WorldWideScience

Sample records for cumulative lead dose

  1. Evaluation of cumulative lead dose and longitudinal changes in structural MRI in former organolead workers

    Science.gov (United States)

    Schwartz, Brian S.; Caffo, Brian; Stewart, Walter F.; Hedlin, Haley; James, Bryan D.; Yousem, David; Davatzikos, Christos

    2010-01-01

    Objective We evaluated whether tibia lead was associated with longitudinal change in brain volumes and white matter lesions in male former lead workers and population-based controls in whom we have previously reported on the cognitive and structural consequences of cumulative lead dose. Methods We used linear regression to identify predictors of change in brain volumes and white matter lesion grade scores, using two MRIs an average of five years apart. Results On average, total brain volume declined almost 30 cm3, predominantly in gray matter. Increasing age at the first MRI was strongly associated with larger declines in volumes and greater increases in white matter lesion scores. Tibia lead was not associated with change in brain volumes or white matter lesion scores. Conclusions In former lead workers in whom cumulative lead dose was associated with progressive declines in cognitive function decades after occupational exposure had ended, cumulative lead dose was associated with earlier persistent effects on brain structure, but not with additional worsening over five years. PMID:20357679

  2. Dose-Response Relationship between Cumulative Occupational Lead Exposure and the Associated Health Damages: A 20-Year Cohort Study of a Smelter in China.

    Science.gov (United States)

    Wu, Yue; Gu, Jun-Ming; Huang, Yun; Duan, Yan-Ying; Huang, Rui-Xue; Hu, Jian-An

    2016-03-16

    Long-term airborne lead exposure, even below official occupational limits, has been found to cause lead poisoning at higher frequencies than expected, which suggests that China's existing occupational exposure limits should be reexamined. A retrospective cohort study was conducted on 1832 smelting workers from 1988 to 2008 in China. These were individuals who entered the plant and came into continuous contact with lead at work for longer than 3 months. The dose-response relationship between occupational cumulative lead exposure and lead poisoning, abnormal blood lead, urinary lead and erythrocyte zinc protoporphyrin (ZPP) were analyzed and the benchmark dose lower bound confidence limits (BMDLs) were calculated. Statistically significant positive correlations were found between cumulative lead dust and lead fumes exposures and workplace seniority, blood lead, urinary lead and ZPP values. A dose-response relationship was observed between cumulative lead dust or lead fumes exposure and lead poisoning (p lead dust and fumes doses were 0.68 mg-year/m³ and 0.30 mg-year/m³ for lead poisoning, respectively. The BMDLs of workplace airborne lead concentrations associated with lead poisoning were 0.02 mg/m³ and 0.01 mg/m³ for occupational exposure lead dust and lead fume, respectively. In conclusion, BMDLs for airborne lead were lower than occupational exposure limits, suggesting that the occupational lead exposure limits need re-examination and adjustment. Occupational cumulative exposure limits (OCELs) should be established to better prevent occupational lead poisoning.

  3. Determination of radionuclides and pathways contributing to cumulative dose

    Energy Technology Data Exchange (ETDEWEB)

    Napier, B.A.

    1992-12-01

    A series of scoping calculations has been undertaken to evaluate the absolute and relative contributions of different radionuclides and exposure pathways to doses that may have been received by individuals living in the vicinity of the Hanford Site. This scoping calculation (Calculation 004) examined the contributions of numerous radionuclides to cumulative dose via environmental exposures and accumulation in foods. Addressed in this calculation were the contributions to organ and effective dose of infants and adults from (1) air submersion and groundshine external dose, (2) inhalation, (3) ingestion of soil by humans, (4) ingestion of leafy vegetables, (5) ingestion of other vegetables and fruits, (6) ingestion of meat, (7) ingestion of eggs, and (8) ingestion of cows' milk from Feeding Regime 1, as described in calculation 002. This calculation specifically addresses cumulative radiation doses to infants and adults resulting from releases occurring over the period 1945 through 1972.

  4. Role of sulfite additives in wine induced asthma: single dose and cumulative dose studies

    OpenAIRE

    Vally, H; Thompson, P.

    2001-01-01

    BACKGROUND—Wine appears to be a significant trigger for asthma. Although sulfite additives have been implicated as a major cause of wine induced asthma, direct evidence is limited. Two studies were undertaken to assess sulfite reactivity in wine sensitive asthmatics. The first study assessed sensitivity to sulfites in wine using a single dose sulfited wine challenge protocol followed by a double blind, placebo controlled challenge. In the second study a cumulative dose su...

  5. Determination of radionuclides and pathways contributing to cumulative dose. Hanford Environmental Dose Reconstruction Project: Dose code recovery activities, Calculation 004

    Energy Technology Data Exchange (ETDEWEB)

    Napier, B.A.

    1992-12-01

    A series of scoping calculations has been undertaken to evaluate the absolute and relative contributions of different radionuclides and exposure pathways to doses that may have been received by individuals living in the vicinity of the Hanford Site. This scoping calculation (Calculation 004) examined the contributions of numerous radionuclides to cumulative dose via environmental exposures and accumulation in foods. Addressed in this calculation were the contributions to organ and effective dose of infants and adults from (1) air submersion and groundshine external dose, (2) inhalation, (3) ingestion of soil by humans, (4) ingestion of leafy vegetables, (5) ingestion of other vegetables and fruits, (6) ingestion of meat, (7) ingestion of eggs, and (8) ingestion of cows` milk from Feeding Regime 1, as described in calculation 002. This calculation specifically addresses cumulative radiation doses to infants and adults resulting from releases occurring over the period 1945 through 1972.

  6. Blood lead levels and cumulative blood lead index (CBLI) as predictors of late neurodevelopment in lead poisoned children

    Science.gov (United States)

    Nie, Linda H.; Wright, Robert O.; Bellinger, David C.; Hussain, Javed; Amarasiriwardena, Chitra; Chettle, David R.; Pejović-Milić, Ana; woolf, Alan; Shannon, Michael

    2011-01-01

    Objective To find the best lead exposure assessment marker for children. Methods We recruited 11 children, calculated a cumulative blood lead index (CBLI) for the children, measured their concurrent BLL, assessed their development, and measured their bone lead level. Results Nine of 11 children had clinically significant neurodevelopment problems. CBLI and current blood lead level, but not the peak lead level, were significantly or marginally negatively associated with the full-scale IQ score. Conclusion Lead exposure at younger age significantly impacts a child’s later neurodevelopment. CBLI may be a better predictor of neurodevelopment than are current or peak blood lead levels. PMID:21827276

  7. Cumulant generating function formula of heat transfer in ballistic systems with lead-lead coupling

    Science.gov (United States)

    Li, Huanan; Agarwalla, Bijay Kumar; Wang, Jian-Sheng

    2012-10-01

    Based on a two-time observation protocol, we consider heat transfer in a given time interval tM in a lead-junction-lead system taking coupling between the leads into account. In view of the two-time observation, consistency conditions are carefully verified in our specific family of quantum histories. Furthermore, its implication is briefly explored. Then using the nonequilibrium Green's function method, we obtain an exact formula for the cumulant generating function for heat transfer between the two leads, valid in both transient and steady-state regimes. Also, a compact formula for the cumulant generating function in the long-time limit is derived, for which the Gallavotti-Cohen fluctuation symmetry is explicitly verified. In addition, we briefly discuss Di Ventra's repartitioning trick regarding whether the repartitioning procedure of the total Hamiltonian affects the nonequilibrium steady-state current fluctuation. All kinds of properties of nonequilibrium current fluctuations, such as the fluctuation theorem in different time regimes, could be readily given according to these exact formulas.

  8. Radiologic imaging in cystic fibrosis: cumulative effective dose and changing trends over 2 decades.

    LENUS (Irish Health Repository)

    O'Connell, Oisin J

    2012-06-01

    With the increasing life expectancy for patients with cystic fibrosis (CF), and a known predisposition to certain cancers, cumulative radiation exposure from radiologic imaging is of increasing significance. This study explores the estimated cumulative effective radiation dose over a 17-year period from radiologic procedures and changing trends of imaging modalities over this period.

  9. Analysis of Cumulative Dose to Implanted Pacemaker According to Various IMRT Delivery Methods: Optimal Dose Delivery Versus Dose Reduction Strategy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong Woo; Hong, Se Mie [Dept. of Radiation Oncology, Konkuk University Medical Center, Seoul (Korea, Republic of)

    2011-11-15

    Cancer patients with implanted cardiac pacemaker occasionally require radiotherapy. Pacemaker may be damaged or malfunction during radiotherapy due to ionizing radiation or electromagnetic interference. Although radiotherapy should be planned to keep the dose to pacemaker as low as possible not to malfunction ideally, current radiation treatment planning (RTP) system does not accurately calculate deposited dose to adjacent field border or area beyond irradiated fields. In terms of beam delivery techniques using multiple intensity modulated fields, dosimetric effect of scattered radiation in high energy photon beams is required to be detailed analyzed based on measurement data. The aim of this study is to evaluate dose discrepancies of pacemaker in a RTP system as compared to measured doses. We also designed dose reduction strategy limited value of 2 Gy for radiation treatment patients with cardiac implanted pacemaker. Total accumulated dose of 145 cGy based on in-vivo dosimetry was satisfied with the recommendation criteria to prevent malfunction of pacemaker in SS technique. However, the 2 mm lead shielder enabled the scattered doses to reduce up to 60% and 40% in the patient and the phantom, respectively. The SS technique with the lead shielding could reduce the accumulated scattered doses less than 100 cGy. Calculated and measured doses were not greatly affected by the beam delivery techniques. In-vivo and measured doses on pacemaker position showed critical dose discrepancies reaching up to 4 times as compared to planned doses in RTP. The current SS technique could deliver lower scattered doses than recommendation criteria, but use of 2 mm lead shielder contributed to reduce scattered doses by 60%. The tertiary lead shielder can be useful to prevent malfunction or electrical damage of implanted pacemakers during radiotherapy. It is required to estimate more accurate scattered doses of the patient or medical device in RTP to design proper dose reduction strategy.

  10. A methodology to split the total cumulative Hp(10) dose into the Hp(10) i doses received during various procedures performed by interventional cardiologist.

    Science.gov (United States)

    Domienik, Joanna

    2017-03-01

    The methodology describing how to split the cumulative Hp(10) dose of interventional cardiologists into Hp(10) i doses received during procedures of various types based on procedure-specific ELDO coefficients and Hp(3) doses per procedure is presented. The appropriate equations for Hp(10) i (Hp(10) for procedure type i), depending on the number of various procedure types (i  =  1 … 4) performed by a particular physician, are derived. The methodology can be applied to whole-body doses measured on the lead apron and therefore can be used for optimisation of work practices in those catheterisation labs where routine dosimeter is worn above the apron.

  11. Mapping of the cumulative β-ray dose on the ground surface surrounding the Fukushima area

    Science.gov (United States)

    Endo, Satoru; Kajimoto, Tsuyoshi; Tanaka, Kenichi; Nguyen, Thanh T.; Hayashi, Gohei; Imanaka, Tetsuji

    2015-01-01

    A large amount of the fission products released by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident on 11 March 2011 was deposited in a wide area from Tohoku to northern Kanto. A map of the estimated cumulative β-ray dose (70 μm dose equivalent) on the soil surface for one year after the FDNPP accident has been prepared using previously reported calculation methods and the 2-km mesh survey data by MEXT. From this map of estimated dose, areas with a high cumulative β-ray dose on the soil surface for one year after the FDNPP accident were found to be located in the Akogi-Teshichiro to Akogi-Kunugidaira region in Namie Town, and in the southern Futaba Town to the northern Tomioka Town region. The highest estimated cumulative β-ray dose was 710 mSv for one year at Akogi-Teshichiro, Namie Town. PMID:26519736

  12. Cumulative high doses of inhaled formoterol have less systemic effects in asthmatic children 6-11 years-old than cumulative high doses of inhaled terbutaline

    DEFF Research Database (Denmark)

    Kaae, Rikke; Agertoft, Lone; Pedersen, Sören

    2004-01-01

    OBJECTIVES: To evaluate high dose tolerability and relative systemic dose potency between inhaled clinically equipotent dose increments of formoterol and terbutaline in children. METHODS: Twenty boys and girls (6-11 years-old) with asthma and normal ECGs were studied. Ten doses of formoterol (Oxis......) 4.5 microg (F4.5) or terbutaline (Bricanyl) 500 microg (T500) were inhaled cumulatively via a dry powder inhaler (Turbuhaler) over 1 h (three patients) or 2.5 h (17 patients) and compared to a day of no treatment, in a randomised, double-blind (active treatments only), crossover trial. Blood...... pressure (BP), ECG, plasma potassium, glucose, lactate, and adverse events were monitored up to 10 h to assess tolerability and relative systemic dose potency. RESULTS: Formoterol and terbutaline had significant beta2-adrenergic effects on most outcomes. Apart from the effect on systolic BP, QRS duration...

  13. Cumulative Doses of T-Cell Depleting Antibody and Cancer Risk after Kidney Transplantation.

    Directory of Open Access Journals (Sweden)

    Jenny H C Chen

    Full Text Available T-cell depleting antibody is associated with an increased risk of cancer after kidney transplantation, but a dose-dependent relationship has not been established. This study aimed to determine the association between cumulative doses of T-cell depleting antibody and the risk of cancer after kidney transplantation. Using data from the Australian and New Zealand Dialysis and Transplant Registry between 1997-2012, we assessed the risk of incident cancer and cumulative doses of T-cell depleting antibody using adjusted Cox regression models. Of the 503 kidney transplant recipients with 2835 person-years of follow-up, 276 (55%, 209 (41% and 18 (4% patients received T-cell depleting antibody for induction, rejection or induction and rejection respectively. The overall cancer incidence rate was 1,118 cancers per 100,000 patient-years, with 975, 1093 and 1377 cancers per 100,000 patient-years among those who had received 1-5 doses, 6-10 doses and >10 doses, respectively. There was no association between cumulative doses of T cell depleting antibody and risk of incident cancer (1-5: referent, 6-10: adjusted hazard ratio (HR 1.19, 95%CI 0.48-2.95, >10: HR 1.42, 95%CI 0.50-4.02, p = 0.801. This lack of association is contradictory to our hypothesis and is likely attributed to the low event rates resulting in insufficient power to detect significant differences.

  14. Relative Pesticide and Exposure Route Contribution to Aggregate and Cumulative Dose in Young Farmworker Children

    Directory of Open Access Journals (Sweden)

    Asa Bradman

    2012-01-01

    Full Text Available The Child-Specific Aggregate Cumulative Human Exposure and Dose (CACHED framework integrates micro-level activity time series with mechanistic exposure equations, environmental concentration distributions, and physiologically-based pharmacokinetic components to estimate exposure for multiple routes and chemicals. CACHED was utilized to quantify cumulative and aggregate exposure and dose estimates for a population of young farmworker children and to evaluate the model for chlorpyrifos and diazinon. Micro-activities of farmworker children collected concurrently with residential measurements of pesticides were used in the CACHED framework to simulate 115,000 exposure scenarios and quantify cumulative and aggregate exposure and dose estimates. Modeled metabolite urine concentrations were not statistically different than concentrations measured in the urine of children, indicating that CACHED can provide realistic biomarker estimates. Analysis of the relative contribution of exposure route and pesticide indicates that in general, chlorpyrifos non-dietary ingestion exposure accounts for the largest dose, confirming the importance of the micro-activity approach. The risk metrics computed from the 115,000 simulations, indicate that greater than 95% of these scenarios might pose a risk to children’s health from aggregate chlorpyrifos exposure. The variability observed in the route and pesticide contributions to urine biomarker levels demonstrate the importance of accounting for aggregate and cumulative exposure in establishing pesticide residue tolerances in food.

  15. Cumulative oxytocin dose during induction of labor according to maternal body mass index.

    Science.gov (United States)

    Roloff, Kristina; Peng, Sheppard; Sanchez-Ramos, Luis; Valenzuela, Guillermo J

    2015-10-01

    To determine the cumulative oxytocin dose needed to achieve vaginal delivery among obese and non-obese women. A retrospective study was undertaken of women with singleton, term (≥37 weeks) pregnancies who delivered at an institution in California, USA, between May 1 and July 31, 2012. Women were deemed to be obese when their body mass index (BMI; calculated as weight in kilograms divided by the square of height in meters) was 30 or above. Cumulative oxytocin doses were calculated for women who achieved vaginal delivery. Overall, 413 women were included. Among 357 women for whom BMI data were available, 204 (57.1%) were obese. Vaginal delivery was achieved in 379 women. Among women who received augmentation after spontaneous labor onset, obese women trended towards more cumulative oxytocin (minimum: 24.7 ± 100.5 mU among women with a BMI of 18.50-24.99; maximum: 1580.5 ± 2530.5 mU among women with a BMI of 35.00-39.99; P=0.086). Women who underwent induction of labor required significantly more oxytocin with increasing BMI class (Plabor. Obese women required a larger cumulative oxytocin dose to achieve vaginal birth during labor induction, but not during augmentation of labor. The physiology of spontaneous labor could supersede or influence the metabolic derangement facing obese patients undergoing induction of labor. Copyright © 2015 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  16. Cumulant generating function formula of heat transfer in ballistic systems with lead-lead coupling and general nonlinear systems

    Science.gov (United States)

    Li, Huanan

    2013-03-01

    Based on a two-time observation protocol, we consider heat transfer in a given time interval tM in a lead-junction-lead system taking coupling between the leads into account. In view of the two-time observation, consistency conditions are carefully verified in our specific family of quantum histories. Furthermore, its implication is briefly explored. Then using the nonequilibrium Green's function method, we obtain an exact formula for the cumulant generating function for heat transfer between the two leads, valid in both transient and steady-state regimes. Also, a compact formula for the cumulant generating function in the long-time limit is derived, for which the Gallavotti-Cohen fluctuation symmetry is explicitly verified. In addition, we briefly discuss Di Ventra's repartitioning trick regarding whether the repartitioning procedure of the total Hamiltonian affects the nonequilibrium steady-state current fluctuation. All kinds of properties of nonequilibrium current fluctuations, such as the fluctuation theorem in different time regimes, could be readily given according to these exact formulas. Finally a practical formalism dealing with cumulants of heat transfer across general nonlinear quantum systems is established based on field theoretical/algebraic method.

  17. Lead-Related Genetic Loci, Cumulative Lead Exposure and Incident Coronary Heart Disease: The Normative Aging Study

    Science.gov (United States)

    Weisskopf, Marc G.; Sparrow, David; Schwartz, Joel; Hu, Howard; Park, Sung Kyun

    2016-01-01

    Background Cumulative exposure to lead is associated with cardiovascular outcomes. Polymorphisms in the δ-aminolevulinic acid dehydratase (ALAD), hemochromatosis (HFE), heme oxygenase-1 (HMOX1), vitamin D receptor (VDR), glutathione S-transferase (GST) supergene family (GSTP1, GSTT1, GSTM1), apolipoprotein E (APOE),angiotensin II receptor-1 (AGTR1) and angiotensinogen (AGT) genes, are believed to alter toxicokinetics and/or toxicodynamics of lead. Objectives We assessed possible effect modification by genetic polymorphisms in ALAD, HFE, HMOX1, VDR, GSTP1, GSTT1, GSTM1, APOE, AGTR1 and AGT individually and as the genetic risk score (GRS) on the association between cumulative lead exposure and incident coronary heart disease (CHD) events. Methods We used K-shell-X-ray fluorescence to measure bone lead levels. GRS was calculated on the basis of 22 lead-related loci. We constructed Cox proportional hazard models to compute adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for incident CHD. We applied inverse probability weighting to account for potential selection bias due to recruitment into the bone lead sub-study. Results Significant effect modification was found by VDR, HMOX1, GSTP1, APOE, and AGT genetic polymorphisms when evaluated individually. Further, the bone lead-CHD associations became larger as GRS increases. After adjusting for potential confounders, a HR of CHD was 2.27 (95%CI: 1.50–3.42) with 2-fold increase in patella lead levels, among participants in the top tertile of GRS. We also detected an increasing trend in HRs across tertiles of GRS (p-trend = 0.0063). Conclusions Our findings suggest that lead-related loci as a whole may play an important role in susceptibility to lead-related CHD risk. These findings need to be validated in a separate cohort containing bone lead, lead-related genetic loci and incident CHD data. PMID:27584680

  18. Localized accumulation of lead within and among bones from lead-dosed goats

    Energy Technology Data Exchange (ETDEWEB)

    Cretacci, Yan [Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, P.O. Box 509, Albany, NY 12201-0509 (United States); Department of Environmental Health Sciences, School of Public Health, The University at Albany, P.O. Box 509, Albany, NY 12201-0509 (United States); Parsons, Patrick J., E-mail: pparsons@wadsworth.org [Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, P.O. Box 509, Albany, NY 12201-0509 (United States); Department of Environmental Health Sciences, School of Public Health, The University at Albany, P.O. Box 509, Albany, NY 12201-0509 (United States)

    2010-01-15

    The principal aim of this study was to gain a better understanding of where lead (Pb) accumulates and how it is distributed, within the bones of dosed goats. Adult goats were periodically dosed with Pb over a number of years for the primary purpose of producing blood pools containing endogenously bound Pb, for the New York State Blood Lead Proficiency Testing Program. Bone samples (e.g., primarily tibia, femur, humerus, and radius) were collected post-mortem from 11 animals and were analyzed for Pb content by acid digestion and electrothermal atomic absorption spectrometry (ETAAS or GFAAS). Average tibia Pb levels were found to correlate strongly with the cumulative Pb dose (r{sup 2}=0.81). However, the concentration of Pb in different bones and even within a small area of the same bone varied tremendously. Blood-rich trabecular (spongy) bone, such as the patella and calcaneus, were much more enriched in Pb than was cortical (compact) bone. In some dosed animals, the Pb concentration in the tibia was markedly higher at the proximal and distal ends of the bone compared to the mid-shaft. The implications of these findings with regard to the noninvasive measurement of lead in bone by XRF methods are discussed.

  19. Estimation of the annual cumulative radiation dose received by the dentist in dental clinics in Chennai

    Directory of Open Access Journals (Sweden)

    Sanarpalayam Chinaswamy Selvamuthukumar

    2014-01-01

    Full Text Available Aim and Objectives: To estimate the annual cumulative radiation dose received by a dentist in a ′less than an ideally sized clinic′ in Chennai. The objective of the study is to estimate the annual cumulative radiation dose received by the dentist at various distances and various angulations from the x-ray tube. Study Design: The head of a mannequin model was mounted on the dental chair to simulate a patient′s head and three thermoluminescent dosimeter (TLD chips were kept at various distances and various angulations, at a constant height. The standard conventional intraoral dental radiographic unit was used, which was kept stationary, with a constant voltage of 70 Kv, 8 mA current, and a constant exposure time of 0.3 seconds. Ninety-two TLD chips were exposed 20 times a day with constant horizontal angulations for a period of one year. The reading from the TLD chips was obtained on a computer through a TLD Badge Reader. Statistical Analysis: Post Hoc tests and One-way analysis of variance (ANOVA were used. Results and Conclusion: A decreasing trend was obtained in the average radiation doses, as the distance increased from the x-ray source, and a highly significant difference in doses (P < 0.001% was found between 4 and 5.5 feet (ft. We found a minimum average radiation dose at an angle of 60° to 80° and behind the tube. The purpose of this study was to create awareness among dental professionals, who had ′less than an ideally sized clinic′. We recommend that the dentist follow guidelines suggested by the National Council on Radiation Protection and Measurements (NCRP, USA. From this study, it is clear that most clinics are of sizes that do not permit this distance (6 ft, and hence, it is recommended that they use suitable barriers.

  20. Age- and gender-specific estimates of cumulative CT dose over 5 years using real radiation dose tracking data in children

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eunsol; Goo, Hyun Woo; Lee, Jae-Yeong [University of Ulsan College of Medicine, Asan Medical Center, Department of Radiology and Research Institute of Radiology, Seoul (Korea, Republic of)

    2015-08-15

    It is necessary to develop a mechanism to estimate and analyze cumulative radiation risks from multiple CT exams in various clinical scenarios in children. To identify major contributors to high cumulative CT dose estimates using actual dose-length product values collected for 5 years in children. Between August 2006 and July 2011 we reviewed 26,937 CT exams in 13,803 children. Among them, we included 931 children (median age 3.5 years, age range 0 days-15 years; M:F = 533:398) who had 5,339 CT exams. Each child underwent at least three CT scans and had accessible radiation dose reports. Dose-length product values were automatically extracted from DICOM files and we used recently updated conversion factors for age, gender, anatomical region and tube voltage to estimate CT radiation dose. We tracked the calculated CT dose estimates to obtain a 5-year cumulative value for each child. The study population was divided into three groups according to the cumulative CT dose estimates: high, ≥30 mSv; moderate, 10-30 mSv; and low, <10 mSv. We reviewed clinical data and CT protocols to identify major contributors to high and moderate cumulative CT dose estimates. Median cumulative CT dose estimate was 5.4 mSv (range 0.5-71.1 mSv), and median number of CT scans was 4 (range 3-36). High cumulative CT dose estimates were most common in children with malignant tumors (57.9%, 11/19). High frequency of CT scans was attributed to high cumulative CT dose estimates in children with ventriculoperitoneal shunt (35 in 1 child) and malignant tumors (range 18-49). Moreover, high-dose CT protocols, such as multiphase abdomen CT (median 4.7 mSv) contributed to high cumulative CT dose estimates even in children with a low number of CT scans. Disease group, number of CT scans, and high-dose CT protocols are major contributors to higher cumulative CT dose estimates in children. (orig.)

  1. Prediction of the cumulated dose for external beam irradiation of prostate cancer patients with 3D-CRT technique

    Directory of Open Access Journals (Sweden)

    Giżyńska Marta

    2016-03-01

    Full Text Available Nowadays in radiotherapy, much effort is taken to minimize the irradiated volume and consequently minimize doses to healthy tissues. In our work, we tested the hypothesis that the mean dose distribution calculated from a few first fractions can serve as prediction of the cumulated dose distribution, representing the whole treatment. We made our tests for 25 prostate cancer patients treated with three orthogonal fields technique. We did a comparison of dose distribution calculated as a sum of dose distribution from each fraction with a dose distribution calculated with isocenter shifted for a mean setup error from a few first fractions. The cumulative dose distribution and predicted dose distributions are similar in terms of gamma (3 mm 3% analysis, under condition that we know setup error from seven first fractions. We showed that the dose distribution calculated for the original plan with the isocenter shifted to the point, defined as the original isocenter corrected of the mean setup error estimated from the first seven fractions supports our hypothesis, i.e. can serve as a prediction for cumulative dose distribution.

  2. Repeated Radionuclide therapy in metastatic paraganglioma leading to the highest reported cumulative activity of 131I-MIBG

    Directory of Open Access Journals (Sweden)

    Ezziddin Samer

    2012-01-01

    Full Text Available Abstract 131I-MIBG therapy for neuroendocrine tumours may be dose limited. The common range of applied cumulative activities is 10-40 GBq. We report the uneventful cumulative administration of 111 GBq (= 3 Ci 131I-MIBG in a patient with metastatic paraganglioma. Ten courses of 131I-MIBG therapy were given within six years, accomplishing symptomatic, hormonal and tumour responses with no serious adverse effects. Chemotherapy with cisplatin/vinblastine/dacarbazine was the final treatment modality with temporary control of disease, but eventually the patient died of progression. The observed cumulative activity of 131I-MIBG represents the highest value reported to our knowledge, and even though 12.6 GBq of 90Y-DOTATOC were added intermediately, no associated relevant bone marrow, hepatic or other toxicity were observed. In an individual attempt to palliate metastatic disease high cumulative activity alone should not preclude the patient from repeat treatment.

  3. Finite-time full counting statistics and factorial cumulants for transport through a quantum dot with normal and superconducting leads

    Science.gov (United States)

    Droste, Stephanie; Governale, Michele

    2016-04-01

    We study the finite-time full counting statistics for subgap transport through a single-level quantum dot tunnel-coupled to one normal and one superconducting lead. In particular, we determine the factorial and the ordinary cumulants both for finite times and in the long-time limit. We find that the factorial cumulants violate the sign criterion, indicating a non-binomial distribution, even in absence of Coulomb repulsion due to the presence of superconducting correlations. At short times the cumulants exhibit oscillations which are a signature of the coherent transfer of Cooper pairs between the dot and the superconductor.

  4. Benchmark Dose Analysis from Multiple Datasets: The Cumulative Risk Assessment for the N-Methyl Carbamate Pesticides

    Science.gov (United States)

    The US EPA’s N-Methyl Carbamate (NMC) Cumulative Risk assessment was based on the effect on acetylcholine esterase (AChE) activity of exposure to 10 NMC pesticides through dietary, drinking water, and residential exposures, assuming the effects of joint exposure to NMCs is dose-...

  5. Estimated cumulative radiation dose received by diagnostic imaging during staging and treatment of operable Ewing sarcoma 2005-2012

    Energy Technology Data Exchange (ETDEWEB)

    Johnsen, Boel [Haukeland University Hospital, Centre for Nuclear Medicine and PET, Department of Radiology, P.O. Box 1400, Bergen (Norway); Fasmer, Kristine Eldevik [Haukeland University Hospital, Department of Oncology, Medical Physics Section, Bergen (Norway); Boye, Kjetil [Norwegian Radium Hospital, Oslo University Hospital, Department of Oncology, Oslo (Norway); Rosendahl, Karen; Aukland, Stein Magnus [Haukeland University Hospital, Department of Radiology, Paediatric Section, Bergen (Norway); University of Bergen, Department of Clinical Medicine, Bergen (Norway); Trovik, Clement [University of Bergen, Department of Clinical Medicine, Bergen (Norway); Haukeland University Hospital, Department of Surgery, Orthopaedic Section, Bergen (Norway); Biermann, Martin [Haukeland University Hospital, Centre for Nuclear Medicine and PET, Department of Radiology, P.O. Box 1400, Bergen (Norway); University of Bergen, Department of Clinical Medicine, Bergen (Norway)

    2017-01-15

    Patients with Ewing sarcoma are subject to various diagnostic procedures that incur exposure to ionising radiation. To estimate the radiation doses received from all radiologic and nuclear imaging episodes during diagnosis and treatment, and to determine whether {sup 18}F-fluorodeoxyglucose positron emission tomography - computed tomography ({sup 18}F-FDG PET-CT) is a major contributor of radiation. Twenty Ewing sarcoma patients diagnosed in Norway in 2005-2012 met the inclusion criteria (age <30 years, operable disease, uncomplicated chemotherapy and surgery, no metastasis or residual disease within a year of diagnosis). Radiation doses from all imaging during the first year were calculated for each patient. The mean estimated cumulative radiation dose for all patients was 34 mSv (range: 6-70), radiography accounting for 3 mSv (range: 0.2-12), CT for 13 mSv (range: 2-28) and nuclear medicine for 18 mSv (range: 2-47). For the patients examined with PET-CT, the mean estimated cumulative effective dose was 38 mSv, of which PET-CT accounted for 14 mSv (37%). There was large variation in number and type of examinations performed and also in estimated cumulative radiation dose. The mean radiation dose for patients examined with PET-CT was 23% higher than for patients not examined with PET-CT. (orig.)

  6. SU-E-J-106: The Use of Deformable Image Registration with Cone-Beam CT for a Better Evaluation of Cumulative Dose to Organs

    Energy Technology Data Exchange (ETDEWEB)

    Fillion, O; Gingras, L; Archambault, L [Universite Laval, Quebec, Quebec (Canada); Centre de recherche du CHU de Quebec, Quebec, Quebec (Canada); Centre de recherche sur le cancer, Quebec, Quebec (Canada)

    2015-06-15

    Purpose: The knowledge of dose accumulation in the patient tissues in radiotherapy helps in determining the treatment outcomes. This project aims at providing a workflow to map cumulative doses that takes into account interfraction organ motion without the need for manual re-contouring. Methods: Five prostate cancer patients were studied. Each patient had a planning CT (pCT) and 5 to 13 CBCT scans. On each series, a physician contoured the prostate, rectum, bladder, seminal vesicles and the intestine. First, a deformable image registration (DIR) of the pCTs onto the daily CBCTs yielded registered CTs (rCT) . This rCT combined the accurate CT numbers of the pCT with the daily anatomy of the CBCT. Second, the original plans (220 cGy per fraction for 25 fractions) were copied on the rCT for dose re-calculation. Third, the DIR software Elastix was used to find the inverse transform from the rCT to the pCT. This transformation was then applied to the rCT dose grid to map the dose voxels back to their pCT location. Finally, the sum of these deformed dose grids for each patient was applied on the pCT to calculate the actual dose delivered to organs. Results: The discrepancy between the planned D98 and D2 and these indices re-calculated on the rCT, are, on average, of −1 ± 1 cGy and 1 ± 2 cGy per fraction, respectively. For fractions with large anatomical motion, the D98 discrepancy on the re-calculated dose grid mapped onto the pCT can raise to −17 ± 4 cGy. The obtained cumulative dose distributions illustrate the same behavior. Conclusion: This approach allowed the evaluation of cumulative doses to organs with the help of uncontoured daily CBCT scans. With this workflow, the easy evaluation of doses delivered for EBRT treatments could ultimately lead to a better follow-up of prostate cancer patients.

  7. A study of the relationship between peak skin dose and cumulative air kerma in interventional neuroradiology and cardiology

    Energy Technology Data Exchange (ETDEWEB)

    Neil, S; Padgham, C; Martin, C J [Health Physics, Gartnavel Royal Hospital, Glasgow G12 0XH (United Kingdom)

    2010-12-01

    A study of peak skin doses (PSDs) during neuroradiology and cardiology interventional procedures has been carried out using Gafchromic XR-RV2 film. Use of mosaics made from squares held in cling film has allowed doses to the head to be mapped successfully. The displayed cumulative air kerma (CAK) has been calibrated in terms of cumulative entrance surface dose (CESD) and results indicate that this can provide a reliable indicator of the PSD in neuroradiology. Results linking PSD to CESD for interventional cardiology were variable, but CAK is still considered to provide the best option for use as an indicator of potential radiation-induced effects. A CESD exceeding 3 Gy is considered a suitable action level for triggering follow-up of patients in neuroradiology and cardiology for possible skin effects. Application of dose action levels defined in this way would affect 8% of neurological embolisation procedures and 5% of cardiology ablation and multiple stent procedures at the hospitals where the investigations were carried out. A close relationship was observed between CESD and dose-area product (DAP) for particular types of procedure, and DAPs of 200-300 Gy cm{sup 2} could be used as trigger levels where CAK readings were not available. The DAP value would depend on the mean field size and would need to be determined for each application.

  8. Do Multiple Concussions Lead to Cumulative Cognitive Deficits? A Literature Review.

    Science.gov (United States)

    Yumul, Joy Noelle; McKinlay, Audrey

    2016-11-01

    A concussion is an important health concern for children and adolescents, particularly in the context of sporting injuries. Some research suggests a cumulative effect from multiple concussions (also referred to as mild traumatic brain injury), which creates a dilemma when considering how to manage children and young persons who may experience multiple concussive events within a sporting season. However, there is very little research regarding the outcomes of multiple concussions and their optimal management. The purpose of this review is to evaluate the evidence regarding the cognitive outcomes of multiple concussions. After assessing the eligibility of the articles from the literature search, 7 studies were identified and included in the review. In most of the available literature, the cognitive outcomes related to multiple concussions are measured during the same developmental age as when the injuries happened. Moreover, most studies that investigated multiple concussions are focused on sports-related injuries, and only some are conducted in children and adolescents in the general population. The current evidence is inconclusive; whereas some studies reported adverse outcomes, others reported null findings. The studies that reported adverse or cumulative effects based their findings on worse cognitive outcomes, more subjective symptoms, and prolonged recovery postinjury. II. Copyright © 2016 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  9. In vivo measurements of lead-210 for assessing cumulative radon exposure in uranium miners

    Energy Technology Data Exchange (ETDEWEB)

    Guilmette, R.A.; Laurer, G.R. [New York Univ. Inst. of Environmental Medicine, Tuxedo, NY (United States); Lambert, W.E.; Gilliland, F.D. [Univ. of New Mexico, Albuquerque, NM (United States)] [and others

    1995-12-01

    It has long been recognized that a major contributor to the uncertainty in risk analysis of lung cancer in uranium and other hard rock miners is the estimation of total radon progeny exposure of individual miners under study. These uncertainties arise from the fact that only a limited number of measurements of airborne {sup 222}Rn progeny concentrations were made in the mines during the times that the miners were being exposed, and that dosimeters capable of integrating the Rn progeny exposures of the miners did not exist. Historically, the cumulative exposures for individual uranium and other hard rock miners have been calculated by combining the employee`s work history, which may or may not have included time spent at different jobs within the mines and at different locations within the mines, with whatever periodic measurements of Rn and Rn progeny were available. The amount and quality of the measurement data varied enormously from mine to mine and from population to population. Because the quality of the exposure data collected during the period of active mining in the United STates cannot now be altered substantially, significant improvement in individual miner exposure estimates is only likely to be achieved if a new cumulative exposure metric is developed and implemented. The decay chain of Rn includes the production of {sup 210}Pb, which can accumulate in the skeleton in amounts proportional to the intake of Rn progeny. We hypothesize that the in vivo measurement of {sup 210}Pb in the skulls of miners will provide such a metric. In summary, the primary purpose of this pilot study to demonstrate the feasibility of measuring {sup 210}Pb in the heads of former uranium miners has been accomplished.

  10. Cumulative lead poisoning in horses in a mining area contaminated with galena

    Energy Technology Data Exchange (ETDEWEB)

    Egan, D.A.; O' Cuill, T.

    1970-06-20

    The diagnosis of lead poisoning in horses exposed to galena-contaminated herbage and air was based on clinical signs, response to calcium versenate therapy and laboratory findings. Chemical analyses of six herbage samples from the area yielded a mean value of 580 ppM lead D/M. Analyses of samples from a nursing mare showed lead values in ppM as follows: faeces, 180 D/M; blood, 0.32 increasing to 0.38 after two weeks; colostrum, 0.24, 0.34, 0.34 Days 1, 2 and 3 respectively, and kidney cortex, 40 wet tissue. Her five-day-old foal had a blood lead value of 0.25 ppM. Samples from a horse, which responded to therapy, had the following lead values in ppM: faeces, 140 D/M; blood, 0.28 increasing to 0.44 after two weeks. Kidney cortices from three dead horses had lead values of 65, 25 and 140 ppM wet tissue. One liver had a lead value of 45 ppM wet tissue. Bovine colostrum and late lactation milk had lead values of 0.54 and 0.28 ppM respectively. 6 references, 3 tables.

  11. Sci—Thur AM: YIS - 11: Estimation of Bladder-Wall Cumulative Dose in Multi-Fraction Image-Based Gynaecological Brachytherapy Using Deformable Point Set Registration

    Energy Technology Data Exchange (ETDEWEB)

    Zakariaee, R [Physics Department, University of British Columbia, Vancouver, BC (Canada); Brown, C J; Hamarneh, G [School of Computing Science, Simon Fraser University, Burnaby, BC (Canada); Parsons, C A; Spadinger, I [British Columbia Cancer Agency, Vancouver, BC (Canada)

    2014-08-15

    Dosimetric parameters based on dose-volume histograms (DVH) of contoured structures are routinely used to evaluate dose delivered to target structures and organs at risk. However, the DVH provides no information on the spatial distribution of the dose in situations of repeated fractions with changes in organ shape or size. The aim of this research was to develop methods to more accurately determine geometrically localized, cumulative dose to the bladder wall in intracavitary brachytherapy for cervical cancer. The CT scans and treatment plans of 20 cervical cancer patients were used. Each patient was treated with five high-dose-rate (HDR) brachytherapy fractions of 600cGy prescribed dose. The bladder inner and outer surfaces were delineated using MIM Maestro software (MIM Software Inc.) and were imported into MATLAB (MathWorks) as 3-dimensional point clouds constituting the “bladder wall”. A point-set registration toolbox for MATLAB, Coherent Point Drift (CPD), was used to non-rigidly transform the bladder-wall points from four of the fractions to the coordinate system of the remaining (reference) fraction, which was chosen to be the emptiest bladder for each patient. The doses were accumulated on the reference fraction and new cumulative dosimetric parameters were calculated. The LENT-SOMA toxicity scores of these patients were studied against the cumulative dose parameters. Based on this study, there was no significant correlation between the toxicity scores and the determined cumulative dose parameters.

  12. Measurement of radiocesium concentration in trees using cumulative gamma radiation dose rate detection systems - A simple presumption for radiocesium concentration in living woods using glass-badge based gamma radiation dose rate detection system

    Energy Technology Data Exchange (ETDEWEB)

    Yoshihara, T.; Hashida, S.N. [Plant Molecular Biology, Laboratory of Environmental Science, Central Research Institute of Electric Power Industry (CRIEPI), 1646 Abiko, Chiba 270-1194 (Japan); Kawachi, N.; Suzui, N.; Yin, Y.G.; Fujimaki, S. [Radiotracer Imaging Gr., Quantum Beam Science Center, Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan); Nagao, Y.; Yamaguchi, M. [Takasaki Advanced Radiation Research Institute, Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma 370-1292 (Japan)

    2014-07-01

    Radiocesium from the severe accident at the Fukushima Dai-ichi Nuclear Power Plant on 11 March 2011 contaminates large areas. After this, a doubt for forest products, especially of mushroom, is indelible at the areas. Pruned woody parts and litters are containing a considerable amount of radiocesium, and generates a problem at incineration and composting. These mean that more attentive survey for each subject is expected; however, the present survey system is highly laborious/expensive and/or non-effective for this purpose. On the other hand, we can see a glass-badge based gamma radiation dose rate detection system. This system always utilized to detect a personal cumulative radiation dose, and thus, it is not suitable to separate a radiation from a specific object. However, if we can separate a radiation from a specific object and relate it with the own radiocesium concentration, it would enable us to presume the specific concentration with just an easy monitoring but without a destruction of the target nature and a complicated process including sampling, pre-treatment, and detection. Here, we present the concept of the measurement and results of the trials. First, we set glass-badges (type FS, Chiyoda Technol Corp., Japan) on a part of bough (approximately 10 cm in diameter) of Japanese flowering cherry trees (Prunus x yedoensis cv. Somei-Yoshino) with four different settings: A, a direct setting without any shield; B, a setting with an aluminum shield between bough and the glass-badge; C, a setting with a lead shield between bough and the glass-badge; D, a setting with a lead shield covering the glass-badge to shut the radiation from the surrounding but from bough. The deduction between the amount of each setting should separate a specific radiation of the bough from unlimited radiation from the surrounding. Even if the hourly dose rate is not enough to count the difference, a moderate cumulative dose would clear the difference. In fact, results demonstrated a

  13. Clinical significance of cumulative biological effective dose and overall treatment time in the treatment of carcinoma cervix

    Directory of Open Access Journals (Sweden)

    Mandal Abhijit

    2007-01-01

    Full Text Available The purpose of this retrospective study is to report the radiotherapy treatment response of, and complications in, patients with cervical cancer on the basis of cumulative biologic effective dose (BED and overall treatment time (OTT. Sixty-four (stage II - 35/64; stage III - 29/64 patients of cervical cancer were treated with combination of external beam radiotherapy (EBRT and low dose rate intracavitary brachytherapy (ICBT. The cumulative BED was calculated at Point A (BED 10 ; and bladder, rectal reference points (BED 2.5 using the linear-quadratic BED equations. The local control (LC rate and 5-year disease-free survival (DFS rate in patients of stage II were comparable for BED 10 < 84.5 and BED 10 > 84.5 but were much higher for BED 10 > 84.5 than BED 10 < 84.5 ( P < 0.01 in stage III patients. In the stage II patients, The LC rate and 5-year DFS rate were comparable for OTT < 50 days and for OTT> 50 days but were much higher in stage III patients with OTT < 50 than OTT> 50 days ( P < 0.001. It was also observed that patients who received BED 2.5 < 105 had lesser rectal ( P < 0.001 and bladder complications than BED 2.5 > 105. Higher rectal complication-free survival (CFS R rate, bladder complication-free survival (CFS B rate and all-type late complication-free survival rate were observed in patients who received BED 2.5 < 105 than BED 2.5 > 105. A balanced, optimal and justified radiotherapy treatment schedule to deliver higher BED 10 (>84.5 and lower BED 2.5 (< 105 in lesser OTT (< 50 days is essential in carcinoma cervix to expect a better treatment outcome in all respects.

  14. Unified registration framework for cumulative dose assessment in cervical cancer across external beam radiotherapy and brachytherapy

    Science.gov (United States)

    Roy, Sharmili; Totman, John J.; Choo, Bok A.

    2016-03-01

    Dose accumulation across External Beam Radiotherapy (EBRT) and Brachytherapy (BT) treatment fractions in cervical cancer is extremely challenging due to structural dissimilarities and large inter-fractional anatomic deformations between the EBRT and BT images. The brachytherapy applicator and the bladder balloon, present only in the BT images, introduce missing structural correspondences for the underlying registration problem. Complex anatomical deformations caused by the applicator and the balloon, different rectum and bladder filling and tumor shrinkage compound the registration difficulties. Conventional free-form registration methods struggle to handle such topological differences. In this paper, we propose a registration pipeline that first transforms the original images to their distance maps based on segmentations of critical organs and then performs non-linear registration of the distance maps. The resulting dense deformation field is then used to transform the original anatomical image. The registration accuracy is evaluated on 27 image pairs from stage 2B-4A cervical cancer patients. The algorithm reaches a Hausdorff distance of close to 0:5 mm for the uterus, 2:2 mm for the bladder and 1:7 mm for the rectum when applied to (EBRT,BT) pairs, taken at time points more than three months apart. This generalized model-free framework can be used to register any combination of EBRT and BT images as opposed to methods in the literature that are tuned for either only (BT,BT) pair, or only (EBRT,EBRT) pair or only (BT,EBRT) pair. A unified framework for 3D dose accumulation across multiple EBRT and BT fractions is proposed to facilitate adaptive personalized radiation therapy.

  15. Benchmark dose of lead inducing anemia at the workplace.

    Science.gov (United States)

    Karita, Kanae; Yano, Eiji; Dakeishi, Miwako; Iwata, Toyoto; Murata, Katsuyuki

    2005-08-01

    To estimate the critical dose of lead inducing anemia in humans, the effects of lead on hemoglobin (Hb) and hematocrit (Hct) levels and red blood cell (RBC) count were examined in 388 male lead-exposed workers with blood lead (BPb) levels of 0.05-5.5 (mean 1.3) micromol/L by using the benchmark dose (BMD) approach. The BPb level was significantly related to Hb (regression coefficient beta=-0.276), RBC (beta=-11.35), and Hct (beta=-0.563) among the workers (p anemia (1.85 micromol/L), based on the WHO criteria, than in those without anemia (1.26 micromol/L). The benchmark dose levels of BPb (i.e., lower 95% confidence limits of BMD), calculated from the K-power model set at an abnormal probability of 5% in unexposed workers and an excess risk of 5% in exposed workers were estimated to be 0.94 micromol/L (19.5 microg/dl) for Hb, 0.94 micromol/L (19.4 microg/dl) for RBC, and 1.43 micromol/L (29.6 microg/dl) for Hct. These findings suggest that reduction in hematopoietic indicators may be initiated at BPbs below the level currently considered without effect.

  16. Effect of lead attenuators on dose in homogeneous phantoms

    Energy Technology Data Exchange (ETDEWEB)

    El-Khatib, E.E.; Podgorsak, E.B.; Pla, C.

    1986-11-01

    In radiotherapy, the radiation beam is sometimes shaped so as to deliver different doses to different organs or give a homogeneous dose to structures of different densities. This objective is achieved by the use of attenuating materials introduced into the beam. These attenuators alter the primary as well as the scattered radiation components of the beam. There is at present no accurate method of dose calculation for these situations. Most calculations are performed considering only the effect of the attenuators on the primary radiation beam and can produce large errors in dosimetry. In the present study, the broad beam attenuation is investigated in homogeneous phantoms for various radiation field sizes, photon beam energies, and depths in phantom. A calculational method taking account of primary as well as first scatter radiation is developed. This method predicts reasonably well the transmission through lead attenuators for the various experimental conditions investigated.

  17. Determining prenatal, early childhood and cumulative long-term lead exposure using micro-spatial deciduous dentine levels.

    Directory of Open Access Journals (Sweden)

    Manish Arora

    Full Text Available The aim of this study was to assess the validity of micro-spatial dentine lead (Pb levels as a biomarker for accurately estimating exposure timing over the prenatal and early childhood periods and long-term cumulative exposure to Pb. In a prospective pregnancy cohort sub-sample of 85 subjects, we compared dentine Pb levels measured using laser ablation-inductively coupled plasma mass spectrometry with Pb concentrations in maternal blood collected in the second and third trimesters, maternal bone, umbilical cord blood, and childhood serial blood samples collected from the ages of 3 months to ≥6 years. We found that Pb levels (as 208Pb:43Ca in dentine formed at birth were significantly associated with cord blood Pb (Spearman ρ = 0.69; n = 27; p<0.0001. The association of prenatal dentine Pb with maternal patella Pb (Spearman ρ = 0.48; n = 59; p<0.0001 was stronger than that observed for tibia Pb levels (Spearman ρ = 0.35; n = 41; p<0.03. When assessing postnatal exposure, we found that Pb levels in dentine formed at 3 months were significantly associated with Pb concentrations in children's blood collected concurrently (Spearman ρ = 0.64; n = 55; p<0.0001. We also found that mean Pb concentrations in secondary dentine (that is formed from root completion to tooth shedding correlated positively with cumulative blood lead index (Spearman ρ = 0.38; n = 75; p<0.0007. Overall, our results support that micro-spatial measurements of Pb in dentine can be reliably used to reconstruct Pb exposure timing over the prenatal and early childhood periods, and secondary dentine holds the potential to estimate long-term exposure up to the time the tooth is shed.

  18. Thyroid dose during neurointerventional procedures: does lead shielding reduce the dose?

    Science.gov (United States)

    Shortt, C P; Fanning, N F; Malone, L; Thornton, J; Brennan, P; Lee, M J

    2007-01-01

    To assess radiation dose to the thyroid in patients undergoing neurointerventional procedures and to evaluate dose reduction to the thyroid by lead shielding. A randomized patient study was undertaken to evaluate the dose reduction by thyroid lead shields and assess their practicality in a clinical setting. Sixty-five patients attending for endovascular treatment of arteriovenous malformations (AVMs) and aneurysms were randomized into one of 2 groups a) No Thyroid Shield and b) Thyroid Lead Shield. Two thermoluminescent dosimeters (TLDs) were placed over the thyroid gland (1 on each side) at constant positions on each patient in both groups. A thyroid lead shield (Pb eq. 0.5 mm) was placed around the neck of patients in the thyroid lead shield group after the neurointerventional radiologist had obtained satisfactory working access above the neck. The total dose-area-product (DAP) value, number and type of digital subtraction angiography (DSA) runs and fluoroscopy time were recorded for all patients. Of the 72 patients who initially attended for neurointerventional procedures, 7 were excluded due to failure to consent or because of procedures involving access to the external carotid circulation. Of the remaining 65 who were randomized, a further 9 were excluded due to; procedureabandonment, unfeasible shield placement or shield interference with the procedure. Patient demographics included mean age of 47.9 yrs (15-74), F:M=1.4:1. Mean fluoroscopy time was 25.9 min. Mean DAP value was 13,134.8 cGy x cm(2) and mean number of DSA runs was 13.4. The mean relative thyroid doses were significantly different (pshielded groups (3.77 mSv/cGy2 x 105). A mean thyroid dose reduction of 48% was seen in the shielded group versus the unshielded group. Considerable doses to the thyroid are incurred during neurointerventional procedures, highlighting the need for increased awareness of patient radiation protection. Thyroid lead shielding yields significant radiation protection, is

  19. Risk of therapy-related leukaemia and preleukaemia after Hodgkin's disease. Relation to age, cumulative dose of alkylating agents, and time from chemotherapy

    DEFF Research Database (Denmark)

    Pedersen-Bjergaard, J; Specht, L; Larsen, S O;

    1987-01-01

    391 patients treated intensively for Hodgkin's disease were followed for up to 15 years to evaluate the risk of therapy-related acute non-lymphocytic leukaemia (t-ANLL) and preleukaemia. Only two independent factors, patient age and cumulative dose of alkylating agents, were related to the risk o...

  20. Dicer1 depletion in male germ cells leads to infertility due to cumulative meiotic and spermiogenic defects.

    Directory of Open Access Journals (Sweden)

    Yannick Romero

    Full Text Available BACKGROUND: Spermatogenesis is a complex biological process that requires a highly specialized control of gene expression. In the past decade, small non-coding RNAs have emerged as critical regulators of gene expression both at the transcriptional and post-transcriptional level. DICER1, an RNAse III endonuclease, is essential for the biogenesis of several classes of small RNAs, including microRNAs (miRNAs and endogenous small interfering RNAs (endo-siRNAs, but is also critical for the degradation of toxic transposable elements. In this study, we investigated to which extent DICER1 is required for germ cell development and the progress of spermatogenesis in mice. PRINCIPAL FINDINGS: We show that the selective ablation of Dicer1 at the early onset of male germ cell development leads to infertility, due to multiple cumulative defects at the meiotic and post-meiotic stages culminating with the absence of functional spermatozoa. Alterations were observed in the first spermatogenic wave and include delayed progression of spermatocytes to prophase I and increased apoptosis, resulting in a reduced number of round spermatids. The transition from round to mature spermatozoa was also severely affected, since the few spermatozoa formed in mutant animals were immobile and misshapen, exhibiting morphological defects of the head and flagellum. We also found evidence that the expression of transposable elements of the SINE family is up-regulated in Dicer1-depleted spermatocytes. CONCLUSIONS/SIGNIFICANCE: Our findings indicate that DICER1 is dispensable for spermatogonial stem cell renewal and mitotic proliferation, but is required for germ cell differentiation through the meiotic and haploid phases of spermatogenesis.

  1. DOSE-RESPONSE MODELING FOR THE ASSESSMENT OF CUMULATIVE RISK DUE TO EXPOSURE TO N-METHYL CARBAMATE PESTICIDES

    Science.gov (United States)

    The US EPAs N-Methyl Carbamate Cumulative Risk Assessment (NMCRA) assesses the effect on acetylcholine esterase (AChE) activity of exposure to 10 N-methyl carbamate (NMC) pesticides through dietary, drinking water, and residential exposures.

  2. Current and historical individual data about exposure of workers in the rayon industry to carbon disulfide and their validity in calculating the cumulative dose.

    Science.gov (United States)

    Göen, Thomas; Schramm, Axel; Baumeister, Thomas; Uter, Wolfgang; Drexler, Hans

    2014-08-01

    The objective of the study was to investigate how exposure to carbon disulfide (CS2) in a rayon-manufacturing plant has changed within two decades and whether it is possible to calculate valid data for the individual cumulative exposure. The data for CS2 concentration in air and biological exposure monitoring (2-thio-1,3-thiaxolidine-4-carboxylic acid (TTCA) in urine) from two cross-sectional studies, performed in 1992 (n = 362) and 2009 (n = 212) in a German rayon-manufacturing plant, were compared to data obtained from company-internal measurements between the studies. Using the data from the cross-sectional studies and company-internal data, cumulative external exposure and the cumulative internal exposure were calculated for each worker. External and internal CS2 exposure of the employees decreased from 1992 (medians 4.0 ppm and 1.63 mgTTCA/g creatinine) to 2009 (medians 2.5 ppm and 0.86 mg/g). However, company-internal CS2 data do not show a straight trend for this period. The annual medians of the company-internal measurement of external exposure to CS2 have varied between 2.7 and 8.4 ppm, in which median values exceeded 5 ppm generally since 2000. The annual medians for the company-internal biomonitoring assessment ranged between 1.2 and 2.8 mg/g creatinine. The cumulative CS2 exposure ranged from 8.5 to 869.5 ppm years for external exposure and between 1.30 and 176.2 mg/g creatinine years for the internal exposure. Significant correlations were found between the current air pollution and the internal exposure in 2009 but also between the cumulative external and internal CS2 exposure. Current exposure data, usually collected in cross-sectional studies, rarely allow a reliable statement on the cumulative dose, because of higher exposure in the past and of fluctuating courses of exposure. On the other hand, company-internal exposure data may be affected by non-representative measurement strategies. Some verification of the reliability of

  3. Histopathology of mallards dosed with lead and selected substitute shot

    Science.gov (United States)

    Locke, L.N.; Irby, H.D.; Bagley, G.E.

    1967-01-01

    The histopathological response of male game farm mallards fed lead, three types of plastic-coated lead, two lead-magnesium alloys, iron, copper, zinc-coated iron, and molybdenum-coated iron shot was studied. Mallards fed lead, plastic-coated lead, or lead-magnesium alloy shot developed a similar pathological response, including the formation of acid-fast intranuclear inclusion bodies in the kidneys. Birds fed iron or molybdenum-coated iron shot developed hemosiderosis of the liver. Two of four mallards fed zinc-coated iron shot also developed hemosiderosis of the liver. No lesions were found in mallards fed copper shot.

  4. Double dose: the cumulative effect of TV viewing at home and in preschool on children's activity patterns and weight status.

    Science.gov (United States)

    Taverno Ross, Sharon; Dowda, Marsha; Saunders, Ruth; Pate, Russell

    2013-05-01

    Little is known about how screen-based sedentary behavior at home and in preschool influences children's health and activity patterns. The current study examined the individual and cumulative influence of TV viewing at home and in preschool on children's physical activity (PA) and weight status. Children (n = 339) attending 16 preschools in South Carolina were grouped into high and low TV groups based on parent report of children's TV viewing at home and director report of TV use/rules in preschool. T-tests and mixed model ANOVAs examined differences in weight status and PA (min/hr) by high and low TV groups. Results revealed that children who were classified as High TV both at home and in pre- school had significantly lower levels of moderate-to-vigorous PA compared with their Low TV counterparts (8.3 (0.3) min/hr vs. 7.6 (0.2) min/hr, p TV groups at home or in preschool when examined individually. These findings demonstrate the importance of total environmental TV exposure on preschooler's PA. Longitudinal and observational research to assess preschoolers' cumulative screen-based sedentary behavior and its relationship with PA and weight status is needed.

  5. A population-based case-control study of Selective Serotonin Reuptake Inhibitors (SSRIs and breast cancer: The impact of duration of use, cumulative dose and latency

    Directory of Open Access Journals (Sweden)

    Lévesque LE

    2010-12-01

    Full Text Available Abstract Background Selective serotonin reuptake inhibitors (SSRIs, a popular class of antidepressants, may increase breast cancer risk by stimulating the secretion of prolactin, a potential tumour promoter. We evaluated the effects of duration of SSRI use, cumulative dose, and latency on the risk of breast cancer by conducting a population-based case-control study utilizing Saskatchewan health databases. Methods Cases included 1,701 women with primary invasive breast cancer diagnosed from 2003 to 2006, and controls consisted of 17,017 women, randomly selected from the population registry. Use of SSRIs was compiled using the Saskatchewan prescription database. Unconditional logistic regression was conducted to evaluate the impact of duration of combined SSRI use (total number of prescriptions dispensed, cumulative dose (total dosage received and timing of use (two or more years, two to seven years and more than seven years prior to index date on the risk of breast cancer. Results Overall, SSRI use was not associated with an increased risk of breast cancer regardless of our definition of cumulative use (total number of prescriptions dispensed and total dosage. In addition, our results indicate that prolonged SSRI use does not have a latent effect on breast cancer risk. Also, our findings are not suggestive of an increased risk of breast cancer with the use of individual SSRIs. Conclusions Our study improved upon most previous studies by having a longer follow-up period, a larger sample size of long-term SSRI users and consideration of risk during specific exposure time windows that take latency into account. Given the potential health benefits of using SSRIs, our results suggest that the issue of breast cancer risk may no longer be a concern for women requiring long-term SSRIs.

  6. Investigation into the effects of lead shielding for fetal dose reduction in CT pulmonary angiography.

    Science.gov (United States)

    Kennedy, E V; Iball, G R; Brettle, D S

    2007-08-01

    This work aims to determine whether lead shielding can be used to decrease the radiation dose to the fetus during CT scans for the diagnosis of pulmonary embolism during early stage pregnancy. An anthropomorphic phantom was modified to contain a 15 cc ionization chamber at the site of the uterus to enable fetal dose to be measured. The effects of a range of scan parameters, positioning of lead and thicknesses of lead were investigated. Fetal dose was lower with lower values of kV(p) and mAs. An increasing thickness of lead decreased the radiation dose to the uterus, as did increasing the proportion of the patient covered by the lead shielding. Fetal dose increased exponentially as the edge of the scan volume moved closer to the point of measurement. In no experiment was the dose to the fetus increased by the presence of the lead. It was found that the fetal radiation dose from a CT scan following a pulmonary embolism protocol can be effectively reduced by the use of lead shielding.

  7. Integration of kerma-area product and cumulative air kerma determination into a skin dose tracking system for fluoroscopic imaging procedures

    Science.gov (United States)

    Vijayan, Sarath; Shankar, Alok; Rudin, Stephen; Bednarek, Daniel R.

    2016-03-01

    The skin dose tracking system (DTS) that we developed provides a color-coded mapping of the cumulative skin dose distribution on a 3D graphic of the patient during fluoroscopic procedures in real time. The DTS has now been modified to also calculate the kerma area product (KAP) and cumulative air kerma (CAK) for fluoroscopic interventions using data obtained in real-time from the digital bus on a Toshiba Infinix system. KAP is the integral of air kerma over the beam area and is typically measured with a large-area transmission ionization chamber incorporated into the collimator assembly. In this software, KAP is automatically determined for each x-ray pulse as the product of the air kerma/ mAs from a calibration file for the given kVp and beam filtration times the mAs per pulse times the length and width of the beam times a field nonuniformity correction factor. Field nonuniformity is primarily the result of the heel effect and the correction factor was determined from the beam profile measured using radio-chromic film. Dividing the KAP by the beam area at the interventional reference point provides the area averaged CAK. The KAP and CAK per x-ray pulse are summed after each pulse to obtain the total procedure values in real-time. The calculated KAP and CAK were compared to the values displayed by the fluoroscopy machine with excellent agreement. The DTS now is able to automatically calculate both KAP and CAK without the need for measurement by an add-on transmission ionization chamber.

  8. Investigation of practical approaches to evaluating cumulative dose for cone beam computed tomography (CBCT) from standard CT dosimetry measurements: a Monte Carlo study

    Science.gov (United States)

    Abuhaimed, Abdullah; Martin, Colin J.; Sankaralingam, Marimuthu; Gentle, David J.

    2015-07-01

    A function called Gx(L) was introduced by the International Commission on Radiation Units and Measurements (ICRU) Report-87 to facilitate measurement of cumulative dose for CT scans within long phantoms as recommended by the American Association of Physicists in Medicine (AAPM) TG-111. The Gx(L) function is equal to the ratio of the cumulative dose at the middle of a CT scan to the volume weighted CTDI (CTDIvol), and was investigated for conventional multi-slice CT scanners operating with a moving table. As the stationary table mode, which is the basis for cone beam CT (CBCT) scans, differs from that used for conventional CT scans, the aim of this study was to investigate the extension of the Gx(L) function to CBCT scans. An On-Board Imager (OBI) system integrated with a TrueBeam linac was simulated with Monte Carlo EGSnrc/BEAMnrc, and the absorbed dose was calculated within PMMA, polyethylene (PE), and water head and body phantoms using EGSnrc/DOSXYZnrc, where the body PE body phantom emulated the ICRU/AAPM phantom. Beams of width 40-500 mm and beam qualities at tube potentials of 80-140 kV were studied. Application of a modified function of beam width (W) termed Gx(W), for which the cumulative dose for CBCT scans f (0) is normalized to the weighted CTDI (CTDIw) for a reference beam of width 40 mm, was investigated as a possible option. However, differences were found in Gx(W) with tube potential, especially for body phantoms, and these were considered to be due to differences in geometry between wide beams used for CBCT scans and those for conventional CT. Therefore, a modified function Gx(W)100 has been proposed, taking the form of values of f (0) at each position in a long phantom, normalized with respect to dose indices f 100(150)x measured with a 100 mm pencil ionization chamber within standard 150 mm PMMA phantoms, using the same scanning parameters, beam widths and positions within the phantom. f 100(150)x averages the dose resulting from

  9. Leukaemia and low dose radiation. Is there an association between leukaemia and cumulative external dose amongst the British Nuclear Fuel plc. (BNFL) workers?

    Energy Technology Data Exchange (ETDEWEB)

    McGeoghegan, D.; Binks, K. [Westlakes Scientific Consulting, Cumbria (United Kingdom)

    2000-05-01

    A detailed examination of the BNFL leukaemia data is presented, for the period 1941-1995, using the recently assembled company wide BNFL epidemiological database and the BNFL leukaemia case-control data set. The association of this occupationally exposed cohort is examined with respect to both leukaemia mortality and leukaemia morbidity. The excess relative risk for total leukaemia excluding chronic lymphatic leukaemia amongst the BNFL radiation workers was found to be 3.64 Sv{sup -1} (90% CI -0.13-11.22); for Sellafield and Springfields this figure was 7.99 Sv{sup -1} (90% CI 1.50-29.5) and -1.97 Sv{sup -1} (90% CI<-2.23-6.11) respectively. A 14-20% increase in risk is noted when dosimetry adjusted for measurement error, is used to determine the excess relative risk. The association between leukaemia and cumulative external radiation is found to be particularly associated with the Sellafield plant; the Springfields plant gave consistently negative risk estimates. (author)

  10. The leaded apron revisited: does it reduce gonadal radiation dose in dental radiology

    Energy Technology Data Exchange (ETDEWEB)

    Wood, R.E.; Harris, A.M.; van der Merwe, E.J.; Nortje, C.J. (Ontario Cancer Institute, Princess Margaret Hospital, Toronto (Canada))

    1991-05-01

    A tissue-equivalent anthropomorphic human phantom was used with a lithium fluoride thermoluminescent dosimetry system to evaluate the radiation absorbed dose to the ovarian and testicular region during dental radiologic procedures. Measurements were made with and without personal lead shielding devices consisting of thyroid collar and apron of 0.25 mm lead thickness equivalence. The radiation absorbed dose with or without lead shielding did not differ significantly from control dosimeters in vertex occlusal and periapical views (p greater than 0.05). Personal lead shielding devices did reduce gonadal dose in the case of accidental exposure (p less than 0.05). A leaded apron of 0.25 mm lead thickness equivalent was permeable to radiation in direct exposure testing.

  11. Optimal Dosing for Targeted Therapies in Oncology: Drug Development Cases Leading by Example.

    Science.gov (United States)

    Sachs, Jeffrey R; Mayawala, Kapil; Gadamsetty, Satvik; Kang, Soonmo Peter; de Alwis, Dinesh P

    2016-03-15

    One of the key objectives of oncology first-in-human trials has often been to establish the maximum tolerated dose (MTD). However, targeted therapies might not exhibit dose-limiting toxicities (DLT) at doses significantly higher than sufficiently active doses, and there is frequently a limited ability to objectively quantify adverse events. Thus, while MTD-based determination of recommended phase II dose may have yielded appropriate dosing for some cytotoxics, targeted therapeutics (including monoclonal antibodies and/or immunotherapies) sometimes need alternative or complementary strategies to help identify dose ranges for a randomized dose-ranging study. One complementary strategy is to define a biologically efficacious dose (BED) using an "effect marker." An effect marker could be a target engagement, pharmacodynamic, or disease progression marker (change in tumor size for solid tumors or bone marrow blast count for some hematologic tumors). Although the concept of BED has been discussed extensively, we review specific examples in which the approach influenced oncology clinical development. Data extracted from the literature and the examples support improving dose selection strategies to benefit patients, providers, and the biopharmaceutical industry. Although the examples illustrate key contributions of effect markers in dose selection, no one-size-fits-all approach to dosing can be justified. Higher-than-optimal dosing can increase toxicity in later trials (and in clinical use), which can have a negative impact on efficacy (via lower adherence or direct sequelae of toxicities). Proper dose selection in oncology should follow a multifactorial decision process leading to a randomized, dose-ranging study instead of a single phase II dose. ©2015 American Association for Cancer Research.

