a good tool for preliminary risk assessment and selection of the most appropriate risk control measures in Polish small and medium size enterprises (SMEs) providing that they are available in the Polish language. This also requires an extensive training of their future users. PMID:24502133

  8. Prenatal cocaine exposure: The role of cumulative environmental risk and maternal harshness in the development of child internalizing behavior problems in Kindergarten

    PubMed Central

    Eiden, Rina D.; Godleski, Stephanie; Colder, Craig R.; Schuetze, Pamela

    2014-01-01

    This study examined the associations between prenatal exposure to cocaine and other substances and child internalizing behavior problems at Kindergarten. We investigated whether maternal harshness or cumulative environmental risk mediated or moderated this association. Participants consisted of 216 (116 cocaine exposed, 100 non-cocaine exposed) mother-infant dyads participating in an ongoing longitudinal study of prenatal cocaine exposure. Results indicated that, as hypothesized, maternal harshness moderated the association between prenatal cocaine exposure to child internalizing in Kindergarten such that prenatal cocaine exposure increased risk for internalizing problems at high levels of maternal harshness from 7 to 36 months and decreased risk at low levels of harshness. Contrary to hypothesis, the association between prenatal cocaine exposure and child internalizing in Kindergarten was not mediated by maternal harshness or cumulative environmental risk. However, cumulative environmental risk (from 1 month of child age to Kindergarten) was predictive of child internalizing behavior problems at Kindergarten. Results have implications for parenting interventions that may be targeted toward reducing maternal harshness in high risk samples characterized by maternal substance use in pregnancy. PMID:24803425

  9. 76 FR 39150 - Updated Noise Exposure Map Notice for Indianapolis International Airport; Indianapolis, Indiana

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-05

    ...The Federal Aviation Administration (FAA) announces its determination that the updated noise exposure maps submitted by the Indianapolis Airport Authority for the Indianapolis International Airport under the provisions of 49 U.S.C. 47501 et seq. (Aviation Safety and Noise Abatement Act) and 14 CFR part 150 are in compliance with applicable...

  10. A Model of International Communication Media Appraisal and Exposure: A Comprehensive Test in Belize.

    ERIC Educational Resources Information Center

    Johnson, J. David; Oliveira, Omar Souki

    A study constituted the fifth phase of a programmatic research effort designed to develop and test a model of international communications media exposure and appraisal. The model posits that three variables--editorial tone, communication potential, and utility--have positive determinant effects on these dependent variables. Research was carried…

  11. Exposure to Intimate Partner Violence, Peer Relations, and Risk for Internalizing Behaviors: A Prospective Longitudinal Study

    ERIC Educational Resources Information Center

    Camacho, Kathleen; Ehrensaft, Miriam K.; Cohen, Patricia

    2012-01-01

    The present study examines the quality of peer relations as a mediator between exposure to IPV (intimate partner violence) and internalizing behaviors in a sample of 129 preadolescents and adolescents (ages 10-18), who were interviewed via telephone as part of a multigenerational, prospective, longitudinal study. Relational victimization is also…

  12. The contribution of different forms of violence exposure to internalizing and externalizing symptoms among young South African adolescents.

    PubMed

    du Plessis, Bernice; Kaminer, Debra; Hardy, Anneli; Benjamin, Arlene

    2015-07-01

    While many youth are exposed to multiple forms of co-occurring violence, the comparative impact of different forms of violence on the mental health of children and adolescents has not been clearly established. Studies from low and middle income countries in particular are lacking. The present study examined the contribution of different forms of violence to internalizing and externalizing symptoms among young adolescents in South Africa. A community-based sample of 616 high school learners completed self-report scales assessing exposure to six different forms of violence and the severity of depression, aggression and conduct disorder symptoms. In bivariate analyses, all six forms of violence were significantly associated with internalizing and externalizing difficulties. When the contribution of all forms of violence to mental health outcomes was examined simultaneously, domestic victimization emerged as the strongest predictor of both internalizing and externalizing difficulties. Cumulative exposure to other forms of violence contributed further to the prediction of aggression and conduct disorder, but not depression. Recommendations for future research, and the implications of the findings for prioritizing the development of violence prevention and intervention initiatives in the South African context, are considered. PMID:25804436

  13. Predicting Return of Fear Following Exposure Therapy With an Implicit Measure of Attitudes

    PubMed Central

    Vasey, Michael W.; Harbaugh, Casaundra N.; Buffington, Adam G.; Jones, Christopher R.; Fazio, Russell H.

    2012-01-01

    We sought to advance understanding of the processes underlying the efficacy of exposure therapy and particularly the phenomenon of return of fear (ROF) following treatment by drawing on a social psychological view of phobias as attitudes. Specifically, a dual process theory of attitude-related behavior predicts that a positive response to exposure therapy may reflect change in either the automatic (the attitude representation itself) or controlled (skills and confidence at coping with the fear) responses to the phobic stimulus, or both. However, if the attitude representation remains negative following treatment, ROF should be more likely. We tested this hypothesis in a clinical sample of individuals with public speaking phobia using a single-session exposure therapy protocol previously shown to be efficacious but also associated with some ROF. Consistent with predictions, a post-treatment implicit measure of attitudes toward public speaking (the Personalized Implicit Association Test [PIAT]) predicted ROF at 1-month follow-up. These results suggest that change in the automatically activated attitude toward the phobic stimulus is an important goal of exposure therapy and that an implicit measure like the PIAT can provide a useful measure of such change by which to gauge the adequacy of exposure treatment and predict its long-term efficacy. PMID:23085186

  14. Predicting return of fear following exposure therapy with an implicit measure of attitudes.

    PubMed

    Vasey, Michael W; Harbaugh, Casaundra N; Buffington, Adam G; Jones, Christopher R; Fazio, Russell H

    2012-12-01

    We sought to advance understanding of the processes underlying the efficacy of exposure therapy and particularly the phenomenon of return of fear (ROF) following treatment by drawing on a social psychological view of phobias as attitudes. Specifically, a dual process theory of attitude-related behavior predicts that a positive response to exposure therapy may reflect change in either the automatic (the attitude representation itself) or controlled (skills and confidence at coping with the fear) responses to the phobic stimulus, or both. However, if the attitude representation remains negative following treatment, ROF should be more likely. We tested this hypothesis in a clinical sample of individuals with public speaking phobia using a single-session exposure therapy protocol previously shown to be efficacious but also associated with some ROF. Consistent with predictions, a post-treatment implicit measure of attitudes toward public speaking (the Personalized Implicit Association Test [PIAT]) predicted ROF at 1-month follow-up. These results suggest that change in the automatically activated attitude toward the phobic stimulus is an important goal of exposure therapy and that an implicit measure like the PIAT can provide a useful measure of such change by which to gauge the adequacy of exposure treatment and predict its long-term efficacy. PMID:23085186

  15. Variation in predicted internal concentrations in relation to PBPK model complexity for rainbow trout.

    PubMed

    Salmina, E S; Wondrousch, D; Kühne, R; Potemkin, V A; Schüürmann, G

    2016-04-15

    The present study is motivated by the increasing demand to consider internal partitioning into tissues instead of exposure concentrations for the environmental toxicity assessment. To this end, physiologically based pharmacokinetic (PBPK) models can be applied. We evaluated the variation in accuracy of PBPK model outcomes depending on tissue constituents modeled as sorptive phases and chemical distribution tendencies addressed by molecular descriptors. The model performance was examined using data from 150 experiments for 28 chemicals collected from US EPA databases. The simplest PBPK model is based on the "Kow-lipid content" approach as being traditional for environmental toxicology. The most elaborated one considers five biological sorptive phases (polar and non-polar lipids, water, albumin and the remaining proteins) and makes use of LSER (linear solvation energy relationship) parameters to describe the compound partitioning behavior. The "Kow-lipid content"-based PBPK model shows more than one order of magnitude difference in predicted and measured values for 37% of the studied exposure experiments while for the most elaborated model this happens only for 7%. It is shown that further improvements could be achieved by introducing corrections for metabolic biotransformation and compound transmission hindrance through a cellular membrane. The analysis of the interface distribution tendencies shows that polar tissue constituents, namely water, polar lipids and proteins, play an important role in the accumulation behavior of polar compounds with H-bond donating functional groups. For compounds without H-bond donating fragments preferable accumulation phases are storage lipids and water depending on compound polarity. PMID:26849323

  16. Pituitary Volume Prospectively Predicts Internalizing Symptoms in Adolescence

    ERIC Educational Resources Information Center

    Zipursky, Amy R.; Whittle, Sarah; Yucel, Murat; Lorenzetti, Valentina; Wood, Stephen J.; Lubman, Dan I.; Simmons, Julian G.; Allen, Nicholas B.

    2011-01-01

    Background: Early adolescence is a critical time for the development of both internalizing and externalizing disorders. We aimed to investigate whether pituitary volume, an index of hypothalamic-pituitary-adrenal (HPA) axis function, represents a vulnerability factor for the emergence of internalizing and externalizing symptoms during adolescence…

  17. Biomarker-Based Calibration of Retrospective Exposure Predictions of Perfluorooctanoic Acid

    PubMed Central

    2015-01-01

    Estimated historical exposures and serum concentrations of perfluorooctanoic acid (PFOA) have been extensively used in epidemiologic studies that examined associations between PFOA exposures and adverse health outcomes among residents in highly exposed areas in the Mid-Ohio Valley. Using measured serum PFOA levels in 2005–2006, we applied two calibration methods to these retrospective exposure predictions: (1) multiplicative calibration and (2) Bayesian pharmacokinetic calibration with larger adjustments to more recent exposure estimates and smaller adjustments to exposure estimates for years farther in the past. We conducted simulation studies of various hypothetical exposure scenarios and compared hypothetical true historical intake rates with estimates based on mis-specified baseline exposure and pharmacokinetic models to find the method with the least bias. The Bayesian method outperformed the multiplicative method if a change to bottled water consumption was not reported or if the half-life of PFOA was mis-specified. On the other hand, the multiplicative method outperformed the Bayesian method if actual tap water consumption rates were systematically overestimated. If tap water consumption rates gradually decreased over time because of substitution with bottled water or other liquids, neither method clearly outperformed another. Calibration of retrospective exposure estimates using recently collected biomarkers may help reduce uncertainties in environmental epidemiologic studies. PMID:24730513

  18. Gene expression patterns predict exposure to PCBs in developing Xenopus laevis tadpoles.

    PubMed

    Jelaso, Anna M; Lehigh-Shirey, Elisabeth; Means, Jay; Ide, Charles F

    2003-01-01

    Polychlorinated biphenyls (PCBs) are ubiquitous environmental contaminants that pose global ecological and human health problems. Although it is well established that PCBs are associated with a variety of adverse health effects in wildlife and in humans, it is often difficult to determine direct cause-and-effect relationships between exposure and specific health outcomes. In this study, gene expression signatures were used to relate exposure to PCBs with altered physiological responses and/or specific health effects. Real-time PCR was used to measure gene expression levels for 10 genes in Xenopus laevis tadpoles (18 days postfertilization, PF) after acute exposure (2 days) to the PCB mixture Aroclor 1254. Specific gene expression signatures correlated with exposure and were predictive of adverse health effects. Exposure to low levels of Aroclor 1254 (5-50 ppb) significantly increased expression of six genes, independent of any health effects; exposure to midlevel concentrations (300-400 ppb) significantly decreased expression levels of two genes, NGF and beta-actin, prior to the onset of observable health effects; exposure to higher doses (500-700 ppb) significantly decreased NGF and beta-actin expression concomitant with the appearance of gross morphological abnormalities, behavioral deficits, and a statistically significant decrease in survival. This study expands upon our previous work that demonstrated an age-dependent susceptibility to Aroclor 1254 in Xenopus laevis tadpoles and that defined specific gene expression signatures as useful bioindicators of exposure and as predictors of overt or impending health effects. PMID:12874807

  19. Mechanistic Modeling to Predict Midazolam Metabolite Exposure from In Vitro Data.

    PubMed

    Nguyen, Hoa Q; Kimoto, Emi; Callegari, Ernesto; Obach, R Scott

    2016-05-01

    Methods to predict the pharmacokinetics of drugs in humans from in vitro data have been established, but corresponding methods to predict exposure to circulating metabolites are unproven. The objective of this study was to use in vitro methods combined with static and dynamic physiologically based pharmacokinetic (PBPK) models to predict metabolite exposures, using midazolam and its major metabolites as a test system. Intrinsic clearances (CLint) of formation of individual metabolites were determined using human liver microsomes. Metabolic CLintof hydroxymidazolam metabolites via oxidation and glucuronidation were also determined. Passive diffusion intrinsic clearances of hydroxymidazolam metabolites were determined using sandwich cultured human hepatocytes and the combination of this term along with the metabolic CLint, and liver blood flow was used to estimate the fraction of the metabolite that can enter the systemic circulation after formation in the liver. The metabolite/parent drug area under the plasma concentration-time curve ratio (AUCm/AUCp) was predicted using a static model relating the fraction of midazolam clearance to each metabolite, the clearance rates of midazolam and hydroxymidazolam metabolites, and the availability of the metabolites. Additionally, the human disposition of midazolam metabolites was simulated using a SimCYP PBPK model. Both approaches yielded AUCm/AUCpratios that were in agreement with the in vivo ratios. This study shows that in vivo midazolam metabolite exposure can be predicted from in vitro data and PBPK modeling. This study emphasized the importance of metabolite systemic availability from its tissue of formation, which remains a challenge to quantitative prediction. PMID:26956641

  20. Do questions reflecting indoor air pollutant exposure from a questionnaire predict direct measure of exposure in owner-occupied houses?

    PubMed

    Loo, C K Jennifer; Foty, Richard G; Wheeler, Amanda J; Miller, J David; Evans, Greg; Stieb, David M; Dell, Sharon D

    2010-08-01

    Home characteristic questions are used in epidemiological studies and clinical settings to assess potentially harmful exposures in the home. The objective of this study was to determine whether questionnaire-reported home characteristics can predict directly measured pollutants. Sixty home inspections were conducted on a subsample of the 2006 population-based Toronto Child Health Evaluation Questionnaire. Indoor/outdoor air and settled dust samples were analyzed. Mean Fel d 1 was higher (p < 0.0001) in homes with a cat (450.58 μg/g) versus without (22.28 μg/g). Mean indoor NO(2) was higher (p = 0.003) in homes with gas stoves (14.98 ppb) versus without (8.31 ppb). Self-reported musty odours predicted higher glucan levels (10554.37 μg/g versus 6308.58 μg/g, p = 0.0077). Der f 1 was predicted by the home's age, but not by reports of carpets, and was higher in homes with mean relative humidity > 50% (61.30 μg/g, versus 6.24 μg/g, p = 0.002). Self-reported presence of a cat, a gas stove, musty odours, mice, and the home's age and indoor relative humidity over 50% predicted measured indoor levels of cat allergens, NO(2), fungal glucan, mouse allergens and dust mite allergens, respectively. These results are helpful for understanding the significance of indoor exposures ascertained by self-reporting in large epidemiological studies and also in the clinical setting. PMID:20948960

  1. Predicting violent behavior: The role of violence exposure and future educational aspirations during adolescence.

    PubMed

    Stoddard, Sarah A; Heinze, Justin E; Choe, Daniel Ewon; Zimmerman, Marc A

    2015-10-01

    Few researchers have explored future educational aspirations as a promotive factor against exposure to community violence in relation to adolescents' violent behavior over time. The present study examined the direct and indirect effect of exposure to community violence prior to 9th grade on attitudes about violence and violent behavior in 12th grade, and violent behavior at age 22 via 9th grade future educational aspirations in a sample of urban African American youth (n = 681; 49% male). Multi-group SEM was used to test the moderating effect of gender. Exposure to violence was associated with lower future educational aspirations. For boys, attitudes about violence directly predicted violent behavior at age 22. For boys, future educational aspirations indirectly predicted less violent behavior at age 22. Implications of the findings and suggestions for future research are discussed. PMID:26282242

  2. Predictive sufficiency and the use of stored internal state

    NASA Technical Reports Server (NTRS)

    Musliner, David J.; Durfee, Edmund H.; Shin, Kang G.

    1994-01-01

    In all embedded computing systems, some delay exists between sensing and acting. By choosing an action based on sensed data, a system is essentially predicting that there will be no significant changes in the world during this delay. However, the dynamic and uncertain nature of the real world can make these predictions incorrect, and thus, a system may execute inappropriate actions. Making systems more reactive by decreasing the gap between sensing and action leaves less time for predictions to err, but still provides no principled assurance that they will be correct. Using the concept of predictive sufficiency described in this paper, a system can prove that its predictions are valid, and that it will never execute inappropriate actions. In the context of our CIRCA system, we also show how predictive sufficiency allows a system to guarantee worst-case response times to changes in its environment. Using predictive sufficiency, CIRCA is able to build real-time reactive control plans which provide a sound basis for performance guarantees that are unavailable with other reactive systems.

  3. Predicting Residential Exposure to Phthalate Plasticizer Emitted from Vinyl Flooring: Sensitivity, Uncertainty, and Implications for Biomonitoring

    PubMed Central

    Xu, Ying; Cohen Hubal, Elaine A.; Little, John C.

    2010-01-01

    Background Because of the ubiquitous nature of phthalates in the environment and the potential for adverse human health effects, an urgent need exists to identify the most important sources and pathways of exposure. Objectives Using emissions of di(2-ethylhexyl) phthalate (DEHP) from vinyl flooring (VF) as an illustrative example, we describe a fundamental approach that can be used to identify the important sources and pathways of exposure associated with phthalates in indoor material. Methods We used a three-compartment model to estimate the emission rate of DEHP from VF and the evolving exposures via inhalation, dermal absorption, and oral ingestion of dust in a realistic indoor setting. Results A sensitivity analysis indicates that the VF source characteristics (surface area and material-phase concentration of DEHP), as well as the external mass-transfer coefficient and ventilation rate, are important variables that influence the steady-state DEHP concentration and the resulting exposure. In addition, DEHP is sorbed by interior surfaces, and the associated surface area and surface/air partition coefficients strongly influence the time to steady state. The roughly 40-fold range in predicted exposure reveals the inherent difficulty in using biomonitoring to identify specific sources of exposure to phthalates in the general population. Conclusions The relatively simple dependence on source and chemical-specific transport parameters suggests that the mechanistic modeling approach could be extended to predict exposures arising from other sources of phthalates as well as additional sources of other semivolatile organic compounds (SVOCs) such as biocides and flame retardants. This modeling approach could also provide a relatively inexpensive way to quantify exposure to many of the SVOCs used in indoor materials and consumer products. PMID:20123613

  4. Predicting particulate (PM10) personal exposure distributions using a random component superposition statistical model.

    PubMed

    Ott, W; Wallace, L; Mage, D

    2000-08-01

    nonambient concentrations are similar across different cities and populations. These results indicate that, if the ambient concentrations were completely controlled and set to zero in all three cities, the median of the remaining personal exposures to PM10 would range from 32.0 micrograms/m3 (Toronto) to 34.4 micrograms/m3 (Phillipsburg) to 48.8 micrograms/m3 (Riverside). The highest-exposed 30% of the population in the three cities would still be exposed to 24-hr average PM10 concentrations of 47-74 micrograms/m3; the highest 20% would be exposed to concentrations of 56-92 micrograms/m3; the highest 10% to concentrations of 88-131 micrograms/m3; and the highest 5% to 133-175 micrograms/m3, due only to indoor sources and activities. The distribution for the difference between personal exposures and indoor concentrations, or the "personal cloud," also was similar in the three cities, with a mean of 30-35 micrograms/m3, suggesting that the personal cloud accounts for more than half of the nonambient component of PM10 personal exposure in the three cities. Using only the ambient measurements in Toronto, the nonambient data from THEES in Phillipsburg was used to predict the entire personal exposure distribution in Toronto. The PM10 exposure distribution predicted by the model showed reasonable agreement with the PM10 personal exposure distribution measured in Toronto. These initial results suggest that the RCS model may be a powerful tool for predicting personal exposure distributions and statistics in other cities where only ambient particle data are available. PMID:11002601

  5. Overall internal exposure to mycotoxins and their occurrence in occupational and residential settings--An overview.

    PubMed

    Fromme, H; Gareis, M; Völkel, W; Gottschalk, C

    2016-03-01

    Mycotoxins are toxic secondary metabolites of various fungal species that can contaminate food and feed, as well as indoor environments. Numerous studies have summarized the adverse health effects of mycotoxins and described severe intoxications of humans and animals. The major health concerns are caused via the alimentary route which unambiguously is the main source for human internal exposure; however, the relevance of other pathways under environmental and occupational conditions should also be considered. Thus firstly, this review aims in summarizing literature data on potentially inhalable mycotoxins occurring in dusts or air in residences and in working environments. Secondly, it gives an overview of the overall internal body burden of mycotoxins in humans in an attempt to characterize total human exposure. These data are also discussed in relation to the current toxicologically based values used for risk assessment. PMID:26725999

  6. International project on individual monitoring and radiation exposure levels in interventional cardiology.

    PubMed

    Padovani, R; Le Heron, J; Cruz-Suarez, R; Duran, A; Lefaure, C; Miller, D L; Sim, H K; Vano, E; Rehani, M; Czarwinski, R

    2011-03-01

    Within the Information System on Occupational Exposure in Medicine, Industry and Research (ISEMIR), a new International Atomic Energy Agency initiative, a Working Group on interventional cardiology, aims to assess staff radiation protection (RP) levels and to propose an international database of occupational exposures. A survey of regulatory bodies (RBs) has provided information at the country level on RP practice in interventional cardiology (IC). Concerning requirements for wearing personal dosemeters, only 57 % of the RB specifies the number and position of dosemeters for staff monitoring. Less than 40 % of the RBs could provide occupational doses. Reported annual median effective dose values (often <0.5 mSv) were lower than expected considering validated data from facility-specific studies, indicating that compliance with continuous individual monitoring is often not achieved in IC. A true assessment of annual personnel doses in IC will never be realised unless a knowledge of monitoring compliance is incorporated into the analysis. PMID:21051431

  7. Use of international data sets to evaluate and validate pathway assessment models applicable to exposure and dose reconstruction at DOE facilities. Progress report, August 1993--January 1994

    SciTech Connect

    Hendrickson, S.M.; Hoffman, F.O.

    1994-03-01

    This project, ``Use of International Data Sets to Evaluate and Validate Pathway Assessment Models Applicable to Exposure and Dose Reconstruction at DOE Facilities,`` grew out of several activities being conducted by the Principal Investigator Dr. F Owen Hoffman. One activity was originally part of the Chernobyl Studies Project and began as Task 7.1D, ``Internal Dose From Direct Contamination of Terrestrial Food Sources.`` The objective of Task 7.1D was to (1) establish a collaborative US USSR effort to improve and validate our methods of forecasting doses and dose commitments from the direct contamination of food sources, and (2) perform experiments and validation studies to improve our ability to predict rapidly and accurately the long-term internal dose from the contamination of agricultural soil. The latter was to include the consideration of remedial measures to block contamination of food grown on contaminated soil. The current objective of this project is to evaluate and validate pathway-assessment models applicable to exposure and dose reconstruction at DOE facilities through use of international data sets. This project incorporates the activity of Task 7.1D into a multinational effort to evaluate data used for the prediction of radionuclide transfer through agricultural and aquatic systems to humans. It also includes participation in two multinational studies, BIOMOVS (BIOspheric MOdel Validation Study) with the Swedish National Institute for Radiation Protection and VAMP (VAlidation of Model Predictions) with the International Atomic Energy Agency, that address testing the performance of models of radionuclide transport through foodchains.

  8. A toxicokinetic study of specifically acting and reactive organic chemicals for the prediction of internal effect concentrations in Scenedesmus vacuolatus.

    PubMed

    Vogs, Carolina; Kühnert, Agnes; Hug, Christine; Küster, Eberhard; Altenburger, Rolf

    2015-01-01

    The toxic potency of chemicals is determined by using the internal effect concentration by accounting for differences in toxicokinetic processes and mechanisms of toxic action. The present study examines toxicokinetics of specifically acting and reactive chemicals in the green algae Scenedesmus vacuolatus by using an indirect method. Concentration depletion in the exposure medium was measured for chemicals of lower (log KOW  < 3: isoproturon, metazachlor, paraquat) and moderate (log KOW 4-5: irgarol, triclosan, N-phenyl-2-naphthylamine) hydrophobicity at 7 to 8 time points over 240 min or 360 min. Uptake and overall elimination rates were estimated by fitting a toxicokinetic model to the observed concentration depletions. The equilibrium of exposure concentrations was reached within minutes to hours or was even not observed within the exposure time. The kinetics of bioconcentration cannot be explained by the chemical's hydrophobicity only, but influential factors such as ionization of chemicals, the ion trapping mechanism, or the potential susceptibility for biotransformation are discussed. Internal effect concentrations associated with 50% inhibition of S. vacuolatus reproduction were predicted by linking the bioconcentration kinetics to the effect concentrations and ranged from 0.0480 mmol/kg wet weight to 7.61 mmol/kg wet weight for specifically acting and reactive chemicals. Knowing the time-course of the internal effect concentration may promote an understanding of toxicity processes such as delayed toxicity, carry-over toxicity, or mixture toxicity in future studies. PMID:25263251

  9. Microdosimetric analysis confirms similar biological effectiveness of external exposure to gamma-rays and internal exposure to 137Cs, 134Cs, and 131I.

    PubMed

    Sato, Tatsuhiko; Manabe, Kentaro; Hamada, Nobuyuki

    2014-01-01

    The risk of internal exposure to 137Cs, 134Cs, and 131I is of great public concern after the accident at the Fukushima-Daiichi nuclear power plant. The relative biological effectiveness (RBE, defined herein as effectiveness of internal exposure relative to the external exposure to γ-rays) is occasionally believed to be much greater than unity due to insufficient discussions on the difference of their microdosimetric profiles. We therefore performed a Monte Carlo particle transport simulation in ideally aligned cell systems to calculate the probability densities of absorbed doses in subcellular and intranuclear scales for internal exposures to electrons emitted from 137Cs, 134Cs, and 131I, as well as the external exposure to 662 keV photons. The RBE due to the inhomogeneous radioactive isotope (RI) distribution in subcellular structures and the high ionization density around the particle trajectories was then derived from the calculated microdosimetric probability density. The RBE for the bystander effect was also estimated from the probability density, considering its non-linear dose response. The RBE due to the high ionization density and that for the bystander effect were very close to 1, because the microdosimetric probability densities were nearly identical between the internal exposures and the external exposure from the 662 keV photons. On the other hand, the RBE due to the RI inhomogeneity largely depended on the intranuclear RI concentration and cell size, but their maximum possible RBE was only 1.04 even under conservative assumptions. Thus, it can be concluded from the microdosimetric viewpoint that the risk from internal exposures to 137Cs, 134Cs, and 131I should be nearly equivalent to that of external exposure to γ-rays at the same absorbed dose level, as suggested in the current recommendations of the International Commission on Radiological Protection. PMID:24919099

  10. Effect of exposure to chlorpyrifos on the cuticular and internal lipid composition of Blattella germanica males.

    PubMed

    Paszkiewicz, Monika; Sikora, Agata; Boguś, Mieczysława I; Włóka, Emilia; Stepnowski, Piotr; Gołębiowski, Marek

    2016-02-01

    The results of our research on the cuticular and internal lipids of Blattella germanica males provide new information on variation in the composition of the cuticular and internal lipids of B. germanica males after exposure to the presence of the insecticide. gas chromatography and gas chromatography-mass spectrometry analyses were used to identify and quantify the cuticular and internal lipid composition in males and males exposed to insecticide. There were significantly more acids having an even number of carbon atoms in the molecule, and these were also generally in higher concentrations. The following acids were in a higher concentration: C16:0 and C18:1, C18:2, C18:0. In both males and males exposed to insecticide, 24 fatty acids ranging from C6 to C22 were determined. However, there was a significantly higher content of fatty acids in the surface lipids of B. germanica males after exposure to insecticide. Our results indicate a higher content of n-alkanes, sterols, particularly cholesterol, fatty acids, and fatty acid methyl esters in the B. germanica surface after exposure to chlorpyrifos than in males that were not exposed. PMID:25641824

  11. Exposure to Movie Reckless Driving in Early Adolescence Predicts Reckless, but Not Inattentive Driving

    PubMed Central

    Kostermans, Evelien; Stoolmiller, Mike; de Leeuw, Rebecca N. H.; Engels, Rutger C. M. E.; Sargent, James D.

    2014-01-01

    Objective We examine the association between exposure to depictions of reckless driving in movies and unsafe driving, modeling inattentive and reckless driving as separate outcomes. Methods Data were obtained by telephone from 1,630 US adolescents aged 10 to 14 years at baseline who were drivers at a survey 6 years later. Exposure to movie reckless driving was measured based on movies seen from a randomly selected list of 50 movie titles that had been content coded for reckless driving among characters. Associations were tested with inattentive and reckless driving behaviors in the subsequent survey–controlling for baseline age, sex, socioeconomic status, parental education, school performance, extracurricular activities, daily television and video/computer game exposure, number of movies watched per week, self-regulation and sensation seeking. Results Exposure to movie reckless driving was common, with approximately 10% of movie characters having driven recklessly. Confirmatory factor analysis revealed a significant distinction between items tapping reckless and inattentive driving at the 6th wave. Age and exposure to movie reckless driving at baseline were directly associated with wave-6 reckless (but not inattentive) driving. Additionally, growth in sensation seeking mediated a prospective relation between the total number of movies watched per week at baseline and reckless driving, independent of exposure to movie reckless driving. Males and high sensation seekers reported lower seatbelt usage and more reckless driving, whereas lower self-regulation predicted inattentive driving. Discussion In this study, exposure to movie reckless driving during early adolescence predicted adolescents’ reckless driving, suggesting a direct modeling effect. Other aspects of movies were also associated with reckless driving, with that association mediated through growth in sensation seeking. Predictors of reckless driving were different from predictors of inattentive driving

  12. [Prediction of short loops in the proteins with internal disorder].

    PubMed

    Deriusheva, E I; Galzitskaia, O V; Serdiuk, I N

    2008-01-01

    New possibility of the FoldUnfold program for prediction of short disordered regions (loops), which appears by using the short window width (3 amino acid residues), was described. For three representatives of the proteins G family the FoldUnfold program predicted almost all short loops and yield results are well compatible with the X-ray structure data. We have classified the loops predicted in the protein Ras-p21 structure in two types. In the first type, loops have high values of the Debye-Waller factor typical of the so-called functional loops (flexible loops). In the other type, loops have lower values of the Debye-Waller factor and can be considered as loops connecting secondary structure elements (rigid loops). When the results of prediction with the use of our program are compared with the results of other programs (PONDR, RONN, DisEMBL, PreLINK, IUPred, GlobPlot 2, FoldIndex), it is seen that the first enables far better prediction of short loop positions. Use of FoldUnfold for ubiquitin-like domain h-PLIC-2 allows to resolve such task as definition of boundary between the structured and unstructured regions in proteins with a big portion of disordered regions. The FoldUnfold program defines a clear boundary between the structured and unstructured regions at amino acid residues 30-31,whereas each of the other programs outlines the boundary from the 28-th amino acid residues through the 70th. PMID:19140328

  13. ANALYSIS OF CONCORDANCE OF PROBABILISTIC AGGREGATE EXPOSURE PREDICTIONS WITH OBSERVED BIOMONITORING RESULTS: AN EXAMPLE USING CTEPP DATA

    EPA Science Inventory

    Three key areas of scientific inquiry in the study of human exposure to environmental contaminants are 1) assessment of aggregate (i.e., multi-pathway, multi-route) exposures, 2) application of probabilistic methods to exposure prediction, and 3) the interpretation of biomarker m...

  14. Exposure to Violence Predicting Cortisol Response During Adolescence and Early Adulthood: Understanding Moderating Factors

    PubMed Central

    Heinze, Justin E.; Miller, Alison L.; Stoddard, Sarah A.; Zimmerman, Marc A.

    2014-01-01

    Previous research on the association between violence and biological stress regulation has been largely cross-sectional, and has also focused on childhood. Using longitudinal data from a low-income, high-risk, predominantly African-American sample (n = 266; 57 % female), we tested hypotheses about the influence of cumulative exposure to violence during adolescence and early adulthood on cortisol responses in early adulthood. We found that cumulative exposure to violence predicted an attenuated cortisol response. Further, we tested whether sex, mothers’ support, or fathers’ support moderated the effect of exposure to violence on cortisol responses. We found that the effect of cumulative exposure to violence on cortisol was modified by sex; specifically, males exposed to violence exhibited a more attenuated response pattern. In addition, the effect of cumulative exposure to violence on cortisol was moderated by the presence of fathers’ support during adolescence. The findings contribute to a better understanding of how cumulative exposure to violence influences biological outcomes, emphasizing the need to understand sex and parental support as moderators of risk. PMID:24458765

  15. Internal exposure of waste incineration workers to organic and inorganic substances.

    PubMed

    Wrbitzky, R; Göen, T; Letzel, S; Frank, F; Angerer, J

    1995-01-01

    One hundred and twenty-two persons employed in an industrial waste incineration plant were examined with respect to organic and inorganic substances which may be produced during the combustion of different waste. The employees were divided into three groups: persons with contact with the incinerator (WI workers, n = 45), periphery workers (n = 54) and management (n = 23). For the evaluation of internal exposure, the levels of lead, cadmium, mercury, benzene, toluene, ethylbenzene and m-xylene in blood, chromium in the erythrocytes, polychlorinated biphenyls, hexachlorobenzene and pentachlorophenol in plasma, and arsenic, chromium, nickel, vanadium, chlorophenols and hydroxypyrene in urine were determined. The internal exposures of the three groups were tested against each other and were compared with the reference values of the general population. Differences between the groups investigated were tested using the U test according to Wilcoxon, Mann and Whitney (P < 0.05). The biological exposure limits valid in Germany (BAT values) were not exceeded in any cases. Compared with the background levels of the German population, certain parameters were exceeded in several employees. Significantly higher levels of the WI workers in comparison to both periphery workers and management were found for toluene in blood (median: 1.1 vs 0.9 vs 0.6 microgram/l). For the lead and cadmium levels in blood and for the urinary excretion of arsenic, 2,4-dichlorophenol and tetrachlorophenols, statistical differences were found only between WI workers and one of the other groups. However, in all cases the elevations were very small and of interest more from the environmental than from the occupational point of view. It must be stressed that this waste incineration plant is very modern in terms of worker health and safety. At older plants without corresponding health and safety measures, higher internal exposure of the employees to hazardous substances may exist. PMID:8847108

  16. Impact of nano titanium dioxide exposure on cellular structure of Anabaena variabilis and evidence of internalization.

    PubMed

    Cherchi, Carla; Chernenko, Tatyana; Diem, Max; Gu, April Z

    2011-04-01

    The present study investigated the impact of nano titanium dioxide (nTiO(2) ) exposure on the cellular structures of the nitrogen-fixing cyanobacteria Anabaena variabilis. Results of the present study showed that nTiO(2) exposure led to observable alteration in various intracellular structures and induced a series of recognized stress responses, including production of reactive oxygen species (ROS), appearance and increase in the abundance of membrane crystalline inclusions, membrane mucilage layer formation, opening of intrathylakoidal spaces, and internal plasma membrane disruption. The production of total ROS in A. variabilis cells increased with increasing nTiO(2) doses and exposure time, and the intracellular ROS contributed to only a small fraction (<10%) of the total ROS measured. The percentage of cells with loss of thylakoids and growth of membrane crystalline inclusions increased as the nTiO(2) dose and exposure time increased compared with controls, suggesting their possible roles in stress response to nTiO(2) , as previously shown for metals. Algal cell surface morphology and mechanical properties were modified by nTiO(2) exposure, as indicated by the increase in cell surface roughness and shifts in cell spring constant determined by atomic force microscopy analysis. The change in cell surface structure and increase in the cellular turgor pressure likely resulted from the structural membrane damage mediated by the ROS production. Transmission electron microscopy (TEM) analysis of nTiO(2) aggregates size distribution seems to suggest possible disaggregation of nTiO(2) aggregates when in close contact with microbial cells, potentially as a result of biomolecules such as DNA excreted by organisms that may serve as a biodispersant. The present study also showed, for the first time, with both TEM and Raman imaging that internalization of nTiO(2) particles through multilayered membranes in algal cells is possible. Environ. Toxicol. Chem. 2011; 30:861-869.

  17. Cigarette smoke exposure induces CFTR internalization and insolubility, leading to airway surface liquid dehydration

    PubMed Central

    Clunes, Lucy A.; Davies, Catrin M.; Coakley, Raymond D.; Aleksandrov, Andrei A.; Henderson, Ashley G.; Zeman, Kirby L.; Worthington, Erin N.; Gentzsch, Martina; Kreda, Silvia M.; Cholon, Deborah; Bennett, William D.; Riordan, John R.; Boucher, Richard C.; Tarran, Robert

    2012-01-01

    Cigarette smoke (CS) exposure induces mucus obstruction and the development of chronic bronchitis (CB). While many of these responses are determined genetically, little is known about the effects CS can exert on pulmonary epithelia at the protein level. We, therefore, tested the hypothesis that CS exerts direct effects on the CFTR protein, which could impair airway hydration, leading to the mucus stasis characteristic of both cystic fibrosis and CB. In vivo and in vitro studies demonstrated that CS rapidly decreased CFTR activity, leading to airway surface liquid (ASL) volume depletion (i.e., dehydration). Further studies revealed that CS induced internalization of CFTR. Surprisingly, CS-internalized CFTR did not colocalize with lysosomal proteins. Instead, the bulk of CFTR shifted to a detergent-resistant fraction within the cell and colocalized with the intermediate filament vimentin, suggesting that CS induced CFTR movement into an aggresome-like, perinuclear compartment. To test whether airway dehydration could be reversed, we used hypertonic saline (HS) as an osmolyte to rehydrate ASL. HS restored ASL height in CS-exposed, dehydrated airway cultures. Similarly, inhaled HS restored mucus transport and increased clearance in patients with CB. Thus, we propose that CS exposure rapidly impairs CFTR function by internalizing CFTR, leading to ASL dehydration, which promotes mucus stasis and a failure of mucus clearance, leaving smokers at risk for developing CB. Furthermore, our data suggest that strategies to rehydrate airway surfaces may provide a novel form of therapy for patients with CB.—Clunes, L. A., Davies, C. M., Coakley, R. D., Aleksandrov, A. A., Henderson, A. G., Zeman, K. L., Worthington, E. N., Gentzsch, M., Kreda, S. M., Cholon, D., Bennett, W. D., Riordan, J. R., Boucher, R. C., Tarran, R. Cigarette smoke exposure induces CFTR internalization and insolubility, leading to airway surface liquid dehydration. PMID:21990373

  18. DNA damage in internal organs after cutaneous exposure to sulphur mustard

    SciTech Connect

    Batal, Mohamed; Boudry, Isabelle; Mouret, Stéphane; Cléry-Barraud, Cécile; Wartelle, Julien; Bérard, Izabel

    2014-07-01

    Sulphur mustard (SM) is a chemical warfare agent that attacks mainly skin, eye and lungs. Due to its lipophilic properties, SM is also able to diffuse through the skin and reach internal organs. DNA represents one of the most critical molecular targets of this powerful alkylating agent which modifies DNA structure by forming monoadducts and biadducts. These DNA lesions are involved in the acute toxicity of SM as well as its long-term carcinogenicity. In the present work we studied the formation and persistence of guanine and adenine monoadducts and guanine biadducts in the DNA of brain, lungs, kidneys, spleen, and liver of SKH-1 mice cutaneously exposed to 2, 6 and 60 mg/kg of SM. SM-DNA adducts were detected in all studied organs, except in liver at the two lowest doses. Brain and lungs were the organs with the highest level of SM-DNA adducts, followed by kidney, spleen and liver. Monitoring the level of adducts for three weeks after cutaneous exposure showed that the lifetime of adducts were not the same in all organs, lungs being the organ with the longest persistence. Diffusion from skin to internal organs was much more efficient at the highest compared to the lowest dose investigated as the result of the loss of the skin barrier function. These data provide novel information on the distribution of SM in tissues following cutaneous exposures and indicate that brain is an important target. - Highlights: • Sulphur mustard reaches internal organs after skin exposure • Adducts are detected in the DNA of internal organs • Brain is the organ with the highest level of DNA damage • The barrier function of skin is lost at high dose of sulphur mustard • DNA adducts persist in organs for 2 or 3 weeks.

  19. Determination of oxidant exposure during ozonation of secondary effluent to predict contaminant removal.

    PubMed

    Zucker, Ines; Avisar, Dror; Mamane, Hadas; Jekel, Martin; Hübner, Uwe

    2016-09-01

    The use of kinetic models to predict oxidation performance in wastewater is limited due to fast ozone depletion during the first milliseconds of the reaction. This paper introduces the Quench Flow Module (QFM), a bench-scale experimental technique developed to measure the first 5-500 milliseconds of ozone depletion for accurate determination of ozone exposure in wastewater-ozonation processes. Calculated ozone exposure in QFM experiments was up to 24% lower than in standard batch experiments, strongly depending on the initial sampling point for measurement in batch experiments. However, oxidation rates of slowly- and moderately-reacting trace organic compounds (TrOCs) were accurately predicted from batch experiments based on integration of ozone depletion and removal of an ozone-resistant probe compound to calculate oxidant exposures. An alternative concept, where ozone and hydroxyl radical exposures are back-calculated from the removal of two probe compounds, was tested as well. Although the QFM was suggested to be an efficient mixing reactor, ozone exposure ranged over three orders of magnitude when different probe compounds reacting moderately with ozone were used for the calculation. These effects were beyond uncertainty ranges for apparent second order rate constants and consistently observed with different ozone-injection techniques, i.e. QFM, batch experiments, bubble columns and venturi injection. This indicates that previously suggested mixing effects are not responsible for the difference and other still unknown factors might be relevant. Results furthermore suggest that ozone exposure calculations from the relative residual concentration of a probe compound are not a promising option for evaluation of ozonation of secondary effluents. PMID:27232995

  20. Environmental Factors Affecting Asthma and Allergies: Predicting and Simulating Downwind Exposure to Airborne Pollen

    NASA Technical Reports Server (NTRS)

    Luvall, Jeffrey; Estes, Sue; Sprigg, William A.; Nickovic, Slobodan; Huete, Alfredo; Solano, Ramon; Ratana, Piyachat; Jiang, Zhangyan; Flowers, Len; Zelicoff, Alan

    2009-01-01

    This slide presentation reviews the environmental factors that affect asthma and allergies and work to predict and simulate the downwind exposure to airborne pollen. Using a modification of Dust REgional Atmosphere Model (DREAM) that incorporates phenology (i.e. PREAM) the aim was to predict concentrations of pollen in time and space. The strategy for using the model to simulate downwind pollen dispersal, and evaluate the results. Using MODerate-resolution Imaging Spectroradiometer (MODIS), to get seasonal sampling of Juniper, the pollen chosen for the study, land cover on a near daily basis. The results of the model are reviewed.

  1. Exposure limits for nanoparticles: report of an international workshop on nano reference values.

    PubMed

    van Broekhuizen, Pieter; van Veelen, Wim; Streekstra, Willem-Henk; Schulte, Paul; Reijnders, Lucas

    2012-07-01

    This article summarizes the outcome of the discussions at the international workshop on nano reference values (NRVs), which was organized by the Dutch trade unions and employers' organizations and hosted by the Social Economic Council in The Hague in September 2011. It reflects the discussions of 80 international participants representing small- and medium-size enterprises (SMEs), large companies, trade unions, governmental authorities, research institutions, and non-governmental organizations (NGOs) from many European countries, USA, India, and Brazil. Issues that were discussed concerned the usefulness and acceptability of precaution-based NRVs as a substitute for health-based occupational exposure limits (OELs) and derived no-effect levels (DNELs) for manufactured nanoparticles (NPs). Topics concerned the metrics for measuring NPs, the combined exposure to manufactured nanomaterials (MNMs) and process-generated NPs, the use of the precautionary principle, the lack of information about the presence of nanomaterials, and the appropriateness of soft regulation for exposure control. The workshop concluded that the NRV, as an 8-h time-weighted average, is a comprehensible and useful instrument for risk management of professional use of MNMs with a dispersible character. The question remains whether NRVs, as advised for risk management by the Dutch employers' organization and trade unions, should be under soft regulation or that a more binding regulation is preferable. PMID:22752096

  2. Modeling the imprecision in prospective dosimetry of internal exposure to uranium.

    PubMed

    Davesne, E; Chojnacki, E; Paquet, F; Blanchardon, E

    2009-02-01

    The dosimetry of internal exposure to radionuclides is performed on the basis of biokinetic and dosimetric models. For prospective purpose, the organ or effective dose resulting from potential conditions of exposure can be calculated by applying these models with dedicated software. However, it is acknowledged that a significant uncertainty is associated with such calculation due to the variability of individual cases and to the possible lack of knowledge about some factors influencing the dosimetry. This uncertainty has been studied in a range of situations by modeling the uncertainty on the model parameters by probability distributions and propagating this uncertainty onto the dose result by Monte Carlo calculation. However, while probability distributions are well adapted to model the known variability of a parameter, they may lead to an unrealistically low estimate of the uncertainty due to a lack of knowledge about some input parameters. Here we present a mathematical method, based on the Dempster-Shafer theory, to deal with such imprecise knowledge. We apply this method to the prospective dosimetry of inhaled uranium dust in the nuclear fuel cycle when its physico-chemical properties are not precisely known. The results show an increased estimation of the range of uncertainty as compared to the application of a probabilistic method. This Dempster-Shafer method may valuably be applied in future prospective dosimetry of internal exposure in order to more realistically estimate the uncertainty resulting from an imprecise knowledge of the parameters of the dose calculation. PMID:19131736

  3. Review of OPFRs in animals and humans: Absorption, bioaccumulation, metabolism, and internal exposure research.

    PubMed

    Hou, Rui; Xu, Yiping; Wang, Zijian

    2016-06-01

    Due to their widespread use, organophosphate flame retardants (OPFRs) are commonly detected in various environmental matrices and have been identified as emerging contaminants. Considering the adverse effects of OPFRs, many researchers have paid their attention on the absorption, bioaccumulation, metabolism and internal exposure processes of OPFRs in animals and humans. In this article, we first review the diverse absorption routes of OPFRs by animals and humans (e.g., inhalation, ingestion, dermal absorption and gill absorption). Bioaccumulation and biomagnification potentials of OPFRs in different types of organisms and food webs are also summarized, based on quite limited available data and results. For metabolism, we review the Phase-I and Phase-II metabolic processes for each type of OPFRs (chlorinated OPFRs, alkyl-OPFRs and aryl-OPFRs) in the animals and humans, as well as toxicokinetic information and putative exposure biomarkers on OPFRs. Finally, we highlight gaps in our knowledge and critical directions for future internal exposure studies of OPFRs in animals and humans. PMID:27010170

  4. Exposure of Polymer Film Thermal Control Materials on the Materials International Space Station Experiment (MISSE)

    NASA Technical Reports Server (NTRS)

    Dever, Joyce; Miller, Sharon; Messer, Russell; Sechkar, Edward; Tollis, Greg

    2002-01-01

    Seventy-nine samples of polymer film thermal control (PFTC) materials have been provided by the National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) for exposure to the low Earth orbit environment on the exterior of the International Space Station (ISS) as part of the Materials International Space Station Experiment (MISSE). MISSE is a materials flight experiment sponsored by the Air Force Research Lab/Materials Lab and NASA. This paper will describe background, objectives, and configurations for the GRC PFTC samples for MISSE. These samples include polyimides, fluorinated polyimides, and Teflon fluorinated ethylene propylene (FEP) with and without second-surface metallizing layers and/or surface coatings. Also included are polyphenylene benzobisoxazole (PBO) and a polyarylene ether benzimidazole (TOR-LM). On August 16, 2001, astronauts installed passive experiment carriers (PECs) on the exterior of the ISS in which were located twenty-eight of the GRC PFTC samples for 1-year space exposure. MISSE PECs for 3-year exposure, which will contain fifty-one GRC PFTC samples, will be installed on the ISS at a later date. Once returned from the ISS, MISSE GRC PFTC samples will be examined for changes in optical and mechanical properties and atomic oxygen (AO) erosion. Additional sapphire witness samples located on the AO exposed trays will be examined for deposition of contaminants.

  5. Dynamic interactions between hydrogeological and exposure parameters in daily dose prediction under uncertainty and temporal variability.

    PubMed

    Kumar, Vikas; de Barros, Felipe P J; Schuhmacher, Marta; Fernàndez-Garcia, Daniel; Sanchez-Vila, Xavier

    2013-12-15

    We study the time dependent interaction between hydrogeological and exposure parameters in daily dose predictions due to exposure of humans to groundwater contamination. Dose predictions are treated stochastically to account for an incomplete hydrogeological and geochemical field characterization, and an incomplete knowledge of the physiological response. We used a nested Monte Carlo framework to account for uncertainty and variability arising from both hydrogeological and exposure variables. Our interest is in the temporal dynamics of the total dose and their effects on parametric uncertainty reduction. We illustrate the approach to a HCH (lindane) pollution problem at the Ebro River, Spain. The temporal distribution of lindane in the river water can have a strong impact in the evaluation of risk. The total dose displays a non-linear effect on different population cohorts, indicating the need to account for population variability. We then expand the concept of Comparative Information Yield Curves developed earlier (see de Barros et al. [29]) to evaluate parametric uncertainty reduction under temporally variable exposure dose. Results show that the importance of parametric uncertainty reduction varies according to the temporal dynamics of the lindane plume. The approach could be used for any chemical to aid decision makers to better allocate resources towards reducing uncertainty. PMID:24011618

  6. International Cooperative for Aerosol Prediction Workshop on Aerosol Forecast Verification

    NASA Technical Reports Server (NTRS)

    Benedetti, Angela; Reid, Jeffrey S.; Colarco, Peter R.

    2011-01-01

    The purpose of this workshop was to reinforce the working partnership between centers who are actively involved in global aerosol forecasting, and to discuss issues related to forecast verification. Participants included representatives from operational centers with global aerosol forecasting requirements, a panel of experts on Numerical Weather Prediction and Air Quality forecast verification, data providers, and several observers from the research community. The presentations centered on a review of current NWP and AQ practices with subsequent discussion focused on the challenges in defining appropriate verification measures for the next generation of aerosol forecast systems.

  7. Internal exposure to organochlorine pollutants and cadmium and self-reported health status: a prospective study.

    PubMed

    Van Larebeke, Nik; Sioen, Isabelle; Hond, Elly Den; Nelen, Vera; Van de Mieroop, Els; Nawrot, Tim; Bruckers, Liesbeth; Schoeters, Greet; Baeyens, Willy

    2015-03-01

    In this paper, based on the Flemish biomonitoring programs, we describe the associations between internal exposure to organochlorine pollutants and to cadmium (measured in 2004-2005 for adults aged 50-65 years) and self-reported health status obtained through a questionnaire in November 2011. Dioxin-like activity in serum showed a significant positive association with risk of cancer for women. After adjustment for confounders and covariates, the odds ratio for an exposure equal to the 90th percentile was 2.4 times higher than for an exposure equal to the 10th percentile. For both men and women dioxin-like activity and serum hexachlorobenzene (HCB) showed a significant positive association with risk of diabetes and of hypertension. Detailed analysis suggested that an increase in BMI might be part of the mechanism through which HCB contributes to diabetes and hypertension. Serum dichlorodiphenyldichloroethylene (p,p'-DDE) concentration showed a significant positive association with diabetes and hypertension in men, but not in women. Serum polychlorinated biphenyl (PCB) 118 showed a significant positive association with diabetes in both men and women, and after adjustment for correlated exposures, also with hypertension in men. Urinary cadmium concentrations showed a significant positive association with hypertension. Urinary cadmium concentrations were (in 2004-2005) significantly higher in persons who felt in less than good health (in 2011) than in persons who felt in very good health. After adjustment for correlated exposures (to HCB, p,p'-DDE and PCB118) marker PCBs showed a significant negative association with diabetes and hypertension. Serum p,p'-DDE showed in men a significant negative association with risk of diseases based on atheromata. Our findings suggest that exposure to pollutants can lead to an important increase in the risk of diseases such as cancer, diabetes and hypertension. Some pollutants may possibly also decrease the risk of some health

  8. Analysis of Noise Exposure Measurements Made Onboard the International Space Station

    NASA Technical Reports Server (NTRS)

    Limardo, Jose G.; Allen, Christopher S.

    2011-01-01

    The International Space Station (ISS) is a unique workplace environment for U.S. astronauts and Russian cosmonauts to conduct research and live for a period of six months or more. Noise has been an enduring environmental physical hazard that has been a challenge for the U.S. space program since before the Apollo era. Noise exposure in ISS poses significant risks to the crewmembers, such as; hearing loss (temporary or permanent), possible disruptions of crew sleep, interference with speech intelligibility and communication, possible interference with crew task performance, and possible reduction in alarm audibility. Acoustic measurements are made aboard ISS and compared to requirements in order to assess the acoustic environment to which the crewmembers are exposed. The purpose of this paper is to describe in detail the noise exposure monitoring program as well as an assessment of the acoustic dosimeter data collected to date. The hardware currently being used for monitoring the noise exposure onboard ISS will be discussed. Acoustic data onboard ISS has been collected since the beginning of ISS (Increment 1, November 2000). Noise exposure data analysis will include acoustic dosimetry logged data from crew-worn during work and sleep periods and also fixed-location measurements from Increment 1 to present day. Noise exposure levels (8-, 16- and 24-hr), LEQ, will also be provided and discussed in this paper. Discussions related to hearing protection will also be included. Future directions and recommendations for the noise exposure monitoring program will be highlighted. This acoustic data is used to ensure a safe and healthy working and living environment for the crewmembers aboard the ISS.

  9. Analysis of Noise Exposure Measurements Acquired Onboard the International Space Station

    NASA Technical Reports Server (NTRS)

    Limardo, Jose G.; Allen, Christopher S.

    2011-01-01

    The International Space Station (ISS) is a unique workplace environment for U.S. astronauts and Russian cosmonauts to conduct research and live for a period of six months or more. Noise has been an enduring environmental physical hazard that has been a challenge for the U.S. space program since before the Apollo era. Noise exposure in ISS poses significant risks to the crewmembers, such as; hearing loss (temporary or permanent), possible disruptions of crew sleep, interference with speech intelligibility and communication, possible interference with crew task performance, and possible reduction in alarm audibility. Acoustic measurements were made onboard ISS and compared to requirements in order to assess the acoustic environment to which the crewmembers are exposed. The purpose of this paper is to describe in detail the noise exposure monitoring program as well as an assessment of the acoustic dosimeter data collected to date. The hardware currently being used for monitoring the noise exposure onboard ISS will be discussed. Acoustic data onboard ISS has been collected since the beginning of ISS (Increment 1, November 2001). Noise exposure data analysis will include acoustic dosimetry logged data from crew-worn dosimeters during work and sleep periods and also fixed-location measurements from Increment 1 to present day. Noise exposure levels (8-, 16- and 24-hr), LEQ, will also be provided and discussed in this paper. Future directions and recommendations for the noise exposure monitoring program will be highlighted. This acoustic data is used to ensure a safe and healthy working and living environment for the crewmembers onboard the ISS.

  10. Comparison of three models for predicting blood lead levels in children: episodic exposures to lead.

    PubMed

    Lakind, J S

    1998-01-01

    A threshold blood lead level in children below which no adverse effects occur has not been identified (CDC, 1991), Therefore, the traditional risk assessment method of relating dose to a reference dose (RfD) for noncancer effects is not applicable to lead. To assess whether environmental lead concentrations may result in adverse health effects, predicted blood lead levels are compared to a blood lead level of 10 micrograms/dL, the current Centers for Disease Control and Prevention level of concern. Children's blood lead levels may be predicted with one of at least three models: USEPA'S Integrated Exposure Uptake Biokinetic Model (IEUBK), and models by O'Flaherty (1993) and Carlisle and Wade (1992). This paper explores the utility of these models for predicting blood lead levels in children, and discusses areas of uncertainty associated with the use of these models in evaluating episodic exposures. It is hoped that this discussion will stimulate interest further researching exposure and health effects from episodic contact with lead contaminated media. PMID:9679219

  11. Atomic Oxygen Exposure of Polyimide Foam for International Space Station Solar Array Wing Blanket Box

    NASA Technical Reports Server (NTRS)

    Finckenor, M. M.; Albyn, K. C.; Watts, E. W.

    2006-01-01

    Onorbit photos of the International Space Station (ISS) solar array blanket box foam pad assembly indicate degradation of the Kapton film covering the foam, leading to atomic oxygen (AO) exposure of the foam. The purpose of this test was to determine the magnitude of particulate generation caused by low-Earth orbital environment exposure of the foam and also by compression of the foam during solar array wing retraction. The polyimide foam used in the ISS solar array wing blanket box assembly is susceptible to significant AO erosion. The foam sample in this test lost one-third of its mass after exposure to the equivalent of 22 mo onorbit. Some particulate was generated by exposure to simulated orbital conditions and the simulated solar array retraction (compression test). However, onorbit, these particles would also be eroded by AO. The captured particles were generally <1 mm, and the particles shaken free of the sample had a maximum size of 4 mm. The foam sample maintained integrity after a compression load of 2.5 psi.

  12. Cigarette smoke exposure induces CFTR internalization and insolubility, leading to airway surface liquid dehydration.