  12. SU-E-T-802: Verification of Implanted Cardiac Pacemaker Doses in Intensity-Modulated Radiation Therapy: Dose Prediction Accuracy and Reduction Effect of a Lead Sheet

    Energy Technology Data Exchange (ETDEWEB)

    Lee, J [Dept. of Radiation Oncology, Konkuk University Medical Center, Seoul (Korea, Republic of); Chung, J [Dept. of Radiation Oncology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

    2015-06-15

    Purpose: To verify delivered doses on the implanted cardiac pacemaker, predicted doses with and without dose reduction method were verified using the MOSFET detectors in terms of beam delivery and dose calculation techniques in intensity-modulated radiation therapy (IMRT). Methods: The pacemaker doses for a patient with a tongue cancer were predicted according to the beam delivery methods [step-and-shoot (SS) and sliding window (SW)], intensity levels for dose optimization, and dose calculation algorithms. Dosimetric effects on the pacemaker were calculated three dose engines: pencil-beam convolution (PBC), analytical anisotropic algorithm (AAA), and Acuros-XB. A lead shield of 2 mm thickness was designed for minimizing irradiated doses to the pacemaker. Dose variations affected by the heterogeneous material properties of the pacemaker and effectiveness of the lead shield were predicted by the Acuros-XB. Dose prediction accuracy and the feasibility of the dose reduction strategy were verified based on the measured skin doses right above the pacemaker using mosfet detectors during the radiation treatment. Results: The Acuros-XB showed underestimated skin doses and overestimated doses by the lead-shield effect, even though the lower dose disagreement was observed. It led to improved dose prediction with higher intensity level of dose optimization in IMRT. The dedicated tertiary lead sheet effectively achieved reduction of pacemaker dose up to 60%. Conclusion: The current SS technique could deliver lower scattered doses than recommendation criteria, however, use of the lead sheet contributed to reduce scattered doses.Thin lead plate can be a useful tertiary shielder and it could not acuse malfunction or electrical damage of the implanted pacemaker in IMRT. It is required to estimate more accurate scattered doses of the patient with medical device to design proper dose reduction strategy.

  13. The cumulative cost of additional wakefulness: dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivation

    Science.gov (United States)

    Van Dongen, Hans P A.; Maislin, Greg; Mullington, Janet M.; Dinges, David F.

    2003-01-01

    OBJECTIVES: To inform the debate over whether human sleep can be chronically reduced without consequences, we conducted a dose-response chronic sleep restriction experiment in which waking neurobehavioral and sleep physiological functions were monitored and compared to those for total sleep deprivation. DESIGN: The chronic sleep restriction experiment involved randomization to one of three sleep doses (4 h, 6 h, or 8 h time in bed per night), which were maintained for 14 consecutive days. The total sleep deprivation experiment involved 3 nights without sleep (0 h time in bed). Each study also involved 3 baseline (pre-deprivation) days and 3 recovery days. SETTING: Both experiments were conducted under standardized laboratory conditions with continuous behavioral, physiological and medical monitoring. PARTICIPANTS: A total of n = 48 healthy adults (ages 21-38) participated in the experiments. INTERVENTIONS: Noctumal sleep periods were restricted to 8 h, 6 h or 4 h per day for 14 days, or to 0 h for 3 days. All other sleep was prohibited. RESULTS: Chronic restriction of sleep periods to 4 h or 6 h per night over 14 consecutive days resulted in significant cumulative, dose-dependent deficits in cognitive performance on all tasks. Subjective sleepiness ratings showed an acute response to sleep restriction but only small further increases on subsequent days, and did not significantly differentiate the 6 h and 4 h conditions. Polysomnographic variables and delta power in the non-REM sleep EEG-a putative marker of sleep homeostasis--displayed an acute response to sleep restriction with negligible further changes across the 14 restricted nights. Comparison of chronic sleep restriction to total sleep deprivation showed that the latter resulted in disproportionately large waking neurobehavioral and sleep delta power responses relative to how much sleep was lost. A statistical model revealed that, regardless of the mode of sleep deprivation, lapses in behavioral alertness

  14. Dosimetric perturbations of a lead shield for surface and interstitial high-dose-rate brachytherapy.

    Science.gov (United States)

    Candela-Juan, Cristian; Granero, Domingo; Vijande, Javier; Ballester, Facundo; Perez-Calatayud, Jose; Rivard, Mark J

    2014-06-01

    In surface and interstitial high-dose-rate brachytherapy with either (60)Co, (192)Ir, or (169)Yb sources, some radiosensitive organs near the surface may be exposed to high absorbed doses. This may be reduced by covering the implants with a lead shield on the body surface, which results in dosimetric perturbations. Monte Carlo simulations in Geant4 were performed for the three radionuclides placed at a single dwell position. Four different shield thicknesses (0, 3, 6, and 10 mm) and three different source depths (0, 5, and 10 mm) in water were considered, with the lead shield placed at the phantom surface. Backscatter dose enhancement and transmission data were obtained for the lead shields. Results were corrected to account for a realistic clinical case with multiple dwell positions. The range of the high backscatter dose enhancement in water is 3 mm for (60)Co and 1 mm for both (192)Ir and (169)Yb. Transmission data for (60)Co and (192)Ir are smaller than those reported by Papagiannis et al (2008 Med. Phys. 35 4898-4906) for brachytherapy facility shielding; for (169)Yb, the difference is negligible. In conclusion, the backscatter overdose produced by the lead shield can be avoided by just adding a few millimetres of bolus. Transmission data provided in this work as a function of lead thickness can be used to estimate healthy organ equivalent dose saving. Use of a lead shield is justified.

  15. An International Pooled Analysis for Obtaining a Benchmark Dose for Environmental Lead Exposure in Children

    DEFF Research Database (Denmark)

    Budtz-Jørgensen, Esben; Bellinger, David; Lanphear, Bruce;

    2013-01-01

    Lead is a recognized neurotoxicant, but estimating effects at the lowest measurable levels is difficult. An international pooled analysis of data from seven cohort studies reported an inverse and supra-linear relationship between blood lead concentrations and IQ scores in children. The lack...... yielding lower confidence limits (BMDLs) of about 0.1-1.0 for the dose leading to a loss of one IQ point. We conclude that current allowable blood lead concentrations need to be lowered and further prevention efforts are needed to protect children from lead toxicity....

  16. Promoter region variation in NFE2L2 influences susceptibility to ototoxicity in patients exposed to high cumulative doses of cisplatin.

    Science.gov (United States)

    Spracklen, T F; Vorster, A A; Ramma, L; Dalvie, S; Ramesar, R S

    2016-07-26

    Ototoxicity is a disabling reaction to cisplatin chemotherapy. Much of the inter-individual variability in the development of hearing impairment among cisplatin-receiving patients has not been fully accounted for. In particular, little is known about the pharmacogenomics of cisplatin-induced ototoxicity. This study sought to investigate the role of variation in five candidate genes in a cohort of South African cancer patients. Five variants within the candidate genes were genotyped in 214 patients, of which SLC22A2 rs316019 and NFE2L2 rs6721961 associated with reduced rates of ototoxicity. In the patients who were exposed to cumulative cisplatin doses ⩾200 mg m(-)(2) (n=113), the variant rs6721961 associated with ototoxicity according to three different grading scales of hearing loss (ASHA, P=0.005; Chang, P=0.028; CTCAE, P=0.004). The NFE2L2 promotor variant rs6721961 may therefore be protective against hearing loss in cisplatin-receiving cancer patients.The Pharmacogenomics Journal advance online publication, 26 July 2016; doi:10.1038/tpj.2016.52.

  17. The Effect of Total Cumulative Dose, Number of Treatment Cycles, Interval between Injections, and Length of Treatment on the Frequency of Occurrence of Antibodies to Botulinum Toxin Type A in the Treatment of Muscle Spasticity

    Science.gov (United States)

    Bakheit, Abdel Magid O.; Liptrot, Anthea; Newton, Rachel; Pickett, Andrew M.

    2012-01-01

    A large cumulative dose of botulinum toxin type A (BoNT-A), frequent injections, a short interval between treatment cycles, and a long duration of treatment have all been suggested, but not confirmed, to be associated with a high incidence of neutralizing antibodies to the neurotoxin. The aim of this study was to investigate whether these…

  18. Characterization of a lead breast shielding for dose reduction in computed tomography*

    OpenAIRE

    Correia,Paula Duarte; Granzotti, Cristiano Roberto Fabri; Santos, Yago da Silva; Brochi,Marco Aurelio Corte; Azevedo-Marques,Paulo Mazzoncini de

    2014-01-01

    Objective Several studies have been published regarding the use of bismuth shielding to protect the breast in computed tomography (CT) scans and, up to the writing of this article, only one publication about barium shielding was found. The present study was aimed at characterizing, for the first time, a lead breast shielding. Materials and Methods The percentage dose reduction and the influence of the shielding on quantitative imaging parameters were evaluated. Dose measurements were made on ...

  19. Influence of lead apron shielding on absorbed doses from cone-beam computed tomography.

    Science.gov (United States)

    Rottke, Dennis; Andersson, Jonas; Ejima, Ken-Ichiro; Sawada, Kunihiko; Schulze, Dirk

    2016-09-24

    The aim of the present work was to investigate absorbed and to calculate effective doses (EDs) in cone-beam computed tomography (CBCT). The study was conducted using examination protocols with and without lead apron shielding. A full-body male RANDO(®) phantom was loaded with 110 GR200A thermoluminescence dosemeter chips at 55 different sites and set up in two different CBCT systems (CS 9500(®), ProMax(®) 3D). Two different protocols were performed: the phantom was set up (1) with and (2) without a lead apron. No statistically significant differences in organ and absorbed doses from regions outside the primary beam could be found when comparing results from exposures with and without lead apron shielding. Consequently, calculating the ED showed no significant differences between the examination protocols with and without lead apron shielding. For the ProMax(®) 3D with shielding, the ED was 149 µSv, and for the examination protocol without shielding 148 µSv (SD = 0.31 µSv). For the CS 9500(®), the ED was 88 and 86 µSv (SD = 0.95 µSv), respectively, with and without lead apron shielding. The results revealed no statistically significant differences in the absorbed doses between examination with and without lead apron shielding, especially in organs outside the primary beam.

  20. Radiation dose reduction to the male gonads during MDCT: the effectiveness of a lead shield.

    Science.gov (United States)

    Hohl, Christian; Mahnken, Andreas H; Klotz, Ernst; Das, Marco; Stargardt, Achim; Mühlenbruch, Georg; Schmidt, Thorsten; Günther, Rolf W; Wildberger, Joachim E

    2005-01-01

    Our study was designed to quantify the effect of a standard gonad shield on the testicular radiation exposure due to scatter during routine abdominopelvic MDCT. Routine abdominopelvic MDCT was performed in 34 patients with gonadal lead shielding and 32 patients without this shielding; the testes were not exposed to the direct beam during the examination. We estimated the testicular dose administered with thermoluminescent dosimetry, taking into account each patient's body weight and body mass index (BMI). With a 1-mm lead shield, the mean testicular dose was reduced from 2.40 to 0.32 mSv, a reduction of 87%. The difference was found to be statistically significant (p Shielding the male gonads reduces the testicular radiation dose during abdominopelvic MDCT significantly and can be recommended for routine use.

  1. Cumulative radiation dose of multiple trauma patients during their hospitalization%多发伤患者住院期间X射线累积有效剂量研究

    Institute of Scientific and Technical Information of China (English)

    王志康; 孙建忠; 赵祖丹

    2012-01-01

    Objective To study the cumulative radiation dose of multiple trauma patients during their hospitalization and to analyze the dose influece factors.Methods The DLP for CT and DR were retrospectively collected from the patients during June,2009 and April,2011 at a university affiliated hospital.The cumulative radiation doses were calculated by summing typical effective doses of the anatomic regions scanned.Results The cumulative radiation doses of 113 patients were collected.The maximum,minimum and the mean values of cumulative effective doses were 153.3,16.48 mSv and(52.3 ± 26.6) mSv.Conclusions Multiple trauma patients have high cumulative radiation exposure.Therefore,the management of cumulative radiation doses should be enhanced.To establish the individualized radiation exposure archives will be helpful for the clinicians and technicians to make decision wheather to image again and how to select the imaging parameters.%目的 研究多发伤患者在院治疗期间的累积医疗X射线检查剂量,探讨其影响因素.方法 回顾性收集2009年6月至2011年4月在本院治疗患者的CT、DR检查记录,CT记录其DLP值,并用各部位转换系数算出有效剂量;DR参照以往研究各部位有效剂量数据.结果 共收集113位患者的X射线检查的累积剂量,剂量范围16.48~153.3 mSv,平均(52.3±26.6)mSv.结论 多发伤患者其累积X射线剂量处于较高的水平.应加强对医疗X射线检查的累积剂量管理,通过建立患者X射线辐射剂量档案管理可能使临床医生、检查技术员重视检查开单的选择以及检查参数的合理设置.

  2. A combined cumulative threshold spectra and digital reconstruction analysis reveal structural alterations of microglia within the prefrontal cortex following low-dose LPS administration.

    Science.gov (United States)

    Kongsui, R; Johnson, S J; Graham, B A; Nilsson, M; Walker, F R

    2015-12-01

    Sickness behaviors have become the focus of great interest in recent years as they represent a clear case of how peripheral disturbances in immune signaling can disrupt quite complex behaviors. In the current study, we were interested in examining whether we could identify any significant morphological disturbances in microglia associated with these sickness-like behaviors in adult male Sprague-Dawley rats. We chose lipopolysaccharide (LPS 100 μg/kg/i.p.), to induce sickness-like behaviors as it is the most well-validated approach to do so in rodents and humans. We were particularly interested in examining changes in microglia within the prefrontal cortex (PFC) as several recent neuroimaging studies have highlighted significant functional changes in this region following peripheral LPS administration. Paraformaldehyde-fixed tissue was collected from animals 24h post LPS administration and labeled immunohistochemically with an antibody directed to bind to Iba-1, a protein known to be involved in the structural remodeling of microglia. To analyze changes, we have made use of two recently described image analysis procedures. The first is known as cumulative threshold spectra (CTS) analysis. The second involves the unsupervised digital reconstruction of microglia. We undertook these complementary analysis of microglial cells in the both the pre- and infralimbic divisions of the PFC. Our results indicated that microglial soma size was significantly enlarged, while cell processes had contracted slightly following LPS administration. To our knowledge this study is to first to definitely demonstrate substantial microglial disturbances within the PFC following LPS delivered at a dose that was sufficient to induce significant sickness-like behavior.

  3. Catarata em corticoterapia sistêmica: prevalência e relação com tempo e dose cumulativa de glicocorticóides Corticosteroid therapy and cataract: prevalence and relation to time of use and cumulative dose

    Directory of Open Access Journals (Sweden)

    Fernanda Ziger

    2003-01-01

    Full Text Available OBJETIVO: O presente estudo teve por finalidade estudar a freqüência de catarata em pacientes reumáticos e usuários crônicos de corticóide, procurando-se correlacionar o seu aparecimento com tempo de uso, dose cumulativa total e doença de fundo. MÉTODOS: Foram estudados 27 pacientes reumáticos usuários crônicos de corticóide, com exame de lâmpada de fenda e calculado o tempo de uso e doses cumulativas de prednisona ou equivalente. RESULTADO: Encontrou-se freqüência de 18,52% de cataratas e não foi possível demonstrar correlação com dose cumulativa do medicamento (p=0,231 ou com o tipo de doença de fundo. Apesar do tempo médio de uso de corticóide ter sido maior entre os pacientes que apresentaram catarata, esta correlação não demostrou significância estatística (p=0,694. CONCLUSÃO: Os autores concluem que esta complicação é relativamente comum e que mais estudos são necessários para melhor entender o processo fisiopatológico implicado na sua formação.PURPOSE: To study cataract prevalence in rheumatic patients who used corticosteroid chronically and to correlate it with time and total corticosteroid dose as well as with the disease that required such treatment. METHODS: We studied 27 rheumatic patients regarding cataract using slit lamp and calculated the total dose of prednisone or equivalent steroids as well as the treatment time. RESULTS: We found an 18.52% prevalence and no correlation with cumulative dose (p=0.231 or with the underlying disease. Although the time of treatment was longer in the group with cataract, no statistically significant difference could be found (p=0.694. CONCLUSION: The authors conclude that cataract is a relativelly common complication of steroid use and that further studies are needed to understand the pathophysiologic process of its formation.

  4. Effect of leaded glasses and thyroid shielding on cone beam CT radiation dose in an adult female phantom.

    Science.gov (United States)

    Goren, A D; Prins, R D; Dauer, L T; Quinn, B; Al-Najjar, A; Faber, R D; Patchell, G; Branets, I; Colosi, D C

    2013-01-01

    This study aims to demonstrate the effectiveness of leaded glasses in reducing the lens of eye dose and of lead thyroid collars in reducing the dose to the thyroid gland of an adult female from dental cone beam CT (CBCT). The effect of collimation on the radiation dose in head organs is also examined. Dose measurements were conducted by placing optically stimulated luminescent dosemeters in an anthropomorphic female phantom. Eye lens dose was measured by placing a dosemeter on the anterior surface of the phantom eye location. All exposures were performed on one commercially available dental CBCT machine, using selected collimation and exposure techniques. Each scan technique was performed without any lead shielding and then repeated with lead shielding in place. To calculate the percent reduction from lead shielding, the dose measured with lead shielding was divided by the dose measured without lead shielding. The percent reduction from collimation was calculated by comparing the dose measured with collimation to the dose measured without collimation. The dose to the internal eye for one of the scans without leaded glasses or thyroid shield was 0.450 cGy and with glasses and thyroid shield was 0.116 cGy (a 74% reduction). The reduction to the lens of the eye was from 0.396 cGy to 0.153 cGy (a 61% reduction). Without glasses or thyroid shield, the thyroid dose was 0.158 cGy; and when both glasses and shield were used, the thyroid dose was reduced to 0.091 cGy (a 42% reduction). Collimation alone reduced the dose to the brain by up to 91%, with a similar reduction in other organs. Based on these data, leaded glasses, thyroid collars and collimation minimize the dose to organs outside the field of view.

  5. Shielding properties of lead-free protective clothing and their impact on radiation doses.

    Science.gov (United States)

    Schlattl, Helmut; Zankl, Maria; Eder, Heinrich; Hoeschen, Christoph

    2007-11-01

    The shielding properties of two different lead-free materials-tin and a compound of 80% tin and 20% bismuth-for protective clothing are compared with those of lead for three typical x-ray spectra generated at tube voltages of 60, 75, and 120 kV. Three different quantities were used to compare the shielding capability of the different materials: (1) Air-kerma attenuation factors in narrow-beam geometry, (2) air-kerma attenuation factors in broad-beam geometry, and (3) ratios of organ and effective doses in the human body for a whole-body irradiation with a parallel beam directed frontally at the body. The thicknesses of tin (0.45 mm) and the tin/bismuth compound (0.41 mm) to be compared against lead correspond to a lead equivalence value of 0.35 mm for the 75 kV spectrum. The narrow-beam attenuation factors for 0.45 mm tin are 54% and 32% lower than those for 0.35 mm lead for 60 and 120 kV; those for 0.41 mm tin/bismuth are 12% and 32% lower, respectively. The decrease of the broad-beam air-kerma attenuation factors compared to lead is 74%, 46%, and 41% for tin and 42%, 26%, and 33% for tin/bismuth and the spectra at 60, 75, and 120 kV, respectively. Therefore, it is recommended that the characterization of the shielding potential of a material should be done by measurements in broad-beam geometry. Since the secondary radiation that is mainly responsible for the shielding reduction in broad-beam geometry is of low penetrability, only more superficially located organs receive significantly enhanced doses. The increase for the dose to the glandular breast tissue (female) compared to being shielded by lead is 143%, 37%, and 45% when shielded by tin, and 35%, 15%, and 39% when shielded by tin/bismuth for 60, 75, and 120 kV, respectively. The effective dose rises by 60%, 6%, and 38% for tin, and 14%, 3% and, 35% for tin/bismuth shielding, respectively.

  6. Comparison between steel and lead shieldings for radiotherapy rooms regarding neutron doses to patients

    Energy Technology Data Exchange (ETDEWEB)

    Silva, M.G.; Rebello, W.F.; Andrade, E.R.; Medeiros, M.P.C.; Mendes, R.M.S.; Braga, K.L.; Gomes, R.G., E-mail: eng.cavaliere@gmail.com, E-mail: ggrprojetos@gmail.com [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil). Secao de Engenharia Nuclear; Silva, A.X., E-mail: ademir@con.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The NCRP Report No. 151, Structural Shielding Design and Evaluation for Megavoltage X- and Gamma-Ray Radiotherapy Facilities, considers, in shielding calculations for radiotherapy rooms, the use of lead and/or steel to be applied on bunker walls. The NCRP Report calculations were performed foreseeing a better protection of people outside the radiotherapy room. However, contribution of lead and steel to patient dose should be taken into account for radioprotection purposes. This work presents calculations performed by MCNPX code in analyzing the Ambient Dose Equivalent due to neutron, H *(10){sub n}, within a radiotherapy room, in the patients area, considering the use of additional shielding of 1 TVL of lead or 1 TVL of steel, positioned at the inner faces of walls and ceiling of a bunker. The head of the linear accelerator Varian 2100/2300 C/D was modeled working at 18MeV, with 5 x 5 cm{sup 2}, 10 x 10 cm{sup 2}, 20 x 20 cm{sup 2}, 30 x 30 cm{sup 2} and 40 x 40 cm{sup 2} openings for jaws and MLC and operating in eight gantry's angles. This study shows that the use of lead generates an average value of H *(10){sub n} at patients area, 8.02% higher than the expected when using steel. Further studies should be performed based on experimental data for comparison with those from MCNPX simulation. (author)

  7. Risk of therapy-related leukaemia and preleukaemia after Hodgkin's disease. Relation to age, cumulative dose of alkylating agents, and time from chemotherapy

    DEFF Research Database (Denmark)

    Pedersen-Bjergaard, J.; Specht, L.; Larsen, S.O.;

    1987-01-01

    .0% (SE 3.0) at 10 years after which time there were no further cases. Calculated from cessation of therapy with alkylating agents, however, the cumulative risk curve increased steeply during the first 1-2 years then gradually levelled out and no new cases were observed beyond 7 years. With a 15-year...

  8. Characterization of a lead breast shielding for dose reduction in computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Correia, Paula Duarte; Brochi, Marco Aurelio Corte; Azevedo-Marques, Paulo Mazzoncini de, E-mail: pauladuarte@usp.br [Universidade de Sao Paulo (FM/RSP), Ribeirao Preto, SP (Brazil). Faculdade de Medicina; Granzotti, Cristiano Roberto Fabri; Santos, Yago da Silva [Universidade de Sao Paulo (FFCLRP/RSP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras

    2014-07-15

    Objective: several studies have been published regarding the use of bismuth shielding to protect the breast in computed tomography (CT) scans and, up to the writing of this article, only one publication about barium shielding was found. The present study was aimed at characterizing, for the first time, a lead breast shielding. Materials and methods: the percentage dose reduction and the influence of the shielding on quantitative imaging parameters were evaluated. Dose measurements were made on a CT equipment with the aid of specific phantoms and radiation detectors. A processing software assisted in the qualitative analysis evaluating variations in average CT number and noise on images. Results: the authors observed a reduction in entrance dose by 30% and in CTDIvol by 17%. In all measurements, in agreement with studies in the literature, the utilization of cotton fiber as spacer object reduced significantly the presence of artifacts on the images. All the measurements demonstrated increase in the average CT number and noise on the images with the presence of the shielding. Conclusion: as expected, the data observed with the use of lead shielding were of the same order as those found in the literature about bismuth shielding. (author)

  9. Relation between treatment efficacy and cumulative dose of alpha interferon in chronic hepatitis B. European Concerted Action on Viral Hepatitis (Eurohep)

    DEFF Research Database (Denmark)

    Krogsgaard, K; Christensen, E; Bindslev, N;

    1996-01-01

    Alpha interferon (IFN) is an established treatment of chronic hepatitis B. The effect has been shown to be dose related, recommended dose regimens being associated with a doubling of the spontaneous, baseline HBeAg to anti-HBe seroconversion rate. However, the efficacy of IFN treatment in relation...

  10. Reduction of operator radiation dose by a pelvic lead shield during cardiac catheterization by radial access: comparison with femoral access.

    Science.gov (United States)

    Lange, Helmut W; von Boetticher, Heiner

    2012-04-01

    This study sought to determine the efficacy of patient pelvic lead shielding for the reduction of operator radiation exposure during cardiac catheterization via the radial access in comparison with the femoral access. Cardiac catheterization via the radial access is associated with significantly increased radiation dose to the patient and the operator. Improvements in radiation protection are needed to minimize this drawback. Pelvic lead shielding has the potential to reduce operator radiation dose. We randomly assigned 210 patients undergoing elective coronary angiography by the same operator to a radial and femoral access with and without pelvic lead shielding of the patient. Operator radiation dose was measured by a radiation dosimeter attached to the outside breast pocket of the lead apron. For radial access, operator dose decreased from 20.9 ± 13.8 μSv to 9.0 ± 5.4 μSv, p lead shielding. For femoral access, it decreased from 15.3 ± 10.4 μSv to 2.9 ± 2.7 μSv, p lead shielding significantly decreased the dose-area product-normalized operator dose (operator dose divided by the dose-area product) by the same amount for radial and femoral access (0.94 ± 0.28 to 0.39 ± 0.19 μSv × Gy(-1) × cm(-2) and 0.70 ± 0.26 to 0.16 ± 0.13 μSv × Gy(-1) × cm(-2), respectively). Pelvic lead shielding is highly effective in reducing operator radiation exposure for radial as well as femoral procedures. However, despite its use, radial access remains associated with a higher operator radiation dose. Copyright © 2012 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  11. An assessment of cumulative external doses from Chernobyl fallout for a forested area in Russia using the optically stimulated luminescence from quartz inclusions in bricks

    DEFF Research Database (Denmark)

    Ramzaev, V.; Bøtter-Jensen, Lars; Thomsen, Kristina Jørkov

    2008-01-01

    Optically stimulated luminescence (OSL) has been used for estimation of the accumulated doses in quartz inclusions obtained from two fired bricks, extracted in July 2004 from a building located in the forested surroundings of the recreational area Novie Bobovichi, the Bryansk Region, Russia...

  12. The Soft Cumulative Constraint

    CERN Document Server

    Petit, Thierry

    2009-01-01

    This research report presents an extension of Cumulative of Choco constraint solver, which is useful to encode over-constrained cumulative problems. This new global constraint uses sweep and task interval violation-based algorithms.

  13. Lead

    Science.gov (United States)

    ... found? Who is at risk? What are the health effects of lead? Get educational material about lead Get certified as a Lead Abatement Worker, or other abatement discipline Lead in drinking water Lead air pollution Test your child Check and maintain your home ...

  14. Effectiveness of pelvic lead blanket to reduce the doses to eye lens and hands of interventional cardiologists and assistant nurses.

    Science.gov (United States)

    Grabowicz, W; Domienik-Andrzejewska, J; Masiarek, K; Górnik, T; Grycewicz, T; Brodecki, M; Lubiński, A

    2017-09-01

    The aim of the present study is to analyse quantitatively the potential reduction of doses to the eye lens and the hands of an operator and a nurse by the use of a pelvic lead blanket during coronary angiography (CA) and percutaneous transluminal coronary angioplasty (PTCA) procedures. Thermoluminescent dosimeters were used to assess dose levels to the left eye lens and fingers on both hands of both physician and nurses during single procedures performed with or without the lead blanket. The measurements were carried out at one medical centre and include dosimetric data from 100 procedures. Additional measurements including physician's and patient's doses were made on phantoms in the laboratory. In order to determine the reduction potential of the lead blanket, the doses normalized to DAP (Dose-Area Product) corresponding to the same position of dosimeter were compared against each other for both procedure categories (with and without protection). There was no statistically significant decrease observed in physicians' and nurses' eye lens doses, nor in doses normalized to DAP due to the use of the lead pelvic shield in clinic. However, some trend in reducing the eye lens doses by this shield can be observed. Regarding finger doses, the differences are statistically significant but only for physicians. The mean DAP-normalised doses to the eye lens and left and right finger of physicians, in the presence of a ceiling-suspended transparent lead shield, were 2.24e-5 ± 1.41e-5 mSv/μGym(2), 2.31e-4 ± 1.21e-4 mSv/μGym(2), and 2.60e-5 ± 1.57e-5 mSv/μGym(2) for standard procedures performed without the lead blanket, and 1.77e-5 ± 1.17e-5 mSv/μGym(2), 1.70e-4 ± 1.01e-4 mSv/μGym(2), and 1.86e-5 ± 1.13e-5 mSv/μGym(2) for procedures performed with it. A comparison of the results from the laboratory and the clinic shows that they are consistent regarding the eye lens, while for fingers it suggests that the dose reduction properties of the lead shield are related to

  15. A comparison of dose savings of lead and lightweight aprons for shielding of 99m-Technetium radiation.

    Science.gov (United States)

    Warren-Forward, Helen; Cardew, Paul; Smith, Bradley; Clack, Llewellyn; McWhirter, Kym; Johnson, Stacey; Wessel, Kimberly

    2007-01-01

    Nuclear medicine technologists (NMTs) have the highest effective doses of radiation among medical workers. With increase in the use of lightweight materials in diagnostic radiography, the aim was to compare the effectiveness of lead and lightweight aprons in shielding from 99m-Technetium ((99m)Tc) gamma rays. The doses received from a scattering phantom to the entrance, 9cm depth and exit of a phantom were measured with LiF:Mg, Cu, P thermoluminescent dosemeters (TLDs). Doses and spectra were assessed without no shielding, with 0.5-mm lead and lightweight aprons. The lead and lightweight aprons decreased entrance surface doses by 76 and 59%, respectively. The spectral analysis showed that the lightweight apron provided better dose reduction at energies lead was 35% more efficient at higher energies. While lead apron demonstrated better shielding, the additional savings should be considered with the weight differential. It is concluded that the lightweight apron is suitable to be worn by NMTs interacting with patients injected with a (99m)Tc labelled radiopharmaceutical.

  16. Experience in Wales (UK) of the optimisation of ortho-phosphate dosing for controlling lead in drinking water.

    Science.gov (United States)

    Hayes, C R; Incledion, S; Balch, M

    2008-06-01

    Dwr Cymru Welsh Water supplies over three million people with drinking water throughout most of Wales (UK). Ortho-phosphate has increasingly been dosed at around 1 mg/L (P) to further reduce the corrosivity of supplies to the lead pipes which connect approximately 30% of houses to water mains in the company's area, additional to long-establish pH adjustment measures. The installation of new ortho-phosphate dosing schemes and the optimisation of these and existing dosing schemes, 29 schemes in total, were subject to a regulatory programme of work, agreed with the Drinking Water Inspectorate (DWI). Optimisation comprised (i) selection of appropriate ortho-phosphate doses by a procedure involving laboratory based plumbosolvency testing linked to zonal lead emission (compliance) modelling, (ii) tight dose control and (iii) extensive monitoring of lead in supply by random daytime (RDT) sampling and by the use of lead pipe test rigs. The successful outcome was confirmed by 99% of over 5,000 RDT samples complying with the future standard of 10 microg/L for lead in drinking water.

  17. A New Design of a Lead-Acrylic Shield for Staff Dose Reduction in Radial and Femoral Access Coronary Catheterization.

    Science.gov (United States)

    Eder, H; Seidenbusch, M C; Treitl, M; Gilligan, P

    2015-10-01

    Today's standard radiation protection during coronary angiography and percutaneous coronary interventions is the combined use of lead acrylic shields and table-mounted lower body protection. Ambient dose measurements, however, have shown that these protection devices need improvement. Using an anthropomorphic physical phantom, various scenarios were investigated with respect to personnel exposure: a) enlarging the shield b) adding a flexible protective curtain to the bottom side of the shield, and c) application of radioprotective patient drapes. For visualization of the dose reduction effect, Monte Carlo simulations were performed. The flexible curtain in contact with the patient's body reduces the ambient dose rate at the operator's position by up to (87.5% ± 7.1) compared to the situation with the bare shield. The use of both the flexible curtain and the patient drape reduces the ambient dose rate by up to (90.8% ± 7). Similar results were achieved for the assisting personnel when they were positioned next to the operator. In addition, the enlarged shield provides better protection of the head region of tall operators. Adding a flexible protective curtain to the bottom side of the shield can protect operators from high doses, especially for body parts which are not protected by lead aprons, e.g. head, and eye lenses. This may be important with respect to lower dose limits for eye lenses in future. The protective effect in real-life working conditions is still being evaluated in an ongoing clinical study. Lead acrylic shields need improvement for a better protection of head and eye lenses. An additional flexible lead curtain at the bottom of the shield can considerably reduce the operator dose. Using the additional lead curtain, lighter protection clothing can be worn. Special eye protection may be no longer needed in most applications. © Georg Thieme Verlag KG Stuttgart · New York.

  18. Lead versus bismuth-antimony shield for fetal dose reduction at different gestational ages at CT pulmonary angiography.

    Science.gov (United States)

    Chatterson, Leslie C; Leswick, David A; Fladeland, Derek A; Hunt, Megan M; Webster, Stephen T

    2011-08-01

    To compare the effective fetal dose reduction at different stages of gestation during maternal computed tomographic (CT) pulmonary angiography by using traditional lead apron and bismuth-antimony shields combined with limited z-axis and tube current. Phantom with gravid prosthesis, 0.5-mm lead, and two grades of bismuth-antimony shield was used. Thermoluminescent dosimeters (TLDs) measured radiation in the first- to third-trimester uterus. Fetal dose was determined for each gestation by using 100 kVp to the costophrenic angles (CPAs) with and without shielding for a total of 12 scans. Eight third-trimester scans were used to compare shields using 120 kVp to CPAs versus those using 100 kVp to the diaphragm. Average fetal dose increased with gestation with use of 100 kVp to CPAs, from 0.11 mGy in first trimester to 0.50 mGy in third trimester. Average third-trimester unshielded fetal dose was reduced from 0.82 mGy by using 120 kVp to CPAs to 0.17 mGy (79%, P Lead apron reduced dose more than either of the bismuth-antimony shields (72%-79% vs 57%-81%) with use of 100 kVp to CPAs. Shields reduced the dose by 73% (lead), 62% (90% attenuation bismuth-antimony), and 72% (95% attenuation bismuth-antimony) (P shields was demonstrated with 100 kVp to the diaphragm (P shields at reducing fetal dose. Shielding improves reduction with no significant difference between lead and bismuth-antimony shields when conservative scanning parameters are observed. © RSNA, 2011.

  19. Persistent increase of blood lead level and suppression of δ-ALAD activity in northern bobwhite quail orally dosed with even a single 2-mm spent lead shot.

    Science.gov (United States)

    Holladay, S D; Kerr, R; Holladay, J P; Meldrum, B; Williams, S M; Gogal, R M

    2012-10-01

    Birds that display grit ingestion behavior are potentially at risk of lead (Pb) poisoning from mistaken ingestion of spent Pb shot pellets. The majority of available studies designed to assess such risk have used unspent shot pellets rather than field-obtained spent shot, which is oxidized and otherwise changed by weathering. Available studies also often administered more or heavier shot pellets to a bird than it might be expected to ingest. The current study dosed northern bobwhite quail (Colinus virginianus) weighing 194.6 ± 23.1 g (female birds) and 199.3 ± 12.2 g (male birds) with one to three spent no. 9 Pb shot collected from a skeet range, with particular interest in the toxicity that may occur from ingestion of a single 2-mm, 50 mg shot. An 8 week post-dosing clinical observation period was employed, over which feed consumption, body weight, blood Pb levels, and a battery of blood physiological parameters were made. Weight loss occurred in the birds, including male birds dosed with one Pb pellet. Erythrocyte delta aminolevulinic acid dehydratase (δ-ALAD) levels were decreased for the duration of the study across exposures and to levels associated with injury in wild bird populations. Decreased ALAD was particularly severe in female birds dosed with one Pb pellet and was still 92 % decreased at 8 weeks after dosing. Together, these results suggest that inadvertent ingestion of a single no. 9 Pb shot pellet can adversely affect the health of northern bobwhite quail.

  20. Influence of the lead ions and low dose radiation on the catalase activity in the maize germinant

    Directory of Open Access Journals (Sweden)

    O. M. Vasilyuk

    2006-02-01

    Full Text Available The experimental results of changes of the catalase activity in the maize germinants under the influence of the lead ions and low doses of radiation separately and simultaneously are presented. The consentration of the lead was 1 · 10 – 4 M and the radiation dozes were 2, 5, 10, and 15 R.

  1. UBIQUITOUS POLLUTANTS FROM CUMULATIVE ...

    Science.gov (United States)

    The occurrence of pharmaceuticals and personal care products (PPCPS) as environmental pollutants is a multifaceted issue whose scope continues to become better delineated since the escalation of concerted attention beginning in the 1980s. PPCPs typically occur as trace environmental pollutants (primarily in surface but also in ground waters) as a result of their widespread, continuous, combined usage in a broad range of human and veterinary therapeutic activities and practices. With respect to the risk-assessment paradigm, the growing body of published work has focused primarily on the origin and occurrence of these substances. Comparatively less is known about human and ecological exposure, and even less about the known or even potential hazards associated with exposure to these anthropogenic substances, many of which are highly bioactive. The continually growing, worldwide importance of freshwater resources underscores the need for ensuring that any aggregate or cumulative impacts on water supplies and resultant potential for human or ecological exposure be minimized. This has prompted the more recent investigations on waste treatment processes for one of the major sources of environmental disposition, namely sewage. Despite the paucity of health effects data for long-term, simultaneous exposure to multiple xenobiotics (particularly PPCPS) at low doses (a major toxicological issue that can be described by the

  2. Cumulative mortality rates in Aedes polynesiensis after feeding on polynesian Wuchereria bancrofti carriers treated with single doses of ivermectin, diethylcarbamazine and placebo.

    Science.gov (United States)

    Cartel, J L; Sechan, Y; Spiegel, A; Nguyen, L; Barbazan, P; Martin, P M; Roux, J F

    1991-12-01

    During a therapeutic trial, batches of 672 to 1979 laboratory-bred Aedes polynesiensis, the mosquito vector of lymphatic filariasis in French Polynesia, were fed on Wuchereria bancrofti carriers one, three and six months after they had been treated with either single doses of ivermectin at 100 mcg/kg, diethylcarbamazine (DEC) at 3 and 6 mg/kg or placebo. High mortality rates were observed during the 15-day period following the blood-meal in mosquitoes fed on carriers treated with microfilaricidal drugs and were significantly higher in mosquitoes fed on carriers treated with ivermectin than in those fed on carriers treated with DEC. Though its intensity decreased with the passage of time, the phenomenon was observed in mosquitoes fed on carriers up to six months after treatment, especially in those fed on carriers treated with ivermectin. By decreasing the number of mosquitoes able to transmit the infection, this lethal effect on Ae. polynesiensis might represent an additional advantage of ivermectin in lymphatic filariasis control programs.

  3. Co-administration of morphine and gabapentin leads to dose dependent synergistic effects in a rat model of postoperative pain.

    Science.gov (United States)

    Papathanasiou, Theodoros; Juul, Rasmus Vestergaard; Heegaard, Anne-Marie; Kreilgaard, Mads; Lund, Trine Meldgaard

    2016-01-20

    Despite much evidence that combination of morphine and gabapentin can be beneficial for managing postoperative pain, the nature of the pharmacological interaction of the two drugs remains unclear. The aim of this study was to assess the interaction of morphine and gabapentin in range of different dose combinations and investigate whether co-administration leads to synergistic effects in a preclinical model of postoperative pain. The pharmacodynamic effects of morphine (1, 3 and 7mg/kg), gabapentin (10, 30 and 100mg/kg) or their combination (9 combinations in total) were evaluated in the rat plantar incision model using an electronic von Frey device. The percentage of maximum possible effect (%MPE) and the area under the response curve (AUC) were used for evaluation of the antihyperalgesic effects of the drugs. Identification of synergistic interactions was based on Loewe additivity response surface analyses. The combination of morphine and gabapentin resulted in synergistic antihyperalgesic effects in a preclinical model of postoperative pain. The synergistic interactions were found to be dose dependent and the increase in observed response compared to the theoretical additive response ranged between 26 and 58% for the synergistic doses. The finding of dose-dependent synergistic effects highlights that choosing the right dose-dose combination is of importance in postoperative pain therapy. Our results indicate benefit of high doses of gabapentin as adjuvant to morphine. If these findings translate to humans, they might have important implications for the treatment of pain in postoperative patients.

  4. Low blood lead level effects on intelligence: can a dose-response curve be determined from the epidemiological data?

    Science.gov (United States)

    Banner, W; Kahn, C M

    2014-02-01

    CONTEXT. Recent publications have graphically demonstrated a curvilinear relationship between measures of intelligence and blood lead levels at low concentrations (dose-response curves. METHODS. Random data based on varied distributions were constructed to simulate a previous study using a single, randomly generated covariate income (Inc) to demonstrate the impact of normally versus exponentially distributed data on the shape of the graph of intelligence quotient (IQ) versus blood lead. We also used an existing database of US blood lead levels and constructed a similar model of income and IQ using both assumptions of distribution for the intermediate variable income. RESULTS. When both lead and income are exponentially distributed, the graph of lead and IQ will be a curve. CONCLUSION. The apparent shape of a dose-response relationship from simulated epidemiological data is nonlinear when one variable and a covariate are exponentially distributed. A non-linear biological relationship should not be assumed and in fact may be the least likely explanation. The use of observational epidemiological data to discern a dose-response relationship between two variables may be misleading.

  5. Lead

    Science.gov (United States)

    ... Chapter 6 Chapter 7 Chapter 8 Chapter 9 Appendix I Appendix II Tables Figures State Programs Alabama Alaska Arizona ... Tool Kit Resources Healthy Homes and Lead Poisoning Prevention Training Center (HHLPPTC) Training Tracks File Formats Help: ...

  6. Current modeling practice may lead to falsely high benchmark dose estimates.

    Science.gov (United States)

    Ringblom, Joakim; Johanson, Gunnar; Öberg, Mattias

    2014-07-01

    Benchmark dose (BMD) modeling is increasingly used as the preferred approach to define the point-of-departure for health risk assessment of chemicals. As data are inherently variable, there is always a risk to select a model that defines a lower confidence bound of the BMD (BMDL) that, contrary to expected, exceeds the true BMD. The aim of this study was to investigate how often and under what circumstances such anomalies occur under current modeling practice. Continuous data were generated from a realistic dose-effect curve by Monte Carlo simulations using four dose groups and a set of five different dose placement scenarios, group sizes between 5 and 50 animals and coefficients of variations of 5-15%. The BMD calculations were conducted using nested exponential models, as most BMD software use nested approaches. "Non-protective" BMDLs (higher than true BMD) were frequently observed, in some scenarios reaching 80%. The phenomenon was mainly related to the selection of the non-sigmoidal exponential model (Effect=a·e(b)(·dose)). In conclusion, non-sigmoid models should be used with caution as it may underestimate the risk, illustrating that awareness of the model selection process and sound identification of the point-of-departure is vital for health risk assessment.

  7. New topology for soft switching converters: realization of a 2 kW converter which can operate under cumulated radiation doses comprised between 1 and 10 mega-rads; Nouvelle topologie de convertisseur a commutation douce: realisation d'un convertisseur 2 kW fonctionnant pour des doses de rayonnement cumulees comprises entre 1 et 10 Mega-rads

    Energy Technology Data Exchange (ETDEWEB)

    Marceau, M. [CEA/Saclay, Dept. d' Electronique et d' Instrumentation Nucleaire (DEIN), 91 - Gif-sur-Yvette (France); Huillet, H.; Ploquin, D. [Gaia Converter, 33 - Merignac (France)

    1998-11-01

    This paper presents a new topology of a patented power converter. This topology applies to DC-DC converters with soft switching operation. The power density reached is of about 4000 W/liter and the efficiency is greater than 90%. This converter, devoted to nuclear applications, has been dimensioned to be able to operate under cumulated radiation doses greater than 1 Mega rads. A functioning principle scheme and a brief description of the topology is reported in this short paper. (J.S.)

  8. Enteric coating can lead to reduced antiplatelet effect of low-dose acetylsalicylic acid

    DEFF Research Database (Denmark)

    Fentz Haastrup, Peter; Grønlykke, Thor; Jarbøl, Dorte Ejg

    2015-01-01

    Low-dose acetylsalicylic acid (ASA) is widely used as antithrombotic prophylaxis. Enteric coated ASA has been developed in order to decrease the risk of gastrointestinal side effects. The consequences of enteric coating on pharmacokinetics and antiplatelet effect of ASA have not systematically been...

  9. A new design of a lead-acrylic shield for staff dose reduction in radial and femoral access coronary catheterization

    Energy Technology Data Exchange (ETDEWEB)

    Eder, H. [Deptartment of Radiation Protection (Germany); Seidenbusch, M.C.; Treitl, M. [Muenchen Univ. Clinical Center (Germany). Inst. for Clinical Radiology; Gilligan, P. [Mater Private Hospital, Dublin (Ireland). Medical Physics

    2015-10-15

    Today's standard radiation protection during coronary angiography and percutaneous coronary interventions is the combined use of lead acrylic shields and table-mounted lower body protection. Ambient dose measurements, however, have shown that these protection devices need improvement. Using an anthropomorphic physical phantom, various scenarios were investigated with respect to personnel exposure: (a) enlarging the shield (b) adding a flexible protective curtain to the bottom side of the shield, and (c) application of radioprotective patient drapes. For visualization of the dose reduction effect, Monte Carlo simulations were performed. The flexible curtain in contact with the patient's body reduces the ambient dose rate at the operator's position by up to (87.5 % ± 7.1) compared to the situation with the bare shield. The use of both the flexible curtain and the patient drape reduces the ambient dose rate by up to (90.8 % ± 7). Similar results were achieved for the assisting personnel when they were positioned next to the operator. In addition, the enlarged shield provides better protection of the head region of tall operators. Adding a flexible protective curtain to the bottom side of the shield can protect operators from high doses, especially for body parts which are not protected by lead aprons, e.g. head, and eye lenses. This may be important with respect to lower dose limits for eye lenses in future. The protective effect in real-life working conditions is still being evaluated in an ongoing clinical study.

  10. Increasing signal intensity within the dentate nucleus and globus pallidus on unenhanced T1W magnetic resonance images in patients with relapsing-remitting multiple sclerosis: correlation with cumulative dose of a macrocyclic gadolinium-based contrast agent, gadobutrol

    Energy Technology Data Exchange (ETDEWEB)

    Stojanov, Dragan A. [University of Nis, Faculty of Medicine, Nis (Serbia); Clinical Center Nis, Center for Radiology, Nis (Serbia); Aracki-Trenkic, Aleksandra [Clinical Center Nis, Center for Radiology, Nis (Serbia); Vojinovic, Slobodan; Ljubisavljevic, Srdjan [University of Nis, Faculty of Medicine, Nis (Serbia); Clinical Center Nis, Clinic for Neurology, Nis (Serbia); Benedeto-Stojanov, Daniela [University of Nis, Faculty of Medicine, Nis (Serbia)

    2016-03-15

    To evaluate correlation between cumulative dose of gadobutrol and signal intensity (SI) within dentate nucleus and globus pallidus on unenhanced T1-weighted images in patients with relapsing-remitting multiple sclerosis (RRMS). Dentate nucleus-to-pons and globus pallidus-to-thalamus SI ratios, and renal and liver functions, were evaluated after multiple intravenous administrations of 0.1 mmol/kg gadobutrol at 27, 96-98, and 168 weeks. We compared SI ratios based on the number of administrations, total amount of gadobutrol administered, and time between injections. Globus pallidus-to-thalamus (p = 0.025) and dentate nucleus-to-pons (p < 0.001) SI ratios increased after multiple gadobutrol administrations, correlated with the number of administrations (ρ = 0.263, p = 0.046, respectively) and depended on the length of administration (p = 0.017, p = 0.037, respectively). Patients receiving gadobutrol at 27 weeks showed the greatest increase in both SI ratios (p = 0.006; p = 0.014, respectively, versus 96-98 weeks). GGT increased at the end of the study (p = 0.004). In patients with RRMS, SI within the dentate nucleus and globus pallidus increased on unenhanced T1-weighted images after multiple gadobutrol injections. Administration of the same total amount of gadobutrol over a shorter period caused greater SI increase. (orig.)

  11. Cumulant expansions for atmospheric flows

    CERN Document Server

    Ait-Chaalal, Farid; Meyer, Bettina; Marston, J B

    2015-01-01

    The equations governing atmospheric flows are nonlinear, and consequently the hierarchy of cumulant equations is not closed. But because atmospheric flows are inhomogeneous and anisotropic, the nonlinearity may manifests itself only weakly through interactions of mean fields with disturbances such as thermals or eddies. In such situations, truncations of the hierarchy of cumulant equations hold promise as a closure strategy. We review how truncations at second order can be used to model and elucidate the dynamics of turbulent atmospheric flows. Two examples are considered. First, we study the growth of a dry convective boundary layer, which is heated from below, leading to turbulent upward energy transport and growth of the boundary layer. We demonstrate that a quasilinear truncation of the equations of motion, in which interactions of disturbances among each other are neglected but interactions with mean fields are taken into account, can successfully capture the growth of the convective boundary layer. Seco...

  12. Blood Lead Concentration Is Not Altered by High Dose Vitamin D Supplementation in Children and Young Adults with HIV

    Science.gov (United States)

    Groleau, Veronique; Herold, Rachel A; Schall, Joan I; Wagner, Julia L; Dougherty, Kelly A; Zemel, Babette S; Rutstein, Richard M; Stallings, Virginia A

    2014-01-01

    OBJECTIVES Optimal vitamin D status is known to have beneficial health effects and vitamin D supplements are commonly used. It has been suggested that vitamin D supplementation may increase blood lead in children and adults with previous lead exposure. The objective was to determine the safety regarding lead toxicity during 12 weeks of high dose vitamin D3 supplementation in children and young adults with HIV. METHODS Subjects with HIV (age 8 to 24 yrs) were randomized to vitamin D3 supplementation of 4000 IU/day or 7000 IU/day and followed at 6 and 12 weeks for changes in 25D and whole blood lead concentration. This was a secondary analysis of a larger study of vitamin D3 supplementation in children and adolescents with HIV. RESULTS In 44 subjects (75% African American), the baseline mean ± SD serum 25D was 48.3 ± 18.6 nmol/L. 50% of subjects had baseline serum 25D 5.0 μg/dL at baseline or during subsequent visits. Whole blood lead and 25D were not correlated at baseline, and were negatively correlated after 12 weeks of supplementation (p= 0.014). Whole blood lead did not differ between those receiving 4000 IU versus 7000 IU of vitamin D3. CONCLUSION High dose vitamin D3 supplementation and the concomitant increased serum 25D did not result in increased whole blood lead concentration in this sample of children and young adults living in a northeastern urban city. PMID:23059649

  13. Ozone Inhalation Leads to a Dose-Dependent Increase of Cytogenetic Damage in Human Lymphocytes

    Science.gov (United States)

    Holland, Nina; Davé, Veronica; Venkat, Subha; Wong, Hofer; Donde, Aneesh; Balmes, John R; Arjomandi, Mehrdad

    2014-01-01

    Ozone is an important constituent of ambient air pollution and represents a major public health concern. Oxidative injury due to ozone inhalation causes the generation of reactive oxygen species and can be genotoxic. To determine whether ozone exposure causes genetic damage in peripheral blood lymphocytes, we employed a well-validated cytokinesis-block micronucleus Cytome assay. Frequencies of micronuclei (MN) and nucleoplasmic bridges (NB) were used as indicators of cytogenetic damage. Samples were obtained from 22 non-smoking healthy subjects immediately before and 24-hr after controlled 4-hr exposures to filtered air, 100 ppb, and 200 ppb ozone while exercising in a repeated-measure study design. Inhalation of ozone at different exposure levels was associated with a significant dose-dependent increase in MN frequency (P < 0.0001) and in the number of cells with more than 1 MN per cell (P < 0.0005). Inhalation of ozone also caused an increase in the number of apoptotic cells (P = 0.002). Airway neutrophilia was associated with an increase in MN frequency (P = 0.033) independent of the direct effects of ozone exposure (P < 0.0001). We also observed significant increases in both MN and NB frequencies after exercise in filtered air, suggesting that physical activity is also an important inducer of oxidative stress. These results corroborate our previous findings that cytogenetic damage is associated with ozone exposure, and show that damage is dose-dependent. Further study of ozone-induced cytogenetic damage in airway epithelial cells could provide evidence for the role of oxidative injury in lung carcinogenesis, and help to address the potential public health implications of exposures to oxidant environments. PMID:25451016

  14. Psychiatric epidemiologic study of occupational lead exposure

    Energy Technology Data Exchange (ETDEWEB)

    Parkinson, D.K.; Ryan, C.; Bromet, E.J.; Connell, M.M.

    1986-02-01

    The association of occupational lead exposure with neuropsychiatric functioning was evaluated using data collected in 1982 in eastern Pennsylvania from 288 lead-exposed workers and 181 nonexposed subjects. Both current and cumulative exposure indices were used. After controlling for age, education, and income, few meaningful differences between exposed and control workers were found on either neuropsychologic or psychosocial variables. Dose-response analyses indicated that among lead-exposed workers, cumulative and current exposure were unrelated to neuropsychologic performance. The only meaningful associations occurred between exposure and level of conflict in interpersonal relationships. The results thus give evidence against hypotheses suggesting adverse neuropsychologic effects.

  15. Usefulness of a lead shielding device for reducing the radiation dose to tissues outside the primary beams during CT.

    Science.gov (United States)

    Chung, Jae-Joon; Cho, Eun-Suk; Kang, Sung Min; Yu, Jeong-Sik; Kim, Dae Jung; Kim, Joo Hee

    2014-12-01

    This study was done to investigate the efficacy of a lead shield in protecting the tissues outside the primary beams, such as the breast and thyroid, by measurement of the entrance skin dose during CT of the brain, neck, abdomen, and lumbar spine. Institutional Review Board approval was obtained. This study included 150 patients (male:female 25:125, age range 15-45 years). In females, brain, lumbar spine, and abdominal CT scans, pre-/post-contrast neck CT scans, and post-contrast liver dynamic CT scans were performed. In males, brain CT scans only were performed. Breast shielding was performed in all females, and thyroid shielding was conducted in patients with brain CT. During all CT studies, the left breast or left thyroid was shielded using a lead shield, and the contralateral side was left unshielded. Thus, each breast or thyroid measurement had its own control for the same demographic data. The efficacy of the shielding of both breasts and thyroids during CT was assessed. During brain, abdominal, lumbar, pre-/post-contrast neck, and post-contrast liver dynamic CT, 33.5, 26.0, 17.4, 26.5, and 16.2 % of the breast skin dose were reduced, respectively. During brain CT, the thyroid skin dose was reduced by 17.9 % (females) and 20.6 % (males). There were statistically significant differences in the skin doses of shielded organs (p shielding during neck and liver dynamic CT was the most effective compared with breast or thyroid shielding during other CT scans. We recommend breast shielding during neck and liver dynamic CT in young female patients to avoid unnecessary radiation exposure.

  16. "Buddha's Light" of Cumulative Particles

    CERN Document Server

    Kopeliovich, Vladimir B; Potashnikova, Irina K

    2014-01-01

    We show analytically that in the cumulative particles production off nuclei multiple interactions lead to a glory-like backward focusing effect. Employing the small phase space method we arrived at a characteristic angular dependence of the production cross section $d\\sigma \\sim 1/ \\sqrt {\\pi - \\theta}$ near the strictly backward direction. This effect takes place for any number $n\\geq 3 $ of interactions of rescattered particle, either elastic or inelastic (with resonance excitations in intermediate states), when the final particle is produced near corresponding kinematical boundary. Such a behaviour of the cross section near the backward direction is in qualitative agreement with some of available data.

  17. [Efficacy of a self-designed protective lead shield in reduction of radiation exposure dose during endoscopic retrograde cholangiopancreatography].

    Science.gov (United States)

    Kim, Yun Jung; Cho, Kwang Bum; Kim, Eun Soo; Park, Kyung Sik; Jang, Byoung Kuk; Chung, Woo Jin; Hwang, Jae Seok

    2011-01-01

    The increasing use of diagnostic and therapeutic endoscopic retrograde cholangiopancreatography (ERCP) calls for greater consideration of radiation exposure risk to endoscopists and assistants, and emphasizes the proper system of radiation protection. This study was designed to assess the effect of a newly developed, self-designed, protective lead shield. A curtain-shaped protective shield composed of seven movable lead plates was developed, each with the following dimensions: depth, 0.1 cm; width, 15 cm; length, 70 cm. The curtain-shaped protective shield was designed to be located between the patient and the endoscopist. Twenty-nine patients (11 men and 18 women) undergoing ERCP between January 2010 and March 2010 were selected for this study. The dose of radiation exposure was recorded with or without the protective lead shield at the level of the head, chest, and pelvis. The measurement was made at 50 cm and 150 cm from the radiation source. The mean patient age was 64 years. The mean patient height and weight was 161.7+/-6.9 cm and 58.9+/-9.9 kg, respectively. The mean body mass index (BMI) was 22.5+/-3.0 kg/m2. Endoscopists received 1522.2+/-537.0 mR/hr without the protective lead shield. At the same distance, radiation exposure was significantly reduced to 68.8+/-88.0 mR/hr with the protective lead shield (p-value>0.0001). The radiation exposure to endoscopists and assistants was significantly reduced by the use of a protective lead shield (p value >0.0001). The amount of radiation exposure during ERCP was related to the patient's BMI (r=0.749, p=0.001). This self-designed, protective lead shield is effective in protecting endoscopists and assistants from radiation exposure.

  18. Cumulative fatigue damage models

    Science.gov (United States)

    Mcgaw, Michael A.

    1988-01-01

    The problem of calculating expected component life under fatigue loading conditions is complicated by the fact that component loading histories contain, in many cases, cyclic loads of widely varying amplitudes. In such a case a cumulative damage model is required, in addition to a fatigue damage criterion, or life relationship, in order to compute the expected fatigue life. The traditional cumulative damage model used in design is the linear damage rule. This model, while being simple to use, can yield grossly unconservative results under certain loading conditions. Research at the NASA Lewis Research Center has led to the development of a nonlinear cumulative damage model, named the double damage curve approach (DDCA), that has greatly improved predictive capability. This model, which considers the life (or loading) level dependence of damage evolution, was applied successfully to two polycrystalline materials, 316 stainless steel and Haynes 188. The cumulative fatigue behavior of the PWA 1480 single-crystal material is currently being measured to determine the applicability of the DDCA for this material.

  19. In Utero Exposure to Low Doses of Bisphenol A Lead to Long-term Deleterious Effects in the Vagina

    Directory of Open Access Journals (Sweden)

    G. Schönfelder

    2002-01-01

    Full Text Available The origins of the “endocrine disrupter hypothesis” may be traced to reports on adolescent daughters born to women who had taken the highly potent synthetic estrogen, diethylstilbestrol, while pregnant, and who developed a rare form of vaginal cancer and adenocarcinoma. Bisphenol A (BPA is an estrogenic chemical that is highly employed in the manufacture of a wide range of consumer products. Some observational studies have suggested that the amounts of BPA to which we are exposed could alter the reproductive organs of developing rodents. We examined the influence of BPA at low doses to address the questions of (a whether in utero exposure affects the vagina of the offspring and (b which mechanisms cause the toxic effects. Gravid Sprague-Dawley dams were administered either 0.1 (low dose or 50 mg/kg per day BPA, the no observed effect level, or 0.2 mg/kg per day 17αethinyl estradiol by gavage. Striking morphological changes were observed in the vagina of postpubertal offspring leading us to examine vaginal estrogen receptor (ER expression because BPA binds to the ERα, which is important for growth of the vaginal epithelium. We show that the full-length ERα is not expressed during estrus in the vagina of female offspring exposed to either dose of BPA when compared to the control group, whereas ERα expression does not differ from the control group during the diestrus stage. ERa downregulation seems to be responsible for the observed altered vaginal morphology.

  20. Cumulative Paired φ-Entropy

    Directory of Open Access Journals (Sweden)

    Ingo Klein

    2016-07-01

    Full Text Available A new kind of entropy will be introduced which generalizes both the differential entropy and the cumulative (residual entropy. The generalization is twofold. First, we simultaneously define the entropy for cumulative distribution functions (cdfs and survivor functions (sfs, instead of defining it separately for densities, cdfs, or sfs. Secondly, we consider a general “entropy generating function” φ, the same way Burbea et al. (IEEE Trans. Inf. Theory 1982, 28, 489–495 and Liese et al. (Convex Statistical Distances; Teubner-Verlag, 1987 did in the context of φ-divergences. Combining the ideas of φ-entropy and cumulative entropy leads to the new “cumulative paired φ-entropy” ( C P E φ . This new entropy has already been discussed in at least four scientific disciplines, be it with certain modifications or simplifications. In the fuzzy set theory, for example, cumulative paired φ-entropies were defined for membership functions, whereas in uncertainty and reliability theories some variations of C P E φ were recently considered as measures of information. With a single exception, the discussions in the scientific disciplines appear to be held independently of each other. We consider C P E φ for continuous cdfs and show that C P E φ is rather a measure of dispersion than a measure of information. In the first place, this will be demonstrated by deriving an upper bound which is determined by the standard deviation and by solving the maximum entropy problem under the restriction of a fixed variance. Next, this paper specifically shows that C P E φ satisfies the axioms of a dispersion measure. The corresponding dispersion functional can easily be estimated by an L-estimator, containing all its known asymptotic properties. C P E φ is the basis for several related concepts like mutual φ-information, φ-correlation, and φ-regression, which generalize Gini correlation and Gini regression. In addition, linear rank tests for scale that

  1. Cumulative radiation exposure in children with cystic fibrosis.

    LENUS (Irish Health Repository)

    O'Reilly, R

    2010-02-01

    This retrospective study calculated the cumulative radiation dose for children with cystic fibrosis (CF) attending a tertiary CF centre. Information on 77 children with a mean age of 9.5 years, a follow up time of 658 person years and 1757 studies including 1485 chest radiographs, 215 abdominal radiographs and 57 computed tomography (CT) scans, of which 51 were thoracic CT scans, were analysed. The average cumulative radiation dose was 6.2 (0.04-25) mSv per CF patient. Cumulative radiation dose increased with increasing age and number of CT scans and was greater in children who presented with meconium ileus. No correlation was identified between cumulative radiation dose and either lung function or patient microbiology cultures. Radiation carries a risk of malignancy and children are particularly susceptible. Every effort must be made to avoid unnecessary radiation exposure in these patients whose life expectancy is increasing.

  2. A low-protein diet combined with low-dose endotoxin leads to changes in glucose homeostasis in weanling rats.

    Science.gov (United States)

    Bandsma, Robert H J; Ackerley, Cameron; Koulajian, Khajag; Zhang, Ling; van Zutphen, Tim; van Dijk, Theo H; Xiao, Changting; Giacca, Adria; Lewis, Gary F

    2015-09-01

    Severe malnutrition is a leading cause of global childhood mortality, and infection and hypoglycemia or hyperglycemia are commonly present. The etiology behind the changes in glucose homeostasis is poorly understood. Here, we generated an animal model of severe malnutrition with and without low-grade inflammation to investigate the effects on glucose homeostasis. Immediately after weaning, rats were fed diets containing 5 [low-protein diet (LP)] or 20% protein [control diet (CTRL)], with or without repeated low-dose intraperitoneal lipopolysaccharide (LPS; 2 mg/kg), to mimic inflammation resulting from infections. After 4 wk on the diets, hyperglycemic clamps or euglycemic hyperinsulinemic clamps were performed with infusion of [U-(13)C6]glucose and [2-(13)C]glycerol to assess insulin secretion, action, and hepatic glucose metabolism. In separate studies, pancreatic islets were isolated for further analyses of insulin secretion and islet morphometry. Glucose clearance was reduced significantly by LP feeding alone (16%) and by LP feeding with LPS administration (43.8%) compared with control during the hyperglycemic clamps. This was associated with a strongly reduced insulin secretion in LP-fed rats in vivo as well as ex vivo in islets but signficantly enhanced whole body insulin sensitivity. Gluconeogenesis rates were unaffected by LP feeding, but glycogenolysis was higher after LP feeding. A protein-deficient diet in young rats leads to a susceptibility to low-dose endotoxin-induced impairment in glucose clearance with a decrease in the islet insulin secretory pathway. A protein-deficient diet is associated with enhanced peripheral insulin sensitivity but impaired insulin-mediated suppression of hepatic glycogenolysis.

  3. Human cumulative culture: a comparative perspective.

    Science.gov (United States)

    Dean, Lewis G; Vale, Gill L; Laland, Kevin N; Flynn, Emma; Kendal, Rachel L

    2014-05-01

    Many animals exhibit social learning and behavioural traditions, but human culture exhibits unparalleled complexity and diversity, and is unambiguously cumulative in character. These similarities and differences have spawned a debate over whether animal traditions and human culture are reliant on homologous or analogous psychological processes. Human cumulative culture combines high-fidelity transmission of cultural knowledge with beneficial modifications to generate a 'ratcheting' in technological complexity, leading to the development of traits far more complex than one individual could invent alone. Claims have been made for cumulative culture in several species of animals, including chimpanzees, orangutans and New Caledonian crows, but these remain contentious. Whilst initial work on the topic of cumulative culture was largely theoretical, employing mathematical methods developed by population biologists, in recent years researchers from a wide range of disciplines, including psychology, biology, economics, biological anthropology, linguistics and archaeology, have turned their attention to the experimental investigation of cumulative culture. We review this literature, highlighting advances made in understanding the underlying processes of cumulative culture and emphasising areas of agreement and disagreement amongst investigators in separate fields.

  4. Dose reduction of scattered photons from concrete walls lined with lead: Implications for improvement in design of megavoltage radiation therapy facility mazes

    Energy Technology Data Exchange (ETDEWEB)

    Al-Affan, I. A. M., E-mail: info@medphys-environment.co.uk; Hugtenburg, R. P.; Piliero, M. [Swansea University, Swansea SA2 8PP (United Kingdom); Bari, D. S. [Swansea University, Swansea SA2 8PP, United Kingdom and University of Zakho, Duhok (Iraq); Al-Saleh, W. M. [Swansea University, Swansea SA2 8PP, United Kingdom and King Saud Bin Abdulaziz University for Health Science, Hofuf (Saudi Arabia); Evans, S. [Department of Medical Physics and Clinical Engineering, Singleton Hospital, Swansea SA2 8QA (United Kingdom); Al-Hasan, M.; Al-Zughul, B. [College of Sciences, Zarqa University, Zarqa (Jordan); Al-Kharouf, S. [The Royal Scientific Society, Amman (Jordan); Ghaith, A. [Association of Arab Universities, Amman (Jordan)

    2015-02-15

    Purpose: This study explores the possibility of using lead to cover part of the radiation therapy facility maze walls in order to absorb low energy photons and reduce the total dose at the maze entrance of radiation therapy rooms. Methods: Experiments and Monte Carlo simulations were utilized to establish the possibility of using high-Z materials to cover the concrete walls of the maze in order to reduce the dose of the scattered photons at the maze entrance. The dose of the backscattered photons from a concrete wall was measured for various scattering angles. The dose was also calculated by the FLUKA and EGSnrc Monte Carlo codes. The FLUKA code was also used to simulate an existing radiotherapy room to study the effect of multiple scattering when adding lead to cover the concrete walls of the maze. Monoenergetic photons were used to represent the main components of the x ray spectrum up to 10 MV. Results: It was observed that when the concrete wall was covered with just 2 mm of lead, the measured dose rate at all backscattering angles was reduced by 20% for photons of energy comparable to Co-60 emissions and 70% for Cs-137 emissions. The simulations with FLUKA and EGS showed that the reduction in the dose was potentially even higher when lead was added. One explanation for the reduction is the increased absorption of backscattered photons due to the photoelectric interaction in lead. The results also showed that adding 2 mm lead to the concrete walls and floor of the maze reduced the dose at the maze entrance by up to 90%. Conclusions: This novel proposal of covering part or the entire maze walls with a few millimeters of lead would have a direct implication for the design of radiation therapy facilities and would assist in upgrading the design of some mazes, especially those in facilities with limited space where the maze length cannot be extended to sufficiently reduce the dose.

  5. Cumulative Timers for Microprocessors

    Science.gov (United States)

    Battle, John O.

    2007-01-01

    It has been proposed to equip future microprocessors with electronic cumulative timers, for essentially the same reasons for which land vehicles are equipped with odometers (total-distance-traveled meters) and aircraft are equipped with Hobbs meters (total-engine-operating time meters). Heretofore, there has been no way to determine the amount of use to which a microprocessor (or a product containing a microprocessor) has been subjected. The proposed timers would count all microprocessor clock cycles and could only be read by means of microprocessor instructions but, like odometers and Hobbs meters, could never be reset to zero without physically damaging the chip.

  6. Cumulative Vehicle Routing Problems

    OpenAIRE

    Kara, &#;mdat; Kara, Bahar Yeti&#;; Yeti&#;, M. Kadri

    2008-01-01

    This paper proposes a new objective function and corresponding formulations for the vehicle routing problem. The new cost function defined as the product of the distance of the arc and the flow on that arc. We call a vehicle routing problem with this new objective function as the Cumulative Vehicle Routing Problem (CumVRP). Integer programming formulations with O(n2) binary variables and O(n2) constraints are developed for both collection and delivery cases. We show that the CumVRP is a gener...

  7. Thyroid equivalent dose in staffs that use neck lead protector in pediatric barium meal; Dose equivalente na tireoide dos profissionais que utilizam o protetor plumbifero nos exames de seed pediatrico

    Energy Technology Data Exchange (ETDEWEB)

    Filipov, Danielle; Sauzen, Jessica; Paschuk, Sergei A., E-mail: dfilipov@utfpr.edu.br [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Schelin, Hugo R.; Denyak, Valeriy [Instituto de Pesquisa Pele Pequeno Principe (IPPP), Curitiba, PR (Brazil); Legnani, Adriano [Hospital Pequeno Principe, Curitiba, PR (Brazil)

    2015-08-15

    The aim of this study is to estimate the thyroid equivalent dose in staffs that perform pediatric barium meal procedures and use neck lead protector. Thermoluminescent Dosimeters (TLDs) were positioned on the lead protectors, used by two professionals. After that, a solid state detector was exposed (with and without the protector above it). Therefore, it was possible to obtain both lead protectors attenuation factors. At the end, average and annual doses received by the TLDs and the thyroid (applying the attenuation factor over the dosimeters doses) were obtained. It was found that the average and annual equivalent doses in the thyroid gland are, respectively, higher than in comparative studies and within the established limits. With these data, it is concluded that the application of radiation protection optimization techniques is required. (author)

  8. Influence of a Commercial Lead Apron on Patient Skin Dose Delivered During Oral and Maxillofacial Examinations under Cone Beam Computed Tomography (CBCT).

    Science.gov (United States)

    Schulze, Ralf Kurt Willy; Sazgar, Mahssa; Karle, Heiko; de Las Heras Gala, Hugo

    2017-08-01

    The purpose of this paper is to investigate the impact of a commercial lead apron on patient skin dose delivered during maxillofacial CBCT in five critical regions by means of solid-state-dosimetry. Five anatomical regions (thyroid gland, left and right breast, gonads, back of the phantom torso) in an adult female anthropomorphic phantom were selected for dose measurement by means of the highly sensitive solid-state dosimeter QUART didoSVM. Ten repeated single exposures were assessed for each patient body region for a total of five commercial CBCT devices with and without a lead apron present. Shielded and non-shielded exposures were compared under the paired Wilcoxon test, with absolute and relative differences computed. Reproducibility was expressed as the coefficient of variation (CV) between the 10 repeated assessments. The highest doses observed at skin level were found at the thyroid (mean shielded ± SD: 450.5 ± 346.7 μGy; non-shielded: 339.2 ± 348.8 μGy, p = 0.4922). Shielding resulted in a highly significant (p shielded dose of approximately 35 μGy. Dose reduction was also significantly lower for the back-region (mean: -65%, p shielded situation. Reproducibility was inversely correlated to skin dose (Rspearman = -0.748, p lead apron, which did not shield this region. Dose reduction by means of a commercial lead apron was significant in all other regions, particularly in the region of the female breast.

  9. Shielding effect of a customized intraoral mold including lead material in high-dose-rate 192-Ir brachytherapy for oral cavity cancer.

    Science.gov (United States)

    Kudoh, Takaharu; Ikushima, Hitoshi; Honda, Eiichi

    2012-01-01

    A high-dose-rate (HDR) 192-Ir brachytherapy using a customized intraoral mold is effective for superficial oral cavity cancer, and the surrounding normal tissue is kept away from the radioactive source with gauze pads and/or mouth piece for reducing the dose on the normal tissues. In the Tokushima university hospital, the mold has a lead shield which utilizes the space prepared with sufficient border-molding by a specific dental technique using modeling compound. In HDR 192-Ir brachytherapy using a lead shielded customized intraoral mold, there are no reports measuring the absorbed dose. The purpose of the present study is to measure the absorbed dose and discuss the optimum thickness of lead in HDR 192-Ir brachytherapy using a customized intraoral mold with lead shield using a 1 cm thickness mimic mold. The thickness of lead in the mold could be changed by varying the arrangement of 0.1 cm thickness sheet of the acrylic resin plate and lead. The measured doses at the lateral surface of the mold with thermo-luminescence dosimeter were reduced to 1.12, 0.79, 0.57, 0.41, 0.31, 0.24 and 0.19 Gy and the ratios to the prescription dose were reduced to 56, 40, 29, 21, 16, 12 and 10 percent as lead thickness increased from 0 to 0.6 cm in 0.1 cm increments, respectively. A 0.3 cm thickness lead was considered to be required for a 1 cm thickness mold, and it was necessary to thicken the lead as much as possible with the constraint of limited space in the oral cavity, especially at the fornix vestibule.

  10. Cumulative environmental effects. Summary

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    This report presents a compilation of knowledge about the state of the environment and human activity in the Norwegian part of the North Sea and Skagerrak. The report gives an overview of pressures and impacts on the environment from normal activity and in the event of accidents. This is used to assess the cumulative environmental effects, which factors have most impact and where the impacts are greatest, and to indicate which problems are expected to be most serious in the future. The report is intended to provide relevant information that can be used in the management of the marine area in the future. It also provides input for the identification of environmental targets and management measures for the North Sea and Skagerrak.(Author)

  11. Maintenance hemodialysis patients have high cumulative radiation exposure.

    LENUS (Irish Health Repository)

    Kinsella, Sinead M

    2010-10-01

    Hemodialysis is associated with an increased risk of neoplasms which may result, at least in part, from exposure to ionizing radiation associated with frequent radiographic procedures. In order to estimate the average radiation exposure of those on hemodialysis, we conducted a retrospective study of 100 patients in a university-based dialysis unit followed for a median of 3.4 years. The number and type of radiological procedures were obtained from a central radiology database, and the cumulative effective radiation dose was calculated using standardized, procedure-specific radiation levels. The median annual radiation dose was 6.9 millisieverts (mSv) per patient-year. However, 14 patients had an annual cumulative effective radiation dose over 20 mSv, the upper averaged annual limit for occupational exposure. The median total cumulative effective radiation dose per patient over the study period was 21.7 mSv, in which 13 patients had a total cumulative effective radiation dose over 75 mSv, a value reported to be associated with a 7% increased risk of cancer-related mortality. Two-thirds of the total cumulative effective radiation dose was due to CT scanning. The average radiation exposure was significantly associated with the cause of end-stage renal disease, history of ischemic heart disease, transplant waitlist status, number of in-patient hospital days over follow-up, and death during the study period. These results highlight the substantial exposure to ionizing radiation in hemodialysis patients.

  12. Preventing Complications from High-Dose Rate Brachytherapy when Treating Mobile Tongue Cancer via the Application of a Modular Lead-Lined Spacer.

    Directory of Open Access Journals (Sweden)

    Shumei Murakami

    Full Text Available To point out the advantages and drawbacks of high-dose rate brachytherapy in the treatment of mobile tongue cancer and indicate the clinical importance of modular lead-lined spacers when applying this technique to patients.First, all basic steps to construct the modular spacer are shown. Second, we simulate and evaluate the dose rate reduction for a wide range of spacer configurations.With increasing distance to the source absorbed doses dropped considerably. Significantly more shielding was obtained when lead was added to the spacer and this effect was most pronounced on shorter (i.e. more clinically relevant distances to the source.The modular spacer represents an important addition to the planning and treatment stages of mobile tongue cancer using HDR-ISBT.

  13. Preventing Complications from High-Dose Rate Brachytherapy when Treating Mobile Tongue Cancer via the Application of a Modular Lead-Lined Spacer.

    Science.gov (United States)

    Murakami, Shumei; Verdonschot, Rinus G; Kakimoto, Naoya; Sumida, Iori; Fujiwara, Masateru; Ogawa, Kazuhiko; Furukawa, Souhei

    2016-01-01

    To point out the advantages and drawbacks of high-dose rate brachytherapy in the treatment of mobile tongue cancer and indicate the clinical importance of modular lead-lined spacers when applying this technique to patients. First, all basic steps to construct the modular spacer are shown. Second, we simulate and evaluate the dose rate reduction for a wide range of spacer configurations. With increasing distance to the source absorbed doses dropped considerably. Significantly more shielding was obtained when lead was added to the spacer and this effect was most pronounced on shorter (i.e. more clinically relevant) distances to the source. The modular spacer represents an important addition to the planning and treatment stages of mobile tongue cancer using HDR-ISBT.

  14. Preventing Complications from High-Dose Rate Brachytherapy when Treating Mobile Tongue Cancer via the Application of a Modular Lead-Lined Spacer

    Science.gov (United States)

    Murakami, Shumei; Verdonschot, Rinus G.; Kakimoto, Naoya; Sumida, Iori; Fujiwara, Masateru; Ogawa, Kazuhiko; Furukawa, Souhei

    2016-01-01

    Purpose To point out the advantages and drawbacks of high-dose rate brachytherapy in the treatment of mobile tongue cancer and indicate the clinical importance of modular lead-lined spacers when applying this technique to patients. Methods First, all basic steps to construct the modular spacer are shown. Second, we simulate and evaluate the dose rate reduction for a wide range of spacer configurations. Results With increasing distance to the source absorbed doses dropped considerably. Significantly more shielding was obtained when lead was added to the spacer and this effect was most pronounced on shorter (i.e. more clinically relevant) distances to the source. Conclusions The modular spacer represents an important addition to the planning and treatment stages of mobile tongue cancer using HDR-ISBT. PMID:27128434

  15. Low dose influenza virus challenge in the ferret leads to increased virus shedding and greater sensitivity to oseltamivir.

    Directory of Open Access Journals (Sweden)

    Anthony C Marriott

    Full Text Available Ferrets are widely used to study human influenza virus infection. Their airway physiology and cell receptor distribution makes them ideal for the analysis of pathogenesis and virus transmission, and for testing the efficacy of anti-influenza interventions and vaccines. The 2009 pandemic influenza virus (H1N1pdm09 induces mild to moderate respiratory disease in infected ferrets, following inoculation with 106 plaque-forming units (pfu of virus. We have demonstrated that reducing the challenge dose to 102 pfu delays the onset of clinical signs by 1 day, and results in a modest reduction in clinical signs, and a less rapid nasal cavity innate immune response. There was also a delay in virus production in the upper respiratory tract, this was up to 9-fold greater and virus shedding was prolonged. Progression of infection to the lower respiratory tract was not noticeably delayed by the reduction in virus challenge. A dose of 104 pfu gave an infection that was intermediate between those of the 106 pfu and 102 pfu doses. To address the hypothesis that using a more authentic low challenge dose would facilitate a more sensitive model for antiviral efficacy, we used the well-known neuraminidase inhibitor, oseltamivir. Oseltamivir-treated and untreated ferrets were challenged with high (106 pfu and low (102 pfu doses of influenza H1N1pdm09 virus. The low dose treated ferrets showed significant delays in innate immune response and virus shedding, delayed onset of pathological changes in the nasal cavity, and reduced pathological changes and viral RNA load in the lung, relative to untreated ferrets. Importantly, these observations were not seen in treated animals when the high dose challenge was used. In summary, low dose challenge gives a disease that more closely parallels the disease parameters of human influenza infection, and provides an improved pre-clinical model for the assessment of influenza therapeutics, and potentially, influenza vaccines.

  16. Computed tomography dose optimisation in cystic fibrosis: A review.

    LENUS (Irish Health Repository)

    Ferris, Helena

    2016-04-28

    Cystic fibrosis (CF) is the most common autosomal recessive disease of the Caucasian population worldwide, with respiratory disease remaining the most relevant source of morbidity and mortality. Computed tomography (CT) is frequently used for monitoring disease complications and progression. Over the last fifteen years there has been a six-fold increase in the use of CT, which has lead to a growing concern in relation to cumulative radiation exposure. The challenge to the medical profession is to identify dose reduction strategies that meet acceptable image quality, but fulfil the requirements of a diagnostic quality CT. Dose-optimisation, particularly in CT, is essential as it reduces the chances of patients receiving cumulative radiation doses in excess of 100 mSv, a dose deemed significant by the United Nations Scientific Committee on the Effects of Atomic Radiation. This review article explores the current trends in imaging in CF with particular emphasis on new developments in dose optimisation.

  17. Cumulate Fragments in Silicic Ignimbrites

    Science.gov (United States)

    Bachmann, O.; Ellis, B. S.; Wolff, J.

    2014-12-01

    Increasingly, studies are concluding that silicic ignimbrites are the result of the amalgamation of multiple discrete magma batches. Yet the existence of discrete batches presents a conundrum for magma generation and storage; if silicic magma batches are not generated nearly in situ in the upper crust, they must traverse, and reside within, a thermally hostile environment with large temperature gradients, resulting in low survivability in their shallow magmatic hearths. The Snake River Plain (Idaho, USA) is a type example of this 'multi-batch' assembly with ignimbrites containing multiple populations of pyroxene crystals, glass shards, and crystal aggregates. The ubiquitous crystal aggregates hint at a mechanism to facilitate the existence of multiple, relatively small batches of rhyolite in the upper crust. These aggregates contain the same plagioclase, pyroxene, and oxide mineral compositions as single phenocrysts of the same minerals in their host rocks, but they have significantly less silicic bulk compositions and lack quartz and sanidine, which occur as single phenocrysts in the deposits. This implies significant crystallization followed by melt extraction from mushy reservoir margins. The extracted melt then continues to evolve (crystallizing sanidine and quartz) while the melt-depleted margins provide an increasingly rigid and refractory network segregating the crystal-poor batches of magma. The hot, refractory, margins insulate the crystal-poor lenses, allowing (1) extended residence in the upper crust, and (2) preservation of chemical heterogeneities among batches. In contrast, systems that produce cumulates richer in low-temperature phases (quartz, K-feldspars, and/or biotite) favour remelting upon recharge, leading to less segregation of eruptible melt pockets and the formation of gradationally zoned ignimbrites. The occurrence of similar crystal aggregates from a variety of magmatic lineages suggests the generality of this process.

  18. Using a mobile transparent plastic-lead-boron shielding barrier to reduce radiation dose exposure in the work place

    Energy Technology Data Exchange (ETDEWEB)

    Parra, S A; Mecozzi, J M

    2001-01-11

    Moveable radiation shielding barriers made of plastic material containing lead and boron can be used to reduce radiation exposure near the work place. Personnel can maneuver and position the transparent radiation shielding barriers anywhere within the work place. The lead in the shielding barrier provides an effective shielding material against radiation exposure (approximately a 1.0 mm lead equivalent protection) while the boron in the shielding barrier provides neutron absorption to reduce the moderation/reflection effects of the shielding materials (approximately a 2% {Delta}k/k reduction).

  19. Reduction of operator radiation dose by a pelvic lead shield during cardiac catheterization by radial access: comparison with femoral access

    National Research Council Canada - National Science Library

    Lange, Helmut W; von Boetticher, Heiner

    2012-01-01

    This study sought to determine the efficacy of patient pelvic lead shielding for the reduction of operator radiation exposure during cardiac catheterization via the radial access in comparison with the femoral access...

  20. A low-protein diet combined with low-dose endotoxin leads to changes in glucose homeostasis in weanling rats

    NARCIS (Netherlands)

    Bandsma, Robert H. J.; Ackerley, Cameron; Koulajian, Khajag; Zhang, Ling; van Zutphen, Tim; van Dijk, Theo H.; Xiao, Changting; Giacca, Adria; Lewis, Gary F.

    2015-01-01

    Severe malnutrition is a leading cause of global childhood mortality, and infection and hypoglycemia or hyperglycemia are commonly present. The etiology behind the changes in glucose homeostasis is poorly understood. Here, we generated an animal model of severe malnutrition with and without low-grad

  1. Lanreotide Autogel 120 mg at extended dosing intervals in patients with acromegaly biochemically controlled with octreotide LAR: the LEAD study.

    Science.gov (United States)

    Neggers, Sebastian J C M M; Pronin, Vyacheslav; Balcere, Inga; Lee, Moon-Kyu; Rozhinskaya, Liudmila; Bronstein, Marcello D; Gadelha, Mônica R; Maisonobe, Pascal; Sert, Caroline; van der Lely, Aart Jan

    2015-09-01

    To evaluate extended dosing intervals (EDIs) with lanreotide Autogel 120 mg in patients with acromegaly previously biochemically controlled with octreotide LAR 10 or 20 mg. Patients with acromegaly had received octreotide LAR 10 or 20 mg/4 weeks for ≥ 6 months and had normal IGF1 levels. Lanreotide Autogel 120 mg was administered every 6 weeks for 24 weeks (phase 1); depending on week-24 IGF1 levels, treatment was then administered every 4, 6 or 8 weeks for a further 24 weeks (phase 2). Hormone levels, patient-reported outcomes and adverse events were assessed. proportion of patients on 6- or 8-week EDIs with normal IGF1 levels at week 48 (study end). 107/124 patients completed the study (15 withdrew from phase 1 and two from phase 2). Of 124 patients enrolled, 77.4% were allocated to 6- or 8-week EDIs in phase 2 and 75.8% (95% CI: 68.3-83.3) had normal IGF1 levels at week 48 with the EDI (primary analysis). A total of 88.7% (83.1-94.3) had normal IGF1 levels after 24 weeks with 6-weekly dosing. GH levels were ≤ 2.5 μg/l in > 90% of patients after 24 and 48 weeks. Patient preferences for lanreotide Autogel 120 mg every 4, 6 or 8 weeks over octreotide LAR every 4 weeks were high. Patients with acromegaly achieving biochemical control with octreotide LAR 10 or 20 mg/4 weeks are possible candidates for lanreotide Autogel 120 mg EDIs. EDIs are effective and well received among such patients. © 2015 European Society of Endocrinology.

  2. Effect of zinc or S-adenosyl-l-methionine on long term administration of low doses of lead to rats.

    Science.gov (United States)

    Muñoz, J J; Roca, C; Santos, J L; Arroyo, M; de Salamanca, R E

    1993-10-01

    Two alternatives for the treatment of lead intoxication, administration of zinc or a thiol donor, S-adenosyl-L-methionine (SAM), were analysed. Rats were exposed to lead (Pb)-acetate (60 mg/l) in drinking water during 90 days; one group also received SO4Zn in water (40 mg/l), while another received both Pb and SAM (5 mg/24 hr intraperitoneally. Erythrocytic delta-aminolaevulinic dehydratase (ALA-D) activity was significantly reduced (P treatments. The high erythrocytic uroporphyrinogen synthetase (URO-S) activity noticed in Pb administered rats, was significantly (P treatment causes a surplus of thiols that allows the full expression of ALA-D catalytic activity.

  3. Climate mitigation: sustainable preferences and cumulative carbon

    Science.gov (United States)

    Buckle, Simon

    2010-05-01

    We develop a stylized AK growth model with both climate damages to ecosystem goods and services and sustainable preferences that allow trade-offs between present discounted utility and long-run climate damages. The simplicity of the model permits analytical solutions. Concern for the long-term provides a strong driver for mitigation action. One plausible specification of sustainable preferences leads to the result that, for a range of initial parameter values, an optimizing agent would choose a level of cumulative carbon dioxide (CO2) emissions independent of initial production capital endowment and CO2 levels. There is no technological change so, for economies with sufficiently high initial capital and CO2 endowments, optimal mitigation will lead to disinvestment. For lower values of initial capital and/or CO2 levels, positive investment can be optimal, but still within the same overall level of cumulative emissions. One striking aspect of the model is the complexity of possible outcomes, in addition to these optimal solutions. We also identify a resource constrained region and several regions where climate damages exceed resources available for consumption. Other specifications of sustainable preferences are discussed, as is the case of a hard constraint on long-run damages. Scientists are currently highlighting the potential importance of the cumulative carbon emissions concept as a robust yet flexible target for climate policymakers. This paper shows that it also has an ethical interpretation: it embodies an implicit trade off in global welfare between present discounted welfare and long-term climate damages. We hope that further development of the ideas presented here might contribute to the research and policy debate on the critical areas of intra- and intergenerational welfare.

  4. Online Scheduling in Manufacturing A Cumulative Delay Approach

    CERN Document Server

    Suwa, Haruhiko

    2013-01-01

    Online scheduling is recognized as the crucial decision-making process of production control at a phase of “being in production" according to the released shop floor schedule. Online scheduling can be also considered as one of key enablers to realize prompt capable-to-promise as well as available-to-promise to customers along with reducing production lead times under recent globalized competitive markets. Online Scheduling in Manufacturing introduces new approaches to online scheduling based on a concept of cumulative delay. The cumulative delay is regarded as consolidated information of uncertainties under a dynamic environment in manufacturing and can be collected constantly without much effort at any points in time during a schedule execution. In this approach, the cumulative delay of the schedule has the important role of a criterion for making a decision whether or not a schedule revision is carried out. The cumulative delay approach to trigger schedule revisions has the following capabilities for the ...

  5. Cigarette smoking leads to persistent and dose-dependent alterations of brain activity and connectivity in anterior insula and anterior cingulate.

    Science.gov (United States)

    Zanchi, Davide; Brody, Arthur L; Montandon, Marie-Louise; Kopel, Rotem; Emmert, Kirsten; Preti, Maria Giulia; Van De Ville, Dimitri; Haller, Sven

    2015-11-01

    Although many smokers try to quit smoking, only about 20-25 percent will achieve abstinence despite 6 months or more of gold-standard treatment. This low success rate suggests long-term changes in the brain related to smoking, which remain poorly understood. We compared ex-smokers to both active smokers and non-smokers using functional magnetic resonance imaging (fMRI) to explore persistent modifications in brain activity and network organization. This prospective and consecutive study includes 18 non-smokers (29.5 ± 6.7 years of age, 11 women), 14 smokers (≥10 cigarettes a day >2 years of smoking, 29.3 ± 6.0 years of age, 10 women) and 14 ex-smokers (>1 year of quitting 30.5 ± 5.7 years of age, 10 women). Participants underwent a block-design fMRI study contrasting smoking cue with control (neutral cue) videos. Data analyses included task-related general linear model, seed-based functional connectivity, voxel-based morphometry (VBM) of gray matter and tract-based spatial statistics (TBSS) of white matter. Smoking cue videos versus control videos activated the right anterior insula in ex-smokers compared with smokers, an effect correlating with cumulative nicotine intake (pack-years). Moreover, ex-smokers had a persistent decrease in functional connectivity between right anterior insula and anterior cingulate cortex (ACC) compared with control participants, but similar to active smokers. Potentially confounding alterations in gray or white matter were excluded in VBM and TBSS analyses. In summary, ex-smokers with long-term nicotine abstinence have persistent and dose-dependent brain network changes notably in the right anterior insula and its connection to the ACC.

  6. The Effect of Low Dose of Lead Acetate on the Fallopian Tubes and the Role of Garlic Extract—A Histomorphic Study on Mouse

    Directory of Open Access Journals (Sweden)

    Naureen Waseem

    2015-02-01

    Full Text Available This study aimed to investigate the effect of lead acetate on the fallopian tube of adult mice and the possible effect of garlic extract in a Laboratory Based Randomized Control Trial. In this study, 30 female BALBc mice were selected and randomly divided into three groups. Ten animals were placed in each group. Group A being the control received only the laboratory diet. Group B was given lead acetate at a dose of 30 mg/kg/day. Group C was given lead acetate at 30 mg/kg/day and garlic extract at 500 mg/kg/day. All treatments were given through oral gavage tube for 60 days. The mice were sacrificed and dissected at the end of 60 days. The fallopian tubes were carefully dissected out and fixed in 10% formalin for routine histological examination. The histological findings in experimental group B showed increase in epithelial height, whereas no such findings were observed in group A and there was slight increase in height in group C. The lead acetate affected the epithelial height in lead acetate treated group which improved when cotreated with garlic extract.

  7. Benchmark dose approach for low-level lead induced haematogenesis inhibition and associations of childhood intelligences with ALAD activity and ALA levels.

    Science.gov (United States)

    Wang, Q; Ye, L X; Zhao, H H; Chen, J W; Zhou, Y K

    2011-04-15

    Lead (Pb) levels, delta-aminolevulinic acid dehydratase (ALAD) activities, zinc protoporphyrin (ZPP) levels in blood, and urinary delta-aminolevulinic acid (ALA) and coproporphyrin (CP) concentrations were measured for 318 environmental Pb exposed children recruited from an area of southeast China. The mean of blood lead (PbB) levels was 75.0μg/L among all subjects. Benchmark dose (BMD) method was conducted to present a lower PbB BMD (lower bound of BMD) of 32.4μg/L (22.7) based on ALAD activity than those based on the other three haematological indices, corresponding to a benchmark response of 1%. Childhood intelligence degrees were not associated significantly with ALAD activities or ALA levels. It was concluded that blood ALAD activity is a sensitive indicator of early haematological damage due to low-level Pb exposures for children.

  8. Electro-cumulation CNF project

    CERN Document Server

    Grishin, V G

    2000-01-01

    bound or free ion current within solid substances; non-plain symmetry; cumulation of the ion interaction. Experimental result: an Ice SuperPolarization. Cold nuclear fusion ? At http://www.shortway.to/to2084 . Keywords: ion, current, solid, symmetry, cumulation, cold nuclear fusion, polarization, depolarization, ionic conductor, superionic conductor, ice, crystal, strain, V-center, V-centre, doped crystal, interstitial impurity, intrinsic color center, high pressure technology, Bridgman, experiment, crowdion, dielectric, proton, layer, defect, lattice, dynamics, electromigration, mobility, muon catalysis, concentration, doping, dopant, conductivity, pycnonuclear reaction, permittivity, dielectric constant, point defects, interstitials, polarizability, imperfection, defect centers, glass, epitaxy, sodium hydroxide, metallic substrate, crystallization, point, tip, susceptibility, ferroelectric, ordering, force, correlation, collective, shift, distortion, coalescence, crowdions, electrolysis.

  9. Analysis of sensory ratings data with cumulative link models

    DEFF Research Database (Denmark)

    Christensen, Rune Haubo Bojesen; Brockhoff, Per B.

    2013-01-01

    Examples of categorical rating scales include discrete preference, liking and hedonic rating scales. Data obtained on these scales are often analyzed with normal linear regression methods or with omnibus Pearson chi2 tests. In this paper we propose to use cumulative link models that allow...... for regression methods similar to linear models while respecting the categorical nature of the observations. We describe how cumulative link models are related to the omnibus chi2 tests and how they can lead to more powerful tests in the non-replicated setting. For replicated categorical ratings data we present...... a quasi-likelihood approach and a mixed effects approach both being extensions of cumulative link models. We contrast population-average and subject-specific interpretations based on these models and discuss how different approaches lead to different tests. In replicated settings, naive tests that ignore...

  10. The Algebra of the Cumulative Percent Operation.

    Science.gov (United States)

    Berry, Andrew J.

    2002-01-01

    Discusses how to help students avoid some pervasive reasoning errors in solving cumulative percent problems. Discusses the meaning of ."%+b%." the additive inverse of ."%." and other useful applications. Emphasizes the operational aspect of the cumulative percent concept. (KHR)

  11. Adaptive strategies for cumulative cultural learning.

    Science.gov (United States)

    Ehn, Micael; Laland, Kevin

    2012-05-21

    The demographic and ecological success of our species is frequently attributed to our capacity for cumulative culture. However, it is not yet known how humans combine social and asocial learning to generate effective strategies for learning in a cumulative cultural context. Here we explore how cumulative culture influences the relative merits of various pure and conditional learning strategies, including pure asocial and social learning, critical social learning, conditional social learning and individual refiner strategies. We replicate the Rogers' paradox in the cumulative setting. However, our analysis suggests that strategies that resolved Rogers' paradox in a non-cumulative setting may not necessarily evolve in a cumulative setting, thus different strategies will optimize cumulative and non-cumulative cultural learning.

  12. A Resource Cost Aware Cumulative

    Science.gov (United States)

    Simonis, Helmut; Hadzic, Tarik

    We motivate and introduce an extension of the well-known cumulative constraint which deals with time and volume dependent cost of resources. Our research is primarily interested in scheduling problems under time and volume variable electricity costs, but the constraint equally applies to manpower scheduling when hourly rates differ over time and/or extra personnel incur higher hourly rates. We present a number of possible lower bounds on the cost, including a min-cost flow, different LP and MIP models, as well as greedy algorithms, and provide a theoretical and experimental comparison of the different methods.

  13. Method for evaluation of doses from ingestion of polonium, bismuth and lead as natural radioactive material(NORM); Metodo de evaluacion de dosis por ingestion de polonio, bismuto y plomo como materiales radiactivos naturales

    Energy Technology Data Exchange (ETDEWEB)

    Pena, Vanessa; Puerta, Anselmo; Morales, Javier, E-mail: vpenam@ullal.edu.co, E-mail: japuerta@unal.edu.co, E-mail: jmorales@unal.cdu.co [Universidad Nacional de Colombia, Medellin (Colombia). Grupo de Fisica Radiologica

    2013-07-01

    In this work was carried out an evaluation of dose from ingestion of radioactive daughters of radon (lead, bismuth and polonium), taking into account ages from three months up to adult men, using the new model of the human alimentary tract HATM and methodology of calculating doses proposed by the ICRP publication 103, which allows the estimation of dose based on the concentration of the radionuclide present in the diet or in the water of consumption.

  14. Stem cell factor leads to reduced blood processing during apheresis or the use of whole blood aliquots to support dose-intensive chemotherapy.

    Science.gov (United States)

    Weaver, A; Testa, N G

    1998-07-01

    The addition of stem cell factor (SCF) to G-CSF and chemotherapy results in a dose-dependent, significantly increased mobilisation of peripheral blood progenitor cells compared with the use of chemotherapy and G-CSF alone. The enhanced mobilisation may benefit patients in several ways. Firstly, in clinical settings where currently multiple aphereses are having to be performed to obtain a specified target number of cells, the addition of SCF may lead to a reduction in this number. Alternatively, when only a single apheresis is currently being performed to obtain sufficient cells then the addition of SCF to the mobilisation regimen would allow between 5- and 8-fold reduction in the volume of blood required to be processed during the apheresis procedure to obtain a specified target of GM-CFC, CD34+ cells and LTC-IC for those receiving the highest dose of SCF (20 microg/kg) plus G-CSF following chemotherapy compared with those patients receiving G-CSF alone following chemotherapy. The increased mobilisation resulting from the addition of SCF to the regimen makes feasible the use of whole blood aliquots to support dose-intensive therapy. We have calculated that in patients mobilised using cyclophosphamide 3 g/m2, SCF 20 microg/kg and G-CSF 5 microg/kg a median 512 ml aliquot of whole blood would contain 2 x 10(6)/kg CD34+ cells and over 3.7 x 10(5)/kg GM-CFC. This aliquot would be sufficient to rescue the patient following a myeloablative therapy. Significantly, because less individual variation was seen after the administration of SCF the patient who showed the worst mobilisation in that group would have the usually required content of 2 x 10(6) CD34+ cells/kg and 1 x 10(5) GM-CFC/kg in only 731 ml of blood.

  15. Determination of transfer factors of uranium, thorium, radium and lead from soil to agricultural product in Japan for estimating internal radiation dose through ingestion

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Tomozo [Radioactive Waste Management Funding and Research Center, Tokyo (Japan); Tashiro, Yoshikazu; Fujinaga, Hideshi [Sumitomo Metal Mining Co. Ltd., Tokai, Ibaraki (Japan); Ishii, Tomoaki; Gunji, Yasuyoshi [Nuclear Fuel Industries Ltd., Tokai, Ibaraki (Japan). Tokai Works

    2002-09-01

    The transfer factors (TFs) of uranium (U), thorium (Th), radium (Ra) and lead (Pb) from soil to agricultural products were determined in order to estimate the internal radiation dose to the human body through ingestion. Samples of rice, potato, onion, cabbage, mandarin orange, spinach, apple and soil were collected from various districts in Japan. After appropriate pretreatment of the samples, concentrations in the sample solutions were measured by Inductively coupled plasma-mass spectrometry (ICP-MS) (for U, Th and Pb) and liquid scintillation counter (for Ra). It was recognized that TFs were 4.9 x 10{sup -6} (apple) and 3.6 x 10{sup -4} (spinach) for U, 2.8 x 10{sup -6} (apple) and 2.3 x 10{sup -4} (spinach) for Th, and 4.0 x 10{sup -3} (hulled rice), 7.0 x 10{sup -5} (onion) and 5.0 x 10{sup -3} (hulled rice) for Pb. The TF of Ra, however, was not determined due to detection limitations. TF values obtained in the present study range from the same order of magnitude to 1/100 compared to the data in Technical Report Series No.364 (TRS364) as reported by IAEA. It was revealed that the internal radiation dose caused by the intake of uranium series radioactive nuclides through agricultural food ingestion was 16 {mu}Sv/y, where Pb was the most contributory nuclide. (author)

  16. 职业性噪声聋的发生、发展规律及与累积噪声暴露剂量的关系研究%The occurrence and development of occupational noise deafness and its relationship with the cumulative noise exposure dose

    Institute of Scientific and Technical Information of China (English)

    王雪琴

    2015-01-01

    Objective: To analyze and investigate the occurrence and development of occupational noise deafness and its re-lationship with the cumulative noise exposure dose (CNE).Methods:Randomly selecting a city and medium-sized enterprises 120 workers and management are as the research object, to the enterprise operating environment noise monitoring, investigation object were measured by pure tone threshold audiometry, calculating the cumulative noise exposure, to investigate the occurrence and occupational noise induced hearing loss.Results: The noise pressure level of the examination site was higher than that in other places; when the CNE increases, high-frequency loss, language frequency loss detection rate had significant difference; oc-cupational noise induced deafness related to rate and development and CNE, to 100 dB (a) years as threshold.Conclusion:The cumulative noise exposure dose and occupational noise induced deafness, the law of development there is a certain relationship, early detection threshold anomaly or high frequency audibility threshold change of patients,, improve efficiency and patient quality of life.%目的:分析和探讨职业性噪声聋的发生、发展规律及与累积噪声暴露剂量(CNE)的关系。方法随机选取某城市中型企业中120名工人及管理者作为研究对象,对企业作业环境噪音进行监测,组织调查对象进行纯音听阈测定,计算累积噪声暴露剂量,探讨与职业性噪声聋的发生、发展规律的关系。结果检查现场噪声声压级均高于其他场所;当CNE升高时,高频损失、语频损失检出率差异明显;职业性噪声聋发生率及发展与CNE有关,以100dB(A)年为阈值。结论累积噪声暴露剂量与职业性噪声聋的发生、发展规律存在一定的关系,早期发现听阈异常或高频听阈改变的患者,及时控制职业噪音暴露量,并按规定调离噪声作业岗位,避免病情进一步发展,提高患者工作效率和生活质量。

  17. Integration of the predictions of two models with dose measurements in a case study of children exposed to the emissions of a lead smelter

    Energy Technology Data Exchange (ETDEWEB)

    Bonnard, R.; McKone, T.E.

    2009-03-01

    The predictions of two source-to-dose models are systematically evaluated with observed data collected in a village polluted by a currently operating secondary lead smelter. Both models were built up from several sub-models linked together and run using Monte-Carlo simulation, to calculate the distribution children's blood lead levels attributable to the emissions from the facility. The first model system is composed of the CalTOX model linked to a recoded version of the IEUBK model. This system provides the distribution of the media-specific lead concentrations (air, soil, fruit, vegetables and blood) in the whole area investigated. The second model consists of a statistical model to estimate the lead deposition on the ground, a modified version of the model HHRAP and the same recoded version of the IEUBK model. This system provides an estimate of the concentration of exposure of specific individuals living in the study area. The predictions of the first model system were improved in terms of accuracy and precision by performing a sensitivity analysis and using field data to correct the default value provided for the leaf wet density. However, in this case study, the first model system tends to overestimate the exposure due to exposed vegetables. The second model was tested for nine children with contrasting exposure conditions. It managed to capture the blood levels for eight of them. In the last case, the exposure of the child by pathways not considered in the model may explain the failure of the model. The interest of this integrated model is to provide outputs with lower variance than the first model system, but at the moment further tests are necessary to conclude about its accuracy.

  18. A paradox of cumulative culture.

    Science.gov (United States)

    Kobayashi, Yutaka; Wakano, Joe Yuichiro; Ohtsuki, Hisashi

    2015-08-21

    Culture can grow cumulatively if socially learnt behaviors are improved by individual learning before being passed on to the next generation. Previous authors showed that this kind of learning strategy is unlikely to be evolutionarily stable in the presence of a trade-off between learning and reproduction. This is because culture is a public good that is freely exploited by any member of the population in their model (cultural social dilemma). In this paper, we investigate the effect of vertical transmission (transmission from parents to offspring), which decreases the publicness of culture, on the evolution of cumulative culture in both infinite and finite population models. In the infinite population model, we confirm that culture accumulates largely as long as transmission is purely vertical. It turns out, however, that introduction of even slight oblique transmission drastically reduces the equilibrium level of culture. Even more surprisingly, if the population size is finite, culture hardly accumulates even under purely vertical transmission. This occurs because stochastic extinction due to random genetic drift prevents a learning strategy from accumulating enough culture. Overall, our theoretical results suggest that introducing vertical transmission alone does not really help solve the cultural social dilemma problem. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Cumulative Trauma Among Mayas Living in Southeast Florida.

    Science.gov (United States)

    Millender, Eugenia I; Lowe, John

    2016-01-04

    Mayas, having experienced genocide, exile, and severe poverty, are at high risk for the consequences of cumulative trauma that continually resurfaces through current fear of an uncertain future. Little is known about the mental health and alcohol use status of this population. This correlational study explored t/he relationship of cumulative trauma as it relates to social determinants of health (years in the United States, education, health insurance status, marital status, and employment), psychological health (depression symptoms), and health behaviors (alcohol use) of 102 Guatemalan Mayas living in Southeast Florida. The results of this study indicated that, as specific social determinants of health and cumulative trauma increased, depression symptoms (particularly among women) and the risk for harmful alcohol use (particularly among men) increased. Identifying risk factors at an early stage before serious disease or problems are manifest provides room for early screening leading to early identification, early treatment, and better outcomes.

  20. USING CUMULATIVE NUMBER DENSITIES TO COMPARE GALAXIES ACROSS COSMIC TIME

    Energy Technology Data Exchange (ETDEWEB)

    Behroozi, Peter S.; Wechsler, Risa H. [Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Stanford, CA 94305 (United States); Marchesini, Danilo [Department of Physics and Astronomy, Tufts University, Medford, MA 02155 (United States); Muzzin, Adam [Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden (Netherlands); Papovich, Casey [Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Stefanon, Mauro [Physics and Astronomy Department, University of Missouri, Columbia, MO 65211 (United States)

    2013-11-01

    Comparing galaxies across redshifts at fixed cumulative number density is a popular way to estimate the evolution of specific galaxy populations. This method ignores scatter in mass accretion histories and galaxy-galaxy mergers, which can lead to errors when comparing galaxies over large redshift ranges (Δz > 1). We use abundance matching in the ΛCDM paradigm to estimate the median change in cumulative number density with redshift and provide a simple fit (+0.16 dex per unit Δz) for progenitors of z = 0 galaxies. We find that galaxy descendants do not evolve in the same way as galaxy progenitors, largely due to scatter in mass accretion histories. We also provide estimates for the 1σ range of cumulative number densities corresponding to galaxy progenitors and descendants. Finally, we discuss some limits on cumulative number density comparisons, which arise due to difficulties measuring physical quantities (e.g., stellar mass) consistently across redshifts. A public tool to calculate cumulative number density evolution for galaxies, as well as approximate halo masses, is available online.

  1. Chronic lead poisoning in steers eating silage contaminated with lead shot - diagnostic criteria

    Energy Technology Data Exchange (ETDEWEB)

    Rice, D.A.; McLoughlin, M.F.; Blanchflower, W.J.; Thompson, T.R.

    1987-10-01

    Lead ingestion is one of the most common causes of poisoning in cattle. Toxicity results most commonly from the consumption of a single high dose of lead although cumulative toxicity resulting from the ingestion of small doses over a prolonged time also occurs. The sources of lead most commonly involved in disease outbreaks are paint, batteries, felt, linoleum and oil. It has traditionally been held that ingested metallic lead does not present a major toxicity risk to cattle because of its low solubility in the rumen and reticulum. More recent evidence suggests that lead shot, if present in silage, can induce toxicity when such silage is eaten by cattle. This communication describes a poisoning outbreak in steers eating lead shot contaminated grass silage. It presents and discusses the limitations of the criteria used for arriving at a diagnosis, including the use of whole blood amino levulinic acid dehydratase (ALAD) concentrations in fresh whole blood and after reactivation with dithiothreitol. Three are differences of opinion, in the literature, regarding the response of erythrocyte ALAD to ingested lead in the bovine. Consequently the results of a small lead feeding trial are also reported here. These results demonstrate a large ALAD response to lead ingestion and justify the use of this test in the confirmation of field cases of lead poisoning in cattle such as the one reported here.

  2. Characterization by Monte Carlo of the dose after a glass shield lead for gamma ray; Caracterizacion por Monte Carlo de la dosis tras un blindaje de vidrio de plomo para rayos gamma

    Energy Technology Data Exchange (ETDEWEB)

    Esteve Sanchez, S.; Gil Conde, M.; Contreras Gonzalez, J. L.; Rosado, J.; Pazyi, V.

    2013-07-01

    When a gamma-ray beam crosses the border between two media characterized by atomic number very different is they produce effects on the distribution of doses near the border difficult to predict with simple models. The case of rays gamma affecting a lead glass is particularly interesting for its application to shielding of common use. interested in studying the importance of the residual dose after the shield. (Author)

  3. 基于累积 Logistic 模型的居民通货膨胀异质性感受的因素研究%Empirical Analysis of Factors Leading to the Heterogeneity of Inflation Perceptions Based on the Cumulative Logistic Model

    Institute of Scientific and Technical Information of China (English)

    段进; 段妍; 朱静平

    2015-01-01

    通过调查问卷获取居民的通货膨胀感受及相关的个人特征等数据,运用累积 Logistic 模型,从心理层面和外部信息层面考量影响居民通货膨胀感受异质性的因素。结果表明,收入满意程度、食品价格、房租价格以及促销手段等是导致我国居民通胀感受异质性的主要因素。鉴此,政府应该提高收入满意度、稳定物价以及调节房价,以期降低通货膨胀感受的异质性。%Data related to inflation perceptions and personal characteristics are acquired through a questionnaire.By using the idea of cumulative logistic model as the empirical methodo-logical approach,this paper empirically analyzes the factors that lead to the heterogeneity of infla-tion perceptions through the psychological and external information aspects of the formation of inflation perceptions.The results show that income satisfaction,food price,rent and marketing are the factors with significant effects on the heterogeneity of inflation perceptions.The govern-ment should enhance income satisfaction,stabilize prices and regulate houses price and rent in or-der to decrease the heterogeneity of inflation perception.

  4. Cumulative human impacts on marine predators

    DEFF Research Database (Denmark)

    Maxwell, Sara M; Hazen, Elliott L; Bograd, Steven J

    2013-01-01

    Stressors associated with human activities interact in complex ways to affect marine ecosystems, yet we lack spatially explicit assessments of cumulative impacts on ecologically and economically key components such as marine predators. Here we develop a metric of cumulative utilization and impact...

  5. Direct reversal of DNA damage by mutant methyltransferase protein protects mice against dose-intensified chemotherapy and leads to in vivo selection of hematopoietic stem cells.

    Science.gov (United States)

    Ragg, S; Xu-Welliver, M; Bailey, J; D'Souza, M; Cooper, R; Chandra, S; Seshadri, R; Pegg, A E; Williams, D A

    2000-09-15

    Direct reversal of O6 adducts caused by chemotherapy agents is accomplished in mammalian cells by the protein O6-methylguanine DNA methyltransferase (MGMT). Some tumors overexpress MGMT and are resistant to alkylator therapy. One future approach to treatment of these tumors may rely on concurrent pharmacological depletion of tumor MGMT with O6-benzylguanine (6-BG) and protection of sensitive tissues, such as hematopoietic stem and progenitor cells, using genetic modification with 6-BG-resistant MGMT mutants. We have used retroviral-mediated gene transfer to transduce murine hematopoietic bone marrow cells with MGMT point mutants showing resistance to 6-BG depletion in vitro. These mutants include proline to alanine and proline to lysine substitutions at the 140 position (P140A and P140K, respectively), which show 40- and 1000-fold resistance to 6-BG compared with wild-type (WT) MGMT. Lethally irradiated mice were reconstituted with murine stem cells transduced with murine stem cell virus retrovirus expressing each mutant, WT MGMT, or mock-infected cells and then treated with a combination of 30 mg/kg 6-BG and 10 mg/kg 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) or with 40 mg/kg BCNU alone. Compared with mice treated with BCNU alone, significant myeloid toxicity and death occurred in mice reconstituted with mock-infected or WT MGMT (0.70; no treatment, <0.1). These data demonstrate that mutant MGMT expressed in the bone marrow can protect mice from time- and dose-intensive chemotherapy and that the combination of 6-BG and BCNU leads to uniform selection of transduced stem cells in vivo in mice.

  6. Structure functions and particle production in the cumulative region two different exponentials

    CERN Document Server

    Braun, M

    1996-01-01

    In the framework of the recently proposed QCD based parton model for the cumulative phenomena in the interactions with nuclei two mechanisms for particle production, direct and spectator ones, are analysed. It is shown that due to final state interactions the leading terms of the direct mechanism contribution are cancelled and the spectator mechanism is the dominant one. It leads to a smaller slope of the cumulative particle production rates compared to the slope of the nuclear structure function in the cumulative region x>1, in agreement with the recent experimental data.

  7. Continuously Cumulating Meta-Analysis and Replicability.

    Science.gov (United States)

    Braver, Sanford L; Thoemmes, Felix J; Rosenthal, Robert

    2014-05-01

    The current crisis in scientific psychology about whether our findings are irreproducible was presaged years ago by Tversky and Kahneman (1971), who noted that even sophisticated researchers believe in the fallacious Law of Small Numbers-erroneous intuitions about how imprecisely sample data reflect population phenomena. Combined with the low power of most current work, this often leads to the use of misleading criteria about whether an effect has replicated. Rosenthal (1990) suggested more appropriate criteria, here labeled the continuously cumulating meta-analytic (CCMA) approach. For example, a CCMA analysis on a replication attempt that does not reach significance might nonetheless provide more, not less, evidence that the effect is real. Alternatively, measures of heterogeneity might show that two studies that differ in whether they are significant might have only trivially different effect sizes. We present a nontechnical introduction to the CCMA framework (referencing relevant software), and then explain how it can be used to address aspects of replicability or more generally to assess quantitative evidence from numerous studies. We then present some examples and simulation results using the CCMA approach that show how the combination of evidence can yield improved results over the consideration of single studies.

  8. Nonlinear cumulative damage model for multiaxial fatigue

    Institute of Scientific and Technical Information of China (English)

    SHANG De-guang; SUN Guo-qin; DENG Jing; YAN Chu-liang

    2006-01-01

    On the basis of the continuum fatigue damage theory,a nonlinear uniaxial fatigue cumulative damage model is first proposed.In order to describe multiaxial fatigue damage characteristics,a nonlinear multiaxial fatigue cumulative damage model is developed based on the critical plane approach,The proposed model can consider the multiaxial fatigue limit,mean hydrostatic pressure and the unseparated characteristic for the damage variables and loading parameters.The recurrence formula of fatigue damage model was derived under multilevel loading,which is used to predict multiaxial fatigue life.The results showed that the proposed nonlinear multiaxial fatigue cumulative damage model is better than Miner's rule.

  9. Occupational Exposure to Knee Loading and the Risk of Osteoarthritis of the Knee: A Systematic Review and a Dose-Response Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Jos Verbeek

    2017-06-01

    Conclusion: There is moderate quality evidence that longer cumulative exposure to kneeling or squatting at work leads to a higher risk of osteoarthritis of the knee. For other exposure, there was no exposure dose-response or there were insufficient data to establish this. More reliable exposure measurements would increase the quality of the evidence.

  10. SCALE/MAVRIC calculation of dose rates measured for a gamma radiation source in a thick-walled transport and storage cask of ductile cast iron with lead inserts

    Science.gov (United States)

    Baumgarten, Werner; Thiele, Holger; Ruprecht, Benjamin; Phlippen, Peter-W.; Schlömer, Luc

    2017-09-01

    Dose rate calculations are important for judging the shielding performance of transport casks for radioactive material. Therefore it is important to have reliable calculation tools. We report on measured and calculated dose rates near a thick-walled transport and storage cask of ductile cast iron with lead inserts and a Co-60 source inside. In a series of experiments the thickness of the inserts was varied, and measured dose rates near the cask were compared with SCALE/MAVRIC 6.1.3 and SCALE/MAVRIC 6.2 calculation results. Deviations from the measurements were found to be higher for increased lead thicknesses. Furthermore, it is shown how the shielding material density, air scattering and accounting for the floor influence the quality of the calculation.

  11. Cumulative risk: toxicity and interactions of physical and chemical stressors.

    Science.gov (United States)

    Rider, Cynthia V; Boekelheide, Kim; Catlin, Natasha; Gordon, Christopher J; Morata, Thais; Selgrade, Maryjane K; Sexton, Kenneth; Simmons, Jane Ellen

    2014-01-01

    Recent efforts to update cumulative risk assessment procedures to incorporate nonchemical stressors ranging from physical to psychosocial reflect increased interest in consideration of the totality of variables affecting human health and the growing desire to develop community-based risk assessment methods. A key roadblock is the uncertainty as to how nonchemical stressors behave in relationship to chemical stressors. Physical stressors offer a reasonable starting place for measuring the effects of nonchemical stressors and their modulation of chemical effects (and vice versa), as they clearly differ from chemical stressors; and "doses" of many physical stressors are more easily quantifiable than those of psychosocial stressors. There is a commonly held belief that virtually nothing is known about the impact of nonchemical stressors on chemically mediated toxicity or the joint impact of coexposure to chemical and nonchemical stressors. Although this is generally true, there are several instances where a substantial body of evidence exists. A workshop titled "Cumulative Risk: Toxicity and Interactions of Physical and Chemical Stressors" held at the 2013 Society of Toxicology Annual Meeting provided a forum for discussion of research addressing the toxicity of physical stressors and what is known about their interactions with chemical stressors, both in terms of exposure and effects. Physical stressors including sunlight, heat, radiation, infectious disease, and noise were discussed in reference to identifying pathways of interaction with chemical stressors, data gaps, and suggestions for future incorporation into cumulative risk assessments.

  12. Cumulative cultural learning: Development and diversity.

    Science.gov (United States)

    Legare, Cristine H

    2017-07-24

    The complexity and variability of human culture is unmatched by any other species. Humans live in culturally constructed niches filled with artifacts, skills, beliefs, and practices that have been inherited, accumulated, and modified over generations. A causal account of the complexity of human culture must explain its distinguishing characteristics: It is cumulative and highly variable within and across populations. I propose that the psychological adaptations supporting cumulative cultural transmission are universal but are sufficiently flexible to support the acquisition of highly variable behavioral repertoires. This paper describes variation in the transmission practices (teaching) and acquisition strategies (imitation) that support cumulative cultural learning in childhood. Examining flexibility and variation in caregiver socialization and children's learning extends our understanding of evolution in living systems by providing insight into the psychological foundations of cumulative cultural transmission-the cornerstone of human cultural diversity.

  13. Calculating Cumulative Binomial-Distribution Probabilities

    Science.gov (United States)

    Scheuer, Ernest M.; Bowerman, Paul N.

    1989-01-01

    Cumulative-binomial computer program, CUMBIN, one of set of three programs, calculates cumulative binomial probability distributions for arbitrary inputs. CUMBIN, NEWTONP (NPO-17556), and CROSSER (NPO-17557), used independently of one another. Reliabilities and availabilities of k-out-of-n systems analyzed. Used by statisticians and users of statistical procedures, test planners, designers, and numerical analysts. Used for calculations of reliability and availability. Program written in C.

  14. Pulmonary instillation of low doses of titanium dioxide nanoparticles in mice leads to particle retention and gene expression changes in the absence of inflammation

    Energy Technology Data Exchange (ETDEWEB)

    Husain, Mainul, E-mail: mainul.husain@hc-sc.gc.ca [Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario K1A 0K9 (Canada); Saber, Anne T., E-mail: ats@nrcwe.dk [The Danish NanoSafety Centre, National Research Centre for the Working Environment, Copenhagen DK-2100 (Denmark); Guo, Charles, E-mail: charles.guo@hc-sc.gc.ca [Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario K1A 0K9 (Canada); Jacobsen, Nicklas R., E-mail: nrj@nrcwe.dk [The Danish NanoSafety Centre, National Research Centre for the Working Environment, Copenhagen DK-2100 (Denmark); Jensen, Keld A., E-mail: kaj@nrcwe.dk [The Danish NanoSafety Centre, National Research Centre for the Working Environment, Copenhagen DK-2100 (Denmark); Yauk, Carole L., E-mail: carole.yauk@hc-sc.gc.ca [Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario K1A 0K9 (Canada); Williams, Andrew, E-mail: andrew.williams@hc-sc.gc.ca [The Danish NanoSafety Centre, National Research Centre for the Working Environment, Copenhagen DK-2100 (Denmark); Vogel, Ulla, E-mail: ubv@nrcwe.dk [The Danish NanoSafety Centre, National Research Centre for the Working Environment, Copenhagen DK-2100 (Denmark); Department of Micro- and Nanotechnology, Technical University of Denmark, Kgs. Lyngby DK-2800 (Denmark); Wallin, Hakan, E-mail: hwa@nrcwe.dk [The Danish NanoSafety Centre, National Research Centre for the Working Environment, Copenhagen DK-2100 (Denmark); Institute of Public Health, University of Copenhagen, Copenhagen DK-1014 (Denmark); Halappanavar, Sabina, E-mail: sabina.halappanavar@hc-sc.gc.ca [Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario K1A 0K9 (Canada)

    2013-06-15

    We investigated gene expression, protein synthesis, and particle retention in mouse lungs following intratracheal instillation of varying doses of nano-sized titanium dioxide (nano-TiO{sub 2}). Female C57BL/6 mice were exposed to rutile nano-TiO{sub 2} via single intratracheal instillations of 18, 54, and 162 μg/mouse. Mice were sampled 1, 3, and 28 days post-exposure. The deposition of nano-TiO{sub 2} in the lungs was assessed using nanoscale hyperspectral microscopy. Biological responses in the pulmonary system were analyzed using DNA microarrays, pathway-specific real-time RT-PCR (qPCR), gene-specific qPCR arrays, and tissue protein ELISA. Hyperspectral mapping showed dose-dependent retention of nano-TiO{sub 2} in the lungs up to 28 days post-instillation. DNA microarray analysis revealed approximately 3000 genes that were altered across all treatment groups (± 1.3 fold; p < 0.1). Several inflammatory mediators changed in a dose- and time-dependent manner at both the mRNA and protein level. Although no influx of neutrophils was detected at the low dose, changes in the expression of several genes and proteins associated with inflammation were observed. Resolving inflammation at the medium dose, and lack of neutrophil influx in the lung fluid at the low dose, were associated with down-regulation of genes involved in ion homeostasis and muscle regulation. Our gene expression results imply that retention of nano-TiO{sub 2} in the absence of inflammation over time may potentially perturb calcium and ion homeostasis, and affect smooth muscle activities. - Highlights: • Pulmonary effects following exposure to low doses of nano-TiO{sub 2} were examined. • Particle retention in lungs was assessed using nanoscale hyperspectral microscopy. • Particles persisted up to 28 days in lungs in all dose groups. • Inflammation was the pathway affected in the high dose group at all time points. • Ion homeostasis and muscle activity pathways were affected in the low dose

  15. Cumulative cultural evolution: the role of teaching.

    Science.gov (United States)

    Castro, Laureano; Toro, Miguel A

    2014-04-21

    In humans, cultural transmission occurs usually by cumulative inheritance, generating complex adaptive behavioral features. Cumulative culture requires key psychological processes (fundamentally imitation and teaching) that are absent or impoverished in non-human primates. In this paper we analyze the role that teaching has played in human cumulative cultural evolution. We assume that a system of cumulative culture generates increasingly adaptive behaviors, that are also more complex and difficult to imitate. Our thesis is that, as cultural traits become more complex, cumulative cultural transmission requires teaching to ensure accurate transmission from one generation to the next. In an increasingly complex cultural environment, we consider that individuals commit errors in imitation. We develop a model of cumulative cultural evolution in a changing environment and show that these errors hamper the process of cultural accumulation. We also show that a system of teaching between parents and offspring that increases the fidelity of imitation unblocks the accumulation and becomes adaptive whenever the gain in fitness compensates the cost of teaching.

  16. Experience of cumulative effects assessment in the UK

    Directory of Open Access Journals (Sweden)

    Piper Jake

    2004-01-01

    Full Text Available Cumulative effects assessment (CEA is a development of environmental impact assessment which attempts to take into account the wider picture of what impacts may affect the environment as a result of either multiple or linear projects, or development plans. CEA is seen as a further valuable tool in promoting sustainable development. The broader canvas upon which the assessment is made leads to a suite of issues such as complexity in methods and assessment of significance, the desirability of co-operation between developers and other parties, new ways of addressing mitigation and monitoring. After outlining the legislative position and the process of CEA, this paper looks at three cases studies in the UK where cumulative assessment has been carried out - the cases concern wind farms, major infrastructure and off-shore developments.

  17. Effect of flow rate and lead/copper pipe sequence on lead release from service lines.

    Science.gov (United States)

    Cartier, Clément; Arnold, Roger B; Triantafyllidou, Simoni; Prévost, Michèle; Edwards, Marc

    2012-09-01

    A pilot experiment examined lead leaching from four representative configurations of service lines including: (1) 100% lead (Pb), (2) 100% copper (Cu), (3) 50% Pb upstream of 50% Cu, and (4) 50% Pb-downstream of 50% Cu using a range of flow rates. The cumulative mass of lead release indicated that a typical partial replacement configuration (50% lead downstream of copper) did not provide a net reduction in lead when compared to 100% lead pipe (85 mg for 50% Pb-downstream versus 83 mg for 100%-Pb) due to galvanic and deposition corrosion. The partially replaced service line configuration also had a much greater likelihood of producing water with "spikes" of lead particulates at higher flow rates, while tending to produce lower levels of lead at very low flow rates. After the first 214 days the galvanic current between copper and lead was only reduced by 34%, proving that galvanic impacts can be highly persistent even in water with optimized corrosion control by dosing of zinc orthophosphate. Finally, this experiment raises concern about the low flow rates used during some prior home sampling events, which may underestimate exposure to lead during normal water use, especially when galvanic Pb:Cu connections are present.

  18. Computed tomography dose optimisation in cystic fibrosis:A review

    Institute of Scientific and Technical Information of China (English)

    Helena Ferris; Maria Twomey; Fiachra Moloney; Siobhan B O’Neill; Kevin Murphy; Owen J O’Connor; Michael Maher

    2016-01-01

    Cystic fibrosis(CF)is the most common autosomal recessive disease of the Caucasian population worldwide,with respiratory disease remaining the most relevant source of morbidity and mortality.Computed tomography(CT)is frequently used for monitoring disease complications and progression.Over the last fifteen years there has been a six-fold increase in the use of CT,which has lead to a growing concern in relation to cumulative radiation exposure.The challenge to the medical profession is to identify dose reduction strategies that meet acceptable image quality,but fulfil the requirements of a diagnostic quality CT.Dose-optimisation,particularly in CT,is essential as it reduces the chances of patients receiving cumulative radiation doses in excess of 100 m Sv,a dose deemed significant by the United Nations Scientific Committee on the Effects of Atomic Radiation.This review article explores the current trends in imaging in CF with particular emphasis on new developments in dose optimisation.

  19. Clinical experience with daily doses of misonidazole

    Energy Technology Data Exchange (ETDEWEB)

    Kogelnik, H.D.; Reinartz, G.; Szepesi, T.; Seitz, W.; Wurst, F.; Mamoli, B.; Wessely, P.; Stark, H.

    1980-11-01

    In this pilot study daily low doses of misonidazole (in the range of 1 to 2 g) up to cumulative doses between 7 and 19 g/m/sup 2/ were used. Serum levels were analysed at different times after administration and according to several dose regimens. We related the cumulative doses to the incidence and severity of the observed peripheral neuropathies. The aim was to find an effective daily low-dose schedule of misonidazole with a clinically acceptable incidence of side effects. Some impressive clinical responses were observed.

  20. Cumulative Phenomena through the Quark-Parton Diagram Summation at Thresholds

    CERN Document Server

    Braun, M A

    1998-01-01

    A microscopic treatment of cumulative phenomena based on perturbative QCD calculations of the corresponding quark diagrams near the threshold is presented. To sum all diagrams like these the special technique based on the recurrence relations was developed. The x-behaviour of the nuclear structure function $F_{2}(x)$ in the cumulative region x>1 was found to be roughly exponential, governed by an effective coupling constant, which depends on the QCD coupling constant and quark mass. Two mechanisms for cumulative particle production, direct and spectator ones, were analysed. It was shown that due to final state interactions the leading terms of the direct mechanism contribution are cancelled and the spectator mechanism is the dominant one. It leads to a smaller slope of the particle production rates compared to the slope of the nuclear structure function in the cumulative region, in agreement with the recent experimental data. The slope difference is due to additional multiple interactions between nuclear and ...

  1. Pulmonary instillation of low doses of titanium dioxide nanoparticles in mice leads to particle retention and gene expression changes in the absence of inflammation

    DEFF Research Database (Denmark)

    Husain, Mainul; Saber, Anne Thoustrup; Guo, Charles

    2013-01-01

    We investigated gene expression, protein synthesis, and particle retention in mouse lungs following intratracheal instillation of varying doses of nano-sized titanium dioxide (nano-TiO2). Female C57BL/6 mice were exposed to rutile nano-TiO2 via single intratracheal instillations of 18, 54, and 162...

  2. Predicting Cumulative Incidence Probability by Direct Binomial Regression

    DEFF Research Database (Denmark)

    Scheike, Thomas H.; Zhang, Mei-Jie

    Binomial modelling; cumulative incidence probability; cause-specific hazards; subdistribution hazard......Binomial modelling; cumulative incidence probability; cause-specific hazards; subdistribution hazard...

  3. Cumulative Culture and Future Thinking: Is Mental Time Travel a Prerequisite to Cumulative Cultural Evolution?

    Science.gov (United States)

    Vale, G. L.; Flynn, E. G.; Kendal, R. L.

    2012-01-01

    Cumulative culture denotes the, arguably, human capacity to build on the cultural behaviors of one's predecessors, allowing increases in cultural complexity to occur such that many of our cultural artifacts, products and technologies have progressed beyond what a single individual could invent alone. This process of cumulative cultural evolution…

  4. High cumulative insulin exposure : a risk factor of atherosclerosis in type 1 diabetes?

    NARCIS (Netherlands)

    Muis, MJ; Bots, ML; Bilo, HJG; Hoogma, RPLM; Hoekstra, JBL; Grobbee, DE; Stolk, RP

    Background: Since insulin therapy might have an atherogenic effect, we studied the relationship between cumulative insulin dose and atherosclerosis in type 1 diabetes. We have focused on patients with type 1 diabetes instead of type 2 diabetes to minimise the effect of insulin resistance as a

  5. Engineering of the PapMV vaccine platform with a shortened M2e peptide leads to an effective one dose influenza vaccine.

    Science.gov (United States)

    Carignan, Damien; Thérien, Ariane; Rioux, Gervais; Paquet, Geneviève; Gagné, Marie-Ève Laliberté; Bolduc, Marilène; Savard, Pierre; Leclerc, Denis

    2015-12-16

    The emergence of highly virulent influenza strains and the risks of pandemics as well as the limited efficiency of the current seasonal vaccines are important public health concerns. There is a major need for new influenza vaccines that would be broadly cross-protective. The ectodomain of matrix protein 2 (M2e) is highly conserved amongst different influenza strains and could be used as a broad spectrum antigen. To overcome its low immunogenicity we have fused a short peptide epitope derived from the human consensus sequence of M2e (amino acids 6-14, EVETPIRNE) to the N-terminus of papaya mosaic virus coat protein. The fusion harboring coat proteins were assembled around a single stranded RNA into virus-like particles (PapMV-sM2e). The resulting PapMV-sM2e rod-shaped particle was stable and indistinguishable from regular PapMV particles. A single intramuscular immunization with PapMV-sM2e was sufficient to mount appreciable levels of CD4 dependent M2e specific total IgG and IgG2a antibody in mice sera. PapMV-sM2e proved to be self-adjuvanting since the addition of PapMV as an exogenous adjuvant did not result in significantly improved antibody titers. In addition, we confirmed the adjuvant property of PapMV-sM2e using the trivalent inactivated flu vaccine as antigen and demonstrated that the newly engineered nanoparticles areas efficacious as an adjuvant than the original PapMV nanoparticles. Upon infection with a sub-lethal dose of influenza, PapMV-sM2e vaccinated animals were completely protected from virus induced morbidity and mortality. Mice immunized with decreasing amounts of PapMV-sM2e and challenged with a more stringent dose of influenza virus displayed dose-dependent levels of protection. Seventy percent of the mice immunized once with the highest dose of PapMV-sM2e survived the challenged. The survival of the mice correlated mainly with the levels of anti-M2e IgG2a antibodies obtained before the infection. These results demonstrate that PapMV-sM2e can

  6. Is cumulated pyrethroid exposure associated with prediabetes?

    DEFF Research Database (Denmark)

    Hansen, Martin Rune; Jørs, Erik; Lander, Flemming;

    2014-01-01

    , cumulative exposure) was assessed from questionnaire data. Participants were asked about symptoms of diabetes. Blood samples were analyzed for glycosylated hemoglobin (HbA1c), a measure of glucose regulation. No association was found between pyrethroid exposure and diabetes symptoms. The prevalence...

  7. Cumulative Disadvantage among the Highly Ambitious.

    Science.gov (United States)

    McClelland, Katherine

    1990-01-01

    Using a social reproduction theory framework, analyzes the process by which high school seniors aspiring to high-level positions are sorted out after graduation. Analyzes early educational attainments and changes in occupational expectations. Shows a process of cumulative disadvantage in which White males are more likely to achieve their goals.…

  8. Pavlovian conditioning and cumulative reinforcement rate.

    Science.gov (United States)

    Harris, Justin A; Patterson, Angela E; Gharaei, Saba

    2015-04-01

    In 5 experiments using delay conditioning of magazine approach with rats, reinforcement rate was varied either by manipulating the mean interval between onset of the conditioned stimulus (CS) and unconditioned stimulus (US) or by manipulating the proportion of CS presentations that ended with the US (trial-based reinforcement rate). Both manipulations influenced the acquisition of responding. In each experiment, a specific comparison was made between 2 CSs that differed in their mean CS-US interval and in their trial-based reinforcement rate, such that the cumulative reinforcement rate-the cumulative duration of the CS between reinforcements-was the same for the 2 CSs. For example, a CS reinforced on 100% of trials with a mean CS-US interval of 60 s was compared with a CS reinforced on 33% of trials and a mean duration of 20 s. Across the 5 experiments, conditioning was virtually identical for the 2 CSs with matched cumulative reinforcement rate. This was true as long as the timing of the US was unpredictable and, thus, response rates were uniform across the length of the CS. We conclude that the effects of CS-US interval and of trial-based reinforcement rate are reducible entirely to their common effect on cumulative reinforcement rate. We discuss the implications of this for rate-based, trial-based, and real-time associative models of conditioning.

  9. An Axiomatization of Cumulative Prospect Theory

    NARCIS (Netherlands)

    Wakker, P.P.; Tversky, A.

    1993-01-01

    This paper presents a method for axiomatizing a variety of models for decision making under uncertainty, including Expected Utility and Cumulative Prospect Theory. This method identifies, for each model, the situations that permit consistent inferences about the ordering of value differences. Exampl

  10. Cumulative Disadvantage among the Highly Ambitious.

    Science.gov (United States)

    McClelland, Katherine

    1990-01-01

    Using a social reproduction theory framework, analyzes the process by which high school seniors aspiring to high-level positions are sorted out after graduation. Analyzes early educational attainments and changes in occupational expectations. Shows a process of cumulative disadvantage in which White males are more likely to achieve their goals.…

  11. Characterization of toxicokinetics and toxicodynamics with linear systems theory: application to lead-associated cognitive decline.