    PubMed

    Clunes, Lucy A; Davies, Catrin M; Coakley, Raymond D; Aleksandrov, Andrei A; Henderson, Ashley G; Zeman, Kirby L; Worthington, Erin N; Gentzsch, Martina; Kreda, Silvia M; Cholon, Deborah; Bennett, William D; Riordan, John R; Boucher, Richard C; Tarran, Robert

    2012-02-01

    Cigarette smoke (CS) exposure induces mucus obstruction and the development of chronic bronchitis (CB). While many of these responses are determined genetically, little is known about the effects CS can exert on pulmonary epithelia at the protein level. We, therefore, tested the hypothesis that CS exerts direct effects on the CFTR protein, which could impair airway hydration, leading to the mucus stasis characteristic of both cystic fibrosis and CB. In vivo and in vitro studies demonstrated that CS rapidly decreased CFTR activity, leading to airway surface liquid (ASL) volume depletion (i.e., dehydration). Further studies revealed that CS induced internalization of CFTR. Surprisingly, CS-internalized CFTR did not colocalize with lysosomal proteins. Instead, the bulk of CFTR shifted to a detergent-resistant fraction within the cell and colocalized with the intermediate filament vimentin, suggesting that CS induced CFTR movement into an aggresome-like, perinuclear compartment. To test whether airway dehydration could be reversed, we used hypertonic saline (HS) as an osmolyte to rehydrate ASL. HS restored ASL height in CS-exposed, dehydrated airway cultures. Similarly, inhaled HS restored mucus transport and increased clearance in patients with CB. Thus, we propose that CS exposure rapidly impairs CFTR function by internalizing CFTR, leading to ASL dehydration, which promotes mucus stasis and a failure of mucus clearance, leaving smokers at risk for developing CB. Furthermore, our data suggest that strategies to rehydrate airway surfaces may provide a novel form of therapy for patients with CB. PMID:21990373

  13. Contribution of internal exposures to the radiological consequences of the Chernobyl accident.

    PubMed

    Balonov, M I; Anspaugh, L R; Bouville, A; Likhtarev, I A

    2007-01-01

    The main pathways leading to exposure of members of the general public due to the Chernobyl accident were external exposure from radionuclides deposited on the ground and ingestion of contaminated terrestrial food products. The collective dose to the thyroid was nearly 1.5 million man Gy in Belarus, Russia and Ukraine with nearly half received by children and adolescents. The collective effective dose received in 1986-2005 by approximately five million residents living in the affected areas of the three countries was approximately 50,000 man Sv with approximately 40% from ingestion. That contribution might have been larger if countermeasures had not been applied. The main radionuclide contributing to both external and internal effective dose is 137Cs with smaller contributions of 134Cs and 90Sr and negligible contribution of transuranic elements. The major demonstrated radiation-caused health effect of the Chernobyl accident has been an elevated incidence of thyroid cancer in children. PMID:17977893

  14. Bacterial meningitis exposure during an international flight: lessons for communicable pathogens.

    PubMed

    Riley, Lyrad K

    2006-07-01

    Air transport of infectious patients presents challenges for screening, post-exposure follow-up of fellow passengers, and international coordination issues. This report illustrates how an index case may not receive a clear diagnosis until days after the flight of interest, complicating treatment and fellow passenger tracking. This patient was diagnosed with meningococcal meningitis after a transatlantic flight with over 200 other passengers. In such cases, prompt initiation of public health measures and rapid coordination between various agencies may be required to limit outbreaks. Similar concerns will likely complicate intentional pathogen exposures; however, there may also be additional challenges related to unfamiliar pathogens and legal or political limitations to information sharing. For meningococcal disease, published guidelines exist to assist in determining which passengers and health-care workers meet criteria for antimicrobial chemoprophylaxis. PMID:16856365

  15. Exposure versus internal dose: Respiratory tract deposition modeling of inhaled asbestos fibers in rats and humans (Presentation Poster)

    EPA Science Inventory

    Exposure to asbestos is associated with respiratory diseases, including asbestosis, lung cancer and mesothelioma. Internal fiber dose depends on fiber inhalability and orientation, fiber density, length and width, and various deposition mechanisms (DM). Species-specific param...

  16. 75 FR 3959 - Noise Exposure Map Notice for Kona International Airport at Keahole, Keahole, North Kona, HI

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-25

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF TRANSPORTATION Federal Aviation Administration Noise Exposure Map Notice for Kona International Airport at Keahole, Keahole, North Kona, HI AGENCY: Federal Aviation Administration, DOT. ACTION: Notice. SUMMARY: The...

  17. The Role of Multicultural Personality in Predicting University Adjustment of International Students in Turkey

    ERIC Educational Resources Information Center

    Kagnici, Dilek Yelda

    2012-01-01

    The study examined how particular demographic and multicultural personality variables might predict university adjustment of international students in Turkey. One hundred and twenty-one international students from five geographical regions, including Middle Central Asia, the Balkans, the Middle East, the Kafkasia Region, and the Russian…

  18. Predicting international medical graduate success on college certification examinations

    PubMed Central

    Schabort, Inge; Mercuri, Mathew; Grierson, Lawrence E.M.

    2014-01-01

    Abstract Objective To determine predictors of international medical graduate (IMG) success in accordance with the priorities highlighted by the Thomson and Cohl judicial report on IMG selection. Design Retrospective assessment using regression analyses to compare the information available at the time of resident selection with those trainees’ national certification examination outcomes. Setting McMaster University in Hamilton, Ont. Participants McMaster University IMG residents who completed the program between 2005 and 2011. Main outcome measures Associations between IMG professional experience or demographic characteristics and examination outcomes. Results The analyses revealed that country of study and performance on the Medical Council of Canada Evaluating Examination are among the predictors of performance on the College of Family Physicians of Canada and the Royal College of Physicians and Surgeons of Canada certification examinations. Of interest, the analyses also suggest discipline-specific relationships between previous professional experience and examination success. Conclusion This work presents a useful technique for further improving our understanding of the performance of IMGs on certification examinations in North America, encourages similar interinstitutional analyses, and provides a foundation for the development of tools to assist with IMG education. PMID:25316762

  19. Emotional attentional control predicts changes in diurnal cortisol secretion following exposure to a prolonged psychosocial stressor.

    PubMed

    Lenaert, Bert; Barry, Tom J; Schruers, Koen; Vervliet, Bram; Hermans, Dirk

    2016-01-01

    Hypothalamic-pituitary-adrenal (HPA) axis irregularities have been associated with several psychological disorders. Hence, the identification of individual difference variables that predict variations in HPA-axis activity represents an important challenge for psychiatric research. We investigated whether self-reported attentional control in emotionally demanding situations prospectively predicted changes in diurnal salivary cortisol secretion following exposure to a prolonged psychosocial stressor. Low ability to voluntarily control attention has previously been associated with anxiety and depressive symptomatology. Attentional control was assessed using the Emotional Attentional Control Scale. In students who were preparing for academic examination, salivary cortisol was assessed before (time 1) and after (time 2) examination. Results showed that lower levels of self-reported emotional attentional control at time 1 (N=90) predicted higher absolute diurnal cortisol secretion and a slower decline in cortisol throughout the day at time 2 (N=71). Difficulty controlling attention during emotional experiences may lead to chronic HPA-axis hyperactivity after prolonged exposure to stress. These results indicate that screening for individual differences may foster prediction of HPA-axis disturbances, paving the way for targeted disorder prevention. PMID:26539967

  20. Aquatic Exposure Predictions of Insecticide Field Concentrations Using a Multimedia Mass-Balance Model.

    PubMed

    Knäbel, Anja; Scheringer, Martin; Stehle, Sebastian; Schulz, Ralf

    2016-04-01

    Highly complex process-driven mechanistic fate and transport models and multimedia mass balance models can be used for the exposure prediction of pesticides in different environmental compartments. Generally, both types of models differ in spatial and temporal resolution. Process-driven mechanistic fate models are very complex, and calculations are time-intensive. This type of model is currently used within the European regulatory pesticide registration (FOCUS). Multimedia mass-balance models require fewer input parameters to calculate concentration ranges and the partitioning between different environmental media. In this study, we used the fugacity-based small-region model (SRM) to calculate predicted environmental concentrations (PEC) for 466 cases of insecticide field concentrations measured in European surface waters. We were able to show that the PECs of the multimedia model are more protective in comparison to FOCUS. In addition, our results show that the multimedia model results have a higher predictive power to simulate varying field concentrations at a higher level of field relevance. The adaptation of the model scenario to actual field conditions suggests that the performance of the SRM increases when worst-case conditions are replaced by real field data. Therefore, this study shows that a less complex modeling approach than that used in the regulatory risk assessment exhibits a higher level of protectiveness and predictiveness and that there is a need to develop and evaluate new ecologically relevant scenarios in the context of pesticide exposure modeling. PMID:26889709

  1. Effects of Exposure to Community Violence on Internalizing Symptoms: Does Desensitization to Violence Occur in African American Youth?

    ERIC Educational Resources Information Center

    Gaylord-Harden, Noni K.; Cunningham, Jamila A.; Zelencik, Brett

    2011-01-01

    The purpose of the current study was to examine the linear and curvilinear associations of exposure to community violence to internalizing symptoms in 251 African American adolescents (mean age = 12.86, SD = 1.28). Participants reported on exposure to community violence, anxiety symptoms, and depressive symptoms. Regression analyses were used to…

  2. [New horizons in medicine. Complexity and predictability in internal medicine].

    PubMed

    Guarini, G; Onofri, E

    1993-10-01

    Being a highly sophisticated structure, the human body should be considered on a physical level as a whole of inter-correlated non-linear dynamic systems, which are by definition, complex systems because they are always conditioned in their operativity by numerous variables. We must draw attention to the opportunity that within the field of medical science the concept of complexity referring to diagnostic, therapeutic and prognostical problems, is distinct between structural and functional. The functional complexity of a system, a phenomena, an event, MY be recognized in its dynamics, only if analysed using modern methods recently brought to light, on the relationship which exist between classic determinism and deterministic chaos. Furthermore, also on practical level, the recent discoveries on the general principles, which are at the base of the functional complexity of non-linear dynamic systems, demonstrate exactly how fragile is the probabilistic predictability which guides a doctor in clinical reasoning in all its various stages; in the gathering of anamnestic and objective data; in the programming the researches aimed at confirming the validness of the diagnosis; in the therapy aimed at reaching the best possible results; in the prognosis which summarize the destiny of the binomial patient illness. The scientific enunciate of universal nature, which demonstrate how, from a tiny uncertainty in the initial functional data of a system, of a phenomena, of an event can unleash a condition of absolute unpredictability, find daily confirmation in both clinical and experimental medicine.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8235036

  3. Adiposity and pathogen exposure predict C-reactive protein in Filipino women.

    PubMed

    McDade, Thomas W; Rutherford, Julienne N; Adair, Linda; Kuzawa, Christopher

    2008-12-01

    Obesity and infectious agents are both sources of inflammatory stimuli that result in increased production of C-reactive protein (CRP). Rates of overweight and obesity are increasing globally, but for many populations, gains in body fat are set against a backdrop of high levels of pathogen exposure. Our primary objective was to evaluate the extent to which adiposity and pathogenicity contribute to a double burden of inflammation in a population currently undergoing the nutrition transition. Measures of adiposity, pathogen exposure, and infectious disease symptoms were evaluated as predictors of high-sensitivity CRP concentration in plasma samples from 1875 women participating in the Cebu Longitudinal Health and Nutrition Survey in the Philippines. Proxy measures of pathogen exposure included household crowding and cleanliness, quality of water source, mode of waste disposal, and fecal exposure. A series of maximum likelihood logistic regression models were used to predict a plasma CRP concentration > 3 mg/L. Waist circumference was the strongest anthropometric predictor of elevated CRP [odds ratio (OR) = 2.29; 95% CI = 2.00, 2.62; P < 0.001]. Presence of infectious disease symptoms (OR = 2.51; 95% CI = 1.84, 3.44; P < 0.001) and level of pathogen exposure (OR = 1.56; 95% CI = 1.15, 2.12; P < 0.01) were also associated with elevated CRP. These associations were independent of socioeconomic status and other health behaviors. Overweight/obesity and infectious exposures are associated with elevated CRP in the Philippines; it is likely that other populations undergoing the nutrition transition are experiencing comparable double burdens of inflammatory stimuli. These results underscore the need for additional research on the contributions of pathogenicity, adiposity, and inflammation to global epidemics of cardiovascular and metabolic diseases. PMID:19022970

  4. ORERP (Off-Site Radiation Exposure Review Project) internal dose estimates for individuals

    SciTech Connect

    Ng, Y.C.; Anspaugh, L.R.; Cederwall, R.T. )

    1990-11-01

    A method was developed to reconstruct the internal radiation dose to off-site individuals who were exposed to fallout from nuclear weapons tests at the Nevada Test Site (NTS). By this method, committed absorbed doses can be estimated for 22 target organs of persons in four age groups and for selected organs of the fetus. Ingestion doses are calculated by combining age-group dose factors and intakes specific for age group, test event, and location as calculated by the PATHWAY food-chain model. Inhalation doses are calculated by combining age-group dose factors and breathing rates, and time-integrated air concentrations that are derived from the ORERP Air-Quality Data Base. Dose estimates are calculated for the radionuclides that contribute significantly to the total dose; these number 20 via the ingestion pathway and 46 via the inhalation pathway. Internal doses to nonspecified individuals and nonspecified fetuses are being reconstructed for each location in the ORERP Town Data Base for which exposure rates and cloud-arrival times are listed. Examples of reconstructing internal dose are presented. This method will also be adapted to reconstruct internal doses from NTS fallout to specific individuals in accordance with the person's age, past residence, life-style, and living pattern.

  5. ORERP (Off-Site Radiation Exposure Review Project) internal dose estimates for individuals.

    PubMed

    Ng, Y C; Anspaugh, L R; Cederwall, R T

    1990-11-01

    A method was developed to reconstruct the internal radiation dose to off-site individuals who were exposed to fallout from nuclear weapons tests at the Nevada Test Site (NTS). By this method, committed absorbed doses can be estimated for 22 target organs of persons in four age groups and for selected organs of the fetus. Ingestion doses are calculated by combining age-group dose factors and intakes specific for age group, test event, and location as calculated by the PATHWAY food-chain model. Inhalation doses are calculated by combining age-group dose factors and breathing rates, and time-integrated air concentrations that are derived from the ORERP Air-Quality Data Base. Dose estimates are calculated for the radionuclides that contribute significantly to the total dose; these number 20 via the ingestion pathway and 46 via the inhalation pathway. Internal doses to nonspecified individuals and nonspecified fetuses are being reconstructed for each location in the ORERP Town Data Base for which exposure rates and cloud-arrival times are listed. Examples of reconstructing internal dose are presented. This method will also be adapted to reconstruct internal doses from NTS fallout to specific individuals in accordance with the person's age, past residence, life-style, and living pattern. PMID:2211124

  6. Exposure to international migration and its effect on childbearing in Turkey.

    PubMed

    White, Kari; Buckley, Cynthia J

    2011-01-01

    International migration alters social norms, family structures, and population development in sending regions. Each of these factors affects fertility, making the impact of international migration on childbearing an increasingly important area of study. In many sending regions, the Demographic and Health Surveys (DHS) provide a promising, but underutilized, source of data for understanding the relationship between international migration and childbearing. Using the household and individual questionnaires in the 2003 Turkish DHS, we develop a multi-layered approach for measuring international migration. We then use these measures to examine differences in childbearing among women in migrant and non-migrant households, assessing the effects of migrant selection and migration-related roles and attitudes on the number of children born. After adjusting for selection characteristics, we find return female migrants and migrant wives are not significantly different from women in non-migrant households; role and attitude differences have only modest impacts on the association between women’s exposure to migration and childbearing. PMID:21717598

  7. Method for the prediction of the effective dose equivalent to the crew of the International Space Station

    NASA Astrophysics Data System (ADS)

    El-Jaby, Samy; Tomi, Leena; Sihver, Lembit; Sato, Tatsuhiko; Richardson, Richard B.; Lewis, Brent J.

    2014-03-01

    This paper describes a methodology for assessing the pre-mission exposure of space crew aboard the International Space Station (ISS) in terms of an effective dose equivalent. In this approach, the PHITS Monte Carlo code was used to assess the particle transport of galactic cosmic radiation (GCR) and trapped radiation for solar maximum and minimum conditions through an aluminum shield thickness. From these predicted spectra, and using fluence-to-dose conversion factors, a scaling ratio of the effective dose equivalent rate to the ICRU ambient dose equivalent rate at a 10 mm depth was determined. Only contributions from secondary neutrons, protons, and alpha particles were considered in this analysis. Measurements made with a tissue equivalent proportional counter (TEPC) located at Service Module panel 327, as captured through a semi-empirical correlation in the ISSCREM code, where then scaled using this conversion factor for prediction of the effective dose equivalent. This analysis shows that at this location within the service module, the total effective dose equivalent is 10-30% less than the total TEPC dose equivalent. Approximately 75-85% of the effective dose equivalent is derived from the GCR. This methodology provides an opportunity for pre-flight predictions of the effective dose equivalent and therefore offers a means to assess the health risks of radiation exposure on ISS flight crew.

  8. Comparison of NIRS approach for prediction of internal quality traits in three fruit species.

    PubMed

    de Oliveira, Gabrieli Alves; Bureau, Sylvie; Renard, Catherine Marie-Geneviève Claire; Pereira-Netto, Adaucto Bellarmino; de Castilhos, Fernanda

    2014-01-15

    NIR Spectroscopy ability was investigated to assess the fruit structure effect (passion fruit, tomato and apricot) on prediction performance of soluble solids content (SSC) and titratable acidity (TA). Relationships between spectral wavelengths and SSC and TA were evaluated through the application of chemometric techniques based on partial least squares (PLS). Good prediction performance was obtained for apricot with correlation coefficients of 0.93 and 0.95 for SSC and TA and root mean square errors of prediction (RMSEP%) of 3.3% and 14.2%, respectively. For the passion fruit and tomato, the prediction models were not satisfactorily accurate due to the high RMSEP. Results showed that NIR technology can be used to evaluate apricot internal quality, however, it was not appropriate to evaluate internal quality in fruits with thick skin, (passion fruit), and/or heterogeneous internal structure (tomato). PMID:24054234

  9. Engineered nanoparticle respiratory exposure and potential risks for cardiovascular toxicity: predictive tests and biomarkers.

    PubMed

    Simeonova, Petia P; Erdely, Aaron

    2009-07-01

    The most attractive properties of engineered nanomaterials for technological applications, including their small size, large surface area, and high reactivity, are also the main factors for their potential toxicity. Based on ambient ultrafine particle research, it is predicted that nanosized particles may have deeper pulmonary deposition, higher biological activity, and a tendency for extrapulmonary translocation compared to larger particles. In this regard, nanoparticle exposure, by direct or indirect mechanisms, may lead to unexpected distant responses, involving the immune system, cardiovascular system, liver, kidney, and brain. The systemic effects may induce or modify the progression of existing diseases such as cardiovascular disease. Current experimental toxicity evaluation of engineered nanomaterials, specifically carbon nanotubes, demonstrated that deposition of these materials in the lung leads to inflammation and fibrosis. The local toxicity is associated with cardiovascular effects related to atherosclerosis. Although translocation of carbon nanotubes into the systemic circulation is hypothetically possible, there is no current evidence to support this hypothesis. However, studies pointed out that carbon nanotube-induced lung inflammation results in a release of inflammatory mediators and activation of blood cells which can contribute to cardiovascular adverse effects. Furthermore, complex protein and gene expression blood analysis can help in development of biomarkers for application in human screening of nanoparticle exposure. Future studies to evaluate the systemic effects of carbon nanotube exposure under workplace or environmental exposure paradigms should be conducted. PMID:19558236

  10. Trauma exposure interacts with impulsivity in predicting emotion regulation and depressive mood

    PubMed Central

    Ceschi, Grazia; Billieux, Joël; Hearn, Melissa; Fürst, Guillaume; Van der Linden, Martial

    2014-01-01

    Background Traumatic exposure may modulate the expression of impulsive behavioral dispositions and change the implementation of emotion regulation strategies associated with depressive mood. Past studies resulted in only limited comprehension of these relationships, especially because they failed to consider impulsivity as a multifactorial construct. Objective Based on Whiteside and Lynam's multidimensional model that identifies four distinct dispositional facets of impulsive-like behaviors, namely urgency, (lack of) premeditation, (lack of) perseverance, and sensation seeking (UPPS), the current study used a sample of community volunteers to investigate whether an interaction exists between impulsivity facets and lifetime trauma exposure in predicting cognitive emotion regulation and depressive mood. Methods Ninety-three adults completed questionnaires measuring lifetime trauma exposure, impulsivity, cognitive emotion regulation, and depressive mood. Results Results showed that trauma-exposed participants with a strong disposition toward urgency (predisposition to act rashly in intense emotional contexts) tended to use fewer appropriate cognitive emotion regulation strategies than other individuals. Unexpectedly, participants lacking in perseverance (predisposition to have difficulties concentrating on demanding tasks) used more appropriate emotion regulation strategies if they had experienced traumatic events during their life than if they had not. Emotion regulation mediated the path between these two impulsivity facets and depressive mood. Conclusions Together, these findings suggest that impulsivity has a differential impact on emotion regulation and depressive mood depending on lifetime exposure to environmental factors, especially traumatic events. PMID:25317255

  11. Exposure to Violence in the Community Predicts Friendships with Academically Disengaged Peers During Middle Adolescence.

    PubMed

    Schwartz, David; Kelly, Brynn M; Mali, Luiza V; Duong, Mylien T

    2016-09-01

    Adolescents who have been exposed to violence in the community often experience subsequent difficulties with academic achievement. Because competence in the classroom is a salient developmental task during the adolescent years, outcomes in this critical context can then have broader implications for social and psychological functioning. In the current study, we tested a hypothesized progression in which the association between violence exposure and deficient achievement is presumed to potentiate friendships with academically disengaged peers. We followed 415 urban adolescents (53 % girls; average age of 14.6 years) for a one-year period, with two annual assessment of psychosocial functioning. Exposure to violence in the community and academic engagement were assessed with a self-report inventory; reciprocated friendships were assessed with a peer interview; and achievement was indexed based on a review of school records. Consistent with our hypotheses, neighborhood violence was associated with deficient classroom achievement. Poor achievement, in turn, mediated associations between community violence exposure and low academic engagement among friends. Our findings highlight pathways though which exposure to community violence potentially predicts later dysfunction. PMID:27138174

  12. Meeting report: international workshop on endocrine disruptors: exposure and potential impact on consumers health.

    PubMed

    Rousselle, C; Ormsby, J N; Schaefer, B; Lampen, A; Platzek, T; Hirsch-Ernst, K; Warholm, M; Oskarsson, A; Nielsen, P J; Holmer, M L; Emond, C

    2013-02-01

    The French Agency for Food, Environmental and Occupational Health and Safety (Anses) hosted a two-day workshop on Endocrine Disruptors: Exposure and Potential Impact on Consumers Health, bringing together participants from international organizations, academia, research institutes and from German, Swedish, Danish and French governmental agencies. The main objective of the workshop was to share knowledge and experiences on endocrine disruptors (ED) exposure and potential impact on consumers' health, to identify current risk assessment practices and knowledge gaps and issue recommendations on research needs and future collaboration. The following topics were reviewed: (1) Definition of ED, (2) endpoints to be considered for Risk assessment (RA) of ED, (3) non-monotonic dose response curves, (4) studies to be considered for RA (regulatory versus academic studies), (5) point of departure and uncertainty factors, (6) exposure assessment, (7) regulatory issues related to ED. The opinions expressed during this workshop reflect day-to-day experiences from scientists, regulators, researchers, and others from many different countries in the fields of risk assessment, and were regarded by the attendees as an important basis for further discussions. Accordingly, the participants underlined the need for more exchange in the future to share experiences and improve the methodology related to risk assessment for endocrine disrupters. PMID:23211416

  13. Predicting children's short-term exposure to pesticides: results of a questionnaire screening approach.

    PubMed Central

    Sexton, Ken; Adgate, John L; Eberly, Lynn E; Clayton, C Andrew; Whitmore, Roy W; Pellizzari, Edo D; Lioy, Paul J; Quackenboss, James J

    2003-01-01

    The ability of questionnaires to predict children's exposure to pesticides was examined as part of the Minnesota Children's Pesticide Exposure Study (MNCPES). The MNCPES focused on a probability sample of 102 children between the ages of 3 and 13 years living in either urban (Minneapolis and St. Paul, MN) or nonurban (Rice and Goodhue Counties in Minnesota) households. Samples were collected in a variety of relevant media (air, food, beverages, tap water, house dust, soil, urine), and chemical analyses emphasized three organophosphate insecticides (chlorpyrifos, diazinon, malathion) and a herbicide (atrazine). Results indicate that the residential pesticide-use questions and overall screening approach used in the MNCPES were ineffective for identifying and oversampling children/households with higher levels of individual target pesticides. PMID:12515690

  14. Predicting exposure-response associations of ambient particulate matter with mortality in 73 Chinese cities.

    PubMed

    Madaniyazi, Lina; Guo, Yuming; Chen, Renjie; Kan, Haidong; Tong, Shilu

    2016-01-01

    Estimating the burden of mortality associated with particulates requires knowledge of exposure-response associations. However, the evidence on exposure-response associations is limited in many cities, especially in developing countries. In this study, we predicted associations of particulates smaller than 10 μm in aerodynamic diameter (PM10) with mortality in 73 Chinese cities. The meta-regression model was used to test and quantify which city-specific characteristics contributed significantly to the heterogeneity of PM10-mortality associations for 16 Chinese cities. Then, those city-specific characteristics with statistically significant regression coefficients were treated as independent variables to build multivariate meta-regression models. The model with the best fitness was used to predict PM10-mortality associations in 73 Chinese cities in 2010. Mean temperature, PM10 concentration and green space per capita could best explain the heterogeneity in PM10-mortality associations. Based on city-specific characteristics, we were able to develop multivariate meta-regression models to predict associations between air pollutants and health outcomes reasonably well. PMID:26452312

  15. Real-Time Aircraft Cosmic Ray Radiation Exposure Predictions from the NAIRAS Model

    NASA Astrophysics Data System (ADS)

    Mertens, C. J.; Tobiska, W.; Kress, B. T.; Xu, X.

    2012-12-01

    The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) is a prototype operational model for predicting commercial aircraft radiation exposure from galactic and solar cosmic rays. NAIRAS predictions are currently streaming live from the project's public website, and the exposure rate nowcast is also available on the SpaceWx smartphone app for iPhone, IPad, and Android. Cosmic rays are the primary source of human exposure to high linear energy transfer radiation at aircraft altitudes, which increases the risk of cancer and other adverse health effects. Thus, the NAIRAS model addresses an important national need with broad societal, public health and economic benefits. There is also interest in extending NAIRAS to the LEO environment to address radiation hazard issues for the emerging commercial spaceflight industry. The processes responsible for the variability in the solar wind, interplanetary magnetic field, solar energetic particle spectrum, and the dynamical response of the magnetosphere to these space environment inputs, strongly influence the composition and energy distribution of the atmospheric ionizing radiation field. Real-time observations are required at a variety of locations within the geospace environment. The NAIRAS model is driven by real-time input data from ground-, atmospheric-, and space-based platforms. During the development of the NAIRAS model, new science questions and observational data gaps were identified that must be addressed in order to obtain a more reliable and robust operational model of atmospheric radiation exposure. The focus of this talk is to present the current capabilities of the NAIRAS model, discuss future developments in aviation radiation modeling and instrumentation, and propose strategies and methodologies of bridging known gaps in current modeling and observational capabilities.

  16. [Development of Chemical Exposure Prediction Model for Aerobic Sewage Treatment Plant for Biochemical Wastewaters].

    PubMed

    Zhou, Lin-jun; Liu, Ji-ning; Shi, Li-li; Feng, Jie; Xu, Yan-hua

    2016-01-15

    Sewage treatment plant (STP) is a key transfer station for chemicals distributed into different environment compartment, and hence models of exposure prediction play a crucial role in the environmental risk assessment and pollution prevention of chemicals. A mass balance model namely Chinese Sewage treatment plant (C-STP(O)) was developed to predict the fate and exposure of chemicals in a conventional sewage treatment plant. The model was expressed as 9 mixed boxes by compartment of air, water, suspended solids, and settled solids. It was based on the minimum input data required on the notification in new chemicals, such as molecular weight, absorption coefficient, vapor pressure, water solubility, ready or inherent biodegradability. The environment conditions ( Temperature = 283 K, wind speed = 2 m x s(-1)) and the classic STP scenario parameters of China, especially the scenario parameters of water quality and sludge properties were adopted in C-STP( 0) model to reflect Chinese characteristics, these parameters were sewage flow of 35 000 m3 x d(-1), influent BOD5 of 0.15 g x L(-1), influent SS of 0.2 kg x m(-3), effluent SS of 0.02 kg x m(-3), BOD5 removal in aerator of 90% sludge density of 1.6 kg x L(3) and organic carbon content of 0.18-0.19. It adopted the fugacity express for mechanism of linear absorption, first-order degradation, Whitman two resistances. An overall interphase transfer constant which was the sum of surface volatilization and stripping was used to assess the volatilization in aerator. The most important and uncertain input value was the biodegradation rate constant, and determination of which required a tier test strategy from ready or inherent biodegradability data to simulate test in STP. An extrapolated criterion of US EPA to derive biodegradation rate constant using the results of ready and inherent biodegradability was compared with that of EU and was recommended. C-STP ( 0 ) was valid to predict the relative emission of volatilization

  17. Levels and predictors of airborne and internal exposure to manganese and iron among welders.

    PubMed

    Pesch, Beate; Weiss, Tobias; Kendzia, Benjamin; Henry, Jana; Lehnert, Martin; Lotz, Anne; Heinze, Evelyn; Käfferlein, Heiko Udo; Van Gelder, Rainer; Berges, Markus; Hahn, Jens-Uwe; Mattenklott, Markus; Punkenburg, Ewald; Hartwig, Andrea; Brüning, Thomas

    2012-01-01

    We investigated airborne and internal exposure to manganese (Mn) and iron (Fe) among welders. Personal sampling of welding fumes was carried out in 241 welders during a shift. Metals were determined by inductively coupled plasma mass spectrometry. Mn in blood (MnB) was analyzed by graphite furnace atom absorption spectrometry. Determinants of exposure levels were estimated with multiple regression models. Respirable Mn was measured with a median of 62 (inter-quartile range (IQR) 8.4-320) μg/m(3) and correlated with Fe (r=0.92, 95% CI 0.90-0.94). Inhalable Mn was measured with similar concentrations (IQR 10-340 μg/m(3)). About 70% of the variance of Mn and Fe could be explained, mainly by the welding process. Ventilation decreased exposure to Fe and Mn significantly. Median concentrations of MnB and serum ferritin (SF) were 10.30 μg/l (IQR 8.33-13.15 μg/l) and 131 μg/l (IQR 76-240 μg/l), respectively. Few welders were presented with low iron stores, and MnB and SF were not correlated (r=0.07, 95% CI -0.05 to 0.20). Regression models revealed a significant association of the parent metal with MnB and SF, but a low fraction of variance was explained by exposure-related factors. Mn is mainly respirable in welding fumes. Airborne Mn and Fe influenced MnB and SF, respectively, in welders. This indicates an effect on the biological regulation of both metals. Mn and Fe were strongly correlated, whereas MnB and SF were not, likely due to higher iron stores among welders. PMID:22377681

  18. Comparison of International Guidelines of Dermal Absorption Tests Used in Pesticides Exposure Assessment for Operators

    PubMed Central

    So, Jaehwan; Ahn, Junyoung; Lee, Tae-Hee; Park, Kyung-Hun; Paik, Min-Kyoung; Jeong, Mihye; Cho, Myung-Haing

    2014-01-01

    The number of farmers who have suffered from non-fatal acute pesticide poisoning has been reported to vary from 5.7% to 86.7% in South Korea since 1975. Absorption through the skin is the main route of exposure to pesticides for farmers who operate with them. Several in vitro tests using the skins of humans or animal and in vivo tests using laboratory animals are introduced for the assessment of human dermal absorption level of pesticides. The objective of this study is to evaluate and compare international guidelines and strategies of dermal absorption assessments and to propose unique approaches for applications into pesticide registration process in our situation. Until present in our situation, pesticide exposure level to operator is determined just using default value of 10 as for skin absorption ratio because of data shortage. Dermal absorption tests are requested to get exposure level of pesticides and to ultimately know the safety of pesticides for operators through the comparison with the value of AOEL. When the exposure level is higher than AOEL, the pesticide cannot be approved. We reviewed the skin absorption test guidelines recommended by OECD, EFSA and EPA. The EPA recommends assessment of skin absorption of pesticides for humans through the TPA which includes all the results of in vitro human and animal and animal in vivo skin absorption studies. OECD and EFSA, employ a tiered approach, which the requirement of further study depends on the results of the former stage study. OECD guidelines accept the analysis of pesticide level absorbed through skin without radioisotope when the recovery using the non-labeled method is within 80~120%. Various factors are reviewed in this study, including the origin of skin (gender, animal species and sites of skin), thickness, temperature and, etc., which can influence the integrity of results. PMID:25584144

  19. Using ecological measures of smoking trigger exposure to predict smoking cessation milestones.

    PubMed

    Minami, Haruka; Tran, Lisa T; McCarthy, Danielle E

    2015-03-01

    This study used ecological momentary assessment data from adult daily smokers attempting to quit smoking to assess relations between exposure to contextual risk factors and cessation failure, latency to a first smoking lapse, or progression from lapse to relapse (smoking 7 days in a row). Participants were adult, daily smokers enrolled in a randomized controlled clinical trial of bupropion SR and individual counseling who were followed to 1 year postquit. Participants reported exposure to high-risk contexts and behaviors, including being where cigarettes were available or smoking was permitted, being around others smoking in prospective, real-time assessment for 2 weeks pre- and 4 weeks postquit. Results showed that greater exposure to contextual risk factors during the prequit did not predict cessation failure. However, Cox regression survival analyses revealed that spending a greater proportion of time where cigarettes were easily available following at least 1 day of abstinence predicted shorter latency to a first lapse, even after controlling for baseline risk factors such as gender, nicotine dependence, depressive symptoms, and living with a smoker. Greater cigarette availability following a lapse was not associated with progression from lapse to relapse with or without baseline risk factors in the model. This suggests that postquit environmental risk factors, such as cigarette availability, increase lapse risk, and stable risk factors, such as living with smokers and higher baseline carbon monoxide level or depressive symptoms, remain potent predictors of progression to relapse. Real-time contextual risk assessments postquit predict lapse above and beyond stable, baseline risk factors. (PsycINFO Database Record PMID:25134024

  20. Prediction in complex systems: The case of the international trade network

    NASA Astrophysics Data System (ADS)

    Vidmer, Alexandre; Zeng, An; Medo, Matúš; Zhang, Yi-Cheng

    2015-10-01

    Predicting the future evolution of complex systems is one of the main challenges in complexity science. Based on a current snapshot of a network, link prediction algorithms aim to predict its future evolution. We apply here link prediction algorithms to data on the international trade between countries. This data can be represented as a complex network where links connect countries with the products that they export. Link prediction techniques based on heat and mass diffusion processes are employed to obtain predictions for products exported in the future. These baseline predictions are improved using a recent metric of country fitness and product similarity. The overall best results are achieved with a newly developed metric of product similarity which takes advantage of causality in the network evolution.

  1. Stem cell responses after radiation exposure: A key to the evaluation and prediction of its effects

    SciTech Connect

    Fliedner, T.M.; Paul, W.; Tibken, B.; Hofer, E.P.

    1996-06-01

    A biomathematical model of granulocytopoiesis is described and used to analyze the blood granulocyte changes seen in the blood of dogs and humans after continuous and after acute external radiation exposure. This allows to relate the cell change pattern seen to the extent of stem cell damage in the hematopoietic bone marrow distributed as semiautonomous units throughout the skeletal bones. The model is described briefly and consists of 8 cellular and 2 regulatory compartments and is described by 37 differential equations. With the help of this model, it can be shown that the chronic radiation exposure of dogs at a rate of between 0.003 and 0.12 Gy per day results in a system failure with subsequent death of the animal, if the stem cell pool decreases below 2.5% of its normal content. In human beings exposed to a single radiation exposure (as seen in radiation accidents) the simulation of the granulocyte pattern results in the finding that a reduction of the stem pool to 5-10% of normal is compatible with the assumption of its {open_quotes}reversible{close_quotes} damage (to be treated by conventional replacement therapy including cytokines), whereas the reduction of blood granulocytes to levels of less than 200-300 per mm{sup 3} on day 5-6 after exposure indicates that no stem cells remain from which a spontaneous regeneration could occur and hence would require a substitution therapy by stem cell transplantation. The same model was used to correlate the changing granulocyte pattern seen after autologous blood stem cell transfusion in patients treated with supralethal radiochemo conditioning regimen. The results indicate a proportionality of progenitor cells in the transfusate with the calculated stem cell number of the modeling exercise. It is proposed to use the pattern of granulocyte changes in the blood as a principal indicator to predict the outcome of a radiation exposure and to select appropriate therapeutic strategies. 29 refs., 7 figs., 2 tabs.

  2. The impact of composite AUC estimates on the prediction of systemic exposure in toxicology experiments.

    PubMed

    Sahota, Tarjinder; Danhof, Meindert; Della Pasqua, Oscar

    2015-06-01

    Current toxicity protocols relate measures of systemic exposure (i.e. AUC, Cmax) as obtained by non-compartmental analysis to observed toxicity. A complicating factor in this practice is the potential bias in the estimates defining safe drug exposure. Moreover, it prevents the assessment of variability. The objective of the current investigation was therefore (a) to demonstrate the feasibility of applying nonlinear mixed effects modelling for the evaluation of toxicokinetics and (b) to assess the bias and accuracy in summary measures of systemic exposure for each method. Here, simulation scenarios were evaluated, which mimic toxicology protocols in rodents. To ensure differences in pharmacokinetic properties are accounted for, hypothetical drugs with varying disposition properties were considered. Data analysis was performed using non-compartmental methods and nonlinear mixed effects modelling. Exposure levels were expressed as area under the concentration versus time curve (AUC), peak concentrations (Cmax) and time above a predefined threshold (TAT). Results were then compared with the reference values to assess the bias and precision of parameter estimates. Higher accuracy and precision were observed for model-based estimates (i.e. AUC, Cmax and TAT), irrespective of group or treatment duration, as compared with non-compartmental analysis. Despite the focus of guidelines on establishing safety thresholds for the evaluation of new molecules in humans, current methods neglect uncertainty, lack of precision and bias in parameter estimates. The use of nonlinear mixed effects modelling for the analysis of toxicokinetics provides insight into variability and should be considered for predicting safe exposure in humans. PMID:25868863

  3. Predicting Developmental Changes in Internalizing Symptoms: Examining the Interplay Between Parenting and Neuroendocrine Stress Reactivity

    PubMed Central

    Kuhlman, Kate R.; Olson, Sheryl L.; Lopez-Duran, Nestor L.

    2015-01-01

    In this study, we examined whether parenting and HPA-axis reactivity during middle childhood predicted increases in internalizing symptoms during the transition to adolescence, and whether HPA-axis reactivity mediated the impact of parenting on internalizing symptoms. The study included 65 children (35 boys) who were assessed at age 5, 7, and 11. Parenting behaviors were assessed via parent report at age 5 and 11. The child’s HPA-axis reactivity was measured at age 7 via a stress task. Internalizing symptoms were measured via teacher reports at age 5 and 11. High maternal warmth at age 5 predicted lower internalizing symptoms at age 11. Also, high reported maternal warmth and induction predicted lower HPA-axis reactivity. Additionally, greater HPA-axis reactivity at age 7 was associated with greater increases in internalizing symptoms from age 5 to 11. Finally, the association between age 5 maternal warmth and age 11 internalizing symptoms was partially mediated by lower cortisol in response to the stress task. Thus, parenting behaviors in early development may influence the physiological stress response system and therefore buffer the development of internalizing symptoms during preadolescence when risk for disorder onset is high. PMID:24009085

  4. International issues on human health effects of exposure to chemical mixtures.

    PubMed Central

    Feron, Victor J; Cassee, Flemming R; Groten, John P; van Vliet, Petronella W; van Zorge, Job A

    2002-01-01

    In this article, we highlight new developments and recent studies concerning adverse human health effects related to chemical mixtures. One group of activities comprises the development of a new computer program for analyzing mixture studies and a mathematical model as a basis for combination rules that predict the toxicity of mixtures. Other new activities in the area of experimental studies are the application of gene expression technologies in mixture research, and pattern recognition as a tool in safety evaluation of complex mixtures. A "bottom-up" approach for chemosensory detection of mixtures has recently been presented. Other topics include a method for the safety evaluation of natural flavoring complexes, and an evaluation of the possible health effects of the simultaneous intake of food additives. Examples of issues related to mixtures of airborne chemicals are potential interaction of fine particles and gaseous pollutants in ambient air, nasal cancer associated with inhaled chemical mixtures, and the recommendation of a limit value for volatile organic compounds. Topics of a more strategic nature include studies concerning the public health effects of large airports, and the development of criteria for a harmonized classification of chemical mixtures. This overview illustrates that strategies to tackle the safety evaluation of combined exposures and complex mixtures as well as models facilitating the interpretation of findings in the context of risk assessment of mixtures have become increasingly important. It is true that exposure of humans to chemical mixtures is the rule rather than the exception, and therefore health risk assessments should focus on mixtures and not on single chemicals. It is also true, however, that humans have learned to cope with exposure to huge numbers of chemicals simultaneously (food, water, air, soil, and consumer products). Therefore, in view of limited resources for toxicological research, the focus in toxicology should be

  5. International issues on human health effects of exposure to chemical mixtures.

    PubMed

    Feron, Victor J; Cassee, Flemming R; Groten, John P; van Vliet, Petronella W; van Zorge, Job A

    2002-12-01

    In this article, we highlight new developments and recent studies concerning adverse human health effects related to chemical mixtures. One group of activities comprises the development of a new computer program for analyzing mixture studies and a mathematical model as a basis for combination rules that predict the toxicity of mixtures. Other new activities in the area of experimental studies are the application of gene expression technologies in mixture research, and pattern recognition as a tool in safety evaluation of complex mixtures. A "bottom-up" approach for chemosensory detection of mixtures has recently been presented. Other topics include a method for the safety evaluation of natural flavoring complexes, and an evaluation of the possible health effects of the simultaneous intake of food additives. Examples of issues related to mixtures of airborne chemicals are potential interaction of fine particles and gaseous pollutants in ambient air, nasal cancer associated with inhaled chemical mixtures, and the recommendation of a limit value for volatile organic compounds. Topics of a more strategic nature include studies concerning the public health effects of large airports, and the development of criteria for a harmonized classification of chemical mixtures. This overview illustrates that strategies to tackle the safety evaluation of combined exposures and complex mixtures as well as models facilitating the interpretation of findings in the context of risk assessment of mixtures have become increasingly important. It is true that exposure of humans to chemical mixtures is the rule rather than the exception, and therefore health risk assessments should focus on mixtures and not on single chemicals. It is also true, however, that humans have learned to cope with exposure to huge numbers of chemicals simultaneously (food, water, air, soil, and consumer products). Therefore, in view of limited resources for toxicological research, the focus in toxicology should be

  6. Adaptation of distortion product otoacoustic emissions predicts susceptibility to acoustic over-exposure in alert rabbits.

    PubMed

    Luebke, Anne E; Stagner, Barden B; Martin, Glen K; Lonsbury-Martin, Brenda L

    2014-04-01

    A noninvasive test was developed in rabbits based on fast adaptation measures for 2f1-f2 distortion-product otoacoustic emissions (DPOAEs). The goal was to evaluate the effective reflex activation, i.e., "functional strength," of both the descending medial olivocochlear efferent reflex (MOC-R) and the middle-ear muscle reflex (MEM-R) through sound activation. Classically, it is assumed that both reflexes contribute toward protecting the inner ear from cochlear damage caused by noise exposure. The DP-gram method described here evaluated the MOC-R effect on DPOAE levels over a two-octave (oct) frequency range. To estimate the related activation of the middle-ear muscles (MEMs), the MEM-R was measured by monitoring the level of the f1-primary tone throughout its duration. Following baseline measures, rabbits were subjected to noise over-exposure. A main finding was that the measured adaptive activity was highly variable between rabbits but less so between the ears of the same animal. Also, together, the MOC-R and MEM-R tests showed that, on average, DPOAE adaptation consisted of a combined contribution from both systems. Despite this shared involvement, the amount of DPOAE adaptation measured for a particular animal's ear predicted that ear's subsequent susceptibility to the noise over-exposure for alert but not for deeply anesthetized rabbits. PMID:25234992

  7. How to quantify exposure to traumatic stress? Reliability and predictive validity of measures for cumulative trauma exposure in a post-conflict population

    PubMed Central

    Wilker, Sarah; Pfeiffer, Anett; Kolassa, Stephan; Koslowski, Daniela; Elbert, Thomas; Kolassa, Iris-Tatjana

    2015-01-01

    Background While studies with survivors of single traumatic experiences highlight individual response variation following trauma, research from conflict regions shows that almost everyone develops posttraumatic stress disorder (PTSD) if trauma exposure reaches extreme levels. Therefore, evaluating the effects of cumulative trauma exposure is of utmost importance in studies investigating risk factors for PTSD. Yet, little research has been devoted to evaluate how this important environmental risk factor can be best quantified. Methods We investigated the retest reliability and predictive validity of different trauma measures in a sample of 227 Ugandan rebel war survivors. Trauma exposure was modeled as the number of traumatic event types experienced or as a score considering traumatic event frequencies. In addition, we investigated whether age at trauma exposure can be reliably measured and improves PTSD risk prediction. Results All trauma measures showed good reliability. While prediction of lifetime PTSD was most accurate from the number of different traumatic event types experienced, inclusion of event frequencies slightly improved the prediction of current PTSD. Conclusions As assessing the number of traumatic events experienced is the least stressful and time-consuming assessment and leads to the best prediction of lifetime PTSD, we recommend this measure for research on PTSD etiology. PMID:26589255

  8. Explicit contextual information selectively contributes to predictive switching of internal models.

    PubMed

    Imamizu, Hiroshi; Sugimoto, Norikazu; Osu, Rieko; Tsutsui, Kiyoka; Sugiyama, Kouichi; Wada, Yasuhiro; Kawato, Mitsuo

    2007-08-01

    Many evidences suggest that the central nervous system (CNS) acquires and switches internal models for adaptive control in various environments. However, little is known about the neural mechanisms responsible for the switching. A recent computational model for simultaneous learning and switching of internal models proposes two separate switching mechanisms: a predictive mechanism purely based on contextual information and a postdictive mechanism based on the difference between actual and predicted sensorimotor feedbacks. This model can switch internal models solely based on contextual information in a predictive fashion immediately after alteration of the environment. Here we show that when subjects simultaneously adapted to alternating blocks of opposing visuomotor rotations, explicit contextual information about the rotations improved the initial performance at block alternations and asymptotic levels of performance within each block but not readaptation speeds. Our simulations using separate switching mechanisms duplicated these effects of contextual information on subject performance and suggest that improvement of initial performance was caused by improved accuracy of the predictive switch while adaptation speed corresponds to a switch dependent on sensorimotor feedback. Simulations also suggested that a slow change in output signals from the switching mechanisms causes contamination of motor commands from an internal model used in the previous context (anterograde interference) and partial destruction of internal models (retrograde interference). Explicit contextual information prevents destruction and assists memory retention by improving the changes in output signals. Thus, the asymptotic levels of performance improved. PMID:17437093

  9. Predicting human exposure and risk from chlorinated indoor swimming pool: a case study.

    PubMed

    Chowdhury, Shakhawat

    2015-08-01

    This study predicted human exposure to disinfection by-products (DBPs) in a chlorinated indoor swimming pool. Human exposure was predicted through ingestion, inhalation, and dermal routes while ingestion exposure was accidental with water intake of 18-34 mL/h. The number of pool attendants and duration and frequency of swimming were in the ranges of 14-62 persons/day, 40-85 min/event, and 26-48 times/year, respectively. Trihalomethanes (THMs) in pool water and air were 28.7-95.5 μg/L and 44.1-133.6 μg/m(3), respectively, while haloacetic acids (HAAs) in pool water were 68.9-158.9 μg/L. The brominated THMs in water and air were 95.4 and 94.3% of total THMs, respectively, while brominated HAAs were 94.4 % of total HAAs. Chronic daily intakes of THMs and HAAs were 2.16 × 10(-5)-3.14 × 10(-3) and 8.4 × 10(-8)-4.6 × 10(-6) mg/kg-day, respectively. The cancer risk from three THMs and two HAAs was 2.46 × 10(-5) with a range of 8.1 × 10(-6)-5.7 × 10(-5), in which THMs contributed 99.6% of total risks. Approximately 99.3% of risks were through inhalation and dermal routes, indicating that the ingestion route may be insignificant. The cancer risks from THMs in swimming pool were 4.06-6.64 times to the cancer risks from THMs in drinking water. PMID:26164734

  10. Characterization of silver nanoparticles in selected consumer products and its relevance for predicting children's potential exposures.

    PubMed

    Tulve, Nicolle S; Stefaniak, Aleksandr B; Vance, Marina E; Rogers, Kim; Mwilu, Samuel; LeBouf, Ryan F; Schwegler-Berry, Diane; Willis, Robert; Thomas, Treye A; Marr, Linsey C

    2015-05-01

    Due to their antifungal, antibacterial, antiviral, and antimicrobial properties, silver nanoparticles (AgNPs) are used in consumer products intended for use by children or in the home. Children may be especially affected by the normal use of consumer products because of their physiological functions, developmental stage, and activities and behaviors. Despite much research to date, children's potential exposures to AgNPs are not well characterized. Our objectives were to characterize selected consumer products containing AgNPs and to use the data to estimate a child's potential non-dietary ingestion exposure. We identified and cataloged 165 consumer products claiming to contain AgNPs that may be used by or near children or found in the home. Nineteen products (textile, liquid, plastic) were selected for further analysis. We developed a tiered analytical approach to determine silver content, form (particulate or ionic), size, morphology, agglomeration state, and composition. Silver was detected in all products except one sippy cup body. Among products in a given category, silver mass contributions were highly variable and not always uniformly distributed within products, highlighting the need to sample multiple areas of a product. Electron microscopy confirmed the presence of AgNPs. Using this data, a child's potential non-dietary ingestion exposure to AgNPs when drinking milk formula from a sippy cup is 1.53 μg Ag/kg. Additional research is needed to understand the number and types of consumer products containing silver and the concentrations of silver in these products in order to more accurately predict children's potential aggregate and cumulative exposures to AgNPs. PMID:25747543

  11. Predicting pulmonary fibrosis in humans after exposure to multi-walled carbon nanotubes (MWCNTs).

    PubMed

    Sharma, Monita; Nikota, Jake; Halappanavar, Sabina; Castranova, Vincent; Rothen-Rutishauser, Barbara; Clippinger, Amy J

    2016-07-01

    The increased production and use of multi-walled carbon nanotubes (MWCNTs) in a diverse array of consumer, medical, and industrial applications have raised concerns about potential human exposure to these materials in the workplace and ambient environments. Inhalation is a primary route of exposure to MWCNTs, and the existing data indicate that they are potentially hazardous to human health. While a 90-day rodent inhalation test (e.g., OECD Test No. 413: subchronic inhalation toxicity: 90-day study or EPA Health Effects Test Guidelines OPPTS 870.3465 90-day inhalation toxicity) is recommended by the U.S. Environmental Protection Agency Office of Pollution Prevention and Toxics for MWCNTs (and other CNTs) if they are to be commercially produced (Godwin et al. in ACS Nano 9:3409-3417, 2015), this test is time and cost-intensive and subject to scientific and ethical concerns. As a result, there has been much interest in transitioning away from studies on animals and moving toward human-based in vitro and in silico models. However, given the multiple mechanisms of toxicity associated with subchronic exposure to inhaled MWCNTs, a battery of non-animal tests will likely be needed to evaluate the key endpoints assessed by the 90-day rodent study. Pulmonary fibrosis is an important adverse outcome related to inhalation exposure to MWCNTs and one that the non-animal approach should be able to assess. This review summarizes the state-of-the-science regarding in vivo and in vitro toxicological methods for predicting MWCNT-induced pulmonary fibrosis. PMID:27215431

  12. External and internal radiation exposure of herbal plants used in Egypt

    NASA Astrophysics Data System (ADS)

    Ahmed, Fawzia; Daif, Manal M.; El-Masry, N. M.; Abo-Elmagd, M.

    2010-01-01

    Herbs in Egypt are imported from different countries and widely used in different forms. Owing to their different origins, the measured radioactivity levels show a broad range. For example, the radium concentrations in the studied herbs ranged from 7.71±0.25 Bq/kg in green tea to 115.08±0.49 Bq/kg in gawafa. 137Cs concentrations were found to be quite different from one herb to another, ranging from below the minimum detectable limit to 12.62±0.42 Bq/kg. Some values are much greater than the UNSCEAR reported values for grain products and vegetables. The external exposure and the uptake of naturally occurring radionuclides were studied in terms of the annual effective absorbed dose and the annual ingestion dose, respectively. The herb store workers are externally exposed due to natural radiation in the herbs. The annual effective absorbed dose was calculated as 282.8 μSv for tilia, a dose which is over half the total annual effective dose due to terrestrial radiation (which is 410 μSv). Thus, it is potentially possible to accumulate excess doses from all herbs in the store which constitute a health hazard to the workers. For internal exposure, assuming a 1 kg/year annual intake for each herb, the annual ingestion doses are lower than the global value and can be further diminished if herbs with lower concentrations of radionuclides are consumed.

  13. HYPOXIC EFFECT ON GROWTH OF PALEOMENETES VULGARIS LARVAE AND OTHER SPECIES: USING CONSTANT EXPOSURE DATA TO PREDICT CYCLIC EXPOSURE RESPONSE

    EPA Science Inventory

    First stage larval marsh grass shrimp, Palaemonetes vulgaris, were exposed to patterns of diurnal, semidiurnal, and constant hypoxia to evaluate effects on growth and to determine if there was a consistent relationship between exposures. A comparison of growth with cyclic exposur...

  14. Model for predicting the effects of laser exposures and eye protection on vision. Interim report, January 1989-January 1990

    SciTech Connect

    Menendez, A.R.; Smith, P.A.

    1990-01-01

    Laser safety standards and eye protection (filters) are designed to limit ocular exposures to prevent retinal lesions, yet eyesafe laser exposures can disrupt vision by causing glare and flashblindness. Protective filters can have opposing effects on vision function. They reduce laser exposures but also reduce task luminance and contrast. Filters alone may interfere with vision and consequently reduce work safety and performance. It is therefore important to be able to predict the effects of both laser exposures and protective filters to assess trade-offs between protection and visual function. This paper briefly reviews the methods, concepts, and experimental database used in our laboratory to predict laser, filter, and laser-plus-filter effects on tasks involving visual detection. The modeling approach uses estimates of the spatial distribution of light in the retinal image of the laser source to predict glare, flashblindness, and retinal lesions. It also considers the non-uniformity of visual abilities across the retina in predicting the impact of a laser exposure of a given size and retinal location. The proposed modeling approach provides a general framework for the interpretation, integration, and application of data from various studies. It has the potential to assess the effects of lasers and eye-protection devices on vision, and to guide visual simulations of the appearance of displays and scenes after laser exposures. The model is far from complete and is complicated by the number of variables affecting laser exposures, vision, and the role of vision in occupational tasks.

  15. Food Emulsifier Glycerin Monostearate Increases Internal Exposure Levels of Six Priority Controlled Phthalate Esters and Exacerbates Their Male Reproductive Toxicities in Rats.

    PubMed

    Gao, Hai-Tao; Xu, Run; Cao, Wei-Xin; Zhou, Xu; Yan, Ye-Hui-Mei; Lu, Lingeng; Xu, Qian; Shen, Yang

    2016-01-01

    Human beings are inevitably exposed to ubiquitous phthalate esters (PAEs). Processed, packaged foods are popular nowadays, in which emulsifiers are frequently added as food additives. It is unclear how emulsifiers affect the bioavailability of ingested PAEs contaminants and their toxicities. The purposes of our study were to explore whether food emulsifier Glycerin Monostearate (GMS) could increase the internal exposure levels of six priority controlled PAEs and affect their reproductive toxicities when male rats are exposed to PAEs mixture (MIXPs). The male rats were exposed to MIXPs by gavage for thirty days in combination with or without given GMS. Phthalate monoesters (MPAEs), primary metabolites of PAEs, in rat urine were used as biomarkers to predict the internal exposure levels of the six PAEs, and their concentrations were determined using UPLC-MS. The reproductive toxicity was evaluated using serum testosterone levels test and histopathology of testes. Results showed that compared to PAEs exposure alone, the internal exposure levels of PAEs increased by 30%-49% in the presence of GMS. PAEs exposure led to the reduction of testosterone level by 23.4%-42.1% in the presence and absence of GMS, respectively, compared to the baseline. Testosterone levels in MIXPs+GMS and DEHP+GMS group were decreased by 9.1% and 13.6%, respectively, compared with MIXPs and DEHP group. Histopathology showed that injuries of testis (deciduous spermatids) were observed, and GMS exacerbated the injuries. The results indicated food emulsifiers chronically taken up might increase safety risks of food PAEs contaminants. PMID:27575856

  16. Food Emulsifier Glycerin Monostearate Increases Internal Exposure Levels of Six Priority Controlled Phthalate Esters and Exacerbates Their Male Reproductive Toxicities in Rats

    PubMed Central

    Gao, Hai-Tao; Xu, Run; Cao, Wei-Xin; Zhou, Xu; Yan, Ye-Hui-Mei; Lu, Lingeng; Xu, Qian; Shen, Yang

    2016-01-01

    Human beings are inevitably exposed to ubiquitous phthalate esters (PAEs). Processed, packaged foods are popular nowadays, in which emulsifiers are frequently added as food additives. It is unclear how emulsifiers affect the bioavailability of ingested PAEs contaminants and their toxicities. The purposes of our study were to explore whether food emulsifier Glycerin Monostearate (GMS) could increase the internal exposure levels of six priority controlled PAEs and affect their reproductive toxicities when male rats are exposed to PAEs mixture (MIXPs). The male rats were exposed to MIXPs by gavage for thirty days in combination with or without given GMS. Phthalate monoesters (MPAEs), primary metabolites of PAEs, in rat urine were used as biomarkers to predict the internal exposure levels of the six PAEs, and their concentrations were determined using UPLC-MS. The reproductive toxicity was evaluated using serum testosterone levels test and histopathology of testes. Results showed that compared to PAEs exposure alone, the internal exposure levels of PAEs increased by 30%-49% in the presence of GMS. PAEs exposure led to the reduction of testosterone level by 23.4%-42.1% in the presence and absence of GMS, respectively, compared to the baseline. Testosterone levels in MIXPs+GMS and DEHP+GMS group were decreased by 9.1% and 13.6%, respectively, compared with MIXPs and DEHP group. Histopathology showed that injuries of testis (deciduous spermatids) were observed, and GMS exacerbated the injuries. The results indicated food emulsifiers chronically taken up might increase safety risks of food PAEs contaminants. PMID:27575856

  17. Spatiotemporal neurodynamics underlying internally and externally driven temporal prediction: a high spatial resolution ERP study.

    PubMed

    Mento, Giovanni; Tarantino, Vincenza; Vallesi, Antonino; Bisiacchi, Patrizia Silvia

    2015-03-01

    Temporal prediction (TP) is a flexible and dynamic cognitive ability. Depending on the internal or external nature of information exploited to generate TP, distinct cognitive and brain mechanisms are engaged with the same final goal of reducing uncertainty about the future. In this study, we investigated the specific brain mechanisms involved in internally and externally driven TP. To this end, we employed an experimental paradigm purposely designed to elicit and compare externally and internally driven TP and a combined approach based on the application of a distributed source reconstruction modeling on a high spatial resolution electrophysiological data array. Specific spatiotemporal ERP signatures were identified, with significant modulation of contingent negative variation and frontal late sustained positivity in external and internal TP contexts, respectively. These different electrophysiological patterns were supported by the engagement of distinct neural networks, including a left sensorimotor and a prefrontal circuit for externally and internally driven TP, respectively. PMID:25203276

  18. Predicting residential exposure to phthalate plasticizer emitted from vinyl flooring: a mechanistic analysis.

    PubMed

    Xu, Ying; Hubal, Elaine A Cohen; Clausen, Per A; Little, John C

    2009-04-01

    A two-room model is developed to estimate the emission rate of di-2-ethylhexyl phthalate (DEHP) from vinyl flooring and the evolving gas-phase and adsorbed surface concentrations in a realistic indoor environment. Because the DEHP emission rate measured in a test chamber may be quite different from the emission rate from the same material in the indoor environment the model provides a convenient means to predict emissions and transport in a more realistic setting. Adsorption isotherms for phthalates and plasticizers on interior surfaces, such as carpet, wood, dust, and human skin, are derived from previous field and laboratory studies. Log-linear relationships between equilibrium parameters and chemical vapor pressure are obtained. The predicted indoor air DEHP concentration at steady state is 0.15 microg/m3. Room 1 reaches steady state within about one year, while the adjacent room reaches steady state about three months later. Ventilation rate has a strong influence on DEHP emission rate while total suspended particle concentration has a substantial impact on gas-phase concentration. Exposure to DEHP via inhalation, dermal absorption, and oral ingestion of dust is evaluated. The model clarifies the mechanisms that govern the release of DEHP from vinyl flooring and the subsequent interactions with interior surfaces, airborne particles, dust, and human skin. Although further model development, parameter identification, and model validation are needed, our preliminary model provides a mechanistic framework that elucidates exposure pathways for phthalate plasticizers, and can most likely be adapted to predict emissions and transport of other semivolatile organic compounds, such as brominated flame retardants and biocides, in a residential environment. PMID:19452889

  19. Media exposure, internalization of the thin ideal, and body dissatisfaction: comparing Asian American and European American college females.