    Science.gov (United States)

    Links, J M; Schwartz, B S; Simon, D; Bandeen-Roche, K; Stewart, W F

    2001-04-01

    We present a theoretical approach to analysis of toxicokinetics and toxicodynamics using linear systems theory. In our approach, we define two impulse response functions that characterize the kinetic behavior of an environmental agent in the body and the dynamic time-course behavior of its effect on the body. This approach provides a formalism for understanding the relation among exposure, dose, and cumulative biologically effective dose and for understanding the implications of an effect time-course on cross-sectional and longitudinal data analyses. We use lead-associated cognitive decline as a specific example where the approach may be applied.

  12. Anemia risk in relation to lead exposure in lead-related manufacturing.

    Science.gov (United States)

    Hsieh, Nan-Hung; Chung, Shun-Hui; Chen, Szu-Chieh; Chen, Wei-Yu; Cheng, Yi-Hsien; Lin, Yi-Jun; You, Su-Han; Liao, Chung-Min

    2017-05-05

    Lead-exposed workers may suffer adverse health effects under the currently regulated blood lead (BPb) levels. However, a probabilistic assessment about lead exposure-associated anemia risk is lacking. The goal of this study was to examine the association between lead exposure and anemia risk among factory workers in Taiwan. We first collated BPb and indicators of hematopoietic function data via health examination records that included 533 male and 218 female lead-exposed workers between 2012 and 2014. We used benchmark dose (BMD) modeling to estimate the critical effect doses for detection of abnormal indicators. A risk-based probabilistic model was used to characterize the potential hazard of lead poisoning for job-specific workers by hazard index (HI). We applied Bayesian decision analysis to determine whether BMD could be implicated as a suitable BPb standard. Our results indicated that HI for total lead-exposed workers was 0.78 (95% confidence interval: 0.50-1.26) with risk occurrence probability of 11.1%. The abnormal risk of anemia indicators for male and female workers could be reduced, respectively, by 67-77% and 86-95% by adopting the suggested BPb standards of 25 and 15 μg/dL. We conclude that cumulative exposure to lead in the workplace was significantly associated with anemia risk. This study suggests that current BPb standard needs to be better understood for the application of lead-exposed population protection in different scenarios to provide a novel standard for health management. Low-level lead exposure risk is an occupational and public health problem that should be paid more attention.

  13. Cumulative receipt of an anti-poverty tax credit for families did not impact tobacco smoking among parents.

    Science.gov (United States)

    Pega, Frank; Gilsanz, Paola; Kawachi, Ichiro; Wilson, Nick; Blakely, Tony

    2017-04-01

    The effect of anti-poverty tax credit interventions on tobacco consumption is unclear. Previous studies have estimated short-term effects, did not isolate the effects of cumulative dose of tax credits, produced conflicting results, and used methods with limited control for some time-varying confounders (e.g., those affected by prior treatment) and treatment regimen (i.e., study participants' tax credit receipt pattern over time). We estimated the longer-term, cumulative effect of New Zealand's Family Tax Credit (FTC) on tobacco consumption, using a natural experiment (administrative errors leading to exogenous variation in FTC receipt) and methods specifically for controlling confounding, reverse causation, and treatment regimen. We extracted seven waves (2002-2009) of the nationally representative Survey of Family, Income and Employment including 4404 working-age (18-65 years) parents in families. The exposure was the total numbers of years of receiving FTC. The outcomes were regular smoking and the average daily number of cigarettes usually smoked at wave 7. We estimated average treatment effects using inverse probability of treatment weighting and marginal structural modelling. Each additional year of receiving FTC affected neither the odds of regular tobacco smoking among all parents (odds ratio 1.02, 95% confidence interval 0.94-1.11), nor the number of cigarettes smoked among parents who smoked regularly (rate ratio 1.01, 95% confidence interval 0.99-1.03). We found no evidence for an association between the cumulative number of years of receiving an anti-poverty tax credit and tobacco smoking or consumption among parents. The assumptions of marginal structural modelling are quite demanding, and we therefore cannot rule out residual confounding. Nonetheless, our results suggest that tax credit programme participation will not increase tobacco consumption among poor parents, at least in this high-income country. Copyright © 2017 Elsevier Ltd. All rights

  14. The use of internal dose biomarkers for assessment of lead exposure and its correlations with anemia and genetic polymorphisms from children living in uncontaminated area

    OpenAIRE

    Glauce Regina Costa de Almeida

    2009-01-01

    Resumo: Devido ao aumento das evidências de que o desenvolvimento mental das crianças pode ser afetado quando elas apresentam concentrações de chumbo no sangue < 10 $g/dL, estudos a respeito de novos biomarcadores de dose interna são necessários, principalmente para se obter informações em relação à exposição de populações residentes em áreas sem contaminação conhecida pelo chumbo. No Brasil, não existe programa nacional para detecção de crianças contaminadas por este metal, as quais são as m...

  15. High frequency of streptococcal bacteraemia during childhood AML therapy irrespective of dose of cytarabine

    DEFF Research Database (Denmark)

    Johannsen, Katrine Helle; Handrup, Mette Møller; Lausen, Birgitte Frederiksen

    2013-01-01

    BACKGROUND: High-dose cytarabine has been associated with a high frequency of viridans group streptococcal (VGS) bacteraemia. VGS bacteraemia causes considerable morbidity and mortality. The Nordic Society of Paediatric Haematology and Oncology (NOPHO)-AML protocols use higher cumulated doses...... following courses with low-dose cytarabine versus courses with high-dose cytarabine. CONCLUSIONS: VGS were the most commonly isolated pathogens causing the most severe infections and the majority of life-threatening infections. A substantial proportion of the strains were resistant to penicillin. The high...... rate of VGS seemed independent of high-dose cytarabine but was more likely caused by the intensive chemotherapy treatment leading to severe mucositis and neutropenia....

  16. Studies on γ-ray induced structural changes in Nd{sup 3+} doped lead alumino silicate glasses by means of thermoluminescence for dosimetric applications in high dose ranges

    Energy Technology Data Exchange (ETDEWEB)

    Sundara Rao, M. [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522 510, Guntur, A.P. (India); Gandhi, Y. [Department of Physics, Kakani Venkata Ratnam College, Nandigama 521 185, A.P. (India); Sanyal, Bhaskar [Food Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Bhargavi, K. [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522 510, Guntur, A.P. (India); Piasecki, M. [Institute of Physics, J. Dlugosz University, Ul. Armii Krajowej 13/15, 42-201 Czestochowa (Poland); Veeraiah, N., E-mail: nvr8@rediffmail.com [Department of Physics, Acharya Nagarjuna University, Nagarjuna Nagar 522 510, Guntur, A.P. (India)

    2014-12-15

    Graphical abstract: TL glow curves of PbO–SiO{sub 2}:Nd{sup 3+} glasses mixed with different concentrations of Al{sub 2}O{sub 3} exposed to γ-rays of dose 5.0 kGy. - Highlights: • TL studies of Nd{sup 3+} ions doped lead alumino silicate glasses were carried out. • Highest TL output was observed in the glasses mixed with 10 mol% of Al{sub 2}O{sub 3}. • Different mechanisms responsible for TL emission were discussed. • Near linearity of the dose response was observed in the dose range of 1.0–3.0 kGy. • These glasses may be useful as dosimeters in processing perishable food commodities. - Abstract: Thermoluminescence (TL) studies on PbO–Al{sub 2}O{sub 3}–SiO{sub 2}:Nd{sup 3+} glasses mixed with varying concentrations of Al{sub 2}O{sub 3} exposed to γ-rays of dose in the range 0–5.0 kGy were carried out. The TL emission exhibited a dosimetric peak at about 185 °C. The TL output under the glow peak increased with increasing Al{sub 2}O{sub 3} and also with the γ-ray dose. The mechanisms responsible for TL emission and enhancement of TL output with increase in the concentration of Al{sub 2}O{sub 3} were quantitatively discussed in terms of induced structural defects in the vicinity of Nd{sup 3+} ions due to interaction of γ-rays with the glass network in the scenario of varying concentration of Al{sub 2}O{sub 3}. The dose response of these glass samples exhibited linear behavior in the medium dose range viz., 1.0–3.0 kGy. Finally, it is concluded that the glass containing the highest concentration of Al{sub 2}O{sub 3} exhibits high TL output and such glasses are useful for dosimetry in the range 1.0–3.0 kGy and hence these glasses may be useful for dosimetry in such high range of doses required for commercial radiation processing of perishable food commodities to extend their shelf-lives.

  17. Ratcheting up the ratchet: on the evolution of cumulative culture.

    Science.gov (United States)

    Tennie, Claudio; Call, Josep; Tomasello, Michael

    2009-08-27

    Some researchers have claimed that chimpanzee and human culture rest on homologous cognitive and learning mechanisms. While clearly there are some homologous mechanisms, we argue here that there are some different mechanisms at work as well. Chimpanzee cultural traditions represent behavioural biases of different populations, all within the species' existing cognitive repertoire (what we call the 'zone of latent solutions') that are generated by founder effects, individual learning and mostly product-oriented (rather than process-oriented) copying. Human culture, in contrast, has the distinctive characteristic that it accumulates modifications over time (what we call the 'ratchet effect'). This difference results from the facts that (i) human social learning is more oriented towards process than product and (ii) unique forms of human cooperation lead to active teaching, social motivations for conformity and normative sanctions against non-conformity. Together, these unique processes of social learning and cooperation lead to humans' unique form of cumulative cultural evolution.

  18. Complexity and demographic explanations of cumulative culture.

    Directory of Open Access Journals (Sweden)

    Adrien Querbes

    Full Text Available Formal models have linked prehistoric and historical instances of technological change (e.g., the Upper Paleolithic transition, cultural loss in Holocene Tasmania, scientific progress since the late nineteenth century to demographic change. According to these models, cumulation of technological complexity is inhibited by decreasing--while favoured by increasing--population levels. Here we show that these findings are contingent on how complexity is defined: demography plays a much more limited role in sustaining cumulative culture in case formal models deploy Herbert Simon's definition of complexity rather than the particular definitions of complexity hitherto assumed. Given that currently available empirical evidence doesn't afford discriminating proper from improper definitions of complexity, our robustness analyses put into question the force of recent demographic explanations of particular episodes of cultural change.

  19. Avoiding Program-Induced Cumulative Overload (PICO).

    Science.gov (United States)

    Orr, Robin; Knapik, Joseph J; Pope, Rodney

    2016-01-01

    This article defines the concept of program-induced cumulative overload (PICO), provides examples, and advises ways to mitigate the adverse effects. PICO is the excessive cumulative physical workload that can be imparted to military personnel by a military training program with an embedded physical training component. PICO can be acute (accumulating within a single day) or chronic (accumulating across the entirety of the program) and results in adverse outcomes for affected personnel, including detrimental fatigue, performance degradation, injuries, or illness. Strategies to mitigate PICO include focusing administration and logistic practices during the development and ongoing management of a trainee program and implementing known musculoskeletal injury prevention strategies. More training is not always better, and trainers need to consider the total amount of physical activity that military personnel experience across both operational training and physical training if PICO is to be mitigated.

  20. Sharing a quota on cumulative carbon emissions

    Science.gov (United States)

    Raupach, Michael R.; Davis, Steven J.; Peters, Glen P.; Andrew, Robbie M.; Canadell, Josep G.; Ciais, Philippe; Friedlingstein, Pierre; Jotzo, Frank; van Vuuren, Detlef P.; Le Quéré, Corinne

    2014-10-01

    Any limit on future global warming is associated with a quota on cumulative global CO2 emissions. We translate this global carbon quota to regional and national scales, on a spectrum of sharing principles that extends from continuation of the present distribution of emissions to an equal per-capita distribution of cumulative emissions. A blend of these endpoints emerges as the most viable option. For a carbon quota consistent with a 2 °C warming limit (relative to pre-industrial levels), the necessary long-term mitigation rates are very challenging (typically over 5% per year), both because of strong limits on future emissions from the global carbon quota and also the likely short-term persistence in emissions growth in many regions.

  1. Structural Vibration Monitoring Using Cumulative Spectral Analysis

    Directory of Open Access Journals (Sweden)

    Satoru Goto

    2013-01-01

    Full Text Available This paper describes a resonance decay estimation for structural health monitoring in the presence of nonstationary vibrations. In structural health monitoring, the structure's frequency response and resonant decay characteristics are very important for understanding how the structure changes. Cumulative spectral analysis (CSA estimates the frequency decay by using the impulse response. However, measuring the impulse response of buildings is impractical due to the need to shake the building itself. In a previous study, we reported on system damping monitoring using cumulative harmonic analysis (CHA, which is based on CSA. The current study describes scale model experiments on estimating the hidden resonance decay under non-stationary noise conditions by using CSA for structural condition monitoring.

  2. Metronomic Treatment with Low-Dose Trofosfamide Leads to a Long-Term Remission in a Patient with Docetaxel-Refractory Advanced Metastatic Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Jochen Greiner

    2010-01-01

    Full Text Available The treatment of metastatic prostate cancer patients refractory to androgen withdrawal and docetaxel therapy is currently discouraging and new therapeutic approaches are vastly needed. Here, we report a long-term remission over one year in a 68-year-old patient with metastatic docetaxel-refractory prostate cancer employing low-dose trofosfamide. The patient suffered from distant failure with several bone lesions and lymph node metastases depicted by a (11 C-Choline positron emission tomography/computerized tomography (PET/CT. After initiation of trofosfamide 100 mg taken orally once a day we observed a steadily decreasing PSA value from initial 46.6 down to 2.1 g/l. The Choline-PET/CT was repeated after 10 months of continuous therapy and demonstrated a partial remission of the bone lesions and a regression of all involved lymph nodes but one. Taken together we found an astonishing and durable activity of the alkylating agent trofosfamide given in a metronomic fashion. We rate the side effects as low and state an excellent therapeutic ratio of this drug in our patient.

  3. Cumulative carbon emissions and the Green Paradox

    OpenAIRE

    Ploeg, Frederick Van der

    2013-01-01

    The green paradox states that a gradually more ambitious climate policy such as a renewables subsidy or an anticipated carbon tax induces fossil fuel owners to extract more rapidly and accelerate global warming. However, if extraction becomes more costly as reserves are depleted, such policies also shorten the fossil fuel era, induce more fossil fuel to be left in the earth, and thus curb cumulative carbon emissions. These consequences are relevant, as global warming depends primarily on cumu...

  4. Expansive Soil Crack Depth under Cumulative Damage

    Directory of Open Access Journals (Sweden)

    Bei-xiao Shi

    2014-01-01

    Full Text Available The crack developing depth is a key problem to slope stability of the expansive soil and its project governance and the crack appears under the roles of dry-wet cycle and gradually develops. It is believed from the analysis that, because of its own cohesion, the expansive soil will have a certain amount of deformation under pulling stress but without cracks. The soil body will crack only when the deformation exceeds the ultimate tensile strain that causes cracks. And it is also believed that, due to the combined effect of various environmental factors, particularly changes of the internal water content, the inherent basic physical properties of expansive soil are weakened, and irreversible cumulative damages are eventually formed, resulting in the development of expansive soil cracks in depth. Starting from the perspective of volumetric strain that is caused by water loss, considering the influences of water loss rate and dry-wet cycle on crack developing depth, the crack developing depth calculation model which considers the water loss rate and the cumulative damages is established. Both the proposal of water loss rate and the application of cumulative damage theory to the expansive soil crack development problems try to avoid difficulties in matrix suction measurement, which will surely play a good role in promoting and improving the research of unsaturated expansive soil.

  5. EPA Workshop on Epigenetics and Cumulative Risk ...

    Science.gov (United States)

    Agenda Download the Workshop Agenda (PDF) The workshop included presentations and discussions by scientific experts pertaining to three topics (i.e., epigenetic changes associated with diverse stressors, key science considerations in understanding epigenetic changes, and practical application of epigenetic tools to address cumulative risks from environmental stressors), to address several questions under each topic, and included an opportunity for attendees to participate in break-out groups, provide comments and ask questions. Workshop Goals The workshop seeks to examine the opportunity for use of aggregate epigenetic change as an indicator in cumulative risk assessment for populations exposed to multiple stressors that affect epigenetic status. Epigenetic changes are specific molecular changes around DNA that alter expression of genes. Epigenetic changes include DNA methylation, formation of histone adducts, and changes in micro RNAs. Research today indicates that epigenetic changes are involved in many chronic diseases (cancer, cardiovascular disease, obesity, diabetes, mental health disorders, and asthma). Research has also linked a wide range of stressors including pollution and social factors with occurrence of epigenetic alterations. Epigenetic changes have the potential to reflect impacts of risk factors across multiple stages of life. Only recently receiving attention is the nexus between the factors of cumulative exposure to environmental

  6. Cumulative stress in research animals: Telomere attrition as a biomarker in a welfare context?

    Science.gov (United States)

    Bateson, Melissa

    2016-02-01

    Progress in improving animal welfare is currently limited by the lack of objective methods for assessing lifetime experience. I propose that telomere attrition, a cellular biomarker of biological age, provides a molecular measure of cumulative experience that could be used to assess the welfare impact of husbandry regimes and/or experimental procedures on non-human animals. I review evidence from humans that telomere attrition is accelerated by negative experiences in a cumulative and dose-dependent manner, but that this attrition can be mitigated or even reversed by positive life-style interventions. Evidence from non-human animals suggests that despite some specific differences in telomere biology, stress-induced telomere attrition is a robust phenomenon, occurring in a range of species including mice and chickens. I conclude that telomere attrition apparently integrates positive and negative experience in an accessible common currency that translates readily to novel species--the Holy Grail of a cumulative welfare indicator.

  7. Comparison of colorimetric and HPLC methods for determination of delta-aminolevulinic acid in urine with reference to dose-response relationship in occupational exposure to lead.

    Science.gov (United States)

    Fukui, Yoshinari; Miki, Mieko; Ukai, Hirohiko; Okamoto, Satoru; Takada, Shiro; Ikeda, Masayuki

    2005-10-01

    Both traditional colorimetry and recently developed HPLC-fluorometry have been in use for determination of delta-aminolevulinic acid in urine (ALA-U), an effect marker of occupational exposure to lead (Pb). The present study was initiated to compare the values by the two methods on an epidemiology basis among workers occupationally exposed to lead (Pb), to estimate quantitatively the colorimetry-associated increment over the values by the HPLC method, to evaluate ALA-U determination in occupational health service for Pb-exposed workers, and to identify a critical Pb-B to induce an elevation in ALA-U. For this purpose, blood and urine samples were collected from three groups of Pb-exposed workers (both men and women in combination, including smokers) and analyzed for Pb in blood (Pb-B; measured in all subjects) and ALA-U (by colorimetry or HPLC), i.e., Group 1 (164 subjects with urinalysis by the two methods), Group 2 (2,923 subjects by colorimetry), and Group 3 (2,540 subjects by HPLC). ALA-U when measured by colorimetry was higher than the values by HPLC, and that the mean difference on a group basis was 1.4 mg/l (in a range of 1.1 to 1.8 mg/l), irrespective of Pb-B levels. It was also found that the increase in ALA-U was small when Pb-B was relatively low (e.g., < or = 40 microg/100 ml), and that the increase on a group basis in response to an increase in Pb-B from 5 to 40 microg/100 ml was as small as < or = 0.6 mg/l. Thus, ALA-U appeared to be not a sensitive marker of Pb effects at low Pb-B levels. ALA-U however increased substantially with a point of inflection at the Pb-B level of about 17-34 microg/100 ml. Thus it was concluded that ALA-U as measured by colorimetry is greater than ALA-U by HPLC by 1.4 mg/l on average irrespective of intensity of Pb-exposure, which may induce bias in evaluation of health effect, and that ALA-U levels will increase when Pb-B is in excess of 17-34 microg/100 ml.

  8. A Cumulant-based Analysis of Nonlinear Magnetospheric Dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Jay R. Johnson; Simon Wing

    2004-01-28

    Understanding magnetospheric dynamics and predicting future behavior of the magnetosphere is of great practical interest because it could potentially help to avert catastrophic loss of power and communications. In order to build good predictive models it is necessary to understand the most critical nonlinear dependencies among observed plasma and electromagnetic field variables in the coupled solar wind/magnetosphere system. In this work, we apply a cumulant-based information dynamical measure to characterize the nonlinear dynamics underlying the time evolution of the Dst and Kp geomagnetic indices, given solar wind magnetic field and plasma input. We examine the underlying dynamics of the system, the temporal statistical dependencies, the degree of nonlinearity, and the rate of information loss. We find a significant solar cycle dependence in the underlying dynamics of the system with greater nonlinearity for solar minimum. The cumulant-based approach also has the advantage that it is reliable even in the case of small data sets and therefore it is possible to avoid the assumption of stationarity, which allows for a measure of predictability even when the underlying system dynamics may change character. Evaluations of several leading Kp prediction models indicate that their performances are sub-optimal during active times. We discuss possible improvements of these models based on this nonparametric approach.

  9. The use of steel and lead shieldings in radiotherapy rooms and its comparison with respect to neutrons doses at patients; Comparacao de blindagens de aco e de chumbo usadas em salas de radioterapia quanto a dose devido a neutrons depositada em pacientes

    Energy Technology Data Exchange (ETDEWEB)

    Silva, M.G.; Rebello, W.F.; Andrade, E.R.; Medeiros, M.P.C.; Mendes, R.M.S.; Braga, K.L.; Gomes, R.G., E-mail: maglosilva15@gmail.com, E-mail: rebello@ime.eb.br, E-mail: fisica.dna@gmail.com, E-mail: eng.cavaliere@gmail.com, E-mail: raphaelmsm@gmail.com, E-mail: kelmo.lins@gmail.com, E-mail: ggrprojetos@gmail.com [Instituto Militar de Engenharia (IME), Rio de Janeiro, RJ (Brazil); Santos, R.F.G., E-mail: raphaelfgsantos@gmail.com [Centro Universitario Anhanguera, Niteroi, RJ (Brazil). Departamento de Engenharia; Silva, Ademir X., E-mail: ademir@con.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The NCRP Report No. 151, Structural Shielding Design and Evaluation for Megavoltage X- and Gamma-Ray Radiotherapy Facilities, considers, in shielding calculations for radiotherapy rooms, the use of lead and/or steel to be applied on bunker walls. The NCRP Report calculations were performed foreseeing a better protection of people outside the radiotherapy room. However, contribution of lead and steel to patient dose should be taken into account for radioprotection purposes. This work presents calculations performed by MCNPX code in analyzing the Ambient Dose Equivalent due to neutron, H*(10){sub n}, within a radiotherapy room, in the patients area, considering the use of additional shielding of 1 TVL of lead or 1 TVL of steel, positioned at the inner faces of walls and ceiling of a bunker. The head of the linear accelerator Varian 2100/2300 C/D was modeled working at 18MeV, with 5x5cm{sup 2}, 10x10cm{sup 2}, 20x20cm{sup 2}, 30x30cm{sup 2} and 40x40cm{sup 2} openings for jaws and MLC and operating in eight gantry's angles. This study shows that the use of lead generates an average value of H*(10){sub n} at patients area, 8.02% higher than the expected when using steel. Further studies should be performed based on experimental data for comparison with those from MCNPX simulation.

  10. Cumulative risks of foster care placement for Danish children

    National Research Council Canada - National Science Library

    Fallesen, Peter; Emanuel, Natalia; Wildeman, Christopher

    2014-01-01

    Although recent research suggests that the cumulative risk of foster care placement is far higher for American children than originally suspected, little is known about the cumulative risk of foster...

  11. Recursive Numerical Evaluation of the Cumulative Bivariate Normal Distribution

    CERN Document Server

    Meyer, Christian

    2010-01-01

    We propose an algorithm for evaluation of the cumulative bivariate normal distribution, building upon Marsaglia's ideas for evaluation of the cumulative univariate normal distribution. The algorithm is mathematically transparent, delivers competitive performance and can easily be extended to arbitrary precision.

  12. Long and Short Term Cumulative Structural Priming Effects

    OpenAIRE

    Kaschak, Michael P.; Kutta, Timothy J.; Coyle, Jacqueline M.

    2012-01-01

    We present six experiments that examine cumulative structural priming effects (i.e., structural priming effects that accumulate across many utterances). Of particular interest is whether (1) cumulative priming effects transfer across language production tasks and (2) the transfer of cumulative priming effects across tasks persists over the course of a week. Our data suggest that cumulative structural priming effects do transfer across language production tasks (e.g., from written stem complet...

  13. Preserved cumulative semantic interference despite amnesia

    Directory of Open Access Journals (Sweden)

    Gary Michael Oppenheim

    2015-05-01

    As predicted by Oppenheim et al’s (2010 implicit incremental learning account, WRP’s BCN RTs demonstrated strong (and significant repetition priming and semantic blocking effects (Figure 1. Similar to typical results from neurally intact undergraduates, WRP took longer to name pictures presented in semantically homogeneous blocks than in heterogeneous blocks, an effect that increased with each cycle. This result challenges accounts that ascribe cumulative semantic interference in this task to explicit memory mechanisms, instead suggesting that the effect has the sort of implicit learning bases that are typically spared in hippocampal amnesia.

  14. Cumulant matching for independent source extraction.

    Science.gov (United States)

    Phlypo, Ronald; Zarzoso, Vicente; Comon, Pierre; Lemahieu, Ignace

    2008-01-01

    In this work we show how one can make use of priors on signal statistics under the form of cumulant guesses to extract an independent source from an observed mixture. The advantage of using statistical priors on the signal lies in the fact that no specific knowledge is needed about its temporal behavior, neither about its spatial distribution. We show that these statistics can be obtained either by reasoning on the theoretical values of a supposed waveform, either by using a subset of the observations from which we know that their statistics are merely hindered by interferences. Results on an electro-cardiographic recording confirm the above assumptions.

  15. A Missing Link in the Evolution of the Cumulative Recorder

    Science.gov (United States)

    Asano, Toshio; Lattal, Kennon A.

    2012-01-01

    A recently recovered cumulative recorder provides a missing link in the evolution of the cumulative recorder from a modified kymograph to a reliably operating, scientifically and commercially successful instrument. The recorder, the only physical evidence of such an early precommercial cumulative recorder yet found, was sent to Keio University in…

  16. Original and cumulative prospect theory: a discussion of empirical differences

    NARCIS (Netherlands)

    P.P. Wakker; H. Fennema

    1997-01-01

    This note discusses differences between prospect theory and cumulative prospect theory. It shows that cumulative prospect theory is not merely a formal correction of some theoretical problems in prospect theory, but it also gives different predictions. Experiments are described that favor cumulative

  17. Cumulative Advantage in the Skill Development of STEM Graduate Students: A Mixed-Methods Study

    Science.gov (United States)

    Feldon, David F.; Maher, Michelle A.; Roksa, Josipa; Peugh, James

    2016-01-01

    Studies of skill development often describe a process of cumulative advantage, in which small differences in initial skill compound over time, leading to increasing skill gaps between those with an initial advantage and those without. We offer evidence of a similar phenomenon accounting for differential patterns of research skill development in…

  18. Cumulative Environmental Management Association : Wood Buffalo Region

    Energy Technology Data Exchange (ETDEWEB)

    Friesen, B. [Syncrude Canada Ltd., Edmonton, AB (Canada)

    2001-07-01

    The recently announced oil sands development of the Wood Buffalo Region in Alberta was the focus of this power point presentation. Both mining and in situ development is expected to total $26 billion and 2.6 million barrels per day of bitumen production. This paper described the economic, social and environmental challenges facing the resource development of this region. In addition to the proposed oil sands projects, this region will accommodate the needs of conventional oil and gas production, forestry, building of pipelines and power lines, municipal development, recreation, tourism, mining exploration and open cast mining. The Cumulative Environmental Management Association (CEMA) was inaugurated as a non-profit association in April 2000, and includes 41 members from all sectors. Its major role is to ensure a sustainable ecosystem and to avoid any cumulative impacts on wildlife. Other work underway includes the study of soil and plant species diversity, and the effects of air emissions on human health, wildlife and vegetation. The bioaccumulation of heavy metals and their impacts on surface water and fish is also under consideration to ensure the quality and quantity of surface water and ground water. 3 figs.

  19. Cumulative environmental management and the oil sands

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    In response to concerns regarding the cumulative environmental impacts of oil sands development within the Athabasca oil sands deposit, the government of Alberta established a Regional Sustainable Development Strategy (RSDS) to balance development with environmental protection. The environmental issues identified through the RSDS were addressed by the Cumulative Environmental Management Association (CEMA). CEMA's boundary is the Wood Buffalo region of northeastern Alberta. It identifies existing and future environmental effects in the region and proposes recommendations to regulatory bodies for reducing environmental impacts associated with oil sands development. This presentation outlined some of the 55 stakeholder representatives of CEMA, including Alberta government departments associated with resource development, oil sand developers within the region, and Aboriginal communities and First Nations. These stakeholders provide input on sector priorities and agree on environmental thresholds. Established working groups also address technical and scientific research issues identified in the RSDS such as sustainable ecosystems; surface waters; trace metals and air contaminants; nitrogen oxides and sulphur dioxides; and land reclamation. To date, CEMA has submitted more than 50 reports and has made 4 major environmental recommendations for trace metal management, ecosystem management tools, a framework for acid deposition management, and a landscape design checklist. tabs., figs.

  20. Higher Order Cumulants in Colorless Partonic Plasma

    CERN Document Server

    Cherif, S; Ladrem, M

    2016-01-01

    Any physical system considered to study the QCD deconfinement phase transition certainly has a finite volume, so the finite size effects are inevitably present. This renders the location of the phase transition and the determination of its order as an extremely difficult task, even in the simplest known cases. In order to identify and locate the colorless QCD deconfinement transition point in finite volume $T_{0}(V)$, a new approach based on the finite-size cumulant expansion of the order parameter and the $\\mathscr{L}_{m,n}$-Method is used.We have shown that both cumulants of higher order and their ratios, associated to the thermodynamical fluctuations of the order parameter, in QCD deconfinement phase transition behave in a particular enough way revealing pronounced oscillations in the transition region. The sign structure and the oscillatory behavior of these in the vicinity of the deconfinement phase transition point might be a sensitive probe and may allow one to elucidate their relation to the QCD phase...

  1. Innovativeness, population size and cumulative cultural evolution.

    Science.gov (United States)

    Kobayashi, Yutaka; Aoki, Kenichi

    2012-08-01

    Henrich [Henrich, J., 2004. Demography and cultural evolution: how adaptive cultural processes can produce maladaptive losses-the Tasmanian case. Am. Antiquity 69, 197-214] proposed a model designed to show that larger population size facilitates cumulative cultural evolution toward higher skill levels. In this model, each newborn attempts to imitate the most highly skilled individual of the parental generation by directly-biased social learning, but the skill level he/she acquires deviates probabilistically from that of the exemplar (cultural parent). The probability that the skill level of the imitator exceeds that of the exemplar can be regarded as the innovation rate. After reformulating Henrich's model rigorously, we introduce an overlapping-generations analog based on the Moran model and derive an approximate formula for the expected change per generation of the highest skill level in the population. For large population size, our overlapping-generations model predicts a much larger effect of population size than Henrich's discrete-generations model. We then investigate by way of Monte Carlo simulations the case where each newborn chooses as his/her exemplar the most highly skilled individual from among a limited number of acquaintances. When the number of acquaintances is small relative to the population size, we find that a change in the innovation rate contributes more than a proportional change in population size to the cumulative cultural evolution of skill level.

  2. Is uveitis associated with topiramate use? A cumulative review

    Directory of Open Access Journals (Sweden)

    Goldberg JL

    2016-08-01

    Full Text Available Jeffrey L Goldberg,1 Amy G Lau,2 Bo Fan,2 Lisa Ford,3 Howard E Greenberg3 1Byers Eye Institute, Stanford University, Palo Alto, CA, 2Janssen Research & Development, LLC, Horsham, PA, 3Janssen Research & Development, LLC, Titusville, NJ, USA Abstract: Occasional reports of uveitis following topiramate use necessitated an investigation of relevant cases from safety databases and published biomedical literature. Data mining of the Food and Drug Administration Adverse Event Reporting System and cumulative review of cases from the global safety database (sponsor database and published literature were conducted to assess association between topiramate use and uveitis. The Food and Drug Administration Adverse Event Reporting System search identified disproportional reporting of uveitis (n=23 and related terms (choroidal detachment, n=25; iridocyclitis, n=17. The postmarketing reporting frequency of uveitis and related events from the global safety database and based on an estimated topiramate exposure of 11,185,740 person-years from launch to April 2015 was 0.38 per 100,000 person-years and assigned as very rare. A total of 14 potential uveitis cases were identified from the cumulative review. Seven of these 14 cases were complicated by inadequate documentation, appearance of uveitic signs following drug withdrawal, or concurrent use of other sulfonamides. In acute angle-closure glaucoma and uveal effusions cases, insufficient evidence for underlying inflammation suggested that uveitis was not a component. Only seven of 14 cases were well documented, potentially topiramate-associated uveitis cases. Uveitis may occur in the setting of topiramate use only in very rare instances. Current evidence did not reveal a dose- or duration-dependent relationship between uveitis and topiramate use. Keywords: topiramate, uveitis, acute angle-closure glaucoma, drug safety, Food and Drug Administration Adverse Event Reporting System, postmarketing 

  3. Steroid therapy and the risk of osteonecrosis in SARS patients: a dose-response meta-analysis.

    Science.gov (United States)

    Zhao, R; Wang, H; Wang, X; Feng, F

    2017-03-01

    This meta-analysis synthesized current evidence from 10 trials to evaluate the association between steroid therapy and osteonecrosis incidence in patients with severe acute respiratory syndrome (SARS). Our results suggest that higher cumulative doses and longer treatment durations of steroids are more likely to lead to the development of osteonecrosis in SARS patients. The link between steroid treatment and the risk of osteonecrosis in SARS patients remains unknown. The present meta-analysis aimed to examine the dose-response association between steroid therapy and osteonecrosis incidence in SARS patients. The sex differences in the development of steroid-induced osteonecrosis were also examined. We searched PubMed, Web of Science, CNKI, and WANFANG for studies that involved steroid therapy and reported osteonecrosis data in SARS patients. Two authors independently extracted the data from the individual studies, and the rate ratio (RR) of osteonecrosis was calculated using random-effect models. Ten studies with 1137 recovered SARS patients met the inclusion criteria. Close relationships between osteonecrosis incidence and both the cumulative dose and treatment duration of steroids were observed. The summary RR of osteonecrosis was 1.57 (95% confidence interval (CI) 1.30-1.89, p SARS patients who received higher cumulative doses and longer treatment durations of steroids were more likely to develop osteonecrosis, and there were no sex differences in this dose-dependent side effect. Our findings suggest that it is important to reduce osteonecrosis risk by modifying the cumulative dose and the treatment duration of steroids in SARS patients.

  4. Cumulative ionizing radiation exposure in patients with end stage kidney disease: a 6-year retrospective analysis.

    LENUS (Irish Health Repository)

    Coyle, Joe

    2011-08-13

    OBJECTIVE: To quantify cumulative exposure to ionizing radiation in patients with end stage kidney disease (ESKD). To investigate factors which may be independently associated with risk of high cumulative effective dose (CED). MATERIALS AND METHODS: The study had local institutional review board ethical approval. We conducted a retrospective study of 394 period prevalent ESKD patients attending a single tertiary referral centre between 2004 and 2009. Patient demographics were obtained from case records. Details of radiological investigations were obtained from the institutional radiology computerized database. CED was calculated using standard procedure specific radiation levels. High exposure was defined as CED > 50 mSv, an exposure which has been reported to increase cancer mortality by 5%. Data were compared using Pearson χ(2) and Mann-Whitney U test or Kruskal-Wallis tests. RESULTS: 394 patients were followed for a median of 4 years (1518 patient years follow-up). Of these 63% were male. Seventeen percent of patients had a CED of >50 mSv. Computed tomography (CT) accounted for 9% of total radiological studies\\/procedures while contributing 61.4% of total study dose. Median cumulative dose and median dose per patient year were significantly higher in the hemodialysis (HD) group (15.13 and 5.79 mSv, respectively) compared to the post-transplant group (2.9 and 0.52 mSv, respectively) (P < 0.001). CONCLUSION: ESKD patients are at risk of cumulative exposure to significant levels of diagnostic radiation. The majority of this exposure is imparted as a result of CT examinations to patients in the HD group.

  5. Childhood poverty and young adults' allostatic load: the mediating role of childhood cumulative risk exposure.

    Science.gov (United States)

    Evans, Gary W; Kim, Pilyoung

    2012-09-01

    Childhood poverty is linked to a host of physical and psychological disorders during childhood and later in life. In the study reported here, we showed that the proportion of childhood spent in poverty from birth to age 9 was linked to elevated allostatic load, a marker of chronic physiological stress, in 17-year-olds. Furthermore, this prospective longitudinal relationship was mediated by cumulative risk exposure at age 13. The greater the duration of early life spent in poverty, the greater the exposure to cumulative risk. This, in turn, leads to elevated allostatic load. Multiple psychological, biological, and neurological pathways likely account for the social patterning of psychological and physical disease.

  6. Ion cumulation by conical cathode electrolysis.

    CERN Document Server

    Grishin, V G

    2002-01-01

    Results of solid-state sodium stearate electrolysis with conical and cylindrical cathodes is presented here. Both electric measurement and conical samples destruction can be explained if a stress developing inside the conical sample is much bigger than in the cylindrical case and there is its unlimited amplification along cone slopes. OTHER KEYWORDS: ion, current, solid, symmetry, cumulation, polarization, depolarization, ionic conductor,superionic conductor, ice, crystal, strain, V-center, V-centre, doped crystal, interstitial impurity, intrinsic color center, high pressure technology, Bridgman, anvil, experiment, crowdion, dielectric, proton, layer, defect, lattice, dynamics, electromigration, mobility, muon catalysis, concentration, doping, dopant, conductivity, pycnonuclear reaction, permittivity, dielectric constant, point defects, interstitials, polarizability, imperfection, defect centers, glass, epitaxy, sodium hydroxide, metallic substrate, crystallization, point, tip, susceptibility, ferroelectric, ...

  7. [Cumulative trauma disorders: work or professional disease?].

    Science.gov (United States)

    de Carvalho, Marcus Vitor Diniz; Cavalcanti, Francisco Ivo Dantas; Soriano, Evelyne Pessoa; de Miranda, Hênio Ferreira

    2009-06-01

    This study aimed at reviewing the Brazilian legislation applied to occupational health. It refers to the diseases embodied in the Repetition Strain Injury (RSI) and Cumulative Trauma Disorders (CTD) regarded as work or professional diseases. This analysis allowed to perform the historical evolution of legislation concerning the issue, noting that the state of the art of regulation on RSI-CTD is anchored in specific regulation present in the Normative Instruction 98/2003, that establishes the diagnostic criteria and classification of RSI-CTD. It was concluded that according to the existing legislation in Brazil, the pathologies related to RSI-CTD are considered as work diseases and their legal effects are similar to the work-related accidents.

  8. Effective dose delivery in atmospheric pressure plasma jets for plasma medicine: a model predictive control approach

    Science.gov (United States)

    Gidon, Dogan; Graves, David B.; Mesbah, Ali

    2017-08-01

    Atmospheric pressure plasma jets (APPJs) have been identified as a promising tool for plasma medicine. This paper aims to demonstrate the importance of using model-based feedback control strategies for safe, reproducible, and therapeutically effective application of APPJs for dose delivery to a target substrate. Key challenges in model-based control of APPJs arise from: (i) the multivariable, nonlinear nature of system dynamics, (ii) the need for constraining the system operation within an operating region that ensures safe plasma treatment, and (iii) the cumulative, nondecreasing nature of dose metrics. To systematically address these challenges, we propose a model predictive control (MPC) strategy for real-time feedback control of a radio-frequency APPJ in argon. To this end, a lumped-parameter, physics-based model is developed for describing the jet dynamics. Cumulative dose metrics are defined for quantifying the thermal and nonthermal energy effects of the plasma on substrate. The closed-loop performance of the MPC strategy is compared to that of a basic proportional-integral control system. Simulation results indicate that the MPC stategy provides a versatile framework for dose delivery in the presence of disturbances, while the safety and practical constraints of the APPJ operation can be systematically handled. Model-based feedback control strategies can lead to unprecedented opportunities for effective dose delivery in plasma medicine.

  9. Investigating the effect among size, growth opportunity and cumulative abnormal returns of the companies

    Directory of Open Access Journals (Sweden)

    Khalil bevali behbahani

    2016-09-01

    Full Text Available The stockholders and investors require identifying main variables that explain stock return. Being aware of variables and achieving an appropriate model can lead to improve their investment and considering that each wise and economic person’s goal is obtain high and more returns, the current research is sought to investigate the effect of company’s characteristics and the ratio of investment on company’s cumulative abnormal returns. Statistical sample which has been used in current research includes 256 listed companies in Tehran Stock Exchange during 2002 to 2013. Dependent variable of current research is cumulative abnormal return. The independent variables whose effects are investigated on cumulative abnormal return include company’s size, growth opportunity. The data are collected and were inserted in Excel file as information database. Testing hypotheses also has been done from multi-variable regression models based on combined data technique using econometric software Eviews. The findings of the research show that there is a positive and significant relationship between company’s size and company’s cumulative abnormal return. There is also a negative and significant relationship between growth opportunities and company’s cumulative abnormal return.

  10. Radiation dose monitoring in the clinical routine

    Energy Technology Data Exchange (ETDEWEB)

    Guberina, Nika [UK Essen (Germany). Radiology

    2017-04-15

    Here we describe the first clinical experiences regarding the use of an automated radiation dose management software to monitor the radiation dose of patients during routine examinations. Many software solutions for monitoring radiation dose have emerged in the last decade. The continuous progress in radiological techniques, new scan features, scanner generations and protocols are the primary challenge for radiation dose monitoring software systems. To simulate valid dose calculations, radiation dose monitoring systems have to follow current trends and stay constantly up-to-date. The dose management software is connected to all devices at our institute and conducts automatic data acquisition and radiation dose calculation. The system incorporates 18 virtual phantoms based on the Cristy phantom family, estimating doses in newborns to adults. Dose calculation relies on a Monte Carlo simulation engine. Our first practical experiences demonstrate that the software is capable of dose estimation in the clinical routine. Its implementation and use have some limitations that can be overcome. The software is promising and allows assessment of radiation doses, like organ and effective doses according to ICRP 60 and ICRP 103, patient radiation dose history and cumulative radiation doses. Furthermore, we are able to determine local diagnostic reference doses. The radiation dose monitoring software systems can facilitate networking between hospitals and radiological departments, thus refining radiation doses and implementing reference doses at substantially lower levels.

  11. Bronchiolitis obliterans organizing pneumonia during low-dose amiodarone therapy

    NARCIS (Netherlands)

    Jessurun, GAJ; Hoogenberg, K; Crijns, HJGM

    1997-01-01

    Two cases of amiodarone-induced pulmonary toxicity during a relatively short period of low-dose amiodarone treatment are reported. The toxicity risk of amiodarone is determined by cumulative factors in individual patients.

  12. Bronchiolitis obliterans organizing pneumonia during low-dose amiodarone therapy

    NARCIS (Netherlands)

    Jessurun, GAJ; Hoogenberg, K; Crijns, HJGM

    Two cases of amiodarone-induced pulmonary toxicity during a relatively short period of low-dose amiodarone treatment are reported. The toxicity risk of amiodarone is determined by cumulative factors in individual patients.

  13. Long and Short Term Cumulative Structural Priming Effects.

    Science.gov (United States)

    Kaschak, Michael P; Kutta, Timothy J; Coyle, Jacqueline M

    We present six experiments that examine cumulative structural priming effects (i.e., structural priming effects that accumulate across many utterances). Of particular interest is whether (1) cumulative priming effects transfer across language production tasks and (2) the transfer of cumulative priming effects across tasks persists over the course of a week. Our data suggest that cumulative structural priming effects do transfer across language production tasks (e.g., from written stem completion to picture description, and from picture description to written stem completion), but only when both tasks are presented in the same experimental session. When cumulative priming effects are established in one task, and the second (changed) task is not presented until a week later, the cumulative priming effects are not observed.

  14. Why Veterinary Medical Educators Should Embrace Cumulative Final Exams.

    Science.gov (United States)

    Royal, Kenneth D

    2017-01-03

    The topic of cumulative final examinations often elicits polarizing opinions from veterinary medical educators. While some faculty prefer cumulative finals, there are many who perceive these types of examinations as problematic. Specifically, faculty often cite cumulative examinations are more likely to cause students' greater stress, which may in turn result in negative student evaluations of teaching. Cumulative finals also restrict the number of items one may present to students on most recent material. While these cited disadvantages may have some merit, the advantages of cumulative examinations far exceed the disadvantages. The purpose of this article is to discuss the advantages of cumulative examinations with respect to learning evidence, grade/score validity, fairness issues, and implications for academic policy.

  15. Analysis of experimental data on correlations between cumulative particles

    Energy Technology Data Exchange (ETDEWEB)

    Vlasov, A.V.; Doroshkevich, E.A.; Leksin, G.A. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation)] [and others

    1995-04-01

    Experimental data on correlations between cumulative particles are analyzed. A space-time and energy-transfer pattern of hadron-nucleus interaction based on both correlation data and data on the inclusive spectra of cumulative particles is considered. A new variable that is convenient for describing the production of cumulative particles is proposed using the concept of symmetry between the one-particle and multiparticle distributions. 32 refs., 9 figs., 1 tab.

  16. Analysis of Memory Codes and Cumulative Rehearsal in Observational Learning

    Science.gov (United States)

    Bandura, Albert; And Others

    1974-01-01

    The present study examined the influence of memory codes varying in meaningfulness and retrievability and cumulative rehearsal on retention of observationally learned responses over increasing temporal intervals. (Editor)

  17. Cumulative Effect of Depression on Dementia Risk

    Directory of Open Access Journals (Sweden)

    J. Olazarán

    2013-01-01

    Full Text Available Objective. To analyze a potential cumulative effect of life-time depression on dementia and Alzheimer’s disease (AD, with control of vascular factors (VFs. Methods. This study was a subanalysis of the Neurological Disorders in Central Spain (NEDICES study. Past and present depression, VFs, dementia status, and dementia due to AD were documented at study inception. Dementia status was also documented after three years. Four groups were created according to baseline data: never depression (nD, past depression (pD, present depression (prD, and present and past depression (prpD. Logistic regression was used. Results. Data of 1,807 subjects were investigated at baseline (mean age 74.3, 59.3% women, and 1,376 (81.6% subjects were evaluated after three years. The prevalence of dementia at baseline was 6.7%, and dementia incidence was 6.3%. An effect of depression was observed on dementia prevalence (OR [CI 95%] 1.84 [1.01–3.35] for prD and 2.73 [1.08–6.87] for prpD, and on dementia due to AD (OR 1.98 [0.98–3.99] for prD and OR 3.98 [1.48–10.71] for prpD (fully adjusted models, nD as reference. Depression did not influence dementia incidence. Conclusions. Present depression and, particularly, present and past depression are associated with dementia at old age. Multiple mechanisms, including toxic effect of depression on hippocampal neurons, plausibly explain these associations.

  18. Cumulative social disadvantage and child health.

    Science.gov (United States)

    Bauman, Laurie J; Silver, Ellen J; Stein, Ruth E K

    2006-04-01

    Disparities in child health are a major public health concern. However, it is unclear whether these are predominantly the result of low income, race, or other social risk factors that may contribute to their health disadvantage. Although others have examined the effects of the accumulation of risk factors, this methodology has not been applied to child health. We tested 4 social risk factors (poverty, minority race/ethnicity, low parental education, and not living with both biological parents) to assess whether they have cumulative effects on child health and examined whether access to health care reduced health disparities. We analyzed data on 57,553 children low parental education, and single-parent household) were consistently associated with child health. These were summed, generating the Social Disadvantage Index (range: 0-3). A total of 43.6% of children had no social disadvantages, 30.8% had 1, 15.6% had 2, and 10.0% had all 3. Compared with those with no social disadvantages, the odds ratios (ORs) of being in "good, fair, or poor health" (versus "excellent or very good") were 1.95 for 1 risk, 3.22 for 2 risks, and 4.06 for 3 risks. ORs of having a chronic condition increased from 1.25 (1 risk) to 1.60 (2 risks) to 2.11 (3 risks). ORs for activity limitation were 1.51 (1 risk) to 2.14 (2 risks) and 2.88 (3 risks). Controlling for health insurance did not affect these findings. The accumulation of social disadvantage among children was strongly associated with poorer child health and having insurance did not reduce the observed health disparities.

  19. A Framework for Treating Cumulative Trauma with Art Therapy

    Science.gov (United States)

    Naff, Kristina

    2014-01-01

    Cumulative trauma is relatively undocumented in art therapy practice, although there is growing evidence that art therapy provides distinct benefits for resolving various traumas. This qualitative study proposes an art therapy treatment framework for cumulative trauma derived from semi-structured interviews with three art therapists and artistic…

  20. Cumulative Effects of Human Activities on Marine Mammal Populations

    Science.gov (United States)

    2015-09-30

    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Cumulative Effects of Human Activities on Marine Mammal ...marine mammals . OBJECTIVES The National Academies of Sciences, Engineering, and Medicine has convened a volunteer committee that will...Review the present scientific understanding of cumulative effects of anthropogenic stressors on marine mammals with a focus on anthropogenic sound

  1. A Framework for Treating Cumulative Trauma with Art Therapy

    Science.gov (United States)

    Naff, Kristina

    2014-01-01

    Cumulative trauma is relatively undocumented in art therapy practice, although there is growing evidence that art therapy provides distinct benefits for resolving various traumas. This qualitative study proposes an art therapy treatment framework for cumulative trauma derived from semi-structured interviews with three art therapists and artistic…

  2. Cumulative Estrogen Exposure and Prospective Memory in Older Women

    Science.gov (United States)

    Hesson, Jacqueline

    2012-01-01

    This study looked at cumulative lifetime estrogen exposure, as estimated with a mathematical index (Index of Cumulative Estrogen Exposure (ICEE)) that included variables (length of time on estrogen therapy, age at menarche and menopause, postmenopausal body mass index, time since menopause, nulliparity and duration of breastfeeding) known to…

  3. Lattice QCD results on cumulant ratios at freeze-out

    CERN Document Server

    Karsch, Frithjof

    2016-01-01

    Ratios of cumulants of net proton-number fluctuations measured by the STAR Collaboration show strong deviations from a skellam distribution, which should describe thermal properties of cumulant ratios, if proton-number fluctuations are generated in equilibrium and a hadron resonance gas (HRG) model would provide a suitable description of thermodynamics at the freeze-out temperature. We present some results on sixth order cumulants entering the calculation of the QCD equation of state at non-zero values of the baryon chemical potential (mu_B) and discuss limitations on the applicability of HRG thermodynamics deduced from a comparison between QCD and HRG model calculations of cumulants of conserved charge fluctuations. We show that basic features of the $\\mu_B$-dependence of skewness and kurtosis ratios of net proton-number fluctuations measured by the STAR Collaboration resemble those expected from a O(mu_B^2) QCD calculation of the corresponding net baryon-number cumulant ratios.

  4. A new family of cumulative indexes for measuring scientific performance.

    Directory of Open Access Journals (Sweden)

    Marcin Kozak

    Full Text Available In this paper we propose a new family of cumulative indexes for measuring scientific performance which can be applied to many metrics, including h index and its variants (here we apply it to the h index, h(2 index and Google Scholar's i10 index. These indexes follow the general principle of repeating the index calculation for the same publication set. Using bibliometric data and reviewer scores for accepted and rejected fellowship applicants we examine how valid the cumulative variant is compared to the original variant. These analyses showed that the cumulative indexes result in higher correlations with the reviewer scores than their original variants. Thus, the cumulative indexes better reflect the assessments by peers than the original variants and are useful extensions of the original indexes. In contrast to many other measures of scientific performance proposed up to now, the cumulative indexes seem not only to be effective, but they are also easy to understand and calculate.

  5. Dose Estimation from Daily and Weekly Dosimetry Data

    Energy Technology Data Exchange (ETDEWEB)

    Ostrouchov, G.

    2001-11-16

    Statistical analyses of data from epidemiologic studies of workers exposed to radiation have been based on recorded annual radiation doses (yearly dose of record). It is usually assumed that the dose values are known exactly, although it is generally recognized that the data contain uncertainty due to measurement error and bias. In our previous work with weekly data, a probability distribution was used to describe an individual's dose during a specific period of time and statistical methods were developed for estimating it from weekly film dosimetry data. This study showed that the yearly dose of record systematically underestimates doses for Oak Ridge National Laboratory (ORNL) workers. This could result in biased estimates of dose-response coefficients and their standard errors. The results of this evaluation raise serious questions about the suitability of the yearly dose of record for direct use in low-dose studies of nuclear industry workers. Here, we extend our previous work to use full information in Pocket meter data and develop the Data Synthesis for Individual Dose Estimation (DSIDE) methodology. Although the DSIDE methodology in this study is developed in the context of daily and weekly data to produce a cumulative yearly dose estimate, in principle it is completely general and can be extended to other time period and measurement combinations. The new methodology takes into account the ''measurement error'' that is produced by the film and pocket-meter dosimetry systems, the biases introduced by policies that lead to recording left-censored doses as zeros, and other measurement and recording practices. The DSIDE method is applied to a sample of dose histories obtained from hard copy dosimetry records at ORNL for the years 1945 to 1955. First, the rigorous addition of daily pocket-meter information shows that the negative bias is generally more severe than was reported in our work based on weekly film data only, however, the

  6. Cumulative and Synergistic Effects of Physical, Biological, and Acoustic Signals on Marine Mammal Habitat Use

    Science.gov (United States)

    2013-10-28

    seasonal breakup of the ice has begun. The bowhead whales detections finally disappear as these mammals begin their annual migration to the Arctic Ocean...Final Report Cumulative and Synergistic Effects of Physical, Biological, and Acoustic Signals on Marine Mammal Habitat Use Jeffrey A Nystuen...signals impact marine mammal habitat use. This is especially critical in areas like the Bering Sea where global climate change can lead to rapid changes

  7. Lead Poisoning

    Science.gov (United States)

    Lead is a metal that occurs naturally in the earth's crust. Lead can be found in all parts of our ... from human activities such as mining and manufacturing. Lead used to be in paint; older houses may ...

  8. A bivariate optimal replacement policy with cumulative repair cost limit under cumulative damage model

    Indian Academy of Sciences (India)

    MIN-T SAI LAI; SHIH-CHIH CHEN

    2016-05-01

    In this paper, a bivariate replacement policy (n, T) for a cumulative shock damage process is presented that included the concept of cumulative repair cost limit. The arrival shocks can be divided into two kinds of shocks. Each type-I shock causes a random amount of damage and these damages are additive. When the total damage exceeds a failure level, the system goes into serious failure. Type-II shock causes the system into minor failure and such a failure can be corrected by minimal repair. When a minor failure occurs, the repaircost will be evaluated and minimal repair is executed if the accumulated repair cost is less than a predetermined limit L. The system is replaced at scheduled time T, at n-th minor failure, or at serious failure. The long-term expected cost per unit time is derived using the expected costs as the optimality criterion. The minimum-cost policy is derived, and existence and uniqueness of the optimal n* and T* are proved. This bivariate optimal replacement policy (n, T) is showed to be better than the optimal T* and the optimal n* policy.

  9. High selection pressure promotes increase in cumulative adaptive culture.

    Directory of Open Access Journals (Sweden)

    Carolin Vegvari

    Full Text Available The evolution of cumulative adaptive culture has received widespread interest in recent years, especially the factors promoting its occurrence. Current evolutionary models suggest that an increase in population size may lead to an increase in cultural complexity via a higher rate of cultural transmission and innovation. However, relatively little attention has been paid to the role of natural selection in the evolution of cultural complexity. Here we use an agent-based simulation model to demonstrate that high selection pressure in the form of resource pressure promotes the accumulation of adaptive culture in spite of small population sizes and high innovation costs. We argue that the interaction of demography and selection is important, and that neither can be considered in isolation. We predict that an increase in cultural complexity is most likely to occur under conditions of population pressure relative to resource availability. Our model may help to explain why culture change can occur without major environmental change. We suggest that understanding the interaction between shifting selective pressures and demography is essential for explaining the evolution of cultural complexity.

  10. Microcanonical thermostatistics analysis without histograms: cumulative distribution and Bayesian approaches

    CERN Document Server

    Alves, Nelson A; Rizzi, Leandro G

    2015-01-01

    Microcanonical thermostatistics analysis has become an important tool to reveal essential aspects of phase transitions in complex systems. An efficient way to estimate the microcanonical inverse temperature $\\beta(E)$ and the microcanonical entropy $S(E)$ is achieved with the statistical temperature weighted histogram analysis method (ST-WHAM). The strength of this method lies on its flexibility, as it can be used to analyse data produced by algorithms with generalised sampling weights. However, for any sampling weight, ST-WHAM requires the calculation of derivatives of energy histograms $H(E)$, which leads to non-trivial and tedious binning tasks for models with continuous energy spectrum such as those for biomolecular and colloidal systems. Here, we discuss two alternative methods that avoid the need for such energy binning to obtain continuous estimates for $H(E)$ in order to evaluate $\\beta(E)$ by using ST-WHAM: (i) a series expansion to estimate probability densities from the empirical cumulative distrib...

  11. The cumulative energy effect for improved ignition timing

    Energy Technology Data Exchange (ETDEWEB)

    Markhotok, A., E-mail: amarhotk@phys.washington.edu [Physics Department, Old Dominion University, Norfolk, Virginia 23529 (United States)

    2015-04-15

    A technique capable of improving timing in ignition applications is proposed. It is based on the use of shock waves propagating in a specific medium that allows achieving extremely high speeds and energies. The model uses the energy cumulation effect in the presence of the shock wave refraction on an interface with plasma. The problem was solved analytically and the effects were demonstrated for a cylindrically symmetrical geometry. Numerical results show very quick and uneven acceleration of different portions of the shock front. Its strong distortions lead to formation of a sharply focused jet near the axis of symmetry. The ability of the shock to achieve extremely high speeds and energies can be useful in design of efficient combustors for hypersonic systems, and possibly offers an alternative way of construction of a nuclear fusion reactor. Recommendations are given in terms of adjustment parameters and can be applied at any problem scale and for various combinations of the strengths of the effects involved in the problem.

  12. Cumulative life course impairment in melanoma and nonmelanoma skin cancer.

    Science.gov (United States)

    Piaserico, Stefano

    2013-01-01

    Patients with skin cancer remain at risk for disease progression or relapse for many years. Therefore, skin cancer may be considered a chronic, life-threatening disease. It could impact on patients lifestyles and social and professional activities. Although no direct study of cumulative life course impairment (CLCI) in skin cancer patients has been carried out, a few studies suggest that skin cancer may strongly impair quality of life and eventually determine a significant CLCI (melanoma more than nonmelanoma skin cancer). Obviously, the life course of patients with melanoma at an advanced stage of the disease may change considerably. A number of cancer-associated problems may determine a CLCI, including familial or professional changes and a reduction of life expectancy may eventually lead to social withdrawal and depressive disorders. Even patients with a low stage disease may experience an important impairment of quality of life and in some cases a CLCI. Some skin cancer patients may have physical and psychological after effects from their cancer surgery. Several patients complain about lymphedema, discomfort experienced from wearing surgical stockings, and diminished range of physical motion postsurgery. A few are concerned about their body image due to surgical scars, and they may consider changing their job position because of the supposed negative impact of scars in visible sites on their ability to perform their job. Some female melanoma survivors may have a reduced desire of having children in the future.

  13. Longhi Games, Internal Reservoirs, and Cumulate Porosity

    Science.gov (United States)

    Morse, S. A.

    2009-05-01

    Fe in plagioclase at an early age, T-rollers (or not) on the Di-Trid boundary in Fo-Di-Sil, the mantle solidus, origins of anorthosites, esoteric uses of Schreinemakers rules and many more topics are all fresh and pleasant memories of John Longhi's prolific and creative work. The Fram-Longhi experimental effect of pressure on plagioclase partitioning with liquid in mafic rocks became essential to an understanding of multiphase Rayleigh fractionation of plagioclase in big layered intrusions. Only by using the pressure effect could I find a good equation through the data for the Kiglapait intrusion, and that result among others required the existence with probability 1.0 of an internal reservoir (Morse, JPet 2008). Knowledge of cumulate porosity is a crucial key to the understanding of layered igneous rocks. We seek both the initial (inverse packing fraction) and residual porosity to find the time and process path from sedimentation to solidification. In the Kiglapait Lower Zone we have a robust estimate of mean residual porosity from the modes of the excluded phases augite, oxides, sulfide, and apatite. To this we apply the maximum variance of plagioclase composition (the An range) to find an algorithm that extends through the Upper Zone and to other intrusions. Of great importance is that all these measurements were made in grain mounts concentrated from typically about 200 g of core or hand specimen, hence the represented sample volume is thousands of times greater than for a thin section. The resulting distribution and scatter of the An range is novel and remarkable. It is V-shaped in the logarithmic representation of stratigraphic height, running from about 20 mole % at both ends (base to top of the Layered Series) to near-zero at 99 PCS. The intercept of the porosity-An range relation gives An range = 3.5 % at zero residual porosity. Petrographic analysis reveals that for PCS less than 95 and greater than 99.9, the An range is intrinsic, i.e. pre-cumulus, for

  14. Sensitivity Tests for Cumulative Damage Function (CDF) for the PGSFR

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Chiwoong; Ha, Kwiseok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    A safety analysis including the design basis and beyond design basis events has been conducted using MARS-LMR. Previous safety limits were based on temperature and the duration time. However, the cumulative damage function (CDF) will be used as the safety limit to evaluate the fuel cladding integrity. Recently, a 4S reactor developed by Toshiba used the same approach for a safety analysis. Therefore, the development a CDF is necessary to evaluate the safety limit for the PGSFR safety analyses. The major keys in the CDF model are behavior of fuel and cladding. It is not easy to obtain a metallic fuel database for a CDF model including the cladding materials. Argonne National Laboratory (ANL) in the United States is the only major leading group for metallic fuel experiments. They conducted various experiments with various facilities and experimental reactors, for example, EBR-II, FFTF, and TREAT. In addition, they have recently been trying to extend their oxide fuel based a severe accident code, SAS4A/SASSYS, to a metallic fuel version using their metallic fuel database. In this study, the preliminary CDF model was supplemented in the MARS-LMR code. The major source was the SAS4A/SASSYS modules related to fuel and cladding transient behaviors.. In addition, a sensitivity test for some parameters in the CDF model was conducted to evaluate the capability of these models and to find the major parameter of fuel failure. The Cumulative Damage Function is a good indicator for a fuel failure. The major parameters for the CDF model are selected including cladding and fuel temperatures, initial pressure and volume in the gas plenum, clad thickness, and fission power in the fuel pin. The most sensitive parameter is the cladding temperature. Also, cladding thickness and gas pressure in the fuel pin are effective parameters on the CDF. During an actual transient, various parameter including sensitivity test parameters in this study will be changed simultaneously. This study can

  15. Cumulative stress and autonomic dysregulation in a community sample.

    Science.gov (United States)

    Lampert, Rachel; Tuit, Keri; Hong, Kwang-Ik; Donovan, Theresa; Lee, Forrester; Sinha, Rajita

    2016-05-01

    Whether cumulative stress, including both chronic stress and adverse life events, is associated with decreased heart rate variability (HRV), a non-invasive measure of autonomic status which predicts poor cardiovascular outcomes, is unknown. Healthy community dwelling volunteers (N = 157, mean age 29 years) participated in the Cumulative Stress/Adversity Interview (CAI), a 140-item event interview measuring cumulative adversity including major life events, life trauma, recent life events and chronic stressors, and underwent 24-h ambulatory ECG monitoring. HRV was analyzed in the frequency domain and standard deviation of NN intervals (SDNN) calculated. Initial simple regression analyses revealed that total cumulative stress score, chronic stressors and cumulative adverse life events (CALE) were all inversely associated with ultra low-frequency (ULF), very low-frequency (VLF) and low-frequency (LF) power and SDNN (all p stress and chronic stress each was significantly associated with SDNN and ULF even after the highly significant contributions of age and sex, with no other covariates accounting for additional appreciable variance. For VLF and LF, both total cumulative stress and chronic stress significantly contributed to the variance alone but were not longer significant after adjusting for race and health behaviors. In summary, total cumulative stress, and its components of adverse life events and chronic stress were associated with decreased cardiac autonomic function as measured by HRV. Findings suggest one potential mechanism by which stress may exert adverse effects on mortality in healthy individuals. Primary preventive strategies including stress management may prove beneficial.

  16. Lead Toxicity

    Science.gov (United States)

    ... including some imported jewelry. What are the health effects of lead? • More commonly, lower levels of lead in children over time may lead to reduced IQ, slow learning, Attention Deficit Hyperactivity Disorder (ADHD), or behavioral issues. • Lead also affects other ...

  17. Methods of calculating radiation absorbed dose.

    Science.gov (United States)

    Wegst, A V

    1987-01-01

    The new tumoricidal radioactive agents being developed will require a careful estimate of radiation absorbed tumor and critical organ dose for each patient. Clinical methods will need to be developed using standard imaging or counting instruments to determine cumulated organ activities with tracer amounts before the therapeutic administration of the material. Standard MIRD dosimetry methods can then be applied.

  18. Entanglement entropy and particle number cumulants of disordered fermions

    Science.gov (United States)

    Burmistrov, I. S.; Tikhonov, K. S.; Gornyi, I. V.; Mirlin, A. D.

    2017-08-01

    We study the entanglement entropy and particle number cumulants for a system of disordered noninteracting fermions in d dimensions. We show, both analytically and numerically, that for a weak disorder the entanglement entropy and the second cumulant (particle number variance) are proportional to each other with a universal coefficient. The corresponding expressions are analogous to those in the clean case but with a logarithmic factor regularized by the mean free path rather than by the system size. We also determine the scaling of higher cumulants by analytical (weak disorder) and numerical means. Finally, we predict that the particle number variance and the entanglement entropy are nonanalytic functions of disorder at the Anderson transition.

  19. Cumulative t-link threshold models for the genetic analysis of calving ease scores

    Directory of Open Access Journals (Sweden)

    Tempelman Robert J

    2003-09-01

    Full Text Available Abstract In this study, a hierarchical threshold mixed model based on a cumulative t-link specification for the analysis of ordinal data or more, specifically, calving ease scores, was developed. The validation of this model and the Markov chain Monte Carlo (MCMC algorithm was carried out on simulated data from normally and t4 (i.e. a t-distribution with four degrees of freedom distributed populations using the deviance information criterion (DIC and a pseudo Bayes factor (PBF measure to validate recently proposed model choice criteria. The simulation study indicated that although inference on the degrees of freedom parameter is possible, MCMC mixing was problematic. Nevertheless, the DIC and PBF were validated to be satisfactory measures of model fit to data. A sire and maternal grandsire cumulative t-link model was applied to a calving ease dataset from 8847 Italian Piemontese first parity dams. The cumulative t-link model was shown to lead to posterior means of direct and maternal heritabilities (0.40 ± 0.06, 0.11 ± 0.04 and a direct maternal genetic correlation (-0.58 ± 0.15 that were not different from the corresponding posterior means of the heritabilities (0.42 ± 0.07, 0.14 ± 0.04 and the genetic correlation (-0.55 ± 0.14 inferred under the conventional cumulative probit link threshold model. Furthermore, the correlation (> 0.99 between posterior means of sire progeny merit from the two models suggested no meaningful rerankings. Nevertheless, the cumulative t-link model was decisively chosen as the better fitting model for this calving ease data using DIC and PBF.

  20. EPA's SHEDS-multimedia model: children's cumulative pyrethroid exposure estimates and evaluation against NHANES biomarker data.

    Science.gov (United States)

    Xue, Jianping; Zartarian, Valerie; Tornero-Velez, Rogelio; Tulve, Nicolle S

    2014-12-01

    The U.S. EPA's SHEDS-Multimedia model was applied to enhance the understanding of children's exposures and doses to multiple pyrethroid pesticides, including major contributing chemicals and pathways. This paper presents combined dietary and residential exposure estimates and cumulative doses for seven commonly used pyrethroids, and comparisons of model evaluation results with NHANES biomarker data for 3-PBA and DCCA metabolites. Model input distributions were fit to publicly available pesticide usage survey data, NHANES, and other studies, then SHEDS-Multimedia was applied to estimate total pyrethroid exposures and doses for 3-5 year olds for one year variability simulations. For dose estimations we used a pharmacokinetic model and two approaches for simulating dermal absorption. SHEDS-Multimedia predictions compared well to NHANES biomarker data: ratios of 3-PBA observed data to SHEDS-Multimedia modeled results were 0.88, 0.51, 0.54 and 1.02 for mean, median, 95th, and 99th percentiles, respectively; for DCCA, the ratios were 0.82, 0.53, 0.56, and 0.94. Modeled time-averaged cumulative absorbed dose of the seven pyrethroids was 3.1 nmol/day (versus 8.4 nmol/day for adults) in the general population (residential pyrethroid use and non-use homes) and 6.7 nmol/day (versus 10.5 nmol/day for adults) in the simulated residential pyrethroid use population. For the general population, contributions to modeled cumulative dose by chemical were permethrin (60%), cypermethrin (22%), and cyfluthrin (16%); for residential use homes, contributions were cypermethrin (49%), permethrin (29%), and cyfluthrin (17%). The primary exposure route for 3-5 year olds in the simulated residential use population was non-dietary ingestion exposure; whereas for the simulated general population, dietary exposure was the primary exposure route. Below the 95th percentile, the major exposure pathway was dietary for the general population; non-dietary ingestion was the major pathway starting below

  1. Use of the cytosensor microphysiometer to predict results of a 21-day cumulative irritation patch test in humans.

    Science.gov (United States)

    Landin, Wendell E; Mun, Greg C; Nims, Raymond W; Harbell, John W

    2007-09-01

    The cytosensor microphysiometer (mu phi) was investigated as a rapid, relatively inexpensive test to predict performance of skin cleansing wipes on the human 21-day cumulative irritation patch test (21CIPT). It indirectly measures metabolic rate changes in L929 cells as a function of test article dose, by measuring the acidification rate in a low-buffer medium. The dose producing a 50% reduction in metabolic rate (MRD50), relative to the baseline rate, is used as a measure of toxicity. The acute toxicity of the mu phi assay can be compared to the chronic toxicity of the 21CIPT, which is based largely on the exposure of test agents to the epidermal cells, resulting in damage and penetration of the stratum corneum leading to cell toxicity. Two series of surfactant-based cleansing wipe products were tested via the mu phi assay and 21CIPT. The first series, consisting of 20 products, was used to determine a prediction model. The second series of 38 products consisted of routine product development formulas or marketed products. Comparing the results from both tests, samples with an MRD50 greater than 50 mg/ml provided a 21CIPT score consistent with a product that performs satisfactorily in the market. When the MRD50 was greater than 78 mg/ml, the 21CIPT score was usually zero. The mu phi may be more sensitive than the 21CIPT for ranking minimally irritating materials. The mu phi assay is useful as a screen for predicting the performance of a wet wipes formula on the 21CIPT, and concurrently reduces the use of animals for safety testing in a product development program for cleansing wipes.

  2. Origins and implications of the relationship between warming and cumulative carbon emissions

    Science.gov (United States)

    Raupach, M. R.; Davis, S. J.; Peters, G. P.; Andrew, R. M.; Canadell, J.; Le Quere, C.

    2014-12-01

    A near-linear relationship between warming (T) and cumulative carbon emissions (Q) is a robust finding from numerous studies. This finding opens biophysical questions concerning (1) its theoretical basis, (2) the treatment of non-CO2 forcings, and (3) uncertainty specifications. Beyond these biophysical issues, a profound global policy question is raised: (4) how can a quota on cumulative emissions be shared? Here, an integrated survey of all four issues is attempted. (1) Proportionality between T and Q is an emergent property of a linear carbon-climate system forced by exponentially increasing CO2 emissions. This idealisation broadly explains past but not future near-proportionality between T and Q: in future, the roles of non-CO2 forcings and carbon-climate nonlinearities become important, and trajectory dependence becomes stronger. (2) The warming effects of short-lived non-CO2 forcers depend on instantaneous rather than cumulative fluxes. However, inertia in emissions trajectories reinstates some of the benefits of a cumulative emissions approach, with residual trajectory dependence comparable to that for CO2. (3) Uncertainties arise from several sources: climate projections, carbon-climate feedbacks, and residual trajectory dependencies in CO2 and other emissions. All of these can in principle be combined into a probability distribution P(T|Q) for the warming T from given cumulative CO2 emissions Q. Present knowledge of P(T|Q) allows quantification of the tradeoff between mitigation ambition and climate risk. (4) Cumulative emissions consistent with a given warming target and climate risk are a finite common resource that will inevitably be shared, creating a tragedy-of-the-commons dilemma. Sharing options range from "inertia" (present distribution of emissions is maintained) to "equity" (cumulative emissions are distributed equally per-capita). Both extreme options lead to emissions distributions that are unrealisable in practice, but a blend of the two

  3. Cumulative Risks of Foster Care Placement for Danish Children

    DEFF Research Database (Denmark)

    Fallesen, Peter; Emanuel, Natalia; Wildeman, Christopher

    2014-01-01

    Although recent research suggests that the cumulative risk of foster care placement is far higher for American children than originally suspected, little is known about the cumulative risk of foster care placement in other countries, which makes it difficult to gauge the degree to which factor...... is for Danish children. Results suggest that at the beginning of the study period (in 1998) the cumulative risk of foster care placement for Danish children was roughly in line with the risk for American children. Yet, by the end of the study period (2010), the risk had declined to half the risk for American...... foster care placement is salient in other contexts. In this article, we provide companion estimates to those provided in recent work on the US by using Danish registry data and synthetic cohort life tables to show how high and unequally distributed the cumulative risk of foster care placement...

  4. Mapping cumulative human impacts in the eastern North Sea

    DEFF Research Database (Denmark)

    Stock, A.; Andersen, Jesper; Heinänen, S.

    of the MSFD; and 3) to deepen the understanding of how errors in expert judgment affect the resulting cumulative human impact maps by means of Monte Carlo simulations. We combined existing data sets on the spatial distribution of 33 anthropogenic stressors (linked to the MSFD pressures) and 28 key habitats....... In contrast, the predicted impacts for much of the Norwegian EEZ and areas far offshore were lower. The Monte Carlo simulations confirmed earlier findings that mapping cumulative impacts is generally "robust", but also showed that specific combinations of errors can seriously change local and regional...... on marine ecosystems have only recently been developed. The aims of our study were: 1) to develop a map of cumulative human impacts for the Danish, Swedish, Norwegian and German parts of the Greater North Sea; 2) to adjust the existing methods for mapping cumulative human impacts to fit the requirements...

  5. Cumulative Production Per Township - SaMiRa

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset contains a selected township grid within the Sagebrush Mineral Resource Assessment project (SaMiRa) study area attributed with cumulative oil and gas...

  6. Macroscopic cumulative fatigue damage of material under nonsymmetrical cycle

    Institute of Scientific and Technical Information of China (English)

    盖秉政

    2002-01-01

    Hashin's macroscopic theory of fatigue damage is further discussed and a new method has been proposed for prediction of cumulative fatigue damage of material and its lifetime under nonsymmetrical cyclic loading.

  7. Translation-Invariant Representation for Cumulative Foot Pressure Images

    CERN Document Server

    Zheng, Shuai; Tan, Tieniu

    2010-01-01

    Human can be distinguished by different limb movements and unique ground reaction force. Cumulative foot pressure image is a 2-D cumulative ground reaction force during one gait cycle. Although it contains pressure spatial distribution information and pressure temporal distribution information, it suffers from several problems including different shoes and noise, when putting it into practice as a new biometric for pedestrian identification. In this paper, we propose a hierarchical translation-invariant representation for cumulative foot pressure images, inspired by the success of Convolutional deep belief network for digital classification. Key contribution in our approach is discriminative hierarchical sparse coding scheme which helps to learn useful discriminative high-level visual features. Based on the feature representation of cumulative foot pressure images, we develop a pedestrian recognition system which is invariant to three different shoes and slight local shape change. Experiments are conducted on...

  8. A semiparametric censoring bias model for estimating the cumulative risk of a false-positive screening test under dependent censoring.

    Science.gov (United States)

    Hubbard, Rebecca A; Miglioretti, Diana L

    2013-03-01

    False-positive test results are among the most common harms of screening tests and may lead to more invasive and expensive diagnostic testing procedures. Estimating the cumulative risk of a false-positive screening test result after repeat screening rounds is, therefore, important for evaluating potential screening regimens. Existing estimators of the cumulative false-positive risk are limited by strong assumptions about censoring mechanisms and parametric assumptions about variation in risk across screening rounds. To address these limitations, we propose a semiparametric censoring bias model for cumulative false-positive risk that allows for dependent censoring without specifying a fixed functional form for variation in risk across screening rounds. Simulation studies demonstrated that the censoring bias model performs similarly to existing models under independent censoring and can largely eliminate bias under dependent censoring. We used the existing and newly proposed models to estimate the cumulative false-positive risk and variation in risk as a function of baseline age and family history of breast cancer after 10 years of annual screening mammography using data from the Breast Cancer Surveillance Consortium. Ignoring potential dependent censoring in this context leads to underestimation of the cumulative risk of false-positive results. Models that provide accurate estimates under dependent censoring are critical for providing appropriate information for evaluating screening tests.

  9. Some Characterization Results on Dynamic Cumulative Residual Tsallis Entropy

    Directory of Open Access Journals (Sweden)

    Madan Mohan Sati

    2015-01-01

    Full Text Available We propose a generalized cumulative residual information measure based on Tsallis entropy and its dynamic version. We study the characterizations of the proposed information measure and define new classes of life distributions based on this measure. Some applications are provided in relation to weighted and equilibrium probability models. Finally the empirical cumulative Tsallis entropy is proposed to estimate the new information measure.

  10. Steps and pips in the history of the cumulative recorder.

    OpenAIRE

    Lattal, Kennon A.

    2004-01-01

    From its inception in the 1930s until very recent times, the cumulative recorder was the most widely used measurement instrument in the experimental analysis of behavior. It was an essential instrument in the discovery and analysis of schedules of reinforcement, providing the first real-time analysis of operant response rates and patterns. This review traces the evolution of the cumulative recorder from Skinner's early modified kymographs through various models developed by Skinner and his co...

  11. Lead Poisoning

    Science.gov (United States)

    ... lead is of microscopic size, invisible to the naked eye. More often than not, children with elevated ... majority of the childhood lead poisoning cases we see today. Children and adults too can get seriously ...

  12. Relational Leading

    DEFF Research Database (Denmark)

    2015-01-01

    This first chapter presents the exploratory and curious approach to leading as relational processes – an approach that pervades the entire book. We explore leading from a perspective that emphasises the unpredictable challenges and triviality of everyday life, which we consider an interesting......, relevant and realistic way to examine leading. The chapter brings up a number of concepts and contexts as formulated by researchers within the field, and in this way seeks to construct a first understanding of relational leading....

  13. Childhood Cumulative Risk Exposure and Adult Amygdala Volume and Function.

    Science.gov (United States)

    Evans, Gary W; Swain, James E; King, Anthony P; Wang, Xin; Javanbakht, Arash; Ho, S Shaun; Angstadt, Michael; Phan, K Luan; Xie, Hong; Liberzon, Israel

    2016-06-01

    Considerable work indicates that early cumulative risk exposure is aversive to human development, but very little research has examined the neurological underpinnings of these robust findings. This study investigates amygdala volume and reactivity to facial stimuli among adults (mean 23.7 years of age, n = 54) as a function of cumulative risk exposure during childhood (9 and 13 years of age). In addition, we test to determine whether expected cumulative risk elevations in amygdala volume would mediate functional reactivity of the amygdala during socioemotional processing. Risks included substandard housing quality, noise, crowding, family turmoil, child separation from family, and violence. Total and left hemisphere adult amygdala volumes were positively related to cumulative risk exposure during childhood. The links between childhood cumulative risk exposure and elevated amygdala responses to emotionally neutral facial stimuli in adulthood were mediated by the corresponding amygdala volumes. Cumulative risk exposure in later adolescence (17 years of age), however, was unrelated to subsequent adult amygdala volume or function. Physical and socioemotional risk exposures early in life appear to alter amygdala development, rendering adults more reactive to ambiguous stimuli such as neutral faces. These stress-related differences in childhood amygdala development might contribute to the well-documented psychological distress as a function of early risk exposure.

  14. Thermodynamic formula for the cumulant generating function of time-averaged current.

    Science.gov (United States)

    Nemoto, Takahiro; Sasa, Shin-ichi

    2011-12-01

    The cumulant generating function of time-averaged current is studied from an operational viewpoint. Specifically, for interacting Brownian particles under nonequilibrium conditions, we show that the first derivative of the cumulant generating function is equal to the expectation value of the current in a modified system with an extra force added, where the modified system is characterized by a variational principle. The formula reminds us of Einstein's fluctuation theory in equilibrium statistical mechanics. Furthermore, since the formula leads to the fluctuation-dissipation relation when the linear response regime is focused on, it is regarded as an extension of the linear response theory to that valid beyond the linear response regime. The formula is also related to previously known theories such as the Donsker-Varadhan theory, the additivity principle, and the least dissipation principle, but it is not derived from them. Examples of its application are presented for a driven Brownian particle on a ring subject to a periodic potential.

  15. On the duration and intensity of cumulative advantage competitions

    Science.gov (United States)

    Jiang, Bo; Sun, Liyuan; Figueiredo, Daniel R.; Ribeiro, Bruno; Towsley, Don

    2015-11-01

    Network growth can be framed as a competition for edges among nodes in the network. As with various other social and physical systems, skill (fitness) and luck (random chance) act as fundamental forces driving competition dynamics. In the context of networks, cumulative advantage (CA)—the rich-get-richer effect—is seen as a driving principle governing the edge accumulation process. However, competitions coupled with CA exhibit non-trivial behavior and little is formally known about duration and intensity of CA competitions. By isolating two nodes in an ideal CA competition, we provide a mathematical understanding of how CA exacerbates the role of luck in detriment of skill. We show, for instance, that when nodes start with few edges, an early stroke of luck can place the less skilled in the lead for an extremely long period of time, a phenomenon we call ‘struggle of the fittest’. We prove that duration of a simple skill and luck competition model exhibit power-law tails when CA is present, regardless of skill difference, which is in sharp contrast to the exponential tails when fitness is distinct but CA is absent. We also prove that competition intensity is always upper bounded by an exponential tail, irrespective of CA and skills. Thus, CA competitions can be extremely long (infinite mean, depending on fitness ratio) but almost never very intense. The theoretical results are corroborated by extensive numerical simulations. Our findings have important implications to competitions not only among nodes in networks but also in contexts that leverage socio-physical models embodying CA competitions.

  16. From image-guided radiotherapy to dose-guided radiotherapy; De la radiotherapie guidee par l'image a la radiotherapie guidee par la dose

    Energy Technology Data Exchange (ETDEWEB)

    Cazoulat, G.; Lesaunier, M.; Simon, A.; Haigron, P.; Acosta, O. [Inserm, U642, 35000 Rennes (France); LTSI, universite de Rennes-1, 35000 Rennes (France); Louvel, G.; Chajon, E.; Leseur, J. [Centre Eugene-Marquis, rue de La-Bataille-Flandres-Dunkerque, CS 44229, 35042 Rennes cedex (France); Lafond, C.; De Crevoisier, R. [Inserm, U642, 35000 Rennes (France); LTSI, universite de Rennes-1, 35000 Rennes (France); Centre Eugene-Marquis, rue de La-Bataille-Flandres-Dunkerque, CS 44229, 35042 Rennes cedex (France)

    2011-12-15

    Purpose. - In case of tumour displacement, image-guided radiotherapy (IGRT) based on the use of cone beam CT (tomographie conique) allows replacing the tumour under the accelerator by rigid registration. Anatomical deformations require however re-planning, involving an estimation of the cumulative dose, session after session. This is the objective of this study. Patients and methods. - Two examples of arc-intensity modulated radiotherapy are presented: a case of prostate cancer (total dose = 80 Gy) with tomographie conique (daily prostate registration) and one head and neck cancer (70 Gy). For the head and neck cancer, the patient had a weekly scanner allowing a dose distribution calculation. The cumulative dose was calculated per voxel on the planning CT after deformation of the dose distribution (with trilinear interpolation) following the transformation given by a non-rigid registration step (Demons registration method) from: either the tomographie conique (prostate), or the weekly CT. The cumulative dose was eventually compared with the planned dose. Results. - In cases of prostate irradiation, the 'cumulative' dose corresponded to the planned dose to the prostate. At the last week of irradiation, it was above the planned dose for the rectum and bladder. The volume of rectal wall receiving more than 50 Gy (V50) was 20% at the planning and 26% at the end of treatment, increasing the risk of rectal toxicity (NTCP) of 14%. For the bladder wall, V50 were 73% and 82%, respectively. In head and neck, the 'cumulative' dose to the parotid exceeded the planned dose (mean dose increasing from 46 Gy to 54 Gy) from the 5. week of irradiation on, suggesting the need for re-planning within the first 5 weeks of radiotherapy. Conclusion. - The deformable registration estimates the cumulative dose delivered in the different anatomical structures. Validation on digital and physical phantoms is however required before clinical evaluation. (authors)

  17. Expansion of the Glauber equation of motion in terms of cumulants powers. Statistical properties of the Glauber equation of motion

    Science.gov (United States)

    Bury, T.

    2012-01-01

    We present an expansion of the Glauber equation of motion in terms of cumulants of the effective fields. We show that we recover a part of the fluctuations with a simple third order expansion. We illustrate the method with an application to the 2D square lattice Ising model with nearest neighbors. For the special case of perturbed non gaussian effective fields, we show that only the first cumulants are significative. Furthermore it can be shown that the resulting distribution is closer to the normal distribution than the unperturbed fields one. It leads to the conclusion that we can consistently truncate the expansion of the exact Glauber equation of motion.

  18. Retrospective study of cumulative diagnostic radiation exposure during childhood in patients with spina bifida.

    Science.gov (United States)

    Smookler, Gregory; Deavenport-Saman, Alexis

    2015-10-01

    The Biological Effects of Ionizing Radiation Committee of the National Academy of Sciences in 2005 and other expert panels have warned that risk of cancer increases with higher doses of radiation. Children with spina bifida and hydrocephalus have far greater exposure to radiation than the average person, starting almost directly after birth and continuing throughout their lifetimes. The purpose of this study was to estimate the amount of ionizing radiation that patients with spina bifida and hydrocephalus are exposed to during childhood from diagnostic imaging. Thirty patients, ages 18 years or older, with spina bifida and hydrocephalus were randomly selected from a spina bifida clinic and their radiology records were reviewed. Descriptive analyses were conducted. The total radiation exposure was then calculated for the study group, and the mean effective dose per patient was determined. In the study group, during their first 18 years, each patient had a mean of 55.1 studies and a median of 45 radiologic studies, a mean of 9.6 brain CT scans, and a mean cumulative effective dose of 81.9 mSv (2.6 mSv/patient/year over 18 years) and a median cumulative effective dose of 77.2 mSV of accumulated radiation exposure (4.5 mSv/patient/year over 18 years). Clinicians should recognize that increased radiation exposure puts patients with spina bifida and hydrocephalus at higher risk for cancer. The population of children and adults with spina bifida and hydrocephalus should be surveyed for incidence of cancer. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Cumulative radiation exposure and cancer risk of patients with ischemic heart diseases from diagnostic and therapeutic imaging procedures

    Energy Technology Data Exchange (ETDEWEB)

    Brix, Gunnar, E-mail: gbrix@bfs.de [Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Ingoldstädter Landstraße 1, D-85764 Oberschleissheim (Germany); Berton, Marc, E-mail: marcberton@web.de [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); Nekolla, Elke, E-mail: enekolla@bfs.de [Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Ingoldstädter Landstraße 1, D-85764 Oberschleissheim (Germany); Lechel, Ursula, E-mail: ulechel@bfs.de [Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Ingoldstädter Landstraße 1, D-85764 Oberschleissheim (Germany); Schegerer, Alexander, E-mail: aschegerer@bfs.de [Department of Medical and Occupational Radiation Protection, Federal Office for Radiation Protection, Ingoldstädter Landstraße 1, D-85764 Oberschleissheim (Germany); Süselbeck, Tim, E-mail: Tim.Sueselbeck@umm.de [Department of Cardiology, University Medical Center Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany); Fink, Christian, E-mail: Christian.Fink@umm.de [Institute of Clinical Radiology and Nuclear Medicine, University Medical Center Mannheim, University of Heidelberg, Theodor-Kutzer-Ufer 1-3, D-68167 Mannheim (Germany)

    2013-11-01

    Objectives: To present a detailed analysis of the cumulative radiation exposure and cancer risk of patients with ischemic heart diseases (IHD) from diagnostic and therapeutic imaging. Methods: For 1219 IHD patients, personal and examination data were retrieved from the information systems of a university hospital. For each patient, cumulative organ doses and the corresponding effective dose (E{sup ¯}) resulting from all imaging procedures performed within 3 months before and 12 months after the date of the diagnosis were calculated. The cumulative lifetime attributable risk (LAR{sup ¯}) of the patients to be diseased by radiation-related cancer was estimated using sex-, age-, and organ-specific risk models. Results: Among the 3870 procedures performed in the IHD patients, the most frequent were radiographic examinations (52.4%) followed by coronary catheter angiographies and percutaneous cardiac interventions (41.3%), CT scans (3.9%), and perfusion SPECT (2.3%). 87% of patient exposure resulted from heart catheter procedures. E{sup ¯} and LAR{sup ¯} were significantly higher in males than females (average, 13.3 vs. 10.3 mSv and 0.09 vs. 0.07%, respectively). Contrary to the effective dose, the cancer risk decreased markedly for both sexes with increasing age. Conclusions: Although IHD patients were partially exposed to considerable amounts of radiation, estimated LAR{sup ¯}s were small as compared to their baseline risk to develop cancer in the remaining life.

  20. Cumulative risks of foster care placement for Danish children.

    Science.gov (United States)

    Fallesen, Peter; Emanuel, Natalia; Wildeman, Christopher

    2014-01-01

    Although recent research suggests that the cumulative risk of foster care placement is far higher for American children than originally suspected, little is known about the cumulative risk of foster care placement in other countries, which makes it difficult to gauge the degree to which factor foster care placement is salient in other contexts. In this article, we provide companion estimates to those provided in recent work on the US by using Danish registry data and synthetic cohort life tables to show how high and unequally distributed the cumulative risk of foster care placement is for Danish children. Results suggest that at the beginning of the study period (in 1998) the cumulative risk of foster care placement for Danish children was roughly in line with the risk for American children. Yet, by the end of the study period (2010), the risk had declined to half the risk for American children. Our results also show some variations by parental ethnicity and sex, but these differences are small. Indeed, they appear quite muted relative to racial/ethnic differences in these risks in the United States. Last, though cumulative risks are similar between Danish and American children (especially at the beginning of the study period), the age-specific risk profiles are markedly different, with higher risks for older Danish children than for older American children.

  1. Latino Mothers' Cumulative Food Insecurity Exposure and Child Body Composition.

    Science.gov (United States)

    Hernandez, Daphne C

    2016-01-01

    To document whether an intergenerational transmission of food insecurity is occurring by assessing low-income foreign-born Latino mothers' experiences with food insecurity as none, once (either childhood or adulthood) or twice (during both childhood and adulthood). Also the association between maternal cumulative food insecurity and children's body composition was examined. Maternal self-reported surveys on retrospective measures of food insecurity during childhood, current measures of food insecurity, and demographics were collected from Houston-area community centers (N = 96). Children's body mass index (BMI) and waist circumference (WC) were directly assessed. Covariate-adjusted logistic regression models analyzed the association between cumulative food insecurity experiences and children's body composition. Fifty-eight percent of mothers experienced food insecurity both as a child and as an adult and 31% of the mothers experienced food insecurity either as a child or adult. Maternal cumulative exposure to food insecurity was unrelated to BMI but was negatively related to elevated WC. Although an intergenerational transmission of food insecurity does exist, maternal cumulative exposure to food insecurity does not impact children's body composition negatively in the short term. Studying the long-term effects of cumulative food insecurity exposure can provide information for the development and timing of obesity interventions.

  2. A semi-parametric censoring bias model for estimating the cumulative risk of a false-positive screening test under dependent censoring

    OpenAIRE

    Hubbard, Rebecca A.; Miglioretti, Diana L.

    2013-01-01

    False-positive test results are among the most common harms of screening tests and may lead to more invasive and expensive diagnostic testing procedures. Estimating the cumulative risk of a false-positive screening test result after repeat screening rounds is therefore important for evaluating potential screening regimens. Existing estimators of the cumulative false-positive risk are limited by strong assumptions about censoring mechanisms and parametric assumptions about variation in risk ac...

  3. Lead Test

    Science.gov (United States)

    ... months, and at 3, 4, 5, and 6 years of age. A blood lead level test should be done only if the risk ... recommended if the person is symptomatic at any level below 70 mcg/dL. Because lead will pass through the blood to an unborn child, pregnant ...

  4. Effective dose and dose to crystalline lens during angiographic procedures; Dose effective et dose au cristallin lors de procedures angiographiques

    Energy Technology Data Exchange (ETDEWEB)

    Pages, J. [QUARAD and Radiology Dept., Vvije Universiteit Brussel (Belgium)

    1998-07-01

    The highest radiation doses levels received by radiologists are observed during interventional procedures. Doses to forehead and neck received by a radiologist executing angiographic examinations at the department of radiology at the academic hospital (AZ-VUB) have been measured for a group of 34 examinations. The doses to crystalline lens and the effective doses for a period of one year have been estimated. For the crystalline lens the maximum dose approaches the ICRP limit, that indicates the necessity for the radiologist to use leaded glasses. (N.C.)

  5. Western red cedar dust exposure and lung function: a dose-response relationship.

    Science.gov (United States)

    Noertjojo, H K; Dimich-Ward, H; Peelen, S; Dittrick, M; Kennedy, S M; Chan-Yeung, M

    1996-10-01

    The relationship between levels of cumulative red cedar dust exposure and decline in lung function was explored in an 11-yr follow-up study of 243 sawmill workers who participated in at least two occasions. We also studied 140 office workers in a similar manner as control subjects. Workers with asthma were excluded from the analysis. During the period of the study, 916 personal and 216 area samples of dust were collected from the sawmill. Cumulative wood dust exposure was calculated for each sawmill worker according to the duration and exposure in each job, based on the geometric mean of all dust measurements for that job. Average daily dust exposure was calculated by dividing the total cumulative exposure by the number of days of work. Workers were divided into low-, medium-, and high-exposure groups with mean daily level of exposure of 0.4 mg/m3, respectively. Sawmill workers had significantly greater declines in FEV1 and FVC compared with office workers adjusted for age, smoking, and initial lung function. A dose-response relationship was observed between the level of exposure and the annual decline in FVC. We conclude that exposure to Western red cedar dust is associated with a greater decline in lung function which may lead to development of chronic airflow limitation.

  6. Radiation Dose Risk and Diagnostic Benefit in Imaging Investigations

    CERN Document Server

    Dobrescu, Lidia

    2015-01-01

    The paper presents many facets of medical imaging investigations radiological risks. The total volume of prescribed medical investigations proves a serious lack in monitoring and tracking of the cumulative radiation doses in many health services. Modern radiological investigations equipment is continuously reducing the total dose of radiation due to improved technologies, so a decrease in per caput dose can be noticed, but the increasing number of investigations has determined a net increase of the annual collective dose. High doses of radiation are cumulated from Computed Tomography investigations. An integrated system for radiation safety of the patients investigated by radiological imaging methods, based on smart cards and Public Key Infrastructure allow radiation absorbed dose data storage.

  7. Race, Space, and Cumulative Disadvantage: A Case Study of the Subprime Lending Collapse.

    Science.gov (United States)

    Rugh, Jacob S; Albright, Len; Massey, Douglas S

    2015-05-01

    In this article, we describe how residential segregation and individual racial disparities generate racialized patterns of subprime lending and lead to financial loss among black borrowers in segregated cities. We conceptualize race as a cumulative disadvantage because of its direct and indirect effects on socioeconomic status at the individual and neighborhood levels, with consequences that reverberate across a borrower's life and between generations. Using Baltimore, Maryland as a case study setting, we combine data from reports filed under the Home Mortgage Disclosure Act with additional loan-level data from mortgage-backed securities. We find that race and neighborhood racial segregation are critical factors explaining black disadvantage across successive stages in the process of lending and foreclosure, controlling for differences in borrower credit scores, income, occupancy status, and loan-to-value ratios. We analyze the cumulative cost of predatory lending to black borrowers in terms of reduced disposable income and lost wealth. We find the cost to be substantial. Black borrowers paid an estimated additional 5 to 11 percent in monthly payments and those that completed foreclosure in the sample lost an excess of $2 million in home equity. These costs were magnified in mostly black neighborhoods and in turn heavily concentrated in communities of color. By elucidating the mechanisms that link black segregation to discrimination we demonstrate how processes of cumulative disadvantage continue to undermine black socioeconomic status in the United States today.

  8. Cumulative pion production via successive collisions in nuclear medium

    CERN Document Server

    Motornenko, A

    2016-01-01

    Production of pions in proton-nucleus (p+A) reactions outside of a kinematical boundary of proton-nucleon collisions, the so-called cumulative effect, is studied. The kinematical restrictions on pions emitted in backward direction in the target rest frame are analyzed. It is shown that cumulative pion production requires a presence of massive baryonic resonances that are produced during successive collisions of projectile with nuclear nucleons. After each successive collision the mass of created resonance may increase and, simultaneously, its longitudinal velocity decreases. Simulations within Ultra relativistic Quantum Molecular Dynamics model reveals that successive collisions of baryonic resonances with nuclear nucleons plays the dominant role in cumulative pion production in p+A reactions.

  9. Solid-state electro-cumulation effect numerical simulation

    CERN Document Server

    Grishin, V G

    2001-01-01

    It is an attempt to simulate as really as possible a crystal's interatomic interaction under conditions of "Solid-state electro-cumulation (super-polarization) effect". Some theoretical and experimental reasons to believe that within solid substances an interparticles interaction could concentrate from the surface to a centre were given formerly. Now, numerical results show the conditions that could make the cumulation more effective. Another keywords: ion, current, solid, symmetry, cumulation, polarization, depolarization, ionic conductor,superionic conductor, ice, crystal, strain, V-center, V-centre, doped crystal, interstitial impurity, intrinsic color center, high pressure technology, Bridgman, anvil, experiment, crowdion, dielectric, proton, layer, defect, lattice, dynamics, electromigration, mobility, muon catalysis, concentration, doping, dopant, conductivity, pycnonuclear reaction, permittivity, dielectric constant, point defects, interstitials, polarizability, imperfection, defect centers, glass, epi...

  10. Association between diastolic blood pressure and cumulative work time

    Directory of Open Access Journals (Sweden)

    Ricardo Cordeiro

    1999-01-01

    Full Text Available Diastolic blood pressure was viewed as a generic indicator of aging, and its association with cumulative work time was studied after controlling for age as a potential confounding factor. The study was conducted among production line workers at a Brazilian tannery in July 1993. The association between diastolic blood pressure and cumulative work time was verified by fitting a second-order linear regression model, where diastolic blood pressure was a function of worker's age and cumulative work time. By fitting the model, one can predict that, in the beginning of working life at the tannery, on average each 1-year period is associated with an increase of about 1.5 mmHg in diastolic blood pressure. The fit obtained highlights one component directly associated with work as part of the rate of pressure increase in the study group. This component is twice as high as that directly associated with age.

  11. Baltic Sea biodiversity status vs. cumulative human pressures

    DEFF Research Database (Denmark)

    Andersen, Jesper H.; Halpern, Benjamin S.; Korpinen, Samuli

    2015-01-01

    Abstract Many studies have tried to explain spatial and temporal variations in biodiversity status of marine areas from a single-issue perspective, such as fishing pressure or coastal pollution, yet most continental seas experience a wide range of human pressures. Cumulative impact assessments have...... been developed to capture the consequences of multiple stressors for biodiversity, but the ability of these assessments to accurately predict biodiversity status has never been tested or ground-truthed. This relationship has similarly been assumed for the Baltic Sea, especially in areas with impaired...... status, but has also never been documented. Here we provide a first tentative indication that cumulative human impacts relate to ecosystem condition, i.e. biodiversity status, in the Baltic Sea. Thus, cumulative impact assessments offer a promising tool for informed marine spatial planning, designation...

  12. Session: What do we know about cumulative or population impacts

    Energy Technology Data Exchange (ETDEWEB)

    Kerlinger, Paul; Manville, Al; Kendall, Bill

    2004-09-01

    This session at the Wind Energy and Birds/Bats workshop consisted of a panel discussion followed by a discussion/question and answer period. The panelists were Paul Kerlinger, Curry and Kerlinger, LLC, Al Manville, U.S. Fish and Wildlife Service, and Bill Kendall, US Geological Service. The panel addressed the potential cumulative impacts of wind turbines on bird and bat populations over time. Panel members gave brief presentations that touched on what is currently known, what laws apply, and the usefulness of population modeling. Topics addressed included which sources of modeling should be included in cumulative impacts, comparison of impacts from different modes of energy generation, as well as what research is still needed regarding cumulative impacts of wind energy development on bird and bat populations.

  13. Cumulant dynamics in a finite population linkage equilibrium theory

    CERN Document Server

    Rattray, M; Rattray, Magnus; Shapiro, Jonathan L.

    1999-01-01

    The evolution of a finite population at linkage equilibrium is described in terms of the dynamics of phenotype distribution cumulants. This provides a powerful method for describing evolutionary transients and we elucidate the relationship between the cumulant dynamics and the diffusion approximation. A separation of time-scales between the first and higher cumulants for low mutation rates is demonstrated in the diffusion limit and provides a significant simplification of the dynamical system. However, the diffusion limit may not be appropriate for strong selection as the standard Fisher-Wright model of genetic drift can break down in this case. Two novel examples of this effect are considered: we shown that the dynamics may depend on the number of loci under strong directional selection and that environmental variance results in a reduced effective population size. We also consider a simple model of a changing environment which cannot be described by a diffusion equation and we derive the optimal mutation ra...

  14. Effect of correlation on cumulants in heavy-ion collisions

    CERN Document Server

    Mishra, D K; Netrakanti, P K

    2015-01-01

    We study the effects of correlation on cumulants and their ratios of net-proton multiplicity distribution which have been measured for central (0-5\\%) Au+Au collisions at Relativistic Heavy Ion Collider (RHIC). This effect has been studied assuming individual proton and anti-proton distributions as Poisson or Negative Binomial Distribution (NBD). In-spite of significantly correlated production due to baryon number, electric charge conservation and kinematical correlations of protons and anti-protons, the measured cumulants of net-proton distribution follow the independent production model. In the present work we demonstrate how the introduction of correlations will affect the cumulants and their ratios for the difference distributions. We have also demonstrated this study using the proton and anti-proton distributions obtained from HIJING event generator.

  15. Modelling the cumulative risk of a false-positive screening test.

    Science.gov (United States)

    Hubbard, Rebecca A; Miglioretti, Diana L; Smith, Robert A

    2010-10-01

    The goal of a screening test is to reduce morbidity and mortality through the early detection of disease; but the benefits of screening must be weighed against potential harms, such as false-positive (FP) results, which may lead to increased healthcare costs, patient anxiety, and other adverse outcomes associated with diagnostic follow-up procedures. Accurate estimation of the cumulative risk of an FP test after multiple screening rounds is important for program evaluation and goal setting, as well as informing individuals undergoing screening what they should expect from testing over time. Estimation of the cumulative FP risk is complicated by the existence of censoring and possible dependence of the censoring time on the event history. Current statistical methods for estimating the cumulative FP risk from censored data follow two distinct approaches, either conditioning on the number of screening tests observed or marginalizing over this random variable. We review these current methods, identify their limitations and possibly unrealistic assumptions, and propose simple extensions to address some of these limitations. We discuss areas where additional extensions may be useful. We illustrate methods for estimating the cumulative FP recall risk of screening mammography and investigate the appropriateness of modelling assumptions using 13 years of data collected by the Breast Cancer Surveillance Consortium (BCSC). In the BCSC data we found evidence of violations of modelling assumptions of both classes of statistical methods. The estimated risk of an FP recall after 10 screening mammograms varied between 58% and 77% depending on the approach used, with an estimate of 63% based on what we feel are the most reasonable modelling assumptions.

  16. Cumulative effects of fecal contamination from combined sewer overflows: Management for source water protection.

    Science.gov (United States)

    Jalliffier-Verne, Isabelle; Heniche, Mourad; Madoux-Humery, Anne-Sophie; Galarneau, Martine; Servais, Pierre; Prévost, Michèle; Dorner, Sarah

    2016-06-01

    The quality of a drinking water source depends largely on upstream contaminant discharges. Sewer overflows can have a large influence on downstream drinking water intakes as they discharge untreated or partially treated wastewaters that may be contaminated with pathogens. This study focuses on the quantification of Escherichia coli discharges from combined sewer overflows (CSOs) and the dispersion and diffusion in receiving waters in order to prioritize actions for source water protection. E. coli concentrations from CSOs were estimated from monitoring data at a series of overflow structures and then applied to the 42 active overflow structures between 2009 and 2012 using a simple relationship based upon the population within the drainage network. From these estimates, a transport-dispersion model was calibrated with data from a monitoring program from both overflow structures and downstream drinking water intakes. The model was validated with 15 extreme events such as a large number of overflows (n > 8) or high concentrations at drinking water intakes. Model results demonstrated the importance of the cumulative effects of CSOs on the degradation of water quality downstream. However, permits are typically issued on a discharge point basis and do not consider cumulative effects. Source water protection plans must consider the cumulative effects of discharges and their concentrations because the simultaneous discharge of multiple overflows can lead to elevated E. coli concentrations at a drinking water intake. In addition, some CSOs have a disproportionate impact on peak concentrations at drinking water intakes. As such, it is recommended that the management of CSOs move away from frequency based permitting at the discharge point to focus on the development of comprehensive strategies to reduce cumulative and peak discharges from CSOs upstream of drinking water intakes.

  17. System Dynamics and Modified Cumulant Neglect Closure Schemes

    DEFF Research Database (Denmark)

    Köylüoglu, H. Ugur; Nielsen, Søren R.K.

    Dealing with multipeaked problems, the goal of the paper is to improve the quality of the approximations for the expectations appearing in the differential equations written for the statistical moments of the state vector, guided by insight in the system dynamics. For systems with polynomial non......-linearities, modifications in the cumulant neglect closure scheme are suggested. The methodology is illustrated using the two wells oscillator. An error analysis is performed to compare the modified and ordinary cumulant neglect closure schemes applied at the second and fourth order levels with the exact results available....

  18. Baltic Sea biodiversity status vs. cumulative human pressures

    DEFF Research Database (Denmark)

    Andersen, Jesper H.; Halpern, Benjamin S.; Korpinen, Samuli

    2015-01-01

    been developed to capture the consequences of multiple stressors for biodiversity, but the ability of these assessments to accurately predict biodiversity status has never been tested or ground-truthed. This relationship has similarly been assumed for the Baltic Sea, especially in areas with impaired...... status, but has also never been documented. Here we provide a first tentative indication that cumulative human impacts relate to ecosystem condition, i.e. biodiversity status, in the Baltic Sea. Thus, cumulative impact assessments offer a promising tool for informed marine spatial planning, designation...

  19. Aspect of cumulative fatigue damage under multiaxial strain cycling.

    Science.gov (United States)

    Zamrik, S. Y.; Tang, P. Y.

    1972-01-01

    The concept of order of loading and its effect on cumulative fatigue damage under multiaxial strain cyclings was investigated. The effect is illustrated through nonlinear relationships between biaxial fatigue damage and cycle-ratio diagrams. Uniaxial theories such as Miner's method, the convergence method, and the double linear damage rule in its special and generalized form, were examined and extended to the biaxial case through the octahedral shear strain theory. The generalized double linear damage rule was found more applicable to biaxial cumulative fatigue damage.

  20. Cumulative Incidence of Cancer After Solid Organ Transplantation

    Science.gov (United States)

    Hall, Erin C.; Pfeiffer, Ruth M.; Segev, Dorry L.; Engels, Eric A.

    2014-01-01

    BACKGROUND Solid organ transplantation recipients have elevated cancer incidence. Estimates of absolute cancer risk after transplantation can inform prevention and screening. METHODS The Transplant Cancer Match Study links the US transplantation registry with 14 state/regional cancer registries. The authors used nonparametric competing risk methods to estimate the cumulative incidence of cancer after transplantation for 2 periods (1987–1999 and 2000–2008). For recipients from 2000 to 2008, the 5-year cumulative incidence, stratified by organ, sex, and age at transplantation, was estimated for 6 preventable or screen-detectable cancers. For comparison, the 5-year cumulative incidence was calculated for the same cancers in the general population at representative ages using Surveillance, Epidemiology, and End Results data. RESULTS Among 164,156 recipients, 8520 incident cancers were identified. The absolute cancer risk was slightly higher for recipients during the period from 2000 to 2008 than during the period from 1987 to 1999 (5-year cumulative incidence: 4.4% vs 4.2%; P =.006); this difference arose from the decreasing risk of competing events (5-year cumulative incidence of death, graft failure, or retransplantation: 26.6% vs 31.9%; P 50 years; range, 0.36%–2.22%). For recipients aged >50 years, the 5-year cumulative incidence was higher for colorectal cancer (range, 0.33%–1.94%) than for the general population at the recommended screening age (aged 50 years: range, 0.25%–0.33%). For recipients aged >50 years, the 5-year cumulative incidence was high for lung cancer among thoracic organ recipients (range, 1.16%–3.87%) and for kidney cancer among kidney recipients (range, 0.53%–0.84%). The 5-year cumulative incidence for prostate cancer and breast cancer was similar or lower in transplantation recipients than at the recommended ages of screening in the general population. CONCLUSIONS Subgroups of transplantation recipients have a high absolute risk

  1. A study of cumulative fatigue damage in AISI 4130 steel

    Science.gov (United States)

    Jeelani, S.; Musial, M.

    1986-01-01

    Experimental data were obtained using AISI 4130 steel under stress ratios of -1 and 0. A study of cumulative fatigue damage using Miner's and Kramer's equations for stress ratios of -1 and 0 for low-high, low-high-mixed, high-low, and high-low-mixed stress sequences has revealed that there is a close agreement between the theoretical and experimental values of fatigue damage and fatigue life. Kramer's equation predicts less conservative and more realistic cumulative fatigue damage than the popularly used Miner's rule does.

  2. Lead Poisoning

    Science.gov (United States)

    ... Topics Environment & Health Healthy Living Pollution Reduce, Reuse, Recycle Science – How It Works The Natural World Games ... OTHERS: Lead has recently been found in some plastic mini-blinds and vertical blinds which were made ...

  3. Checking Fine and Gray subdistribution hazards model with cumulative sums of residuals

    DEFF Research Database (Denmark)

    Li, Jianing; Scheike, Thomas; Zhang, Mei Jie

    2015-01-01

    Recently, Fine and Gray (J Am Stat Assoc 94:496–509, 1999) proposed a semi-parametric proportional regression model for the subdistribution hazard function which has been used extensively for analyzing competing risks data. However, failure of model adequacy could lead to severe bias in parameter...... estimation, and only a limited contribution has been made to check the model assumptions. In this paper, we present a class of analytical methods and graphical approaches for checking the assumptions of Fine and Gray’s model. The proposed goodness-of-fit test procedures are based on the cumulative sums...

  4. Cumulative Impacts of Energy and Climate Change Policies on Carbon Leakage

    Energy Technology Data Exchange (ETDEWEB)

    Varma, A.; Milnes, R.; Miller, K.; Williams, E. [AEA Technology plc, London (United Kingdom); De Bruyn, S.; Brinke, L. [CE Delft, Delft (Netherlands)

    2012-02-15

    Carbon leakage occurs when climate change policy aimed at reducing carbon dioxide emissions in one country leads to an increase in carbon dioxide emissions in a country that is not bound by these policies. Given that climate change is a global issue, carbon leakage impacts upon the effectiveness of climate change policies. This independent study examines the cumulative impact of climate change policies on carbon leakage. The report brings together findings and analysis from a wide range of primary literature in this area and where possible, conclusions relevant to the UK are drawn.

  5. Dose computation in conformal radiation therapy including geometric uncertainties: Methods and clinical implications

    Science.gov (United States)

    Rosu, Mihaela

    The aim of any radiotherapy is to tailor the tumoricidal radiation dose to the target volume and to deliver as little radiation dose as possible to all other normal tissues. However, the motion and deformation induced in human tissue by ventilatory motion is a major issue, as standard practice usually uses only one computed tomography (CT) scan (and hence one instance of the patient's anatomy) for treatment planning. The interfraction movement that occurs due to physiological processes over time scales shorter than the delivery of one treatment fraction leads to differences between the planned and delivered dose distributions. Due to the influence of these differences on tumors and normal tissues, the tumor control probabilities and normal tissue complication probabilities are likely to be impacted upon in the face of organ motion. In this thesis we apply several methods to compute dose distributions that include the effects of the treatment geometric uncertainties by using the time-varying anatomical information as an alternative to the conventional Planning Target Volume (PTV) approach. The proposed methods depend on the model used to describe the patient's anatomy. The dose and fluence convolution approaches for rigid organ motion are discussed first, with application to liver tumors and the rigid component of the lung tumor movements. For non-rigid behavior a dose reconstruction method that allows the accumulation of the dose to the deforming anatomy is introduced, and applied for lung tumor treatments. Furthermore, we apply the cumulative dose approach to investigate how much information regarding the deforming patient anatomy is needed at the time of treatment planning for tumors located in thorax. The results are evaluated from a clinical perspective. All dose calculations are performed using a Monte Carlo based algorithm to ensure more realistic and more accurate handling of tissue heterogeneities---of particular importance in lung cancer treatment planning.

  6. Residual, direct and cumulative effect of zinc application on wheat and rice yield under rice-wheat syst

    Directory of Open Access Journals (Sweden)

    R. Khan

    2009-05-01

    Full Text Available Zinc (Zn deficiency is prevalent particularly on calcareous soils of arid and semiarid region. A field experiment was conducted to investigate the direct, residual and cumulative effect of zinc on the yield of wheat and rice in permanent layout for two consecutive years, 2004-05 and 2005-06 at Arid Zone Research Institute D.I. Khan. Soil under study was deficient in Zn (0.8 mg kg-1. Effect of Zn on yield, Zn concentrations in leaf and soils were assessed using wheat variety Naseer-2000 and rice variety IRRI-6. Three rates of Zn, ranging from 0 to 10 kg ha-1 in soil, were applied as zinc sulphate (ZnSO4. 7H2O along with basal dose fertilization of nitrogen, phosphorus and potassium. Mature leaf and soil samples were collected at panicle initiation stage. The results showed that grain yield of wheat and rice was significantly increased by the direct application of 5 and 10 kg Zn ha-1. Highest grain yield of wheat (5467 kg ha-1 was recorded with the direct application of 10 kg Zn ha-1 while 4994 kg ha-1 was recorded with the cumulative application of 10 kg Zn ha-1 but the yield increase due to residual effect of Zn was statistically lower than the cumulative effect of Zn. Maximum paddy yield was recorded with the cumulative application ofZn followed by residual and direct applied 10 and 5 kg Zn kg ha-1, respectively. Zn concentration in soils ranged from 0.3 to 1.5 mg kg-1 in wheat and 0.24 to 2.40 mg kg-1 in rice, while in leaves it ranged from 18-48 mg kg-1 in wheat and 15-52 mg kg-1 in rice. The concentration of Zn in soil and leaves increased due to the treatments in the order; cumulative > residual > direct effect > control (without Zn. The yield attributes like 1000- grain weight, number of spikes, spike length and plant height were increased by the residual, direct and cumulative effect of Zn levels; however, the magnitude of increase was higher in cumulative effect than residual and direct effect of Zn, respectively. Under Zn-deficient soil

  7. A Parametric Cumulative Sum Statistic for Person Fit

    Science.gov (United States)

    Armstrong, Ronald D.; Shi, Min

    2009-01-01

    This article develops a new cumulative sum (CUSUM) statistic to detect aberrant item response behavior. Shifts in behavior are modeled with quadratic functions and a series of likelihood ratio tests are used to detect aberrancy. The new CUSUM statistic is compared against another CUSUM approach as well as traditional person-fit statistics. A…

  8. RECURSIVE CLASSIFICATION OF MQAM SIGNALS BASED ON HIGHER ORDER CUMULANTS

    Institute of Scientific and Technical Information of China (English)

    Chen Weidong; Yang Shaoquan

    2002-01-01

    A new feature based on higher order cumulants is proposed for classification of MQAM signals. Theoretical analysis justify that the new feature is invariant with respect to translation (shift), scale and rotation transform of signal constellations, and can suppress color or white additive Gaussian noise. Computer simulation shows that the proposed recursive orderreduction based classification algorithm can classify MQAM signals with any order.

  9. Hierarchical Bayesian parameter estimation for cumulative prospect theory

    NARCIS (Netherlands)

    Nilsson, H.; Rieskamp, J.; Wagenmakers, E.-J.

    2011-01-01

    Cumulative prospect theory (CPT Tversky & Kahneman, 1992) has provided one of the most influential accounts of how people make decisions under risk. CPT is a formal model with parameters that quantify psychological processes such as loss aversion, subjective values of gains and losses, and

  10. Cumulative psychosocial stress, coping resources, and preterm birth.

    Science.gov (United States)

    McDonald, Sheila W; Kingston, Dawn; Bayrampour, Hamideh; Dolan, Siobhan M; Tough, Suzanne C

    2014-12-01

    Preterm birth constitutes a significant international public health issue, with implications for child and family well-being. High levels of psychosocial stress and negative affect before and during pregnancy are contributing factors to shortened gestation and preterm birth. We developed a cumulative psychosocial stress variable and examined its association with early delivery controlling for known preterm birth risk factors and confounding environmental variables. We further examined this association among subgroups of women with different levels of coping resources. Utilizing the All Our Babies (AOB) study, an ongoing prospective pregnancy cohort study in Alberta, Canada (n = 3,021), multinomial logistic regression was adopted to examine the independent effect of cumulative psychosocial stress and preterm birth subgroups compared to term births. Stratified analyses according to categories of perceived social support and optimism were undertaken to examine differential effects among subgroups of women. Cumulative psychosocial stress was a statistically significant risk factor for late preterm birth (OR = 1.73; 95 % CI = 1.07, 2.81), but not for early preterm birth (OR = 2.44; 95 % CI = 0.95, 6.32), controlling for income, history of preterm birth, pregnancy complications, reproductive history, and smoking in pregnancy. Stratified analyses showed that cumulative psychosocial stress was a significant risk factor for preterm birth at psychosocial stress on the risk for early delivery.

  11. The proportional odds cumulative incidence model for competing risks

    DEFF Research Database (Denmark)

    Eriksson, Frank; Li, Jianing; Scheike, Thomas

    2015-01-01

    We suggest an estimator for the proportional odds cumulative incidence model for competing risks data. The key advantage of this model is that the regression parameters have the simple and useful odds ratio interpretation. The model has been considered by many authors, but it is rarely used in pr...

  12. Is learning in problem-based learning cumulative?

    NARCIS (Netherlands)

    E.H.J. Yew (Elaine); E. Chng (Esther); H.G. Schmidt (Henk)

    2011-01-01

    textabstractProblem-based learning (PBL) is generally organized in three phases, involving collaborative and self-directed learning processes. The hypothesis tested here is whether learning in the different phases of PBL is cumulative, with learning in each phase depending on that of the previous ph

  13. Cumulative assessment : Strategic choices to influence students' study effort

    NARCIS (Netherlands)

    Kerdijk, Wouter; Tio, Rene A.; Mulder, B. Florentine; Cohen-Schotanus, Janke

    2013-01-01

    Background: It has been asserted that assessment can and should be used to drive students' learning. In the current study, we present a cumulative assessment program in which test planning, repeated testing and compensation are combined in order to influence study effort. The program is aimed at hel

  14. Repeated mild injury causes cumulative damage to hippocampal cells

    NARCIS (Netherlands)

    E.J. Matser (Amy); C.I. de Zeeuw (Chris); J.T. Weber (John)

    2002-01-01

    textabstractAn interesting hypothesis in the study of neurotrauma is that repeated traumatic brain injury may result in cumulative damage to cells of the brain. However, post-injury sequelae are difficult to address at the cellular level in vivo. Therefore, it is necessary to compl

  15. The effects of cumulative practice on mathematics problem solving.

    Science.gov (United States)

    Mayfield, Kristin H; Chase, Philip N

    2002-01-01

    This study compared three different methods of teaching five basic algebra rules to college students. All methods used the same procedures to teach the rules and included four 50-question review sessions interspersed among the training of the individual rules. The differences among methods involved the kinds of practice provided during the four review sessions. Participants who received cumulative practice answered 50 questions covering a mix of the rules learned prior to each review session. Participants who received a simple review answered 50 questions on one previously trained rule. Participants who received extra practice answered 50 extra questions on the rule they had just learned. Tests administered after each review included new questions for applying each rule (application items) and problems that required novel combinations of the rules (problem-solving items). On the final test, the cumulative group outscored the other groups on application and problem-solving items. In addition, the cumulative group solved the problem-solving items significantly faster than the other groups. These results suggest that cumulative practice of component skills is an effective method of training problem solving.

  16. A Parametric Cumulative Sum Statistic for Person Fit

    Science.gov (United States)

    Armstrong, Ronald D.; Shi, Min

    2009-01-01

    This article develops a new cumulative sum (CUSUM) statistic to detect aberrant item response behavior. Shifts in behavior are modeled with quadratic functions and a series of likelihood ratio tests are used to detect aberrancy. The new CUSUM statistic is compared against another CUSUM approach as well as traditional person-fit statistics. A…

  17. Variable cultural acquisition costs constrain cumulative cultural evolution.

    Directory of Open Access Journals (Sweden)

    Alex Mesoudi

    Full Text Available One of the hallmarks of the human species is our capacity for cumulative culture, in which beneficial knowledge and technology is accumulated over successive generations. Yet previous analyses of cumulative cultural change have failed to consider the possibility that as cultural complexity accumulates, it becomes increasingly costly for each new generation to acquire from the previous generation. In principle this may result in an upper limit on the cultural complexity that can be accumulated, at which point accumulated knowledge is so costly and time-consuming to acquire that further innovation is not possible. In this paper I first review existing empirical analyses of the history of science and technology that support the possibility that cultural acquisition costs may constrain cumulative cultural evolution. I then present macroscopic and individual-based models of cumulative cultural evolution that explore the consequences of this assumption of variable cultural acquisition costs, showing that making acquisition costs vary with cultural complexity causes the latter to reach an upper limit above which no further innovation can occur. These models further explore the consequences of different cultural transmission rules (directly biased, indirectly biased and unbiased transmission, population size, and cultural innovations that themselves reduce innovation or acquisition costs.

  18. Cumulative index 1981-1985, Volumes 138-157.

    Science.gov (United States)

    1985-01-01

    This cumulative index also includes listings of all major papers from the American Journal of Neuroradiology, American Journal of Roentgenology, Clinics in Diagnostic Ultrasound, Journal of Computer Assisted Tomography, Journal of Ultrasound in Medicine, RadioGraphics, Radiologic Clinics of North America, Seminars in Nuclear Medicine, Seminars in Roentgenology, and Seminars in Ultrasound, CT and MR.

  19. Cumulative index 1981-1985, Volumes 138-157

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    This cumulative index also includes listings of all major papers from the American Journal of Neuroradiology, American Journal of Roentgenology, Clinics in Diagnostic Ultrasound, Journal of Computer Assisted Tomography, Journal of Ultrasound in Medicine, RadioGraphics, Radiologic Clinics of North America, Seminars in Nuclear Medicine, Seminars in Roentgenology, and Seminars in Ultrasound, CT and MR.

  20. Ecotoxicology: Lead

    Science.gov (United States)

    Scheuhammer, A.M.; Beyer, W.N.; Schmitt, C.J.; Jorgensen, Sven Erik; Fath, Brian D.

    2008-01-01

    Lead (Pb) is a naturally occurring metallic element; trace concentrations are found in all environmental media and in all living things. However, certain human activities, especially base metal mining and smelting; combustion of leaded gasoline; the use of Pb in hunting, target shooting, and recreational angling; the use of Pb-based paints; and the uncontrolled disposal of Pb-containing products such as old vehicle batteries and electronic devices have resulted in increased environmental levels of Pb, and have created risks for Pb exposure and toxicity in invertebrates, fish, and wildlife in some ecosystems.

  1. The role of cumulative physical work load in symptomatic knee osteoarthritis – a case-control study in Germany

    Directory of Open Access Journals (Sweden)

    Abolmaali Nasreddin

    2008-07-01

    Full Text Available Abstract Objectives To examine the dose-response relationship between cumulative exposure to kneeling and squatting as well as to lifting and carrying of loads and symptomatic knee osteoarthritis (OA in a population-based case-control study. Methods In five orthopedic clinics and five practices we recruited 295 male patients aged 25 to 70 with radiographically confirmed knee osteoarthritis associated with chronic complaints. A total of 327 male control subjects were recruited. Data were gathered in a structured personal interview. To calculate cumulative exposure, the self-reported duration of kneeling and squatting as well as the duration of lifting and carrying of loads were summed up over the entire working life. Results The results of our study support a dose-response relationship between kneeling/squatting and symptomatic knee osteoarthritis. For a cumulative exposure to kneeling and squatting > 10.800 hours, the risk of having radiographically confirmed knee osteoarthritis as measured by the odds ratio (adjusted for age, region, weight, jogging/athletics, and lifting or carrying of loads is 2.4 (95% CI 1.1–5.0 compared to unexposed subjects. Lifting and carrying of loads is significantly associated with knee osteoarthritis independent of kneeling or similar activities. Conclusion As the knee osteoarthritis risk is strongly elevated in occupations that involve both kneeling/squatting and heavy lifting/carrying, preventive efforts should particularly focus on these "high-risk occupations".

  2. A novel mutation in the RYR2 gene leading to catecholaminergic polymorphic ventricular tachycardia and paroxysmal atrial fibrillation: dose-dependent arrhythmia-event suppression by β-blocker therapy.

    Science.gov (United States)

    Kazemian, Pedram; Gollob, Michael H; Pantano, Alfredo; Oudit, Gavin Y

    2011-01-01

    Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a genetic condition that presents with exercise-induced polymorphic arrhythmias. We describe a case report of a 25-year-old woman who had a cardiac arrest due to ventricular fibrillation. Genetic analysis revealed a novel missense mutation in exon 90 of the ryanodine receptor (RyR2) gene resulting in substitution of arginine for serine at residue 4153 (S4153R). The patient received an implantable cardioverter-defibrillator and low-dose β-blocker therapy. She had recurrent polymorphic ventricular arrhythmias treated with appropriate cardioverter-defibrillator shocks and paroxysmal atrial fibrillation. Titration of β-blocker to a much higher dose suppressed further episodes of ventricular arrhythmia and paroxysmal atrial fibrillation, resulting in reduction in device therapies.

  3. Growth response to a changing environment-Impacts of tropospheric ozone dose on photosynthesis of Norway spruce forests in Austria

    Science.gov (United States)

    Liu, Xiaozhen; Pietsch, Stephan; Hasenauer, Hubert

    2010-05-01

    Tropospheric ozone is an important air pollutant, although plants have active defense strategies (e.g. antioxidants), the cumulative ozone dose may lead to chronic damages to plant tissues. Ozone enters into plants through stomata and reacts with other chemicals to create toxic compounds. This affects plant photosynthesis and may reduce CO2 fixation, and consequently growth. Open top cambers (OTC) are usually used to study the effects of elevated ozone levels on photosynthesis; whereas field studies with on site occurring ozone levels are rare. A recent modelling study on Norway spruce stands in Austria exhibited trends in model errors indicating that an increase in ozone dose leads to a reduction in volume increment. This study aims to explore how different ozone doses affect photosynthesis under field conditions and may translate into growth response for 12 stands of Norway spruce, distributed along an ozone concentration gradient across Austria. A LI-6400xt photosynthesis system was utilized to collect physiological parameters including net photosynthesis, stomata conductance, internal CO2 concentration, transpiration, etc. Chlorophyll fluorescence data was collected by using a PEA chlorophyll fluorescence meter, and chlorophyll content was measured. Morphological characteristics and soil samples were also analyzed. Ozone dose to leaf tissue was calculated from external ozone concentration, the conductance of the stomata to ozone, the leaf area index and the time span of the day when ozone uptake takes place. Our results confirm that increasing cumulative ozone dose reduces maximum assimilation rate and carboxylation efficiency under field conditions. Our final goal is to quantify how far this ozone induced reduction in assimilation power ultimately translates into a growth reduction of Norway spruce in Austria.

  4. Multiple anatomy optimization of accumulated dose

    Energy Technology Data Exchange (ETDEWEB)

    Watkins, W. Tyler, E-mail: watkinswt@virginia.edu; Siebers, Jeffrey V. [Department of Radiation Oncology, University of Virginia, Charlottesville, Virginia 22908 and Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States); Moore, Joseph A. [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, Maryland 21231 and Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States); Gordon, James [Henry Ford Health System, Detroit, Michigan 48202 and Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States); Hugo, Geoffrey D. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia 23298 (United States)

    2014-11-01

    Purpose: To investigate the potential advantages of multiple anatomy optimization (MAO) for lung cancer radiation therapy compared to the internal target volume (ITV) approach. Methods: MAO aims to optimize a single fluence to be delivered under free-breathing conditions such that the accumulated dose meets the plan objectives, where accumulated dose is defined as the sum of deformably mapped doses computed on each phase of a single four dimensional computed tomography (4DCT) dataset. Phantom and patient simulation studies were carried out to investigate potential advantages of MAO compared to ITV planning. Through simulated delivery of the ITV- and MAO-plans, target dose variations were also investigated. Results: By optimizing the accumulated dose, MAO shows the potential to ensure dose to the moving target meets plan objectives while simultaneously reducing dose to organs at risk (OARs) compared with ITV planning. While consistently superior to the ITV approach, MAO resulted in equivalent OAR dosimetry at planning objective dose levels to within 2% volume in 14/30 plans and to within 3% volume in 19/30 plans for each lung V20, esophagus V25, and heart V30. Despite large variations in per-fraction respiratory phase weights in simulated deliveries at high dose rates (e.g., treating 4/10 phases during single fraction beams) the cumulative clinical target volume (CTV) dose after 30 fractions and per-fraction dose were constant independent of planning technique. In one case considered, however, per-phase CTV dose varied from 74% to 117% of prescription implying the level of ITV-dose heterogeneity may not be appropriate with conventional, free-breathing delivery. Conclusions: MAO incorporates 4DCT information in an optimized dose distribution and can achieve a superior plan in terms of accumulated dose to the moving target and OAR sparing compared to ITV-plans. An appropriate level of dose heterogeneity in MAO plans must be further investigated.

  5. Leading men

    DEFF Research Database (Denmark)

    Bekker-Nielsen, Tønnes

    2016-01-01

    Through a systematic comparison of c. 50 careers leading to the koinarchate or high priesthood of Asia, Bithynia, Galatia, Lycia, Macedonia and coastal Pontus, as described in funeral or honorary inscriptions of individual koinarchs, it is possible to identify common denominators but also...

  6. Lead grids

    CERN Multimedia

    1974-01-01

    One of the 150 lead grids used in the multiwire proportional chamber g-ray detector. The 0.75 mm diameter holes are spaced 1 mm centre to centre. The grids were made by chemical cutting techniques in the Godet Workshop of the SB Physics.

  7. CUMULANTS OF STOCHASTIC RESPONSE FOR A CLASS OF SPECIAL NONHOLONOMIC SYSTEMS

    Institute of Scientific and Technical Information of China (English)

    SHANG MEI; ZHANG YI

    2001-01-01

    This paper studies the response cumulants for a kind of special nonholonomic systems under non-Gaussian, delta- correlated excitations. We present a new methodology for formulating the equations governing the evolution of the response cumulants of the stochastic dynamic systems. The response cumulant differential equations (CDEs) derived can be used to calculate the response cumulants for both linear and nonlinear systems. One example is given to illustrate how to use the CDEs for calculating response cumulants.

  8. Normal tissue tolerance to external beam radiation therapy: The mandible; Dose de tolerance des tissus sains: la mandibule

    Energy Technology Data Exchange (ETDEWEB)

    Berger, A.; Bensadoun, R.J. [Service d' oncologie radiotherapie, PRC, CHU de la Miletrie, 86 - Poitiers (France)

    2010-07-15

    Describing dose constraints for organs at risk in external beam radiotherapy is a key-point in order to maximize the therapeutic ratio. In head and neck irradiation, mandible is frequently exposed to ionising radiation-related complications. Those complications will be exposed after a short description of anatomical and physiopathological aspects. A literature search was performed using the Pubmed-Medline database, with following keywords (Osteoradionecrosis, Radiotherapy, Mandible, Toxicity, Organ at risk, Trismus). Incidence and dose constraints will be reported. The incidence of osteoradionecrosis decreased since the 1990, but it remains a dreaded late complication of head and neck cancer radiotherapy. It essentially occurs with cumulative doses of 66 Gy on the mandible (standard fractionation) applied to a significant volume. Respecting oral care is crucial to avoid this kind of complication. The respect of the dose-constraint described should not lead to under treat tumor bed in a curative intent. Trismus related to ionising radiation is poorly described. Literature data cannot lead to describe precise dose constraints. (authors)

  9. Optimization of the cumulative risk assessment of pesticides and biocides using computational techniques: Pilot project

    DEFF Research Database (Denmark)

    Jonsdottir, Svava Osk; Reffstrup, Trine Klein; Petersen, Annette

    This pilot project is intended as the first step in developing a computational strategy to assist in refining methods for higher tier cumulative and aggregate risk assessment of exposure to mixture of pesticides and biocides. For this purpose, physiologically based toxicokinetic (PBTK) models were...... developed for two compounds, tebuconazole and prochloraz, and a binary mixture of these compounds in two species, rat and human. PBTK models can be used to estimate the concentration levels (internal doses) of toxic substances and their metabolites in blood and tissue, by a collection of differential...... the models. Exposure scenarios were constructed based on findings of pesticide residues in food of ordinary consumers, and assessment of dermal exposure of professional workers. PBTK simulations were carried using these scenarios....

  10. Non-chemical stressors and cumulative risk assessment: an overview of current initiatives and potential air pollutant interactions.

    Science.gov (United States)

    Lewis, Ari S; Sax, Sonja N; Wason, Susan C; Campleman, Sharan L

    2011-06-01

    Regulatory agencies are under increased pressure to consider broader public health concerns that extend to multiple pollutant exposures, multiple exposure pathways, and vulnerable populations. Specifically, cumulative risk assessment initiatives have stressed the importance of considering both chemical and non-chemical stressors, such as socioeconomic status (SES) and related psychosocial stress, in evaluating health risks. The integration of non-chemical stressors into a cumulative risk assessment framework has been largely driven by evidence of health disparities across different segments of society that may also bear a disproportionate risk from chemical exposures. This review will discuss current efforts to advance the field of cumulative risk assessment, highlighting some of the major challenges, discussed within the construct of the traditional risk assessment paradigm. Additionally, we present a summary of studies of potential interactions between social stressors and air pollutants on health as an example of current research that supports the incorporation of non-chemical stressors into risk assessment. The results from these studies, while suggestive of possible interactions, are mixed and hindered by inconsistent application of social stress indicators. Overall, while there have been significant advances, further developments across all of the risk assessment stages (i.e., hazard identification, exposure assessment, dose-response, and risk characterization) are necessary to provide a scientific basis for regulatory actions and effective community interventions, particularly when considering non-chemical stressors. A better understanding of the biological underpinnings of social stress on disease and implications for chemical-based dose-response relationships is needed. Furthermore, when considering non-chemical stressors, an appropriate metric, or series of metrics, for risk characterization is also needed. Cumulative risk assessment research will benefit

  11. Who Leads China's Leading Universities?

    Science.gov (United States)

    Huang, Futao

    2017-01-01

    This study attempts to identify the major characteristics of two different groups of institutional leaders in China's leading universities. The study begins with a review of relevant literature and theory. Then, there is a brief introduction to the selection of party secretaries, deputy secretaries, presidents and vice presidents in leading…

  12. A cumulative entropy method for distribution recognition of model error

    Science.gov (United States)

    Liang, Yingjie; Chen, Wen

    2015-02-01

    This paper develops a cumulative entropy method (CEM) to recognize the most suitable distribution for model error. In terms of the CEM, the Lévy stable distribution is employed to capture the statistical properties of model error. The strategies are tested on 250 experiments of axially loaded CFT steel stub columns in conjunction with the four national building codes of Japan (AIJ, 1997), China (DL/T, 1999), the Eurocode 4 (EU4, 2004), and United States (AISC, 2005). The cumulative entropy method is validated as more computationally efficient than the Shannon entropy method. Compared with the Kolmogorov-Smirnov test and root mean square deviation, the CEM provides alternative and powerful model selection criterion to recognize the most suitable distribution for the model error.

  13. Petrogenesis of the nakhlite meteorites - Evidence from cumulate mineral zoning

    Science.gov (United States)

    Harvey, Ralph P.; Mcsween, Harry Y., Jr.