    PubMed

    Nouri, Mahsa; Hill, Laura G; Orrell-Valente, Joan K

    2011-09-01

    Internalization of the thin ideal mediates the media exposure-body dissatisfaction relation in young adult European American females. There is little related research on Asian Americans. We used structural equations modeling to test: (1) whether media exposure was associated with body dissatisfaction in Asian American young adult females, (2) internalization of the thin ideal mediated any such association, and (3) whether the mediational model provided equivalent fit for European American and Asian American samples. Participants were 287 college females (154 Asian Americans, 133 European Americans). Internalization of the thin ideal explained the media exposure-body dissatisfaction association equally well for both groups. Results suggest that Asian Americans may be employing unhealthy weight control behaviors, and may be prone to developing eating disorders, at rates similar to European American young adult females. Clinicians need to screen carefully for body dissatisfaction, unhealthy weight control behaviors, and eating disorders in Asian American females. PMID:21775227

  20. Internalization and re-expression of antigens of human melanoma cells following exposure to monoclonal antibody

    SciTech Connect

    Wang, B.S.; Lumanglas, A.L.; Silva, J.; Ruszala-Mallon, V.; Durr, F.E.

    1987-04-15

    Modulation of the surface membrane of human Sk-Mel-28 melanoma cells by monoclonal antibody (MoAb) 96.5 recognizing p97 determinants was examined using direct radioimmunoassay and indirect fluorescent antibody-staining techniques. It was determined that the majority of /sup 111/In-labeled antibody that remained associated with cells after a 24-hr incubation at 37 degrees C had been internalized because MoAb 96.5 was no longer visible on the cell surface. A second treatment of these cells with the same antibody 24 hr later not only increased the cell-associated radioactivity, reflecting an increase of total antibody bound, but also rendered these cells membrane immunofluorescent again, indicating the re-expression of surface antigens. Autoradiographs of the electrophoretically analyzed membrane components of Sk-Mel-28 cells further demonstrated the appearance of newly synthesized 97-kDa proteins that were immunoprecipitable with MoAb 96.5. Taken together, the present findings suggest that p97 antigens undergo endocytosis in Sk-Mel-28 cells following exposure to MoAb 96.5. However, the same antigens were regenerated and expressed on the cell surface within a period of 24 hr. The re-expression of tumor cell surface antigen following initial internalization of the MoAb-antigen complex may have implications for diagnosis and therapy.

  1. Preliminary studies for the ORganics Exposure in Orbit (OREOcube) Experiment on the International Space Station

    NASA Astrophysics Data System (ADS)

    Alonzo, Jason; Fresneau, A.; Elsaesser, A.; Chan, J.; Breitenbach, A.; Ehrenfreund, P.; Ricco, A.; Salama, F.; Mattioda, A.; Santos, O.; Cottin, H.; Dartois, E.; d'Hendecourt, L.; Demets, R.; Foing, B.; Martins, Z.; Sephton, M.; Spaans, M.; Quinn, R.

    2013-01-01

    Organic compounds that survive in uncommon space environments are an important astrobiology focus. The ORganics Exposure in Orbit (OREOcube) experiment will investigate, in real time, chemical changes in organic compounds exposed to low Earth orbit radiation conditions on an International Space Station (ISS) external platform. OREOcube is packaged as an identical pair of 10-cm cube instruments, each weighing < 2 kg and containing a highly capable UV-Visible-NIR spectrometer, a 24-sample carousel, and integral optics enabling use of the Sun as light source for spectroscopy, along with the electronics, microcontroller, and data storage to make each cube an autonomous stand-alone instrument package requiring only a standard power and data interface. We have characterized the influence of mineralogically relevant inorganic materials on the stability, modification, and degradation of the organic molecules under ground laboratory experimental conditions. The results of our laboratory experiments will be used as the basis for the selection of samples for further investigations on the OREOcube ISS experiment. OREOcube is an international collaboration between the European Space Agency, the National Aeronautics and Space Administration, and University partners.

  2. Monte Carlo and analytical model predictions of leakage neutron exposures from passively scattered proton therapy

    SciTech Connect

    Pérez-Andújar, Angélica; Zhang, Rui; Newhauser, Wayne

    2013-12-15

    Purpose: Stray neutron radiation is of concern after radiation therapy, especially in children, because of the high risk it might carry for secondary cancers. Several previous studies predicted the stray neutron exposure from proton therapy, mostly using Monte Carlo simulations. Promising attempts to develop analytical models have also been reported, but these were limited to only a few proton beam energies. The purpose of this study was to develop an analytical model to predict leakage neutron equivalent dose from passively scattered proton beams in the 100-250-MeV interval.Methods: To develop and validate the analytical model, the authors used values of equivalent dose per therapeutic absorbed dose (H/D) predicted with Monte Carlo simulations. The authors also characterized the behavior of the mean neutron radiation-weighting factor, w{sub R}, as a function of depth in a water phantom and distance from the beam central axis.Results: The simulated and analytical predictions agreed well. On average, the percentage difference between the analytical model and the Monte Carlo simulations was 10% for the energies and positions studied. The authors found that w{sub R} was highest at the shallowest depth and decreased with depth until around 10 cm, where it started to increase slowly with depth. This was consistent among all energies.Conclusion: Simple analytical methods are promising alternatives to complex and slow Monte Carlo simulations to predict H/D values. The authors' results also provide improved understanding of the behavior of w{sub R} which strongly depends on depth, but is nearly independent of lateral distance from the beam central axis.

  3. Attempting to Predict Success in the Qualifying Round of the International Chemistry Olympiad

    ERIC Educational Resources Information Center

    Urhahne, Detlef; Ho, Lok Hang; Parchmann, Ilka; Nick, Sabine

    2012-01-01

    The aim of this study was trying to predict success in the qualifying round for the International Chemistry Olympiad (IChO) on the basis of the expectancy-value model of achievement motivation by Eccles et al. The investigation with 52 participants, including 14 females, was conducted during the third of four qualifying rounds of the IChO in…

  4. Predicting Individuals' Turnover and Internal Transfer Behavior. Wisconsin Working Paper 6-82-31.

    ERIC Educational Resources Information Center

    Taylor, M. Susan; Covaleski, Mark A.

    Researchers have spent considerable time and effort in the last 5 years developing process models to explain individuals' job turnover behavior. To examine the predictability of internal job transfers and turnover behavior from individuals' work values, career plans, and job satisfaction, nurses (N=160) completed questionnaires on demographic…

  5. Extreme Appraisals of Internal States and Bipolar Symptoms: The Hypomanic Attitudes and Positive Predictions Inventory

    ERIC Educational Resources Information Center

    Dodd, Alyson L.; Mansell, Warren; Morrison, Anthony P.; Tai, Sara

    2011-01-01

    The Hypomanic Attitudes and Positive Predictions Inventory (HAPPI; W. Mansell, 2006) was developed to assess multiple, extreme, self-relevant appraisals of internal states. The present study aimed to validate the HAPPI in a clinical sample. Participants (N = 50) with a diagnosis of bipolar disorder (confirmed by a structured clinical interview)…

  6. Prediction of 3D internal organ position from skin surface motion: results from electromagnetic tracking studies

    NASA Astrophysics Data System (ADS)

    Wong, Kenneth H.; Tang, Jonathan; Zhang, Hui J.; Varghese, Emmanuel; Cleary, Kevin R.

    2005-04-01

    An effective treatment method for organs that move with respiration (such as the lungs, pancreas, and liver) is a major goal of radiation medicine. In order to treat such tumors, we need (1) real-time knowledge of the current location of the tumor, and (2) the ability to adapt the radiation delivery system to follow this constantly changing location. In this study, we used electromagnetic tracking in a swine model to address the first challenge, and to determine if movement of a marker attached to the skin could accurately predict movement of an internal marker embedded in an organ. Under approved animal research protocols, an electromagnetically tracked needle was inserted into a swine liver and an electromagnetically tracked guidewire was taped to the abdominal skin of the animal. The Aurora (Northern Digital Inc., Waterloo, Canada) electromagnetic tracking system was then used to monitor the position of both of these sensors every 40 msec. Position readouts from the sensors were then tested to see if any of the movements showed correlation. The strongest correlations were observed between external anterior-posterior motion and internal inferior-superior motion, with many other axes exhibiting only weak correlation. We also used these data to build a predictive model of internal motion by taking segments from the data and using them to derive a general functional relationship between the internal needle and the external guidewire. For the axis with the strongest correlation, this model enabled us to predict internal organ motion to within 1 mm.

  7. Biomarkers of World Trade Center Particulate Matter Exposure: Physiology of distal airway and blood biomarkers that predict FEV1 decline

    PubMed Central

    Weiden, Michael D.; Kwon, Sophia; Caraher, Erin; Berger, Kenneth I.; Reibman, Joan; Rom, William N.; Prezant, David J.; Nolan, Anna

    2016-01-01

    Biomarkers can be important predictors of disease severity and progression. The intense exposure to particulates and other toxins from the destruction of the World Trade Center (WTC) overwhelmed the lung’s normal protective barriers. The Fire Department of New York (FDNY) cohort not only had baseline pre-exposure lung function measures but also had serum samples banked soon after their WTC exposure. This well phenotyped group of highly exposed first responders is an ideal cohort for biomarker discovery and eventual validation. Disease progression was heterogeneous in this group in that some individuals subsequently developed abnormal lung function while others recovered. Airflow obstruction predominated in WTC exposed patients who were symptomatic. Multiple independent disease pathways may cause this abnormal FEV1 after irritant exposure. WTC exposure activates one or more of these pathways causing abnormal FEV1 in an individual. Our hypothesis was that serum biomarkers expressed within 6 months after World Trade Center (WTC) exposure reflect active disease pathways and predict subsequent development or protection from abnormal FEV1predictive biomarkers of WTC-LI. We have identified biomarkers of Inflammation, metabolic derangement, protease/antiprotease balance and vascular injury expressed in serum within 6 months of WTC exposure that were predictive of their FEV1 up to 7 years after their WTC exposure. Predicting future risk of airway injury after particulate exposures can focus monitoring and early treatment on a subset of patients in greatest need of these services. PMID:26024341

  8. Biomarkers of World Trade Center Particulate Matter Exposure: Physiology of Distal Airway and Blood Biomarkers that Predict FEV₁ Decline.

    PubMed

    Weiden, Michael D; Kwon, Sophia; Caraher, Erin; Berger, Kenneth I; Reibman, Joan; Rom, William N; Prezant, David J; Nolan, Anna

    2015-06-01

    Biomarkers can be important predictors of disease severity and progression. The intense exposure to particulates and other toxins from the destruction of the World Trade Center (WTC) overwhelmed the lung's normal protective barriers. The Fire Department of New York (FDNY) cohort not only had baseline pre-exposure lung function measures but also had serum samples banked soon after their WTC exposure. This well-phenotyped group of highly exposed first responders is an ideal cohort for biomarker discovery and eventual validation. Disease progression was heterogeneous in this group in that some individuals subsequently developed abnormal lung function while others recovered. Airflow obstruction predominated in WTC-exposed patients who were symptomatic. Multiple independent disease pathways may cause this abnormal FEV1 after irritant exposure. WTC exposure activates one or more of these pathways causing abnormal FEV1 in an individual. Our hypothesis was that serum biomarkers expressed within 6 months after WTC exposure reflect active disease pathways and predict subsequent development or protection from abnormal FEV1 below the lower limit of normal known as WTC-Lung Injury (WTC-LI). We utilized a nested case-cohort control design of previously healthy never smokers who sought subspecialty pulmonary evaluation to explore predictive biomarkers of WTC-LI. We have identified biomarkers of inflammation, metabolic derangement, protease/antiprotease balance, and vascular injury expressed in serum within 6 months of WTC exposure that were predictive of their FEV1 up to 7 years after their WTC exposure. Predicting future risk of airway injury after particulate exposures can focus monitoring and early treatment on a subset of patients in greatest need of these services. PMID:26024341

  9. Intimate Partner Violence Exposure Predicts PTSD Treatment Engagement and Outcome in Cognitive Processing Therapy

    PubMed Central

    Iverson, Katherine M.; Resick, Patricia A.; Suvak, Michael K.; Walling, Sherry; Taft, Casey T.

    2012-01-01

    Intimate partner violence (IPV) exposure was examined as a predictor of treatment engagement (i.e., starting and completing therapy) and treatment outcome in 150 women taking part in a dismantling study of cognitive processing therapy (CPT) for posttraumatic stress disorder (PTSD; Resick et al., 2008). Results indicate that women in a current intimate relationship with recent IPV (i.e., past year) were less likely to begin treatment relative to women who reported past IPV only or no history of IPV. For women who began treatment, IPV exposure was not predictive of whether or not they completed treatment. Among women who began treatment, the frequency of IPV was associated with treatment outcome such that women who experienced more frequent IPV exhibited larger reductions in PTSD and depression symptoms over the course of treatment, but experienced similar levels of PTSD and depression severity at the 6-month follow-up. Findings highlight the importance of targeting treatment engagement among women who report recent IPV and suggest that women who have experienced frequent IPV respond well to CPT treatment in spite of their IPV experiences. PMID:21496509

  10. Importance of environmental and biomass dynamics in predicting chemical exposure in ecological risk assessment.

    PubMed

    Morselli, Melissa; Semplice, Matteo; De Laender, Frederik; Van den Brink, Paul J; Di Guardo, Antonio

    2015-09-01

    In ecological risk assessment, exposure is generally modelled assuming static conditions, herewith neglecting the potential role of emission, environmental and biomass dynamics in affecting bioavailable concentrations. In order to investigate the influence of such dynamics on predicted bioavailable concentrations, the spatially-resolved dynamic model "ChimERA fate" was developed, incorporating macrophyte and particulate/dissolved organic carbon (POC/DOC) dynamics into a water-sediment system. An evaluation against three case studies revealed a satisfying model performance. Illustrative simulations then highlighted the potential spatio-temporal variability of bioavailable concentrations after a pulsed emission of four chemicals in a system composed of a pond connected to its inflow and outflow streams. Changes in macrophyte biomass and POC/DOC levels caused exposure variations which were up to a factor of 4.5 in time and even more significant (several orders of magnitude) in space, especially for highly hydrophobic chemicals. ChimERA fate thus revealed to be a useful tool to investigate such variations and to identify those environmental and ecological conditions in which risk is expected to be highest. PMID:25967479

  11. Estrogen Metabolism and Exposure in a Genotypic-Phenotypic Model for Breast Cancer Risk Prediction

    PubMed Central

    Crooke, Philip S.; Justenhoven, Christina; Brauch, Hiltrud; Dawling, Sheila; Roodi, Nady; Higginbotham, Kathryn S. P.; Plummer, W. Dale; Schuyler, Peggy A.; Sanders, Melinda E; Page, David L.; Smith, Jeffrey R.; Dupont, William D.; Parl, Fritz F.

    2012-01-01

    Background Current models of breast cancer risk prediction do not directly reflect mammary estrogen metabolism or genetic variability in exposure to carcinogenic estrogen metabolites. Methods We developed a model that simulates the kinetic effect of genetic variants of the enzymes CYP1A1, CYP1B1, and COMT on the production of the main carcinogenic estrogen metabolite, 4-hydroxyestradiol (4-OHE2), expressed as area under the curve metric (4-OHE2-AUC). The model also incorporates phenotypic factors (age, body mass index, hormone replacement therapy, oral contraceptives, family history), which plausibly influence estrogen metabolism and the production of 4-OHE2. We applied the model to two independent, population-based breast cancer case-control groups, the German GENICA study (967 cases, 971 controls) and the Nashville Breast Cohort (NBC; 465 cases, 885 controls). Results In the GENICA study, premenopausal women at the 90th percentile of 4-OHE2-AUC among control subjects had a risk of breast cancer that was 2.30 times that of women at the 10th control 4-OHE2-AUC percentile (95% CI 1.7 – 3.2, P = 2.9 × 10−7). This relative risk was 1.89 (95% CI 1.5 – 2.4, P = 2.2 × 10−8) in postmenopausal women. In the NBC, this relative risk in postmenopausal women was 1.81 (95% CI 1.3 – 2.6, P = 7.6 × 10−4), which increased to 1.83 (95% CI 1.4 – 2.3, P = 9.5 × 10−7) when a history of proliferative breast disease was included in the model. Conclusions The model combines genotypic and phenotypic factors involved in carcinogenic estrogen metabolite production and cumulative estrogen exposure to predict breast cancer risk. Impact The estrogen carcinogenesis-based model has the potential to provide personalized risk estimates. PMID:21610218

  12. Post-Extinction Conditional Stimulus Valence Predicts Reinstatement Fear: Relevance for Long Term Outcomes of Exposure Therapy

    PubMed Central

    Zbozinek, Tomislav D.; Hermans, Dirk; Prenoveau, Jason M.; Liao, Betty; Craske, Michelle G.

    2014-01-01

    Exposure therapy for anxiety disorders is translated from fear conditioning and extinction. While exposure therapy is effective in treating anxiety, fear sometimes returns after exposure. One pathway for return of fear is reinstatement: unsignaled unconditional stimuli following completion of extinction. The present study investigated the extent to which valence of the conditional stimulus (CS+) after extinction predicts return of CS+ fear after reinstatement. Participants (N = 84) engaged in a differential fear conditioning paradigm and were randomized to reinstatement or non-reinstatement. We hypothesized that more negative post-extinction CS+ valence would predict higher CS+ fear after reinstatement relative to non-reinstatement and relative to extinction retest. Results supported the hypotheses and suggest that strategies designed to decrease negative valence of the CS+ may reduce the return of fear via reinstatement following exposure therapy. PMID:24957680

  13. Exposure and food web transfer of pharmaceuticals in ospreys (Pandion haliaetus): Predictive model and empirical data

    USGS Publications Warehouse

    Lazarus, Rebecca; Rattner, Barnett A.; Du, Bowen; McGowan, Peter C.; Blazer, Vicki; Ottinger, Mary Ann

    2015-01-01

    The osprey (Pandion haliaetus) is a well-known sentinel of environmental contamination, yet no studies have traced pharmaceuticals through the water–fish–osprey food web. A screening-level exposure assessment was used to evaluate the bioaccumulation potential of 113 pharmaceuticals and metabolites, and an artificial sweetener in this food web. Hypothetical concentrations in water reflecting “wastewater effluent dominated” or “dilution dominated” scenarios were combined with pH-specific bioconcentration factors (BCFs) to predict uptake in fish. Residues in fish and osprey food intake rate were used to calculate the daily intake (DI) of compounds by an adult female osprey. Fourteen pharmaceuticals and a drug metabolite with a BCF greater than 100 and a DI greater than 20 µg/kg were identified as being most likely to exceed the adult human therapeutic dose (HTD). These 15 compounds were also evaluated in a 40 day cumulative dose exposure scenario using first-order kinetics to account for uptake and elimination. Assuming comparable absorption to humans, the half-lives (t1/2) for an adult osprey to reach the HTD within 40 days were calculated. For 3 of these pharmaceuticals, the estimated t1/2 in ospreys was less than that for humans, and thus an osprey might theoretically reach or exceed the HTD in 3 to 7 days. To complement the exposure model, 24 compounds were quantified in water, fish plasma, and osprey nestling plasma from 7 potentially impaired locations in Chesapeake Bay. Of the 18 analytes detected in water, 8 were found in fish plasma, but only 1 in osprey plasma (the antihypertensive diltiazem). Compared to diltiazem detection rate and concentrations in water (10/12 detects,

  14. International Federation of Gynecology and Obstetrics opinion on reproductive health impacts of exposure to toxic environmental chemicals.

    PubMed

    Di Renzo, Gian Carlo; Conry, Jeanne A; Blake, Jennifer; DeFrancesco, Mark S; DeNicola, Nathaniel; Martin, James N; McCue, Kelly A; Richmond, David; Shah, Abid; Sutton, Patrice; Woodruff, Tracey J; van der Poel, Sheryl Ziemin; Giudice, Linda C

    2015-12-01

    Exposure to toxic environmental chemicals during pregnancy and breastfeeding is ubiquitous and is a threat to healthy human reproduction. There are tens of thousands of chemicals in global commerce, and even small exposures to toxic chemicals during pregnancy can trigger adverse health consequences. Exposure to toxic environmental chemicals and related health outcomes are inequitably distributed within and between countries; universally, the consequences of exposure are disproportionately borne by people with low incomes. Discrimination, other social factors, economic factors, and occupation impact risk of exposure and harm. Documented links between prenatal exposure to environmental chemicals and adverse health outcomes span the life course and include impacts on fertility and pregnancy, neurodevelopment, and cancer. The global health and economic burden related to toxic environmental chemicals is in excess of millions of deaths and billions of dollars every year. On the basis of accumulating robust evidence of exposures and adverse health impacts related to toxic environmental chemicals, the International Federation of Gynecology and Obstetrics (FIGO) joins other leading reproductive health professional societies in calling for timely action to prevent harm. FIGO recommends that reproductive and other health professionals advocate for policies to prevent exposure to toxic environmental chemicals, work to ensure a healthy food system for all, make environmental health part of health care, and champion environmental justice. PMID:26433469

  15. Arsenic, internal cancers, and issues in inference from studies of low-level exposures in human populations

    SciTech Connect

    Cantor, Kenneth P. Lubin, Jay H.

    2007-08-01

    Epidemiologic data from regions of the world with very high levels of arsenic in drinking water (> 150 {mu}g/L) show a strong association between arsenic exposure and risk of several internal cancers. A causal interpretation of the data is warranted based on the strength and consistency of study findings. At lower levels of exposure (< 100 {mu}g/L), in the absence of unambiguous human data, extrapolation from the high-exposure studies has been used to estimate risk. Misclassification of exposure usually results in depressing observed levels of risk, and studies conducted in populations with exposures below 100 {mu}g/L have been limited by the challenge of estimating past exposures, a critically important aspect of studying relative small increases in risk. Relatively small study size contributes to the variability of findings in most studies and makes interpretation of results all the more challenging. The effects on risk estimates of exposure misclassification and small study size under various scenarios are graphically illustrated. Efforts are underway to improve exposure assessment in a large case-control study of bladder cancer in a region of the United States with moderately elevated levels of arsenic in drinking water.

  16. Neonatal hair analysis contribution to establishing a gestational drug exposure profile and predicting a withdrawal syndrome.

    PubMed

    Vinner, Elisabeth; Vignau, Jean; Thibault, Denise; Codaccioni, Xavier; Brassart, Claudie; Humbert, Luc; Lhermitte, Michel

    2003-08-01

    Recently, interest in hair analysis in such fields as drug abuse, driving, or for clinical purposes (determination of drug-exposed neonates especially) has grown because of the highly sensitive method of detection (GC-MS) that can now be applied. Neonates born to drug-addicted mothers can suffer from neonatal withdrawal syndrome (NWS), which requires morphine treatment in its severe forms. To assess and measure toxicologic factors predicting the appearance and the severity of this syndrome, matrices such as urine, meconium, and hair are necessary. Cannabinoids, opiates, cocaine (and its metabolites), and methadone in particular were determined in the various matrices collected in 17 mother/neonate pairs. An immunologic screening method was used, and quantification was achieved with GC-MS. In spite of some bias (color, length, race) that might hinder an accurate interpretation, the results of hair analysis makes it possible to confirm a fetal drug exposure and to reinforce the diagnosis of the NWS observed, particularly when results obtained in other matrices are negative. Hair analysis contributes to our ability to predict a NWS. PMID:12883224

  17. ESTIMATION OF INTERNAL EXPOSURE TO URANIUM WITH UNCERTAINTY FROM URINALYSIS DATA USING THE InDEP COMPUTER CODE

    PubMed Central

    Anderson, Jeri L.; Apostoaei, A. Iulian; Thomas, Brian A.

    2015-01-01

    The National Institute for Occupational Safety and Health (NIOSH) is currently studying mortality in a cohort of 6409 workers at a former uranium processing facility. As part of this study, over 220 000 urine samples were used to reconstruct organ doses due to internal exposure to uranium. Most of the available computational programs designed for analysis of bioassay data handle a single case at a time, and thus require a significant outlay of time and resources for the exposure assessment of a large cohort. NIOSH is currently supporting the development of a computer program, InDEP (Internal Dose Evaluation Program), to facilitate internal radiation exposure assessment as part of epidemiological studies of both uranium- and plutonium-exposed cohorts. A novel feature of InDEP is its batch processing capability which allows for the evaluation of multiple study subjects simultaneously. InDEP analyses bioassay data and derives intakes and organ doses with uncertainty estimates using least-squares regression techniques or using the Bayes’ Theorem as applied to internal dosimetry (Bayesian method). This paper describes the application of the current version of InDEP to formulate assumptions about the characteristics of exposure at the study facility that were used in a detailed retrospective intake and organ dose assessment of the cohort. PMID:22683620

  18. Adolescent Anabolic/Androgenic Steroids: Aggression and Anxiety During Exposure Predict Behavioral Responding During Withdrawal in Syrian Hamsters (Mesocricetus auratus)

    PubMed Central

    Ricci, Lesley A.; Morrison, Thomas R.; Melloni, Richard H.

    2014-01-01

    In the U.S. and worldwide anabolic/androgenic steroid use remains high in the adolescent population. This is concerning given that anabolic/androgenic steroid use is associated with a higher incidence of aggressive behavior during exposure and anxiety during withdrawal. This study uses pubertal Syrian hamsters (Mesocricetus auratus) to investigate the hypothesis that an inverse behavioral relationship exists between anabolic/androgenic steroid-induced aggression and anxiety across adolescent exposure and withdrawal. In the first experiment, we examined aggression and anxiety during adolescent anabolic/androgenic steroid exposure and withdrawal. Adolescent anabolic/androgenic steroid administration produced significant increases in aggression and decreases in anxiety during the exposure period followed by significant decreases in aggression and increases in anxiety during anabolic/androgenic steroid withdrawal. In a second experiment, anabolic/androgenic steroid exposed animals were separated into groups based on their aggressive response during the exposure period and then tested for anxiety during exposure and then for both aggression and anxiety during withdrawal. Data were analyzed using a within subjects repeated measures predictive analysis. Linear regression analysis revealed that the difference in aggressive responding between the anabolic/androgenic steroid exposure and withdrawal periods was a significant predictor of differences in anxiety for both days of testing. Moreover, the combined data suggest that the decrease in aggressive behavior from exposure to withdrawal predicts an increase in anxiety-like responding within these same animals during this time span. Together these findings indicate that early anabolic/androgenic steroid exposure has potent aggression- and anxiety- eliciting effects and that these behavioral changes occur alongside a predictive relationship that exists between these two behaviors over time. PMID:24126136

  19. Justification of diagnostic medical exposures: some practical issues. Report of an International Atomic Energy Agency Consultation

    PubMed Central

    Malone, J; Guleria, R; Craven, C; Horton, P; Järvinen, H; Mayo, J; O’reilly, G; Picano, E; Remedios, D; Le Heron, J; Rehani, M; Holmberg, O; Czarwinski, R

    2012-01-01

    Objectives The Radiation Protection of Patients Unit of the International Atomic Energy Agency (IAEA) is concerned about the effectiveness of justification of diagnostic medical exposures. Recent published work and the report of an initial IAEA consultation in the area gave grounds for such concerns. There is a significant level of inappropriate usage, and, in some cases, a poor level of awareness of dose and risk among some key groups involved. This article aims to address this. Methods The IAEA convened a second group of experts in November 2008 to review practical and achievable actions that might lead to more effective justification. Results This report summarises the matters that this group considered and the outcome of their deliberations. There is a need for improved communication, both within professions and between professionals on one hand, and between professionals and the patients/public on the other. Coupled with this, the issue of consent to imaging procedures was revisited. The need for good evidence-based referral guidelines or criteria of acceptability was emphasised, as was the need for their global adaptation and dissemination. Conclusion Clinical audit was regarded as a key tool in ensuring that justification becomes an effective, transparent and accountable part of normal radiological practice. In summary, justification would be facilitated by the “3 As”: awareness, appropriateness and audit. PMID:21343316

  20. Waste incineration: estimation of the workers' internal exposure to PCB, PAH chlorophenols and other relevant agents

    NASA Astrophysics Data System (ADS)

    Angerer, Juergen; Heinzow, B.; Reimann, D. O.; Knorz, W.; Lehnert, G.

    1993-03-01

    Fifty-four persons occupied in a municipal waste incinerator were examined with respect to their internal exposure to organic substances which are possibly produced during pyrolysis of organic matter. For this purpose the levels of benzene of blood, polychlorinated biphenyls (PCB) and hexachlorobenzene (HCB) in plasma as well as mono- (MCP), di- (DCP), tri- (TCP), tetra- (TECP) and pentachlorophenols (PCP) and hydroxypyrene in urine have been determined. Four hundred thirty-one men and women were examined for control purposes. Statistical significantly higher values for the workers were found for the excretion of hydroxypyrene 2,5/2,4-DCP, 2,4,5 TCP, and for the HCB level in plasma. For the concentrations of 4-MCP and 2,3,4,6-2,3,5,6-TECP the controls had significantly higher concentrations in urine than the workers in the incineration plant. No significant differences between workers and controls were detected with respect to benzene in blood, 2,4,6-TCP and PCP in urine, and to the levels of PCP congeners in plasma. The elevated levels of hydroxypyrene, 2,4-/2,5 DCP, 2,4,5-TCP, and HCB in biological material may be related to the incineration of the waste. These elevations, however, are very small and attract attention more from the environmental than from the occupational point of view.

  1. Monte Carlo and analytical model predictions of leakage neutron exposures from passively scattered proton therapy

    PubMed Central

    Pérez-Andújar, Angélica; Zhang, Rui; Newhauser, Wayne

    2013-01-01

    Purpose: Stray neutron radiation is of concern after radiation therapy, especially in children, because of the high risk it might carry for secondary cancers. Several previous studies predicted the stray neutron exposure from proton therapy, mostly using Monte Carlo simulations. Promising attempts to develop analytical models have also been reported, but these were limited to only a few proton beam energies. The purpose of this study was to develop an analytical model to predict leakage neutron equivalent dose from passively scattered proton beams in the 100-250-MeV interval. Methods: To develop and validate the analytical model, the authors used values of equivalent dose per therapeutic absorbed dose (H/D) predicted with Monte Carlo simulations. The authors also characterized the behavior of the mean neutron radiation-weighting factor, \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\overline {w_R }\\end{document}wR¯, as a function of depth in a water phantom and distance from the beam central axis. Results: The simulated and analytical predictions agreed well. On average, the percentage difference between the analytical model and the Monte Carlo simulations was 10% for the energies and positions studied. The authors found that \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} \\overline {w_R }\\end{document}wR¯ was highest at the shallowest depth and decreased with depth until around 10 cm, where it started to increase slowly with depth. This was consistent among all energies. Conclusion: Simple analytical methods are promising alternatives to complex and slow Monte Carlo simulations

  2. International scale implementation of the CNOSSOS-EU road traffic noise prediction model for epidemiological studies.

    PubMed

    Morley, D W; de Hoogh, K; Fecht, D; Fabbri, F; Bell, M; Goodman, P S; Elliott, P; Hodgson, S; Hansell, A L; Gulliver, J

    2015-11-01

    The EU-FP7-funded BioSHaRE project is using individual-level data pooled from several national cohort studies in Europe to investigate the relationship of road traffic noise and health. The detailed input data (land cover and traffic characteristics) required for noise exposure modelling are not always available over whole countries while data that are comparable in spatial resolution between different countries is needed for harmonised exposure assessment. Here, we assess the feasibility using the CNOSSOS-EU road traffic noise prediction model with coarser input data in terms of model performance. Starting with a model using the highest resolution datasets, we progressively introduced lower resolution data over five further model runs and compared noise level estimates to measurements. We conclude that a low resolution noise model should provide adequate performance for exposure ranking (Spearman's rank = 0.75; p < 0.001), but with relatively large errors in predicted noise levels (RMSE = 4.46 dB(A)). PMID:26232738

  3. Impacts of stage-specific acute pesticide exposure on predicted population structure of the soft-shell clam, Mya arenaria.

    PubMed

    Lindsay, S; Chasse, J; Butler, R A; Morrill, W; Van Beneden, R J

    2010-07-01

    A combined laboratory and modeling approach was used to assess the impact of selected pesticides on early life stages of the soft-shell clam, Mya arenaria. Clams were exposed for 24h as veligers or pediveligers to the broad-spectrum herbicide hexazinone [3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1h,3h)-dione; Velpar], the phenoxyacetic acid herbicide, 2,4-D (2,4-dichlorophenoxyacetic acid; Agway Super BK 32), or phosmet (Imidan). In addition, juvenile clams were exposed for 24h to 2,4-D and their growth monitored for 21 months. Laboratory experiments indicated veligers were more sensitive to acute pesticide exposure than pediveligers, with 2,4-D exposed veligers exhibiting the lowest survival among all treatments. Relative to controls, juvenile clams exposed to 0.5 ppm 2,4-D had enhanced survival following the initial 3 months of grow out. Juveniles exposed to 0.5, 5 and 10 ppm 2,4-D showed an initial growth delay relative to control clams, but at 21 months post-exposure these clams were significantly larger than control clams. Data from the larval and juvenile exposures were used to generate a stage-specific matrix model to predict the effect of pesticide exposure on clam populations. Impacts on simulated clam populations varied with the pesticide and stage exposed. For example, 2,4-D exposure of veligers and pediveligers significantly reduced predicted recruitment as well as population growth rate compared to controls, but juvenile exposure to 2,4-D did not significantly reduce population growth rate. With the exception of veligers exposed to 10 ppm, hexazinone exposure at the both veliger and pediveliger stages significantly reduced predicted recruitment success compared to 0 ppm controls. Hexazinone exposure also reduced modeled population growth rates, but these reductions were only slight in the pediveliger exposure simulations. Veliger and pediveliger exposure to phosmet reduced modeled population growth rate in a dose-dependent fashion

  4. Impacts of stage-specific acute pesticide exposure on predicted population structure of the soft-shell clam, Mya arenaria

    PubMed Central

    Lindsay, S.; Chasse, J.; Butler, R.A.; Morrill, W.; Van Beneden, R.J.

    2010-01-01

    A combined laboratory and modeling approach was used to assess the impact of selected pesticides on early life stages of the soft-shell clam, Mya arenaria. Clams were exposed for 24 h as veligers or pediveligers to the broad-spectrum herbicide hexazinone [3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4 (1h,3h)-dione; (Velpar®)], the phenoxyacetic acid herbicide, 2,4-D (2,4- dichlorophenoxyacetic acid; Agway® Super BK 32), or phosmet (Imidan®). In addition, juvenile clams were exposed for 24 h to 2,4-D and their growth monitored for 21 months. Laboratory experiments indicated veligers were more sensitive to acute pesticide exposure than pediveligers, with 2,4-D exposed veligers exhibiting the lowest survival among all treatments. Relative to controls, juvenile clams exposed to 0.5 ppm 2,4-D had enhanced survival following the initial 3 months of grow out. Juveniles exposed to 0.5 ppm, 5 ppm and 10 ppm 2,4-D showed an initial growth delay relative to control clams, but at 21 months post exposure these clams were significantly larger than control clams. Data from the larval and juvenile exposures were used to generate a stage-specific matrix model to predict the effect of pesticide exposure on clam populations. Impacts on simulated clam populations varied with the pesticide and stage exposed. For example, 2,4-D exposure of veligers and pediveligers significantly reduced predicted recruitment as well as population growth rate compared to controls, but juvenile exposure to 2,4-D did not significantly reduce population growth rate. With the exception of veligers exposed to 10 ppm, hexazinone exposure at the both veliger and pediveliger stages significantly reduced predicted recruitment success compared to 0 ppm controls. Hexazinone exposure also reduced modeled population growth rates, but these reductions were only slight in the pediveliger exposure simulations. Veliger and pediveliger exposure to phosmet reduced modeled population growth rate in a dose

  5. Interfacial shear modeling and flow predictions for internal film condesation flows

    NASA Technical Reports Server (NTRS)

    Narain, A.

    1992-01-01

    Internal flow of pure vapor experiencing film condesation on the walls of a straight duct is studied. The commonly occuring case of turbulent (or laminar) vapor flow in the core and laminar flow of the liquid condensate-with or without waves on the interface-is emphasized. We propose and implement a new first principle methodolgy which model interfacial shear with the help of reliable experimental data on heat transfer rates. Other details of the flow are predicted with the help of this model. These predictions are shown to be in agreement with relevant experimental data. Correlations for film thickness and heat transfer rates are also given.

  6. The Relative Contribution of Internal and Model Variabilities to the Uncertainty in Decadal Climate Predictions

    NASA Astrophysics Data System (ADS)

    Strobach, Ehud; Bel, Golan

    2016-04-01

    Decadal climate predictions, which are initialized with observed conditions, are characterized by two main sources of uncertainties--internal and model variabilities. The former is due to the sensitivity of the models to the initial conditions, and the latter is due to the different predictions of different models. There is not much that can be done to reduce the internal variability; however, there are several methods for reducing the model variability--for example, using an ensemble weighted according to the past performance of the models rather than an equally weighted ensemble. Quantifying the contribution of each of these sources can help in assessing the potential reduction of the total uncertainty of these climate predictions. We used an ensemble of climate model simulations, from the CMIP5 decadal experiments, that includes different climate models and several initializations for each of the models, to analyze the uncertainties on a decadal time scale. Time series of the monthly and annual means of the surface temperature and wind components were established for the variability analysis. The analysis focused on the contributions of the internal and model variabilities and the total uncertainty. We found that different definitions of the anomaly resulted in different conclusions regarding the variability of the ensemble. However, some features of the uncertainty were common to all the anomalies we considered. In particular, we found that (i) over decadal time scales, there is no considerable increase in the uncertainty with time; (ii) the model variability is more sensitive to the annual cycle than the internal variability (this, in turn, results in a maximal uncertainty during the winter in the northern hemisphere); (iii) the uncertainty of the surface temperature prediction is dominated by the model variability, whereas the uncertainty of the surface wind components is determined by both the model and the internal variabilities. Analysis of the spatial

  7. Incorporating High-Throughput Exposure Predictions with Dosimetry-Adjusted In Vitro Bioactivity to Inform Chemical Toxicity Testing

    EPA Science Inventory

    We previously integrated dosimetry and exposure with high-throughput screening (HTS) to enhance the utility of ToxCast™ HTS data by translating in vitro bioactivity concentrations to oral equivalent doses (OEDs) required to achieve these levels internally. These OEDs were compare...

  8. An internal model of head kinematics predicts the influence of head orientation on reflexive eye movements

    NASA Astrophysics Data System (ADS)

    Zupan, L. H.; Merfeld, D. M.

    2005-09-01

    Our sense of self-motion and self-orientation results from combining information from different sources. We hypothesize that the central nervous system (CNS) uses internal models of the laws of physics to merge cues provided by different sensory systems. Different models that include internal models have been proposed; we focus herein on that referred to as the sensory weighting model (Zupan et al 2002 Biol. Cybern. 86 209-30). For simplicity, we isolate the portion of the sensory weighting model that estimates head angular velocity: it includes an inverse internal model of head kinematics and an 'idiotropic' vector aligned with the main body axis. Following a post-rotatory tilt in the dark, which is a rapid tilt following a constant-velocity rotation about an earth-vertical axis, the inverse internal model is applied to conflicting vestibular signals. Consequently, the CNS computes an inaccurate estimate of head angular velocity that shifts toward alignment with an estimate of gravity. Since reflexive eye movements known as vestibulo-ocular reflexes (VOR) compensate for this estimate of head angular velocity, the model predicts that the VOR rotation axis shifts toward alignment with this estimate of gravity and that the VOR time constant depends on final head orientation. These predictions are consistent with experimental data.

  9. An internal model of head kinematics predicts the influence of head orientation on reflexive eye movements.

    PubMed

    Zupan, L H; Merfeld, D M

    2005-09-01

    Our sense of self-motion and self-orientation results from combining information from different sources. We hypothesize that the central nervous system (CNS) uses internal models of the laws of physics to merge cues provided by different sensory systems. Different models that include internal models have been proposed; we focus herein on that referred to as the sensory weighting model. For simplicity, we isolate the portion of the sensory weighting model that estimates head angular velocity: it includes an inverse internal model of head kinematics and an 'idiotropic' vector aligned with the main body axis. Following a post-rotatory tilt in the dark, which is a rapid tilt following a constant-velocity rotation about an earth-vertical axis, the inverse internal model is applied to conflicting vestibular signals. Consequently, the CNS computes an inaccurate estimate of head angular velocity that shifts toward alignment with an estimate of gravity. Since reflexive eye movements known as vestibulo-ocular reflexes (VOR) compensate for this estimate of head angular velocity, the model predicts that the VOR rotation axis shifts toward alignment with this estimate of gravity and that the VOR time constant depends on final head orientation. These predictions are consistent with experimental data. PMID:16135883

  10. Predicting the Match Outcome in One Day International Cricket Matches, while the Game is in Progress

    PubMed Central

    Bailey, Michael; Clarke, Stephen R.

    2006-01-01

    Millions of dollars are wagered on the outcome of one day international (ODI) cricket matches, with a large percentage of bets occurring after the game has commenced. Using match information gathered from all 2200 ODI matches played prior to January 2005, a range of variables that could independently explain statistically significant proportions of variation associated with the predicted run totals and match outcomes were created. Such variables include home ground advantage, past performances, match experience, performance at the specific venue, performance against the specific opposition, experience at the specific venue and current form. Using a multiple linear regression model, prediction variables were numerically weighted according to statistical significance and used to predict the match outcome. With the use of the Duckworth-Lewis method to determine resources remaining, at the end of each completed over, the predicted run total of the batting team could be updated to provide a more accurate prediction of the match outcome. By applying this prediction approach to a holdout sample of matches, the efficiency of the “in the run ”wagering market could be assessed. Preliminary results suggest that the market is prone to overreact to events occurring throughout the course of the match, thus creating brief inefficiencies in the wagering market. Key Points In excess of 80% of monies wagered on the outcome of ODI matches are placed after the match has commenced. Using all past data from ODI matches, multiple linear regression models are constructed to predict team totals and margin of victory. By combining match information with prediction models, an ‘in the run’ prediction process is created for ODI matches. PMID:24357940

  11. International Low-Earth-Orbit Spacecraft Materials Test Program Initiated for Better Prediction of Durability and Performance

    NASA Technical Reports Server (NTRS)

    Rutledge, Sharon K.

    1999-01-01

    Spacecraft in low Earth orbit (LEO) are subjected to many components of the environment, which can cause them to degrade much more rapidly than intended and greatly shorten their functional life. The atomic oxygen, ultraviolet radiation, and cross contamination present in LEO can affect sensitive surfaces such as thermal control paints, multilayer insulation, solar array surfaces, and optical surfaces. The LEO Spacecraft Materials Test (LEO-SMT) program is being conducted to assess the effects of simulated LEO exposure on current spacecraft materials to increase understanding of LEO degradation processes as well as to enable the prediction of in-space performance and durability. Using ground-based simulation facilities to test the durability of materials currently flying in LEO will allow researchers to compare the degradation evidenced in the ground-based facilities with that evidenced on orbit. This will allow refinement of ground laboratory test systems and the development of algorithms to predict the durability and performance of new materials in LEO from ground test results. Accurate predictions based on ground tests could reduce development costs and increase reliability. The wide variety of national and international materials being tested represent materials being functionally used on spacecraft in LEO. The more varied the types of materials tested, the greater the probability that researchers will develop and validate predictive models for spacecraft long-term performance and durability. Organizations that are currently participating in the program are ITT Research Institute (USA), Lockheed Martin (USA), MAP (France), SOREQ Nuclear Research Center (Israel), TNO Institute of Applied Physics (The Netherlands), and UBE Industries, Ltd. (Japan). These represent some of the major suppliers of thermal control and sensor materials currently flying in LEO. The participants provide materials that are exposed to selected levels of atomic oxygen, vacuum ultraviolet

  12. Childhood trauma predicts antidepressant response in adults with major depression: data from the randomized international study to predict optimized treatment for depression.

    PubMed

    Williams, L M; Debattista, C; Duchemin, A-M; Schatzberg, A F; Nemeroff, C B

    2016-01-01

    Few reliable predictors indicate which depressed individuals respond to antidepressants. Several studies suggest that a history of early-life trauma predicts poorer response to antidepressant therapy but results are variable and limited in adults. The major goal of the present study was to evaluate the role of early-life trauma in predicting acute response outcomes to antidepressants in a large sample of well-characterized patients with major depressive disorder (MDD). The international Study to Predict Optimized Treatment for Depression (iSPOT-D) is a randomized clinical trial with enrollment from December 2008 to January 2012 at eight academic and nine private clinical settings in five countries. Patients (n=1008) meeting DSM-IV criteria for MDD and 336 matched healthy controls comprised the study sample. Six participants withdrew due to serious adverse events. Randomization was to 8 weeks of treatment with escitalopram, sertraline or venlafaxine with dosage adjusted by the participant's treating clinician per routine clinical practice. Exposure to 18 types of traumatic events before the age of 18 was assessed using the Early-Life Stress Questionnaire. Impact of early-life stressors-overall trauma 'load' and specific type of abuse-on treatment outcomes measures: response: (⩾50% improvement on the 17-item Hamilton Rating Scale for Depression, HRSD17 or on the 16-item Quick Inventory of Depressive Symptomatology-Self-Rated, QIDS_SR16) and remission (score ⩽7 on the HRSD17 and ⩽5 on the QIDS_SR16). Trauma prevalence in MDD was compared with controls. Depressed participants were significantly more likely to report early-life stress than controls; 62.5% of MDD participants reported more than two traumatic events compared with 28.4% of controls. The higher rate of early-life trauma was most apparent for experiences of interpersonal violation (emotional, sexual and physical abuses). Abuse and notably abuse occurring at ⩽7 years of age predicted poorer outcomes

  13. Prediction of noise levels and annoyance from aircraft run-ups at Vancouver International Airport.

    PubMed

    Scherebnyj, Katrina; Hodgson, Murray

    2007-10-01

    Annoyance complaints resulting from engine run-ups have been increasing at Vancouver International Airport for several years. To assist the Airport in managing run-up noise levels, a prediction tool based on a Green's function parabolic equation (GFPE) model has been consolidated, evaluated, and applied. It was extended to include more realistic atmospheric and ground input parameters. Measurements were made of the noise-radiation characteristics of a CRJ200 jet aircraft. The GFPE model was validated by comparing predictions with results in the literature. A sensitivity analysis showed that predicted levels are relatively insensitive to small variations in geometry and ground impedance, but relatively sensitive to variations in wind speed, atmosphere type, and aircraft heading and power setting. Predicted noise levels were compared with levels measured at noise monitoring terminals. For the four cases for which all input information was available, agreement was within 10 dBA. For events for which some information had to be estimated, predictions were within 20 dBA. The predicted annoyance corresponding to the run-up events considered ranged from 1.8% to 9.5% of people awoken, suggesting that noise complaints can be expected. PMID:17902830

  14. An index of prenatal steroid exposure predicts adult face perception skills.

    PubMed

    Leow, Mei Chern; Davis, Greg

    2012-12-01

    Face perception skills are fundamental to social cognition, yet they vary markedly across individuals. This diversity has stimulated controversy over the relative contributions of genetic factors, prenatal environment, and postnatal experience to face perception. Recent twin studies have found that face perception is heritable, highlighting the potential for substantial prenatal determination of these skills. In contrast, previous work on potential influences of the prenatal hormonal environment on social cognition have found no association between 2D:4D, a marker for prenatal androgen exposure, and processing of facial emotional expressions, apparently precluding a major role for prenatal hormones in governing face perception. We propose that substantial predictive relationships between 2D:4D and face perception may have been masked in previous work because the task employed required both face perception and processing of others' emotions, the latter component being greatly influenced by circulating hormones in adults. To assess prenatal hormone influences on face perception without requiring emotion processing, we related 2D:4D to the face inversion effect (FIE), a measure of the recruitment of specialist face processes to visual perception. The magnitude of the resulting predictive relationship (r = .52) compared surprisingly well with that found between identical twins' face perception (rs = .27-.61), suggesting that mechanisms of 2D:4D may account for a substantial proportion of perinatal influences on face processing. Furthermore, we employed 2D:4D as a common scale to map individual differences in the FIE onto prenatal testosterone:estrogen ratios, assayed by Lutchmaya, Baron-Cohen, Raggatt, Knickmeyer, and Manning (Early Human Development 77:23-28, 2004). The substantial overlap between the two data sets further implicates prenatal steroids in adult face perception skills. PMID:23011910

  15. Perception of affordances during long-term exposure to weightlessness in the International Space station.

    PubMed

    Bourrelly, Aurore; McIntyre, Joseph; Luyat, Marion

    2015-09-01

    On Earth, visual eye height (VEH)--the distance from the observer's line of gaze to the ground in the visual scene--constitutes an effective cue in perceiving affordance such as the passability through apertures, based on the assumption that one's feet are on the ground. In the present study, we questioned whether an observer continues to use VEH to estimate the width of apertures during long-term exposure to weightlessness, where contact with the floor is not required. Ten astronauts were tested in preflight, inflight in the International Space Station, and postflight sessions. They were asked to adjust the opening of a virtual doorway displayed on a laptop device until it was perceived to be just wide enough to pass through (i.e., the critical aperture). We manipulated VEH by raising and lowering the level of the floor in the visual scene. We observed an effect of VEH manipulation on the critical aperture. When VEH decreased, the critical aperture decreased too, suggesting that widths relative to the body were perceived to be larger when VEH was smaller. There was no overall significant session effect, but the analysis of between-subjects variability revealed two participant profile groups. The effect of weightlessness was different for these two groups even though the VEH strategy remained operational during spaceflight. This study shows that the VEH strategy appears to be very robust and can be used, if necessary, in inappropriate circumstances such as free-floating, perhaps promoted by the nature of the visual scene. PMID:26224263

  16. Parental occupational pesticide exposure and the risk of childhood leukemia in the offspring: Findings from the Childhood Leukemia International Consortium

    PubMed Central

    Bailey, Helen D; Fritschi, Lin; Infante-Rivard, Claire; Glass, Deborah C; Miligi, Lucia; Dockerty, John D; Lightfoot, Tracy; Clavel, Jacqueline; Roman, Eve; Spector, Logan G; Kaatsch, Peter; Metayer, Catherine; Magnani, Corrado; Milne, Elizabeth; Polychronopoulou, Sophia; Simpson, Jill; Rudant, Jérémie; Sidi, Vasiliki; Rondelli, Roberto; Orsi, Laurent; Kang, Alice; Petridou, Eleni; Schüz, Joachim

    2014-01-01

    Maternal occupational pesticide exposure during pregnancy and/or paternal occupational pesticide exposure around conception have been suggested to increase risk of leukemia in the offspring. With a view to providing insight in this area we pooled individual level data from 13 case-control studies participating in the Childhood Leukemia International Consortium (CLIC). Occupational data were harmonized to a compatible format. Pooled individual analyses were undertaken using unconditional logistic regression. Using exposure data from mothers of 8,236 cases, and 14,850 controls, and from fathers of 8,169 cases and 14,201 controls the odds ratio (OR) for maternal exposure during pregnancy and the risk of acute lymphoblastic leukemia (ALL) was 1.01 (95% confidence interval (CI) 0.78, 1.30) and for paternal exposure around conception 1.20 (95% 1.06, 1.38). For acute myeloid leukemia (AML), the OR for maternal exposure during pregnancy was 1.94 (CI 1.19, 3.18) and for paternal exposure around conception 0.91 (CI 0.66, 1.24.) based on data from 1,329 case and 12,141 control mothers, and 1,231 case and 11,383 control fathers. Our finding of a significantly increased risk of AML in the offspring with maternal exposure to pesticides during pregnancy is consistent with previous reports. We also found a slight increase in risk of ALL with paternal exposure around conception which appeared to be more evident in children diagnosed at the age of five years or more and those with T cell ALL which raises interesting questions on possible mechanisms. PMID:24700406

  17. Exposure prediction approaches used in air pollution epidemiology studies: Keyfindings and future recommendations

    EPA Science Inventory

    Many epidemiologic studies of the health effects of exposure to ambient air pollution use measurements from central-site monitors as their exposure estimate. However, measurements from central-site monitors may lack the spatial and temporal resolution required to capture exposure...

  18. The influence of physicochemical properties on the internal dose of trihalomethanes in humans following a controlled showering exposure.

    PubMed

    Silva, Lalith K; Backer, Lorraine C; Ashley, David L; Gordon, Sydney M; Brinkman, Marielle C; Nuckols, John R; Wilkes, Charles R; Blount, Benjamin C

    2013-01-01

    Although disinfection of domestic water supply is crucial for protecting public health from waterborne diseases, this process forms potentially harmful by-products, such as trihalomethanes (THMs). We evaluated the influence of physicochemical properties of four THMs (chloroform, bromodichloromethane, dibromochloromethane, and bromoform) on the internal dose after showering. One hundred volunteers showered for 10 min in a controlled setting with fixed water flow, air flow, and temperature. We measured THMs in shower water, shower air, bathroom air, and blood samples collected at various time intervals. The geometric mean (GM) for total THM concentration in shower water was 96.2 μg/l. The GM of total THM in air increased from 5.8 μg/m(3) pre shower to 351 μg/m(3) during showering. Similarly, the GM of total-blood THM concentration increased from 16.5 ng/l pre shower to 299 ng/l at 10 min post shower. THM levels were significantly correlated between different matrices (e.g. dibromochloromethane levels) in water and air (r=0.941); blood and water (r=0.845); and blood and air (r=0.831). The slopes of best-fit lines for THM levels in water vs air and blood vs air increased with increasing partition coefficient of water/air and blood/air. The slope of the correlation plot of THM levels in water vs air decreased in a linear (r=0.995) fashion with increasing Henry's law constant. The physicochemical properties (volatility, partition coefficients, and Henry's law constant) are useful parameters for predicting THM movement between matrices and understanding THM exposure during showering. PMID:22829048

  19. Internal migration and urbanization in China: impacts on population exposure to household air pollution (2000-2010).

    PubMed

    Aunan, Kristin; Wang, Shuxiao

    2014-05-15

    Exposure to fine particles ≤ 2.5 μm in aerodynamic diameter (PM2.5) from incomplete combustion of solid fuels in household stoves, denoted household air pollution (HAP), is a major contributor to ill health in China and globally. Chinese households are, however, undergoing a massive transition to cleaner household fuels. The objective of the present study is to establish the importance of internal migration when it comes to the changing household fuel use pattern and the associated exposure to PM2.5 for the period 2000 to 2010. We also estimate health benefits of the fuel transition in terms of avoided premature deaths. Using China Census data on population, migration, and household fuel use for 2000 and 2010 we identify the size, place of residence, and main cooking fuel of sub-populations in 2000 and 2010, respectively. We combine these data with estimated exposure levels for the sub-populations and estimate changes in population exposure over the decade. We find that the population weighted exposure (PWE) for the Chinese population as a whole was reduced by 52 (36-70) μg/m(3) PM2.5 over the decade, and that about 60% of the reduction can be linked to internal migration. During the same period the migrant population, in total 261 million people, was subject to a reduced population weighted exposure (ΔPWE) of 123 (87-165) μg/m(3) PM2.5. The corresponding figure for non-migrants is 34 (23-47) μg/m(3). The largest ΔPWE was estimated for rural-to-urban migrants (138 million people), 214 (154-283) μg/m(3). The estimated annual health benefit associated with the reduced exposure in the total population is 31 (26-37) billion USD, corresponding to 0.4% of the Chinese GDP. PMID:24598149

  20. State-of-the-Science Report on Predictive Models and Modeling Approaches for Characterizing and Evaluating Exposure to Nanomaterials

    EPA Science Inventory

    This state-of-the-science review was undertaken to identify fate and transport models and alternative modeling approaches that could be used to predict exposure to engineered nanomaterials (ENMs) released into the environment, specifically, for aquatic systems. The development of...

  1. Predicting Adaptive Response to Fadrozole Exposure: Computational Model of the Fathead Minnow Hypothalamic-Pituitary-Gonadal Axis

    EPA Science Inventory

    Exposure to endocrine disrupting chemicals can affect reproduction and development in both humans and wildlife. We are developing a mechanistic mathematical model of the hypothalamic-pituitary-gonadal (HPG) axis in female fathead minnows to predict dose-response and time-course (...

  2. Predicting Adaptive Response to Fadrozole Exposure:Computational Model of the Fathead MinnowsHypothalamic-Pituitary-Gonadal Axis

    EPA Science Inventory

    Exposure to endocrine disrupting chemicals can affect reproduction and development in both humans and wildlife. We are developing a mechanistic mathematical model of the hypothalamic-pituitary-gonadal (HPG) axis in female fathead minnows to predict doseresponse and time-course (...

  3. Retrospective Exposure Estimation and Predicted versus Observed Serum Perfluorooctanoic Acid Concentrations for Participants in the C8 Health Project

    PubMed Central

    Vieira, Verónica M.; Ryan, P. Barry; Steenland, Kyle; Bartell, Scott M.

    2011-01-01

    Background: People living or working in eastern Ohio and western West Virginia have been exposed to perfluorooctanoic acid (PFOA) released by DuPont Washington Works facilities. Objectives: Our objective was to estimate historical PFOA exposures and serum concentrations experienced by 45,276 non-occupationally exposed participants in the C8 Health Project who consented to share their residential histories and a 2005–2006 serum PFOA measurement. Methods: We estimated annual PFOA exposure rates for each individual based on predicted calibrated water concentrations and predicted air concentrations using an environmental fate and transport model, individual residential histories, and maps of public water supply networks. We coupled individual exposure estimates with a one-compartment absorption, distribution, metabolism, and excretion (ADME) model to estimate time-dependent serum concentrations. Results: For all participants (n = 45,276), predicted and observed median serum concentrations in 2005–2006 are 14.2 and 24.3 ppb, respectively [Spearman’s rank correlation coefficient (rs) = 0.67]. For participants who provided daily public well water consumption rate and who had the same residence and workplace in one of six municipal water districts for 5 years before the serum sample (n = 1,074), predicted and observed median serum concentrations in 2005–2006 are 32.2 and 40.0 ppb, respectively (rs = 0.82). Conclusions: Serum PFOA concentrations predicted by linked exposure and ADME models correlated well with observed 2005–2006 human serum concentrations for C8 Health Project participants. These individualized retrospective exposure and serum estimates are being used in a variety of epidemiologic studies being conducted in this region. PMID:21813367

  4. Thyroid cancer in the Marshallese: relative risk of short-lived internal emitters and external radiation exposure

    SciTech Connect

    Lessard, E.T.; Brill, A.B.; Adams, W.H.