    1992-01-01

    Attention is given to a simple igneous petrogenesis for the meteorite Nakhla, which was previously called into question because Mg/Fe ratios in olivine indicate substantial disequilibrium between the predominant cumulus minerals (olivine and augite). Comparative analyses of simulated diffusive zoning and the observed cumulus mineral zoning for all three nakhlites (Nakhla, Governador Valadares, and Lafayette) show that their current compositions do not necessarily reflect parental magma compositions. Diffusion has altered primary cumulus compositions to varying degrees, Nakhla being the least affected, and Lafayette being almost completely reequilibrated. Since mineral zoning in each meteorite is strongly concentric around mesostasis areas, it is inferred that reaction with intercumulus liquid has controlled the observed zoning. It is argued that the nakhlites appear to be a series of relatively simple cumulate rocks which have undergone various amounts of late-magmatic and subsolidus diffusion, possibly reflecting their relative positions in a cooling cumulate pile.

  14. Cumulative dietary exposure of the population of Denmark to pesticides

    DEFF Research Database (Denmark)

    Jensen, Bodil Hamborg; Petersen, Annette; Nielsen, Elsa

    2015-01-01

    We used the Hazard Index (HI) method to carry out a cumulative risk assessment after chronic dietary exposure to all monitored pesticides in fruit, vegetables and cereals for various consumer groups in Denmark. Residue data for all the pesticides were obtained from the Danish monitoring programme...... that included processing factors and set non-detects to ½ LOR, but limited the correction (Model 3), gave the most realistic exposure estimate. With Model 3 the HI was calculated to be 0.44 for children and 0.18 for adults, indicating that there is no risk of adverse health effects following chronic cumulative...... exposure to the pesticides found in fruit, vegetables and cereals on the Danish market. The HI was below 1 even for consumers who eat more than 550 g of fruit and vegetables per day, corresponding to 1/3 of the population. Choosing Danish-produced commodities whenever possible could reduce the HI...

  15. Cumulative impacts of oil fields on northern alaskan landscapes.

    Science.gov (United States)

    Walker, D A; Webber, P J; Binnian, E F; Everett, K R; Lederer, N D; Nordstrand, E A; Walker, M D

    1987-11-06

    Proposed further developments on Alaska's Arctic Coastal Plain raise questions about cumulative effects on arctic tundra ecosystems of development of multiple large oil fields. Maps of historical changes to the Prudhoe Bay Oil Field show indirect impacts can lag behind planned developments by many years and the total area eventually disturbed can greatly exceed the planned area of construction. For example, in the wettest parts of the oil field (flat thaw-lake plains), flooding and thermokarst covered more than twice the area directly affected by roads and other construction activities. Protecting critical wildlife habitat is the central issue for cumulative impact analysis in northern Alaska. Comprehensive landscape planning with the use of geographic information system technology and detailed geobotanical maps can help identify and protect areas of high wildlife use.

  16. Effective Carrier Sensing in CSMA Networks under Cumulative Interference

    CERN Document Server

    Fu, Liqun; Huang, Jianwei

    2009-01-01

    This paper proposes and investigates the concept of a safe carrier-sensing range that can guarantee interference safe (also termed hidden-node-free) transmissions in CSMA networks under the cumulative interference model. Compared with the safe carrier-sensing range under the commonly assumed but less realistic pairwise interference model, we show that the safe carrier-sensing range required under the cumulative interference model is larger by a constant multiplicative factor. The concept of a safe carrier-sensing range, although amenable to elegant analytical results, is inherently not compatible with the conventional power threshold carrier-sensing mechanism (e.g., that used in IEEE 802.11). Specifically, the absolute power sensed by a node in the conventional mechanism does not contain enough information for it to derive its distances from other concurrent transmitter nodes. We show that, fortunately, a carrier-sensing mechanism called Incremental-Power Carrier-Sensing (IPCS) can realize the carrier-sensing...

  17. Cumulants and Correlation Functions vs the QCD phase diagram

    CERN Document Server

    Bzdak, Adam; Strodthoff, Nils

    2016-01-01

    In this note we discuss the relation of particle number cumulants and correlation functions related to them. It is argued that measuring couplings of the genuine correlation functions could provide cleaner information on possible non-trivial dynamics in heavy-ion collisions. We extract integrated multi-particle correlation functions from the presently available experimental data on proton cumulants. We find that the STAR data contain significant four-particle correlations, at least at the lower energies, with indication of changing dynamics in central collisions. We also find that these correlations are rather long-ranged in rapidity. Finally based on the signs of genuine correlation functions we provide exclusion plots for the QCD phase diagram.

  18. Cumulants of heat transfer across nonlinear quantum systems

    Science.gov (United States)

    Li, Huanan; Agarwalla, Bijay Kumar; Li, Baowen; Wang, Jian-Sheng

    2013-12-01

    We consider thermal conduction across a general nonlinear phononic junction. Based on two-time observation protocol and the nonequilibrium Green's function method, heat transfer in steady-state regimes is studied, and practical formulas for the calculation of the cumulant generating function are obtained. As an application, the general formalism is used to study anharmonic effects on fluctuation of steady-state heat transfer across a single-site junction with a quartic nonlinear on-site pinning potential. An explicit nonlinear modification to the cumulant generating function exact up to the first order is given, in which the Gallavotti-Cohen fluctuation symmetry is found still valid. Numerically a self-consistent procedure is introduced, which works well for strong nonlinearity.

  19. Seasonal climate change patterns due to cumulative CO2 emissions

    Science.gov (United States)

    Partanen, Antti-Ilari; Leduc, Martin; Damon Matthews, H.

    2017-07-01

    Cumulative CO2 emissions are near linearly related to both global and regional changes in annual-mean surface temperature. These relationships are known as the transient climate response to cumulative CO2 emissions (TCRE) and the regional TCRE (RTCRE), and have been shown to remain approximately constant over a wide range of cumulative emissions. Here, we assessed how well this relationship holds for seasonal patterns of temperature change, as well as for annual-mean and seasonal precipitation patterns. We analyzed an idealized scenario with CO2 concentration growing at an annual rate of 1% using data from 12 Earth system models from the Coupled Model Intercomparison Project Phase 5 (CMIP5). Seasonal RTCRE values for temperature varied considerably, with the highest seasonal variation evident in the Arctic, where RTCRE was about 5.5 °C per Tt C for boreal winter and about 2.0 °C per Tt C for boreal summer. Also the precipitation response in the Arctic during boreal winter was stronger than during other seasons. We found that emission-normalized seasonal patterns of temperature change were relatively robust with respect to time, though they were sub-linear with respect to emissions particularly near the Arctic. Moreover, RTCRE patterns for precipitation could not be quantified robustly due to the large internal variability of precipitation. Our results suggest that cumulative CO2 emissions are a useful metric to predict regional and seasonal changes in precipitation and temperature. This extension of the TCRE framework to seasonal and regional climate change is helpful for communicating the link between emissions and climate change to policy-makers and the general public, and is well-suited for impact studies that could make use of estimated regional-scale climate changes that are consistent with the carbon budgets associated with global temperature targets.

  20. Heavy metal cumulation in crops after the sewage sludge application

    Directory of Open Access Journals (Sweden)

    Gondová Andrea

    1998-12-01

    Full Text Available During 1995 - 1996 the crops samples after the sewage sludge application were collected. The heavy metals cumulation in investigated crops from Bardejov increased in order: Zn > Cu > Pb > Ni > Cr > Cd and Banská Bystrica : Zn > Cu > Cr > Ni > Pb > Cd. Heavy metals contents after the sewage sludge application were increased in comparison with the highest admissible concentration in eatable part of crops. The sewage sludge application were not recommended in soils for the growth of vegetables

  1. Finite-volume cumulant expansion in QCD-colorless plasma

    Energy Technology Data Exchange (ETDEWEB)

    Ladrem, M. [Taibah University, Physics Department, Faculty of Science, Al-Madinah, Al-Munawwarah (Saudi Arabia); Physics Department, Algiers (Algeria); ENS-Vieux Kouba (Bachir El-Ibrahimi), Laboratoire de Physique et de Mathematiques Appliquees (LPMA), Algiers (Algeria); Ahmed, M.A.A. [Taibah University, Physics Department, Faculty of Science, Al-Madinah, Al-Munawwarah (Saudi Arabia); ENS-Vieux Kouba (Bachir El-Ibrahimi), Laboratoire de Physique et de Mathematiques Appliquees (LPMA), Algiers (Algeria); Taiz University in Turba, Physics Department, Taiz (Yemen); Alfull, Z.Z. [Taibah University, Physics Department, Faculty of Science, Al-Madinah, Al-Munawwarah (Saudi Arabia); Cherif, S. [ENS-Vieux Kouba (Bachir El-Ibrahimi), Laboratoire de Physique et de Mathematiques Appliquees (LPMA), Algiers (Algeria); Ghardaia University, Sciences and Technologies Department, Ghardaia (Algeria)

    2015-09-15

    Due to the finite-size effects, the localization of the phase transition in finite systems and the determination of its order, become an extremely difficult task, even in the simplest known cases. In order to identify and locate the finite-volume transition point T{sub 0}(V) of the QCD deconfinement phase transition to a colorless QGP, we have developed a new approach using the finite-size cumulant expansion of the order parameter and the L{sub mn}-method. The first six cumulants C{sub 1,2,3,4,5,6} with the corresponding under-normalized ratios (skewness Σ, kurtosis κ, pentosis Π{sub ±}, and hexosis H{sub 1,2,3}) and three unnormalized combinations of them, (O = σ{sup 2}κΣ{sup -1},U = σ{sup -2}Σ{sup -1},N = σ{sup 2}κ) are calculated and studied as functions of (T, V). A new approach, unifying in a clear and consistent way the definitions of cumulant ratios, is proposed.Anumerical FSS analysis of the obtained results has allowed us to locate accurately the finite-volume transition point. The extracted transition temperature value T{sub 0}(V) agrees with that expected T{sub 0}{sup N}(V) from the order parameter and the thermal susceptibility χ{sub T} (T, V), according to the standard procedure of localization to within about 2%. In addition to this, a very good correlation factor is obtained proving the validity of our cumulants method. The agreement of our results with those obtained by means of other models is remarkable. (orig.)

  2. The cumulation of methylmercury in fish (Poecilia reticulata)

    Energy Technology Data Exchange (ETDEWEB)

    Stary, J.; Kratzer, K.; Havlik, B.; Prasilova, J.; Hanusova, J.

    1980-01-01

    Methylmercury labelled with mercury-203 was used for the investigation of the uptake and the release of methylmercury in fish. It has been found that methylmercury compounds adsorbed on fish food remain completely in fish and that they are released with the biological half-time of 110 days. The cumulation of methylmercury from water is very rapid. Equations for the calculation of the concentration of methylmercury in fish were derived and compared with the uptake of phenylmercury and inorganic mercury.

  3. Erupted cumulate fragments in rhyolites from Lipari (Aeolian Islands)

    Science.gov (United States)

    Forni, Francesca; Ellis, Ben S.; Bachmann, Olivier; Lucchi, Federico; Tranne, Claudio A.; Agostini, Samuele; Dallai, Luigi

    2015-12-01

    Over the last ~267 ky, the island of Lipari has erupted magmas ranging in compositions from basaltic andesites to rhyolites, with a notable compositional gap in the dacite field. Bulk geochemical and isotopic compositions of the volcanic succession, in conjunction with major and trace elemental compositions of minerals, indicate that the rhyolites were dominantly generated via crystal fractionation processes, with subordinate assimilation. Radiogenic (Sr, Nd, and Pb) and stable (O) isotopes independently suggest ≤30 % of crustal contamination with the majority of it occurring in mafic compositions, likely relatively deep in the system. Within the rhyolites, crystal-rich, K2O-rich enclaves are common. In contrast to previous interpretations, we suggest that these enclaves represent partial melting, remobilization and eruption of cumulate fragments left-over from rhyolite melt extraction. Cumulate melting and remobilization is supported by the presence of (1) resorbed, low-temperature minerals (biotite and sanidine), providing the potassic signature to these clasts, (2) reacted Fo-rich olivine, marking the presence of mafic recharge, (3) An38-21 plagioclase, filling the gap in feldspar composition between the andesites and the rhyolites and (4) strong enrichment in Sr and Ba in plagioclase and sanidine, suggesting crystallization from a locally enriched melt. Based on Sr-melt partitioning, the high-Sr plagioclase would require ~2300 ppm Sr in the melt, a value far in excess of Sr contents in Lipari and Vulcano magmas (50-1532 ppm) but consistent with melting of a feldspar-rich cumulate. Due to the presence of similar crystal-rich enclaves within the rhyolites from Vulcano, we propose that the eruption of remobilized cumulates associated with high-SiO2 rhyolites may be a common process at the Aeolian volcanoes, as already attested for a variety of volcanic systems around the world.

  4. [Cumulative effect of Coriolis acceleration on coronary hemodynamics].

    Science.gov (United States)

    Lapaev, E V; Bednenko, V S

    1985-01-01

    Time-course variations in coronary circulation and cardiac output were measured in 29 healthy test subjects who performed tests with a continuous cumulation of Coriolis accelerations and in 12 healthy test subjects who were exposed to Coriolis accelerations combined with acute hypoxia. Adaptive changes in coronary circulation were seen. It is recommended to monitor coronary circulation during vestibulometric tests as part of medical expertise of the flying personnel.

  5. Leading Cities

    DEFF Research Database (Denmark)

    Pogner, Karl-Heinz

    2017-01-01

    and technical engineering; Smart Cities) is very prominent in the traditional mass media discourse, in PR / PA of tech companies and traditional municipal administrations; whereas the second one (participation; Livable Cities) is mostly enacted in social media, (local) initiatives, movements, (virtual......) communities, new forms of urban governance in municipal administration and co-competitive city networks. Both forms seem to struggle for getting voice and power in the discourses, negotiations, struggles, and conflicts in Urban Governance about the question how to manage or lead (in) a city. Talking about...

  6. Cumulative Risk Assessment Toolbox: Methods and Approaches for the Practitioner

    Directory of Open Access Journals (Sweden)

    Margaret M. MacDonell

    2013-01-01

    Full Text Available The historical approach to assessing health risks of environmental chemicals has been to evaluate them one at a time. In fact, we are exposed every day to a wide variety of chemicals and are increasingly aware of potential health implications. Although considerable progress has been made in the science underlying risk assessments for real-world exposures, implementation has lagged because many practitioners are unaware of methods and tools available to support these analyses. To address this issue, the US Environmental Protection Agency developed a toolbox of cumulative risk resources for contaminated sites, as part of a resource document that was published in 2007. This paper highlights information for nearly 80 resources from the toolbox and provides selected updates, with practical notes for cumulative risk applications. Resources are organized according to the main elements of the assessment process: (1 planning, scoping, and problem formulation; (2 environmental fate and transport; (3 exposure analysis extending to human factors; (4 toxicity analysis; and (5 risk and uncertainty characterization, including presentation of results. In addition to providing online access, plans for the toolbox include addressing nonchemical stressors and applications beyond contaminated sites and further strengthening resource accessibility to support evolving analyses for cumulative risk and sustainable communities.

  7. Finite Volume Cumulant Expansion in QCD-Colorless Plasma

    CERN Document Server

    Ladrem, M; Al-Full, Z; Cherif, S

    2015-01-01

    Due to the finite size effects, the localisation of the phase transition in finite systems and the determination of its order, become an extremely difficult task, even in the simplest known cases. In order to identify and locate the finite volume transition point $T_{0}(V)$ of the QCD deconfinement phase transition to a Colorless QGP, we have developed a new approach using the finite size cumulant expansion of the order parameter and the $L_{mn}$-method. The first six cumulants $C_{1,2,3,4,5,6}$ with the corresponding under-normalized ratios(skewness $\\Sigma$, kurtosis $\\kappa$ ,pentosis $\\Pi_{\\pm}$ and hexosis $\\mathcal{H}_{1,2,3}$) and three unnormalized combinations of them ($\\mathcal{O}={\\mathcal{\\sigma }^{2} \\mathcal{\\kappa } }{\\mathbf{\\Sigma }^{-1} }$, $\\mathcal{U} ={\\mathcal{\\sigma }^{-2} \\mathbf{\\Sigma }^{-1} }$, $\\mathcal{N} = \\mathcal{\\sigma }^{2} \\mathcal{\\kappa }$) are calculated and studied as functions of $(T,V)$. A new approach, unifying in a clear and consistent way the definitions of cumulant...

  8. Cumulative Risk Assessment Toolbox: Methods and Approaches for the Practitioner

    Science.gov (United States)

    MacDonell, Margaret M.; Haroun, Lynne A.; Teuschler, Linda K.; Rice, Glenn E.; Hertzberg, Richard C.; Butler, James P.; Chang, Young-Soo; Clark, Shanna L.; Johns, Alan P.; Perry, Camarie S.; Garcia, Shannon S.; Jacobi, John H.; Scofield, Marcienne A.

    2013-01-01

    The historical approach to assessing health risks of environmental chemicals has been to evaluate them one at a time. In fact, we are exposed every day to a wide variety of chemicals and are increasingly aware of potential health implications. Although considerable progress has been made in the science underlying risk assessments for real-world exposures, implementation has lagged because many practitioners are unaware of methods and tools available to support these analyses. To address this issue, the US Environmental Protection Agency developed a toolbox of cumulative risk resources for contaminated sites, as part of a resource document that was published in 2007. This paper highlights information for nearly 80 resources from the toolbox and provides selected updates, with practical notes for cumulative risk applications. Resources are organized according to the main elements of the assessment process: (1) planning, scoping, and problem formulation; (2) environmental fate and transport; (3) exposure analysis extending to human factors; (4) toxicity analysis; and (5) risk and uncertainty characterization, including presentation of results. In addition to providing online access, plans for the toolbox include addressing nonchemical stressors and applications beyond contaminated sites and further strengthening resource accessibility to support evolving analyses for cumulative risk and sustainable communities. PMID:23762048

  9. 4D Near-Field Source Localization Using Cumulant

    Directory of Open Access Journals (Sweden)

    Zhao Feng

    2007-01-01

    Full Text Available This paper proposes a new cumulant-based algorithm to jointly estimate four-dimensional (4D source parameters of multiple near-field narrowband sources. Firstly, this approach proposes a new cross-array, and constructs five high-dimensional Toeplitz matrices using the fourth-order cumulants of some properly chosen sensor outputs; secondly, it forms a parallel factor (PARAFAC model in the cumulant domain using these matrices, and analyzes the unique low-rank decomposition of this model; thirdly, it jointly estimates the frequency, two-dimensional (2D directions-of-arrival (DOAs, and range of each near-field source from the matrices via the low-rank three-way array (TWA decomposition. In comparison with some available methods, the proposed algorithm, which efficiently makes use of the array aperture, can localize sources using sensors. In addition, it requires neither pairing parameters nor multidimensional search. Simulation results are presented to validate the performance of the proposed method.

  10. 4D Near-Field Source Localization Using Cumulant

    Directory of Open Access Journals (Sweden)

    Junying Zhang

    2007-01-01

    Full Text Available This paper proposes a new cumulant-based algorithm to jointly estimate four-dimensional (4D source parameters of multiple near-field narrowband sources. Firstly, this approach proposes a new cross-array, and constructs five high-dimensional Toeplitz matrices using the fourth-order cumulants of some properly chosen sensor outputs; secondly, it forms a parallel factor (PARAFAC model in the cumulant domain using these matrices, and analyzes the unique low-rank decomposition of this model; thirdly, it jointly estimates the frequency, two-dimensional (2D directions-of-arrival (DOAs, and range of each near-field source from the matrices via the low-rank three-way array (TWA decomposition. In comparison with some available methods, the proposed algorithm, which efficiently makes use of the array aperture, can localize N−3 sources using N sensors. In addition, it requires neither pairing parameters nor multidimensional search. Simulation results are presented to validate the performance of the proposed method.

  11. Childhood poverty and health: cumulative risk exposure and stress dysregulation.

    Science.gov (United States)

    Evans, Gary W; Kim, Pilyoung

    2007-11-01

    A massive literature documents the inverse association between poverty or low socioeconomic status and health, but little is known about the mechanisms underlying this robust relation. We examined longitudinal relations between duration of poverty exposure since birth, cumulative risk exposure, and physiological stress in two hundred seven 13-year-olds. Chronic stress was assessed by basal blood pressure and overnight cortisol levels; stress regulation was assessed by cardiovascular reactivity to a standard acute stressor and recovery after exposure to this stressor. Cumulative risk exposure was measured by multiple physical (e.g., substandard housing) and social (e.g., family turmoil) risk factors. The greater the number of years spent living in poverty, the more elevated was overnight cortisol and the more dysregulated was the cardiovascular response (i.e., muted reactivity). Cardiovascular recovery was not affected by duration of poverty exposure. Unlike the duration of poverty exposure, concurrent poverty (i.e., during adolescence) did not affect these physiological stress outcomes. The effects of childhood poverty on stress dysregulation are largely explained by cumulative risk exposure accompanying childhood poverty.

  12. Multiway Filtering Based on Fourth-Order Cumulants

    Directory of Open Access Journals (Sweden)

    Salah Bourennane

    2005-05-01

    Full Text Available We propose a new multiway filtering based on fourth-order cumulants for the denoising of noisy data tensor with correlated Gaussian noise. The classical multiway filtering is based on the TUCKALS3 algorithm that computes a lower-rank tensor approximation. The presented method relies on the statistics of the analyzed multicomponent signal. We first recall how the well-known lower rank-(K1,…,KN tensor approximation processed by TUCKALS3 alternating least square algorithm exploits second-order statistics. Then, we propose to introduce the fourth-order statistics in the TUCKALS3-based method. Indeed, the use of fourth-order cumulants enables to remove the Gaussian components of an additive noise. In the presented method the estimation of the n-mode projector on the n-mode signal subspace are built from the eigenvectors associated with the largest eigenvalues of a fourth-order cumulant slice matrix instead of a covariance matrix. Each projector is applied by means of the n-mode product operator on the n-mode of the data tensor. The qualitative results of the improved multiway TUCKALS3-based filterings are shown for the case of noise reduction in a color image and multicomponent seismic data.

  13. Cumulative risk hypothesis: Predicting and preventing child maltreatment recidivism.

    Science.gov (United States)

    Solomon, David; Åsberg, Kia; Peer, Samuel; Prince, Gwendolyn

    2016-08-01

    Although Child Protective Services (CPS) and other child welfare agencies aim to prevent further maltreatment in cases of child abuse and neglect, recidivism is common. Having a better understanding of recidivism predictors could aid in preventing additional instances of maltreatment. A previous study identified two CPS interventions that predicted recidivism: psychotherapy for the parent, which was related to a reduced risk of recidivism, and temporary removal of the child from the parent's custody, which was related to an increased recidivism risk. However, counter to expectations, this previous study did not identify any other specific risk factors related to maltreatment recidivism. For the current study, it was hypothesized that (a) cumulative risk (i.e., the total number of risk factors) would significantly predict maltreatment recidivism above and beyond intervention variables in a sample of CPS case files and that (b) therapy for the parent would be related to a reduced likelihood of recidivism. Because it was believed that the relation between temporary removal of a child from the parent's custody and maltreatment recidivism is explained by cumulative risk, the study also hypothesized that that the relation between temporary removal of the child from the parent's custody and recidivism would be mediated by cumulative risk. After performing a hierarchical logistic regression analysis, the first two hypotheses were supported, and an additional predictor, psychotherapy for the child, also was related to reduced chances of recidivism. However, Hypothesis 3 was not supported, as risk did not significantly mediate the relation between temporary removal and recidivism.

  14. Cumulative radiation exposure from diagnostic imaging in intensive care unit patients

    Institute of Scientific and Technical Information of China (English)

    Fiachra Moloney; Daniel Fama; Maria Twomey; Ruth O’Leary; Conor Houlihane; Kevin P Murphy; Siobhan B O’Neill; Owen J O’Connor; Dorothy Breen; Michael M Maher

    2016-01-01

    AIM:To quantify cumulative effective dose of intensive care unit(ICU)patients attributable to diagnostic imaging.METHODS:This was a prospective,interdisciplinary study conducted in the ICU of a large tertiary referral and level 1 trauma center.Demographic and clinical data including age,gender,date of ICU admission,primary reason for ICU admission,APACHE Ⅱ score,length of stay,number of days intubated,date of death or discharge,and re-admission data was collected on all patients admitted over a 1-year period.The overall radiation exposure was quantified by the cumulative effective radiation dose(CED)in millisieverts(mS v)and calculated using reference effective doses published by the United Kingdom National Radiation Protection Board.Pediatric patients were selected for subgroupanalysis.RESULTS:A total of 2737 studies were performedin 421 patients.The total CED was 1704 m Sv with a median CED of 1.5 mS v(IQR 0.04-6.6 mS v).Total CED in pediatric patients was 74.6 mS v with a median CED of 0.07 mS v(IQR 0.01-4.7 mS v).Chest radiography was the most commonly performed examination accounting for 83% of all studies but only 2.7% of total CED.Computed tomography(CT)accounted for 16% of all studies performed and contributed 97% of total CED.Trauma patients received a statistically significant higher dose [median CED 7.7 mS v(IQR 3.5-13.8 mS v)] than medical [median CED 1.4 m Sv(IQR 0.05-5.4 m Sv)] and surgical [median CED 1.6 mS v(IQR 0.04-7.5 mS v)] patients.Length of stay in ICU [OR = 1.12(95%CI:1.079-1.157)] was identified as an independent predictor of receiving a CED greater than 15 mS v.CONCLUSION:Trauma patients and patients with extended ICU admission times are at increased risk of higher CEDs.CED should be minimized where feasible,especially in young patients.

  15. El Carreto o Cumulá - Aspidosperma Dugandii Standl El Carreto o Cumulá - Aspidosperma Dugandii Standl

    Directory of Open Access Journals (Sweden)

    Dugand Armando

    1944-03-01

    Full Text Available Nombres vulgares: Carreto (Atlántico, Bolívar, Magdalena; Cumulá, Cumulá (Cundinamarca, ToIima. Según el Dr. Emilio Robledo (Lecciones de Bot. ed. 3, 2: 544. 1939 el nombre Carreto también es empleado en Puerto Berrío (Antioquia. El mismo autor (loc. cit. da el nombre Comulá para una especie indeterminada de Viburnum en Mariquita (Tolima y J. M. Duque, refiriendose a la misma planta y localidad (en Bot. Gen. Colomb. 340, 356. 1943 atribuye este nombre vulgar al Aspidosperma ellipticum Rusby.  Sin embargo, las muestras de madera de Cumulá o Comulá que yo he examinado, procedentes de la región de Mariquita -una de las cuales me fue recientemente enviada por el distinguido ictiólogo Sr. Cecil Miles- pertenecen sin duda alguna al A. Dugandii StandI. Por otra parte, Santiago Cortés (FI. Colomb. 206. 1898; ed, 2: 239. 1912 cita el Cumulá "de Anapoima y otros lugares del (rio Magdalena" diciendo que pertenece a las Leguminosas, pero la brevísima descripción que este autor hace de la madera "naranjada y notable por densidad, dureza y resistencia a la humedad", me induce a creer que se trata del mismo Cumula coleccionado recientemente en Tocaima, ya que esta población esta situada a pocos kilómetros de Anapoima. Nombres vulgares: Carreto (Atlántico, Bolívar, Magdalena; Cumulá, Cumulá (Cundinamarca, ToIima. Según el Dr. Emilio Robledo (Lecciones de Bot. ed. 3, 2: 544. 1939 el nombre Carreto también es empleado en Puerto Berrío (Antioquia. El mismo autor (loc. cit. da el nombre Comulá para una especie indeterminada de Viburnum en Mariquita (Tolima y J. M. Duque, refiriendose a la misma planta y localidad (en Bot. Gen. Colomb. 340, 356. 1943 atribuye este nombre vulgar al Aspidosperma ellipticum Rusby.  Sin embargo, las muestras de madera de Cumulá o Comulá que yo he examinado, procedentes de la región de Mariquita -una de las cuales me fue recientemente enviada por el distinguido ictiólogo Sr. Cecil Miles- pertenecen sin

  16. Cumulative Radiative Forcing Implications of Deployment Strategies for Carbon Capture and Storage

    Science.gov (United States)

    Sathre, R. C.; Masanet, E.

    2011-12-01

    Carbon capture and storage (CCS) is increasingly discussed as a potential means of mitigating the climate disruption associated with fossil fuel use. Some technologies for capturing, transporting, and sequestering carbon dioxide (CO2) are already mature, while others technologies under development may lead to more cost- and energy-efficient CCS systems. Various elements of CCS systems are currently in operation at relatively small scale, but will need to be scaled up very substantially in order to make a significant contribution to climate change mitigation. Because the rate of fossil fuel CO2 emission is continuing to increase and the emitted CO2 will remain in the atmosphere for long time periods, the speed at which CCS is deployed will strongly affect the cumulative CO2 emission and the climate impacts. To better understand these issues, in this analysis we integrate scenario forecasting of energy supply systems, life cycle emission modeling, and time-dependent calculations of cumulative radiative forcing. We develop a series of CCS deployment scenarios that describe plausible future trajectories for CCS implementation in the US electric power plant fleet. The scenarios incorporate dimensions such as speed of deployment build-out, year of initiating deployment, efficiency of capture technology, and installation in new power plants vs. retrofitting existing plants. We conduct life cycle greenhouse gas (GHG) emissions analyses of each scenario to estimate annual emission profiles of CO2, CH4, and N2O over a 90-year time horizon, from 2010 to 2100. We then model the atmospheric dynamics of the emitted GHGs including atmospheric decay and instantaneous radiative forcing patterns over time. Finally, we determine the cumulative radiative forcing of each scenario, which we use as a proxy for surface temperature change and resulting disruption to physical, ecological and social systems. The results show strong climate mitigation benefits of early, aggressive

  17. Effects of low doses; Effet des faibles doses

    Energy Technology Data Exchange (ETDEWEB)

    Le Guen, B. [Electricite de France (EDF-LAM-SCAST), 93 - Saint-Denis (France)

    2001-07-01

    Actually, even though it is comfortable for the risk management, the hypothesis of the dose-effect relationship linearity is not confirmed for any model. In particular, in the area of low dose rate delivered by low let emitters. this hypothesis is debated at the light of recent observations, notably these ones relative to the mechanisms leading to genetic instability and induction eventuality of DNA repair. The problem of strong let emitters is still to solve. (N.C.)

  18. Mismatch or cumulative stress : Toward an integrated hypothesis of programming effects

    NARCIS (Netherlands)

    Nederhof, Esther; Schmidt, Mathias V.

    2012-01-01

    This paper integrates the cumulative stress hypothesis with the mismatch hypothesis, taking into account individual differences in sensitivity to programming. According to the cumulative stress hypothesis, individuals are more likely to suffer from disease as adversity accumulates. According to the

  19. Estimation of occupational cosmic radiation exposure among airline personnel: Agreement between a job-exposure matrix, aggregate, and individual dose estimates.

    Science.gov (United States)

    Talibov, Madar; Salmelin, Raili; Lehtinen-Jacks, Susanna; Auvinen, Anssi

    2017-04-01

    Job-exposure matrices (JEM) are used for exposure assessment in occupational studies, but they can involve errors. We assessed agreement between the Nordic Occupational Cancer Studies JEM (NOCCA-JEM) and aggregate and individual dose estimates for cosmic radiation exposure among Finnish airline personnel. Cumulative cosmic radiation exposure for 5,022 airline crew members was compared between a JEM and aggregate and individual dose estimates. The NOCCA-JEM underestimated individual doses. Intraclass correlation coefficient was 0.37, proportion of agreement 64%, kappa 0.46 compared with individual doses. Higher agreement was achieved with aggregate dose estimates, that is annual medians of individual doses and estimates adjusted for heliocentric potentials. The substantial disagreement between NOCCA-JEM and individual dose estimates of cosmic radiation may lead to exposure misclassification and biased risk estimates in epidemiological studies. Using aggregate data may provide improved estimates. Am. J. Ind. Med. 60:386-393, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  20. Mapping cumulative noise from shipping to inform marine spatial planning.

    Science.gov (United States)

    Erbe, Christine; MacGillivray, Alexander; Williams, Rob

    2012-11-01

    Including ocean noise in marine spatial planning requires predictions of noise levels on large spatiotemporal scales. Based on a simple sound transmission model and ship track data (Automatic Identification System, AIS), cumulative underwater acoustic energy from shipping was mapped throughout 2008 in the west Canadian Exclusive Economic Zone, showing high noise levels in critical habitats for endangered resident killer whales, exceeding limits of "good conservation status" under the EU Marine Strategy Framework Directive. Error analysis proved that rough calculations of noise occurrence and propagation can form a basis for management processes, because spending resources on unnecessary detail is wasteful and delays remedial action.

  1. The Carvedilol Prospective Randomized Cumulative Survival (COPERNICUS) trial.

    Science.gov (United States)

    Eichhorn, Eric J; Bristow, Michael R

    2001-01-01

    Previous trials (Metoprolol CR/XL Randomised Intervention Trial in Congestive Heart Failure [MERIT-HF], Cardiac Insufficiency Bisoprolol Study [CIBIS] II) have demonstrated a mortality benefit of beta-adrenergic blockade in patients with mild to moderate heart failure. The recent Carvedilol Prospective Randomized Cumulative Survival (COPERNICUS) trial has extended these results to a more advanced patient population. This trial did not, however, include patients who could not reach compensation, patients with far advanced heart failure symptoms, or a significant number of black patients. Future studies of beta-blockade may focus on these patients or patients with asymptomatic left ventricular dysfunction.

  2. Neutron source capability assessment for cumulative fission yields measurements

    Energy Technology Data Exchange (ETDEWEB)

    Descalle, M A; Dekin, W; Kenneally, J

    2011-04-06

    A recent analysis of high-quality cumulative fission yields data for Pu-239 published in the peer-reviewed literature showed that the quoted experimental uncertainties do not allow a clear statement on how the fission yields vary as a function of energy. [Prussin2009] To make such a statement requires a set of experiments with well 'controlled' and understood sources of experimental errors to reduce uncertainties as low as possible, ideally in the 1 to 2% range. The Inter Laboratory Working Group (ILWOG) determined that Directed Stockpile Work (DSW) would benefit from an experimental program with the stated goal to reduce the measurement uncertainties significantly in order to make a definitive statement of the relationship of energy dependence to the cumulative fission yields. Following recent discussions between Lawrence Livermore National Laboratory (LLNL) and Los Alamos National Laboratory (LANL), there is a renewed interest in developing a concerted experimental program to measure fission yields in a neutron energy range from thermal energy (0.025 eV) to 14 MeV with an emphasis on discrete energies from 0.5 to 4 MeV. Ideally, fission yields would be measured at single energies, however, in practice there are only 'quasi-monoenergetic' neutrons sources of finite width. This report outlines a capability assessment as of June 2011 of available neutron sources that could be used as part of a concerted experimental program to measure cumulative fission yields. In a framework of international collaborations, capabilities available in the United States, at the Atomic Weapons Establishment (AWE) in the United Kingdom and at the Commissariat Energie Atomique (CEA) in France are listed. There is a need to develop an experimental program that will reduce the measurement uncertainties significantly in order to make a definitive statement of the relationship of energy dependence to the cumulative fission yields. Fission and monoenergetic neutron sources

  3. The Carvedilol Prospective Randomized Cumulative Survival (COPERNICUS trial

    Directory of Open Access Journals (Sweden)

    Bristow Michael R

    2001-02-01

    Full Text Available Abstract Previous trials (Metoprolol CR/XL Randomised Intervention Trial in Congestive Heart Failure [MERIT-HF], Cardiac Insufficiency Bisoprolol Study [CIBIS] II have demonstrated a mortality benefit of β-adrenergic blockade in patients with mild to moderate heart failure. The recent Carvedilol Prospective Randomized Cumulative Survival (COPERNICUS trial has extended these results to a more advanced patient population. This trial did not, however, include patients who could not reach compensation, patients with far advanced heart failure symptoms, or a significant number of black patients. Future studies of β-blockade may focus on these patients or patients with asymptomatic left ventricular dysfunction.

  4. Generalized Cumulative Residual Entropy for Distributions with Unrestricted Supports

    Directory of Open Access Journals (Sweden)

    Noomane Drissi

    2008-01-01

    Full Text Available We consider the cumulative residual entropy (CRE a recently introduced measure of entropy. While in previous works distributions with positive support are considered, we generalize the definition of CRE to the case of distributions with general support. We show that several interesting properties of the earlier CRE remain valid and supply further properties and insight to problems such as maximum CRE power moment problems. In addition, we show that this generalized CRE can be used as an alternative to differential entropy to derive information-based optimization criteria for system identification purpose.

  5. Dose response problems in carcinogenesis.

    Science.gov (United States)

    Crump, K S

    1979-03-01

    The estimation of risks from exposure to carcinogens is an important problem from the viewpoint of protection of human health. It also poses some very difficult dose-response problems. Two dose-response models may fit experimental data about equally well and yet predict responses that differ by many orders of magnitude at low doses. Mechanisms of carcinogenesis are not sufficiently understood so that the shape of the dose-response curve at low doses can be satisfactorily predicted. Mathematical theories of carcinogenesis and statistical procedures can be of use with dose-reponse problems such as this and, in addition, can lead to a better understanding of the mechanisms of carcinogenesis. In this paper, mathematical dose-response models of carcinogenesis are considered as well as various proposed dose-response procedures for estimating carcinogenic risks at low doses. Areas are suggested in which further work may be useful. These areas include experimental design problems, statistical procedures for use with time-to-occurrence data, and mathematical models that incorporate such biological features as pharmacokinetics of carcinogens, synergistic effects, DNA repair, susceptible subpopulations, and immune reactions.

  6. Embryo quality is the main factor affecting cumulative live birth rate after elective single embryo transfer in fresh stimulation cycles.

    Science.gov (United States)

    Niinimäki, Maarit; Veleva, Zdravka; Martikainen, Hannu

    2015-11-01

    The study was aimed to evaluate which factors affect the cumulative live birth rate after elective single embryo transfer in women younger than 36 years. Additionally, number of children in women with more than one delivery per ovum pick-up after fresh elective single embryo transfer and subsequent frozen embryo transfers was assessed. Retrospective cohort study analysing data of a university hospital's infertility clinic in 2001-2010. A total of 739 IVF/ICSI cycles with elective single embryo transfer were included. Analyses were made per ovum pick-up including fresh and subsequent frozen embryo transfers. Factors affecting cumulative live birth rates were examined in uni- and multivariate analyses. A secondary endpoint was the number of children born after all treatments. In the fresh cycles, the live birth rate was 29.2% and the cumulative live birth rate was 51.3%, with a twin rate of 3.4%. In the multivariate analysis, having two (odds ratio (OR) 1.73; 95% confidence interval (CI) 1.12-2.67) or ≥3 top embryos (OR 2.66; 95% CI 1.79-3.95) was associated with higher odds for live birth after fresh and frozen embryo cycles. Age, body mass index, duration of infertility, diagnosis or total gonadotropin dose were not associated with the cumulative live birth rate. In cycles with one top embryo, the cumulative live birth rate was 40.2%, whereas it was 64.1% in those with at least three top embryos. Of women who had a live birth in the fresh cycle, 20.4% had more than one child after all frozen embryo transfers. Among women with three or more top embryos after ovum pick-up, 16.1% gave birth to more than one child. The cumulative live birth rate in this age group varies from 40% to 64% and is dependent on the quality of embryos. Women with three or more top embryos have good chance of having more than one child per ovum pick-up without elevated risk of multiple pregnancies. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  7. Determining source cumulants in femtoscopy with Gram-Charlier and Edgeworth series

    DEFF Research Database (Denmark)

    Eggers, H. C.; De Kock, M. B.; Schmiegel, Jürgen

    2011-01-01

    Lowest-order cumulants provide important information on the shape of the emission source in femtoscopy. For the simple case of noninteracting identical particles, we show how the fourth-order source cumulant can be determined from measured cumulants in momentum space. The textbook Gram–Charlier s...

  8. High-resolution harmonic retrieval using the full fourth-order cumulant

    NARCIS (Netherlands)

    Vossen, S.H.J.A.; Naus, H.W.L.; Zwamborn, A.P.M.

    2010-01-01

    The harmonic retrieval (HR) problem concerns the estimation of the frequencies in a sum of real or complex harmonics. Both correlation and cumulant-based approaches are used for this purpose. Cumulant-based HR algorithms use a single 1-D slice of the fourth-order cumulant that is estimated directly

  9. 75 FR 69662 - Workshop: Cumulative Mixtures Risk of Six Selected Phthalates in Support of Summary Information...

    Science.gov (United States)

    2010-11-15

    ... AGENCY Workshop: Cumulative Mixtures Risk of Six Selected Phthalates in Support of Summary Information on...: Notice of Peer Consultation Workshop on the Cumulative Mixtures Risk of Six Selected Phthalates; Request... phthalates as set forth in the National Academies of Science (NAS) report ``Phthalates and Cumulative...

  10. Insights into integrating cumulative effects and collaborative co-management for migratory tundra caribou herds in the Northwest Territories, Canada

    Directory of Open Access Journals (Sweden)

    Anne Gunn

    2014-12-01

    Full Text Available Globally, many migratory mammals are facing threats. In northern Canada, large annual ranges expose migratory caribou to an array of human activities, including industrial exploration and development. Recognition that responses to human activities can accumulate for caribou is long-standing, but is heightened by recent declines in caribou abundance. For example, since the mid-1990s, the Bathurst herd has declined by approximately 90%, leading to severe harvest restrictions. More mines are being proposed and developed across the herd's annual range, raising questions about cumulative effects. Despite progress on assessment techniques, aboriginal groups are expressing strong concerns and frustration about gaps in responsibilities for who should monitor, mitigate, and manage cumulative effects. The core of the concern is sustainability and the related trade-offs between industrial developments relative to continued access to healthy caribou for harvesting. We offer insights into how these concerns can be addressed by building on existing concepts (adaptive management and approaches (herd management.

  11. Making the case for cumulative impacts assessment : modelling the potential impacts of climate change, harvesting, oil and gas, and fire

    Energy Technology Data Exchange (ETDEWEB)

    Yamasaki, S.H.; Duchesneau, R.; Doyon, F. [Inst. quebecois d' Amenagement de la Foret feuillue, Ripon, PQ (Canada); Russell, J.S. [Millar Western Forest Products Ltd., Whitecourt, AB (Canada); Gooding, T. [Forestry Corp., Edmonton, AB (Canada)

    2008-05-15

    Oil and gas activities and wildfires are altering the composition, age-class structure, and spatial configuration of Alberta's forests. Climate change may also be modifying forest dynamics which will lead to important changes in the future. This paper presented a landscape model designed to simulate the long-term cumulative effects of forestry, oil and gas activities, climate change, wildlife, and demographic change for the Whitecourt forest management area. Various landscape scenarios were presented for the forest, and key indicators for biodiversity and forest productivity were evaluated. Multiple disturbance agents were simulated in order to detect potential interactions among disturbance agents. Results of the study showed that climate and demographic changes will intensify the impacts of fires on timber supplies. It was concluded that cumulative impacts assessments and spatial and temporal stochastic modelling should be included in forest management practices. 34 refs., 2 tabs., 22 figs.

  12. The seven-year cumulative survival rate of Osstem implants

    Science.gov (United States)

    Kim, Young-Kyun; Kim, Bum-Su; Yun, Pil-Young; Mun, Sang-Un; Yi, Yang-Jin; Jeong, Kyung-In

    2014-01-01

    Objectives This study was performed to analyze the cumulative survival rate of Osstem implants (Osstem Implant Co., Ltd.) over a seven-year period. Materials and Methods A total of 105 patients who had 467 Osstem implants that were placed at the Section of Dentistry, Seoul National University Bundang Hospital (Seongnam, Korea) from June 2003 through December 2005 were analyzed. The life table method and a cross-tubulation analysis, log rank test were used to evaluate the survival curve and the influence that the prognostic factors. The prognostic factors, i.e., age and gender of patients, diameter and length, type of implants, bone graft history and loading time were determined with a Cox proportional hazard model based on logistic regression analysis. Results The seven-year cumulative survival rate of Osstem implants was 95.37%. The Cox proportional hazard model revealed that the following factors had a significant influence on survival rate; increased diameter, reduced prosthetic loading period and performance of bone grafting. Conclusion The osstem implants showed satisfactory results over the seven-year study period. PMID:24868503

  13. Cumulative human threats on fish biodiversity components in Tunisian waters

    Directory of Open Access Journals (Sweden)

    F. BEN RAIS LASRAM

    2015-02-01

    Full Text Available Human activities are increasingly impacting biodiversity. To improve conservation planning measures in an ecosystem-based management context, we need to explore how the effects of these activities interact with different biodiversity components. In this study, we used a semi-quantitative method to assess the cumulative impacts of human activities on three biodiversity components (species richness, phylogenetic diversity, and functional diversity in Tunisia’s exclusive economic zone. For each of the nine activities considered, we developed an understanding of their effects from local studies and the expert opinion of stakeholders with country-specific experience. We mapped the cumulative effects and the three biodiversity components and then assessed the degree to which these elements overlapped using an overlap index. This is the first time such an assessment has been made for Tunisia’s marine ecosystems and our assessment highlight the inappropriateness of current conservation measures. The results of this study have specific application for the prioritization of future management actions.

  14. Cumulative human threats on fish biodiversity components in Tunisian waters

    Directory of Open Access Journals (Sweden)

    F. BEN RAIS LASRAM

    2014-06-01

    Full Text Available Human activities are increasingly impacting biodiversity. To improve conservation planning measures in an ecosystem-based management context, we need to explore how the effects of these activities interact with different biodiversity components. In this study, we used a semi-quantitative method to assess the cumulative impacts of human activities on three biodiversity components (species richness, phylogenetic diversity, and functional diversity in Tunisia’s exclusive economic zone. For each of the nine activities considered, we developed an understanding of their effects from local studies and the expert opinion of stakeholders with country-specific experience. We mapped the cumulative effects and the three biodiversity components and then assessed the degree to which these elements overlapped using an overlap index. This is the first time such an assessment has been made for Tunisia’s marine ecosystems and our assessment highlight the inappropriateness of current conservation measures. The results of this study have specific application for the prioritization of future management actions.

  15. Cumulative dietary exposure of the population of Denmark to pesticides.

    Science.gov (United States)

    Jensen, Bodil Hamborg; Petersen, Annette; Nielsen, Elsa; Christensen, Tue; Poulsen, Mette Erecius; Andersen, Jens Hinge

    2015-09-01

    We used the Hazard Index (HI) method to carry out a cumulative risk assessment after chronic dietary exposure to all monitored pesticides in fruit, vegetables and cereals for various consumer groups in Denmark. Residue data for all the pesticides were obtained from the Danish monitoring programme during the period 2004-2011. Food consumption data were obtained from DANSDA (the DAnish National Survey of Diet and physical Activity) for the period 2005-2008. The calculations were made using three different models to cope with residues below the limit of reporting (LOR). We concluded that a model that included processing factors and set non-detects to ½ LOR, but limited the correction (Model 3), gave the most realistic exposure estimate. With Model 3 the HI was calculated to be 0.44 for children and 0.18 for adults, indicating that there is no risk of adverse health effects following chronic cumulative exposure to the pesticides found in fruit, vegetables and cereals on the Danish market. The HI was below 1 even for consumers who eat more than 550 g of fruit and vegetables per day, corresponding to 1/3 of the population. Choosing Danish-produced commodities whenever possible could reduce the HI by a factor of 2.

  16. Extraction of Facial Feature Points Using Cumulative Histogram

    CERN Document Server

    Paul, Sushil Kumar; Bouakaz, Saida

    2012-01-01

    This paper proposes a novel adaptive algorithm to extract facial feature points automatically such as eyebrows corners, eyes corners, nostrils, nose tip, and mouth corners in frontal view faces, which is based on cumulative histogram approach by varying different threshold values. At first, the method adopts the Viola-Jones face detector to detect the location of face and also crops the face region in an image. From the concept of the human face structure, the six relevant regions such as right eyebrow, left eyebrow, right eye, left eye, nose, and mouth areas are cropped in a face image. Then the histogram of each cropped relevant region is computed and its cumulative histogram value is employed by varying different threshold values to create a new filtering image in an adaptive way. The connected component of interested area for each relevant filtering image is indicated our respective feature region. A simple linear search algorithm for eyebrows, eyes and mouth filtering images and contour algorithm for nos...

  17. Cumulative Effects Assessment: Linking Social, Ecological, and Governance Dimensions

    Directory of Open Access Journals (Sweden)

    Marian Weber

    2012-06-01

    Full Text Available Setting social, economic, and ecological objectives is ultimately a process of social choice informed by science. In this special feature we provide a multidisciplinary framework for the use of cumulative effects assessment in land use planning. Forest ecosystems are facing considerable challenges driven by population growth and increasing demands for resources. In a suite of case studies that span the boreal forest of Western Canada to the interior Atlantic forest of Paraguay we show how transparent and defensible methods for scenario analysis can be applied in data-limited regions and how social dimensions of land use change can be incorporated in these methods, particularly in aboriginal communities that have lived in these ecosystems for generations. The case studies explore how scenario analysis can be used to evaluate various land use options and highlight specific challenges with identifying social and ecological responses, determining thresholds and targets for land use, and integrating local and traditional knowledge in land use planning. Given that land use planning is ultimately a value-laden and often politically charged process we also provide some perspective on various collective and expert-based processes for identifying cumulative impacts and thresholds. The need for good science to inform and be informed by culturally appropriate democratic processes calls for well-planned and multifaceted approaches both to achieve an informed understanding of both residents and governments of the interactive and additive changes caused by development, and to design action agendas to influence such change at the ecological and social level.

  18. Cumulative hierarchies and computability over universes of sets

    Directory of Open Access Journals (Sweden)

    Domenico Cantone

    2008-05-01

    Full Text Available Various metamathematical investigations, beginning with Fraenkel’s historical proof of the independence of the axiom of choice, called for suitable definitions of hierarchical universes of sets. This led to the discovery of such important cumulative structures as the one singled out by von Neumann (generally taken as the universe of all sets and Godel’s universe of the so-called constructibles. Variants of those are exploited occasionally in studies concerning the foundations of analysis (according to Abraham Robinson’s approach, or concerning non-well-founded sets. We hence offer a systematic presentation of these many structures, partly motivated by their relevance and pervasiveness in mathematics. As we report, numerous properties of hierarchy-related notions such as rank, have been verified with the assistance of the ÆtnaNova proof-checker.Through SETL and Maple implementations of procedures which effectively handle the Ackermann’s hereditarily finite sets, we illustrate a particularly significant case among those in which the entities which form a universe of sets can be algorithmically constructed and manipulated; hereby, the fruitful bearing on pure mathematics of cumulative set hierarchies ramifies into the realms of theoretical computer science and algorithmics.

  19. Prefiltering and Cumulant Based Harmonic Retrieval in Mixed ARMA Noises

    Institute of Scientific and Technical Information of China (English)

    LIShenghong; LIJianhua; XUEZhi; CHENLiya

    2005-01-01

    Harmonic retrieval is an important issue in the the field of statistical signal processing. However, in the case of harmonic retrieval in mixed colored Gaussian and Non-Gaussian Autoregressive movingaverage (ARMA) noises, the corresponding existing approaches can not retrieve a harmonic signal either with quadratic phase coupling components, or with cubic phase coupling components, or when the colored non-Gaussian ARMA noise is symmetrically distributed. In this paper, a new general approach is proposed to retrieve a one-dimensional real harmonic signal in the above mixed ARMA noises. A suitable filter is first used to remove all the sharp power spectrum peaks of the noisy observed process, then some kind of fourth-order cumulant is employed to identify the Autoregressive (AR) parameter values of the colored non-Gaussian ARMA noise model. After the real noisy observed data are filtered with the identified AR parameter values again, cumulant based methods can be made use of to retrieve the harmonics. The proposed new approach can be applied to retrieve a one-dimensional real harmonic signal in the above mixed colored Gaussian and non-Gaussian ARMA noises with no restrictions on the phase coupling of the harmonics and the distribution of the colored non-Gaussian ARMA noise. Simulation examples are presented to demonstrate its effectiveness.

  20. Petrogenesis of the nakhlite meteorites: Evidence from cumulate mineral zoning

    Energy Technology Data Exchange (ETDEWEB)

    Harvey, R.P.; McSween, H.Y. Jr. (Univ. of Tennessee, Knoxville (United States))

    1992-04-01

    A simple igneous petrogenesis for the meteorite Nakhla has previously been called into question because Mg/Fe ratios in olivine indicate substantial disequilibrium between the predominant cumulus minerals (olivine and augite). Comparative analyses of simulated diffusive zoning and the observed cumulus mineral zoning for all three nakhlites (Nakhla, Governador Valadares, and Lafayette) show that their current compositions do not necessarily reflect parental magma compositions. Instead, diffusion has altered primary cumulus compositions to varying degrees, Nakhla being the least affected, and Lafayette being almost completely re-equilibrated. Only the cores of augite grains in Nakhla and Governador Valadares appear to have preserved their original compositions. Mineral zoning in each meteorite is strongly concentric around mesostasis areas, suggesting that reaction with intercumulus liquid has controlled the observed zoning. The presence of pigeonite and orthopyroxene overgrowths in Nakhla and Governador Valadares, and of poikilitic orthopyroxene enclosing olivine relicts in Lafayette, indicate substantial late-magmatic reactions. Two-pyroxene geothermometry for Lafayette indicates temperatures around 95C, suggesting subsolidus equilibration as well. The nakhlites appear to be a series of relatively simple cumulate rocks which have undergone various amounts of late-magmatic and subsolidus diffusion, possibly reflecting their relative positions in a cooling cumulate pile.

  1. Cumulative distribution functions associated with bubble-nucleation processes in cavitation

    KAUST Repository

    Watanabe, Hiroshi

    2010-11-15

    Bubble-nucleation processes of a Lennard-Jones liquid are studied by molecular dynamics simulations. Waiting time, which is the lifetime of a superheated liquid, is determined for several system sizes, and the apparent finite-size effect of the nucleation rate is observed. From the cumulative distribution function of the nucleation events, the bubble-nucleation process is found to be not a simple Poisson process but a Poisson process with an additional relaxation time. The parameters of the exponential distribution associated with the process are determined by taking the relaxation time into account, and the apparent finite-size effect is removed. These results imply that the use of the arithmetic mean of the waiting time until a bubble grows to the critical size leads to an incorrect estimation of the nucleation rate. © 2010 The American Physical Society.

  2. Cumulant-Based Coherent Signal Subspace Method for Bearing and Range Estimation

    Directory of Open Access Journals (Sweden)

    Bourennane Salah

    2007-01-01

    Full Text Available A new method for simultaneous range and bearing estimation for buried objects in the presence of an unknown Gaussian noise is proposed. This method uses the MUSIC algorithm with noise subspace estimated by using the slice fourth-order cumulant matrix of the received data. The higher-order statistics aim at the removal of the additive unknown Gaussian noise. The bilinear focusing operator is used to decorrelate the received signals and to estimate the coherent signal subspace. A new source steering vector is proposed including the acoustic scattering model at each sensor. Range and bearing of the objects at each sensor are expressed as a function of those at the first sensor. This leads to the improvement of object localization anywhere, in the near-field or in the far-field zone of the sensor array. Finally, the performances of the proposed method are validated on data recorded during experiments in a water tank.

  3. Cumulative effects of road de-icing salt on amphibian behavior.

    Science.gov (United States)

    Denoël, Mathieu; Bichot, Marion; Ficetola, Gentile Francesco; Delcourt, Johann; Ylieff, Marc; Kestemont, Patrick; Poncin, Pascal

    2010-08-15

    Despite growing evidence of the detrimental effect of chemical substances on organisms, limited research has focused on changes in behavioral patterns, in part due to the difficulties to obtain detailed quantitative data. Recent developments in efficient computer-based video analyses have allowed testing pesticide effects on model species such as the zebrafish. However, these new techniques have not yet been applied to amphibians and directly to conservation issues, i.e., to assess toxicological risks on threatened species. We used video-tracking analyses to test a quantitative effect of an environmental contaminant on the locomotion of amphibian tadpoles (Rana temporaria) by taking into account cumulative effects. Because recent research has demonstrated effects of de-icing salts on survival and community structure, we used sodium chloride in our experimental design (25 replicates, 4 concentrations, 4 times) to test for an effect at the scale of behavior at environmentally relevant concentrations. Analysis of 372 1-h video-tracks (5 samples/s) showed a complex action of salts on behavioral patterns with a dose and cumulative response over time. Although no effects were found on mortality or growth, the highest salt concentrations reduced the speed and movement of tadpoles in comparison with control treatments. The reduced locomotor performance could have detrimental consequences in terms of tadpoles' responses to competition and predation and may be an indicator of the low concentration effect of the contaminant. On one hand, this study demonstrates the usefulness of examining behavior to address conservation issues and understand the complex action of environmental factors and, more particularly, pollutants on organisms. On the other hand, our results highlight the need of new computerized techniques to quantitatively analyze these patterns.

  4. [Analysis of the cumulative solar ultraviolet radiation in Mexico].

    Science.gov (United States)

    Castanedo-Cázares, Juan Pablo; Torres-Álvarez, Bertha; Portales-González, Bárbara; Martínez-Rosales, Karla; Hernández-Blanco, Diana

    2016-01-01

    The incidence of skin cancer has increased in Mexico in recent years. Ultraviolet radiation is the main risk factor associated. Due to the need to develop strategies to prevent skin cancer, the aim of the study was to estimate the UV intensity in several representative regions of Mexico, the average annual UV dose of these populations, and the potential benefit of applying sunscreen at different ages. The intensity of UV radiation was quantified by remote and terrestrial radiometry. The dose of UV exposure was measured in minimal erythema doses using validated models for face and arms. The benefit of using a sunscreen was calculated with the use of a sunscreen with SPF 15 from birth to age 70. The UV radiation is lower in December and greater in the period from May to July. The region with a lower annual dose is Tijuana; and the higher annual dose is in the Mexico City area. The annual difference between these regions was 58 %. Through life, a low SPF sunscreen can reduce up to 66 % of the received UV dose. The geographical location is a risk factor for accumulation of UV radiation in Mexico. Since childhood, people receive high amounts of it; however, most of this dose can be reduced using any commercially available sunscreen, if applied strategically.

  5. The excess risk of major osteoporotic fractures in hypothyroidism is driven by cumulative hyperthyroid as opposed to hypothyroid time

    DEFF Research Database (Denmark)

    Abrahamsen, Bo; Jørgensen, Henrik L; Laulund, Anne Sofie

    2015-01-01

    The long-term relationship between hypothyroidism and fracture risk is challenging to dissect because of the modifying influence of subsequent thyroxine replacement with the potential for excessive replacement doses. We studied changes in serum thyrotropin concentration (TSH) over time and associ......The long-term relationship between hypothyroidism and fracture risk is challenging to dissect because of the modifying influence of subsequent thyroxine replacement with the potential for excessive replacement doses. We studied changes in serum thyrotropin concentration (TSH) over time...... as a predictor of fracture risk in postmenopausal women whereas hypothyroid time predicted increased fracture risk in men below age 75 years. In conclusion, among patients who present with an elevated TSH, the long-term risk of hip and other osteoporotic fractures is strongly related to the cumulative duration...

  6. Cyclosporine induces progressive attenuation of baroreceptor heart rate response and cumulative pressor response in conscious unrestrained rats.

    Science.gov (United States)

    Shaltout, Hossam A; Abdel-Rahman, Abdel A

    2003-06-01

    Cyclosporine A (CsA) use is associated with hypertension and reduced baroreceptor sensitivity (BRS), but the underlying mechanisms remain unresolved. In this study, we investigated whether CsA attenuation of BRS is 1) dependent on treatment regimen, and 2) causative of the pressor response. Furthermore, we investigated whether a reduction in plasma testosterone contributes to BRS attenuation caused by short-term CsA administration. The effects of the clinically used CsA formulation (15 mg/kg/day i.v. for 5 days) on mean arterial pressure (MAP), heart rate, BRS, and body weight were investigated in conscious rats. CsA caused reproducible pressor responses (15.1 +/- 3.0 mm Hg) starting after the first dose and continuing through the 5 days of the study. BRS and baseline MAP were inversely related in the CsA group because of a progressive reduction in BRS, which started on day 2 and reached approximately 50% of baseline on day 5 and a cumulative elevation in MAP. The inverse BRS and MAP responses required daily administration of CsA because neither response was evident throughout the 5-day observation period after a single dose of CsA. Plasma testosterone levels were similar in all groups, whereas the body weight decreased approximately 10% in the CsA group on day 5. These findings suggest 1) CsA attenuation of BRS is relatively rapid and cumulative; 2) the attenuation of BRS may contribute to the delayed, but not to the acute, pressor elicited by CsA; and 3) the cumulative reduction in BRS caused by short-term (5-day) CsA treatment is not testosterone-related.

  7. Testing a cumulative and aggregate exposure model using biomonitoring studies and dietary records for Italian vineyard spray operators.

    Science.gov (United States)

    Kennedy, Marc C; Glass, C Richard; Fustinoni, Silvia; Moretto, Angelo; Mandic-Rajcevic, Stefan; Riso, Patrizia; Turrini, Aida; van der Voet, Hilko; Hetmanski, Michel T; Fussell, Richard J; van Klaveren, Jacob D

    2015-05-01

    The need for improved tools to estimate the cumulative and aggregate exposure to compounds such as plant protection products (PPPs) is recognised in the EU Regulation 1107/2009. A new model has been developed to estimate the exposure within a population to single compounds or compounds within a Cumulative Action Group, considering dietary and non-dietary sources and multiple exposure routes. To test the model a field study was carried out in Italy with operators applying tebuconazole fungicides, with measurements of dermal exposure collected. Whole urine samples were collected and analysed to provide values for the absorbed dose of tebuconazole, with duplicate diet samples collected and analysed as a measure of dietary exposures. The model provided predicted values of exposure for combined dietary and non-dietary routes of exposures which were compared to the measured absorbed dose values based on urinary analysis. The model outputs provided mean daily exposure values of 1.77 (± 1.96) µg a.s./kg BW which are comparable to measured mean values from the biomonitoring field study of 1.73 (± 1.31) µg a.s./kg BW. To supplement the limited measurement data available, comparisons against other models were also made and found to be comparable.

  8. Use of a Cumulative Risk Scale to Predict Poor Intellectual and Academic Outcomes in Childhood Epilepsy.

    Science.gov (United States)

    Kavanaugh, Brian C; Scarborough, Vanessa Ramos; Salorio, Cynthia F

    2016-06-01

    Discrete risk factors for poor outcomes in childhood epilepsy have been identified, but it is unclear whether the combined effect of several risk factors better predicts outcome. The Epilepsy Cumulative Risk Scale was developed to quantify cumulative risk for poor outcomes in childhood epilepsy. Participants included 156 clinic-referred children with epilepsy. The Epilepsy Cumulative Risk Scale was developed using variables previously associated with functional outcomes. Scale utility was examined through its association with intellectual and academic functioning. All Epilepsy Cumulative Risk Scale variables were significantly associated with functioning. The Total Score (ie, cumulative effect) was most strongly correlated with cognition and academic skills. A Total Score ≥ 5 had the best sensitivity and specificity for differentiating those at high risk for poor outcomes. The Epilepsy Cumulative Risk Scale shows promise as a practical, data-driven tool for quantification of cumulative risk for poor outcomes in childhood epilepsy and may be helpful in detecting those needing referral for additional services.

  9. Accurate estimation of dose distributions inside an eye irradiated with {sup 106}Ru plaques

    Energy Technology Data Exchange (ETDEWEB)

    Brualla, L.; Sauerwein, W. [Universitaetsklinikum Essen (Germany). NCTeam, Strahlenklinik; Sempau, J.; Zaragoza, F.J. [Universitat Politecnica de Catalunya, Barcelona (Spain). Inst. de Tecniques Energetiques; Wittig, A. [Marburg Univ. (Germany). Klinik fuer Strahlentherapie und Radioonkologie

    2013-01-15

    Background: Irradiation of intraocular tumors requires dedicated techniques, such as brachytherapy with {sup 106}Ru plaques. The currently available treatment planning system relies on the assumption that the eye is a homogeneous water sphere and on simplified radiation transport physics. However, accurate dose distributions and their assessment demand better models for both the eye and the physics. Methods: The Monte Carlo code PENELOPE, conveniently adapted to simulate the beta decay of {sup 106}Ru over {sup 106}Rh into {sup 106}Pd, was used to simulate radiation transport based on a computerized tomography scan of a patient's eye. A detailed geometrical description of two plaques (models CCA and CCB) from the manufacturer BEBIG was embedded in the computerized tomography scan. Results: The simulations were firstly validated by comparison with experimental results in a water phantom. Dose maps were computed for three plaque locations on the eyeball. From these maps, isodose curves and cumulative dose-volume histograms in the eye and for the structures at risk were assessed. For example, it was observed that a 4-mm anterior displacement with respect to a posterior placement of a CCA plaque for treating a posterior tumor would reduce from 40 to 0% the volume of the optic disc receiving more than 80 Gy. Such a small difference in anatomical position leads to a change in the dose that is crucial for side effects, especially with respect to visual acuity. The radiation oncologist has to bring these large changes in absorbed dose in the structures at risk to the attention of the surgeon, especially when the plaque has to be positioned close to relevant tissues. Conclusion: The detailed geometry of an eye plaque in computerized and segmented tomography of a realistic patient phantom was simulated accurately. Dose-volume histograms for relevant anatomical structures of the eye and the orbit were obtained with unprecedented accuracy. This represents an important step

  10. Influência de doses crescentes de chumbo sobre o teor e o conteúdo de nutrientes e Pb em mudas de ipê-roxo (Tabebuia impetiginosa (Mart. Standl. Influence of increasing lead levels on nutrient and Pb content and accumulation in ipê-roxo (Tabebuia impetiginosa (Mart. Standl. seedlings

    Directory of Open Access Journals (Sweden)

    Haroldo Nogueira de Paiva

    2003-04-01

    Full Text Available O efeito da aplicação de chumbo sobre o teor e o conteúdo de nutrientes e Pb na raiz, no caule e nas folhas de mudas de ipê-roxo (Tabebuia impetiginosa (Mart. Standl. foi estudado em um experimento realizado em casa de vegetação do Departamento de Ciência do Solo da Universidade Federal de Lavras. As mudas foram cultivadas em solução nutritiva de Clark e submetidas a doses crescentes de Pb: 0, 48, 96, 192 e 288 mimol/l. O experimento foi conduzido em delineamento estatístico de blocos ao acaso, e após 60 dias de exposição ao metal pesado foram feitas avaliações do teor e do conteúdo de macro, micronutrientes e chumbo na matéria seca de raiz, caule e folha. Os resultados mostraram que a aplicação de chumbo aumentou o teor de P e praticamente não afetou os teores de S, Ca e Mg nas mudas. De modo geral os teores de Cu, Fe e Mn sofreram redução, o teor de Zn não foi afetado, enquanto o conteúdo de macro e de micronutrientes sofreu redução. O teor de Pb na matéria seca de raiz, caule e folha aumentou com as doses aplicadas, principalmente na raiz, e se mostrou pouco móvel nas plantas analisadas.The effect of lead application on nutrient and Pb content and accumulation in ipê-roxo (Tabebuia impetiginosa (Mart. Standl. seedlings was studied in an experiment conducted under greenhouse conditions at the Soil Science Department of the Federal University of Lavras. The seedlings were cultivated in Clark nutrient solution and submitted to increasing Pb levels: 0, 48, 96, 192 and 288 mumol/l. The experiment was arranged in a randomized block design and after 60 days of exposure to the heavy metals, evaluations of macro and micronutrient and lead content and accumulation in the root, stem and leaf dry matter were made. The results showed that lead application increased P content and practically did not affect S, Ca and Mg contents. Cu, Fe and Mn contents, in general, presented a reduction; Zn content was not affected while macro

  11. Mathematical modeling of detonation initiation via flow cumulation effects

    Science.gov (United States)

    Semenov, I.; Utkin, P.; Akhmedyanov, I.

    2016-07-01

    The paper concerns two problems connected with the idea of gaseous detonation initiation via flow cumulation effects and convergence of relatively weak shock waves (SW). The first one is the three-dimensional (3D) numerical investigation of shock-to-detonation transition (SDT) in methane-air mixture in a tube with parabolic contraction followed by the tube section of narrow diameter and conical expansion. The second problem is the numerical study of the start-up of the model small-scale hydrogen electrochemical pulse detonation engine with the use of electrical discharge generating the toroidal SW. The investigation is performed by means of numerical simulation with the use of modern high-performance computing systems.

  12. Practical management of cumulative anthropogenic impacts with working marine examples

    DEFF Research Database (Denmark)

    Kyhn, Line Anker; Wright, Andrew J.

    2014-01-01

    for petroleum. Human disturbances, including the noise almost ubiquitously associated with human activity, are likely to increase the incidence, magnitude, and duration of adverse effects on marine life, including stress responses. Stress responses have the potential to induce fitness consequences...... for individuals, which add to more obvious directed takes (e.g., hunting or fishing) to increase the overall population-level impact. To meet the requirements of marine spatial planning and ecosystem-based management, many efforts are ongoing to quantify the cumulative impacts of all human actions on marine...... species or populations. Meanwhile, regulators face the challenge of managing these accumulating and interacting impacts with limited scientific guidance. We believe there is scientific support for capping the level of impact for (at a minimum) populations in decline or with unknown statuses. This cap...

  13. Effects of Surface Emitting and Cumulative Collisions on Elliptic Flow

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-Li; WU Feng-Juan; ZHANG Jing-Bo; TANG Gui-Xin; HUO Lei

    2008-01-01

    @@ The integral and differential elliptic flow of partons is calculated using the multiphase transport model for Au+Au collisions at centre-of-mass energy √SNN=200 GeV.It is shown that elliptic flow of partons freezing out at early time,which is affected mainly by surface emittance,decreases with time and elliptic flow of partons freezing out at late time,which is dominated by cumulative collisions,increases with time.The elliptic flow of partons freezing out early has a large contribution to the flatting of curve of final differential elliptic flow at large transverse momentum.It is argued that the effect of surface emittance is not neglectable.

  14. Modelling the evolution and diversity of cumulative culture

    Science.gov (United States)

    Enquist, Magnus; Ghirlanda, Stefano; Eriksson, Kimmo

    2011-01-01

    Previous work on mathematical models of cultural evolution has mainly focused on the diffusion of simple cultural elements. However, a characteristic feature of human cultural evolution is the seemingly limitless appearance of new and increasingly complex cultural elements. Here, we develop a general modelling framework to study such cumulative processes, in which we assume that the appearance and disappearance of cultural elements are stochastic events that depend on the current state of culture. Five scenarios are explored: evolution of independent cultural elements, stepwise modification of elements, differentiation or combination of elements and systems of cultural elements. As one application of our framework, we study the evolution of cultural diversity (in time as well as between groups). PMID:21199845

  15. Cumulative Laws,Team Assembling Mechanisms Determining Network Structure

    Institute of Scientific and Technical Information of China (English)

    WU Bin; LIU Qi; YE Qi

    2008-01-01

    A number of researching works have shed light on the field of complex networks recently.We investigate a wide range of real-world networks and find several interesting phenomena.Firstly,almost all of these networks evolve by overlapping new small graphs on former networks.Secondly,not only the degree sequence of the mature network follows a power-law distribution,but also the distribution of the cumulative occurrence times during the growing process are revealed to have a heavy tail.Existing network evolving models do not provide interpretation to these phenomena.We suggest a model based on the team assembling mechanism,which is extracted from the growing processes of real-world networks and requires simple parameters,and produces networks exhibiting these properties observed in the present study and in previous works.

  16. Modelling the evolution and diversity of cumulative culture.

    Science.gov (United States)

    Enquist, Magnus; Ghirlanda, Stefano; Eriksson, Kimmo

    2011-02-12

    Previous work on mathematical models of cultural evolution has mainly focused on the diffusion of simple cultural elements. However, a characteristic feature of human cultural evolution is the seemingly limitless appearance of new and increasingly complex cultural elements. Here, we develop a general modelling framework to study such cumulative processes, in which we assume that the appearance and disappearance of cultural elements are stochastic events that depend on the current state of culture. Five scenarios are explored: evolution of independent cultural elements, stepwise modification of elements, differentiation or combination of elements and systems of cultural elements. As one application of our framework, we study the evolution of cultural diversity (in time as well as between groups).

  17. Cumulative early life adversity predicts longevity in wild baboons.

    Science.gov (United States)

    Tung, Jenny; Archie, Elizabeth A; Altmann, Jeanne; Alberts, Susan C

    2016-04-19

    In humans and other animals, harsh circumstances in early life predict morbidity and mortality in adulthood. Multiple adverse conditions are thought to be especially toxic, but this hypothesis has rarely been tested in a prospective, longitudinal framework, especially in long-lived mammals. Here we use prospective data on 196 wild female baboons to show that cumulative early adversity predicts natural adult lifespan. Females who experience ≥3 sources of early adversity die a median of 10 years earlier than females who experience ≤1 adverse circumstances (median lifespan is 18.5 years). Females who experience the most adversity are also socially isolated in adulthood, suggesting that social processes partially explain the link between early adversity and adult survival. Our results provide powerful evidence for the developmental origins of health and disease and indicate that close ties between early adversity and survival arise even in the absence of health habit and health care-related explanations.

  18. The cumulative effect of risk compensation on infection preventive measures.

    Science.gov (United States)

    Maxin, Daniel; Sega, Laurentiu; Eaton, Lisa

    2016-12-01

    We study several epidemic models (with and without gender structure) that incorporate risk compensation behavior in response to a lower chance of acquiring the infection as a result of preventive measures that are only partially effective. We show that the cumulative risk compensation that occurs between a high risk susceptible and infectious individual may play an important role in whether the implementation of these measures is successful in lowering the epidemic reproductive number. In addition, we show that certain levels of risk compensation may cancel the benefit of the low infection risk practiced by diagnosed infectious individuals when the goal is a reduction of the epidemic reproductive number. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Cumulative semantic interference for associative relations in language production.

    Science.gov (United States)

    Rose, Sebastian Benjamin; Abdel Rahman, Rasha

    2016-07-01

    Associations between conceptual representations and thematic relations play an important role in the organization of semantic memory. However, language production research on semantic context effects shows that associative (e.g., dog and bone) and categorical relations (dog and horse) seem to diverge. While categorical contexts typically induce semantic interference that has traditionally been taken to reflect competitive lexical selection, evidence for comparable associative modulations is rare. In three experiments we tested whether thematic associations between objects induce cumulative interference in the continuous naming paradigm, assuming that this paradigm hampers lexical selection via the activation of highly active lexical cohorts steadily increasing in size. Indeed, naming times increased linearly with each newly named member of thematic contexts irrespective of the pre-activation of associations before the naming task (Experiment 1), and irrespective of whether categorical links were partially included (Experiments 1 and 2) or entirely absent (Experiment 3). These findings demonstrate that different types of semantic relations induce interference.

  20. EXPERIMENTAL VALIDATION OF CUMULATIVE SURFACE LOCATION ERROR FOR TURNING PROCESSES

    Directory of Open Access Journals (Sweden)

    Adam K. Kiss

    2016-02-01

    Full Text Available The aim of this study is to create a mechanical model which is suitable to investigate the surface quality in turning processes, based on the Cumulative Surface Location Error (CSLE, which describes the series of the consecutive Surface Location Errors (SLE in roughing operations. In the established model, the investigated CSLE depends on the currently and the previously resulted SLE by means of the variation of the width of cut. The phenomenon of the system can be described as an implicit discrete map. The stationary Surface Location Error and its bifurcations were analysed and flip-type bifurcation was observed for CSLE. Experimental verification of the theoretical results was carried out.

  1. Cumulative protons in 12C fragmentation at intermediate energy

    Directory of Open Access Journals (Sweden)

    Abramov B.M.

    2014-03-01

    Full Text Available In the FRAGM experiment at heavy ion accelerator complex TWAC-ITEP, the proton yields at an angle 3.5° have been measured in fragmentation of carbon ions at T0 = 0.3, 0.6, 0.95 and 2.0 GeV/nucleon on beryllium target. The data are presented as invariant proton yields on cumulative variable x in the range 0.9 < x < 2.4. Proton spectra cover six orders of invariant cross section magnitude. They have been analyzed in the framework of quark cluster fragmentation model. Fragmentation functions of quarkgluon string model are used. The probabilities of the existence of multi-quark clusters in carbon nuclei are estimated to be 8–12% for six-quark clusters and 0.2–0.6% for ninequark clusters.

  2. The modified cumulant expansion for two-dimensional isotropic turbulence

    Science.gov (United States)

    Tatsumi, T.; Yanase, S.

    1981-09-01

    The two-dimensional isotropic turbulence in an incompressible fluid is investigated using the modified zero fourth-order cumulant approximation. The dynamical equation for the energy spectrum obtained under this approximation is solved numerically and the similarity laws governing the solution in the energy-containing and enstrophy-dissipation ranges are derived analytically. At large Reynolds numbers the numerical solutions yield the k to the -3rd power inertial subrange spectrum which was predicted by Kraichnan (1967), Leith (1968) and Batchelor (1969), assuming a finite enstrophy dissipation in the inviscid limit. The energy-containing range is found to satisfy an inviscid similarity while the enstrophy-dissipation range is governed by the quasi-equilibrium similarity with respect to the enstrophy dissipation as proposed by Batchelor (1969). There exists a critical time which separates the initial period and the similarity period in which the enstrophy dissipation vanishes and remains non-zero respectively in the inviscid limit.

  3. Cumulative Incidence Association Models for Bivariate Competing Risks Data.

    Science.gov (United States)

    Cheng, Yu; Fine, Jason P

    2012-03-01

    Association models, like frailty and copula models, are frequently used to analyze clustered survival data and evaluate within-cluster associations. The assumption of noninformative censoring is commonly applied to these models, though it may not be true in many situations. In this paper, we consider bivariate competing risk data and focus on association models specified for the bivariate cumulative incidence function (CIF), a nonparametrically identifiable quantity. Copula models are proposed which relate the bivariate CIF to its corresponding univariate CIFs, similarly to independently right censored data, and accommodate frailty models for the bivariate CIF. Two estimating equations are developed to estimate the association parameter, permitting the univariate CIFs to be estimated either parametrically or nonparametrically. Goodness-of-fit tests are presented for formally evaluating the parametric models. Both estimators perform well with moderate sample sizes in simulation studies. The practical use of the methodology is illustrated in an analysis of dementia associations.

  4. Multifocal Electroretinography after High Dose Chloroquine Therapy for Malaria

    Directory of Open Access Journals (Sweden)

    Aline Correa de Carvalho

    2013-01-01

    Full Text Available Purpose: To investigate changes in multifocal electroretinography (mfERG parameters associated with high dose chloroquine therapy for treatment of malaria in the Amazonia region of Brazil. Methods: Forty-eight subjects who had received chloroquine treatment for single or multiple malaria infections with a cumulative dose ranging from 1,050 to 27,000mg were included. The control group consisted of 37 healthy aged-matched subjects. Data was collected on amplitude and implicit time of the N1, P1 and N2 waves in the central macular hexagon (R1 and in five concentric rings at different retinal eccentricities (R2-R6. Results: No significant difference was observed in any mfERG parameter between chloroquine treated patients and control subjects. A comparison with previous data obtained from patients with rheumatologic disorders in the same region of Brazil who had received larger cumulative doses of chloroquine and had displayed mfERG changes, indicated that retinal toxicity seems to be dependent on cumulative dose. Conclusion: Lack of mfERG changes in the current study suggests that intensive high dose chloroquine therapy for treatment of malaria is not associated with retinal toxicity.

  5. Patient exposure: description of cumulative irradiation of patients treated in interventional cardiology; Exposition des patients: description de l'irradiation cumulee des patients traites en cardiologie interventionnelle

    Energy Technology Data Exchange (ETDEWEB)

    Odile Bernier, M.O. [Institut de Radioprotection et de Surete Nucleaire, Laboratoire d ' Epidemiologie, 92 - Fontenay aux Roses (France)

    2009-07-01

    Despite its clinical benefits, interventional cardiology induces cumulative exposure to ionizing radiation and may entail an important irradiation of the patient at the cutaneous level as well as for organs at the vicinity of the heart. The author briefly reports a study performed on a sample of 1591 patients who have been submitted to at least one corono-graphy or one angioplasty during 2005. Based on clinical characteristics and dose-area-product measurements, the doses received by lung, oesophagus, bone medulla and breast have been computed

  6. County-level cumulative environmental quality associated with cancer incidence.

    Science.gov (United States)

    Jagai, Jyotsna S; Messer, Lynne C; Rappazzo, Kristen M; Gray, Christine L; Grabich, Shannon C; Lobdell, Danelle T

    2017-08-01

    Individual environmental exposures are associated with cancer development; however, environmental exposures occur simultaneously. The Environmental Quality Index (EQI) is a county-level measure of cumulative environmental exposures that occur in 5 domains. The EQI was linked to county-level annual age-adjusted cancer incidence rates from the Surveillance, Epidemiology, and End Results (SEER) Program state cancer profiles. All-site cancer and the top 3 site-specific cancers for male and female subjects were considered. Incident rate differences (IRDs; annual rate difference per 100,000 persons) and 95% confidence intervals (CIs) were estimated using fixed-slope, random intercept multilevel linear regression models. Associations were assessed with domain-specific indices and analyses were stratified by rural/urban status. Comparing the highest quintile/poorest environmental quality with the lowest quintile/best environmental quality for overall EQI, all-site county-level cancer incidence rate was positively associated with poor environmental quality overall (IRD, 38.55; 95% CI, 29.57-47.53) and for male (IRD, 32.60; 95% CI, 16.28-48.91) and female (IRD, 30.34; 95% CI, 20.47-40.21) subjects, indicating a potential increase in cancer incidence with decreasing environmental quality. Rural/urban stratified models demonstrated positive associations comparing the highest with the lowest quintiles for all strata, except the thinly populated/rural stratum and in the metropolitan/urbanized stratum. Prostate and breast cancer demonstrated the strongest positive associations with poor environmental quality. We observed strong positive associations between the EQI and all-site cancer incidence rates, and associations differed by rural/urban status and environmental domain. Research focusing on single environmental exposures in cancer development may not address the broader environmental context in which cancers develop, and future research should address cumulative environmental

  7. Economic and policy implications of the cumulative carbon budget

    Science.gov (United States)

    Allen, M. R.; Otto, F. E. L.; Otto, A.; Hepburn, C.

    2014-12-01

    The importance of cumulative carbon emissions in determining long-term risks of climate change presents considerable challenges to policy makers. The traditional notion of "total CO2-equivalent emissions", which forms the backbone of agreements such as the Kyoto Protocol and the European Emissions Trading System, is fundamentally flawed. Measures to reduce short-lived climate pollutants benefit the current generation, while measures to reduce long-lived climate pollutants benefit future generations, so there is no sense in which they can ever be considered equivalent. Debates over the correct metric used to compute CO2-equivalence are thus entirely moot: both long-lived and short-lived emissions will need to be addressed if all generations are to be protected from dangerous climate change. As far as long-lived climate pollutants are concerned, the latest IPCC report highlights the overwhelming importance of carbon capture and storage in determining the cost of meeting the goal of limiting anthropogenic warming to two degrees. We will show that this importance arises directly from the cumulative carbon budget and the role of CCS as the technology of last resort before economic activity needs to be restricted to meet ambitious climate targets. It highlights the need to increase the rate of CCS deployment by orders of magnitude if the option of avoiding two degrees is to be retained. The difficulty of achieving this speed of deployment through conventional incentives and carbon-pricing mechanisms suggests a need for a much more direct mandatory approach. Despite their theoretical economic inefficiency, the success of recent regulatory measures in achieving greenhouse gas emissions reductions in jurisdictions such as the United States suggests an extension of the regulatory approach could be a more effective and politically acceptable means of achieving adequately rapid CCS deployment than conventional carbon taxes or cap-and-trade systems.

  8. Fast motion-including dose error reconstruction for VMAT with and without MLC tracking

    DEFF Research Database (Denmark)

    Ravkilde, Thomas; Keall, Paul J.; Grau, Cai

    2014-01-01

    of the algorithm for reconstruction of dose and motion-induced dose errors throughout the tracking and non-tracking beam deliveries was quantified. Doses were reconstructed with a mean dose difference relative to the measurements of -0.5% (5.5% standard deviation) for cumulative dose. More importantly, the root......-mean-square deviation between reconstructed and measured motion-induced 3%/3 mm γ failure rates (dose error) was 2.6%. The mean computation time for each calculation of dose and dose error was 295 ms. The motion-including dose reconstruction allows accurate temporal and spatial pinpointing of errors in absorbed dose...... validate a simple model for fast motion-including dose error reconstruction applicable to intrafractional QA of MLC tracking treatments of moving targets. MLC tracking experiments were performed on a standard linear accelerator with prototype MLC tracking software guided by an electromagnetic transponder...

  9. A Conceptual Framework for the Assessment of Cumulative Exposure to Air Pollution at a Fine Spatial Scale.

    Science.gov (United States)

    Wahida, Kihal-Talantikite; Padilla, Cindy M; Denis, Zmirou-Navier; Olivier, Blanchard; Géraldine, Le Nir; Philippe, Quenel; Séverine, Deguen

    2016-03-15

    Many epidemiological studies examining long-term health effects of exposure to air pollutants have characterized exposure by the outdoor air concentrations at sites that may be distant to subjects' residences at different points in time. The temporal and spatial mobility of subjects and the spatial scale of exposure assessment could thus lead to misclassification in the cumulative exposure estimation. This paper attempts to fill the gap regarding cumulative exposure assessment to air pollution at a fine spatial scale in epidemiological studies investigating long-term health effects. We propose a conceptual framework showing how major difficulties in cumulative long-term exposure assessment could be surmounted. We then illustrate this conceptual model on the case of exposure to NO₂ following two steps: (i) retrospective reconstitution of NO₂ concentrations at a fine spatial scale; and (ii) a novel approach to assigning the time-relevant exposure estimates at the census block level, using all available data on residential mobility throughout a 10- to 20-year period prior to that for which the health events are to be detected. Our conceptual framework is both flexible and convenient for the needs of different epidemiological study designs.

  10. Dose estimation for repeated phosphorus-32 ingestion in human subjects

    Energy Technology Data Exchange (ETDEWEB)

    Chao, J.H.; Tseng, C.L.; Hsieh, W.A.; Hung, D.Z.; Chang, W.P. E-mail: wpc94@mailsrv.ym.edu.tw

    2001-01-15

    Dose estimation was conducted for internal phosphorus-32 exposure in one young male subject from repeated oral mis-ingestion for >1 year. Since disclosure for previous continuous contamination, a series of urine samples were collected from this individual weekly for a period of >2 months. P-32 radioactivity in urine samples were measured by the acid precipitation method. Estimation for retrospective total effective dose equivalent received by this subject was conducted for cumulative internal dose estimation. A minimum of 9.4 mSv was estimated for an assumed single ingestion. As this was a rare case in radiation protection and internal radiation dosimetry, its implications were of considerable significance.

  11. Cumulative Interarrival Time Distributions of Freeway Entrance Ramp Traffic for Traffic Simulations

    Directory of Open Access Journals (Sweden)

    Erdinç Öner

    2013-02-01

    Full Text Available Cumulative interarrival time (IAT distributions for signalized and non-signalized freeway entrance ramps were developed to be used in digital computer traffic simulation models. The data from four different non-signalized entrance ramps (three ramps with a single lane, one ramp with two lanes and two different signalized entrance ramps (both with a single lane were used for developing the cumulative IAT distributions. The cumulative IAT distributions for the signalized and non-signalized entrance ramps were compared with each other and with the cumulative IAT distributions of the lanes for freeways. The comparative results showed that the cumulative IAT distributions for non-signalized entrance ramps are very close to the leftmost lane of a 3-lane freeway where the maximum absolute difference between the cumulative IAT distribution of the leftmost lane of a 3-lane freeway and the entrance ramps cumulative IAT distribution was 3%. The cumulative IAT distribution for the signalized entrance ramps was found to be different from the non-signalized entrance ramp cumulative IAT distribution. The approximated cumulative IAT distributions for signalized and non-signalized entrance ramp traffic for any hourly traffic volume from a few vehicles/hour up to 2,500 vehicles/hour can be obtained at http://www.ohio.edu/orite/research/uitds.cfm.

  12. Radiation therapy for stage IIA and IIB testicular seminoma: peripheral dose calculations and risk assessments

    Science.gov (United States)

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

    2015-03-01

    This study was conducted to calculate the peripheral dose to critical structures and assess the radiation risks from modern radiotherapy for stage IIA/IIB testicular seminoma. A Monte Carlo code was used for treatment simulation on a computational phantom representing an average adult. The initial treatment phase involved anteroposterior and posteroanaterior modified dog-leg fields exposing para-aortic and ipsilateral iliac lymph nodes followed by a cone-down phase for nodal mass irradiation. Peripheral doses were calculated using different modified dog-leg field dimensions and an extended conventional dog-leg portal. The risk models of the BEIR-VII report and ICRP-103 were combined with dosimetric calculations to estimate the probability of developing stochastic effects. Radiotherapy for stage IIA seminoma with a target dose of 30 Gy resulted in a range of 23.0-603.7 mGy to non-targeted peripheral tissues and organs. The corresponding range for treatment of stage IIB disease to a cumulative dose of 36 Gy was 24.2-633.9 mGy. A dose variation of less than 13% was found by altering the field dimensions. Radiotherapy with the conventional instead of the modern modified dog-leg field increased the peripheral dose up to 8.2 times. The calculated heart doses of 589.0-632.9 mGy may increase the risk for developing cardiovascular diseases whereas the testicular dose of more than 231.9 mGy may lead to a temporary infertility. The probability of birth abnormalities in the offspring of cancer survivors was below 0.13% which is much lower than the spontaneous mutation rate. Abdominoplevic irradiation may increase the lifetime intrinsic risk for the induction of secondary malignancies by 0.6-3.9% depending upon the site of interest, patient’s age and tumor dose. Radiotherapy for stage IIA/IIB seminoma with restricted fields and low doses is associated with an increased morbidity. These data may allow the definition of a risk-adapted follow-up scheme for long

  13. Quantifying process-based mitigation strategies in historical context: separating multiple cumulative effects on river meander migration.

    Directory of Open Access Journals (Sweden)

    Alexander K Fremier

    Full Text Available Environmental legislation in the US (i.e. NEPA requires defining baseline conditions on current rather than historical ecosystem conditions. For ecosystems with long histories of multiple environmental impacts, this baseline method can subsequently lead to a significantly altered environment; this has been termed a 'sliding baseline'. In river systems, cumulative effects caused by flow regulation, channel revetment and riparian vegetation removal significantly impact floodplain ecosystems by altering channel dynamics and precluding subsequent ecosystem processes, such as primary succession. To quantify these impacts on floodplain development processes, we used a model of river channel meander migration to illustrate the degree to which flow regulation and riprap impact migration rates, independently and synergistically, on the Sacramento River in California, USA. From pre-dam conditions, the cumulative effect of flow regulation alone on channel migration is a reduction by 38%, and 42-44% with four proposed water diversion project scenarios. In terms of depositional area, the proposed water project would reduce channel migration 51-71 ha in 130 years without current riprap in place, and 17-25 ha with riprap. Our results illustrate the utility of a modeling approach for quantifying cumulative impacts. Model-based quantification of environmental impacts allow scientists to separate cumulative and synergistic effects to analytically define mitigation measures. Additionally, by selecting an ecosystem process that is affected by multiple impacts, it is possible to consider process-based mitigation scenarios, such as the removal of riprap, to allow meander migration and create new floodplains and allow for riparian vegetation recruitment.

  14. Using Physiologically-Based Pharmacokinetic Models to Incorporate Chemical and Non-Chemical Stressors into Cumulative Risk Assessment: A Case Study of Pesticide Exposures

    Directory of Open Access Journals (Sweden)

    Jonathan I. Levy

    2012-05-01

    Full Text Available Cumulative risk assessment has been proposed as an approach to evaluate the health risks associated with simultaneous exposure to multiple chemical and non-chemical stressors. Physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD models can allow for the inclusion and evaluation of multiple stressors, including non-chemical stressors, but studies have not leveraged PBPK/PD models to jointly consider these disparate exposures in a cumulative risk context. In this study, we focused on exposures to organophosphate (OP pesticides for children in urban low-income environments, where these children would be simultaneously exposed to other pesticides (including pyrethroids and non-chemical stressors that may modify the effects of these exposures (including diet. We developed a methodological framework to evaluate chemical and non-chemical stressor impacts on OPs, utilizing an existing PBPK/PD model for chlorpyrifos. We evaluated population-specific stressors that would influence OP doses or acetylcholinesterase (AChE inhibition, the relevant PD outcome. We incorporated the impact of simultaneous exposure to pyrethroids and dietary factors on OP dose through the compartments of metabolism and PD outcome within the PBPK model, and simulated combinations of stressors across multiple exposure ranges and potential body weights. Our analyses demonstrated that both chemical and non-chemical stressors can influence the health implications of OP exposures, with up to 5-fold variability in AChE inhibition across combinations of stressor values for a given OP dose. We demonstrate an approach for modeling OP risks in the presence of other population-specific environmental stressors, providing insight about co-exposures and variability factors that most impact OP health risks and contribute to children’s cumulative health risk from pesticides. More generally, this framework can be used to inform cumulative risk assessment for any compound impacted by

  15. Cumulative risk assessment for plasticizer-contaminated food using the hazard index approach.

    Science.gov (United States)

    Chang, J W; Chen, C Y; Yan, B R; Chang, M H; Tseng, S H; Kao, Y M; Chen, J C; Lee, C C

    2014-06-01

    Phthalates strongly and adversely affect reproduction, development and liver function. We did a cumulative risk assessment for simultaneous exposure to nine phthalates using the hazard index (HI) and the levels of nine phthalates in 1200 foodstuff samples. DEHP (di-2-ethylhexyl phthalate) present the highest level (mean: 0.443 mg/kg) in 1200 samples, and the highest average daily dose (ADD) was found in DEHP, ΣDBP(i + n) (the sum of dibutyl phthalate [DBP] isomers [DnBP + DiBP]) posed the highest risk potential of all the phthalates. In seven phthalates, the 95th percentiles of the ADDs for ΣDBP(i + n) in 0-6-yr-old children accounted for 91% (79-107%) of the tolerable daily intake, and the 95th percentiles of the HIs for the anti-androgenic effects of five phthalates in 0-3-yr-old children and 4-6-yr-old girls were >1. We conclude that the health of younger Taiwanese may be adversely affected by overexposure of phthalate-contaminated foods.

  16. Anti-irritants II: Efficacy against cumulative irritation

    DEFF Research Database (Denmark)

    Andersen, Flemming; Hedegaard, Kathryn; Petersen, Thomas Kongstad

    2006-01-01

    of 4 alleged AI (nifedipine, (-)-alpha-bisabolol, canola oil and glycerol) was studied on experimentally induced acute irritation in healthy volunteers, and only glycerol showed dose-related response and effects potentially better than no treatment. The acute irritation model only allowed a small...

  17. Existence of Solutions of a Riccati Differential System from a General Cumulant Control Problem

    Directory of Open Access Journals (Sweden)

    Stanley R. Liberty

    2011-01-01

    Full Text Available We study a system of infinitely many Riccati equations that arise from a cumulant control problem, which is a generalization of regulator problems, risk-sensitive controls, minimal cost variance controls, and k-cumulant controls. We obtain estimates for the existence intervals of solutions of the system. In particular, new existence conditions are derived for solutions on the horizon of the cumulant control problem.

  18. Experimental assessment of cumulative temperature and UV-B radiation effects on Mediterranean plankton metabolism

    KAUST Repository

    Garcia-Corral, Lara S.

    2015-07-07

    The Mediterranean Sea is a vulnerable region for climate change, warming at higher rates compare to the global ocean. Warming leads to increased stratification of the water column and enhanced the oligotrophic nature of the Mediterranean Sea. The oligotrophic waters are already highly transparent, however, exposure of Mediterranean plankton to ultraviolet radiation (UV-B and UV-A) may increase further if the waters become more oligotrophic, thereby, allowing a deeper UV radiation penetration and likely enhancing impacts to biota. Here we experimentally elucidate the cumulative effects of warming and natural UV-B radiation on the net community production (NCP) of plankton communities. We conducted five experiments at monthly intervals, from June to October 2013, and evaluated the responses of NCP to ambient UV-B radiation and warming (+3°C), alone and in combination, in a coastal area of the northwest Mediterranean Sea. UV-B radiation and warming lead to reduced NCP and resulted in a heterotrophic (NCP < 0) metabolic balance. Both UV-B radiation and temperature, showed a significant individual effect in NCP across treatments and time. However, their joint effect showed to be synergistic as the interaction between them (UV × Temp) was statistically significant in most of the experiments performed. Our results showed that both drivers, would affect the gas exchange of CO2−O2 from and to the atmosphere and the role of plankton communities in the Mediterranean carbon cycle.

  19. Experimental assessment of cumulative temperature and UV-B radiation effects on Mediterranean plankton metabolism

    Directory of Open Access Journals (Sweden)

    Lara S. eGarcia-Corral

    2015-07-01

    Full Text Available The Mediterranean Sea is a vulnerable region for climate change, warming at higher rates compare to the global ocean. Warming leads to increased stratification of the water column and enhanced the oligotrophic nature of the Mediterranean Sea. The oligotrophic waters are already highly transparent, however, exposure of Mediterranean plankton to ultraviolet radiation (UV-B and UV-A may increase further if the waters become more oligotrophic, thereby, allowing a deeper UV radiation penetration and likely enhancing impacts to biota.Here we experimentally elucidate the cumulative effects of warming and natural UV-B radiation on the net community production (NCP of plankton communities. We conducted five experiments at monthly intervals, from June to October 2013, and evaluated the responses of NCP to ambient UV-B radiation and warming (+3ºC, alone and in combination, in a coastal area of the northwest Mediterranean Sea. UV-B radiation and warming lead to reduced net community production and resulted in a heterotrophic (NCP<0 metabolic balance. Both UV-B radiation and temperature, showed a significant individual effect in NCP across treatments and time. However, their joint effect showed to be synergistic as the interaction between them (UV x Temp was statistically significant in most of the experiments performed. Our results showed that both drivers, would affect the gas exchange of CO2-O2 from and to the atmosphere and the role of plankton communities in the Mediterranean carbon cycle

  20. Low Dose Sarin Leads To Murine Cardiac Dysfunction

    Science.gov (United States)

    2010-03-01

    killing of three dogs by a nerve agent (Robertson, 2002). These events demonstrate the intent and willingness of such organizations to employ chemical...Echocardiography. The American Journal of Cardiology , 1381 - 1386. Damodaran, T. V., Jones, K. H., Patel, A. G., & Abou-Donia, M. B. (2003). Sarin...Gonzadlez, A., & Querejeta, R. (2001). Clinical Aspects of Hypertensive Myocardial Fibrosis. Current Opinion in Cardiology , 328 - 335. Duncan, A. M

  1. Pediatric patient doses in interventional cardiology procedures; Doses em paciente pediatrico em procedimentos de cardiologia intervencionista

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, R.B.; Murata, C.H.; Moreira, A.C., E-mail: rbitelli2012@gmail.com, E-mail: camila.murata@gmail.com, E-mail: antonio.xray@gmail.com [Universidade Federal de Sao Paulo (UNIFESP), Sao Paulo, SP (Brazil). Escola Pulista de Medicina; Khoury, H.J.; Borras, C., E-mail: hjkhoury@gmail.com, E-mail: cariborras@starpower.net [Universidade Federal de Pernambuco (DEN/UFPE), Recife, PE (Brazil). Dept. de Engenharia Nuclear; Silva, M.S.R da, E-mail: msrochas2003@yahoo.com.br [Instituto Federal de Educacao, Ciencia e Tecnologia de Pernambuco (IFPE), Recife, PE (Brazil)

    2014-07-01

    The radiation doses from interventional procedures is relevant when treating children because of their greater radiosensitivity compared with adults. The purposes of this paper were to estimate the dose received by 18 pediatric patients who underwent cardiac interventional procedures and to correlate the maximum entrance surface air kerma (Ke,max), estimated with radiochromic films, with the cumulative air kerma values displayed at the end of procedures. This study was performed in children up to 6 years. The study was performed in two hospitals, one located in Recife and the other one in São Paulo. The x-ray imaging systems used were Phillips Allura 12 model with image intensifier system and a Phillips Allura FD10 flat panel system. To estimate the Ke,max on the patient’s skin radiochromic films(Gafchromic XR-RV2) were used. These values were estimated from the maximum optical density measured on film using a calibration curve. The results showed cumulative air kerma values ranging from 78.3- 500.0mGy, with a mean value of 242,3 mGy. The resulting Ke,max values ranged from 20.0-461.8 mGy, with a mean value of 208,8 mGy. The Ke,max values were correlated with the displayed cumulative air kerma values. The correlation factor R² was 0.78, meaning that the value displayed in the equipment’s console can be useful for monitoring the skin absorbed dose throughout the procedure. The routine fluoroscopy time records is not able by itself alert the physician about the risk of dose exceeding the threshold of adverse reactions, which can vary from an early erythema to serious harmful skin damage. (author)

  2. Scenario dependency of the transient climate response to cumulative emissions

    Science.gov (United States)

    Turner, Katherine; Williams, Ric; Oschlies, Andreas

    2017-04-01

    The transient climate response to emissions (TCRE), in relating surface temperature changes to cumulative carbon emissions, provides a means of estimating carbon budgets from global warming benchmarks. Current Earth System Model results indicate that the TCRE is linear and scenario-independent. We explore the sensitivity of the TCRE to scenario and model parameter uncertainties using 8 configurations of the UVic Earth System Model of Intermediate Complexity, forced by 2 twenty-first-century emissions scenarios (RCP 4.5 and 8.5). We find that the TCRE is higher under RCP 4.5 than 8.5 by 0.3-0.8 K/1000 Pg C and shows opposing nonlinear tendencies in these scenarios: an increase of 0.15-0.5 K/1000 Pg C over RCP 4.5 and a decrease of 0-0.7 K/1000 Pg C over RCP 8.5. These differences are robust across model configurations with perturbed land and ocean parametrizations and are the result of the decreased efficiency of heat transport into the deep ocean under decelerating emissions.

  3. INTERACTIVE VISUALIZATION OF PROBABILITY AND CUMULATIVE DENSITY FUNCTIONS

    KAUST Repository

    Potter, Kristin

    2012-01-01

    The probability density function (PDF), and its corresponding cumulative density function (CDF), provide direct statistical insight into the characterization of a random process or field. Typically displayed as a histogram, one can infer probabilities of the occurrence of particular events. When examining a field over some two-dimensional domain in which at each point a PDF of the function values is available, it is challenging to assess the global (stochastic) features present within the field. In this paper, we present a visualization system that allows the user to examine two-dimensional data sets in which PDF (or CDF) information is available at any position within the domain. The tool provides a contour display showing the normed difference between the PDFs and an ansatz PDF selected by the user and, furthermore, allows the user to interactively examine the PDF at any particular position. Canonical examples of the tool are provided to help guide the reader into the mapping of stochastic information to visual cues along with a description of the use of the tool for examining data generated from an uncertainty quantification exercise accomplished within the field of electrophysiology.

  4. Model-checking techniques based on cumulative residuals.

    Science.gov (United States)

    Lin, D Y; Wei, L J; Ying, Z

    2002-03-01

    Residuals have long been used for graphical and numerical examinations of the adequacy of regression models. Conventional residual analysis based on the plots of raw residuals or their smoothed curves is highly subjective, whereas most numerical goodness-of-fit tests provide little information about the nature of model misspecification. In this paper, we develop objective and informative model-checking techniques by taking the cumulative sums of residuals over certain coordinates (e.g., covariates or fitted values) or by considering some related aggregates of residuals, such as moving sums and moving averages. For a variety of statistical models and data structures, including generalized linear models with independent or dependent observations, the distributions of these stochastic processes tinder the assumed model can be approximated by the distributions of certain zero-mean Gaussian processes whose realizations can be easily generated by computer simulation. Each observed process can then be compared, both graphically and numerically, with a number of realizations from the Gaussian process. Such comparisons enable one to assess objectively whether a trend seen in a residual plot reflects model misspecification or natural variation. The proposed techniques are particularly useful in checking the functional form of a covariate and the link function. Illustrations with several medical studies are provided.

  5. Cumulative sum quality control for calibrated breast density measurements

    Energy Technology Data Exchange (ETDEWEB)

    Heine, John J.; Cao Ke; Beam, Craig [Cancer Prevention and Control Division, Moffitt Cancer Center, 12902 Magnolia Drive, Tampa, Florida 33612 (United States); Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago, 1603 W. Taylor St., Chicago, Illinois 60612 (United States)

    2009-12-15

    Purpose: Breast density is a significant breast cancer risk factor. Although various methods are used to estimate breast density, there is no standard measurement for this important factor. The authors are developing a breast density standardization method for use in full field digital mammography (FFDM). The approach calibrates for interpatient acquisition technique differences. The calibration produces a normalized breast density pixel value scale. The method relies on first generating a baseline (BL) calibration dataset, which required extensive phantom imaging. Standardizing prospective mammograms with calibration data generated in the past could introduce unanticipated error in the standardized output if the calibration dataset is no longer valid. Methods: Sample points from the BL calibration dataset were imaged approximately biweekly over an extended timeframe. These serial samples were used to evaluate the BL dataset reproducibility and quantify the serial calibration accuracy. The cumulative sum (Cusum) quality control method was used to evaluate the serial sampling. Results: There is considerable drift in the serial sample points from the BL calibration dataset that is x-ray beam dependent. Systematic deviation from the BL dataset caused significant calibration errors. This system drift was not captured with routine system quality control measures. Cusum analysis indicated that the drift is a sign of system wear and eventual x-ray tube failure. Conclusions: The BL calibration dataset must be monitored and periodically updated, when necessary, to account for sustained system variations to maintain the calibration accuracy.

  6. Enhanced cumulative sum charts for monitoring process dispersion.

    Science.gov (United States)

    Abujiya, Mu'azu Ramat; Riaz, Muhammad; Lee, Muhammad Hisyam

    2015-01-01

    The cumulative sum (CUSUM) control chart is widely used in industry for the detection of small and moderate shifts in process location and dispersion. For efficient monitoring of process variability, we present several CUSUM control charts for monitoring changes in standard deviation of a normal process. The newly developed control charts based on well-structured sampling techniques - extreme ranked set sampling, extreme double ranked set sampling and double extreme ranked set sampling, have significantly enhanced CUSUM chart ability to detect a wide range of shifts in process variability. The relative performances of the proposed CUSUM scale charts are evaluated in terms of the average run length (ARL) and standard deviation of run length, for point shift in variability. Moreover, for overall performance, we implore the use of the average ratio ARL and average extra quadratic loss. A comparison of the proposed CUSUM control charts with the classical CUSUM R chart, the classical CUSUM S chart, the fast initial response (FIR) CUSUM R chart, the FIR CUSUM S chart, the ranked set sampling (RSS) based CUSUM R chart and the RSS based CUSUM S chart, among others, are presented. An illustrative example using real dataset is given to demonstrate the practicability of the application of the proposed schemes.

  7. Detection of abrupt baseline length changes using cumulative sums

    Science.gov (United States)

    Janssen, Volker

    2009-06-01

    Dynamic processes are usually monitored by collecting a time series of observations, which is then analysed in order to detect any motion or non-standard behaviour. Geodetic examples include the monitoring of dams, bridges, high-rise buildings, landslides, volcanoes and tectonic motion. The cumulative sum (CUSUM) test is recognised as a popular means to detect changes in the mean and/or the standard deviation of a time series and has been applied to various monitoring tasks. This paper briefly describes the CUSUM technique and how it can be utilised for the detection of small baseline length changes by differencing two perpendicular baselines sharing a common site. A simulation is carried out in order to investigate the expected behaviour of the resulting CUSUM charts for a variety of typical deformation monitoring scenarios. This simulation shows that using first differences (between successive epochs) as input, rather than the original baseline lengths, produces clear peaks or jumps in the differenced CUSUM time series when a sudden change in baseline length occurs. These findings are validated by analysing several GPS baseline pairs of a network deployed to monitor the propagation of an active ice shelf rift on the Amery Ice Shelf, East Antarctica.

  8. Estimation of cumulative cadmium intake causing Itai-itai disease.

    Science.gov (United States)

    Inaba, Takeya; Kobayashi, Etsuko; Suwazono, Yasushi; Uetani, Mirei; Oishi, Mitsuhiro; Nakagawa, Hideaki; Nogawa, Koji

    2005-11-15

    This study was undertaken to estimate the amount of cadmium (Cd) exposure needed for the development of Itai-itai disease. The investigated subjects comprised 82 Itai-itai disease patients and 11 persons requiring observation who were admitted in 1977 and 1978 for medical testing. With the period when the Itai-itai disease patients started to perceive leg/back pain defined as the 'mild disease onset', and the period when they experienced the most severe manifestations such as ambulatory disturbance and bone fractures defined as 'severe disease onset'. Relative cumulative person number distribution according to life time cadmium intake (LCD) at mild disease onset, severe disease onset, and time of death was depicted as an sigmoid curve and the establishment of probit regression lines was demonstrated between them. LCD at the time when mild disease onset and severe disease onset were recognized in half of the Itai-itai disease patients was 3.1 and 3.8 g, respectively. Furthermore, LCD at the time when mild disease onset and severe disease onset were recognized in 5% of the Itai-itai disease patients was calculated to be 2.6 and 3.3 g, respectively. The present results clarify that Itai-itai disease, the most severe stage of chronic Cd poisoning, occurs at levels of Cd consumption amounting to approximately three-fold of those currently seen in Japan.

  9. LINGUISTIC DETERMINISM, CUMULATIVE EVOLUTION AND DEVELOPMENT OF SCIENTIFIC KNOWLEDGE

    Directory of Open Access Journals (Sweden)

    Sukhoverkhov A. V.

    2015-01-01

    Full Text Available The main purpose of this study is to examine how language and its historically inherited content and structure allows accumulating knowledge and determines the development of the individuals, culture and science. The article shows the theoretical drawbacks of modern "pragmatic turn" in which language is depicted only as a derivate of natural, cultural and cognitive systems. Instead, it is stated that language, in addition to all of the above, have to be considered also as a relatively independent basis and one of the causes that determine individual and social development. For that reason, the study examines the system nature of language, thought and culture, their environmental and social "embeddiness", a close relationship with other sign systems and with various forms of social activities. From that point, theoretical reduction of multiple relations and varying causes in complex ecological and social systems only to bilateral relations of language-thought, language-culture are revised. Particular attention is paid to the role of language in the accumulation and systematization of scientific knowledge and the transmission of cultural traditions. In that context, language is seen as part of the non-genetic inheritance systems, "social a priori" that determines the content and creates conditions for cumulative social evolution. Therefore, it is maintained that the comprehensive studies of language and its significance for culture and science have to embrace within a systems approach both the linguistic and pragmatic "turns"

  10. Simulation of the cumulative hydrological response to green infrastructure

    Science.gov (United States)

    Avellaneda, P. M.; Jefferson, A. J.; Grieser, J. M.; Bush, S. A.

    2017-04-01

    In this study, we evaluated the cumulative hydrologic performance of green infrastructure in a residential area of the city of Parma, Ohio, draining to a tributary of the Cuyahoga River. Green infrastructure included the following spatially distributed devices: 16 street-side bioretention cells, 7 rain gardens, and 37 rain barrels. Data consisted of rainfall and outfall flow records for a wide range of storm events, including pretreatment and treatment periods. The Stormwater Management Model was calibrated and validated to predict the hydrologic response of green infrastructure. The calibrated model was used to quantify annual water budget alterations and discharge frequency over a 6 year simulation period. For the study catchment, we observed a treatment effect with increases of 1.4% in evaporation, 7.6% in infiltration, and a 9.0% reduction in surface runoff. The hydrologic performance of green infrastructure was evaluated by comparing the flow duration curve for pretreatment and treatment outfall flow scenarios. The flow duration curve shifted downward for the green infrastructure scenario. Discharges with a 0.5, 1, 2, and 5 year return period were reduced by an average of 29%. Parameter and predictive uncertainties were inspected by implementing a Bayesian statistical approach.

  11. A New Tool for Seismology--the Cumulative Spectral Power

    CERN Document Server

    Peters, Randall D

    2007-01-01

    The power spectral density (PSD) function is commonly used to specify seismometer performance. It is derived from the FFT of acceleration and correction is made for the transfer function of the instrument that generated the data. As with any such spectrum of density (`per Hz') type, the noise inherent to a PSD is large. This article illustrates the value of a function that is derived from the PSD and for which the influence of noise is significantly reduced. Called the cumulative spectral power (CSP), it is obtained from the PSD through the noise-reducing process of integration. The maximum of the CSP (corresponding to the longest graphed value of the period) provides a means for estimating the total vibrational power of the earth. The present author has significantly simplified the process of PSD generation. Thus routine graphing is straightforwared-of first the FFT, followed by the generation of both a PSD and its associated CSP. The unique properties of the CSP make it valuable for the study of a variety o...

  12. A shock process with a non-cumulative damage

    Energy Technology Data Exchange (ETDEWEB)

    Finkelstein, M.S.; Zarudnij, V.I

    2001-01-01

    Two types of non-cumulative damage shock models are considered. Based on the distribution of damage, caused by a shock effecting a system, the intervals with small, intermediate and large damage are introduced. The initial homogeneous Poisson shock process is split into three homogeneous Poisson processes and studied independently. Several criteria of failure are considered, based on the assumption that shocks with a small level of damage are harmless for a system, shocks with a large level of damage results in the system's failure and shocks with an intermediate level of damage can result in the system's failure only with some probability. The second model is based on an assumption that shocks with a small level of damage are harmless to a system, if they are not too close to each other. The probability of the system's failure-free performance in [0,t) is derived explicitly. Simple asymptotic exponential approximations are obtained The accuracy of this method is analyzed. Possible generalizations are discussed.

  13. Cumulative signal transmission in nonlinear reaction-diffusion networks.

    Directory of Open Access Journals (Sweden)

    Diego A Oyarzún

    Full Text Available Quantifying signal transmission in biochemical systems is key to uncover the mechanisms that cells use to control their responses to environmental stimuli. In this work we use the time-integral of chemical species as a measure of a network's ability to cumulatively transmit signals encoded in spatiotemporal concentrations. We identify a class of nonlinear reaction-diffusion networks in which the time-integrals of some species can be computed analytically. The derived time-integrals do not require knowledge of the solution of the reaction-diffusion equation, and we provide a simple graphical test to check if a given network belongs to the proposed class. The formulae for the time-integrals reveal how the kinetic parameters shape signal transmission in a network under spatiotemporal stimuli. We use these to show that a canonical complex-formation mechanism behaves as a spatial low-pass filter, the bandwidth of which is inversely proportional to the diffusion length of the ligand.

  14. New tests of cumulative prospect theory and the priority heuristic

    Directory of Open Access Journals (Sweden)

    Michael H. Birnbaum

    2008-04-01

    Full Text Available Previous tests of cumulative prospect theory (CPT and of the priority heuristic (PH found evidence contradicting these two models of risky decision making. However, those tests were criticized because they had characteristics that might ``trigger'' use of other heuristics. This paper presents new tests that avoid those characteristics. Expected values of the gambles are nearly equal in each choice. In addition, if a person followed expected value (EV, expected utility (EU, CPT, or PH in these tests, she would shift her preferences in the same direction as shifts in EV or EU. In contrast, the transfer of attention exchange model (TAX and a similarity model predict that people will reverse preferences in the opposite direction. Results contradict the PH, even when PH is modified to include a preliminary similarity evaluation using the PH parameters. New tests of probability-consequence interaction were also conducted. Strong interactions were observed, contrary to PH. These results add to the growing bodies of evidence showing that neither CPT nor PH is an accurate description of risky decision making.

  15. Cumulative creep fatigue damage in 316 stainless steel

    Science.gov (United States)

    Mcgaw, Michael A.

    1989-01-01

    The cumulative creep-fatigue damage behavior of 316 stainless steel at 1500 F was experimentally established for the two-level loading cases of fatigue followed by fatigue, creep fatigue followed by fatigue, and fatigue followed by creep fatigue. The two-level loadings were conducted such that the lower life (high strain) cycling was applied first for a controlled number of cycles and the higher life (low strain) cycling was conducted as the second level to failure. The target life levels in this study were 100 cycles to failure for both the fatigue and creep-fatigue lowlife loading, 5000 cycles to failure for the higher life fatigue loading and 10,000 cycles to failure for the higher life creep-fatigue loading. The failed specimens are being examined both fractographically and metallographically to ascertain the nature of the damaging mechanisms that produced failure. Models of creep-fatigue damage accumulation are being evaluated and knowledge of the various damaging mechanisms is necessary to ensure that predictive capability is instilled in the final failure model.

  16. Cumulative biological impacts of The Geysers geothermal development

    Energy Technology Data Exchange (ETDEWEB)

    Brownell, J.A.

    1981-10-01

    The cumulative nature of current and potential future biological impacts from full geothermal development in the steam-dominated portion of The Geysers-Calistoga KGRA are identified by the California Energy Commission staff. Vegetation, wildlife, and aquatic resources information have been reviewed and evaluated. Impacts and their significance are discussed and staff recommendations presented. Development of 3000 MW of electrical energy will result in direct vegetation losses of 2790 acres, based on an estimate of 11.5% loss per lease-hold of 0.93 acres/MW. If unmitigated, losses will be greater. Indirect vegetation losses and damage occur from steam emissions which contain elements (particularly boron) toxic to vegetation. Other potential impacts include chronic low-level boron exposure, acid rain, local climate modification, and mechanical damage. A potential exists for significant reduction and changes in wildlife from direct habitat loss and development influences. Highly erosive soils create the potential for significant reduction of aquatic resources, particularly game fish. Toxic spills have caused some temporary losses of aquatic species. Staff recommends monitoring and implementation of mitigation measures at all geothermal development stages.

  17. Cumulative Causation, Market Transition, and Emigration from China

    Science.gov (United States)

    Liang, Zai; Chunyu, Miao David; Zhuang, Guotu; Ye, Wenzhen

    2009-01-01

    In this paper, we report findings from a recent survey of international migration from China's Fujian province to the United States. We take advantage of the ethnosurvey approach as used in the Mexican Migration Project. Surveys were done in migrant-sending communities in China as well as in destination communities of New York City. We derive hypotheses from two strands of recent studies-the international migration literature and the market transition debate. Our results are in general consistent with hypotheses derived from cumulative causation of migration. However, because of the geographical location of China as compared to Mexico, there are some differences between the two countries in terms of particular migration patterns to the United States. As expected, at the community level, migration prevalence ratio (measuring migration networks) increases the propensity of migration for other members in the community. In contrast, having a household member migrated previously does not increase the propensity of migration of other household members until debt for previous migration is paid off. Our research clearly demonstrates the value of bringing the case of China into the comparative study of international migration. With respect to market transition theory, we find that political power continues to be an important factor in the order of social stratification in the coastal Fujian province. PMID:19569396

  18. Tin- and Lead-Based Perovskite Solar Cells under Scrutiny: An Environmental Perspective

    DEFF Research Database (Denmark)

    Serrano-Luján, Lucía; Espinosa Martinez, Nieves; Larsen-Olsen, Thue Trofod

    2015-01-01

    The effect of substituting lead with tin in perovskite-based solar cells (PSCs) has shows that lead is preferred over tin by a lower cumulative energy demand. The results, which also include end-of-life management, show that a recycling scenario that carefully handles emission of lead enables use...

  19. Lung cancer risk at low doses of alpha particles.

    Science.gov (United States)

    Hofmann, W; Katz, R; Zhang, C X

    1986-10-01

    A survey of inhabitant exposures arising from the inhalation of 222Rn and 220Rn progeny, and lung cancer mortality has been carried out in two adjacent areas in Guangdong Province, People's Republic of China, designated as the "high background" and the "control" area. Annual exposure rates are 0.38 working level months (WLM) per year in the high background, and 0.16 WLM/yr in the control area. In 14 yr of continuous study, from 1970 to 1983, age-adjusted mortality rates were found to be 2.7 per 10(5) living persons of all ages in the high background area, and 2.9 per 10(5) living persons in the control area. From this data, we conclude that we are unable to determine excess lung cancers over the normal fluctuations below a cumulative exposure of 15 WLM. This conclusion is supported by lung cancer mortality data from Austrian and Finnish high-background areas. A theoretical analysis of epidemiological data on human lung cancer incidence from inhaled 222Rn and 220Rn progeny, which takes into account cell killing as competitive with malignant transformation, leads to the evaluation of a risk factor which is either a linear-exponential or a quadratic-exponential function of the alpha-particle dose. Animal lung cancer data and theoretical considerations can be supplied to support either hypothesis. Thus we conclude that at our current stage of knowledge both the linear-exponential and the quadratic-exponential extrapolation to low doses seem to be equally acceptable for Rn-induced lung cancer risk, possibly suggesting a linear-quadratic transformation function with an exponential cell-killing term, or the influence of risk-modifying factors such as repair or proliferation stimuli.

  20. Tc-99 m diethylenetriamine-pentaacetic acid (DTPA): is it reliable for assessment of methotrexate-induced cumulative effect on renal filtration in rheumatoid arthritis patients?

    Science.gov (United States)

    Amin, Amr; Effat, Dina; Goher, Nabila; Ramadan, Basma

    2013-12-01

    Methotrexate (MTX) is commonly employed as the initial DMARD used for the treatment of rheumatoid arthritis (RA). We aimed to contribute to the safety profile of MTX by assessing its cumulative effect on renal filtration. A total of 52 RA adult female patients with normal baseline serum creatinine and GFR at the initial diagnosis of the disease were included. Group 1 (G1) included 30 patients (mean age 40.4 ± 4.4 years) on MTX and NSAIDS, while 22 RA patients (mean age 38.5 ± 8.2 years) who received NSAIDs only served as control group (G2). Renal function was assessed by GFR measurement using technetium diethylenetriamine-pentaacetic acid (Tc-99 m DTPA) at a point of the study time corresponding to disease duration. Twenty-one out of thirty (70 %) in G1 showed reduced GFR compared to 6/22 (27.3 %) in G2 (P = 0.007), with 3.3 ± 0.5 % annual reduction in GFR. Reduced GFR in G1 showed significant negative correlation with age (r = -0.396, P = 0.005), MTX cumulative dose (r = -0.263, P = 0.049), MTX-intake duration (r = -0.293, P = 0.031) and NSAIDs-intake duration (r = -0.344, P = 0.014). Low-dose MTX has a slow cumulative effect on renal filtration manifested by GFR reduction overtime that could be monitored by Tc-99 m DTPA.

  1. Teratogen update: lead and pregnancy.

    Science.gov (United States)

    Bellinger, David C

    2005-06-01

    This review focuses on the impacts of lead exposure on reproductive health and outcomes. High levels of paternal lead exposure (>40 microg/dl or >25 microg/dl for a period of years) appear to reduce fertility and to increase the risks of spontaneous abortion and reduced fetal growth (preterm delivery, low birth weight). Maternal blood lead levels of approximately 10 microg/dl have been linked to increased risks of pregnancy hypertension, spontaneous abortion, and reduced offspring neurobehavioral development. Somewhat higher maternal lead levels have been linked to reduced fetal growth. Some studies suggest a link between increased parental lead exposure and congenital malformations, although considerable uncertainty remains regarding the specific malformations and the dose-response relationships. Common methodological weaknesses of studies include potential exposure misclassifications due to the frequent unavailability of exposure biomarker measurements at biologically appropriate times and uncertainty regarding the best exposure biomarker(s) for the various outcomes. A special concern with regard to the pregnant woman is the possibility that a fetus might be exposed to lead mobilized from bone stores as a result of pregnancy-related metabolic changes, making fetal lead exposure the result of exposure to exogenous lead during pregnancy and exposure to endogenous lead accumulated by the woman prior to pregnancy. By reducing bone resorption, increased calcium intake during the second half of pregnancy might reduce the mobilization of lead from bone compartments, even at low blood lead levels. Subgroups of women who incurred substantial exposures to lead prior to pregnancy should be considered to be at increased risk.

  2. Acoustic dose and acoustic dose-rate.

    Science.gov (United States)

    Duck, Francis

    2009-10-01

    Acoustic dose is defined as the energy deposited by absorption of an acoustic wave per unit mass of the medium supporting the wave. Expressions for acoustic dose and acoustic dose-rate are given for plane-wave conditions, including temporal and frequency dependencies of energy deposition. The relationship between the acoustic dose-rate and the resulting temperature increase is explored, as is the relationship between acoustic dose-rate and radiation force. Energy transfer from the wave to the medium by means of acoustic cavitation is considered, and an approach is proposed in principle that could allow cavitation to be included within the proposed definitions of acoustic dose and acoustic dose-rate.

  3. Soil is an important pathway of human lead exposure.

    OpenAIRE

    Mielke, H W; Reagan, P L

    1998-01-01

    This review shows the equal or greater importance of leaded gasoline-contaminated dust compared to lead-based paint to the child lead problem, and that soil lead, resulting from leaded gasoline and pulverized lead-based paint, is at least or more important than lead-based paint (intact and not pulverized) as a pathway of human lead exposure. Because lead-based paint is a high-dose source, the biologically relevant dosage is similar to lead in soil. Both lead-based paint and soil lead are asso...

  4. Soil is an important pathway of human lead exposure.

    OpenAIRE

    Mielke, H W; Reagan, P L

    1998-01-01

    This review shows the equal or greater importance of leaded gasoline-contaminated dust compared to lead-based paint to the child lead problem, and that soil lead, resulting from leaded gasoline and pulverized lead-based paint, is at least or more important than lead-based paint (intact and not pulverized) as a pathway of human lead exposure. Because lead-based paint is a high-dose source, the biologically relevant dosage is similar to lead in soil. Both lead-based paint and soil lead are asso...

  5. Cumulative phase delay imaging - A new contrast enhanced ultrasound modality

    Energy Technology Data Exchange (ETDEWEB)

    Demi, Libertario, E-mail: l.demi@tue.nl; Sloun, Ruud J. G. van; Mischi, Massimo [Lab. of Biomedical Diagnostics, Dept. of Electrical Eng., Eindhoven University of Technology (Netherlands); Wijkstra, Hessel [Lab. of Biomedical Diagnostics, Dept. of Electrical Eng., Eindhoven University of Technology (Netherlands); Academic Medical Center, Urology Dept., University of Amsterdam (Netherlands)

    2015-10-28

    Recently, a new acoustic marker for ultrasound contrast agents (UCAs) has been introduced. A cumulative phase delay (CPD) between the second harmonic and fundamental pressure wave field components is in fact observable for ultrasound propagating through UCAs. This phenomenon is absent in the case of tissue nonlinearity and is dependent on insonating pressure and frequency, UCA concentration, and propagation path length through UCAs. In this paper, ultrasound images based on this marker are presented. The ULA-OP research platform, in combination with a LA332 linear array probe (Esaote, Firenze Italy), were used to image a gelatin phantom containing a PVC plate (used as a reflector) and a cylindrical cavity measuring 7 mm in diameter (placed in between the observation point and the PVC plate). The cavity contained a 240 µL/L SonoVueO{sup ®} UCA concentration. Two insonating frequencies (3 MHz and 2.5 MHz) were used to scan the gelatine phantom. A mechanical index MI = 0.07, measured in water at the cavity location with a HGL-0400 hydrophone (Onda, Sunnyvale, CA), was utilized. Processing the ultrasound signals backscattered from the plate, ultrasound images were generated in a tomographic fashion using the filtered back-projection method. As already observed in previous studies, significantly higher CPD values are measured when imaging at a frequency of 2.5 MHz, as compared to imaging at 3 MHz. In conclusion, these results confirm the applicability of the discussed CPD as a marker for contrast imaging. Comparison with standard contrast-enhanced ultrasound imaging modalities will be the focus of future work.

  6. CUMULATIVE IMPACT OF YOGA PRACTICE ON QUALITY OF LI FE

    Directory of Open Access Journals (Sweden)

    Usha Rani

    2013-05-01

    Full Text Available ABSTRACT: The present study was conducted with two main objec tives. First it aims to experiment whether the ancient system of yoga can bring about change in the quality of life of its practitioners. The second objective was to study the cumulative im pact of yoga practice on Quality of Life. The study was conducted on four independent groups of y oga practitioners that varied in their length of experience in yoga practice. The first group compri sed of 76 subjects (49 male and 27 female with a mean age of 39 years (SD=9.8. All the participan ts in this group are novice practitioners. They have participated in the study immediately after th eir admission into yoga class. The second group comprised of 23 subjects (14 male and 9 female wit h a mean age of 34.2 years (SD= 11.07. Their length of experience in yoga practice is 3 months. The third group comprised of 18 subjects (11male and 7 female with a mean age of 33.83 year s (SD=9.33. Their length of experience in yoga practice is six months. The fourth group comprised of 17 subjects (11 male and 6 female with a mean age of 32.8 years (SD=9.5. Their length exper ience is 12 months. All the four independent groups were administered a questionnaire on Quality of Life (WHOQOL-BREF. The results on QOL gave scores on to tal quality of life and separate scores on Domain 1 (dealing with physical health Domain 2 (d ealing with psychological aspects, Domain 3 (dealing with social relationships and Domain 4 (d ealing with environmental aspects.

  7. Measuring a fair and ambitious climate agreement using cumulative emissions

    Science.gov (United States)

    Peters, Glen P.; Andrew, Robbie M.; Solomon, Susan; Friedlingstein, Pierre

    2015-10-01

    Policy makers have called for a ‘fair and ambitious’ global climate agreement. Scientific constraints, such as the allowable carbon emissions to avoid exceeding a 2 °C global warming limit with 66% probability, can help define ambitious approaches to climate targets. However, fairly sharing the mitigation challenge to meet a global target involves human values rather than just scientific facts. We develop a framework based on cumulative emissions of carbon dioxide to compare the consistency of countries’ current emission pledges to the ambition of keeping global temperatures below 2 °C, and, further, compare two alternative methods of sharing the remaining emission allowance. We focus on the recent pledges and other official statements of the EU, USA, and China. The EU and US pledges are close to a 2 °C level of ambition only if the remaining emission allowance is distributed based on current emission shares, which is unlikely to be viewed as ‘fair and ambitious’ by others who presently emit less. China’s stated emissions target also differs from measures of global fairness, owing to emissions that continue to grow into the 2020s. We find that, combined, the EU, US, and Chinese pledges leave little room for other countries to emit CO2 if a 2 °C limit is the objective, essentially requiring all other countries to move towards per capita emissions 7 to 14 times lower than the EU, USA, or China by 2030. We argue that a fair and ambitious agreement for a 2 °C limit that would be globally inclusive and effective in the long term will require stronger mitigation than the goals currently proposed. Given such necessary and unprecedented mitigation and the current lack of availability of some key technologies, we suggest a new diplomatic effort directed at ensuring that the necessary technologies become available in the near future.

  8. Cumulative Effects of Barriers on the Movements of Forest Birds

    Directory of Open Access Journals (Sweden)

    Marc Bélisle

    2002-01-01

    Full Text Available Although there is a consensus of opinion that habitat fragmentation has deleterious effects on animal populations, primarily by inhibiting dispersal among remaining patches, there have been few explicit demonstrations of the ways by which degraded habitats actually constrain individual movement. Two impediments are primarily responsible for this paucity: it is difficult to separate the effects of habitat fragmentation (configuration from habitat loss (composition, and conventional measures of fragmented habitats are assumed to be, but probably are not, isotropic. We addressed these limitations by standardizing differences in forest cover in a clearly anisotropic configuration of habitat fragmentation by conducting a homing experiment with three species of forest birds in the Bow Valley of Banff National Park, Canada. Birds were translocated (1.2-3.5  km either parallel or perpendicular to four/five parallel barriers that are assumed to impede the cross-valley travel of forest-dependent animals. Taken together, individuals exhibited longer return times when they were translocated across these barriers, but differences among species suggest a more complex interpretation. A long-distance migrant (Yellow-rumped Warbler, Dendroica coronata behaved as predicted, but a short-distance migrant (Golden-crowned Kinglet, Regulus satrapa was indifferent to barrier configuration. A resident (Red-breasted Nuthatch, Sitta canadensis exhibited longer return times when it was translocated parallel to the barriers. Our results suggest that an anisotropic arrangement of small, open areas in fragmented landscapes can have a cumulative barrier effect on the movement of forest animals, but that both modelers and managers will have to acknowledge potentially counterintuitive differences among species to predict the effect that these may have on individual movement and, ultimately, dispersal.

  9. Use of Cumulative Examinations at U.S. Schools of Pharmacy.

    Science.gov (United States)

    Ryan, Gina J.; Nykamp, Diane

    2000-01-01

    Surveyed department of pharmacy chairs at 77 schools of pharmacy about current use of cumulative exams. Found that more than 80 percent do not administer cumulative exams and that the primary rationale for such exams is to encourage students to review material prior to advancement; they are rarely used to determine advancement. (EV)

  10. The Scarring Effects of Bankruptcy: Cumulative Disadvantage across Credit and Labor Markets

    Science.gov (United States)

    Maroto, Michelle

    2012-01-01

    As the recent economic crisis has demonstrated, inequality often spans credit and labor markets, supporting a system of cumulative disadvantage. Using data from the National Longitudinal Survey of Youth, this research draws on stigma, cumulative disadvantage and status characteristics theories to examine whether credit and labor markets intersect…

  11. Origin of path independence between cumulative CO2 emissions and global warming

    Science.gov (United States)

    Seshadri, Ashwin K.

    2017-02-01

    Observations and GCMs exhibit approximate proportionality between cumulative carbon dioxide (CO2 ) emissions and global warming. Here we identify sufficient conditions for the relationship between cumulative CO2 emissions and global warming to be independent of the path of CO2 emissions; referred to as "path independence". Our starting point is a closed form expression for global warming in a two-box energy balance model (EBM), which depends explicitly on cumulative emissions, airborne fraction and time. Path independence requires that this function can be approximated as depending on cumulative emissions alone. We show that path independence arises from weak constraints, occurring if the timescale for changes in cumulative emissions (equal to ratio between cumulative emissions and emissions rate) is small compared to the timescale for changes in airborne fraction (which depends on CO2 uptake), and also small relative to a derived climate model parameter called the damping-timescale, which is related to the rate at which deep-ocean warming affects global warming. Effects of uncertainties in the climate model and carbon cycle are examined. Large deep-ocean heat capacity in the Earth system is not necessary for path independence, which appears resilient to climate modeling uncertainties. However long time-constants in the Earth system carbon cycle are essential, ensuring that airborne fraction changes slowly with timescale much longer than the timescale for changes in cumulative emissions. Therefore path independence between cumulative emissions and warming cannot arise for short-lived greenhouse gases.

  12. Short- and Long-Term Effects of Cumulative Finals on Student Learning

    Science.gov (United States)

    Khanna, Maya M.; Brack, Amy S. Badura; Finken, Laura L.

    2013-01-01

    In two experiments, we examined the benefits of cumulative and noncumulative finals on students' short- and long-term course material retention. In Experiment 1, we examined results from course content exams administered immediately after course finals. Course sections including cumulative finals had higher content exam scores than sections…

  13. Cumulative effects of planned industrial development and climate change on marine ecosystems

    Directory of Open Access Journals (Sweden)

    Cathryn Clarke Murray

    2015-07-01

    Full Text Available With increasing human population, large scale climate changes, and the interaction of multiple stressors, understanding cumulative effects on marine ecosystems is increasingly important. Two major drivers of change in coastal and marine ecosystems are industrial developments with acute impacts on local ecosystems, and global climate change stressors with widespread impacts. We conducted a cumulative effects mapping analysis of the marine waters of British Columbia, Canada, under different scenarios: climate change and planned developments. At the coast-wide scale, climate change drove the largest change in cumulative effects with both widespread impacts and high vulnerability scores. Where the impacts of planned developments occur, planned industrial and pipeline activities had high cumulative effects, but the footprint of these effects was comparatively localized. Nearshore habitats were at greatest risk from planned industrial and pipeline activities; in particular, the impacts of planned pipelines on rocky intertidal habitats were predicted to cause the highest change in cumulative effects. This method of incorporating planned industrial development in cumulative effects mapping allows explicit comparison of different scenarios with the potential to be used in environmental impact assessments at various scales. Its use allows resource managers to consider cumulative effect hotspots when making decisions regarding industrial developments and avoid unacceptable cumulative effects. Management needs to consider both global and local stressors in managing marine ecosystems for the protection of biodiversity and the provisioning of ecosystem services.

  14. Aging and Cumulative Inequality: How Does Inequality Get Under the Skin?

    Science.gov (United States)

    Ferraro, Kenneth F.; Shippee, Tetyana Pylypiv

    2009-01-01

    Purpose: This article draws from cumulative disadvantage and life course theories to develop a new theory for the social scientific study of aging. Design and Methods: Five axioms of "cumulative inequality (CI) theory" are articulated to identify how life course trajectories are influenced by early and accumulated inequalities but can be modified…

  15. The Scarring Effects of Bankruptcy: Cumulative Disadvantage across Credit and Labor Markets

    Science.gov (United States)

    Maroto, Michelle

    2012-01-01

    As the recent economic crisis has demonstrated, inequality often spans credit and labor markets, supporting a system of cumulative disadvantage. Using data from the National Longitudinal Survey of Youth, this research draws on stigma, cumulative disadvantage and status characteristics theories to examine whether credit and labor markets intersect…

  16. Cumulative Advantage and Success-Breeds-Success: The Value of Time Pattern Analysis.

    Science.gov (United States)

    Huber, John C.