    1985-01-01

    In a study of the comparative effects of internal versus external irradiation of the thyroid in young people, we determined that the dose from internal irradiation of the thyroid with short-lived internal emitters produced several times less thyroid cancer than did the same dose of radiation given externally. We determined this finding for a group of 85 Marshall Islands children, who were less than 10 years of age at the time of exposure and who were accidentially exposed to internal and external thyroid radiation at an average level of 1400 rad. The external risk coefficient ranged between 2.5 and 4.9 cancers per million person-rad-years at risk, and thus, from our computations, the internal risk coefficient for the Marshallese children was estimated to range between 1.0 and 1.4 cancers per million person-rad-years at risk. In contrast, for individual more than 10 years of age at the time of exposure, the dose from internal irradiation of the thyroid with short-lived internal emitters produced several times more thyroid cancer than did the same dose of radiation given externally. The external risk coefficients for the older age groups were reported in the literature to be in the range of 1.0 to 3.3 cancers per million person-rad-years-at risk. We computed internal risk coefficients of 3.3 to 8.1 cancers per million person-rad-years at risk for adolescent and adult groups. This higher sensitivity to cancer induction in the exposed adolescents and adults, is different from that seen in other exposed groups. 14 refs., 8 tabs.

  5. Limited internal radiation exposure associated with resettlements to a radiation-contaminated homeland after the Fukushima Daiichi nuclear disaster.

    PubMed

    Tsubokura, Masaharu; Kato, Shigeaki; Nihei, Masahiko; Sakuma, Yu; Furutani, Tomoyuki; Uehara, Keisuke; Sugimoto, Amina; Nomura, Shuhei; Hayano, Ryugo; Kami, Masahiro; Watanobe, Hajime; Endo, Yukou

    2013-01-01

    Resettlement to their radiation-contaminated hometown could be an option for people displaced at the time of a nuclear disaster; however, little information is available on the safety implications of these resettlement programs. Kawauchi village, located 12-30 km southwest of the Fukushima Daiichi nuclear power plant, was one of the 11 municipalities where mandatory evacuation was ordered by the central government. This village was also the first municipality to organize the return of the villagers. To assess the validity of the Kawauchi villagers' resettlement program, the levels of internal Cesium (Cs) exposures were comparatively measured in returnees, commuters, and non-returnees among the Kawauchi villagers using a whole body counter. Of 149 individuals, 5 villagers had traceable levels of Cs exposure; the median detected level was 333 Bq/body (range, 309-1050 Bq/kg), and 5.3 Bq/kg (range, 5.1-18.2 Bq/kg). Median annual effective doses of villagers with traceable Cs were 1.1 x 10(-2) mSv/y (range, 1.0 x 10(-2)-4.1 x 10(-2) mSv/y). Although returnees had higher chances of consuming locally produced vegetables, Cochran-Mantel-Haenszel test showed that their level of internal radiation exposure was not significantly higher than that in the other 2 groups (p=0.643). The present findings in Kawauchi village imply that it is possible to maintain internal radiation exposure at very low levels even in a highly radiation-contaminated region at the time of a nuclear disaster. Moreover, the risks for internal radiation exposure could be limited with a strict food control intervention after resettlement to the radiation-contaminated village. It is crucial to establish an adequate number of radio-contaminated testing sites within the village, to provide immediate test result feedback to the villagers, and to provide education regarding the importance of re-testing in reducing the risk of high internal radiation exposure. PMID:24312602

  6. Limited Internal Radiation Exposure Associated with Resettlements to a Radiation-Contaminated Homeland after the Fukushima Daiichi Nuclear Disaster

    PubMed Central

    Tsubokura, Masaharu; Kato, Shigeaki; Nihei, Masahiko; Sakuma, Yu; Furutani, Tomoyuki; Uehara, Keisuke; Sugimoto, Amina; Nomura, Shuhei; Hayano, Ryugo; Kami, Masahiro; Watanobe, Hajime; Endo, Yukou

    2013-01-01

    Resettlement to their radiation-contaminated hometown could be an option for people displaced at the time of a nuclear disaster; however, little information is available on the safety implications of these resettlement programs. Kawauchi village, located 12–30 km southwest of the Fukushima Daiichi nuclear power plant, was one of the 11 municipalities where mandatory evacuation was ordered by the central government. This village was also the first municipality to organize the return of the villagers. To assess the validity of the Kawauchi villagers’ resettlement program, the levels of internal Cesium (Cs) exposures were comparatively measured in returnees, commuters, and non-returnees among the Kawauchi villagers using a whole body counter. Of 149 individuals, 5 villagers had traceable levels of Cs exposure; the median detected level was 333 Bq/body (range, 309–1050 Bq/kg), and 5.3 Bq/kg (range, 5.1–18.2 Bq/kg). Median annual effective doses of villagers with traceable Cs were 1.1 x 10-2 mSv/y (range, 1.0 x 10-2-4.1 x 10-2 mSv/y). Although returnees had higher chances of consuming locally produced vegetables, Cochran-Mantel-Haenszel test showed that their level of internal radiation exposure was not significantly higher than that in the other 2 groups (p=0.643). The present findings in Kawauchi village imply that it is possible to maintain internal radiation exposure at very low levels even in a highly radiation-contaminated region at the time of a nuclear disaster. Moreover, the risks for internal radiation exposure could be limited with a strict food control intervention after resettlement to the radiation-contaminated village. It is crucial to establish an adequate number of radio-contaminated testing sites within the village, to provide immediate test result feedback to the villagers, and to provide education regarding the importance of re-testing in reducing the risk of high internal radiation exposure. PMID:24312602

  7. Parental occupational paint exposure and risk of childhood leukemia in the offspring: Findings from the Childhood Leukemia International Consortium

    PubMed Central

    Bailey, Helen D; Fritschi, Lin; Metayer, Catherine; Infante-Rivard, Claire; Magnani, Corrado; Petridou, Eleni; Roman, Eve; Spector, Logan G; Kaatsch, Peter; Clavel, Jacqueline; Milne, Elizabeth; Dockerty, John D; Glass, Deborah C; Lightfoot, Tracy; Miligi, Lucia; Rudant, Jérémie; Baka, Margarita; Rondelli, Roberto; Amigou, Alicia; Simpson, Jill; Kang, Alice; Moschovi, Maria; Schüz, Joachim

    2014-01-01

    Purpose It has been suggested that parental occupational paint exposure around the time of conception or pregnancy increases the risk of childhood leukemia in the offspring. Methods We obtained individual level data from 13 case-control studies participating in the Childhood Leukemia International Consortium (CLIC). Occupational data were harmonized to a compatible format. Meta-analyses of study-specific odds ratios (ORs) were undertaken, as well as pooled analyses of individual data using unconditional logistic regression. Results Using individual data from fathers of 8,185 cases and 14,210 controls, the pooled OR for paternal exposure around conception and risk of acute lymphoblastic leukaemia (ALL) was 0.93 (95% confidence interval (CI) 0.76, 1.14). Analysis of data from 8,156 ALL case mothers and 14,568 control mothers produced a pooled OR of 0.81 (95% CI 0.39, 1.68) for exposure during pregnancy. For acute myeloid leukaemia (AML), the pooled ORs for paternal and maternal exposure were 0.96 (95% CI 0.65, 1.41) and 1.31 (95% CI 0.38, 4.47) respectively, based on data from 1,231 case and 11,392 control fathers and 1,329 case and 12,141 control mothers. Heterogeneity among the individual studies ranged from low to modest. Conclusions Null findings for paternal exposure for both ALL and AML are consistent with previous reports. Despite the large sample size, results for maternal exposure to paints in pregnancy were based on small numbers of exposed. Overall, we found no evidence that parental occupational exposure to paints increases the risk of leukemia in the offspring, but further data on home exposure are needed. PMID:25088805

  8. Examining the Effects of External or Internal Radiation Exposure of Juvenile Mice on Late Morbidity after Infection with Influenza A.

    PubMed

    Misra, Ravi S; Johnston, Carl J; Groves, Angela M; DeDiego, Marta L; St Martin, Joe; Reed, Christina; Hernady, Eric; Miller, Jen-Nie; Love, Tanzy; Finkelstein, Jacob N; Williams, Jacqueline P

    2015-07-01

    A number of investigators have suggested that exposure to low-dose radiation may pose a potentially serious health risk. However, the majority of these studies have focused on the short-term rather than long-term effects of exposure to fixed source radiation, and few have examined the effects of internal contamination. Additionally, very few studies have focused on exposure in juveniles, when organs are still developing and could be more sensitive to the toxic effects of radiation. To specifically address whether early-life radiation injury may affect long-term immune competence, we studied 14-day-old juvenile pups that were either 5 Gy total-body irradiated or injected internally with 50 μCi soluble (137)Cs, then infected with influenza A virus at 26 weeks after exposure. After influenza infection, all groups demonstrated immediate weight loss. We found that externally irradiated, infected animals failed to recover weight relative to age-matched infected controls, but internally (137)Cs contaminated and infected animals had a weight recovery with a similar rate and degree as controls. Externally and internally irradiated mice demonstrated reduced levels of club cell secretory protein (CCSP) message in their lungs after influenza infection. The externally irradiated group did not recover CCSP expression even at the two-week time point after infection. Although the antibody response and viral titers did not appear to be affected by either radiation modality, there was a slight increase in monocyte chemoattractant protein (MCP)-1 expression in the lungs of externally irradiated animals 14 days after influenza infection, with increased cellular infiltration present. Notably, an increase in the number of regulatory T cells was seen in the mediastinal lymph nodes of irradiated mice relative to uninfected mice. These data confirm the hypothesis that early-life irradiation may have long-term consequences on the immune system, leading to an altered antiviral response

  9. Examining the Effects of External or Internal Radiation Exposure of Juvenile Mice on Late Morbidity after Infection with Influenza A

    PubMed Central

    Misra, Ravi S.; Johnston, Carl J.; Groves, Angela M.; DeDiego, Marta L.; St Martin, Joe; Reed, Christina; Hernady, Eric; Miller, Jen-nie; Love, Tanzy; Finkelstein, Jacob N.; Williams, Jacqueline P.

    2015-01-01

    A number of investigators have suggested that exposure to low-dose radiation may pose a potentially serious health risk. However, the majority of these studies have focused on the short-term rather than long-term effects of exposure to fixed source radiation, and few have examined the effects of internal contamination. Additionally, very few studies have focused on exposure in juveniles, when organs are still developing and could be more sensitive to the toxic effects of radiation. To specifically address whether early-life radiation injury may affect long-term immune competence, we studied 14-day-old juvenile pups that were either 5 Gy total-body irradiated or injected internally with 50 μCi soluble 137Cs, then infected with influenza A virus at 26 weeks after exposure. After influenza infection, all groups demonstrated immediate weight loss. We found that externally irradiated, infected animals failed to recover weight relative to age-matched infected controls, but internally 137Cs contaminated and infected animals had a weight recovery with a similar rate and degree as controls. Externally and internally irradiated mice demonstrated reduced levels of club cell secretory protein (CCSP) message in their lungs after influenza infection. The externally irradiated group did not recover CCSP expression even at the two-week time point after infection. Although the antibody response and viral titers did not appear to be affected by either radiation modality, there was a slight increase in monocyte chemo-attractant protein (MCP)-1 expression in the lungs of externally irradiated animals 14 days after influenza infection, with increased cellular infiltration present. Notably, an increase in the number of regulatory T cells was seen in the mediastinal lymph nodes of irradiated mice relative to uninfected mice. These data confirm the hypothesis that early-life irradiation may have long-term consequences on the immune system, leading to an altered antiviral response. PMID

  10. Lead risk assessment for children in Hungary by predicting their blood lead levels using US EPA integrated Exposure Uptake Biokinetic model.

    PubMed

    Hassanien, M A; Horváth, A

    1999-08-01

    The US EPA integrated Exposure Uptake Biokinetic (IEUBK 0.99d) lead exposure for children was validated, updated, and applied to predict mean blood lead levels based on lead uptake from multiple sources and provide assessment of risk. Surveys were carried out around houses in a polluted area (Heves, Hungary) in 1995. The collected data from that area have shown very high levels of lead in soil. In some cases the level of lead in soil has reached more than 1000 times the allowable limit value used (100 mg/kg) in Hungary. Moreover, the concentration of lead in air was measured and the concentration of lead in air varied from 0.05-1.83 micrograms/m3. The environmental data within the community were used to predict the children blood lead levels and to compare the observed estimates with the other predicted ones. The age of the investigated group of children varied from 0-60 months. The estimated blood lead levels have illustrated variation according to age, sex, and the specific site. It can be concluded from this study that the model can be used on a wide range to give us an excellent picture for site cleanup, to decision makers, and finally to use the environmental data to predict blood lead level for the community or population. Results of several validation exercises utilizing the IEUBK model comparing predicted and measured blood lead levels with international guidelines and the percent of risk of exceeding a specific blood lead level (i.e., 10 micrograms/dl) are presented in this paper. PMID:10499150

  11. Smoking and degree of occupational exposure: are internal analyses in cohort studies likely to be confounded by smoking status

    SciTech Connect

    Siemiatycki, J.; Wacholder, S.; Dewar, R.; Wald, L.; Begin, D.; Richardson, L.; Rosenman, K.; Gerin, M.

    1988-01-01

    Occupational cohort studies are usually carried out without the benefit of information on smoking habits of cohort members. One common approach to avoid confounding bias related to smoking habits is to carry out an internal analysis, comparing workers with different degrees of occupational exposure. The premise behind this approach is that within a cohort there is unlikely to be correlation between degree of exposure and smoking habits. If this were untrue, smoking could confound the disease-exposure relationships. Our purpose was to verify the premise. The study sample consisted of 857 French-Canadian men born between 1910 and 1930, with 11 or fewer years of education, and interviewed around 1980 in the context of an occupational cancer case-control study. For each man we had information on smoking habits, job history, and a history of the chemicals he was exposed to in each of his jobs. We computed two indices of the dirtiness of workers' job histories: one based on the job titles held by the man and a second based on the degree of exposures to workplace substances. There was no correlation between these indices of job dirtiness and smoking history. We also examined the smoking-exposure relationship among the subsets of men who had been occupationally exposed to ten especially noticeable substances. Within the subsets, there was no indication of a consistent difference among the smoking subgroups in level or duration of exposure to these index substances. These findings do not support the view that nonsmokers sought out cleaner job environments than smokers; they imply that internal analyses of dose-response in cohort studies are unlikely to be seriously confounded by smoking habits.

  12. Determination of platinum in blood and urine as a tool for the biological monitoring of internal exposure

    NASA Astrophysics Data System (ADS)

    Schaller, Karl H.; Angerer, Juergen; Alt, Friedrich; Messerschmidt, Juergen; Weber, Andreas

    1993-03-01

    The increased industrial use of platinum has led to a growing need for the determination of platinum levels in biological materials. Concern about the release of toxic material from catalytic converters in motor vehicles in the environment and about occupational platinum exposure of employees working in the assembly of motor vehicle catalyzers and recycling led us to establish background and internal exposure levels in human body fluids. The development of an analytical procedure, based on adsorptive voltammetry with an extremely high power of detection (2 pg Pt absolute) for the determination in body fluids made population studies reliable and practicable. The methods are described and the reliability criteria are presented. For 13 not occupationally exposed persons the platinum levels ranged in urine from exposure levels, which exceeded the German MAK value of 2 (mu) g/m3. Platinum concentrations in human biological materials seem to be suitable as internal exposure indicators.

  13. Internal Radiation Exposure Dose in Iwaki City, Fukushima Prefecture after the Accident at Fukushima Dai-ichi Nuclear Power Plant

    PubMed Central

    Orita, Makiko; Hayashida, Naomi; Nukui, Hiroshi; Fukuda, Naoko; Kudo, Takashi; Matsuda, Naoki; Fukushima, Yoshiko; Takamura, Noboru

    2014-01-01

    As a result of the accident at the Fukushima Daiichi Nuclear Power Plant (FNPP) on 11 March 2011, a huge amount of radionuclides, including radiocesium, was released and spread over a wide area of eastern Japan. Although three years have passed since the accident, residents around the FNPP are anxious about internal radiation exposure due to radiocesium. In this study, we screened internal radiation exposure doses in Iwaki city of Fukushima prefecture, using a whole-body counter. The first screening was conducted from October 2012 to February 2013, and the second screening was conducted from May to November 2013. Study participants were employees of ALPINE and their families who underwent examination. A total of 2,839 participants (1,366 men and 1,473 women, 1–86 years old) underwent the first screening, and 2,092 (1,022 men and 1,070 women, 1–86 years old) underwent the second screening. The results showed that 99% of subjects registered below 300 Bq per body in the first screening, and all subjects registered below 300 Bq per body in the second screening. The committed effective dose ranged from 0.01–0.06 mSv in the first screening and 0.01–0.02 mSv in the second screening. Long-term follow-up studies are needed to avoid unnecessary chronic internal exposure and to reduce anxiety among the residents by communicating radiation health risks. PMID:25478794

  14. The GRB luminosity function: prediction of the internal shock model and comparison to observations

    SciTech Connect

    Zitouni, H.; Daigne, F.; Mochkovitch, R.

    2008-05-22

    We compute the expected GRB luminosity function in the internal shock model. We find that if the population of GRB central engines produces all kind of relativistic outflows, from very smooth to highly variable, the luminosity function has to branchs: at low luminosity, the distribution is dominated by low efficiency GRBs and is close to a power law of slope -0.5, whereas at high luminosity, the luminosity function follows the distribution of injected kinetic power. Using Monte Carlo simulations and several observational constrains (BATSE logN-logP diagram, peak energy distribution of bright BATSE bursts, fraction of XRFs in the HETE2 sample), we show that it is currently impossible to distinguish between a single power law or a broken power law luminosity function. However, when the second case is considered, the low-luminosity slope is found to be -0.6{+-}0.2, which is compatible with the prediction of the internal shock model.

  15. Comparative international analysis of radiofrequency exposure surveys of mobile communication radio base stations

    PubMed Central

    Rowley, Jack T; Joyner, Ken H

    2012-01-01

    This paper presents analyses of data from surveys of radio base stations in 23 countries across five continents from the year 2000 onward and includes over 173,000 individual data points. The research compared the results of the national surveys, investigated chronological trends and compared exposures by technology. The key findings from this data are that irrespective of country, the year and cellular technology, exposures to radio signals at ground level were only a small fraction of the relevant human exposure standards. Importantly, there has been no significant increase in exposure levels since the widespread introduction of 3G mobile services, which should be reassuring for policy makers and negate the need for post-installation measurements at ground level for compliance purposes. There may be areas close to antennas where compliance levels could be exceeded. Future potential work includes extending the study to additional countries, development of cumulative exposure distributions and investigating the possibility of linking exposure measurements to population statistics to assess the distribution of exposure levels relative to population percentiles. PMID:22377680

  16. Pleural plaques related to “take-home” exposure to asbestos: An international case series

    PubMed Central

    Peretz, Alon; Van Hee, Victor C; Kramer, Mordechai R; Pitlik, Silvio; Keifer, Matthew C

    2008-01-01

    Context: While a large number of studies indicate the risks of high-level exposures to asbestos in the workplace setting, a relatively small number of studies describe the risk of pleural disease related to “take-home” asbestos brought into the household by workers exposed to asbestos. Consequently, the risk of pleural disease in family members of asbestos-exposed workers is likely underappreciated. Case presentations: Two families of siblings, one in Israel and one in the US, were evaluated because of their significant exposures to asbestos brought into the home by family members with heavy occupational exposures. Two of the four children of an asbestos cement debagger in Petach Tikvah, Israel and two children of a pipe lagger in a naval shipyard near Seattle, Washington, manifested benign pleural disease without parenchymal disease, despite having no occupational exposure to asbestos. Discussion: These cases illustrate that “take-home” asbestos exposure may lead to pleural disease at higher rates than commonly realized. Relevance to clinical practice: Providers should recognize that due to the potential for “take-home” exposures, asbestos-related disease in a patient may be a marker for disease in household contacts. Patients with family members heavily exposed to asbestos should be strongly encouraged to quit smoking in an effort to reduce any further carcinogenic exposures. Additionally, workplace control and regulation of asbestos use should be emphasized to protect both workers and their families. PMID:20428401

  17. Nomograms for predicting survival and recurrence in patients with adenoid cystic carcinoma. An international collaborative study

    PubMed Central

    Ganly, Ian; Amit, Moran; Kou, Lei; Palmer, Frank L.; Migliacci, Jocelyn; Katabi, Nora; Yu, Changhong; Kattan, Michael W.; Binenbaum, Yoav; Sharma, Kanika; Naomi, Ramer; Abib, Agbetoba; Miles, Brett; Yang, Xinjie; Lei, Delin; Bjoerndal, Kristine; Godballe, Christian; Mücke, Thomas; Wolff, Klaus-Dietrich; Fliss, Dan; Eckardt, André M.; Chiara, Copelli; Sesenna, Enrico; Ali, Safina; Czerwonka, Lukas; Goldstein, David P.; Gil, Ziv; Patel, Snehal G.

    2016-01-01

    Background Due to the rarity of adenoid cystic carcinoma (ACC), information on outcome is based upon small retrospective case series. The aim of our study was to create a large multiinstitutional international dataset of patients with ACC in order to design predictive nomograms for outcome. Methods ACC patients managed at 10 international centers were identified. Patient, tumor, and treatment characteristics were recorded and an international collaborative dataset created. Multivariable competing risk models were then built to predict the 10 year recurrence free probability (RFP), distant recurrence free probability (DRFP), overall survival (OS) and cancer specific mortality (CSM). All predictors of interest were added in the starting full models before selection, including age, gender, tumor site, clinical T stage, perineural invasion, margin status, pathologic N-status, and M-status. Stepdown method was used in model selection to choose predictive variables. An external dataset of 99 patients from 2 other institutions was used to validate the nomograms. Findings Of 438 ACC patients, 27.2% (119/438) died from ACC and 38.8% (170/438) died of other causes. Median follow-up was 56 months (range 1–306). The nomogram for OS had 7 variables (age, gender, clinical T stage, tumor site, margin status, pathologic N-status and M-status) with a concordance index (CI) of 0.71. The nomogram for CSM had the same variables, except margin status, with a concordance index (CI) of 0.70. The nomogram for RFP had 7 variables (age, gender, clinical T stage, tumor site, margin status, pathologic N status and perineural invasion) (CI 0.66). The nomogram for DRFP had 6 variables (gender, clinical T stage, tumor site, pathologic N-status, perineural invasion and margin status) (CI 0.64). Concordance index for the external validation set were 0.76, 0.72, 0.67 and 0.70 respectively. Interpretation Using an international collaborative database we have created the first nomograms which

  18. Sixth International Conference on Precipitation: Predictability of Rainfall at the Various Scales. Abstracts

    SciTech Connect

    1998-06-29

    This volume contains abstracts of the papers presented at the Sixth International Conference on Precipitation: Predictability of Rainfall at the various scales, held at the Mauna Lani Bay and Bungalows, Hawaii, June 29 - July 1, 1998. The main goal of the conference was to bring together meteorologists, hydrologists, mathematicians, physicists, statisticians, and all others who are interested in fundamental principles governing the physical processes of precipitation. The results of the previous conferences have been published in issues of the Journal of Geophysical Research and Journal of Applied Meteorology. A similar format is planned for papers of this conference.

  19. Internal state variable approach for predicting stiffness reductions in fibrous laminated composites with matrix cracks

    NASA Technical Reports Server (NTRS)

    Lee, Jong-Won; Allen, D. H.; Harris, C. E.

    1989-01-01

    A mathematical model utilizing the internal state variable concept is proposed for predicting the upper bound of the reduced axial stiffnesses in cross-ply laminates with matrix cracks. The axial crack opening displacement is explicitly expressed in terms of the observable axial strain and the undamaged material properties. A crack parameter representing the effect of matrix cracks on the observable axial Young's modulus is calculated for glass/epoxy and graphite/epoxy material systems. The results show that the matrix crack opening displacement and the effective Young's modulus depend not on the crack length, but on its ratio to the crack spacing.

  20. CONTROVERSIES IN EPILEPSY – DEBATES HELD DURING THE FOURTH INTERNATIONAL WORKSHOP ON SEIZURE PREDICTION

    PubMed Central

    Frei, Mark G.; Zaveri, Hitten P.; Arthurs, Susan; Bergey, Gregory K.; Jouny, Christophe; Lehnertz, Klaus; Gotman, Jean; Osorio, Ivan; Netoff, Theoden I.; Freeman, Walter J.; Jefferys, John; Worrell, Gregory; Le Van Quyen, Michel; Schiff, Steven J.; Mormann, Florian

    2010-01-01

    Debates on 6 controversial topics were held during the Fourth International Workshop on Seizure Prediction (IWSP4) convened in Kansas City (July 4–7, 2009). The topics were 1) Ictogenesis: focus vs. network? 2) Spikes and seizures: step-relatives or siblings? 3) Ictogenesis: a result of hyposynchrony? 4) Can focal seizures be caused by excessive inhibition? 5) Do high-frequency oscillations (HFOs) provide relevant independent information? and 6) Phase synchronization – is it worthwhile as measured? This manuscript, written by the IWSP4 organizing committee and the debaters, summarizes the arguments presented during the debates. PMID:20708976

  1. International policy and advisory response regarding children's exposure to radio frequency electromagnetic fields (RF-EMF).

    PubMed

    Redmayne, Mary

    2016-01-01

    Radiofrequency electromagnetic field (RF-EMF) exposure regulations/guidelines generally only consider acute effects, and not chronic, low exposures. Concerns for children's exposure are warranted due to the amazingly rapid uptake of many wireless devices by increasingly younger children. This review of policy and advice regarding children's RF-EMF exposure draws material from a wide variety of sources focusing on the current situation. This is not a systematic review, but aims to provide a representative cross-section of policy and advisory responses within set boundaries. There are a wide variety of approaches which I have categorized and tabulated ranging from ICNIRP/IEEE guidelines and "no extra precautions needed" to precautionary or scientific much lower maxima and extensive advice to minimize RF-EMF exposure, ban advertising/sale to children, and add exposure information to packaging. Precautionary standards use what I term an exclusion principle. The wide range of policy approaches can be confusing for parents/carers of children. Some consensus among advisory organizations would be helpful acknowledging that, despite extensive research, the highly complex nature of both RF-EMF and the human body, and frequent technological updates, means simple assurance of long-term safety cannot be guaranteed. Therefore, minimum exposure of children to RF-EMF is recommended. This does not indicate need for alarm, but mirrors routine health-and-safety precautions. Simple steps are suggested. ICNIRP guidelines need to urgently publish how the head, torso, and limbs' exposure limits were calculated and what safety margin was applied since this exposure, especially to the abdomen, is now dominant in many children. PMID:26091083

  2. International Space Station Bacteria Filter Element Post-Flight Testing and Service Life Prediction

    NASA Technical Reports Server (NTRS)

    Perry, J. L.; von Jouanne, R. G.; Turner, E. H.

    2003-01-01

    The International Space Station uses high efficiency particulate air (HEPA) filters to remove particulate matter from the cabin atmosphere. Known as Bacteria Filter Elements (BFEs), there are 13 elements deployed on board the ISS's U.S. Segment. The pre-flight service life prediction of 1 year for the BFEs is based upon performance engineering analysis of data collected during developmental testing that used a synthetic dust challenge. While this challenge is considered reasonable and conservative from a design perspective, an understanding of the actual filter loading is required to best manage the critical ISS Program resources. Thus testing was conducted on BFEs returned from the ISS to refine the service life prediction. Results from this testing and implications to ISS resource management are discussed. Recommendations for realizing significant savings to the ISS Program are presented.

  3. Measuring and Predicting the Internal Structure of Semiconductor Nanocrystals through Raman Spectroscopy.

    PubMed

    Mukherjee, Prabuddha; Lim, Sung Jun; Wrobel, Tomasz P; Bhargava, Rohit; Smith, Andrew M

    2016-08-31

    Nanocrystals composed of mixed chemical domains have diverse properties that are driving their integration in next-generation electronics, light sources, and biosensors. However, the precise spatial distribution of elements within these particles is difficult to measure and control, yet profoundly impacts their quality and performance. Here we synthesized a unique series of 42 different quantum dot nanocrystals, composed of two chemical domains (CdS:CdSe), arranged in 7 alloy and (core)shell structural classes. Chemometric analyses of far-field Raman spectra accurately classified their internal structures from their vibrational signatures. These classifications provide direct insight into the elemental arrangement of the alloy as well as an independent prediction of fluorescence quantum yield. This nondestructive, rapid approach can be broadly applied to greatly enhance our capacity to measure, predict and monitor multicomponent nanomaterials for precise tuning of their structures and properties. PMID:27472011

  4. Internal rotation for predicting conformational population of 1,2-difluorethane and 1,2-dichloroethane

    NASA Astrophysics Data System (ADS)

    Venâncio, Mateus F.; Dos Santos, Hélio F.; De Almeida, Wagner B.

    2016-06-01

    The contribution of internal rotation to the thermal correction of Gibbs free energy (ΔG) is estimated using the quantum pendulum model (QPM) to solve the characteristic Schrödinger equation. The procedure is applied to theoretical prediction of conformational population of 1,2-difluorethane (1,2-DFE) and 1,2-dichloroethane (1,2-DCE) molecules. The predicted population for the anti form was 37% and 75%, for 1,2-DFE and 1,2-DCE respectively, in excellent agreement with experimental gas phase data available, 37 ± 5% and 78 ± 5%. These results provide great support to the use of the QPM model to account for the low vibrational frequency modes effect on the calculation of thermodynamic properties.

  5. Radiation transport modeling and assessment to better predict radiation exposure, dose, and toxicological effects to human organs on long duration space flights

    NASA Astrophysics Data System (ADS)

    Denkins, Pamela; Badhwar, Gautam; Obot, Victor; Wilson, Bobby; Jejelewo, Olufisayo

    2001-08-01

    NASA is very interested in improving its ability to monitor and forecast the radiation levels that pose a health risk to space-walking astronauts as they construct the International Space Station and astronauts that will participate in long-term and deep-space missions. Human exploratory missions to the moon and Mars within the next quarter century, will expose crews to transient radiation from solar particle events which include high-energy galactic cosmic rays and high-energy protons. Because the radiation levels in space are high and solar activity is presently unpredictable, adequate shielding is needed to minimize the deleterious health effects of exposure to radiation. Today, numerous models have been developed and used to predict radiation exposure. Such a model is the Space Environment Information Systems (SPENVIS) modeling program, developed by the Belgian Institute for Space Aeronautics. SPENVIS, which has been assessed to be an excellent tool in characterizing the radiation environment for microelectronics and investigating orbital debris, is being evaluated for its usefulness with determining the dose and dose-equivalent for human exposure. Thus far, the calculations for dose-depth relations under varying shielding conditions have been in agreement with calculations done using HZETRN and PDOSE, which are well-known and widely used models for characterizing the environments for human exploratory missions. There is disagreement when assessing the impact of secondary radiation particles since SPENVIS does a crude estimation of the secondary radiation particles when calculating LET versus Flux. SPENVIS was used to model dose-depth relations for the blood-forming organs. Radiation sickness and cancer are life-threatening consequences resulting from radiation exposure. In space, exposure to radiation generally includes all of the critical organs. Biological and toxicological impacts have been included for discussion along with alternative risk mitigation

  6. Modelling the exposure to chemicals for risk assessment: a comprehensive library of multimedia and PBPK models for integration, prediction, uncertainty and sensitivity analysis - the MERLIN-Expo tool.

    PubMed

    Ciffroy, P; Alfonso, B; Altenpohl, A; Banjac, Z; Bierkens, J; Brochot, C; Critto, A; De Wilde, T; Fait, G; Fierens, T; Garratt, J; Giubilato, E; Grange, E; Johansson, E; Radomyski, A; Reschwann, K; Suciu, N; Tanaka, T; Tediosi, A; Van Holderbeke, M; Verdonck, F

    2016-10-15

    MERLIN-Expo is a library of models that was developed in the frame of the FP7 EU project 4FUN in order to provide an integrated assessment tool for state-of-the-art exposure assessment for environment, biota and humans, allowing the detection of scientific uncertainties at each step of the exposure process. This paper describes the main features of the MERLIN-Expo tool. The main challenges in exposure modelling that MERLIN-Expo has tackled are: (i) the integration of multimedia (MM) models simulating the fate of chemicals in environmental media, and of physiologically based pharmacokinetic (PBPK) models simulating the fate of chemicals in human body. MERLIN-Expo thus allows the determination of internal effective chemical concentrations; (ii) the incorporation of a set of functionalities for uncertainty/sensitivity analysis, from screening to variance-based approaches. The availability of such tools for uncertainty and sensitivity analysis aimed to facilitate the incorporation of such issues in future decision making; (iii) the integration of human and wildlife biota targets with common fate modelling in the environment. MERLIN-Expo is composed of a library of fate models dedicated to non biological receptor media (surface waters, soils, outdoor air), biological media of concern for humans (several cultivated crops, mammals, milk, fish), as well as wildlife biota (primary producers in rivers, invertebrates, fish) and humans. These models can be linked together to create flexible scenarios relevant for both human and wildlife biota exposure. Standardized documentation for each model and training material were prepared to support an accurate use of the tool by end-users. One of the objectives of the 4FUN project was also to increase the confidence in the applicability of the MERLIN-Expo tool through targeted realistic case studies. In particular, we aimed at demonstrating the feasibility of building complex realistic exposure scenarios and the accuracy of the

  7. Radiation transport modeling and assessment to better predict radiation exposure, dose, and toxicological effects to human organs on long duration space flights

    NASA Technical Reports Server (NTRS)

    Denkins, P.; Badhwar, G.; Obot, V.; Wilson, B.; Jejelewo, O.

    2001-01-01

    NASA is very interested in improving its ability to monitor and forecast the radiation levels that pose a health risk to space-walking astronauts as they construct the International Space Station and astronauts that will participate in long-term and deep-space missions. Human exploratory missions to the moon and Mars within the next quarter century, will expose crews to transient radiation from solar particle events which include high-energy galactic cosmic rays and high-energy protons. Because the radiation levels in space are high and solar activity is presently unpredictable, adequate shielding is needed to minimize the deleterious health effects of exposure to radiation. Today, numerous models have been developed and used to predict radiation exposure. Such a model is the Space Environment Information Systems (SPENVIS) modeling program, developed by the Belgian Institute for Space Aeronautics. SPENVIS, which has been assessed to be an excellent tool in characterizing the radiation environment for microelectronics and investigating orbital debris, is being evaluated for its usefulness with determining the dose and dose-equivalent for human exposure. Thus far. the calculations for dose-depth relations under varying shielding conditions have been in agreement with calculations done using HZETRN and PDOSE, which are well-known and widely used models for characterizing the environments for human exploratory missions. There is disagreement when assessing the impact of secondary radiation particles since SPENVIS does a crude estimation of the secondary radiation particles when calculating LET versus Flux. SPENVIS was used to model dose-depth relations for the blood-forming organs. Radiation sickness and cancer are life-threatening consequences resulting from radiation exposure. In space. exposure to radiation generally includes all of the critical organs. Biological and toxicological impacts have been included for discussion along with alternative risk mitigation

  8. Radiation transport modeling and assessment to better predict radiation exposure, dose, and toxicological effects to human organs on long duration space flights.

    PubMed

    Denkins, P; Badhwar, G; Obot, V; Wilson, B; Jejelewo, O

    2001-01-01

    NASA is very interested in improving its ability to monitor and forecast the radiation levels that pose a health risk to space-walking astronauts as they construct the International Space Station and astronauts that will participate in long-term and deep-space missions. Human exploratory missions to the moon and Mars within the next quarter century, will expose crews to transient radiation from solar particle events which include high-energy galactic cosmic rays and high-energy protons. Because the radiation levels in space are high and solar activity is presently unpredictable, adequate shielding is needed to minimize the deleterious health effects of exposure to radiation. Today, numerous models have been developed and used to predict radiation exposure. Such a model is the Space Environment Information Systems (SPENVIS) modeling program, developed by the Belgian Institute for Space Aeronautics. SPENVIS, which has been assessed to be an excellent tool in characterizing the radiation environment for microelectronics and investigating orbital debris, is being evaluated for its usefulness with determining the dose and dose-equivalent for human exposure. Thus far. the calculations for dose-depth relations under varying shielding conditions have been in agreement with calculations done using HZETRN and PDOSE, which are well-known and widely used models for characterizing the environments for human exploratory missions. There is disagreement when assessing the impact of secondary radiation particles since SPENVIS does a crude estimation of the secondary radiation particles when calculating LET versus Flux. SPENVIS was used to model dose-depth relations for the blood-forming organs. Radiation sickness and cancer are life-threatening consequences resulting from radiation exposure. In space. exposure to radiation generally includes all of the critical organs. Biological and toxicological impacts have been included for discussion along with alternative risk mitigation

  9. Prediction of Indoor Air Exposure from Outdoor Air Quality Using an Artificial Neural Network Model for Inner City Commercial Buildings.

    PubMed

    Challoner, Avril; Pilla, Francesco; Gill, Laurence

    2015-12-01

    NO₂ and particulate matter are the air pollutants of most concern in Ireland, with possible links to the higher respiratory and cardiovascular mortality and morbidity rates found in the country compared to the rest of Europe. Currently, air quality limits in Europe only cover outdoor environments yet the quality of indoor air is an essential determinant of a person's well-being, especially since the average person spends more than 90% of their time indoors. The modelling conducted in this research aims to provide a framework for epidemiological studies by the use of publically available data from fixed outdoor monitoring stations to predict indoor air quality more accurately. Predictions are made using two modelling techniques, the Personal-exposure Activity Location Model (PALM), to predict outdoor air quality at a particular building, and Artificial Neural Networks, to model the indoor/outdoor relationship of the building. This joint approach has been used to predict indoor air concentrations for three inner city commercial buildings in Dublin, where parallel indoor and outdoor diurnal monitoring had been carried out on site. This modelling methodology has been shown to provide reasonable predictions of average NO₂ indoor air quality compared to the monitored data, but did not perform well in the prediction of indoor PM2.5 concentrations. Hence, this approach could be used to determine NO₂ exposures more rigorously of those who work and/or live in the city centre, which can then be linked to potential health impacts. PMID:26633448

  10. Prediction of Indoor Air Exposure from Outdoor Air Quality Using an Artificial Neural Network Model for Inner City Commercial Buildings

    PubMed Central

    Challoner, Avril; Pilla, Francesco; Gill, Laurence

    2015-01-01

    NO2 and particulate matter are the air pollutants of most concern in Ireland, with possible links to the higher respiratory and cardiovascular mortality and morbidity rates found in the country compared to the rest of Europe. Currently, air quality limits in Europe only cover outdoor environments yet the quality of indoor air is an essential determinant of a person’s well-being, especially since the average person spends more than 90% of their time indoors. The modelling conducted in this research aims to provide a framework for epidemiological studies by the use of publically available data from fixed outdoor monitoring stations to predict indoor air quality more accurately. Predictions are made using two modelling techniques, the Personal-exposure Activity Location Model (PALM), to predict outdoor air quality at a particular building, and Artificial Neural Networks, to model the indoor/outdoor relationship of the building. This joint approach has been used to predict indoor air concentrations for three inner city commercial buildings in Dublin, where parallel indoor and outdoor diurnal monitoring had been carried out on site. This modelling methodology has been shown to provide reasonable predictions of average NO2 indoor air quality compared to the monitored data, but did not perform well in the prediction of indoor PM2.5 concentrations. Hence, this approach could be used to determine NO2 exposures more rigorously of those who work and/or live in the city centre, which can then be linked to potential health impacts. PMID:26633448

  11. Developing an International Register of Clinical Prediction Rules for Use in Primary Care: A Descriptive Analysis

    PubMed Central

    Keogh, Claire; Wallace, Emma; O’Brien, Kirsty K.; Galvin, Rose; Smith, Susan M.; Lewis, Cliona; Cummins, Anthony; Cousins, Grainne; Dimitrov, Borislav D.; Fahey, Tom

    2014-01-01

    PURPOSE We describe the methodology used to create a register of clinical prediction rules relevant to primary care. We also summarize the rules included in the register according to various characteristics. METHODS To identify relevant articles, we searched the MEDLINE database (PubMed) for the years 1980 to 2009 and supplemented the results with searches of secondary sources (books on clinical prediction rules) and personal resources (eg, experts in the field). The rules described in relevant articles were classified according to their clinical domain, the stage of development, and the clinical setting in which they were studied. RESULTS Our search identified clinical prediction rules reported between 1965 and 2009. The largest share of rules (37.2%) were retrieved from PubMed. The number of published rules increased substantially over the study decades. We included 745 articles in the register; many contained more than 1 clinical prediction rule study (eg, both a derivation study and a validation study), resulting in 989 individual studies. In all, 434 unique rules had gone through derivation; however, only 54.8% had been validated and merely 2.8% had undergone analysis of their impact on either the process or outcome of clinical care. The rules most commonly pertained to cardiovascular disease, respiratory, and musculoskeletal conditions. They had most often been studied in the primary care or emergency department settings. CONCLUSIONS Many clinical prediction rules have been derived, but only about half have been validated and few have been assessed for clinical impact. This lack of thorough evaluation for many rules makes it difficult to retrieve and identify those that are ready for use at the point of patient care. We plan to develop an international web-based register of clinical prediction rules and computer-based clinical decision support systems. PMID:25024245

  12. IRESPred: Web Server for Prediction of Cellular and Viral Internal Ribosome Entry Site (IRES)

    PubMed Central

    Kolekar, Pandurang; Pataskar, Abhijeet; Kulkarni-Kale, Urmila; Pal, Jayanta; Kulkarni, Abhijeet

    2016-01-01

    Cellular mRNAs are predominantly translated in a cap-dependent manner. However, some viral and a subset of cellular mRNAs initiate their translation in a cap-independent manner. This requires presence of a structured RNA element, known as, Internal Ribosome Entry Site (IRES) in their 5′ untranslated regions (UTRs). Experimental demonstration of IRES in UTR remains a challenging task. Computational prediction of IRES merely based on sequence and structure conservation is also difficult, particularly for cellular IRES. A web server, IRESPred is developed for prediction of both viral and cellular IRES using Support Vector Machine (SVM). The predictive model was built using 35 features that are based on sequence and structural properties of UTRs and the probabilities of interactions between UTR and small subunit ribosomal proteins (SSRPs). The model was found to have 75.51% accuracy, 75.75% sensitivity, 75.25% specificity, 75.75% precision and Matthews Correlation Coefficient (MCC) of 0.51 in blind testing. IRESPred was found to perform better than the only available viral IRES prediction server, VIPS. The IRESPred server is freely available at http://bioinfo.net.in/IRESPred/. PMID:27264539

  13. IRESPred: Web Server for Prediction of Cellular and Viral Internal Ribosome Entry Site (IRES).

    PubMed

    Kolekar, Pandurang; Pataskar, Abhijeet; Kulkarni-Kale, Urmila; Pal, Jayanta; Kulkarni, Abhijeet

    2016-01-01

    Cellular mRNAs are predominantly translated in a cap-dependent manner. However, some viral and a subset of cellular mRNAs initiate their translation in a cap-independent manner. This requires presence of a structured RNA element, known as, Internal Ribosome Entry Site (IRES) in their 5' untranslated regions (UTRs). Experimental demonstration of IRES in UTR remains a challenging task. Computational prediction of IRES merely based on sequence and structure conservation is also difficult, particularly for cellular IRES. A web server, IRESPred is developed for prediction of both viral and cellular IRES using Support Vector Machine (SVM). The predictive model was built using 35 features that are based on sequence and structural properties of UTRs and the probabilities of interactions between UTR and small subunit ribosomal proteins (SSRPs). The model was found to have 75.51% accuracy, 75.75% sensitivity, 75.25% specificity, 75.75% precision and Matthews Correlation Coefficient (MCC) of 0.51 in blind testing. IRESPred was found to perform better than the only available viral IRES prediction server, VIPS. The IRESPred server is freely available at http://bioinfo.net.in/IRESPred/. PMID:27264539

  14. Exposure Pathways, Biomarkers and the Exposome: Predictions, Insight, and Uncertainty (SOT presentation - CE lecture)

    EPA Science Inventory

    The risk posed to human health by any of the thousands of untested anthropogenic chemicals in our environment is a function of both the hazard presented by the chemical and the extent of exposure. However, many chemicals lack estimates of exposure intake, limiting the understandi...

  15. UNITED STATES METEOROLOGICAL DATA - DAILY AND HOURLY FILES TO SUPPORT PREDICTIVE EXPOSURE MODELING

    EPA Science Inventory

    ORD numerical models for pesticide exposure include a model of spray drift (AgDisp), a cropland pesticide persistence model (PRZM), a surface water exposure model (EXAMS), and a model of fish bioaccumulation (BASS). A unified climatological database for these models has been asse...

  16. Suppression on Your Own Terms: Internally Generated Displays of Craving Suppression Predict Rebound Effects

    PubMed Central

    Sayers, W. Michael; Sayette, Michael A.

    2015-01-01

    Research on emotion suppression has shown a rebound effect, in which expression of the targeted emotion increases following a suppression attempt. In prior investigations, participants have been explicitly instructed to suppress their responses, which has drawn the act of suppression into metaconsciousness. Yet emerging research emphasizes the importance of nonconscious approaches to emotion regulation. This study is the first in which a craving rebound effect was evaluated without simultaneously raising awareness about suppression. We aimed to link spontaneously occurring attempts to suppress cigarette craving to increased smoking motivation assessed immediately thereafter. Smokers (n = 66) received a robust cued smoking-craving manipulation while their facial responses were videotaped and coded using the Facial Action Coding System. Following smoking-cue exposure, participants completed a behavioral choice task previously found to index smoking motivation. Participants evincing suppression-related facial expressions during cue exposure subsequently valued smoking more than did those not displaying these expressions, which suggests that internally generated suppression can exert powerful rebound effects. PMID:23842957

  17. Use of international data sets to evaluate and validate pathway assessment models applicable to exposure and dose reconstruction at DOE facilities. Progress report, March--May 1994

    SciTech Connect

    Anspaugh, L.R.; Hendrickson, S.M.; Hoffman, F.O.

    1994-06-01

    The project described in this report was the result of a Memorandum of Cooperation between the US and the former-USSR following the accident at the Chernobyl Nuclear Power Plant Unit 4. A joint program was established to improve the safety of nuclear power plants and to understand the implications of environmental releases. The task of Working Group 7 was ``to develop jointly methods to project rapidly the health effects of any future nuclear reactor accident.`` The current objective of this project is to evaluate and validate pathway-assessment models applicable to exposure and dose reconstruction at DOE facilities through use of international data sets. This project incorporates data used for the prediction of radionuclide transfer through agricultural and aquatic systems to humans. It also includes participation in two multinational studies, BIOMOVS (Biospheric Model Validation Study) with the Swedish National Institute for Radiation Protection and VAMP (Validation of Model Predictions) with the International Atomic Energy Agency, that address testing the performance of models of radionuclide transport through foodchains. In the future, this project will be considered separately from the Chernobyl Studies Project and the essential activities of former Task 7.1D will be folded within the broader umbrella of the BIOMOVS and VAMP projects. The Working Group Leader of Task 7.1D will continue to provide oversight for this project.

  18. Internalizing and externalizing traits predict changes in sleep efficiency in emerging adulthood: an actigraphy study

    PubMed Central

    Yaugher, Ashley C.; Alexander, Gerianne M.

    2015-01-01

    Research on psychopathology and experimental studies of sleep restriction support a relationship between sleep disruption and both internalizing and externalizing disorders. The objective of the current study was to extend this research by examining sleep, impulsivity, antisocial personality traits, and internalizing traits in a university sample. Three hundred and eighty six individuals (161 males) between the ages of 18 and 27 years (M = 18.59, SD = 0.98) wore actigraphs for 7 days and completed established measures of disorder-linked personality traits and sleep quality (i.e., Personality Assessment Inventory (PAI), Triarchic Psychopathy Measure, Barratt Impulsiveness Scale-11, and the Pittsburgh Sleep Quality Index). As expected, sleep measures and questionnaire scores fell within the normal range of values and sex differences in sleep and personality were consistent with previous research results. Similar to findings in predominantly male forensic psychiatric settings, higher levels of impulsivity predicted poorer subjective sleep quality in both women and men. Consistent with well-established associations between depression and sleep, higher levels of depression in both sexes predicted poorer subjective sleep quality. Bidirectional analyses showed that better sleep efficiency decreases depression. Finally, moderation analyses showed that gender does have a primary role in sleep efficiency and marginal effects were found. The observed relations between sleep and personality traits in a typical university sample add to converging evidence of the relationship between sleep and psychopathology and may inform our understanding of the development of psychopathology in young adulthood. PMID:26500575

  19. Internalizing and externalizing traits predict changes in sleep efficiency in emerging adulthood: an actigraphy study.

    PubMed

    Yaugher, Ashley C; Alexander, Gerianne M

    2015-01-01

    Research on psychopathology and experimental studies of sleep restriction support a relationship between sleep disruption and both internalizing and externalizing disorders. The objective of the current study was to extend this research by examining sleep, impulsivity, antisocial personality traits, and internalizing traits in a university sample. Three hundred and eighty six individuals (161 males) between the ages of 18 and 27 years (M = 18.59, SD = 0.98) wore actigraphs for 7 days and completed established measures of disorder-linked personality traits and sleep quality (i.e., Personality Assessment Inventory (PAI), Triarchic Psychopathy Measure, Barratt Impulsiveness Scale-11, and the Pittsburgh Sleep Quality Index). As expected, sleep measures and questionnaire scores fell within the normal range of values and sex differences in sleep and personality were consistent with previous research results. Similar to findings in predominantly male forensic psychiatric settings, higher levels of impulsivity predicted poorer subjective sleep quality in both women and men. Consistent with well-established associations between depression and sleep, higher levels of depression in both sexes predicted poorer subjective sleep quality. Bidirectional analyses showed that better sleep efficiency decreases depression. Finally, moderation analyses showed that gender does have a primary role in sleep efficiency and marginal effects were found. The observed relations between sleep and personality traits in a typical university sample add to converging evidence of the relationship between sleep and psychopathology and may inform our understanding of the development of psychopathology in young adulthood. PMID:26500575

  20. HELLE: Health Effects of Low Level Exposures/ Gezondheidseffecten van lage blootstellingniveaus [International workshop: Influence of low level exposures to chemicals and radiation on human and ecological health

    SciTech Connect

    Schoten, Eert

    1998-11-26

    The Health Council is closely involved in establishing the scientific foundation of exposure limits for substances and radiation in order to protect public health. Through the years, the Council has contributed to the formulation of principles and procedures, both for carcinogenic and for noncarcinogenic agents. As a rule, the discussion with regard to the derivation of health-based recommended exposure limits centers around the appropriateness of extrapolation methods (What can be inferred from data on high exposure levels and on experimental animals?). Generally speaking, there is a lack of direct information on the health effects of low levels of exposure. Effects at these levels cannot usually be detected by means of traditional animal experiments or epidemiological research. The capacity of these analytical instruments to distinguish between ''signal'' and ''noise'' is inadequate in most cases. Annex B of this report contains a brief outline of the difficulties and the established methods for tackling this problem. In spite of this, the hope exists that the posited weak signals, if they are indeed present, can be detected by other means. The search will have to take place on a deeper level. In other words, effort must be made to discover what occurs at underlying levels of biological organization when organisms are exposed to low doses of radiation or substances. Molecular and cell biology provide various methods and techniques which give an insight into the processes within the cell. This results in an increase in the knowledge about the molecular and cellular effects of exposure to agents, or stated differently, the working mechanisms which form the basis of the health effects. Last year, the Health Council considered that the time was ripe to take stock of the state of knowledge in this field. To this end, an international working conference was held from 19 to 21 October 1997, entitled ''Health Effects of Low Level Exposures: Scientific Developments and

  1. Executive Function Predicts Adaptive Behavior in Children with Histories of Heavy Prenatal Alcohol Exposure and Attention Deficit/Hyperactivity Disorder

    PubMed Central

    Ware, Ashley L.; Crocker, Nicole; O’Brien, Jessica W.; Deweese, Benjamin N.; Roesch, Scott C.; Coles, Claire D.; Kable, Julie A.; May, Philip A.; Kalberg, Wendy O.; Sowell, Elizabeth R.; Jones, Kenneth Lyons; Riley, Edward P.; Mattson, Sarah N.

    2011-01-01

    Purpose of Study Prenatal exposure to alcohol often results in disruption to discrete cognitive and behavioral domains, including executive function (EF) and adaptive functioning. In the current study, the relation between these two domains was examined in children with histories of heavy prenatal alcohol exposure, non-exposed children with a diagnosis of attention-deficit/hyperactivity disorder (ADHD), and typically developing controls. Methods As part of a multisite study, three groups of children (8-18y, M = 12.10) were tested: children with histories of heavy prenatal alcohol exposure (ALC, N=142), non-exposed children with ADHD (ADHD, N=82), and typically developing controls (CON, N=133) who did not have ADHD or a history of prenatal alcohol exposure. Children completed subtests of the Delis-Kaplan Executive Function System (D-KEFS) and their primary caregivers completed the Vineland Adaptive Behavior Scales-II (VABS). Data were analyzed using regression analyses. Results Analyses showed that EF measures were predictive of adaptive abilities and significant interactions between D-KEFS measures and group were present. For the ADHD group, the relation between adaptive abilities and EF was more general, with three of the four EF measures showing a significant relation with adaptive score. In contrast, for the ALC group, this relation was specific to the nonverbal EF measures. In the CON group, performance on EF tasks did not predict adaptive scores over the influence of age. Conclusion These results support prior research in ADHD suggesting that EF deficits are predictive of poorer adaptive behavior and extend this finding to include children with heavy prenatal exposure to alcohol. However, the relation between EF and adaptive ability differed by group, suggesting unique patterns of abilities in these children. These results provide enhanced understanding of adaptive deficits in these populations, as well as demonstrate the ecological validity of laboratory

  2. Progress in Space Weather Modeling and Observations Needed to Improve the Operational NAIRAS Model Aircraft Radiation Exposure Predictions

    NASA Astrophysics Data System (ADS)

    Mertens, C. J.; Kress, B. T.; Wiltberger, M. J.; Tobiska, W.; Xu, X.

    2011-12-01

    The Nowcast of Atmospheric Ionizing Radiation for Aviation Safety (NAIRAS) is a prototype operational model for predicting commercial aircraft radiation exposure from galactic and solar cosmic rays. NAIRAS predictions are currently streaming live from the project's public website, and the exposure rate nowcast is also available on the SpaceWx smartphone app for iPhone, IPad, and Android. Cosmic rays are the primary source of human exposure to high linear energy transfer radiation at aircraft altitudes, which increases the risk of cancer and other adverse health effects. Thus, the NAIRAS model addresses an important national need with broad societal, public health and economic benefits. The processes responsible for the variability in the solar wind, interplanetary magnetic field, solar energetic particle spectrum, and the dynamical response of the magnetosphere to these space environment inputs, strongly influence the composition and energy distribution of the atmospheric ionizing radiation field. During the development of the NAIRAS model, new science questions were identified that must be addressed in order to obtain a more reliable and robust operational model of atmospheric radiation exposure. Addressing these science questions require improvements in both space weather modeling and observations. The focus of this talk is to present these science questions, the proposed methodologies for addressing these science questions, and the anticipated improvements to the operational predictions of atmospheric radiation exposure. The overarching goal of this work is to provide a decision support tool for the aviation industry that will enable an optimal balance to be achieved between minimizing health risks to passengers and aircrew while simultaneously minimizing costs to the airline companies.

  3. Adolescents' internalizing and externalizing problems predict their affect-specific HPA and HPG axes reactivity.

    PubMed

    Han, Georges; Miller, Jonas G; Cole, Pamela M; Zahn-Waxler, Carolyn; Hastings, Paul D

    2015-09-01

    We examined psychopathology-neuroendocrine associations in relation to the transition into adolescence within a developmental framework that acknowledged the interdependence of the HPA and HPG hormone systems in the regulation of responses to everyday affective contexts. Saliva samples were collected during anxiety and anger inductions from 51 young adolescents (M 13.47, SD = .60 years) to evaluate cortisol, DHEA, and testosterone responses. Internalizing and externalizing problems were assessed at pre-adolescence (M = 9.27, SD = .58 years) while youths were in elementary school and concurrently with hormones in early adolescence. Externalizing problems from elementary school predicted adolescents' reduced DHEA reactivity during anxiety induction. Follow up analyses simultaneously examining the contributions of elementary school and adolescent problems showed a trend suggesting that youths with higher levels of internalizing problems during elementary school eventuated in a profile of heightened DHEA reactivity as adolescents undergoing anxiety induction. For both the anxiety and the anger inductions, it was normative for DHEA and testosterone to be positively coupled. Adolescents with high externalizing problems but low internalizing problems marshaled dual axes co-activation during anger induction in the form of positive cortisol-testosterone coupling. This is some of the first evidence suggesting affective context determines whether dual axes coupling is reflective of normative or problematic functioning in adolescence. PMID:25604092

  4. Predicting Internalizing Problems in Chinese Children: the Unique and Interactive Effects of Parenting and Child Temperament

    PubMed Central

    Muhtadie, Luma; Zhou, Qing; Eisenberg, Nancy; Wang, Yun

    2012-01-01

    The additive and interactive relations of parenting styles (authoritative and authoritarian parenting) and child temperament (anger/frustration, sadness, and effortful control) to children’s internalizing problems were examined in a 3.8-year longitudinal study of 425 Chinese children (6 – 9 years) from Beijing. At Wave 1, parents self-reported on their parenting styles, and parents and teachers rated child temperament. At Wave 2, parents, teachers, and children rated children’s internalizing problems. Structural equation modeling indicated that the main effect of authoritative parenting, and the interactions of authoritarian parenting × effortful control and authoritative parenting × anger/frustration (parents’ reports only) prospectively and uniquely predicted internalizing problems. The above results did not vary by child sex and remained significant after controlling for co-occurring externalizing problems. These findings suggest that: a) children with low effortful control may be particularly susceptible to the adverse effect of authoritarian parenting, and b) the benefit of authoritative parenting may be especially important for children with high anger/frustration. PMID:23880383

  5. Predicting internalizing problems in Chinese children: the unique and interactive effects of parenting and child temperament.