    1998-01-01

    For the case of the distribution of papers across authors, the Success-Breeds-Success or Cumulative Advantage model is a popular candidate for informetrics. The method of time pattern of publication for individual authors can be used to discriminate between Cumulative Advantage and non-uniform giftedness models. The non-uniform giftedness model is…

  17. 43 CFR 46.115 - Consideration of past actions in the analysis of cumulative effects.

    Science.gov (United States)

    2010-10-01

    ... Environmental Quality § 46.115 Consideration of past actions in the analysis of cumulative effects. When... Memorandum on Consideration of Past Actions in Cumulative Effects Analysis” dated June 24, 2005, or any... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Consideration of past actions in...

  18. UNIDIMENSIONALITY AND CUMULATIVENESS OF THE LONELINESS SCALE USING MOKKEN-SCALE-ANALYSIS FOR POLYCHOTOMOUS ITEMS

    NARCIS (Netherlands)

    MOORER, P; SUURMEIJER, TPBM

    1993-01-01

    The unidimensionality and cumulativeness of the Loneliness Scale of De Jong-Gierveld was investigated using the Mokken Scale Analysis for polychotomous items. 10 of the 11 items of the original Loneliness Scale constituted a unidimensional, cumulative scale, with a homogeneity coefficient H of 0.37

  19. The effects of antipoverty programs on children's cumulative level of poverty-related risk.

    Science.gov (United States)

    Gassman-Pines, Anna; Yoshikawa, Hirokazu

    2006-11-01

    The authors examined the effects of antipoverty programs on children's cumulative poverty-related risk and the relationship between cumulative poverty-related risk and child outcomes among low-income families. Samples included 419 children ages 3-10 years in the New Hope program and 759 children ages 2-9 years in the Minnesota Family Investment Program (MFIP), which tested 2 program approaches. Nine poverty-related risks made up the measure of cumulative risk. Both MFIP program approaches reduced cumulative poverty-related risk. New Hope reduced cumulative poverty-related risk among long-term welfare recipients. In both New Hope and MFIP, significant linear relationships between cumulative poverty-related risk and parent-reported behavior problems and school achievement were found. Cumulative poverty-related risk partially mediated the impacts of the MFIP programs on children's behavior problems. Among long-term welfare recipients, cumulative poverty-related risk partially mediated New Hope's impact on parent-reported school achievement.

  20. 14 CFR Section 18 - Objective Classification-Cumulative Effect of Changes in Accounting Principles

    Science.gov (United States)

    2010-01-01

    ... of Changes in Accounting Principles Section 18 Section 18 Aeronautics and Space OFFICE OF THE... Objective Classification—Cumulative Effect of Changes in Accounting Principles 98Cumulative Effect of Changes in Accounting Principles. Record here the difference between the amount of retained earnings...

  1. Asymptotic growth of cumulative and regenerative beam break-up instabilities in accelerators

    Science.gov (United States)

    Lau, Y. Y.

    1988-06-01

    It is found that the asymptotic growth of the cumulative beam break up instability is independent of the focusing magnetic field, according to the model of Panofsky and Bander. The analysis is extended to include the transition from the cumulative to the regenerative type, both in the presence and absence of a focusing magnetic field.

  2. A Cumulative Damage Reliability Model on the Basis of Contact Fatigue of the Rolling Bearing

    Institute of Scientific and Technical Information of China (English)

    HUANG Li

    2006-01-01

    A cumulative damage reliability model of contact fatigue of the rolling bearing is more identical with the actual conditions. It is put forward on the basis of contact fatigue life probability distribution of the rolling bearing that obey Weibull distribution and rest on the Miner cumulative damage theory. Finally a case is given to predict the reliability of bearing roller by using these models.

  3. Estimating multi-factor cumulative watershed effects on fish populations with an individual-based model

    Science.gov (United States)

    Bret C. Harvey; Steven F. Railsback

    2007-01-01

    While the concept of cumulative effects is prominent in legislation governing environmental management, the ability to estimate cumulative effects remains limited. One reason for this limitation is that important natural resources such as fish populations may exhibit complex responses to changes in environmental conditions, particularly to alteration of multiple...

  4. Countermeasures to Neurobehavioral Deficits from Cumulative Partial Sleep Deprivation During Space Flight

    Science.gov (United States)

    Dinges, David F.

    1999-01-01

    sleep attacks. The prevention of cumulative performance deficits and neuroendocrine disruption from sleep restriction during extended duration space flight involves finding the most effective ways to obtain sleep in order to maintain the high-level cognitive and physical performance functions required for manned space flight. There is currently a critical deficiency in knowledge of the effects of how variations in sleep duration and timing relate to the most efficient return of performance per unit time invested in sleep during long-duration missions, and how the nature of sleep physiology (i.e., sleep stages, sleep electroencephalographic [EEG] power spectral analyses) change as a function of sleep restriction and performance degradation. The primary aim of this project is to meet these critical deficiencies through utilization of a response surface experimental paradigm, testing in a dose-response manner, varying combinations of sleep duration and timing, for the purpose of establishing how to most effectively limit the cumulative adverse effects on human performance and physiology of chronic sleep restriction in space operations.

  5. Evaluation of Rectal Dose During High-Dose-Rate Intracavitary Brachytherapy for Cervical Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Sha, Rajib Lochan [Department of Radiation Physics, Indo-American Cancer Institute and Research Centre, Hyderabad (India); Department of Physics, Osmania University, Hyderabad (India); Reddy, Palreddy Yadagiri [Department of Physics, Osmania University, Hyderabad (India); Rao, Ramakrishna [Department of Radiation Physics, MNJ Institute of Oncology and Regional Cancer Center, Hyderabad (India); Muralidhar, Kanaparthy R. [Department of Radiation Physics, Indo-American Cancer Institute and Research Centre, Hyderabad (India); Kudchadker, Rajat J., E-mail: rkudchad@mdanderson.org [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)

    2011-01-01

    High-dose-rate intracavitary brachytherapy (HDR-ICBT) for carcinoma of the uterine cervix often results in high doses being delivered to surrounding organs at risk (OARs) such as the rectum and bladder. Therefore, it is important to accurately determine and closely monitor the dose delivered to these OARs. In this study, we measured the dose delivered to the rectum by intracavitary applications and compared this measured dose to the International Commission on Radiation Units and Measurements rectal reference point dose calculated by the treatment planning system (TPS). To measure the dose, we inserted a miniature (0.1 cm{sup 3}) ionization chamber into the rectum of 86 patients undergoing radiation therapy for cervical carcinoma. The response of the miniature chamber modified by 3 thin lead marker rings for identification purposes during imaging was also characterized. The difference between the TPS-calculated maximum dose and the measured dose was <5% in 52 patients, 5-10% in 26 patients, and 10-14% in 8 patients. The TPS-calculated maximum dose was typically higher than the measured dose. Our study indicates that it is possible to measure the rectal dose for cervical carcinoma patients undergoing HDR-ICBT. We also conclude that the dose delivered to the rectum can be reasonably predicted by the TPS-calculated dose.

  6. External dose reconstruction in tooth enamel of Techa riverside residents

    Energy Technology Data Exchange (ETDEWEB)

    Shishkina, E.A.; Volchkova, A.Yu.; Krivoschapov, V.A.; Degteva, M.O. [Urals Research Center for Radiation Medicine, Chelyabinsk (Russian Federation); Timofeev, Y.S.; Zalyapin, V.I. [Southern Urals State University, Chelyabinsk (Russian Federation); Fattibene, P.; Della Monaca, S.; De Coste, V. [Istituto Superiore di Sanita e Istituto Nazionale di Fisica Nucleare, Rome (Italy); Wieser, A. [Helmholtz Zentrum Muenchen, German Research Centre for Environmental Health, Neuherberg (Germany); Ivanov, D.V. [M.N. Mikheev Institute of Metal Physics, Ural Division of the Russian Academy of Sciences, Ekaterinburg (Russian Federation); Ural Federal University, Yekaterinburg (Russian Federation); Anspaugh, L.R. [University of Utah, Salt Lake City, UT (United States)

    2016-11-15

    This study summarizes the 20-year efforts for dose reconstruction in tooth enamel of the Techa riverside residents exposed to ionizing radiation as a result of radionuclide releases into the river in 1949-1956. It represents the first combined analysis of all the data available on EPR dosimetry with teeth of permanent residents of the Techa riverside territory. Results of electron paramagnetic resonance (EPR) measurements of 302 teeth donated by 173 individuals living permanently in Techa riverside settlements over the period of 1950-1952 were analyzed. These people were residents of villages located at the free-flowing river stream or at the banks of stagnant reservoirs such as ponds or blind river forks. Cumulative absorbed doses measured using EPR are from several sources of exposure, viz., background radiation, internal exposure due to bone-seeking radionuclides ({sup 89}Sr, {sup 90}Sr/{sup 90}Y), internal exposure due to {sup 137}Cs/{sup 137m}Ba incorporated in soft tissues, and anthropogenic external exposure. The purpose of the present study was to evaluate the contribution of different sources of enamel exposure and to deduce external doses to be used for validation of the Techa River Dosimetry System (TRDS). Since various EPR methods were used, harmonization of these methods was critical. Overall, the mean cumulative background dose was found to be 63 ± 47 mGy; cumulative internal doses due to {sup 89}Sr and {sup 90}Sr/{sup 90}Y were within the range of 10-110 mGy; cumulative internal doses due to {sup 137}Cs/{sup 137m}Ba depend on the distance from the site of releases and varied from 1 mGy up to 90 mGy; mean external doses were maximum for settlements located at the banks of stagnant reservoirs (∝500 mGy); in contrast, external doses for settlements located along the free-flowing river stream did not exceed 160 mGy and decreased downstream with increasing distance from the site of release. External enamel doses calculated using the TRDS code and

  7. Cumulative second-harmonic generation of Lamb waves propagating in a two-layered solid plate

    Institute of Scientific and Technical Information of China (English)

    Xiang Yan-Xun; Deng Ming-Xi

    2008-01-01

    The physical process of cumulative second-harmonic generation of Lamb waves propagating in a two-layered solid plate is presented by using the second-order perturbation and the technique of nonlinear reflection of acoustic waves at an interface.In general,the cumulative second-harmonic generation of a dispersive guided wave propagation does not occur.However,the present paper shows that the second-harmonic of Lamb wave propagation arising from the nonlinear interaction of the partial bulk acoustic waves and the restriction of the three boundaries of the solid plates does have a cumulative growth effect if some conditions are satisfied.Through boundary condition and initial condition of excitation,the analytical expression of cumulative second-harmonic of Lamb waves propagation is determined.Numerical results show the cumulative effect of Lamb waves on second-harmonic field patterns.

  8. Toxicity of Lead and Proposed Substitute Shot to Mallards

    Science.gov (United States)

    Longcore, J.R.; Andrews, R.; Locke, L.N.; Bagley, G.E.; Young, L.T.

    1974-01-01

    Poisoning of North American waterfowl resulting from the ingestion of lead shot by ducks, geese, and swans causes an estimated annual mortality of 2 to 3% of the population (Bellrose 1959). To alleviate this problem the search for a suitable substitute for lead has been underway since the early 1950's. Proposed substitutes for lead shot were evaluated in a series of acute toxicity tests with pen-reared mallards (Anas platyrhynchos). Most candidate materials were as toxic to ducks as commercial lead shot. Coating or alloying lead with other metals only delayed mortality among dosed ducks. The reputedly 'disintegrable' lead shot with the water-soluble binder and the lead containing biochemical additives were also as toxic to mallards as the commercial lead shot. Mortality was not significantly different among lead-dosed adult or first-year hen and drake pen-reared mallards; lead-dosed adult, wild mallards of both sexes; and lead-dosed adult, male black ducks (Anas rubripes). The ingestion of one lead shot, size 4, by each of 80 pen-reared mallards caused an average 19% mortality. The presence and type of grit in the gizzard had a measurable effect on erosion of ingested shot and on shot retention among dosed mallards. Significantly fewer lead-dosed ducks died when fed crushed oystershell grit than when fed either quartz grit or no grit.

  9. Patient cumulative radiation exposure in interventional cardiology; Exposition cumulee aux rayonnements ionisants des patients en cardiologie interventionnelle: caracteristiques cliniques et dosimetriques

    Energy Technology Data Exchange (ETDEWEB)

    Bernier, M.O.; Jacob, S.; Laurier, D. [Institut de radioprotection et de surete nucleaire (IRSN), DRPH, SRBE, LEPID, Fontenay-aux-Roses (France); Maccia, C. [Centre d' assurance de qualite des applications technologiques dans le domaine de la sante - CAATS, Bourg-la-Reine (France); Bar, O.; Blanchard, D. [Clinique Saint-Gatien, Tours (France); Catelinois, O. [Institut de veille sanitaire, St Maurice (France)

    2012-01-15

    Interventional cardiology procedures can involve potentially high doses of radiation to the patients. Stochastic effects of ionising radiation - radiation-induced cancers in the long term - may occur. We analysed clinical characteristics and dosimetric data in a population of patients undergoing interventional cardiology. In all, 1 591 patients who had undergone coronarography and/or angioplasty in the course of a year at the Saint-Gatien Clinic in Tours (France) were included. Information on patients' individual clinical characteristics and Dose-Area Product values were collected. Organ doses to the lung, oesophagus, bone marrow and breast were mathematically evaluated. The median age of patients was 70 years. Their median cumulative dose-area product value was 48.4 Gy.cm{sup 2} for the whole year and the median effective dose was 9.7 mSv. The median organ doses were 41 mGy for the lung, 31 mGy for the oesophagus, 10 mGy for the bone marrow and 4 mGy for the breast. Levels of doses close to the heart appear to be rather high in the case of repeated interventional cardiology procedures. Clinical characteristics should be taken into account when planning epidemiological studies on potential radiation-induced cancers. (authors)

  10. Benchmark Dose Modeling

    Science.gov (United States)

    Finite doses are employed in experimental toxicology studies. Under the traditional methodology, the point of departure (POD) value for low dose extrapolation is identified as one of these doses. Dose spacing necessarily precludes a more accurate description of the POD value. ...

  11. Comparative evaluation of bioprotective action of zinc in organic and inorganicform on osteotropism of lead in experimental conditions

    Directory of Open Access Journals (Sweden)

    Biletska E.M.

    2016-12-01

    Full Text Available Chemical aggression of technogenic pollution of the environment, according to experts, is the leading risk factor for population health. A systematic entry of contaminants in the related life-supporting environments – air, water, plant and animal food products by direct and indirect migration chains creates both integrated and combined effect on the body. It should be noted that a chemical factor, on the one hand, is the least studied in this respect, on the other hand it represents the most significant and rapidly growing environmental threat to human health. In the human body bone tissue has the highest cumulative properties against many xenobiotics, in particular to heavy metals, among which lead is the leader in relationship to the bone tissue. In this regard, the goal is to study peculiarities of different forms of zinc on calcium content in bone tissue in lead intoxication. As a result of researches it is established that low dosed effect of lead during subacute experience causes a significant decrease of calcium content in the bone tissue by 28% in comparison with those of control group of animals, this reduces its density and becomes a risk factor for the development of osteopenic and osteoporotic state of the organism. Combined effect of lead and organic and inorganic forms of zinc zeliably increases calcium content by 16.43% and 22,04% respectively, as compared with lead group, suggesting protective properties of zinc in lead intoxication due to the effect of bioantagonism. In the isolated introduction of organic and inorganic forms of zinc, calcium content in the bone tissue increases by 1.4 and 2.04 times respectively, as compared with the control group. The obtained results confirm osteoprotective action of zinc, particularly of organic forms in lead intoxication and give reason to believe that in the system "lead – zinc" effect of biological antagonism is formed.

  12. Therapeutic potential of intermittent hypoxia: a matter of dose.

    Science.gov (United States)

    Navarrete-Opazo, Angela; Mitchell, Gordon S

    2014-11-15

    Intermittent hypoxia (IH) has been the subject of considerable research in recent years, and triggers a bewildering array of both detrimental and beneficial effects in multiple physiological systems. Here, we review the extensive literature concerning IH and its impact on the respiratory, cardiovascular, immune, metabolic, bone, and nervous systems. One major goal is to define relevant IH characteristics leading to safe, protective, and/or therapeutic effects vs. pathogenesis. To understand the impact of IH, it is essential to define critical characteristics of the IH protocol under investigation, including potentially the severity of hypoxia within episodes, the duration of hypoxic episodes, the number of hypoxic episodes per day, the pattern of presentation across time (e.g., within vs. consecutive vs. alternating days), and the cumulative time of exposure. Not surprisingly, severe/chronic IH protocols tend to be pathogenic, whereas any beneficial effects are more likely to arise from modest/acute IH exposures. Features of the IH protocol most highly associated with beneficial vs. pathogenic outcomes include the level of hypoxemia within episodes and the number of episodes per day. Modest hypoxia (9-16% inspired O2) and low cycle numbers (3-15 episodes per day) most often lead to beneficial effects without pathology, whereas severe hypoxia (2-8% inspired O2) and more episodes per day (48-2,400 episodes/day) elicit progressively greater pathology. Accumulating evidence suggests that "low dose" IH (modest hypoxia, few episodes) may be a simple, safe, and effective treatment with considerable therapeutic potential for multiple clinical disorders.

  13. Lead Poisoning Prevention Tips

    Science.gov (United States)

    ... or removed safely. How are children exposed to lead? Lead-based paint and lead contaminated dust are ... What can be done to prevent exposure to lead? It is important to determine the construction year ...

  14. Lead (Pb) Air Pollution

    Science.gov (United States)

    ... States Environmental Protection Agency Search Search Lead (Pb) Air Pollution Share Facebook Twitter Google+ Pinterest Contact Us As ... and protect aquatic and terrestrial ecosystems. Lead (Pb) Air Pollution Lead Air Pollution Basics How does lead get ...

  15. Predicting Cumulative Watershed Effects using Spatially Explicit Models

    Science.gov (United States)

    MacDonald, L. H.; Litschert, S.

    2004-12-01

    Cumulative watershed effects /(CWEs/) result from the combined effects of land disturbances distributed over both space and time. They are of concern because changes in flow and sediment yields can adversely affect aquatic habitat, channel morphology, water yields, and water quality. The assessment procedures currently used by agencies such as the U.S. Forest Service generally rely on a lumped approach to quantify disturbance, despite the widespread recognition that site conditions and location do matter! The overall goal of our work is to develop spatially-explicit models to quantify changes in flow and sediment yields. Key objectives include: use of readily available GIS data; ease of use for resource managers with minimal GIS experience; modularity so that models can be added or updated; and allowing users to select the models and values for key parameters. The DeltaQ model calculates changes in peak, median, and low flows due to forest management activities and fires. Inputs include GIS data with disturbance polygons, an initial change in flow rate, and the time to recovery. Data from paired watershed studies are provided to help guide the user. The initial version of FORest Erosion Simulation Tools /(FOREST/) calculates sediment production from forest harvest, fires, and unpaved roads. Additional modules are being developed to deliver this sediment to the stream channel and route it to downstream locations. In accordance with our objectives, the user can predict sediment production rates using different empirical equations, assign an initial sediment production rate and a specified linear recovery period, or develop a look-up table based on local knowledge, published values, or data from other models such as WEPP. The required GIS layers vary according to the model/(s/) selected, but generally include past disturbances /(e.g., fires and timber harvest/), roads, and elevation. Outputs include GIS layers and text files that can be subjected to additional

  16. Using the {sup 60}Co source to assess the dose received by risky organs during a cancer brain treatment; L'utilisation de la source {sup 60}Co pour evaluer la dose recue par les organes a risques au cours d'un traitement cerebral de cancer

    Energy Technology Data Exchange (ETDEWEB)

    Faik Ouahab, Z.; Jehouani, A.; Ghassoun, J.; Senhou, N. [EPRA, Departement of Physics, Cadi Ayyad University, Faculty of Science, Semlalia, BP. 2390, Marrakech (Morocco); Mouhssine, D. [Centre de traitement Al Kindy, Bd ibn Sina 2 et 3 Rue Al Kindy 20000, Casablanca (Morocco); Groetz, J.E. [Universite de Franche-Comte, Laboratoire de Chimie Physique et Rayonnements Alain Chambaudet, UMR CEA E4, 16, route de Gray, 25030 Besancon Cedex (France)

    2010-07-01

    Summary of an investigation of exposures associated with brain cancer treatment for a child in order to determine the level of doses received by the different organs at risk during the treatment. Measurements have been performed at the vicinity of a cobalto therapy apparatus. Then, cumulative doses in each organ have been compared to admitted doses with respect to the organ

  17. Adult learning and social inequalities: Processes of equalisation or cumulative disadvantage?

    Science.gov (United States)

    Kilpi-Jakonen, Elina; Vono de Vilhena, Daniela; Blossfeld, Hans-Peter

    2015-08-01

    Adult learning is an increasingly important form of education in globalised and aging societies. While current policy recommendations tend to focus on increasing participation rates, the authors of this article argue that higher participation rates do not necessarily lead to lower social/educational inequalities in participation. The aim of this paper is to examine the relationship between social inequalities and adult learning by exploring cross-national patterns of participation in different adult learning activities and the consequences of participation on individual labour market trajectories. The empirical basis of the paper is an analysis of 13 country studies (as well as two cross-national analyses) brought together by the international comparative research project "Education as a lifelong process - comparing educational trajectories in modern societies" ( eduLIFE). Despite wide variations in participation rates across countries, mechanisms of social/educational inequality in engagement in job-related adult learning tend to be relatively similar across countries, in particular with regard to non-formal learning. Effects tend most frequently to be a presence of cumulative advantage, though in some countries a certain degree of equalisation is noticeable with regard to formal adult education. The authors conclude that it is relatively clear that currently almost no country is truly able to reduce social inequalities through adult learning. Their recommendation is that public policy makers should place greater emphasis on making adult learning more accessible (in terms of entry requirements, affordability as well as motivation) to underrepresented groups, in particular those who are educationally disadvantaged.

  18. The cumulative effects of using fine particles and cyanobacteria for rehabilitation of disturbed active sand dunes

    Science.gov (United States)

    Zaady, Eli; Katra, Itzhak; Barkai, Daniel; Knoll, Yaakov; Sarig, Shlomo

    2016-04-01

    One of the main problems in desertified lands worldwide is active wind-borne sand dunes, which lead to covering of fertile soils and agricultural fields. In regions with more than 100 mm of annual rainfall, sand dunes may be naturally stabilized by biocrusts (biological soil crusts). One of the main restraints of biocrust development is the typical lack of fine particles in sand dunes. Our study investigated the combined application of fine particles [coal fly-ash <100 micrometer] and bio-inoculant of filamentous cyanobacteria, isolated from nearby natural stabilized sand dunes, on the soil surface of active sands for increasing resistance to wind erosion. Boundary-layer wind tunnel experiments were conducted in experimental plots within a greenhouse for examining the effects of adding coal fly-ash and bio-inoculant to active sands. The biocrust development was evaluated via several physical and bio-physiological variables. In all the physical measurements and the bio-physiological variables, the treatment of "sand+inoculum+coal fly-ash" showed significant differences from the "sand-control". The combination led to the best results of surface stabilization in boundary-layer wind tunnel experiments, with the lowest sand fluxes. The filamentous cyanobacteria use the fine particles of the coal fly-ash as bridges for growing toward and adhering to the large sand particles. The cumulative effects of biocrusts and coal fly-ash enhance soil surface stabilization and may allow long-term sustainability.

  19. A global review of cumulative pressure and impact assessments in marine environment

    Directory of Open Access Journals (Sweden)

    Samuli Korpinen

    2016-08-01

    Full Text Available Ever more extensive use of marine space by human activities and greater demands for marine natural resources has led to increases in both duration and spatial extent of pressures on the marine environment. In parallel, the global crisis of decreasing biodiversity and loss of habitats has revitalized scientific research on human impacts and lead to methodological development of cumulative pressure and impact assessments (CPIA. In Europe alone, almost twenty CPIAs have been published in the past 10 years and some more in other sea regions of the world. In this review, we have analysed 36 recent marine CPIAs and focused on their methodological approaches. We were especially interested in uncovering methodological similarities, identifying best practices and analysing whether the CPIAs have addressed the recent criticism. The review results showed surprisingly similar methodological approaches in >50% of the studies, raising hopes for finding coherence in international assessment efforts. Although the CPIA methods showed relatively few innovative approaches for addressing the major caveats of previous CPIAs, the most recent studies indicate that improved approaches may be soon found.

  20. Fluid Overload and Cumulative Thoracostomy Output Are Associated With Surgical Site Infection After Pediatric Cardiothoracic Surgery.

    Science.gov (United States)

    Sochet, Anthony A; Nyhan, Aoibhinn; Spaeder, Michael C; Cartron, Alexander M; Song, Xiaoyan; Klugman, Darren; Brown, Anna T

    2017-08-01

    To determine the impact of cumulative, postoperative thoracostomy output, amount of bolus IV fluids and peak fluid overload on the incidence and odds of developing a deep surgical site infection following pediatric cardiothoracic surgery. A single-center, nested, retrospective, matched case-control study. A 26-bed cardiac ICU in a 303-bed tertiary care pediatric hospital. Cases with deep surgical site infection following cardiothoracic surgery were identified retrospectively from January 2010 through December 2013 and individually matched to controls at a ratio of 1:2 by age, gender, Risk Adjustment for Congenital Heart Surgery score, Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery category, primary cardiac diagnosis, and procedure. None. Twelve cases with deep surgical site infection were identified and matched to 24 controls without detectable differences in perioperative clinical characteristics. Deep surgical site infection cases had larger thoracostomy output and bolus IV fluid volumes at 6, 24, and 48 hours postoperatively compared with controls. For every 1 mL/kg of thoracostomy output, the odds of developing a deep surgical site infection increase by 13%. By receiver operative characteristic curve analysis, a cutoff of 49 mL/kg of thoracostomy output at 48 hours best discriminates the development of deep surgical site infection (sensitivity 83%, specificity 83%). Peak fluid overload was greater in cases than matched controls (12.5% vs 6%; p thoracostomy output were associated with deep surgical site infection after pediatric cardiothoracic surgery. We suspect the observed increased thoracostomy output, fluid overload, and IV fluid boluses may have altered antimicrobial prophylaxis. Although analysis of additional pharmacokinetic data is warranted, providers may consider modification of antimicrobial prophylaxis dosing or alterations in fluid management and diuresis in response to assessment of peak fluid overload and fluid

  1. Cumulative sessions of repetitive transcranial magnetic stimulation (rTMS) build up facilitation to subsequent TMS-mediated behavioural disruptions.

    Science.gov (United States)

    Valero-Cabré, Antoni; Pascual-Leone, Alvaro; Rushmore, Richard J

    2008-02-01

    A single session of repetitive transcranial magnetic stimulation (rTMS) can induce behavioural effects that outlast the duration of the stimulation train itself (off-line effects). Series of rTMS sessions on consecutive days are being used for therapeutic applications in a variety of disorders and are assumed to lead to the build-up of cumulative effects. However, no studies have carefully assessed this notion. In the present study we applied 30 daily sessions of 1 Hz rTMS (continuous train of 20 min) to repeatedly modulate activity in the posterior parietal cortex and associated neural systems in two intact cats. We assessed the effect on visuospatial orientation before and after each stimulation session. Cumulative sessions of rTMS progressively induced visuospatial neglect-like 'after-effects' of greater magnitude (from 5-10% to 40-50% error levels) and increasing spatial extent (from 90-75 degrees to 45-30 degrees eccentricity locations), affecting the visual hemifield contralateral to the stimulated hemisphere. Nonetheless, 60 min after each TMS session, visual detection-localization abilities repeatedly returned to baseline levels. Furthermore, no lasting behavioural effect could be demonstrated at any time across the study, when subjects were tested 1 or 24 h post-rTMS. We conclude that the past history of periodically cumulative rTMS sessions builds up a lasting 'memory', resulting in increased facilitation to subsequent TMS-induced disruptions. Such a phenomenon allows a behavioural effect of progressively higher magnitude, but equal duration, in response to individual TMS interventions.

  2. Dual guidance (CT and fluoroscopy) vertebroplasty: radiation dose to radiologists. How much and where?

    Energy Technology Data Exchange (ETDEWEB)

    Amoretti, Nicolas; Lesbats, Virginie; Marcy, Pierre-Yves; Amoretti, Marie-eve; Maratos, Yvonne; Ianessi, Antoine; Boileau, Pascal [Centre hospitalier universitaire, Radiology Department, Nice (France); Hauger, Olivier [CHU de Bordeaux, Unite d' Imagerie Osteo-articulaire, Hopital Pellegrin, Bordeaux (France)

    2010-12-15

    The goal of this study was to evaluate the radiation received by the practitioner when performing percutaneous vertebroplasty guided by CT and fluoroscopy for specific anatomical sites: orbits, hands, ankles, and thorax (under lead-lined apron). Twenty-four vertebroplasties were performed on 18 patients. The anatomical site that was most exposed to radiation was the right hand (0.37 mSv on average). This study demonstrates a significant correlation between the irradiation dose and fluoroscopy duration, reflecting both the quantity of primary-beam radiation and backscattered radiation. The right hand (P = 0.03), left hand (P = 0.02), and the left orbit (P < 0.0001) are the anatomical zones that are the most affected by the combination of these two types of radiation, with cumulative irradiation doses of 0.45, 0.2, and 0.14 mSv, respectively. There was a significant correlation between the patient weight and radiation of the left hand (P = 0.03), the left orbit (P = 0.03), and the thorax (P = 0.02), confirming the major influence of backscattered radiation. The most irradiated anatomical sites limiting the number of interventions are the left orbit and the right hand. (orig.)

  3. Assessing environmental impacts on stream water quality: the use of cumulative flux and cumulative flux difference approaches to deforestation of the Hafren Forest, mid-Wales

    Directory of Open Access Journals (Sweden)

    C. Neal

    2002-01-01

    Full Text Available A method for examining the impacts of disturbance on stream water quality based on paired catchment “controlâ€? and “responseâ€? water quality time series is described in relation to diagrams of cumulative flux and cumulative flux difference. The paper describes the equations used and illustrates the patterns expected for idealised flux changes followed by an application to stream water quality data for a spruce forested catchment, the Hore, subjected to clear fell. The water quality determinands examined are sodium, chloride, nitrate, calcium and acid neutralisation capacity. The anticipated effects of felling are shown in relation to reduction in mist capture and nitrate release with felling as well as to the influence of weathering and cation exchange mechanisms, but in a much clearer way than observed previously using other approaches. Keywords: Plynlimon, stream, Hore, acid neutralisation capacity, calcium, chloride, nitrate, sodium, cumulative flux, flux

  4. Elaboration of a concept for the cumulative environmental exposure assessment of biocides

    Energy Technology Data Exchange (ETDEWEB)

    Gross, Rita; Bunke, Dirk; Moch, Katja [Oeko-Institut e.V. - Institut fuer Angewandte Oekologie e.V., Freiburg im Breisgau (Germany); Gartiser, Stefan [Hydrotox GmbH, Freiburg im Breisgau (Germany)

    2011-12-15

    Article 10(1) of the EU Biocidal Products Directive 98/8/EC (BPD) requires that for the inclusion of an active substance in Annex I, Annex IA or IB, cumulation effects from the use of biocidal products containing the same active substance shall be taken into account, where relevant. The study proves the feasibility of a technical realisation of Article 10(1) of the BPD and elaborates a first concept for the cumulative environmental exposure assessment of biocides. Existing requirements concerning cumulative assessments in other regulatory frameworks have been evaluated and their applicability for biocides has been examined. Technical terms and definitions used in this context were documented with the aim to harmonise terminology with other frameworks and to set up a precise definition within the BPD. Furthermore, application conditions of biocidal products have been analysed to find out for which cumulative exposure assessments may be relevant. Different parameters were identified which might serve as indicators for the relevance of cumulative exposure assessments. These indicators were then integrated in a flow chart by means of which the relevance of cumulative exposure assessments can be checked. Finally, proposals for the technical performance of cumulative exposure assessments within the Review Programme have been elaborated with the aim to bring the results of the project into the upcoming development and harmonization processes on EU level. (orig.)

  5. The cumulative semantic cost does not reflect lexical selection by competition☆

    Science.gov (United States)

    Navarrete, Eduardo; Mahon, Bradford Z.; Caramazza, Alfonso

    2010-01-01

    The cumulative semantic cost describes a phenomenon in which picture naming latencies increase monotonically with each additional within-category item that is named in a sequence of pictures. Here we test whether the cumulative semantic cost requires the assumption of lexical selection by competition. In Experiment 1 participants named a sequence of pictures, while in Experiment 2 participants named words instead of pictures, preceded by a gender marked determiner. We replicate the basic cumulative semantic cost with pictures (Exp. 1) and show that there is no cumulative semantic cost for word targets (Exp. 2). This pattern was replicated in Experiment 3 in which pictures and words were named along with their gender marked definite determiner, and were intermingled within the same experimental design. In addition, Experiment 3 showed that while picture naming induces a cumulative semantic cost for subsequently named words, word naming does not induce a cumulative semantic cost for subsequently named pictures. These findings suggest that the cumulative semantic cost arises prior to lexical selection and that the effect arises due to incremental changes to the connection weights between semantic and lexical representations. PMID:20347062

  6. Lead Aprons Are a Lead Exposure Hazard.

    Science.gov (United States)

    Burns, Kevin M; Shoag, Jamie M; Kahlon, Sukhraj S; Parsons, Patrick J; Bijur, Polly E; Taragin, Benjamin H; Markowitz, Morri

    2017-05-01

    To determine whether lead-containing shields have lead dust on the external surface. Institutional review board approval was obtained for this descriptive study of a convenience sample of 172 shields. Each shield was tested for external lead dust via a qualitative rapid on-site test and a laboratory-based quantitative dust wipe analysis, flame atomic absorption spectrometry (FAAS). The χ(2) test was used to test the association with age, type of shield, lead sheet thickness, storage method, and visual and radiographic appearance. Sixty-three percent (95% confidence interval [CI]: 56%-70%) of the shields had detectable surface lead by FAAS and 50% (95% CI: 43%-57%) by the qualitative method. Lead dust by FAAS ranged from undetectable to 998 μg/ft(2). The quantitative detection of lead was significantly associated with the following: (1) visual appearance of the shield (1 = best, 3 = worst): 88% of shields that scored 3 had detectable dust lead; (2) type of shield: a greater proportion of the pediatric patient, full-body, and thyroid shields were positive than vests and skirts; (3) use of a hanger for storage: 27% of shields on a hanger were positive versus 67% not on hangers. Radiographic determination of shield intactness, thickness of interior lead sheets, and age of shield were unrelated to presence of surface dust lead. Sixty-three percent of shields had detectable surface lead that was associated with visual appearance, type of shield, and storage method. Lead-containing shields are a newly identified, potentially widespread source of lead exposure in the health industry. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  7. Purine metabolism in patients with gout: the role of lead.

    Science.gov (United States)

    Miranda-Carús, E; Mateos, F A; Sanz, A G; Herrero, E; Ramos, T; Puig, J G

    1997-01-01

    Primary gout is characterized by increased plasma and decreased urinary concentrations of hypoxanthine, xanthine and uric acid. To examine whether lead could explain the disturbance of purine metabolism in gout, we determined hypoxanthine, xanthine and uric acid metabolism and 5-day cumulative urinary lead excretion rates after an EDTA (calcium disodium edetate) test in 27 patients with primary gout and reduced creatinine clearance (C(cr)) and in 50 patients with gout and normal C(cr). The results were compared to those obtained in 26 normal subjects matched for age. All gout patients evidenced a marked renal underexcretion of hypoxanthine, xanthine and uric acid relative to their increased plasma levels. Purine metabolism was remarkably similar in both gout groups except for a significantly lower uric acid excretion in patients with reduced C(cr). Blood lead levels and cumulative lead excretion rates were significantly higher in gout patients with renal failure as compared to patients with normal C(cr). Fourteen patients (52%) with renal insufficiency and 6 (12%) with normal C(cr) showed increased lead excretion rates (95% Cl for the difference, 29-51%, p < 0.001). Mobilizable lead was not significantly correlated with serum or urinary purine concentrations. Hypoxanthine, xanthine and uric acid underexcretion was similar in gout patients with increased or normal cumulative lead excretion rates. The prevalence of atheromatosis and arterial hypertension together was significantly higher in gout patients with renal failure than in patients with normal C(cr) (81 vs. 60%, 95% Cl for the difference, 11-31%, p < 0.005). These results indicate that lead is not a significant contributor to the renal underexcretion of purines in gout. An increased mobilizable lead is not by itself evidence that lead is the cause of the renal insufficiency in patients with primary gout. Atheromatous nephropathy and/or nephroangiosclerosis may explain impaired renal function in patients with

  8. Oil spill characterization in the hybrid polarity SAR domain using log-cumulants

    Science.gov (United States)

    Espeseth, Martine M.; Skrunes, Stine; Brekke, Camilla; Salberg, Arnt-Børre; Jones, Cathleen E.; Holt, Benjamin

    2016-10-01

    Log-cumulants have proven to be an interesting tool for evaluating the statistical properties of potential oil spills in polarimetric Synthetic Aperture Radar (SAR) data within the common horizontal (H) and vertical (V) polarization basis. The use of first, second, and third order sample log-cumulants has shown potential for evaluating the texture and the statistical distributions, as well as discriminating oil from look-alikes. Log-cumulants are cumulants derived in the log-domain and can be applied to both single-polarization and multipolarization SAR data. This study is the first to investigate the differences between hybrid-polarity (HP) and full-polarimetric (FP) modes based on the sample log-cumulants of various oil slicks and open water from nine Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) scenes acquired off the coast of Norway in 2015. The sample log-cumulants calculated from the HP intensities show similar statistical behavior to the FP ones, resulting in a similar interpretation of the sample log-cumulants from HP and FP. Approximately eight hours after release the sample log-cumulants representing emulsion slicks have become more similar to the open water compared to plant oil. We find that the sample log-cumulants of the various oil slicks and open water varies between the scenes and also between the slicks and open water. This might be due to changes in ocean and wind condition, the initial slick properties, and/or the difference in the weathering process of the oil slicks.

  9. Cumulative Measurement Errors for Dynamic Testing of Space Flight Hardware

    Science.gov (United States)

    Winnitoy, Susan

    2012-01-01

    measurements during hardware motion and contact. While performing dynamic testing of an active docking system, researchers found that the data from the motion platform, test hardware and two external measurement systems exhibited frame offsets and rotational errors. While the errors were relatively small when considering the motion scale overall, they substantially exceeded the individual accuracies for each component. After evaluating both the static and dynamic measurements, researchers found that the static measurements introduced significantly more error into the system than the dynamic measurements even though, in theory, the static measurement errors should be smaller than the dynamic. In several cases, the magnitude of the errors varied widely for the static measurements. Upon further investigation, researchers found the larger errors to be a consequence of hardware alignment issues, frame location and measurement technique whereas the smaller errors were dependent on the number of measurement points. This paper details and quantifies the individual and cumulative errors of the docking system and describes methods for reducing the overall measurement error. The overall quality of the dynamic docking tests for flight hardware verification was improved by implementing these error reductions.

  10. Assessment of radiation doses due to normal operation, incidents and accidents of the final disposal facility; Kaeytetyn ydinpolttoaineen loppusijoituslaitoksen normaalikaeytoen, kaeyttoehaeirioeiden ja onnettomuustilanteiden aiheuttamien saeteilyannosten arviointi

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, J.; Raiko, H.; Suolanen, V.; Ilvonen, M. [VTT Energy, Espoo (Finland)

    1999-03-01

    Radiation doses for workers of the encapsulation and disposal facility and for inhabitants in the environment caused by the facility during its operation were considered. The study covers both the normal operation of the plant and some hypothetical incidents and accidents. Occupational radiation doses inside the plant during normal operation are based on the design basis, assuming that highest permitted dose levels are prevailing in control rooms during fuel transfer and encapsulation processes. Release through the ventilation stack is assumed to be filtered both in normal operation and in hypothetical incident and accident cases. Calculation of the offsite doses from normal operation is based on the hypothesis that one fuel pin per 100 fuel bundles for all batches of spent fuel transported to the encapsulation facility is leaking. The release magnitude in incidents and accidents is based on the event chains, which lead to loss of fuel pin tightness followed by a discharge of radionuclides into the handling chamber and to some degree through the ventilation stack into atmosphere. The weather data measured at the Olkiluoto meteorological mast was employed for calculating of offsite doses. Therefore doses could be calculated in a large amount of different dispersion conditions, the statistical frequencies of which have, been measured. Finally doses were combined into cumulative distributions, from which a dose value representing the 99.5 % confidence level, is presented. The dose values represent the exposure of a critical group, which is assumed to live at the distance of 200 meters from the encapsulation and disposal plant and thus it will receive the largest doses in most dispersion conditions. Exposure pathways considered were: cloudsnine, inhalation, groundshine and nutrition (milk of cow, meat of cow, green vegetables, grain and root vegetables). Nordic seasonal variation is included in ingestion dose models. The results obtained indicate that offsite doses

  11. Assessing patient dose in interventional fluoroscopy using patient-dependent hybrid phantoms

    Science.gov (United States)

    Johnson, Perry Barnett

    Interventional fluoroscopy uses ionizing radiation to guide small instruments through blood vessels or other body pathways to sites of clinical interest. The technique represents a tremendous advantage over invasive surgical procedures, as it requires only a small incision, thus reducing the risk of infection and providing for shorter recovery times. The growing use and increasing complexity of interventional procedures, however, has resulted in public health concerns regarding radiation exposures, particularly with respect to localized skin dose. Tracking and documenting patient-specific skin and internal organ dose has been specifically identified for interventional fluoroscopy where extended irradiation times, multiple projections, and repeat procedures can lead to some of the largest doses encountered in radiology. Furthermore, inprocedure knowledge of localized skin doses can be of significant clinical importance to managing patient risk and in training radiology residents. In this dissertation, a framework is presented for monitoring the radiation dose delivered to patients undergoing interventional procedures. The framework is built around two key points, developing better anthropomorphic models, and designing clinically relevant software systems for dose estimation. To begin, a library of 50 hybrid patient-dependent computational phantoms was developed based on the UF hybrid male and female reference phantoms. These phantoms represent a different type of anthropomorphic model whereby anthropometric parameters from an individual patient are used during phantom selection. The patient-dependent library was first validated and then used in two patient-phantom matching studies focused on cumulative organ and local skin dose. In terms of organ dose, patient-phantom matching was shown most beneficial for estimating the dose to large patients where error associated with soft tissue attenuation differences could be minimized. For small patients, inherent difference

  12. Lead and the Romans

    Science.gov (United States)

    Reddy, Aravind; Braun, Charles L.

    2010-01-01

    Lead poisoning has been a problem since early history and continues into modern times. An appealing characteristic of lead is that many lead salts are sweet. In the absence of cane and beet sugars, early Romans used "sugar of lead" (lead acetate) to sweeten desserts, fruits, and sour wine. People most at risk would have been those who…

  13. Lead and the Romans

    Science.gov (United States)

    Reddy, Aravind; Braun, Charles L.

    2010-01-01

    Lead poisoning has been a problem since early history and continues into modern times. An appealing characteristic of lead is that many lead salts are sweet. In the absence of cane and beet sugars, early Romans used "sugar of lead" (lead acetate) to sweeten desserts, fruits, and sour wine. People most at risk would have been those who consumed the…

  14. SU-F-P-19: Fetal Dose Estimate for a High-Dose Fluoroscopy Guided Intervention Using Modern Data Tools

    Energy Technology Data Exchange (ETDEWEB)

    Moirano, J [University of Washington, Seattle, WA (United States)

    2016-06-15

    Purpose: An accurate dose estimate is necessary for effective patient management after a fetal exposure. In the case of a high-dose exposure, it is critical to use all resources available in order to make the most accurate assessment of the fetal dose. This work will demonstrate a methodology for accurate fetal dose estimation using tools that have recently become available in many clinics, and show examples of best practices for collecting data and performing the fetal dose calculation. Methods: A fetal dose estimate calculation was performed using modern data collection tools to determine parameters for the calculation. The reference point air kerma as displayed by the fluoroscopic system was checked for accuracy. A cumulative dose incidence map and DICOM header mining were used to determine the displayed reference point air kerma. Corrections for attenuation caused by the patient table and pad were measured and applied in order to determine the peak skin dose. The position and depth of the fetus was determined by ultrasound imaging and consultation with a radiologist. The data collected was used to determine a normalized uterus dose from Monte Carlo simulation data. Fetal dose values from this process were compared to other accepted calculation methods. Results: An accurate high-dose fetal dose estimate was made. Comparison to accepted legacy methods were were within 35% of estimated values. Conclusion: Modern data collection and reporting methods ease the process for estimation of fetal dose from interventional fluoroscopy exposures. Many aspects of the calculation can now be quantified rather than estimated, which should allow for a more accurate estimation of fetal dose.

  15. Low dose ionizing radiation induced acoustic neuroma: A putative link?

    Directory of Open Access Journals (Sweden)

    Sachin A Borkar

    2012-01-01

    Full Text Available Although exposure to high dose ionizing radiation (following therapeutic radiotherapy has been incriminated in the pathogenesis of many brain tumors, exposure to chronic low dose ionizing radiation has not yet been shown to be associated with tumorigenesis. The authors report a case of a 50-year-old atomic reactor scientist who received a cumulative dose of 78.9 mSv over a 10-year period and was detected to have an acoustic neuroma another 15 years later. Although there is no proof that exposure to ionizing radiation was the cause for the development of the acoustic neuroma, this case highlights the need for extended follow-up periods following exposure to low dose ionizing radiation.

  16. Growth Hormone Gene Polymorphism and Its Association with Partial Cumulative Milk Yields of Holstein Friesian Dairy Cattle

    Directory of Open Access Journals (Sweden)

    R. Misrianti

    2012-12-01

    Full Text Available Growth hormone gene (GH gene plays an important role in regulating body growth and in developing mammary gland, similar with its interaction to specific receptors. The GH gene has been considered as one of candidate gene associated with selection on lactation trait and milk production. This study was aimed to determine genetic polymorphism of the GH-AluI gene and to associate its genotype variants on various 15-d partial cumulative milk yields in Holstein Friesian (HF dairy cows. A number of 370 blood samples were collected from six HF populations, respectively from small dairy farmer under the supervision of the North Bandung Milk Cooperation (NBMC in Cilumber (98 and Pasir Kemis village (96, Dairy Cattle Breeding and Improvement Station (Cikole DCBIS Cikole (88, Lembang Artificial Insemination Center (Lembang AIC (17, Singosari Artificial Insemination Center (Singosari AIC (32, and Cipelang Livestock Embryo Center (Cipelang LEC (40. A polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP method was used to identify variant genotypes of the GH gene using AluI restriction enzyme. Genotyping results produced only two genotypes, i.e. LL and LV genotypes, without VV genotype. Frequency of the former was dominant, whilst that was low for the latter (89% vs. 11%; leading to the frequency of L allele was very high (94% compared to that of V allele (6%. No significant association between variant genotypes (LL and LV and various 15-d partial cumulative milk yields.

  17. A balanced solution to the cumulative threat of industrialized wind farm development on cinereous vultures (Aegypius monachus) in south-eastern Europe.

    Science.gov (United States)

    Vasilakis, Dimitris P; Whitfield, D Philip; Kati, Vassiliki

    2017-01-01

    Wind farm development can combat climate change but may also threaten bird populations' persistence through collision with wind turbine blades if such development is improperly planned strategically and cumulatively. Such improper planning may often occur. Numerous wind farms are planned in a region hosting the only cinereous vulture population in south-eastern Europe. We combined range use modelling and a Collision Risk Model (CRM) to predict the cumulative collision mortality for cinereous vulture under all operating and proposed wind farms. Four different vulture avoidance rates were considered in the CRM. Cumulative collision mortality was expected to be eight to ten times greater in the future (proposed and operating wind farms) than currently (operating wind farms), equivalent to 44% of the current population (103 individuals) if all proposals are authorized (2744 MW). Even under the most optimistic scenario whereby authorized proposals will not collectively exceed the national target for wind harnessing in the study area (960 MW), cumulative collision mortality would still be high (17% of current population) and likely lead to population extinction. Under any wind farm proposal scenario, over 92% of expected deaths would occur in the core area of the population, further implying inadequate spatial planning and implementation of relevant European legislation with scant regard for governmental obligations to protect key species. On the basis of a sensitivity map we derive a spatially explicit solution that could meet the national target of wind harnessing with a minimum conservation cost of less than 1% population loss providing that the population mortality (5.2%) caused by the operating wind farms in the core area would be totally mitigated. Under other scenarios, the vulture population would probably be at serious risk of extinction. Our 'win-win' approach is appropriate to other potential conflicts where wind farms may cumulatively threaten wildlife

  18. A balanced solution to the cumulative threat of industrialized wind farm development on cinereous vultures (Aegypius monachus) in south-eastern Europe

    Science.gov (United States)

    Whitfield, D. Philip; Kati, Vassiliki

    2017-01-01

    Wind farm development can combat climate change but may also threaten bird populations’ persistence through collision with wind turbine blades if such development is improperly planned strategically and cumulatively. Such improper planning may often occur. Numerous wind farms are planned in a region hosting the only cinereous vulture population in south-eastern Europe. We combined range use modelling and a Collision Risk Model (CRM) to predict the cumulative collision mortality for cinereous vulture under all operating and proposed wind farms. Four different vulture avoidance rates were considered in the CRM. Cumulative collision mortality was expected to be eight to ten times greater in the future (proposed and operating wind farms) than currently (operating wind farms), equivalent to 44% of the current population (103 individuals) if all proposals are authorized (2744 MW). Even under the most optimistic scenario whereby authorized proposals will not collectively exceed the national target for wind harnessing in the study area (960 MW), cumulative collision mortality would still be high (17% of current population) and likely lead to population extinction. Under any wind farm proposal scenario, over 92% of expected deaths would occur in the core area of the population, further implying inadequate spatial planning and implementation of relevant European legislation with scant regard for governmental obligations to protect key species. On the basis of a sensitivity map we derive a spatially explicit solution that could meet the national target of wind harnessing with a minimum conservation cost of less than 1% population loss providing that the population mortality (5.2%) caused by the operating wind farms in the core area would be totally mitigated. Under other scenarios, the vulture population would probably be at serious risk of extinction. Our ‘win-win’ approach is appropriate to other potential conflicts where wind farms may cumulatively threaten wildlife

  19. Jinde Lead lead smelting project starts construction

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>On Dec.20,the lead smelting project of Jiangxi Jinde Lead started construction in Dexin as a technical renovation project on environmental treatment of Jiangxi Metallurgical Group.The project is the one with the largest investment of Provincial Metallurgical Group in non-ferrous

  20. Surface dose in intracavitary orthovoltage radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Podgorsak, M.B.; Schreiner, L.J.; Podgorsak, E.B. (Department of Physics, McGill University, Montreal, PQ (Canada) Department of Radiation Oncology, McGill University, Montreal, PQ (Canada))

    1990-07-01

    Radiotherapy with orthovoltage techniques is often the prime treatment for localized superficial malignancies. Surface doses and depth doses measured with cylindrical and end-window Farmer chambers are presented for various orthovoltage x-ray beams in the range from 80 to 300 kVp, both for open beams and beams collimated with commercial intracavitary leaded-glass cones. For radiation fields collimated by a diaphragm positioned at a distance from the patient surface (open beams) there is a small skin-sparing effect. On the other hand, the surface doses with commercial leaded-glass intracavitary cones can exhibit a fivefold increase compared to the open-beam dose maxima. Beyond a depth of {similar to}0.2 mm in a tissue-equivalent phantom, the doses measured for open beams and beams collimated with intracavitary cones are essentially identical. The increase in the surface dose observed with intracavitary cones is attributed to photoelectrons and recoil electrons produced in the cones. The high surface doses are measured by thin-wall parallel-plate ionization chambers but cannot be measured with cylindrical Farmer chambers since these chambers have wall thicknesses too large for the transmission of electrons produced in the cone. Since cylindrical Farmer chambers are typically used for calibration of radiation output, the high surface doses produced by the intracavitary cones may be overlooked; they can, however, be reduced to open-beam values by simple modifications to the cones.

  1. Relationship between cumulative BMI and symptomatic, psychosocial, and medical outcomes in patients with borderline personality disorder.

    Science.gov (United States)

    Frankenburg, Frances R; Zanarini, Mary C

    2011-08-01

    We examined the relationship between cumulative body mass index (BMI) and symptomatic, psychosocial, and medical outcomes in patients with borderline personality disorder (BPD). Two hundred female borderline patients were weighed and measured during their index admission. They were subsequently interviewed at six-, eight-, and 10-year intervals. Over 10 years of prospective follow-up, increases in cumulative BMI were significantly associated with self-mutilation and dissociation (but not suicide attempts). Increases in cumulative BMI were also significantly associated with having no life partner, a poor work or school history, being on disability, being rated with a GAF score in the fair or poor range, and having a low income. In addition, increases in BMI were related to having two or more other medical conditions and using costly forms of health care. Increases in cumulative BMI may be a marker for adverse symptomatic, functional, and medical outcomes in patients with BPD.

  2. Deliberative Democracy, Institution Building, and the Pragmatics of Cumulative Effects Assessment

    Directory of Open Access Journals (Sweden)

    John R. Parkins

    2011-09-01

    Full Text Available Cumulative effects assessment is a process of scientific analysis, social choice, and public policy development, yet the linkages among these domains are often less than transparent. Limits to scientific and technical assessment, issues of power and control of information, and episodic forms of civic engagement represent serious challenges to meaningful understanding of cumulative effects assessment and land-use planning. In articulating these challenges, I draw on case studies from Ontario's Lands for Life and Alberta's Land-use Framework to illustrate current limitations to cumulative effects assessment on public lands in Canada. As a partial remedy for these limitations, insights into a pragmatic approach to impact assessment, in contrast to decisionistic and technocratic approaches, offer a way forward through a more robust integration of scientific information, civic engagement, and public policy development. I also identify a need for longer-standing institutions that are dedicated to regional planning and cumulative effects assessment in Canada.

  3. TESTING FOR DIFFERENCES BETWEEN CUMULATIVE DISTRIBUTION FUNCTIONS FROM COMPLEX ENVIRONMENTAL SAMPLING SURVEYS

    Science.gov (United States)

    The U.S. Environmental Protection Agency's Environmental Monitoring and Assessment Program (EMAP) employs the cumulative distribution function (cdf) to measure the status of quantitative variables for resources of interest. The ability to compare cdf's for a resource from, say,...

  4. Statistical Methods for Estimating the Cumulative Risk of Screening Mammography Outcomes

    NARCIS (Netherlands)

    Hubbard, R.A.; Ripping, T.M.; Chubak, J.; Broeders, M.J.; Miglioretti, D.L.

    2016-01-01

    BACKGROUND: This study illustrates alternative statistical methods for estimating cumulative risk of screening mammography outcomes in longitudinal studies. METHODS: Data from the US Breast Cancer Surveillance Consortium (BCSC) and the Nijmegen Breast Cancer Screening Program in the Netherlands were

  5. Evaluating Cumulative Ecosystem Response to Restoration Projects in the Columbia River Estuary, Annual Report 2007

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Gary E.; Diefenderfer, Heida L.; Borde, Amy B.; Dawley, Earl M.; Ebberts, Blaine D.; Putman, Douglas A.; Roegner, G. C.; Russell, Micah; Skalski, John R.; Thom, Ronald M.; Vavrinec, John

    2008-10-01

    The goal of this multi-year study (2004-2010) is to develop a methodology to evaluate the cumulative effects of multiple habitat restoration projects intended to benefit ecosystems supporting juvenile salmonids in the lower Columbia River and estuary. Literature review in 2004 revealed no existing methods for such an evaluation and suggested that cumulative effects could be additive or synergistic. Field research in 2005, 2006, and 2007 involved intensive, comparative studies paired by habitat type (tidal swamp vs. marsh), trajectory (restoration vs. reference site), and restoration action (tide gate vs. culvert vs. dike breach). The field work established two kinds of monitoring indicators for eventual cumulative effects analysis: core and higher-order indicators. Management implications of limitations and applications of site-specific effectiveness monitoring and cumulative effects analysis were identified.

  6. The seemingly quixotic pursuit of a cumulative psychological science: introduction to the special issue.

    Science.gov (United States)

    Curran, Patrick J

    2009-06-01

    The goal of any empirical science is to pursue the construction of a cumulative base of knowledge upon which the future of the science may be built. However, there is mixed evidence that the science of psychology can accurately be characterized by such a cumulative progression. Indeed, some argue that the development of a truly cumulative psychological science is not possible with the current paradigms of hypothesis testing in single-study designs. The author explores this controversy as a framework to introduce the 6 articles that make up this special issue on the integration of data and empirical findings across multiple studies. The author proposes that the methods and techniques described in this set of articles can significantly propel researchers forward in their ongoing quest to build a cumulative psychological science. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

  7. CUMULATIVE DISTRIBUTION FUNCTIONS FOR THE TEMPERATURE THRESHOLD FOR THE ONSET OF CARBON STEEL CORROSION

    Energy Technology Data Exchange (ETDEWEB)

    K.G. Mon

    1998-05-15

    The purpose of this calculation is to process the cumulative distribution functions (CDFs) characterizing the temperature threshold for the onset of corrosion provided by expert elicitation and minimize the set of values to 200 points for use in WAPDEG.

  8. Aerospace Medicine and Biology: A cumulative index to the 1980 issues

    Science.gov (United States)

    1981-01-01

    A cumulative index to the abstracts contained in the Supplements 203 through 214 of Aerospace Medicine and Biology: A Continuing Bibliography is presented. It includes three indexes--subject, personal author, and corporate source.

  9. Comparison of the radiological and chemical toxicity of lead

    Energy Technology Data Exchange (ETDEWEB)

    Beitel, G.A.; Mott, S.

    1995-03-01

    This report estimates the worst-case radiological dose to an individual from ingested lead containing picocurie levels of radionuclides and then compares the calculated radiological health effects to the chemical toxic effects from that same lead. This comparison provides an estimate of the consequences of inadvertently recycling, in the commercial market, lead containing nominally undetectable concentrations of radionuclides. Quantitative expressions for the radiological and chemical toxicities of lead are based on concentrations of lead in the blood stream. The result shows that the chemical toxicity of lead is a greater health hazard, by orders of magnitude, than any probable companion radiation dose.

  10. Lead - nutritional considerations

    Science.gov (United States)

    Lead poisoning - nutritional considerations; Toxic metal - nutritional considerations ... Markowitz M. Lead poisoning. In: Kliegman RM, Behrman RE, Jenson HB, ... Emergency Medicine: Concepts and Clinical Practice . 8th ed. ...

  11. Mapping cumulative environmental effects, social vulnerability, and health in the San Joaquin Valley, California.

    Science.gov (United States)

    Huang, Ganlin; London, Jonathan

    2012-05-01

    To understand the social distribution of environmental hazards, methods to assess cumulative effects and their health implications are needed. We developed a cumulative environmental hazard index integrating environmental data on pollution sites, air quality, and pesticide use; a social vulnerability index to measure residents' resources to prevent or mitigate health effects; and a health index. We found that communities in California's San Joaquin Valley with high social vulnerability face more environmental burdens and have worse health conditions.

  12. Cumulative Incidence of Cancer among People with AIDS in the United States

    Science.gov (United States)

    Simard, Edgar P.; Pfeiffer, Ruth M.; Engels, Eric A.

    2010-01-01

    BACKGROUND As people with acquired immunodeficiency syndrome (AIDS) live longer due to highly active antiretroviral therapy (HAART, widely available since 1996), the overall burden of cancer may increase. METHODS A population-based record linkage study identified cancers in 472,378 people with AIDS (1980–2006). Using non-parametric competing risk methods, we estimated cumulative incidence of cancer across 3 calendar periods (AIDS onset in 1980–1989, 1990–1995, and 1996–2006). RESULTS Measured at 5-years after AIDS onset, cumulative incidence of AIDS-defining cancer (ADC) declined sharply across AIDS calendar periods (from 18% in 1980–1989, to 11% in 1990–1995, to 4.2% in 1996–2006 [i.e., HAART era]). Cumulative incidence of Kaposi sarcoma declined from 14.3% during 1980–1989 to 6.7% during 1990–1995 to 1.8% during 1996–2006. Non-Hodgkin lymphoma (NHL) cumulative incidence declined from 3.8% during 1990–1995 to 2.2% during 1996–2006; during the HAART era, NHL was the commonest (53%) ADC. Cumulative incidence of non-AIDS-defining cancer (NADC) increased from 1.1% to 1.5% with no change thereafter (1.0%, 1996–2006), in part due to declines in competing mortality. However, cumulative incidence increased steadily over time for specific NADCs (anal cancer, Hodgkin lymphoma, and liver cancer). Lung cancer cumulative incidence increased from 0.14% during 1980–1989 to 0.32% during 1990–1995, with no change thereafter. CONCLUSIONS We noted dramatically declining cumulative incidence of 2 major ADCs (Kaposi sarcoma and NHL) and increases in some NADCs (specifically cancers of the anus, liver, and lung, and Hodgkin lymphoma). As HIV/AIDS is increasingly managed as a chronic disease, greater attention should be focused on cancer screening and prevention. PMID:20960504

  13. Radiation optic neuropathy and retinopathy with low dose (20 Gy radiation treatment

    Directory of Open Access Journals (Sweden)

    Crandall E. Peeler

    2016-10-01

    Conclusions and importance: Though cumulative radiation doses to the anterior visual pathway of less than 50 Gy are traditionally felt to be safe, it is important to consider not just the total exposure but also the size of individual fractions. The single-dose threshold for RON in proton beam treatment has yet to be defined. Our case suggests that fractions of less than 10 Gy should be delivered to minimize the risk of optic nerve injury.

  14. The Challenge of Developing Social Indicators for Cumulative Effects Assessment and Land Use Planning

    Directory of Open Access Journals (Sweden)

    John R. Parkins

    2011-06-01

    Full Text Available This paper provides a synopsis on social indicators as relevant to cumulative effects assessment and land use planning. Although much has been done to better understand the social dimensions of environmental assessment, empirical work has been lacking on social indicators that could be used either as measurable inputs or outputs for cumulative effects assessment and land use planning in different kinds of communities and regions. Cumulative effects models currently in practice often fail to address deeper issues of community and regional well-being. Against this gap, social scientists are being asked to make reliable generalizations about functional, measurable relationships between certain social indicators and land use change or scenarios. To address this challenge, the Alberta Research Council held a two-day workshop in 2005 with social scientists. The workshop resulted in a list of prioritized social indicators that could be included in cumulative effects modeling/assessments and land use planning. The top five social indicators included population growth rate, education attainment, self-assessed quality of life, equity, i.e., distribution of benefits, and locus of control. Although consensus on social indicators and social thresholds for cumulative effects models was not reached, the insight gained from the workshop will help inform future cumulative effects assessment and land use planning.

  15. Assessing the cumulative impact of disturbance on canopy structure and chemistry in Appalachian forests

    Science.gov (United States)

    Deel, Lindsay N.

    Eastern forests experience a range of disturbance events over time, from stand-replacing disturbances, such as clear cuts, to ephemeral disturbances, such as insect outbreaks. By understanding the cumulative impact of disturbances on canopy structure and chemistry, we can gain insight into management strategies, assess a variety of ecosystem services, and even contribute to a larger body of knowledge on global climate change. I transformed a series of Landsat images spanning approximately 25 years into cumulative disturbance maps covering Green Ridge State Forest and Savage River State Forest in western Maryland. Intensive field surveys collected during the summer of 2009 provided measurements of canopy N and estimates of canopy cover, understory cover, and leaf cover. I used AVIRIS imagery flown concurrently with field data collection to map canopy nitrogen across both forests. Through this project, I tested the impact of cumulative disturbance on forest canopy cover and canopy nitrogen. I found that increased values of cumulative disturbance had a measurable negative impact on forest canopy structure and canopy nitrogen. Moreover, by testing varying methods of summing cumulative disturbance, I found that past disturbances diminish over time in importance, yet still influence the current canopy structure and canopy N of a forest. Thus, my study suggests that Landsat time series data can be synthesized into cumulative metrics incorporating multiple disturbance types, which help explain important disturbance-mediated changes in ecosystem functions.

  16. Cone beam CT for dental and maxillofacial imaging: dose matters

    OpenAIRE

    Pauwels, Ruben

    2015-01-01

    The widespread use of cone-beam CT (CBCT) in dentistry has led to increasing concern regarding justification and optimisation of CBCT exposures. When used as a substitute to multidetector CT (MDCT), CBCT can lead to significant dose reduction; however, low-dose protocols of current-generation MDCTs show that there is an overlap between CBCT and MDCT doses. More importantly, although the 3D information provided by CBCT can often lead to improved diagnosis and treatment compared with 2D radiogr...

  17. Assessing dose rate distributions in VMAT plans

    Science.gov (United States)

    Mackeprang, P.-H.; Volken, W.; Terribilini, D.; Frauchiger, D.; Zaugg, K.; Aebersold, D. M.; Fix, M. K.; Manser, P.

    2016-04-01

    Dose rate is an essential factor in radiobiology. As modern radiotherapy delivery techniques such as volumetric modulated arc therapy (VMAT) introduce dynamic modulation of the dose rate, it is important to assess the changes in dose rate. Both the rate of monitor units per minute (MU rate) and collimation are varied over the course of a fraction, leading to different dose rates in every voxel of the calculation volume at any point in time during dose delivery. Given the radiotherapy plan and machine specific limitations, a VMAT treatment plan can be split into arc sectors between Digital Imaging and Communications in Medicine control points (CPs) of constant and known MU rate. By calculating dose distributions in each of these arc sectors independently and multiplying them with the MU rate, the dose rate in every single voxel at every time point during the fraction can be calculated. Independently calculated and then summed dose distributions per arc sector were compared to the whole arc dose calculation for validation. Dose measurements and video analysis were performed to validate the calculated datasets. A clinical head and neck, cranial and liver case were analyzed using the tool developed. Measurement validation of synthetic test cases showed linac agreement to precalculated arc sector times within  ±0.4 s and doses  ±0.1 MU (one standard deviation). Two methods for the visualization of dose rate datasets were developed: the first method plots a two-dimensional (2D) histogram of the number of voxels receiving a given dose rate over the course of the arc treatment delivery. In similarity to treatment planning system display of dose, the second method displays the dose rate as color wash on top of the corresponding computed tomography image, allowing the user to scroll through the variation over time. Examining clinical cases showed dose rates spread over a continuous spectrum, with mean dose rates hardly exceeding 100 cGy min-1 for conventional

  18. Cumulative Childhood Trauma and Adult Sexual Satisfaction: Mediation by Affect Dysregulation and Sexual Anxiety in Men and Women.

    Science.gov (United States)

    Bigras, Noémie; Daspe, Marie-Ève; Godbout, Natacha; Briere, John; Sabourin, Stéphane

    2017-05-19

    Childhood cumulative trauma (CCT) refers to an amalgam of childhood maltreatment experiences that can lead to a range of symptoms and problems in adulthood. The current study examined an integrative model of CCT for its relevance to psychosexual adjustment in adult survivors. A total of 620 participants aged 18 years and over completed a questionnaire assessing early life experiences, affect dysregulation, sexual anxiety, and sexual satisfaction. Path analyses confirmed the hypothesis that CCT is associated with affect dysregulation and sexual anxiety that, in turn, predict lower levels of sexual satisfaction. The validity of this mediational model was demonstrated for different operationalizations of CCT. The results suggested that sex therapists, who are likely to encounter CCT survivors in their practice, should consider targeting affect dysregulation in their efforts to decrease sexual anxiety and increase sexual satisfaction.

  19. Cryogenic current leads

    Energy Technology Data Exchange (ETDEWEB)

    Zizek, F.

    1982-01-01

    Theoretical, technical and design questions are examined of cryogenic current leads for SP of magnetic systems. Simplified mathematical models are presented for the current leads. To illustrate modeling, the calculation is made of the real current leads for 500 A and three variants of current leads for 1500 A for the enterprise ''Shkoda.''

  20. Learn about Lead

    Science.gov (United States)

    ... old and younger are most susceptible to the effects of lead. Children Even low levels of lead in the blood ... simple blood test to check you or your child for lead exposure. You may also want to test your home for sources ... and Technology Lead Laws and Regulations Outreach and Grants En ...