    PubMed

    Muhtadie, Luma; Zhou, Qing; Eisenberg, Nancy; Wang, Yun

    2013-08-01

    The additive and interactive relations of parenting styles (authoritative and authoritarian parenting) and child temperament (anger/frustration, sadness, and effortful control) to children's internalizing problems were examined in a 3.8-year longitudinal study of 425 Chinese children (aged 6-9 years) from Beijing. At Wave 1, parents self-reported on their parenting styles, and parents and teachers rated child temperament. At Wave 2, parents, teachers, and children rated children's internalizing problems. Structural equation modeling indicated that the main effect of authoritative parenting and the interactions of Authoritarian Parenting × Effortful Control and Authoritative Parenting × Anger/Frustration (parents' reports only) prospectively and uniquely predicted internalizing problems. The above results did not vary by child sex and remained significant after controlling for co-occurring externalizing problems. These findings suggest that (a) children with low effortful control may be particularly susceptible to the adverse effect of authoritarian parenting and (b) the benefit of authoritative parenting may be especially important for children with high anger/frustration. PMID:23880383

  6. Predicting Changes in PM Exposure Over Time at U.S. Trucking Terminals Using Structural Equation Modeling Techniques

    PubMed Central

    Davis, Mary E.; Laden, Francine; Hart, Jaime E.; Garshick, Eric; Blicharz, Andrew; Smith, Thomas J.

    2009-01-01

    This study analyzes the temporal variability of occupational and environmental exposures to fine particulate matter in the U.S. trucking industry and tests the predictive ability of a novel multilayer statistical approach to occupational exposure modeling using structural equation modeling (SEM) techniques. For these purposes, elemental carbon mass in PM<1 µm at six U.S. trucking terminals were measured twice during the same season up to 2 years apart, observing concentrations in the indoor loading dock (median EC: period 1 = 0.65 µg/m3; period 2 = 0.94 µg/m3 ) and outdoor background location (median EC: period 1 = 0.46 µg/m3 ; period 2 = 0.67 µg/m3 ), as well as in the truck cabs of local drivers while on the road (median EC: period 1=1.09 µg/m3 ; period 2 = 1.07 µg/m3 ). There was a general trend toward higher exposures during the second sampling trips; however, these differences were statistically significant in only a few cases and were largely attributable to changes in weather patterns (wind speed, precipitation, etc.). Once accounting for systematic prediction errors in background concentrations, the SEM approach provided a strong fit for work-related exposures in this occupational setting. PMID:19367483

  7. Spatiotemporal characteristics of internal radiation exposure in evacuees and first responders after the radiological accident in fukushima.

    PubMed

    Morita, Naoko; Miura, Miwa; Yoshida, Masahiro; Kumagai, Atsushi; Ohtsuru, Akira; Usa, Toshiro; Kudo, Takashi; Takamura, Noboru; Yamashita, Shunichi; Matsuda, Naoki

    2013-09-01

    After the Tokyo Electric Power Company Fukushima Daiichi nuclear power plant accident on March 11, 2011, the reconstruction of early internal radiation doses in residents of Fukushima plays a major role in evaluating their future heath risk, including thyroid cancer by internal radioiodine. Internal radioactivity was measured using a whole body counter (WBC) at the Nagasaki University Medical School to evaluate the health risks of residents and short term visitors in Fukushima. Measurable (131)I, (134)Cs and (137)Cs were detected altogether in 49 out of 196 people who were in Fukushima prefecture at any time during March 11 and April 20, 2011. In 49 people, the 90 percentile of the thyroid equivalent dose by (131)I and the committed effective dose (total effective dose over a lifetime) by the sum of (134)Cs and (137)Cs was 3 mSv and 0.06 mSv, respectively. The radionuclide intakes in early evacuees who left Fukushima before March 16 were more than five times as high as in the responders who moved to Fukushima later. The intake ratio of (131)I/(137)Cs of the earlier evacuees was approximately three. The spatial analysis of 16 evacuees to the south indicated a reduction of internal radioactivity depending on the distance from the nuclear power plant. Among them, high internal (131)I radioactivity in 6 people in a particular evacuation route could be explained by the arrival of a radioactive cloud with a high airborne (131)I/(137)Cs ratio to the environment, as predicted by atmospheric dispersion simulations. Overall, the actual internal radioactivity assessed by a WBC examination comparatively agreed with the predicted airborne radioactivity. These results suggest that the accurate estimation of internal doses in the first week after the radiological accident is critical for the dose reconstruction. The evaluation of internal doses of residents based on their evacuation routes and the advanced estimation of airborne radioactivity from the atmospheric dispersion model

  8. Home Away Home: Better Understanding of the Role of Social Support in Predicting Cross-Cultural Adjustment among International Students

    ERIC Educational Resources Information Center

    Baba, Yoko; Hosoda, Megumi

    2014-01-01

    Numerous studies have examined international students' adjustment problems, yet, these studies have not explored the mechanisms through which social support operates in the context of stressful events in predicting cross-cultural adjustment among international students. Using Barrera's (1988) models of social support, the present study…

  9. Estimating Time-Varying PCB Exposures Using Person-Specific Predictions to Supplement Measured Values: A Comparison of Observed and Predicted Values in Two Cohorts of Norwegian Women

    PubMed Central

    Nøst, Therese Haugdahl; Breivik, Knut; Wania, Frank; Rylander, Charlotta; Odland, Jon Øyvind; Sandanger, Torkjel Manning

    2015-01-01

    Background Studies on the health effects of polychlorinated biphenyls (PCBs) call for an understanding of past and present human exposure. Time-resolved mechanistic models may supplement information on concentrations in individuals obtained from measurements and/or statistical approaches if they can be shown to reproduce empirical data. Objectives Here, we evaluated the capability of one such mechanistic model to reproduce measured PCB concentrations in individual Norwegian women. We also assessed individual life-course concentrations. Methods Concentrations of four PCB congeners in pregnant (n = 310, sampled in 2007–2009) and postmenopausal (n = 244, 2005) women were compared with person-specific predictions obtained using CoZMoMAN, an emission-based environmental fate and human food-chain bioaccumulation model. Person-specific predictions were also made using statistical regression models including dietary and lifestyle variables and concentrations. Results CoZMoMAN accurately reproduced medians and ranges of measured concentrations in the two study groups. Furthermore, rank correlations between measurements and predictions from both CoZMoMAN and regression analyses were strong (Spearman’s r > 0.67). Precision in quartile assignments from predictions was strong overall as evaluated by weighted Cohen’s kappa (> 0.6). Simulations indicated large inter-individual differences in concentrations experienced in the past. Conclusions The mechanistic model reproduced all measurements of PCB concentrations within a factor of 10, and subject ranking and quartile assignments were overall largely consistent, although they were weak within each study group. Contamination histories for individuals predicted by CoZMoMAN revealed variation between study subjects, particularly in the timing of peak concentrations. Mechanistic models can provide individual PCB exposure metrics that could serve as valuable supplements to measurements. Citation Nøst TH, Breivik K, Wania F

  10. Stochastic modelling for biodosimetry: Predicting the chromosomal response to radiation at different time points after exposure

    NASA Astrophysics Data System (ADS)

    Deperas-Standylo, Joanna; Gudowska-Nowak, Ewa; Ritter, Sylvia

    2014-07-01

    Cytogenetic data accumulated from the experiments with peripheral blood lymphocytes exposed to densely ionizing radiation clearly demonstrate that for particles with linear energy transfer (LET) >100 keV/ μm the derived relative biological effectiveness (RBE) will strongly depend on the time point chosen for the analysis. A reasonable prediction of radiation-induced chromosome damage and its distribution among cells can be achieved by exploiting Monte Carlo methodology along with the information about the radius of the penetrating ion-track and the LET of the ion beam. In order to examine the relationship between the track structure and the distribution of aberrations induced in human lymphocytes and to clarify the correlation between delays in the cell cycle progression and the aberration burden visible at the first post-irradiation mitosis, we have analyzed chromosome aberrations in lymphocytes exposed to Fe-ions with LET values of 335 keV/ μm and formulated a Monte Carlo model which reflects time-delay in mitosis of aberrant cells. Within the model the frequency distributions of aberrations among cells follow the pattern of local energy distribution and are well approximated by a time-dependent compound Poisson statistics. The cell-division cycle of undamaged and aberrant cells and chromosome aberrations are modelled as a renewal process represented by a random sum of (independent and identically distributed) random elements S N = ∑ N i=0 X i . Here N stands for the number of particle traversals of cell nucleus, each leading to a statistically independent formation of X i aberrations. The parameter N is itself a random variable and reflects the cell cycle delay of heavily damaged cells. The probability distribution of S N follows a general law for which the moment generating function satisfies the relation Φ S N = Φ N ( Φ X i ). Formulation of the Monte Carlo model which allows to predict expected fluxes of aberrant and non-aberrant cells has been based

  11. Predictable internal brain dynamics in EEG and its relation to conscious states

    PubMed Central

    Yoo, Jaewook; Kwon, Jaerock; Choe, Yoonsuck

    2014-01-01

    Consciousness is a complex and multi-faceted phenomenon defying scientific explanation. Part of the reason why this is the case is due to its subjective nature. In our previous computational experiments, to avoid such a subjective trap, we took a strategy to investigate objective necessary conditions of consciousness. Our basic hypothesis was that predictive internal dynamics serves as such a condition. This is in line with theories of consciousness that treat retention (memory), protention (anticipation), and primary impression as the tripartite temporal structure of consciousness. To test our hypothesis, we analyzed publicly available sleep and awake electroencephalogram (EEG) data. Our results show that EEG signals from awake or rapid eye movement (REM) sleep states have more predictable dynamics compared to those from slow-wave sleep (SWS). Since awakeness and REM sleep are associated with conscious states and SWS with unconscious or less consciousness states, these results support our hypothesis. The results suggest an intricate relationship among prediction, consciousness, and time, with potential applications to time perception and neurorobotics. PMID:24917813

  12. Predictions of secondary neutrons and their importance to radiation effects inside the International Space Station

    NASA Technical Reports Server (NTRS)

    Armstrong, T. W.; Colborn, B. L.

    2001-01-01

    As part of a study funded by NASA MSFC to assess thecontribution of secondary particles in producing radiation damage to optoelectronics devices located on the International Space Station (IS), Monte Carlo calculations have been made to predict secondary spectra vs. shielding inside ISS modules and in electronics boxes attached on the truss (Armstrong and Colborn, 1998). The calculations take into account secondary neutron, proton, and charged pion production from the ambient galactic cosmic-ray (GCR) proton, trapped proton, and neutron albedo environments. Comparisons of the predicted neutron spectra with measurments made on the Mir space station and other spacecraft have also been made (Armstrong and Colborn, 1998). In this paper, some initial results from folding the predicted neutron spectrum inside ISS modules from Armstrong and Colborn (1998) with several types of radiation effects response functions related to electronics damage and astronaut-dose are given. These results provide an estimate of the practical importance of neutrons compared to protons in assessing radiation effects for the ISS. Also, the important neutron energy ranges for producing these effects have been estimated, which provides guidance for onboard neutron measurement requirements.

  13. Predictions of secondary neutrons and their importance to radiation effects inside the International Space Station.

    PubMed

    Armstrong, T W; Colborn, B L

    2001-06-01

    As part of a study funded by NASA MSFC to assess thecontribution of secondary particles in producing radiation damage to optoelectronics devices located on the International Space Station (IS), Monte Carlo calculations have been made to predict secondary spectra vs. shielding inside ISS modules and in electronics boxes attached on the truss (Armstrong and Colborn, 1998). The calculations take into account secondary neutron, proton, and charged pion production from the ambient galactic cosmic-ray (GCR) proton, trapped proton, and neutron albedo environments. Comparisons of the predicted neutron spectra with measurments made on the Mir space station and other spacecraft have also been made (Armstrong and Colborn, 1998). In this paper, some initial results from folding the predicted neutron spectrum inside ISS modules from Armstrong and Colborn (1998) with several types of radiation effects response functions related to electronics damage and astronaut-dose are given. These results provide an estimate of the practical importance of neutrons compared to protons in assessing radiation effects for the ISS. Also, the important neutron energy ranges for producing these effects have been estimated, which provides guidance for onboard neutron measurement requirements. PMID:11852942

  14. Predicted reduction in lung cancer risk following cessation of smoking and radon exposure

    SciTech Connect

    Ennever, F.K. )

    1990-03-01

    Recently there has been considerable public and regulatory concern that radon, produced by the decay of naturally occurring uranium, can accumulate in homes, offices, and schools at levels that may substantially increase the risk of lung cancer. The major cause of lung cancer is smoking, and radon appears to interact multiplicatively with smoking in causing lung cancer. Thus, the most effective way to reduce the increased risk of lung cancer resulting from radon exposure is to cease smoking. In this paper, a model for the risks associated with radon exposure that was developed by a committee of the National Academy of Sciences is used to calculate the benefits, in terms of reduction in lifetime risk of lung cancer, of ceasing to smoke, ceasing radon exposure, or ceasing both. Ceasing to smoke is considerably more beneficial than ceasing radon exposure, and thus policymakers addressing the health effects of radon should place priority on encouraging individuals to stop smoking.

  15. Predicting dredging-associated effects to coral reefs in Apra Harbor, Guam - Part 1: Sediment exposure modeling.

    PubMed

    Gailani, Joseph Z; Lackey, Tahirih C; King, David B; Bryant, Duncan; Kim, Sung-Chan; Shafer, Deborah J

    2016-03-01

    Model studies were conducted to investigate the potential coral reef sediment exposure from dredging associated with proposed development of a deepwater wharf in Apra Harbor, Guam. The Particle Tracking Model (PTM) was applied to quantify the exposure of coral reefs to material suspended by the dredging operations at two alternative sites. Key PTM features include the flexible capability of continuous multiple releases of sediment parcels, control of parcel/substrate interaction, and the ability to efficiently track vast numbers of parcels. This flexibility has facilitated simulating the combined effects of sediment released from clamshell dredging and chiseling within Apra Harbor. Because the rate of material released into the water column by some of the processes is not well understood or known a priori, the modeling approach was to bracket parameters within reasonable ranges to produce a suite of potential results from multiple model runs. Sensitivity analysis to model parameters is used to select the appropriate parameter values for bracketing. Data analysis results include mapping the time series and the maximum values of sedimentation, suspended sediment concentration, and deposition rate. Data were used to quantify various exposure processes that affect coral species in Apra Harbor. The goal of this research is to develop a robust methodology for quantifying and bracketing exposure mechanisms to coral (or other receptors) from dredging operations. These exposure values were utilized in an ecological assessment to predict effects (coral reef impacts) from various dredging scenarios. PMID:26692413

  16. Cover-up of the effects of internal exposure by residual radiation from the atomic bombing of Hiroshima and Nagasaki.

    PubMed

    Sawada, Shoji

    2007-01-01

    The criteria certifying atomic bomb disease adopted by the Japanese government are very different from the actual state of the survivors. The criteria are based on epidemiological research by the Radiation Effects Research Foundation, the successor to the Atomic Bomb Casualty Commission (ABCC). The ABCC studied only the effects of primary radiation from the atomic bombing on the survivors of Hiroshima and Nagasaki, and ignored the damage from residual radiation. Analysis of the incidence of acute radiation disease, the rate of chromosomal aberrations, and the relative risks of chronic disease among the survivors, shows that the effects of residual radiation from fallout exceeds that of primary radiation in the area more than 1.5-1.7 km distant from the hypocentre of the Hiroshima bombing. The effects of internal exposure due to intake of tiny radioactive particles are more severe than those of external exposure, explaining the difference between the official criteria and the actual state of the survivors. PMID:17370859

  17. Assessment of occupational exposure to PAHs in an Estonian coke oven plant- correlation of total external exposure to internal dose measured as 1-hydroxypyrene concentration.

    PubMed

    Kuljukka, T; Vaaranrinta, R; Mutanen, P; Veidebaum, T; Sorsa, M; Kalliokoski, P; Peltonen, K

    1997-01-01

    The exposure of cokery workers to polynuclear aromatic hydrocarbons at an Estonian oil shale processing plant was assessed by using occupational hygiene and biomonitoring measurements which were carried out twice, in midwinter and in the autumn. To assess the external dose of polynuclear aromatic hydrocarbons, pyrene and benzo[a]pyrene concentrations were measured from the breathing zone of workers during a workshift. Skin contamination with pyrene and benzo[a]pyrene was assessed by skin wipe sampling before and after the workshift. As a biomarker of overall exposure to polynuclear aromatic hydrocarbons, and as an integral of all absorption routes of pyrene, 1-hydroxypyrene concentration was measured from post shift urine samples. Of the personal air samples, 18% exceeded the Finnish threshold limit value of benzo[a]pyrene (10 μg m(-3)). Mean value (two separate measurements together) for benzo[a]pyrene was 5.7 μg m(-3) and for pyrene, 8.1 μg m(-3). Based on skin wipe sample analyses, the skin contamination was also obvious. The mean value of benzo[a]pyrene in the samples collected after the shift was 1.2 ng cm(-2). Benzo[a]pyrene was not found in control samples. The mean value of urinary 1-hydroxypyrene concentration was 6.0 μmol mol(-1) creatinine for the exposed workers and 0.5 μmol mol(-1) creatinine for the controls. This study undoubtedly shows the usefulness of 1-hydroxypyrene as an indicator of internal dose of polynuclear aromatic hydrocarbons. It can be concluded that the cokery workers at the Kohtla-Järve plant are exposed to high concentrations of polynuclear aromatic compounds, and the exposure level is considerably higher during the winter measurements. PMID:23889064

  18. 78 FR 79061 - Noise Exposure Map Notice; Key West International Airport, Key West, FL

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-27

    ... Nagy, Federal Aviation Administration, Orlando Airports District Office, 5950 Hazeltine National Drive Citadel International Building, Suite 400, Orlando, FL 32822, 407-812-6331. SUPPLEMENTARY INFORMATION... Aviation Administration, Orlando Airports District Office, 5950 Hazeltine National Drive,...

  19. 78 FR 9449 - Noise Exposure Map Notice, Southwest Florida International Airport, Fort Myers, FL

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-08

    ... FURTHER INFORMATION CONTACT: Allan Nagy, Federal Aviation Administration, Orlando Airports District Office, 5950 Hazeltine National Drive Citadel International Building, Suite 400, Orlando, FL 32822, 407-812...: Federal Aviation Administration, Orlando Airports District Office, 5950 Hazeltine National Drive,...

  20. Internal exposure to pollutants measured in blood and urine of Flemish adolescents in function of area of residence.

    PubMed

    Schroijen, C; Baeyens, W; Schoeters, G; Den Hond, E; Koppen, G; Bruckers, L; Nelen, V; Van De Mieroop, E; Bilau, M; Covaci, A; Keune, H; Loots, I; Kleinjans, J; Dhooge, W; Van Larebeke, N

    2008-04-01

    The Centre for Environment and Health in Flanders, the Northern part of Belgium, started a biomonitoring program on adolescents in 2003. 1679 adolescents residing in nine areas with different patterns of pollution participated in the study. Possible confounding effects of lifestyle and personal characteristics were taken into account. The geometric mean levels of cadmium and lead in whole blood amounted to 0.36 and 21.7 microg l(-1), those of PCBs, DDE and HCB in serum to 68, 94 and 20.9 ng g(-1) fat, and those of 1-hydroxypyrene and t,t'-muconic acid in urine to 88 ng g(-1) creatinine and 72 microg g(-1) creatinine. Significant regional differences in internal lead, cadmium, PCBs, DDE and HCB exposure were observed in function of area of residence, even after adjustment for age, sex, smoking (and body mass index for the chlorinated compounds). Compared to a reference mean, internal exposure was significantly higher in one or more of the areas: Cd and Pb in the Antwerp agglomeration, Cd in the Antwerp harbour, PCBs in the Ghent agglomeration, PCBs, DDE and HCB in the Ghent harbour, Cd, PCBs, DDE and HCB in the rural area, DDE in Olen and in the Albert canal areas. Adolescents living in an area with intensive fruit cultivation (showing overall the lowest values) and, surprisingly, in areas around household waste incinerators (average of six areas), had no significantly increased internal exposures. Subjects from separate areas around waste incinerators showed significant differences in body load of various environmental contaminants. PMID:18221770

  1. An evaluation of early countermeasures to reduce the risk of internal radiation exposure after the Fukushima nuclear incident in Japan.

    PubMed

    Nomura, Shuhei; Tsubokura, Masaharu; Gilmour, Stuart; Hayano, Ryugo S; Watanabe, Yuni N; Kami, Masahiro; Kanazawa, Yukio; Oikawa, Tomoyoshi

    2016-05-01

    After a radiation-release incident, intake of radionuclides in the initial stage immediately following the incident may be the major contributor to total internal radiation exposure for individuals in affected areas. However, evaluation of early internal contamination risk is greatly lacking. This study assessed the relationship between initial stage evacuation/indoor sheltering and internal radiation contamination levels 4 months after the 2011 Fukushima nuclear incident in Japan and estimated potential pathways of the contamination. The study population comprised 525 participants in the internal radiation screening program at Minamisoma Municipal General Hospital, 23 km north of the Fukushima nuclear plant. The analysed dataset included the results of a screening performed in July 2011, 4 months after the incident, and of a questionnaire on early-incident response behaviours, such as sheltering indoors and evacuations, completed by participants. Association between such early countermeasures and internal contamination levels of cesium-134 were assessed using Tobit multiple regression analyses. Our study shows that individuals who evacuated to areas outside Fukushima Prefecture had similar contamination levels of cesium-134 to individuals who stayed in Fukushima (relative risk: 0.86; 95% confidence interval: 0.74-0.99). Time spent outdoors had no significant relationship with contamination levels. The effects of inhalation from radiological plumes released from the nuclear plant on total internal radiation contamination might be so low as to be undetectable by the whole-body counting unit used to examine participants. Given the apparent limited effectiveness of evacuation and indoor sheltering on internal contamination, the decision to implement such early responses to a radiation-release incident should be made by carefully balancing their potential benefits and health risks. PMID:26363171

  2. Chaotic time series prediction for prenatal exposure to polychlorinated biphenyls in umbilical cord blood using the least squares SEATR model.

    PubMed

    Xu, Xijin; Tang, Qian; Xia, Haiyue; Zhang, Yuling; Li, Weiqiu; Huo, Xia

    2016-01-01

    Chaotic time series prediction based on nonlinear systems showed a superior performance in prediction field. We studied prenatal exposure to polychlorinated biphenyls (PCBs) by chaotic time series prediction using the least squares self-exciting threshold autoregressive (SEATR) model in umbilical cord blood in an electronic waste (e-waste) contaminated area. The specific prediction steps basing on the proposal methods for prenatal PCB exposure were put forward, and the proposed scheme's validity was further verified by numerical simulation experiments. Experiment results show: 1) seven kinds of PCB congeners negatively correlate with five different indices for birth status: newborn weight, height, gestational age, Apgar score and anogenital distance; 2) prenatal PCB exposed group at greater risks compared to the reference group; 3) PCBs increasingly accumulated with time in newborns; and 4) the possibility of newborns suffering from related diseases in the future was greater. The desirable numerical simulation experiments results demonstrated the feasibility of applying mathematical model in the environmental toxicology field. PMID:27118260

  3. Chaotic time series prediction for prenatal exposure to polychlorinated biphenyls in umbilical cord blood using the least squares SEATR model

    PubMed Central

    Xu, Xijin; Tang, Qian; Xia, Haiyue; Zhang, Yuling; Li, Weiqiu; Huo, Xia

    2016-01-01

    Chaotic time series prediction based on nonlinear systems showed a superior performance in prediction field. We studied prenatal exposure to polychlorinated biphenyls (PCBs) by chaotic time series prediction using the least squares self-exciting threshold autoregressive (SEATR) model in umbilical cord blood in an electronic waste (e-waste) contaminated area. The specific prediction steps basing on the proposal methods for prenatal PCB exposure were put forward, and the proposed scheme’s validity was further verified by numerical simulation experiments. Experiment results show: 1) seven kinds of PCB congeners negatively correlate with five different indices for birth status: newborn weight, height, gestational age, Apgar score and anogenital distance; 2) prenatal PCB exposed group at greater risks compared to the reference group; 3) PCBs increasingly accumulated with time in newborns; and 4) the possibility of newborns suffering from related diseases in the future was greater. The desirable numerical simulation experiments results demonstrated the feasibility of applying mathematical model in the environmental toxicology field. PMID:27118260

  4. A dynamic Monte Carlo model for predicting radiant exposure distribution in dental composites: model development and verifications

    NASA Astrophysics Data System (ADS)

    Chen, Yin-Chu; Ferracane, Jack L.; Prahl, Scott A.

    2005-03-01

    Photo-cured dental composites are widely used in dental practices to restore teeth due to the esthetic appearance of the composites and the ability to cure in situ. However, their complex optical characteristics make it difficult to understand the light transport within the composites and to predict the depth of cure. Our previous work showed that the absorption and scattering coefficients of the composite changed after the composite was cured. The static Monte Carlo simulation showed that the penetration of radiant exposures differed significantly for cured and uncured optical properties. This means that a dynamic model is required for accurate prediction of radiant exposure in the composites. The purpose of this study was to develop and verify a dynamic Monte Carlo (DMC) model simulating light propagation in dental composites that have dynamic optical properties while photons are absorbed. The composite was divided into many small cubes, each of which had its own scattering and absorption coefficients. As light passed through the composite, the light was scattered and absorbed. The amount of light absorbed in each cube was calculated using Beer's Law and was used to determine the next optical properties in that cube. Finally, the predicted total reflectance and transmittance as well as the optical property during curing were verified numerically and experimentally. Our results showed that the model predicted values agreed with the theoretical values within 1% difference. The DMC model results are comparable with experimental results within 5% differences.

  5. Chaotic time series prediction for prenatal exposure to polychlorinated biphenyls in umbilical cord blood using the least squares SEATR model

    NASA Astrophysics Data System (ADS)

    Xu, Xijin; Tang, Qian; Xia, Haiyue; Zhang, Yuling; Li, Weiqiu; Huo, Xia

    2016-04-01

    Chaotic time series prediction based on nonlinear systems showed a superior performance in prediction field. We studied prenatal exposure to polychlorinated biphenyls (PCBs) by chaotic time series prediction using the least squares self-exciting threshold autoregressive (SEATR) model in umbilical cord blood in an electronic waste (e-waste) contaminated area. The specific prediction steps basing on the proposal methods for prenatal PCB exposure were put forward, and the proposed scheme’s validity was further verified by numerical simulation experiments. Experiment results show: 1) seven kinds of PCB congeners negatively correlate with five different indices for birth status: newborn weight, height, gestational age, Apgar score and anogenital distance; 2) prenatal PCB exposed group at greater risks compared to the reference group; 3) PCBs increasingly accumulated with time in newborns; and 4) the possibility of newborns suffering from related diseases in the future was greater. The desirable numerical simulation experiments results demonstrated the feasibility of applying mathematical model in the environmental toxicology field.

  6. Surgical Exposure to Control the Distal Internal Carotid Artery at the Base of the Skull during Carotid Aneurysm Repair.

    PubMed

    Davis, Laura; Zeitouni, Anthony; Makhoul, Nicholas; Steinmetz, Oren K

    2016-07-01

    Extracranial carotid artery aneurysms are rare. Treatment options for these lesions include endovascular interventions, such as coiling and stenting, or surgical reconstruction, such as resection and primary reanastomosis, or interposition bypass grafting. In this report, we describe the surgical technique used to perform surgical repair of an internal carotid artery aneurysm extending up to the base of the skull. Anterior exposure of the infratemporal fossa and distal control of the carotid artery at the level of the carotid canal was achieved through a transcervical approach, performing double mandibular osteotomies with superior reflection of the middle mandibular section. PMID:26902936

  7. High energy channelling and the experimental search for the internal clock predicted by Louis de Broglie

    NASA Astrophysics Data System (ADS)

    Remillieux, J.; Artru, X.; Bajard, M.; Chehab, R.; Chevallier, M.; Curceanu, C.; Dabagov, S.; Dauvergne, D.; Guérin, H.; Gouanère, M.; Kirsch, R.; Krimmer, J.; Poizat, J.-C.; Ray, C.; Takabayashi, Y.; Testa, E.

    2015-07-01

    This paper gives a short review of the past and recent activities of the Atomic Collisions in Solids Lyon-group, in collaboration with other groups, in the field of high energy channelling. The ion-channelling programme was performed at GANIL-Caen and at GSI-Darmstadt. The electron-channelling programme started at ALS-Saclay for relativistic incident energies and was then extended to SPS-CERN for ultra-relativistic energies. The last part of this paper presents the electron-channelling experiments performed originally at ALS-Saclay, then at BTF-Frascati and more recently at LS-Saga, in order to observe the electron "internal clock" predicted in 1924 by L. de Broglie.

  8. Validation with experiments on simplified numerical prediction of hybrid rocket internal ballistics

    NASA Astrophysics Data System (ADS)

    Funami, Yuki; Shimada, Toru

    2012-11-01

    In order to design hybrid rocket engines, we have developed a numerical prediction approach to the internal ballistics. The key point is its cost performance. Therefore simple but efficient models are required. Fluid phenomenon and thermal conduction phenomenon in a solid fuel should be treated time-dependently, because characteristic times of these phenomena are longer than those of other phenomena. Besides, they are solved with the energy-flux balance equation at the solid fuel surface to determine the regression rate. It is confirmed that numerical evaluation of time- and space-averaged regression rate is the same order of magnitude as that in experiments. However, the factors n in ṙ¯ = aG¯oxn differ between calculations and experiments.

  9. Internalizing symptoms and rumination: the prospective prediction of familial and peer emotional victimization experiences during adolescence.

    PubMed

    Shapero, Benjamin G; Hamilton, Jessica L; Liu, Richard T; Abramson, Lyn Y; Alloy, Lauren B

    2013-12-01

    Adolescence is marked by increases in stressful life events. Although research has demonstrated that depressed individuals generate stress, few studies investigate the generation of emotional victimization. The current study examined the effects of rumination and internalizing symptoms on experiences of peer victimization and familial emotional abuse. Participants were 216 adolescents (M = 14-years-old; 58% female; 47% African-American) who completed two assessments. Results showed that rumination predicted peer victimization and emotional abuse. The effect of rumination on emotional victimization is heightened for those who have higher levels of depression symptoms. That is, individuals who ruminate and who have depression symptoms experience increases in both peer emotional victimization and parental emotional abuse. This study builds upon prior research and indicates that rumination may be a stronger predictor of emotional victimization than symptoms of depression or anxiety. Identifying underlying mechanisms may yield targets for interventions aimed at addressing the chronic nature of depression. PMID:24215953

  10. Numerical Prediction of Transient Axial Thrust and Internal Flows in a Rocket Engine Turbopump

    NASA Technical Reports Server (NTRS)

    VanHooser, Katherine; Bailey, John W.; Majumdar, Alok

    1999-01-01

    This paper presents the application of the Generalized Fluid System Simulation Program (GFSSP) to model the time-dependent flow in a complex secondary flow circuit of the turbopump of the Fastrac engine currently under development at Marshall Space Flight Center. GFSSP is a general purpose computer program for analyzing steady-state and time-dependant flowrates, pressures, temperatures, and concentrations in a complex flow network. The program employs a finite volume formulation of mass, momentum and energy conservation equations in conjunction with the thermodynamic equation of state of real fluids. GFSSP was used to calculate the axial thrust and internal flow distribution of the Fastrac engine turbopump during the start and shut down transients. The models discussed in this paper use boundary conditions that were extracted from turbopump test data. The GFSSP predicted turbopump secondary flow passage pressures and temperatures were compared with actual measured values.

  11. Predictive factors for percutaneous and mucocutaneous exposure among healthcare workers in a developing country.

    PubMed

    Türe, Zeynep; Ulu Kiliç, Ayşegül; Cevahir, Fatma; Altun, Dilek; Özhan, Esra; Alp, Emine

    2016-09-01

    The aim of this study is to determine the risk factors for percutaneous and mucocutaneous exposures in healthcare workers (HCW) in one of the largest centers of a middle income country, Turkey. This study has a retrospective design. HCWs who presented between August 2011 and June 2013, with Occupational Exposures (OEs) (cases) and those without (controls) were included. Demographic information was collected from infection control committee documents. A questionnaire was used to ask the HCWs about their awareness of preventive measures. HCWs who work with intensive work loads such as those found in emergency departments or intensive care units have a higher risk of OEs. Having heavy workloads and hours increases the risk of percutaneous and mucocutaneous exposures. For that reason the most common occupation groups are nurses and cleaning staff who are at risk of OEs. Increasing work experience has reduced the frequency of OEs. PMID:26164279

  12. Space Environment Exposure Results from the MISSE 5 Polymer Film Thermal Control Experiment on the International Space Station

    NASA Technical Reports Server (NTRS)

    Miller, Sharon K. R.; Dever, Joyce A.

    2009-01-01

    It is known that polymer films can degrade in space due to exposure to the environment, but the magnitude of the mechanical property degradation and the degree to which the different environmental factors play a role in it is not well understood. This paper describes the results of an experiment flown on the Materials International Space Station Experiment (MISSE) 5 to determine the change in tensile strength and % elongation of some typical polymer films exposed in a nadir facing environment on the International Space Station and where possible compare to similar ram and wake facing experiments flown on MISSE 1 to get a better indication of the role the different environments play in mechanical property change.

  13. The Dynamic International Prognostic Scoring System for myelofibrosis predicts outcomes after hematopoietic cell transplantation.

    PubMed

    Scott, Bart L; Gooley, Ted A; Sorror, Mohamed L; Rezvani, Andrew R; Linenberger, Michael L; Grim, Jonathan; Sandmaier, Brenda M; Myerson, David; Chauncey, Thomas R; Storb, Rainer; Buxhofer-Ausch, Veronika; Radich, Jerald P; Appelbaum, Frederick R; Deeg, H Joachim

    2012-03-15

    Studies by the International Working Group showed that the prognosis of myelofibrosis patients is predicted by the Dynamic International Prognostic Scoring System (DIPSS) risk categorization, which includes patient age, constitutional symptoms, hemoglobin, leukocyte count, and circulating blasts. We evaluated the prognostic usefulness of the DIPSS in 170 patients with myelofibrosis, 12 to 78 years of age (median, 51.5 years of age), who received hematopoietic cell transplantation (HCT) between 1990 and 2009 from related (n = 86) or unrelated donors (n = 84). By DIPSS, 21 patients had low-risk disease, 48 had intermediate-1, 50 had intermediate-2, and 51 had high-risk disease. Five-year incidence of relapse, relapse-free survival, overall survival, and nonrelapse mortality for all patients were 10%, 57%, 57%, and 34%, respectively. Among patients with DIPSS high-risk disease, the hazard ratio for post-HCT mortality was 4.11 (95% CI, 1.44-11.78; P = .008), and for nonrelapse mortality was 3.41 (95% CI, 1.15-10.09; P = .03) compared with low-risk patients. After a median follow-up of 5.9 years, the median survivals have not been reached for DIPSS risk groups low and intermediate-1, and were 7 and 2.5 years for intermediate-2 and high-risk patients, respectively. Thus, HCT was curative for a large proportion of patients with myelofibrosis, and post-HCT success was dependent on pre-HCT DIPSS classification. PMID:22234678

  14. Development of Urinary Biomarkers for Internal Exposure by Cesium-137 Using a Metabolomics Approach in Mice

    PubMed Central

    Goudarzi, Maryam; Weber, Waylon; Mak, Tytus D.; Chung, Juijung; Doyle-Eisele, Melanie; Melo, Dunstana; Brenner, David J.; Guilmette, Raymond A.; Fornace, Albert J.

    2014-01-01

    Cesium-137 is a fission product of uranium and plutonium in nuclear reactors and is released in large quantities during nuclear explosions or detonation of an improvised device containing this isotope. This environmentally persistent radionuclide undergoes radioactive decay with the emission of beta particles as well as gamma radiation. Exposure to 137Cs at high doses can cause acute radiation sickness and increase risk for cancer and death. The serious health risks associated with 137Cs exposure makes it critical to understand how it affects human metabolism and whether minimally invasive and easily accessible samples such as urine and serum can be used to triage patients in case of a nuclear disaster or a radiologic event. In this study, we have focused on establishing a time-dependent metabolomic profile for urine collected from mice injected with 137CsCl. The samples were collected from control and exposed mice on days 2, 5, 20 and 30 after injection. The samples were then analyzed by ultra-performance liquid chromatography coupled to time-of-flight mass spectrometry (UPLC/TOFMS) and processed by an array of informatics and statistical tools. A total of 1,412 features were identified in ESI+ and ESI− modes from which 200 were determined to contribute significantly to the separation of metabolomic profiles of controls from those of the different treatment time points. The results of this study highlight the ease of use of the UPLC/TOFMS platform in finding urinary biomarkers for 137Cs exposure. Pathway analysis of the statistically significant metabolites suggests perturbations in several amino acid and fatty acid metabolism pathways. The results also indicate that 137Cs exposure causes: similar changes in the urinary excretion levels of taurine and citrate as seen with external-beam gamma radiation; causes no attenuation in the levels of hexanoylglycine and N-acetylspermidine; and has unique effects on the levels of isovalerylglycine and tiglylglycine. PMID

  15. Development of urinary biomarkers for internal exposure by cesium-137 using a metabolomics approach in mice.

    PubMed

    Goudarzi, Maryam; Weber, Waylon; Mak, Tytus D; Chung, Juijung; Doyle-Eisele, Melanie; Melo, Dunstana; Brenner, David J; Guilmette, Raymond A; Fornace, Albert J

    2014-01-01

    Cesium-137 is a fission product of uranium and plutonium in nuclear reactors and is released in large quantities during nuclear explosions or detonation of an improvised device containing this isotope. This environmentally persistent radionuclide undergoes radioactive decay with the emission of beta particles as well as gamma radiation. Exposure to (137)Cs at high doses can cause acute radiation sickness and increase risk for cancer and death. The serious health risks associated with (137)Cs exposure makes it critical to understand how it affects human metabolism and whether minimally invasive and easily accessible samples such as urine and serum can be used to triage patients in case of a nuclear disaster or a radiologic event. In this study, we have focused on establishing a time-dependent metabolomic profile for urine collected from mice injected with (137)CsCl. The samples were collected from control and exposed mice on days 2, 5, 20 and 30 after injection. The samples were then analyzed by ultra-performance liquid chromatography coupled to time-of-flight mass spectrometry (UPLC/TOFMS) and processed by an array of informatics and statistical tools. A total of 1,412 features were identified in ESI(+) and ESI(-) modes from which 200 were determined to contribute significantly to the separation of metabolomic profiles of controls from those of the different treatment time points. The results of this study highlight the ease of use of the UPLC/TOFMS platform in finding urinary biomarkers for (137)Cs exposure. Pathway analysis of the statistically significant metabolites suggests perturbations in several amino acid and fatty acid metabolism pathways. The results also indicate that (137)Cs exposure causes: similar changes in the urinary excretion levels of taurine and citrate as seen with external-beam gamma radiation; causes no attenuation in the levels of hexanoylglycine and N-acetylspermidine; and has unique effects on the levels of isovalerylglycine and

  16. Chronic exposure to a gambling-like schedule of reward predictive stimuli can promote sensitization to amphetamine in rats

    PubMed Central

    Zack, Martin; Featherstone, Robert E.; Mathewson, Sarah; Fletcher, Paul J.

    2014-01-01

    Addiction is considered to be a brain disease caused by chronic exposure to drugs. Sensitization of brain dopamine (DA) systems partly mediates this effect. Pathological gambling (PG) is considered to be a behavioral addiction. Therefore, PG may be caused by chronic exposure to gambling. Identifying a gambling-induced sensitization of DA systems would support this possibility. Gambling rewards evoke DA release. One episode of slot machine play shifts the DA response from reward delivery to onset of cues (spinning reels) for reward, in line with temporal difference learning principles. Thus, conditioned stimuli (CS) play a key role in DA responses to gambling. In primates, DA response to a CS is strongest when reward probability is 50%. Under this schedule the CS elicits an expectancy of reward but provides no information about whether it will occur on a given trial. During gambling, a 50% schedule should elicit maximal DA release. This closely matches reward frequency (46%) on a commercial slot machine. DA release can contribute to sensitization, especially for amphetamine. Chronic exposure to a CS that predicts reward 50% of the time could mimic this effect. We tested this hypothesis in three studies with rats. Animals received 15 × 45-min exposures to a CS that predicted reward with a probability of 0, 25, 50, 75, or 100%. The CS was a light; the reward was a 10% sucrose solution. After training, rats received a sensitizing regimen of five separate doses (1 mg/kg) of d-amphetamine. Lastly they received a 0.5 or 1 mg/kg amphetamine challenge prior to a 90-min locomotor activity test. In all three studies the 50% group displayed greater activity than the other groups in response to both challenge doses. Effect sizes were modest but consistent, as reflected by a significant group × rank association (ϕ = 0.986, p = 0.025). Chronic exposure to a gambling-like schedule of reward predictive stimuli can promote sensitization to amphetamine much like exposure to

  17. A stochastic simulation framework for the prediction of strategic noise mapping and occupational noise exposure using the random walk approach.

    PubMed

    Han, Lim Ming; Haron, Zaiton; Yahya, Khairulzan; Bakar, Suhaimi Abu; Dimon, Mohamad Ngasri

    2015-01-01

    Strategic noise mapping provides important information for noise impact assessment and noise abatement. However, producing reliable strategic noise mapping in a dynamic, complex working environment is difficult. This study proposes the implementation of the random walk approach as a new stochastic technique to simulate noise mapping and to predict the noise exposure level in a workplace. A stochastic simulation framework and software, namely RW-eNMS, were developed to facilitate the random walk approach in noise mapping prediction. This framework considers the randomness and complexity of machinery operation and noise emission levels. Also, it assesses the impact of noise on the workers and the surrounding environment. For data validation, three case studies were conducted to check the accuracy of the prediction data and to determine the efficiency and effectiveness of this approach. The results showed high accuracy of prediction results together with a majority of absolute differences of less than 2 dBA; also, the predicted noise doses were mostly in the range of measurement. Therefore, the random walk approach was effective in dealing with environmental noises. It could predict strategic noise mapping to facilitate noise monitoring and noise control in the workplaces. PMID:25875019

  18. A Stochastic Simulation Framework for the Prediction of Strategic Noise Mapping and Occupational Noise Exposure Using the Random Walk Approach

    PubMed Central

    Haron, Zaiton; Bakar, Suhaimi Abu; Dimon, Mohamad Ngasri

    2015-01-01

    Strategic noise mapping provides important information for noise impact assessment and noise abatement. However, producing reliable strategic noise mapping in a dynamic, complex working environment is difficult. This study proposes the implementation of the random walk approach as a new stochastic technique to simulate noise mapping and to predict the noise exposure level in a workplace. A stochastic simulation framework and software, namely RW-eNMS, were developed to facilitate the random walk approach in noise mapping prediction. This framework considers the randomness and complexity of machinery operation and noise emission levels. Also, it assesses the impact of noise on the workers and the surrounding environment. For data validation, three case studies were conducted to check the accuracy of the prediction data and to determine the efficiency and effectiveness of this approach. The results showed high accuracy of prediction results together with a majority of absolute differences of less than 2 dBA; also, the predicted noise doses were mostly in the range of measurement. Therefore, the random walk approach was effective in dealing with environmental noises. It could predict strategic noise mapping to facilitate noise monitoring and noise control in the workplaces. PMID:25875019

  19. Relation between dietary acrylamide exposure and biomarkers of internal dose in Canadian teenagers.

    PubMed

    Brisson, Benjamin; Ayotte, Pierre; Normandin, Louise; Gaudreau, Éric; Bienvenu, Jean-François; Fennell, Timothy R; Blanchet, Carole; Phaneuf, Denise; Lapointe, Caroline; Bonvalot, Yvette; Gagné, Michelle; Courteau, Marilène; Snyder, Rodney W; Bouchard, Michèle

    2014-01-01

    Acrylamide (AA) is a probable human carcinogen found in several foods. Little information is available regarding exposure of adolescents, a subgroup potentially consuming more AA-rich foods. We investigated the relationship between dietary AA intake and levels of biomarkers of exposure (urinary metabolites and hemoglobin adducts) in 195 non-smoking teenagers of Montreal Island aged 10-17 years. Dietary habits and personal characteristics were documented by questionnaire. AA and its metabolites were quantified in 12-h urine collections by LC-MS/MS. Hemoglobin adducts from 165 blood samples were also analyzed by LC-MS/MS. Most prevalent urinary metabolites were NACP and NACP-S, with respective geometric mean concentrations of 31.2 and 14.2 μmol/mol creatinine. Geometric mean concentrations of AAVal and GAVal (hemoglobin adducts of AA and glycidamide (GA) with N-terminal valine residues) were 45.4 and 45.6 pmol/g globin, respectively. AA intake during the 2 days before urine collection was a significant predictor of NACP+NACP-S urinary concentrations (P<0.0001). AA intakes during the month before blood collection (P<0.0001) and passive smoking (P<0.05) were associated with adduct levels. Levels of hemoglobin adducts were above biomonitoring equivalent values corresponding to a 1 × 10(-4) excess cancer risk, which may indicate the need to reduce AA exposure in the population. PMID:23756700

  20. Characterization of the contribution of buccal absorption to internal exposure to bisphenol A through the diet.

    PubMed

    Guignard, Davy; Gauderat, Glenn; Gayrard, Véronique; Lacroix, Marlène Z; Picard-Hagen, Nicole; Puel, Sylvie; Toutain, Pierre-Louis; Viguié, Catherine

    2016-07-01

    The gavage route is often used for the toxicological evaluation of food contaminants. This route does not take into account absorption of the toxicants through the buccal mucosa, as evidenced in dogs for bisphenol A (BPA). Our goal was to determine the functional significance of buccal BPA absorption during dietary exposure. Four ewes received BPA by nasogastric gavage (100 mg/kg) and through food pellets (10 mg/kg), 13 days apart. The time course of serum concentrations of BPA and its main metabolite BPA-G was submitted to non-compartmental analysis. The dietary route led to 3-fold higher bioavailability as compared to gavage. The ratio of BPA-G to BPA concentrations varied greatly over time after the food administration, but not after gavage, suggesting a delayed metabolism of BPA after dietary exposure. The maximum entrance rate of BPA in the systemic circulation, determined by deconvolution analysis, was much higher after dietary administration than after gavage and a biphasic pattern of BPA entry was observed in 3 of the 4 ewes. Our results evidenced a dual mechanism of BPA absorption (buccal and digestive) after dietary exposure and highlight the necessity to take buccal absorption into account when evaluating food contaminants. PMID:27090580

  1. Early-life cockroach allergen and polycyclic aromatic hydrocarbon exposures predict cockroach sensitization among inner-city children

    PubMed Central

    Perzanowski, Matthew S.; Chew, Ginger L.; Divjan, Adnan; Jung, Kyung Hwa; Ridder, Robert; Tang, Deliang; Diaz, Diurka; Goldstein, Inge F.; Kinney, Patrick L.; Rundle, Andrew G.; Camann, David E.; Perera, Frederica P.; Miller, Rachel L.

    2013-01-01

    Background Sensitization to cockroach is one of the strongest identified risk factors for greater asthma morbidity in low-income, urban communities; however, the timing of exposures relevant to development of sensitization has not been elucidated fully. Further, exposure to combustion byproducts, including polycyclic aromatic hydrocarbons (PAHs), may augment the development of allergic sensitization. Objective To test the hypotheses that domestic cockroach allergen measured prenatally would predict cockroach sensitization in early childhood, and that this association would be greater for children exposed to higher concentrations of PAHs. Methods Dominican and African-American pregnant women living in NYC were enrolled. In the third trimester, expectant mothers wore personal air samplers for measurement of 8 nonvolatile PAHs and the semi-volatile PAH pyrene, and dust was collected from homes for allergen measurement. Glutathione-s-transferase mu (GSTM1) gene polymorphisms were measured in children. Allergen-specific IgE was measured from the children at ages 2, 3, 5 and 7 years. Results Bla g2 in prenatal kitchen dust predicted cockroach sensitization at age 5–7 years [adjusted relative risk (RR) 1.15; P = 0.001; n = 349]. The association was observed only among children above [RR 1.22; P = 0.001], but not below [RR 1.07; P = 0.24] median sum of 8 nonvolatile PAH levels. The association was most pronounced among children with higher PAH and null in the GSTM1 gene [RR 1.54; P = 0.001]. Conclusions Prenatal exposure to cockroach allergen was associated with a greater risk of developing allergic sensitization. This risk was increased by exposure to nonvolatile PAHs, with children null for the GSTM1 mutation particularly vulnerable. Key messages Domestic exposure to cockroach allergen measured prenatally predicted sensitization to cockroach at age 5–7 years. Cockroach allergen predicted sensitization only among children also exposed to higher levels of airborne non

  2. Predicting thunderstorms, lightning and sprites for global observations from the International Space Station

    NASA Astrophysics Data System (ADS)

    Yair, Yoav; Stendel, Martin; Chanrion, Olivier; Neubert, Torsten; Moalem, Meir; Silber, Israel; Price, Colin

    2016-04-01

    The THOR experiment on the International Space Station (ISS) was conducted by Danish astronaut, Andreas Mogensen, during September 1-10, 2015. The aim was to observe over-shooting cumulonimbus turrets, lightning and TLEs with an optical camera through the windows of the PIRS module. To maximize the chances of success, we developed a strategy to predict locations of thunderstorm targets up to three days in advance. The long lead-time was required by the astronaut activity planners that attempted to accommodate many experiments during a short time. The prediction strategy relied on the methodology developed for the MEIDEX experiment on board the space shuttle Columbia (in 2003) and later refined for JAXA's Cosmic Shore campaign from the ISS (in 2011). New and additional components were added to the forecast that enabled us to distill and prioritize a daily target-list with specific viewing angles computed relative to the ISS position and attitude. We present results of the verification procedure for the thunderstorm forecasts, using WWLLN data for selected regions and times during the mission, when high-priority targets were identified as suitable for observation. The methodology proves to be accurate and reliable and can be replicated in future space-based campaigns.

  3. Electrodynamic Dust Shields on the International Space Station: Exposure to the Space Environment

    NASA Technical Reports Server (NTRS)

    Calle, C. I.; Hogue, M. D.; Johansen, M. R.; Yim, H.; Delaune, P. B.; Clements, J. S.

    2012-01-01

    Electrodynamic Dust Shields (EDS) have been in development at NASA as a dust mitigation method for lunar and Martian missions. An active dust mitigation strategy. such as that provided by the EDS, that can remove dust from surfaces, is of crucial importance to the planetary exploration program. We report on the development of a night experiment to fully ex pose four EDS panels to the space environment. This flight experiment is part of the Materials International Space Station experiment X(MISSE-X). an external platform on the International Space Station that will expose materials to the space environment.

  4. Estimation of Internal Radiation Dose from both Immediate Releases and Continued Exposures to Contaminated Materials

    SciTech Connect

    Napier, Bruce A.

    2012-03-26

    A brief description is provided of the basic concepts related to 'internal dose' and how it differs from doses that result from radioactive materials and direct radiation outside of the body. The principles of radiation dose reconstruction, as applied to both internal and external doses, is discussed based upon a recent publication prepared by the US National Council on Radiation Protection and Measurements. Finally, ideas are introduced related to residual radioactive contamination in the environment that has resulted from the releases from the damaged reactors and also to the management of wastes that may be generated in both regional cleanup and NPP decommissioning.

  5. Estimation of internal radiation dose from both immediate releases and continued exposures to contaminated materials.

    PubMed

    Napier, Bruce

    2012-03-01

    A brief description is provided of the basic concepts related to 'internal dose' and how it differs from doses that result from radioactive materials and direct radiation outside of the body. The principles of radiation dose reconstruction, as applied to both internal and external doses, are discussed on the basis of a recent publication prepared by the US National Council on Radiation Protection and Measurements. Finally, ideas are introduced related to residual radioactive contamination in the environment that has resulted from the releases from damaged reactors and also to the management of wastes that may be generated in both regional cleanup and decommissioning of the Fukushima nuclear power plant. PMID:22395282

  6. Epidemiology of recreational exposure to freshwater cyanobacteria – an international prospective cohort study

    PubMed Central

    Stewart, Ian; Webb, Penelope M; Schluter, Philip J; Fleming, Lora E; Burns, John W; Gantar, Miroslav; Backer, Lorraine C; Shaw, Glen R

    2006-01-01

    Background Case studies and anecdotal reports have documented a range of acute illnesses associated with exposure to cyanobacteria and their toxins in recreational waters. The epidemiological data to date are limited; we sought to improve on the design of some previously conducted studies in order to facilitate revision and refinement of guidelines for exposure to cyanobacteria in recreational waters. Methods A prospective cohort study was conducted to investigate the incidence of acute symptoms in individuals exposed, through recreational activities, to low (cell surface area <2.4 mm2/mL), medium (2.4–12.0 mm2/mL) and high (>12.0 mm2/mL) levels of cyanobacteria in lakes and rivers in southeast Queensland, the central coast area of New South Wales, and northeast and central Florida. Multivariable logistic regression analyses were employed; models adjusted for region, age, smoking, prior history of asthma, hay fever or skin disease (eczema or dermatitis) and clustering by household. Results Of individuals approached, 3,595 met the eligibility criteria, 3,193 (89%) agreed to participate and 1,331 (37%) completed both the questionnaire and follow-up interview. Respiratory symptoms were 2.1 (95%CI: 1.1–4.0) times more likely to be reported by subjects exposed to high levels of cyanobacteria than by those exposed to low levels. Similarly, when grouping all reported symptoms, individuals exposed to high levels of cyanobacteria were 1.7 (95%CI: 1.0–2.8) times more likely to report symptoms than their low-level cyanobacteria-exposed counterparts. Conclusion A significant increase in reporting of minor self-limiting symptoms, particularly respiratory symptoms, was associated with exposure to higher levels of cyanobacteria of mixed genera. We suggest that exposure to cyanobacteria based on total cell surface area above 12 mm2/mL could result in increased incidence of symptoms. The potential for severe, life-threatening cyanobacteria-related illness is likely to be

  7. Differential Exposure and Reactivity to Interpersonal Stress Predict Sex Differences in Adolescent Depression

    ERIC Educational Resources Information Center

    Shih, Josephine H.; Eberhart, Nicole K.; Hammen, Constance L.; Brennan, Patricia A.

    2006-01-01

    This study tested the hypothesis that higher rates of depression in adolescent girls are explained by their greater exposure and reactivity to stress in the interpersonal domain in a large sample of 15-year-olds. Findings indicate that adolescent girls experienced higher levels of total and interpersonal episodic stress, whereas boys experienced…

  8. High-Throughput Dietary Exposure Predictions for Chemical Migrants from Food Packaging Materials

    EPA Science Inventory

    United States Environmental Protection Agency researchers have developed a Stochastic Human Exposure and Dose Simulation High -Throughput (SHEDS-HT) model for use in prioritization of chemicals under the ExpoCast program. In this research, new methods were implemented in SHEDS-HT...

  9. Maladaptive Self-Appraisals before Trauma Exposure Predict Posttraumatic Stress Disorder

    ERIC Educational Resources Information Center

    Bryant, Richard A.; Guthrie, Rachel M.

    2007-01-01

    This study tested the proposal that negative appraisals represent a risk factor for developing posttraumatic stress disorder (PTSD) after trauma. Trainee firefighters (N = 68) were assessed during training (before trauma exposure) for PTSD, history of traumatic events, and tendency to engage in negative appraisals. Firefighters were reassessed 4…

  10. A Systems Approach to Assessing Risk: The Role of Metabolism Research in Describing and Predicting Exposure

    EPA Science Inventory

    An important component of assessing risk is defining the exposure of a chemical stressor to a target organism. Often the chemical stressor is assumed to be a single compound even when it is comprised of different stereoisomers (e.g., pyrethroids and 1,2,4-triazole fungicides), w...

  11. Prediction of Asbestos Exposure Resulting From Asbestos Aerosolization Determined Using the Releasable Asbestos Field Sampler (RAFS)

    EPA Science Inventory

    Activity-based sampling (ABS) used to evaluate breathing zone exposure to a contaminant present in soil resulting from various activities, involves breathing zone sampling for contaminants while that activity is performed. A probabilistic model based upon aerosol physics and flui...

  12. SEVESO WOMEN'S HEALTH STUDY: DOES ZONE OF RESIDENCE PREDICT INDIVIDUAL TCDD EXPOSURE? (R824761)

    EPA Science Inventory

    The compound, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), is produced as an unwanted by-product of various chemical reactions and combustion processes, including the manufacture of chlorinated phenols and derivatives. In animals, TCDD exposure is associated with toxic, car...

  13. Predicting Residential Exposure to Phthalate Plasticizer Emitted from Vinyl Flooring: Sensitivity, Uncertainty, and Implications for Biomonitoring

    EPA Science Inventory

    Given the ubiquitous nature of phthalates in the environment and the potential for adverse human health impacts, there is a need to understand the potential human exposure. A three-compartment model is developed to estimate the emission rate of di-2-ethylhexyl phthalate (DEHP) f...

  14. Developmental ethanol exposure-induced sleep fragmentation predicts adult cognitive impairment.

    PubMed

    Wilson, D A; Masiello, K; Lewin, M P; Hui, M; Smiley, J F; Saito, M

    2016-05-13

    Developmental ethanol (EtOH) exposure can lead to long-lasting cognitive impairment, hyperactivity, and emotional dysregulation among other problems. In healthy adults, sleep plays an important role in each of these behavioral manifestations. Here we explored circadian rhythms (activity, temperature) and slow-wave sleep (SWS) in adult mice that had received a single day of EtOH exposure on postnatal day 7 and saline littermate controls. We tested for correlations between slow-wave activity and both contextual fear conditioning and hyperactivity. Developmental EtOH resulted in adult hyperactivity within the home cage compared to controls but did not significantly modify circadian cycles in activity or temperature. It also resulted in reduced and fragmented SWS, including reduced slow-wave bout duration and increased slow-wave/fast-wave transitions over 24-h periods. In the same animals, developmental EtOH exposure also resulted in impaired contextual fear conditioning memory. The impairment in memory was significantly correlated with SWS fragmentation. Furthermore, EtOH-treated animals did not display a post-training modification in SWS which occurred in controls. In contrast to the memory impairment, sleep fragmentation was not correlated with the developmental EtOH-induced hyperactivity. Together these results suggest that disruption of SWS and its plasticity are a secondary contributor to a subset of developmental EtOH exposure's long-lasting consequences. PMID:26892295

  15. Does Preschool Education Exposure Predict Children's Academic and Behavioural Outcomes in China?

    ERIC Educational Resources Information Center

    Li, Yanfang; Lv, Ying; Huntsinger, Carol S.

    2015-01-01

    Relationships between exposure to preschool education and children's academic and social outcomes have been documented in Western countries. There is a lack of comparable research in China, where preschool education is relatively formal, but rather flexible in arrangement. We conducted research at six public kindergartens in a large Chinese…

  16. CYTOKINE PROFILES DO NOT PREDICT ANTIBODY RESPONSES AND RESPIRATORY HYPERRESPONSIVENESS FOLLOWING DERMAL EXPOSURE TO ISOCYANATES

    EPA Science Inventory

    Rationale: Cytokine profiling of local lymph node responses following dermal exposure has been proposed as a test to identify chemicals that pose a risk of occupational asthma. The present study tested the hypothesis that relative differences in cytokine profiles for dini...

  17. Predicting Fractures in an International Cohort using Risk Factor Algorithms, Without Bone Mineral Density

    PubMed Central

    Sambrook, Philip N; Flahive, Julie; Hooven, Fred H; Boonen, Steven; Chapurlat, Roland; Lindsay, Robert; Nguyen, Tuan V; Díez-Perez, Adolfo; Pfeilschifter, Johannes; Greenspan, Susan L; Hosmer, David; Netelenbos, J Coen; Adachi, Jonathan D; Watts, Nelson B; Cooper, Cyrus; Roux, Christian; Rossini, Maurizio; Siris, Ethel S; Silverman, Stuart; Saag, Kenneth G; Compston, Juliet E; LaCroix, Andrea; Gehlbach, Stephen

    2016-01-01

    Clinical risk factors are associated with increased probability of fracture in postmenopausal women. We sought to compare prediction models using self-reported clinical risk factors, excluding bone-mineral density (BMD), to predict incident fracture among postmenopausal women. The GLOW study enrolled women aged ≥55 years were seen at 723 primary care practices in 10 countries. The population comprised 19,586 women aged ≥60 years who were not receiving anti-osteoporosis medication and were followed annually for 2 years. Self-administered questionnaires were used to collect data on characteristics, fracture risk factors, previous fractures, and health status. The main outcome measure compares the c index for models using the WHO Fracture Risk (FRAX), the Garvan Fracture Risk Calculator (FRC), and a simple model using age and prior fracture. Over 2 years, 880 women reported incident fractures including 69 hip fractures, 468 “major fractures” (as defined by FRAX) and 583 “osteoporotic fractures” (as defined by FRC). Using baseline clinical risk factors, both FRAX and FRC showed moderate ability to correctly order hip fracture times (c index for hip fracture: 0.78 and 0.76, respectively). C indices for “major” and “osteoporotic” fractures showed lower values, at 0.61 and 0.64. Neither algorithm was better than the model based on age+fracture history alone (c index for hip fracture: 0.78). In conclusion, estimation of fracture risk in an international primary care population of postmenopausal women can be made using clinical risk factors alone, without BMD. However, more sophisticated models incorporating multiple clinical risk factors including falls were not superior to more parsimonious models in predicting future fracture in this population. PMID:21887705

  18. Evaluation of fall Sun Exposure Score in predicting vitamin D status in young Canadian adults, and the influence of ancestry.

    PubMed

    Sham, Lauren; Yeh, E Ann; Magalhaes, Sandra; Parra, Esteban J; Gozdzik, Agnes; Banwell, Brenda; Hanwell, Heather E

    2015-04-01

    Query of sun-related habits or ancestry could help screen for risk of vitamin D insufficiency (serum 25-hydroxyvitamin D<75nmol/L). We evaluated the association between Sun Exposure Score (calculated from recall of Time Exposed to Sun and Skin Exposed to Sun in the previous week), demographics and anthropometrics (including self-reported ancestry and skin melanin reflectometry), and serum 25(OH)D levels in healthy young Canadian adults in the Greater Toronto Area (GTA; 43°N) during fall. 310 adults (67% female) of European, East Asian, and South Asian ancestries were evaluated. The median (interquartile range) 25(OH)D level was 49.7nmol/L (36.7-70.3) and 80% of participants were vitamin D insufficient. The vast majority of those of East and South Asian ancestry were vitamin D insufficient (91% and 97%, respectively), as were 55% of those of European ancestry. Sun Exposure Score and 25(OH)D concentrations were not associated after accounting for confounders. A multivariable model showed ancestry, recent summer sun exposure, sex, melanin, vitamin D intake, age and year of study significantly predicted 25(OH)D concentration; ancestry was the strongest independent predictor (adjusted R(2)=43%). Although Sun Exposure Score was not a significant predictor of serum 25(OH)D levels, inquiry of ancestry has potential use in screening for vitamin D insufficiency. PMID:25752862

  19. Predicting personal exposure of Windsor, Ontario residents to volatile organic compounds using indoor measurements and survey data

    NASA Astrophysics Data System (ADS)

    Stocco, Corinne; MacNeill, Morgan; Wang, Daniel; Xu, Xiaohong; Guay, Mireille; Brook, Jeff; Wheeler, Amanda J.

    As part of a multi-year personal exposure monitoring campaign, we collected personal, indoor, and outdoor levels of 188 volatile organic compounds (VOCs). In 2005, data were obtained for 48 non-smoking adults from Windsor, Ontario in order to assess their exposure to VOCs based on their daily routines and characteristics of their homes. During the 8-week winter and summer sampling sessions, five repeated 24-h measurements were obtained for each home. This paper focuses on the analysis of 18 VOCs: 11 have been declared toxic as defined under the Canadian Environmental Protection Act, [1999. Statutes of Canada. Act assented to September 14, 1999. Ottawa: Queen's Printer. Available at Canada Gazette (Part III) 22(3): (Chapter 33). http://canadagazette.gc.ca/partIII/1999/g3-02203.pdf], and seven are commonly found in household and personal care products. Results of mixed effects models indicate that personal exposure to these VOCs can be largely predicted by indoor concentrations, with models including indoor concentrations found to have an r2 value for the fixed effects ranging from 58.4% to 87.2% for the CEPA toxic VOCs and from 41.7% to 90.1% for the commonly found VOCs. Given that people spend the majority of their time inside their home, characteristics of the home such as air exchange rates, type of garage, and type of stove have a greater potential to impact personal exposures.

  20. Constructing Predictive Estimates for Worker Exposure to Radioactivity During Decommissioning: Analysis of Completed Decommissioning Projects - Master Thesis

    SciTech Connect

    Dettmers, Dana Lee; Eide, Steven Arvid

    2002-10-01

    An analysis of completed decommissioning projects is used to construct predictive estimates for worker exposure to radioactivity during decommissioning activities. The preferred organizational method for the completed decommissioning project data is to divide the data by type of facility, whether decommissioning was performed on part of the facility or the complete facility, and the level of radiation within the facility prior to decommissioning (low, medium, or high). Additional data analysis shows that there is not a downward trend in worker exposure data over time. Also, the use of a standard estimate for worker exposure to radioactivity may be a best estimate for low complete storage, high partial storage, and medium reactor facilities; a conservative estimate for some low level of facility radiation facilities (reactor complete, research complete, pits/ponds, other), medium partial process facilities, and high complete research facilities; and an underestimate for the remaining facilities. Limited data are available to compare different decommissioning alternatives, so the available data are reported and no conclusions can been drawn. It is recommended that all DOE sites and the NRC use a similar method to document worker hours, worker exposure to radiation (person-rem), and standard industrial accidents, injuries, and deaths for all completed decommissioning activities.

  1. "Mugging Up" versus "Exposure": International Schools and Social Mobility in Hyderabad, India

    ERIC Educational Resources Information Center

    Gilbertson, Amanda

    2014-01-01

    Drawing on 12 months of fieldwork in Hyderabad, India, this paper describes the emergence of "international" schools that are only accessible to upper-middle class and elite families and provide forms of cultural capital increasingly important for middle-class employment--"communication skills", "open-mindedness" and…

  2. Assessing exposure in epidemiologic studies to disinfection by-products in drinking water: report from an international workshop.

    PubMed Central

    Arbuckle, Tye E; Hrudey, Steve E; Krasner, Stuart W; Nuckols, Jay R; Richardson, Susan D; Singer, Philip; Mendola, Pauline; Dodds, Linda; Weisel, Clifford; Ashley, David L; Froese, Kenneth L; Pegram, Rex A; Schultz, Irvin R; Reif, John; Bachand, Annette M; Benoit, Frank M; Lynberg, Michele; Poole, Charles; Waller, Kirsten

    2002-01-01

    The inability to accurately assess exposure has been one of the major shortcomings of epidemiologic studies of disinfection by-products (DBPs) in drinking water. A number of contributing factors include a) limited information on the identity, occurrence, toxicity, and pharmacokinetics of the many DBPs that can be formed from chlorine, chloramine, ozone, and chlorine dioxide disinfection; b) the complex chemical interrelationships between DBPs and other parameters within a municipal water distribution system; and c) difficulties obtaining accurate and reliable information on personal activity and water consumption patterns. In May 2000, an international workshop was held to bring together various disciplines to develop better approaches for measuring DBP exposure for epidemiologic studies. The workshop reached consensus about the clear need to involve relevant disciplines (e.g., chemists, engineers, toxicologists, biostatisticians and epidemiologists) as partners in developing epidemiologic studies of DBPs in drinking water. The workshop concluded that greater collaboration of epidemiologists with water utilities and regulators should be encouraged in order to make regulatory monitoring data more useful for epidemiologic studies. Similarly, exposure classification categories in epidemiologic studies should be chosen to make results useful for regulatory or policy decision making. PMID:11834463

  3. Contacting passengers after exposure to measles on an international flight: Implications for responding to new disease threats and bioterrorism.

    PubMed

    Lasher, Lara E; Ayers, Tracy L; Amornkul, Pauli N; Nakatab, Michele N; Effler, Paul V

    2004-01-01

    On May 21, 2000, a passenger with measles traveled from Japan to Hawai'i on a seven-hour flight. When the flight landed, the U.S. Public Health Service (USPHS) Quarantine Station in Honolulu alerted passengers that a suspected case of measles had been identified, but they were not detained. The next day, to offer appropriate post-exposure prophylaxis, the Hawai'i Department of Health (HDOH) attempted to contact all passengers from the flight using information from the airline, U.S. Customs declaration forms, and tour agencies. Of 335 total passengers, 270 (81%) were successfully reached and provided complete information. The mean time from exposure to contact for all respondents was 61 hours (95% confidence interval 57, 66). A total of 202 (75%) of the responding passengers were contacted within 72 hours after exposure, the time period during which administration of measles vaccine would have provided protection for susceptible individuals. The time-to-contact was significantly longer for passengers who did not stay in hotels than for hotel guests. Customs forms proved to be of limited utility in contacting international travelers. This experience highlights the need for more complete and timely methods of contacting passengers potentially exposed to infectious agents aboard flights. PMID:15313108

  4. Does adolescent's exposure to parental intimate partner conflict and violence predict psychological distress and substance use in young adulthood? A longitudinal study.

    PubMed

    Schiff, Miriam; Plotnikova, Maria; Dingle, Kaeleen; Williams, Gail M; Najman, Jake; Clavarino, Alexandra

    2014-12-01

    Little is known about the extent to which parental conflict and violence differentially impact on offspring mental health and substance use. Using data from a longitudinal birth cohort study this paper examines: whether offspring exposure to parental intimate partner violence (involving physical violence which may include conflicts and/or disagreements) or parental intimate partner conflict (conflicting interactions and disagreements only) are associated with offspring depression, anxiety and substance use in early adulthood (at age 21); and whether these associations are independent of maternal background, depression and anxiety and substance use. Data (n=2,126 women and children) were taken from a large-scale Australian birth-cohort study, the Mater University of Queensland Study of Pregnancy (MUSP). IPC and IPV were measured at the 14-year follow-up. Offspring mental health outcomes--depression, anxiety and substance use--were assessed at the 21-year follow-up using the Composite International Diagnostic Interview (CIDI). Offspring of women experiencing IPV at the 14-year follow-up were more likely to manifest anxiety, nicotine, alcohol and cannabis disorders by the 21-year follow-up. These associations remained after adjustment for maternal anxiety, depression, and other potential confounders. Unlike males who experience anxiety disorders after exposure to IPV, females experience depressive and alcohol use disorders. IPV predicts offspring increased levels of substance abuse and dependence in young adulthood. Gender differences suggest differential impact. PMID:25082429

  5. Validation and predictive utility of the Sociocultural Attitudes Toward Appearance Questionnaire for Eating Disorders (SATAQ-ED): internalization of sociocultural ideals predicts weight gain.

    PubMed

    Heinberg, Leslie J; Coughlin, Janelle Wilder; Pinto, Angela Marinilli; Haug, Nancy; Brode, Cassie; Guarda, Angela S

    2008-09-01

    A widely used measure of societal influences on body image and eating disturbances--the Sociocultural Attitudes Toward Appearance Questionnaire (SATAQ) was validated in women with eating disorders. The original SATAQ and measures of convergence and divergence were administered to 165 eating disordered inpatients. Factor analyses were conducted to determine the underlying structure of the SATAQ. Convergent validity, diagnostic category norms and the predictive utility of the revised SATAQ were examined. Factor analyses indicated three factors: Internalization, Awareness, and Success. Internalization significantly predicted treatment success after controlling for admission BMI and drive for thinness. The revised SATAQ-ED measures multiple aspects of societal influence, predicts short-term outcome, and can be a useful tool for evaluating potential outcome and treatment efficacy. PMID:18640081

  6. Pharmacokinetics in Drug Discovery: An Exposure-Centred Approach to Optimising and Predicting Drug Efficacy and Safety.

    PubMed

    Reichel, Andreas; Lienau, Philip

    2016-01-01

    The role of pharmacokinetics (PK) in drug discovery is to support the optimisation of the absorption, distribution, metabolism and excretion (ADME) properties of lead compounds with the ultimate goal to attain a clinical candidate which achieves a concentration-time profile in the body that is adequate for the desired efficacy and safety profile. A thorough characterisation of the lead compounds aiming at the identification of the inherent PK liabilities also includes an early generation of PK/PD relationships linking in vitro potency and target exposure/engagement with expression of pharmacological activity (mode-of-action) and efficacy in animal studies. The chapter describes an exposure-centred approach to lead generation, lead optimisation and candidate selection and profiling that focuses on a stepwise generation of an understanding between PK/exposure and PD/efficacy relationships by capturing target exposure or surrogates thereof and cellular mode-of-action readouts in vivo. Once robust PK/PD relationship in animal PD models has been constructed, it is translated to anticipate the pharmacologically active plasma concentrations in patients and the human therapeutic dose and dosing schedule which is also based on the prediction of the PK behaviour in human as described herein. The chapter outlines how the level of confidence in the predictions increases with the level of understanding of both the PK and the PK/PD of the new chemical entities (NCE) in relation to the disease hypothesis and the ability to propose safe and efficacious doses and dosing schedules in responsive patient populations. A sound identification of potential drug metabolism and pharmacokinetics (DMPK)-related development risks allows proposing of an effective de-risking strategy for the progression of the project that is able to reduce uncertainties and to increase the probability of success during preclinical and clinical development. PMID:26330260

  7. Research Needs and Impacts in Predictive Simulation for Internal Combustion Engines (PreSICE)

    SciTech Connect

    Eckerle, Wayne; Rutland, Chris; Rohlfing, Eric; Singh, Gurpreet; McIlroy, Andrew

    2011-03-03

    This report is based on a SC/EERE Workshop to Identify Research Needs and Impacts in Predictive Simulation for Internal Combustion Engines (PreSICE), held March 3, 2011, to determine strategic focus areas that will accelerate innovation in engine design to meet national goals in transportation efficiency. The U.S. has reached a pivotal moment when pressures of energy security, climate change, and economic competitiveness converge. Oil prices remain volatile and have exceeded $100 per barrel twice in five years. At these prices, the U.S. spends $1 billion per day on imported oil to meet our energy demands. Because the transportation sector accounts for two-thirds of our petroleum use, energy security is deeply entangled with our transportation needs. At the same time, transportation produces one-quarter of the nation’s carbon dioxide output. Increasing the efficiency of internal combustion engines is a technologically proven and cost-effective approach to dramatically improving the fuel economy of the nation’s fleet of vehicles in the near- to mid-term, with the corresponding benefits of reducing our dependence on foreign oil and reducing carbon emissions. Because of their relatively low cost, high performance, and ability to utilize renewable fuels, internal combustion engines—including those in hybrid vehicles—will continue to be critical to our transportation infrastructure for decades. Achievable advances in engine technology can improve the fuel economy of automobiles by over 50% and trucks by over 30%. Achieving these goals will require the transportation sector to compress its product development cycle for cleaner, more efficient engine technologies by 50% while simultaneously exploring innovative design space. Concurrently, fuels will also be evolving, adding another layer of complexity and further highlighting the need for efficient product development cycles. Current design processes, using “build and test” prototype engineering, will not

  8. A method for calculating Bayesian uncertainties on internal doses resulting from complex occupational exposures.

    PubMed

    Puncher, M; Birchall, A; Bull, R K

    2012-08-01

    Estimating uncertainties on doses from bioassay data is of interest in epidemiology studies that estimate cancer risk from occupational exposures to radionuclides. Bayesian methods provide a logical framework to calculate these uncertainties. However, occupational exposures often consist of many intakes, and this can make the Bayesian calculation computationally intractable. This paper describes a novel strategy for increasing the computational speed of the calculation by simplifying the intake pattern to a single composite intake, termed as complex intake regime (CIR). In order to assess whether this approximation is accurate and fast enough for practical purposes, the method is implemented by the Weighted Likelihood Monte Carlo Sampling (WeLMoS) method and evaluated by comparing its performance with a Markov Chain Monte Carlo (MCMC) method. The MCMC method gives the full solution (all intakes are independent), but is very computationally intensive to apply routinely. Posterior distributions of model parameter values, intakes and doses are calculated for a representative sample of plutonium workers from the United Kingdom Atomic Energy cohort using the WeLMoS method with the CIR and the MCMC method. The distributions are in good agreement: posterior means and Q(0.025) and Q(0.975) quantiles are typically within 20 %. Furthermore, the WeLMoS method using the CIR converges quickly: a typical case history takes around 10-20 min on a fast workstation, whereas the MCMC method took around 12-72 hr. The advantages and disadvantages of the method are discussed. PMID:22355169

  9. Viability of barley seeds after long-term exposure to outer side of international space station

    NASA Astrophysics Data System (ADS)

    Sugimoto, Manabu; Ishii, Makoto; Mori, Izumi C.; Elena, Shagimardanova; Gusev, Oleg A.; Kihara, Makoto; Hoki, Takehiro; Sychev, Vladimir N.; Levinskikh, Margarita A.; Novikova, Natalia D.; Grigoriev, Anatoly I.

    2011-09-01

    Barley seeds were exposed to outer space for 13 months in a vented metal container without a climate control system to assess the risk of physiological and genetic mutation during long-term storage in space. The space-stored seeds (S0 generation), with an 82% germination rate in 50 seeds, lost about 20% of their weight after the exposure. The germinated seeds showed normal growth, heading, and ripening. The harvested seeds (S1 generation) also germinated and reproduced (S2 generation) as did the ground-stored seeds. The culm length, ear length, number of seed, grain weight, and fertility of the plants from the space-stored seeds were not significantly different from those of the ground-stored seeds in each of the S0 and S1 generation. Furthermore, the S1 and S2 space-stored seeds respectively showed similar β-glucan content to those of the ground-stored seeds. Amplified fragment length polymorphism analysis with 16 primer combinations showed no specific fragment that appears or disappears significantly in the DNA isolated from the barley grown from the space-stored seeds. Though these data are derived from nine S0 space-stored seeds in a single exposure experiment, the results demonstrate the preservation of barley seeds in outer space for 13 months without phenotypic or genotypic changes and with healthy and vigorous growth in space.

  10. Do Time in Child Care and Peer Group Exposure Predict Poor Socioemotional Adjustment in Norway?

    ERIC Educational Resources Information Center

    Solheim, Elisabet; Wichstrøm, Lars; Belsky, Jay; Berg-Nielsen, Turid Suzanne

    2013-01-01

    Extensive exposure to nonparental child care during the first 4.5 years of life has been demonstrated in some American studies to negatively affect children's socioemotional functioning. Data from 935 preschool children who averaged 54.9 (SD = 3.0) months of age, from Trondheim, Norway were used to examine whether such negative effects, would…

  11. Coastal Vertebrate Exposure to Predicted Habitat Changes Due to Sea Level Rise

    NASA Astrophysics Data System (ADS)

    Hunter, Elizabeth A.; Nibbelink, Nathan P.; Alexander, Clark R.; Barrett, Kyle; Mengak, Lara F.; Guy, Rachel K.; Moore, Clinton T.; Cooper, Robert J.

    2015-12-01

    Sea level rise (SLR) may degrade habitat for coastal vertebrates in the Southeastern United States, but it is unclear which groups or species will be most exposed to habitat changes. We assessed 28 coastal Georgia vertebrate species for their exposure to potential habitat changes due to SLR using output from the Sea Level Affecting Marshes Model and information on the species' fundamental niches. We assessed forecasted habitat change up to the year 2100 using three structural habitat metrics: total area, patch size, and habitat permanence. Almost all of the species ( n = 24) experienced negative habitat changes due to SLR as measured by at least one of the metrics. Salt marsh and ocean beach habitats experienced the most change (out of 16 categorical land cover types) across the three metrics and species that used salt marsh extensively (rails and marsh sparrows) were ranked highest for exposure to habitat changes. Species that nested on ocean beaches (Diamondback Terrapins, shorebirds, and terns) were also ranked highly, but their use of other foraging habitats reduced their overall exposure. Future studies on potential effects of SLR on vertebrates in southeastern coastal ecosystems should focus on the relative importance of different habitat types to these species' foraging and nesting requirements. Our straightforward prioritization approach is applicable to other coastal systems and can provide insight to managers on which species to focus resources, what components of their habitats need to be protected, and which locations in the study area will provide habitat refuges in the face of SLR.

  12. Coastal Vertebrate Exposure to Predicted Habitat Changes Due to Sea Level Rise.

    PubMed

    Hunter, Elizabeth A; Nibbelink, Nathan P; Alexander, Clark R; Barrett, Kyle; Mengak, Lara F; Guy, Rachel K; Moore, Clinton T; Cooper, Robert J

    2015-12-01

    Sea level rise (SLR) may degrade habitat for coastal vertebrates in the Southeastern United States, but it is unclear which groups or species will be most exposed to habitat changes. We assessed 28 coastal Georgia vertebrate species for their exposure to potential habitat changes due to SLR using output from the Sea Level Affecting Marshes Model and information on the species' fundamental niches. We assessed forecasted habitat change up to the year 2100 using three structural habitat metrics: total area, patch size, and habitat permanence. Almost all of the species (n = 24) experienced negative habitat changes due to SLR as measured by at least one of the metrics. Salt marsh and ocean beach habitats experienced the most change (out of 16 categorical land cover types) across the three metrics and species that used salt marsh extensively (rails and marsh sparrows) were ranked highest for exposure to habitat changes. Species that nested on ocean beaches (Diamondback Terrapins, shorebirds, and terns) were also ranked highly, but their use of other foraging habitats reduced their overall exposure. Future studies on potential effects of SLR on vertebrates in southeastern coastal ecosystems should focus on the relative importance of different habitat types to these species' foraging and nesting requirements. Our straightforward prioritization approach is applicable to other coastal systems and can provide insight to managers on which species to focus resources, what components of their habitats need to be protected, and which locations in the study area will provide habitat refuges in the face of SLR. PMID:26163199

  13. Coastal vertebrate exposure to predicted habitat changes due to sea level rise

    USGS Publications Warehouse

    Hunter, Elizabeth A.; Nibbelink, Nathan P.; Alexander, Clark R.; Barrett, Kyle; Mengak, Lara F.; Guy, Rachel; Moore, Clinton; Cooper, Robert J.

    2015-01-01

    Sea level rise (SLR) may degrade habitat for coastal vertebrates in the Southeastern United States, but it is unclear which groups or species will be most exposed to habitat changes. We assessed 28 coastal Georgia vertebrate species for their exposure to potential habitat changes due to SLR using output from the Sea Level Affecting Marshes Model and information on the species’ fundamental niches. We assessed forecasted habitat change up to the year 2100 using three structural habitat metrics: total area, patch size, and habitat permanence. Almost all of the species (n = 24) experienced negative habitat changes due to SLR as measured by at least one of the metrics. Salt marsh and ocean beach habitats experienced the most change (out of 16 categorical land cover types) across the three metrics and species that used salt marsh extensively (rails and marsh sparrows) were ranked highest for exposure to habitat changes. Species that nested on ocean beaches (Diamondback Terrapins, shorebirds, and terns) were also ranked highly, but their use of other foraging habitats reduced their overall exposure. Future studies on potential effects of SLR on vertebrates in southeastern coastal ecosystems should focus on the relative importance of different habitat types to these species’ foraging and nesting requirements. Our straightforward prioritization approach is applicable to other coastal systems and can provide insight to managers on which species to focus resources, what components of their habitats need to be protected, and which locations in the study area will provide habitat refuges in the face of SLR.

  14. A critical review and analysis of the use of exposure- and flux-based ozone indices for predicting vegetation effects

    NASA Astrophysics Data System (ADS)

    Musselman, Robert C.; Lefohn, Allen S.; Massman, William J.; Heath, Robert L.

    Early studies of plant response to ozone (O 3) utilized concentration-based metrics, primarily by summarizing the commonly monitored hourly average data sets. Research with the O 3 concentration parameter led to the recognition that both peak concentrations and cumulative effects are important when relating plant response to O 3. The US and Canada currently use O 3 concentration-based (exposure-based) parameters for ambient air quality standards for protecting vegetation; the European countries use exposure-based critical levels to relate O 3 to vegetation response. Because plant response is thought to be more closely related to O 3 absorbed into leaf tissue, recent research has been focused on flux-based O 3 parameters. Even though flux-based indices may appear to be more biologically relevant than concentration-based indices, there are limitations associated with their use. The current set of flux-based indices assumes that the plant has no defense mechanism to detoxify O 3. This is a serious limitation. In this paper, we review the literature on exposure- and flux-based indices for predicting plant response. Both exposure- and flux-based metrics may overestimate plant response. At this time, flux-based models that take into consideration detoxification mechanisms (referred to as effective flux) provide the best approach to relate O 3 to plant response. However, because there is considerable uncertainty in quantifying the various defense mechanisms, effective flux at this time is difficult to quantify. Without adequate effective-flux based models, exposure-based O 3 metrics appear to be the only practical measure for use in relating ambient air quality standards to vegetation response.

  15. Predicting wafer-level IP error due to particle-induced EUVL reticle distortion during exposure chucking

    NASA Astrophysics Data System (ADS)

    Ramaswamy, Vasu; Mikkelson, Andrew; Engelstad, Roxann; Lovell, Edward

    2005-11-01

    The mechanical distortion of an EUVL mask from mounting in an exposure tool can be a significant source of wafer-level image placement error. In particular, the presence of debris lodged between the reticle and chuck can cause the mask to experience out-of-plane distortion and in-plane distortion. A thorough understanding of the response of the reticle/particle/chuck system during electrostatic chucking is necessary to predict the resulting effects of such particle contamination on image placement accuracy. In this research, finite element modeling is employed to simulate this response for typical clamping conditions.

  16. Optimal camera exposure for video surveillance systems by predictive control of shutter speed, aperture, and gain

    NASA Astrophysics Data System (ADS)

    Torres, Juan; Menéndez, José Manuel

    2015-02-01

    This paper establishes a real-time auto-exposure method to guarantee that surveillance cameras in uncontrolled light conditions take advantage of their whole dynamic range while provide neither under nor overexposed images. State-of-the-art auto-exposure methods base their control on the brightness of the image measured in a limited region where the foreground objects are mostly located. Unlike these methods, the proposed algorithm establishes a set of indicators based on the image histogram that defines its shape and position. Furthermore, the location of the objects to be inspected is likely unknown in surveillance applications. Thus, the whole image is monitored in this approach. To control the camera settings, we defined a parameters function (Ef ) that linearly depends on the shutter speed and the electronic gain; and is inversely proportional to the square of the lens aperture diameter. When the current acquired image is not overexposed, our algorithm computes the value of Ef that would move the histogram to the maximum value that does not overexpose the capture. When the current acquired image is overexposed, it computes the value of Ef that would move the histogram to a value that does not underexpose the capture and remains close to the overexposed region. If the image is under and overexposed, the whole dynamic range of the camera is therefore used, and a default value of the Ef that does not overexpose the capture is selected. This decision follows the idea that to get underexposed images is better than to get overexposed ones, because the noise produced in the lower regions of the histogram can be removed in a post-processing step while the saturated pixels of the higher regions cannot be recovered. The proposed algorithm was tested in a video surveillance camera placed at an outdoor parking lot surrounded by buildings and trees which produce moving shadows in the ground. During the daytime of seven days, the algorithm was running alternatively together

  17. Endocannabinoid-Dependent Modulation of Phasic Dopamine Signaling Encodes External and Internal Reward-Predictive Cues

    PubMed Central

    Wenzel, Jennifer M.; Cheer, Joseph F.

    2014-01-01

    The mesolimbic dopamine (DA) system plays an integral role in incentive motivation and reward seeking and a growing body of evidence identifies signal transduction at cannabinoid receptors as a critical modulator of this system. Indeed, administration of exogenous cannabinoids results in burst firing of DA neurons of the ventral tegmental area and increases extracellular DA in the nucleus accumbens (NAcc). Implementation of fast-scan cyclic voltammetry (FSCV) confirms the ability of cannabinoids to augment DA within the NAcc on a subsecond timescale. The use of FSCV along with newly developed highly selective pharmacological compounds advances our understanding of how cannabinoids influence DA transmission and highlights a role for endocannabinoid-modulated subsecond DAergic activation in the incentive motivational properties of not only external, but also internal reward-predictive cues. For example, our laboratory has recently demonstrated that in mice responding under a fixed-interval (FI) schedule for food reinforcement, fluctuations in NAcc DA signal the principal cue predictive of reinforcer availability – time. That is, as the interval progresses, NAcc DA levels decline leading to accelerated food seeking and the resulting characteristic FI scallop pattern of responding. Importantly, administration of WIN 55,212-2, a synthetic cannabinoid agonist, or JZL184, an indirect cannabinoid agonist, increases DA levels during the interval and disrupts this pattern of responding. Along with a wealth of other reports, these results illustrate the role of cannabinoid receptor activation in the regulation of DA transmission and the control of temporally guided reward seeking. The current review will explore the striatal beat frequency model of interval timing as it pertains to cannabinoid signaling and propose a neurocircuitry through which this system modulates interoceptive time cues. PMID:25225488

  18. Greater exposure to sexual content in popular movies predicts earlier sexual debut and increased sexual risk taking.

    PubMed

    O'Hara, Ross E; Gibbons, Frederick X; Gerrard, Meg; Li, Zhigang; Sargent, James D

    2012-09-01

    Early sexual debut is associated with risky sexual behavior and an increased risk of unplanned pregnancy and sexually transmitted infections later in life. The relations among early movie sexual exposure (MSE), sexual debut, and risky sexual behavior in adulthood (i.e., multiple sexual partners and inconsistent condom use) were examined in a longitudinal study of U.S. adolescents. MSE was measured using the Beach method, a comprehensive procedure for media content coding. Controlling for characteristics of adolescents and their families, analyses showed that MSE predicted age of sexual debut, both directly and indirectly through changes in sensation seeking. MSE also predicted engagement in risky sexual behaviors both directly and indirectly via early sexual debut. These results suggest that MSE may promote sexual risk taking both by modifying sexual behavior and by accelerating the normal rise in sensation seeking during adolescence. PMID:22810165

  19. Exposure conditions of reactor internals of Rovno VVER-440 NPP units 1 and 2

    SciTech Connect

    Grytsenko, O.V.; Pugach, S.M.; Diemokhin, V.L.; Bukanov, V.N.; Marek, M.; Vandlik, S.

    2011-07-01

    Results of determination of irradiation conditions for vessel internals of VVER-440 reactor No. 1 and 2 at Rovno Nuclear Power Plant, obtained by specialists at Inst. for Nuclear Research Kyiv (Ukraine)), and Nuclear Research Inst. Rez (Czech Republic)), are presented. To calculate neutron transport, detailed calculation models of these reactors were prepared. Distribution of neutron flux functionals on the surface of reactor VVER-440 baffle and core barrel for different core loads was studied. Agreement between results obtained by specialists at Inst. for Nuclear Research and at Nuclear Research Inst. is shown. (authors)

  20. Does Occupational Exposure of Shahid Dastghieb International Airport Workers to Radiofrequency Radiation Affect Their Short Term Memory and Reaction Time?

    PubMed Central

    Jarideh, S.; Taeb, S.; Pishva, S. M.; Haghani, M.; Sina, S.; Mortazavi, S. A. R.; Hosseini, M. A.; Nematollahi, S.; Shokrpour, N.; Hassan Shahi, M.; Mortazavi, S. M. J.

    2015-01-01

    Background Airport workers are continuously exposed to different levels of radiofrequency microwave (RF/MW) radiation emitted by radar equipments. Radars are extensively used in military and aviation industries. Over the past several years, our lab has focused on the health effects of exposure to different sources of electromagnetic fields such as cellular phones, mobile base stations, mobile phone jammers, laptop computers, radars, dentistry cavitrons and MRI. The main goal of this study was to investigate if occupational exposure of Shahid Dastghieb international airport workers to radiofrequency radiation affects their short term memory and reaction time. Methods Thirty two airport workers involved in duties at control and approach tower (21 males and 11 females), with the age range of 27-67 years old (mean age of 37.38), participated voluntary in this study. On the other hand, 29 workers (13 males, and 16 females) whose offices were in the city with no exposure history to radar systems were also participated in this study as the control group. The employees’ reaction time and short term memory were analyzed using a standard visual reaction time (VRT) test software and the modified Wechsler memory scale test, respectively. Results The mean± SD values for the reaction times of the airport employees (N=32) and the control group (N=29) were 0.45±0.12 sec and 0.46±0.17 sec, respectively.  Moreover, in the four subset tests; i.e. paired words, forward digit span, backward digit span and word recognition, the following points were obtained for the airport employees and the control group, respectively: (i) pair words test: 28.00±13.13 and 32.07±11.65, (ii) forward digit span: 8.38±1.40 and 9.03±1.32, (iii) backward digit span: 5.54±1.87 and 6.31±1.46, and (iv) word recognition: 5.73±2.36 and 6.50±1.93. These differences were not statistically significant. Conclusion The occupational exposure of the employees to the RF radiation in Shahid Dastghieb

  1. Prediction of moisture and temperature changes in composites during atmospheric exposure

    NASA Technical Reports Server (NTRS)

    Tompkins, S. S.; Tenney, D. R.; Unnan, J.

    1978-01-01

    The effects of variations in diffusion coefficients, surface properties of the composite, panel tilt, ground reflection, and geographical location on the moisture concentration profiles and average moisture content of composite laminates were studied analytically. A heat balance which included heat input due to direct and sky diffuse solar radiation, ground reflection, and heat loss due to reradiation and convection was used to determine the temperature of composites during atmospheric exposure. The equilibrium moisture content was assumed proportional to the relative humidity of the air in the boundary layer of the composite. Condensation on the surface was neglected. Histograms of composite temperatures were determined and compared with those for the ambient environment.

  2. MISSE PEACE Polymers: An International Space Station Environmental Exposure Experiment Being Conducted

    NASA Technical Reports Server (NTRS)

    deGroh, Kim K.; Banks, Bruce A.; Hammerstrom, Anne; Youngstrom, Erica; Kaminski, Carolyn; Marx, Laura; Fine, Elizabeth; Gummow, Jonathan D.; Wright, Douglas

    2002-01-01

    As part of the Materials International Space Station Experiment (MISSE), 41 different polymers are being exposed for approximately 1 1/2 years to the low-Earth-orbit (LEO) environment on the exterior of the International Space Station. MISSE is a materials flight experiment sponsored by the Air Force Research Lab/Materials Lab and NASA, and is the first external experiment on the space station. A similar set of 41 polymers will be flown as part of the Polymer Erosion and Contamination Experiment (PEACE) a shuttle flight experiment that is being developed at the NASA Glenn Research Center collaboratively with the Hathaway Brown School for girls. Therefore, these 41 polymers are collectively called the MISSE PEACE Polymers. The purpose of the MISSE PEACE Polymers experiment is to determine how durable polymers are in the LEO space environment where spacecraft, such as the space station, orbit. Polymers are commonly used as spacecraft materials because of their desirable properties such as good flexibility, low density, and certain electrical properties or optical properties (such as a low solar absorptance and high thermal emittance). Two examples of the use of polymers on the exterior of spacecraft exposed to the space environment include metalized Teflon FEP (fluorinated ethylene propylene, DuPont) thermal control materials on the Hubble Space Telescope, and polyimide Kapton (DuPont) solar array blankets.

  3. Geriatric assessment predicts survival and toxicities in elderly myeloma patients: an International Myeloma Working Group report.

    PubMed

    Palumbo, Antonio; Bringhen, Sara; Mateos, Maria-Victoria; Larocca, Alessandra; Facon, Thierry; Kumar, Shaji K; Offidani, Massimo; McCarthy, Philip; Evangelista, Andrea; Lonial, Sagar; Zweegman, Sonja; Musto, Pellegrino; Terpos, Evangelos; Belch, Andrew; Hajek, Roman; Ludwig, Heinz; Stewart, A Keith; Moreau, Philippe; Anderson, Kenneth; Einsele, Hermann; Durie, Brian G M; Dimopoulos, Meletios A; Landgren, Ola; San Miguel, Jesus F; Richardson, Paul; Sonneveld, Pieter; Rajkumar, S Vincent

    2015-03-26

    We conducted a pooled analysis of 869 individual newly diagnosed elderly patient data from 3 prospective trials. At diagnosis, a geriatric assessment had been performed. An additive scoring system (range 0-5), based on age, comorbidities, and cognitive and physical conditions, was developed to identify 3 groups: fit (score = 0, 39%), intermediate fitness (score = 1, 31%), and frail (score ≥2, 30%). The 3-year overall survival was 84% in fit, 76% in intermediate-fitness (hazard ratio [HR], 1.61; P = .042), and 57% in frail (HR, 3.57; P < .001) patients. The cumulative incidence of grade ≥3 nonhematologic adverse events at 12 months was 22.2% in fit, 26.4% in intermediate-fitness (HR, 1.23; P = .217), and 34.0% in frail (HR, 1.74; P < .001) patients. The cumulative incidence of treatment discontinuation at 12 months was 16.5% in fit, 20.8% in intermediate-fitness (HR, 1.41; P = .052), and 31.2% in frail (HR, 2.21; P < .001) patients. Our frailty score predicts mortality and the risk of toxicity in elderly myeloma patients. The International Myeloma Working group proposes this score for the measurement of frailty in designing future clinical trials. These trials are registered at www.clinicaltrials.gov as #NCT01093136 (EMN01), #NCT01190787 (26866138MMY2069), and #NCT01346787 (IST-CAR-506). PMID:25628469

  4. International ring trial of the epidermal equivalent sensitizer potency assay: reproducibility and predictive-capacity.

    PubMed

    Teunis, Marc A T; Spiekstra, Sander W; Smits, Mieke; Adriaens, Els; Eltze, Tobias; Galbiati, Valentina; Krul, Cyrille; Landsiedel, Robert; Pieters, Raymond; Reinders, Judith; Roggen, Erwin; Corsini, Emanuela; Gibbs, Susan

    2014-01-01

    This study describes the international ring trial of the epidermal-equivalent (EE) sensitizer potency assay. This assay does not distinguish a sensitizer from a non-sensitizer, but may classify known skin sensitizers according to their potency. It assesses the chemical concentration resulting in 50% cytotoxicity (EE-EC50) or the 2-fold increase in IL-1α (IL-1α2x). Four laboratories received 13 coded sensitizers. Reproducible results were obtained in each laboratory. A binary prediction model, EC50≥7 mg/ml=weak to moderate sensitizer and EC50<7 mg/ml=strong to extreme sensitizer had an accuracy of 77%. A superior EE (EC50 and IL-1α2x) correlation was observed with human in vivo DSA05 data compared to LLNA-EC3 data. Human in vivo NOEL and LLNA-EC3 data correlated to a similar extent to in vitro EE data. Our results indicate that this easily transferable EE potency assay is suitable for testing chemical allergens of unknown potencies and may now be ready for further validation, providing complementary potency information to other assays already undergoing validation for assessing skin sensitization potential. PMID:24535238

  5. Geriatric assessment predicts survival and toxicities in elderly myeloma patients: an International Myeloma Working Group report

    PubMed Central

    Bringhen, Sara; Mateos, Maria-Victoria; Larocca, Alessandra; Facon, Thierry; Kumar, Shaji K.; Offidani, Massimo; McCarthy, Philip; Evangelista, Andrea; Lonial, Sagar; Zweegman, Sonja; Musto, Pellegrino; Terpos, Evangelos; Belch, Andrew; Hajek, Roman; Ludwig, Heinz; Stewart, A. Keith; Moreau, Philippe; Anderson, Kenneth; Einsele, Hermann; Durie, Brian G. M.; Dimopoulos, Meletios A.; Landgren, Ola; San Miguel, Jesus F.; Richardson, Paul; Sonneveld, Pieter; Rajkumar, S. Vincent

    2015-01-01

    We conducted a pooled analysis of 869 individual newly diagnosed elderly patient data from 3 prospective trials. At diagnosis, a geriatric assessment had been performed. An additive scoring system (range 0-5), based on age, comorbidities, and cognitive and physical conditions, was developed to identify 3 groups: fit (score = 0, 39%), intermediate fitness (score = 1, 31%), and frail (score ≥2, 30%). The 3-year overall survival was 84% in fit, 76% in intermediate-fitness (hazard ratio [HR], 1.61; P = .042), and 57% in frail (HR, 3.57; P < .001) patients. The cumulative incidence of grade ≥3 nonhematologic adverse events at 12 months was 22.2% in fit, 26.4% in intermediate-fitness (HR, 1.23; P = .217), and 34.0% in frail (HR, 1.74; P < .001) patients. The cumulative incidence of treatment discontinuation at 12 months was 16.5% in fit, 20.8% in intermediate-fitness (HR, 1.41; P = .052), and 31.2% in frail (HR, 2.21; P < .001) patients. Our frailty score predicts mortality and the risk of toxicity in elderly myeloma patients. The International Myeloma Working group proposes this score for the measurement of frailty in designing future clinical trials. These trials are registered at www.clinicaltrials.gov as #NCT01093136 (EMN01), #NCT01190787 (26866138MMY2069), and #NCT01346787 (IST-CAR-506). PMID:25628469

  6. Dead certain: confidence and conservatism predict aggression in simulated international crisis decision-making.

    PubMed

    Johnson, Dominic D P; McDermott, Rose; Cowden, Jon; Tingley, Dustin

    2012-03-01

    Evolutionary psychologists have suggested that confidence and conservatism promoted aggression in our ancestral past, and that this may have been an adaptive strategy given the prevailing costs and benefits of conflict. However, in modern environments, where the costs and benefits of conflict can be very different owing to the involvement of mass armies, sophisticated technology, and remote leadership, evolved tendencies toward high levels of confidence and conservatism may continue to be a contributory cause of aggression despite leading to greater costs and fewer benefits. The purpose of this paper is to test whether confidence and conservatism are indeed associated with greater levels of aggression-in an explicitly political domain. We present the results of an experiment examining people's levels of aggression in response to hypothetical international crises (a hostage crisis, a counter-insurgency campaign, and a coup). Levels of aggression (which range from concession to negotiation to military attack) were significantly predicted by subjects' (1) confidence that their chosen policy would succeed, (2) score on a liberal-conservative scale, (3) political party affiliation, and (4) preference for the use of military force in real-world U.S. policy toward Iraq and Iran. We discuss the possible adaptive and maladaptive implications of confidence and conservatism for the prospects of war and peace in the modern world. PMID:22450767

  7. Predicted effects of tritium exposure on fast-acting piezoelectric valves for gas fueling at TFTR

    SciTech Connect

    Gill, J.T.; Pierce, C.W.

    1985-09-01

    The prospects for using piezoelectrically-driven valves with elastomeric or thermoplastic poppets in tritium gas service have been investigated. A modeling study of a typical valve incorporating ethylene-propylene rubber (EPR) or high density polyethylene (HDPE) was performed. Equations were developed linking applied voltage; ceramic bimorph preloading force, elastic deflection modulus, and specific deflection force (per volt applied); polymer elastic modulus, thickness, seal surface area, and compression (to make seal); elastomer compression set; thermoplastic creep modulus; and flow gap between seat and polymer tip. It was determined that, while EPR should seal the valve orifice more easily, HDPE should produce a valve flow rate vs. voltage curve less variant with time and exposure. Both should, however, be sealable and allow flow curves perturbed by less than or equal to 10% of full scale after approx. 100 days of exposure to 10/sup 5/ Pa (1 atm) T/sub 2/ gas (equivalent to approx. 7 x 10/sup 7/ rad=7 x 10/sup 5/ Gy dosage).

  8. Predicted Effects of Tritium Exposures on Fast-Acting Piezoelectric Valves for Gas Fueling at TFTR

    SciTech Connect

    Gill, J. T.; Pierce, C. W.

    1985-04-01

    The prospects for using piezoelectrically-driven valves with elastomeric or thermoplastic poppets in tritium gas service have been investigated. A modelling study of a typical valve incorporating ethylene-propylene rubber (EPR) or high density polyethylene (HDPE) was performed. Equations were developed linking applied voltage; ceramic bimorph preloading force, elastic deflection modulus, and specific deflection force (per volt applied); polymer elastic modulus, thickness, seal surface area, and compression (to make seal); elastomer compression set; thermoplastic creep modulus; and flow gap between seat and polymer tip. It was determined that, while EPR should seal the valve orifice more easily, HDPE should produce a valve flow rate vs. voltage curve less variant with time and exposure. Both should, however, be sealable and allow flow curves perturbed by less than or equal to 10% of full scale after ~100 days of exposure to 10{sup}5 Pa (1 atm) T{sub}2 gas (equivalent to ~7 x 10{sup}7 rad = 7 x 10{sup}5 Gy dosage).

  9. Assessment and prediction of whole-body vibration exposure in transport truck drivers.

    PubMed

    Nitti, Rocco; De Santis, Paolo

    2010-01-01

    The European Directive 2002/44/EC on the minimum Health and Safety prescriptions regarding the exposure of workers to vibrations, was implemented in Italy through the Legislative Decree 187/2005, recently amended by the Legislative Decree 81/2008. The Decrees contain legal obligations and minimum requirements for the evaluation by direct measurement, which is the reference method, although not always appropriate or necessary, and by means of vibration data banks or information provided by equipment manufacturers. The values assessed must be representative of the actual working environment: in order to adapt assessed values to real working conditions it may be useful to adopt some statistical models. Statistically significant relationships were observed by means of a multiple linear regression on a limited set of measures on different models of trucks, in different operating conditions and settings: the relative influence of predictor variables was then assessed. Finally a short digression about the evolution of the suspension fitting has been made in order to briefly describe the historical context of WBV exposure level reduction and the state of the art of industrial vehicle comfort improvement technologies. PMID:20953079

  10. Exposure to violence predicts poor educational outcomes in young children in South Africa and Malawi

    PubMed Central

    Sherr, L.; Hensels, I. S.; Skeen, S.; Tomlinson, M.; Roberts, K. J.; Macedo, A.

    2016-01-01

    Background Violence during childhood may affect short and long-term educational factors. There is scant literature on younger children from resource poor settings. Methods This study assessed child violence experiences (harsh punishment and exposure to domestic or community violence) and school enrolment, progress and attendance in children attending community-based organisations in South Africa and Malawi (n=989) at baseline and at 15 months' follow-up, examining differential experience of HIV positive, HIV affected and HIV unaffected children. Results Violence exposure was high: 45.4% experienced some form of psychological violence, 47.8% physical violence, 46.7% domestic violence and 41.8% community violence. Primary school enrolment was 96%. Violence was not associated with school enrolment at baseline but, controlling for baseline, children exposed to psychological violence for discipline were more than ten times less likely to be enrolled at follow-up (OR 0.09; 95% CI 0.01 to 0.57). Harsh discipline was associated with poor school progress. For children HIV positive a detrimental effect of harsh physical discipline was found on school performance (OR 0.10; 95% CI 0.02 to 0.61). Conclusion Violence experiences were associated with a number of educational outcomes, which may have long-term consequences. Community-based organisations may be well placed to address such violence, with a particular emphasis on the challenges faced by children who are HIV positive. PMID:26678567

  11. Measured and predicted airshed concentrations of methyl bromide in an agricultural valley and applications to exposure assessment

    NASA Astrophysics Data System (ADS)

    Honaganahalli, Puttanna S.; Seiber, James N.

    A field study was conducted in September 1995 to measure the ambient atmospheric concentrations of methyl bromide (MeBr) in the Salinas Valley, California. Air concentrations of MeBr were measured at 11 sites located on the adjacent mountains, valley floor and at the Pacific Ocean coast over a 4-d period. The concentrations ranged up to 8.98 μg m -3. Industrial Source Complex Short Term 3 (ISCST3) and CALPUFF dispersion model simulations were performed with several fumigated fields serving as sources, using two estimates of source strengths from published flux values. CALPUFF was driven by 3D meteorology from CALMET. With the lower of the two estimates, the ISCST3 model underpredicted concentrations for 76% of data and averaged 66% of measured, and the CALPUFF model also underpredicted concentrations for 67% of observations and averaged 84% of measured. With the higher of the two estimates the ISCST3 overpredicted by a factor of two for 67% of data, and CALPUFF overpredicted concentrations by a factor of 1.6 for over 50% of data. Between the model predicted and measured concentrations, the coefficient of determination, R 2, was ≈0.7 for both source strengths with ISCST3 model. The R 2 with CALPUFF model was 0.55 and 0.82 with source strength estimated from two prior flux studies. The margin of exposure (MOE) for the population of the city of Salinas was calculated based on the measured ambient concentrations and compared with the current benchmark used by US-EPA and California Department of Pesticide Regulation for acceptable human health risk. Based on the models predicted worst-case exposure concentration, the MOE for acute effects was approximately 10,000. For chronic effects it was approximately 100, indicating a need for attention to exposure to MeBr in areas of intense methyl bromide use.

  12. Internal exposure to uranium in a pooled cohort of gaseous diffusion plant workers.

    PubMed

    Anderson, Jeri L; Apostoaei, A Iulian; Yiin, James H; Fleming, Donald A; Tseng, Chih-Yu; Chen, Pi-Hsueh

    2016-03-01

    Intakes and absorbed organ doses were estimated for 29 303 workers employed at three former US gaseous diffusion plants as part of a study of cause-specific mortality and cancer incidence in uranium enrichment workers. Uranium urinalysis data (>600 000 urine samples) were available for 58 % of the pooled cohort. Facility records provided uranium gravimetric and radioactivity concentration data and allowed estimation of enrichment levels of uranium to which workers may have been exposed. Urine data were generally recorded with facility department numbers, which were also available in study subjects' work histories. Bioassay data were imputed for study subjects with no recorded sample results (33 % of pooled cohort) by assigning department average urine uranium concentration. Gravimetric data were converted to 24-h uranium activity excretion using department average specific activities. Intakes and organ doses were calculated assuming chronic exposure by inhalation to a 5-µm activity median aerodynamic diameter aerosol of soluble uranium. Median intakes varied between 0.31 and 0.74 Bq d(-1) for the three facilities. Median organ doses for the three facilities varied between 0.019 and 0.051, 0.68 and 1.8, 0.078 and 0.22, 0.28 and 0.74, and 0.094 and 0.25 mGy for lung, bone surface, red bone marrow, kidneys, and liver, respectively. Estimated intakes and organ doses for study subjects with imputed bioassay data were similar in magnitude. PMID:26113578

  13. Characterization of silver nanoparticles in selected consumer products and its relevance for predicting children’s potential exposures

    PubMed Central

    Tulve, Nicolle S.; Stefaniak, Aleksandr B.; Vance, Marina E.; Rogers, Kim; Mwilu, Samuel; LeBouf, Ryan F.; Schwegler-Berry, Diane; Willis, Robert; Thomas, Treye A.; Marr, Linsey C.

    2015-01-01

    Due to their antifungal, antibacterial, antiviral, and antimicrobial properties, silver nanoparticles (AgNPs) are used in consumer products intended for use by children or in the home. Children may be especially affected by the normal use of consumer products because of their physiological functions, developmental stage, and activities and behaviors. Despite much research to date, children’s potential exposures to AgNPs are not well characterized. Our objectives were to characterize selected consumer products containing AgNPs and to use the data to estimate a child’s potential non-dietary ingestion exposure. We identified and cataloged 165 consumer products claiming to contain AgNPs that may be used by or near children or found in the home. Nineteen products (textile, liquid, plastic) were selected for further analysis. We developed a tiered analytical approach to determine silver content, form (particulate or ionic), size, morphology, agglomeration state, and composition. Silver was detected in all products except one sippy cup body. Among products in a given category, silver mass contributions were highly variable and not always uniformly distributed within products, highlighting the need to sample multiple areas of a product. Electron microscopy confirmed the presence of AgNPs. Using this data, a child’s potential non-dietary ingestion exposure to AgNPs when drinking milk formula from a sippy cup is 1.53 μg Ag/kg. Additional research is needed to understand the number and types of consumer products containing silver and the concentrations of silver in these products in order to more accurately predict children’s potential aggregate and cumulative exposures to AgNPs. PMID:25747543

  14. The heart of the story: peripheral physiology during narrative exposure predicts charitable giving.

    PubMed

    Barraza, Jorge A; Alexander, Veronika; Beavin, Laura E; Terris, Elizabeth T; Zak, Paul J

    2015-02-01

    Emotionally laden narratives are often used as persuasive appeals by charitable organizations. Physiological responses to a narrative may explain why some people respond to an appeal while others do not. In this study we tested whether autonomic and hormonal activity during a narrative predict subsequent narrative influence via charitable giving. Participants viewed a brief story of a father's experience with his 2-year-old son who has terminal cancer. After the story, participants were presented with an opportunity to donate some of their study earnings to a related charity. Measures derived from cardiac and electrodermal activity, including HF-HRV, significantly predicted donor status. Time-series GARCH models of physiology during the narrative further differentiated donors from non-donors. Moreover, cardiac activity and experienced concern were found to covary from moment-to-moment across the narrative. Our findings indicate that the physiological response to a stimulus, herein a narrative, can predict influence as indexed by stimulus-related behavior. PMID:25617658

  15. Prediction of exposure-response relationships to support first-in-human study design.

    PubMed

    Gibbs, John P

    2010-12-01

    In drug development, phase 1 first-in-human studies represent a major milestone as the drug moves from preclinical discovery to clinical development activities. The safety of human subjects is paramount to the conduct of these studies and regulatory considerations guide activities. Forces of evolution on the pharmaceutical industry are re-shaping the first-in-human dose selection strategy. Namely, high attrition rates in part due to lack of efficacy have led to the re-organization of research and development organizations around the umbrella of translational research. Translational research strives to bring basic research advances into the clinic and support the reverse transfer of information to enhance compound selection strategies. Pharmacokinetic/pharmacodynamic (PK/PD) modeling holds a unique position in translational research by attempting to integrate diverse sets of information. PK/PD modeling has demonstrated utility in dose selection and trial design for later stages of drug development and is now being employed with greater prevalence in the translational research setting to manage risk (i.e., oncology and inflammation/immunology). Moving from empirical E (max) models to more mechanistic representations of the biological system, a higher fidelity of human predictions is expected. Strategies that have proven useful for PK predictions are being applied to PK/PD predictions. This review article examines examples of the application of PK/PD modeling in establishing target concentrations for supporting first-in-human study design. PMID:20967521

  16. Prenatal tobacco exposure predicts differential brain function during working memory in early adolescence: a preliminary investigation.

    PubMed

    Bennett, David S; Mohamed, Feroze B; Carmody, Dennis P; Malik, Muhammed; Faro, Scott H; Lewis, Michael

    2013-03-01

    Children prenatally exposed to tobacco exhibit higher rates of learning and emotional-behavioral problems related to worse working memory performance. Brain function, however, among tobacco exposed children while performing a working memory task has not previously been examined. This study compared the brain function of tobacco-exposed (n = 7) and unexposed (n = 11) 12-year-olds during a number N-back working memory task using an event-related functional magnetic resonance imaging (fMRI) design. Prenatal alcohol exposure, neonatal medical problems, environmental risk, and sex were statistically controlled. Tobacco-exposed children showed greater activation in inferior parietal regions, whereas unexposed children showed greater activation in inferior frontal regions. These differences were observed in the context of correct responses, suggesting that exposed and unexposed children use different brain regions and approaches to succeed in working memory tasks. Implications for future research and intervention are discussed. PMID:22820891

  17. Combining datasets to predict the effects of regulation of environmental lead exposure in housing stock.

    PubMed

    Strauss, W J; Carroll, R J; Bortnick, S M; Menkedick, J R; Schultz, B D

    2001-03-01

    A model for children's blood lead concentrations as a function of environmental lead exposures was developed by combining two nationally representative sources of data that characterize the marginal distributions of blood lead and environmental lead with a third regional dataset that contains joint measures of blood lead and environmental lead. The complicating factor addressed in this article was the fact that methods for assessing environmental lead were different in the national and regional datasets. Relying on an assumption of transportability (that although the marginal distributions of blood lead and environmental lead may be different between the regional dataset and the nation as a whole, the joint relationship between blood lead and environmental lead is the same), the model makes use of a latent variable approach to estimate the joint distribution of blood lead and environmental lead nationwide. PMID:11252599

  18. Predicting Internalizing and Externalizing Problems at Five Years by Child and Parental Factors in Infancy and Toddlerhood

    ERIC Educational Resources Information Center

    Mantymaa, Mirjami; Puura, Kaija; Luoma, Ilona; Latva, Reija; Salmelin, Raili K.; Tamminen, Tuula

    2012-01-01

    This study examined child and parental factors in infancy and toddlerhood predicting subclinical or clinical levels of internalizing and externalizing problems at 5 years of age. Ninety-six children and their families participated. They were assessed when the children were 4-10 weeks old (T1), 2 years (T2) and 5 years old (T3). Child risks…

  19. The Effectiveness of Traditional Admissions Criteria in Predicting College and Graduate Success for American and International Students

    ERIC Educational Resources Information Center

    Fu, Yanfei

    2012-01-01

    This study examines the effectiveness of traditional admissions criteria, including prior GPA, SAT, GRE, and TOEFL in predicting undergraduate and graduate academic success for American and international students at a large public university in the southwestern United States. Included are the admissions and enrollment data for 25,017 undergraduate…

  20. Silver Nanowire Exposure Results in Internalization and Toxicity to Daphnia Magna

    PubMed Central

    Scanlan, Leona D.; Reed, Robert B.; Loguinov, Alexandre V.; Antczak, Philipp; Tagmount, Abderrahmane; Aloni, Shaul; Nowinski, Daniel Thomas; Luong, Pauline; Tran, Christine; Karunaratne, Nadeeka; Pham, Don; Lin, Xin Xin; Falciani, Francesco; Higgins, Chris P.; Ranville, James F.; Vulpe, Chris D.; Gilbert, Benjamin

    2013-01-01

    Nanowires (NWs), high-aspect-ratio nanomaterials, are increasingly used in technological materials and consumer products and may have toxicological characteristics distinct from nanoparticles. We carried out a comprehensive evaluation of the physico-chemical stability of four silver nanowires (AgNWs) of two sizes and coatings and their toxicity to Daphnia magna. Inorganic aluminum-doped silica coatings were less effective than organic poly(vinyl pyrrolidone) coatings at preventing silver oxidation or Ag+ release and underwent a significant morphological transformation within one-hour following addition to low ionic strength Daphnia growth media. All AgNWs were highly toxic to D. magna but less toxic than ionic silver. Toxicity varied as a function of AgNW dimension, coating and solution chemistry. Ag+ release in the media could not account for observed AgNW toxicity. Single-particle inductively coupled plasma mass spectrometry (spICPMS) distinguished and quantified dissolved and nanoparticulate silver in microliter-scale volumes of Daphnia magna hemolymph with a limit of detection of approximately 10 ppb. The silver levels within the hemolymph of Daphnia exposed to both Ag+ and AgNW met or exceeded the initial concentration in the growth medium, indicating effective accumulation during filter feeding. Silver-rich particles were the predominant form of silver in hemolymph following exposure to both AgNWs and Ag+. Scanning electron microscopy (SEM) imaging of dried hemolymph found both AgNWs and silver precipitates that were not present in the AgNW stock or the growth medium. Both organic and inorganic coatings on the AgNW were transformed during ingestion or absorption. Pathway, gene ontology and clustering analyses of gene expression response indicated effects of AgNWs distinct from ionic silver on Daphnia magna. PMID:24099093

  1. Chromosome aberrations in workers with exposure to α-particle radiation from internal deposits of plutonium: expectations from in vitro studies and comparisons with workers with predominantly external γ-radiation exposure.

    PubMed

    Curwen, Gillian B; Sotnik, Natalia V; Cadwell, Kevin K; Azizova, Tamara V; Hill, Mark A; Tawn, E Janet

    2015-05-01

    mFISH analysis of chromosome aberration profiles of 47 and 144 h lymphocyte cultures following exposure to 193 mGy α-particle radiation confirmed that the frequency of stable aberrant cells and stable cells carrying translocations remains constant through repeated cell divisions. Age-specific rates and in vitro dose-response curves were used to derive expected translocation yields in nine workers from the Mayak nuclear facility in Russia. Five had external exposure to γ-radiation, two of whom also had exposure to neutrons, and four had external exposure to γ-radiation and internal exposure to α-particle radiation from incorporated plutonium. Doubts over the appropriateness of the dose response used to estimate translocations from the neutron component made interpretation difficult in two of the workers with external exposure, but the other three had translocation yields broadly in line with expectations. Three of the four plutonium workers had translocation yields in line with expectations, thus supporting the application of the recently derived in vitro α-particle dose response for translocations in stable cells. Overall this report demonstrates that with adequate reference in vitro dose-response curves, translocation yield has the potential to be a useful tool in the validation of red bone marrow doses resulting from mixed exposure to external and internal radiation. PMID:25649482

  2. Skeletal dosimetry in a voxel-based rat phantom for internal exposures to photons and electrons

    SciTech Connect

    Xie Tianwu; Han Dao; Liu Yang; Sun Wenjuan; Liu Qian

    2010-05-15

    Purpose: The skeleton makes a significant contribution to the whole body absorbed dose evaluation of rats, since the bone marrow and bone surface in the skeleton express high radiosensitivity and are considered to be important dose-limiting tissues. The bone marrow can be categorized as red bone marrow (RBM) and yellow bone marrow (YBM). It is important to investigate the bone marrow in skeletal dosimetry. Methods: Cryosectional color images of the skeleton of a 156 g rat were segmented into mineral bone (including cortical bone and trabecular bone), RBM, and YBM. These three tissue types were identified at 40 different bone sites and integrated into a previously developed voxel-based rat computational phantom. Photon and electron skeletal absorbed fractions were then calculated using the MCNPX Monte Carlo code. Results: Absorbed fraction (AF) and specific absorbed fraction (SAF) for mineral bone, RBM, and YBM at the 40 different bone sites were established for monoenergetic photon and electron sources placed in 18 organs and seven bone sites. Discrete photon energy was varied from 0.01 to 5.0 MeV in 21 discrete steps, while 21 discrete electron energies were studied, from 0.1 to 10.0 MeV. The trends and values found were consistent with the results of other researchers [M. G. Stabin, T. E. Peterson, G. E. Holburn, and M. A. Emmons, ''Voxel-based mouse and rat models for internal dose calculations,'' J. Nucl. Med. 47, 655-659 (2006)]. S-factors for the radionuclides {sup 169}Er, {sup 143}Pr, {sup 89}Sr, {sup 32}P, and {sup 90}Y, located in 18 organs and seven bone sites for the skeleton, were calculated and are provided in detail. Conclusions: For internal dose calculations, the AF data reveal that the mineral bone in the rat skeletal system is responsible for significant attenuation of gamma rays, especially at low energies. The photon SAF curves of RBM show that, for photon energies greater than 0.6 MeV, there is an increase in secondary photons emitted from the

  3. Failure behavior of internally pressurized flawed and unflawed steam generator tubing at high temperatures -- Experiments and comparison with model predictions

    SciTech Connect

    Majumdar, S.; Shack, W.J.; Diercks, D.R.; Mruk, K.; Franklin, J.; Knoblich, L.

    1998-03-01

    This report summarizes experimental work performed at Argonne National Laboratory on the failure of internally pressurized steam generator tubing at high temperatures ({le} 700 C). A model was developed for predicting failure of flawed and unflawed steam generator tubes under internal pressure and temperature histories postulated to occur during severe accidents. The model was validated by failure tests on specimens with part-through-wall axial and circumferential flaws of various lengths and depths, conducted under various constant and ramped internal pressure and temperature conditions. The failure temperatures predicted by the model for two temperature and pressure histories, calculated for severe accidents initiated by a station blackout, agree very well with tests performed on both flawed and unflawed specimens.

  4. AMBIENT PARTICULATE MATTER EXPOSURES: A COMPARISON OF SHEDS-PM EXPOSURE MODEL PREDICTIONS AND ESTIMATES DERIVED FROM MEASUREMENTS COLLECTED DURING NERL'S RTP PM PANEL STUDY

    EPA Science Inventory

    The US EPA National Exposure Research Laboratory (NERL) is currently refining and evaluating a population exposure model for particulate matter (PM), called the Stochastic Human Exposure and Dose Simulation (SHEDS-PM) model. The SHEDS-PM model estimates the population distribu...

  5. SHEDS-PM: A POPULATION EXPOSURE MODEL FOR PREDICTING DISTRIBUTIONS OF PM EXPOSURE AND DOSE FROM BOTH OUTDOOR AND INDOOR SOURCES

    EPA Science Inventory

    The US EPA National Exposure Research Laboratory (NERL) has developed a population exposure and dose model for particulate matter (PM), called the Stochastic Human Exposure and Dose Simulation (SHEDS) model. SHEDS-PM uses a probabilistic approach that incorporates both variabi...

  6. Effects of Physiological Internal Noise on Model Predictions of Concurrent Vowel Identification for Normal-Hearing Listeners

    PubMed Central

    Woo, Jihwan; Won, Jong Ho

    2016-01-01

    Previous studies have shown that concurrent vowel identification improves with increasing temporal onset asynchrony of the vowels, even if the vowels have the same fundamental frequency. The current study investigated the possible underlying neural processing involved in concurrent vowel perception. The individual vowel stimuli from a previously published study were used as inputs for a phenomenological auditory-nerve (AN) model. Spectrotemporal representations of simulated neural excitation patterns were constructed (i.e., neurograms) and then matched quantitatively with the neurograms of the single vowels using the Neurogram Similarity Index Measure (NSIM). A novel computational decision model was used to predict concurrent vowel identification. To facilitate optimum matches between the model predictions and the behavioral human data, internal noise was added at either neurogram generation or neurogram matching using the NSIM procedure. The best fit to the behavioral data was achieved with a signal-to-noise ratio (SNR) of 8 dB for internal noise added at the neurogram but with a much smaller amount of internal noise (SNR of 60 dB) for internal noise added at the level of the NSIM computations. The results suggest that accurate modeling of concurrent vowel data from listeners with normal hearing may partly depend on internal noise and where internal noise is hypothesized to occur during the concurrent vowel identification process. PMID:26866811

  7. Risk prediction models: I. Development, internal validation, and assessing the incremental value of a new (bio)marker.

    PubMed

    Moons, Karel G M; Kengne, Andre Pascal; Woodward, Mark; Royston, Patrick; Vergouwe, Yvonne; Altman, Douglas G; Grobbee, Diederick E

    2012-05-01

    Prediction models are increasingly used to complement clinical reasoning and decision making in modern medicine in general, and in the cardiovascular domain in particular. Developed models first and foremost need to provide accurate and (internally and externally) validated estimates of probabilities of specific health conditions or outcomes in targeted patients. The adoption of such models must guide physician's decision making and an individual's behaviour, and consequently improve individual outcomes and the cost-effectiveness of care. In a series of two articles we review the consecutive steps generally advocated for risk prediction model research. This first article focuses on the different aspects of model development studies, from design to reporting, how to estimate a model's predictive performance and the potential optimism in these estimates using internal validation techniques, and how to quantify the added or incremental value of new predictors or biomarkers (of whatever type) to existing predictors. Each step is illustrated with empirical examples from the cardiovascular field. PMID:22397945

  8. Sensitivity to Secondhand Smoke Exposure Predicts Smoking Susceptibility in 8 to 13 Year-Old Never Smokers

    PubMed Central

    Lessov-Schlaggar, Christina N.; Wahlgren, Dennis R.; Liles, Sandy; Jones, Jennifer A.; Ji, Ming; Hughes, Suzanne C.; Swan, Gary E.; Hovell, Melbourne F.

    2010-01-01

    Purpose To investigate the sensitivity to secondhand smoke exposure (SHSe) in preteens age 8 to 13 who have never smoked, and to determine whether SHSe sensitivity predicts smoking susceptibility. Methods We assessed sensitivity to SHSe using reactions commonly used for assessment of sensitivity to the first smoked cigarette (e.g., feeling dizzy), and investigated the factor structure of these reactions for the purpose of data reduction. We examined the association of each reaction measure and summary score with demographic characteristics and with smoking susceptibility, using logistic regression and ordinal logistic regression. Results One factor was identified that captured physical/unpleasant reactions. Older preteens and preteens with more highly educated parents reported fewer reactions to SHSe. More African American preteens reported feeling relaxed or calm compared to all other racial/ethnic groups. Experiencing physical/unpleasant reactions to SHSe predicted lower risk for smoking susceptibility. Conclusions This was the first study to extend analytical methodology for sensitivity to active smoking to sensitivity to SHSe in youth who have never smoked. Results suggest a desensitization process with age and lower sensitivity to some reactions in preteens from more highly educated households. Preteens who have more aversive experience s with SHSe tend to be less susceptible to smoking than those who experience fewer aversive reactions. Assessment of sensitivity to SHSe is a novel approach to the study of cigarette use etiology and may contribute to better prediction of smoking initiation. PMID:21338893

  9. Aircraft noise-induced awakenings are more reasonably predicted from relative than from absolute sound exposure levels.

    PubMed

    Fidell, Sanford; Tabachnick, Barbara; Mestre, Vincent; Fidell, Linda

    2013-11-01

    Assessment of aircraft noise-induced sleep disturbance is problematic for several reasons. Current assessment methods are based on sparse evidence and limited understandings; predictions of awakening prevalence rates based on indoor absolute sound exposure levels (SELs) fail to account for appreciable amounts of variance in dosage-response relationships and are not freely generalizable from airport to airport; and predicted awakening rates do not differ significantly from zero over a wide range of SELs. Even in conjunction with additional predictors, such as time of night and assumed individual differences in "sensitivity to awakening," nominally SEL-based predictions of awakening rates remain of limited utility and are easily misapplied and misinterpreted. Probabilities of awakening are more closely related to SELs scaled in units of standard deviates of local distributions of aircraft SELs, than to absolute sound levels. Self-selection of residential populations for tolerance of nighttime noise and habituation to airport noise environments offer more parsimonious and useful explanations for differences in awakening rates at disparate airports than assumed individual differences in sensitivity to awakening. PMID:24180775

  10. Predicting the microbial exposure risks in urban floods using GIS, building simulation, and microbial models.

    PubMed

    Taylor, Jonathon; Biddulph, Phillip; Davies, Michael; Lai, Ka man

    2013-01-01

    London is expected to experience more frequent periods of intense rainfall and tidal surges, leading to an increase in the risk of flooding. Damp and flooded dwellings can support microbial growth, including mould, bacteria, and protozoa, as well as persistence of flood-borne microorganisms. The amount of time flooded dwellings remain damp will depend on the duration and height of the flood, the contents of the flood water, the drying conditions, and the building construction, leading to particular properties and property types being prone to lingering damp and human pathogen growth or persistence. The impact of flooding on buildings can be simulated using Heat Air and Moisture (HAM) models of varying complexity in order to understand how water can be absorbed and dry out of the building structure. This paper describes the simulation of the drying of building archetypes representative of the English building stock using the EnergyPlus based tool 'UCL-HAMT' in order to determine the drying rates of different abandoned structures flooded to different heights and during different seasons. The results are mapped out using GIS in order to estimate the spatial risk across London in terms of comparative flood vulnerability, as well as for specific flood events. Areas of South and East London were found to be particularly vulnerable to long-term microbial exposure following major flood events. PMID:23266909

  11. Restrained eating predicts effortful self-control as indicated by heart rate variability during food exposure.

    PubMed

    Geisler, Fay C M; Kleinfeldt, Anne; Kubiak, Thomas

    2016-01-01

    When confronted with food, restrained eaters have to inhibit the pursuit of the short-term goal of enjoying their food for the sake of the long-term goal of controlling their weight. Thus, restrained eating creates a self-control situation. In the present study we investigated the initiation of effortful self-control by food cues in accordance with the level of restrained eating. We expected that a preceding act of self-control would moderate the association between restrained eating and effortful self-control initiated by food cues. Participants (N=111) were randomly assigned to a task requiring self-control or a task not requiring self-control. Subsequently, participants were exposed to palatable food, and effortful self-control was measured via heart rate variability (HRV). Restrained eating was associated with enhanced HRV during food exposure after exercising self-control but not after not exercising self-control. The results indicate that maintaining dieting goals results in food cues initiating effortful self-control after a preceding act of self-control. We suggest considering the effect of acts of self-control when modeling the initial steps on the path from food cues to unsuccessful restrained eating. PMID:26500202

  12. Prevalence and Associated Factors of Secondhand Smoke Exposure among Internal Chinese Migrant Women of Reproductive Age: Evidence from China's Labor-Force Dynamic Survey.

    PubMed

    Gong, Xiao; Luo, Xiaofeng; Ling, Li

    2016-04-01

    Secondhand smoke (SHS) is a major risk factor for poor health outcomes among women in China, where proportionately few women smoke. This is especially the case as it pertains to women's reproductive health, specifically migrant women who are exposed to SHS more than the population at large. There are several factors which may increase migrant women's risk of SHS exposure. This paper aims to investigate the prevalence and associated factors of SHS exposure among internal Chinese migrant women of reproductive age. The data used were derived from the 2014 Chinese Labor Dynamic Survey, a national representative panel survey. The age-adjusted rate of SHS exposure of women of reproductive age with migration experience was of 43.46% (95% CI: 40.73%-46.40%), higher than those without migration experience (35.28% (95% CI: 33.66%-36.97%)). Multivariate analysis showed that participants with a marital status of "Widowed" had statistically lower exposure rates, while those with a status of "Cohabitation" had statistically higher exposure. Those with an undergraduate degree or above had statistically lower SHS exposure. Those with increasing levels of social support, and those who currently smoke or drink alcohol, had statistically higher SHS exposure. Participants' different work-places had an effect on their SHS exposure, with outdoor workers statistically more exposed. Our findings suggest that urgent tobacco control measures should be taken to reduce smoking prevalence and SHS exposure. Specific attention should be paid to protecting migrant women of reproductive age from SHS. PMID:27043604

  13. A comparison of exposure to risk factors for giardiasis in non-travellers, domestic travellers and international travellers in a Canadian community, 2006-2012.

    PubMed

    Swirski, A L; Pearl, D L; Peregrine, A S; Pintar, K

    2016-04-01

    The purpose of this study is to determine how demographic and exposure factors related to giardiasis vary between travel and endemic cases. Exposure and demographic data were gathered by public health inspectors from giardiasis cases reported from the Region of Waterloo from 2006 to 2012. Logistic regression models were fit to assess differences in exposure to risk factors for giardiasis between international travel-related cases and Canadian acquired cases while controlling for age and sex. Multinomial regression models were also fit to assess the differences in risk profiles between international and domestic travel-related cases and endemic cases. Travel-related cases (both international and domestic) were more likely to go camping or kayaking, and consume untreated water compared to endemic cases. Domestic travel-related cases were more likely to visit a petting zoo or farm compared to endemic cases, and were more likely to swim in freshwater compared to endemic cases and international travel-related cases. International travellers were more likely to swim in an ocean compared to both domestic travel-related and endemic cases. These findings demonstrate that travel-related and endemic cases have different risk exposure profiles which should be considered for appropriately targeting health promotion campaigns. PMID:26419277

  14. ROUTEMAP model for predicting noise exposure from aircraft operations on Military Training Routes

    NASA Astrophysics Data System (ADS)

    Lucas, Michael J.; Plotkin, Kenneth J.

    1988-09-01

    Low altitude, high speed training operations are routinely conducted along specially designated Military Training Routes (MTRs). The location of these routes is continually changed for a variety of reasons. Each new route requires an environmental assessment to determine the community noise impact. A computer program, ROUTEMAP, is described which calculates the noise level on the ground along an MTR corridor. Program ROUTEMAP is a menu-driven program that runs on any IBM PC or PC-compatible computer. ROUTEMAP requires MS DOS Version 2.0 or later, with at least one megabyte of available disk space, 640 K of random access memory, and an 8087/80287 math coprocessor. The model requires the Air Force planner to specify the nature of the flight activity for the segment of the route in question. The information needed for each aircraft type are the number of day and night operations during a month, and nominal values for the airspeed, engine power setting, and altitude. In addition, the user must input whether the activity is usually under visual or instrument flying rules and if there are single or multiple flight tracks within the route corridor. With this input data, the program computes the onset rate-adjusted monthly day-night average A-weighted sound level, L sub dnmr in dB for ground positions located within 13 miles of the route centerline. For comparison purposes, the program also computes the monthly average A-weighted noise exposure level without the penalty for high onset rates and without the penalty for operations during the night. The program also computes the probability of being highly annoyed as a function of the L sub dnmr values. This information, along with the noise-compatible land-use guides normally associated with planning around airbases, can be used to interpret the noise resulting from military training route operations.

  15. Women's interest in visual sexual stimuli varies with menstrual cycle phase at first exposure and predicts later interest.

    PubMed

    Wallen, Kim; Rupp, Heather A

    2010-02-01

    This study investigated whether women's interest in visual sexual stimuli varied with their hormonal state. Viewing times of 30 women, 15 normal cycling (NC) and 15 oral contracepting (OC), to sexually explicit photos were measured at three different times. NC women were tested during their menstrual, periovulatory, and luteal phases, and OC women were tested at equivalent temporal intervals. Subjects viewed stimuli as long as desired, thus viewing time measured subject interest. Subjective ratings of stimulus sexual attractiveness were obtained on each test. There was no overall relationship between menstrual cycle phase and viewing time. However the participant's menstrual cycle phase during first exposure to sexual stimuli predicted subsequent interest in sexual stimuli during the next two tests. NC women who first viewed stimuli during their periovulatory phase looked longer at the sexual stimuli across all sessions than did women first tested in their luteal phase. OC women first exposed to the sexual stimuli during menstruation looked longer at the stimuli across all sessions than did OC women first exposed at other test phases. Neither current test phase nor initial cycle phase influenced subjective ratings. Women had increased interest in sexual stimuli across all sessions if first exposed to sexual stimuli when endogenous estrogens were most likely highest. These data suggest that women's interest in visual sexual stimuli is modulated by hormones such that the hormonal condition at first exposure possibly determines the stimuli's emotional valence, markedly affecting subsequent interest in sexual stimuli. PMID:20034495

  16. Reducing overlay sampling for APC-based correction per exposure by replacing measured data with computational prediction

    NASA Astrophysics Data System (ADS)

    Noyes, Ben F.; Mokaberi, Babak; Oh, Jong Hun; Kim, Hyun Sik; Sung, Jun Ha; Kea, Marc

    2016-03-01

    One of the keys to successful mass production of sub-20nm nodes in the semiconductor industry is the development of an overlay correction strategy that can meet specifications, reduce the number of layers that require dedicated chuck overlay, and minimize measurement time. Three important aspects of this strategy are: correction per exposure (CPE), integrated metrology (IM), and the prioritization of automated correction over manual subrecipes. The first and third aspects are accomplished through an APC system that uses measurements from production lots to generate CPE corrections that are dynamically applied to future lots. The drawback of this method is that production overlay sampling must be extremely high in order to provide the system with enough data to generate CPE. That drawback makes IM particularly difficult because of the throughput impact that can be created on expensive bottleneck photolithography process tools. The goal is to realize the cycle time and feedback benefits of IM coupled with the enhanced overlay correction capability of automated CPE without impacting process tool throughput. This paper will discuss the development of a system that sends measured data with reduced sampling via an optimized layout to the exposure tool's computational modelling platform to predict and create "upsampled" overlay data in a customizable output layout that is compatible with the fab user CPE APC system. The result is dynamic CPE without the burden of extensive measurement time, which leads to increased utilization of IM.

  17. The use of a sweetener substitution method to predict dietary exposures for the intense sweetener rebaudioside A.

    PubMed

    Renwick, A G

    2008-07-01

    There are more published dietary exposure data for intense sweeteners than for any other group of food additives. Data are available for countries with different patterns of sweetener approvals and also for population groups with high potential intakes, such as children and diabetic subjects. These data provide a secure basis for predicting the potential intakes of a novel intense sweetener by adjustment of the reported intakes of different sweeteners in mg/kg body weight by their relative sweetness intensities. This approach allows the possibility that a novel sweetener attains the same pattern and extent of use as the existing sweeteners. The intakes by high consumers of other sweeteners allows for possible brand loyalty to the novel sweetener. Using this method, the estimated dietary exposures for rebaudioside A in average and high consumers are predicted to be 1.3 and 3.4mg/kg body weight per day for the general population, 2.1 and 5.0mg/kg body weight per day for children and 3.4 and 4.5mg/kg body weight per day for children with diabetes. The temporary ADI defined by the JECFA for steviol glycosides [JECFA, 2005. Steviol glycosides. In: 63rd Meeting of the Joint FAO/WHO Expert Committee on Food Additives. World Health Organization (WHO), Geneva, Switzerland, WHO Technical Report Series 928, pp. 34-39] was set at 0-2mg/kg body weight (expressed as steviol equivalents); after correction for the difference in molecular weights, these estimated intakes of rebaudioside A are equivalent to daily steviol intakes of less than 2mg/kg. In consequence, this analysis shows that the intakes of rebaudioside A would not exceed the JECFA temporary ADI set for steviol glycosides. PMID:18547702

  18. Mothers' Adult Attachment Interview ratings predict preschool children's IQ following domestic violence exposure.

    PubMed

    Busch, Amy L; Lieberman, Alicia F

    2010-11-01

    This study examined links between mothers' Adult Attachment Interview ratings (AAI; Main, Goldwyn, & Hesse, 2003) and their preschool children's IQ among 70 families who had experienced domestic violence. As predicted, children displayed significantly stronger verbal and perceptual-organizational abilities when their mothers exhibited more secure, i.e. coherent, states of mind regarding attachment. Mothers' coherence of mind on the AAI explained 18% of the variance in children's Verbal IQ and 12% of the variance in children's Performance IQ, after controlling for maternal education. Mothers' attachment security also was related to children's total IQ score, but this association was accounted for by effects on children's Verbal IQ. Children whose mothers were rated as unclassifiable on the AAI and those whose mothers were unresolved/insecure had lower IQ scores. Although mothers who appeared more secure on the AAI were more sensitively responsive toward their children, mediational analyses suggested that there was a direct link between mothers' security and children's IQ that was not explained by sensitive parenting. This suggests that clinical interventions for children exposed to domestic violence should include helping their mothers achieve coherent ways of thinking about their own childhood experiences, including past trauma. PMID:20931412

  19. Effectiveness of UK and International A-Level Assessment in Predicting Performance in Engineering

    ERIC Educational Resources Information Center

    Birch, David M.; Rienties, Bart

    2014-01-01

    In many universities, admissions decisions are made based upon the advanced-level (A-Level) results. The purpose of this study was to assess the value of A-level and international equivalents as a predictor of early achievement in higher education. About 135 UK and 92 international undergraduate engineering students from 35 countries were assessed…

  20. Predicting the impacts of new technology aircraft on international air transportation demand

    NASA Technical Reports Server (NTRS)

    Ausrotas, R. A.

    1981-01-01

    International air transportation to and from the United States was analyzed. Long term and short term effects and causes of travel are described. The applicability of econometric methods to forecast passenger travel is discussed. A nomograph is developed which shows the interaction of economic growth, airline yields, and quality of service in producing international traffic.

  1. Prediction of paraquat exposure and toxicity in clinically ill poisoned patients: a model based approach

    PubMed Central

    Wunnapuk, Klintean; Mohammed, Fahim; Gawarammana, Indika; Liu, Xin; Verbeeck, Roger K; Buckley, Nicholas A; Roberts, Michael S; Musuamba, Flora T

    2014-01-01

    Aims Paraquat poisoning is a medical problem in many parts of Asia and the Pacific. The mortality rate is extremely high as there is no effective treatment. We analyzed data collected during an ongoing cohort study on self-poisoning and from a randomized controlled trial assessing the efficacy of immunosuppressive therapy in hospitalized paraquat-intoxicated patients. The aim of this analysis was to characterize the toxicokinetics and toxicodynamics of paraquat in this population. Methods A non-linear mixed effects approach was used to perform a toxicokinetic/toxicodynamic population analysis in a cohort of 78 patients. Results The paraquat plasma concentrations were best fitted by a two compartment toxicokinetic structural model with first order absorption and first order elimination. Changes in renal function were used for the assessment of paraquat toxicodynamics. The estimates of toxicokinetic parameters for the apparent clearance, the apparent volume of distribution and elimination half-life were 1.17 l h−1, 2.4 l kg−1 and 87 h, respectively. Renal function, namely creatinine clearance, was the most significant covariate to explain between patient variability in paraquat clearance.This model suggested that a reduction in paraquat clearance occurred within 24 to 48 h after poison ingestion, and afterwards the clearance was constant over time. The model estimated that a paraquat concentration of 429 μg l−1 caused 50% of maximum renal toxicity. The immunosuppressive therapy tested during this study was associated with only 8% improvement of renal function. Conclusion The developed models may be useful as prognostic tools to predict patient outcome based on patient characteristics on admission and to assess drug effectiveness during antidote drug development. PMID:24697850

  2. Help-Seeking and Internal Obstacles to Receiving Support in the Wake of Community Violence Exposure: The Case of Arab and Jewish Adolescents in Israel

    ERIC Educational Resources Information Center

    Guterman, Neil B.; Haj-Yahia, Muhammad M.; Vorhies, Vanessa; Ismayilova, Leyla; Leshem, Becky

    2010-01-01

    We examined help-seeking and internal obstacles to receiving psychosocial support in the wake of community violence exposure in a sample of 1,835 Arab and Jewish adolescents living in Israel. Paper and pencil surveys conducted in schools examined adolescents' personal victimization and witnessing of community violence in the past year, and then…

  3. Thinking Through Computational Exposure as an Evolving Paradign Shift for Exposure Science: Development and Application of Predictive Models from Big Data

    EPA Science Inventory

    Symposium Abstract: Exposure science has evolved from a time when the primary focus was on measurements of environmental and biological media and the development of enabling field and laboratory methods. The Total Exposure Assessment Method (TEAM) studies of the 1980s were class...

  4. Neural correlates of sensory prediction errors in monkeys: evidence for internal models of voluntary self-motion in the cerebellum.

    PubMed

    Cullen, Kathleen E; Brooks, Jessica X

    2015-02-01

    During self-motion, the vestibular system makes essential contributions to postural stability and self-motion perception. To ensure accurate perception and motor control, it is critical to distinguish between vestibular sensory inputs that are the result of externally applied motion (exafference) and that are the result of our own actions (reafference). Indeed, although the vestibular sensors encode vestibular afference and reafference with equal fidelity, neurons at the first central stage of sensory processing selectively encode vestibular exafference. The mechanism underlying this reafferent suppression compares the brain's motor-based expectation of sensory feedback with the actual sensory consequences of voluntary self-motion, effectively computing the sensory prediction error (i.e., exafference). It is generally thought that sensory prediction errors are computed in the cerebellum, yet it has been challenging to explicitly demonstrate this. We have recently addressed this question and found that deep cerebellar nuclei neurons explicitly encode sensory prediction errors during self-motion. Importantly, in everyday life, sensory prediction errors occur in response to changes in the effector or world (muscle strength, load, etc.), as well as in response to externally applied sensory stimulation. Accordingly, we hypothesize that altering the relationship between motor commands and the actual movement parameters will result in the updating in the cerebellum-based computation of exafference. If our hypothesis is correct, under these conditions, neuronal responses should initially be increased--consistent with a sudden increase in the sensory prediction error. Then, over time, as the internal model is updated, response modulation should decrease in parallel with a reduction in sensory prediction error, until vestibular reafference is again suppressed. The finding that the internal model predicting the sensory consequences of motor commands adapts for new

  5. Dietary exposure to, and internal organ transfer of, selected halogenated organic compounds in birds eating fish from the Southern Baltic.

    PubMed

    Falkowska, Lucyna; Reindl, Andrzej R

    2015-01-01

    The aim of this study was to assess the effect of a marine diet on the accumulation, magnification, maternal transfer and detoxification of chlorinated organic pollutants on the highest trophic level in the Baltic Sea. Results showed that birds eating whole herring received the highest doses of herbicides > pesticides > fungicides > polychlorinated dibenzofurans (PCDFs) > polychlorinated dibenzo-para-dioxins (PCDDs). The toxicity of PCDD/Fs in a penguin's 24-h alimentary exposure was estimated at 7.77 ng TEQ-WHO2005. Among pesticides, the highest concentrations--both in fish and penguin tissue--were those of the pp-DDE isomer. In terms of herbicides, simazine and terbutrine were predominant. The majority of Persistent Organic Pollutants (POPs) underwent accumulation and magnification, and these factors were observed to increase with the birds' age. Guano was found to be an effective means of elimination for all of the studied xenobiotics. Maternal transfer of PCDD/Fs into eggs from internal tissues was most prominent for highly chlorinated dioxins and low chlorinated furans. PMID:26121018

  6. A study on the effect of the internal exposure to (210)Po on the excretion of urinary proteins in rats.

    PubMed

    Sadi, Baki; Li, Chunsheng; Ko, Raymond; Daka, Joseph; Yusuf, Hamdi; Wyatt, Heather; Surette, Joel; Priest, Nick; Hamada, Nobuyuki

    2016-05-01

    This study was designed to assess the feasibility of a noninvasive urine specimen for the detection of proteins as indicators of internal exposure to ionizing radiation. Three groups of rats (five in each group) were intravenously injected with 1601 ± 376, 10,846 ± 591 and 48,467 ± 2812 Bq of (210)Po in citrate form. A sham-exposed control group of five rats was intravenously injected with sterile physiological saline. Daily urine samples were collected over 4 days following injection. Purification and pre-concentration of urinary proteins were carried out by ultrafiltration using a 3000 Da molecular weight cutoff membrane filter. The concentration of common urinary proteins, namely albumin, alpha-1-acid glycoprotein, immunoglobulins IgA and IgG, was measured by an enzyme-linked immunosorbent assay. Urinary excretion of albumin decreased dose-dependently (p < 0.05) 96 h post-injection relative to the control group. In contrast, no statistically significant effects were observed for other proteins tested. The dose-dependent decrease in urinary excretion of albumin observed in this study underscores the need for further research, which may lead to the discovery of new biomarkers that would reflect the changes in the primary target organs for deposition of (210)Po. PMID:26961776

  7. Evolution of a predictive internal model in an embodied and situated agent.

    PubMed

    Gigliotta, Onofrio; Pezzulo, Giovanni; Nolfi, Stefano; Nolfi, Sefano

    2011-12-01

    We show how simulated robots evolved for the ability to display a context-dependent periodic behavior can spontaneously develop an internal model and rely on it to fulfill their task when sensory stimulation is temporarily unavailable. The analysis of some of the best evolved agents indicates that their internal model operates by anticipating sensory stimuli. More precisely, it anticipates functional properties of the next sensory state rather than the exact state that sensors will assume. The characteristics of the states that are anticipated and of the sensorimotor rules that determine how the agents react to the experienced states, however, ensure that they produce very similar behaviour during normal and blind phases in which sensory stimulation is available or is self-generated by the agent, respectively. Agents' internal models also ensure an effective transition during the phases in which agents' internal dynamics is decoupled and re-coupled with the sensorimotor flow. Our results suggest that internal models might have arisen for behavioral reasons and successively exapted for other cognitive functions. Moreover, the obtained results suggest that self-generated internal states should not necessarily match in detail the corresponding sensory states and might rather encode more abstract and motor-oriented information. PMID:21604186

  8. Evaluation of the Relationship between Current Internal 137Cs Exposure in Residents and Soil Contamination West of Chernobyl in Northern Ukraine.

    PubMed

    Kimura, Yuko; Okubo, Yuka; Hayashida, Naomi; Takahashi, Jumpei; Gutevich, Alexander; Chorniy, Sergiy; Kudo, Takashi; Takamura, Noboru

    2015-01-01

    After the Chernobyl Nuclear Power Plant accident, the residents living around the Chernobyl were revealed to have been internally exposed to 137Cs through the intake of contaminated local foods. To evaluate the current situation of internal 137Cs exposure and the relationship between the 137Cs soil contamination and internal exposure in residents, we investigated the 137Cs body burden in residents who were living in 10 selected cities from the northern part of the Zhitomir region, Ukraine, and collected soil samples from three family farms and wild forests of each city to measured 137Cs concentrations. The total number of study participants was 36,862, of which 68.9% of them were female. After 2010, the annual effective doses were less than 0.1 mSv in over 90% of the residents. The 137Cs body burden was significantly higher in autumn than other seasons (p < 0.001) and in residents living in more contaminated areas (p < 0.001). We also found a significant correlation between the proportion of residents in each city with an estimated annual exposure dose exceeding 0.1 mSv and 137Cs concentration of soil samples from family farms (r = 0.828, p = 0.003). In conclusion, more than 25 years after the Chernobyl accident, the internal exposure doses to residents living in contaminated areas of northern Ukraine is limited but still related to 137Cs soil contamination. Furthermore, the consumption of local foods is considered to be the cause of internal exposure. PMID:26402065

  9. Evaluation of the Relationship between Current Internal 137Cs Exposure in Residents and Soil Contamination West of Chernobyl in Northern Ukraine

    PubMed Central

    Kimura, Yuko; Okubo, Yuka; Hayashida, Naomi; Takahashi, Jumpei; Gutevich, Alexander; Chorniy, Sergiy; Kudo, Takashi; Takamura, Noboru

    2015-01-01

    After the Chernobyl Nuclear Power Plant accident, the residents living around the Chernobyl were revealed to have been internally exposed to 137Cs through the intake of contaminated local foods. To evaluate the current situation of internal 137Cs exposure and the relationship between the 137Cs soil contamination and internal exposure in residents, we investigated the 137Cs body burden in residents who were living in 10 selected cities from the northern part of the Zhitomir region, Ukraine, and collected soil samples from three family farms and wild forests of each city to measured 137Cs concentrations. The total number of study participants was 36,862, of which 68.9% of them were female. After 2010, the annual effective doses were less than 0.1 mSv in over 90% of the residents. The 137Cs body burden was significantly higher in autumn than other seasons (p < 0.001) and in residents living in more contaminated areas (p < 0.001). We also found a significant correlation between the proportion of residents in each city with an estimated annual exposure dose exceeding 0.1 mSv and 137Cs concentration of soil samples from family farms (r = 0.828, p = 0.003). In conclusion, more than 25 years after the Chernobyl accident, the internal exposure doses to residents living in contaminated areas of northern Ukraine is limited but still related to 137Cs soil contamination. Furthermore, the consumption of local foods is considered to be the cause of internal exposure. PMID:26402065

  10. Little girls in a grown up world: Exposure to sexualized media, internalization of sexualization messages, and body image in 6-9 year-old girls.

    PubMed

    Slater, Amy; Tiggemann, Marika

    2016-09-01

    Despite widespread public concern about the early sexualization of young girls, as yet there has been little empirical examination of potential negative effects. In the present study a sample of 300 6-9 year-old girls completed individual interviews assessing exposure to sexualized media, internalization of sexualized messages (measured via preference for sexualized clothing), and body image attitudes (body esteem, body dissatisfaction). Exposure to sexualized media was found to be correlated with internalization of sexualization messages, itself correlated with negative body image. The findings provide preliminary evidence that sexualized messages appear to be internalized by very young girls which, in turn, has negative implications for how they feel about their bodies. PMID:27236473

  11. Mercury: a prediction for bulk chemical composition and internal structure in readiness for new MESSENGER data

    NASA Astrophysics Data System (ADS)

    Prentice, A. J.

    2008-12-01

    The MESSENGER spacecraft has confirmed that Mercury's magnetic field is dominantly dipolar and due to an active dynamo in a molten outer core (Solomon et al, 2008 Science 321 59). An energy source is needed to maintain this dynamo. Either liquid iron is freezing at the surface of an inner solid core (as proposed here) or solid iron is precipitating within an outer sulphur-rich core (Chen et al, 2008 GRL 35 L07201). If the outer core does not contain sulphur and consists solely of pure metal (Fe, Ni, Cr,..), then an active dynamo is inconsistent with previous numerical models for the radiogenic thermal evolution of the planet. Those earlier models found that the present temperature at the core/mantle boundary (CMB) is ~ 500 K below the melting temperature of metal ~ 2030 K for a CMB pressure of 70 kbar. The earlier calculations were based on low lunar abundances of U and Th. Here I present a new model for the bulk chemical composition, thermal evolution and current internal structure of Mercury. The model is based on the modern Laplacian theory of solar system origin (Prentice, 1978 Moon Planets 19 341; 2001 Earth Moon & Planets 87 11; 2006 Publ. Astron. Soc. Aust. (PASA) 23 1; 2008 - URL below). A key feature of this theory is that the planets formed from a concentric system of gas rings (n = 0, 1, 2,..) that were shed by the contracting protosolar cloud. The temperatures Tn of the rings scale with mean orbital radius Rn closely as Tn ~ Rn-0.9. Mercury plays a crucial role in calibrating this relationship because of a condensation process of metal/silicate fractionation (Lewis, 1972 EPSL 15 286). Choosing Tn ~ 1630 K for mean orbit gas ring pressure of 0.17 bar, the condensate consists mostly of Fe-Ni-Cr (mass fraction 0.671), gehlenite (0.190) and Mg-silicates (0.081). It has mean density 5.30 g/cm3. Na, K and S are absent. The mass fractions of U and Th, namely 5.66 × 10-8 & 2.08 × 10-7, are a factor of 4.3 times greater than those of the proto-Earth condensate

  12. Use of international data sets to evaluate and validate pathway assessment models applicable to exposure and dose reconstruction at DOE facilities. Monthly progress reports and final report, October--December 1994

    SciTech Connect

    Hoffman, F.O.

    1995-04-01

    The objective of Task 7.lD was to (1) establish a collaborative US-USSR effort to improve and validate our methods of forecasting doses and dose commitments from the direct contamination of food sources, and (2) perform experiments and validation studies to improve our ability to predict rapidly and accurately the long-term internal dose from the contamination of agricultural soil. At early times following an accident, the direct contamination of pasture and food stuffs, particularly leafy vegetation and grain, can be of great importance. This situation has been modeled extensively. However, models employed then to predict the deposition, retention and transport of radionuclides in terrestrial environments employed concepts and data bases that were more than a decade old. The extent to which these models have been tested with independent data sets was limited. The data gathered in the former-USSR (and elsewhere throughout the Northern Hemisphere) offered a unique opportunity to test model predictions of wet and dry deposition, agricultural foodchain bioaccumulation, and short- and long-term retention, redistribution, and resuspension of radionuclides from a variety of natural and artificial surfaces. The current objective of this project is to evaluate and validate pathway-assessment models applicable to exposure and dose reconstruction at DOE facilities through use of international data sets. This project incorporates the activity of Task 7.lD into a multinational effort to evaluate models and data used for the prediction of radionuclide transfer through agricultural and aquatic systems to humans. It also includes participation in two studies, BIOMOVS (BIOspheric MOdel Validation Study) with the Swedish National Institute for Radiation Protection and VAMP (VAlidation of Model Predictions) with the International Atomic Energy Agency, that address testing the performance of models of radionuclide transport through foodchains.

  13. Internal and Predictive Validity of the French Health of the Nation Outcome Scales: Need for Future Directions

    PubMed Central

    Golay, Philippe; Basterrechea, Louis; Conus, Philippe; Bonsack, Charles

    2016-01-01

    The Health of the Nation Outcome Scales (HoNOS) is a widely used measure of health and social functioning of people with mental illness. The goals of this study were to verify the internal validity of the one factor and several four-factor scoring structures and to evaluate the predictive validity of HoNOS items with regards to duration of hospitalization, probability of readmission in the following year and time before readmission. 6175 hospital stays at the department of psychiatry of Lausanne University Hospital were screened and the first HoNOS of each patient was taken into account (N = 2722). Data were analyzed through Confirmatory Factor Analysis (CFA) and the predictive validity of HoNOS items was evaluated with two approaches: item level regressions and latent class analysis (LCA). CFA indicated that the suggested factor structures were not supported by the data. Predictive validity of the 12 items was weak but LCA revealed five distinct and meaningful profiles that were related to length of stay or readmission. HoNOS may be more adapted to the evaluation of patients case-mix rather than to the individual level and concepts such as predictive validity may be more appropriate than internal validity to guide its use. PMID:27483015

  14. Endocrine disrupting chemicals-Linking internal exposure to vitellogenin levels and ovotestis in Abramis brama from Dutch surface waters.

    PubMed

    Reinen, Jelle; Suter, Marc J-F; Vögeli, A Christiane; Fernandez, Mariana F; Kiviranta, Hannu; Eggen, Rik I L; Vermeulen, Nico P E

    2010-11-01

    The exposure of male bream from three Dutch freshwater locations to endocrine disrupting compounds (EDCs) and corresponding effects are described in this study. Fish specimen displaying reproductive disorders associated with high levels of plasma vitellogenin (VTG) concentrations and occurrence of ovotestis (OT) were investigated. To provide information on the full spectrum of EDCs in fish tissue, adipose tissue samples of individual fish were analyzed for nearly 130 chemicals targeting different compound classes (bisphenols, alkylphenols, pesticides, polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), hydroxylated polychlorinated biphenyls (OH-PCBs), polybrominated diphenyl ethers (PBDEs) and biphenyls (PBBs)) and steroid hormones. To establish whether tissue from specimen with reproductive disorders shows a spectrum of EDCs that is qualitatively and quantitatively different from that of controls free of symptoms, bioassay-directed fractionation was performed using the recombinant yeast estrogen screen (YES), the E-Screen bioassay, the human sulfotransferase 1E1 (SULT1E1) inhibition assay, and the coumestrol-based estrogen receptor α (ERα) high resolution screening (HRS) assay. No differences in estrogenicity could be observed between the cases and controls and steroidal estrogens accounted for the majority of estrogenicity found in the complex mixtures. In this study, the combination of the different assays employed to measure total estrogenicity and the SULT1E1 inhibition does not predict the outcome of unwanted physiological effects, however, it can be used to determine the presence of EDCs in fish samples and their estrogenic effects. PMID:21787654

  15. Toxicokinetics of perfluorooctane sulfonate in birds under environmentally realistic exposure conditions and development of a kinetic predictive model.

    PubMed

    Tarazona, J V; Rodríguez, C; Alonso, E; Sáez, M; González, F; San Andrés, M D; Jiménez, B; San Andrés, M I

    2015-01-22

    This article describes the toxicokinetics of perfluorooctane sulfonate (PFOS) in birds under low repeated dosing, equivalent to 0.085 μg/kg per day, representing environmentally realistic exposure conditions. The best fitting was provided by a simple pseudo monocompartmental first-order kinetics model, regulated by two rates, with a pseudo first-order dissipation half-life of 230 days, accounting for real elimination as well as binding of PFOS to non-exchangeable structures. The calculated assimilation efficiency was 0.66 with confidence intervals of 0.64 and 0.68. The model calculations confirmed that the measured maximum concentrations were still far from the steady state situation, which for this dose regime, was estimated at a value of about 65 μg PFOS/L serum achieved after a theoretical 210 weeks continuous exposure. The results confirm a very different kinetics than that observed in single-dose experiments confirming clear dose-related differences in apparent elimination rates in birds, as described for humans and monkeys; suggesting that a capacity-limited saturable process should also be considered in the kinetic behavior of PFOS in birds. Pseudo first-order kinetic models are highly convenient and frequently used for predicting bioaccumulation of chemicals in livestock and wildlife; the study suggests that previous bioaccumulation models using half-lives obtained at high doses are expected to underestimate the biomagnification potential of PFOS. The toxicokinetic parameters presented here can be used for higher-tier bioaccumulation estimations of PFOS in chickens and as surrogate values for modeling PFOS kinetics in wild bird species. PMID:25445721

  16. The Australian study of HIV and injecting Drug Use. Part II: predicting exposure to hepatitis C and hepatitis B.

    PubMed

    Carruthers, S J; Loxley, W M; Phillips, M; Bevan, J S

    1997-09-01

    Researchers agree that while hepatitis B maybe in control, hepatitis C is present in epidemic proportions among injecting drug users and that current HIV prevention strategies have not been sufficient to halt the spread of this hepatitis virus, although there is some evidence to suggest that incidence rates are stabilizing. Since there is no effective cure and it is unlikely that a vaccine will become available in the foreseeable future all efforts to control the spread of hepatitis C must rely on education and prevention strategies. The Australian Study of HIV and Injecting Drug Use is a cross-sectional national study designed to investigate exposure to and risks for infection with bloodborne viruses. Of those volunteering a usable blood sample for hepatitis C antibody and hepatitis B core antibody testing 55% and 19%, respectively, returned reactive test results. Logistic regression statistical models were used to identify risk factors for hepatitis C and hepatitis B. Risk factors for hepatitis C were identified as duration of use, use of opiates on last injecting occasion, education level, treatment status and having a history of sexually transmissible diseases. Risk factors associated with hepatitis B were duration of use, and use of opiates on last injecting occasion. The lack of identifiable risk factors for hepatitis B suggest that past rather than current injecting and sexual behaviour patterns are required to predict accurately risk of exposure to hepatitis B. In addition to this, one-third of respondents reported being vaccinated against hepatitis B. Respondents perceived themselves to be at greater risk from hepatitis C than from hepatitis B or HIV. A discussion of strategies needed to prevent the spread of the hepatitis viruses will be presented along with recommendations for further research. PMID:16203430

  17. MOVING FROM EXTERNAL EXPOSURE CONCENTRATION TO INTERNAL DOSE: DURATION EXTRAPOLATION BASED ON PHYSIOLOGICALLY-BASED PHARMACOKINETIC-MODEL DERIVED ESTIMATES OF INTERNAL DOSE

    EPA Science Inventory

    The potential human health risk(s) from exposure to chemicals under conditions for which adequate human or animal data are not available must frequently be assessed. Exposure scenario is particularly important for the acute neurotoxic effects of volatile organic compounds (VOCs)...

  18. Turbofan forced mixer-nozzle internal flowfield. Volume 2: Computational fluid dynamic predictions

    NASA Technical Reports Server (NTRS)

    Werle, M. J.; Vasta, V. N.

    1982-01-01

    A general program was conducted to develop and assess a computational method for predicting the flow properties in a turbofan forced mixed duct. The detail assessment of the resulting computer code is presented. It was found that the code provided excellent predictions of the kinematics of the mixing process throughout the entire length of the mixer nozzle. The thermal mixing process between the hot core and cold fan flows was found to be well represented in the low speed portion of the flowfield.

  19. Pre-Exposure Rabies Vaccination among US International Travelers: Findings from the Global TravEpiNet Consortium

    PubMed Central

    Dolan, Samantha B.; Sotir, Mark J.; Han, Pauline; Blanton, Jesse D.; Rao, Sowmya R.; LaRocque, Regina C.; Ryan, Edward T.

    2014-01-01

    Abstract Background: People who travel to areas with high rabies endemicity and have animal contact are at increased risk for rabies exposure. We examined characteristics of international travelers queried regarding rabies vaccination during pretravel consultations at Global TravEpiNet (GTEN) practices during 2009–2010. Material and Methods: We performed bivariate and multivariable analyses of data collected from 18 GTEN clinics. Travel destinations were classified by strength level of rabies vaccination recommendation. Results: Of 13,235 travelers, 226 (2%) reported previous rabies vaccination, and 406 (3%) received rabies vaccine at the consultation. Common travel purposes for these 406 travelers were leisure (26%), research/education (17%), and nonmedical service work (14%). Excluding the 226 who were previously vaccinated, 8070 (62%) of 13,009 travelers intended to visit one or more countries with a strong recommendation for rabies vaccination; 1675 (21%) of these 8070 intended to travel for 1 month or more. Among these 1675 travelers, 145 (9%) were vaccinated, 498 (30%) declined vaccination, 832 (50%) had itineraries that clinicians determined did not indicate vaccination, and 200 (12%) remained unvaccinated for other reasons. In both bivariate and multivariate analyses, travelers with trip durations >6 months versus 1–3 months (adjusted odds ratio [OR]=4.9 [95% confidence interval [CI] 2.1, 11.4]) and those traveling for “research/education” or to “provide medical care” (adjusted OR=5.1 [95% CI 1.9, 13.7] and 9.5 [95% CI 2.2, 40.8], respectively), compared with leisure travelers, were more likely to receive rabies vaccination. Conclusions: Few travelers at GTEN clinics received rabies vaccine, although many planned trips 1 month long or more to a strong-recommendation country. Clinicians often determined that vaccine was not indicated, and travelers often declined vaccine when it was offered. The decision to vaccinate should take into account the

  20. A novel airlift reactor enhanced by funnel internals and hydrodynamics prediction by the CFD method.

    PubMed

    Zhang, Tao; Wei, Chaohai; Feng, Chunhua; Zhu, Jialiang

    2012-01-01

    Airlift reactors have been used widely in many industrial processes, but little work has been conducted on such reactors integrated with internals. In this study, a novel airlift reactor with a funnel internal was developed to achieve better flow conditions and advantages in biological processes. The CFD (computational fluid dynamics) simulation method was employed to investigate the effect of the funnel internals on hydrodynamic properties in the reactor. A CFD model was developed for gas-liquid two-phase flow simulation in a bench-scale reactor. Grid-independent simulation results were verified with global-scale experimental data. The results showed that the local or global gas holdup could be enhanced by 15% and that turbulent kinetic energy could be reduced by a maximum of 7.8% when the superficial gas velocity was 1 cm/s. These features are beneficial for applications in stress-sensitive biological processes. PMID:22119313

  1. Comparison of Edge and Internal Transport Barriers in Drift Wave Predictive Simulations

    SciTech Connect

    Weiland, J.; Crombe, K.; Mantica, P.; Naulin, V.; Tala, T.

    2011-10-03

    We have simulated the formation of an internal transport barrier on JET including a self-consistent treatment of ion and electron temperatures and poloidal and toroidal momentum.Similar simulations of edge transport barriers, including the L-H transition have also been made. However, here only poloidal momentum and the temperatures were simulated. The internal barrier included an anomalous spinup of poloidal momentum similar to that in the experiment. Also the edge barrier was accompanied by a spinup of poloidal momentum. The experimental density (with no barrier) was used and kept fixed for the internal barrier. For the edge barrier the edge density was varied and it turned out that a lower edge density gave a stronger barrier. Electromagnetic and nonlocal effects were important for both types of barriers.

  2. Predictive dose-based estimation of systemic exposure multiples in mouse and monkey relative to human for antisense oligonucleotides with 2'-o-(2-methoxyethyl) modifications.

    PubMed

    Yu, Rosie Z; Grundy, John S; Henry, Scott P; Kim, Tae-Won; Norris, Daniel A; Burkey, Jennifer; Wang, Yanfeng; Vick, Andrew; Geary, Richard S

    2015-01-01

    Evaluation of species differences and systemic exposure multiples (or ratios) in toxicological animal species versus human is an ongoing exercise during the course of drug development. The systemic exposure ratios are best estimated by directly comparing area under the plasma concentration-time curves (AUCs), and sometimes by comparing the dose administered, with the dose being adjusted either by body surface area (BSA) or body weight (BW). In this study, the association between AUC ratio and the administered dose ratio from animals to human were studied using a retrospective data-driven approach. The dataset included nine antisense oligonucleotides (ASOs) with 2'-O-(2-methoxyethyl) modifications, evaluated in two animal species (mouse and monkey) following single and repeated parenteral administrations. We found that plasma AUCs were similar between ASOs within the same species, and are predictable to human exposure using a single animal species, either mouse or monkey. Between monkey and human, the plasma exposure ratio can be predicted directly based on BW-adjusted dose ratios, whereas between mouse and human, the exposure ratio would be nearly fivefold lower in mouse compared to human based on BW-adjusted dose values. Thus, multiplying a factor of 5 for the mouse BW-adjusted dose would likely provide a reasonable AUC exposure estimate in human at steady-state. PMID:25602582

  3. Predictive Dose-Based Estimation of Systemic Exposure Multiples in Mouse and Monkey Relative to Human for Antisense Oligonucleotides With 2′-O-(2-Methoxyethyl) Modifications

    PubMed Central

    Yu, Rosie Z; Grundy, John S; Henry, Scott P; Kim, Tae-Won; Norris, Daniel A; Burkey, Jennifer; Wang, Yanfeng; Vick, Andrew; Geary, Richard S

    2015-01-01

    Evaluation of species differences and systemic exposure multiples (or ratios) in toxicological animal species versus human is an ongoing exercise during the course of drug development. The systemic exposure ratios are best estimated by directly comparing area under the plasma concentration-time curves (AUCs), and sometimes by comparing the dose administered, with the dose being adjusted either by body surface area (BSA) or body weight (BW). In this study, the association between AUC ratio and the administered dose ratio from animals to human were studied using a retrospective data-driven approach. The dataset included nine antisense oligonucleotides (ASOs) with 2′-O-(2-methoxyethyl) modifications, evaluated in two animal species (mouse and monkey) following single and repeated parenteral administrations. We found that plasma AUCs were similar between ASOs within the same species, and are predictable to human exposure using a single animal species, either mouse or monkey. Between monkey and human, the plasma exposure ratio can be predicted directly based on BW-adjusted dose ratios, whereas between mouse and human, the exposure ratio would be nearly fivefold lower in mouse compared to human based on BW-adjusted dose values. Thus, multiplying a factor of 5 for the mouse BW-adjusted dose would likely provide a reasonable AUC exposure estimate in human at steady-state. PMID:25602582

  4. The Role of Nativism, Ethnocentrism, and Nationalism in Predicting Students' Propensity to Study International Business.

    ERIC Educational Resources Information Center

    Al-Khatib, Jamal; And Others

    1996-01-01

    A study tested the hypothesis that nativism, ethnocentrism, and nationalism have a direct negative effect on students' choice to study international business. Subjects were 222 incoming freshman business students at 4 universities. Results indicated high levels of nativism and ethnocentrism, but not nationalism, were major inhibitors to studying…

  5. Interactions between Rejection Sensitivity and Supportive Relationships in the Prediction of Adolescents' Internalizing Difficulties

    ERIC Educational Resources Information Center

    McDonald, Kristina L.; Bowker, Julie C.; Rubin, Kenneth H.; Laursen, Brett; Duchene, Melissa S.

    2010-01-01

    Rejection sensitivity, the tendency to anxiously or angrily expect rejection, is associated with internalizing difficulties during childhood and adolescence. The primary goal of the present study was to examine whether supportive parent-child relationships and friendships moderate associations that link angry and anxious rejection sensitivity to…

  6. Prevalence and Associated Factors of Secondhand Smoke Exposure among Internal Chinese Migrant Women of Reproductive Age: Evidence from China’s Labor-Force Dynamic Survey

    PubMed Central

    Gong, Xiao; Luo, Xiaofeng; Ling, Li

    2016-01-01

    Secondhand smoke (SHS) is a major risk factor for poor health outcomes among women in China, where proportionately few women smoke. This is especially the case as it pertains to women’s reproductive health, specifically migrant women who are exposed to SHS more than the population at large. There are several factors which may increase migrant women’s risk of SHS exposure. This paper aims to investigate the prevalence and associated factors of SHS exposure among internal Chinese migrant women of reproductive age. The data used were derived from the 2014 Chinese Labor Dynamic Survey, a national representative panel survey. The age-adjusted rate of SHS exposure of women of reproductive age with migration experience was of 43.46% (95% CI: 40.73%–46.40%), higher than those without migration experience (35.28% (95% CI: 33.66%–36.97%)). Multivariate analysis showed that participants with a marital status of “Widowed” had statistically lower exposure rates, while those with a status of “Cohabitation” had statistically higher exposure. Those with an undergraduate degree or above had statistically lower SHS exposure. Those with increasing levels of social support, and those who currently smoke or drink alcohol, had statistically higher SHS exposure. Participants’ different work-places had an effect on their SHS exposure, with outdoor workers statistically more exposed. Our findings suggest that urgent tobacco control measures should be taken to reduce smoking prevalence and SHS exposure. Specific attention should be paid to protecting migrant women of reproductive age from SHS. PMID:27043604

  7. Reliability of internal prediction/estimation and its application. I. Adaptive action selection reflecting reliability of value function.

    PubMed

    Sakaguchi, Yutaka; Takano, Mitsuo

    2004-09-01

    This article proposes an adaptive action-selection method for a model-free reinforcement learning system, based on the concept of the 'reliability of internal prediction/estimation'. This concept is realized using an internal variable, called the Reliability Index (RI), which estimates the accuracy of the internal estimator. We define this index for a value function of a temporal difference learning system and substitute it for the temperature parameter of the Boltzmann action-selection rule. Accordingly, the weight of exploratory actions adaptively changes depending on the uncertainty of the prediction. We use this idea for tabular and weighted-sum type value functions. Moreover, we use the RI to adjust the learning coefficient in addition to the temperature parameter, meaning that the reliability becomes a general basis for meta-learning. Numerical experiments were performed to examine the behavior of the proposed method. The RI-based Q-learning system demonstrated its features when the adaptive learning coefficient and large RI-discount rate (which indicate how the RI values of future states are reflected in the RI value of the current state) were introduced. Statistical tests confirmed that the algorithm spent more time exploring in the initial phase of learning, but accelerated learning from the midpoint of learning. It is also shown that the proposed method does not work well with the actor-critic models. The limitations of the proposed method and its relationship to relevant research are discussed. PMID:15312837

  8. Dimensions of Maternal Parenting and Infants' Autonomic Functioning Interactively Predict Early Internalizing Behavior Problems.

    PubMed

    Wagner, Nicholas J; Propper, Cathi; Gueron-Sela, Noa; Mills-Koonce, W Roger

    2016-04-01

    Developmental pathways to childhood internalizing behavior problems are complex, with both environmental and child-level factors contributing to their emergence. The authors use data from a prospective longitudinal study (n = 206) to examine the associations between dimensions of caregiving experiences in the first year of life and anxious/depressed and withdrawn behaviors in early childhood. Additionally, the authors examine the extent to which these associations were moderated by infants' autonomic functioning in the first year of life indexed using measures of respiratory sinus arrhythmia (RSA) and heart period (HP). Findings suggest that higher levels of maternal sensitivity in infancy are associated with fewer anxious/depressed and withdrawn behaviors at age 3 years. Negative intrusiveness was found to be positively associated with children's anxious/depressed behaviors but not withdrawn behaviors. Further, moderation analyses suggested that the link between negative intrusive parenting during infancy and subsequent anxious/depressed behaviors is exacerbated for infants with average or low baseline HP and that positive engaging parenting during infancy was negatively related to withdrawn behaviors for infants demonstrating average to high levels baseline HP. Interestingly, RSA was not found to moderate the associations between parenting in infancy and later internalizing behavior problems suggesting that, during infancy, overall autonomic functioning may have greater implications for the development of internalizing behaviors than do parasympathetic influences alone. Implications of these findings and future directions for research are discussed. PMID:26063322

  9. [New international initiatives to create systems of effective risk prediction and food safety].

    PubMed

    Efimochkinal, N R; Bagryantseva, E C; Dupouy, E C; Khotimchenko, S A; Permyakov, E V; Sheveleva, S A; Arnautov, O V

    2016-01-01

    Ensuring food safety is one of the most important problems that is directly related to health protection of the population. The problem is particularly relevant on aglobalscale because ofincreasingnumberoffood-borne diseases andimportance of the health consequence early detection. In accordance with the position of the Codex Alimentarius Commission, food safety concept also includes quality. In this case, creation of the national, supranational and international early warning systems related to the food safety, designed with the purpose to prevent or minimize risks on different stages of the food value chain in various countries, regions and climate zones specific to national nutrition and lifestyle in different groups of population, gains particular importance. The article describes the principles and working examples of international, supranational and national food safety early warning systems. Great importance is given to the hazards of microbial origin - emergent pathogens. Example of the rapid reaction to the appearance of cases, related to the melanin presence in infant formula, are presented. Analysis of the current food safety and quality control system in Russian Federation shows that main improvements are mostly related to the development of the efficient monitoring, diagnostics and rapid alert procedures forfood safety on interregional and international levels that will allow to estimate real contamination of food with the most dangerous pathogens, chemical and biological contaminants, and the development of the electronic database and scientifically proved algorithms for food safety and quality management for targeted prevention activities against existing and emerging microbiological and other etiology risks, and public health protection. PMID:27455605

  10. An efficient numerical method for predicting the evolution of internal variables and springback in bending under tension at large strains

    NASA Astrophysics Data System (ADS)

    Alexandrov, Sergei; Jeng, Yeau-Ren

    2013-12-01

    Quite a general elastic/plastic material model including evolution equations for internal variables is adopted to predict the distribution of material properties and springback in plane strain bending under tension at large strains. A transformation equation to connect Lagrangian and Eulerian coordinates is used to reduce the original boundary value problem to a system of hyperbolic equations. This system is then solved by the method of characteristics combined with a finite difference scheme. In a particular case of elastic/plastic hardening materials (in this case the only internal variable is the equivalent plastic strain) an analytic solution is available in the literature. Using this solution it is demonstrated that the accuracy of the numerical method is very high.

  11. The Predictive Power of Family History Measures of Alcohol and Drug Problems and Internalizing Disorders In A College Population

    PubMed Central

    Kendler, Kenneth S; Edwards, Alexis; Myers, John; Cho, Seung Bin; Adkins, Amy; Dick, Danielle

    2015-01-01

    A family history (FH) of psychiatric and substance use problems is a potent risk factor for common internalizing and externalizing disorders. In a large web-based assessment of mental health in college students, we developed a brief set of screening questions for a FH of alcohol problems (AP), drug problems (DP) and depression-anxiety in four classes of relatives (father, mother, aunts/uncles/grandparents, and siblings) as reported by the student. Positive reports of a history of AP, DP, and depression-anxiety were substantially correlated within relatives. These FH measures predicted in the student, in an expected pattern, dimensions of personality and impulsivity, alcohol consumption and problems, smoking and nicotine dependence, use of illicit drugs, and symptoms of depression and anxiety. Using the mean score from the four classes of relatives was more predictive than using a familial/sporadic dichotomy. Interactions were seen between the FH of AP, DP, and depression-anxiety and peer deviance in predicting symptoms of alcohol and tobacco dependence. As the students aged, the FH of AP became a stronger predictor of alcohol problems. While we cannot directly assess the validity of these FH reports, the pattern of findings suggest that our brief screening items were able to assess, with some accuracy, the FH of substance misuse and internalizing psychiatric disorders in relatives. If correct, these measures can play an important role in the creation of developmental etiologic models for substance and internalizing psychiatric disorders which constitute one of the central goals of the overall project. PMID:25946510

  12. The predictive power of family history measures of alcohol and drug problems and internalizing disorders in a college population.

    PubMed

    Kendler, Kenneth S; Edwards, Alexis; Myers, John; Cho, Seung Bin; Adkins, Amy; Dick, Danielle

    2015-07-01

    A family history (FH) of psychiatric and substance use problems is a potent risk factor for common internalizing and externalizing disorders. In a large web-based assessment of mental health in college students, we developed a brief set of screening questions for a FH of alcohol problems (AP), drug problems (DP) and depression-anxiety in four classes of relatives (father, mother, aunts/uncles/grandparents, and siblings) as reported by the student. Positive reports of a history of AP, DP, and depression-anxiety were substantially correlated within relatives. These FH measures predicted in the student, in an expected pattern, dimensions of personality and impulsivity, alcohol consumption and problems, smoking and nicotine dependence, use of illicit drugs, and symptoms of depression and anxiety. Using the mean score from the four classes of relatives was more predictive than using a familial/sporadic dichotomy. Interactions were seen between the FH of AP, DP, and depression-anxiety and peer deviance in predicting symptoms of alcohol and tobacco dependence. As the students aged, the FH of AP became a stronger predictor of alcohol problems. While we cannot directly assess the validity of these FH reports, the pattern of findings suggest that our brief screening items were able to assess, with some accuracy, the FH of substance misuse and internalizing psychiatric disorders in relatives. If correct, these measures can play an important role in the creation of developmental etiologic models for substance and internalizing psychiatric disorders which constitute one of the central goals of the overall project. PMID:25946510

  13. A review of steps taken to create an international virtual laboratory at NASA Langley for aerodynamic prediction and comparison

    NASA Astrophysics Data System (ADS)

    Lamar, John E.; Cronin, Catherine K.; Scott, Laura E.

    2004-04-01

    A review of the steps taken to establish an international virtual laboratory (VL) at the NASA Langley Research Center for aerodynamic prediction and comparison of flight data in the post-09/11/2001 cyber-terrorist environment is detailed here. The key features of the VL include an intuitive, web-based user interface for ease of access, a secure high-speed Internet connection between browser and server, a relational database architecture for data and information search, and a secure file-storage system. The detailed planning and handling of such issues as security, computer firewall access and legal protection of data are provided.

  14. Other Perspectives for Developing Exposure Estimates: “SHEDS-Lite: Rapid Scenario-Based ExposurePredictions for Chemicals with Near-Field and Dietary Pathways”

    EPA Science Inventory

    Creative advances in exposure science are needed to support efficient and effective evaluation and management of chemical risks, particularly for chemicals in consumer products. This presentation will describe the development of EPA’s screening-level, probabilistic SHEDS-Li...

  15. Fukushima simulation experiment: assessing the effects of chronic low-dose-rate internal 137Cs radiation exposure on litter size, sex ratio, and biokinetics in mice

    PubMed Central

    Nakajima, Hiroo; Yamaguchi, Yoshiaki; Yoshimura, Takashi; Fukumoto, Manabu; Todo, Takeshi

    2015-01-01

    To investigate the transgenerational effects of chronic low-dose-rate internal radiation exposure after the Fukushima Daiichi Nuclear Power Plant accident in Japan, 18 generations of mice were maintained in a radioisotope facility, with free access to drinking water containing 137CsCl (0 and 100 Bq/ml). The 137Cs distribution in the organs of the mice was measured after long-term ad libitum intake of the 137CsCl water. The litter size and the sex ratio of the group ingesting the 137Cs water were compared with those of the control group, for all 18 generations of mice. No significant difference was noted in the litter size or the sex ratio between the mice in the control group and those in the group ingesting the 137Cs water. The fixed internal exposure doses were ∼160 Bq/g and 80 Bq/g in the muscles and other organs, respectively. PMID:26825299

  16. Fukushima simulation experiment: assessing the effects of chronic low-dose-rate internal 137Cs radiation exposure on litter size, sex ratio, and biokinetics in mice.

    PubMed

    Nakajima, Hiroo; Yamaguchi, Yoshiaki; Yoshimura, Takashi; Fukumoto, Manabu; Todo, Takeshi

    2015-12-01

    To investigate the transgenerational effects of chronic low-dose-rate internal radiation exposure after the Fukushima Daiichi Nuclear Power Plant accident in Japan, 18 generations of mice were maintained in a radioisotope facility, with free access to drinking water containing (137)CsCl (0 and 100 Bq/ml). The (137)Cs distribution in the organs of the mice was measured after long-term ad libitum intake of the (137)CsCl water. The litter size and the sex ratio of the group ingesting the (137)Cs water were compared with those of the control group, for all 18 generations of mice. No significant difference was noted in the litter size or the sex ratio between the mice in the control group and those in the group ingesting the (137)Cs water. The fixed internal exposure doses were ∼160 Bq/g and 80 Bq/g in the muscles and other organs, respectively. PMID:26825299

  17. Use of QSARs in international decision-making frameworks to predict health effects of chemical substances.

    PubMed Central

    Cronin, Mark T D; Jaworska, Joanna S; Walker, John D; Comber, Michael H I; Watts, Christopher D; Worth, Andrew P

    2003-01-01

    This article is a review of the use of quantitative (and qualitative) structure-activity relationships (QSARs and SARs) by regulatory agencies and authorities to predict acute toxicity, mutagenicity, carcinogenicity, and other health effects. A number of SAR and QSAR applications, by regulatory agencies and authorities, are reviewed. These include the use of simple QSAR analyses, as well as the use of multivariate QSARs, and a number of different expert system approaches. PMID:12896862

  18. Prediction of fire smoke exposure and air quality degradation: toward a high resolution coupled fire-atmosphere model

    NASA Astrophysics Data System (ADS)

    Mari, Céline; Strada, Susanna; Filippi, Jean-Baptiste; Bosseur, Frederic; Pialat, Xavier; Humberto Amorin, Jorge; Borrego, Carlos; Freitas, Saulo; Longo, Karla; Martins, Vera; Miranda, Ana Isabel; Monteiro, Alexandra; Paugam, Ronan

    2013-04-01

    Wildfires release significant amounts of trace gas and aerosols into the atmosphere. Firefighters are exposed to wildland fire smoke with adverse health effects. At larger scale, depending on meteorological conditions and fire characteristics, fire emissions can efficiently reduce air quality and visibility, even far away from emission sources. Uncertainties in fire emissions and fire plume dynamics are two important factors which substantially limit the capability of current models to predict smoke exposure and air quality degradation. A collaborative effort recently started in France to develop a coupled fire-atmosphere model based on the fire propagation model ForeFire, developed at the University of Corsica, and the mesoscale non-hydrostatic meteorological model Meso-NH, developed by the University of Toulouse and Meteo-France. ForeFire is a semi-physical model based on an analytical estimation of the rate of spread and an integration with a front tracking method. The fire model is used to provide gridded heating, water vapor and chemical fluxes at high temporal and spatial resolutions to Meso-NH. The coupled model was used in two configurations depending on the spatial resolution: with or without the feedback of the atmosphere on the fire propagation. At kilometric resolution, the model is used off-line to simulate two Mediterranean fires: an arson wildfire that burned in 2005 near Lancon-de-Provence, south-eastern France, and a well documented episode of the Lisbon 2003 fires (in collaboration with the University of Aveiro, Portugal). The question of the injection height is treated with an adaptation of the eddy-diffusivity/mass flux approach for convective boundary layer and compared to the 1D Plume Rise Model (developed at INPE) in contrasted meteorological scenarios. At higher resolution, the two-way coupled model is tested on idealized and real fire cases including ozone chemistry. Future required developments on surface emissions and combustion chemistry

  19. Predicting the demand of physician workforce: an international model based on "crowd behaviors"

    PubMed Central

    2012-01-01

    Background Appropriateness of physician workforce greatly influences the quality of healthcare. When facing the crisis of physician shortages, the correction of manpower always takes an extended time period, and both the public and health personnel suffer. To calculate an appropriate number of Physician Density (PD) for a specific country, this study was designed to create a PD prediction model, based on health-related data from many countries. Methods Twelve factors that could possibly impact physicians' demand were chosen, and data of these factors from 130 countries (by reviewing 195) were extracted. Multiple stepwise-linear regression was used to derive the PD prediction model, and a split-sample cross-validation procedure was performed to evaluate the generalizability of the results. Results Using data from 130 countries, with the consideration of the correlation between variables, and preventing multi-collinearity, seven out of the 12 predictor variables were selected for entry into the stepwise regression procedure. The final model was: PD = (5.014 - 0.128 × proportion under age 15 years + 0.034 × life expectancy)2, with R2 of 80.4%. Using the prediction equation, 70 countries had PDs with "negative discrepancy", while 58 had PDs with "positive discrepancy". Conclusion This study provided a regression-based PD model to calculate a "norm" number of PD for a specific country. A large PD discrepancy in a country indicates the needs to examine physician's workloads and their well-being, the effectiveness/efficiency of medical care, the promotion of population health and the team resource management. PMID:22448781

  20. International H2O Project (IHOP) 2002: Datasets Related to Atmospheric Moisture and Rainfall Prediction

    DOE Data Explorer

    Schanot, Allen [IHOP 2002 PI; Friesen, Dick [IHOP 2002 PI

    IHOP 2002 was a field experiment that took place over the Southern Great Plains of the United States from 13 May to 25 June 2002. The chief aim of IHOP_2002 was improved characterization of the four-dimensional (4-D) distribution of water vapor and its application to improving the understanding and prediction of convection. The region was an optimal location due to existing experimental and operational facilities, strong variability in moisture, and active convection [copied from http://www.eol.ucar.edu/projects/ihop/]. The project's master list of data identifies 146 publicly accessible datasets.

  1. Workshop Summary: International Cooperative for Aerosol Prediction Workshop On Aerosol Forecast Verification

    NASA Technical Reports Server (NTRS)

    Benedetti, Angela; Reid, Jeffrey S.; Colarco, Peter R.

    2011-01-01

    The purpose of this workshop was to reinforce the working partnership between centers who are actively involved in global aerosol forecasting, and to discuss issues related to forecast verification. Participants included representatives from operational centers with global aerosol forecasting requirements, a panel of experts on Numerical Weather Prediction and Air Quality forecast verification, data providers, and several observers from the research community. The presentations centered on a review of current NWP and AQ practices with subsequent discussion focused on the challenges in defining appropriate verification measures for the next generation of aerosol forecast systems.

  2. Predicting academic performance and clinical competency for international dental students: seeking the most efficient and effective measures.

    PubMed

    Stacey, D Graham; Whittaker, John M

    2005-02-01

    Measures used in the selection of international dental students to a U.S. D.D.S. program were examined to identify the grouping that most effectively and efficiently predicted academic performance and clinical competency. Archival records from the International Dental Program (IDP) at Loma Linda University provided data on 171 students who had trained in countries outside the United States. The students sought admission to the D.D.S. degree program, successful completion of which qualified them to sit for U.S. licensure. As with most dental schools, competition is high for admission to the D.D.S. program. The study's goal was to identify what measures contributed to a fair and accurate selection process for dental school applicants from other nations. Multiple regression analyses identified National Board Part II and dexterity measures as significant predictors of academic performance and clinical competency. National Board Part I, TOEFL, and faculty interviews added no significant additional help in predicting eventual academic performance and clinical competency. PMID:15689612

  3. Prediction of pressure loss and heat transfer in internal cooling passages.

    PubMed

    Hermanson, K; Parneix, S; von Wolfersdorf, J; Semmler, K

    2001-05-01

    This paper reports CFD-simulations of the turbulent flow, pressure loss and heat transfer occurring in ribbed passages. The channel section is rectangular, with an aspect ratio of 2.04. Ribs are square cross-section, their height is 10% of the channel height, and their inclination is varied from 90 degrees to 33 degrees. Reynolds number is 30,000. Three turbulence models (k-epsilon wall functions and 2-layer, V2F) are used and compared to the experimental data of Cho et al. All three models accurately predict the pressure losses due to the ribs and the qualitative heat transfer distribution on the ribbed wall. However, only the V2F model can accurately reproduce the absolute heat transfer levels, this at all inclination angles. The correlation developed by Han and co-workers for smaller rib-heights under-predicts the friction factor and wall heat transfer level on the current configuration. This shows the danger of using a correlation outside of its application range. PMID:11460660

  4. Minimum exposure limits and measured relationships between the vitamin D, erythema and international commission on non-ionizing radiation protection solar ultraviolet.

    PubMed

    Downs, Nathan; Parisi, Alfio; Butler, Harry; Turner, Joanna; Wainwright, Lisa

    2015-01-01

    The International Commission on Non-Ionizing Radiation Protection (ICNIRP) has established guidelines for exposure to ultraviolet radiation in outdoor occupational settings. Spectrally weighted ICNIRP ultraviolet exposures received by the skin or eye in an 8 h period are limited to 30 J m(-2). In this study, the time required to reach the ICNIRP exposure limit was measured daily in 10 min intervals upon a horizontal plane at a subtropical Australian latitude over a full year and compared with the effective Vitamin D dose received to one-quarter of the available skin surface area for all six Fitzpatrick skin types. The comparison of measured solar ultraviolet exposures for the full range of sky conditions in the 2009 measurement period, including a major September continental dust event, show a clear relationship between the weighted ICNIRP and the effective vitamin D dose. Our results show that the horizontal plane ICNIRP ultraviolet exposure may be used under these conditions to provide minimum guidelines for the healthy moderation of vitamin D, scalable to each of the six Fitzpatrick skin types. PMID:25407011

  5. Exposure to dioxin and nonneoplastic mortality in the expanded IARC international cohort study of phenoxy herbicide and chlorophenol production workers and sprayers.

    PubMed Central

    Vena, J; Boffetta, P; Becher, H; Benn, T; Bueno-de-Mesquita, H B; Coggon, D; Colin, D; Flesch-Janys, D; Green, L; Kauppinen, T; Littorin, M; Lynge, E; Mathews, J D; Neuberger, M; Pearce, N; Pesatori, A C; Saracci, R; Steenland, K; Kogevinas, M

    1998-01-01

    The authors studied noncancer mortality among phenoxyacid herbicide and chlorophenol production workers and sprayers included in an international study comprising 36 cohorts from 12 countries followed from 1939 to 1992. Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin or higher chlorinated dioxins (TCDD/HCD) was discerned from job records and company questionnaires with validation by biologic and environmental measures. Standard mortality ratio analyses suggested a moderate healthy worker effect for all circulatory diseases, especially ischemic heart disease, among both those exposed and those not exposed to TCDD/HCD. In Poisson regression analyses, exposure to TCDD/HCD was not associated with increased mortality from cerebrovascular disease. However, an increased risk for circulatory disease, especially ischemic heart disease (rate ratio [RR] 1.67, 95% confidence interval [Cl] 1.23-2.26) and possibly diabetes (RR 2.25, 95% Cl 0.53-9.50), was present among TCDD/HCD-exposed workers. Risks tended to be higher 10 to 19 years after first exposure and for those exposed for a duration of 10 to 19 years. Mortality from suicide was comparable to that for the general population for all workers exposed to herbicides or chlorophenols and was associated with short latency and duration of exposure. More refined investigations of the ischemic heart disease and TCDD/HCD exposure association are warranted. PMID:9599712

  6. Age-Related Changes in Predictive Capacity Versus Internal Model Adaptability: Electrophysiological Evidence that Individual Differences Outweigh Effects of Age.

    PubMed

    Bornkessel-Schlesewsky, Ina; Philipp, Markus; Alday, Phillip M; Kretzschmar, Franziska; Grewe, Tanja; Gumpert, Maike; Schumacher, Petra B; Schlesewsky, Matthias

    2015-01-01

    Hierarchical predictive coding has been identified as a possible unifying principle of brain function, and recent work in cognitive neuroscience has examined how it may be affected by age-related changes. Using language comprehension as a test case, the present study aimed to dissociate age-related changes in prediction generation versus internal model adaptation following a prediction error. Event-related brain potentials (ERPs) were measured in a group of older adults (60-81 years; n = 40) as they read sentences of the form "The opposite of black is white/yellow/nice." Replicating previous work in young adults, results showed a target-related P300 for the expected antonym ("white"; an effect assumed to reflect a prediction match), and a graded N400 effect for the two incongruous conditions (i.e. a larger N400 amplitude for the incongruous continuation not related to the expected antonym, "nice," versus the incongruous associated condition, "yellow"). These effects were followed by a late positivity, again with a larger amplitude in the incongruous non-associated versus incongruous associated condition. Analyses using linear mixed-effects models showed that the target-related P300 effect and the N400 effect for the incongruous non-associated condition were both modulated by age, thus suggesting that age-related changes affect both prediction generation and model adaptation. However, effects of age were outweighed by the interindividual variability of ERP responses, as reflected in the high proportion of variance captured by the inclusion of by-condition random slopes for participants and items. We thus argue that - at both a neurophysiological and a functional level - the notion of general differences between language processing in young and older adults may only be of limited use, and that future research should seek to better understand the causes of interindividual variability in the ERP responses of older adults and its relation to cognitive performance. PMID

  7. Unpacking Trauma Exposure Risk Factors and Differential Pathways of Influence: Predicting Postwar Mental Distress in Bosnian Adolescents

    ERIC Educational Resources Information Center

    Layne, Christopher M.; Olsen, Joseph A.; Baker, Aaron; Legerski, John-Paul; Isakson, Brian; Pasalic, Alma; Durakovic-Belko, Elvira; Dapo, Nermin; Campara, Nihada; Arslanagic, Berina; Saltzman, William R.; Pynoos, Robert S.

    2010-01-01

    Methods are needed for quantifying the potency and differential effects of risk factors to identify at-risk groups for theory building and intervention. Traditional methods for constructing war exposure measures are poorly suited to "unpack" differential relations between specific types of exposure and specific outcomes. This study of 881 Bosnian…

  8. Characterisation of Growth and Ultrastructural Effects of the Xanthoria elegans Photobiont After 1.5 Years of Space Exposure on the International Space Station.

    PubMed

    Brandt, Annette; Posthoff, Eva; de Vera, Jean-Pierre; Onofri, Silvano; Ott, Sieglinde

    2016-06-01

    The lichen Xanthoria elegans has been exposed to space and simulated Mars-analogue environment in the Lichen and Fungi Experiment (LIFE) on the EXPOSE-E facility at the International Space Station (ISS). This long-term exposure of 559 days tested the ability of various organisms to cope with either low earth orbit (LEO) or Mars-analogue conditions, such as vacuum, Mars-analogue atmosphere, rapid temperature cycling, cosmic radiation of up to 215 ± 16 mGy, and insolation of accumulated doses up to 4.87 GJm(-2), including up to 0.314 GJm(-2) of UV irradiation. In a previous study, X. elegans demonstrated considerable resistance towards these conditions by means of photosynthetic activity as well as by post-exposure metabolic activity of 50-80% in the algal and 60-90% in the fungal symbiont (Brandt et al. Int J Astrobiol 14(3):411-425, 2015). The two objectives of the present study were complementary: First, to verify the high post-exposure viability by using a qualitative cultivation assay. Second, to characterise the cellular damages by transmission electron microscopy (TEM) which were caused by the space and Mars-analogue exposure conditions of LIFE. Since the algal symbiont of lichens is considered as the more susceptible partner (de Vera and Ott 2010), the analyses focused on the photobiont. The study demonstrated growth and proliferation of the isolated photobiont after all exposure conditions of LIFE. The ultrastructural analysis of the algal cells provided an insight to cellular damages caused by long-term exposure and highlighted that desiccation-induced breakdown of cellular integrity is more pronounced under the more severe space vacuum than under Mars-analogue atmospheric conditions. In conclusion, desiccation-induced damages were identified as a major threat to the photobiont of X. elegans. Nonetheless, a fraction of the photobiont cells remained cultivable after all exposure conditions tested in LIFE. PMID:26526425

  9. Characterisation of Growth and Ultrastructural Effects of the Xanthoria elegans Photobiont After 1.5 Years of Space Exposure on the International Space Station

    NASA Astrophysics Data System (ADS)

    Brandt, Annette; Posthoff, Eva; de Vera, Jean-Pierre; Onofri, Silvano; Ott, Sieglinde

    2016-06-01

    The lichen Xanthoria elegans has been exposed to space and simulated Mars-analogue environment in the Lichen and Fungi Experiment (LIFE) on the EXPOSE-E facility at the International Space Station (ISS). This long-term exposure of 559 days tested the ability of various organisms to cope with either low earth orbit (LEO) or Mars-analogue conditions, such as vacuum, Mars-analogue atmosphere, rapid temperature cycling, cosmic radiation of up to 215 ± 16 mGy, and insolation of accumulated doses up to 4.87 GJm-2, including up to 0.314 GJm-2 of UV irradiation. In a previous study, X. elegans demonstrated considerable resistance towards these conditions by means of photosynthetic activity as well as by post-exposure metabolic activity of 50-80 % in the algal and 60-90 % in the fungal symbiont (Brandt et al. Int J Astrobiol 14(3):411-425, 2015). The two objectives of the present study were complementary: First, to verify the high post-exposure viability by using a qualitative cultivation assay. Second, to characterise the cellular damages by transmission electron microscopy (TEM) which were caused by the space and Mars-analogue exposure conditions of LIFE. Since the algal symbiont of lichens is considered as the more susceptible partner (de Vera and Ott 2010), the analyses focused on the photobiont. The study demonstrated growth and proliferation of the isolated photobiont after all exposure conditions of LIFE. The ultrastructural analysis of the algal cells provided an insight to cellular damages caused by long-term exposure and highlighted that desiccation-induced breakdown of cellular integrity is more pronounced under the more severe space vacuum than under Mars-analogue atmospheric conditions. In conclusion, desiccation-induced damages were identified as a major threat to the photobiont of X. elegans. Nonetheless, a fraction of the photobiont cells remained cultivable after all exposure conditions tested in LIFE.

  10. Effects of tissue conductivity and electrode area on internal electric fields in a numerical human model for ELF contact current exposures

    NASA Astrophysics Data System (ADS)

    Tarao, H.; Kuisti, H.; Korpinen, L.; Hayashi, N.; Isaka, K.

    2012-05-01

    Contact currents flow through the human body when a conducting object with different potential is touched. There are limited reports on numerical dosimetry for contact current exposure compared with electromagnetic field exposures. In this study, using an anatomical human adult male model, we performed numerical calculation of internal electric fields resulting from 60 Hz contact current flowing from the left hand to the left foot as a basis case. Next, we performed a variety of similar calculations with varying tissue conductivity and contact area, and compared the results with the basis case. We found that very low conductivity of skin and a small electrode size enhanced the internal fields in the muscle, subcutaneous fat and skin close to the contact region. The 99th percentile value of the fields in a particular tissue type did not reliably account for these fields near the electrode. In the arm and leg, the internal fields for the muscle anisotropy were identical to those in the isotropy case using a conductivity value longitudinal to the muscle fibre. Furthermore, the internal fields in the tissues abreast of the joints such as the wrist and the elbow, including low conductivity tissues, as well as the electrode contact region, exceeded the ICNIRP basic restriction for the general public with contact current as the reference level value.

  11. Dependence of the climate prediction skill on spatiotemporal scales: Internal versus radiatively-forced contribution

    NASA Astrophysics Data System (ADS)

    Volpi, D.; Doblas-Reyes, F. J.; GarcíA-Serrano, J.; Guemas, V.

    2013-06-01

    This article aims at quantifying the improvement in climate prediction skill as a function of temporal (from monthly to decadal) and spatial scales (from grid point to global) when initializing a perturbed parameter ensemble of the Hadley Centre Climate Model. The focus is on near-surface temperature and precipitation in the Tropical band, the Northern and Southern hemispheres. For temperature, the forecast system reproduces the dominant impact of the external forcing at global spatial scale and at decadal time scales. There are significant improvements with initialization for the first 40 forecast months in the global and tropical domains. In the Northern (Southern) hemisphere, the initialization increases the skill in the first 12 (20) months on regional but not hemispheric scales. The initialization has a stronger impact in the model variants with a weaker global-mean temperature trend. For precipitation, the initialization corrects the negative correlation found at global and tropical scales.

  12. Using metabolic flux data to further constrain the metabolic solution space and predict internal flux patterns: the Escherichia coli spectrum.

    PubMed

    Wiback, Sharon J; Mahadevan, Radhakrishnan; Palsson, Bernhard Ø

    2004-05-01

    Constraint-based metabolic modeling has been used to capture the genome-scale, systems properties of an organism's metabolism. The first generation of these models has been built on annotated gene sequence. To further this field, we now need to develop methods to incorporate additional "omic" data types including transcriptomics, metabolomics, and fluxomics to further facilitate the construction, validation, and predictive capabilities of these models. The work herein combines metabolic flux data with an in silico model of central metabolism of Escherichia coli for model centric integration of the flux data. The extreme pathways for this network, which define the allowable solution space for all possible flux distributions, are analyzed using the alpha-spectrum. The alpha-spectrum determines which extreme pathways can and cannot contribute to the metabolic flux distribution for a given condition and gives the allowable range of weightings on each extreme pathway that can contribute. Since many extreme pathways cannot be used under certain conditions, the result is a "condition-specific" solution space that is a subset of the original solution space. The alpha-spectrum results are used to create a "condition-specific" extreme pathway matrix that can be analyzed using singular value decomposition (SVD). The first mode of the SVD analysis characterizes the solution space for a given condition. We show that SVD analysis of the alpha-spectrum extreme pathway matrix that incorporates measured uptake and byproduct secretion rates, can predict internal flux trends for different experimental conditions. These predicted internal flux trends are, in general, consistent with the flux trends measured using experimental metabolic flux analysis techniques. PMID:15083512

  13. Predicting global thunderstorm activity for sprite observations from the International Space Station

    NASA Astrophysics Data System (ADS)

    Yair, Y.; Mezuman, K.; Ziv, B.; Priente, M.; Glickman, M.; Takahashi, Y.; Inoue, T.

    2012-04-01

    The global rate of sprites occurring above thunderstorms, estimated from the ISUAL satellite data, is ~0.5 per minute (Chen et al., 2008). During the summer 2011, in the framework of the "Cosmic Shore" project, we conducted a concentrated attempt to image sprites from the ISS. The methodology for target selection was based on that developed for the space shuttle MEIDEX sprite campaign (Ziv et al., 2004). There are several types of convective systems generating thunderstorms which differ in their effectiveness for sprite production (Lyons et al., 2009), and so we had to evaluate the ability of the predicted storms to produce sprites. We used the Aviation Weather Center (http://aviationweather.gov) daily significant weather forecast maps (SIGWX) to select regions with high probability for convective storms and lightning such that they were within the camera filed-of-view as deduced from the ISS trajectory and distance to the limb. In order to enhance the chance for success, only storms with predicted "Frequent Cb" and cloud tops above 45 Kft (~14 km) were selected. Additionally, we targeted tropical storms and hurricanes over the oceans. The accuracy of the forecast method enabled obtaining the first-ever color images of sprites from space. We will report the observations showing various types of sprites in many different geographical locations, and correlated parent lightning properties derived from ELF and global and local lightning location networks. Chen, A. B., et al. (2008), Global distributions and occurrence rates of transient luminous events, J. Geophys. Res., 113,A08306, doi:10.1029/2008JA013101 Lyons, W. A., et al. (2009), The meteorological and electrical structure of TLE-producing convective storms. In: Betz et al. (eds.): Lighting: principles instruments and applications, Springer-Science + Business Media B.V.. Ziv, B., Y. Yair, K. Pressman and M. Fullekrug, (2004), Verification of the Aviation Center global forecasts of Mesoscale Convective Systems

  14. Internally directed cognition and mindfulness: an integrative perspective derived from predictive and reactive control systems theory

    PubMed Central

    Tops, Mattie; Boksem, Maarten A. S.; Quirin, Markus; IJzerman, Hans; Koole, Sander L.

    2013-01-01

    In the present paper, we will apply the predictive and reactive control systems (PARCS) theory as a framework that integrates competing theories of neural substrates of awareness by describing the “default mode network” (DMN) and anterior insula (AI) as parts of two different behavioral and homeostatic control systems. The DMN, a network that becomes active at rest when there is no external stimulation or task to perform, has been implicated in self-reflective awareness and prospection. By contrast, the AI is associated with awareness and task-related attention. This has led to competing theories stressing the role of the DMN in self-awareness vs. the role of interoceptive and emotional information integration in the AI in awareness of the emotional moment. In PARCS, the respective functions of the DMN and AI in a specific control system explains their association with different qualities of awareness, and how mental states can shift from one state (e.g., prospective self-reflection) to the other (e.g., awareness of the emotional moment) depending on the relative dominance of control systems. These shifts between reactive and predictive control are part of processes that enable the intake of novel information, integration of this novel information within existing knowledge structures, and the creation of a continuous personal context in which novel information can be integrated and understood. As such, PARCS can explain key characteristics of mental states, such as their temporal and spatial focus (e.g., a focus on the here and now vs. the future; a first person vs. a third person perspective). PARCS further relates mental states to brain states and functions, such as activation of the DMN or hemispheric asymmetry in frontal cortical functions. Together, PARCS deepens the understanding of a broad range of mental states, including mindfulness, mind wandering, rumination, autobiographical memory, imagery, and the experience of self. PMID:24904455

  15. Performance Assessment of the Commercial CFD Software for the Prediction of the Reactor Internal Flow

    NASA Astrophysics Data System (ADS)

    Lee, Gong Hee; Bang, Young Seok; Woo, Sweng Woong; Kim, Do Hyeong; Kang, Min Ku

    2014-06-01

    As the computer hardware technology develops the license applicants for nuclear power plant use the commercial CFD software with the aim of reducing the excessive conservatism associated with using simplified and conservative analysis tools. Even if some of CFD software developer and its user think that a state of the art CFD software can be used to solve reasonably at least the single-phase nuclear reactor problems, there is still limitation and uncertainty in the calculation result. From a regulatory perspective, Korea Institute of Nuclear Safety (KINS) is presently conducting the performance assessment of the commercial CFD software for nuclear reactor problems. In this study, in order to examine the validity of the results of 1/5 scaled APR+ (Advanced Power Reactor Plus) flow distribution tests and the applicability of CFD in the analysis of reactor internal flow, the simulation was conducted with the two commercial CFD software (ANSYS CFX V.14 and FLUENT V.14) among the numerous commercial CFD software and was compared with the measurement. In addition, what needs to be improved in CFD for the accurate simulation of reactor core inlet flow was discussed.

  16. DARTAB: a program to combine airborne radionuclide environmental exposure data with dosimetric and health effects data to generate tabulations of predicted health impacts

    SciTech Connect

    Begovich, C.L.; Eckerman, K.F.; Schlatter, E.C.; Ohr, S.Y.; Chester, R.O.

    1981-08-01

    The DARTAB computer code combines radionuclide environmental exposure data with dosimetric and health effects data to generate tabulations of the predicted impact of radioactive airborne effluents. DARTAB is independent of the environmental transport code used to generate the environmental exposure data and the codes used to produce the dosimetric and health effects data. Therefore human dose and risk calculations need not be added to every environmental transport code. Options are included in DARTAB to permit the user to request tabulations by various topics (e.g., cancer site, exposure pathway, etc.) to facilitate characterization of the human health impacts of the effluents. The DARTAB code was written at ORNL for the US Environmental Protection Agency, Office of Radiation Programs.

  17. Prolonged exposure to high and variable phenylalanine levels over the lifetime predicts brain white matter integrity in children with phenylketonuria.

    PubMed

    Hood, Anna; Antenor-Dorsey, Jo Ann V; Rutlin, Jerrel; Hershey, Tamara; Shimony, Joshua S; McKinstry, Robert C; Grange, Dorothy K; Christ, Shawn E; Steiner, Robert; White, Desiree A

    2015-01-01

    In this study, we retrospectively examined the microstructural white matter integrity of children with early- and continuously-treated PKU (N=36) in relation to multiple indices of phenylalanine (Phe) control over the lifetime. White matter integrity was assessed using mean diffusivity (MD) from diffusion tensor imaging (DTI). Eight lifetime indices of Phe control were computed to reflect average Phe (mean, index of dietary control), variability in Phe (standard deviation, standard error of estimate, % spikes), change in Phe with age (slope), and prolonged exposure to Phe (mean exposure, standard deviation exposure). Of these indices, mean Phe, mean exposure, and standard deviation exposure were the most powerful predictors of widespread microstructural white matter integrity compromise. Findings from the two previously unexamined exposure indices reflected the accumulative effects of elevations and variability in Phe. Given that prolonged exposure to elevated and variable Phe was particularly detrimental to white matter integrity, Phe should be carefully monitored and controlled throughout childhood, without liberalization of Phe control as children with PKU age. PMID:25481106

  18. Prolonged Exposure to High and Variable Phenylalanine Levels over the Lifetime Predicts Brain White Matter Integrity in Children with Phenylketonuria

    PubMed Central

    Hood, Anna; Antenor-Dorsey, Jo Ann V.; Rutlin, Jerrel; Hershey, Tamara; Shimony, Joshua S.; McKinstry, Robert C.; Grange, Dorothy K.; Christ, Shawn E.; Steiner, Robert; White, Desiree A.

    2014-01-01

    In this study, we retrospectively examined the microstructural white matter integrity of children with early- and continuously-treated PKU (N = 36) in relation to multiple indices of phenylalanine (Phe) control over the lifetime. White matter integrity was assessed using mean diffusivity (MD) from diffusion tensor imaging (DTI). Eight lifetime indices of Phe control were computed to reflect average Phe (mean, index of dietary control), variability in Phe (standard deviation, standard error of estimate, % spikes), change in Phe with age (slope), and prolonged exposure to Phe (mean exposure, standard deviation exposure). Of these indices, mean Phe, mean exposure, and standard deviation exposure were the most powerful predictors of widespread microstructural white matter integrity compromise. Findings from the two previously unexamined exposure indices reflected the accumulative effects of elevations and variability in Phe. Given that prolonged exposure to elevated and variable Phe was particularly detrimental to white matter integrity, Phe should be carefully monitored and controlled throughout childhood, without liberalization of Phe control as children with PKU age. PMID:25481106

  19. Prediction and Analysis of Post-Translational Pyruvoyl Residue Modification Sites from Internal Serines in Proteins

    PubMed Central

    Jiang, Yang; Li, Bi-Qing; Zhang, Yuchao; Feng, Yuan-Ming; Gao, Yu-Fei; Zhang, Ning; Cai, Yu-Dong

    2013-01-01

    Most of pyruvoyl-dependent proteins observed in prokaryotes and eukaryotes are critical regulatory enzymes, which are primary targets of inhibitors for anti-cancer and anti-parasitic therapy. These proteins undergo an autocatalytic, intramolecular self-cleavage reaction in which a covalently bound pyruvoyl group is generated on a conserved serine residue. Traditional detections of the modified serine sites are performed by experimental approaches, which are often labor-intensive and time-consuming. In this study, we initiated in an attempt for the computational predictions of such serine sites with Feature Selection based on a Random Forest. Since only a small number of experimentally verified pyruvoyl-modified proteins are collected in the protein database at its current version, we only used a small dataset in this study. After removing proteins with sequence identities >60%, a non-redundant dataset was generated and was used, which contained only 46 proteins, with one pyruvoyl serine site for each protein. Several types of features were considered in our method including PSSM conservation scores, disorders, secondary structures, solvent accessibilities, amino acid factors and amino acid occurrence frequencies. As a result, a pretty good performance was achieved in our dataset. The best 100.00% accuracy and 1.0000 MCC value were obtained from the training dataset, and 93.75% accuracy and 0.8441 MCC value from the testing dataset. The optimal feature set contained 9 features. Analysis of the optimal feature set indicated the important roles of some specific features in determining the pyruvoyl-group-serine sites, which were consistent with several results of earlier experimental studies. These selected features may shed some light on the in-depth understanding of the mechanism of the post-translational self-maturation process, providing guidelines for experimental validation. Future work should be made as more pyruvoyl-modified proteins are found and the method

  20. Predicting outcome after traumatic brain injury: practical prognostic models based on large cohort of international patients

    PubMed Central

    2008-01-01

    Objective To develop and validate practical prognostic models for death at 14 days and for death or severe disability six months after traumatic brain injury. Design Multivariable logistic regression to select variables that were independently associated with two patient outcomes. Two models designed: “basic” model (demographic and clinical variables only) and “CT” model (basic model plus results of computed tomography). The models were subsequently developed for high and low-middle income countries separately. Setting Medical Research Council (MRC) CRASH Trial. Subjects 10 008 patients with traumatic brain injury. Models externally validated in a cohort of 8509. Results The basic model included four predictors: age, Glasgow coma scale, pupil reactivity, and the presence of major extracranial injury. The CT model also included the presence of petechial haemorrhages, obliteration of the third ventricle or basal cisterns, subarachnoid bleeding, midline shift, and non-evacuated haematoma. In the derivation sample the models showed excellent discrimination (C statistic above 0.80). The models showed good calibration graphically. The Hosmer-Lemeshow test also indicated good calibration, except for the CT model in low-middle income countries. External validation for unfavourable outcome at six months in high income countries showed that basic and CT models had good discrimination (C statistic 0.77 for both models) but poorer calibration. Conclusion Simple prognostic models can be used to obtain valid predictions of relevant outcomes in patients with traumatic brain injury. PMID:18270239

  1. Mercury: a final prediction for internal thermal and physical structure, prior to MESSENGER data

    NASA Astrophysics Data System (ADS)

    Prentice, A. J.

    2008-05-01

    The confirmation by the NASA MESSENGER spacecraft that Mercury has an internal magnetic field that is well described by a dipole nearly aligned with the spin axis strongly suggests that the planet may have an outer core of molten metal (S. Solomon, MESSENGER news release of 30 January 2008). The existence of an internal layer of liquid has also been invoked to explain radar measurements of the large amplitude of the longitudinal libration of Mercury relative to the value expected for a wholly solid planet (J.L. Margot et al 2007 Science 316 710). The existence of molten metal in the planet`s interior is surprising since previous numerical models for the thermal evolution of the planet, calculated on the basis of the heat released by the decay of the radioactive isotopes of U and Th, indicated that the present temperature at the edge of the metal core is only ~ 1200 K (cf. Siegfried & Solomon 1974 Icarus 23 192) . This value is well below the melting temperature Tm = 2030 K of Fe-Ni alloy at the core/mantle boundary (CMB) pressure of ~ 70 kbar. Those earlier thermal calculations were, however, based on low abundances of U and Th found in lunar samples. Prentice (2008 LPSC 2008 abs. # 1945.pdf - see URL below) has put forward a new model for the bulk chemical composition of Mercury. It is based on the idea that this planet condensed from a gas ring that was cast off by the protosolar cloud close to the planet`s present orbit. The temperature of the gas ring Tn at the moment of detachment from the cloud is 1628 K and the pressure on the mean orbit of the ring is 0.168 bar. Because Tn is so high, the condensate contains a much reduced proportion of magnesium silicates relative to metals. This is because metals have a much lower vapour pressure than those silicates. The condensate consists mostly of Fe-Ni-Cr-Co-V (mass fraction 0.671), gehlenite (0.190) and Mg-silicates (0.081). What is really important in the gas ring model of solar system origin, however, is that the

  2. A Perceptual Pathway to Bias: Interracial Exposure Reduces Abrupt Shifts in Real-Time Race Perception That Predict Mixed-Race Bias.

    PubMed

    Freeman, Jonathan B; Pauker, Kristin; Sanchez, Diana T

    2016-04-01

    In two national samples, we examined the influence of interracial exposure in one's local environment on the dynamic process underlying race perception and its evaluative consequences. Using a mouse-tracking paradigm, we found in Study 1 that White individuals with low interracial exposure exhibited a unique effect of abrupt, unstable White-Black category shifting during real-time perception of mixed-race faces, consistent with predictions from a neural-dynamic model of social categorization and computational simulations. In Study 2, this shifting effect was replicated and shown to predict a trust bias against mixed-race individuals and to mediate the effect of low interracial exposure on that trust bias. Taken together, the findings demonstrate that interracial exposure shapes the dynamics through which racial categories activate and resolve during real-time perceptions, and these initial perceptual dynamics, in turn, may help drive evaluative biases against mixed-race individuals. Thus, lower-level perceptual aspects of encounters with racial ambiguity may serve as a foundation for mixed-race prejudice. PMID:26976082

  3. Capture of cosmic dusts and exposure of organics on the International Space Station: Objectives of the Tanpopo Mission

    NASA Astrophysics Data System (ADS)

    Kobayashi, Kensei

    Finding of a wide variety of organic compounds contained in extraterrestrial bodies such as carbonaceous chondrites and comets suggested that they were important materials for the first life on the Earth. Cosmic dusts (interplanetary dust particles; IDPs) were believed to have been important carriers of extraterrestrial organics, since IDPs could deliver organics to the primitive Earth more safely than asteroids and comets. Since most IDPs have been collected in such terrestrial environments as ocean sediments, Antarctic ices, and air in stratosphere, it is difficult to judge whether biooranics found in IDPs were extraterrestrial origins or not. Thus it would be of importance to collect IDPs out of the terrestrial biosphere. We are planning the Tanpopo Mission by utilizing the Exposed Facility of Japan Experimental Module (JEM/EF) of the International Space Station (ISS). Two types of experiments will be done in the Tanpopo Mission: Capture experiments and exposure experiments. In order to collect cosmic dusts (including IDPs) on the ISS, we are going to use extra-low density aerogel, since both cosmic dusts and ISS are moving at 8 km s-1 or over. We have developed novel aerogel whose density is 0.01 g cm-3. After the return of the aerogel blocks after 1 to a few years’ stay on JEM/EF, organic compounds in the captured dusts will be characterized by a wide variety of analytical techniques including FT-IR, XANES, and MS. Amino acid enantiomers will be determined after HF digestion and acid hydrolysis. A number of amino acids were detected in water extract of carbonaceous chondrites. It is controversial whether meteorites contain free amino acids or amino acid precursors. When dusts are formed from meteorites or comets in interplanetary space, they are exposed to high-energy particles and photons. In order to evaluate stability and possible alteration of amino acid-related compounds, we chose amino acids (glycine and isovaline) and hydantoins (precursors of amino

  4. Internal exposure to trace elements in non-smoking residents living in a northern Taiwan industrial city.

    PubMed

    Lin, Tser-Sheng; Wu, Chin-Ching

    2011-12-01

    A total of 94 (54 males, 40 females) healthy adult residents living in an industrial city in northern Taiwan were recruited to study their exposure to industrial metals by measuring their blood levels of V, Cr, Mn, Ni, Co, As, Se, Mo, Cd, Pb, and W. All participants were non-smokers without obvious direct occupational exposure to these elements, although by working in administrative sectors in industrial facilities their indirect or potential exposure was increased. The average concentrations of V, Cr, Mn, Ni, Co, As, Se, Mo, Cd, Pb, and W in blood were 0.30, 1.49, 15.1, 3.84, 2.73, 21.1, 204, 3.2, 0.76, 51.1, and 0.40 ng/mL, respectively. These values were significantly higher than reference values reported for the general population, in some cases exceeding those of occupationally exposed workers. The principal component and correlation analyses among blood element levels suggested that the predominant sources of exposure were glass manufacturing and traffic-related sources. Despite of some limitations, the study demonstrates that the residents in this industrial area may suffer adverse chronic health effects attributable to exposures to these elements. PMID:21409473

  5. AQUATIC FATE AND TRANSPORT MODELING TECHNIQUES FOR PREDICTING ENVIRONMENTAL EXPOSURE TO ORGANIC PESTICIDES AND OTHER TOXICANTS - A COMPARATIVE STUDY

    EPA Science Inventory

    Exposure assessment enhanced by mathematical modeling has become an accepted technique for evaluating the environmental risk associated with the release of toxic substances into various environmental media. Mathematical models for analyzing the behavior of toxic substances in riv...

  6. CYTOKINE RESPONSES TO DERMAL ISOCYANATE EXPOSURE IN DRAINING LYMPH NODES ARE NOT PREDICTIVE OF AIRWAY RESPONSES AFTER AIRWAY CHALLENGE

    EPA Science Inventory

    Exposure to low molecular weight chemicals including isocyanates has been linked to occupational asthma. A strong need exists for the rapid and accurate identification of chemical respiratory sensitizers. Recently, some investigators have proposed that chemicals may be identified...

  7. Endocrine disrupting chemicals in fish: developing exposure indicators and predictive models of effects based on mechanism of action

    EPA Science Inventory

    Knowledge of possible toxic mechanisms/modes of action (MOA) of chemicals can provide valuable insights as to appropriate methods for assessing exposure and effects, such as reducing uncertainties related to extrapolation across species, endpoints and chemical structure. However,...

  8. Computational Prediction of Muscle Moments During ARED Squat Exercise on the International Space Station.

    PubMed

    Fregly, Benjamin J; Fregly, Christopher D; Kim, Brandon T

    2015-12-01

    Prevention of muscle atrophy caused by reduced mechanical loading in microgravity conditions remains a challenge for long-duration spaceflight. To combat leg muscle atrophy, astronauts on the International Space Station (ISS) often perform squat exercise using the Advanced Resistive Exercise Device (ARED). While the ARED is effective at building muscle strength and volume on Earth, NASA researchers do not know how closely ARED squat exercise on the ISS replicates Earth-level squat muscle moments, or how small variations in exercise form affect muscle loading. This study used dynamic simulations of ARED squat exercise on the ISS to address these two questions. A multibody dynamic model of the complete astronaut-ARED system was constructed in OpenSim. With the ARED base locked to ground and gravity set to 9.81 m/s², we validated the model by reproducing muscle moments, ground reaction forces, and foot center of pressure (CoP) positions for ARED squat exercise on Earth. With the ARED base free to move relative to the ISS and gravity set to zero, we then used the validated model to simulate ARED squat exercise on the ISS for a reference squat motion and eight altered squat motions involving changes in anterior-posterior (AP) foot or CoP position on the ARED footplate. The reference squat motion closely reproduced Earth-level muscle moments for all joints except the ankle. For the altered squat motions, changing the foot position was more effective at altering muscle moments than was changing the CoP position. All CoP adjustments introduced an undesirable shear foot reaction force that could cause the feet to slip on the ARED footplate, while some foot and CoP adjustments introduced an undesirable sagittal plane foot reaction moment that would cause the astronaut to rotate off the ARED footplate without the use of some type of foot fixation. Our results provide potentially useful information for achieving desired increases or decreases in specific muscle moments

  9. A consistent geodynamic model for predicting the velocity and plate-internal deformation of Eurasia

    NASA Astrophysics Data System (ADS)

    Govers, Rob; Garcia-Sancho, Candela; Warners-Ruckstuhl, Karin; van der Burgt, Janneke; Wortel, Rinus

    2015-04-01

    often quoted collision age of ˜50Ma. Forces (and the corresponding stresses) drive permanent deformation on both geological time scales and short time scales, e.g., earthquakes. Low stress magnitudes may result in strain if the material is weak, high stresses may give no strain in strong materials. Our next step therefore is to use geological information on the strength of the lithosphere. We show new results of our work on using estimates of the mechanical properties of the lithosphere to predict surface deformation.

  10. Ultrafine particle levels at an international port of entry between the US and Mexico: exposure implications for users, workers, and neighbors.

    PubMed

    Olvera, Hector A; Lopez, Mario; Guerrero, Veronica; Garcia, Humberto; Li, Wen-Whai

    2013-01-01

    Exposure to diesel-emitted particles has been linked to increased cancer risk and cardiopulmonary diseases. Because of their size (<100 nm), exposure to ultrafine particles (UFPs) emitted from heavy-duty diesel vehicles (HDDV) might result in greater health risks than those associated with larger particles. Seasonal UFP levels at the International Bridge of the Americas, which connects the US and Mexico and has high HDDV traffic demands, were characterized. Hourly average UFP concentrations ranged between 1.7 × 10(3)/cc and 2.9 × 10(5)/cc with a mean of 3.5 × 10(4)/cc. Wind speeds <2 m s(-1) and temperatures <15 °C were associated with particle number concentrations above normal conditions. The presence of HDDV had the strongest impact on local UFP levels. Varying particle size distributions were associated with south- and northbound HDDV traffic. Peak exposure occurred on weekday afternoons. Although in winter, high exposure episodes were also observed in the morning. Particle number concentrations were estimated to reach background levels at 400 m away from traffic. The populations exposed to UFP above background levels include law enforcement officers, street vendors, private commuters, and commercial vehicle drivers as well as neighbors on both sides of the border, including a church and several schools. PMID:23321858

  11. Clinical and Biologic Features Predictive of Survival After Relapse of Neuroblastoma: A Report From the International Neuroblastoma Risk Group Project

    PubMed Central

    London, Wendy B.; Castel, Victoria; Monclair, Tom; Ambros, Peter F.; Pearson, Andrew D.J.; Cohn, Susan L.; Berthold, Frank; Nakagawara, Akira; Ladenstein, Ruth L.; Iehara, Tomoko; Matthay, Katherine K.

    2011-01-01

    Purpose Survival after neuroblastoma relapse is poor. Understanding the relationship between clinical and biologic features and outcome after relapse may help in selection of optimal therapy. Our aim was to determine which factors were significantly predictive of postrelapse overall survival (OS) in patients with recurrent neuroblastoma—particularly whether time from diagnosis to first relapse (TTFR) was a significant predictor of OS. Patients and Methods Patients with first relapse/progression were identified in the International Neuroblastoma Risk Group (INRG) database. Time from study enrollment until first event and OS time starting from first event were calculated. Cox regression models were used to calculate the hazard ratio of increased death risk and perform survival tree regression. TTFR was tested in a multivariable Cox model with other factors. Results In the INRG database (N = 8,800), 2,266 patients experienced first progression/relapse. Median time to relapse was 13.2 months (range, 1 day to 11.4 years). Five-year OS from time of first event was 20% (SE, ± 1%). TTFR was statistically significantly associated with OS time in a nonlinear relationship; patients with TTFR of 36 months or longer had the lowest risk of death, followed by patients who relapsed in the period of 0 to less than 6 months or 18 to 36 months. Patients who relapsed between 6 and 18 months after diagnosis had the highest risk of death. TTFR, age, International Neuroblastoma Staging System stage, and MYCN copy number status were independently predictive of postrelapse OS in multivariable analysis. Conclusion Age, stage, MYCN status, and TTFR are significant prognostic factors for postrelapse survival and may help in the design of clinical trials evaluating novel agents. PMID:21768459

  12. In the elderly, failure to update internal models leads to over-optimistic predictions about upcoming actions.

    PubMed

    Lafargue, Gilles; Noël, Myriam; Luyat, Marion

    2013-01-01

    Before an action is performed, the brain simulates the body's dynamic behavior in relation to the environment, estimates the possible outcomes and assesses the feasibility of potential actions. Here, we tested a hypothesis whereby age-related changes in sensorimotor abilities result in failure to update internal models of action in the elderly. Young and older adults were required to judge in advance whether or not they could stand on an inclined plane (Experiment 1). Relative to young adults, elderly adults overestimated their postural capabilities: although the two groups made similar feasibility judgments, elderly participants showed significantly worse postural performance levels. This tendency to overestimate their own ability persisted when elderly adults had to not only estimate the feasibility of an action but also endanger themselves by walking towards an obstacle that was too high for them to clear (Experiment 2). An age-related failure to update internal models may prompt the elderly to make over-optimistic predictions about upcoming actions. In turn, this may favor risky motor decision-making and promote falls. PMID:23326312

  13. Prediction of the vibro-acoustic behavior of a submerged shell non periodically stiffened by internal frames.

    PubMed

    Maxit, Laurent; Ginoux, Jean-Marc

    2010-07-01

    This paper describes the development of a numerical model to predict the vibro-acoustic behavior of an externally fluid loaded shell with non-uniformly space stiffeners and transversal bulkheads. This model constitutes an extension of the existing semi-analytic capability in predicting the acoustics of axisymmetric structures. It is based on the circumferential admittance approach (CAA) which consists in substructuring the problem so that the fluid loaded shell constitutes one subsystem and the frames constitute other independent subsystems. These subsystems are coupled together by assembling the circumferential admittances that characterize each uncoupled subsystem. Different numerical approaches can be used to estimate these admittances. The standard finite element code is well adapted for evaluating the admittances of the internal frames whatever their cross-section geometries and material properties. Classical discretization methods such as finite elements and boundary elements are too time-consuming for the fluid loaded shell. To avoid this obstacle, three different approaches with different degrees of approximation are proposed to estimate the shell admittances. Comparisons with a reference case are proposed to evaluate the accuracy and the efficiency of each of these three approaches. With the optimal approach, CAA gives very good results in satisfactory computing time. It is well-adapted for analyzing the behavior of a submarine pressure hull in a wide frequency range of interest. PMID:20649209

  14. The HART II International Workshop: An Assessment of the State-of-the-Art in Comprehensive Code Prediction

    NASA Technical Reports Server (NTRS)

    vanderWall, Berend G.; Lim, Joon W.; Smith, Marilyn J.; Jung, Sung N.; Bailly, Joelle; Baeder, James D.; Boyd, D. Douglas, Jr.

    2013-01-01

    Significant advancements in computational fluid dynamics (CFD) and their coupling with computational structural dynamics (CSD, or comprehensive codes) for rotorcraft applications have been achieved recently. Despite this, CSD codes with their engineering level of modeling the rotor blade dynamics, the unsteady sectional aerodynamics and the vortical wake are still the workhorse for the majority of applications. This is especially true when a large number of parameter variations is to be performed and their impact on performance, structural loads, vibration and noise is to be judged in an approximate yet reliable and as accurate as possible manner. In this article, the capabilities of such codes are evaluated using the HART II International Workshop database, focusing on a typical descent operating condition which includes strong blade-vortex interactions. A companion article addresses the CFD/CSD coupled approach. Three cases are of interest: the baseline case and two cases with 3/rev higher harmonic blade root pitch control (HHC) with different control phases employed. One setting is for minimum blade-vortex interaction noise radiation and the other one for minimum vibration generation. The challenge is to correctly predict the wake physics-especially for the cases with HHC-and all the dynamics, aerodynamics, modifications of the wake structure and the aero-acoustics coming with it. It is observed that the comprehensive codes used today have a surprisingly good predictive capability whe